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1

Evaluation of Anonymity Providing Techniques using Queuing Theory Dogan Kesdogan  

E-print Network

"How much did you waste waiting in line this week?" With this question, he expresses the aim of queuingEvaluation of Anonymity Providing Techniques using Queuing Theory Dogan Kesdogan IBM Thomas J In our work we use queuing theory both for security (i.e. anonymity) and performance analysis. A well

2

An Application of Queuing Theory to Waterfowl Migration  

Microsoft Academic Search

Abstract: There has always been great interest in the migration of waterfowl and other birds. We have applied queuing theory to modelling waterfowl migration, beginning with a prototype system for the Rocky Mountain Population of trumpeter swans (Cygnus buccinator) in Western North America. The queuing model can be classified as a D\\/BB\\/28 system, and we describe the input sources, service

Richard S. Sojda; John E. Cornely; Leigh H. Fredrickson

3

Queuing theory models for computer networks  

NASA Technical Reports Server (NTRS)

A set of simple queuing theory models which can model the average response of a network of computers to a given traffic load has been implemented using a spreadsheet. The impact of variations in traffic patterns and intensities, channel capacities, and message protocols can be assessed using them because of the lack of fine detail in the network traffic rates, traffic patterns, and the hardware used to implement the networks. A sample use of the models applied to a realistic problem is included in appendix A. Appendix B provides a glossary of terms used in this paper. This Ames Research Center computer communication network is an evolving network of local area networks (LANs) connected via gateways and high-speed backbone communication channels. Intelligent planning of expansion and improvement requires understanding the behavior of the individual LANs as well as the collection of networks as a whole.

Galant, David C.

1989-01-01

4

Solving of waiting lines models in the airport using queuing theory model and linear programming  

E-print Network

1 Solving of waiting lines models in the airport using queuing theory model and linear programming common queuing situations and present mathematical models for analysing waiting lines following certain and to business applications of waiting lines. 1-Introduction: The study of waiting lines, called queuing theory

Paris-Sud XI, Université de

5

Applying Queuing and Probability Theory to Predict Organizational Behaviors  

E-print Network

Applying Queuing and Probability Theory to Predict Organizational Behaviors Bryan Horling Multi information into the organizational model. Such a model can be used to make detailed predictions of how we will demonstrate this potential by describing how an organizationally-driven information retrieval

Massachusetts at Amherst, University of

6

CDA6530: Performance Models of Computers and Networks Chapter 4: Elementary Queuing Theory  

E-print Network

;DefinitionDefinition Queuing system: Queuing system: a buffer (waiting room), service facility (one or moreCDA6530: Performance Models of Computers and Networks Chapter 4: Elementary Queuing Theory #12 (response) time, Service time + waiting time number in system number in system, server utilization, etc. 2

Zou, Cliff C.

7

CDA6530: Performance Models of Computers and Networks Chapter 6: Elementary Queuing Theory  

E-print Network

;2 Definition Queuing system: a buffer (waiting room), service facility (one or more servers) a schedulingCDA6530: Performance Models of Computers and Networks Chapter 6: Elementary Queuing Theory #12) arrive to such a system throughput, sojourn (response) time, Service time + waiting time number

Zou, Cliff C.

8

Application of queuing theory in inventory systems with substitution flexibility  

NASA Astrophysics Data System (ADS)

Considering the competition in today's business environment, tactical planning of a supply chain becomes more complex than before. In many multi-product inventory systems, substitution flexibility can improve profits. This paper aims to prepare a comprehensive substitution inventory model, where an inventory system with two substitute products with ignorable lead time has been considered, and effects of simultaneous ordering have been examined. In this paper, demands of customers for both of the products have been regarded as stochastic parameters, and queuing theory has been used to construct a mathematical model. The model has been coded by C++, and it has been analyzed due to a real example, where the results indicate efficiency of proposed model.

Seyedhoseini, S. M.; Rashid, Reza; Kamalpour, Iman; Zangeneh, Erfan

2015-01-01

9

Using Queuing Theory and Simulation Model to Optimize Hospital Pharmacy Performance  

PubMed Central

Background: Hospital pharmacy is responsible for controlling and monitoring the medication use process and ensures the timely access to safe, effective and economical use of drugs and medicines for patients and hospital staff. Objectives: This study aimed to optimize the management of studied outpatient pharmacy by developing suitable queuing theory and simulation technique. Patients and Methods: A descriptive-analytical study conducted in a military hospital in Iran, Tehran in 2013. A sample of 220 patients referred to the outpatient pharmacy of the hospital in two shifts, morning and evening, was selected to collect the necessary data to determine the arrival rate, service rate, and other data needed to calculate the patients flow and queuing network performance variables. After the initial analysis of collected data using the software SPSS 18, the pharmacy queuing network performance indicators were calculated for both shifts. Then, based on collected data and to provide appropriate solutions, the queuing system of current situation for both shifts was modeled and simulated using the software ARENA 12 and 4 scenarios were explored. Results: Results showed that the queue characteristics of the studied pharmacy during the situation analysis were very undesirable in both morning and evening shifts. The average numbers of patients in the pharmacy were 19.21 and 14.66 in the morning and evening, respectively. The average times spent in the system by clients were 39 minutes in the morning and 35 minutes in the evening. The system utilization in the morning and evening were, respectively, 25% and 21%. The simulation results showed that reducing the staff in the morning from 2 to 1 in the receiving prescriptions stage didn't change the queue performance indicators. Increasing one staff in filling prescription drugs could cause a decrease of 10 persons in the average queue length and 18 minutes and 14 seconds in the average waiting time. On the other hand, simulation results showed that in the evening, decreasing the staff from 2 to 1 in the delivery of prescription drugs, changed the queue performance indicators very little. Increasing a staff to fill prescription drugs could cause a decrease of 5 persons in the average queue length and 8 minutes and 44 seconds in the average waiting time. Conclusions: The patients' waiting times and the number of patients waiting to receive services in both shifts could be reduced by using multitasking persons and reallocating them to the time-consuming stage of filling prescriptions, using queuing theory and simulation techniques. PMID:24829791

Bahadori, Mohammadkarim; Mohammadnejhad, Seyed Mohsen; Ravangard, Ramin; Teymourzadeh, Ehsan

2014-01-01

10

Allocation of computer ports within a terminal switching network: an application of queuing theory to gandalf port contenders  

SciTech Connect

Queuing theory is applied to the problem of assigning computer ports within a terminal switching network to maximize the likelihood of instant connect. A brief background of the network is included to focus on the statement of the problem.

Vahle, M.O.

1982-03-01

11

Queuing theory to guide the implementation of a heart failure inpatient registry program.  

