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Sample records for coupled logistic maps

  1. Electronically-implemented coupled logistic maps

    NASA Astrophysics Data System (ADS)

    L'Her, Alexandre; Amil, Pablo; Rubido, Nicolás; Marti, Arturo C.; Cabeza, Cecilia

    2016-03-01

    The logistic map is a paradigmatic dynamical system originally conceived to model the discrete-time demographic growth of a population, which shockingly, shows that discrete chaos can emerge from trivial low-dimensional non-linear dynamics. In this work, we design and characterize a simple, low-cost, easy-to-handle, electronic implementation of the logistic map. In particular, our implementation allows for straightforward circuit-modifications to behave as different one-dimensional discrete-time systems. Also, we design a coupling block in order to address the behavior of two coupled maps, although, our design is unrestricted to the discrete-time system implementation and it can be generalized to handle coupling between many dynamical systems, as in a complex system. Our findings show that the isolated and coupled maps' behavior has a remarkable agreement between the experiments and the simulations, even when fine-tuning the parameters with a resolution of ~10-3. We support these conclusions by comparing the Lyapunov exponents, periodicity of the orbits, and phase portraits of the numerical and experimental data for a wide range of coupling strengths and map's parameters.

  2. Noisy coupled logistic maps in the vicinity of chaos threshold.

    PubMed

    Tirnakli, Ugur; Tsallis, Constantino

    2016-04-01

    We focus on a linear chain of N first-neighbor-coupled logistic maps in the vicinity of their edge of chaos in the presence of a common noise. This model, characterised by the coupling strength ϵ and the noise width σmax, was recently introduced by Pluchino et al. [Phys. Rev. E 87, 022910 (2013)]. They detected, for the time averaged returns with characteristic return time τ, possible connections with q-Gaussians, the distributions which optimise, under appropriate constraints, the nonadditive entropy, Sq, basis of nonextensive statistics mechanics. Here, we take a closer look on this model, and numerically obtain probability distributions which exhibit a slight asymmetry for some parameter values, in variance with simple q-Gaussians. Nevertheless, along many decades, the fitting with q-Gaussians turns out to be numerically very satisfactory for wide regions of the parameter values, and we illustrate how the index q evolves with (N,τ,ϵ,σmax). It is nevertheless instructive on how careful one must be in such numerical analysis. The overall work shows that physical and/or biological systems that are correctly mimicked by this model are thermostatistically related to nonextensive statistical mechanics when time-averaged relevant quantities are studied. PMID:27131493

  3. Noisy coupled logistic maps in the vicinity of chaos threshold

    NASA Astrophysics Data System (ADS)

    Tirnakli, Ugur; Tsallis, Constantino

    2016-04-01

    We focus on a linear chain of N first-neighbor-coupled logistic maps in the vicinity of their edge of chaos in the presence of a common noise. This model, characterised by the coupling strength ɛ and the noise width σmax, was recently introduced by Pluchino et al. [Phys. Rev. E 87, 022910 (2013)]. They detected, for the time averaged returns with characteristic return time τ, possible connections with q-Gaussians, the distributions which optimise, under appropriate constraints, the nonadditive entropy, Sq, basis of nonextensive statistics mechanics. Here, we take a closer look on this model, and numerically obtain probability distributions which exhibit a slight asymmetry for some parameter values, in variance with simple q-Gaussians. Nevertheless, along many decades, the fitting with q-Gaussians turns out to be numerically very satisfactory for wide regions of the parameter values, and we illustrate how the index q evolves with ( N , τ , ɛ , σ m a x ) . It is nevertheless instructive on how careful one must be in such numerical analysis. The overall work shows that physical and/or biological systems that are correctly mimicked by this model are thermostatistically related to nonextensive statistical mechanics when time-averaged relevant quantities are studied.

  4. Controlling spatiotemporal chaos in one- and two-dimensional coupled logistic map lattices

    SciTech Connect

    Astakhov, V.V.; Anishchenko, V.S.; Strelkova, G.I.; Shabunin, A.V.

    1996-06-01

    A method of control of spatiotemporal chaos in lattices of coupled maps is proposed in this work. Forms of spatiotemporal perturbations of a system parameter are analytically determined for one- and two-dimensional logistic map lattices with different kinds of coupling to stabilize chosen spatiotemporal states previously unstable. The results are illustrated by numerical simulation. Controlled transition from the regime of spatiotemporal chaos to the previously chosen regular spatiotemporal patterns is demonstrated. {copyright} {ital 1996 American Institute of Physics.}

  5. Bifurcation behaviors of synchronized regions in logistic map networks with coupling delay

    SciTech Connect

    Tang, Longkun E-mail: xqwu@whu.edu.cn; Wu, Xiaoqun E-mail: xqwu@whu.edu.cn; Lu, Jun-an; Lü, Jinhu

    2015-03-15

    Network synchronized regions play an extremely important role in network synchronization according to the master stability function framework. This paper focuses on network synchronous state stability via studying the effects of nodal dynamics, coupling delay, and coupling way on synchronized regions in Logistic map networks. Theoretical and numerical investigations show that (1) network synchronization is closely associated with its nodal dynamics. Particularly, the synchronized region bifurcation points through which the synchronized region switches from one type to another are in good agreement with those of the uncoupled node system, and chaotic nodal dynamics can greatly impede network synchronization. (2) The coupling delay generally impairs the synchronizability of Logistic map networks, which is also dominated by the parity of delay for some nodal parameters. (3) A simple nonlinear coupling facilitates network synchronization more than the linear one does. The results found in this paper will help to intensify our understanding for the synchronous state stability in discrete-time networks with coupling delay.

  6. Dependence of Initial Value on Pattern Formation for a Logistic Coupled Map Lattice

    PubMed Central

    Xu, Li; Zhang, Guang; Cui, Haoyue

    2016-01-01

    The logistic coupled map lattices (LCML) have been widely investigated as well as their pattern dynamics. The patterns formation may depend on not only fluctuations of system parameters, but variation of the initial conditions. However, the mathematical discussion is quite few for the effect of initial values so far. The present paper is concerned with the pattern formation for a two-dimensional Logistic coupled map lattice, where any initial value can be linear expressed by corresponding eigenvectors, and patterns formation can be determined by selecting the corresponding eigenvectors. A set of simulations are conducted whose results demonstrate the fact. The method utilized in the present paper could be applied to other discrete systems as well. PMID:27382964

  7. Synchronous slowing down in coupled logistic maps via random network topology.

    PubMed

    Wang, Sheng-Jun; Du, Ru-Hai; Jin, Tao; Wu, Xing-Sen; Qu, Shi-Xian

    2016-01-01

    The speed and paths of synchronization play a key role in the function of a system, which has not received enough attention up to now. In this work, we study the synchronization process of coupled logistic maps that reveals the common features of low-dimensional dissipative systems. A slowing down of synchronization process is observed, which is a novel phenomenon. The result shows that there are two typical kinds of transient process before the system reaches complete synchronization, which is demonstrated by both the coupled multiple-period maps and the coupled multiple-band chaotic maps. When the coupling is weak, the evolution of the system is governed mainly by the local dynamic, i.e., the node states are attracted by the stable orbits or chaotic attractors of the single map and evolve toward the synchronized orbit in a less coherent way. When the coupling is strong, the node states evolve in a high coherent way toward the stable orbit on the synchronized manifold, where the collective dynamics dominates the evolution. In a mediate coupling strength, the interplay between the two paths is responsible for the slowing down. The existence of different synchronization paths is also proven by the finite-time Lyapunov exponent and its distribution. PMID:27021897

  8. Synchronous slowing down in coupled logistic maps via random network topology

    NASA Astrophysics Data System (ADS)

    Wang, Sheng-Jun; Du, Ru-Hai; Jin, Tao; Wu, Xing-Sen; Qu, Shi-Xian

    2016-03-01

    The speed and paths of synchronization play a key role in the function of a system, which has not received enough attention up to now. In this work, we study the synchronization process of coupled logistic maps that reveals the common features of low-dimensional dissipative systems. A slowing down of synchronization process is observed, which is a novel phenomenon. The result shows that there are two typical kinds of transient process before the system reaches complete synchronization, which is demonstrated by both the coupled multiple-period maps and the coupled multiple-band chaotic maps. When the coupling is weak, the evolution of the system is governed mainly by the local dynamic, i.e., the node states are attracted by the stable orbits or chaotic attractors of the single map and evolve toward the synchronized orbit in a less coherent way. When the coupling is strong, the node states evolve in a high coherent way toward the stable orbit on the synchronized manifold, where the collective dynamics dominates the evolution. In a mediate coupling strength, the interplay between the two paths is responsible for the slowing down. The existence of different synchronization paths is also proven by the finite-time Lyapunov exponent and its distribution.

  9. Synchronous slowing down in coupled logistic maps via random network topology

    PubMed Central

    Wang, Sheng-Jun; Du, Ru-Hai; Jin, Tao; Wu, Xing-Sen; Qu, Shi-Xian

    2016-01-01

    The speed and paths of synchronization play a key role in the function of a system, which has not received enough attention up to now. In this work, we study the synchronization process of coupled logistic maps that reveals the common features of low-dimensional dissipative systems. A slowing down of synchronization process is observed, which is a novel phenomenon. The result shows that there are two typical kinds of transient process before the system reaches complete synchronization, which is demonstrated by both the coupled multiple-period maps and the coupled multiple-band chaotic maps. When the coupling is weak, the evolution of the system is governed mainly by the local dynamic, i.e., the node states are attracted by the stable orbits or chaotic attractors of the single map and evolve toward the synchronized orbit in a less coherent way. When the coupling is strong, the node states evolve in a high coherent way toward the stable orbit on the synchronized manifold, where the collective dynamics dominates the evolution. In a mediate coupling strength, the interplay between the two paths is responsible for the slowing down. The existence of different synchronization paths is also proven by the finite-time Lyapunov exponent and its distribution. PMID:27021897

  10. Group multiple-image encoding and watermarking using coupled logistic maps and gyrator wavelet transform.

    PubMed

    Abuturab, Muhammad Rafiq

    2015-10-01

    A novel method of group multiple-image encoding and watermarking using coupled logistic maps and gyrator wavelet transform is presented. The proposed method employs three different groups of multiple images. The color images of each group are individually segregated into R, G, and B channels. Each channel is first permutated by using a sequence of chaotic pairs generated with a system of two symmetrically coupled identical logistic maps and then gyrator transformed. The gyrator spectrum of each channel is multiplied together and then modulated by a random phase function to obtain a corresponding multiplex channel. The encoded multiplex image is restituted through a concatenation of R, G, and B multiplex channels. The phase and amplitude functions of the first, second, and third groups of encoded multiplex images are generated. The host image is a single-level 2D discrete wavelet transformed to decompose into LL, HL, LH, and HH subbands. HL, LH, and HH subbands are then replaced with phase functions of the first, second, and third groups, respectively. Finally, the resultant image is an inverse single-level 2D discrete wavelet transformed to construct a watermarked image. The three groups of multiple images are protected not only by the encryption algorithm but also visually by the host image. Thus, a high level of security can be achieved. Each group includes group decryption keys, and each image of the group comprises individual decryption keys beside parameters of coupled logistic maps and gyrator transform. As a result, the key space is very large. The decryption system can be realized by using an optoelectronic device. The numerical simulation results confirm the validity and security of the proposed scheme. PMID:26479935

  11. A note on Verhulst's logistic equation and related logistic maps

    NASA Astrophysics Data System (ADS)

    Ranferi Gutiérrez, M.; Reyes, M. A.; Rosu, H. C.

    2010-05-01

    We consider the Verhulst logistic equation and a couple of forms of the corresponding logistic maps. For the case of the logistic equation we show that using the general Riccati solution only changes the initial conditions of the equation. Next, we consider two forms of corresponding logistic maps reporting the following results. For the map xn + 1 = rxn(1 - xn) we propose a new way to write the solution for r = -2 which allows better precision of the iterative terms, while for the map xn + 1 - xn = rxn(1 - xn + 1) we show that it behaves identically to the logistic equation from the standpoint of the general Riccati solution, which is also provided herein for any value of the parameter r.

  12. On some generalized discrete logistic maps

    PubMed Central

    Radwan, Ahmed G.

    2012-01-01

    Recently, conventional logistic maps have been used in different vital applications like modeling and security. However, unfortunately the conventional logistic maps can tolerate only one changeable parameter. In this paper, three different generalized logistic maps are introduced with arbitrary powers which can be reduced to the conventional logistic map. The added parameter (arbitrary power) increases the degree of freedom of each map and gives us a versatile response that can fit many applications. Therefore, the conventional logistic map is considered only a special case from each proposed map. This new parameter increases the flexibility of the system, and illustrates the performance of the conventional system within any required neighborhood. Many cases will be illustrated showing the effect of the arbitrary power and the equation parameter on the number of equilibrium points, their locations, stability conditions, and bifurcation diagrams up to the chaotic behavior. PMID:25685414

  13. Visualizing the Logistic Map with a Microcontroller

    ERIC Educational Resources Information Center

    Serna, Juan D.; Joshi, Amitabh

    2012-01-01

    The logistic map is one of the simplest nonlinear dynamical systems that clearly exhibits the route to chaos. In this paper, we explore the evolution of the logistic map using an open-source microcontroller connected to an array of light-emitting diodes (LEDs). We divide the one-dimensional domain interval [0,1] into ten equal parts, an associate…

  14. Effect of randomness in logistic maps

    NASA Astrophysics Data System (ADS)

    Khaleque, Abdul; Sen, Parongama

    2015-01-01

    We study a random logistic map xt+1 = atxt[1 - xt] where at are bounded (q1 ≤ at ≤ q2), random variables independently drawn from a distribution. xt does not show any regular behavior in time. We find that xt shows fully ergodic behavior when the maximum allowed value of at is 4. However , averaged over different realizations reaches a fixed point. For 1 ≤ at ≤ 4, the system shows nonchaotic behavior and the Lyapunov exponent is strongly dependent on the asymmetry of the distribution from which at is drawn. Chaotic behavior is seen to occur beyond a threshold value of q1(q2) when q2(q1) is varied. The most striking result is that the random map is chaotic even when q2 is less than the threshold value 3.5699⋯ at which chaos occurs in the nonrandom map. We also employ a different method in which a different set of random variables are used for the evolution of two initially identical x values, here the chaotic regime exists for all q1 ≠ q2 values.

  15. Chaos-based secure communication system using logistic map

    NASA Astrophysics Data System (ADS)

    Singh, Narendra; Sinha, Aloka

    2010-03-01

    We propose a new opto-electronic secure communication system using logistic map and pulse position modulation. A modified version of the electronic circuit of the logistic map is used to generate the chaotic signal. Pulse position modulation scheme together with the logistic map has been used to encrypt the signal. Optical fiber has been used to demonstrate the proposed scheme. Eye pattern has been used to verify the noise-like nature of the encrypted signal. Opto-electronic implementation of the technique has been carried out. Experimental results are presented to verify the validity of the proposed technique.

  16. Time-delayed coupled logistic capacity model in population dynamics

    NASA Astrophysics Data System (ADS)

    Cáceres, Manuel O.

    2014-08-01

    This study proposes a delay-coupled system based on the logistic equation that models the interaction of a population with its varying environment. The integro-diferential equations of the model are presented in terms of a distributed time-delayed coupled logistic-capacity equation. The model eliminates the need for a prior knowledge of the maximum saturation environmental carrying capacity value. Therefore the dynamics toward the final attractor in a distributed time-delayed coupled logistic-capacity model is studied. Exact results are presented, and analytical conclusions have been done in terms of the two parameters of the model.

  17. Reverse bifurcation and fractal of the compound logistic map

    NASA Astrophysics Data System (ADS)

    Wang, Xingyuan; Liang, Qingyong

    2008-07-01

    The nature of the fixed points of the compound logistic map is researched and the boundary equation of the first bifurcation of the map in the parameter space is given out. Using the quantitative criterion and rule of chaotic system, the paper reveal the general features of the compound logistic map transforming from regularity to chaos, the following conclusions are shown: (1) chaotic patterns of the map may emerge out of double-periodic bifurcation and (2) the chaotic crisis phenomena and the reverse bifurcation are found. At the same time, we analyze the orbit of critical point of the compound logistic map and put forward the definition of Mandelbrot-Julia set of compound logistic map. We generalize the Welstead and Cromer's periodic scanning technology and using this technology construct a series of Mandelbrot-Julia sets of compound logistic map. We investigate the symmetry of Mandelbrot-Julia set and study the topological inflexibility of distributing of period region in the Mandelbrot set, and finds that Mandelbrot set contain abundant information of structure of Julia sets by founding the whole portray of Julia sets based on Mandelbrot set qualitatively.

  18. The dynamics of coupled logistic social groups

    NASA Astrophysics Data System (ADS)

    McCartney, Mark; Glass, David H.

    2015-06-01

    A society made up of a network of social groups is investigated. Each group is partitioned into two mutually exclusive subsets with the movement of members between the two subsets being modelled via a logistic-like equation. We consider various ways in which the groups in the network may influence each other, via both group size and the utility groups place on the possible subsets. Scenarios where social groups act as 'agenda setters' for the rest of the society are considered. A number of analytic and numerical results are presented.

  19. Dynamics of strongly coupled spatially distributed logistic equations with delay

    NASA Astrophysics Data System (ADS)

    Kashchenko, I. S.; Kashchenko, S. A.

    2015-04-01

    The dynamics of a system of two logistic delay equations with spatially distributed coupling is studied. The coupling coefficient is assumed to be sufficiently large. Special nonlinear systems of parabolic equations are constructed such that the behavior of their solutions is determined in the first approximation by the dynamical properties of the original system.

  20. Deciphering an Image Cipher Based on Mixed Transformed Logistic Maps

    NASA Astrophysics Data System (ADS)

    Liu, Yuansheng; Fan, Hua; Xie, Eric Yong; Cheng, Ge; Li, Chengqing

    2015-12-01

    Since John von Neumann suggested utilizing Logistic map as a random number generator in 1947, a great number of encryption schemes based on Logistic map and/or its variants have been proposed. This paper re-evaluates the security of an image cipher based on transformed logistic maps and proves that the image cipher can be deciphered efficiently under two different conditions: (1) two pairs of known plain-images and the corresponding cipher-images with computational complexity of O(218 + L); (2) two pairs of chosen plain-images and the corresponding cipher-images with computational complexity of O(L), where L is the number of pixels in the plain-image. In contrast, the required condition in the previous deciphering method is 87 pairs of chosen plain-images and the corresponding cipher-images with computational complexity of O(27 + L). In addition, three other security flaws existing in most Logistic-map-based ciphers are also reported.

  1. C*-algebras associated with reversible extensions of logistic maps

    NASA Astrophysics Data System (ADS)

    Kwaśniewski, Bartosz K.

    2012-10-01

    The construction of reversible extensions of dynamical systems presented in a previous paper by the author and A.V. Lebedev is enhanced, so that it applies to arbitrary mappings (not necessarily with open range). It is based on calculating the maximal ideal space of C*-algebras that extends endomorphisms to partial automorphisms via partial isometric representations, and involves a new set of 'parameters' (the role of parameters is played by chosen sets or ideals). As model examples, we give a thorough description of reversible extensions of logistic maps and a classification of systems associated with compression of unitaries generating homeomorphisms of the circle. Bibliography: 34 titles.

  2. C*-algebras associated with reversible extensions of logistic maps

    SciTech Connect

    Kwasniewski, Bartosz K

    2012-10-31

    The construction of reversible extensions of dynamical systems presented in a previous paper by the author and A.V. Lebedev is enhanced, so that it applies to arbitrary mappings (not necessarily with open range). It is based on calculating the maximal ideal space of C*-algebras that extends endomorphisms to partial automorphisms via partial isometric representations, and involves a new set of 'parameters' (the role of parameters is played by chosen sets or ideals). As model examples, we give a thorough description of reversible extensions of logistic maps and a classification of systems associated with compression of unitaries generating homeomorphisms of the circle. Bibliography: 34 titles.

  3. Landslide Hazard Mapping in Rwanda Using Logistic Regression

    NASA Astrophysics Data System (ADS)

    Piller, A.; Anderson, E.; Ballard, H.

    2015-12-01

    Landslides in the United States cause more than $1 billion in damages and 50 deaths per year (USGS 2014). Globally, figures are much more grave, yet monitoring, mapping and forecasting of these hazards are less than adequate. Seventy-five percent of the population of Rwanda earns a living from farming, mostly subsistence. Loss of farmland, housing, or life, to landslides is a very real hazard. Landslides in Rwanda have an impact at the economic, social, and environmental level. In a developing nation that faces challenges in tracking, cataloging, and predicting the numerous landslides that occur each year, satellite imagery and spatial analysis allow for remote study. We have focused on the development of a landslide inventory and a statistical methodology for assessing landslide hazards. Using logistic regression on approximately 30 test variables (i.e. slope, soil type, land cover, etc.) and a sample of over 200 landslides, we determine which variables are statistically most relevant to landslide occurrence in Rwanda. A preliminary predictive hazard map for Rwanda has been produced, using the variables selected from the logistic regression analysis.

  4. Heterogeneous, weakly coupled map lattices

    NASA Astrophysics Data System (ADS)

    Sotelo Herrera, M.a. Dolores; San Martín, Jesús; Porter, Mason A.

    2016-07-01

    Coupled map lattices (CMLs) are often used to study emergent phenomena in nature. It is typically assumed (unrealistically) that each component is described by the same map, and it is important to relax this assumption. In this paper, we characterize periodic orbits and the laminar regime of type-I intermittency in heterogeneous weakly coupled map lattices (HWCMLs). We show that the period of a cycle in an HWCML is preserved for arbitrarily small coupling strengths even when an associated uncoupled oscillator would experience a period-doubling cascade. Our results characterize periodic orbits both near and far from saddle-node bifurcations, and we thereby provide a key step for examining the bifurcation structure of heterogeneous CMLs.

  5. Image encryption using the two-dimensional logistic chaotic map

    NASA Astrophysics Data System (ADS)

    Wu, Yue; Yang, Gelan; Jin, Huixia; Noonan, Joseph P.

    2012-01-01

    Chaos maps and chaotic systems have been proved to be useful and effective for cryptography. In our study, the two-dimensional logistic map with complicated basin structures and attractors are first used for image encryption. The proposed method adopts the classic framework of the permutation-substitution network in cryptography and thus ensures both confusion and diffusion properties for a secure cipher. The proposed method is able to encrypt an intelligible image into a random-like one from the statistical point of view and the human visual system point of view. Extensive simulation results using test images from the USC-SIPI image database demonstrate the effectiveness and robustness of the proposed method. Security analysis results of using both the conventional and the most recent tests show that the encryption quality of the proposed method reaches or excels the current state-of-the-art methods. Similar encryption ideas can be applied to digital data in other formats (e.g., digital audio and video). We also publish the cipher MATLAB open-source-code under the web page https://sites.google.com/site/tuftsyuewu/source-code.

  6. A new image encryption algorithm based on logistic chaotic map with varying parameter.

    PubMed

    Liu, Lingfeng; Miao, Suoxia

    2016-01-01

    In this paper, we proposed a new image encryption algorithm based on parameter-varied logistic chaotic map and dynamical algorithm. The parameter-varied logistic map can cure the weaknesses of logistic map and resist the phase space reconstruction attack. We use the parameter-varied logistic map to shuffle the plain image, and then use a dynamical algorithm to encrypt the image. We carry out several experiments, including Histogram analysis, information entropy analysis, sensitivity analysis, key space analysis, correlation analysis and computational complexity to evaluate its performances. The experiment results show that this algorithm is with high security and can be competitive for image encryption. PMID:27066326

  7. Some aspects of the synchronization in coupled maps.

    PubMed

    de Souza Pinto, Sandro E; Lunardi, José T; Saleh, Abdala M; Batista, Antonio M

    2005-09-01

    We numerically study the synchronization behavior of a coupled map lattice consisting of a chain of chaotic logistic maps exhibiting power law interactions. We report two main results. First, we find a practical lower bound in the lattice size in order that this system could be considered in the thermodynamic limit in numerical simulations. Second, we observe the existence of a strong correlation between the Lyapunov dimension and the averaged synchronization time. PMID:16241623

  8. Some aspects of the synchronization in coupled maps

    NASA Astrophysics Data System (ADS)

    de Souza Pinto, Sandro E.; Lunardi, José T.; Saleh, Abdala M.; Batista, Antonio M.

    2005-09-01

    We numerically study the synchronization behavior of a coupled map lattice consisting of a chain of chaotic logistic maps exhibiting power law interactions. We report two main results. First, we find a practical lower bound in the lattice size in order that this system could be considered in the thermodynamic limit in numerical simulations. Second, we observe the existence of a strong correlation between the Lyapunov dimension and the averaged synchronization time.

  9. Evolution of probability densities in stochastic coupled map lattices

    NASA Astrophysics Data System (ADS)

    Losson, Jérôme; Mackey, Michael C.

    1995-08-01

    This paper describes the statistical properties of coupled map lattices subjected to the influence of stochastic perturbations. The stochastic analog of the Perron-Frobenius operator is derived for various types of noise. When the local dynamics satisfy rather mild conditions, this equation is shown to possess either stable, steady state solutions (i.e., a stable invariant density) or density limit cycles. Convergence of the phase space densities to these limit cycle solutions explains the nonstationary behavior of statistical quantifiers at equilibrium. Numerical experiments performed on various lattices of tent, logistic, and shift maps with diffusivelike interelement couplings are examined in light of these theoretical results.

  10. Re-Purposing Google Maps Visualisation for Teaching Logistics Systems

    ERIC Educational Resources Information Center

    Cheong, France; Cheong, Christopher; Jie, Ferry

    2012-01-01

    Routing is the process of selecting appropriate paths and ordering waypoints in a network. It plays an important part in logistics and supply chain management as choosing the optimal route can minimise distribution costs. Routing optimisation, however, is a difficult problem to solve and computer software is often used to determine the best route.…

  11. Exploring dynamical systems and chaos using the logistic map model of population change

    NASA Astrophysics Data System (ADS)

    Groff, Jeffrey R.

    2013-10-01

    The logistic map difference equation is encountered in the theoretical ecology literature as a mathematical model of population change for organisms with non-overlapping generations and density-dependent dynamics influenced solely by intraspecific interactions. This article presents the logistic map as a simple model suitable for introducing students to the properties of dynamical systems including periodic orbits, bifurcations, and deterministic chaos. After a brief historical and mathematical introduction to models of population change and the logistic map, the article summarizes the logistic map activities I teach in my introductory physics laboratories for non-physics majors. The logistic map laboratory introduces the many bioscience students in my courses to a foundational model in population ecology that has inspired ecologists to recognize the importance of nonlinear dynamics in real populations. Although I use this activity in courses for non-majors, the logistic map model of population change could also be taught to physics majors to introduce properties of dynamical systems while demonstrating an application of mathematical modeling outside of traditional physics.

  12. Quantum image encryption based on generalized affine transform and logistic map

    NASA Astrophysics Data System (ADS)

    Liang, Hao-Ran; Tao, Xiang-Yang; Zhou, Nan-Run

    2016-03-01

    Quantum circuits of the generalized affine transform are devised based on the novel enhanced quantum representation of digital images. A novel quantum image encryption algorithm combining the generalized affine transform with logistic map is suggested. The gray-level information of the quantum image is encrypted by the XOR operation with a key generator controlled by the logistic map, while the position information of the quantum image is encoded by the generalized affine transform. The encryption keys include the independent control parameters used in the generalized affine transform and the logistic map. Thus, the key space is large enough to frustrate the possible brute-force attack. Numerical simulations and analyses indicate that the proposed algorithm is realizable, robust and has a better performance than its classical counterpart in terms of computational complexity.

  13. Quantum image encryption based on generalized affine transform and logistic map

    NASA Astrophysics Data System (ADS)

    Liang, Hao-Ran; Tao, Xiang-Yang; Zhou, Nan-Run

    2016-07-01

    Quantum circuits of the generalized affine transform are devised based on the novel enhanced quantum representation of digital images. A novel quantum image encryption algorithm combining the generalized affine transform with logistic map is suggested. The gray-level information of the quantum image is encrypted by the XOR operation with a key generator controlled by the logistic map, while the position information of the quantum image is encoded by the generalized affine transform. The encryption keys include the independent control parameters used in the generalized affine transform and the logistic map. Thus, the key space is large enough to frustrate the possible brute-force attack. Numerical simulations and analyses indicate that the proposed algorithm is realizable, robust and has a better performance than its classical counterpart in terms of computational complexity.

  14. Coupled map networks as communication schemes

    NASA Astrophysics Data System (ADS)

    García, P.; Parravano, A.; Cosenza, M. G.; Jiménez, J.; Marcano, A.

    2002-04-01

    Networks of chaotic coupled maps are considered as string and language generators. It is shown that such networks can be used as encrypting systems where the cipher text contains information about the evolution of the network and also about the way to select the plain text symbols from the string associated with the network evolution. The secret key provides the network parameters, such as the coupling strengths.

  15. Marine biological metapopulation with coupled logistic growth functions: The MSY and quasi MSY

    NASA Astrophysics Data System (ADS)

    Husniah, H.; Supriatna, A. K.

    2014-02-01

    In this paper we develop a mathematical model for a harvested marine biological stock. The stock consists of two discretely separated sub-stocks which are connected by the dispersal of individuals, and hence forms a metapopulation structure. The model assumes that the production function of each stock follows a logistic equation, hence the full system of the stocks governed by a couple of logistic equations. We find the formula of the maximum sustainable yield (MSY) for each sub-stock, which is extendable to a metapopulation with several discretely separated sub-populations. We also give a numerical simulation to illustrate the application of the formula for two-patch case, based on the quasi maximum sustainable yield. The simulation shows that ignoring the existence of the coupling of the system resulting in a lower total harvest from the population. This indicates a financial lost potential arising from an inappropriate recognition of a metapopulation structure in a fishery industry.

  16. Landslide susceptibility mapping along road corridors in the Indian Himalayas using Bayesian logistic regression models

    NASA Astrophysics Data System (ADS)

    Das, Iswar; Stein, Alfred; Kerle, Norman; Dadhwal, Vinay K.

    2012-12-01

    Landslide susceptibility mapping (LSM) along road corridors in the Indian Himalayas is an essential exercise that helps planners and decision makers in determining the severity of probable slope failure areas. Logistic regression is commonly applied for this purpose, as it is a robust and straightforward technique that is relatively easy to handle. Ordinary logistic regression as a data-driven technique, however, does not allow inclusion of prior information. This study presents Bayesian logistic regression (BLR) for landslide susceptibility assessment along road corridors. The methodology is tested in a landslide-prone area in the Bhagirathi river valley in the Indian Himalayas. Parameter estimates from BLR are compared with those obtained from ordinary logistic regression. By means of iterative Markov Chain Monte Carlo simulation, BLR provides a rich set of results on parameter estimation. We assessed model performance by the receiver operator characteristics curve analysis, and validated the model using 50% of the landslide cells kept apart for testing and validation. The study concludes that BLR performs better in posterior parameter estimation in general and the uncertainty estimation in particular.

  17. Double precision errors in the logistic map: statistical study and dynamical interpretation.

    PubMed

    Oteo, J A; Ros, J

    2007-09-01

    The nature of the round-off errors that occur in the usual double precision computation of the logistic map is studied in detail. Different iterative regimes from the whole panoply of behaviors exhibited in the bifurcation diagram are examined, histograms of errors in trajectories given, and for the case of fully developed chaos an explicit formula is found. It is shown that the statistics of the largest double precision error as a function of the map parameter is characterized by jumps whose location is determined by certain boundary crossings in the bifurcation diagram. Both jumps and locations seem to present geometric convergence characterized by the two first Feigenbaum constants. Eventually, a comparison with Benford's law for the distribution of the leading digit of compilation of numbers is discussed. PMID:17930330

  18. Pascal (Yang Hui) triangles and power laws in the logistic map

    NASA Astrophysics Data System (ADS)

    Velarde, Carlos; Robledo, Alberto

    2015-04-01

    We point out the joint occurrence of Pascal triangle patterns and power-law scaling in the standard logistic map, or more generally, in unimodal maps. It is known that these features are present in its two types of bifurcation cascades: period and chaotic-band doubling of attractors. Approximate Pascal triangles are exhibited by the sets of lengths of supercycle diameters and by the sets of widths of opening bands. Additionally, power-law scaling manifests along periodic attractor supercycle positions and chaotic band splitting points. Consequently, the attractor at the mutual accumulation point of the doubling cascades, the onset of chaos, displays both Gaussian and power-law distributions. Their combined existence implies both ordinary and exceptional statistical-mechanical descriptions of dynamical properties.

  19. Experimental system of coupled map lattices

    NASA Astrophysics Data System (ADS)

    Ma, Yu-Han; Huang, Lan-Qing; Sun, Chu-Min; Li, Xiao-Wen

    2015-06-01

    We design an optical feedback loop system consisting of a liquid-crystal spatial light modulator (SLM), a lens, polarizers, a CCD camera, and a computer. The system images every SLM pixel onto one camera pixel. The light intensity on the camera pixel shows a nonlinear relationship with the phase shift applied by the SLM. Every pixel behaves as a nonlinear map, and we can control the interaction of pixels. Therefore, this feedback loop system can be regarded as a spatially extended system. This experimental coupled map has variable dimensions, which can be up to 512 by 512. The system can be used to study high-dimensional problems that computer simulations cannot handle.

  20. Spatiotemporal chaos is one- and two-dimensional coupled map lattices

    SciTech Connect

    Kaneko, Kunihiko

    1988-01-01

    Coupled map lattices are investigated as a model for spatiotemporal chaos. Pattern dynamics in diffusively coupled logistic lattice is briefly reviewed with the use of power spectra, domain distribution, and Lyapunov spectra. Mechanism of pattern selection with the suppression of chaos is discussed. Pattern dynamics on a 2-dimensional lattice is shown. In a weak coupling regime, a similarity with the one-dimensional case is found; frozen random pattern, pattern selection, Brownian motion of a chaotic string, and intermittent collapse of the pattern with selective flicker noise. In a strong coupling regime, frozen pattern is found to be unstable by the surface tension, which is in contrast with the one-dimensional case. Convective coupling model is introduced in connection with the fluid turbulence of Navier--Stokes type. Soliton turbulence and vortex turbulence in the model are reported. Physical implications of coupled map lattices are discussed.

  1. Image encryption with chaotically coupled chaotic maps

    NASA Astrophysics Data System (ADS)

    Pisarchik, A. N.; Zanin, M.

    2008-10-01

    We present a novel secure cryptosystem for direct encryption of color images, based on chaotically coupled chaotic maps. The proposed cipher provides good confusion and diffusion properties that ensures extremely high security because of the chaotic mixing of pixels’ colors. Information is mixed and distributed over a complete image using a complex strategy that makes known plaintext attack unfeasible. The encryption algorithm guarantees the three main goals of cryptography: strong cryptographic security, short encryption/decryption time, and robustness against noise and other external disturbances. Due to the high speed, the proposed cryptosystem is suitable for application in real-time communication systems.

  2. A Logistic Regression Mixture Model for Interval Mapping of Genetic Trait Loci Affecting Binary Phenotypes

    PubMed Central

    Deng, Weiping; Chen, Hanfeng; Li, Zhaohai

    2006-01-01

    Often in genetic research, presence or absence of a disease is affected by not only the trait locus genotypes but also some covariates. The finite logistic regression mixture models and the methods under the models are developed for detection of a binary trait locus (BTL) through an interval-mapping procedure. The maximum-likelihood estimates (MLEs) of the logistic regression parameters are asymptotically unbiased. The null asymptotic distributions of the likelihood-ratio test (LRT) statistics for detection of a BTL are found to be given by the supremum of a χ2-process. The limiting null distributions are free of the null model parameters and are determined explicitly through only four (backcross case) or nine (intercross case) independent standard normal random variables. Therefore a threshold for detecting a BTL in a flanking marker interval can be approximated easily by using a Monte Carlo method. It is pointed out that use of a threshold incorrectly determined by reading off a χ2-probability table can result in an excessive false BTL detection rate much more severely than many researchers might anticipate. Simulation results show that the BTL detection procedures based on the thresholds determined by the limiting distributions perform quite well when the sample sizes are moderately large. PMID:16272416

  3. Coupled map lattice model of jet breakup

    SciTech Connect

    Minich, R W; Schwartz, A J; Baker, E L

    2001-01-25

    An alternative approach is described to evaluate the statistical nature of the breakup of shaped charge liners. Experimental data from ductile and brittle copper jets are analyzed in terms of velocity gradient, deviation of {Delta}V from linearity, R/S analysis, and the Hurst exponent within the coupled map lattice model. One-dimensional simulations containing 600 zones of equal mass and using distinctly different force-displacement curves are generated to simulate ductile and brittle behavior. A particle separates from the stretching jet when an element of material reaches the failure criterion. A simple model of a stretching rod using brittle, semi-brittle, and ductile force-displacement curves is in agreement with the experimental results for the Hurst exponent and the phase portraits and indicates that breakup is a correlated phenomenon.

  4. Color image encryption by using Yang-Gu mixture amplitude-phase retrieval algorithm in gyrator transform domain and two-dimensional Sine logistic modulation map

    NASA Astrophysics Data System (ADS)

    Sui, Liansheng; Liu, Benqing; Wang, Qiang; Li, Ye; Liang, Junli

    2015-12-01

    A color image encryption scheme is proposed based on Yang-Gu mixture amplitude-phase retrieval algorithm and two-coupled logistic map in gyrator transform domain. First, the color plaintext image is decomposed into red, green and blue components, which are scrambled individually by three random sequences generated by using the two-dimensional Sine logistic modulation map. Second, each scrambled component is encrypted into a real-valued function with stationary white noise distribution in the iterative amplitude-phase retrieval process in the gyrator transform domain, and then three obtained functions are considered as red, green and blue channels to form the color ciphertext image. Obviously, the ciphertext image is real-valued function and more convenient for storing and transmitting. In the encryption and decryption processes, the chaotic random phase mask generated based on logistic map is employed as the phase key, which means that only the initial values are used as private key and the cryptosystem has high convenience on key management. Meanwhile, the security of the cryptosystem is enhanced greatly because of high sensitivity of the private keys. Simulation results are presented to prove the security and robustness of the proposed scheme.

  5. Short-term cascaded hydroelectric system scheduling based on chaotic particle swarm optimization using improved logistic map

    NASA Astrophysics Data System (ADS)

    He, Yaoyao; Yang, Shanlin; Xu, Qifa

    2013-07-01

    In order to solve the model of short-term cascaded hydroelectric system scheduling, a novel chaotic particle swarm optimization (CPSO) algorithm using improved logistic map is introduced, which uses the water discharge as the decision variables combined with the death penalty function. According to the principle of maximum power generation, the proposed approach makes use of the ergodicity, symmetry and stochastic property of improved logistic chaotic map for enhancing the performance of particle swarm optimization (PSO) algorithm. The new hybrid method has been examined and tested on two test functions and a practical cascaded hydroelectric system. The experimental results show that the effectiveness and robustness of the proposed CPSO algorithm in comparison with other traditional algorithms.

  6. Universal renormalization-group dynamics at the onset of chaos in logistic maps and nonextensive statistical mechanics

    NASA Astrophysics Data System (ADS)

    Baldovin, F.; Robledo, A.

    2002-10-01

    We uncover the dynamics at the chaos threshold μ∞ of the logistic map and find that it consists of trajectories made of intertwined power laws that reproduce the entire period-doubling cascade that occurs for μ<μ∞. We corroborate this structure analytically via the Feigenbaum renormalization-group (RG) transformation and find that the sensitivity to initial conditions has precisely the form of a q exponential, of which we determine the q index and the q-generalized Lyapunov coefficient λq. Our results are an unequivocal validation of the applicability of the nonextensive generalization of Boltzmann-Gibbs statistical mechanics to critical points of nonlinear maps.

  7. LINEAR COUPLING CORRECTION WITH N-TURN MAPS.

    SciTech Connect

    FISCHER,W.

    2003-05-12

    The linear one-turn map of a storage ring contains coupling information on which a correction algorithm can be based. In principal, the one-turn matrix can be fitted from turn-by-turn data of beam position monitors after a kick was applied. However, the so obtained coupling information often sinks into the noise floor. The signal-to-noise ratio of the coupling information can be greatly enhanced by fitting maps for larger turn numbers N, equal to half the beat period. With the so obtained N-turn map an automated global coupling correction is possible without the need for a tune change. This is demonstrated for the Relativistic Heavy Ion Collider where the algorithm is implemented for operational use at injection.

  8. Dynamic plasticity in coupled avian midbrain maps

    NASA Astrophysics Data System (ADS)

    Atwal, Gurinder Singh

    2004-12-01

    Internal mapping of the external environment is carried out using the receptive fields of topographic neurons in the brain, and in a normal barn owl the aural and visual subcortical maps are aligned from early experiences. However, instantaneous misalignment of the aural and visual stimuli has been observed to result in adaptive behavior, manifested by functional and anatomical changes of the auditory processing system. Using methods of information theory and statistical mechanics a model of the adaptive dynamics of the aural receptive field is presented and analyzed. The dynamics is determined by maximizing the mutual information between the neural output and the weighted sensory neural inputs, admixed with noise, subject to biophysical constraints. The reduced costs of neural rewiring, as in the case of young barn owls, reveal two qualitatively different types of receptive field adaptation depending on the magnitude of the audiovisual misalignment. By letting the misalignment increase with time, it is shown that the ability to adapt can be increased even when neural rewiring costs are high, in agreement with recent experimental reports of the increased plasticity of the auditory space map in adult barn owls due to incremental learning. Finally, a critical speed of misalignment is identified, demarcating the crossover from adaptive to nonadaptive behavior.

  9. Arithmetic properties of mirror map and quantum coupling

    NASA Astrophysics Data System (ADS)

    Lian, Bong H.; Yau, Shing-Tung

    1996-02-01

    We study some arithmetic properties of the mirror maps and the quantum Yukawa couplings for some 1-parameter deformations of Calabi-Yau manifolds. First we use the Schwarzian differential equation, which we derived previously, to characterize the mirror map in each case. For algebraic K3 surfaces, we solve the equation in terms of the J-function. By deriving explicit modular relations we prove that some K3 mirror maps are algebraic over the genus zero function field Q( J). This leads to a uniform proof that those mirror maps have integral Fourier coefficients. Regarding the maps as Riemann mappings, we prove that they are genus zero functions. By virtue of the Conway-Norton conjecture (proved by Borcherds using Frenkel-Lepowsky-Meurman's Moonshine module), we find that these maps are actually the reciprocals of the Thompson series for certain conjugacy classes in the Griess-Fischer group. This also gives, as an immediate consequence, a second proof that those mirror maps are integral. We thus conjecture a surprising connection between K3 mirror maps and the Thompson series. For threefolds, we construct a formal nonlinear ODE for the quantum coupling reduced mod p. Under the mirror hypothesis and an integrality assumption, we derive mod p congurences for the Fourier coefficients. For the quintics, we deduce, (at least for 5× d) that the degree d instanton numbers n d are divisible by 53 — a fact first conjectured by Clemens.

  10. Susceptibility mapping of shallow landslides using kernel-based Gaussian process, support vector machines and logistic regression

    NASA Astrophysics Data System (ADS)

    Colkesen, Ismail; Sahin, Emrehan Kutlug; Kavzoglu, Taskin

    2016-06-01

    Identification of landslide prone areas and production of accurate landslide susceptibility zonation maps have been crucial topics for hazard management studies. Since the prediction of susceptibility is one of the main processing steps in landslide susceptibility analysis, selection of a suitable prediction method plays an important role in the success of the susceptibility zonation process. Although simple statistical algorithms (e.g. logistic regression) have been widely used in the literature, the use of advanced non-parametric algorithms in landslide susceptibility zonation has recently become an active research topic. The main purpose of this study is to investigate the possible application of kernel-based Gaussian process regression (GPR) and support vector regression (SVR) for producing landslide susceptibility map of Tonya district of Trabzon, Turkey. Results of these two regression methods were compared with logistic regression (LR) method that is regarded as a benchmark method. Results showed that while kernel-based GPR and SVR methods generally produced similar results (90.46% and 90.37%, respectively), they outperformed the conventional LR method by about 18%. While confirming the superiority of the GPR method, statistical tests based on ROC statistics, success rate and prediction rate curves revealed the significant improvement in susceptibility map accuracy by applying kernel-based GPR and SVR methods.

  11. Competitively coupled maps for hiding secret visual information

    NASA Astrophysics Data System (ADS)

    Vaidelys, M.; Ziaukas, P.; Ragulskis, M.

    2016-02-01

    A novel digital image hiding scheme based on competitively coupled maps is presented in this paper. Self-organizing patterns produced by an array of non-diffusively coupled nonlinear maps are exploited to conceal the secret. The secret image is represented in the form of a dot-skeleton representation and is embedded into a spatially homogeneous initial state far below the noise level. Self-organizing patterns leak the secret image at a predefined set of system parameters. Computational experiments are used to demonstrate the effectiveness and the security of the proposed image hiding scheme.

  12. Coupled skinny baker's maps and the Kaplan-Yorke conjecture

    NASA Astrophysics Data System (ADS)

    Gröger, Maik; Hunt, Brian R.

    2013-09-01

    The Kaplan-Yorke conjecture states that for ‘typical’ dynamical systems with a physical measure, the information dimension and the Lyapunov dimension coincide. We explore this conjecture in a neighborhood of a system for which the two dimensions do not coincide because the system consists of two uncoupled subsystems. We are interested in whether coupling ‘typically’ restores the equality of the dimensions. The particular subsystems we consider are skinny baker's maps, and we consider uni-directional coupling. For coupling in one of the possible directions, we prove that the dimensions coincide for a prevalent set of coupling functions, but for coupling in the other direction we show that the dimensions remain unequal for all coupling functions. We conjecture that the dimensions prevalently coincide for bi-directional coupling. On the other hand, we conjecture that the phenomenon we observe for a particular class of systems with uni-directional coupling, where the information and Lyapunov dimensions differ robustly, occurs more generally for many classes of uni-directionally coupled systems (also called skew-product systems) in higher dimensions.

  13. Quasistable states in globally coupled tent map systems

    NASA Astrophysics Data System (ADS)

    Chawanya, Tsuyoshi

    2003-09-01

    The characteristics of long lasting but not perpetual chaotic states appear in a wide parameter region in a globally coupled overcritical tent map system are exhibited. The lifetime of the transient state has essential relevance with the system size. In some parameter region, the lifetime saturates at a certain level, while in another region it seems to diverge as the size of the system grows. In order to uncover the dynamical structures in large system size limit, the dynamics of one-body distribution is investigated as an idealized model for the infinitely large coupled map system. Obtained numerical results indicate the correspondence between the characteristics of long transient behavior in finite size system and that of the attractor or the ruin of attractor in the idealized model.

  14. Nonequilibrium Probabilistic Dynamics of the Logistic Map at the Edge of Chaos

    NASA Astrophysics Data System (ADS)

    Borges, Ernesto P.; Tsallis, Constantino; Añaños, Garín F.; de Oliveira, Paulo Murilo

    2002-12-01

    We consider nonequilibrium probabilistic dynamics in logisticlike maps xt+1=1-a|xt|z, (z>1) at their chaos threshold: We first introduce many initial conditions within one among W>>1 intervals partitioning the phase space and focus on the unique value qsen<1 for which the entropic form Sq≡(1- ∑i=1Wpqi)/(q-1) linearly increases with time. We then verify that Sqsen(t)-Sqsen(∞) vanishes like t-1/[qrel(W)-1] [qrel(W)>1]. We finally exhibit a new finite-size scaling, qrel(∞)-qrel(W)~W- |qsen|. This establishes quantitatively, for the first time, a long pursued relation between sensitivity to the initial conditions and relaxation, concepts which play central roles in nonextensive statistical mechanics.

  15. A revised logistic regression equation and an automated procedure for mapping the probability of a stream flowing perennially in Massachusetts

    USGS Publications Warehouse

    Bent, Gardner C.; Steeves, Peter A.

    2006-01-01

    A revised logistic regression equation and an automated procedure were developed for mapping the probability of a stream flowing perennially in Massachusetts. The equation provides city and town conservation commissions and the Massachusetts Department of Environmental Protection a method for assessing whether streams are intermittent or perennial at a specific site in Massachusetts by estimating the probability of a stream flowing perennially at that site. This information could assist the environmental agencies who administer the Commonwealth of Massachusetts Rivers Protection Act of 1996, which establishes a 200-foot-wide protected riverfront area extending from the mean annual high-water line along each side of a perennial stream, with exceptions for some urban areas. The equation was developed by relating the observed intermittent or perennial status of a stream site to selected basin characteristics of naturally flowing streams (defined as having no regulation by dams, surface-water withdrawals, ground-water withdrawals, diversion, wastewater discharge, and so forth) in Massachusetts. This revised equation differs from the equation developed in a previous U.S. Geological Survey study in that it is solely based on visual observations of the intermittent or perennial status of stream sites across Massachusetts and on the evaluation of several additional basin and land-use characteristics as potential explanatory variables in the logistic regression analysis. The revised equation estimated more accurately the intermittent or perennial status of the observed stream sites than the equation from the previous study. Stream sites used in the analysis were identified as intermittent or perennial based on visual observation during low-flow periods from late July through early September 2001. The database of intermittent and perennial streams included a total of 351 naturally flowing (no regulation) sites, of which 85 were observed to be intermittent and 266 perennial

  16. Coupled mutagenesis screens and genetic mapping in zebrafish.

    PubMed Central

    Rawls, John F; Frieda, Matthew R; McAdow, Anthony R; Gross, Jason P; Clayton, Chad M; Heyen, Candy K; Johnson, Stephen L

    2003-01-01

    Forward genetic analysis is one of the principal advantages of the zebrafish model system. However, managing zebrafish mutant lines derived from mutagenesis screens and mapping the corresponding mutations and integrating them into the larger collection of mutations remain arduous tasks. To simplify and focus these endeavors, we developed an approach that facilitates the rapid mapping of new zebrafish mutations as they are generated through mutagenesis screens. We selected a minimal panel of 149 simple sequence length polymorphism markers for a first-pass genome scan in crosses involving C32 and SJD inbred lines. We also conducted a small chemical mutagenesis screen that identified several new mutations affecting zebrafish embryonic melanocyte development. Using our first-pass marker panel in bulked-segregant analysis, we were able to identify the genetic map positions of these mutations as they were isolated in our screen. Rapid mapping of the mutations facilitated stock management, helped direct allelism tests, and should accelerate identification of the affected genes. These results demonstrate the efficacy of coupling mutagenesis screens with genetic mapping. PMID:12663538

  17. Normally attracting manifolds and periodic behavior in one-dimensional and two-dimensional coupled map lattices

    NASA Astrophysics Data System (ADS)

    Giberti, Claudio; Vernia, Cecilia

    1994-12-01

    We consider diffusively coupled logistic maps in one- and two-dimensional lattices. We investigate periodic behaviors as the coupling parameter varies, i.e., existence and bifurcations of some periodic orbits with the largest domain of attraction. Similarity and differences between the two lattices are shown. For small coupling the periodic behavior appears to be characterized by a number of periodic orbits structured in such a way to give rise to distinct, reverse period-doubling sequences. For intermediate values of the coupling a prominent role in the dynamics is played by the presence of normally attracting manifolds that contain periodic orbits. The dynamics on these manifolds is very weakly hyperbolic, which implies long transients. A detailed investigation allows the understanding of the mechanism of their formation. A complex bifurcation is found which causes an attracting manifold to become unstable.

  18. From globally coupled maps to complex-systems biology

    NASA Astrophysics Data System (ADS)

    Kaneko, Kunihiko

    2015-09-01

    Studies of globally coupled maps, introduced as a network of chaotic dynamics, are briefly reviewed with an emphasis on novel concepts therein, which are universal in high-dimensional dynamical systems. They include clustering of synchronized oscillations, hierarchical clustering, chimera of synchronization and desynchronization, partition complexity, prevalence of Milnor attractors, chaotic itinerancy, and collective chaos. The degrees of freedom necessary for high dimensionality are proposed to equal the number in which the combinatorial exceeds the exponential. Future analysis of high-dimensional dynamical systems with regard to complex-systems biology is briefly discussed.

  19. From globally coupled maps to complex-systems biology

    SciTech Connect

    Kaneko, Kunihiko

    2015-09-15

    Studies of globally coupled maps, introduced as a network of chaotic dynamics, are briefly reviewed with an emphasis on novel concepts therein, which are universal in high-dimensional dynamical systems. They include clustering of synchronized oscillations, hierarchical clustering, chimera of synchronization and desynchronization, partition complexity, prevalence of Milnor attractors, chaotic itinerancy, and collective chaos. The degrees of freedom necessary for high dimensionality are proposed to equal the number in which the combinatorial exceeds the exponential. Future analysis of high-dimensional dynamical systems with regard to complex-systems biology is briefly discussed.

  20. Winnerless competition in coupled Lotka-Volterra maps

    NASA Astrophysics Data System (ADS)

    González-Díaz, L. A.; Gutiérrez, E. D.; Varona, P.; Cabrera, J. L.

    2013-07-01

    Winnerless competition is analyzed in coupled maps with discrete temporal evolution of the Lotka-Volterra type of arbitrary dimension. Necessary and sufficient conditions for the appearance of structurally stable heteroclinic cycles as a function of the model parameters are deduced. It is shown that under such conditions winnerless competition dynamics is fully exhibited. Based on these conditions different cases characterizing low, intermediate, and high dimensions are therefore computationally recreated. An analytical expression for the residence times valid in the N-dimensional case is deduced and successfully compared with the simulations.

  1. Mean-Field Coupling of Identical Expanding Circle Maps

    NASA Astrophysics Data System (ADS)

    Sélley, Fanni; Bálint, Péter

    2016-06-01

    Globally coupled doubling maps are studied in this paper. In this setting and for finitely many sites, two distinct bifurcation values of the coupling strength have been identified in the literature, corresponding to the emergence of contracting directions (Koiller and Young in Nonlinearity, 23(5):1121, 2010) and, specifically for N=3 sites, to the loss of ergodicity (Fernandez in Journal of Statistical Physics, 154(4):999-1029, 2014). On the one hand, we reconsider these results and provide an interpretation of the observed dynamical phenomena in terms of the synchronization of the sites. On the other hand, we initiate a new point of view which focuses on the evolution of distributions and allows to incorporate the investigation of a continuum of sites. In particular, we observe phenomena that is analogous to the limit states of the contracting regime of N=3 sites.

  2. Mean-Field Coupling of Identical Expanding Circle Maps

    NASA Astrophysics Data System (ADS)

    Sélley, Fanni; Bálint, Péter

    2016-08-01

    Globally coupled doubling maps are studied in this paper. In this setting and for finitely many sites, two distinct bifurcation values of the coupling strength have been identified in the literature, corresponding to the emergence of contracting directions (Koiller and Young in Nonlinearity, 23(5):1121, 2010) and, specifically for N=3 sites, to the loss of ergodicity (Fernandez in Journal of Statistical Physics, 154(4):999-1029, 2014). On the one hand, we reconsider these results and provide an interpretation of the observed dynamical phenomena in terms of the synchronization of the sites. On the other hand, we initiate a new point of view which focuses on the evolution of distributions and allows to incorporate the investigation of a continuum of sites. In particular, we observe phenomena that is analogous to the limit states of the contracting regime of N=3 sites.

  3. Coupled Hydrological and Hydraulic Modeling for Flood Mapping

    NASA Astrophysics Data System (ADS)

    Drobot, Radu; Draghia, Aurelian

    2014-05-01

    The delineation of the flooded areas involves both hydrological and hydraulic modeling. Usually, the hydrological and hydraulic processes are separately treated. In the proposed methodology, the coupled modeling of the hydrological and hydraulic processes is used. The calibration and validation of the hydrological parameters is undertaken based on historical floods using the corresponding precipitations for the same period. The calibration process was more complicated in the presence of reservoirs, when not only the discharges downstream but also the water level in the reservoirs had to be accurately reproduced. The time step for precipitation is 1 hour, corresponding to the concentration time of the smallest catchments. The maximum annual precipitation for different time steps (1; 3; 6; 24 hours) were statistically processed and based on these results the cumulative rainfall curves and the synthetic hyetographs were derived. The rainfall duration is depending on the concentration time. Mike 11 with UHM module based on SCS model was used for coupled hydrological and hydraulic modeling. The coupled hydrological and hydraulic simulation for the scaled precipitation leads both at the computation of the components which contribute to the generation of the P% flood at the Hydrometric stations as well as to the determination of the discharge hydrograph along the main river. Based on these results the flood hazard maps were obtained using a DTM based on Lidar data. The methodology was applied for a river basin in Romania of 12500 km2.

  4. GIS-based groundwater spring potential mapping in the Sultan Mountains (Konya, Turkey) using frequency ratio, weights of evidence and logistic regression methods and their comparison

    NASA Astrophysics Data System (ADS)

    Ozdemir, Adnan

    2011-12-01

    SummaryIn this study, groundwater spring potential maps produced by three different methods, frequency ratio, weights of evidence, and logistic regression, were evaluated using validation data sets and compared to each other. Groundwater spring occurrence potential maps in the Sultan Mountains (Konya, Turkey) were constructed using the relationship between groundwater spring locations and their causative factors. Groundwater spring locations were identified in the study area from a topographic map. Different thematic maps of the study area, such as geology, topography, geomorphology, hydrology, and land use/cover, have been used to identify groundwater potential zones. Seventeen spring-related parameter layers of the entire study area were used to generate groundwater spring potential maps. These are geology (lithology), fault density, distance to fault, relative permeability of lithologies, elevation, slope aspect, slope steepness, curvature, plan curvature, profile curvature, topographic wetness index, stream power index, sediment transport capacity index, drainage density, distance to drainage, land use/cover, and precipitation. The predictive capability of each model was determined by the area under the relative operating characteristic curve. The areas under the curve for frequency ratio, weights of evidence and logistic regression methods were calculated as 0.903, 0.880, and 0.840, respectively. These results indicate that frequency ratio and weights of evidence models are relatively good estimators, whereas logistic regression is a relatively poor estimator of groundwater spring potential mapping in the study area. The frequency ratio model is simple; the process of input, calculation and output can be readily understood. The produced groundwater spring potential maps can serve planners and engineers in groundwater development plans and land-use planning.

  5. Delays, Connection Topology, and Synchronization of Coupled Chaotic Maps

    NASA Astrophysics Data System (ADS)

    Atay, Fatihcan M.; Jost, Jürgen; Wende, Andreas

    2004-04-01

    We consider networks of coupled maps where the connections between units involve time delays. We show that, similar to the undelayed case, the synchronization of the network depends on the connection topology, characterized by the spectrum of the graph Laplacian. Consequently, scale-free and random networks are capable of synchronizing despite the delayed flow of information, whereas regular networks with nearest-neighbor connections and their small-world variants generally exhibit poor synchronization. On the other hand, connection delays can actually be conducive to synchronization, so that it is possible for the delayed system to synchronize where the undelayed system does not. Furthermore, the delays determine the synchronized dynamics, leading to the emergence of a wide range of new collective behavior which the individual units are incapable of producing in isolation.

  6. Dynamics of coupled maps with a conservation law

    NASA Astrophysics Data System (ADS)

    Grigoriev, R. O.; Cross, M. C.