PubMed

OBJECTIVE The authors previously implemented an electronic heart failure registry at a large academic hospital to identify heart failure patients and to connect these patients with appropriate discharge services. Despite significant improvements in patient identification and connection rates, time to connection remained high, with an average delay of 3.2 days from the time patients were admitted to the time connections were made. Our objective for this current study was to determine the most effective solution to minimize time to connection. DESIGN We used a queuing theory model to simulate 3 different potential solutions to decrease the delay from patient identification to connection with discharge services. MEASUREMENTS The measures included average rate at which patients were being connected to the post discharge heart failure services program, average number of patients in line, and average patient waiting time. RESULTS Using queuing theory model simulations, we were able to estimate for our current system the minimum rate at which patients need to be connected (262 patients/mo), the ideal patient arrival rate (174 patients/mo) and the maximal patient arrival rate that could be achieved by adding 1 extra nurse (348 patients/mo). CONCLUSIONS Our modeling approach was instrumental in helping us characterize key process parameters and estimate the impact of adding staff on the time between identifying patients with heart failure and connecting them with appropriate discharge services. PMID:19390108

Zai, Adrian H; Farr, Kit M; Grant, Richard W; Mort, Elizabeth; Ferris, Timothy G; Chueh, Henry C

2009-01-01

12

T-Cell Activation: A Queuing Theory Analysis at Low Agonist Density J. R. Wedagedera* and N. J. Burroughsy  

E-print Network

T-Cell Activation: A Queuing Theory Analysis at Low Agonist Density J. R. Wedagedera* and N. J, University of Warwick, Coventry, United Kingdom ABSTRACT We analyze a simple linear triggering model of the T-cell,arobustnessanalysisshowsthatthesepropertiesaredegradedwhenthequeueparameters aresubject tovariation--for example, under stochasticity in the ligand number in the cell-cell interface

Wedagedera, Janak R.

13

Application of queuing theory to patient satisfaction at a tertiary hospital in Nigeria  

PubMed Central

Background: Queuing theory is the mathematical approach to the analysis of waiting lines in any setting where arrival rate of subjects is faster than the system can handle. It is applicable to healthcare settings where the systems have excess capacity to accommodate random variations. Materials and Methods: A cross-sectional descriptive survey was done. Questionnaires were administered to patients who attended the general outpatient department. Observations were also made on the queuing model and the service discipline at the clinic. Questions were meant to obtain demographic characteristics and the time spent on the queue by patients before being seen by a doctor, time spent with the doctor, their views about the time spent on the queue and useful suggestions on how to reduce the time spent on the queue. A total of 210 patients were surveyed. Results: Majority of the patients (164, 78.1%) spent 2 h or less on the queue before being seen by a doctor and less than 1 h to see the doctor. Majority of the patients (144, 68.5%) were satisfied with the time they spent on the queue before being seen by a doctor. Useful suggestions proffered by the patients to decrease the time spent on the queue before seeing a doctor at the clinic included: that more doctors be employed (46, 21.9%), that doctors should come to work on time (25, 11.9%), that first-come-first served be observed strictly (32, 15.2%) and others suggested that the records staff should desist from collecting bribes from patients in order to place their cards before others. The queuing method employed at the clinic is the multiple single channel type and the service discipline is priority service. The patients who spent less time on the queue (<1 h) before seeing the doctor were more satisfied than those who spent more time (P < 0.05). Conclusion: The study has revealed that majority of the patients were satisfied with the practice at the general outpatient department. However, there is a need to employ measures to respond to the suggestions given by the patients who are the beneficiaries of the hospital services. PMID:23661902

Ameh, Nkeiruka; Sabo, B.; Oyefabi, M. O.

2013-01-01

14

Effects of diversity and procrastination in priority queuing theory: The different power law regimes  

NASA Astrophysics Data System (ADS)

Empirical analyses show that after the update of a browser, or the publication of the vulnerability of a software, or the discovery of a cyber worm, the fraction of computers still using the older browser or software version, or not yet patched, or exhibiting worm activity decays as a power law ˜1/t? with 0queuing theory, of a target task which has the lowest priority compared to all other tasks that flow on the computer of an individual. We identify a “time deficit” control parameter ? and a bifurcation to a regime where there is a nonzero probability for the target task to never be completed. The distribution of waiting time T until the completion of the target task has the power law tail ˜1/t1/2 , resulting from a first-passage solution of an equivalent Wiener process. Taking into account a diversity of time deficit parameters in a population of individuals, the power law tail is changed into 1/t? , with ??(0.5,?) , including the well-known case 1/t . We also study the effect of “procrastination,” defined as the situation in which the target task may be postponed or delayed even after the individual has solved all other pending tasks. This regime provides an explanation for even slower apparent decay and longer persistence.

Saichev, A.; Sornette, D.

2010-01-01

15

Effects of diversity and procrastination in priority queuing theory: the different power law regimes.  

PubMed

Empirical analyses show that after the update of a browser, or the publication of the vulnerability of a software, or the discovery of a cyber worm, the fraction of computers still using the older browser or software version, or not yet patched, or exhibiting worm activity decays as a power law approximately 1/t(alpha) with 0queuing theory, of a target task which has the lowest priority compared to all other tasks that flow on the computer of an individual. We identify a "time deficit" control parameter beta and a bifurcation to a regime where there is a nonzero probability for the target task to never be completed. The distribution of waiting time T until the completion of the target task has the power law tail approximately 1/t(1/2), resulting from a first-passage solution of an equivalent Wiener process. Taking into account a diversity of time deficit parameters in a population of individuals, the power law tail is changed into 1/t(alpha), with alpha is an element of (0.5,infinity), including the well-known case 1/t. We also study the effect of "procrastination," defined as the situation in which the target task may be postponed or delayed even after the individual has solved all other pending tasks. This regime provides an explanation for even slower apparent decay and longer persistence. PMID:20365433

Saichev, A; Sornette, D

2010-01-01

16

Improving queuing service at McDonald's  

NASA Astrophysics Data System (ADS)

Fast food restaurants are popular among price-sensitive youths and working adults who value the conducive environment and convenient services. McDonald's chains of restaurants promote their sales during lunch hours by offering package meals which are perceived to be inexpensive. These promotional lunch meals attract good response, resulting in occasional long queues and inconvenient waiting times. A study is conducted to monitor the distribution of waiting time, queue length, customer arrival and departure patterns at a McDonald's restaurant located in Kuala Lumpur. A customer survey is conducted to gauge customers' satisfaction regarding waiting time and queue length. An android app named Que is developed to perform onsite queuing analysis and report key performance indices. The queuing theory in Que is based upon the concept of Poisson distribution. In this paper, Que is utilized to perform queuing analysis at this McDonald's restaurant with the aim of improving customer service, with particular reference to reducing queuing time and shortening queue length. Some results will be presented.

Koh, Hock Lye; Teh, Su Yean; Wong, Chin Keat; Lim, Hooi Kie; Migin, Melissa W.

2014-07-01

17

On Some Common Interests Among Reliability, Inventory, and Queuing  

Microsoft Academic Search

Queuing networks can be used to model maintained systems. Under many conditions, closed-network queuing theory can be applied to ascertain the availability of such systems. Multi-echelon repairable-item inventory systems are one such class. Problems of common interest to the reliability, queuing, and inventory communities are highlighted, and solution techniques for these problems are presented.

Donald Gross; Douglas R. Miller; Richard M. Soland

1985-01-01

18

The application of queuing theory to the modelling of CP-140 aircraft communications  

NASA Astrophysics Data System (ADS)

Several authors have argued that queueing models can be used to predict workload and performance of operators under the single channel hypothesis of man's information processing capability. A simple exponential, single server queueing model is used to investigate the application of queueing theory to communication and navigation tasks performed aboard the CP-140 Aurora aircraft. It was anticipated that the model would provide insight into how individual tasks with low workloads combine to create high workload situations. The results, however, indicated problems originating from the data and the model. A new model was recommended as well as an appropriate data collection technique for the application of queueing theory to multi-task situations.

Campbell, E. L.

1989-06-01

19

The application of queuing theory to the modelling of CP140 aircraft communications  

Microsoft Academic Search

Several authors have argued that queueing models can be used to predict workload and performance of operators under the single channel hypothesis of man's information processing capability. A simple exponential, single server queueing model is used to investigate the application of queueing theory to communication and navigation tasks performed aboard the CP-140 Aurora aircraft. It was anticipated that the model

E. L. Campbell

1989-01-01

20

Closed loop credit-based flow control with internal backpressure in input and output queued switches  

Microsoft Academic Search

A credit-based flow control scheme is very effective for handling cells of the ABR or controlled transfer service class in ATM networks. The properties of immediate ramp-up after congestion and the impossibility of buffer overflow by construction are what makes this method very attractive. For best results, many switches along the route must support flow control, acting as virtual source\\/destination

Rainer Schoenen; Achim Dahlhoff

2000-01-01

21

Single Queuing Systems M/M/1 queuing system  

E-print Network

64 Single Queuing Systems M/M/1 queuing system -- arrival process is a Poisson process (or) inter-arrival time density (t) = T is an exponentially distributed r.v. no arrivals in a time interval-t) t t 1-t t M/M/1 #12;72 )()()()( )( 11 tPtPtP dt tdP nnn n n-1 n+1n flows into state flows out

Chen, Ing-Ray

22

Analytic Modeling Queuing Models with Single  

E-print Network

Analytic Modeling Queuing Models with Single Service Facility 1 Characteristics of a Service Facility · Number of servers · Queuing discipline ­ default is FCFS · Number of queuing spaces (or buffers ­ elapsed time from arrival to departure · Waiting time ­ time spent in queue · Number of customers

Shihada, Basem

23

FPGA PROTOTYPE QUEUING MODULE FOR HIGH PERFORMANCE ATM SWITCHING  

E-print Network

FPGA PROTOTYPE QUEUING MODULE FOR HIGH PERFORMANCE ATM SWITCHING H. Duan, J. W. Lockwood, and S. M module of the Illinois Pulsar-based Optical INTconnect iPOINT Asynchronous Trans- fer Mode ATM testbed are dropped when the queue is full. Opto-electronic and electro-optic conversions and clock recovery are done

Lockwood, John W.

24

Bounds on Average Delays and Queue Size Averages and Variances in Input-Queued Cell-Based Switches  

Microsoft Academic Search

In this paper we develop a general methodology, mainly based upon Lyapunov functions, to derive bounds on average delays, and on queue size averages and variances of complex systems of queues. We then apply this methodology to input-buffered, cell-based switch and router ar- chitectures. These architectures require a scheduling algorithm to select at each slot a subset of input-buffered cells

Emilio Leonardi; Marco Mellia; Fabio Neri; Marco Ajmone Marsan

2001-01-01

25

Capacity Utilization Study for Aviation Security Cargo Inspection Queuing System  

SciTech Connect

In this paper, we conduct performance evaluation study for an aviation security cargo inspection queuing system for material flow and accountability. The queuing model employed in our study is based on discrete-event simulation and processes various types of cargo simultaneously. Onsite measurements are collected in an airport facility to validate the queuing model. The overall performance of the aviation security cargo inspection system is computed, analyzed, and optimized for the different system dynamics. Various performance measures are considered such as system capacity, residual capacity, throughput, capacity utilization, subscribed capacity utilization, resources capacity utilization, subscribed resources capacity utilization, and number of cargo pieces (or pallets) in the different queues. These metrics are performance indicators of the system s ability to service current needs and response capacity to additional requests. We studied and analyzed different scenarios by changing various model parameters such as number of pieces per pallet, number of TSA inspectors and ATS personnel, number of forklifts, number of explosives trace detection (ETD) and explosives detection system (EDS) inspection machines, inspection modality distribution, alarm rate, and cargo closeout time. The increased physical understanding resulting from execution of the queuing model utilizing these vetted performance measures should reduce the overall cost and shipping delays associated with new inspection requirements.

Allgood, Glenn O [ORNL; Olama, Mohammed M [ORNL; Lake, Joe E [ORNL; Brumback, Daryl L [ORNL

2010-01-01

26

Capacity utilization study for aviation security cargo inspection queuing system  

NASA Astrophysics Data System (ADS)

In this paper, we conduct performance evaluation study for an aviation security cargo inspection queuing system for material flow and accountability. The queuing model employed in our study is based on discrete-event simulation and processes various types of cargo simultaneously. Onsite measurements are collected in an airport facility to validate the queuing model. The overall performance of the aviation security cargo inspection system is computed, analyzed, and optimized for the different system dynamics. Various performance measures are considered such as system capacity, residual capacity, throughput, capacity utilization, subscribed capacity utilization, resources capacity utilization, subscribed resources capacity utilization, and number of cargo pieces (or pallets) in the different queues. These metrics are performance indicators of the system's ability to service current needs and response capacity to additional requests. We studied and analyzed different scenarios by changing various model parameters such as number of pieces per pallet, number of TSA inspectors and ATS personnel, number of forklifts, number of explosives trace detection (ETD) and explosives detection system (EDS) inspection machines, inspection modality distribution, alarm rate, and cargo closeout time. The increased physical understanding resulting from execution of the queuing model utilizing these vetted performance measures should reduce the overall cost and shipping delays associated with new inspection requirements.

Allgood, Glenn O.; Olama, Mohammed M.; Lake, Joe E.; Brumback, Daryl

2010-04-01

27

SCHEDULING IN A QUEUING SYSTEM WITH ASYNCHRONOUSLY  

E-print Network

SCHEDULING IN A QUEUING SYSTEM WITH ASYNCHRONOUSLY VARYING SERVICE RATES MAAATTTTTTHHHEEEWWW@research.bell-labs.com We consider the following queuing system which arises as a model of a wireless link shared; waiting customers of each flow are placed in a queue+ The sequence of server states m~t!, t 0

Ramanan, Kavita

28

Application of queuing model in Dubai's busiest megaplex  

NASA Astrophysics Data System (ADS)

This paper provides a study and analysis of the extremely busy booking counters at the Megaplex in Dubai using the queuing model and simulation. Dubai is an emirate in UAE with a multicultural population. Majority of the population in Dubai is foreign born. Cinema is one of the major forms of entertainment. There are more than 13 megaplexes each with a number of screens ranging from 3 to 22. They screen movies in English, Arabic, Hindi and other languages. It has been observed that during the weekends megaplexes attract a large number of crowd resulting in long queues at the booking counters. One of the busiest megaplex was selected for the study. Queuing theory satisfies the model when tested in real time situation. The concepts of arrival rate, service rate, utilization rate, waiting time in the system, average number of people in the queue, using Little's Theorem and M/M/s queuing model along with simulation software have been used to suggest an empirical solution. The aim of the paper is twofold-To assess the present situation at the Megaplex and give recommendations to optimize the use of booking counters.

Bhagchandani, Maneesha; Bajpai, Priti

2013-09-01

29

Queuing register uses fluid logic elements  

NASA Technical Reports Server (NTRS)

Queuing register /a multistage bit-shifting device/ uses a series of pure fluid elements to perform the required logic operations. The register has several stages of three-state pure fluid elements combined with two-input NOR gates.

1966-01-01

30

Jamming transition in traffic flow under the priority queuing protocol  

NASA Astrophysics Data System (ADS)

Packet traffic in complex networks undergoes the jamming transition from free-flow to congested state as the number of packets in the system increases. Here we study such jamming transition when queues are operated by the priority queuing protocol and packets are guided by the dynamic routing protocol. We introduce a minimal model in which there are two types of packets distinguished by whether priority is assigned. Based on numerical simulations, we show that traffic is improved in the congested region under the priority queuing protocol, and it is worsened in the free-flow region. Also, we find that at the transition point, the waiting-time distribution follows a power law, and the power spectrum of traffic exhibits a crossover between two 1/f? behaviors with two different exponents ?<2 in low- and high-frequency regime, respectively. This crossover is originated from a characteristic waiting time of packets in the queue.