    1997-06-01

    A particularly simple model belonging to a wide class of coupled maps which obey a local conservation law is studied. The phase structure of the system and the types of the phase transitions are determined. It is argued that the structure of the phase diagram is robust with respect to mild violations of the conservation law. Critical exponents possibly determining a new universality class are calculated for a set of independent order parameters. Numerical evidence is produced suggesting that the singularity in the density of Lyapunov exponents at λ=0 is a reflection of the singularity in the density of Fourier modes (a "Van Hove" singularity) and disappears if the conservation law is broken. Applicability of the Lyapunov dimension to the description of spatiotemporal chaos in a system with a conservation law is discussed.

  7. Dynamics of coupled maps with a conservation law.

    PubMed

    Grigoriev, R. O.; Cross, M. C.

    1997-06-01

    A particularly simple model belonging to a wide class of coupled maps which obey a local conservation law is studied. The phase structure of the system and the types of the phase transitions are determined. It is argued that the structure of the phase diagram is robust with respect to mild violations of the conservation law. Critical exponents possibly determining a new universality class are calculated for a set of independent order parameters. Numerical evidence is produced suggesting that the singularity in the density of Lyapunov exponents at lambda=0 is a reflection of the singularity in the density of Fourier modes (a "Van Hove" singularity) and disappears if the conservation law is broken. Applicability of the Lyapunov dimension to the description of spatiotemporal chaos in a system with a conservation law is discussed. (c) 1997 American Institute of Physics. PMID:12779659

  8. Logistic regression and artificial neural network models for mapping of regional-scale landslide susceptibility in volcanic mountains of West Java (Indonesia)

    NASA Astrophysics Data System (ADS)

    Ngadisih, Bhandary, Netra P.; Yatabe, Ryuichi; Dahal, Ranjan K.

    2016-05-01

    West Java Province is the most landslide risky area in Indonesia owing to extreme geo-morphological conditions, climatic conditions and densely populated settlements with immense completed and ongoing development activities. So, a landslide susceptibility map at regional scale in this province is a fundamental tool for risk management and land-use planning. Logistic regression and Artificial Neural Network (ANN) models are the most frequently used tools for landslide susceptibility assessment, mainly because they are capable of handling the nature of landslide data. The main objective of this study is to apply logistic regression and ANN models and compare their performance for landslide susceptibility mapping in volcanic mountains of West Java Province. In addition, the model application is proposed to identify the most contributing factors to landslide events in the study area. The spatial database built in GIS platform consists of landslide inventory, four topographical parameters (slope, aspect, relief, distance to river), three geological parameters (distance to volcano crater, distance to thrust and fault, geological formation), and two anthropogenic parameters (distance to road, land use). The logistic regression model in this study revealed that slope, geological formations, distance to road and distance to volcano are the most influential factors of landslide events while, the ANN model revealed that distance to volcano crater, geological formation, distance to road, and land-use are the most important causal factors of landslides in the study area. Moreover, an evaluation of the model showed that the ANN model has a higher accuracy than the logistic regression model.

  9. Multinomial Logistic Regression Predicted Probability Map To Visualize The Influence Of Socio-Economic Factors On Breast Cancer Occurrence in Southern Karnataka

    NASA Astrophysics Data System (ADS)

    Madhu, B.; Ashok, N. C.; Balasubramanian, S.

    2014-11-01

    Multinomial logistic regression analysis was used to develop statistical model that can predict the probability of breast cancer in Southern Karnataka using the breast cancer occurrence data during 2007-2011. Independent socio-economic variables describing the breast cancer occurrence like age, education, occupation, parity, type of family, health insurance coverage, residential locality and socioeconomic status of each case was obtained. The models were developed as follows: i) Spatial visualization of the Urban- rural distribution of breast cancer cases that were obtained from the Bharat Hospital and Institute of Oncology. ii) Socio-economic risk factors describing the breast cancer occurrences were complied for each case. These data were then analysed using multinomial logistic regression analysis in a SPSS statistical software and relations between the occurrence of breast cancer across the socio-economic status and the influence of other socio-economic variables were evaluated and multinomial logistic regression models were constructed. iii) the model that best predicted the occurrence of breast cancer were identified. This multivariate logistic regression model has been entered into a geographic information system and maps showing the predicted probability of breast cancer occurrence in Southern Karnataka was created. This study demonstrates that Multinomial logistic regression is a valuable tool for developing models that predict the probability of breast cancer Occurrence in Southern Karnataka.

  10. From deterministic cellular automata to coupled map lattices

    NASA Astrophysics Data System (ADS)

    García-Morales, Vladimir

    2016-07-01

    A general mathematical method is presented for the systematic construction of coupled map lattices (CMLs) out of deterministic cellular automata (CAs). The entire CA rule space is addressed by means of a universal map for CAs that we have recently derived and that is not dependent on any freely adjustable parameters. The CMLs thus constructed are termed real-valued deterministic cellular automata (RDCA) and encompass all deterministic CAs in rule space in the asymptotic limit κ \\to 0 of a continuous parameter κ. Thus, RDCAs generalize CAs in such a way that they constitute CMLs when κ is finite and nonvanishing. In the limit κ \\to ∞ all RDCAs are shown to exhibit a global homogeneous fixed-point that attracts all initial conditions. A new bifurcation is discovered for RDCAs and its location is exactly determined from the linear stability analysis of the global quiescent state. In this bifurcation, fuzziness gradually begins to intrude in a purely deterministic CA-like dynamics. The mathematical method presented allows to get insight in some highly nontrivial behavior found after the bifurcation.

  11. Directed percolation criticality due to stochastic switching between attractive and repulsive coupling in coupled circle maps.

    PubMed

    Sonawane, Abhijeet R

    2010-05-01

    We study a lattice model where the coupling stochastically switches between repulsive (subtractive) and attractive (additive) at each site with probability p at every time instant. We observe that such a kind of coupling stabilizes the local fixed point of a circle map, with the resultant globally stable attractor providing a unique absorbing state. Interestingly, a continuous phase transition is observed from the absorbing state to spatiotemporal chaos via spatiotemporal intermittency for a range of values of p . It is interesting to note that the transition falls in class of directed percolation. Static and spreading exponents along with relevant scaling laws are found to be obeyed confirming the directed percolation universality class in spatiotemporal intermittency regime. PMID:20866306

  12. Spectral and Spatial-Based Classification for Broad-Scale Land Cover Mapping Based on Logistic Regression

    PubMed Central

    Mallinis, Georgios; Koutsias, Nikos

    2008-01-01

    Improvement of satellite sensor characteristics motivates the development of new techniques for satellite image classification. Spatial information seems to be critical in classification processes, especially for heterogeneous and complex landscapes such as those observed in the Mediterranean basin. In our study, a spectral classification method of a LANDSAT-5 TM imagery that uses several binomial logistic regression models was developed, evaluated and compared to the familiar parametric maximum likelihood algorithm. The classification approach based on logistic regression modelling was extended to a contextual one by using autocovariates to consider spatial dependencies of every pixel with its neighbours. Finally, the maximum likelihood algorithm was upgraded to contextual by considering typicality, a measure which indicates the strength of class membership. The use of logistic regression for broad-scale land cover classification presented higher overall accuracy (75.61%), although not statistically significant, than the maximum likelihood algorithm (64.23%), even when the latter was refined following a spatial approach based on Mahalanobis distance (66.67%). However, the consideration of the spatial autocovariate in the logistic models significantly improved the fit of the models and increased the overall accuracy from 75.61% to 80.49%.

  13. Using a binary logistic regression method and GIS for evaluating and mapping the groundwater spring potential in the Sultan Mountains (Aksehir, Turkey)

    NASA Astrophysics Data System (ADS)

    Ozdemir, Adnan

    2011-07-01

    SummaryThe purpose of this study is to produce a groundwater spring potential map of the Sultan Mountains in central Turkey, based on a logistic regression method within a Geographic Information System (GIS) environment. Using field surveys, the locations of the springs (440 springs) were determined in the study area. In this study, 17 spring-related factors were used in the analysis: geology, relative permeability, land use/land cover, precipitation, elevation, slope, aspect, total curvature, plan curvature, profile curvature, wetness index, stream power index, sediment transport capacity index, distance to drainage, distance to fault, drainage density, and fault density map. The coefficients of the predictor variables were estimated using binary logistic regression analysis and were used to calculate the groundwater spring potential for the entire study area. The accuracy of the final spring potential map was evaluated based on the observed springs. The accuracy of the model was evaluated by calculating the relative operating characteristics. The area value of the relative operating characteristic curve model was found to be 0.82. These results indicate that the model is a good estimator of the spring potential in the study area. The spring potential map shows that the areas of very low, low, moderate and high groundwater spring potential classes are 105.586 km 2 (28.99%), 74.271 km 2 (19.906%), 101.203 km 2 (27.14%), and 90.05 km 2 (24.671%), respectively. The interpretations of the potential map showed that stream power index, relative permeability of lithologies, geology, elevation, aspect, wetness index, plan curvature, and drainage density play major roles in spring occurrence and distribution in the Sultan Mountains. The logistic regression approach has not yet been used to delineate groundwater potential zones. In this study, the logistic regression method was used to locate potential zones for groundwater springs in the Sultan Mountains. The evolved model

  14. A comparative study of frequency ratio, weights of evidence and logistic regression methods for landslide susceptibility mapping: Sultan Mountains, SW Turkey

    NASA Astrophysics Data System (ADS)

    Ozdemir, Adnan; Altural, Tolga

    2013-03-01

    This study evaluated and compared landslide susceptibility maps produced with three different methods, frequency ratio, weights of evidence, and logistic regression, by using validation datasets. The field surveys performed as part of this investigation mapped the locations of 90 landslides that had been identified in the Sultan Mountains of south-western Turkey. The landslide influence parameters used for this study are geology, relative permeability, land use/land cover, precipitation, elevation, slope, aspect, total curvature, plan curvature, profile curvature, wetness index, stream power index, sediment transportation capacity index, distance to drainage, distance to fault, drainage density, fault density, and spring density maps. The relationships between landslide distributions and these parameters were analysed using the three methods, and the results of these methods were then used to calculate the landslide susceptibility of the entire study area. The accuracy of the final landslide susceptibility maps was evaluated based on the landslides observed during the fieldwork, and the accuracy of the models was evaluated by calculating each model's relative operating characteristic curve. The predictive capability of each model was determined from the area under the relative operating characteristic curve and the areas under the curves obtained using the frequency ratio, logistic regression, and weights of evidence methods are 0.976, 0.952, and 0.937, respectively. These results indicate that the frequency ratio and weights of evidence models are relatively good estimators of landslide susceptibility in the study area. Specifically, the results of the correlation analysis show a high correlation between the frequency ratio and weights of evidence results, and the frequency ratio and logistic regression methods exhibit correlation coefficients of 0.771 and 0.727, respectively. The frequency ratio model is simple, and its input, calculation and output processes are

  15. Synchronized states and multistability in a random network of coupled discontinuous maps

    SciTech Connect

    Nag, Mayurakshi; Poria, Swarup

    2015-08-15

    The synchronization behavior of coupled chaotic discontinuous maps over a ring network with dynamic random connections is reported in this paper. It is observed that random rewiring stabilizes one of the two strongly unstable fixed points of the local map. Depending on initial conditions, the network synchronizes to different unstable fixed points, which signifies the existence of synchronized multistability in the complex network. Moreover, the length of discontinuity of the local map has an important role in generating windows of different synchronized fixed points. Synchronized fixed point and synchronized periodic orbits are found in the network depending on coupling strength and different parameter values of the local map. We have identified the existence of period subtracting bifurcation with respect to coupling strength in the network. The range of coupling strength for the occurrence of synchronized multistable spatiotemporal fixed points is determined. This range strongly depends upon the dynamic rewiring probability and also on the local map.

  16. Abstraction in Concept Map and Coupled Outline Knowledge Representation.

    ERIC Educational Resources Information Center

    Alpert, Sherman R.

    2003-01-01

    Describes a computer-based concept mapping tool that provides rich representational capabilities, including dynamic imagery (video, animated images, sound) and multiple levels of abstraction. The tool can automatically translate a concept map into an alternative representation-an outline-that contains all of the knowledge contained in a…

  17. Geographic information systems and logistic regression for high-resolution malaria risk mapping in a rural settlement of the southern Brazilian Amazon

    PubMed Central

    2013-01-01

    Background In Brazil, 99% of the cases of malaria are concentrated in the Amazon region, with high level of transmission. The objectives of the study were to use geographic information systems (GIS) analysis and logistic regression as a tool to identify and analyse the relative likelihood and its socio-environmental determinants of malaria infection in the Vale do Amanhecer rural settlement, Brazil. Methods A GIS database of georeferenced malaria cases, recorded in 2005, and multiple explanatory data layers was built, based on a multispectral Landsat 5 TM image, digital map of the settlement blocks and a SRTM digital elevation model. Satellite imagery was used to map the spatial patterns of land use and cover (LUC) and to derive spectral indices of vegetation density (NDVI) and soil/vegetation humidity (VSHI). An Euclidian distance operator was applied to measure proximity of domiciles to potential mosquito breeding habitats and gold mining areas. The malaria risk model was generated by multiple logistic regression, in which environmental factors were considered as independent variables and the number of cases, binarized by a threshold value was the dependent variable. Results Out of a total of 336 cases of malaria, 133 positive slides were from inhabitants at Road 08, which corresponds to 37.60% of the notifications. The southern region of the settlement presented 276 cases and a greater number of domiciles in which more than ten cases/home were notified. From these, 102 (30.36%) cases were caused by Plasmodium falciparum and 174 (51.79%) cases by Plasmodium vivax. Malaria risk is the highest in the south of the settlement, associated with proximity to gold mining sites, intense land use, high levels of soil/vegetation humidity and low vegetation density. Conclusions Mid-resolution, remote sensing data and GIS-derived distance measures can be successfully combined with digital maps of the housing location of (non-) infected inhabitants to predict relative

  18. Image encryption using chaotic coupled map lattices with time-varying delays

    NASA Astrophysics Data System (ADS)

    Tang, Yang; Wang, Zidong; Fang, Jian-an

    2010-09-01

    In this paper, a novel image encryption scheme using coupled map lattices (CML) with time delay is proposed. By employing discretized tent map to shuffle the positions of image pixels and then using delayed coupled map lattices (DCML) to confuse the relationship between the plain-image and the cipher-image, image encryption algorithms with permutation-diffusion structure are introduced in detail. In the process of generating keystream, the time-varying delay is also embedded in our proposed scheme to enhance the security. Theoretical analysis and computer experiments confirm that the new algorithm possesses high security for practical image encryption.

  19. Mapping Capacitive Coupling Among Pixels in a Sensor Array

    NASA Technical Reports Server (NTRS)

    Seshadri, Suresh; Cole, David M.; Smith, Roger M.

    2010-01-01

    An improved method of mapping the capacitive contribution to cross-talk among pixels in an imaging array of sensors (typically, an imaging photodetector array) has been devised for use in calibrating and/or characterizing such an array. The method involves a sequence of resets of subarrays of pixels to specified voltages and measurement of the voltage responses of neighboring non-reset pixels.

  20. Jieke theory and logistic model

    SciTech Connect

    Cao, H.; Feng, G.

    1996-06-01

    What is a shell or a JIEKE (in Chinese) is introduced firstly, jieke is a sort of system boundary. From the concept of jieke theory, a new logistic model which takes account of the switch effect of the jieke is suggested. The model is analyzed and nonlinear mapping of the model is made. The results show the feature of the switch logistic model far differ from the original logistic model. {copyright} {ital 1996 American Institute of Physics.}

  1. Logistic Regression

    NASA Astrophysics Data System (ADS)

    Grégoire, G.

    2014-12-01

    The logistic regression originally is intended to explain the relationship between the probability of an event and a set of covariables. The model's coefficients can be interpreted via the odds and odds ratio, which are presented in introduction of the chapter. The observations are possibly got individually, then we speak of binary logistic regression. When they are grouped, the logistic regression is said binomial. In our presentation we mainly focus on the binary case. For statistical inference the main tool is the maximum likelihood methodology: we present the Wald, Rao and likelihoods ratio results and their use to compare nested models. The problems we intend to deal with are essentially the same as in multiple linear regression: testing global effect, individual effect, selection of variables to build a model, measure of the fitness of the model, prediction of new values… . The methods are demonstrated on data sets using R. Finally we briefly consider the binomial case and the situation where we are interested in several events, that is the polytomous (multinomial) logistic regression and the particular case of ordinal logistic regression.

  2. Phase transitions in coupled map lattices and in associated probabilistic cellular automata.

    PubMed

    Just, Wolfram

    2006-10-01

    Analytical tools are applied to investigate piecewise linear coupled map lattices in terms of probabilistic cellular automata. The so-called disorder condition of probabilistic cellular automata is closely related with attracting sets in coupled map lattices. The importance of this condition for the suppression of phase transitions is illustrated by spatially one-dimensional systems. Invariant densities and temporal correlations are calculated explicitly. Ising type phase transitions are found for one-dimensional coupled map lattices acting on repelling sets and for a spatially two-dimensional Miller-Huse-like system with stable long time dynamics. Critical exponents are calculated within a finite size scaling approach. The relevance of detailed balance of the resulting probabilistic cellular automaton for the critical behavior is pointed out. PMID:17155155

  3. Mapping inter-element coupling in metamaterials: Scaling down to infrared

    NASA Astrophysics Data System (ADS)

    Tatartschuk, E.; Gneiding, N.; Hesmer, F.; Radkovskaya, A.; Shamonina, E.

    2012-05-01

    The coupling between arbitrarily positioned and oriented split ring resonators is investigated up to THz frequencies. Two different analytical approaches are used, one based on circuits and the other on field quantities that includes retardation. These are supplemented by numerical simulations and experiments in the GHz range, and by simulations in the THz range. The field approach makes it possible to determine separately the electric and magnetic coupling coefficients which, depending on orientation, may reinforce or may cancel each other. Maps of coupling are produced for arbitrary orientations of two co-planar split rings resonant at around 2 GHz and then with the geometry scaled down to be resonant at around 100 THz. We prove that the inertia of electrons at high frequencies results in a dramatic change in the maps of coupling, due to reduction of the magnetic contribution. Our approach could facilitate the design of metamaterials in a wide frequency range up to the saturation of the resonant frequency.

  4. Stability and synchronization of coupled Rulkov map-based neurons with chemical synapses

    NASA Astrophysics Data System (ADS)

    Hu, Dongpo; Cao, Hongjun

    2016-06-01

    The stability and synchronization analysis of two chaotic Rulkov maps coupled by bidirectional and symmetric chemical synapses are taken into account. As a function of intrinsic control parameters α, σ, η, reversal potential v, synaptic parameters θ, k, and external chemical coupling strength gc, conditions for stability of a fixed point for this system are derived. Some typical domains are chosen for numerical simulations which include time evolution of transmembrane voltages and phase portraits, and both of them are presented for theoretical analysis. Based on the master stability functions approach and calculation of the maximum Lyapunov exponents of synchronization errors, synchronized regions of the coupled neurons and a strip-shaped chaotic structure in parameter-space are obtained. Specially, given some values of control parameter α, we propose interval ranges of coupling strength gc in which the two chaotic Rulkov map-based neurons can be synchronized completely. It is shown that there exist different transition mechanisms of the neuronal spiking and bursting synchronization. The synchronized regions will become smaller and smaller as control parameter α or synaptic parameter θ increases. Nevertheless, the coupled neurons can at first transit from desynchrony to in-phase synchronization, and then to complete synchronization as chemical coupling strength gc increases. Compared with control parameter α and synaptic parameter θ, chemical coupling strength gc plays an opposite role in the process of synchronization transition. These findings could be useful for further understanding the role of two chaotic Rulkov maps coupled by bidirectional and symmetric chemical synapses in the field of cooperative behaviors of coupled neurons.

  5. Electron-Vibration Coupling in Molecular Materials: Assignment of Vibronic Modes from Photoelectron Momentum Mapping

    NASA Astrophysics Data System (ADS)

    Graus, M.; Grimm, M.; Metzger, C.; Dauth, M.; Tusche, C.; Kirschner, J.; Kümmel, S.; Schöll, A.; Reinert, F.

    2016-04-01

    Electron-phonon coupling is one of the most fundamental effects in condensed matter physics. We here demonstrate that photoelectron momentum mapping can reveal and visualize the coupling between specific vibrational modes and electronic excitations. When imaging molecular orbitals with high energy resolution, the intensity patterns of photoelectrons of the vibronic sidebands of molecular states show characteristic changes due to the distortion of the molecular frame in the vibronically excited state. By comparison to simulations, an assignment of specific vibronic modes is possible, thus providing unique information on the coupling between electronic and vibronic excitation.

  6. Electron-Vibration Coupling in Molecular Materials: Assignment of Vibronic Modes from Photoelectron Momentum Mapping.

    PubMed

    Graus, M; Grimm, M; Metzger, C; Dauth, M; Tusche, C; Kirschner, J; Kümmel, S; Schöll, A; Reinert, F

    2016-04-01

    Electron-phonon coupling is one of the most fundamental effects in condensed matter physics. We here demonstrate that photoelectron momentum mapping can reveal and visualize the coupling between specific vibrational modes and electronic excitations. When imaging molecular orbitals with high energy resolution, the intensity patterns of photoelectrons of the vibronic sidebands of molecular states show characteristic changes due to the distortion of the molecular frame in the vibronically excited state. By comparison to simulations, an assignment of specific vibronic modes is possible, thus providing unique information on the coupling between electronic and vibronic excitation. PMID:27104726

  7. Scaling law for the Lyapunov spectra in globally coupled tent maps

    NASA Astrophysics Data System (ADS)

    Morita, Satoru

    1998-10-01

    The collective motions in globally coupled tent maps are investigated in terms of Lyapunov spectra. The scattered states are separated into two distinct phases by the characteristics of the Lyapunov spectra. In the weak-coupling phase, the Lyapunov spectra obey a scaling law with varying system size. This scaling law holds even in the strong-coupling phase except for the singular property of the largest Lyapunov exponent. The Lyapunov exponents are estimated theoretically by using the random field approximation. These approximate results reveal the relation between the Lyapunov exponents and the distribution of the elements. Furthermore, the features of the band structure in the distribution are explored.

  8. Texture Analysis of Chaotic Coupled Map Lattices Based Image Encryption Algorithm

    NASA Astrophysics Data System (ADS)

    Khan, Majid; Shah, Tariq; Batool, Syeda Iram

    2014-09-01

    As of late, data security is key in different enclosures like web correspondence, media frameworks, therapeutic imaging, telemedicine and military correspondence. In any case, a large portion of them confronted with a few issues, for example, the absence of heartiness and security. In this letter, in the wake of exploring the fundamental purposes of the chaotic trigonometric maps and the coupled map lattices, we have presented the algorithm of chaos-based image encryption based on coupled map lattices. The proposed mechanism diminishes intermittent impact of the ergodic dynamical systems in the chaos-based image encryption. To assess the security of the encoded image of this scheme, the association of two nearby pixels and composition peculiarities were performed. This algorithm tries to minimize the problems arises in image encryption.

  9. Extensive numerical investigations on the ergodic properties of two coupled Pomeau-Manneville maps

    NASA Astrophysics Data System (ADS)

    Sala, Matteo; Manchein, Cesar; Artuso, Roberto

    2015-11-01

    We present extensive numerical investigations on the ergodic properties of two identical Pomeau-Manneville maps interacting on the unit square through a diffusive linear coupling. The system exhibits anomalous statistics, as expected, but with strong deviations from the single intermittent map: Such differences are characterized by numerical experiments with densities which do not have singularities in the marginal fixed point, escape and Poincaré recurrence time statistics that share a power-law decay exponent modified by a clear dimensional scaling, while the rate of phase-space filling and the convergence of ensembles of Lyapunov exponents show a stretched instead of pure exponential behavior. In spite of the lack of rigorous results about this system, the dependence on both the intermittency and the coupling parameters appears to be smooth, paving the way for further analytical development. We remark that dynamical exponents appear to be independent of the (nonzero) coupling strength.

  10. A coupled map lattice model for rheological chaos in sheared nematic liquid crystals.

    PubMed

    Kamil, S M; Menon, Gautam I; Sinha, Sudeshna

    2010-12-01

    A variety of complex fluids under shear exhibit complex spatiotemporal behavior, including what is now termed rheological chaos, at moderate values of the shear rate. Such chaos associated with rheological response occurs in regimes where the Reynolds number is very small. It must thus arise as a consequence of the coupling of the flow to internal structural variables describing the local state of the fluid. We propose a coupled map lattice model for such complex spatiotemporal behavior in a passively sheared nematic liquid crystal using local maps constructed so as to accurately describe the spatially homogeneous case. Such local maps are coupled diffusively to nearest and next-nearest neighbors to mimic the effects of spatial gradients in the underlying equations of motion. We investigate the dynamical steady states obtained as parameters in the map and the strength of the spatial coupling are varied, studying local temporal properties at a single site as well as spatiotemporal features of the extended system. Our methods reproduce the full range of spatiotemporal behavior seen in earlier one-dimensional studies based on partial differential equations. We report results for both the one- and two-dimensional cases, showing that spatial coupling favors uniform or periodically time-varying states, as intuitively expected. We demonstrate and characterize regimes of spatiotemporal intermittency out of which chaos develops. Our work indicates that similar simplified lattice models of the dynamics of complex fluids under shear should provide useful ways to access and quantify spatiotemporal complexity in such problems, in addition to representing a fast and numerically tractable alternative to continuum representations. PMID:21198093

  11. Slice-Based Formal Specification Measures -- Mapping Coupling and Cohesion Measures to Formal Z

    NASA Technical Reports Server (NTRS)

    Bollin, Andreas

    2010-01-01

    This paper demonstrates that existing slice-based measures can reasonably be mapped to the field of state-based specification languages. By making use of Z specifications this contribution renews the idea of slice-profiles and derives coupling and cohesion measures for them. The measures are then assessed by taking a critical look at their sensitiveness in respect to modifications on the specification source. The presented study shows that slice-based coupling and cohesion measures have the potential to be used as quality indicators for specifications as they reflect the changes in the structure of a specification as accustomed from their program-related pendants.

  12. Chaos analysis and delayed-feedback control in a discrete dynamic coupled map traffic model

    NASA Astrophysics Data System (ADS)

    Fang, Yaling; Shi, Zhongke

    2015-03-01

    The presence of chaos in traffic flow is studied using a modified discrete dynamic coupled map model which is derived from both the flow-density-speed fundamental diagram and Del Castillo's speed-density model. The modified model employs occupancy as its new variable and introduces a coupling strength with the consideration of effect of the front adjacent vehicle. And we analyze its stability of the control system and provide a procedure to design the decentralized delayed-feedback controllers for the traffic control system. These theoretical results are illustrated by numerical simulations.

  13. Electrical coupling in ensembles of nonexcitable cells: modeling the spatial map of single cell potentials.

    PubMed

    Cervera, Javier; Manzanares, Jose Antonio; Mafe, Salvador

    2015-02-19

    We analyze the coupling of model nonexcitable (non-neural) cells assuming that the cell membrane potential is the basic individual property. We obtain this potential on the basis of the inward and outward rectifying voltage-gated channels characteristic of cell membranes. We concentrate on the electrical coupling of a cell ensemble rather than on the biochemical and mechanical characteristics of the individual cells, obtain the map of single cell potentials using simple assumptions, and suggest procedures to collectively modify this spatial map. The response of the cell ensemble to an external perturbation and the consequences of cell isolation, heterogeneity, and ensemble size are also analyzed. The results suggest that simple coupling mechanisms can be significant for the biophysical chemistry of model biomolecular ensembles. In particular, the spatiotemporal map of single cell potentials should be relevant for the uptake and distribution of charged nanoparticles over model cell ensembles and the collective properties of droplet networks incorporating protein ion channels inserted in lipid bilayers. PMID:25622192

  14. Common Coupled Fixed Point Theorems for Two Hybrid Pairs of Mappings under φ-ψ Contraction

    PubMed Central

    Handa, Amrish

    2014-01-01

    We introduce the concept of (EA) property and occasional w-compatibility for hybrid pair F : X × X → 2X and f : X → X. We also introduce common (EA) property for two hybrid pairs F, G : X → 2X and f, g : X → X. We establish some common coupled fixed point theorems for two hybrid pairs of mappings under φ-ψ contraction on noncomplete metric spaces. An example is also given to validate our results. We improve, extend and generalize several known results. The results of this paper generalize the common fixed point theorems for hybrid pairs of mappings and essentially contain fixed point theorems for hybrid pair of mappings. PMID:27340688

  15. Biomass Logistics

    SciTech Connect

    J. Richard Hess; Kevin L. Kenney; William A. Smith; Ian Bonner; David J. Muth

    2015-04-01

    Equipment manufacturers have made rapid improvements in biomass harvesting and handling equipment. These improvements have increased transportation and handling efficiencies due to higher biomass densities and reduced losses. Improvements in grinder efficiencies and capacity have reduced biomass grinding costs. Biomass collection efficiencies (the ratio of biomass collected to the amount available in the field) as high as 75% for crop residues and greater than 90% for perennial energy crops have also been demonstrated. However, as collection rates increase, the fraction of entrained soil in the biomass increases, and high biomass residue removal rates can violate agronomic sustainability limits. Advancements in quantifying multi-factor sustainability limits to increase removal rate as guided by sustainable residue removal plans, and mitigating soil contamination through targeted removal rates based on soil type and residue type/fraction is allowing the use of new high efficiency harvesting equipment and methods. As another consideration, single pass harvesting and other technologies that improve harvesting costs cause biomass storage moisture management challenges, which challenges are further perturbed by annual variability in biomass moisture content. Monitoring, sampling, simulation, and analysis provide basis for moisture, time, and quality relationships in storage, which has allowed the development of moisture tolerant storage systems and best management processes that combine moisture content and time to accommodate baled storage of wet material based upon “shelf-life.” The key to improving biomass supply logistics costs has been developing the associated agronomic sustainability and biomass quality technologies and processes that allow the implementation of equipment engineering solutions.

  16. Breaking of Ergodicity in Expanding Systems of Globally Coupled Piecewise Affine Circle Maps

    NASA Astrophysics Data System (ADS)

    Fernandez, Bastien

    2014-02-01

    To identify and to explain coupling-induced phase transitions in coupled map lattices (CML) has been a lingering enigma for about two decades. In numerical simulations, this phenomenon has always been observed preceded by a lowering of the Lyapunov dimension, suggesting that the transition might require changes of linear stability. Yet, recent proofs of co-existence of several phases in specially designed models work in the expanding regime where all Lyapunov exponents remain positive. In this paper, we consider a family of CML composed by piecewise expanding individual map, global interaction and finite number of sites, in the weak coupling regime where the CML is uniformly expanding. We show, mathematically for and numerically for , that a transition in the asymptotic dynamics occurs as the coupling strength increases. The transition breaks the (Milnor) attractor into several chaotic pieces of positive Lebesgue measure, with distinct empiric averages. It goes along with various symmetry breaking, quantified by means of magnetization-type characteristics. Despite that it only addresses finite-dimensional systems, to some extend, this result reconciles the previous ones as it shows that loss of ergodicity/symmetry breaking can occur in basic CML, independently of any decay in the Lyapunov dimension.

  17. Effective dipole moment for the mode coupling instability: Mapping of self-consistent wake models

    SciTech Connect

    Roecker, T. B.; Zhdanov, S. K.; Ivlev, A. V.; Morfill, G. E.; Lampe, M.; Joyce, G.

    2012-07-15

    The theory of the mode coupling instability operating in two-dimensional plasma crystals is generalized, by employing the linear plasma response formalism to describe the interparticle interactions self-consistently. In this approach, the underlying ion distribution function is calculated from first principles. Subthermal and suprathermal regimes of the ion flow are considered. A mapping procedure is proposed, which relates the self-consistent coupling coefficients to the effective dipole moment of the wake-the parameter which characterizes the mode coupling in the framework of the conventionally used Yukawa/point-wake model. The importance of the self-consistent approach is demonstrated by comparing the theoretically obtained dipole moments with the values deduced from experiments.

  18. The logistics of choice.

    PubMed

    Killeen, Peter R

    2015-07-01

    The generalized matching law (GML) is reconstructed as a logistic regression equation that privileges no particular value of the sensitivity parameter, a. That value will often approach 1 due to the feedback that drives switching that is intrinsic to most concurrent schedules. A model of that feedback reproduced some features of concurrent data. The GML is a law only in the strained sense that any equation that maps data is a law. The machine under the hood of matching is in all likelihood the very law that was displaced by the Matching Law. It is now time to return the Law of Effect to centrality in our science. PMID:25988932

  19. A quasi-classical mapping approach to vibrationally coupled electron transport in molecular junctions

    SciTech Connect

    Li, Bin; Miller, William H.; Wilner, Eli Y.; Thoss, Michael

    2014-03-14

    We develop a classical mapping approach suitable to describe vibrationally coupled charge transport in molecular junctions based on the Cartesian mapping for many-electron systems [B. Li and W. H. Miller, J. Chem. Phys. 137, 154107 (2012)]. To properly describe vibrational quantum effects in the transport characteristics, we introduce a simple transformation rewriting the Hamiltonian in terms of occupation numbers and use a binning function to facilitate quantization. The approach provides accurate results for the nonequilibrium Holstein model for a range of bias voltages, vibrational frequencies, and temperatures. It also captures the hallmarks of vibrational quantum effects apparent in step-like structure in the current-voltage characteristics at low temperatures as well as the phenomenon of Franck-Condon blockade.

  20. Mapping sea ice leads with a coupled numeric/symbolic system

    NASA Technical Reports Server (NTRS)

    Key, J.; Schweiger, A. J.; Maslanik, J. A.

    1990-01-01

    A method is presented which facilitates the detection and delineation of leads with single-channel Landsat data by coupling numeric and symbolic procedures. The procedure consists of three steps: (1) using the dynamic threshold method, an image is mapped to a lead/no lead binary image; (2) the likelihood of fragments to be real leads is examined with a set of numeric rules; and (3) pairs of objects are examined geometrically and merged where possible. The processing ends when all fragments are merged and statistical characteristics are determined, and a map of valid lead objects are left which summarizes useful physical in the lead complexes. Direct implementation of domain knowledge and rapid prototyping are two benefits of the rule-based system. The approach is found to be more successfully applied to mid- and high-level processing, and the system can retrieve statistics about sea-ice leads as well as detect the leads.

  1. The mapping of yeast's G-protein coupled receptor with an atomic force microscope

    NASA Astrophysics Data System (ADS)

    Takenaka, Musashi; Miyachi, Yusuke; Ishii, Jun; Ogino, Chiaki; Kondo, Akihiko

    2015-03-01

    An atomic force microscope (AFM) can measure the adhesion force between a sample and a cantilever while simultaneously applying a rupture force during the imaging of a sample. An AFM should be useful in targeting specific proteins on a cell surface. The present study proposes the use of an AFM to measure the adhesion force between targeting receptors and their ligands, and to map the targeting receptors. In this study, Ste2p, one of the G protein-coupled receptors (GPCRs), was chosen as the target receptor. The specific force between Ste2p on a yeast cell surface and a cantilever modified with its ligand, α-factor, was measured and found to be approximately 250 pN. In addition, through continuous measuring of the cell surface, a mapping of the receptors on the cell surface could be performed, which indicated the differences in the Ste2p expression levels. Therefore, the proposed AFM system is accurate for cell diagnosis.

  2. The use of maps in the analysis of networks of coupled neuronal oscillators

    NASA Astrophysics Data System (ADS)

    Goel, Pranay

    In this thesis we study aspects of periodic activity in model mutually-coupled oscillators inspired by the nervous system. We define and use maps describing the timing of activity on successive cycles. The central theme here is to examine emergent behavior in networks through the properties of the individual oscillators. In the first chapter, we describe Phase Response Curves (PRCs), which map the changes in the period of an oscillator to perturbations at different phases along the cycle. We consider various networks of oscillators, pulse-coupled through their PRCs: rings, chains, arrays, and global coupling. We study conditions under which stable patterns, such as synchrony and waves, may be found. In the second and third chapters, we model beta (12--30 Hz) and gamma (30--80 Hz) rhythms in the nervous system in reduced networks of excitatory and inhibitory neurons. We look at the intriguing results of experiments that show increases in beta band activity in human MEGs upon taking the sedative Diapam. We show that the model network is able to mimic the experimental data. The model then clarifies the inhibitory action of the drug in tissue. We look at another experiment that finds disruption of long-range synchrony of gamma oscillations in transgenic mice with altered excitatory kinetics. We study this behavior in a reduced network that encodes for conduction delays across spatially distal sites. The model provides an explanation of this phenomenon in terms of the properties of the cells involved in generating the rhythm. In our analyses, we use maps to study stability of the patterns of activity.

  3. Spatiotemporal structure of Lyapunov vectors in chaotic coupled-map lattices

    NASA Astrophysics Data System (ADS)

    Szendro, Ivan G.; Pazó, Diego; Rodríguez, Miguel A.; López, Juan M.

    2007-08-01

    The spatiotemporal dynamics of Lyapunov vectors (LVs) in spatially extended chaotic systems is studied by means of coupled-map lattices. We determine intrinsic length scales and spatiotemporal correlations of LVs corresponding to the leading unstable directions by translating the problem to the language of scale-invariant growing surfaces. We find that the so-called characteristic LVs exhibit spatial localization, strong clustering around given spatiotemporal loci, and remarkable dynamic scaling properties of the corresponding surfaces. In contrast, the commonly used backward LVs (obtained through Gram-Schmidt orthogonalization) spread all over the system and do not exhibit dynamic scaling due to artifacts in the dynamical correlations by construction.

  4. Spatiotemporal dynamics of a digital phase-locked loop based coupled map lattice system

    SciTech Connect

    Banerjee, Tanmoy Paul, Bishwajit; Sarkar, B. C.

    2014-03-15

    We explore the spatiotemporal dynamics of a coupled map lattice (CML) system, which is realized with a one dimensional array of locally coupled digital phase-locked loops (DPLLs). DPLL is a nonlinear feedback-controlled system widely used as an important building block of electronic communication systems. We derive the phase-error equation of the spatially extended system of coupled DPLLs, which resembles a form of the equation of a CML system. We carry out stability analysis for the synchronized homogeneous solutions using the circulant matrix formalism. It is shown through extensive numerical simulations that with the variation of nonlinearity parameter and coupling strength the system shows transitions among several generic features of spatiotemporal dynamics, viz., synchronized fixed point solution, frozen random pattern, pattern selection, spatiotemporal intermittency, and fully developed spatiotemporal chaos. We quantify the spatiotemporal dynamics using quantitative measures like average quadratic deviation and spatial correlation function. We emphasize that instead of using an idealized model of CML, which is usually employed to observe the spatiotemporal behaviors, we consider a real world physical system and establish the existence of spatiotemporal chaos and other patterns in this system. We also discuss the importance of the present study in engineering application like removal of clock-skew in parallel processors.

  5. On the bifurcation structure of the mean-field fluctuation in the globally coupled tent map systems

    NASA Astrophysics Data System (ADS)

    Chawanya, Tsuyoshi; Morita, Satoru

    1998-05-01

    A theoretical analysis on the behavior of the globally coupled tent map systems based on the kinetics of the mean-field value is presented. We investigated the nature of the mean-field fluctuation in large system size limit, and uncovered the existence of a complicated bifurcation structure that leads the appearance of collective motion with the increase of the coupling strength. The way to the appearance of the collective motion sensitively depends on the gradient a of individual tent-maps. For a belonging to a set which is dense in ( 2, 2 ), the collective motion appears when the coupling strength exceeds a certain threshold value, while for a belonging to another dense set in ( 2, 2 ), any non-zero coupling will induce the collective motion. The dependence of the amplitude of mean-field fluctuation on the coupling strength is also obtained as a function of the parameter a and the coupling strength.

  6. Strain pseudospins with power-law interactions: Glassy textures of a cooled coupled-map lattice

    NASA Astrophysics Data System (ADS)

    Shenoy, S. R.; Lookman, T.

    2008-10-01

    We consider a spin-1 model of strain pseudospins S(r⃗)=0,±1 that arise from a triple-well Landau free energy for a square/rectangle or “austenite-martensite” structural transformation of a two-dimensional lattice. The pseudospin model has elastic-compatibility-induced power-law anisotropic (PLA) interactions and no quenched disorder. The iteratively solved local mean-field equations for ⟨S(r⃗,t)⟩ form a temperature-dependent PLA-coupled nonlinear-map lattice, where t is the iteration “time.” On cooling at a constant rate, the excess entropy shows a weak roll-off near a temperature T=Tg and a sharper elbow at a lower T∗ , just above a Kauzmann-type TK where the excess entropy would have become negative. The crossover temperatures Tg,T∗ decrease logarithmically with cooling rate and mark stability changes in spatiotemporal attractors of the cooled PLA-coupled map. Three phases in ⟨S(r⃗,t)⟩ are found, with textures of the martensitic-variant domain walls as “inherent structures.” There is a high-temperature (T>Tg) fine scale phase of feathery domain walls and an intermediate temperature (Tg>T>T∗) phase of mazelike domain walls, with both showing square-wave oscillations as predominantly period-two attractors but with minority-frequency subharmonic clusters. Finally, there is a low-temperature freezing (T∗>T) to a static fixed point or period-one attractor of coarse, irregular bidiagonal twins, as in a strain glass. A Haar-wavelet analysis is used to identify the local attractor dynamics. A central result is that dynamically heterogeneous and mobile low-strain droplets act as catalysts, and can form correlated chains or transient “catalytic corrals” to incubate an emerging local texture. The hotspot lifetime vanishes linearly in T-TK , suggesting that TK is a dynamic spinodal limit for generating the “austenitic” catalyst, the disappearance of which drives a trapping into one of many bidiagonal glassy states. The model has

  7. Maps of CMB lensing deflection from N-body simulations in Coupled Dark Energy Cosmologies

    SciTech Connect

    Carbone, Carmelita; Baldi, Marco; Baccigalupi, Carlo E-mail: marco.baldi5@unibo.it E-mail: bacci@sissa.it

    2013-09-01

    We produce lensing potential and deflection-angle maps in order to simulate the weak gravitational lensing of the Cosmic Microwave Background (CMB) via ray-tracing through the COupled Dark Energy Cosmological Simulations (CoDECS), the largest suite of N-body simulations to date for interacting Dark Energy cosmologies. The constructed maps faithfully reflect the N-body cosmic structures on a range of scales going from the arcminute to the degree scale, limited only by the resolution and extension of the simulations. We investigate the variation of the lensing pattern due to the underlying Dark Energy (DE) dynamics, characterised by different background and perturbation behaviours as a consequence of the interaction between the DE field and Cold Dark Matter (CDM). In particular, we study in detail the results from three cosmological models differing in the background and perturbations evolution at the epoch in which the lensing cross section is most effective, corresponding to a redshift of ∼ 1, with the purpose to isolate their imprints in the lensing observables, regardless of the compatibility of these models with present constraints. The scenarios investigated here include a reference ΛCDM cosmology, a standard coupled DE (cDE) scenario, and a ''bouncing'' cDE scenario. For the standard cDE scenario, we find that typical differences in the lensing potential result from two effects: the enhanced growth of linear CDM density fluctuations with respect to the ΛCDM case, and the modified nonlinear dynamics of collapsed structures induced by the DE-CDM interaction. As a consequence, CMB lensing highlights the DE impact in the cosmological expansion, even in the degenerate case where the amplitude of the linear matter density perturbations, parametrised through σ{sub 8}, is the same in both the standard cDE and ΛCDM cosmologies. For the ''bouncing'' scenario, we find that the two opposite behaviours of the lens density contrast and of the matter abundance lead to

  8. Nanoscale mapping of plasmon and exciton in ZnO tetrapods coupled with Au nanoparticles

    NASA Astrophysics Data System (ADS)

    Bertoni, Giovanni; Fabbri, Filippo; Villani, Marco; Lazzarini, Laura; Turner, Stuart; van Tendeloo, Gustaaf; Calestani, Davide; Gradečak, Silvija; Zappettini, Andrea; Salviati, Giancarlo

    2016-01-01

    Metallic nanoparticles can be used to enhance optical absorption or emission in semiconductors, thanks to a strong interaction of collective excitations of free charges (plasmons) with electromagnetic fields. Herein we present direct imaging at the nanoscale of plasmon-exciton coupling in Au/ZnO nanostructures by combining scanning transmission electron energy loss and cathodoluminescence spectroscopy and mapping. The Au nanoparticles (~30 nm in diameter) are grown in-situ on ZnO nanotetrapods by means of a photochemical process without the need of binding agents or capping molecules, resulting in clean interfaces. Interestingly, the Au plasmon resonance is localized at the Au/vacuum interface, rather than presenting an isotropic distribution around the nanoparticle. On the contrary, a localization of the ZnO signal has been observed inside the Au nanoparticle, as also confirmed by numerical simulations.

  9. Nanoscale mapping of plasmon and exciton in ZnO tetrapods coupled with Au nanoparticles.

    PubMed

    Bertoni, Giovanni; Fabbri, Filippo; Villani, Marco; Lazzarini, Laura; Turner, Stuart; Van Tendeloo, Gustaaf; Calestani, Davide; Gradečak, Silvija; Zappettini, Andrea; Salviati, Giancarlo

    2016-01-01

    Metallic nanoparticles can be used to enhance optical absorption or emission in semiconductors, thanks to a strong interaction of collective excitations of free charges (plasmons) with electromagnetic fields. Herein we present direct imaging at the nanoscale of plasmon-exciton coupling in Au/ZnO nanostructures by combining scanning transmission electron energy loss and cathodoluminescence spectroscopy and mapping. The Au nanoparticles (~30 nm in diameter) are grown in-situ on ZnO nanotetrapods by means of a photochemical process without the need of binding agents or capping molecules, resulting in clean interfaces. Interestingly, the Au plasmon resonance is localized at the Au/vacuum interface, rather than presenting an isotropic distribution around the nanoparticle. On the contrary, a localization of the ZnO signal has been observed inside the Au nanoparticle, as also confirmed by numerical simulations. PMID:26754789

  10. Coupled map car-following model and its delayed-feedback control

    NASA Astrophysics Data System (ADS)

    Konishi, Keiji; Kokame, Hideki; Hirata, Kentaro

    1999-10-01

    This paper proposes a coupled map car-following traffic model, which describes a dynamical behavior of a group of road vehicles running in a single lane without overtaking. This model consists of a lead vehicle and following vehicles, which have a piecewise linear optimal velocity function. When the lead-vehicle speed is varied, we can observe a traffic jam in the group of the vehicles. We derive a condition under which the traffic jam never occurs in our model. Furthermore, in order to suppress the traffic jam, for each vehicle we use a dynamic version of decentralized delayed-feedback control proposed in [Konishi, Hirai, and Kokame, Phys. Rev. E 58, 3055 (1998)], and provide a systematic procedure for designing the controller.

  11. From the Dynamics of Coupled Map Lattices to the Psychological Arrow of Time

    NASA Astrophysics Data System (ADS)

    Atmanspacher, Harald; Filk, Thomas; Scheingraber, Herbert

    2006-10-01

    Stable neuronal assemblies are generally regarded as neural correlates of mental representations. Their temporal sequence corresponds to the experience of a direction of time, sometimes called the psychological time arrow. We show that the stability of particular, biophysically motivated models of neuronal assemblies, called coupled map lattices, is supported by causal interactions among neurons and obstructed by non-causal or anti-causal interactions among neurons. This surprising relation between causality and stability suggests that those neuronal assemblies that are stable due to causal neuronal interactions, and thus correlated with mental representations, generate a psychological time arrow. Yet this impact of causal interactions among neurons on the directed sequence of mental representations does not rule out the possibility of mentally less efficacious non-causal or anti-causal interactions among neurons.

  12. Nanoscale mapping of plasmon and exciton in ZnO tetrapods coupled with Au nanoparticles

    DOE PAGESBeta

    Bertoni, Giovanni; Fabbri, Filippo; Villani, Marco; Lazzarini, Laura; Turner, Stuart; Van Tendeloo, Gustaaf; Calestani, Davide; Gradečak, Silvija; Zappettini, Andrea; Salviati, Giancarlo

    2016-01-12

    Metallic nanoparticles can be used to enhance optical absorption or emission in semiconductors, thanks to a strong interaction of collective excitations of free charges (plasmons) with electromagnetic fields. Herein we present direct imaging at the nanoscale of plasmon-exciton coupling in Au/ZnO nanostructures by combining scanning transmission electron energy loss and cathodoluminescence spectroscopy and mapping. The Au nanoparticles (~30 nm in diameter) are grown in-situ on ZnO nanotetrapods by means of a photochemical process without the need of binding agents or capping molecules, resulting in clean interfaces. Interestingly, the Au plasmon resonance is localized at the Au/vacuum interface, rather than presentingmore » an isotropic distribution around the nanoparticle. Moreover, on the contrary, a localization of the ZnO signal has been observed inside the Au nanoparticle, as also confirmed by numerical simulations.« less

  13. Tight coupling between coral reef morphology and mapped resilience in the Red Sea.

    PubMed

    Rowlands, Gwilym; Purkis, Sam; Bruckner, Andrew

    2016-04-30

    Lack of knowledge on the conservation value of different reef types can stymie decision making, and result in less optimal management solutions. Addressing the information gap of coral reef resilience, we produce a map-based Remote Sensed Resilience Index (RSRI) from data describing the spatial distribution of stressors, and properties of reef habitats on the Farasan Banks, Saudi Arabia. We contrast the distribution of this index among fourteen reef types, categorized on a scale of maturity that includes juvenile (poorly aggraded), mature (partially aggraded), and senile (fully aggraded) reefs. Sites with high reef resilience can be found in most detached reef types; however they are most common in mature reefs. We aim to stimulate debate on the coupling that exists between geomorphology and conservation biology, and consider how such information can be used to inform management decisions. PMID:26621578

  14. Feedback control scheme of traffic jams based on the coupled map car-following model

    NASA Astrophysics Data System (ADS)

    Zhou, Tong; Sun, Di-Hua; Zhao, Min; Li, Hua-Min

    2013-09-01

    Based on the pioneering work of Konishi et al. [Phys. Rev. E (1999) 60 4000], a new feedback control scheme is presented to suppress traffic jams based on the coupled map car-following model under the open boundary condition. The effect of the safe headway on the traffic system is considered. According to the control theory, the condition under which traffic jams can be suppressed is analyzed. The results are compared with the previous results concerning congestion control. The simulations show that the suppression performance of our scheme on traffic jams is better than those of the previous schemes, although all the schemes can suppress traffic jams. The simulation results are consistent with theoretical analyses.

  15. Nanoscale mapping of plasmon and exciton in ZnO tetrapods coupled with Au nanoparticles

    PubMed Central

    Bertoni, Giovanni; Fabbri, Filippo; Villani, Marco; Lazzarini, Laura; Turner, Stuart; Van Tendeloo, Gustaaf; Calestani, Davide; Gradečak, Silvija; Zappettini, Andrea; Salviati, Giancarlo

    2016-01-01

    Metallic nanoparticles can be used to enhance optical absorption or emission in semiconductors, thanks to a strong interaction of collective excitations of free charges (plasmons) with electromagnetic fields. Herein we present direct imaging at the nanoscale of plasmon-exciton coupling in Au/ZnO nanostructures by combining scanning transmission electron energy loss and cathodoluminescence spectroscopy and mapping. The Au nanoparticles (~30 nm in diameter) are grown in-situ on ZnO nanotetrapods by means of a photochemical process without the need of binding agents or capping molecules, resulting in clean interfaces. Interestingly, the Au plasmon resonance is localized at the Au/vacuum interface, rather than presenting an isotropic distribution around the nanoparticle. On the contrary, a localization of the ZnO signal has been observed inside the Au nanoparticle, as also confirmed by numerical simulations. PMID:26754789

  16. Antibody epitopes on g protein-coupled receptors mapped with genetically encoded photoactivatable cross-linkers.

    PubMed

    Ray-Saha, Sarmistha; Huber, Thomas; Sakmar, Thomas P

    2014-03-01

    We developed a strategy for creating epitope maps of monoclonal antibodies (mAbs) that bind to G protein-coupled receptors (GPCRs) containing photo-cross-linkers. Using human CXC chemokine receptor 4 (CXCR4) as a model system, we genetically incorporated the photolabile unnatural amino acid p-azido-l-phenylalanine (azF) at various positions within extracellular loop 2 (EC2). We then mapped the interactions of the azF-CXCR4 variants with mAb 12G5 using targeted loss-of-function studies and photo-cross-linking in whole cells in a microplate-based format. We used a novel variation of a whole cell enzyme-linked immunosorbent assay to quantitate cross-linking efficiency. 12G5 cross-linked primarily to residues 184, 178, and 189 in EC2 of CXCR4. Mapping of the data to the crystal structure of CXCR4 showed a distinct mAb epitope footprint with the photo-cross-linked residues clustered around the loss-of-function sites. We also used the targeted photo-cross-linking approach to study the interaction of human CC chemokine receptor 5 (CCR5) with PRO 140, a humanized mAb that inhibits human immunodeficiency virus-1 cellular entry, and 2D7. The mAbs produced distinct cross-linking patterns on EC2 of CCR5. PRO 140 cross-linked primarily to residues 174 and 175 at the amino-terminal end of EC2, and 2D7 cross-linked mainly to residues 170, 176, and 184. These results were mapped to the recent crystal structure of CCR5 in complex with maraviroc, showing cross-linked residues at the tip of the maraviroc binding crevice formed by EC2. As a strategy for mapping mAb epitopes on GPCRs, our targeted photo-cross-linking method is complementary to loss-of-function mutagenesis results and should be especially useful for studying mAbs with discontinuous epitopes. PMID:24490954

  17. The uses of emotion maps in research and clinical practice with families and couples: methodological innovation and critical inquiry.

    PubMed

    Gabb, Jacqui; Singh, Reenee

    2015-03-01

    We explore how "emotion maps" can be productively used in clinical assessment and clinical practice with families and couples. This graphic participatory method was developed in sociological studies to examine everyday family relationships. Emotion maps enable us to effectively "see" the dynamic experience and emotional repertoires of family life. Through the use of a case example, in this article we illustrate how emotion maps can add to the systemic clinicians' repertoire of visual methods. For clinicians working with families, couples, and young people, the importance of gaining insight into how lives are lived, at home, cannot be understated. Producing emotion maps can encourage critical personal reflection and expedite change in family practice. Hot spots in the household become visualized, facilitating dialogue on prevailing issues and how these events may be perceived differently by different family members. As emotion maps are not reliant on literacy or language skills they can be equally completed by parents and children alike, enabling children's perspective to be heard. Emotion maps can be used as assessment tools, to demonstrate the process of change within families. Furthermore, emotion maps can be extended to use through technology and hence are well suited particularly to working with young people. We end the article with a wider discussion of the place of emotions and emotion maps within systemic psychotherapy. PMID:25091031

  18. Using geotypes for landslide hazard assessment and mapping: a coupled field and GIS-based method

    NASA Astrophysics Data System (ADS)

    Bilgot, S.; Parriaux, A.

    2009-04-01

    Switzerland is exceptionally subjected to landslides; indeed, about 10% of its area is considered as unstable. Making this observation, its Department of the Environment (BAFU) introduces in 1997 a method to realize landslide hazard maps. It is routinely used but, like most of the methods applied in Europe to map unstable areas, it is mainly based on the signs of previous or current phenomena (geomorphologic mapping, archive consultation, etc.) even though instabilities can appear where there is nothing to show that they existed earlier. Furthermore, the transcription from the geomorphologic map to the hazard map can vary according to the geologist or the geographer who realizes it: this method is affected by a certain lack of transparency. The aim of this project is to introduce the bedrock of a new method for landslide hazard mapping; based on instability predisposition assessment, it involves the designation of main factors for landslide susceptibility, their integration in a GIS to calculate a landslide predisposition index and the implementation of new methods to evaluate these factors; to be competitive, these processes have to be both cheap and quick. To identify the most important parameters to consider for assessing slope stability, we chose a large panel of topographic, geomechanic and hydraulic parameters and tested their importance by calculating safety factors on theoretical landslides using Geostudio 2007®; thus, we could determine that slope, cohesion, hydraulic conductivity and saturation play an important role in soil stability. After showing that cohesion and hydraulic conductivity of loose materials are strongly linked to their granulometry and plasticity index, we implemented two new field tests, one based on teledetection and one coupled sedimentometric and blue methylen test to evaluate these parameters. From these data, we could deduce approximated values of maximum cohesion and saturated hydraulic conductivity. The hydraulic conductivity of

  19. The Uses of Emotion Maps in Research and Clinical Practice with Families and Couples: Methodological Innovation and Critical Inquiry

    PubMed Central

    Gabb, Jacqui; Singh, Reenee

    2015-01-01

    We explore how “emotion maps” can be productively used in clinical assessment and clinical practice with families and couples. This graphic participatory method was developed in sociological studies to examine everyday family relationships. Emotion maps enable us to effectively “see” the dynamic experience and emotional repertoires of family life. Through the use of a case example, in this article we illustrate how emotion maps can add to the systemic clinicians’ repertoire of visual methods. For clinicians working with families, couples, and young people, the importance of gaining insight into how lives are lived, at home, cannot be understated. Producing emotion maps can encourage critical personal reflection and expedite change in family practice. Hot spots in the household become visualized, facilitating dialogue on prevailing issues and how these events may be perceived differently by different family members. As emotion maps are not reliant on literacy or language skills they can be equally completed by parents and children alike, enabling children's perspective to be heard. Emotion maps can be used as assessment tools, to demonstrate the process of change within families. Furthermore, emotion maps can be extended to use through technology and hence are well suited particularly to working with young people. We end the article with a wider discussion of the place of emotions and emotion maps within systemic psychotherapy. PMID:25091031

  20. Coupling ocean colour remote sensing data into physical-ecosystem models: mapping uncertainty distributions from space.

    NASA Astrophysics Data System (ADS)

    McKee, David; Twardowski, Mike; Trees, Chuck; Sanjuan-Calzado, Violeta

    2013-04-01

    Ocean colour remote sensing (OCRS) has transformed our understanding of complex feedback processes linking physical forcing events to biogeochemical responses. With continuous daily global coverage extending beyond the last decade, OCRS has become established as an essential global climate variable with potential use as a sensitive indicator of regional and global response to changing climate. There is increasing focus on use of OCRS data for validation and assimilation into coupled physical-ecosystem models for both environmental and operational applications. It is therefore essential that OCRS data products are not only optimised for maximum accuracy, but are also provided to end users with appropriate uncertainties. A simple spectral deconvolution model will be presented along with a new bootstrap approach for estimating product uncertainties. This approach can be adapted for both remote sensing and in situ data, opening up the possibility of mapping uncertainty distributions in 3-D for the first time, and can be applied to other established OCRS data products, including the existent historic data set. Ecosystem models seek to reproduce and predict ocean biogeochemical processes, where the models are constrained by physical parameters such as: wind, currents, density and light. The hydrographic aspects of marine ecosystems can generally be defined through ocean circulation models, which are largely independent of the ecosystem itself. The physical optics determining the light environment, on the other hand, are two-way coupled with ecosystem models since light interacts with seawater and suspended constituents. The Optical Physical and Ecosystem Regional Assessment (OPERA) model proposes a more comprehensive and challenging approach, where all optical interactions occurring within the volume of water are taken into account, thus providing a more accurate definition of light dependent processes.

  1. Coupling ocean colour remote sensing data into physical-ecosystem models: mapping uncertainty distributions from space.

    NASA Astrophysics Data System (ADS)

    McKee, David; Twardowski, Mike; Trees, Chuck; Sanjuan Calzado, Violeta

    2014-05-01

    Ocean colour remote sensing (OCRS) has transformed our understanding of complex feedback processes linking physical forcing events to biogeochemical responses. With continuous daily global coverage extending beyond the last decade, OCRS has become established as an essential global climate variable with potential use as a sensitive indicator of regional and global response to changing climate. There is increasing focus on use of OCRS data for validation and assimilation into coupled physical-ecosystem models for both environmental and operational applications. It is therefore essential that OCRS data products are not only optimised for maximum accuracy, but are also provided to end users with appropriate uncertainties. A simple spectral deconvolution model will be presented along with a new bootstrap approach for estimating product uncertainties. This approach can be adapted for both remote sensing and in situ data, opening up the possibility of mapping uncertainty distributions in 3-D for the first time, and can be applied to other established OCRS data products, including the existent historic data set. Ecosystem models seek to reproduce and predict ocean biogeochemical processes, where the models are constrained by physical parameters such as: wind, currents, density and light. The hydrographic aspects of marine ecosystems can generally be defined through ocean circulation models, which are largely independent of the ecosystem itself. The physical optics determining the light environment, on the other hand, are two-way coupled with ecosystem models since light interacts with seawater and suspended constituents. The Optical Physical and Ecosystem Regional Assessment (OPERA) model proposes a more comprehensive and challenging approach, where all optical interactions occurring within the volume of water are taken into account, thus providing a more accurate definition of light dependent processes.

  2. KSC ISS Logistics Support

    NASA Technical Reports Server (NTRS)

    Tellado, Joseph

    2014-01-01

    The presentation contains a status of KSC ISS Logistics Operations. It basically presents current top level ISS Logistics tasks being conducted at KSC, current International Partner activities, hardware processing flow focussing on late Stow operations, list of KSC Logistics POC's, and a backup list of Logistics launch site services. This presentation is being given at the annual International Space Station (ISS) Multi-lateral Logistics Maintenance Control Panel meeting to be held in Turin, Italy during the week of May 13-16. The presentatiuon content doesn't contain any potential lessons learned.

  3. Numerically exploring habitat fragmentation effects on populations using cell-based coupled map lattices.

    PubMed

    Bevers, M; Flather, C H

    1999-02-01

    We examine habitat size, shape, and arrangement effects on populations using a discrete reaction-diffusion model. Diffusion is modeled passively and applied to a cellular grid of territories forming a coupled map lattice. Dispersal mortality is proportional to the amount of nonhabitat and fully occupied habitat surrounding a given cell, with distance decay. After verifying that our model produces the results expected for single patches of uniform habitat, we investigate heterogeneous and fragmented model landscapes. In heterogeneous single-patch systems near critical patch size, populations approach Gaussian spatial distributions with total population constrained by the capacity of the most limiting cell. In fragmented habitat landscapes, threshold effects are more complex and parametrically sensitive. The results from our experiments suggest the following: the ability to achieve persistence in hyperdispersed patchy habitats by adding similarly fragmented patches requires meeting threshold reproduction rates; persistent metapopulations in which no local population is individually persistent appear when dispersal distances and reproduction rates are both high, but only within narrow parameter ranges that are close to extinction thresholds; successful use of stepping-stone patches to support metapopulation systems appears unlikely for passively diffusing species; elongated patches offer early colonization advantages, but blocky patches offer greater population resilience near extinction thresholds. A common theme running through our findings is that population viability estimates may depend on our ability to determine when population and habitat systems are approaching extinction threshold conditions. PMID:9925809

  4. Heterogeneous delays making parents synchronized: A coupled maps on Cayley tree model

    NASA Astrophysics Data System (ADS)

    Singh, Aradhana; Jalan, Sarika

    2014-06-01

    We study the phase synchronized clusters in the diffusively coupled maps on the Cayley tree networks for heterogeneous delay values. Cayley tree networks comprise of two parts: the inner nodes and the boundary nodes. We find that heterogeneous delays lead to various cluster states, such as; (a) cluster state consisting of inner nodes and boundary nodes, and (b) cluster state consisting of only boundary nodes. The former state may comprise of nodes from all the generations forming self-organized cluster or nodes from few generations yielding driven clusters depending upon on the parity of heterogeneous delay values. Furthermore, heterogeneity in delays leads to the lag synchronization between the siblings lying on the boundary by destroying the exact synchronization among them. The time lag being equal to the difference in the delay values. The Lyapunov function analysis sheds light on the destruction of the exact synchrony among the last generation nodes. To the end we discuss the relevance of our results with respect to their applications in the family business as well as in understanding the occurrence of genetic diseases.

  5. Bifurcations, crisis, unstable dimension variability and the spreading transition in the coupled sine circle map system

    NASA Astrophysics Data System (ADS)

    Das, A.; Jabeen, Z.; Gupte, N.

    2014-12-01

    The dynamical behavior of spatially extended dynamical systems can have interesting consequences for their statistics. We demonstrate this in a specific context, a system of coupled sine circle maps, and discuss the interconnection between the statistical and dynamical behaviors of the system. The system has an interesting phase diagram in parameter space wherein a spreading transition is seen across an infection line, with spatio-temporal and spatial intermittency of distinct universality classes (directed percolation and non-directed percolation) seen in the spreading/non-spreading regimes. The dynamical origins of the spreading transition, lie in a crisis arising from a tangent bifurcation in the system. In addition to changing the statistics, and therefore the universality class of the system, the crisis also has dynamical consequences. Unstable dimension variability is seen in the neighbourhood of this crisis, and multiple routes to crisis are seen due to the presence of multi-attractor solutions. We examine the system using a variety of characterizers such as finite time Lyapunov exponents and their distributions. We discuss the signatures of the phenomena seen in the quantifiers, and also whether similar techniques can be extended to other situations. Finally, we demonstrate the success of the quantifiers in another regime, spatio-temporal intermittency with travelling wave laminar solutions, and a solitonic regime.

  6. Mapping.

    ERIC Educational Resources Information Center

    Kinney, Douglas M.; McIntosh, Willard L.

    1979-01-01

    The area of geological mapping in the United States in 1978 increased greatly over that reported in 1977; state geological maps were added for California, Idaho, Nevada, and Alaska last year. (Author/BB)

  7. Packaging for logistical support

    NASA Astrophysics Data System (ADS)

    Twede, Diana; Hughes, Harold

    Logistical packaging is conducted to furnish protection, utility, and communication for elements of a logistical system. Once the functional requirements of space logistical support packaging have been identified, decision-makers have a reasonable basis on which to compare package alternatives. Flexible packages may be found, for example, to provide adequate protection and superior utility to that of rigid packages requiring greater storage and postuse waste volumes.

  8. COUPLING

    DOEpatents

    Hawke, B.C.

    1963-02-26

    This patent relates to a releasable coupling connecting a control rod to a control rod drive. This remotely operable coupling mechanism can connect two elements which are laterally and angviarly misaligned, and provides a means for sensing the locked condition of the elements. The coupling utilizes a spherical bayonet joint which is locked against rotation by a ball detent lock. (AEC)

  9. Significant Improvements to LOGIST.

    ERIC Educational Resources Information Center

    Wingersky, Marilyn S.

    The computer program LOGIST (Wingersky, Patrick, and Lord, 1988) estimates the item parameters and the examinee's abilities for Birnbaum's three-parameter logistic item response theory model using Newton's method for solving the joint maximum likelihood equations. In 1989, Martha Stocking discovered a problem with this procedure in that when the…

  10. Regional Mapping of Coupled Fluxes of Carbon and Water Using Multi-Sensor Fusion Techniques

    NASA Astrophysics Data System (ADS)

    Schull, M. A.; Anderson, M. C.; Semmens, K. A.; Yang, Y.; Gao, F.; Hain, C.; Houborg, R.

    2014-12-01

    In an ever-changing climate there is an increasing need to measure the fluxes of water, energy and carbon for decision makers to implement policies that will help mitigate the effects of climate change. In an effort to improve drought monitoring, water resource management and agriculture assessment capabilities, a multi-scale and multi-sensor framework for routine mapping of land-surface fluxes of water and energy at field to regional scales has been established. The framework uses the ALEXI (Atmosphere Land Exchange Inverse)/DisALEXI (Disaggregated ALEXI) suite of land-surface models forced by remotely sensed data from Landsat, MODIS (MODerate resolution Imaging Spectroradiometer), and GOES (Geostationary Operational Environmental Satellite). Land-surface temperature (LST) can be an effective substitute for in-situ surface moisture observations and a valuable metric for constraining land-surface fluxes at sub-field scales. The adopted multi-scale thermal-based land surface modeling framework facilitates regional to local downscaling of water and energy fluxes by using a combination of shortwave reflective and thermal infrared (TIR) imagery from GOES (4-10 km; hourly), MODIS (1 km; daily), and Landsat (30-100 m; bi-weekly). In this research the ALEXI/DisALEXI modeling suite is modified to incorporate carbon fluxes using a stomatal resistance module, which replaces the Priestley-Taylor latent heat approximation. In the module, canopy level nominal light-use-efficiency (βn) is the parameter that modulates the flux of water and carbon in and out of the canopy. Leaf chlorophyll (Chl) is a key parameter for quantifying variability in photosynthetic efficiency to facilitate the spatial distribution of coupled carbon and water retrievals. Spatial distribution of Chl are retrieved from Landsat (30 m) using a surface reflectance dataset as input to the REGularized canopy reFLECtance (REGFLEC) tool. The modified ALEXI/DisALEXI suite is applied to regions of rain fed and

  11. Chaotic Polynomial Maps

    NASA Astrophysics Data System (ADS)

    Zhang, Xu

    This paper introduces a class of polynomial maps in Euclidean spaces, investigates the conditions under which there exist Smale horseshoes and uniformly hyperbolic invariant sets, studies the chaotic dynamical behavior and strange attractors, and shows that some maps are chaotic in the sense of Li-Yorke or Devaney. This type of maps includes both the Logistic map and the Hénon map. For some diffeomorphisms with the expansion dimension equal to one or two in three-dimensional spaces, the conditions under which there exist Smale horseshoes and uniformly hyperbolic invariant sets on which the systems are topologically conjugate to the two-sided fullshift on finite alphabet are obtained; for some expanding maps, the chaotic region is analyzed by using the coupled-expansion theory and the Brouwer degree theory. For three types of higher-dimensional polynomial maps with degree two, the conditions under which there are Smale horseshoes and uniformly hyperbolic invariant sets are given, and the topological conjugacy between the maps on the invariant sets and the two-sided fullshift on finite alphabet is obtained. Some interesting maps with chaotic attractors and positive Lyapunov exponents in three-dimensional spaces are found by using computer simulations. In the end, two examples are provided to illustrate the theoretical results.

  12. Nonequilibrium thermodynamics in the strong coupling and non-Markovian regime based on a reaction coordinate mapping

    NASA Astrophysics Data System (ADS)

    Strasberg, Philipp; Schaller, Gernot; Lambert, Neill; Brandes, Tobias

    2016-07-01

    We propose a method to study the thermodynamic behaviour of small systems beyond the weak coupling and Markovian approximation, which is different in spirit from conventional approaches. The idea is to redefine the system and environment such that the effective, redefined system is again coupled weakly to Markovian residual baths and thus, allows to derive a consistent thermodynamic framework for this new system–environment partition. To achieve this goal we make use of the reaction coordinate (RC) mapping, which is a general method in the sense that it can be applied to an arbitrary (quantum or classical and even time-dependent) system coupled linearly to an arbitrary number of harmonic oscillator reservoirs. The core of the method relies on an appropriate identification of a part of the environment (the RC), which is subsequently included as a part of the system. We demonstrate the power of this concept by showing that non-Markovian effects can significantly enhance the steady state efficiency of a three-level-maser heat engine, even in the regime of weak system–bath coupling. Furthermore, we show for a single electron transistor coupled to vibrations that our method allows one to justify master equations derived in a polaron transformed reference frame.

  13. A secure double-image sharing scheme based on Shamir's three-pass protocol and 2D Sine Logistic modulation map in discrete multiple-parameter fractional angular transform domain

    NASA Astrophysics Data System (ADS)

    Sui, Liansheng; Duan, Kuaikuai; Liang, Junli

    2016-05-01

    A secure double-image sharing scheme is proposed by using the Shamir's three-pass protocol in the discrete multiple-parameter fractional angular transform domain. First, an enlarged image is formed by assembling two plain images successively in the horizontal direction and scrambled in the chaotic permutation process, in which the sequences of chaotic pairs are generated by the two-dimensional Sine Logistic modulation map. Second, the scrambled image is divided into two components which are used to constitute a complex image. One component is normalized and regarded as the phase part of the complex image as well as other is considered as the amplitude part. Finally, the complex image is shared between the sender and the receiver by using the Shamir's three-pass protocol, in which the discrete multiple-parameter fractional angular transform is used as the encryption function due to its commutative property. The proposed double-image sharing scheme has an obvious advantage that the key management is convenient without distributing the random phase mask keys in advance. Moreover, the security of the image sharing scheme is enhanced with the help of extra parameters of the discrete multiple-parameter fractional angular transform. To the best of our knowledge, this is the first report on integrating the Shamir's three-pass protocol with double-image sharing scheme in the information security field. Simulation results and security analysis verify the feasibility and effectiveness of the proposed scheme.

  14. Green Logistics Management

    NASA Astrophysics Data System (ADS)

    Chang, Yoon S.; Oh, Chang H.

    Nowadays, environmental management becomes a critical business consideration for companies to survive from many regulations and tough business requirements. Most of world-leading companies are now aware that environment friendly technology and management are critical to the sustainable growth of the company. The environment market has seen continuous growth marking 532B in 2000, and 590B in 2004. This growth rate is expected to grow to 700B in 2010. It is not hard to see the environment-friendly efforts in almost all aspects of business operations. Such trends can be easily found in logistics area. Green logistics aims to make environmental friendly decisions throughout a product lifecycle. Therefore for the success of green logistics, it is critical to have real time tracking capability on the product throughout the product lifecycle and smart solution service architecture. In this chapter, we introduce an RFID based green logistics solution and service.

  15. COUPLING

    DOEpatents

    Frisch, E.; Johnson, C.G.

    1962-05-15

    A detachable coupling arrangement is described which provides for varying the length of the handle of a tool used in relatively narrow channels. The arrangement consists of mating the key and keyhole formations in the cooperating handle sections. (AEC)

  16. Visualizing fossilization using laser ablation-inductively coupled plasma-mass spectrometry maps of trace elements in Late Cretaceous bones

    USGS Publications Warehouse

    Koenig, A.E.; Rogers, R.R.; Trueman, C.N.

    2009-01-01

    Elemental maps generated by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) provide a previously unavailable high-resolution visualization of the complex physicochemical conditions operating within individual bones during the early stages of diagenesis and fossilization. A selection of LA-ICP-MS maps of bones collected from the Late Cretaceous of Montana (United States) and Madagascar graphically illustrate diverse paths to recrystallization, and reveal unique insights into geochemical aspects of taphonomic history. Some bones show distinct gradients in concentrations of rare earth elements and uranium, with highest concentrations at external bone margins. Others exhibit more intricate patterns of trace element uptake related to bone histology and its control on the flow paths of pore waters. Patterns of element uptake as revealed by LA-ICP-MS maps can be used to guide sampling strategies, and call into question previous studies that hinge upon localized bulk samples of fossilized bone tissue. LA-ICP-MS maps also allow for comparison of recrystallization rates among fossil bones, and afford a novel approach to identifying bones or regions of bones potentially suitable for extracting intact biogeochemical signals. ?? 2009 Geological Society of America.

  17. Mapping of coupling hot spots of satellite derived latent heat flux in indian agro-climatic regions

    NASA Astrophysics Data System (ADS)

    Choudhury, I.

    2014-11-01

    This study focuses on the understanding and mapping of coupling hotspots of LE versus terrestrial and meteorological parameters. Single source surface energy balance model was used to derive surface energy balance parameters. Agro climatic region wise monthly information of terrestrial, energy balance and meteorological parameters were derived during June- September from decadal analysis of MODIS data (2003-2012) over India (68-100°E, 5-40°N) at 5 km spatial resolution. Information on rainfall was obtained from gridded rainfall data (1° × 1° spatial resolution) from Indian Meteorological Department (IMD). The spatiotemporal variability of the parameters such as rainfall, evapotranspiration (ET), evaporative fraction (EF), soil water index (SWI), land surface temperature (LST) and air temperature (Ta) showed strong influence on seasonal LE fluctuation. LE showed positive linear coupling with ET (0.52 coupling with LST (0.63 ≤ R2 ≤ 0.87), Ta (0.55 < R2 ≤ 0.83). The pixel based knowledge of the parameters was incorporated into hierarchical decision rule algorithm and pixel-by-pixel segmentation of monthly coupling of LE versus parameters (ET, EF, SWI, LST, Ta) was generated. The rainfall zonations in a spatiotemporal domain were done based on the LE couplings that clearly demarcated the highest (West Coast Plains and Hills Region, Himalayan region), moderate (Gangetic Plains and Hills Regions, and the Plateau and Hills Regions) and lowest rainfall (Western dry region) areas. The transition of zone-wise availability of rainfall (both surplus and deficient) can be very well understood from the seasonal dynamics of the LE couplings.

  18. Logistics planning for phased programs.

    NASA Technical Reports Server (NTRS)

    Cook, W. H.

    1973-01-01

    It is pointed out that the proper and early integration of logistics planning into the phased program planning process will drastically reduce these logistics costs. Phased project planning is a phased approach to the planning, approval, and conduct of major research and development activity. A progressive build-up of knowledge of all aspects of the program is provided. Elements of logistics are discussed together with aspects of integrated logistics support, logistics program planning, and logistics activities for phased programs. Continuing logistics support can only be assured if there is a comprehensive sequential listing of all logistics activities tied to the program schedule and a real-time inventory of assets.

  19. Ab initio Mapping of Interlayer Coupling in Transition Metal Dichalcogenides and Graphene

    NASA Astrophysics Data System (ADS)

    Fang, Shiang; Kaxiras, Efthimios

    Two-dimensional layered materials cover a wide variety of physics phenomena, such as topological phases, superconductivity, magnetism and charge density waves. Owing to the layered geometry and the van der Waals interactions in between, stacks of these van der Waals layered materials provide a venue to create a heterostructure with various physics properties. The interaction between different physics properties is particular interesting to engineer the material with the desired properties. One of the crucial ingredient in understanding the heterostructure is the interlayer coupling in between. In the literature, such kind of coupling has been proposed in various empirical forms. However, a true ab initio coupling model is still lacking. For the first time, here we have derived such interlayer coupling model from the first principle calculations based on the Wannier transformation of graphene stacks. We further investigate the Fermi velocity renormalization, van Hove singularities and the moire pattern for electron localization. Such microscopic understanding of the interlayer coupling would shed light on orbital hybridization and transport in multilayer stacks. This work was supported by the STC Center for Integrated Quantum Materials, NSF Grant No. DMR-1231319, and by ARO MURI Award No. W911NF-14-0247.

  20. Mapping large areas of radioactively contaminated land with a self adapted, handheld, GPS coupled, scintillation detector.

    PubMed

    Paridaens, Johan

    2008-03-01

    In Belgium, during several decennia, a phosphate plant discharged radium chloride containing waste water into two small rivers. One of those is part of a hydrographically very complex ecosystem with lots of small tributaries and hundreds of hectares of flooding zones. Hence, the river banks and large parts of these flooding zones have become contaminated with radium, heavy metals and chlorides. During a foot campaign, using a home made portable data logging system, consisting of a commercial 2.5 kg NaI detector, a computer mouse sized GPS, and a small pocket PC, the radioactive contamination of about 600 ha of sometimes very rough terrain was measured and mapped. The resulting very detailed radium contamination maps shed a whole new light on the water flow patterns of the ecosystem. The apparatus can also be used for efficiently guiding sampling campaigns for investigating other types of contamination. The ground maps are also compared to existing maps from helicopter measurements, evaluating strengths and weaknesses from both methods. PMID:17904702

  1. Practical Session: Logistic Regression

    NASA Astrophysics Data System (ADS)

    Clausel, M.; Grégoire, G.

    2014-12-01

    An exercise is proposed to illustrate the logistic regression. One investigates the different risk factors in the apparition of coronary heart disease. It has been proposed in Chapter 5 of the book of D.G. Kleinbaum and M. Klein, "Logistic Regression", Statistics for Biology and Health, Springer Science Business Media, LLC (2010) and also by D. Chessel and A.B. Dufour in Lyon 1 (see Sect. 6 of http://pbil.univ-lyon1.fr/R/pdf/tdr341.pdf). This example is based on data given in the file evans.txt coming from http://www.sph.emory.edu/dkleinb/logreg3.htm#data.

  2. Experimental mapping of nonlinear dynamics in synchronized coupled semiconductor laser networks

    NASA Astrophysics Data System (ADS)

    Argyris, Apostolos; Bourmpos, Michail; Syvridis, Dimitris

    2015-05-01

    The potential of conventional semiconductor lasers to generate complex and chaotic dynamics at a bandwidth that extends up to tens of GHz turns them into useful components in applications oriented to sensing and security. Specifically, latest theoretical and experimental works have demonstrated the capability of mutually coupled semiconductor lasers to exhibit a joint behaviour under various conditions. In an uncoupled network consisting of N similar SLs - representing autonomous nodes in the network - each node emits an optical signal of various dynamics depending on its biasing conditions and internal properties. These nodes remain unsynchronized unless appropriate coupling and biasing conditions apply. A synchronized behaviour can be in principle observed in sub-groups of lasers or in the overall laser network. In the present work, experimental topologies that employ eight SLs, under diverse biasing and coupling conditions, are built and investigated. The deployed systems incorporate off-the-shelf fiber-optic communications components operating at the 1550nm spectral window. The role of emission wavelength detuning of each participating node in the network - at GHz level - is evaluated.

  3. Critical avalanches and subsampling in map-based neural networks coupled with noisy synapses.

    PubMed

    Girardi-Schappo, M; Kinouchi, O; Tragtenberg, M H R

    2013-08-01

    Many different kinds of noise are experimentally observed in the brain. Among them, we study a model of noisy chemical synapse and obtain critical avalanches for the spatiotemporal activity of the neural network. Neurons and synapses are modeled by dynamical maps. We discuss the relevant neuronal and synaptic properties to achieve the critical state. We verify that networks of functionally excitable neurons with fast synapses present power-law avalanches, due to rebound spiking dynamics. We also discuss the measuring of neuronal avalanches by subsampling our data, shedding light on the experimental search for self-organized criticality in neural networks. PMID:24032969

  4. Model of globally coupled Duffing flows

    NASA Astrophysics Data System (ADS)

    Shimada, Tokuzo; Moriya, Takanobu

    2014-03-01

    A Duffing oscillator in a certain parameter range shows period-doubling that has the same Feigenbaum ratio as the logistic map, which is an important issue in universality in chaos. In this paper a globally coupled lattice of Duffing flows (GCFL), which is a natural extension of the globally coupled logistic map lattice (GCML), is constructed. It is observed that GCFL inherits various intriguing properties of GCML and that universality at the level of elements is thus lifted to that of systems. Phase diagrams for GCFL are determined, which are essentially the same as those for GCML. Similar to the two-clustered periodic attractor of GCML, the GCFL two-clustered attractor exhibits a successive period-doubling with an increase of population imbalance between the clusters (\\vartheta -bifurcation). A nontrivial distinction between the GCML and GCFL attractors that originates from the symmetry in the Duffing equation is investigated in detail.

  5. Conceptualising and mapping coupled estuary, coast and inner shelf sediment systems

    NASA Astrophysics Data System (ADS)

    French, Jon; Burningham, Helene; Thornhill, Gillian; Whitehouse, Richard; Nicholls, Robert J.

    2016-03-01

    Whilst understanding and predicting the effects of coastal change are primarily modelling problems, it is essential that we have appropriate conceptual frameworks for (1) the formalisation of existing knowledge; (2) the formulation of relevant scientific questions and management issues; (3) the implementation and deployment of predictive models; and (4) meaningful engagement involvement of stakeholders. Important progress continues to be made on the modelling front, but our conceptual frameworks have not evolved at a similar pace. Accordingly, this paper presents a new approach that re-engages with formal systems analysis and provides a mesoscale geomorphological context within which the coastal management challenges of the 21st century can be more effectively addressed. Coastal and Estuarine System Mapping (CESM) is founded on an ontology of landforms and human interventions that is partly inspired by the coastal tract concept and its temporal hierarchy of sediment sharing systems, but places greater emphasis on a hierarchy of spatial scales. This extends from coastal regions, through landform complexes, to landforms, the morphological adjustment of which is constrained by diverse forms of human intervention. Crucially, CESM integrates open coastal environments with estuaries and relevant portions of the inner shelf that have previously been treated separately. In contrast to the nesting of littoral cells that has hitherto framed shoreline management planning, CESM charts a complex web of interactions, of which a sub-set of mass transfer pathways defines the sediment budget, and a multitude of human interventions constrains natural landform behaviour. Conducted within a geospatial framework, CESM constitutes a form of knowledge formalisation in which disparate sources of information (published research, imagery, mapping, raw data etc.) are generalised into usable knowledge. The resulting system maps provide a framework for the development and application of

  6. Mapping differential interactomes by affinity purification coupled with data independent mass spectrometry acquisition

    PubMed Central

    Lambert, Jean-Philippe; Ivosev, Gordana; Couzens, Amber L.; Larsen, Brett; Taipale, Mikko; Lin, Zhen-Yuan; Zhong, Quan; Lindquist, Susan; Vidal, Marc; Aebersold, Ruedi; Pawson, Tony; Bonner, Ron; Tate, Stephen; Gingras, Anne-Claude

    2013-01-01

    Characterizing changes in protein-protein interactions associated with sequence variants (e.g. disease-associated mutations or splice forms) or following exposure to drugs, growth factors or hormones is critical to understanding how protein complexes are built, localized and regulated. Affinity purification (AP) coupled with mass spectrometry permits the analysis of protein interactions under near-physiological conditions, yet monitoring interaction changes requires the development of a robust and sensitive quantitative approach, especially for large-scale studies where cost and time are major considerations. To this end, we have coupled AP to data-independent mass spectrometric acquisition (SWATH), and implemented an automated data extraction and statistical analysis pipeline to score modulated interactions. Here, we use AP-SWATH to characterize changes in protein-protein interactions imparted by the HSP90 inhibitor NVP-AUY922 or melanoma-associated mutations in the human kinase CDK4. We show that AP-SWATH is a robust label-free approach to characterize such changes, and propose a scalable pipeline for systems biology studies. PMID:24162924

  7. Correlated 3D Nanoscale Mapping and Simulation of Coupled Plasmonic Nanoparticles

    PubMed Central

    2015-01-01

    Electron tomography in combination with electron energy-loss spectroscopy (EELS) experiments and simulations was used to unravel the interplay between structure and plasmonic properties of a silver nanocuboid dimer. The precise 3D geometry of the particles fabricated by means of electron beam lithography was reconstructed through electron tomography, and the full three-dimensional information was used as an input for simulations of energy-loss spectra and plasmon resonance maps. Excellent agreement between experiment and theory was found throughout, bringing the comparison between EELS imaging and simulations to a quantitative and correlative level. In addition, interface mode patterns, normally masked by the projection nature of a transmission microscopy investigation, could be unambiguously identified through tomographic reconstruction. This work overcomes the need for geometrical assumptions or symmetry restrictions of the sample in simulations and paves the way for detailed investigations of realistic and complex plasmonic nanostructures. PMID:26495933

  8. Coupling Satellite and Ground-Based Instruments to Map Climate Forcing by Anthropogenic Aerosols

    NASA Technical Reports Server (NTRS)

    Charlson, Robert J.; Anderson, Theodore L.; Hostetler, Chris (Technical Monitor)

    2000-01-01

    Climate forcing by anthropogenic aerosols is a significant but highly uncertain factor in global climate change. Only satellites can offer the global coverage essential to reducing this uncertainty; however, satellite measurements must be coupled with correlative, in situ measurements both to constrain the aerosol optical properties required in satellite retrieval algorithms and to provide chemical identification of aerosol sources. This grant funded the first two years of a three-year project which seeks to develop methodologies for combining spaceborne lidar with in-situ aerosol data sets to improve estimates of direct aerosol climate forcing. Progress under this two-year grant consisted in the development and deployment of a new in-situ capability for measuring aerosol 180' backscatter and the extinction-to-backscatter ratio. This new measurement capacity allows definitive lidar/in-situ comparisons and improves our ability to interpret lidar data in terms of climatically relevant quantities such as the extinction coefficient and optical depth. Measurements were made along the coast of Washington State, in Central Illinois, over the Indian Ocean, and in the Central Pacific. Thus, this research, combined with previous measurements by others, is rapidly building toward a global data set of extinction-to-backscatter ratio for key aerosol types. Such information will be critical to interpreting lidar data from the upcoming PICASSO-CENA, or P-C, satellite mission. Another aspect of this project is to investigate innovative ways to couple the lidar-satellite signal with targeted in-situ measurements toward a direct determination of aerosol forcing. This aspect is progressing in collaboration with NASA Langley's P-C lidar simulator and radiative transfer modeling by the University of Lille, France.

  9. Coupling Satellite and Ground-Based Instruments to Map Climate Forcing by Anthropogenic Aerosol

    NASA Technical Reports Server (NTRS)

    Charlson, Robert J.; Anderson, Theodore L.; Hostetler, Chris (Technical Monitor)

    2000-01-01

    Climate forcing by anthropogenic aerosols is a significant but highly uncertain factor in global climate change. Only satellites can offer the global coverage essential to reducing this uncertainty; however, satellite measurements must be coupled with correlative, in situ measurements both to constrain the aerosol optical properties required in satellite retrieval algorithms and to provide chemical identification of aerosol sources. This grant funded the third year of a three-year project which seeks to develop methodologies for combining spaceborne lidar with in-situ aerosol data sets to improve estimates of direct aerosol climate forcing. Progress under this one-year grant consisted in analysis and publication of field studies using a new in-situ capability for measuring aerosol 180 deg backscatter and the extinction-to-backscatter ratio. This new measurement capacity allows definitive lidar/in-situ comparisons and improves our ability to interpret lidar data in terms of climatically relevant quantities such as the extinction coefficient and optical depth. Analyzed data consisted of measurements made along the coast of Washington State, in Central Illinois, over the Indian Ocean, and in the Central Pacific. Thus, this research, combined with previous measurements by others, is rapidly building toward a global data set of extinction-to-backscatter ratio for key aerosol types. Such information will be critical to interpreting lidar data from the upcoming PICASSO-CENA, or P-C, satellite mission. Another aspect of this project is to investigate innovative ways to couple the lidar-satellite signal with target in-situ measurements toward a direct determination of aerosol forcing. This aspect is progressing in collaboration with NASA Langley's P-C lidar simulator.

  10. Mapping functional group free energy patterns at protein occluded sites: nuclear receptors and G-protein coupled receptors.

    PubMed

    Lakkaraju, Sirish Kaushik; Yu, Wenbo; Raman, E Prabhu; Hershfeld, Alena V; Fang, Lei; Deshpande, Deepak A; MacKerell, Alexander D

    2015-03-23

    Occluded ligand-binding pockets (LBP) such as those found in nuclear receptors (NR) and G-protein coupled receptors (GPCR) represent a significant opportunity and challenge for computer-aided drug design. To determine free energies maps of functional groups of these LBPs, a Grand-Canonical Monte Carlo/Molecular Dynamics (GCMC/MD) strategy is combined with the Site Identification by Ligand Competitive Saturation (SILCS) methodology. SILCS-GCMC/MD is shown to map functional group affinity patterns that recapitulate locations of functional groups across diverse classes of ligands in the LBPs of the androgen (AR) and peroxisome proliferator-activated-γ (PPARγ) NRs and the metabotropic glutamate (mGluR) and β2-adreneric (β2AR) GPCRs. Inclusion of protein flexibility identifies regions of the binding pockets not accessible in crystal conformations and allows for better quantitative estimates of relative ligand binding affinities in all the proteins tested. Differences in functional group requirements of the active and inactive states of the β2AR LBP were used in virtual screening to identify high efficacy agonists targeting β2AR in Airway Smooth Muscle (ASM) cells. Seven of the 15 selected ligands were found to effect ASM relaxation representing a 46% hit rate. Hence, the method will be of use for the rational design of ligands in the context of chemical biology and the development of therapeutic agents. PMID:25692383

  11. Mapping Functional Group Free Energy Patterns at Protein Occluded Sites: Nuclear Receptors and G-Protein Coupled Receptors

    PubMed Central

    2015-01-01

    Occluded ligand-binding pockets (LBP) such as those found in nuclear receptors (NR) and G-protein coupled receptors (GPCR) represent a significant opportunity and challenge for computer-aided drug design. To determine free energies maps of functional groups of these LBPs, a Grand-Canonical Monte Carlo/Molecular Dynamics (GCMC/MD) strategy is combined with the Site Identification by Ligand Competitive Saturation (SILCS) methodology. SILCS-GCMC/MD is shown to map functional group affinity patterns that recapitulate locations of functional groups across diverse classes of ligands in the LBPs of the androgen (AR) and peroxisome proliferator-activated-γ (PPARγ) NRs and the metabotropic glutamate (mGluR) and β2-adreneric (β2AR) GPCRs. Inclusion of protein flexibility identifies regions of the binding pockets not accessible in crystal conformations and allows for better quantitative estimates of relative ligand binding affinities in all the proteins tested. Differences in functional group requirements of the active and inactive states of the β2AR LBP were used in virtual screening to identify high efficacy agonists targeting β2AR in Airway Smooth Muscle (ASM) cells. Seven of the 15 selected ligands were found to effect ASM relaxation representing a 46% hit rate. Hence, the method will be of use for the rational design of ligands in the context of chemical biology and the development of therapeutic agents. PMID:25692383

  12. Mapping of single-site magnetic anisotropy tensors in weakly coupled spin clusters by torque magnetometry.

    PubMed

    Rigamonti, Luca; Cornia, Andrea; Nava, Andrea; Perfetti, Mauro; Boulon, Marie-Emmanuelle; Barra, Anne-Laure; Zhong, Xiaoliang; Park, Kyungwha; Sessoli, Roberta

    2014-08-28

    Single-crystal torque magnetometry performed on weakly-coupled polynuclear systems provides access to a complete description of single-site anisotropy tensors. Variable-temperature, variable-field torque magnetometry was used to investigate triiron(III) complex [Fe3La(tea)2(dpm)6] (Fe3La), a lanthanum(III)-centred variant of tetrairon(III) single molecule magnets (Fe4) (H3tea = triethanolamine, Hdpm = dipivaloylmethane). Due to the presence of the diamagnetic lanthanoid, magnetic interactions among iron(III) ions (si = 5/2) are very weak (<0.1 cm(−1)) and the magnetic response of Fe3La is predominantly determined by single-site anisotropies. The local anisotropy tensors were found to have Di > 0 and to be quasi-axial with |Ei/Di| ~ 0.05. Their hard axes form an angle of approximately 70° with the threefold molecular axis, which therefore corresponds to an easy magnetic direction for the molecule. The resulting picture was supported by a High Frequency EPR investigation and by DFT calculations. Our study confirms that the array of peripheral iron(III) centres provides substantially noncollinear anisotropy contributions to the ground state of Fe4 complexes, which are of current interest in molecular magnetism and spintronics. PMID:25014192

  13. Delay-induced cluster patterns in coupled Cayley tree networks

    NASA Astrophysics Data System (ADS)

    Singh, A.; Jalan, S.

    2013-07-01

    We study effects of delay in diffusively coupled logistic maps on the Cayley tree networks. We find that smaller coupling values exhibit sensitiveness to value of delay, and lead to different cluster patterns of self-organized and driven types. Whereas larger coupling strengths exhibit robustness against change in delay values, and lead to stable driven clusters comprising nodes from last generation of the Cayley tree. Furthermore, introduction of delay exhibits suppression as well as enhancement of synchronization depending upon coupling strength values. To the end we discuss the importance of results to understand conflicts and cooperations observed in family business.

  14. Steganalysis using logistic regression

    NASA Astrophysics Data System (ADS)

    Lubenko, Ivans; Ker, Andrew D.

    2011-02-01

    We advocate Logistic Regression (LR) as an alternative to the Support Vector Machine (SVM) classifiers commonly used in steganalysis. LR offers more information than traditional SVM methods - it estimates class probabilities as well as providing a simple classification - and can be adapted more easily and efficiently for multiclass problems. Like SVM, LR can be kernelised for nonlinear classification, and it shows comparable classification accuracy to SVM methods. This work is a case study, comparing accuracy and speed of SVM and LR classifiers in detection of LSB Matching and other related spatial-domain image steganography, through the state-of-art 686-dimensional SPAM feature set, in three image sets.

  15. A control method applied to mixed traffic flow for the coupled-map car-following model

    NASA Astrophysics Data System (ADS)

    Cheng, Rong-Jun; Han, Xiang-Lin; Lo, Siu-Ming; Ge, Hong-Xia

    2014-03-01

    In light of previous work [Phys. Rev. E 60 4000 (1999)], a modified coupled-map car-following model is proposed by considering the headways of two successive vehicles in front of a considered vehicle described by the optimal velocity function. The non-jam conditions are given on the basis of control theory. Through simulation, we find that our model can exhibit a better effect as p = 0.65, which is a parameter in the optimal velocity function. The control scheme, which was proposed by Zhao and Gao, is introduced into the modified model and the feedback gain range is determined. In addition, a modified control method is applied to a mixed traffic system that consists of two types of vehicle. The range of gains is also obtained by theoretical analysis. Comparisons between our method and that of Zhao and Gao are carried out, and the corresponding numerical simulation results demonstrate that the temporal behavior of traffic flow obtained using our method is better than that proposed by Zhao and Gao in mixed traffic systems.

  16. Spatially-resolved mapping of history-dependent coupled electrochemical and electronical behaviors of electroresistive NiO

    NASA Astrophysics Data System (ADS)

    Sugiyama, Issei; Kim, Yunseok; Jesse, Stephen; Strelcov, Evgheni; Kumar, Amit; Tselev, Alexander; Rahani, Ehasan Kabiri; Shenoy, Vivek B.; Yamamoto, Takahisa; Shibata, Naoya; Ikuhara, Yuichi; Kalinin, Sergei V.

    2014-10-01

    Bias-induced oxygen ion dynamics underpins a broad spectrum of electroresistive and memristive phenomena in oxide materials. Although widely studied by device-level and local voltage-current spectroscopies, the relationship between electroresistive phenomena, local electrochemical behaviors, and microstructures remains elusive. Here, the interplay between history-dependent electronic transport and electrochemical phenomena in a NiO single crystalline thin film with a number of well-defined defect types is explored on the nanometer scale using an atomic force microscopy-based technique. A variety of electrochemically-active regions were observed and spatially resolved relationship between the electronic and electrochemical phenomena was revealed. The regions with pronounced electroresistive activity were further correlated with defects identified by scanning transmission electron microscopy. Using fully coupled mechanical-electrochemical modeling, we illustrate that the spatial distribution of strain plays an important role in electrochemical and electroresistive phenomena. These studies illustrate an approach for simultaneous mapping of the electronic and ionic transport on a single defective structure level such as dislocations or interfaces, and pave the way for creating libraries of defect-specific electrochemical responses.

  17. Spatially-resolved mapping of history-dependent coupled electrochemical and electronical behaviors of electroresistive NiO

    SciTech Connect

    Sugiyama, Issei; Kim, Yunseok; Jesse, Stephen; Strelcov, Evgheni; Kumar, Amit; Tselev, Alexander; Rahani, Ehasan Kabiri; Shenoy, Vivek B.; Yamamoto, Takahisa; Shibata, Naoya; Ikuhara, Yuichi; Kalinin, Sergei V.

    2014-10-22

    Bias-induced oxygen ion dynamics underpins a broad spectrum of electroresistive and memristive phenomena in oxide materials. Although widely studied by device-level and local voltage-current spectroscopies, the relationship between electroresistive phenomena, local electrochemical behaviors, and microstructures remains elusive. Here, the interplay between history-dependent electronic transport and electrochemical phenomena in a NiO single crystalline thin film with a number of well-defined defect types is explored on the nanometer scale using an atomic force microscopy-based technique. A variety of electrochemically-active regions were observed and spatially resolved relationship between the electronic and electrochemical phenomena was revealed. The regions with pronounced electroresistive activity were further correlated with defects identified by scanning transmission electron microscopy. Using fully coupled mechanical-electrochemical modeling, we illustrate that the spatial distribution of strain plays an important role in electrochemical and electroresistive phenomena. In conclusion, these studies illustrate an approach for simultaneous mapping of the electronic and ionic transport on a single defective structure level such as dislocations or interfaces, and pave the way for creating libraries of defect-specific electrochemical responses.

  18. Spatially-resolved mapping of history-dependent coupled electrochemical and electronical behaviors of electroresistive NiO

    DOE PAGESBeta

    Sugiyama, Issei; Kim, Yunseok; Jesse, Stephen; Strelcov, Evgheni; Kumar, Amit; Tselev, Alexander; Rahani, Ehasan Kabiri; Shenoy, Vivek B.; Yamamoto, Takahisa; Shibata, Naoya; et al

    2014-10-22

    Bias-induced oxygen ion dynamics underpins a broad spectrum of electroresistive and memristive phenomena in oxide materials. Although widely studied by device-level and local voltage-current spectroscopies, the relationship between electroresistive phenomena, local electrochemical behaviors, and microstructures remains elusive. Here, the interplay between history-dependent electronic transport and electrochemical phenomena in a NiO single crystalline thin film with a number of well-defined defect types is explored on the nanometer scale using an atomic force microscopy-based technique. A variety of electrochemically-active regions were observed and spatially resolved relationship between the electronic and electrochemical phenomena was revealed. The regions with pronounced electroresistive activity were furthermore » correlated with defects identified by scanning transmission electron microscopy. Using fully coupled mechanical-electrochemical modeling, we illustrate that the spatial distribution of strain plays an important role in electrochemical and electroresistive phenomena. In conclusion, these studies illustrate an approach for simultaneous mapping of the electronic and ionic transport on a single defective structure level such as dislocations or interfaces, and pave the way for creating libraries of defect-specific electrochemical responses.« less

  19. Spatially-resolved mapping of history-dependent coupled electrochemical and electronical behaviors of electroresistive NiO

    PubMed Central

    Sugiyama, Issei; Kim, Yunseok; Jesse, Stephen; Strelcov, Evgheni; Kumar, Amit; Tselev, Alexander; Rahani, Ehasan Kabiri; Shenoy, Vivek B.; Yamamoto, Takahisa; Shibata, Naoya; Ikuhara, Yuichi; Kalinin, Sergei V.

    2014-01-01

    Bias-induced oxygen ion dynamics underpins a broad spectrum of electroresistive and memristive phenomena in oxide materials. Although widely studied by device-level and local voltage-current spectroscopies, the relationship between electroresistive phenomena, local electrochemical behaviors, and microstructures remains elusive. Here, the interplay between history-dependent electronic transport and electrochemical phenomena in a NiO single crystalline thin film with a number of well-defined defect types is explored on the nanometer scale using an atomic force microscopy-based technique. A variety of electrochemically-active regions were observed and spatially resolved relationship between the electronic and electrochemical phenomena was revealed. The regions with pronounced electroresistive activity were further correlated with defects identified by scanning transmission electron microscopy. Using fully coupled mechanical-electrochemical modeling, we illustrate that the spatial distribution of strain plays an important role in electrochemical and electroresistive phenomena. These studies illustrate an approach for simultaneous mapping of the electronic and ionic transport on a single defective structure level such as dislocations or interfaces, and pave the way for creating libraries of defect-specific electrochemical responses. PMID:25335689

  20. Space Shuttle operational logistics plan

    NASA Technical Reports Server (NTRS)

    Botts, J. W.

    1983-01-01

    The Kennedy Space Center plan for logistics to support Space Shuttle Operations and to establish the related policies, requirements, and responsibilities are described. The Directorate of Shuttle Management and Operations logistics responsibilities required by the Kennedy Organizational Manual, and the self-sufficiency contracting concept are implemented. The Space Shuttle Program Level 1 and Level 2 logistics policies and requirements applicable to KSC that are presented in HQ NASA and Johnson Space Center directives are also implemented.

  1. Technical issues: logistics. AAMC.

    PubMed

    Stillman, P L

    1993-06-01

    The author states that she became interested in standardized patients (SPs) around 20 years ago as a means of developing a more uniform and effective way to provide instruction and evaluation of basic clinical skills. She reflects upon in detail: (1) the logistics of using SPs in teaching; (2) how SPs are used in assessment; (3) what aspects of performance SPs can be trained to record and evaluate; (4) issues concerning checklists; (5) evaluation of interviewing skills; (6) evaluation of written communication skills; (7) importance of defining what is being tested; (8) various kinds and uses of inter-station exercises and problems of scoring them; (9) case development and the various sources for case material; (10) ways to generate scores; (11) selecting and training SPs; (12) role of the faculty and primary importance of bedside training with real patients; and (13) pros and cons of national versus single-school efforts to use SPs. She concludes by cautioning that further research must be done before SPs can be used for high-stakes certifying and licensing examinations. PMID:8507311

  2. Multinomial logistic regression ensembles.

    PubMed

    Lee, Kyewon; Ahn, Hongshik; Moon, Hojin; Kodell, Ralph L; Chen, James J

    2013-05-01

    This article proposes a method for multiclass classification problems using ensembles of multinomial logistic regression models. A multinomial logit model is used as a base classifier in ensembles from random partitions of predictors. The multinomial logit model can be applied to each mutually exclusive subset of the feature space without variable selection. By combining multiple models the proposed method can handle a huge database without a constraint needed for analyzing high-dimensional data, and the random partition can improve the prediction accuracy by reducing the correlation among base classifiers. The proposed method is implemented using R, and the performance including overall prediction accuracy, sensitivity, and specificity for each category is evaluated on two real data sets and simulation data sets. To investigate the quality of prediction in terms of sensitivity and specificity, the area under the receiver operating characteristic (ROC) curve (AUC) is also examined. The performance of the proposed model is compared to a single multinomial logit model and it shows a substantial improvement in overall prediction accuracy. The proposed method is also compared with other classification methods such as the random forest, support vector machines, and random multinomial logit model. PMID:23611203

  3. Mapping of lead, magnesium and copper accumulation in plant tissues by laser-induced breakdown spectroscopy and laser-ablation inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Kaiser, J.; Galiová, M.; Novotný, K.; Červenka, R.; Reale, L.; Novotný, J.; Liška, M.; Samek, O.; Kanický, V.; Hrdlička, A.; Stejskal, K.; Adam, V.; Kizek, R.

    2009-01-01

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) were utilized for mapping the accumulation of Pb, Mg and Cu with a resolution up to 200 μm in a up to cm × cm area of sunflower ( Helianthus annuus L.) leaves. The results obtained by LIBS and LA-ICP-MS are compared with the outcomes from Atomic Absorption Spectrometry (AAS) and Thin-Layer Chromatography (TLC). It is shown that laser-ablation based analytical methods can substitute or supplement these techniques mainly in the cases when a fast multi-elemental mapping of a large sample area is needed.

  4. Logistic Regression: Concept and Application

    ERIC Educational Resources Information Center

    Cokluk, Omay

    2010-01-01

    The main focus of logistic regression analysis is classification of individuals in different groups. The aim of the present study is to explain basic concepts and processes of binary logistic regression analysis intended to determine the combination of independent variables which best explain the membership in certain groups called dichotomous…

  5. 2D elemental mapping of sections of human kidney stones using laser ablation inductively-coupled plasma-mass spectrometry: Possibilities and limitations

    NASA Astrophysics Data System (ADS)

    Vašinová Galiová, Michaela; Čopjaková, Renata; Škoda, Radek; Štěpánková, Kateřina; Vaňková, Michaela; Kuta, Jan; Prokeš, Lubomír; Kynický, Jindřich; Kanický, Viktor

    2014-10-01

    A 213 nm Nd:YAG-based laser ablation (LA) system coupled to quadrupole-based inductively coupled plasma-mass spectrometer and an ArF* excimer-based LA-system coupled to a double-focusing sector field inductively coupled plasma-mass spectrometer were employed to study the spatial distribution of various elements in kidney stones (uroliths). Sections of the surfaces of uroliths were ablated according to line patterns to investigate the elemental profiles for the different urolith growth zones. This exploratory study was mainly focused on the distinguishing of the main constituents of urinary calculus fragments by means of LA-ICP-mass spectrometry. Changes in the ablation rate for oxalate and phosphate phases related to matrix density and hardness are discussed. Elemental association was investigated on the basis of 2D mapping. The possibility of using NIST SRM 1486 Bone Meal as an external standard for calibration was tested. It is shown that LA-ICP-MS is helpful for determination of the mineralogical composition and size of all phases within the analyzed surface area, for tracing down elemental associations and for documenting the elemental content of urinary stones. LA-ICP-MS results (elemental contents and maps) are compared to those obtained with electron microprobe analysis and solution analysis ICP-MS.

  6. Fungible weights in logistic regression.

    PubMed

    Jones, Jeff A; Waller, Niels G

    2016-06-01

    In this article we develop methods for assessing parameter sensitivity in logistic regression models. To set the stage for this work, we first review Waller's (2008) equations for computing fungible weights in linear regression. Next, we describe 2 methods for computing fungible weights in logistic regression. To demonstrate the utility of these methods, we compute fungible logistic regression weights using data from the Centers for Disease Control and Prevention's (2010) Youth Risk Behavior Surveillance Survey, and we illustrate how these alternate weights can be used to evaluate parameter sensitivity. To make our work accessible to the research community, we provide R code (R Core Team, 2015) that will generate both kinds of fungible logistic regression weights. (PsycINFO Database Record PMID:26651981

  7. Tailored logistics: the next advantage.

    PubMed

    Fuller, J B; O'Conor, J; Rawlinson, R

    1993-01-01

    How many top executives have ever visited with managers who move materials from the factory to the store? How many still reduce the costs of logistics to the rent of warehouses and the fees charged by common carriers? To judge by hours of senior management attention, logistics problems do not rank high. But logistics have the potential to become the next governing element of strategy. Whether they know it or not, senior managers of every retail store and diversified manufacturing company compete in logistically distinct businesses. Customer needs vary, and companies can tailor their logistics systems to serve their customers better and more profitably. Companies do not create value for customers and sustainable advantage for themselves merely by offering varieties of goods. Rather, they offer goods in distinct ways. A particular can of Coca-Cola, for example, might be a can of Coca-Cola going to a vending machine, or a can of Coca-Cola that comes with billing services. There is a fortune buried in this distinction. The goal of logistics strategy is building distinct approaches to distinct groups of customers. The first step is organizing a cross-functional team to proceed through the following steps: segmenting customers according to purchase criteria, establishing different standards of service for different customer segments, tailoring logistics pipelines to support each segment, and creating economics of scale to determine which assets can be shared among various pipelines. The goal of establishing logistically distinct businesses is familiar: improved knowledge of customers and improved means of satisfying them. PMID:10126157

  8. NASA Space Rocket Logistics Challenges

    NASA Technical Reports Server (NTRS)

    Neeley, James R.; Jones, James V.; Watson, Michael D.; Bramon, Christopher J.; Inman, Sharon K.; Tuttle, Loraine

    2014-01-01

    The Space Launch System (SLS) is the new NASA heavy lift launch vehicle and is scheduled for its first mission in 2017. The goal of the first mission, which will be uncrewed, is to demonstrate the integrated system performance of the SLS rocket and spacecraft before a crewed flight in 2021. SLS has many of the same logistics challenges as any other large scale program. Common logistics concerns for SLS include integration of discreet programs geographically separated, multiple prime contractors with distinct and different goals, schedule pressures and funding constraints. However, SLS also faces unique challenges. The new program is a confluence of new hardware and heritage, with heritage hardware constituting seventy-five percent of the program. This unique approach to design makes logistics concerns such as commonality especially problematic. Additionally, a very low manifest rate of one flight every four years makes logistics comparatively expensive. That, along with the SLS architecture being developed using a block upgrade evolutionary approach, exacerbates long-range planning for supportability considerations. These common and unique logistics challenges must be clearly identified and tackled to allow SLS to have a successful program. This paper will address the common and unique challenges facing the SLS programs, along with the analysis and decisions the NASA Logistics engineers are making to mitigate the threats posed by each.

  9. Identification of sRNA interacting with a transcript of interest using MS2-affinity purification coupled with RNA sequencing (MAPS) technology

    PubMed Central

    Lalaouna, David; Massé, Eric

    2015-01-01

    RNA sequencing (RNAseq) technology recently allowed the identification of thousands of small RNAs (sRNAs) within the prokaryotic kingdom. However, drawing the comprehensive interaction map of a sRNA remains a challenging task. To address this problem, we recently developed a method called MAPS (MS2 affinity purification coupled with RNA sequencing) to characterize the full targetome of specific sRNAs. This method enabled the identification of target RNAs interacting with sRNAs, regardless of the type of regulation (positive or negative), type of targets (mRNA, tRNA, sRNA) or their abundance. We also demonstrated that we can use this technology to perform a reverse MAPS experiment, where an RNA fragment of interest is used as bait to identify interacting sRNAs. Here, we demonstrated that RybB and MicF sRNAs co-purified with internal transcribed spacers (ITS) of metZ–metW–metV tRNA transcript, confirming results obtained with MS2-RybB MAPS. Both raw and analyzed RNAseq data are available in GEO database (GSE66517). PMID:26484242

  10. Logistics Management: New trends in the Reverse Logistics

    NASA Astrophysics Data System (ADS)

    Antonyová, A.; Antony, P.; Soewito, B.

    2016-04-01

    Present level and quality of the environment are directly dependent on our access to natural resources, as well as their sustainability. In particular production activities and phenomena associated with it have a direct impact on the future of our planet. Recycling process, which in large enterprises often becomes an important and integral part of the production program, is usually in small and medium-sized enterprises problematic. We can specify a few factors, which have direct impact on the development and successful application of the effective reverse logistics system. Find the ways to economically acceptable model of reverse logistics, focusing on converting waste materials for renewable energy, is the task in progress.

  11. Lessons in logistics from Somalia.

    PubMed

    Kemball-Cook, D; Stephenson, R

    1984-03-01

    By February 1981 the refugee relief operation in Somalia was close to breakdown. The Governor of Somalia and the United Nations High Commission for Refugees (UNHCR) contracted the agency CARE to manage the logistics of the operation. By August 1981 over 99 % of food received at Mogadishu was reaching the camps. Here we describe this apparent success, and attempt to diagnose the contributing factors. Chief among these are dynamic leadership, 'systems' management, adaptability of personnel, the use of professional Indian food monitors in the camps, and the support given by the Government. The chief qualification on the success of the operation has been the continued dependency on expatriate expertise. General conclusions are offered relating to the management of logistics in relief operations. The most important conclusion is that there is a prime need for logistics to be centralized in a single organization at the start of major emergencies. We point to the current inadequacy in an international relief system which fails to ensure this, and suggest that a new or existing part of the United Nations family be given a 'brief for in-country logistics' to become a UN Emergency Logistics Office. PMID:20958559

  12. Logistic Stick-Breaking Process

    PubMed Central

    Ren, Lu; Du, Lan; Carin, Lawrence; Dunson, David B.

    2013-01-01

    A logistic stick-breaking process (LSBP) is proposed for non-parametric clustering of general spatially- or temporally-dependent data, imposing the belief that proximate data are more likely to be clustered together. The sticks in the LSBP are realized via multiple logistic regression functions, with shrinkage priors employed to favor contiguous and spatially localized segments. The LSBP is also extended for the simultaneous processing of multiple data sets, yielding a hierarchical logistic stick-breaking process (H-LSBP). The model parameters (atoms) within the H-LSBP are shared across the multiple learning tasks. Efficient variational Bayesian inference is derived, and comparisons are made to related techniques in the literature. Experimental analysis is performed for audio waveforms and images, and it is demonstrated that for segmentation applications the LSBP yields generally homogeneous segments with sharp boundaries. PMID:25258593

  13. Logistics background study: underground mining

    SciTech Connect

    Hanslovan, J. J.; Visovsky, R. G.

    1982-02-01

    Logistical functions that are normally associated with US underground coal mining are investigated and analyzed. These functions imply all activities and services that support the producing sections of the mine. The report provides a better understanding of how these functions impact coal production in terms of time, cost, and safety. Major underground logistics activities are analyzed and include: transportation and personnel, supplies and equipment; transportation of coal and rock; electrical distribution and communications systems; water handling; hydraulics; and ventilation systems. Recommended areas for future research are identified and prioritized.

  14. Continual Improvement in Shuttle Logistics

    NASA Technical Reports Server (NTRS)

    Flowers, Jean; Schafer, Loraine

    1995-01-01

    It has been said that Continual Improvement (CI) is difficult to apply to service oriented functions, especially in a government agency such as NASA. However, a constrained budget and increasing requirements are a way of life at NASA Kennedy Space Center (KSC), making it a natural environment for the application of CI tools and techniques. This paper describes how KSC, and specifically the Space Shuttle Logistics Project, a key contributor to KSC's mission, has embraced the CI management approach as a means of achieving its strategic goals and objectives. An overview of how the KSC Space Shuttle Logistics Project has structured its CI effort and examples of some of the initiatives are provided.

  15. Logistics support of space facilities

    NASA Technical Reports Server (NTRS)

    Lewis, William C.

    1988-01-01

    The logistic support of space facilities is described, with special attention given to the problem of sizing the inventory of ready spares kept at the space facility. Where possible, data from the Space Shuttle Orbiter is extrapolated to provide numerical estimates for space facilities. Attention is also given to repair effort estimation and long duration missions.

  16. NASA Space Rocket Logistics Challenges

    NASA Technical Reports Server (NTRS)

    Bramon, Chris; Neeley, James R.; Jones, James V.; Watson, Michael D.; Inman, Sharon K.; Tuttle, Loraine

    2014-01-01

    The Space Launch System (SLS) is the new NASA heavy lift launch vehicle in development and is scheduled for its first mission in 2017. SLS has many of the same logistics challenges as any other large scale program. However, SLS also faces unique challenges. This presentation will address the SLS challenges, along with the analysis and decisions to mitigate the threats posed by each.

  17. 3D mapping of geological contacts by coupling Aerial Laser Scanning, Gigapixel photography and open access pictures

    NASA Astrophysics Data System (ADS)

    Nguyen, Liliane; Guerin, Antoine; Abellán, Antonio; Carrea, Dario; Derron, Marc-Henri; Jaboyedoff, Michel

    2015-04-01

    Multiple sources of geological data exist nowadays, most of them are in 2D (e.g. geological maps, geological panoramic sketch), and only a few are in 3D (e.g. block diagram). One of the current challenges in geological mapping consists not only in providing a more consistent 3D data, but also in pursuing a gathering and a harmonisation of the geological information in order to obtain a more consistent interpretations of the 3D geological models. New remote sensing techniques have significantly improved the representation of three-dimensional surfaces during the last decade, especially for steep and inaccessible rockcliffs. Therefore, we present an exploratory study aiming to find a reliable method for carrying out a three-dimensional mapping of geological contacts using a High Resolution Digital Elevation Model (HRDEM) with a 1 meter cell size. To this end, we selected the "Scex Rouge Mountain" as pilot study area. This outcrop, which is located in the Diablerets Massif (Vaud, Swiss Alps), has the particularity to present very distinguishable folded geological boundaries on its Southern face. The Southern slope belongs to the Wildhorn nappe, which is mainly composed of sedimentary rocks. The top-layer is composed of siliceous limestones, the well-visible fold layer is the "Pygurus layer" and consist of sandy limestone. Finally the bottom-layer includes marly schist and clayey limestones. At first, different sources of information has been draped on the HRDEM of the Scex Rouge Mountain, including not only classical geological maps (1:25 000) but also different sources of imagery (e.g. gigapixel panoramas, open access images, etc.). In a second step, several three-dimensional polylines have been drawn following the geological limit on each drapped HRDEM. Then we investigated the accuracy of 2D classical geological maps by comparing these geological limits with the drawn 3D polylines. Furthermore, in order to evaluate the accuracy of the method, a ground truth needs

  18. Identifying changes in dissolved organic matter content and characteristics by fluorescence spectroscopy coupled with self-organizing map and classification and regression tree analysis during wastewater treatment.