Kim, K.; Kahng, B.; Kim, D.

2009-06-01

31

Queuing Models of Tertiary Storage  

NASA Technical Reports Server (NTRS)

Large scale scientific projects generate and use large amounts of data. For example, the NASA Earth Observation System Data and Information System (EOSDIS) project is expected to archive one petabyte per year of raw satellite data. This data is made automatically available for processing into higher level data products and for dissemination to the scientific community. Such large volumes of data can only be stored in robotic storage libraries (RSL's) for near-line access. A characteristic of RSL's is the use of a robot arm that transfers media between a storage rack and the read/write drives, thus multiplying the capacity of the system. The performance of the RSL's can be a critical limiting factor for the performance of the archive system. However, the many interacting components of an RSL make a performance analysis difficult. In addition, different RSL components can have widely varying performance characteristics. This paper describes our work to develop performance models of an RSL in isolation. Next we show how the RSL model can be incorporated into a queuing network model. We use the models to make some example performance studies of archive systems. The models described in this paper, developed for the NASA EODIS project, are implemented in C with a well defined interface. The source code, accompanying documentation, and also sample JAVA applets are available at: http://www.cis.ufl.edu/ted/

Johnson, Theodore

1996-01-01

32

Theory-Based Stakeholder Evaluation  

ERIC Educational Resources Information Center

This article introduces a new approach to program theory evaluation called theory-based stakeholder evaluation or the TSE model for short. Most theory-based approaches are program theory driven and some are stakeholder oriented as well. Practically, all of the latter fuse the program perceptions of the various stakeholder groups into one unitary…

Hansen, Morten Balle; Vedung, Evert

2010-01-01

33

Packet-Mode Emulation of Output-Queued Switches  

E-print Network

Packet-Mode Emulation of Output-Queued Switches Hagit Attiya, David Hay, Member, IEEE, and Isaac is, a perfect emulation), regardless of the switch speedup. In addition, simpler algorithms can mimic confirm that packet-mode emulation with reasonable relative queuing delay can be achieved with moderate

Keslassy, Isaac

34

KalmanQueue: An Adaptive Approach to Virtual Queuing  

E-print Network

Pass is a virtual queuing system that allows some theme park customers to significantly cut down their waiting timeKalmanQueue: An Adaptive Approach to Virtual Queuing February 10, 2004 Abstract Quick are not significantly affected and (2) maximum waiting time for QuickPass users is small. To build a solid foundation

Morrow, James A.

35

Performance evaluation of centralized maintenance workshop by using Queuing Networks  

E-print Network

Performance evaluation of centralized maintenance workshop by using Queuing Networks Zineb Simeu on the queuing network models. Simulation results are given in order to illustrate the influence of different parameters, like arrival rate of the failed equipments and the waiting time of the equipment Keywords

Paris-Sud XI, Université de

36

Some queuing network models of computer systems  

NASA Technical Reports Server (NTRS)

Queuing network models of a computer system operating with a single workload type are presented. Program algorithms are adapted for use on the Texas Instruments SR-52 programmable calculator. By slightly altering the algorithm to process the G and H matrices row by row instead of column by column, six devices and an unlimited job/terminal population could be handled on the SR-52. Techniques are also introduced for handling a simple load dependent server and for studying interactive systems with fixed multiprogramming limits.

Herndon, E. S.

1980-01-01

37

Queuing network approach for building evacuation planning  

NASA Astrophysics Data System (ADS)

The complex behavior of pedestrians in a limited space layout can explicitly be modeled using an M/G/C/C state dependent queuing network. This paper implements the approach to study pedestrian flows through various corridors in a topological network. The best arrival rates and their impacts to the corridors' performances in terms of the throughput, blocking probability, expected number of occupants in the system and expected travel time were first measured using the M/G/C/C analytical model. These best arrival rates were then fed to its Network Flow Programming model to find the best arrival rates to source corridors and routes optimizing the network's total throughput. The analytical results were then validated using a simulation model. Various results of this study can be used to support the current Standard Operating Procedures (SOP) to efficiently and safely evacuate people in emergency cases.

Ishak, Nurhanis; Khalid, Ruzelan; Baten, Md. Azizul; Nawawi, Mohd. Kamal Mohd.

2014-12-01

38

Non-Equilibrium Statistical Physics of Currents in Queuing Networks  

E-print Network

We consider a stable open queuing network as a steady non-equilibrium system of interacting particles. The network is completely specified by its underlying graphical structure, type of interaction at each node, and the ...

Chernyak, Vladimir Y.

39

FIFO Queuing of Constant Length Fully Synchronous Jobs  

E-print Network

FIFO Queuing of Constant Length Fully Synchronous Jobs Vandy Berten, Raymond Devillers and Guy.e. there is always at least one job waiting in the input queue, and that all jobs have the same length, i

Louchard, Guy

40

The Impact of Autocorrelation on Queuing Systems Miron Livny +, Benjamin Melamed # and Athanassios K. Tsiolis +  

E-print Network

the queue size and waiting time processes in a queuing system with independent exponential services and gam­­ ­­ The Impact of Autocorrelation on Queuing Systems Miron Livny +, Benjamin Melamed these empirical results and makes some recommendations to practitioners of performance analysis of queuing systems

41

An application of a queuing model for sea states  

NASA Astrophysics Data System (ADS)

Unimodal approaches in design practice have shown inconsistencies in terms of directionality and limitations for accurate sea states description. Spectral multimodality needs to be included in the description of the wave climate. It can provide information about the coexistence of different wave systems originating from different meteorological events, such as locally generated wind waves and swell systems from distant storms. A 20 years dataset (1989-2008) for a location on the North Sea (K13, 53.2°N 3.2°E) has been retrieved from the ECMWF ERA- Interim re-analysis data archive, providing a consistent and homogeneous dataset. The work focuses on the joint and conditional probability distributions of wind sea and swell systems. For marine operations and design applications, critical combinations of wave systems may exist. We define a critical sea state on the basis of a set of thresholds, which can be not necessarily extreme, the emphasis is given to the dangerous combination of different wave systems concerning certain operations (i.e. small vessels navigation, dredging). The distribution of non-operability windows is described by a point process model with random and independent events, whose occurrences and lengths can be described only probabilistically. These characteristics allow to treat the emerging patterns as a part of a queuing system. According to this theory, generally adopted for several applications including traffic flows and waiting lines, the input process describes the sequence of requests for a service and the service mechanism the length of time that these requests will occupy the facilities. For weather-driven processes at sea an alternating renewal process appears as a suitable model. It consists of a sequence of critical events (period of inoperability), each of random duration, separated by calms, also of random durations. Inoperability periods and calms are assumed independent. In this model it is not possible more than one critical event occurring at the same time. The analysis is carried out taking into account the thresholds' selection and the seasonality.

Loffredo, L.; Monbaliu, J.; Anderson, C.

2012-04-01

42

A queueing theory based model for business continuity in hospitals.  