    PubMed

    Yu, Huibin; Song, Yonghui; Liu, Ruixia; Pan, Hongwei; Xiang, Liancheng; Qian, Feng

    2014-10-01

    The stabilization of latent tracers of dissolved organic matter (DOM) of wastewater was analyzed by three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy coupled with self-organizing map and classification and regression tree analysis (CART) in wastewater treatment performance. DOM of water samples collected from primary sedimentation, anaerobic, anoxic, oxic and secondary sedimentation tanks in a large-scale wastewater treatment plant contained four fluorescence components: tryptophan-like (C1), tyrosine-like (C2), microbial humic-like (C3) and fulvic-like (C4) materials extracted by self-organizing map. These components showed good positive linear correlations with dissolved organic carbon of DOM. C1 and C2 were representative components in the wastewater, and they were removed to a higher extent than those of C3 and C4 in the treatment process. C2 was a latent parameter determined by CART to differentiate water samples of oxic and secondary sedimentation tanks from the successive treatment units, indirectly proving that most of tyrosine-like material was degraded by anaerobic microorganisms. C1 was an accurate parameter to comprehensively separate the samples of the five treatment units from each other, indirectly indicating that tryptophan-like material was decomposed by anaerobic and aerobic bacteria. EEM fluorescence spectroscopy in combination with self-organizing map and CART analysis can be a nondestructive effective method for characterizing structural component of DOM fractions and monitoring organic matter removal in wastewater treatment process. PMID:25065793

  19. Sparse maps--A systematic infrastructure for reduced-scaling electronic structure methods. II. Linear scaling domain based pair natural orbital coupled cluster theory.

    PubMed

    Riplinger, Christoph; Pinski, Peter; Becker, Ute; Valeev, Edward F; Neese, Frank

    2016-01-14

    Domain based local pair natural orbital coupled cluster theory with single-, double-, and perturbative triple excitations (DLPNO-CCSD(T)) is a highly efficient local correlation method. It is known to be accurate and robust and can be used in a black box fashion in order to obtain coupled cluster quality total energies for large molecules with several hundred atoms. While previous implementations showed near linear scaling up to a few hundred atoms, several nonlinear scaling steps limited the applicability of the method for very large systems. In this work, these limitations are overcome and a linear scaling DLPNO-CCSD(T) method for closed shell systems is reported. The new implementation is based on the concept of sparse maps that was introduced in Part I of this series [P. Pinski, C. Riplinger, E. F. Valeev, and F. Neese, J. Chem. Phys. 143, 034108 (2015)]. Using the sparse map infrastructure, all essential computational steps (integral transformation and storage, initial guess, pair natural orbital construction, amplitude iterations, triples correction) are achieved in a linear scaling fashion. In addition, a number of additional algorithmic improvements are reported that lead to significant speedups of the method. The new, linear-scaling DLPNO-CCSD(T) implementation typically is 7 times faster than the previous implementation and consumes 4 times less disk space for large three-dimensional systems. For linear systems, the performance gains and memory savings are substantially larger. Calculations with more than 20 000 basis functions and 1000 atoms are reported in this work. In all cases, the time required for the coupled cluster step is comparable to or lower than for the preceding Hartree-Fock calculation, even if this is carried out with the efficient resolution-of-the-identity and chain-of-spheres approximations. The new implementation even reduces the error in absolute correlation energies by about a factor of two, compared to the already accurate

  20. Comparison of Logistic Regression and Random Forests techniques for shallow landslide susceptibility assessment in Giampilieri (NE Sicily, Italy)

    NASA Astrophysics Data System (ADS)

    Trigila, Alessandro; Iadanza, Carla; Esposito, Carlo; Scarascia-Mugnozza, Gabriele

    2015-11-01

    The aim of this work is to define reliable susceptibility models for shallow landslides using Logistic Regression and Random Forests multivariate statistical techniques. The study area, located in North-East Sicily, was hit on October 1st 2009 by a severe rainstorm (225 mm of cumulative rainfall in 7 h) which caused flash floods and more than 1000 landslides. Several small villages, such as Giampilieri, were hit with 31 fatalities, 6 missing persons and damage to buildings and transportation infrastructures. Landslides, mainly types such as earth and debris translational slides evolving into debris flows, were triggered on steep slopes and involved colluvium and regolith materials which cover the underlying metamorphic bedrock. The work has been carried out with the following steps: i) realization of a detailed event landslide inventory map through field surveys coupled with observation of high resolution aerial colour orthophoto; ii) identification of landslide source areas; iii) data preparation of landslide controlling factors and descriptive statistics based on a bivariate method (Frequency Ratio) to get an initial overview on existing relationships between causative factors and shallow landslide source areas; iv) choice of criteria for the selection and sizing of the mapping unit; v) implementation of 5 multivariate statistical susceptibility models based on Logistic Regression and Random Forests techniques and focused on landslide source areas; vi) evaluation of the influence of sample size and type of sampling on results and performance of the models; vii) evaluation of the predictive capabilities of the models using ROC curve, AUC and contingency tables; viii) comparison of model results and obtained susceptibility maps; and ix) analysis of temporal variation of landslide susceptibility related to input parameter changes. Models based on Logistic Regression and Random Forests have demonstrated excellent predictive capabilities. Land use and wildfire

  1. Multisource information fusion for logistics

    NASA Astrophysics Data System (ADS)

    Woodley, Robert; Petrov, Plamen; Noll, Warren

    2011-05-01

    Current Army logistical systems and databases contain massive amounts of data that need an effective method to extract actionable information. The databases do not contain root cause and case-based analysis needed to diagnose or predict breakdowns. A system is needed to find data from as many sources as possible, process it in an integrated fashion, and disseminate information products on the readiness of the fleet vehicles. 21st Century Systems, Inc. introduces the Agent- Enabled Logistics Enterprise Intelligence System (AELEIS) tool, designed to assist logistics analysts with assessing the availability and prognostics of assets in the logistics pipeline. AELEIS extracts data from multiple, heterogeneous data sets. This data is then aggregated and mined for data trends. Finally, data reasoning tools and prognostics tools evaluate the data for relevance and potential issues. Multiple types of data mining tools may be employed to extract the data and an information reasoning capability determines what tools are needed to apply them to extract information. This can be visualized as a push-pull system where data trends fire a reasoning engine to search for corroborating evidence and then integrate the data into actionable information. The architecture decides on what reasoning engine to use (i.e., it may start with a rule-based method, but, if needed, go to condition based reasoning, and even a model-based reasoning engine for certain types of equipment). Initial results show that AELEIS is able to indicate to the user of potential fault conditions and root-cause information mined from a database.

  2. Logistics, electronic commerce, and the environment

    NASA Astrophysics Data System (ADS)

    Sarkis, Joseph; Meade, Laura; Talluri, Srinivas

    2002-02-01

    Organizations realize that a strong supporting logistics or electronic logistics (e-logistics) function is important from both commercial and consumer perspectives. The implications of e-logistics models and practices cover the forward and reverse logistics functions of organizations. They also have direct and profound impact on the natural environment. This paper will focus on a discussion of forward and reverse e-logistics and their relationship to the natural environment. After discussion of the many pertinent issues in these areas, directions of practice and implications for study and research are then described.

  3. Conformational entropic maps of functional coupling domains in GPCR activation: A case study with beta2 adrenergic receptor

    NASA Astrophysics Data System (ADS)

    Liu, Fan; Abrol, Ravinder; Goddard, William, III; Dougherty, Dennis

    2014-03-01

    Entropic effect in GPCR activation is poorly understood. Based on the recent solved structures, researchers in the GPCR structural biology field have proposed several ``local activating switches'' that consisted of a few number of conserved residues, but have long ignored the collective dynamical effect (conformational entropy) of a domain comprised of an ensemble of residues. A new paradigm has been proposed recently that a GPCR can be viewed as a composition of several functional coupling domains, each of which undergoes order-to-disorder or disorder-to-order transitions upon activation. Here we identified and studied these functional coupling domains by comparing the local entropy changes of each residue between the inactive and active states of the β2 adrenergic receptor from computational simulation. We found that agonist and G-protein binding increases the heterogeneity of the entropy distribution in the receptor. This new activation paradigm and computational entropy analysis scheme provides novel ways to design functionally modified mutant and identify new allosteric sites for GPCRs. The authors thank NIH and Sanofi for funding this project.

  4. Novel coupling scheme to control dynamics of coupled discrete systems

    NASA Astrophysics Data System (ADS)

    Shekatkar, Snehal M.; Ambika, G.

    2015-08-01

    We present a new coupling scheme to control spatio-temporal patterns and chimeras on 1-d and 2-d lattices and random networks of discrete dynamical systems. The scheme involves coupling with an external lattice or network of damped systems. When the system network and external network are set in a feedback loop, the system network can be controlled to a homogeneous steady state or synchronized periodic state with suppression of the chaotic dynamics of the individual units. The control scheme has the advantage that its design does not require any prior information about the system dynamics or its parameters and works effectively for a range of parameters of the control network. We analyze the stability of the controlled steady state or amplitude death state of lattices using the theory of circulant matrices and Routh-Hurwitz criterion for discrete systems and this helps to isolate regions of effective control in the relevant parameter planes. The conditions thus obtained are found to agree well with those obtained from direct numerical simulations in the specific context of lattices with logistic map and Henon map as on-site system dynamics. We show how chimera states developed in an experimentally realizable 2-d lattice can be controlled using this scheme. We propose this mechanism can provide a phenomenological model for the control of spatio-temporal patterns in coupled neurons due to non-synaptic coupling with the extra cellular medium. We extend the control scheme to regulate dynamics on random networks and adapt the master stability function method to analyze the stability of the controlled state for various topologies and coupling strengths.

  5. Developing a Computational Environment for Coupling MOR Data, Maps, and Models: The Virtual Research Vessel (VRV) Prototype

    NASA Astrophysics Data System (ADS)

    Wright, D. J.; O'Dea, E.; Cushing, J. B.; Cuny, J. E.; Toomey, D. R.; Hackett, K.; Tikekar, R.

    2001-12-01

    ) and model coupling (e.g., ability to run tool composition locally but access input data from the web, APIs to support coupling such as invoking programs that are running remotely, and help in writing data wrappers to publish programs); (5) support of migration paths for prototyped model coupling; and (6) export of marine geological data and data analysis to the undergraduate classroom (VRV-ET, "Educational Tool"). See the main VRV web site at http://oregonstate.edu/dept/vrv and the VRV-ET web site at: http://www.cs.uoregon.edu/research/vrv-et.

  6. Comparing the Discrete and Continuous Logistic Models

    ERIC Educational Resources Information Center

    Gordon, Sheldon P.

    2008-01-01

    The solutions of the discrete logistic growth model based on a difference equation and the continuous logistic growth model based on a differential equation are compared and contrasted. The investigation is conducted using a dynamic interactive spreadsheet. (Contains 5 figures.)

  7. Research on 6R Military Logistics Network

    NASA Astrophysics Data System (ADS)

    Jie, Wan; Wen, Wang

    The building of military logistics network is an important issue for the construction of new forces. This paper has thrown out a concept model of 6R military logistics network model based on JIT. Then we conceive of axis spoke y logistics centers network, flexible 6R organizational network, lean 6R military information network based grid. And then the strategy and proposal for the construction of the three sub networks of 6Rmilitary logistics network are given.

  8. Mini pressurized logistics module (MPLM)

    NASA Astrophysics Data System (ADS)

    Vallerani, E.; Brondolo, D.; Basile, L.

    1996-06-01

    The MPLM Program was initiated through a Memorandum of Understanding (MOU) between the United States' National Aeronautics and Space Administration (NASA) and Italy's ASI, the Italian Space Agency, that was signed on 6 December 1991. The MPLM is a pressurized logistics module that will be used to transport supplies and materials (up to 20,000 lb), including user experiments, between Earth and International Space Station Alpha (ISSA) using the Shuttle, to support active and passive storage, and to provide a habitable environment for two people when docked to the Station. The Italian Space Agency has selected Alenia Spazio to develop MPLM modules that have always been considered a key element for the new International Space Station taking benefit from its design flexibility and consequent possible cost saving based on the maximum utilization of the Shuttle launch capability for any mission. In the frame of the very recent agreement between the U.S. and Russia for cooperation in space, that foresees the utilization of MIR 1 hardware, the Italian MPLM will remain an important element of the logistics system, being the only pressurized module designed for re-entry. Within the new scenario of anticipated Shuttle flights to MIR 1 during Space Station phase 1, MPLM remains a candidate for one or more missions to provide MIR 1 resupply capabilities and advanced ISSA hardware/procedures verification. Based on the concept of Flexible Carriers, Alenia Spazio is providing NASA with three MPLM flight units that can be configured according to the requirements of the Human-Tended Capability (HTC) and Permanent Human Capability (PHC) of the Space Station. Configurability will allow transportation of passive cargo only, or a combination of passive and cold cargo accommodated in R/F racks. Having developed and qualified the baseline configuration with respect to the worst enveloping condition, each unit could be easily configured to the passive or active version depending upon the

  9. Logistics Handbook, 1976. Colorado Outward Bound School.

    ERIC Educational Resources Information Center

    Colorado Outward Bound School, Denver.

    Logistics, a support mission, is vital to the successful operation of the Colorado Outward Bound School (COBS) courses. Logistics is responsible for purchasing, maintaining, transporting, and replenishing a wide variety of items, i.e., food, mountaineering and camping equipment, medical and other supplies, and vehicles. The Logistics coordinator…

  10. Mapping physiological G protein-coupled receptor signaling pathways reveals a role for receptor phosphorylation in airway contraction

    PubMed Central

    Bradley, Sophie J.; Iglesias, Max Maza; Kong, Kok Choi; Butcher, Adrian J.; Plouffe, Bianca; Goupil, Eugénie; Bourgognon, Julie-Myrtille; Macedo-Hatch, Timothy; LeGouill, Christian; Russell, Kirsty; Laporte, Stéphane A.; König, Gabriele M.; Kostenis, Evi; Bouvier, Michel; Chung, Kian Fan; Amrani, Yassine; Tobin, Andrew B.

    2016-01-01

    G protein-coupled receptors (GPCRs) are known to initiate a plethora of signaling pathways in vitro. However, it is unclear which of these pathways are engaged to mediate physiological responses. Here, we examine the distinct roles of Gq/11-dependent signaling and receptor phosphorylation-dependent signaling in bronchial airway contraction and lung function regulated through the M3-muscarinic acetylcholine receptor (M3-mAChR). By using a genetically engineered mouse expressing a G protein-biased M3-mAChR mutant, we reveal the first evidence, to our knowledge, of a role for M3-mAChR phosphorylation in bronchial smooth muscle contraction in health and in a disease state with relevance to human asthma. Furthermore, this mouse model can be used to distinguish the physiological responses that are regulated by M3-mAChR phosphorylation (which include control of lung function) from those responses that are downstream of G protein signaling. In this way, we present an approach by which to predict the physiological/therapeutic outcome of M3-mAChR–biased ligands with important implications for drug discovery. PMID:27071102

  11. Multisensory representation of frequency across audition and touch: High density electrical mapping reveals early sensory-perceptual coupling

    PubMed Central

    Butler, John S.; Foxe, John J.; Fiebelkorn, Ian C.; Mercier, Manuel; Molholm, Sophie

    2013-01-01

    The frequency of environmental vibrations is sampled by two of the major sensory systems, audition and touch, notwithstanding that these signals are transduced through very different physical media and entirely separate sensory epithelia. Psychophysical studies have shown that manipulating frequency in audition or touch can have a significant cross-sensory impact on perceived frequency in the other sensory system, pointing to intimate links between these senses during computation of frequency. In this regard, the frequency of a vibratory event can be thought of as a multisensory perceptual construct. In turn, electrophysiological studies point to temporally early multisensory interactions that occur in hierarchically early sensory regions where convergent inputs from the auditory and somatosensory systems are to be found. A key question pertains to the level of processing at which the multisensory integration of featural information such as frequency occurs. Do the sensory systems calculate frequency independently before this information is combined, or is this feature calculated in an integrated fashion during pre-attentive sensory processing? The well-characterized mismatch negativity, an electrophysiological response that indexes pre-attentive detection of a change within the context of a regular pattern of stimulation, served as our dependent measure. High-density electrophysiological recordings were made in humans while they were presented with separate blocks of somatosensory, auditory, and audio-somatosensory “standards” and “deviants”, where the deviant differed in frequency. Multisensory effects were identified beginning at ~200ms, with the multisensory MMN significantly different from the sum of the unisensory MMNs. This provides compelling evidence for preattentive coupling between the somatosensory and auditory channels in the cortical representation of frequency. PMID:23115172

  12. Multisensory representation of frequency across audition and touch: high density electrical mapping reveals early sensory-perceptual coupling.

    PubMed

    Butler, John S; Foxe, John J; Fiebelkorn, Ian C; Mercier, Manuel R; Molholm, Sophie

    2012-10-31

    The frequency of environmental vibrations is sampled by two of the major sensory systems, audition and touch, notwithstanding that these signals are transduced through very different physical media and entirely separate sensory epithelia. Psychophysical studies have shown that manipulating frequency in audition or touch can have a significant cross-sensory impact on perceived frequency in the other sensory system, pointing to intimate links between these senses during computation of frequency. In this regard, the frequency of a vibratory event can be thought of as a multisensory perceptual construct. In turn, electrophysiological studies point to temporally early multisensory interactions that occur in hierarchically early sensory regions where convergent inputs from the auditory and somatosensory systems are to be found. A key question pertains to the level of processing at which the multisensory integration of featural information, such as frequency, occurs. Do the sensory systems calculate frequency independently before this information is combined, or is this feature calculated in an integrated fashion during preattentive sensory processing? The well characterized mismatch negativity, an electrophysiological response that indexes preattentive detection of a change within the context of a regular pattern of stimulation, served as our dependent measure. High-density electrophysiological recordings were made in humans while they were presented with separate blocks of somatosensory, auditory, and audio-somatosensory "standards" and "deviants," where the deviant differed in frequency. Multisensory effects were identified beginning at ∼200 ms, with the multisensory mismatch negativity (MMN) significantly different from the sum of the unisensory MMNs. This provides compelling evidence for preattentive coupling between the somatosensory and auditory channels in the cortical representation of frequency. PMID:23115172

  13. Mitogen-Activated Protein Kinase 8 (MAP3K8) Mediates the Signaling Pathway of Estradiol Stimulating Progesterone Production Through G Protein-Coupled Receptor 30 (GPR30) in Mouse Corpus Luteum.

    PubMed

    Liu, Ying; Li, Yueqin; Zhang, Di; Liu, Jiali; Gou, Kemian; Cui, Sheng

    2015-05-01

    The corpus luteum (CL) is a transient endocrine gland developed from the ovulated follicles, and the most important function is to synthesize and secrete progesterone (P(4)), a key hormone to maintain normal pregnancy and estrous cycle in most mammals. It is known that estrogen has a vital role in stimulating P(4) synthesis in CL, but it still remains unclear about the mechanism of estradiol (E(2)) regulating P(4) production in CL. Our results here first show that all of the CL cells express MAPK 8 (MAP3K8), and the MAP3K8 level is much higher at the midstage than at the early and late stages during CL development. The further functional studies show that the forced inhibition of endogenous MAP3K8 by using MAP3K8 small interfering RNA and MAP3K8 signaling inhibitor (MAP3K8i) in the luteal cells significantly block the P(4) synthesis and neutralize the enhancing effect of E(2) on P(4) production in the CL. In addition, our results here demonstrate that the stimulating effect of E(2) on P(4) synthesis relies on the estrogen no-classical protein-coupled receptor 30, and MAP3K8 is involved in mediating the protein-coupled receptor 30signaling of E(2) affecting P(4) synthesis via stimulating ERK phosphorylation. These novel findings are critical for our understanding the ovary physiology and pathological mechanism. PMID:25763610

  14. Country logistics performance and disaster impact.

    PubMed

    Vaillancourt, Alain; Haavisto, Ira

    2016-04-01

    The aim of this paper is to deepen the understanding of the relationship between country logistics performance and disaster impact. The relationship is analysed through correlation analysis and regression models for 117 countries for the years 2007 to 2012 with disaster impact variables from the International Disaster Database (EM-DAT) and logistics performance indicators from the World Bank. The results show a significant relationship between country logistics performance and disaster impact overall and for five out of six specific logistic performance indicators. These specific indicators were further used to explore the relationship between country logistic performance and disaster impact for three specific disaster types (epidemic, flood and storm). The findings enhance the understanding of the role of logistics in a humanitarian context with empirical evidence of the importance of country logistics performance in disaster response operations. PMID:26282578

  15. Logistic equation of arbitrary order

    NASA Astrophysics Data System (ADS)

    Grabowski, Franciszek

    2010-08-01

    The paper is concerned with the new logistic equation of arbitrary order which describes the performance of complex executive systems X vs. number of tasks N, operating at limited resources K, at non-extensive, heterogeneous self-organization processes characterized by parameter f. In contrast to the classical logistic equation which exclusively relates to the special case of sub-extensive homogeneous self-organization processes at f=1, the proposed model concerns both homogeneous and heterogeneous processes in sub-extensive and super-extensive areas. The parameter of arbitrary order f, where -∞

  16. Elemental mapping in fossil tooth root section of Ursus arctos by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS).

    PubMed

    Vašinová Galiová, M; Nývltová Fišáková, M; Kynický, J; Prokeš, L; Neff, H; Mason, A Z; Gadas, P; Košler, J; Kanický, V

    2013-02-15

    Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to map the matrix (Ca, P) and trace (Ba, Sr, Zn) elements in the root section of a fossilized brown bear (Ursus arctos) tooth. Multielemental analysis was performed on a (2.5 × 1.5)cm(2) area. For elemental distribution, a UP 213 laser ablation system was coupled either with a quadrupole or a time of flight ICP-MS. The cementum and dentine on the slice of the sample surface were clearly distinguishable, especially changes in elemental distribution in the summer and winter bands in the fossil root dentine. Migration and diet of U. arctos were determined on the basis of fluctuations in Sr/Zn ratio and their contents. Quantification was accomplished with standard reference material of bone meal (NIST 1486) and by the use of electron microprobe analysis (EMPA). Changes in Sr/Zn and Sr/Ba ratios relating to the season, and composition of food during the lifetime of the animal are discussed on basis of analysis of light stable isotopes. It was observed that there was an increase in the Sr/Zn ratio during the winter season caused by a reduction of food intake during hibernation. Above mentioned inferences drawn from elemental data obtained by LA-ICP-MS were confirmed independently by determination of carbon, nitrogen and strontium isotopes. Moreover, diagenesis and its interfering influence on the biogenic composition of cementum and dentine were resolved. According to the distribution and/or content of the element of interest, post-mortem alterations were revealed. Namely, U, Na, Fe, Mg and F predicate about the suitability of the selected area for determination of migration and diet. PMID:23598013

  17. Construction of invariant whiskered tori by a parameterization method. Part II: Quasi-periodic and almost periodic breathers in coupled map lattices

    NASA Astrophysics Data System (ADS)

    Fontich, Ernest; de la Llave, Rafael; Sire, Yannick

    2015-09-01

    We construct quasi-periodic and almost periodic solutions for coupled Hamiltonian systems on an infinite lattice which is translation invariant. The couplings can be long range, provided that they decay moderately fast with respect to the distance. For the solutions we construct, most of the sites are moving in a neighborhood of a hyperbolic fixed point, but there are oscillating sites clustered around a sequence of nodes. The amplitude of these oscillations does not need to tend to zero. In particular, the almost periodic solutions do not decay at infinity. The main result is an a posteriori theorem. We formulate an invariance equation. Solutions of this equation are embeddings of an invariant torus on which the motion is conjugate to a rotation. We show that, if there is an approximate solution of the invariance equation that satisfies some non-degeneracy conditions, there is a true solution close by. This does not require that the system is close to integrable, hence it can be used to validate numerical calculations or formal expansions. The proof of this a posteriori theorem is based on a Nash-Moser iteration, which does not use transformation theory. Simpler versions of the scheme were developed in [28]. One technical tool, important for our purposes, is the use of weighted spaces that capture the idea that the maps under consideration are local interactions. Using these weighted spaces, the estimates of iterative steps are similar to those in finite dimensional spaces. In particular, the estimates are independent of the number of nodes that get excited. Using these techniques, given two breathers, we can place them apart and obtain an approximate solution, which leads to a true solution nearby. By repeating the process infinitely often, we can get solutions with infinitely many frequencies which do not tend to zero at infinity.

  18. Finite-element analyses of blade and slot coating flows using an implicit pseudo-solid domain mapping technique coupled with unstructured grids

    SciTech Connect

    Chen, K.S.; Schunk, P.R.; Sackinger, P.A.

    1994-12-04

    In coating processes (e.g. in blade coating) the flow domain inherently contains free surfaces and three-phase contact lines, and characteristic length scales of flow features in the dimension transverse to the web-movement vary by an order of magnitude or more from a fraction of a millimeter or more to tens of microns or less). The presence of free surfaces and three-phase contact lines, and the sudden changes of flow geometry and directions create difficulties in theoretical analyses of such flows. Though simulations of coating flows via finite-element methods using structured grids have been reportedly demonstrated in the literature, achieving high efficiency of such numerical experiments remains a grand challenge -- mainly due to difficulties in local mesh-refinement and in avoiding unacceptably distorted grids. High efficiency of computing steady flow fields under various process conditions is crucial in shortening turn-around time in design and optimization of coating-flow processes. In this paper we employ a fully-implicit, pseudo-solid, domain mapping technique coupled with unstructured meshes to analyze blade and slot coating flows using Galerkin`s method with finite element basis functions. We demonstrate the robustness and efficiency of our unique technique in circumventing shortcomings of mesh-motion schemes currently being used in the coating-flow research community. Our goal is to develop an efficient numerical tool, together with a suitable optimization toolkit, that can be used routinely in design and optimization of coating-flow processes.

  19. Optimal distributions for multiplex logistic networks.

    PubMed

    Solá Conde, Luis E; Used, Javier; Romance, Miguel

    2016-06-01

    This paper presents some mathematical models for distribution of goods in logistic networks based on spectral analysis of complex networks. Given a steady distribution of a finished product, some numerical algorithms are presented for computing the weights in a multiplex logistic network that reach the equilibrium dynamics with high convergence rate. As an application, the logistic networks of Germany and Spain are analyzed in terms of their convergence rates. PMID:27368801

  20. Integrated Computer System of Management in Logistics

    NASA Astrophysics Data System (ADS)

    Chwesiuk, Krzysztof

    2011-06-01

    This paper aims at presenting a concept of an integrated computer system of management in logistics, particularly in supply and distribution chains. Consequently, the paper includes the basic idea of the concept of computer-based management in logistics and components of the system, such as CAM and CIM systems in production processes, and management systems for storage, materials flow, and for managing transport, forwarding and logistics companies. The platform which integrates computer-aided management systems is that of electronic data interchange.

  1. Optimal distributions for multiplex logistic networks

    NASA Astrophysics Data System (ADS)

    Solá Conde, Luis E.; Used, Javier; Romance, Miguel

    2016-06-01

    This paper presents some mathematical models for distribution of goods in logistic networks based on spectral analysis of complex networks. Given a steady distribution of a finished product, some numerical algorithms are presented for computing the weights in a multiplex logistic network that reach the equilibrium dynamics with high convergence rate. As an application, the logistic networks of Germany and Spain are analyzed in terms of their convergence rates.

  2. Logistics Reduction Technologies for Exploration Missions

    NASA Technical Reports Server (NTRS)

    Broyan, James L., Jr.; Ewert, Michael K.; Fink, Patrick W.

    2014-01-01

    Human exploration missions under study are limited by the launch mass capacity of existing and planned launch vehicles. The logistical mass of crew items is typically considered separate from the vehicle structure, habitat outfitting, and life support systems. Although mass is typically the focus of exploration missions, due to its strong impact on launch vehicle and habitable volume for the crew, logistics volume also needs to be considered. NASA's Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) Project is developing six logistics technologies guided by a systems engineering cradle-to-grave approach to enable after-use crew items to augment vehicle systems. Specifically, AES LRR is investigating the direct reduction of clothing mass, the repurposing of logistical packaging, the use of autonomous logistics management technologies, the processing of spent crew items to benefit radiation shielding and water recovery, and the conversion of trash to propulsion gases. Reduction of mass has a corresponding and significant impact to logistical volume. The reduction of logistical volume can reduce the overall pressurized vehicle mass directly, or indirectly benefit the mission by allowing for an increase in habitable volume during the mission. The systematic implementation of these types of technologies will increase launch mass efficiency by enabling items to be used for secondary purposes and improve the habitability of the vehicle as mission durations increase. Early studies have shown that the use of advanced logistics technologies can save approximately 20 m(sup 3) of volume during transit alone for a six-person Mars conjunction class mission.

  3. Analysis of Jingdong Mall Logistics Distribution Model

    NASA Astrophysics Data System (ADS)

    Shao, Kang; Cheng, Feng

    In recent years, the development of electronic commerce in our country to speed up the pace. The role of logistics has been highlighted, more and more electronic commerce enterprise are beginning to realize the importance of logistics in the success or failure of the enterprise. In this paper, the author take Jingdong Mall for example, performing a SWOT analysis of their current situation of self-built logistics system, find out the problems existing in the current Jingdong Mall logistics distribution and give appropriate recommendations.

  4. FUTURE LOGISTICS AND OPERATIONAL ADAPTABILITY

    SciTech Connect

    Houck, Roger P.

    2009-10-01

    While we cannot predict the future, we can ascertain trends and examine them through the use of alternative futures methodologies and tools. From a logistics perspective, we know that many different futures are possible, all of which are obviously dependent on decisions we make in the present. As professional logisticians we are obligated to provide the field - our Soldiers - with our best professional opinion of what will result in success on the battlefield. Our view of the future should take history and contemporary conflict into account, but it must also consider that continuity with the past cannot be taken for granted. If we are too focused on past and current experience, then our vision of the future will be limited indeed. On the one hand, the future must be explained in language that does not defy common sense. On the other hand, the pace of change is such that we must conduct qualitative and quantitative trend analyses, forecasting, and explorative scenario development in ways that allow for significant breaks - or "shocks" - that may "change the game". We will need capabilities and solutions that are constantly evolving - and improving - to match the operational tempo of a radically changing threat environment. For those who provide quartermaster services, this article will briefly examine what this means from the perspective of creating what might be termed a preferred future.

  5. Biomass supply logistics and infrastructure.

    PubMed

    Sokhansanj, Shahabaddine; Hess, J Richard

    2009-01-01

    Feedstock supply system encompasses numerous unit operations necessary to move lignocellulosic feedstock from the place where it is produced (in the field or on the stump) to the start of the conversion process (reactor throat) of the biorefinery. These unit operations, which include collection, storage, preprocessing, handling, and transportation, represent one of the largest technical and logistics challenges to the emerging lignocellulosic biorefining industry. This chapter briefly reviews the methods of estimating the quantities of biomass, followed by harvesting and collection processes based on current practices on handling wet and dry forage materials. Storage and queuing are used to deal with seasonal harvest times, variable yields, and delivery schedules. Preprocessing can be as simple as grinding and formatting the biomass for increased bulk density or improved conversion efficiency, or it can be as complex as improving feedstock quality through fractionation, tissue separation, drying, blending, and densification. Handling and transportation consists of using a variety of transport equipment (truck, train, ship) for moving the biomass from one point to another. The chapter also provides typical cost figures for harvest and processing of biomass. PMID:19768612

  6. Biomass Supply Logistics and Infrastructure

    SciTech Connect

    Sokhansanj, Shahabaddine

    2009-04-01

    Feedstock supply system encompasses numerous unit operations necessary to move lignocellulosic feedstock from the place where it is produced (in the field or on the stump) to the start of the conversion process (reactor throat) of the Biorefinery. These unit operations, which include collection, storage, preprocessing, handling, and transportation, represent one of the largest technical and logistics challenges to the emerging lignocellulosic biorefining industry. This chapter briefly reviews methods of estimating the quantities of biomass followed by harvesting and collection processes based on current practices on handling wet and dry forage materials. Storage and queuing are used to deal with seasonal harvest times, variable yields, and delivery schedules. Preprocessing can be as simple as grinding and formatting the biomass for increased bulk density or improved conversion efficiency, or it can be as complex as improving feedstock quality through fractionation, tissue separation, drying, blending, and densification. Handling and Transportation consists of using a variety of transport equipment (truck, train, ship) for moving the biomass from one point to another. The chapter also provides typical cost figures for harvest and processing of biomass.

  7. Biomass Supply Logistics and Infrastructure

    NASA Astrophysics Data System (ADS)

    Sokhansanj, Shahabaddine; Hess, J. Richard

    Feedstock supply system encompasses numerous unit operations necessary to move lignocellulosic feedstock from the place where it is produced (in the field or on the stump) to the start of the conversion process (reactor throat) of the biorefinery. These unit operations, which include collection, storage, preprocessing, handling, and transportation, represent one of the largest technical and logistics challenges to the emerging lignocellulosic biorefining industry. This chapter briefly reviews the methods of estimating the quantities of biomass, followed by harvesting and collection processes based on current practices on handling wet and dry forage materials. Storage and queuing are used to deal with seasonal harvest times, variable yields, and delivery schedules. Preprocessing can be as simple as grinding and formatting the biomass for increased bulk density or improved conversion efficiency, or it can be as complex as improving feedstock quality through fractionation, tissue separation, drying, blending, and densification. Handling and transportation consists of using a variety of transport equipment (truck, train, ship) for moving the biomass from one point to another. The chapter also provides typical cost figures for harvest and processing of biomass.

  8. Coupling Self-Organizing Maps with a Naïve Bayesian classifier: A case study for classifying Vermont streams using geomorphic, habitat and biological assessment data

    NASA Astrophysics Data System (ADS)

    Fytilis, N.; Rizzo, D. M.

    2012-12-01

    Environmental managers are increasingly required to forecast the long-term effects and the resilience or vulnerability of biophysical systems to human-generated stresses. Mitigation strategies for hydrological and environmental systems need to be assessed in the presence of uncertainty. An important aspect of such complex systems is the assessment of variable uncertainty on the model response outputs. We develop a new classification tool that couples a Naïve Bayesian Classifier with a modified Kohonen Self-Organizing Map to tackle this challenge. For proof-of-concept, we use rapid geomorphic and reach-scale habitat assessments data from over 2500 Vermont stream reaches (~1371 stream miles) assessed by the Vermont Agency of Natural Resources (VTANR). In addition, the Vermont Department of Environmental Conservation (VTDEC) estimates stream habitat biodiversity indices (macro-invertebrates and fish) and a variety of water quality data. Our approach fully utilizes the existing VTANR and VTDEC data sets to improve classification of stream-reach habitat and biological integrity. The combined SOM-Naïve Bayesian architecture is sufficiently flexible to allow for continual updates and increased accuracy associated with acquiring new data. The Kohonen Self-Organizing Map (SOM) is an unsupervised artificial neural network that autonomously analyzes properties inherent in a given a set of data. It is typically used to cluster data vectors into similar categories when a priori classes do not exist. The ability of the SOM to convert nonlinear, high dimensional data to some user-defined lower dimension and mine large amounts of data types (i.e., discrete or continuous, biological or geomorphic data) makes it ideal for characterizing the sensitivity of river networks in a variety of contexts. The procedure is data-driven, and therefore does not require the development of site-specific, process-based classification stream models, or sets of if-then-else rules associated with

  9. Standards for Standardized Logistic Regression Coefficients

    ERIC Educational Resources Information Center

    Menard, Scott

    2011-01-01

    Standardized coefficients in logistic regression analysis have the same utility as standardized coefficients in linear regression analysis. Although there has been no consensus on the best way to construct standardized logistic regression coefficients, there is now sufficient evidence to suggest a single best approach to the construction of a…

  10. Exploration Mission Benefits From Logistics Reduction Technologies

    NASA Technical Reports Server (NTRS)

    Broyan, James Lee, Jr.; Ewert, Michael K.; Schlesinger, Thilini

    2016-01-01

    Technologies that reduce logistical mass, volume, and the crew time dedicated to logistics management become more important as exploration missions extend further from the Earth. Even modest reductions in logistical mass can have a significant impact because it also reduces the packaging burden. NASA's Advanced Exploration Systems' Logistics Reduction Project is developing technologies that can directly reduce the mass and volume of crew clothing and metabolic waste collection. Also, cargo bags have been developed that can be reconfigured for crew outfitting, and trash processing technologies are under development to increase habitable volume and improve protection against solar storm events. Additionally, Mars class missions are sufficiently distant that even logistics management without resupply can be problematic due to the communication time delay with Earth. Although exploration vehicles are launched with all consumables and logistics in a defined configuration, the configuration continually changes as the mission progresses. Traditionally significant ground and crew time has been required to understand the evolving configuration and to help locate misplaced items. For key mission events and unplanned contingencies, the crew will not be able to rely on the ground for logistics localization assistance. NASA has been developing a radio-frequency-identification autonomous logistics management system to reduce crew time for general inventory and enable greater crew self-response to unplanned events when a wide range of items may need to be located in a very short time period. This paper provides a status of the technologies being developed and their mission benefits for exploration missions.

  11. Comparison of logistic equations for population growth.

    PubMed

    Jensen, A L

    1975-12-01

    Two different forms of the logistic equation for population growth appear in the ecological literature. In the form of the logistic equation that appears in recent ecology textbooks the parameters are the instantaneous rate of natural increase per individual and the carrying capacity of the environment. In the form of the logistic equation that appears in some older literature the parameters are the instantaneous birth rate per individual and the carrying capacity. The decision whether to use one form or the other depends on which form of the equation is biologically more realistic. In this study the form of the logistic equation in which the instantaneous birth rate per individual is a parameter is shown to be more realistic in terms of the birth and death processes of population growth. Application of the logistic equation to calculate yield from an exploited fish population also shows that the parameters must be the instantaneous birth rate per individual and the carrying capacity. PMID:1203427

  12. Role of Protein Kinase C, PI3-kinase and Tyrosine Kinase in Activation of MAP Kinase by Glucose and Agonists of G-protein Coupled Receptors in INS-1 Cells

    PubMed Central

    Böcker, Dietmar

    2001-01-01

    MAP (mitogen-activated protein) kinase (also called Erk 1/2) plays a crucial role in cell proliferation and differentiation. Its impact on secretory events is less well established. The interplay of protein kinase C (PKC), PI3-kinase nd cellular tyrosine kinase with MAP kinase activity using inhibitors and compounds such as glucose, phorbol 12-myristate 13-acetate (PMA) and agonists of G-protein coupled receptors like gastrin releasing peptide (GRP), oxytocin (OT) and glucose-dependent insulinotropic peptide (GIP) was investigated in INS-1 cells, an insulin secreting cell line. MAP kinase activity was determined by using a peptide derived from the EGF receptor as a MAP kinase substrate and [ P 32 ]ATP. Glucose as well as GRP, OT and GIP exhibited a time-dependent increase in MAP kinase activity with a maximum at time point 2.5 min. All further experiments were performed using 2.5 min incubations. The flavone PD 098059 is known to bind to the inactive forms of MEK1 (MAPK/ERK-Kinase) thus preventing activation by upstream activators. 20 μM PD 098059 ( IC 50 =51 μM) inhibited MAP kinase stimulated by either glucose, GRP, OT, GIP or PMA. Inhibiton (“downregulation”) of PKC by a long term (22h) pretreatment with 1 μM PMA did not influence MAP kinase activity when augmented by either of the above mentioned compound. To investigate whether PI3-kinase and cellular tyrosine kinase are involved in G-protein mediated effects on MAP kinase, inhibitors were used: 100 nM wortmannin (PI3-kinase inhibitor) reduced the effects of GRP, OT and GIP but not that of PMA; 100 μM genistein (tyrosine kinase inhibitor) inhibited the stimulatory effect of either above mentioned compound on MAP kinase activation. Inhibition of MAP kinase by 20 μM PD 098059 did not influence insulin secretion modulated by either compound (glucose, GRP, OT or GIP). [ H 3 ]Thymidine incorporation, however, was severely inhibited by PD 098059. Thus MAP kinase is important for INS-1 cell proliferation but

  13. Lunar Surface Architecture Utilization and Logistics Support Assessment

    NASA Astrophysics Data System (ADS)

    Bienhoff, Dallas; Findiesen, William; Bayer, Martin; Born, Andrew; McCormick, David

    2008-01-01

    Crew and equipment utilization and logistics support needs for the point of departure lunar outpost as presented by the NASA Lunar Architecture Team (LAT) and alternative surface architectures were assessed for the first ten years of operation. The lunar surface architectures were evaluated and manifests created for each mission. Distances between Lunar Surface Access Module (LSAM) landing sites and emplacement locations were estimated. Physical characteristics were assigned to each surface element and operational characteristics were assigned to each surface mobility element. Stochastic analysis was conducted to assess probable times to deploy surface elements, conduct exploration excursions, and perform defined crew activities. Crew time is divided into Outpost-related, exploration and science, overhead, and personal activities. Outpost-related time includes element deployment, EVA maintenance, IVA maintenance, and logistics resupply. Exploration and science activities include mapping, geological surveys, science experiment deployment, sample analysis and categorizing, and physiological and biological tests in the lunar environment. Personal activities include sleeping, eating, hygiene, exercising, and time off. Overhead activities include precursor or close-out tasks that must be accomplished but don't fit into the other three categories such as: suit donning and doffing, airlock cycle time, suit cleaning, suit maintenance, post-landing safing actions, and pre-departure preparations. Equipment usage time, spares, maintenance actions, and Outpost consumables are also estimated to provide input into logistics support planning. Results are normalized relative to the NASA LAT point of departure lunar surface architecture.

  14. Exploration Mission Benefits From Logistics Reduction Technologies

    NASA Technical Reports Server (NTRS)

    Broyan, James Lee, Jr.; Schlesinger, Thilini; Ewert, Michael K.

    2016-01-01

    Technologies that reduce logistical mass, volume, and the crew time dedicated to logistics management become more important as exploration missions extend further from the Earth. Even modest reductions in logical mass can have a significant impact because it also reduces the packing burden. NASA's Advanced Exploration Systems' Logistics Reduction Project is developing technologies that can directly reduce the mass and volume of crew clothing and metabolic waste collection. Also, cargo bags have been developed that can be reconfigured for crew outfitting and trash processing technologies to increase habitable volume and improve protection against solar storm events are under development. Additionally, Mars class missions are sufficiently distant that even logistics management without resupply can be problematic due to the communication time delay with Earth. Although exploration vehicles are launched with all consumables and logistics in a defined configuration, the configuration continually changes as the mission progresses. Traditionally significant ground and crew time has been required to understand the evolving configuration and locate misplaced items. For key mission events and unplanned contingencies, the crew will not be able to rely on the ground for logistics localization assistance. NASA has been developing a radio frequency identification autonomous logistics management system to reduce crew time for general inventory and enable greater crew self-response to unplanned events when a wide range of items may need to be located in a very short time period. This paper provides a status of the technologies being developed and there mission benefits for exploration missions.

  15. Logistics Modeling for Lunar Exploration Systems

    NASA Technical Reports Server (NTRS)

    Andraschko, Mark R.; Merrill, R. Gabe; Earle, Kevin D.

    2008-01-01

    The extensive logistics required to support extended crewed operations in space make effective modeling of logistics requirements and deployment critical to predicting the behavior of human lunar exploration systems. This paper discusses the software that has been developed as part of the Campaign Manifest Analysis Tool in support of strategic analysis activities under the Constellation Architecture Team - Lunar. The described logistics module enables definition of logistics requirements across multiple surface locations and allows for the transfer of logistics between those locations. A key feature of the module is the loading algorithm that is used to efficiently load logistics by type into carriers and then onto landers. Attention is given to the capabilities and limitations of this loading algorithm, particularly with regard to surface transfers. These capabilities are described within the context of the object-oriented software implementation, with details provided on the applicability of using this approach to model other human exploration scenarios. Some challenges of incorporating probabilistics into this type of logistics analysis model are discussed at a high level.

  16. ISS Logistics Hardware Disposition and Metrics Validation

    NASA Technical Reports Server (NTRS)

    Rogers, Toneka R.

    2010-01-01

    I was assigned to the Logistics Division of the International Space Station (ISS)/Spacecraft Processing Directorate. The Division consists of eight NASA engineers and specialists that oversee the logistics portion of the Checkout, Assembly, and Payload Processing Services (CAPPS) contract. Boeing, their sub-contractors and the Boeing Prime contract out of Johnson Space Center, provide the Integrated Logistics Support for the ISS activities at Kennedy Space Center. Essentially they ensure that spares are available to support flight hardware processing and the associated ground support equipment (GSE). Boeing maintains a Depot for electrical, mechanical and structural modifications and/or repair capability as required. My assigned task was to learn project management techniques utilized by NASA and its' contractors to provide an efficient and effective logistics support infrastructure to the ISS program. Within the Space Station Processing Facility (SSPF) I was exposed to Logistics support components, such as, the NASA Spacecraft Services Depot (NSSD) capabilities, Mission Processing tools, techniques and Warehouse support issues, required for integrating Space Station elements at the Kennedy Space Center. I also supported the identification of near-term ISS Hardware and Ground Support Equipment (GSE) candidates for excessing/disposition prior to October 2010; and the validation of several Logistics Metrics used by the contractor to measure logistics support effectiveness.

  17. Pattern formation, logistics, and maximum path probability

    NASA Astrophysics Data System (ADS)

    Kirkaldy, J. S.

    1985-05-01

    The concept of pattern formation, which to current researchers is a synonym for self-organization, carries the connotation of deductive logic together with the process of spontaneous inference. Defining a pattern as an equivalence relation on a set of thermodynamic objects, we establish that a large class of irreversible pattern-forming systems, evolving along idealized quasisteady paths, approaches the stable steady state as a mapping upon the formal deductive imperatives of a propositional function calculus. In the preamble the classical reversible thermodynamics of composite systems is analyzed as an externally manipulated system of space partitioning and classification based on ideal enclosures and diaphragms. The diaphragms have discrete classification capabilities which are designated in relation to conserved quantities by descriptors such as impervious, diathermal, and adiabatic. Differentiability in the continuum thermodynamic calculus is invoked as equivalent to analyticity and consistency in the underlying class or sentential calculus. The seat of inference, however, rests with the thermodynamicist. In the transition to an irreversible pattern-forming system the defined nature of the composite reservoirs remains, but a given diaphragm is replaced by a pattern-forming system which by its nature is a spontaneously evolving volume partitioner and classifier of invariants. The seat of volition or inference for the classification system is thus transferred from the experimenter or theoretician to the diaphragm, and with it the full deductive facility. The equivalence relations or partitions associated with the emerging patterns may thus be associated with theorems of the natural pattern-forming calculus. The entropy function, together with its derivatives, is the vehicle which relates the logistics of reservoirs and diaphragms to the analog logistics of the continuum. Maximum path probability or second-order differentiability of the entropy in isolation are

  18. Front-End Analysis Cornerstone of Logistics

    NASA Technical Reports Server (NTRS)

    Nager, Paul J.

    2000-01-01

    The presentation provides an overview of Front-End Logistics Support Analysis (FELSA), when it should be performed, benefits of performing FELSA and why it should be performed, how it is conducted, and examples.

  19. Satellite rainfall retrieval by logistic regression

    NASA Technical Reports Server (NTRS)

    Chiu, Long S.

    1986-01-01

    The potential use of logistic regression in rainfall estimation from satellite measurements is investigated. Satellite measurements provide covariate information in terms of radiances from different remote sensors.The logistic regression technique can effectively accommodate many covariates and test their significance in the estimation. The outcome from the logistical model is the probability that the rainrate of a satellite pixel is above a certain threshold. By varying the thresholds, a rainrate histogram can be obtained, from which the mean and the variant can be estimated. A logistical model is developed and applied to rainfall data collected during GATE, using as covariates the fractional rain area and a radiance measurement which is deduced from a microwave temperature-rainrate relation. It is demonstrated that the fractional rain area is an important covariate in the model, consistent with the use of the so-called Area Time Integral in estimating total rain volume in other studies. To calibrate the logistical model, simulated rain fields generated by rainfield models with prescribed parameters are needed. A stringent test of the logistical model is its ability to recover the prescribed parameters of simulated rain fields. A rain field simulation model which preserves the fractional rain area and lognormality of rainrates as found in GATE is developed. A stochastic regression model of branching and immigration whose solutions are lognormally distributed in some asymptotic limits has also been developed.

  20. Logistics Reduction Technologies for Exploration Missions

    NASA Technical Reports Server (NTRS)

    Broyan, James L., Jr.; Ewert, Michael K.; Fink, Patrick W.

    2014-01-01

    Human exploration missions under study are very limited by the launch mass capacity of existing and planned vehicles. The logistical mass of crew items is typically considered separate from the vehicle structure, habitat outfitting, and life support systems. Consequently, crew item logistical mass is typically competing with vehicle systems for mass allocation. NASA's Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) Project is developing five logistics technologies guided by a systems engineering cradle-to-grave approach to enable used crew items to augment vehicle systems. Specifically, AES LRR is investigating the direct reduction of clothing mass, the repurposing of logistical packaging, the use of autonomous logistics management technologies, the processing of spent crew items to benefit radiation shielding and water recovery, and the conversion of trash to propulsion gases. The systematic implementation of these types of technologies will increase launch mass efficiency by enabling items to be used for secondary purposes and improve the habitability of the vehicle as the mission duration increases. This paper provides a description and the challenges of the five technologies under development and the estimated overall mission benefits of each technology.

  1. NASA Space Exploration Logistics Workshop Proceedings

    NASA Technical Reports Server (NTRS)

    deWeek, Oliver; Evans, William A.; Parrish, Joe; James, Sarah

    2006-01-01

    As NASA has embarked on a new Vision for Space Exploration, there is new energy and focus around the area of manned space exploration. These activities encompass the design of new vehicles such as the Crew Exploration Vehicle (CEV) and Crew Launch Vehicle (CLV) and the identification of commercial opportunities for space transportation services, as well as continued operations of the Space Shuttle and the International Space Station. Reaching the Moon and eventually Mars with a mix of both robotic and human explorers for short term missions is a formidable challenge in itself. How to achieve this in a safe, efficient and long-term sustainable way is yet another question. The challenge is not only one of vehicle design, launch, and operations but also one of space logistics. Oftentimes, logistical issues are not given enough consideration upfront, in relation to the large share of operating budgets they consume. In this context, a group of 54 experts in space logistics met for a two-day workshop to discuss the following key questions: 1. What is the current state-of the art in space logistics, in terms of architectures, concepts, technologies as well as enabling processes? 2. What are the main challenges for space logistics for future human exploration of the Moon and Mars, at the intersection of engineering and space operations? 3. What lessons can be drawn from past successes and failures in human space flight logistics? 4. What lessons and connections do we see from terrestrial analogies as well as activities in other areas, such as U.S. military logistics? 5. What key advances are required to enable long-term success in the context of a future interplanetary supply chain? These proceedings summarize the outcomes of the workshop, reference particular presentations, panels and breakout sessions, and record specific observations that should help guide future efforts.

  2. ISS Update: Logistics Reduction and Repurposing (Part 2)

    NASA Video Gallery

    Public Affairs Officer Brandi Dean interviews Sarah Shull, Deputy Project Manager Logistics Reduction and Repurposing. Shull, who is with the Advanced Exploration Systems, discusses the Logistics t...

  3. ISS Update: Logistics Reduction and Repurposing (Part 1)

    NASA Video Gallery

    Public Affairs Officer Brandi Dean interviews Sarah Shull, Deputy Project Manager Logistics Reduction and Repurposing. Shull, who is with the Advanced Exploration Systems, discusses the Logistics t...

  4. A numerical study of synchronization in the process of biochemical substance exchange in a diffusively coupled ring of cells

    NASA Astrophysics Data System (ADS)

    Mihailović, Dragutin T.; Balaž, Igor; Arsenić, Ilija

    2013-04-01

    In this paper we numerically investigate a model of a diffusively coupled ring of cells. To model the dynamics of individual cells we propose a map with cell affinity, which is a generalization of the logistic map. First, the basic features of a one-cell system are studied in terms of the Lyapunov exponent, Kolmogorov complexity and Sample Entropy. Second, the notion of observational heterarchy, which is a perpetual negotiation process between different levels of the description of a phenomenon, is reviewed. After these preliminaries, we study how the active coupling induced by the consideration of the observational heterarchy modifies the synchronization property of the model with N=100 cells. It is shown numerically that the active coupling enhances synchronization of biochemical substance exchange in several different conditions of cell affinity.

  5. Logistics Lessons Learned in NASA Space Flight

    NASA Technical Reports Server (NTRS)

    Evans, William A.; DeWeck, Olivier; Laufer, Deanna; Shull, Sarah

    2006-01-01

    The Vision for Space Exploration sets out a number of goals, involving both strategic and tactical objectives. These include returning the Space Shuttle to flight, completing the International Space Station, and conducting human expeditions to the Moon by 2020. Each of these goals has profound logistics implications. In the consideration of these objectives,a need for a study on NASA logistics lessons learned was recognized. The study endeavors to identify both needs for space exploration and challenges in the development of past logistics architectures, as well as in the design of space systems. This study may also be appropriately applied as guidance in the development of an integrated logistics architecture for future human missions to the Moon and Mars. This report first summarizes current logistics practices for the Space Shuttle Program (SSP) and the International Space Station (ISS) and examines the practices of manifesting, stowage, inventory tracking, waste disposal, and return logistics. The key findings of this examination are that while the current practices do have many positive aspects, there are also several shortcomings. These shortcomings include a high-level of excess complexity, redundancy of information/lack of a common database, and a large human-in-the-loop component. Later sections of this report describe the methodology and results of our work to systematically gather logistics lessons learned from past and current human spaceflight programs as well as validating these lessons through a survey of the opinions of current space logisticians. To consider the perspectives on logistics lessons, we searched several sources within NASA, including organizations with direct and indirect connections with the system flow in mission planning. We utilized crew debriefs, the John Commonsense lessons repository for the JSC Mission Operations Directorate, and the Skylab Lessons Learned. Additionally, we searched the public version of the Lessons Learned

  6. Reverse logistics in the construction industry.

    PubMed

    Hosseini, M Reza; Rameezdeen, Raufdeen; Chileshe, Nicholas; Lehmann, Steffen

    2015-06-01

    Reverse logistics in construction refers to the movement of products and materials from salvaged buildings to a new construction site. While there is a plethora of studies looking at various aspects of the reverse logistics chain, there is no systematic review of literature on this important subject as applied to the construction industry. Therefore, the objective of this study is to integrate the fragmented body of knowledge on reverse logistics in construction, with the aim of promoting the concept among industry stakeholders and the wider construction community. Through a qualitative meta-analysis, the study synthesises the findings of previous studies and presents some actions needed by industry stakeholders to promote this concept within the real-life context. First, the trend of research and terminology related with reverse logistics is introduced. Second, it unearths the main advantages and barriers of reverse logistics in construction while providing some suggestions to harness the advantages and mitigate these barriers. Finally, it provides a future research direction based on the review. PMID:26018543

  7. Humanitarian response: improving logistics to save lives.

    PubMed

    McCoy, Jessica

    2008-01-01

    Each year, millions of people worldwide are affected by disasters, underscoring the importance of effective relief efforts. Many highly visible disaster responses have been inefficient and ineffective. Humanitarian agencies typically play a key role in disaster response (eg, procuring and distributing relief items to an affected population, assisting with evacuation, providing healthcare, assisting in the development of long-term shelter), and thus their efficiency is critical for a successful disaster response. The field of disaster and emergency response modeling is well established, but the application of such techniques to humanitarian logistics is relatively recent. This article surveys models of humanitarian response logistics and identifies promising opportunities for future work. Existing models analyze a variety of preparation and response decisions (eg, warehouse location and the distribution of relief supplies), consider both natural and manmade disasters, and typically seek to minimize cost or unmet demand. Opportunities to enhance the logistics of humanitarian response include the adaptation of models developed for general disaster response; the use of existing models, techniques, and insights from the literature on commercial supply chain management; the development of working partnerships between humanitarian aid organizations and private companies with expertise in logistics; and the consideration of behavioral factors relevant to a response. Implementable, realistic models that support the logistics of humanitarian relief can improve the preparation for and the response to disasters, which in turn can save lives. PMID:19069032

  8. Using Cultural Algorithms to Improve Intelligent Logistics

    NASA Astrophysics Data System (ADS)

    Ochoa, Alberto; García, Yazmani; Yañez, Javier; Teymanoglu, Yaddik

    Today the issue of logistics is a very important within companies to the extent that some have departments devoted exclusively to it. This has evolved over time and today is a fundamental aspect in the fight business seeking to consolidate or remain leaders in their field. With the above we know that logistics can be divided into different classes, however, in this regard, our study is based on the timely distribution to the customer with a lower cost, higher sales and better utilization of space resulting in excellent service. Finally, prepare a comparative analysis of the results with respect to another method of optimization solution space.

  9. Asymptotic behavior of degenerate logistic equations

    NASA Astrophysics Data System (ADS)

    Arrieta, José M.; Pardo, Rosa; Rodríguez-Bernal, Aníbal

    2015-12-01

    We analyze the asymptotic behavior of positive solutions of parabolic equations with a class of degenerate logistic nonlinearities of the type λu - n (x)uρ. An important characteristic of this work is that the region where the logistic term n (ṡ) vanishes, that is K0 = { x : n (x) = 0 }, may be non-smooth. We analyze conditions on λ, ρ, n (ṡ) and K0 guaranteeing that the solution starting at a positive initial condition remains bounded or blows up as time goes to infinity. The asymptotic behavior may not be the same in different parts of K0.

  10. Applying waste logistics modeling to regional planning

    SciTech Connect

    Holter, G.M.; Khawaja, A.; Shaver, S.R.; Peterson, K.L.

    1995-05-01

    Waste logistics modeling is a powerful analytical technique that can be used for effective planning of future solid waste storage, treatment, and disposal activities. Proper waste management is essential for preventing unacceptable environmental degradation from ongoing operations, and is also a critical part of any environmental remediation activity. Logistics modeling allows for analysis of alternate scenarios for future waste flowrates and routings, facility schedules, and processing or handling capacities. Such analyses provide an increased understanding of the critical needs for waste storage, treatment, transport, and disposal while there is still adequate lead time to plan accordingly. They also provide a basis for determining the sensitivity of these critical needs to the various system parameters. This paper discusses the application of waste logistics modeling concepts to regional planning. In addition to ongoing efforts to aid in planning for a large industrial complex, the Pacific Northwest Laboratory (PNL) is currently involved in implementing waste logistics modeling as part of the planning process for material recovery and recycling within a multi-city region in the western US.