PubMed

Clinical activities can be seen as results of precise and defined events' succession where every single phase is characterized by a waiting time which includes working duration and possible delay. Technology makes part of this process. For a proper business continuity management, planning the minimum number of devices according to the working load only is not enough. A risk analysis on the whole process should be carried out in order to define which interventions and extra purchase have to be made. Markov models and reliability engineering approaches can be used for evaluating the possible interventions and to protect the whole system from technology failures. The following paper reports a case study on the application of the proposed integrated model, including risk analysis approach and queuing theory model, for defining the proper number of device which are essential to guarantee medical activity and comply the business continuity management requirements in hospitals. PMID:24109839

Miniati, R; Cecconi, G; Dori, F; Frosini, F; Iadanza, E; Biffi Gentili, G; Niccolini, F; Gusinu, R

2013-01-01

43

A queuing model for meteor burst packet communication systems  

Microsoft Academic Search

A discrete-time queuing model for the performance of a meteor-burst packet communication system is analyzed using matrix analytic methods. Not only is the system subject to interruptions due to the intermittence of the ionization layer, but its analysis is further complicated by the necessity to retransmit packets that have error or that occur at the tail end of a period

Y. Chandramouli; M. F. Neuts; V. Ramaswami

1989-01-01

44

The entrepreneurship of resource-based theory  

Microsoft Academic Search

This paper examines the relationship between resource-based theory and entrepreneurship and develops insights that advance the boundaries of resource-based theory and begin to address important questions in entrepreneurship. We extend the boundaries of resource-based theory to include the cognitive ability of individual entrepreneurs. Entrepreneurs have individual-specific resources that facilitate the recognition of new opportunities and the assembling of resources for

Sharon A. Alvarez; Lowell W. Busenitz

2001-01-01

45

Performance evaluation for an optical hybrid switch with circuit queued reservations  

NASA Astrophysics Data System (ADS)

We provide here a new loss model for an optical hybrid switch that can function as an optical burst switch or optical circuit switch or both simultaneously. We introduce the feature of circuit queued reservation. That is, if a circuit request arrives and cannot find a free wavelength, and if there are not too many requests queued for reservations, it may join a queue and wait until such wavelength becomes available. We first present an analysis based on a 3-dimension state-space Markov chain that provides exact results for the blocking probabilities of bursts and circuits. We also provide results for the proportion of circuits that are delayed and the mean delay of the circuits that are delay. Because it is difficult to exactly compute the blocking probability in realistic scenarios with a large number of wavelengths, we derive computationally scalable and accurate approximations which are based on reducing the 3-dimension state space into a single dimension. These scalable approximations that can produce performance results in a fraction of a second can readily enable switch dimensioning.

Wong, Eric W. M.; Zukerman, Moshe

2005-11-01

46

Using multi-class queuing network to solve performance models of e-business sites.  

PubMed

Due to e-business's variety of customers with different navigational patterns and demands, multi-class queuing network is a natural performance model for it. The open multi-class queuing network(QN) models are based on the assumption that no service center is saturated as a result of the combined loads of all the classes. Several formulas are used to calculate performance measures, including throughput, residence time, queue length, response time and the average number of requests. The solution technique of closed multi-class QN models is an approximate mean value analysis algorithm (MVA) based on three key equations, because the exact algorithm needs huge time and space requirement. As mixed multi-class QN models, include some open and some closed classes, the open classes should be eliminated to create a closed multi-class QN so that the closed model algorithm can be applied. Some corresponding examples are given to show how to apply the algorithms mentioned in this article. These examples indicate that multi-class QN is a reasonably accurate model of e-business and can be solved efficiently. PMID:14663849

Zheng, Xiao-ying; Chen, De-ren

2004-01-01

47

Modified weighted fair queuing for packet scheduling in mobile WiMAX networks  

NASA Astrophysics Data System (ADS)

The increase of user mobility and the need for data access anytime also increases the interest in broadband wireless access (BWA). The best available quality of experience for mobile data service users are assured for IEEE 802.16e based users. The main problem of assuring a high QOS value is how to allocate available resources among users in order to meet the QOS requirement for criteria such as delay, throughput, packet loss and fairness. There is no specific standard scheduling mechanism stated by IEEE standards, which leaves it for implementer differentiation. There are five QOS service classes defined by IEEE 802.16: Unsolicited Grant Scheme (UGS), Extended Real Time Polling Service (ertPS), Real Time Polling Service (rtPS), Non Real Time Polling Service (nrtPS) and Best Effort Service (BE). Each class has different QOS parameter requirements for throughput and delay/jitter constraints. This paper proposes Modified Weighted Fair Queuing (MWFQ) scheduling scenario which was based on Weighted Round Robin (WRR) and Weighted Fair Queuing (WFQ). The performance of MWFQ was assessed by using above five QoS criteria. The simulation shows that using the concept of total packet size calculation improves the network's performance.

Satrya, Gandeva B.; Brotoharsono, Tri

2013-03-01

48

Time-varying priority queuing models for human dynamics  

NASA Astrophysics Data System (ADS)

Queuing models provide insight into the temporal inhomogeneity of human dynamics, characterized by the broad distribution of waiting times of individuals performing tasks. We theoretically study the queuing model of an agent trying to execute a task of interest, the priority of which may vary with time due to the agent's “state of mind.” However, its execution is disrupted by other tasks of random priorities. By considering the priority of the task of interest either decreasing or increasing algebraically in time, we analytically obtain and numerically confirm the bimodal and unimodal waiting time distributions with power-law decaying tails, respectively. These results are also compared to the updating time distribution of papers in arXiv.org and the processing time distribution of papers in Physical Review journals. Our analysis helps to understand human task execution in a more realistic scenario.

Jo, Hang-Hyun; Pan, Raj Kumar; Kaski, Kimmo

2012-06-01

49

Time-Varying Priority Queuing Models for Human Dynamics  

E-print Network

Queuing models provide insight into the temporal inhomogeneity of human dynamics, characterized by the broad distribution of waiting times of individuals performing tasks. We study the queuing model of an agent trying to execute a task of interest, the priority of which may vary with time due to the agent's "state of mind." However, its execution can be disrupted by other tasks of random priorities. By considering the priority of the task of interest either decreasing or increasing algebraically in time, we analytically obtain and numerically confirm the bimodal and unimodal waiting time distributions with power-law decaying tails, respectively. These results are also compared to the updating time distribution of papers in the arXiv and the processing time distribution of papers in Physical Review journals. Our analysis helps to understand the human task execution behavior in a more realistic scenario.

Jo, Hang-Hyun; Kaski, Kimmo

2011-01-01

50

Time-varying priority queuing models for human dynamics.  