  11. A Logistic Regression Model for Personnel Selection.

    ERIC Educational Resources Information Center

    Raju, Nambury S.; And Others

    1991-01-01

    A two-parameter logistic regression model for personnel selection is proposed. The model was tested with a database of 84,808 military enlistees. The probability of job success was related directly to trait levels, addressing such topics as selection, validity generalization, employee classification, selection bias, and utility-based fair…

  12. Biomass round bales infield aggregation logistic scenarios

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biomass bales often need to be aggregated (collected into groups and transported) to a field-edge stack for temporary storage for feedlots or processing facilities. Aggregating the bales with the least total distance involved is a goal of producers and bale handlers. Several logistics scenarios for ...

  13. Predicting Social Trust with Binary Logistic Regression

    ERIC Educational Resources Information Center

    Adwere-Boamah, Joseph; Hufstedler, Shirley

    2015-01-01

    This study used binary logistic regression to predict social trust with five demographic variables from a national sample of adult individuals who participated in The General Social Survey (GSS) in 2012. The five predictor variables were respondents' highest degree earned, race, sex, general happiness and the importance of personally assisting…

  14. Linear Logistic Test Modeling with R

    ERIC Educational Resources Information Center

    Baghaei, Purya; Kubinger, Klaus D.

    2015-01-01

    The present paper gives a general introduction to the linear logistic test model (Fischer, 1973), an extension of the Rasch model with linear constraints on item parameters, along with eRm (an R package to estimate different types of Rasch models; Mair, Hatzinger, & Mair, 2014) functions to estimate the model and interpret its parameters. The…

  15. LOGISTICS OF ECOLOGICAL SAMPLING ON LARGE RIVERS

    EPA Science Inventory

    The objectives of this document are to provide an overview of the logistical problems associated with the ecological sampling of boatable rivers and to suggest solutions to those problems. It is intended to be used as a resource for individuals preparing to collect biological dat...

  16. Mission Benefits Analysis of Logistics Reduction Technologies

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K.; Broyan, James L.

    2012-01-01

    Future space exploration missions will need to use less logistical supplies if humans are to live for longer periods away from our home planet. Anything that can be done to reduce initial mass and volume of supplies or reuse or recycle items that have been launched will be very valuable. Reuse and recycling also reduce the trash burden and associated nuisances, such as smell, but require good systems engineering and operations integration to reap the greatest benefits. A systems analysis was conducted to quantify the mass and volume savings of four different technologies currently under development by NASA fs Advanced Exploration Systems (AES) Logistics Reduction and Repurposing project. Advanced clothing systems lead to savings by direct mass reduction and increased wear duration. Reuse of logistical items, such as packaging, for a second purpose allows fewer items to be launched. A device known as a heat melt compactor drastically reduces the volume of trash, recovers water and produces a stable tile that can be used instead of launching additional radiation protection. The fourth technology, called trash ]to ]supply ]gas, can benefit a mission by supplying fuel such as methane to the propulsion system. This systems engineering work will help improve logistics planning and overall mission architectures by determining the most effective use, and reuse, of all resources.

  17. Mission Benefits Analysis of Logistics Reduction Technologies

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K.; Broyan, James Lee, Jr.

    2013-01-01

    Future space exploration missions will need to use less logistical supplies if humans are to live for longer periods away from our home planet. Anything that can be done to reduce initial mass and volume of supplies or reuse or recycle items that have been launched will be very valuable. Reuse and recycling also reduce the trash burden and associated nuisances, such as smell, but require good systems engineering and operations integration to reap the greatest benefits. A systems analysis was conducted to quantify the mass and volume savings of four different technologies currently under development by NASA s Advanced Exploration Systems (AES) Logistics Reduction and Repurposing project. Advanced clothing systems lead to savings by direct mass reduction and increased wear duration. Reuse of logistical items, such as packaging, for a second purpose allows fewer items to be launched. A device known as a heat melt compactor drastically reduces the volume of trash, recovers water and produces a stable tile that can be used instead of launching additional radiation protection. The fourth technology, called trash-to-gas, can benefit a mission by supplying fuel such as methane to the propulsion system. This systems engineering work will help improve logistics planning and overall mission architectures by determining the most effective use, and reuse, of all resources.

  18. Comparison of multinomial logistic regression and logistic regression: which is more efficient in allocating land use?

    NASA Astrophysics Data System (ADS)

    Lin, Yingzhi; Deng, Xiangzheng; Li, Xing; Ma, Enjun

    2014-12-01

    Spatially explicit simulation of land use change is the basis for estimating the effects of land use and cover change on energy fluxes, ecology and the environment. At the pixel level, logistic regression is one of the most common approaches used in spatially explicit land use allocation models to determine the relationship between land use and its causal factors in driving land use change, and thereby to evaluate land use suitability. However, these models have a drawback in that they do not determine/allocate land use based on the direct relationship between land use change and its driving factors. Consequently, a multinomial logistic regression method was introduced to address this flaw, and thereby, judge the suitability of a type of land use in any given pixel in a case study area of the Jiangxi Province, China. A comparison of the two regression methods indicated that the proportion of correctly allocated pixels using multinomial logistic regression was 92.98%, which was 8.47% higher than that obtained using logistic regression. Paired t-test results also showed that pixels were more clearly distinguished by multinomial logistic regression than by logistic regression. In conclusion, multinomial logistic regression is a more efficient and accurate method for the spatial allocation of land use changes. The application of this method in future land use change studies may improve the accuracy of predicting the effects of land use and cover change on energy fluxes, ecology, and environment.

  19. Incorporating maps of leaf chlorophyll in a thermal-based two-source energy balance scheme for mapping coupled fluxes of carbon and water exchange at a range of scales

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A light-use efficiency (LUE) based model of canopy resistance was recently implemented within a thermal-based Two-Source Energy Balance (TSEB) scheme facilitating coupled simulations of land-surface fluxes of water, energy and CO2 exchange from field to regional scales (Anderson et al., 2008). The L...

  20. Computer Aided Instruction in Teaching Thematic Mapping.

    ERIC Educational Resources Information Center

    Baumann, Paul R.

    A newly developed instructional system for introductory college geography links the computer with the geographer's most traditional and essential tool--the thematic map. The use of the computer overcomes the logistical and mechanical problems associated with the teaching of thematic mapping to large groups and helps the students to focus upon the…

  1. Integrated tracking of components by engineering and logistics utilizing logistics asset tracking system

    NASA Technical Reports Server (NTRS)

    Renfroe, Michael B.; Mcdonald, Edward J.; Bradshaw, Kimberly

    1988-01-01

    The Logistics Asset Tracking System (LATS) devised by NASA contains data on Space Shuttle LRUs that are daily updated to reflect such LRU status changes as repair due to failure or modification due to changing engineering requirements. The implementation of LATS has substantially increased personnel responsiveness, preventing costly delays in Space Shuttle processing and obviating hardware cannibalization. An evaluation is presented of LATS achievements in the direction of an integrated logistical support posture.

  2. Imbalanced Learning Based on Logistic Discrimination

    PubMed Central

    Guo, Huaping; Zhi, Weimei; Liu, Hongbing; Xu, Mingliang

    2016-01-01

    In recent years, imbalanced learning problem has attracted more and more attentions from both academia and industry, and the problem is concerned with the performance of learning algorithms in the presence of data with severe class distribution skews. In this paper, we apply the well-known statistical model logistic discrimination to this problem and propose a novel method to improve its performance. To fully consider the class imbalance, we design a new cost function which takes into account the accuracies of both positive class and negative class as well as the precision of positive class. Unlike traditional logistic discrimination, the proposed method learns its parameters by maximizing the proposed cost function. Experimental results show that, compared with other state-of-the-art methods, the proposed one shows significantly better performance on measures of recall, g-mean, f-measure, AUC, and accuracy. PMID:26880877

  3. Technological Support for Logistics Transportation Systems

    NASA Astrophysics Data System (ADS)

    Bujak, Andrzej; Śliwa, Zdzisław; Gębczyńska, Alicja

    The modern world is changing introducing robots, remotely controlled vehicles and other crewless means of transportation to reduce people's mistakes, as the main cause of incidents and crashes during traffic. New technologies are supporting operators and drivers, and according to some studies they can even replace them. Such programs as: AHS, UAH, IVBSS or MTVR are under development to improve traffic flow and its safety, to reduce traffic hazards and crashes. It is necessary to analyze such concepts and implement them boldly, including Polish logistics' companies, new programs, highways' system etc., as they will be applied in the future, so it is necessary to prepare logistics infrastructure ahead of time in order to capitalize on these improvements. The problem is quite urgent as transportation in the country must not be outdated to meet clients' expectations and to keep pace with competing foreign companies.

  4. Exact solution to fractional logistic equation

    NASA Astrophysics Data System (ADS)

    West, Bruce J.

    2015-07-01

    The logistic equation is one of the most familiar nonlinear differential equations in the biological and social sciences. Herein we provide an exact solution to an extension of this equation to incorporate memory through the use of fractional derivatives in time. The solution to the fractional logistic equation (FLE) is obtained using the Carleman embedding technique that allows the nonlinear equation to be replaced by an infinite-order set of linear equations, which we then solve exactly. The formal series expansion for the initial value solution of the FLE is shown to be expressed in terms of a series of weighted Mittag-Leffler functions that reduces to the well known analytic solution in the limit where the fractional index for the derivative approaches unity. The numerical integration to the FLE provides an excellent fit to the analytic solution. We propose this approach as a general technique for solving a class of nonlinear fractional differential equations.

  5. Model selection for logistic regression models

    NASA Astrophysics Data System (ADS)

    Duller, Christine

    2012-09-01

    Model selection for logistic regression models decides which of some given potential regressors have an effect and hence should be included in the final model. The second interesting question is whether a certain factor is heterogeneous among some subsets, i.e. whether the model should include a random intercept or not. In this paper these questions will be answered with classical as well as with Bayesian methods. The application show some results of recent research projects in medicine and business administration.

  6. Moment closure and the stochastic logistic model.

    PubMed

    Nåsell, Ingemar

    2003-03-01

    The quasi-stationary distribution of the stochastic logistic model is studied in the parameter region where its body is approximately normal. Improved asymptotic approximations of its first three cumulants are derived. It is shown that the same results can be derived with the aid of the moment closure method. This indicates that the moment closure method leads to expressions for the cumulants that are asymptotic approximations of the cumulants of the quasi-stationary distribution. PMID:12615498

  7. Is dispersal always beneficial to carrying capacity? New insights from the multi-patch logistic equation.

    PubMed

    Arditi, Roger; Lobry, Claude; Sari, Tewfik

    2015-12-01

    The standard model for the dynamics of a fragmented density-dependent population is built from several local logistic models coupled by migrations. First introduced in the 1970s and used in innumerable articles, this standard model applied to a two-patch situation has never been completely analysed. Here, we complete this analysis and we delineate the conditions under which fragmentation associated to dispersal is either beneficial or detrimental to total population abundance. Therefore, this is a contribution to the SLOSS question. Importantly, we also show that, depending on the underlying mechanism, there is no unique way to generalize the logistic model to a patchy situation. In many cases, the standard model is not the correct generalization. We analyse several alternative models and compare their predictions. Finally, we emphasize the shortcomings of the logistic model when written in the r-K parameterization and we explain why Verhulst's original polynomial expression is to be preferred. PMID:26472064

  8. Transfer Learning Based on Logistic Regression

    NASA Astrophysics Data System (ADS)

    Paul, A.; Rottensteiner, F.; Heipke, C.

    2015-08-01

    In this paper we address the problem of classification of remote sensing images in the framework of transfer learning with a focus on domain adaptation. The main novel contribution is a method for transductive transfer learning in remote sensing on the basis of logistic regression. Logistic regression is a discriminative probabilistic classifier of low computational complexity, which can deal with multiclass problems. This research area deals with methods that solve problems in which labelled training data sets are assumed to be available only for a source domain, while classification is needed in the target domain with different, yet related characteristics. Classification takes place with a model of weight coefficients for hyperplanes which separate features in the transformed feature space. In term of logistic regression, our domain adaptation method adjusts the model parameters by iterative labelling of the target test data set. These labelled data features are iteratively added to the current training set which, at the beginning, only contains source features and, simultaneously, a number of source features are deleted from the current training set. Experimental results based on a test series with synthetic and real data constitutes a first proof-of-concept of the proposed method.

  9. Genetically encoded photo-cross-linkers map the binding site of an allosteric drug on a G protein-coupled receptor.

    PubMed

    Grunbeck, Amy; Huber, Thomas; Abrol, Ravinder; Trzaskowski, Bartosz; Goddard, William A; Sakmar, Thomas P

    2012-06-15

    G protein-coupled receptors (GPCRs) are dynamic membrane proteins that bind extracellular molecules to transduce signals. Although GPCRs represent the largest class of therapeutic targets, only a small percentage of their ligand-binding sites are precisely defined. Here we describe the novel application of targeted photo-cross-linking using unnatural amino acids to obtain structural information about the allosteric binding site of a small molecule drug, the CCR5-targeted HIV-1 co-receptor blocker maraviroc. PMID:22455376

  10. Space Station - An integrated approach to operational logistics support

    NASA Technical Reports Server (NTRS)

    Hosmer, G. J.

    1986-01-01

    Development of an efficient and cost effective operational logistics system for the Space Station will require logistics planning early in the program's design and development phase. This paper will focus on Integrated Logistics Support (ILS) Program techniques and their application to the Space Station program design, production and deployment phases to assure the development of an effective and cost efficient operational logistics system. The paper will provide the methodology and time-phased programmatic steps required to establish a Space Station ILS Program that will provide an operational logistics system based on planned Space Station program logistics support.

  11. Micro-Logistics Analysis for Human Space Exploration

    NASA Technical Reports Server (NTRS)

    Cirillo, William; Stromgren, Chel; Galan, Ricardo

    2008-01-01

    Traditionally, logistics analysis for space missions has focused on the delivery of elements and goods to a destination. This type of logistics analysis can be referred to as "macro-logistics". While the delivery of goods is a critical component of mission analysis, it captures only a portion of the constraints that logistics planning may impose on a mission scenario. The other component of logistics analysis concerns the local handling of goods at the destination, including storage, usage, and disposal. This type of logistics analysis, referred to as "micro-logistics", may also be a primary driver in the viability of a human lunar exploration scenario. With the rigorous constraints that will be placed upon a human lunar outpost, it is necessary to accurately evaluate micro-logistics operations in order to develop exploration scenarios that will result in an acceptable level of system performance.

  12. The Application used RFID in Third Party Logistics*

    NASA Astrophysics Data System (ADS)

    Mingxiu, Zheng; Chunchang, Fu; Minggen, Yang

    RFID is a non-contact automatic identification technology, which will be the future information storage extraction and processing technology. In recent years the mainstream of the large-scale development has manifested the situation. RFID is the key technology of tripartite logistics information and automation. RFID-based logistics system can enlarge the logistics operation capacity, and improve labor productivity to reduce logistics operations mistakes.

  13. Research and design of logistical information system based on SOA

    NASA Astrophysics Data System (ADS)

    Zhang, Bo

    2013-03-01

    Through the study on the existing logistics information systems and SOA technology, based on the current situation of enterprise logistics management and business features, this paper puts forward a SOA-based logistics system design program. This program is made in the WCF framework, with the combination of SOA and the actual characteristics of logistics enterprises, is simple to realize, easy to operate, and has strong expansion characteristic, therefore has high practical value.

  14. 77 FR 46653 - Defense Logistics Agency Privacy Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-06

    ... of the Secretary 32 CFR Part 323 RIN 0790-AI86 Defense Logistics Agency Privacy Program AGENCY: Defense Logistics Agency, DoD. ACTION: Proposed rule with request for comments. SUMMARY: The Defense Logistics Agency (DLA) is proposing to amend the DLA Privacy Program Regulation. The DLA Privacy...

  15. Using Dominance Analysis to Determine Predictor Importance in Logistic Regression

    ERIC Educational Resources Information Center

    Azen, Razia; Traxel, Nicole

    2009-01-01

    This article proposes an extension of dominance analysis that allows researchers to determine the relative importance of predictors in logistic regression models. Criteria for choosing logistic regression R[superscript 2] analogues were determined and measures were selected that can be used to perform dominance analysis in logistic regression. A…

  16. Metadata for ReVA logistic regression dataset

    USGS Publications Warehouse

    LaMotte, Andrew E.

    2004-01-01

    The U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency's Regional Vulnerability Assessment Program, has developed a set of statistical tools to support regional-scale, ground-water quality and vulnerability assessments. The Regional Vulnerability Assessment Program goals are to develop and demonstrate approaches to comprehensive, regional-scale assessments that effectively inform water-resources managers and decision-makers as to the magnitude, extent, distribution, and uncertainty of current and anticipated environmental risks. The U.S. Geological Survey is developing and exploring the use of statistical probability models to characterize the relation between ground-water quality and geographic factors in the Mid-Atlantic Region. Available water-quality data obtained from U.S. Geological Survey National Water-Quality Assessment Program studies conducted in the Mid-Atlantic Region were used in association with geographic data (land cover, geology, soils, and others) to develop logistic-regression equations that use explanatory variables to predict the presence of a selected water-quality parameter exceeding specified management concentration thresholds. The resulting logistic-regression equations were transformed to determine the probability, P(X), of a water-quality parameter exceeding a specified management threshold. Additional statistical procedures modified by the U.S. Geological Survey were used to compare the observed values to model-predicted values at each sample point. In addition, procedures to evaluate the confidence of the model predictions and estimate the uncertainty of the probability value were developed and applied. The resulting logistic-regression models were applied to the Mid-Atlantic Region to predict the spatial probability of nitrate concentrations exceeding specified management thresholds. These thresholds are usually set or established by regulators or managers at national or local levels. At management

  17. Mapping Antiretroviral Drugs in Tissue by IR-MALDESI MSI Coupled to the Q Exactive and Comparison with LC-MS/MS SRM Assay

    NASA Astrophysics Data System (ADS)

    Barry, Jeremy A.; Robichaud, Guillaume; Bokhart, Mark T.; Thompson, Corbin; Sykes, Craig; Kashuba, Angela D. M.; Muddiman, David C.

    2014-12-01

    This work describes the coupling of the IR-MALDESI imaging source with the Q Exactive mass spectrometer. IR-MALDESI MSI was used to elucidate the spatial distribution of several HIV drugs in cervical tissues that had been incubated in either a low or high concentration. Serial sections of those analyzed by IR-MALDESI MSI were homogenized and analyzed by LC-MS/MS to quantify the amount of each drug present in the tissue. By comparing the two techniques, an agreement between the average intensities from the imaging experiment and the absolute quantities for each drug was observed. This correlation between these two techniques serves as a prerequisite to quantitative IR-MALDESI MSI. In addition, a targeted MS2 imaging experiment was also conducted to demonstrate the capabilities of the Q Exactive and to highlight the added selectivity that can be obtained with SRM or MRM imaging experiments.

  18. Mapping antiretroviral drugs in tissue by IR-MALDESI MSI coupled to the Q Exactive and comparison with LC-MS/MS SRM Assay

    PubMed Central

    Barry, Jeremy A.; Robichaud, Guillaume; Bokhart, Mark T.; Thompson, Corbin; Sykes, Craig; Kashuba, Angela D.M.; Muddiman, David C.

    2014-01-01

    This work describes the coupling of the IR-MALDESI imaging source with the Q Exactive mass spectrometer. IR-MALDESI MSI was used to elucidate the spatial distribution of several HIV drugs in cervical tissues that had been incubated in either a low or high concentration. Serial sections to those analyzed by IR-MALDESI MSI were homogenized and analyzed by LC-MS/MS to quantify the amount of each drug present in the tissue. By comparing the two techniques, an agreement between the average intensities from the imaging experiment with the absolute quantities for each drug was observed. This correlation between these two techniques serves as a prerequisite to quantitative IR-MALDESI MSI. In addition, a targeted MS2 imaging experiment was also conducted to demonstrate the capabilities of the Q Exactive and to highlight the added selectivity that can be obtained with SRM or MRM imaging experiments. PMID:24744212

  19. Remote sensing and GIS-based landslide hazard analysis and cross-validation using multivariate logistic regression model on three test areas in Malaysia

    NASA Astrophysics Data System (ADS)

    Pradhan, Biswajeet

    2010-05-01

    This paper presents the results of the cross-validation of a multivariate logistic regression model using remote sensing data and GIS for landslide hazard analysis on the Penang, Cameron, and Selangor areas in Malaysia. Landslide locations in the study areas were identified by interpreting aerial photographs and satellite images, supported by field surveys. SPOT 5 and Landsat TM satellite imagery were used to map landcover and vegetation index, respectively. Maps of topography, soil type, lineaments and land cover were constructed from the spatial datasets. Ten factors which influence landslide occurrence, i.e., slope, aspect, curvature, distance from drainage, lithology, distance from lineaments, soil type, landcover, rainfall precipitation, and normalized difference vegetation index (ndvi), were extracted from the spatial database and the logistic regression coefficient of each factor was computed. Then the landslide hazard was analysed using the multivariate logistic regression coefficients derived not only from the data for the respective area but also using the logistic regression coefficients calculated from each of the other two areas (nine hazard maps in all) as a cross-validation of the model. For verification of the model, the results of the analyses were then compared with the field-verified landslide locations. Among the three cases of the application of logistic regression coefficient in the same study area, the case of Selangor based on the Selangor logistic regression coefficients showed the highest accuracy (94%), where as Penang based on the Penang coefficients showed the lowest accuracy (86%). Similarly, among the six cases from the cross application of logistic regression coefficient in other two areas, the case of Selangor based on logistic coefficient of Cameron showed highest (90%) prediction accuracy where as the case of Penang based on the Selangor logistic regression coefficients showed the lowest accuracy (79%). Qualitatively, the cross

  20. Supporting Regularized Logistic Regression Privately and Efficiently.

    PubMed

    Li, Wenfa; Liu, Hongzhe; Yang, Peng; Xie, Wei

    2016-01-01

    As one of the most popular statistical and machine learning models, logistic regression with regularization has found wide adoption in biomedicine, social sciences, information technology, and so on. These domains often involve data of human subjects that are contingent upon strict privacy regulations. Concerns over data privacy make it increasingly difficult to coordinate and conduct large-scale collaborative studies, which typically rely on cross-institution data sharing and joint analysis. Our work here focuses on safeguarding regularized logistic regression, a widely-used statistical model while at the same time has not been investigated from a data security and privacy perspective. We consider a common use scenario of multi-institution collaborative studies, such as in the form of research consortia or networks as widely seen in genetics, epidemiology, social sciences, etc. To make our privacy-enhancing solution practical, we demonstrate a non-conventional and computationally efficient method leveraging distributing computing and strong cryptography to provide comprehensive protection over individual-level and summary data. Extensive empirical evaluations on several studies validate the privacy guarantee, efficiency and scalability of our proposal. We also discuss the practical implications of our solution for large-scale studies and applications from various disciplines, including genetic and biomedical studies, smart grid, network analysis, etc. PMID:27271738

  1. Reducing food losses by intelligent food logistics

    PubMed Central

    Jedermann, Reiner; Nicometo, Mike; Uysal, Ismail; Lang, Walter

    2014-01-01

    The need to feed an ever-increasing world population makes it obligatory to reduce the millions of tons of avoidable perishable waste along the food supply chain. A considerable share of these losses is caused by non-optimal cold chain processes and management. This Theme Issue focuses on technologies, models and applications to monitor changes in the product shelf life, defined as the time remaining until the quality of a food product drops below an acceptance limit, and to plan successive chain processes and logistics accordingly to uncover and prevent invisible or latent losses in product quality, especially following the first-expired-first-out strategy for optimized matching between the remaining shelf life and the expected transport duration. This introductory article summarizes the key findings of this Theme Issue, which brings together research study results from around the world to promote intelligent food logistics. The articles include three case studies on the cold chain for berries, bananas and meat and an overview of different post-harvest treatments. Further contributions focus on the required technical solutions, such as the wireless sensor and communication system for remote quality supervision, gas sensors to detect ethylene as an indicator of unwanted ripening and volatile components to indicate mould infections. The final section of this introduction discusses how improvements in food quality can be targeted by strategic changes in the food chain. PMID:24797131

  2. Reducing food losses by intelligent food logistics.

    PubMed

    Jedermann, Reiner; Nicometo, Mike; Uysal, Ismail; Lang, Walter

    2014-06-13

    The need to feed an ever-increasing world population makes it obligatory to reduce the millions of tons of avoidable perishable waste along the food supply chain. A considerable share of these losses is caused by non-optimal cold chain processes and management. This Theme Issue focuses on technologies, models and applications to monitor changes in the product shelf life, defined as the time remaining until the quality of a food product drops below an acceptance limit, and to plan successive chain processes and logistics accordingly to uncover and prevent invisible or latent losses in product quality, especially following the first-expired-first-out strategy for optimized matching between the remaining shelf life and the expected transport duration. This introductory article summarizes the key findings of this Theme Issue, which brings together research study results from around the world to promote intelligent food logistics. The articles include three case studies on the cold chain for berries, bananas and meat and an overview of different post-harvest treatments. Further contributions focus on the required technical solutions, such as the wireless sensor and communication system for remote quality supervision, gas sensors to detect ethylene as an indicator of unwanted ripening and volatile components to indicate mould infections. The final section of this introduction discusses how improvements in food quality can be targeted by strategic changes in the food chain. PMID:24797131

  3. Supporting Regularized Logistic Regression Privately and Efficiently

    PubMed Central

    Li, Wenfa; Liu, Hongzhe; Yang, Peng; Xie, Wei

    2016-01-01

    As one of the most popular statistical and machine learning models, logistic regression with regularization has found wide adoption in biomedicine, social sciences, information technology, and so on. These domains often involve data of human subjects that are contingent upon strict privacy regulations. Concerns over data privacy make it increasingly difficult to coordinate and conduct large-scale collaborative studies, which typically rely on cross-institution data sharing and joint analysis. Our work here focuses on safeguarding regularized logistic regression, a widely-used statistical model while at the same time has not been investigated from a data security and privacy perspective. We consider a common use scenario of multi-institution collaborative studies, such as in the form of research consortia or networks as widely seen in genetics, epidemiology, social sciences, etc. To make our privacy-enhancing solution practical, we demonstrate a non-conventional and computationally efficient method leveraging distributing computing and strong cryptography to provide comprehensive protection over individual-level and summary data. Extensive empirical evaluations on several studies validate the privacy guarantee, efficiency and scalability of our proposal. We also discuss the practical implications of our solution for large-scale studies and applications from various disciplines, including genetic and biomedical studies, smart grid, network analysis, etc. PMID:27271738

  4. Preliminary analysis of an integrated logistics system for OSSA payloads. Volume 2: OSSA integrated logistics support strategy

    NASA Technical Reports Server (NTRS)

    Palguta, T.; Bradley, W.; Stockton, T.

    1988-01-01

    The purpose is to outline an Office of Space Science and Applications (OSSA) integrated logistics support strategy that will ensure effective logistics support of OSSA payloads at an affordable life-cycle cost. Program objectives, organizational relationships, and implementation of the logistics strategy are discussed.

  5. Complex Logistics Strategy for Industrial Companies in Slovakia

    NASA Astrophysics Data System (ADS)

    Horňáková, Natália; Hudák, Ján; Vidová, Helena

    2014-12-01

    Presented paper is a part of the dissertation thesis titled as "A proposal to develop Complex Logistics Strategy for industrial companies. The result of the thesis will be a methodology for developing a Complex Logistics Strategy for industrial companies in Slovakia. The main aim of the paper is to present some trends and strategies in Logistics and clarify the need of resolving the issue of Logistics Strategy based on the theoretical knowledge, case studies and analysis of current state of Logistics Strategies in industrial companies in Slovakia and other European countries.

  6. Flexible use and technique extension of logistics management

    NASA Astrophysics Data System (ADS)

    Xiong, Furong

    2011-10-01

    As we all know, the origin of modern logistics was in the United States, developed in Japan, became mature in Europe, and expanded in China. This is a historical development of the modern logistics recognized track. Due to China's economic and technological development, and with the construction of Shanghai International Shipping Center and Shanghai Yangshan International Deepwater development, China's modern logistics industry will attain a leap-forward development of a strong pace, and will also catch up with developed countries in the Western modern logistics level. In this paper, the author explores the flexibility of China's modern logistics management techniques to extend the use, and has certain practical and guidance significances.

  7. Space Shuttle Orbiter logistics - Managing in a dynamic environment

    NASA Technical Reports Server (NTRS)

    Renfroe, Michael B.; Bradshaw, Kimberly

    1990-01-01

    The importance and methods of monitoring logistics vital signs, logistics data sources and acquisition, and converting data into useful management information are presented. With the launch and landing site for the Shuttle Orbiter project at the Kennedy Space Center now totally responsible for its own supportability posture, it is imperative that logistics resource requirements and management be continually monitored and reassessed. Detailed graphs and data concerning various aspects of logistics activities including objectives, inventory operating levels, customer environment, and data sources are provided. Finally, some lessons learned from the Shuttle Orbiter project and logistics options which should be considered by other space programs are discussed.

  8. Logistics of Guinea Worm Disease Eradication in South Sudan

    PubMed Central

    Jones, Alexander H.; Becknell, Steven; Withers, P. Craig; Ruiz-Tiben, Ernesto; Hopkins, Donald R.; Stobbelaar, David; Makoy, Samuel Yibi

    2014-01-01

    From 2006 to 2012, the South Sudan Guinea Worm Eradication Program reduced new Guinea worm disease (dracunculiasis) cases by over 90%, despite substantial programmatic challenges. Program logistics have played a key role in program achievements to date. The program uses disease surveillance and program performance data and integrated technical–logistical staffing to maintain flexible and effective logistical support for active community-based surveillance and intervention delivery in thousands of remote communities. Lessons learned from logistical design and management can resonate across similar complex surveillance and public health intervention delivery programs, such as mass drug administration for the control of neglected tropical diseases and other disease eradication programs. Logistical challenges in various public health scenarios and the pivotal contribution of logistics to Guinea worm case reductions in South Sudan underscore the need for additional inquiry into the role of logistics in public health programming in low-income countries. PMID:24445199

  9. Analysis of Logistics in Support of a Human Lunar Outpost

    NASA Technical Reports Server (NTRS)

    Cirillo, William; Earle, Kevin; Goodliff, Kandyce; Reeves, j. D.; Andrashko, Mark; Merrill, R. Gabe; Stromgren, Chel

    2008-01-01

    Strategic level analysis of the integrated behavior of lunar transportation system and lunar surface system architecture options is performed to inform NASA Constellation Program senior management on the benefit, viability, affordability, and robustness of system design choices. This paper presents an overview of the approach used to perform the campaign (strategic) analysis, with an emphasis on the logistics modeling and the impacts of logistics resupply on campaign behavior. An overview of deterministic and probabilistic analysis approaches is provided, with a discussion of the importance of each approach to understanding the integrated system behavior. The logistics required to support lunar surface habitation are analyzed from both 'macro-logistics' and 'micro-logistics' perspectives, where macro-logistics focuses on the delivery of goods to a destination and micro-logistics focuses on local handling of re-supply goods at a destination. An example campaign is provided to tie the theories of campaign analysis to results generation capabilities.

  10. Integration of logistic regression, Markov chain and cellular automata models to simulate urban expansion

    NASA Astrophysics Data System (ADS)

    Jokar Arsanjani, Jamal; Helbich, Marco; Kainz, Wolfgang; Darvishi Boloorani, Ali

    2013-04-01

    This research analyses the suburban expansion in the metropolitan area of Tehran, Iran. A hybrid model consisting of logistic regression model, Markov chain (MC), and cellular automata (CA) was designed to improve the performance of the standard logistic regression model. Environmental and socio-economic variables dealing with urban sprawl were operationalised to create a probability surface of spatiotemporal states of built-up land use for the years 2006, 2016, and 2026. For validation, the model was evaluated by means of relative operating characteristic values for different sets of variables. The approach was calibrated for 2006 by cross comparing of actual and simulated land use maps. The achieved outcomes represent a match of 89% between simulated and actual maps of 2006, which was satisfactory to approve the calibration process. Thereafter, the calibrated hybrid approach was implemented for forthcoming years. Finally, future land use maps for 2016 and 2026 were predicted by means of this hybrid approach. The simulated maps illustrate a new wave of suburban development in the vicinity of Tehran at the western border of the metropolis during the next decades.

  11. A Multi-Stage Reverse Logistics Network Problem by Using Hybrid Priority-Based Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Lee, Jeong-Eun; Gen, Mitsuo; Rhee, Kyong-Gu

    Today remanufacturing problem is one of the most important problems regarding to the environmental aspects of the recovery of used products and materials. Therefore, the reverse logistics is gaining become power and great potential for winning consumers in a more competitive context in the future. This paper considers the multi-stage reverse Logistics Network Problem (m-rLNP) while minimizing the total cost, which involves reverse logistics shipping cost and fixed cost of opening the disassembly centers and processing centers. In this study, we first formulate the m-rLNP model as a three-stage logistics network model. Following for solving this problem, we propose a Genetic Algorithm pri (GA) with priority-based encoding method consisting of two stages, and introduce a new crossover operator called Weight Mapping Crossover (WMX). Additionally also a heuristic approach is applied in the 3rd stage to ship of materials from processing center to manufacturer. Finally numerical experiments with various scales of the m-rLNP models demonstrate the effectiveness and efficiency of our approach by comparing with the recent researches.

  12. The response of the inductively coupled argon plasma to solvent plasma load: spatially resolved maps of electron density obtained from the intensity of one argon line

    NASA Astrophysics Data System (ADS)

    Weir, D. G. J.; Blades, M. W.

    1994-12-01

    A survey of spatially resolved electron number density ( ne) in the tail cone of the inductively coupled argon plasma (ICAP) is presented: all of the results of the survey have been radially inverted by numerical, asymmetric Abel inversion. The survey extends over the entire volume of the plasma beyond the exit of the ICAP torch; It extends over distances of z = 5-25 mm downstream from the induction coil, and over radial distances of ± 8 mm from the discharge axis. The survey also explores a range of inner argon flow rates ( QIN), solvent plasma load ( Qspl) and r.f. power: moreover, it explores loading by water, methanol and chloroform. Throughout the survey, ne was determined from the intensity of one, optically thin argon line, by a method which assumes that the atomic state distribution function (ASDF) for argon lies close to local thermal equilibrium (LTE). The validity of this assumption is reviewed. Also examined are the discrepancies between ne from this method and ne from Stark broadening measurements. With the error taken into account, the results of the survey reveal how time averaged values of ne in the ICAP respond over an extensive, previously unexplored range of experimental parameters. Moreover, the spatial information lends insight into how the thermal conditions and the transport of energy respond. Overall, the response may be described in terms of energy consumption along the axial channel and thermal pinch within the induction region. The predominating effect depends on the solvent plasma load, the solvent composition, the robustness of the discharge, and the distribution of solvent material over the argon stream.

  13. The ETS domain transcriptional repressor Anterior open inhibits MAP kinase and Wingless signaling to couple tracheal cell fate with branch identity.

    PubMed

    Caviglia, Sara; Luschnig, Stefan

    2013-03-01

    Cells at the tips of budding branches in the Drosophila tracheal system generate two morphologically different types of seamless tubes. Terminal cells (TCs) form branched lumenized extensions that mediate gas exchange at target tissues, whereas fusion cells (FCs) form ring-like connections between adjacent tracheal metameres. Each tracheal branch contains a specific set of TCs, FCs, or both, but the mechanisms that select between the two tip cell types in a branch-specific fashion are not clear. Here, we show that the ETS domain transcriptional repressor anterior open (aop) is dispensable for directed tracheal cell migration, but plays a key role in tracheal tip cell fate specification. Whereas aop globally inhibits TC and FC specification, MAPK signaling overcomes this inhibition by triggering degradation of Aop in tip cells. Loss of aop function causes excessive FC and TC specification, indicating that without Aop-mediated inhibition, all tracheal cells are competent to adopt a specialized fate. We demonstrate that Aop plays a dual role by inhibiting both MAPK and Wingless signaling, which induce TC and FC fate, respectively. In addition, the branch-specific choice between the two seamless tube types depends on the tracheal branch identity gene spalt major, which is sufficient to inhibit TC specification. Thus, a single repressor, Aop, integrates two different signals to couple tip cell fate selection with branch identity. The switch from a branching towards an anastomosing tip cell type may have evolved with the acquisition of a main tube that connects separate tracheal primordia to generate a tubular network. PMID:23444354

  14. Stochastic dynamics and logistic population growth.

    PubMed

    Méndez, Vicenç; Assaf, Michael; Campos, Daniel; Horsthemke, Werner

    2015-06-01

    The Verhulst model is probably the best known macroscopic rate equation in population ecology. It depends on two parameters, the intrinsic growth rate and the carrying capacity. These parameters can be estimated for different populations and are related to the reproductive fitness and the competition for limited resources, respectively. We investigate analytically and numerically the simplest possible microscopic scenarios that give rise to the logistic equation in the deterministic mean-field limit. We provide a definition of the two parameters of the Verhulst equation in terms of microscopic parameters. In addition, we derive the conditions for extinction or persistence of the population by employing either the momentum-space spectral theory or the real-space Wentzel-Kramers-Brillouin approximation to determine the probability distribution function and the mean time to extinction of the population. Our analytical results agree well with numerical simulations. PMID:26172687

  15. Green Packaging Management of Logistics Enterprises

    NASA Astrophysics Data System (ADS)

    Zhang, Guirong; Zhao, Zongjian

    From the connotation of green logistics management, we discuss the principles of green packaging, and from the two levels of government and enterprises, we put forward a specific management strategy. The management of green packaging can be directly and indirectly promoted by laws, regulations, taxation, institutional and other measures. The government can also promote new investment to the development of green packaging materials, and establish specialized institutions to identify new packaging materials, standardization of packaging must also be accomplished through the power of the government. Business units of large scale through the packaging and container-based to reduce the use of packaging materials, develop and use green packaging materials and easy recycling packaging materials for proper packaging.

  16. Space station synergetic RAM-logistics analysis

    NASA Technical Reports Server (NTRS)

    Dejulio, Edmund T.; Leet, Joel H.

    1988-01-01

    NASA's Space Station Maintenance Planning and Analysis (MP&A) Study is a step in the overall Space Station Program to define optimum approaches for on-orbit maintenance planning and logistics support. The approach used in the MP&A study and the analysis process used are presented. Emphasis is on maintenance activities and processes that can be accomplished on orbit within the known design and support constraints of the Space Station. From these analyses, recommendations for maintainability/maintenance requirements are established. The ultimate goal of the study is to reduce on-orbit maintenance requirements to a practical and safe minimum, thereby conserving crew time for productive endeavors. The reliability, availability, and maintainability (RAM) and operations performance evaluation models used were assembled and developed as part of the MP&A study and are described. A representative space station system design is presented to illustrate the analysis process.

  17. Stochastic dynamics and logistic population growth

    NASA Astrophysics Data System (ADS)

    Méndez, Vicenç; Assaf, Michael; Campos, Daniel; Horsthemke, Werner

    2015-06-01

    The Verhulst model is probably the best known macroscopic rate equation in population ecology. It depends on two parameters, the intrinsic growth rate and the carrying capacity. These parameters can be estimated for different populations and are related to the reproductive fitness and the competition for limited resources, respectively. We investigate analytically and numerically the simplest possible microscopic scenarios that give rise to the logistic equation in the deterministic mean-field limit. We provide a definition of the two parameters of the Verhulst equation in terms of microscopic parameters. In addition, we derive the conditions for extinction or persistence of the population by employing either the momentum-space spectral theory or the real-space Wentzel-Kramers-Brillouin approximation to determine the probability distribution function and the mean time to extinction of the population. Our analytical results agree well with numerical simulations.

  18. Using multiple logistic regression and GIS technology to predict landslide hazard in northeast Kansas, USA

    USGS Publications Warehouse

    Ohlmacher, G.C.; Davis, J.C.

    2003-01-01

    Landslides in the hilly terrain along the Kansas and Missouri rivers in northeastern Kansas have caused millions of dollars in property damage during the last decade. To address this problem, a statistical method called multiple logistic regression has been used to create a landslide-hazard map for Atchison, Kansas, and surrounding areas. Data included digitized geology, slopes, and landslides, manipulated using ArcView GIS. Logistic regression relates predictor variables to the occurrence or nonoccurrence of landslides within geographic cells and uses the relationship to produce a map showing the probability of future landslides, given local slopes and geologic units. Results indicated that slope is the most important variable for estimating landslide hazard in the study area. Geologic units consisting mostly of shale, siltstone, and sandstone were most susceptible to landslides. Soil type and aspect ratio were considered but excluded from the final analysis because these variables did not significantly add to the predictive power of the logistic regression. Soil types were highly correlated with the geologic units, and no significant relationships existed between landslides and slope aspect. ?? 2003 Elsevier Science B.V. All rights reserved.

  19. Development of a comprehensive logistics and warfighting simulation system.

    SciTech Connect

    Hummel, J. R.

    1998-08-12

    An efficient logistics system is critical to the success of military operations. Recently, the Department of Defense (DoD) has begun to move from a ''just in case'' logistics system that relies on large stores of inventoried materials toward a ''just in time'' system based on obtaining and delivering supplies when and where they are needed. For this new logistics concept to operate smoothly and responsively and be highly robust, one must understand the interrelationships between warfighting and logistics, such as the impact of losses of logistics links/nodes and the changing pace of warfighting operations. Two DoD programs, the Distributed Intelligent Agents for Logistics (DIAL) and the Warfighting Logistics Technology and Assessment Environment (WLTAE), are focusing on different aspects of this problem. These programs are being integrated to develop a Comprehensive Logistics and Warfighting System (CLAWS) that can be used to address a variety of different logistics applications in the military arena. In this paper, we describe how CLAWS will be developed, including the development of a generalized Federation Object Model that could be used in a variety of logistics and military operations applications.

  20. Estimating Contraceptive Prevalence Using Logistics Data for Short-Acting Methods: Analysis Across 30 Countries

    PubMed Central

    Cunningham, Marc; Brown, Niquelle; Sacher, Suzy; Hatch, Benjamin; Inglis, Andrew; Aronovich, Dana

    2015-01-01

    Background: Contraceptive prevalence rate (CPR) is a vital indicator used by country governments, international donors, and other stakeholders for measuring progress in family planning programs against country targets and global initiatives as well as for estimating health outcomes. Because of the need for more frequent CPR estimates than population-based surveys currently provide, alternative approaches for estimating CPRs are being explored, including using contraceptive logistics data. Methods: Using data from the Demographic and Health Surveys (DHS) in 30 countries, population data from the United States Census Bureau International Database, and logistics data from the Procurement Planning and Monitoring Report (PPMR) and the Pipeline Monitoring and Procurement Planning System (PipeLine), we developed and evaluated 3 models to generate country-level, public-sector contraceptive prevalence estimates for injectable contraceptives, oral contraceptives, and male condoms. Models included: direct estimation through existing couple-years of protection (CYP) conversion factors, bivariate linear regression, and multivariate linear regression. Model evaluation consisted of comparing the referent DHS prevalence rates for each short-acting method with the model-generated prevalence rate using multiple metrics, including mean absolute error and proportion of countries where the modeled prevalence rate for each method was within 1, 2, or 5 percentage points of the DHS referent value. Results: For the methods studied, family planning use estimates from public-sector logistics data were correlated with those from the DHS, validating the quality and accuracy of current public-sector logistics data. Logistics data for oral and injectable contraceptives were significantly associated (P<.05) with the referent DHS values for both bivariate and multivariate models. For condoms, however, that association was only significant for the bivariate model. With the exception of the CYP

  1. ADAPTIVELY IMPROVING LONG DISTANCE NETWORK TRANSFERS WITH LOGISTICS

    SciTech Connect

    LaBissoniere, D.; Roche, K.

    2007-01-01

    Long distance data movement is an essential activity of modern computing. However, the congestion control mechanisms in the Internet’s Transmission Control Protocol (TCP) severely limit the bandwidth achieved by long distance data transfers. The throughput of such transfers can be improved by applying the logistical technique of breaking a single long distance transfer into multiple shorter transfers. This technique can result in signifi cantly improved throughput while still respecting the shared nature of the Internet by not attempting to circumvent the TCP congestion controls. This technique has been incorporated into an algorithm which attempts to dynamically schedule transfers for optimal throughput. The algorithm couples graph techniques with real-time latency and bandwidth measurements to discover the best path and adaptively respond to network dynamics. The algorithm shows improvements in speed and fl exibility over standard data transfer methods such as FTP. Specifi c transfers tests performed between Oak Ridge National Laboratory and a destination in Sunnyvale, CA show throughput increases by a factor of two.

  2. 78 FR 73872 - Agency Information Collection Activities: Proposed Collection; Comment Request; Logistics...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ...; Comment Request; Logistics Capability Assistance Tool (LCAT) AGENCY: Federal Emergency Management Agency... accordance with the Paperwork Reduction Act of 1995, this notice seeks comments concerning the Logistics... Repass, Program Analyst, Logistics Management Directorate, Logistics Plans & Exercises Division,...

  3. 78 FR 37814 - Tesoro Corporation and Tesoro Logistics Operations LLC; Analysis of Proposed Agreement Containing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-24

    ... Tesoro Corporation and Tesoro Logistics Operations LLC; Analysis of Proposed Agreement Containing Consent... Tesoro Logistics Operations LLC (``Respondents''). On December 6, 2012, Respondents executed related.... Tesoro Logistics Operations LLC Tesoro Logistics Operations LLC, a limited liability company, is a...

  4. 76 FR 28757 - Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ... of the Secretary Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense Logistics Agency Actions AGENCY: Defense Logistics Agency, Department of Defense. ACTION: Notice of Availability (NOA) of Revised Defense Logistics Agency Regulation. SUMMARY: The Defense...

  5. Active Mapping.

    ERIC Educational Resources Information Center

    Day, Dennis

    1994-01-01

    Explains a social studies lesson for third graders that uses KidPix, a computer software graphics program to help students make maps and map keys. Advantages to using the computer versus hand drawing maps are discussed, and an example of map requirements for the lesson is included. (LRW)

  6. Concept Mapping.

    ERIC Educational Resources Information Center

    Callison, Daniel

    2001-01-01

    Explains concept mapping as a heuristic device that is helpful in visualizing the relationships between and among ideas. Highlights include how to begin a map; brainstorming; map applications, including document or information summaries and writing composition; and mind mapping to strengthen note-taking. (LRW)

  7. Space Station logistics policy - Risk management from the top down

    NASA Technical Reports Server (NTRS)

    Paules, Granville; Graham, James L., Jr.

    1990-01-01

    Considerations are presented in the area of risk management specifically relating to logistics and system supportability. These considerations form a basis for confident application of concurrent engineering principles to a development program, aiming at simultaneous consideration of support and logistics requirements within the engineering process as the system concept and designs develop. It is shown that, by applying such a process, the chances of minimizing program logistics and supportability risk in the long term can be improved. The problem of analyzing and minimizing integrated logistics risk for the Space Station Freedom Program is discussed.

  8. Use of Ubiquitous Technologies in Military Logistic System in Iran

    NASA Astrophysics Data System (ADS)

    Jafari, P.; Sadeghi-Niaraki, A.

    2013-09-01

    This study is about integration and evaluation of RFID and ubiquitous technologies in military logistic system management. Firstly, supply chain management and the necessity of a revolution in logistic systems especially in military area, are explained. Secondly RFID and ubiquitous technologies and the advantages of their use in supply chain management are introduced. Lastly a system based on these technologies for controlling and increasing the speed and accuracy in military logistic system in Iran with its unique properties, is presented. The system is based on full control of military logistics (supplies) from the time of deployment to replenishment using sensor network, ubiquitous and RFID technologies.

  9. Logistics Reduction and Repurposing Beyond Low Earth Orbit

    NASA Technical Reports Server (NTRS)

    Broyan, James Lee, Jr.; Ewert, Michael K.

    2011-01-01

    All human space missions, regardless of destination, require significant logistical mass and volume that is strongly proportional to mission duration. Anything that can be done to reduce initial mass and volume of supplies or reuse items that have been launched will be very valuable. Often, the logistical items require disposal and represent a trash burden. Utilizing systems engineering to analyze logistics from cradle-to-grave and then to potential reuse, can minimize logistics contributions to total mission architecture mass. In NASA's Advanced Exploration Systems Logistics Reduction and Repurposing Project , various tasks will reduce the intrinsic mass of logistical packaging, enable reuse and repurposing of logistical packaging and carriers for other habitation, life support, crew health, and propulsion functions, and reduce or eliminate the nuisances aspects of trash at the same time. Repurposing reduces the trash burden and eliminates the need for hardware whose function can be provided by use of spent logistic items. However, these reuse functions need to be identified and built into future logical systems to enable them to effectively have a secondary function. These technologies and innovations will help future logistic systems to support multiple exploration missions much more efficiently.

  10. Contour Mapping

    NASA Technical Reports Server (NTRS)

    1995-01-01

    In the early 1990s, the Ohio State University Center for Mapping, a NASA Center for the Commercial Development of Space (CCDS), developed a system for mobile mapping called the GPSVan. While driving, the users can map an area from the sophisticated mapping van equipped with satellite signal receivers, video cameras and computer systems for collecting and storing mapping data. George J. Igel and Company and the Ohio State University Center for Mapping advanced the technology for use in determining the contours of a construction site. The new system reduces the time required for mapping and staking, and can monitor the amount of soil moved.

  11. Nowcasting sunshine number using logistic modeling

    NASA Astrophysics Data System (ADS)

    Brabec, Marek; Badescu, Viorel; Paulescu, Marius

    2013-04-01

    In this paper, we present a formalized approach to statistical modeling of the sunshine number, binary indicator of whether the Sun is covered by clouds introduced previously by Badescu (Theor Appl Climatol 72:127-136, 2002). Our statistical approach is based on Markov chain and logistic regression and yields fully specified probability models that are relatively easily identified (and their unknown parameters estimated) from a set of empirical data (observed sunshine number and sunshine stability number series). We discuss general structure of the model and its advantages, demonstrate its performance on real data and compare its results to classical ARIMA approach as to a competitor. Since the model parameters have clear interpretation, we also illustrate how, e.g., their inter-seasonal stability can be tested. We conclude with an outlook to future developments oriented to construction of models allowing for practically desirable smooth transition between data observed with different frequencies and with a short discussion of technical problems that such a goal brings.

  12. Source Recertification, Refurbishment, and Transfer Logistics

    SciTech Connect

    Gastelum, Zoe N.; Duckworth, Leesa L.; Greenfield, Bryce A.; Doll, Stephanie R.

    2013-09-01

    The 2012 Gap Analysis of Department of Energy Radiological Sealed Sources, Standards, and Materials for Safeguards Technology Development [1] report, and the subsequent Reconciliation of Source Needs and Surpluses across the U.S. Department of Energy National Laboratory Complex [2] report, resulted in the identification of 33 requests for nuclear or radiological sealed sources for which there was potentially available, suitable material from within the U.S. Department of Energy (DOE) complex to fill the source need. Available, suitable material was defined by DOE laboratories as material slated for excess, or that required recertification or refurbishment before being used for safeguards technology development. This report begins by outlining the logistical considerations required for the shipment of nuclear and radiological materials between DOE laboratories. Then, because of the limited need for transfer of matching sources, the report also offers considerations for an alternative approach – the shipment of safeguards equipment between DOE laboratories or technology testing centers. Finally, this report addresses repackaging needs for the two source requests for which there was available, suitable material within the DOE complex.

  13. Logistics engineering education from the point of view environment

    NASA Astrophysics Data System (ADS)

    Bányai, Ágota

    2010-05-01

    A new field of MSc programme offered by the Faculty of Mechanical Engineering and Informatics of the University of Miskolc is represented by the programme in logistics engineering. The Faculty has always laid great emphasis on assigning processes connected with environment protection and globalisation issues the appropriate weight in its programmes. This is based on the fact that the Faculty has initiated and been involved in a great number of research and development projects with a substantial emphasis on the fundamental principles of sustainable development. The objective of the programme of logistics engineering is to train engineers who, in possession of the science, engineering, economic, informatics and industrial, transportation technological knowledge related to the professional field of logistics, are able to analyse, design, organise, and control logistics processes and systems (freight transportation, materials handling, storage, commissioning, loading, purchasing, distribution and waste management) as well as to design and develop machinery and equipment as the elements of logistic systems and also to be involved in their manufacture and quality control and are able to control their operation. The programme prepares its students for performing the logistics management tasks in a company, for creative participation in solving research and development problems in logistics and for pursuing logistics studies in doctoral programmes. There are several laboratories available for practice-oriented training. The 'Integrated Logistics Laboratory' consists of various fixed and mobile, real industrial, i.e. not model-level equipment, the integration of which in one system facilitates not only the presentation, examination and development of the individual self-standing facilities, but the study of their interaction as well in terms of mechatronics, engineering, control engineering, informatics, identification technology and logistics. The state

  14. Logistic Regression: Going beyond Point-and-Click.

    ERIC Educational Resources Information Center

    King, Jason E.

    A review of the literature reveals that important statistical algorithms and indices pertaining to logistic regression are being underused. This paper describes logistic regression in comparison with discriminant analysis and linear regression, and suggests that some techniques only accessible through computer syntax should be consulted in…

  15. Bayesian Estimation of the Logistic Positive Exponent IRT Model

    ERIC Educational Resources Information Center

    Bolfarine, Heleno; Bazan, Jorge Luis

    2010-01-01

    A Bayesian inference approach using Markov Chain Monte Carlo (MCMC) is developed for the logistic positive exponent (LPE) model proposed by Samejima and for a new skewed Logistic Item Response Theory (IRT) model, named Reflection LPE model. Both models lead to asymmetric item characteristic curves (ICC) and can be appropriate because a symmetric…

  16. A Model for Logistics Systems Engineering Management Education in Europe.

    ERIC Educational Resources Information Center

    Naim, M.; Lalwani, C.; Fortuin, L.; Schmidt, T.; Taylor, J.; Aronsson, H.

    2000-01-01

    Presents the need for a systems and process perspective of logistics, and develops a template for a logistics education course. The template addresses functional, process, and supply chain needs and was developed by a number of university partners with core skills in different traditional disciplines. (Contains 31 references.) (Author/WRM)

  17. Preliminary analysis of an integrated logistics system for OSSA payloads

    NASA Technical Reports Server (NTRS)

    Palguta, T.; Bradley, W.; Stockton, T.

    1988-01-01

    The results of studies of the Office of Space Science and Applications' (OSSA) need for an integrated logistics system to support OSSA payloads, whether attached to the Space Station or free-flying are detailed. An executive summary, the integrated logistics support strategy, preparation of planning documents and a supportability analysis of the 1.8 meter centrifuge are discussed.

  18. The Impact of Logistical Resources on Prereferral Team Acceptability

    ERIC Educational Resources Information Center

    Yetter, Georgette; Doll, Beth

    2007-01-01

    This study investigated the impact of logistical resources on the acceptability of student assistance team consultation to school staff. Elementary and middle school staff (N=113) completed a measure of the acceptability of prereferral intervention team procedures while also rating the importance of five logistical supports for effective team…

  19. Logistics Reduction and Repurposing Beyond Low Earth Orbit

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K.; Broyan, James L., Jr.

    2012-01-01

    All human space missions, regardless of destination, require significant logistical mass and volume that is strongly proportional to mission duration. Anything that can be done to reduce initial mass and volume of supplies or reuse items that have been launched will be very valuable. Often, the logistical items require disposal and represent a trash burden. Logistics contributions to total mission architecture mass can be minimized by considering potential reuse using systems engineering analysis. In NASA's Advanced Exploration Systems "Logistics Reduction and Repurposing Project," various tasks will reduce the intrinsic mass of logistical packaging, enable reuse and repurposing of logistical packaging and carriers for other habitation, life support, crew health, and propulsion functions, and reduce or eliminate the nuisance aspects of trash at the same time. Repurposing reduces the trash burden and eliminates the need for hardware whose function can be provided by use of spent logistical items. However, these reuse functions need to be identified and built into future logical systems to enable them to effectively have a secondary function. These technologies and innovations will help future logistics systems to support multiple exploration missions much more efficiently.

  20. Dynamic Plasticity of Coupled Cortical Maps

    NASA Astrophysics Data System (ADS)

    Atwal, G. S.

    2003-03-01

    Spatiotemporal location of an object may be achieved by inference from a combination of different noisy stimuli such as in the case of barn owls which locate prey using both aural and visual stimuli. The symbolic representation of an event is carried out using the receptive fields of neurons in the cortex, and in a normal barn owl the aural and visual receptive fields are aligned from early experiences. However, misalignment induced by the wearing of prismatic glasses may result in adaptive behavior, manifested by physical modification of the receptive fields. A model of this dynamic plasticity is presented and analyzed by maximising the weighted information of both sensory neural outputs, demonstrating a transition from adaptive to non-adaptive behavior as the rate of misalignment increases.

  1. RICH MAPS

    EPA Science Inventory

    Michael Goodchild recently gave eight reasons why traditional maps are limited as communication devices, and how interactive internet mapping can overcome these limitations. In the past, many authorities in cartography, from Jenks to Bertin, have emphasized the importance of sim...

  2. Kentucky map

    NASA Astrophysics Data System (ADS)

    A wall-sized geological map of Kentucky, the product of 18 years of work, has just been released. Produced by the U.S. Geological Survey (USGS) in cooperation with the Kentucky Geological Survey (KGS) at the University of Kentucky, the map is unique, according to state geologist Donald Haney, because it is the first and only state map ever produced in detailed form from geologic quadrangle maps already available from the KGS.At a scale of 1:250,000, the map shows the surface distribution of various types of rock throughout the state, as well as geologic structure, faults, and surface coal beds. Numerous geologic sections, stratigraphic diagrams, correlation charts, and structure sections accompany the map. Compiled by R. C. McDowell and S. L. Moore of the USGS and by G. J . Grabowski of the KGS, the map was made by photoreducing and generalizing the detailed geologic quadrangle maps.

  3. Map adventures

    USGS Publications Warehouse

    1994-01-01

    Map Adventures, with seven accompanying lessons, is appropriate for grades K-3. Students will learn basic concepts for visualizing objects from different perspectives and how to understand /and use maps.