PubMed

Queuing models provide insight into the temporal inhomogeneity of human dynamics, characterized by the broad distribution of waiting times of individuals performing tasks. We theoretically study the queuing model of an agent trying to execute a task of interest, the priority of which may vary with time due to the agent's "state of mind." However, its execution is disrupted by other tasks of random priorities. By considering the priority of the task of interest either decreasing or increasing algebraically in time, we analytically obtain and numerically confirm the bimodal and unimodal waiting time distributions with power-law decaying tails, respectively. These results are also compared to the updating time distribution of papers in arXiv.org and the processing time distribution of papers in Physical Review journals. Our analysis helps to understand human task execution in a more realistic scenario. PMID:23005156

Jo, Hang-Hyun; Pan, Raj Kumar; Kaski, Kimmo

2012-06-01

51

Output-queued switch emulation by fabrics with limited memory  

Microsoft Academic Search

The output-queued (OQ) switch is often considered an ideal packet switching architecture for providing quality-of-service guarantees. Unfortunately, the high-speed memory requirements of the OQ switch prevent its use for large-scale devices. A previous result indicates that a crossbar switch fabric combined with lower speed input and output memory and two times speedup can exactly emulate an OQ switch; however, the

Robert B. Magill; Charles E. Rohrs; Robert L. Stevenson

2003-01-01

52

Priority Queuing Models for Hospital Intensive Care Units and Impacts to Severe Case Patients  

PubMed Central

This paper examines several different queuing models for intensive care units (ICU) and the effects on wait times, utilization, return rates, mortalities, and number of patients served. Five separate intensive care units at an urban hospital are analyzed and distributions are fitted for arrivals and service durations. A system-based simulation model is built to capture all possible cases of patient flow after ICU admission. These include mortalities and returns before and after hospital exits. Patients are grouped into 9 different classes that are categorized by severity and length of stay (LOS). Each queuing model varies by the policies that are permitted and by the order the patients are admitted. The first set of models does not prioritize patients, but examines the advantages of smoothing the operating schedule for elective surgeries. The second set analyzes the differences between prioritizing admissions by expected LOS or patient severity. The last set permits early ICU discharges and conservative and aggressive bumping policies are contrasted. It was found that prioritizing patients by severity considerably reduced delays for critical cases, but also increased the average waiting time for all patients. Aggressive bumping significantly raised the return and mortality rates, but more conservative methods balance quality and efficiency with lowered wait times without serious consequences. PMID:24551379

Hagen, Matthew S.; Jopling, Jeffrey K; Buchman, Timothy G; Lee, Eva K.

2013-01-01

53

Priority queuing models for hospital intensive care units and impacts to severe case patients.  

PubMed

This paper examines several different queuing models for intensive care units (ICU) and the effects on wait times, utilization, return rates, mortalities, and number of patients served. Five separate intensive care units at an urban hospital are analyzed and distributions are fitted for arrivals and service durations. A system-based simulation model is built to capture all possible cases of patient flow after ICU admission. These include mortalities and returns before and after hospital exits. Patients are grouped into 9 different classes that are categorized by severity and length of stay (LOS). Each queuing model varies by the policies that are permitted and by the order the patients are admitted. The first set of models does not prioritize patients, but examines the advantages of smoothing the operating schedule for elective surgeries. The second set analyzes the differences between prioritizing admissions by expected LOS or patient severity. The last set permits early ICU discharges and conservative and aggressive bumping policies are contrasted. It was found that prioritizing patients by severity considerably reduced delays for critical cases, but also increased the average waiting time for all patients. Aggressive bumping significantly raised the return and mortality rates, but more conservative methods balance quality and efficiency with lowered wait times without serious consequences. PMID:24551379

Hagen, Matthew S; Jopling, Jeffrey K; Buchman, Timothy G; Lee, Eva K

2013-01-01

54

Based on Regular Expression Matching of Evaluation of the Task Performance in WSN: A Queue Theory Approach  

PubMed Central

Due to the limited resources of wireless sensor network, low efficiency of real-time communication scheduling, poor safety defects, and so forth, a queuing performance evaluation approach based on regular expression match is proposed, which is a method that consists of matching preprocessing phase, validation phase, and queuing model of performance evaluation phase. Firstly, the subset of related sequence is generated in preprocessing phase, guiding the validation phase distributed matching. Secondly, in the validation phase, the subset of features clustering, the compressed matching table is more convenient for distributed parallel matching. Finally, based on the queuing model, the sensor networks of task scheduling dynamic performance are evaluated. Experiments show that our approach ensures accurate matching and computational efficiency of more than 70%; it not only effectively detects data packets and access control, but also uses queuing method to determine the parameters of task scheduling in wireless sensor networks. The method for medium scale or large scale distributed wireless node has a good applicability. PMID:25401151

Cui, Kai; Zhou, Kuanjiu; Yu, Yanshuo

2014-01-01

55

Computer-based theory of strategies  

SciTech Connect

Some of the objectives and working tools of a new area of study, tentatively called theory of strategies, are described. It is based on the methodology of artificial intelligence, decision theory, utility theory, operations research and digital gaming. The latter refers to computing activity that incorporates model building, simulation and learning programs in conflict situations. The author also discusses three long-term projects which aim at automatically analyzing and synthesizing strategies. 27 references.

Findler, N.V.

1983-01-01

56

Evaluation of SIP Proxy Server Performance: Packet-Level Measurements and Queuing Model  

E-print Network

Evaluation of SIP Proxy Server Performance: Packet-Level Measurements and Queuing Model Ramesh which the service and waiting times within the kernel and the SIP layer can be easily obtained. (2) We time consists of the processing and queuing delays at the SPS and User-Agent Server (UAS). The SPS

57

CROSS-LAYER COMBINING OF QUEUING WITH ADAPTIVE MODULATION AND CODING OVER WIRELESS LINKS  

E-print Network

CROSS-LAYER COMBINING OF QUEUING WITH ADAPTIVE MODULATION AND CODING OVER WIRELESS LINKS Qingwen waiting to be transmitted, adaptive modulation and coding (AMC) at the physical layer have been queuing effects are taken into account at the data link layer. In this paper, we analyze the perfor- mance

Giannakis, Georgios

58

THEORY BASED PRODUCTION AND PROJECT MANAGEMENT  

Microsoft Academic Search

This paper gives an overview of an ongoing project endeavouring to advance theory-based production and project management, and the rationale for this approach is briefly justified. The status of the theoretical foundation of production management, project management and allied disciplines is discussed, with emphasis on metaphysical grounding of theories, as well as the nature of the heuristic solution method commonly

Lauri Koskela; Guilherme Henrich; Robert Owen; Ruben Vrijhoef

59

Final Report for ?Queuing Network Models of Performance of High End Computing Systems?  

SciTech Connect

The primary objective of this project is to perform general research into queuing network models of performance of high end computing systems. A related objective is to investigate and predict how an increase in the number of nodes of a supercomputer will decrease the running time of a user's software package, which is often referred to as the strong scaling problem. We investigate the large, MPI-based Linux cluster MCR at LLNL, running the well-known NAS Parallel Benchmark (NPB) applications. Data is collected directly from NPB and also from the low-overhead LLNL profiling tool mpiP. For a run, we break the wall clock execution time of the benchmark into four components: switch delay, MPI contention time, MPI service time, and non-MPI computation time. Switch delay is estimated from message statistics. MPI service time and non-MPI computation time are calculated directly from measurement data. MPI contention is estimated by means of a queuing network model (QNM), based in part on MPI service time. This model of execution time validates reasonably well against the measured execution time, usually within 10%. Since the number of nodes used to run the application is a major input to the model, we can use the model to predict application execution times for various numbers of nodes. We also investigate how the four components of execution time scale individually as the number of nodes increases. Switch delay and MPI service time scale regularly. MPI contention is estimated by the QNM submodel and also has a fairly regular pattern. However, non-MPI compute time has a somewhat irregular pattern, possibly due to caching effects in the memory hierarchy. In contrast to some other performance modeling methods, this method is relatively fast to set up, fast to calculate, simple for data collection, and yet accurate enough to be quite useful.

Buckwalter, J

2005-09-28

60

Optimal Floating and Queuing Strategies: The Logic of Territory Choice.  

PubMed

This is a response to a recent article by Hanna Kokko and William J. Sutherland (American Naturalist 152:354-366), who consider evolutionarily stable territory acceptance rules for animals that face the decision between settling on a poor territory now (which is then retained for life) or waiting for better habitat to become available later (taking a chance of dying before reproducing). In contrast to these authors, we argue that the evolutionarily stable threshold quality above which territories are acceptable does depend on whether individuals compete for a single territory (queuing) or for multiple territories (floating) and also on whether access to territories is determined by a hierarchy among waiting individuals. More specifically, we show the following: First, if the choice is between floating and settling, the evolutionarily stable acceptance threshold is such that threshold territories yield an expected lifetime reproductive success (LRS) of 1-µF, the survival probability of a floater. Second, if the choice is between queuing and settling, the evolutionarily stable threshold may correspond to any LRS between 1-µF and unity. Third, the number of nonbreeding individuals in the population is maximized at a threshold of unity. In other words, the evolutionarily stable threshold does not maximize the nonbreeding fraction of the population. We argue that models of territory choice should carefully specify the mechanism of choice because some choice processes (e.g., indiscriminate habitat use above the threshold) do not admit an evolutionarily stable acceptance rule. PMID:10753078

Pen; Weissing

2000-04-01

61

Design and development of cell queuing, processing, and scheduling modules for the iPOINT input-buffered ATM testbed  

NASA Astrophysics Data System (ADS)

This dissertation presents the concepts, principles, performance, and implementation of input queuing and cell-scheduling modules for the Illinois Pulsar-based Optical INTerconnect (iPOINT) input-buffered Asynchronous Transfer Mode (ATM) testbed. Input queuing (IQ) ATM switches are well suited to meet the requirements of current and future ultra-broadband ATM networks. The IQ structure imposes minimum memory bandwidth requirements for cell buffering, tolerates bursty traffic, and utilizes memory efficiently for multicast traffic. The lack of efficient cell queuing and scheduling solutions has been a major barrier to build high-performance, scalable IQ-based ATM switches. This dissertation proposes a new Three-Dimensional Queue (3DQ) and a novel Matrix Unit Cell Scheduler (MUCS) to remove this barrier. 3DQ uses a linked-list architecture based on Synchronous Random Access Memory (SRAM) to combine the individual advantages of per-virtual-circuit (per-VC) queuing, priority queuing, and N-destination queuing. It avoids Head of Line (HOL) blocking and provides per-VC Quality of Service (QoS) enforcement mechanisms. Computer simulation results verify the QoS capabilities of 3DQ. For multicast traffic, 3DQ provides efficient usage of cell buffering memory by storing multicast cells only once. Further, the multicast mechanism of 3DQ prevents a congested destination port from blocking other less- loaded ports. The 3DQ principle has been prototyped in the Illinois Input Queue (iiQueue) module. Using Field Programmable Gate Array (FPGA) devices, SRAM modules, and integrated on a Printed Circuit Board (PCB), iiQueue can process incoming traffic at 800 Mb/s. Using faster circuit technology, the same design is expected to operate at the OC-48 rate (2.5 Gb/s). MUCS resolves the output contention by evaluating the weight index of each candidate and selecting the heaviest. It achieves near-optimal scheduling and has a very short response time. The algorithm originates from a heuristic strategy that leads to 'socially optimal' solutions, yielding a maximum number of contention-free cells being scheduled. A novel mixed digital-analog circuit has been designed to implement the MUCS core functionality. The MUCS circuit maps the cell scheduling computation to the capacitor charging and discharging procedures that are conducted fully in parallel. The design has a uniform circuit structure, low interconnect counts, and low chip I/O counts. Using 2 ?m CMOS technology, the design operates on a 100 MHz clock and finds a near-optimal solution within a linear processing time. The circuit has been verified at the transistor level by HSPICE simulation. During this research, a five-port IQ-based optoelectronic iPOINT ATM switch has been developed and demonstrated. It has been fully functional with an aggregate throughput of 800 Mb/s. The second-generation IQ-based switch is currently under development. Equipped with iiQueue modules and MUCS module, the new switch system will deliver a multi-gigabit aggregate throughput, eliminate HOL blocking, provide per-VC QoS, and achieve near-100% link bandwidth utilization. Complete documentation of input modules and trunk module for the existing testbed, and complete documentation of 3DQ, iiQueue, and MUCS for the second-generation testbed are given in this dissertation.

Duan, Haoran

1997-12-01

62

Social queuing in animal societies: a dynamic model of reproductive skew  

PubMed Central

Previously developed models of reproductive skew have overlooked one of the main reasons why subordinates might remain in a group despite restricted opportunities to breed: the possibility of social queuing, i.e. acquiring dominant status in the future. Here, we present a dynamic ESS model of skew in animal societies that incorporates both immediate and future fitness consequences of the decisions taken by group members, based on their probability of surviving from one season to the next (when post-breeding survival probabilities drop to zero, our analysis reduces to the model produced by Reeve and Ratnieks in 1993, which considered only a single breeding season). This allows us to compare the delayed benefits of philopatry and the immediate opportunities for independent breeding. We show that delayed benefits greatly reduce the need for dominants to offer reproductive concessions to retain subordinates peacefully in the group. Moreover, this effect is strong enough that differences in survival have a much greater impact on the group structure than differences in other parameters, such as relatedness. When the possibility of acceding to dominant status is taken into account, groups where the dominant completely monopolizes reproduction can be stable, even if they consist of unrelated individuals, and even if subordinates have a reasonably high probability of winning a fight for dominance. Finally, we show that stable groups are possible even if association leads to a decrease in current productivity. Subordinates may still stand to gain from group membership under these circumstances, as acquiring breeding positions by queuing may be more efficient than the attempt to establish a new territory. At the same time, the dominant may be unable to exclude unwelcome subordinates, may enjoy increased survival when they are present, or may gain indirect benefits from allowing relatives to stay and queue for dominance. We conclude that reproductive skew in animal groups, ranging from eusocial insect colonies to mating aggregations (leks), will be strongly influenced by the future prospects of group members.

Kokko, H.; Johnstone, R. A.

1999-01-01

63

A complexity theory based on Boolean algebra  

Microsoft Academic Search

A projection of a Boolean function is a function obtained by substituting for each of its variables a variable, the negation of a variable, or a constant. Reducibilities among computational problems under this relation of projection are considered. It is shown that much of what is of everyday relevance in Turing-machine-based complexity theory can be replicated easily and naturally in

Sven Skyum; Leslie G. Valiant

1985-01-01

64

Jigsaw Cooperative Learning: Acid-Base Theories  

ERIC Educational Resources Information Center

This study focused on investigating the effectiveness of jigsaw cooperative learning instruction on first-year undergraduates' understanding of acid-base theories. Undergraduates' opinions about jigsaw cooperative learning instruction were also investigated. The participants of this study were 38 first-year undergraduates in chemistry education…

Tarhan, Leman; Sesen, Burcin Acar

2012-01-01

65

A number theory based image coding  

Microsoft Academic Search

A new number theory based image data compression coding scheme useful for onboard applications and ground applications is proposed. The salient feature is that it gives an optimal compression and it is simple and fast. It works on variable size blocks of image data. It is useful for remote sensing and satellite applications. The implementation does not increase hardware complexity

S. Jagannathan; P. Nagabhushan; K. Chidananda Gowda; R. K. Rajangam

1996-01-01

66

Introduction to Queuing Networks MATH 35800 Solutions to Problem Sheet 2 Autumn 2014  

E-print Network

1 Introduction to Queuing Networks MATH 35800 Solutions to Problem Sheet 2 Autumn 2014 1. First the discussion above. 3. (a) If Xt is the number waiting at the bust stop, then the state space is the set

Collins, Sean

67

Modeling Crowd Behavior Based on Social Comparison Theory: Extended Abstract  

E-print Network

Modeling Crowd Behavior Based on Social Comparison Theory: Extended Abstract Natalie Fridman model of crowd behavior, based on Festinger's Social Comparison Theory, a social psychology theory known. In computer science, models are often simplistic and typically not tied to specific cognitive science theories

Kaminka, Gal A.