  4. Logistics engineering education from the point of view environment

    NASA Astrophysics Data System (ADS)

    Bányai, Ágota

    2010-05-01

    A new field of MSc programme offered by the Faculty of Mechanical Engineering and Informatics of the University of Miskolc is represented by the programme in logistics engineering. The Faculty has always laid great emphasis on assigning processes connected with environment protection and globalisation issues the appropriate weight in its programmes. This is based on the fact that the Faculty has initiated and been involved in a great number of research and development projects with a substantial emphasis on the fundamental principles of sustainable development. The objective of the programme of logistics engineering is to train engineers who, in possession of the science, engineering, economic, informatics and industrial, transportation technological knowledge related to the professional field of logistics, are able to analyse, design, organise, and control logistics processes and systems (freight transportation, materials handling, storage, commissioning, loading, purchasing, distribution and waste management) as well as to design and develop machinery and equipment as the elements of logistic systems and also to be involved in their manufacture and quality control and are able to control their operation. The programme prepares its students for performing the logistics management tasks in a company, for creative participation in solving research and development problems in logistics and for pursuing logistics studies in doctoral programmes. There are several laboratories available for practice-oriented training. The 'Integrated Logistics Laboratory' consists of various fixed and mobile, real industrial, i.e. not model-level equipment, the integration of which in one system facilitates not only the presentation, examination and development of the individual self-standing facilities, but the study of their interaction as well in terms of mechatronics, engineering, control engineering, informatics, identification technology and logistics. The state

  5. The spatial prediction of landslide susceptibility applying artificial neural network and logistic regression models: A case study of Inje, Korea

    NASA Astrophysics Data System (ADS)

    Saro, Lee; Woo, Jeon Seong; Kwan-Young, Oh; Moung-Jin, Lee

    2016-02-01

    The aim of this study is to predict landslide susceptibility caused using the spatial analysis by the application of a statistical methodology based on the GIS. Logistic regression models along with artificial neutral network were applied and validated to analyze landslide susceptibility in Inje, Korea. Landslide occurrence area in the study were identified based on interpretations of optical remote sensing data (Aerial photographs) followed by field surveys. A spatial database considering forest, geophysical, soil and topographic data, was built on the study area using the Geographical Information System (GIS). These factors were analysed using artificial neural network (ANN) and logistic regression models to generate a landslide susceptibility map. The study validates the landslide susceptibility map by comparing them with landslide occurrence areas. The locations of landslide occurrence were divided randomly into a training set (50%) and a test set (50%). A training set analyse the landslide susceptibility map using the artificial network along with logistic regression models, and a test set was retained to validate the prediction map. The validation results revealed that the artificial neural network model (with an accuracy of 80.10%) was better at predicting landslides than the logistic regression model (with an accuracy of 77.05%). Of the weights used in the artificial neural network model, `slope' yielded the highest weight value (1.330), and `aspect' yielded the lowest value (1.000). This research applied two statistical analysis methods in a GIS and compared their results. Based on the findings, we were able to derive a more effective method for analyzing landslide susceptibility.

  6. Forest Fire Mapping

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The Fire Logistics Airborne Mapping Equipment (FLAME) system, mounted in a twin-engine and airplane operated by the U.S. Forest Service (USFS) of the U.S. Department of Agriculture (USDA), is an airborne instrument for detecting and pinpointing forest fires that might escape ground detection. The FLAME equipment rack includes the operator interface, a video monitor, the system's control panel and film output. FLAME's fire detection sensor is an infrared line scanner system that identifies fire boundaries. Sensor's information is correlated with the aircraft's position and altitude at the time the infrared imagery is acquired to fix the fire's location on a map. System can be sent to a fire locale anywhere in the U.S. at the request of a regional forester. USFS felt a need for a more advanced system to deliver timely fire information to fire management personnel in the decade of the 1990s. The Jet Propulsion Laboratory (JPL) conducted a study, jointly sponsored by NASA and USDA, on what advanced technologies might be employed to produce an end-to-end thermal infrared fire detection and mapping system. That led to initiation of the Firefly system, currently in development at JPL and targeted for operational service beginning in 1992. Firefly will employ satellite-reference position fixing and provide performance superior to FLAME.

  7. A fast, streaming SIMD Extensions 2, logistic squashing function.

    PubMed

    Milner, J J; Grandison, A J

    2008-12-01

    Schraudolph proposed an excellent exponential approximation providing increased performance particularly suited to the logistic squashing function used within many neural networking applications. This note applies Intel's streaming SIMD Extensions 2 (SSE2), where SIMD is single instruction multiple data, of the Pentium IV class processor to Schraudolph's technique, further increasing the performance of the logistic squashing function. It was found that the calculation of the new 32-bit SSE2 logistic squashing function described here was up to 38 times faster than the conventional exponential function and up to 16 times faster than a Schraudolph-style 32-bit method on an Intel Pentium D 3.6 GHz CPU. PMID:18624654

  8. Radio Frequency Identification Queuing & Geo-Location (RAQGEO): A spatial solution to inventory management at XYZ Logistics, Inc

    NASA Astrophysics Data System (ADS)

    Griffiths, Bradley Joseph

    New supply chain management methods using radio frequency identification (RFID) and global positioning system (GPS) technology are quickly being adopted by companies as various inventory management benefits are being realized. For example, companies such as Nippon Yusen Kaisha (NYK) Logistics use the technology coupled with geospatial support systems for distributors to quickly find and manage freight containers. Traditional supply chain management methods require pen-to-paper reporting, searching inventory on foot, and human data entry. Some companies that prioritize supply chain management have not adopted the new technology, because they may feel that their traditional methods save the company expenses. This thesis serves as a pilot study that examines how information technology (IT) utilizing RFID and GPS technology can serve to increase workplace productivity, decrease human labor associated with inventorying, plus be used for spatial analysis by management. This pilot study represents the first attempt to couple RFID technology with Geographic Information Systems (GIS) in supply chain management efforts to analyze and locate mobile assets by exploring costs and benefits of implementation plus how the technology can be employed. This pilot study identified a candidate to implement a new inventory management method as XYZ Logistics, Inc. XYZ Logistics, Inc. is a fictitious company but represents a factual corporation. The name has been changed to provide the company with anonymity and to not disclose confidential business information. XYZ Logistics, Inc., is a nation-wide company that specializes in providing space solutions for customers including portable offices, storage containers, and customizable buildings.

  9. Chaotic maps, Hamiltonian flows, and Holographic methods.

    SciTech Connect

    Curtright, T. L.; Zachos, C. K.; High Energy Physics; Univ. of Miami

    2010-01-01

    Holographic functional methods are introduced as probes of discrete time-stepped maps that lead to chaotic behavior. The methods provide continuous time interpolation between the time steps, thereby revealing the maps to be quasi-Hamiltonian systems underlain by novel potentials that govern the motion of a perceived point particle. Between turning points, the particle is strictly driven by Hamiltonian dynamics, but at each encounter with a turning point the potential changes abruptly, loosely analogous to the switchbacks on a mountain road. A sequence of successively deepening switchback potentials explains, in physical terms, the frequency cascade and trajectory folding that occur on the particular route to chaos revealed by the logistic map.

  10. Intriguing structures in iterative maps motivated by N-body problem

    NASA Astrophysics Data System (ADS)

    Mittal, Ashok Kumar; Gupta, Ashok Kumar

    2011-03-01

    Conventional approaches to modeling any system try to incorporate increasingly realistic features into the model, thereby making it more and more complex. An opposite approach seeks to build simpler and simpler conceptual models capable of capturing some observed features of a system. This trend began with Lorenz, who simplified models of the atmosphere to obtain the Lorenz model consisting of a system of only three equations. Despite the simplicity of these equations, this system displayed surprisingly rich properties, and has been used as a conceptual model in diverse disciplines. Poincare maps help study ordinary differential equations from a qualitative perspective. Several investigators like Henon and Feigenbaum followed this simplification approach. Instead of investigating Poincare maps of realistic systems, they, along with several others, investigated simple maps for their own sake. Despite lack of realism, this approach proved to be very fruitful. A map, as simple as the Logistic map, became an important conceptual modeling paradigm. It provided a tool for understanding bifurcation routes to chaos, which were verified experimentally through various experiments in diverse fields. Coupled map lattices (CML) help explore partial differential equations (PDE). Further simplification led to the introduction of Cellular Automata (CA). These fields continue to be explored with vigor and have given rise to a rich body of knowledge, conceptually useful over a wide spectrum of disciplines. In this paper, we follow the simplification approach for modeling the N-body problem. N-body simulations, say in Gravitation, give rise to filamentary structures. Such structures are observed in the actual observed Galactic distribution. The mechanism for creation of such structures is not well understood. We present a simple iterative dynamical model, motivated by the N-body problem, which, though unrealistic, produces such filamentary structures. This model also exhibits a

  11. 76 FR 54468 - Petra Pet, Inc. (a/k/a Petrapport) v. Panda Logistics Limited; Panda Logistics Co., Ltd. (f/k/a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ... Petra Pet, Inc. (a/k/a Petrapport) v. Panda Logistics Limited; Panda Logistics Co., Ltd. (f/k/a panda... Petra Pet, Inc. (a/k/a Petrapport), hereinafter ``Complainant,'' against Respondents Panda Logistics Limited, Panda Logistics Co., Ltd. (f/k/a Panda Int'l Transportation Co., Ltd), and RDM Solutions...

  12. Expendable launch vehicles in Space Station Freedom logistics resupply operations

    NASA Technical Reports Server (NTRS)

    Newman, J. Steven; Courtney, Roy L.; Brunt, Peter

    1990-01-01

    The projected Space Station Freedom (SSF) annual logistics resupply requirements were predicted to exceed the 1988 baseline Shuttle resupply system capability. This paper examines the implications of employing a 'mixed fleet' of Shuttles and ELVs to provide postassembly, steady-state logistics resupply. The study concluded that ELVs supported by the OMV could provide the additional required resupply capability with one to three launches per annum. However, the study determined that such a capability would require significant programmatic commitments, including baseline SSF OMV accommodations, on-orbit OMV monoprop replenishment capability, and substantial economics investments. The study also found the need for a half-size pressurized logistics module for the increase in the efficiency of logistics manifesting on the Shuttle as well as ELVs.

  13. Sparse logistic regression with Lp penalty for biomarker identification.

    PubMed

    Liu, Zhenqiu; Jiang, Feng; Tian, Guoliang; Wang, Suna; Sato, Fumiaki; Meltzer, Stephen J; Tan, Ming

    2007-01-01

    In this paper, we propose a novel method for sparse logistic regression with non-convex regularization Lp (p <1). Based on smooth approximation, we develop several fast algorithms for learning the classifier that is applicable to high dimensional dataset such as gene expression. To the best of our knowledge, these are the first algorithms to perform sparse logistic regression with an Lp and elastic net (Le) penalty. The regularization parameters are decided through maximizing the area under the ROC curve (AUC) of the test data. Experimental results on methylation and microarray data attest the accuracy, sparsity, and efficiency of the proposed algorithms. Biomarkers identified with our methods are compared with that in the literature. Our computational results show that Lp Logistic regression (p <1) outperforms the L1 logistic regression and SCAD SVM. Software is available upon request from the first author. PMID:17402921

  14. MODELING SNAKE MICROHABITAT FROM RADIOTELEMETRY STUDIES USING POLYTOMOUS LOGISTIC REGRESSION

    EPA Science Inventory

    Multivariate analysis of snake microhabitat has historically used techniques that were derived under assumptions of normality and common covariance structure (e.g., discriminant function analysis, MANOVA). In this study, polytomous logistic regression (PLR which does not require ...

  15. Research challenges in municipal solid waste logistics management.

    PubMed

    Bing, Xiaoyun; Bloemhof, Jacqueline M; Ramos, Tania Rodrigues Pereira; Barbosa-Povoa, Ana Paula; Wong, Chee Yew; van der Vorst, Jack G A J

    2016-02-01

    During the last two decades, EU legislation has put increasing pressure on member countries to achieve specified recycling targets for municipal household waste. These targets can be obtained in various ways choosing collection methods, separation methods, decentral or central logistic systems, etc. This paper compares municipal solid waste (MSW) management practices in various EU countries to identify the characteristics and key issues from a waste management and reverse logistics point of view. Further, we investigate literature on modelling municipal solid waste logistics in general. Comparing issues addressed in literature with the identified issues in practice result in a research agenda for modelling municipal solid waste logistics in Europe. We conclude that waste recycling is a multi-disciplinary problem that needs to be considered at different decision levels simultaneously. A holistic view and taking into account the characteristics of different waste types are necessary when modelling a reverse supply chain for MSW recycling. PMID:26704064

  16. Multi-Purpose Logistics Module (MPLM) Cargo Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Zampiceni, John J.; Harper, Lon T.

    2002-01-01

    This paper describes the New Shuttle Orbiter's Multi- Purpose Logistics Modulo (MPLM) Cargo Heat Exchanger (HX) and associated MPLM cooling system. This paper presents Heat Exchanger (HX) design and performance characteristics of the system.

  17. Large unbalanced credit scoring using Lasso-logistic regression ensemble.

    PubMed

    Wang, Hong; Xu, Qingsong; Zhou, Lifeng

    2015-01-01

    Recently, various ensemble learning methods with different base classifiers have been proposed for credit scoring problems. However, for various reasons, there has been little research using logistic regression as the base classifier. In this paper, given large unbalanced data, we consider the plausibility of ensemble learning using regularized logistic regression as the base classifier to deal with credit scoring problems. In this research, the data is first balanced and diversified by clustering and bagging algorithms. Then we apply a Lasso-logistic regression learning ensemble to evaluate the credit risks. We show that the proposed algorithm outperforms popular credit scoring models such as decision tree, Lasso-logistic regression and random forests in terms of AUC and F-measure. We also provide two importance measures for the proposed model to identify important variables in the data. PMID:25706988

  18. NASA Advanced Explorations Systems: Concepts for Logistics to Living

    NASA Technical Reports Server (NTRS)

    Shull, Sarah A.; Howe, A. Scott; Flynn, Michael T.; Howard, Robert

    2012-01-01

    The NASA Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) project strives to enable a largely mission-independent cradle-to-grave-to-cradle approach to minimize logistics contributions to total mission architecture mass. The goals are to engineer logistics materials, common crew consumables, and container configurations to meet the following five basic goals: 1. Minimize intrinsic logistics mass and improve ground logistics flexibility. 2. Allow logistics components to be directly repurposed for on-orbit non-logistics functions (e.g., crew cabin outfitting) thereby indirectly reducing mass/volume. 3. Compact and process logistics that have not been directly repurposed to generate useful on-orbit components and/or compounds (e.g., radiation shielding, propellant, other usable chemical constituents). 4. Enable long-term stable storage and disposal of logistics end products that cannot be reused or repurposed (e.g., compaction for volume reduction, odor control, and maintenance of crew cabin hygienic conditions). 5. Allow vehicles in different mission phases to share logistics resources. This paper addresses the work being done to meet the second goal, the direct repurposing of logistics components to meet other on-orbit needs, through a strategy termed Logistics to Living (L2L). L2L has several areas but can be defined as repurposing or converting logistical items (bags, containers, foam, components, etc.) into useful crew items or life support augmentation on-orbit after they have provided their primary logistics function. The intent is that by repurposing items, dedicated crew items do not have to be launched and overall launch mass is decreased. For non-LEO missions, the vehicle interior volume will be relatively fixed so L2L will enable this volume to be used more effectively through reuse and rearrangement of logistical components. Past work in the area of L2L has already conceptually developed several potential technologies [Howe

  19. Reducing Mission Logistics with Multipurpose Cargo Transfer Bags

    NASA Technical Reports Server (NTRS)

    Baccus, Shelley; Broyan, James Lee, Jr.; Borrego, Melissa

    2016-01-01

    The Logistics Reduction (LR) project within Advanced Exploration Systems (AES) is tasked with reducing logistical mass and repurposing logistical items. Multipurpose Cargo Transfer Bags (MCTB) have been designed such that they can serve the same purpose as a Cargo Transfer Bag (CTB), the common logistics carrying bag for the International Space Station (ISS). After use as a cargo carrier, a regular CTB becomes trash, whereas the MCTB can be unfolded into a flat panel for reuse. Concepts and potential benefits for various MCTB applications will be discussed including partitions, crew quarters, solar radiation storm shelters, acoustic blankets, and forward osmosis water processing. Acoustic MCTBs are currently in use on ISS to reduce the noise generated by the T2 treadmill, which reaches the hazard limit at high speeds. The development of the AMCTB included identification of keep-out zones, acoustic properties, deployment considerations, and structural testing. Features developed for these considerations are applicable to MCTBs for all crew outfitting applications.

  20. A note on 'A generalized two-sex logistic model'.

    PubMed

    Maxin, D; Sega, L

    2015-01-01

    We re-visit the recently published paper on a generalization of the two-sex logistic model by Maxin and Sega [A generalized two-sex logistic model, J. Biol. Dyn. 7(1) (2013), pp. 302-318]. We show that the logistic assumption of a non-increasing birth rate can be replaced by a more general assumption of a non-increasing ratio between the female/male birth and mortality rate. In this note we indicate the changes necessary in the proofs of the theorems in [D. Maxin and L. Sega, A generalized two-sex logistic model, J. Biol. Dyn. 7(1) (2013), pp. 302--318] and discuss several situations where this new assumption is useful. PMID:25653171

  1. Multipurpose Cargo Transfer Bags fro Reducing Exploration Mission Logistics

    NASA Technical Reports Server (NTRS)

    Baccus, Shelley; Broyan, James Lee, Jr.; Borrego, Melissa

    2016-01-01

    The Logistics Reduction (LR) project within the Advanced Exploration Systems (AES) division is tasked with reducing logistical mass and repurposing logistical items. Multipurpose Cargo Transfer Bags (MCTB) have been designed such that they can serve the same purpose as a Cargo Transfer Bag (CTB), the common logistics carrying bag for the International Space Station (ISS). After use as a cargo carrier, a regular CTB becomes trash, whereas the MCTB can be unfolded into a flat panel for reuse. Concepts and potential benefits for various MCTB applications will be discussed including partitions, crew quarters, solar radiation storm shelters, acoustic blankets, and forward osmosis water processing. Acoustic MCTBs are currently in use on ISS to reduce the noise generated by the T2 treadmill, which reaches the hazard limit at high speeds. The development of the AMCTB included identification of keep out zones, acoustic properties, deployment considerations, and structural testing. Features developed for these considerations are applicable to MCTBs for all crew outfitting applications.

  2. Virus evolutionary genetic algorithm for task collaboration of logistics distribution

    NASA Astrophysics Data System (ADS)

    Ning, Fanghua; Chen, Zichen; Xiong, Li

    2005-12-01

    In order to achieve JIT (Just-In-Time) level and clients' maximum satisfaction in logistics collaboration, a Virus Evolutionary Genetic Algorithm (VEGA) was put forward under double constraints of logistics resource and operation sequence. Based on mathematic description of a multiple objective function, the algorithm was designed to schedule logistics tasks with different due dates and allocate them to network members. By introducing a penalty item, make span and customers' satisfaction were expressed in fitness function. And a dynamic adaptive probability of infection was used to improve performance of local search. Compared to standard Genetic Algorithm (GA), experimental result illustrates the performance superiority of VEGA. So the VEGA can provide a powerful decision-making technique for optimizing resource configuration in logistics network.

  3. Large Unbalanced Credit Scoring Using Lasso-Logistic Regression Ensemble

    PubMed Central

    Wang, Hong; Xu, Qingsong; Zhou, Lifeng

    2015-01-01

    Recently, various ensemble learning methods with different base classifiers have been proposed for credit scoring problems. However, for various reasons, there has been little research using logistic regression as the base classifier. In this paper, given large unbalanced data, we consider the plausibility of ensemble learning using regularized logistic regression as the base classifier to deal with credit scoring problems. In this research, the data is first balanced and diversified by clustering and bagging algorithms. Then we apply a Lasso-logistic regression learning ensemble to evaluate the credit risks. We show that the proposed algorithm outperforms popular credit scoring models such as decision tree, Lasso-logistic regression and random forests in terms of AUC and F-measure. We also provide two importance measures for the proposed model to identify important variables in the data. PMID:25706988

  4. Computing measures of explained variation for logistic regression models.

    PubMed

    Mittlböck, M; Schemper, M

    1999-01-01

    The proportion of explained variation (R2) is frequently used in the general linear model but in logistic regression no standard definition of R2 exists. We present a SAS macro which calculates two R2-measures based on Pearson and on deviance residuals for logistic regression. Also, adjusted versions for both measures are given, which should prevent the inflation of R2 in small samples. PMID:10195643

  5. Oshkosh Logistic Management and Public Relations Responsibilities at NASA Langley

    NASA Technical Reports Server (NTRS)

    Beck, Danielle

    1995-01-01

    The central focus of my study for the summer of 1995 was to provide logistical support to Margaret Hunt, the logistics manager of the OSHKOSH airshow. In this capacity responsibilities included making arrangements for participants from NASA centers and SBIR companies for their stay in Wisconsin, while visiting the airshow, and managing staff for exhibits and the aerospace theater. A secondary purpose was to serve in other public service capacities by writing news releases, fact sheets, announcements, and articles for the Researcher News.

  6. Airship logistics: The LTA vehicle; a total cargo system

    NASA Technical Reports Server (NTRS)

    Hackney, L. R. M.

    1975-01-01

    Design considerations for logistics are dealt with as they pertain to the large rigid LTA vehicle as either a commercial or military cargo carrier. Pertinent factors discussed are: (1) the basic mission; (2) types of payload; (3) the payload space in regards to configuration and sizing, its capacity, and its loadability. A logistic capability comparison of selected cargo airships versus jumbo jets is also made.

  7. Contractivity for nonautonomous logistic equation with piecewise constant delays

    NASA Astrophysics Data System (ADS)

    Nakata, Yukihiko; Kuroda, Masataka; Muroya, Yoshiaki

    2009-05-01

    In this paper, we extend the result in [Y. Muroya, Persistence, contractivity and global stability in logistic equations with piecewise constant delays, J. Math. Anal. Appl. 270 (2002) 602-635] to nonautonomous logistic equations with piecewise constant arguments and establish two sufficient conditions for contractivity-like property, from which the global asymptotic stability of the solutions of this equation is derived, even if the effect of delays dominates over the instantaneous feedback. We offer two examples to illustrate our results.

  8. Information logistics: A production-line approach to information services

    NASA Technical Reports Server (NTRS)

    Adams, Dennis; Lee, Chee-Seng

    1991-01-01

    Logistics can be defined as the process of strategically managing the acquisition, movement, and storage of materials, parts, and finished inventory (and the related information flow) through the organization and its marketing channels in a cost effective manner. It is concerned with delivering the right product to the right customer in the right place at the right time. The logistics function is composed of inventory management, facilities management, communications unitization, transportation, materials management, and production scheduling. The relationship between logistics and information systems is clear. Systems such as Electronic Data Interchange (EDI), Point of Sale (POS) systems, and Just in Time (JIT) inventory management systems are important elements in the management of product development and delivery. With improved access to market demand figures, logisticians can decrease inventory sizes and better service customer demand. However, without accurate, timely information, little, if any, of this would be feasible in today's global markets. Information systems specialists can learn from logisticians. In a manner similar to logistics management, information logistics is concerned with the delivery of the right data, to the ring customer, at the right time. As such, information systems are integral components of the information logistics system charged with providing customers with accurate, timely, cost-effective, and useful information. Information logistics is a management style and is composed of elements similar to those associated with the traditional logistics activity: inventory management (data resource management), facilities management (distributed, centralized and decentralized information systems), communications (participative design and joint application development methodologies), unitization (input/output system design, i.e., packaging or formatting of the information), transportations (voice, data, image, and video communication systems

  9. Analysis of efficiency of waste reverse logistics for recycling.

    PubMed

    Veiga, Marcelo M

    2013-10-01

    Brazil is an agricultural country with the highest pesticide consumption in the world. Historically, pesticide packaging has not been disposed of properly. A federal law requires the chemical industry to provide proper waste management for pesticide-related products. A reverse logistics program was implemented, which has been hailed a great success. This program was designed to target large rural communities, where economy of scale can take place. Over the last 10 years, the recovery rate has been very poor in most small rural communities. The objective of this study was to analyze the case of this compulsory reverse logistics program for pesticide packaging under the recent Brazilian Waste Management Policy, which enforces recycling as the main waste management solution. This results of this exploratory research indicate that despite its aggregate success, the reverse logistics program is not efficient for small rural communities. It is not possible to use the same logistic strategy for small and large communities. The results also indicate that recycling might not be the optimal solution, especially in developing countries with unsatisfactory recycling infrastructure and large transportation costs. Postponement and speculation strategies could be applied for improving reverse logistics performance. In most compulsory reverse logistics programs, there is no economical solution. Companies should comply with the law by ranking cost-effective alternatives. PMID:23997069

  10. Using Logistic Regression to Predict the Probability of Debris Flows in Areas Burned by Wildfires, Southern California, 2003-2006

    USGS Publications Warehouse

    Rupert, Michael G.; Cannon, Susan H.; Gartner, Joseph E.; Michael, John A.; Helsel, Dennis R.

    2008-01-01

    Logistic regression was used to develop statistical models that can be used to predict the probability of debris flows in areas recently burned by wildfires by using data from 14 wildfires that burned in southern California during 2003-2006. Twenty-eight independent variables describing the basin morphology, burn severity, rainfall, and soil properties of 306 drainage basins located within those burned areas were evaluated. The models were developed as follows: (1) Basins that did and did not produce debris flows soon after the 2003 to 2006 fires were delineated from data in the National Elevation Dataset using a geographic information system; (2) Data describing the basin morphology, burn severity, rainfall, and soil properties were compiled for each basin. These data were then input to a statistics software package for analysis using logistic regression; and (3) Relations between the occurrence or absence of debris flows and the basin morphology, burn severity, rainfall, and soil properties were evaluated, and five multivariate logistic regression models were constructed. All possible combinations of independent variables were evaluated to determine which combinations produced the most effective models, and the multivariate models that best predicted the occurrence of debris flows were identified. Percentage of high burn severity and 3-hour peak rainfall intensity were significant variables in all models. Soil organic matter content and soil clay content were significant variables in all models except Model 5. Soil slope was a significant variable in all models except Model 4. The most suitable model can be selected from these five models on the basis of the availability of independent variables in the particular area of interest and field checking of probability maps. The multivariate logistic regression models can be entered into a geographic information system, and maps showing the probability of debris flows can be constructed in recently burned areas of

  11. Mapping Van

    NASA Technical Reports Server (NTRS)

    1994-01-01

    A NASA Center for the Commercial Development of Space (CCDS) - developed system for satellite mapping has been commercialized for the first time. Global Visions, Inc. maps an area while driving along a road in a sophisticated mapping van equipped with satellite signal receivers, video cameras and computer systems for collecting and storing mapping data. Data is fed into a computerized geographic information system (GIS). The resulting amps can be used for tax assessment purposes, emergency dispatch vehicles and fleet delivery companies as well as other applications.

  12. Preliminary analysis of an integrated logistics system for OSSA payloads. Volume 3: OSSA integrated logistics support planning document

    NASA Technical Reports Server (NTRS)

    Palguta, T.; Bradley, W.; Stockton, T.

    1988-01-01

    Guidance in preparing and updating an integrated logistics support plan (ILSP) is given. Clear, concise, and detailed instructions are provided on the preparation and content of an ILSP in order to ensure a quality document that reflects total program requirements.

  13. An Optimal Hierarchical Decision Model for a Regional Logistics Network with Environmental Impact Consideration

    PubMed Central

    Zhang, Dezhi; Li, Shuangyan

    2014-01-01

    This paper proposes a new model of simultaneous optimization of three-level logistics decisions, for logistics authorities, logistics operators, and logistics users, for regional logistics network with environmental impact consideration. The proposed model addresses the interaction among the three logistics players in a complete competitive logistics service market with CO2 emission charges. We also explicitly incorporate the impacts of the scale economics of the logistics park and the logistics users' demand elasticity into the model. The logistics authorities aim to maximize the total social welfare of the system, considering the demand of green logistics development by two different methods: optimal location of logistics nodes and charging a CO2 emission tax. Logistics operators are assumed to compete with logistics service fare and frequency, while logistics users minimize their own perceived logistics disutility given logistics operators' service fare and frequency. A heuristic algorithm based on the multinomial logit model is presented for the three-level decision model, and a numerical example is given to illustrate the above optimal model and its algorithm. The proposed model provides a useful tool for modeling competitive logistics services and evaluating logistics policies at the strategic level. PMID:24977209

  14. Using Logistic Regression and Random Forests multivariate statistical methods for landslide spatial probability assessment in North-Est Sicily, Italy

    NASA Astrophysics Data System (ADS)

    Trigila, Alessandro; Iadanza, Carla; Esposito, Carlo; Scarascia-Mugnozza, Gabriele

    2015-04-01

    North-East Sicily is strongly exposed to shallow landslide events. On October, 1st 2009 a severe rainstorm (225.5 mm of cumulative rainfall in 9 hours) caused flash floods and more than 1000 landslides, which struck several small villages as Giampilieri, Altolia, Molino, Pezzolo, Scaletta Zanclea, Itala, with 31 fatalities, 6 missing persons and damage to buildings and transportation infrastructures. Landslides, mainly consisting in earth and debris translational slides evolving into debris flows, triggered on steep slopes involving colluvium and regolith materials which cover the underlying metamorphic bedrock of Peloritani Mountains. In this area catchments are small (about 10 square kilometres), elongated, with steep slopes, low order streams, short time of concentration, and discharge directly into the sea. In the past, landslides occurred at Altolia in 1613 and 2000, at Molino in 1750, 1805 and 2000, at Giampilieri in 1791, 1918, 1929, 1932, 2000 and on October 25, 2007. The aim of this work is to define susceptibility models for shallow landslides using multivariate statistical analyses in the Giampilieri area (25 square kilometres). A detailed landslide inventory map has been produced, as the first step, through field surveys coupled with the observation of high resolution aerial colour orthophoto taken immediately after the event. 1,490 initiation zones have been identified; most of them have planimetric dimensions ranging between tens to few hundreds of square metres. The spatial hazard assessment has been focused on the detachment areas. Susceptibility models, performed in a GIS environment, took into account several parameters. The morphometric and hydrologic parameters has been derived from a detailed LiDAR 1×1 m. Square grid cells of 4×4 m were adopted as mapping units, on the basis of the area-frequency distribution of the detachment zones, and the optimal representation of the local morphometric conditions (e.g. slope angle, plan curvature). A

  15. AIAA/SOLE Space Logistics Symposium, 4th, Cocoa Beach, FL, Nov. 4-6, 1991, Technical Papers

    SciTech Connect

    Not Available

    1991-01-01

    Various papers on space logistics are presented. The general topics addressed include: commercial space systems operations and logistics; operations and logistics technology development; space operations and logistics CE, TQM, and LCC; ground systems infrastructure development supporting space operations; logistics support of orbital operations; logistics software, data, and documentation; ground operations supporting space operations; automation, robotics, and manned systems operations and logistics; Space Station operations and logistics; launch operations and processing support for space programs, space transportation operations and logistics, Space Exploration Initiative support.

  16. Undersea Mapping.

    ERIC Educational Resources Information Center

    DiSpezio, Michael A.

    1991-01-01

    Presented is a cooperative learning activity in which students assume different roles in an effort to produce a relief map of the ocean floor. Materials, procedures, definitions, student roles, and questions are discussed. A reproducible map for the activity is provided. (CW)

  17. Question Mapping

    ERIC Educational Resources Information Center

    Martin, Josh

    2012-01-01

    After accepting the principal position at Farmersville (TX) Junior High, the author decided to increase instructional rigor through question mapping because of the success he saw using this instructional practice at his prior campus. Teachers are the number one influence on student achievement (Marzano, 2003), so question mapping provides a…

  18. Map Adventures.

    ERIC Educational Resources Information Center

    Geological Survey (Dept. of Interior), Reston, VA.

    This curriculum packet about maps, with seven accompanying lessons, is appropriate for students in grades K-3. Students learn basic concepts for visualizing objects from different perspectives and how to understand and use maps. Lessons in the packet center on a story about a little girl, Nikki, who rides in a hot-air balloon that gives her, and…

  19. Helix coupling

    DOEpatents

    Ginell, W.S.

    1982-03-17

    A coupling for connecting helix members in series, which consists of a pair of U-shaped elements, one of which is attached to each helix end with the U sections of the elements interlocked. The coupling is particularly beneficial for interconnecting helical Nitinol elements utilized in thermal actuators or engines. Each coupling half is attached to the associated helix at two points, thereby providing axial load while being easily removed from the helix, and reusable.

  20. Helix coupling

    DOEpatents

    Ginell, William S.

    1989-04-25

    A coupling for connecting helix members in series, which consists of a pair of U-shaped elements, one of which is attached to each helix end with the "U" sections of the elements interlocked. The coupling is particularly beneficial for interconnecting helical Nitinol elements utilized in thermal actuators or engines. Each coupling half is attached to the associated helix at two points, thereby providing axial load while being easily removed from the helix, and reusable.

  1. Improvement in fresh fruit and vegetable logistics quality: berry logistics field studies.

    PubMed

    do Nascimento Nunes, M Cecilia; Nicometo, Mike; Emond, Jean Pierre; Melis, Ricardo Badia; Uysal, Ismail

    2014-06-13

    Shelf life of fresh fruits and vegetables is greatly influenced by environmental conditions. Increasing temperature usually results in accelerated loss of quality and shelf-life reduction, which is not physically visible until too late in the supply chain to adjust logistics to match shelf life. A blackberry study showed that temperatures inside pallets varied significantly and 57% of the berries arriving at the packinghouse did not have enough remaining shelf life for the longest supply routes. Yet, the advanced shelf-life loss was not physically visible. Some of those pallets would be sent on longer supply routes than necessary, creating avoidable waste. Other studies showed that variable pre-cooling at the centre of pallets resulted in physically invisible uneven shelf life. We have shown that using simple temperature measurements much waste can be avoided using 'first expiring first out'. Results from our studies showed that shelf-life prediction should not be based on a single quality factor as, depending on the temperature history, the quality attribute that limits shelf life may vary. Finally, methods to use air temperature to predict product temperature for highest shelf-life prediction accuracy in the absence of individual sensors for each monitored product have been developed. Our results show a significant reduction of up to 98% in the root-mean-square-error difference between the product temperature and air temperature when advanced estimation methods are used. PMID:24797135

  2. Chaotic and stable perturbed maps: 2-cycles and spatial models

    NASA Astrophysics Data System (ADS)

    Braverman, E.; Haroutunian, J.

    2010-06-01

    As the growth rate parameter increases in the Ricker, logistic and some other maps, the models exhibit an irreversible period doubling route to chaos. If a constant positive perturbation is introduced, then the Ricker model (but not the classical logistic map) experiences period doubling reversals; the break of chaos finally gives birth to a stable two-cycle. We outline the maps which demonstrate a similar behavior and also study relevant discrete spatial models where the value in each cell at the next step is defined only by the values at the cell and its nearest neighbors. The stable 2-cycle in a scalar map does not necessarily imply 2-cyclic-type behavior in each cell for the spatial generalization of the map.

  3. Dual Use of Packaging on the Moon: Logistics-2-Living

    NASA Technical Reports Server (NTRS)

    Howe, A. Scott; Howard, Robert

    2010-01-01

    This paper describes a modular packaging system for logistics that can be reconfigured into internal outfitting for a lunar outpost, including desks, chairs, partitions, cabinets, and radiation shielding. Logistics include clothes, equipment, food, and other consumables needed to sustain the crew for the duration of the mission. A significant mass penalty is required for the packaging and handling of logistics for re-supply of short to long-term space missions that must be brought out of the gravity well on a launch vehicle. Once the supplies have been exhausted, the packaging material is typically of no further use and is discarded. If a scheme can be developed that reuses the logistics packaging, the mass penalty can be reduced. In this research, a modular packaging system has been devised as a kit-of-parts that can be used for both handling logistics supplies, and then reconfigured into desks, chairs, partitions, cabinets, and radiation shielding. The system is derived from a standard International Space Station (ISS)-type Cargo Transfer Bag (CTB), using soft, unfoldable box-like containers with stiff metal inserts. The empty hydrogen-impregnated CTBs can be used as-is for cabinets, opened up for use as partitions, or draped over the habitat as layers of radiation shielding. Stiff metal inserts can be reconfigured into desks and other useful outfitting.

  4. Application of logistic analysis to the history of physics.

    SciTech Connect

    LePoire, D. J.; Environmental Assessment

    2005-05-01

    Recently, two analyses have tried to put technological progress in a larger context. One interpretation hypothesizes that technological progress is likely to continue at increasingly higher rates of change. Another interpretation, which includes data from the beginning of the universe to the present, suggests that the universe is approaching a transition point in a logistic development of complexity. This logistic development is similar to the way ideas or products diffuse in a population, i.e., the rate of discovery in a field of knowledge is proportional to the amount discovered and the amount to be discovered. To test a part of this hypothesis, a leading indicator field (fundamental physics) was identified and the events in the history of this field were analyzed. Twelve subfields were identified and grouped into six stages. Each stage seemed to demonstrate a logistic-like development. By analyzing both the median time of development and the characteristic time of development of these stages, the overall development of this one field was found to suggest logistic development. These data seem to indicate that development in fundamental physics is slowing down, with at least one subfield beyond string physics yet to be developed. The data tend to support the hypothesis that a knowledge field can develop logistically.

  5. Cradle-to-Grave Logistic Technologies for Exploration Missions

    NASA Technical Reports Server (NTRS)

    Broyan, James L.; Ewert, Michael K.; Shull, Sarah

    2013-01-01

    Human exploration missions under study are very limited by the launch mass capacity of exiting and planned vehicles. The logistical mass of crew items is typically considered separate from the vehicle structure, habitat outfitting, and life support systems. Consequently, crew item logistical mass is typically competing with vehicle systems for mass allocation. NASA is Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) Project is developing four logistics technologies guided by a systems engineering cradle-to-grave approach to enable used crew items to augment vehicle systems. Specifically, AES LRR is investigating the direct reduction of clothing mass, the repurposing of logistical packaging, the processing of spent crew items to benefit radiation shielding and water recovery, and the conversion of trash to propulsion supply gases. The systematic implementation of these types of technologies will increase launch mass efficiency by enabling items to be used for secondary purposes and improve the habitability of the vehicle as the mission duration increases. This paper provides a description, benefits, and challenges of the four technologies under development and a status of progress at the mid ]point of the three year AES project.

  6. Logistics support economy and efficiency through consolidation and automation

    NASA Technical Reports Server (NTRS)

    Savage, G. R.; Fontana, C. J.; Custer, J. D.

    1985-01-01

    An integrated logistics support system, which would provide routine access to space and be cost-competitive as an operational space transportation system, was planned and implemented to support the NSTS program launch-on-time goal of 95 percent. A decision was made to centralize the Shuttle logistics functions in a modern facility that would provide office and training space and an efficient warehouse area. In this warehouse, the emphasis is on automation of the storage and retrieval function, while utilizing state-of-the-art warehousing and inventory management technology. This consolidation, together with the automation capabilities being provided, will allow for more effective utilization of personnel and improved responsiveness. In addition, this facility will be the prime support for the fully integrated logistics support of the operations era NSTS and reduce the program's management, procurement, transportation, and supply costs in the operations era.

  7. A Formal Approach for Milk-Run Transport Logistics

    NASA Astrophysics Data System (ADS)

    Satoh, Ichiro

    A formal approach for specifying and reasoning about earth-friendly logistics management systems is presented. To reduce fossil fuel consumption and carbon dioxide emissions resulting from transport, we must enhance the transport efficiency of trucks, which play an essential role as carriers in modern logistics services. This paper addresses the milk-run approach. It is one of the most effective and popular solutions to this problem, but it makes it be complicated to implement in a logistics management system. We propose a language for specifying the routes of trucks and an order relation between the requirements of routes and the possible routes of trucks. The former is formulated as process calculus and the latter selects suitable trucks according to their routes.

  8. Estimating the exceedance probability of rain rate by logistic regression

    NASA Technical Reports Server (NTRS)

    Chiu, Long S.; Kedem, Benjamin

    1990-01-01

    Recent studies have shown that the fraction of an area with rain intensity above a fixed threshold is highly correlated with the area-averaged rain rate. To estimate the fractional rainy area, a logistic regression model, which estimates the conditional probability that rain rate over an area exceeds a fixed threshold given the values of related covariates, is developed. The problem of dependency in the data in the estimation procedure is bypassed by the method of partial likelihood. Analyses of simulated scanning multichannel microwave radiometer and observed electrically scanning microwave radiometer data during the Global Atlantic Tropical Experiment period show that the use of logistic regression in pixel classification is superior to multiple regression in predicting whether rain rate at each pixel exceeds a given threshold, even in the presence of noisy data. The potential of the logistic regression technique in satellite rain rate estimation is discussed.

  9. Flood susceptible analysis at Kelantan river basin using remote sensing and logistic regression model

    NASA Astrophysics Data System (ADS)

    Pradhan, Biswajeet

    Recently, in 2006 and 2007 heavy monsoons rainfall have triggered floods along Malaysia's east coast as well as in southern state of Johor. The hardest hit areas are along the east coast of peninsular Malaysia in the states of Kelantan, Terengganu and Pahang. The city of Johor was particularly hard hit in southern side. The flood cost nearly billion ringgit of property and many lives. The extent of damage could have been reduced or minimized if an early warning system would have been in place. This paper deals with flood susceptibility analysis using logistic regression model. We have evaluated the flood susceptibility and the effect of flood-related factors along the Kelantan river basin using the Geographic Information System (GIS) and remote sensing data. Previous flooded areas were extracted from archived radarsat images using image processing tools. Flood susceptibility mapping was conducted in the study area along the Kelantan River using radarsat imagery and then enlarged to 1:25,000 scales. Topographical, hydrological, geological data and satellite images were collected, processed, and constructed into a spatial database using GIS and image processing. The factors chosen that influence flood occurrence were: topographic slope, topographic aspect, topographic curvature, DEM and distance from river drainage, all from the topographic database; flow direction, flow accumulation, extracted from hydrological database; geology and distance from lineament, taken from the geologic database; land use from SPOT satellite images; soil texture from soil database; and the vegetation index value from SPOT satellite images. Flood susceptible areas were analyzed and mapped using the probability-logistic regression model. Results indicate that flood prone areas can be performed at 1:25,000 which is comparable to some conventional flood hazard map scales. The flood prone areas delineated on these maps correspond to areas that would be inundated by significant flooding

  10. Health care logistics: who has the ball during disaster?

    PubMed Central

    VanVactor, Jerry D.

    2011-01-01

    In contemporary organizations, a wide gamut of options is available for sustaining and supporting health care operations. When disaster strikes, despite having tenable plans for routine replenishment and operations, many organizations find themselves ill-prepared, ill-equipped, and without effective mechanisms in place to sustain operations during the immediate aftermath of a crisis. Health care operations can be abruptly halted due to the non-availability of supply. The purpose of this work is to add to a necessary, growing body of works related specifically to health care logistics preparedness and disaster mitigation. Logistics management is a specialized genre of expertise within the health care industry and is largely contributive to the success or failure of health care organizations. Logistics management requires extensive collaboration among multiple stakeholders—internal and external to an organization. Effective processes and procedures can be largely contributive to the success or failure of organizational operations. This article contributes to the closure of an obvious gap in professional and academic literature related to disaster health care logistics management and provides timely insight into a potential problem for leaders industry-wide. One critical aspect of disaster planning is regard for competent logistics management and the effective provision of necessary items when they are needed most. In many communities, there seems to be little evidence available regarding health care logistics involvement in disaster planning; at times, evidence of planning efforts perceptibly end at intra-organizational doors within facilities. Strategic planners are being continually reminded that health care organizations serve a principal role in emergency preparedness planning and must be prepared to fulfill the associated possibilities without notification. The concern is that not enough attention is being paid to repeated lessons being observed in disasters

  11. Logistics Reduction and Repurposing Technology for Long Duration Space Missions

    NASA Technical Reports Server (NTRS)

    Broyan, James L.; Chu, Andrew; Ewert, Michael K.

    2014-01-01

    One of NASA's Advanced Exploration Systems (AES) projects is the Logistics Reduction and Repurposing (LRR) project, which has the goal of reducing logistics resupply items through direct and indirect means. Various technologies under development in the project will reduce the launch mass of consumables and their packaging, enable reuse and repurposing of items and make logistics tracking more efficient. Repurposing also reduces the trash burden onboard spacecraft and indirectly reduces launch mass by replacing some items on the manifest. Examples include reuse of trash as radiation shielding or propellant. This paper provides the status of the LRR technologies in their third year of development under AES. Advanced clothing systems (ACS) are being developed to enable clothing to be worn longer, directly reducing launch mass. ACS has completed a ground exercise clothing study in preparation for an International Space Station (ISS) technology demonstration in 2014. Development of launch packaging containers and other items that can be repurposed on-orbit as part of habitation outfitting has resulted in a logistics-to-living (L2L) concept. L2L has fabricated and evaluated several multi-purpose cargo transfer bags (MCTBs) for potential reuse on orbit. Autonomous logistics management (ALM) is using radio frequency identification (RFID) to track items and thus reduce crew requirements for logistics functions. An RFID dense reader prototype is under construction and plans for integrated testing are being made. Development of a heat melt compactor (HMC) second generation unit for processing trash into compact and stable tiles is nearing completion. The HMC prototype compaction chamber has been completed and system development testing is underway. Research has been conducted on the conversion of trash-to-gas (TtG) for high levels of volume reduction and for use in propulsion systems. A steam reformation system was selected for further system definition of the TtG technology

  12. Logistics: An integral part of cost efficient space operations

    NASA Technical Reports Server (NTRS)

    Montgomery, Ann D.

    1996-01-01

    The logistics of space programs and its history within NASA are discussed, with emphasis on manned space flight and the Space Shuttle program. The lessons learned and the experience gained during these programs are reported on. Key elements of logistics are highlighted, and the problems and issues that can be expected to arise in relation to the support of long-term space operations and future space programs, are discussed. Such missions include the International Space Station program and the reusable launch vehicle. Possible solutions to the problems identified are outlined.

  13. On an approximate method for the delay logistic equation

    NASA Astrophysics Data System (ADS)

    Röst, Gergely

    2011-09-01

    This note concerns with the asymptotic properties of solutions of the delay logistic equation. In particular, we point out some false statements in the recent paper Khan et al. [Khan H, Liao SJ, Mohapatra RN, Vajravelu K. An analytical solution for a nonlinear time-delay model in biology. Commun Nonlinear Sci Numer Simulat 2009;14:3141-3148]. Moreover, we show that the author's method is not able to reveal the basic and important features of the dynamics of the delay logistic equation, and gives misleading results.

  14. Semantic Mapping.

    ERIC Educational Resources Information Center

    Johnson, Dale D.; And Others

    1986-01-01

    Describes semantic mapping, an effective strategy for vocabulary instruction that involves the categorical structuring of information in graphic form and requires students to relate new words to their own experience and prior knowledge. (HOD)

  15. Mapping Biodiversity.

    ERIC Educational Resources Information Center

    World Wildlife Fund, Washington, DC.

    This document features a lesson plan that examines how maps help scientists protect biodiversity and how plants and animals are adapted to specific ecoregions by comparing biome, ecoregion, and habitat. Samples of instruction and assessment are included. (KHR)

  16. Direct interaction and functional coupling between human 5-HT6 receptor and the light chain 1 subunit of the microtubule-associated protein 1B (MAP1B-LC1).

    PubMed

    Kim, Soon-Hee; Kim, Dong Hyuk; Lee, Kang Ho; Im, Sun-Kyoung; Hur, Eun-Mi; Chung, Kwang Chul; Rhim, Hyewhon

    2014-01-01

    Serotonin (5-HT) receptors of type 6 (5-HT6R) play important roles in mood, psychosis, and eating disorders. Recently, a growing number of studies support the use of 5-HT6R-targeting compounds as promising drug candidates for treating cognitive dysfunction associated with Alzheimer's disease. However, the mechanistic linkage between 5-HT6R and such functions remains poorly understood. By using yeast two-hybrid, GST pull-down, and co-immunoprecipitation assays, here we show that human 5-HT6R interacts with the light chain 1 (LC1) subunit of MAP1B protein (MAP1B-LC1), a classical microtubule-associated protein highly expressed in the brain. Functionally, we have found that expression of MAP1B-LC1 regulates serotonin signaling in a receptor subtype-specific manner, specifically controlling the activities of 5-HT6R, but not those of 5-HT4R and 5-HT7R. In addition, we have demonstrated that MAP1B-LC1 increases the surface expression of 5-HT6R and decreases its endocytosis, suggesting that MAP1B-LC1 is involved in the desensitization and trafficking of 5-HT6R via a direct interaction. Together, we suggest that signal transduction pathways downstream of 5-HT6R are regulated by MAP1B, which might play a role in 5-HT6R-mediated signaling in the brain. PMID:24614691

  17. Direct Interaction and Functional Coupling between Human 5-HT6 Receptor and the Light Chain 1 Subunit of the Microtubule-Associated Protein 1B (MAP1B-LC1)

    PubMed Central

    Kim, Soon-Hee; Kim, Dong Hyuk; Lee, Kang Ho; Im, Sun-Kyoung; Hur, Eun-Mi; Chung, Kwang Chul; Rhim, Hyewhon

    2014-01-01

    Serotonin (5-HT) receptors of type 6 (5-HT6R) play important roles in mood, psychosis, and eating disorders. Recently, a growing number of studies support the use of 5-HT6R-targeting compounds as promising drug candidates for treating cognitive dysfunction associated with Alzheimer’s disease. However, the mechanistic linkage between 5-HT6R and such functions remains poorly understood. By using yeast two-hybrid, GST pull-down, and co-immunoprecipitation assays, here we show that human 5-HT6R interacts with the light chain 1 (LC1) subunit of MAP1B protein (MAP1B-LC1), a classical microtubule-associated protein highly expressed in the brain. Functionally, we have found that expression of MAP1B-LC1 regulates serotonin signaling in a receptor subtype-specific manner, specifically controlling the activities of 5-HT6R, but not those of 5-HT4R and 5-HT7R. In addition, we have demonstrated that MAP1B-LC1 increases the surface expression of 5-HT6R and decreases its endocytosis, suggesting that MAP1B-LC1 is involved in the desensitization and trafficking of 5-HT6R via a direct interaction. Together, we suggest that signal transduction pathways downstream of 5-HT6R are regulated by MAP1B, which might play a role in 5-HT6R-mediated signaling in the brain. PMID:24614691

  18. Map Separates

    USGS Publications Warehouse

    U.S. Geological Survey

    2001-01-01

    U.S. Geological Survey (USGS) topographic maps are printed using up to six colors (black, blue, green, red, brown, and purple). To prepare your own maps or artwork based on maps, you can order separate black-and-white film positives or negatives for any color printed on a USGS topographic map, or for one or more of the groups of related features printed in the same color on the map (such as drainage and drainage names from the blue plate.) In this document, examples are shown with appropriate ink color to illustrate the various separates. When purchased, separates are black-and-white film negatives or positives. After you receive a film separate or composite from the USGS, you can crop, enlarge or reduce, and edit to add or remove details to suit your special needs. For example, you can adapt the separates for making regional and local planning maps or for doing many kinds of studies or promotions by using the features you select and then printing them in colors of your choice.

  19. Venus mapping

    NASA Technical Reports Server (NTRS)

    Batson, R. M.; Morgan, H. F.; Sucharski, Robert

    1991-01-01

    Semicontrolled image mosaics of Venus, based on Magellan data, are being compiled at 1:50,000,000, 1:10,000,000, 1:5,000,000, and 1:1,000,000 scales to support the Magellan Radar Investigator (RADIG) team. The mosaics are semicontrolled in the sense that data gaps were not filled and significant cosmetic inconsistencies exist. Contours are based on preliminary radar altimetry data that is subjected to revision and improvement. Final maps to support geologic mapping and other scientific investigations, to be compiled as the dataset becomes complete, will be sponsored by the Planetary Geology and Geophysics Program and/or the Venus Data Analysis Program. All maps, both semicontrolled and final, will be published as I-maps by the United States Geological Survey. All of the mapping is based on existing knowledge of the spacecraft orbit; photogrammetric triangulation, a traditional basis for geodetic control on planets where framing cameras were used, is not feasible with the radar images of Venus, although an eventual shift of coordinate system to a revised spin-axis location is anticipated. This is expected to be small enough that it will affect only large-scale maps.

  20. Optical coupling

    NASA Astrophysics Data System (ADS)

    Bock, J. J.; Gundersen, J.; Lee, A. T.; Richards, P. L.; Wollack, E.

    2009-03-01

    This paper describes contributions to the CMBpol Technology Study Workshop concerning optical coupling structures. These are structures in or near the focal plane which convert the free space wave to a superconducting microstrip on a SI wafer, or to the waveguide input to a HEMT receiver. In addition to an introduction and conclusions by the editor, this paper includes independent contributions by Bock on 'Planar Antenna-Coupled Bolometers for CMB Polarimetry', by Gunderson and Wollack on 'Millimeter-Wave Platlet Feeds', and by Lee on 'Multi-band Dual-Polarization Lens-coupled Planar Antennas for Bolometric CMB polarimetry.'

  1. 77 FR 5788 - PetroLogistics Natural Gas Storage, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-06

    ... Energy Regulatory Commission PetroLogistics Natural Gas Storage, LLC; Notice of Application Take notice that on January 27, 2012, PetroLogistics Natural Gas Storage, LLC (PetroLogistics), 4470 Bluebonnet... previously filed application in Docket No. CP11-50-000. Specifically, PetroLogistics request to amend...

  2. 76 FR 544 - PetroLogistics Natural Gas Storage, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-05

    ... Energy Regulatory Commission PetroLogistics Natural Gas Storage, LLC; Notice of Application December 28, 2010. Take notice that on December 14, 2010, PetroLogistics Natural Gas Storage, LLC (PetroLogistics... parallel PetroLogistics' existing header; (3) constructing two new compressor units, totaling...

  3. 77 FR 20618 - PetroLogistics Natural Gas Storage, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-05

    ... Energy Regulatory Commission PetroLogistics Natural Gas Storage, LLC; Notice of Application Take notice that on March 22, 2012, PetroLogistics Natural Gas Storage, LLC (PetroLogistics), 4470 Bluebonnet Blvd..., and CP07-429-000, as amended in Docket No. CP10-66-000. Specifically, PetroLogistics request to...

  4. 75 FR 43944 - Membership of the Defense Logistics Agency (DLA) Senior Executive Service (SES) Performance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... Defense Logistics Agency Membership of the Defense Logistics Agency (DLA) Senior Executive Service (SES... 16, 2010. ADDRESSES: Defense Logistics Agency, 8725 John J. Kingman Road, Suite 2533, Fort Belvoir... Resources (J-14), Defense Logistics Agency, (703) 767-6447. SUPPLEMENTARY INFORMATION: In accordance with...

  5. 75 FR 49917 - PetroLogistics Natural Gas Storage, LLC; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-16

    ... Energy Regulatory Commission PetroLogistics Natural Gas Storage, LLC; Notice of Application August 3, 2010. Take notice that on July 21, 2010, PetroLogistics Natural Gas Storage, LLC (PetroLogistics), 4470..., measuring, and appurtenant facilities in order to connect the cavern to PetroLogistics' existing...

  6. On the Usefulness of a Multilevel Logistic Regression Approach to Person-Fit Analysis

    ERIC Educational Resources Information Center

    Conijn, Judith M.; Emons, Wilco H. M.; van Assen, Marcel A. L. M.; Sijtsma, Klaas

    2011-01-01

    The logistic person response function (PRF) models the probability of a correct response as a function of the item locations. Reise (2000) proposed to use the slope parameter of the logistic PRF as a person-fit measure. He reformulated the logistic PRF model as a multilevel logistic regression model and estimated the PRF parameters from this…

  7. 76 FR 53119 - Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-25

    ... of Availability (NOA) in the Federal Register (76 FR 28757) announcing the revised Defense Logistics... Office of the Secretary Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense Logistics Agency Actions AGENCY: Defense Logistics Agency, Department of Defense....

  8. 77 FR 22576 - Possible Revocation of Ocean Transportation Intermediary License No. 021899-Trans World Logistics...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-16

    ... Possible Revocation of Ocean Transportation Intermediary License No. 021899--Trans World Logistics Corporation; Order To Show Cause Trans World Logistics Corporation (Trans World Logistics) is an Indiana... Licensing (BCL) indicate that Trans World Logistics maintains its principal offices at 702 Penny...

  9. 77 FR 52713 - PetroLogistics Natural Gas Storage, LLC; Notice of Request Under Blanket Authorization

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-30

    ... Energy Regulatory Commission PetroLogistics Natural Gas Storage, LLC; Notice of Request Under Blanket Authorization Take notice that on August 17, 2012, PetroLogistics Natural Gas Storage, LLC (PetroLogistics... Iberville Parish, Louisiana, under PetroLogistics' blanket certificate issued in Docket No. CP07-427-000,...

  10. Segment of Challenger's right wing unloaded at KSC Logistics Facility

    NASA Technical Reports Server (NTRS)

    1986-01-01

    a 9'7' x 16' segment of Challenger's right wing is unloaded at the Logistics Facility after being off-loaded from the rescue and salvage ship USS Opportune. It was located and recovered by Navy divers from the Opportune about 12 nautical miles northeast of Cape Canaveral in 70 feet of water.

  11. Logistics modeling of future solid waste storage, treatment, and disposal

    SciTech Connect

    Holter, G.M.; Stiles, D.L.; Shaver, S.R.; Armacost, L.L.

    1993-11-01

    Logistics modeling is a powerful analytical technique for effective planning of waste storage, treatment, and disposal activities. Logistics modeling facilitates analyses of alternate scenarios for future waste flows, facility schedules, and processing or handling capacities. These analyses provide an increased understanding of the specific needs for waste storage, treatment, and disposal while adequate time remains to plan accordingly. They also help to determine the sensitivity of these needs to various system parameters. This paper discusses a logistics modeling system developed by the Pacific Northwest Laboratory (PNL) to aid in solid waste planning for a large industrial complex managing many different types and classifications of waste. The basic needs for such a system are outlined, and the approach adopted in developing the system is described. A key component of this approach is the development of a conceptual model that provides a flexible framework for modeling the waste management system and addressing the range of logistics and economic issues involved. Developing an adequate description of the waste management system being analyzed is discussed. Examples are then provided of the types of analyses that have been conducted. The potential application of this modeling system to different settings is also examined.

  12. Multinomial logistic regression-based feature selection for hyperspectral data

    NASA Astrophysics Data System (ADS)

    Pal, Mahesh

    2012-02-01

    This paper evaluates the performance of three feature selection methods based on multinomial logistic regression, and compares the performance of the best multinomial logistic regression-based feature selection approach with the support vector machine based recurring feature elimination approach. Two hyperspectral datasets, one consisting of 65 features (DAIS data) and other with 185 features (AVIRIS data) were used. Result suggests that a total of between 15 and 10 features selected by using the multinomial logistic regression-based feature selection approach as proposed by Cawley and Talbot achieve a significant improvement in classification accuracy in comparison to the use of all the features of the DAIS and AVIRIS datasets. In addition to the improved performance, the Cawley and Talbot approach does not require any user-defined parameter, thus avoiding the requirement of a model selection stage. In comparison, the other two multinomial logistic regression-based feature selection approaches require one user-defined parameter and do not perform as well as the Cawley and Talbot approach in terms of (i) the number of features required to achieve classification accuracy comparable to that achieved using the full dataset, and (ii) the classification accuracy achieved by the selected features. The Cawley and Talbot approach was also found to be computationally more efficient than the SVM-RFE technique, though both use the same number of selected features to achieve an equal or even higher level of accuracy than that achieved with full hyperspectral datasets.

  13. The imperative for stronger vaccine supply and logistics systems.

    PubMed

    Zaffran, Michel; Vandelaer, Jos; Kristensen, Debra; Melgaard, Bjørn; Yadav, Prashant; Antwi-Agyei, K O; Lasher, Heidi

    2013-04-18

    With the introduction of new vaccines, developing countries are facing serious challenges in their vaccine supply and logistics systems. Storage capacity bottlenecks occur at national, regional, and district levels and system inefficiencies threaten vaccine access, availability, and quality. As countries adopt newer and more expensive vaccines and attempt to reach people at different ages and in new settings, their logistics systems must be strengthened and optimized. As a first step, national governments, donors, and international agencies have crafted a global vision for 2020 vaccine supply and logistics systems with detailed plans of action to achieve five priority objectives. Vaccine products and packaging are designed to meet the needs of developing countries. Immunization supply systems support efficient and effective vaccine delivery. The environmental impact of energy, materials, and processes used in immunization systems is minimized. Immunization information systems enable better and more timely decision-making. Competent and motivated personnel are empowered to handle immunization supply chain issues. Over the next decade, vaccine supply and logistics systems in nearly all developing countries will require significant investments of time and resources from global and national partners, donors, and governments. These investments are critical if we are to reach more people with current and newer vaccines. PMID:23598495

  14. "Contested Rights": The Pedagogy and Logistics of Hosting Constitution Day

    ERIC Educational Resources Information Center

    Miracle, Amanda; Smith, Michael; Anderson, Kevin; Catlett, Rob

    2016-01-01

    To seriously consider one's rights under the US Constitution, one must grapple with the realization that many rights are not absolute. Instead, they are contested. But how to introduce younger students to such a complex concept, given short attention spans? In this article, we discuss the opportunities, pitfalls, and planning logistics of the 2013…

  15. Modeling logistic performance in quantitative microbial risk assessment.

    PubMed

    Rijgersberg, Hajo; Tromp, Seth; Jacxsens, Liesbeth; Uyttendaele, Mieke

    2010-01-01

    In quantitative microbial risk assessment (QMRA), food safety in the food chain is modeled and simulated. In general, prevalences, concentrations, and numbers of microorganisms in media are investigated in the different steps from farm to fork. The underlying rates and conditions (such as storage times, temperatures, gas conditions, and their distributions) are determined. However, the logistic chain with its queues (storages, shelves) and mechanisms for ordering products is usually not taken into account. As a consequence, storage times-mutually dependent in successive steps in the chain-cannot be described adequately. This may have a great impact on the tails of risk distributions. Because food safety risks are generally very small, it is crucial to model the tails of (underlying) distributions as accurately as possible. Logistic performance can be modeled by describing the underlying planning and scheduling mechanisms in discrete-event modeling. This is common practice in operations research, specifically in supply chain management. In this article, we present the application of discrete-event modeling in the context of a QMRA for Listeria monocytogenes in fresh-cut iceberg lettuce. We show the potential value of discrete-event modeling in QMRA by calculating logistic interventions (modifications in the logistic chain) and determining their significance with respect to food safety. PMID:20055976

  16. Vehicle scheduling schemes for commercial and emergency logistics integration.

    PubMed

    Li, Xiaohui; Tan, Qingmei

    2013-01-01

    In modern logistics operations, large-scale logistics companies, besides active participation in profit-seeking commercial business, also play an essential role during an emergency relief process by dispatching urgently-required materials to disaster-affected areas. Therefore, an issue has been widely addressed by logistics practitioners and caught researchers' more attention as to how the logistics companies achieve maximum commercial profit on condition that emergency tasks are effectively and performed satisfactorily. In this paper, two vehicle scheduling models are proposed to solve the problem. One is a prediction-related scheme, which predicts the amounts of disaster-relief materials and commercial business and then accepts the business that will generate maximum profits; the other is a priority-directed scheme, which, firstly groups commercial and emergency business according to priority grades and then schedules both types of business jointly and simultaneously by arriving at the maximum priority in total. Moreover, computer-based simulations are carried out to evaluate the performance of these two models by comparing them with two traditional disaster-relief tactics in China. The results testify the feasibility and effectiveness of the proposed models. PMID:24391724

  17. Vehicle Scheduling Schemes for Commercial and Emergency Logistics Integration

    PubMed Central

    Li, Xiaohui; Tan, Qingmei

    2013-01-01

    In modern logistics operations, large-scale logistics companies, besides active participation in profit-seeking commercial business, also play an essential role during an emergency relief process by dispatching urgently-required materials to disaster-affected areas. Therefore, an issue has been widely addressed by logistics practitioners and caught researchers' more attention as to how the logistics companies achieve maximum commercial profit on condition that emergency tasks are effectively and performed satisfactorily. In this paper, two vehicle scheduling models are proposed to solve the problem. One is a prediction-related scheme, which predicts the amounts of disaster-relief materials and commercial business and then accepts the business that will generate maximum profits; the other is a priority-directed scheme, which, firstly groups commercial and emergency business according to priority grades and then schedules both types of business jointly and simultaneously by arriving at the maximum priority in total. Moreover, computer-based simulations are carried out to evaluate the performance of these two models by comparing them with two traditional disaster-relief tactics in China. The results testify the feasibility and effectiveness of the proposed models. PMID:24391724

  18. Stability analysis of a stochastic logistic model with infinite delay

    NASA Astrophysics Data System (ADS)

    Liu, Meng; Fan, Dejun; Wang, Ke

    2013-09-01

    This report is concerned with a stochastic logistic equation with infinite delay. We establish the sufficient conditions for global asymptotical stability of the zero solution and the positive equilibrium. Some classical results are improved and extended. Several numerical simulations are introduced to illustrate the main results.

  19. Flower Power: Sunflowers as a Model for Logistic Growth

    ERIC Educational Resources Information Center

    Fernandez, Eileen; Geist, Kristi A.

    2011-01-01

    Logistic growth displays an interesting pattern: It starts fast, exhibiting the rapid growth characteristic of exponential models. As time passes, it slows in response to constraints such as limited resources or reallocation of energy. The growth continues to slow until it reaches a limit, called capacity. When the growth describes a population,…

  20. Sourcing for Parameter Estimation and Study of Logistic Differential Equation

    ERIC Educational Resources Information Center

    Winkel, Brian J.

    2012-01-01

    This article offers modelling opportunities in which the phenomena of the spread of disease, perception of changing mass, growth of technology, and dissemination of information can be described by one differential equation--the logistic differential equation. It presents two simulation activities for students to generate real data, as well as…

  1. Detecting Differential Item Functioning Using Logistic Regression Procedures.

    ERIC Educational Resources Information Center

    Swaminathan, Hariharan; Rogers, H. Jane

    1990-01-01

    A logistic regression model for characterizing differential item functioning (DIF) between two groups is presented. A distinction is drawn between uniform and nonuniform DIF in terms of model parameters. A statistic for testing the hypotheses of no DIF is developed, and simulation studies compare it with the Mantel-Haenszel procedure. (Author/TJH)

  2. Charter Starters Leadership Training Workbook 1: Start-Up Logistics.

    ERIC Educational Resources Information Center

    Ley, Joyce

    This workbook is the first in a series devoted to all areas of charter-school development. It addresses the logistics of starting a school, such as drafting a charter, creating a vision and mission, accessing expert information, navigating the application process, acquiring a facility, establishing a legal entity, and contracting for services. The…

  3. 77 FR 39662 - Hazardous Materials; Reverse Logistics (RRR)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ... final rule issued under docket HM-215K (76 FR 3308, January 19, 2011), PHMSA began phasing out the ORM-D... Federal Register published on April 11, 2000 (65 FR 19477) or you may visit http://www.dot.gov/privacy... an NPRM that will propose to simplify the regulations for reverse logistics shipments and...

  4. Hierarchical Logistic Regression: Accounting for Multilevel Data in DIF Detection

    ERIC Educational Resources Information Center

    French, Brian F.; Finch, W. Holmes

    2010-01-01

    The purpose of this study was to examine the performance of differential item functioning (DIF) assessment in the presence of a multilevel structure that often underlies data from large-scale testing programs. Analyses were conducted using logistic regression (LR), a popular, flexible, and effective tool for DIF detection. Data were simulated…

  5. Co-integration Model of Logistics Infrastructure Investment and Regional Economic Growth in Central China

    NASA Astrophysics Data System (ADS)

    Hu, Kai; Gan, Xiao-qing; Gao, Kuo

    The speed of logistics infrastructures investment in Central China is still lower than other regions since the rise of the central region strategy was put forward. And the ration of freight turnover was also being down. The analysis with the relations among the central region of the logistics investment, logistics value-added and GDP, found that three variables exists co-integration relation. And found that the investment in logistics infrastructure was the Granger reason of the GDP, the investment in logistics infrastructure and logistics value-added was the Granger reason for each other. According to the analysis, some countermeasures be put forward as following: accelerate the speed of logistics investment, optimize logistics environment, promote the logistics capability, reduce logistics cost, and so on.

  6. Mapping dynamical systems onto complex networks

    NASA Astrophysics Data System (ADS)

    Borges, E. P.; Cajueiro, D. O.; Andrade, R. F. S.

    2007-08-01

    The objective of this study is to design a procedure to characterize chaotic dynamical systems, in which they are mapped onto a complex network. The nodes represent the regions of space visited by the system, while the edges represent the transitions between these regions. Parameters developed to quantify the properties of complex networks, including those related to higher order neighbourhoods, are used in the analysis. The methodology is tested on the logistic map, focusing on the onset of chaos and chaotic regimes. The corresponding networks were found to have distinct features that are associated with the particular type of dynamics that generated them.

  7. The role of logistic constraints in termite construction of chambers and tunnels.

    PubMed

    Ladley, Dan; Bullock, Seth

    2005-06-21

    In previous models of the building behaviour of termites, physical and logistic constraints that limit the movement of termites and pheromones have been neglected. Here, we present an individual-based model of termite construction that includes idealized constraints on the diffusion of pheromones, the movement of termites, and the integrity of the architecture that they construct. The model allows us to explore the extent to which the results of previous idealized models (typically realised in one or two dimensions via a set of coupled partial differential equations) generalize to a physical, 3-D environment. Moreover we are able to investigate new processes and architectures that rely upon these features. We explore the role of stigmergic recruitment in pillar formation, wall building, and the construction of royal chambers, tunnels and intersections. In addition, for the first time, we demonstrate the way in which the physicality of partially built structures can help termites to achieve efficient tunnel structures and to establish and maintain entrances in royal chambers. As such we show that, in at least some cases, logistic constraints can be important or even necessary in order for termites to achieve efficient, effective constructions. PMID:15808875

  8. Using Logistic Regression To Predict the Probability of Debris Flows Occurring in Areas Recently Burned By Wildland Fires

    USGS Publications Warehouse

    Rupert, Michael G.; Cannon, Susan H.; Gartner, Joseph E.

    2003-01-01

    Logistic regression was used to predict the probability of debris flows occurring in areas recently burned by wildland fires. Multiple logistic regression is conceptually similar to multiple linear regression because statistical relations between one dependent variable and several independent variables are evaluated. In logistic regression, however, the dependent variable is transformed to a binary variable (debris flow did or did not occur), and the actual probability of the debris flow occurring is statistically modeled. Data from 399 basins located within 15 wildland fires that burned during 2000-2002 in Colorado, Idaho, Montana, and New Mexico were evaluated. More than 35 independent variables describing the burn severity, geology, land surface gradient, rainfall, and soil properties were evaluated. The models were developed as follows: (1) Basins that did and did not produce debris flows were delineated from National Elevation Data using a Geographic Information System (GIS). (2) Data describing the burn severity, geology, land surface gradient, rainfall, and soil properties were determined for each basin. These data were then downloaded to a statistics software package for analysis using logistic regression. (3) Relations between the occurrence/non-occurrence of debris flows and burn severity, geology, land surface gradient, rainfall, and soil properties were evaluated and several preliminary multivariate logistic regression models were constructed. All possible combinations of independent variables were evaluated to determine which combination produced the most effective model. The multivariate model that best predicted the occurrence of debris flows was selected. (4) The multivariate logistic regression model was entered into a GIS, and a map showing the probability of debris flows was constructed. The most effective model incorporates the percentage of each basin with slope greater than 30 percent, percentage of land burned at medium and high burn severity

  9. Parametric mapping

    NASA Astrophysics Data System (ADS)

    Branch, Allan C.

    1998-01-01

    Parametric mapping (PM) lies midway between older and proven artificial landmark based guidance systems and yet to be realized vision based guidance systems. It is a simple yet effective natural landmark recognition system offering freedom from the need for enhancements to the environment. Development of PM systems can be inexpensive and rapid and they are starting to appear in commercial and industrial applications. Together with a description of the structural framework developed to generically describe robot mobility, this paper illustrates clearly the parts of any mobile robot navigation and guidance system and their interrelationships. Among other things, the importance of the richness of the reference map, and not necessarily the sensor map, is introduced, the benefits of dynamic path planners to alleviate the need for separate object avoidance, and the independence of the PM system to the type of sensor input is shown.

  10. LOGISTIC FUNCTION PROFILE FIT: A least-squares program for fitting interface profiles to an extended logistic function

    SciTech Connect

    Kirchhoff, William H.

    2012-09-15

    The extended logistic function provides a physically reasonable description of interfaces such as depth profiles or line scans of surface topological or compositional features. It describes these interfaces with the minimum number of parameters, namely, position, width, and asymmetry. Logistic Function Profile Fit (LFPF) is a robust, least-squares fitting program in which the nonlinear extended logistic function is linearized by a Taylor series expansion (equivalent to a Newton-Raphson approach) with no apparent introduction of bias in the analysis. The program provides reliable confidence limits for the parameters when systematic errors are minimal and provides a display of the residuals from the fit for the detection of systematic errors. The program will aid researchers in applying ASTM E1636-10, 'Standard practice for analytically describing sputter-depth-profile and linescan-profile data by an extended logistic function,' and may also prove useful in applying ISO 18516: 2006, 'Surface chemical analysis-Auger electron spectroscopy and x-ray photoelectron spectroscopy-determination of lateral resolution.' Examples are given of LFPF fits to a secondary ion mass spectrometry depth profile, an Auger surface line scan, and synthetic data generated to exhibit known systematic errors for examining the significance of such errors to the extrapolation of partial profiles.

  11. Prosthesis coupling

    NASA Technical Reports Server (NTRS)

    Reswick, J. B.; Mooney, V.; Bright, C. W.; Owens, L. J. (Inventor)

    1979-01-01

    A coupling for use in an apparatus for connecting a prosthesis to the bone of a stump of an amputated limb is described which permits a bio-compatible carbon sleeve forming a part of the prosthesis connector to float so as to prevent disturbing the skin seal around the carbon sleeve. The coupling includes a flexible member interposed between a socket that is inserted within an intermedullary cavity of the bone and the sleeve. A lock pin is carried by the prosthesis and has a stem portion which is adapted to be coaxially disposed and slideably within the tubular female socket for securing the prosthesis to the stump. The skin around the percutaneous carbon sleeve is able to move as a result of the flexing coupling so as to reduce stresses caused by changes in the stump shape and/or movement between the bone and the flesh portion of the stump.

  12. FLEXIBLE COUPLING

    DOEpatents

    Babelay, E.F.

    1962-02-13

    A flexible shaft coupling for operation at speeds in excess of 14,000 rpm is designed which requires no lubrication. A driving sleeve member and a driven sleeve member are placed in concentric spaced relationship. A torque force is transmitted to the driven member from the driving member through a plurality of nylon balls symmetrically disposed between the spaced sleeves. The balls extend into races and recesses within the respective sleeve members. The sleeve members have a suitable clearance therebetween and the balls have a suitable radial clearance during operation of the coupling to provide a relatively loose coupling. These clearances accommodate for both parallel and/or angular misalignments and avoid metal-tometal contact between the sleeve members during operation. Thus, no lubrication is needed, and a minimum of vibrations is transmitted between the sleeve members. (AEC)

  13. Assessing the spatial variability of weights of landslide causal factors in different regions from Romania, using logistic regression

    NASA Astrophysics Data System (ADS)

    Margarint, M. C.; Grozavu, A.; Patriche, C. V.

    2012-04-01

    Landslides represent a significant natural hazard in hilly areas of Romania which cause important damages. The scientific interest for landslide susceptibility mapping is quite recent and standardized through legislation. However, there is need for improving the methodology, in order for the susceptibility maps to constitute a sound basis for territorial planning. The logistic regression is one of the main statistical methods used for assessing terrain susceptibility for landsliding. There are different degrees of weighting the landslide causal factors mentioned in the scientific literature, but with large variations. This study aims to identify the range of variation of landslide causal factors for different regions in Romania. The following factors were taken into consideration: slope angle, terrain altitude, terrain curvature (mean, plan and profile), soil type, lithologic class, land use, distance from drainage network and roads, mean annual precipitations. Four square perimeters of 15x15 km were chosen from representative regions in terms of spatial extent of landslides: two situated in the central-northern part of the Moldavian Plateau, one in the Transylvania Depression and one in the Moldavian Subcarpathians. The logistic regression was applied separately for the four sectors. In order to monitor the differences in the final results, numerous attempts have been made, starting from landslides polygons acquired from both the topographic maps at scale 1:25.000 (1984-1985 edition) and the ortophotoimages (2005-2006). The other elements were acquired from cartographic materials at appropriate scales, according the international methodology. The data integration was accomplished in the georeferenced environment provided by TNTMips 6.9 ArcGIS 9.3 and SAGA 2.0.8 software packages, while the statistical analysis was performed using Excel 2003 and XLSTAT 2010 trial version. Maps for all landslide causal factors were achieved for each perimeter. The logistic

  14. The Soufriere Hills Volcano, Montserrat, is "log logistic"

    NASA Astrophysics Data System (ADS)

    Connor, C.; Sparks, S.; Mason, R.; Bonadonna, C.; Young, S.; Lejeune, A.

    2002-12-01

    The Soufriere Hills Volcano, Montserrat, experienced a remarkable episode of activity in September-October, 1997. During this period, 75 vulcanian explosions generated plumes that commonly rose between 5 to 15 km a.s.l. accompanied by pyroclastic flows. Repose intervals between vulcanian explosions varied from 2.77 to 33.7 hrs, with a median repose interval of 9.0 hr and mean of 9.6 hr. During the eruption, this narrow range of repose intervals was used in a practical way to provide qualitative forecasts of volcanic hazard. We analyzed repose intervals for these 75 vulcanian explosions and discovered they fit a log logistic distribution with > 99% confidence. This comparatively simple, two parameter model accounts for departures from a classical material failure model (Weibull distribution) at long repose intervals, and serves as the basis for improved hazard forecasts. The crucial differences between Weibull, and log logistic probability models for volcano repose interval are illustrated by comparing their hazard functions. For Weibull distributions the hazard increases indefinitely: the volcano must erupt explosively eventually and as time increases the probability of an eruption in the next time interval becomes much greater. In contrast the log logistic hazard function goes through a simple maximum. We note that largest magnitude eruptions in the time series, deduced from column height estimates and seismic explosion amplitudes, correlate with the peak in the log logistic hazard function. The excellent model fit is explained in terms of two competing processes operating in the upper conduit on different time scales. Gas bubble pressure increases with time due to exsolution and due to rheological stiffening of magma of magma following an abrupt decompression caused by a previous explosion. Once bubble gas pressure exceeds the tensile strength of the magma an explosion occurs - a material failure model that should follow a Weibull distribution. However, this

  15. Memphis Maps.

    ERIC Educational Resources Information Center

    Hyland, Stanley; Cox, David; Martin, Cindy

    1998-01-01

    The Memphis Maps program, a collaborative effort of Memphis (Tennessee) educational institutions, public agencies, a bank, and community programs, trains local students in Geographic Information Systems technology and provides the community with valuable demographic and assessment information. The program is described, and factors contributing to…

  16. Ariane Transfer Vehicle - Logistic support to Space Station Freedom

    NASA Astrophysics Data System (ADS)

    Cougnet, C.; Ricaud, C.; Deutscher, N.

    The attractiveness of the Ariane 5 and Ariane transfer vehicle (ATV) is described: it avoids the one-sidedness of the National STS, it increases the lift capacity to meet the demands of the Space Station, and it offers a system independent of, but consistent with, the STS in providing backup contingency capability. The Ariane 5/ATV system is able to launch and transfer any cargo module to the Space Station Freedom (SSF) and dispose of it at the end of the mission. Consideration is given to Space Station and SSF logistic support, and ATV operations and design. Diagrams are provided to illustrate the ATV's requirements and capability; an ATV mission toward the SSF; ATV design and components; the ATV's attitude, layout, and the architecture of the main propulsion system and avionic; and the ATV's performance. It is demonstrated that the Ariane 5/ATV system would be an adequate complement to the NSTS for logistic support of the SSF.

  17. Modeling urban growth with geographically weighted multinomial logistic regression

    NASA Astrophysics Data System (ADS)

    Luo, Jun; Kanala, Nagaraj Kapi

    2008-10-01

    Spatial heterogeneity is usually ignored in previous land use change studies. This paper presents a geographically weighted multinomial logistic regression model for investigating multiple land use conversion in the urban growth process. The proposed model makes estimation at each sample location and generates local coefficients of driving factors for land use conversion. A Gaussian function is used for determine the geographic weights guarantying that all other samples are involved in the calibration of the model for one location. A case study on Springfield metropolitan area is conducted. A set of independent variables are selected as driving factors. A traditional multinomial logistic regression model is set up and compared with the proposed model. Spatial variations of coefficients of independent variables are revealed by investigating the estimations at sample locations.

  18. In-space propellant logistics. Volume 4: Project planning data

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The prephase A conceptual project planning data as it pertains to the development of the selected logistics module configuration transported into earth orbit by the space shuttle orbiter. The data represents the test, implementation, and supporting research and technology requirements for attaining the propellant transfer operational capability for early 1985. The plan is based on a propellant module designed to support the space-based tug with cryogenic oxygen-hydrogen propellants. A logical sequence of activities that is required to define, design, develop, fabricate, test, launch, and flight test the propellant logistics module is described. Included are the facility and ground support equipment requirements. The schedule of activities are based on the evolution and relationship between the R and T, the development issues, and the resultant test program.

  19. Interacting Bose gas, the logistic law, and complex networks

    NASA Astrophysics Data System (ADS)

    Sowa, A.

    2015-01-01

    We discuss a mathematical link between the Quantum Statistical Mechanics and the logistic growth and decay processes. It is based on an observation that a certain nonlinear operator evolution equation, which we refer to as the Logistic Operator Equation (LOE), provides an extension of the standard model of noninteracting bosons. We discuss formal solutions (asymptotic formulas) for a special calibration of the LOE, which sets it in the number-theoretic framework. This trick, in the tradition of Julia and Bost-Connes, makes it possible for us to tap into the vast resources of classical mathematics and, in particular, to construct explicit solutions of the LOE via the Dirichlet series. The LOE is applicable to a range of modeling and simulation tasks, from characterization of interacting boson systems to simulation of some complex man-made networks. The theoretical results enable numerical simulations, which, in turn, shed light at the unique complexities of the rich and multifaceted models resulting from the LOE.

  20. Antibiotic lock therapy: review of technique and logistical challenges

    PubMed Central

    Justo, Julie Ann; Bookstaver, P Brandon

    2014-01-01

    Antibiotic lock therapy (ALT) for the prevention and treatment of catheter-related bloodstream infections is a simple strategy in theory, yet its real-world application may be delayed or avoided due to technical questions and/or logistical challenges. This review focuses on these latter aspects of ALT, including preparation information for a variety of antibiotic lock solutions (ie, aminoglycosides, beta-lactams, fluoroquinolones, folate antagonists, glycopeptides, glycylcyclines, lipopeptides, oxazolidinones, polymyxins, and tetracyclines) and common clinical issues surrounding ALT administration. Detailed data regarding concentrations, additives, stability/compatibility, and dwell times are summarized. Logistical challenges such as lock preparation procedures, use of additives (eg, heparin, citrate, or ethylenediaminetetraacetic acid), timing of initiation and therapy duration, optimal dwell time and catheter accessibility, and risks of ALT are also described. Development of local protocols is recommended in order to avoid these potential barriers and encourage utilization of ALT where appropriate. PMID:25548523

  1. Applying simulation and logistics modeling to tansportation issues

    SciTech Connect

    Funkhouser, B.R.; Ballweg, E.L.; Mackoy, R.D.

    1995-08-15

    This paper describes an application where transportation logistics and simulation tools are integrated to create a modeling environment for transportation planning. The Transportation Planning Model (TPM) is a tool developed for the Department of Energy (DOE) to aid in the long-term planning of their transportation resources. The focus of the tool is to aid DOE and Sandia National Laboratory analysts in the planning of future fleet sizes, driver and support personnel sizes, base site locations, and resource balancing among the base sites. The design approach is to develop a rapid modeling environment which integrates graphical user interfaces, logistics optimizing tools, and simulation modeling. Using the TPM an analyst can easily set up a shipment scenario and perform multiple ``What If`` evaluations. The TPM has been developed on personal computers using commercial off-the-shelf software tools under the WINDOW{reg_sign} operating environment.

  2. In-space propellant logistics. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The study addresses the systems and operational problems associated with the transport, transfer, and storage of cryogenic propellants in low earth orbits. The safety problems connected with in-space propellant logistics operations are also considered.Correlation between the two projects was maintained by including safety considerations, resulting from the system safety analysis, in the trade studies and evaluations of alternate operating concepts in the systems operations analysis.

  3. Security controls in the Stockpoint Logistics Integrated Communications Environment (SPLICE)

    NASA Astrophysics Data System (ADS)

    Arseneault, D. S.

    1985-03-01

    This thesis examines security controls specified and implemented in the Stock Point Logistics Integrated Communications Environment (SPLICE) project. Controls provided by the Defense Data Network and the Tandem operating system are reviewed. Alternatives from current literature in areas of authentication, encryption, and dial-port protection are reviewed for the purpose of suggesting enhancements. Issues discussed apply to most interactive/decentralized systems in operation today and include administrative as well as technical recommendations.

  4. Logistics Operations Management Center: Maintenance Support Baseline (LOMC-MSB)

    NASA Technical Reports Server (NTRS)

    Kurrus, R.; Stump, F.

    1995-01-01

    The Logistics Operations Management Center Maintenance Support Baseline is defined. A historical record of systems, applied to and deleted from, designs in support of future management and/or technical analysis is provided. All Flight elements, Ground Support Equipment, Facility Systems and Equipment and Test Support Equipment for which LOMC has responsibilities at Kennedy Space Center and other locations are listed. International Space Station Alpha Program documentation is supplemented. The responsibility of the Space Station Launch Site Support Office is established.

  5. Estimating Logistics Support of Reusable Launch Vehicles During Conceptual Design

    NASA Technical Reports Server (NTRS)

    Morris, W. D.; White, N. H.; Davies, W. T.; Ebeling, C. E.

    1997-01-01

    Methods exist to define the logistics support requirements for new aircraft concepts but are not directly applicable to new launch vehicle concepts. In order to define the support requirements and to discriminate among new technologies and processing choices for these systems, NASA Langley Research Center (LaRC) is developing new analysis methods. This paper describes several methods under development, gives their current status, and discusses the benefits and limitations associated with their use.

  6. [Outliers and robust logistic regression in Health Sciences].

    PubMed

    Cutanda Henríquez, Francisco

    2008-01-01

    Logistic regression methods have many applications in Health Sciences. There is a vast literature about procedures to be followed and the way to find the estimators for the parameters from the observed values, and these methods are implemented to all the usual statistical packages. These estimators are of the 'maximum likelihood' kind, i.e., they are the ones that make the observed values the most probable among all the models that could have been used. The good properties of the maximum likelihood estimators are widely demonstrated. However, there are some practical circumstances that may cause the presence of 'outliers', i.e., observed values not corresponding to the logistic model we are assuming as a hypothesis. Occasionally, these anomalous observations can have a strong effect on the fit, and lead the study to the wrong conclusion. The causes of these outliers depend on the particular study, but it is possible to point out classification errors, observations (subjects) with special features which have not been taken into account, uncertainty in the measurement of some parameters, etc. The problem with maximum likelihood estimators is that they are not 'robust', i.e., their sensitivity to outliers could be arbitrarily large, and a minority of outliers could lead to a wrong logistic model. In this work, we will show two cases illustrating possible consequences, and we will discuss the application of robust methods. PMID:19180273

  7. Automatic Ammunition Identification Technology Project. Ammunition Logistics Program

    SciTech Connect

    Weil, B.

    1993-03-01

    The Automatic Ammunition Identification Technology (AAIT) Project is an activity of the Robotics & Process Systems Division at the Oak Ridge National Laboratory (ORNL) for the US Army`s Project Manager-Ammunition Logistics (PM-AMMOLOG) at the Picatinny Arsenal in Picatinny, New Jersey. The project objective is to evaluate new two-dimensional bar code symbologies for potential use in ammunition logistics systems and automated reloading equipment. These new symbologies are a significant improvement over typical linear bar codes since machine-readable alphanumeric messages up to 2000 characters long are achievable. These compressed data symbologies are expected to significantly improve logistics and inventory management tasks and permit automated feeding and handling of ammunition to weapon systems. The results will be increased throughout capability, better inventory control, reduction of human error, lower operation and support costs, and a more timely re-supply of various weapon systems. This paper will describe the capabilities of existing compressed data symbologies and the symbol testing activities being conducted at ORNL for the AAIT Project.

  8. Classifying machinery condition using oil samples and binary logistic regression

    NASA Astrophysics Data System (ADS)

    Phillips, J.; Cripps, E.; Lau, John W.; Hodkiewicz, M. R.

    2015-08-01

    The era of big data has resulted in an explosion of condition monitoring information. The result is an increasing motivation to automate the costly and time consuming human elements involved in the classification of machine health. When working with industry it is important to build an understanding and hence some trust in the classification scheme for those who use the analysis to initiate maintenance tasks. Typically "black box" approaches such as artificial neural networks (ANN) and support vector machines (SVM) can be difficult to provide ease of interpretability. In contrast, this paper argues that logistic regression offers easy interpretability to industry experts, providing insight to the drivers of the human classification process and to the ramifications of potential misclassification. Of course, accuracy is of foremost importance in any automated classification scheme, so we also provide a comparative study based on predictive performance of logistic regression, ANN and SVM. A real world oil analysis data set from engines on mining trucks is presented and using cross-validation we demonstrate that logistic regression out-performs the ANN and SVM approaches in terms of prediction for healthy/not healthy engines.

  9. Evaluating sediment chemistry and toxicity data using logistic regression modeling

    USGS Publications Warehouse

    Field, L.J.; MacDonald, D.D.; Norton, S.B.; Severn, C.G.; Ingersoll, C.G.

    1999-01-01

    This paper describes the use of logistic-regression modeling for evaluating matching sediment chemistry and toxicity data. Contaminant- specific logistic models were used to estimate the percentage of samples expected to be toxic at a given concentration. These models enable users to select the probability of effects of concern corresponding to their specific assessment or management objective or to estimate the probability of observing specific biological effects at any contaminant concentration. The models were developed using a large database (n = 2,524) of matching saltwater sediment chemistry and toxicity data for field-collected samples compiled from a number of different sources and geographic areas. The models for seven chemicals selected as examples showed a wide range in goodness of fit, reflecting high variability in toxicity at low concentrations and limited data on toxicity at higher concentrations for some chemicals. The models for individual test endpoints (e.g., amphipod mortality) provided a better fit to the data than the models based on all endpoints combined. A comparison of the relative sensitivity of two amphipod species to specific contaminants illustrated an important application of the logistic model approach.

  10. Emergency management logistics must become emergency supply chain management.

    PubMed

    Young, Richard R; Peterson, Matthew R

    2014-01-01

    Much has been written about how emergency management (EM) needs to look to the future regarding issues of resource management (monetary, human, and material). Constraints on budgets are ongoing and the staffing of emergency response activities is often difficult because volunteers have little to no training. The management of material resources has also been a challenge because 1) the categories of material vary by the type of emergency, 2) the necessary quantities of material are often not located near the ultimate point of need, and 3) the transportation assets are rarely available in the form and quantity required to allow timely and effective response. The logistics and resource management functions of EM (what we refer to as EM logistics) have been largely reactive, with little to no pre-event planning for potential demand. We applied the Supply Chain Operational Reference (SCOR) model to EM logistics in an effort to transform it to an integrated and scalable system of physical, information, and financial flows into which are woven the functions of sourcing, making, delivering, and returning, with an overarching planning function that transcends the organizational boundaries of participants. The result is emergency supply chain management, which embraces many more participants who share in a larger quantity of more useful information about the resources that need to be deployed when responding to and recovering from emergency events. PMID:24828913

  11. Logistics Process Analysis ToolProcess Analysis Tool

    Energy Science and Technology Software Center (ESTSC)

    2008-03-31

    LPAT is the resulting integrated system between ANL-developed Enhanced Logistics Intra Theater Support Tool (ELIST) sponsored by SDDC-TEA and the Fort Future Virtual Installation Tool (sponsored by CERL). The Fort Future Simulation Engine was an application written in the ANL Repast Simphony framework and used as the basis for the process Anlysis Tool (PAT) which evolved into a stand=-along tool for detailed process analysis at a location. Combined with ELIST, an inter-installation logistics component wasmore » added to enable users to define large logistical agent-based models without having to program. PAT is the evolution of an ANL-developed software system called Fort Future Virtual Installation Tool (sponsored by CERL). The Fort Future Simulation Engine was an application written in the ANL Repast Simphony framework and used as the basis for the Process Analysis Tool(PAT) which evolved into a stand-alone tool for detailed process analysis at a location (sponsored by the SDDC-TEA).« less

  12. Distribution of submerged aquatic vegetation in the St. Louis River estuary: Maps and models

    EPA Science Inventory

    In late summer of 2011 and 2012 we used echo-sounding gear to map the distribution of submerged aquatic vegetation (SAV) in the St. Louis River Estuary (SLRE). From these data we produced maps of SAV distribution and we created logistic models to predict the probability of occurr...

  13. “Pure chaotic” orbits of one-dimensional maps have third-order correlation

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Takashi; Ichimura, Atsushi

    1984-04-01

    The triple-time-correlation function for the logistic map and the tent map, both for the uppermost values of their parameters, are calculated analytically and orbits of these systems are shown to be different from a pseudo-random-number sequence generated on a computer. Violation of the time-reversal invariance by these orbits is also discussed.

  14. Demand Analysis of Logistics Information Matching Platform: A Survey from Highway Freight Market in Zhejiang Province

    NASA Astrophysics Data System (ADS)

    Chen, Daqiang; Shen, Xiahong; Tong, Bing; Zhu, Xiaoxiao; Feng, Tao

    With the increasing competition in logistics industry and promotion of lower logistics costs requirements, the construction of logistics information matching platform for highway transportation plays an important role, and the accuracy of platform design is the key to successful operation or not. Based on survey results of logistics service providers, customers and regulation authorities to access to information and in-depth information demand analysis of logistics information matching platform for highway transportation in Zhejiang province, a survey analysis for framework of logistics information matching platform for highway transportation is provided.

  15. A novel color image encryption scheme using alternate chaotic mapping structure

    NASA Astrophysics Data System (ADS)

    Wang, Xingyuan; Zhao, Yuanyuan; Zhang, Huili; Guo, Kang

    2016-07-01

    This paper proposes an color image encryption algorithm using alternate chaotic mapping structure. Initially, we use the R, G and B components to form a matrix. Then one-dimension logistic and two-dimension logistic mapping is used to generate a chaotic matrix, then iterate two chaotic mappings alternately to permute the matrix. For every iteration, XOR operation is adopted to encrypt plain-image matrix, then make further transformation to diffuse the matrix. At last, the encrypted color image is obtained from the confused matrix. Theoretical analysis and experimental results has proved the cryptosystem is secure and practical, and it is suitable for encrypting color images.

  16. Measuring the uncertainty of coupling

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaojun; Shang, Pengjian

    2015-06-01

    A new information-theoretic measure, called coupling entropy, is proposed here to detect the causal links in complex systems by taking into account the inner composition alignment of temporal structure. It is a permutation-based asymmetric association measure to infer the uncertainty of coupling between two time series. The coupling entropy is found to be effective in the analysis of Hénon maps, where different noises are added to test its accuracy and sensitivity. The coupling entropy is also applied to analyze the relationship between unemployment rate and CPI change in the U.S., where the CPI change turns out to be the driving variable while the unemployment rate is the responding one.

  17. A technique for determining viable military logistics support alternatives

    NASA Astrophysics Data System (ADS)

    Hester, Jesse Stuart

    A look at today's US military will see them operating much beyond the scope of protecting and defending the United States. These operations now consist of, but are not limited to humanitarian aid, disaster relief, peace keeping, and conflict resolution. This broad spectrum of operational environments has necessitated a transformation of the individual military services to a hybrid force that is attempting to leverage the inherent and emerging capabilities and strengths of all those under the umbrella of the Department of Defense (DOD), this concept has been coined Joint Operations. Supporting Joint Operations requires a new approach to determining a viable military logistics support system. The logistics architecture for these operations has to accommodate scale, time, varied mission objectives, and imperfect information. Compounding the problem is the human in the loop (HITL) decision maker (DM) who is a necessary component for quickly assessing and planning logistics support activities. Past outcomes are not necessarily good indicators of future results, but they can provide a reasonable starting point for planning and prediction of specific needs for future requirements. Adequately forecasting the necessary logistical support structure and commodities needed for any resource intensive environment has progressed well beyond stable demand assumptions to one in which dynamic and nonlinear environments can be captured with some degree of fidelity and accuracy. While these advances are important, a holistic approach that allows exploration of the operational environment or design space does not exist to guide the military logistician in a methodical way to support military forecasting activities. To bridge this capability gap, a method called Adaptive Technique for Logistics Architecture Solutions (ATLAS) has been developed. This method provides a process that facilitates the use of techniques and tools that filter and provide relevant information to the DM. By doing

  18. Determination of riverbank erosion probability using Locally Weighted Logistic Regression

    NASA Astrophysics Data System (ADS)

    Ioannidou, Elena; Flori, Aikaterini; Varouchakis, Emmanouil A.; Giannakis, Georgios; Vozinaki, Anthi Eirini K.; Karatzas, George P.; Nikolaidis, Nikolaos

    2015-04-01

    Riverbank erosion is a natural geomorphologic process that affects the fluvial environment. The most important issue concerning riverbank erosion is the identification of the vulnerable locations. An alternative to the usual hydrodynamic models to predict vulnerable locations is to quantify the probability of erosion occurrence. This can be achieved by identifying the underlying relations between riverbank erosion and the geomorphological or hydrological variables that prevent or stimulate erosion. Thus, riverbank erosion can be determined by a regression model using independent variables that are considered to affect the erosion process. The impact of such variables may vary spatially, therefore, a non-stationary regression model is preferred instead of a stationary equivalent. Locally Weighted Regression (LWR) is proposed as a suitable choice. This method can be extended to predict the binary presence or absence of erosion based on a series of independent local variables by using the logistic regression model. It is referred to as Locally Weighted Logistic Regression (LWLR). Logistic regression is a type of regression analysis used for predicting the outcome of a categorical dependent variable (e.g. binary response) based on one or more predictor variables. The method can be combined with LWR to assign weights to local independent variables of the dependent one. LWR allows model parameters to vary over space in order to reflect spatial heterogeneity. The probabilities of the possible outcomes are modelled as a function of the independent variables using a logistic function. Logistic regression measures the relationship between a categorical dependent variable and, usually, one or several continuous independent variables by converting the dependent variable to probability scores. Then, a logistic regression is formed, which predicts success or failure of a given binary variable (e.g. erosion presence or absence) for any value of the independent variables. The

  19. 76 FR 58263 - Kenai Pipe Line Company; Tesoro Alaska Company; Tesoro Logistics Operations, LLC; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Kenai Pipe Line Company; Tesoro Alaska Company; Tesoro Logistics Operations... Company (Tesoro Alaska), and Tesoro Logistics, LLC (TLO) (collectively, Tesoro) filed a Request...

  20. Comparing performances of heuristic and logistic regression models for a spatial landslide susceptibility assessment in Maramures, County, Northwestern Romania

    NASA Astrophysics Data System (ADS)

    Mǎgut, F. L.; Zaharia, S.; Glade, T.; Irimuş, I. A.

    2012-04-01

    Various methods exist in analyzing spatial landslide susceptibility and classing the results in susceptibility classes. The prediction of spatial landslide distribution can be performed by using a variety of methods based on GIS techniques. The two very common methods of a heuristic assessment and a logistic regression model are employed in this study in order to compare their performance in predicting the spatial distribution of previously mapped landslides for a study area located in Maramureš County, in Northwestern Romania. The first model determines a susceptibility index by combining the heuristic approach with GIS techniques of spatial data analysis. The criteria used for quantifying each susceptibility factor and the expression used to determine the susceptibility index are taken from the Romanian legislation (Governmental Decision 447/2003). This procedure is followed in any Romanian state-ordered study which relies on financial support. The logistic regression model predicts the spatial distribution of landslides by statistically calculating regressive coefficients which describe the dependency of previously mapped landslides on different factors. The identified shallow landslides correspond generally to Pannonian marl and Quaternary contractile clay deposits. The study region is located in the Northwestern part of Romania, including the Baia Mare municipality, the capital of Maramureš County. The study focuses on the former piedmontal region situated to the south of the volcanic mountains Gutâi, in the Baia Mare Depression, where most of the landslide activity has been recorded. In addition, a narrow sector of the volcanic mountains which borders the city of Baia Mare to the north has also been included to test the accuracy of the models in different lithologic units. The results of both models indicate a general medium landslide susceptibility of the study area. The more detailed differences will be discussed with respect to the advantages and

  1. Research on the Environmental Performance Evaluation of Electronic Waste Reverse Logistics Enterprise

    NASA Astrophysics Data System (ADS)

    Yang, Yu-Xiang; Chen, Fei-Yang; Tong, Tong

    According to the characteristic of e-waste reverse logistics, environmental performance evaluation system of electronic waste reverse logistics enterprise is proposed. We use fuzzy analytic hierarchy process method to evaluate the system. In addition, this paper analyzes the enterprise X, as an example, to discuss the evaluation method. It's important to point out attributes and indexes which should be strengthen during the process of ewaste reverse logistics and provide guidance suggestions to domestic e-waste reverse logistics enterprises.

  2. Logistic Regression for Seismically Induced Landslide Predictions: Using Uniform Hazard and Geophysical Layers as Predictor Variables

    NASA Astrophysics Data System (ADS)

    Nowicki, M. A.; Hearne, M.; Thompson, E.; Wald, D. J.

    2012-12-01

    Seismically induced landslides present a costly and often fatal threats in many mountainous regions. Substantial effort has been invested to understand where seismically induced landslides may occur in the future. Both slope-stability methods and, more recently, statistical approaches to the problem are described throughout the literature. Though some regional efforts have succeeded, no uniformly agreed-upon method is available for predicting the likelihood and spatial extent of seismically induced landslides. For use in the U. S. Geological Survey (USGS) Prompt Assessment of Global Earthquakes for Response (PAGER) system, we would like to routinely make such estimates, in near-real time, around the globe. Here we use the recently produced USGS ShakeMap Atlas of historic earthquakes to develop an empirical landslide probability model. We focus on recent events, yet include any digitally-mapped landslide inventories for which well-constrained ShakeMaps are also available. We combine these uniform estimates of the input shaking (e.g., peak acceleration and velocity) with broadly available susceptibility proxies, such as topographic slope and surface geology. The resulting database is used to build a predictive model of the probability of landslide occurrence with logistic regression. The landslide database includes observations from the Northridge, California (1994); Wenchuan, China (2008); ChiChi, Taiwan (1999); and Chuetsu, Japan (2004) earthquakes; we also provide ShakeMaps for moderate-sized events without landslide for proper model testing and training. The performance of the regression model is assessed with both statistical goodness-of-fit metrics and a qualitative review of whether or not the model is able to capture the spatial extent of landslides for each event. Part of our goal is to determine which variables can be employed based on globally-available data or proxies, and whether or not modeling results from one region are transferrable to

  3. Logistical Consideration in Computer-Based Screening of Astronaut Applicants

    NASA Technical Reports Server (NTRS)

    Galarza, Laura

    2000-01-01

    This presentation reviews the logistical, ergonomic, and psychometric issues and data related to the development and operational use of a computer-based system for the psychological screening of astronaut applicants. The Behavioral Health and Performance Group (BHPG) at the Johnson Space Center upgraded its astronaut psychological screening and selection procedures for the 1999 astronaut applicants and subsequent astronaut selection cycles. The questionnaires, tests, and inventories were upgraded from a paper-and-pencil system to a computer-based system. Members of the BHPG and a computer programmer designed and developed needed interfaces (screens, buttons, etc.) and programs for the astronaut psychological assessment system. This intranet-based system included the user-friendly computer-based administration of tests, test scoring, generation of reports, the integration of test administration and test output to a single system, and a complete database for past, present, and future selection data. Upon completion of the system development phase, four beta and usability tests were conducted with the newly developed system. The first three tests included 1 to 3 participants each. The final system test was conducted with 23 participants tested simultaneously. Usability and ergonomic data were collected from the system (beta) test participants and from 1999 astronaut applicants who volunteered the information in exchange for anonymity. Beta and usability test data were analyzed to examine operational, ergonomic, programming, test administration and scoring issues related to computer-based testing. Results showed a preference for computer-based testing over paper-and -pencil procedures. The data also reflected specific ergonomic, usability, psychometric, and logistical concerns that should be taken into account in future selection cycles. Conclusion. Psychological, psychometric, human and logistical factors must be examined and considered carefully when developing and

  4. Prediction of siRNA potency using sparse logistic regression.

    PubMed

    Hu, Wei; Hu, John

    2014-06-01

    RNA interference (RNAi) can modulate gene expression at post-transcriptional as well as transcriptional levels. Short interfering RNA (siRNA) serves as a trigger for the RNAi gene inhibition mechanism, and therefore is a crucial intermediate step in RNAi. There have been extensive studies to identify the sequence characteristics of potent siRNAs. One such study built a linear model using LASSO (Least Absolute Shrinkage and Selection Operator) to measure the contribution of each siRNA sequence feature. This model is simple and interpretable, but it requires a large number of nonzero weights. We have introduced a novel technique, sparse logistic regression, to build a linear model using single-position specific nucleotide compositions which has the same prediction accuracy of the linear model based on LASSO. The weights in our new model share the same general trend as those in the previous model, but have only 25 nonzero weights out of a total 84 weights, a 54% reduction compared to the previous model. Contrary to the linear model based on LASSO, our model suggests that only a few positions are influential on the efficacy of the siRNA, which are the 5' and 3' ends and the seed region of siRNA sequences. We also employed sparse logistic regression to build a linear model using dual-position specific nucleotide compositions, a task LASSO is not able to accomplish well due to its high dimensional nature. Our results demonstrate the superiority of sparse logistic regression as a technique for both feature selection and regression over LASSO in the context of siRNA design. PMID:21091052

  5. The Impact of Flight Hardware Scavenging on Space Logistics

    NASA Technical Reports Server (NTRS)

    Oeftering, Richard C.

    2011-01-01

    For a given fixed launch vehicle capacity the logistics payload delivered to the moon may be only roughly 20 percent of the payload delivered to the International Space Station (ISS). This is compounded by the much lower flight frequency to the moon and thus low availability of spares for maintenance. This implies that lunar hardware is much more scarce and more costly per kilogram than ISS and thus there is much more incentive to preserve hardware. The Constellation Lunar Surface System (LSS) program is considering ways of utilizing hardware scavenged from vehicles including the Altair lunar lander. In general, the hardware will have only had a matter of hours of operation yet there may be years of operational life remaining. By scavenging this hardware the program, in effect, is treating vehicle hardware as part of the payload. Flight hardware may provide logistics spares for system maintenance and reduce the overall logistics footprint. This hardware has a wide array of potential applications including expanding the power infrastructure, and exploiting in-situ resources. Scavenging can also be seen as a way of recovering the value of, literally, billions of dollars worth of hardware that would normally be discarded. Scavenging flight hardware adds operational complexity and steps must be taken to augment the crew s capability with robotics, capabilities embedded in flight hardware itself, and external processes. New embedded technologies are needed to make hardware more serviceable and scavengable. Process technologies are needed to extract hardware, evaluate hardware, reconfigure or repair hardware, and reintegrate it into new applications. This paper also illustrates how scavenging can be used to drive down the cost of the overall program by exploiting the intrinsic value of otherwise discarded flight hardware.

  6. Using and Interpreting Logistic Regression: A Guide for Teachers and Students.

    ERIC Educational Resources Information Center

    Lottes, Ilsa L.; And Others

    1996-01-01

    Defines and illustrates basic concepts of dichotomous logistic regression (DLR) and presents strategies for teaching these concepts. Strategies include using analogies between ordinary least squares regression and logistic regression; illustrating concepts with contingency tables; and linking logistic regression concepts to interpretation of…

  7. And Who Will Teach Them? An Investigation of the Logistics PhD Market

    ERIC Educational Resources Information Center

    Golicic, Susan L.; Bobbitt, L. Michelle; Frankel, Robert; Clinton, Steven R.

    2004-01-01

    At a time when there is high demand for logistics/supply chain education at the undergraduate and master's levels, there is short supply of logistics PhDs to take faculty positions. In this research, the authors used both primary and secondary research to confirm the gap between supply and demand of logistics/supply-chain scholars. Their study…

  8. Exploring the Lived Experiences of Program Managers Regarding an Automated Logistics Environment

    ERIC Educational Resources Information Center

    Allen, Ronald Timothy

    2014-01-01

    Automated Logistics Environment (ALE) is a new term used by Navy and aerospace industry executives to describe the aggregate of logistics-related information systems that support modern aircraft weapon systems. The development of logistics information systems is not always well coordinated among programs, often resulting in solutions that cannot…

  9. Preliminary analysis of an integrated logistics system for OSSA payloads. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    Palguta, T.; Bradley, W.; Stockton, T.

    1988-01-01

    The purpose is to describe the logistics study background and approach to providing estimates of of logistics support requirements for Office of Space Science and Applications' payloads in the Space Station era. A concise summary is given of the study results. Future logistics support analysis tasks are identified.

  10. 77 FR 62469 - Defense Logistics Agency Freedom of Information Act Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-15

    ... beginning to process a new or pending request from the requester (see OMB Fee Guidelines, 52 FR at 10012... of the Secretary 32 CFR Part 300 Defense Logistics Agency 32 CFR Part 1285 RIN 0790-AI87 Defense Logistics Agency Freedom of Information Act Program AGENCY: Defense Logistics Agency, DoD. ACTION:...

  11. 76 FR 28226 - Ndahendekire Barbara v. African Shipping; Njoroge Muhia; Alco Logistics, Llc; Brenda Alexander...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-16

    ... Ndahendekire Barbara v. African Shipping; Njoroge Muhia; Alco Logistics, Llc; Brenda Alexander; and AIR 7 Seas... ``Complainant,'' against African Shipping; Njoroge Muhia, ALCO Logistics, LLC; Brenda Alexander; and Air 7 Seas Transport Logistics, Inc.; hereinafter ``Respondents''. Complainant asserts that she is acting agent...

  12. 76 FR 72391 - Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ... (DLA) published a Notice of Availability (NOA) in the Federal Register (76 FR 28757) announcing the... of the Secretary Defense Logistics Agency Revised Regulation 1000.22, Environmental Considerations in Defense Logistics Agency Actions AGENCY: Defense Logistics Agency, Department of Defense. ACTION:...

  13. 77 FR 55817 - Delek Crude Logistics, LLC; Notice of Petition for Waiver

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-11

    ... Energy Regulatory Commission Delek Crude Logistics, LLC; Notice of Petition for Waiver Take notice that on June 11, 2012, Delek Crude Logistics, LLC (``Delek Crude'') respectfully requests that the Federal... Commission's regulations with respect to the East Texas Crude Logistics crude oil pipeline system. Any...

  14. Tubular Coupling

    NASA Technical Reports Server (NTRS)

    Rosenbaum, Bernard J. (Inventor)

    2000-01-01

    A system for coupling a vascular overflow graft or cannula to a heart pump. A pump pipe outlet is provided with an external tapered surface which receives the end of a compressible connula. An annular compression ring with a tapered internal bore surface is arranged about the cannula with the tapered internal surface in a facing relationship to the external tapered surface. The angle of inclination of the tapered surfaces is converging such that the spacing between the tapered surfaces decreases from one end of the external tapered surface to the other end thereby providing a clamping action of the tapered surface on a cannula which increases as a function of the length of cannula segment between the tapered surfaces. The annular compression ring is disposed within a tubular locking nut which threadedly couples to the pump and provides a compression force for urging the annular ring onto the cannula between the tapered surfaces. The nut has a threaded connection to the pump body. The threaded coupling to the pump body provides a compression force for the annular ring. The annular ring has an annular enclosure space in which excess cannula material from the compression between the tapered surfaces to "bunch up" in the space and serve as an enlarged annular ring segment to assist holding the cannula in place. The clamped cannula provides a seamless joint connection to the pump pipe outlet where the clamping force is uniformly applied to the cannula because of self alignment of the tapered surfaces. The nut can be easily disconnected to replace the pump if necessary.

  15. NASA Shuttle Logistics Depot (NSLD) - The application of ATE

    NASA Technical Reports Server (NTRS)

    Simpkins, Lorenz G.; Jenkins, Henry C.; Mauceri, A. Jack

    1990-01-01

    The concept of the NASA Shuttle Logistics Depot (NSLD) developed for the Space Shuttle Orbiter Program is described. The function of the NSLD at Cape Canaveral is to perform the acceptance and diagnostic testing of the Shuttle's space-rated line-replaceable units and shop-replaceable units (SRUs). The NSLD includes a comprehensive electronic automatic test station, program development stations, and assorted manufacturing support equipment (including thermal and vibration test equipment, special test equipment, and a card SRU test system). The depot activities also include the establishment of the functions for manufacturing of mechanical parts, soldering, welding, painting, clean room operation, procurement, and subcontract management.

  16. Logistic ex Vivo Lung Perfusion for Hyperimmunized Patients.

    PubMed

    De Wolf, Julien; Puyo, Philippe; Bonnette, Pierre; Roux, Antoine; Le Guen, Morgan; Parquin, François; Chapelier, Alain; Sage, Edouard

    2016-09-01

    Hyperimmunized patients have restricted access to lung transplantation because of the low rate of donor lung availability. Sensitization to human leukocyte antigen is associated with acute rejection, allograft dysfunction, and decreased survival. Prospective crossmatching could allow matching a lung graft with the recipient; however, such a strategy would increase graft ischemia, with a worse impact on the long-term results of lung transplantation. We used logistic ex vivo lung perfusion for 3 patients at the Foch Hospital while waiting for a negative result of the prospective crossmatching and then moved forward to lung transplantation. All patients are alive 3 years after bilateral lung transplantation. PMID:27549543

  17. Benefits of VTOL aircraft in offshore petroleum logistics support

    NASA Technical Reports Server (NTRS)

    Wilcox, D. E.; Shovlin, M. D.

    1975-01-01

    The mission suitability and potential economic benefits of advanced VTOL aircraft were investigated for logistics support of petroleum operations in the North Sea and the Gulf of Mexico. Concepts such as the tilt rotor and lift/cruise fan are promising for future operations beyond 150 miles offshore, where their high cruise efficiency provides savings in trip time, fuel consumption, and capital investment. Depending upon mission requirements, the aircraft operating costs are reduced by as much as 20 percent to 50 percent from those of current helicopters.

  18. Stochastic growth logistic model with aftereffect for batch fermentation process

    NASA Astrophysics Data System (ADS)

    Rosli, Norhayati; Ayoubi, Tawfiqullah; Bahar, Arifah; Rahman, Haliza Abdul; Salleh, Madihah Md

    2014-06-01

    In this paper, the stochastic growth logistic model with aftereffect for the cell growth of C. acetobutylicum P262 and Luedeking-Piret equations for solvent production in batch fermentation system is introduced. The parameters values of the mathematical models are estimated via Levenberg-Marquardt optimization method of non-linear least squares. We apply Milstein scheme for solving the stochastic models numerically. The effciency of mathematical models is measured by comparing the simulated result and the experimental data of the microbial growth and solvent production in batch system. Low values of Root Mean-Square Error (RMSE) of stochastic models with aftereffect indicate good fits.

  19. Scheduling algorithm for mission planning and logistics evaluation users' guide

    NASA Technical Reports Server (NTRS)

    Chang, H.; Williams, J. M.

    1976-01-01

    The scheduling algorithm for mission planning and logistics evaluation (SAMPLE) program is a mission planning tool composed of three subsystems; the mission payloads subsystem (MPLS), which generates a list of feasible combinations from a payload model for a given calendar year; GREEDY, which is a heuristic model used to find the best traffic model; and the operations simulation and resources scheduling subsystem (OSARS), which determines traffic model feasibility for available resources. The SAMPLE provides the user with options to allow the execution of MPLS, GREEDY, GREEDY-OSARS, or MPLS-GREEDY-OSARS.

  20. Stochastic growth logistic model with aftereffect for batch fermentation process

    SciTech Connect

    Rosli, Norhayati; Ayoubi, Tawfiqullah; Bahar, Arifah; Rahman, Haliza Abdul; Salleh, Madihah Md

    2014-06-19

    In this paper, the stochastic growth logistic model with aftereffect for the cell growth of C. acetobutylicum P262 and Luedeking-Piret equations for solvent production in batch fermentation system is introduced. The parameters values of the mathematical models are estimated via Levenberg-Marquardt optimization method of non-linear least squares. We apply Milstein scheme for solving the stochastic models numerically. The effciency of mathematical models is measured by comparing the simulated result and the experimental data of the microbial growth and solvent production in batch system. Low values of Root Mean-Square Error (RMSE) of stochastic models with aftereffect indicate good fits.

  1. Programmable Thermostat Module Upgrade for the Multipurpose Logistics Module

    NASA Technical Reports Server (NTRS)

    Clark, D. W.; Glasgow, S. d.; Reagan, S. E.; Presson, K. H.; Howard, D. E.; Smith, D. A.

    2007-01-01

    The STS-121/ULF 1.1 mission was the maiden flight of the programmable thermostat module (PTM) system used to control the 28 V shell heaters on the multi-purpose logistics module (MPLM). These PTMs, in conjunction with a data recorder module (DRM), provide continuous closed loop temperature control and data recording of MPLM on-orbit heater operations. This Technical Memorandum discusses the hardware design, development, test, and verification (DDT&V) activities performed at the Marshall Space Flight Center as well as the operational implementation and mission performance.

  2. Robust Logistic and Probit Methods for Binary and Multinomial Regression

    PubMed Central

    Tabatabai, MA; Li, H; Eby, WM; Kengwoung-Keumo, JJ; Manne, U; Bae, S; Fouad, M; Singh, KP

    2015-01-01

    In this paper we introduce new robust estimators for the logistic and probit regressions for binary, multinomial, nominal and ordinal data and apply these models to estimate the parameters when outliers or inluential observations are present. Maximum likelihood estimates don't behave well when outliers or inluential observations are present. One remedy is to remove inluential observations from the data and then apply the maximum likelihood technique on the deleted data. Another approach is to employ a robust technique that can handle outliers and inluential observations without removing any observations from the data sets. The robustness of the method is tested using real and simulated data sets. PMID:26078914

  3. Ranked Tag Recommendation Systems Based on Logistic Regression

    NASA Astrophysics Data System (ADS)

    Quevedo, J. R.; Montañés, E.; Ranilla, J.; Díaz, I.

    This work proposes an approach to tag recommendation based on a logistic regression based system. The goal of the method is to support users of current social network systems by providing a rank of new meaningful tags for a resource. This system provides a ranked tag set and it feeds on different posts depending on the resource for which the user requests the recommendation. The performance of this approach is tested according to several evaluation measures, one of them proposed in this paper (F_1^+). The experiments show that this learning system outperforms certain benchmark recommenders.

  4. SpaceNet: Modeling and Simulating Space Logistics

    NASA Technical Reports Server (NTRS)

    Lee, Gene; Jordan, Elizabeth; Shishko, Robert; de Weck, Olivier; Armar, Nii; Siddiqi, Afreen

    2008-01-01

    This paper summarizes the current state of the art in interplanetary supply chain modeling and discusses SpaceNet as one particular method and tool to address space logistics modeling and simulation challenges. Fundamental upgrades to the interplanetary supply chain framework such as process groups, nested elements, and cargo sharing, enabled SpaceNet to model an integrated set of missions as a campaign. The capabilities and uses of SpaceNet are demonstrated by a step-by-step modeling and simulation of a lunar campaign.

  5. Landslide susceptibility assessment using logistic regression and its comparison with a rock mass classification system, along a road section in the northern Himalayas (India)

    NASA Astrophysics Data System (ADS)

    Das, Iswar; Sahoo, Sashikant; van Westen, Cees; Stein, Alfred; Hack, Robert

    2010-02-01

    Landslide studies are commonly guided by ground knowledge and field measurements of rock strength and slope failure criteria. With increasing sophistication of GIS-based statistical methods, however, landslide susceptibility studies benefit from the integration of data collected from various sources and methods at different scales. This study presents a logistic regression method for landslide susceptibility mapping and verifies the result by comparing it with the geotechnical-based slope stability probability classification (SSPC) methodology. The study was carried out in a landslide-prone national highway road section in the northern Himalayas, India. Logistic regression model performance was assessed by the receiver operator characteristics (ROC) curve, showing an area under the curve equal to 0.83. Field validation of the SSPC results showed a correspondence of 72% between the high and very high susceptibility classes with present landslide occurrences. A spatial comparison of the two susceptibility maps revealed the significance of the geotechnical-based SSPC method as 90% of the area classified as high and very high susceptible zones by the logistic regression method corresponds to the high and very high class in the SSPC method. On the other hand, only 34% of the area classified as high and very high by the SSPC method falls in the high and very high classes of the logistic regression method. The underestimation by the logistic regression method can be attributed to the generalisation made by the statistical methods, so that a number of slopes existing in critical equilibrium condition might not be classified as high or very high susceptible zones.

  6. Chaotic dynamics of Yang-Mills field as source of particle couplings and masses

    SciTech Connect

    Goldfain, E.

    1995-04-01

    Dynamics of classical uniform Yang-Mills fields is explored from the viewpoint of universal route to chaos in nonlinear systems. The author shows how the path to nonintegrable behavior of the field is equivalent to the period doubling bifurcation of the logistic map. Universal scalings of the growth parameter yield the full set of Standard Model couplings. Hamiltonian formulation in action-angle variables leads to the physics of phase transitions in classical lattice models. The ground state phase diagram of the system with {open_quotes}antiferromagnetic{close_quotes} interaction is known to exhibit a devil`s staircase form. Linking the staircase attributes to the asymptotic freedom of the gauge coupling yields an universal mass equation. Critical exponent is found to depend on the number of field flavors. Further solving the model for various stability plateaus renders the spectrum of particle masses in the low energy framework. Agreement between theory and experimental results is confirmed for the photon/graviton pair, weak bosons, leptons and quarks. The approach offers an intriguing explanation of the dymanical origin of the physical mass and on the internal hierarchy of particle families.

  7. Generalized Fiducial Inference for Binary Logistic Item Response Models.

    PubMed

    Liu, Yang; Hannig, Jan

    2016-06-01

    Generalized fiducial inference (GFI) has been proposed as an alternative to likelihood-based and Bayesian inference in mainstream statistics. Confidence intervals (CIs) can be constructed from a fiducial distribution on the parameter space in a fashion similar to those used with a Bayesian posterior distribution. However, no prior distribution needs to be specified, which renders GFI more suitable when no a priori information about model parameters is available. In the current paper, we apply GFI to a family of binary logistic item response theory models, which includes the two-parameter logistic (2PL), bifactor and exploratory item factor models as special cases. Asymptotic properties of the resulting fiducial distribution are discussed. Random draws from the fiducial distribution can be obtained by the proposed Markov chain Monte Carlo sampling algorithm. We investigate the finite-sample performance of our fiducial percentile CI and two commonly used Wald-type CIs associated with maximum likelihood (ML) estimation via Monte Carlo simulation. The use of GFI in high-dimensional exploratory item factor analysis was illustrated by the analysis of a set of the Eysenck Personality Questionnaire data. PMID:26769340

  8. Fuel cell technology for prototype logistic fuel cell mobile systems

    SciTech Connect

    Sederquist, R.A.; Garow, J.

    1995-08-01

    Under the aegis of the Advanced Research Project Agency`s family of programs to develop advanced technology for dual use applications, International Fuel Cells Corporation (IFC) is conducting a 39 month program to develop an innovative system concept for DoD Mobile Electric Power (MEP) applications. The concept is to integrate two technologies, the phosphoric acid fuel cell (PAFC) with an auto-thermal reformer (ATR), into an efficient fuel cell power plant of nominally 100-kilowatt rating which operates on logistic fuels (JP-8). The ATR fuel processor is the key to meeting requirements for MEP (including weight, volume, reliability, maintainability, efficiency, and especially operation on logistic fuels); most of the effort is devoted to ATR development. An integrated demonstration test unit culminates the program and displays the benefits of the fuel cell system, relative to the standard 100-kilowatt MEP diesel engine generator set. A successful test provides the basis for proceeding toward deployment. This paper describes the results of the first twelve months of activity during which specific program aims have remained firm.

  9. Definition of main pollen season using a logistic model.

    PubMed

    Ribeiro, Helena; Cunha, Mário; Abreu, Ilda

    2007-01-01

    This paper proposes a method to unify the definition of the main pollen season based on statistical analysis. For this, an aerobiological study was carried out in Porto region (Portugal), from 2003-2005 using a 7-day Hirst-type volumetric spore trap. To define the main pollen season, a non-linear logistic regression model was fitted to the values of the accumulated sum of the daily airborne pollen concentration from several allergological species. An important feature of this method is that the main pollen season will be characterized by the model parameters calculated. These parameters are identifiable aspects of the flowering phenology, and determine not only the beginning and end of the main pollen season, but are also influenced by the meteorological conditions. The results obtained with the proposed methodology were also compared with two of the most used percentage methods. The logistic model fitted well with the sum of accumulated pollen. The explained variance was always higher than 97%, and the exponential part of the predicted curve was well adjusted to the time when higher atmospheric pollen concentration was sampled. The comparison between the different methods tested showed large divergence in the duration and end dates of the main pollen season of the studied species. PMID:18247462

  10. Multipurpose Logistics Module, Leonardo, Rests in Discovery's Payload Bay

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This in-orbit close up shows the Italian Space Agency-built multipurpose Logistics Module (MPLM), Leonardo, the primary cargo of the STS-102 mission, resting in the payload bay of the Space Shuttle Orbiter Discovery. The Leonardo MPLM is the first of three such pressurized modules that will serve as the International Space Station's (ISS') moving vans, carrying laboratory racks filled with equipment, experiments, and supplies to and from the Station aboard the Space Shuttle. The cylindrical module is approximately 21-feet long and 15- feet in diameter, weighing almost 4.5 tons. It can carry up to 10 tons of cargo in 16 standard Space Station equipment racks. Of the 16 racks the module can carry, 5 can be furnished with power, data, and fluid to support refrigerators or freezers. In order to function as an attached station module as well as a cargo transport, the logistics module also includes components that provide life support, fire detection and suppression, electrical distribution, and computer functions. The eighth station assembly flight and NASA's 103rd overall flight, STS-102 launched March 8, 2001 for an almost 13 day mission.

  11. STS-102 Onboard Photograph-Multi-Purpose Logistics Module, Leonardo

    NASA Technical Reports Server (NTRS)

    2001-01-01

    A crewmember of Expedition One, cosmonaut Yuri P. Gidzenko, is dwarfed by transient hardware aboard Leonardo, the Italian Space Agency-built Multi-Purpose Logistics Module (MPLM), a primary cargo of the STS-102 mission. The Leonardo MPLM is the first of three such pressurized modules that will serve as the International Space Station's (ISS's) moving vans, carrying laboratory racks filled with equipment, experiments and supplies to and from the Space Station aboard the Space Shuttle. The cylindrical module is approximately 21-feet long and 15- feet in diameter, weighing almost 4.5 tons. It can carry up to 10 tons of cargo into 16 standard Space Station equipment racks. Of the 16 racks the module can carry, 5 can be furnished with power, data, and fluid to support refrigerators or freezers. In order to function as an attached station module as well as a cargo transport, the logistics module also includes components that provide life support, fire detection and suppression, electrical distribution, and computer functions. The eighth Shuttle mission to visit the ISS, the STS-102 mission served as a crew rotation flight. It delivered the Expedition Two crew to the Station and returned the Expedition One crew back to Earth.

  12. STS-102 Onboard Photograph Inside Multipurpose Logistics Module, Leonardo

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Pilot James M. Kelly (left) and Commander James D. Wetherbee for the STS-102 mission, participate in the movement of supplies inside Leonardo, the Italian Space Agency built Multipurpose Logistics Module (MPLM). In this particular photograph, the two are handling a film magazine for the IMAX cargo bay camera. The primary cargo of the STS-102 mission, the Leonardo MPLM is the first of three such pressurized modules that will serve as the International Space Station's (ISS') moving vans, carrying laboratory racks filled with equipment, experiments, and supplies to and from the Station aboard the Space Shuttle. The cylindrical module is approximately 21-feet long and 15- feet in diameter, weighing almost 4.5 tons. It can carry up to 10 tons of cargo in 16 standard Space Station equipment racks. Of the 16 racks the module can carry, 5 can be furnished with power, data, and fluid to support refrigerators or freezers. In order to function as an attached station module as well as a cargo transport, the logistics module also includes components that provide life support, fire detection and suppression, electrical distribution, and computer functions. The eighth station assembly flight, the STS-102 mission also served as a crew rotation flight. It delivered the Expedition Two crew to the Station and returned the Expedition One crew back to Earth.

  13. Managing NASA's International Space Station Logistics and Maintenance Program

    NASA Technical Reports Server (NTRS)

    Butina, Anthony

    2001-01-01

    The International Space Station's Logistics and Maintenance program has had to develop new technologies and a management approach for both space and ground operations. The ISS will be a permanently manned orbiting vehicle that has no landing gear, no international borders, and no organizational lines - it is one Station that must be supported by one crew, 24 hours a day, 7 days a week, 365 days a year. It flies partially assembled for a number of years before it is finally completed in 2006. It has over 6,000 orbital replaceable units (ORU), and spare parts which number into the hundreds of thousands, from 127 major US vendors and 70 major international vendors. From conception to operation, the ISS requires a unique approach in all aspects of development and operations. Today the dream is coming true; hardware is flying and hardware is failing. The system has been put into place to support the Station for both space and ground operations. It started with the basic support concept developed for Department of Defense systems, and then it was tailored for the unique requirements of a manned space vehicle. Space logistics is a new concept that has wide reaching consequences for both space travel and life on Earth. This paper discusses what type of organization has been put into place to support both space and ground operations and discusses each element of that organization. In addition, some of the unique operations approaches this organization has had to develop is discussed.

  14. Change point testing in logistic regression models with interaction term.

    PubMed

    Fong, Youyi; Di, Chongzhi; Permar, Sallie

    2015-04-30

    A threshold effect takes place in situations where the relationship between an outcome variable and a predictor variable changes as the predictor value crosses a certain threshold/change point. Threshold effects are often plausible in a complex biological system, especially in defining immune responses that are protective against infections such as HIV-1, which motivates the current work. We study two hypothesis testing problems in change point models. We first compare three different approaches to obtaining a p-value for the maximum of scores test in a logistic regression model with change point variable as a main effect. Next, we study the testing problem in a logistic regression model with the change point variable both as a main effect and as part of an interaction term. We propose a test based on the maximum of likelihood ratios test statistic and obtain its reference distribution through a Monte Carlo method. We also propose a maximum of weighted scores test that can be more powerful than the maximum of likelihood ratios test when we know the direction of the interaction effect. In simulation studies, we show that the proposed tests have a correct type I error and higher power than several existing methods. We illustrate the application of change point model-based testing methods in a recent study of immune responses that are associated with the risk of mother to child transmission of HIV-1. PMID:25612253

  15. Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR FT-IR) Mapping Coupled with Multivariate Curve Resolution (MCR) for Studying the Miscibility of Chlorobutyl Rubber/Polyamide-12 Blends.

    PubMed

    Tang, Yongjiao; Jing, Nan; Zhang, Pudun

    2015-11-01

    A series of chlorobutyl rubber/polyamide-12 (CIIR/PA-12) blends compatibilized by different amounts of maleic anhydride (MAH) grafted polypropylene (PP-g-MAH) were investigated by attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) mapping. Multivariate curve resolution (MCR) was used to process the FT-IR images. Both the spectra of pure components in the blends and their concentration distributions in a micro-region were acquired. Our results demonstrated that the blend with 15 parts per hundred rubber PP-g-MAH showed the best miscibility. An amide interphase and an imide interphase were inferred by analyzing the spectra of MCR component 3 of the blends with and without PP-g-MAH, respectively. Correspondingly, two different compatibilizing mechanisms were proposed for these blends. PMID:26647055

  16. Dark coupling

    SciTech Connect

    Gavela, M.B.; Hernández, D.; Honorez, L. Lopez; Mena, O.; Rigolin, S. E-mail: d.hernandez@uam.es E-mail: omena@ific.uv.es

    2009-07-01

    The two dark sectors of the universe—dark matter and dark energy—may interact with each other. Background and linear density perturbation evolution equations are developed for a generic coupling. We then establish the general conditions necessary to obtain models free from non-adiabatic instabilities. As an application, we consider a viable universe in which the interaction strength is proportional to the dark energy density. The scenario does not exhibit ''phantom crossing'' and is free from instabilities, including early ones. A sizeable interaction strength is compatible with combined WMAP, HST, SN, LSS and H(z) data. Neutrino mass and/or cosmic curvature are allowed to be larger than in non-interacting models. Our analysis sheds light as well on unstable scenarios previously proposed.

  17. Thermoacoustic couple

    DOEpatents

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1983-10-04

    An apparatus and method for determining acoustic power density level and its direction in a fluid using a single sensor are disclosed. The preferred embodiment of the apparatus, which is termed a thermoacoustic couple, consists of a stack of thin, spaced apart polymeric plates, selected ones of which include multiple bimetallic thermocouple junctions positioned along opposite end edges thereof. The thermocouple junctions are connected in series in the nature of a thermopile, and are arranged so as to be responsive to small temperature differences between the opposite edges of the plates. The magnitude of the temperature difference, as represented by the magnitude of the electrical potential difference generated by the thermopile, is found to be directly related to the level of acoustic power density in the gas.

  18. How detailed should earthquake hazard maps be: comparing the performance of Japan's maps to uniform, randomized, and smoothed maps

    NASA Astrophysics Data System (ADS)

    Brooks, Edward; Stein, Seth; Spencer, Bruce; Liu, Mian

    2016-04-01

    Earthquake hazard maps forecast future shaking via assumptions about where, when, and how large future earthquakes will be. These assumptions involve the known earthquake history, models of fault geometry and motion, and geodetic data. Maps are made more detailed as additional data and more complicated models become available. However, the extent to which this process produces better forecasts of shaking is unknown. We explore this issue by comparing how well a 510-year-long record of earthquake shaking in Japan is described by the Japanese national hazard (JNH) maps, uniform maps, and randomized maps. Surprisingly, as measured by the metric implicit in the JNH maps, i.e. that during the chosen time interval the predicted shaking should be exceeded only at a specific fraction of the sites, both uniform and randomized maps do better than the actual maps. However, using as a metric the squared misfit between maximum observed shaking and that predicted, the JNH maps do better than uniform or randomized maps. Similarly, by the squared misfit metric, map performance improves up to a ~75-150 km smoothing window, and then decreases with further smoothing. Because the maps were made by using other data and models to try to predict future earthquake shaking, rather than by fitting past shaking data, these results are probably not an artifact of hindcasting rather than forecasting. They suggest that hazard models and the resulting maps can be over-parameterized, in that including too high a level of detail to describe past earthquakes may lower the maps' ability to forecast what will occur in the future. For example in Nepal, where GPS data show no significant variation in coupling between areas that have had recent large earthquakes and those that have not, past earthquakes likely do not show which parts are more at risk, and the entire area can be regarded as equally hazardous.

  19. Assessing the spatial variability of coefficients of landslide predictors in different regions of Romania using logistic regression

    NASA Astrophysics Data System (ADS)

    Mărgărint, M. C.; Grozavu, A.; Patriche, C. V.

    2013-12-01

    In landslide susceptibility assessment, an important issue is the correct identification of significant contributing factors, which leads to the improvement of predictions regarding this type of geomorphologic processes. In the scientific literature, different weightings are assigned to these factors, but contain large variations. This study aims to identify the spatial variability and range of variation for the coefficients of landslide predictors in different geographical conditions. Four sectors of 15 km × 15 km (225 km2) were selected for analysis from representative regions in Romania in terms of spatial extent of landslides, situated both on the hilly areas (the Transylvanian Plateau and Moldavian Plateau) and lower mountain region (Subcarpathians). The following factors were taken into consideration: elevation, slope angle, slope height, terrain curvature (mean, plan and profile), distance from drainage network, slope aspect, land use, and lithology. For each sector, landslide inventory, digital elevation model and thematic layers of the mentioned predictors were achieved and integrated in a georeferenced environment. The logistic regression was applied separately for the four study sectors as the statistical method for assessing terrain landsliding susceptibility. Maps of landslide susceptibility were produced, the values of which were classified by using the natural breaks method (Jenks). The accuracy of the logistic regression outcomes was evaluated using the ROC (receiver operating characteristic) curve and AUC (area under the curve) parameter, which show values between 0.852 and 0.922 for training samples, and between 0.851 and 0.940 for validation samples. The values of coefficients are generally confined within the limits specified by the scientific literature. In each sector, landslide susceptibility is essentially related to some specific predictors, such as the slope angle, land use, slope height, and lithology. The study points out that the

  20. Mission Engineering of a Rapid Cycle Spacecraft Logistics Fleet

    NASA Technical Reports Server (NTRS)

    Holladay, Jon; McClendon, Randy (Technical Monitor)

    2002-01-01

    The requirement for logistics re-supply of the International Space Station has provided a unique opportunity for engineering the implementation of NASA's first dedicated pressurized logistics carrier fleet. The NASA fleet is comprised of three Multi-Purpose Logistics Modules (MPLM) provided to NASA by the Italian Space Agency in return for operations time aboard the International Space Station. Marshall Space Flight Center was responsible for oversight of the hardware development from preliminary design through acceptance of the third flight unit, and currently manages the flight hardware sustaining engineering and mission engineering activities. The actual MPLM Mission began prior to NASA acceptance of the first flight unit in 1999 and will continue until the de-commission of the International Space Station that is planned for 20xx. Mission engineering of the MPLM program requires a broad focus on three distinct yet inter-related operations processes: pre-flight, flight operations, and post-flight turn-around. Within each primary area exist several complex subsets of distinct and inter-related activities. Pre-flight processing includes the evaluation of carrier hardware readiness for space flight. This includes integration of payload into the carrier, integration of the carrier into the launch vehicle, and integration of the carrier onto the orbital platform. Flight operations include the actual carrier operations during flight and any required real-time ground support. Post-flight processing includes de-integration of the carrier hardware from the launch vehicle, de-integration of the payload, and preparation for returning the carrier to pre-flight staging. Typical space operations are engineered around the requirements and objectives of a dedicated mission on a dedicated operational platform (i.e. Launch or Orbiting Vehicle). The MPLM, however, has expanded this envelope by requiring operations with both vehicles during flight as well as pre-launch and post

  1. Two logistic models for the prediction of hypothyroidism in pregnancy

    PubMed Central

    2011-01-01

    Background The mounting evidence linking hypothyroidism during pregnancy with poor pregnancy outcome underscores the need for screening and, therefore, a search for more reliable and cheaper screening methods. Methods The study was conducted in two phases. The phase one study comprised of healthy women in different stages of pregnancy who attended routine antenatal clinic at St Theresa's Maternity Hospital, Enugu, Nigeria from September 6 to October 18 1994. In this study the variables compared between the hypothyroid and non-hypothyroid pregnant women were maternal age, the number of the pregnancy or gravidity, gestational age, social class, body weight, height, the clinically assessed size of the thyroid gland, serum free thyroxin (FT4) and serum thyrotrophin (TSH). Based on the parameter differences between the two comparison groups of pregnant women two Logistic models, Model I and Model 11, were derived to differentiate the hypothyroid group from their non-hypothyroid counterparts. The two logistic models were then applied in a prospective validation study involving 197 pregnant women seen at presentation in Mother of Christ Specialist Hospital and Maternity, Ogui Road, Enugu from March 2002 to November 2007 Findings The findings were that 82 (50.3%) of the 163 pregnant women had thyroid gland enlargement while 60 (36.8%) had hypothyroidism as defined by FT4 values below and/or TSH above their laboratory reference ranges. The pregnant subjects with hypothyroidism, compared with their non-hypothyroid counterparts, were characterized by a higher gravidity (p < 0.01), a higher body weight (p < 0.01), a higher goiter prevalence rate (p < 0.01) and a more advanced gestational age (p < 0.0001). A significant, positive correlation was also found between body weight and gestational age (r = 0.5; p < 0.01) At the cut-off point for Model l (fitted with gravidity, thyroid size and gestational age) it had a sensitivity of 100%, a specificity of 72.8% and an overall

  2. Landslide susceptibility analysis with logistic regression model based on FCM sampling strategy

    NASA Astrophysics Data System (ADS)

    Wang, Liang-Jie; Sawada, Kazuhide; Moriguchi, Shuji

    2013-08-01

    Several mathematical models are used to predict the spatial distribution characteristics of landslides to mitigate damage caused by landslide disasters. Although some studies have achieved excellent results around the world, few studies take the inter-relationship of the selected points (training points) into account. In this paper, we present the Fuzzy c-means (FCM) algorithm as an optimal method for choosing the appropriate input landslide points as training data. Based on different combinations of the Fuzzy exponent (m) and the number of clusters (c), five groups of sampling points were derived from formal seed cells points and applied to analyze the landslide susceptibility in Mizunami City, Gifu Prefecture, Japan. A logistic regression model is applied to create the models of the relationships between landslide-conditioning factors and landslide occurrence. The pre-existing landslide bodies and the area under the relative operative characteristic (ROC) curve were used to evaluate the performance of all the models with different m and c. The results revealed that Model no. 4 (m=1.9, c=4) and Model no. 5 (m=1.9, c=5) have significantly high classification accuracies, i.e., 90.0%. Moreover, over 30% of the landslide bodies were grouped under the very high susceptibility zone. Otherwise, Model no. 4 and Model no. 5 had higher area under the ROC curve (AUC) values, which were 0.78 and 0.79, respectively. Therefore, Model no. 4 and Model no. 5 offer better model results for landslide susceptibility mapping. Maps derived from Model no. 4 and Model no. 5 would offer the local authorities crucial information for city planning and development.

  3. On the use of evidence in humanitarian logistics research.

    PubMed

    Pedraza-Martinez, Alfonso J; Stapleton, Orla; Van Wassenhove, Luk N

    2013-07-01

    This paper presents the reflections of the authors on the differences between the language and the approach of practitioners and academics to humanitarian logistics problems. Based on a long-term project on fleet management in the humanitarian sector, involving both large international humanitarian organisations and academics, it discusses how differences in language and approach to such problems may create a lacuna that impedes trust. In addition, the paper provides insights into how academic research evidence adapted to practitioner language can be used to bridge the gap. When it is communicated appropriately, evidence strengthens trust between practitioners and academics, which is critical for long-term projects. Once practitioners understand the main trade-offs included in academic research, they can supply valuable feedback to motivate new academic research. Novel research problems promote innovation in the use of traditional academic methods, which should result in a win-win situation: relevant solutions for practice and advances in academic knowledge. PMID:23905767

  4. Techno-economic analysis of biofuel production considering logistic configurations.

    PubMed

    Li, Qi; Hu, Guiping

    2016-04-01

    In the study, a techno-economic analysis method considering logistic configurations is proposed. The economic feasibility of a low temperature biomass gasification pathway and an integrated pathway with fast pyrolysis and bio-oil gasification are evaluated and compared with the proposed method in Iowa. The results show that both pathways are profitable, biomass gasification pathway could achieve an Internal Rate of Return (IRR) of 10.00% by building a single biorefinery and integrated bio-oil gasification pathway could achieve an IRR of 3.32% by applying decentralized supply chain structure. A Monte-Carlo simulation considering interactions among parameters is also proposed and conducted, which indicates that both pathways are at high risk currently. PMID:26859327

  5. ISS ECLSS: 3 Years of Logistics for Maintenance

    NASA Technical Reports Server (NTRS)

    Shkedi, Brienne; Thompson, Dean

    2004-01-01

    The International Space Station (ISS) Environmental Control and Life Support System (ECLSS) is designed to be maintainable. During the 3 years since the ISS US Lab became operational, there have been numerous ECLSS Orbital Replacement Units (ORUs) launched and returned to Maintain the ECLSS operation in the US segments. The maintenance logistics have provided tools for maintenance, replaced limited life ORUs and failed ORUs, upgraded ECLSS hardware to improve reliability and placed critical spares onboard prior to need. In most cases, the removed ORUs have been returned for either failure analysis and repair or refurbishment. This paper describes the ECLSS manifesting history and maintenance events and quantifies the numbers of ECLSS items, weights, and volumes.

  6. A solution to the problem of separation in logistic regression.

    PubMed

    Heinze, Georg; Schemper, Michael

    2002-08-30

    The phenomenon of separation or monotone likelihood is observed in the fitting process of a logistic model if the likelihood converges while at least one parameter estimate diverges to +/- infinity. Separation primarily occurs in small samples with several unbalanced and highly predictive risk factors. A procedure by Firth originally developed to reduce the bias of maximum likelihood estimates is shown to provide an ideal solution to separation. It produces finite parameter estimates by means of penalized maximum likelihood estimation. Corresponding Wald tests and confidence intervals are available but it is shown that penalized likelihood ratio tests and profile penalized likelihood confidence intervals are often preferable. The clear advantage of the procedure over previous options of analysis is impressively demonstrated by the statistical analysis of two cancer studies. PMID:12210625

  7. Bifurcation Analysis of Equilibria in Competitive Logistic Networks with Adaptation

    NASA Astrophysics Data System (ADS)

    Raimondi, A.; Tebaldi, C.

    2008-04-01

    A general n-node network is considered for which, in absence of interactions, each node is governed by a logistic equation. Interactions among the nodes take place in the form of competition, which also includes adaptive abilities through a (short term) memory effect. As a consequence the dynamics of the network is governed by a system of n2 nonlinear ordinary differential equations. As a first step, equilibria and their stability are investigated analytically for the general network in dependence of the relevant parameters, namely the strength of competition, the adaptation rate and the network size. The existence of classes of invariant subspaces, related to symmetries, allows the introduction of a reduced model, four dimensional, where n appears as a parameter, which give full account of existence and stability for the equilibria in the network.

  8. Watershed inventory, Ravenna Training and Logistics Site, Ohio

    USGS Publications Warehouse

    Ostheimer, Chad J.; Tertuliani, John S.

    2003-01-01

    The Ohio Army National Guard (OHARNG) conducts training activities on the lands it manages to fulfill its primary mission of maintaining combat readiness. One of the training areas OHARNG manages is the Ravenna Training and Logistics Site (RTLS). This facility is co-located with the Ravenna Army Ammunition Plant (RVAAP) in Portage and Trumbull Counties, Ohio. Training activities can subject watersheds to various effects. Although environmental effects from training activities cannot be completely avoided, OHARNG is actively seeking for ways to minimize such effects in accordance with Federal, State, and local laws and regulations. This report presents the results of a study by the U.S. Geological Survey (USGS), in cooperation with the OHARNG, to inventory current conditions of the watersheds that drain the RTLS/RVAAP facility. As part of the inventory, a digital geographic database was developed.

  9. Flood analysis using generalized logistic models in partial duration series

    NASA Astrophysics Data System (ADS)

    Bhunya, P. K.; Singh, R. D.; Berndtsson, R.; Panda, S. N.

    2012-02-01

    SummaryAs a generalization of the commonly assumed Poisson distribution (PD) used to estimate the annual number of peaks over threshold in partial duration series (PDS) model, the negative binomial (NB) distribution is proposed in this study. Instead of generalized pareto distribution (GPD) and exponential distribution (ED) models popularly applied to predict the probability of the exceedances of peak over threshold, the performance of the general logistic distribution (GLD) models is analyzed. Two different models for analyzing extreme hydrologic events are compared, based on, PDS and annual maximum series (AMS), respectively. The performance of the two models in terms of uncertainty of T-year event estimator [ q( T)] is evaluated in the cases of estimation with the method of moments (MOMs), maximum likelihood (ML), and probability weighted moments (PWMs). The annual maximum distribution corresponding to a PDS model with Poisson distributed count of peaks above threshold and GLD for flood exceedances was found to be an extreme value type I (EV1) distribution. The comparison between PDS and AMS is made using ratio of variance of the T-year event estimates, which is derived analytically after checking the reliability of the expressions with Monte Carlo simulations. The results reveal that the AMS/NB-GLD and PDS/GLD models using PWM estimation method give least variance of flood estimates with the PDS model giving marginally better results. From the overall results, it was observed that the Poisson distribution performs better, where the difference between mean ( μ) and variance of counts of threshold exceedances is small otherwise the NB distribution is found to be efficient when used in combination with generalized logistic distribution in the PDS model, and this is more prominent for μ < 1.4. Hence, in such cases when the PDS data have a mean less than this, the AMS/NB-GLD and PDS/GLD should be a better model for q( T) estimation as compared to PDS/ED.

  10. Quaternary geologic map of Minnesota

    NASA Technical Reports Server (NTRS)

    Goebel, J. E.

    1977-01-01

    The Quaternary Geologic Map of Minnesota is a compilation based both on the unique characteristics of satellite imagery and on the results of previous field investigations, both published and unpublished. The use of satellite imagery has made possible the timely and economical construction of this map. LANDSAT imagery interpretation proved more useful than expected. Most of the geologic units could be identified by extrapolating from specific sites where the geology had been investigated into areas where little was known. The excellent geographic registry coupled with the multi-spectral record of these images served to identify places where the geologic materials responded to their ecological environment and where the ecology responded to the geologic materials. Units were well located on the map at the scale selected for the study. Contacts between till units could be placed with reasonable accuracy. The reference points that were used to project delineations between units (rivers, lakes, hills, roads and other features), which had not been accurately located on early maps, could be accurately located with the help of the imagery. The tonal and color contrasts, the patterns reflecting geologic change and the resolution of the images permitted focusing attention on features which could be represented at the final scale of the map without distraction by other interesting but site-specific details.

  11. Kinetic Characterization of Strongly Coupled Systems

    SciTech Connect

    Knapek, C. A.; Ivlev, A. V.; Klumov, B. A.; Morfill, G. E.; Samsonov, D.

    2007-01-05

    We propose a simple method to determine the local coupling strength {gamma} experimentally, by linking the individual particle dynamics with the local density and crystal structure of a 2D plasma crystal. By measuring particle trajectories with high spatial and temporal resolution we obtain the first maps of {gamma} and temperature at individual particle resolution. We employ numerical simulations to test this new method, and discuss the implications to characterize strongly coupled systems.

  12. Mental Health Experts’ Perspectives on Barriers to Dissemination of Couples Treatment for Alcohol Use Disorders

    PubMed Central

    Schonbrun, Yael Chatav; Stuart, Gregory L.; Wetle, Terrie; Glynn, Tiffany R.; Titelius, Elise N.; Strong, David

    2016-01-01

    Despite evidence supporting the efficacy of couples-based approaches to treating alcohol problems, provision of such treatments has been limited. To better understand the limited use of this treatment, the current study explored barriers to the adoption of couples treatment for alcohol use disorders. Experts in alcohol treatment, couples treatment, and behavioral couples treatment for alcohol problems (n = 12) were interviewed on this topic; interview transcripts were analyzed using grounded theory qualitative procedures. All mental health experts endorsed the perspective that implementation and acceptance of couples treatment posed difficulties for providers. Four themes (logistical barriers at the provider level, logistical barriers at the system levels, provider treatment preferences, and lack of appropriate training) were identified. Results from the current study provide guidance in addressing barriers to the adoption of couples-based treatments. PMID:22449088

  13. Human Mind Maps

    ERIC Educational Resources Information Center

    Glass, Tom

    2016-01-01

    When students generate mind maps, or concept maps, the maps are usually on paper, computer screens, or a blackboard. Human Mind Maps require few resources and little preparation. The main requirements are space where students can move around and a little creativity and imagination. Mind maps can be used for a variety of purposes, and Human Mind…

  14. Extraction of potential debris source areas by logistic regression technique: a case study from Barla, Besparmak and Kapi mountains (NW Taurids, Turkey)

    NASA Astrophysics Data System (ADS)

    Tunusluoglu, M. C.; Gokceoglu, C.; Nefeslioglu, H. A.; Sonmez, H.

    2008-03-01

    Debris flow is one of the most destructive mass movements. Sometimes regional debris flow susceptibility or hazard assessments can be more difficult than the other mass movements. Determination of debris accumulation zones and debris source areas, which is one of the most crucial stages in debris flow investigations, can be too difficult because of morphological restrictions. The main goal of the present study is to extract debris source areas by logistic regression analyses based on the data from the slopes of the Barla, Besparmak and Kapi Mountains in the SW part of the Taurids Mountain belt of Turkey, where formation of debris material are clearly evident and common. In this study, in order to achieve this goal, extensive field observations to identify the areal extent of debris source areas and debris material, air-photo studies to determine the debris source areas and also desk studies including Geographical Information System (GIS) applications and statistical assessments were performed. To justify the training data used in logistic regression analyses as representative, a random sampling procedure was applied. By using the results of the logistic regression analysis, the debris source area probability map of the region is produced. However, according to the field experiences of the authors, the produced map yielded over-predicted results. The main source of the over-prediction is structural relation between the bedding planes and slope aspects on the basis of the field observations, for the generation of debris, the dip of the bedding planes must be taken into consideration regarding the slope face. In order to eliminate this problem, in this study, an approach has been developed using probability distribution of the aspect values. With the application of structural adjustment, the final adjusted debris source area probability map is obtained for the study area. The field observations revealed that the actual debris source areas in the field coincide with

  15. Concept Mapping

    PubMed Central

    Brennan, Laura K.; Brownson, Ross C.; Kelly, Cheryl; Ivey, Melissa K.; Leviton, Laura C.

    2016-01-01

    Background From 2003 to 2008, 25 cross-sector, multidisciplinary community partnerships funded through the Active Living by Design (ALbD) national program designed, planned, and implemented policy and environmental changes, with complementary programs and promotions. This paper describes the use of concept-mapping methods to gain insights into promising active living intervention strategies based on the collective experience of community representatives implementing ALbD initiatives. Methods Using Concept Systems software, community representatives (n=43) anonymously generated actions and changes in their communities to support active living (183 original statements, 79 condensed statements). Next, respondents (n=26, from 23 partnerships) sorted the 79 statements into self-created categories, or active living intervention approaches. Respondents then rated statements based on their perceptions of the most important strategies for creating community changes (n=25, from 22 partnerships) and increasing community rates of physical activity (n=23, from 20 partnerships). Cluster analysis and multidimensional scaling were used to describe data patterns. Results ALbD community partnerships identified three active living intervention approaches with the greatest perceived importance to create community change and increase population levels of physical activity: changes to the built and natural environment, partnership and collaboration efforts, and land-use and transportation policies. The relative importance of intervention approaches varied according to subgroups of partnerships working with different populations. Conclusions Decision makers, practitioners, and community residents can incorporate what has been learned from the 25 community partnerships to prioritize active living policy, physical project, promotional, and programmatic strategies for work in different populations and settings. PMID:23079266

  16. Maps & minds : mapping through the ages

    USGS Publications Warehouse

    U.S. Geological Survey

    1984-01-01

    Throughout time, maps have expressed our understanding of our world. Human affairs have been influenced strongly by the quality of maps available to us at the major turning points in our history. "Maps & Minds" traces the ebb and flow of a few central ideas in the mainstream of mapping. Our expanding knowledge of our cosmic neighborhood stems largely from a small number of simple but grand ideas, vigorously pursued.

  17. Mapping: A Course.

    ERIC Educational Resources Information Center

    Whitmore, Paul M.

    1988-01-01

    Reviews the history of cartography. Describes the contributions of Strabo and Ptolemy in early maps. Identifies the work of Gerhard Mercator as the most important advancement in mapping. Discusses present mapping standards from history. (CW)

  18. A development of logistics management models for the Space Transportation System

    NASA Technical Reports Server (NTRS)

    Carrillo, M. J.; Jacobsen, S. E.; Abell, J. B.; Lippiatt, T. F.

    1983-01-01

    A new analytic queueing approach was described which relates stockage levels, repair level decisions, and the project network schedule of prelaunch operations directly to the probability distribution of the space transportation system launch delay. Finite source population and limited repair capability were additional factors included in this logistics management model developed specifically for STS maintenance requirements. Data presently available to support logistics decisions were based on a comparability study of heavy aircraft components. A two-phase program is recommended by which NASA would implement an integrated data collection system, assemble logistics data from previous STS flights, revise extant logistics planning and resource requirement parameters using Bayes-Lin techniques, and adjust for uncertainty surrounding logistics systems performance parameters. The implementation of these recommendations can be expected to deliver more cost-effective logistics support.

  19. The effect of high leverage points on the logistic ridge regression estimator having multicollinearity

    NASA Astrophysics Data System (ADS)

    Ariffin, Syaiba Balqish; Midi, Habshah

    2014-06-01

    This article is concerned with the performance of logistic ridge regression estimation technique in the presence of multicollinearity and high leverage points. In logistic regression, multicollinearity exists among predictors and in the information matrix. The maximum likelihood estimator suffers a huge setback in the presence of multicollinearity which cause regression estimates to have unduly large standard errors. To remedy this problem, a logistic ridge regression estimator is put forward. It is evident that the logistic ridge regression estimator outperforms the maximum likelihood approach for handling multicollinearity. The effect of high leverage points are then investigated on the performance of the logistic ridge regression estimator through real data set and simulation study. The findings signify that logistic ridge regression estimator fails to provide better parameter estimates in the presence of both high leverage points and multicollinearity.

  20. Modeling the dynamics of urban growth using multinomial logistic regression: a case study of Jiayu County, Hubei Province, China

    NASA Astrophysics Data System (ADS)

    Nong, Yu; Du, Qingyun; Wang, Kun; Miao, Lei; Zhang, Weiwei

    2008-10-01

    Urban growth modeling, one of the most important aspects of land use and land cover change study, has attracted substantial attention because it helps to comprehend the mechanisms of land use change thus helps relevant policies made. This study applied multinomial logistic regression to model urban growth in the Jiayu county of Hubei province, China to discover the relationship between urban growth and the driving forces of which biophysical and social-economic factors are selected as independent variables. This type of regression is similar to binary logistic regression, but it is more general because the dependent variable is not restricted to two categories, as those previous studies did. The multinomial one can simulate the process of multiple land use competition between urban land, bare land, cultivated land and orchard land. Taking the land use type of Urban as reference category, parameters could be estimated with odds ratio. A probability map is generated from the model to predict where urban growth will occur as a result of the computation.

  1. 76 FR 5578 - PetroLogistics Natural Gas Storage Company, LLC; Notice of Intent To Prepare an Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-01

    ... Energy Regulatory Commission PetroLogistics Natural Gas Storage Company, LLC; Notice of Intent To Prepare...Logistics Natural Gas Storage Company, LLC (PetroLogistics) in Iberville Parish, Louisiana. This EA will be... PetroLogistics provided to landowners. This fact sheet addresses a number of typically asked...

  2. 77 FR 17471 - PetroLogistics Natural Gas Storage Company, LLC; Notice of Availability of the Environmental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-26

    ... Energy Regulatory Commission PetroLogistics Natural Gas Storage Company, LLC; Notice of Availability of... Choctaw Hub Expansion Project (Project) proposed by PetroLogistics Natural Gas Storage, LLC (PetroLogistics) in the above-referenced docket. PetroLogistics requests authorization to build and operate...

  3. 41 CFR 101-26.602 - Fuels and packaged petroleum products obtained from or through the Defense Logistics Agency.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... petroleum products obtained from or through the Defense Logistics Agency. 101-26.602 Section 101-26.602... Logistics Agency. (a) Agencies shall be governed by the provisions of this § 101-26.602 in satisfying... petroleum products from or through the Defense Logistics Agency. (b) The Defense Logistics Agency has...

  4. Soil Carbon Decomposition: "Quality control" or logistic challenge?

    NASA Astrophysics Data System (ADS)

    Kleber, M.

    2011-12-01

    A long tradition of soil organic matter research has generated the belief that there is "stable" soil organic carbon, thought to be recalcitrant because molecular compounds such as aromatic rings and aliphatic chains are joined to polymeric macromolecules by processes of secondary syntheses. The Carbon-Quality Temperature (CQT) theory posits that such materials should be considered "low quality" substrates, because they would require large Arrhenius activation energies for full conversion to CO2. This, in turn, has generated the notion that recalcitrant organic matter should be more temperature sensitive to elevated temperatures than less complex, more "labile" soil organic matter. Yet the molecular properties of stable carbon are elusive - so far, it has not been possible to parameterize molecular recalcitrance in a context -independent fashion. Classic humic substances and even charcoal are readily broken down when placed in an environment where microorganisms with a suitable catabolic toolbox can resort to a plentiful supply of cometabolites and oxygen. At the same time we find labile substrates such as glucose to survive for decades when enclosed within soil aggregates. What then determines the temperature sensitivity of decomposition? Should the scientific community continue to hunt for some molecular proxy for organic matter quality (such as degree of polymerization, aromaticity, aqueous solubility etc) to predict the fate of soil organic carbon in a changing world? This contribution proposes a fundamentally different approach by treating soils as reaction vessels analogous to an industrial bioreactor. Soils are considered as capable of processing dead plant material in all its molecular variations. Decomposition is seen as constrained by environmental drivers, microbial ecology and community composition, and the physical structure of the soil environment. The hypotheses is put forward that, compared to variations in the logistic status of the soil reactor

  5. Feedstock Logistics Datasets from DOE's Bioenergy Knowledge Discovery Framework (KDF)

    DOE Data Explorer

    The Bioenergy Knowledge Discovery Framework invites users to discover the power of bioenergy through an interface that provides extensive access to research data and literature, GIS mapping tools, and collaborative networks. The Bioenergy KDF supports efforts to develop a robust and sustainable bioenergy industry. The KDF facilitates informed decision making by providing a means to synthesize, analyze, and visualize vast amounts of information in a relevant and succinct manner. It harnesses Web 2.0 and social networking technologies to build a collective knowledge system that can better examine the economic and environmental impacts of development options for biomass feedstock production, biorefineries, and related infrastructure. Holdings include datasets, models, and maps. [from https://www.bioenergykdf.net/content/about

  6. Application of frequency ratio and logistic regression to active rock glacier occurrence in the Andes of San Juan, Argentina

    NASA Astrophysics Data System (ADS)

    Angillieri, María Yanina Esper

    2010-01-01

    This study employs statistical modeling techniques and geomorphological mapping to analyze the distribution of active rock glaciers in relation to altitude, aspect, slope, lithology and solar radiation using optical remote sensing techniques with GIS. The study area includes a portion of the Dry Andes of the Cordillera Frontal of San Juan around 30°S latitude, where few geomorphological studies have been conducted. Over 155 rock glaciers have been identified, and 85 are considered active. The relationship between the variables and the rock glaciers distribution was analyzed using the frequency ratio method and logistic regression models. The analytical results show that elevations > 3824 m a.s.l., a south-facing or east-facing aspect, areas with relatively low solar radiation, and slope between 2° and 20° favor the existence of the rock glaciers, and demonstrate that lithology and slope exert major influences.

  7. Improving the Reverse Logistics Respecting Principles of Sustainable Development in an Industrial Company

    NASA Astrophysics Data System (ADS)

    Fidlerová, Helena; Mĺkva, Miroslava

    2016-06-01

    Reverse logistics, the movement of materials back up the supply chain, is recognised by many organisations as an opportunity for adding value. The paper considers the theoretical framework and the conception of reverse logistics in literature and practice. The objective of the article is to propose tangible solutions which eliminate the imbalances in reverse logistics and improve the waste management in the company. The case study focuses on the improvement in the process of waste packaging in the context of sustainable development as a part of reverse logistics in the surveyed industrial company in Slovakia.

  8. Analysis of Transportation and Logistics Challenges Affecting the Deployment of Larger Wind Turbines: Summary of Results

    SciTech Connect

    Cotrell, J.; Stehly, T.; Johnson, J.; Roberts, J. O.; Parker, Z.; Scott, G.; Heimiller, D.

    2014-01-01

    There is relatively little literature that characterizes transportation and logistics challenges and the associated effects on U.S. wind markets. The objectives of this study were to identify the transportation and logistics challenges, assess the associated impacts, and provide recommendations for strategies and specific actions to address the challenges. The authors primarily relied on interviews with wind industry project developers, original equipment manufacturers, and transportation and logistics companies to obtain the information and industry perspectives needed for this study. They also reviewed published literature on trends and developments in increasing wind turbine size, logistics, and transportation issues.

  9. Improvement of logistics education from the point of view environmental management

    NASA Astrophysics Data System (ADS)

    Bányai, Á.

    2009-04-01

    The paper briefly presents the influence of environmental management on the improvement of the logistics education and research structure of the Department of Materials Handling and Logistics at the University of Miskolc, Hungary. The logistics, as an integrated science offers a very good possibility to demonstrate the effect of new innovative knowledge on the migration of the priorities of education and research of sciences. The importance of logistics in the field of recycling (or in wider sense in the field of environmental management) can be justified by the high proportion of logistic costs (as investment and operation costs) and these costs show that optimum logistic solutions are able to decrease the financial outcomes and lead to the establishment of a profitable system. Technological change constantly creates new demands on both education and research. The most important objective of the department is to create a unique logistics education in the country. For this reason the department offered up-to-date integrated knowledge at all level: undergraduate, master degree and PhD education. The integration of logistics means traditionally the joint use of technology of material handling, method of material flow, technology method of traffic, information technology, management sciences, production technology, marketing, market research, technology of services, mathematics and optimization, communication technology, system engineering, electronics and automation, mechatronics [1, 3]. The education and research portfolio of the department followed this tradition till 1993. The new lectures in the field of sustainability (logistics of recycling, logistics of quality management and recycling, closed loop economy, EU logistics or global logistics) became more and more important in the logistics education. The results of fast developments in closed loop economy, recycling, waste management, environmental protection are more and more used in the industry and this

  10. Climate Change, Hydrology and Landscapes of America's Heartland: A Coupled Natural-Human System

    NASA Astrophysics Data System (ADS)

    Lant, C.; Misgna, G.; Secchi, S.; Schoof, J. T.

    2012-12-01

    This paper will present a methodological overview of an NSF-funded project under the Coupled Natural and Human System program. Climate change, coupled with variations and changes in economic and policy environments and agricultural techniques, will alter the landscape of the U.S. Midwest. Assessing the effects of these changes on watersheds, and thus on water quantity, water quality, and agricultural production, entails modeling a coupled natural-human system capable of answering research questions such as: (1) How will the climate of the U.S. Midwest change through the remainder of the 21st Century? (2) How will climate change, together with changing markets and policies, affect land use patterns at various scales, from the U.S. Midwest, to agricultural regions, to watersheds, to farms and fields? (3) Under what policies and prices does landscape change induced by climate change generate a positive or a negative feedback through changes in carbon storage, evapotranspiration, and albedo? (4) Will climate change expand or diminish the agricultural production and ecosystem service generation capacities of specific watersheds? Such research can facilitate early adaptation and make a timely contribution to the successful integration of agricultural, environmental, and trade policy. Rural landscapes behave as a system through a number of feedback mechanisms: climatic, agro-technology, market, and policy. Methods, including agent-based modeling, SWAT modeling, map algebra using logistic regression, and genetic algorithms for analyzing each of these feedback mechanisms will be described. Selected early results that link sub-system models and incorporate critical feedbacks will also be presented.igure 1. Overall Modeling framework for Climate Change, Hydrology and Landscapes of America's Heartland.

  11. Concept formation vs. logistic regression: predicting death in trauma patients.

    PubMed

    Hadzikadic, M; Hakenewerth, A; Bohren, B; Norton, J; Mehta, B; Andrews, C

    1996-10-01

    This study compares two classification models used to predict survival of injured patients entering the emergency department. Concept formation is a machine learning technique that summarizes known examples cases in the form of a tree. After the tree is constructed, it can then be used to predict the classification of new cases. Logistic regression, on the other hand, is a statistical model that allows for a quantitative relationship for a dichotomous event with several independent variables. The outcome (dependent) variable must have only two choices, e.g. does or does not occur, alive or dead, etc. The result of this model is an equation which is then used to predict the probability of class membership of a new case. The two models were evaluated on a trauma registry database composed of information on all trauma patients admitted in 1992 to a Level I trauma center. A total of 2155 records. representing all trauma patients admitted for more than 24 h or who died in the Emergency Department, were grouped into two databases as follows: (1) discharge status of 'died' (containing 151 records), and (2) any discharge status other than 'died' (containing 2004 records). Both databases contained the same variables. PMID:8955858

  12. Strategy and logistics for the New World Order. Master's thesis

    SciTech Connect

    Gildersleeve, C.W.

    1990-12-01

    An interdisciplinary analysis of the post-Cold War world to determine the optimal strategy to attain the national interests of the United States, and the requisite logistic structure to support that strategy. The optimal solution is found to be a strategy based on multinational defense centered on a permanent force of United Nations garrison port complexes. This multilateral force would be augmented by as small a national defense force as necessary to ensure national security. The theses endeavors to reconnect the cultural and philosophical past of the United States with its immediate future. National interests are identified through examination of American Pragmatism and the philosophies of John Locke and Jean-Jacques Rousseau. To determine the current status of common defense, based upon the Foreign Military Sales system, and analysis of current data is accomplished. Future threats to the United States are examined with special emphasis on nuclear terrorism. The ability of Islamic nations in North Africa and the Middle East to produce significant quantities of uranium is demonstrated. The grave political as well as ongoing environmental consequences of this recent capability are discussed in detail.

  13. Application of Bayesian Logistic Regression to Mining Biomedical Data

    PubMed Central

    Avali, Viji R.; Cooper, Gregory F.; Gopalakrishnan, Vanathi

    2014-01-01

    Mining high dimensional biomedical data with existing classifiers is challenging and the predictions are often inaccurate. We investigated the use of Bayesian Logistic Regression (B-LR) for mining such data to predict and classify various disease conditions. The analysis was done on twelve biomedical datasets with binary class variables and the performance of B-LR was compared to those from other popular classifiers on these datasets with 10-fold cross validation using the WEKA data mining toolkit. The statistical significance of the results was analyzed by paired two tailed t-tests and non-parametric Wilcoxon signed-rank tests. We observed overall that B-LR with non-informative Gaussian priors performed on par with other classifiers in terms of accuracy, balanced accuracy and AUC. These results suggest that it is worthwhile to explore the application of B-LR to predictive modeling tasks in bioinformatics using informative biological prior probabilities. With informative prior probabilities, we conjecture that the performance of B-LR will improve. PMID:25954328

  14. Hybrid coronary artery revascularization: logistics and program development.

    PubMed

    Friedrich, Guy J; Jonetzko, Patricja; Bonaros, Nikos; Schachner, Thomas; Danzmayr, Michael; Kofler, Ruth; Laufer, G; Pachinger, O; Bonatti, Johannes

    2005-01-01

    Planning hybrid coronary artery revascularization--a combination of cardiac surgery with percutaneous procedures--requires, at first sight, a very complex logistical setup. Technical and equipment related details should be defined as early as possible in order to have time for training of all OR personnel involved. The most challenging aspect in OR-located hybrid coronary revascularization remains a very close cooperation of cardiac surgeons and interventional cardiologists. This teamwork does include indication findings and subsequent referral of multivessel coronary artery disease patients to hybrid procedures, as well as high individual flexibility of interventionalists and surgeons. The major prerequisite for this cooperation is a mutual acceptance of different revascularization approaches and the intent to combine their most striking advantages. Intraoperative graft angiography during coronary artery bypass grafting (CABG) procedures is one important step toward simultaneous hybrid coronary revascularization procedures. We describe our experience with on table angiography using a mobile C-arm for intraoperative imaging. This fluoroscopy system can in selected cases be used for simultaneous hybrid procedures. PMID:16112939

  15. NALDA (Naval Aviation Logistics Data Analysis) CAI (computer aided instruction)

    SciTech Connect

    Handler, B.H. ); France, P.A.; Frey, S.C.; Gaubas, N.F.; Hyland, K.J.; Lindsey, A.M.; Manley, D.O. ); Hunnum, W.H. ); Smith, D.L. )

    1990-07-01

    Data Systems Engineering Organization (DSEO) personnel developed a prototype computer aided instruction CAI system for the Naval Aviation Logistics Data Analysis (NALDA) system. The objective of this project was to provide a CAI prototype that could be used as an enhancement to existing NALDA training. The CAI prototype project was performed in phases. The task undertaken in Phase I was to analyze the problem and the alternative solutions and to develop a set of recommendations on how best to proceed. The findings from Phase I are documented in Recommended CAI Approach for the NALDA System (Duncan et al., 1987). In Phase II, a structured design and specifications were developed, and a prototype CAI system was created. A report, NALDA CAI Prototype: Phase II Final Report, was written to record the findings and results of Phase II. NALDA CAI: Recommendations for an Advanced Instructional Model, is comprised of related papers encompassing research on computer aided instruction CAI, newly developing training technologies, instructional systems development, and an Advanced Instructional Model. These topics were selected because of their relevancy to the CAI needs of NALDA. These papers provide general background information on various aspects of CAI and give a broad overview of new technologies and their impact on the future design and development of training programs. The paper within have been index separately elsewhere.

  16. Radio frequency identification enabled wireless sensing for intelligent food logistics.

    PubMed

    Zou, Zhuo; Chen, Qiang; Chen, Qing; Uysal, Ismail; Zheng, Lirong

    2014-06-13

    Future technologies and applications for the Internet of Things (IoT) will evolve the process of the food supply chain and create added value of business. Radio frequency identifications (RFIDs) and wireless sensor networks (WSNs) have been considered as the key technological enablers. Intelligent tags, powered by autonomous energy, are attached on objects, networked by short-range wireless links, allowing the physical parameters such as temperatures and humidities as well as the location information to seamlessly integrate with the enterprise information system over the Internet. In this paper, challenges, considerations and design examples are reviewed from system, implementation and application perspectives, particularly with focus on intelligent packaging and logistics for the fresh food tracking and monitoring service. An IoT platform with a two-layer network architecture is introduced consisting of an asymmetric tag-reader link (RFID layer) and an ad-hoc link between readers (WSN layer), which are further connected to the Internet via cellular or Wi-Fi. Then, we provide insights into the enabling technology of RFID with sensing capabilities. Passive, semi-passive and active RFID solutions are discussed. In particular, we describe ultra-wideband radio RFID which has been considered as one of the most promising techniques for ultra-low-power and low-cost wireless sensing. Finally, an example is provided in the form of an application in fresh food tracking services and corresponding field testing results. PMID:24797140

  17. Weirton Steel Corporation logistics and integrated scheduling. Final report

    SciTech Connect

    Guzzetta, M.B.

    1996-06-01

    In order to remain competitive in the changing steel market, US steel producers restructured by taking on foreign and domestic partners, closing facilities and/or trimming work forces, and modernizing their steel making facilities. However, very little was done to develop production management technology to complement these changes. The Logistics and Integrated Scheduling program (LIS) was undertaken to address this issue. LIS is an information management system that delivers better customer service, better quality materials, and a just-in-time delivery system. It involves three major components: (1) material marking and sensing: advanced R&D applied to determining cost effective, feasible solutions to passive inventory; (2) material inventory and tracking: advanced technology applied to managing inventory movement; (3) planning and scheduling: beginning with annual production plans, order management, and operational constraints, the ability to build integrated schedules capable of pull through and push through scheduling for various plant capability levels and location configurations with rapid turnaround capability. LIS provides accurate, automated tracking of material flows throughout the mill, the collection and analysis of production data, and automated schedule optimization.

  18. Comment on ``Correlated noise in a logistic growth model''

    NASA Astrophysics Data System (ADS)

    Behera, Anita; O'Rourke, S. Francesca C.

    2008-01-01

    We argue that the results published by Ai [Phys. Rev. E 67, 022903 (2003)] on “correlated noise in logistic growth” are not correct. Their conclusion that, for larger values of the correlation parameter λ , the cell population is peaked at x=0 , which denotes a high extinction rate, is also incorrect. We find the reverse behavior to their results, that increasing λ promotes the stable growth of tumor cells. In particular, their results for the steady-state probability, as a function of cell number, at different correlation strengths, presented in Figs. 1 and 2 of their paper show different behavior than one would expect from the simple mathematical expression for the steady-state probability. Additionally, their interpretation that at small values of cell number the steady-state probability increases as the correlation parameter is increased is also questionable. Another striking feature in their Figs. 1 and 3 is that, for the same values of the parameters λ and α , their simulation produces two different curves, both qualitatively and quantitatively.

  19. Efficient Logistic Regression Designs Under an Imperfect Population Identifier

    PubMed Central

    Albert, Paul S.; Liu, Aiyi; Nansel, Tonja

    2013-01-01

    Summary Motivated by actual study designs, this article considers efficient logistic regression designs where the population is identified with a binary test that is subject to diagnostic error. We consider the case where the imperfect test is obtained on all participants, while the gold standard test is measured on a small chosen subsample. Under maximum-likelihood estimation, we evaluate the optimal design in terms of sample selection as well as verification. We show that there may be substantial efficiency gains by choosing a small percentage of individuals who test negative on the imperfect test for inclusion in the sample (e.g., verifying 90% test-positive cases). We also show that a two-stage design may be a good practical alternative to a fixed design in some situations. Under optimal and nearly optimal designs, we compare maximum-likelihood and semi-parametric efficient estimators under correct and misspecified models with simulations. The methodology is illustrated with an analysis from a diabetes behavioral intervention trial. PMID:24261471

  20. Risk factors for temporomandibular disorder: Binary logistic regression analysis

    PubMed Central

    Magalhães, Bruno G.; de-Sousa, Stéphanie T.; de Mello, Victor V C.; da-Silva-Barbosa, André C.; de-Assis-Morais, Mariana P L.; Barbosa-Vasconcelos, Márcia M V.

    2014-01-01

    Objectives: To analyze the influence of socioeconomic and demographic factors (gender, economic class, age and marital status) on the occurrence of temporomandibular disorder. Study Design: One hundred individuals from urban areas in the city of Recife (Brazil) registered at Family Health Units was examined using Axis I of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) which addresses myofascial pain and joint problems (disc displacement, arthralgia, osteoarthritis and oesteoarthrosis). The Brazilian Economic Classification Criteria (CCEB) was used for the collection of socioeconomic and demographic data. Then, it was categorized as Class A (high social class), Classes B/C (middle class) and Classes D/E (very poor social class). The results were analyzed using Pearson’s chi-square test for proportions, Fisher’s exact test, nonparametric Mann-Whitney test and Binary logistic regression analysis. Results: None of the participants belonged to Class A, 72% belonged to Classes B/C and 28% belonged to Classes D/E. The multivariate analysis revealed that participants from Classes D/E had a 4.35-fold greater chance of exhibiting myofascial pain and 11.3-fold greater chance of exhibiting joint problems. Conclusions: Poverty is a important condition to exhibit myofascial pain and joint problems. Key words:Temporomandibular joint disorders, risk factors, prevalence. PMID:24316706