68

The Scope of Usage-Based Theory  

PubMed Central

Usage-based approaches typically draw on a relatively small set of cognitive processes, such as categorization, analogy, and chunking to explain language structure and function. The goal of this paper is to first review the extent to which the “cognitive commitment” of usage-based theory has had success in explaining empirical findings across domains, including language acquisition, processing, and typology. We then look at the overall strengths and weaknesses of usage-based theory and highlight where there are significant debates. Finally, we draw special attention to a set of culturally generated structural patterns that seem to lie beyond the explanation of core usage-based cognitive processes. In this context we draw a distinction between cognition permitting language structure vs. cognition entailing language structure. As well as addressing the need for greater clarity on the mechanisms of generalizations and the fundamental units of grammar, we suggest that integrating culturally generated structures within existing cognitive models of use will generate tighter predictions about how language works. PMID:23658552

Ibbotson, Paul

2013-01-01

69

Application of queuing models to electronic toll collection  

NASA Astrophysics Data System (ADS)

Electronic Toll Collection (ETC) via Automatic Vehicle Identification (AVI) technology has significantly altered traffic operations during toll collection. In particular, the value of the average processing rate of a lane providing both ETC service as well as a traditional service, fluctuates over the rush hour between the average value of the processing rate of the traditional service and the capacity of the ETC service. This study develops a queuing model to address the changing processing rates for the different mixed lanes. The model is applied to the westbound 9-lane portion of the Holland East Plaza in Orlando, FLorida. Data is evaluated for 6 different rush hours that include 3 different configuration patterns implemented over a period of 3 years. In the first configuration, only the traditional toll collection services are provided. In another configuration, all traditional lanes become mixed to include ETC except for the center lane, which becomes a lane dedicated solely to ETC service. In a final configuration, two lanes become dedicated to ETC service.

Zarrillo, Marguerite L.; Radwan, A. E.; Al-Deek, H. M.

1998-01-01

70

Spectrally queued feature selection for robotic visual odometery  

NASA Astrophysics Data System (ADS)

Over the last two decades, research in Unmanned Vehicles (UV) has rapidly progressed and become more influenced by the field of biological sciences. Researchers have been investigating mechanical aspects of varying species to improve UV air and ground intrinsic mobility, they have been exploring the computational aspects of the brain for the development of pattern recognition and decision algorithms and they have been exploring perception capabilities of numerous animals and insects. This paper describes a 3 month exploratory applied research effort performed at the US ARMY Research, Development and Engineering Command's (RDECOM) Tank Automotive Research, Development and Engineering Center (TARDEC) in the area of biologically inspired spectrally augmented feature selection for robotic visual odometry. The motivation for this applied research was to develop a feasibility analysis on multi-spectrally queued feature selection, with improved temporal stability, for the purposes of visual odometry. The intended application is future semi-autonomous Unmanned Ground Vehicle (UGV) control as the richness of data sets required to enable human like behavior in these systems has yet to be defined.

Pirozzo, David M.; Frederick, Philip A.; Hunt, Shawn; Theisen, Bernard; Del Rose, Mike

2011-01-01

71

Harmonic-Oscillator-Based Effective Theory  

E-print Network

I describe harmonic-oscillator-based effective theory (HOBET) and explore the extent to which the effects of excluded higher-energy oscillator shells can be represented by a contact-gradient expansion in next-to-next-to-leading order (NNLO). I find the expansion can be very successful provided the energy dependence of the effective interaction, connected with missing long-wavelength physics associated with low-energy breakup channels, is taken into account. I discuss a modification that removes operator mixing from HOBET, simplifying the task of determining the parameters of an NNLO interaction.

W. C. Haxton

2006-08-06

72

1142 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 4, NO. 3, MAY 2005 Queuing With Adaptive Modulation and Coding Over  

E-print Network

1142 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 4, NO. 3, MAY 2005 Queuing With Adaptive sufficient data waiting to be transmitted, adaptive modulation and coding (AMC) schemes at the physical layer valid when queuing effects are taken into account at the data link layer. In this paper, we analyze

Zhou, Shengli

73

Core-Stateless Proportional Fair Queuing for AF Traffic Gang Cheng, Kai Xu, Ye Tian, and Nirwan Ansari  

E-print Network

Core-Stateless Proportional Fair Queuing for AF Traffic Gang Cheng, Kai Xu, Ye Tian, and Nirwan Institute of Technology, Newark, NJ 07102, USA Abstract-- Proportional fair queuing is to ensure that a flow passing through the network only consumes a fair share of the network resource that is proportional to its

Ansari, Nirwan

74

Modelling Pedestrian Travel Time and the Design of Facilities: A Queuing Approach  

PubMed Central

Pedestrian movements are the consequence of several complex and stochastic facts. The modelling of pedestrian movements and the ability to predict the travel time are useful for evaluating the performance of a pedestrian facility. However, only a few studies can be found that incorporate the design of the facility, local pedestrian body dimensions, the delay experienced by the pedestrians, and level of service to the pedestrian movements. In this paper, a queuing based analytical model is developed as a function of relevant determinants and functional factors to predict the travel time on pedestrian facilities. The model can be used to assess the overall serving rate or performance of a facility layout and correlate it to the level of service that is possible to provide the pedestrians. It has also the ability to provide a clear suggestion on the designing and sizing of pedestrian facilities. The model is empirically validated and is found to be a robust tool to understand how well a particular walking facility makes possible comfort and convenient pedestrian movements. The sensitivity analysis is also performed to see the impact of some crucial parameters of the developed model on the performance of pedestrian facilities. PMID:23691055

Rahman, Khalidur; Abdul Ghani, Noraida; Abdulbasah Kamil, Anton; Mustafa, Adli; Kabir Chowdhury, Md. Ahmed

2013-01-01

75

A New Glauber Theory based on Multiple Scattering Theory  

E-print Network

Glauber theory for nucleus-nucleus scattering at high incident energies is reformulated so as to become applicable also for the scattering at intermediate energies. We test validity of the eikonal and adiabatic approximations used in the formulation, and discuss the relation between the present theory and the conventional Glauber calculations with either the empirical nucleon-nucleon profile function or the modified one including the in-medium effect.

Masanobu Yahiro; Kosho Minomo; Kazuyuki Ogata; Mitsuji Kawai

2008-07-24

76

Modelling tissue behaviour based on hyperelasticity theory.  

PubMed

The tissues are during their physiological function, e.g., in the course of growth, adolescence, and aging, subjected to a cyclic mechanical loading and to large displacements and rotations as well. A tissue free of all external tractions is in a state that minimizes its internal power. In the course of aging of the tissues, for instance in the wall of the aorta, the vein, and also in the myocardium or heart valves, the decrease of the water content and increase of the collagen content occurs; while in compact and trabecular bone the contents of both mineral substances and collagen, undergo reduction. In accordance with it, the strain energy function and the constitutive equations of living tissue based on the hyperelasticity theory using rotationless strain were studied. On the base of the proposed eigenvalue decomposition of the rotationless strain tensor and hyperelasticity the strain energy function was formulated as depending on biological time of tissue. The quantity of strain energy function per unit of the biological time, which essentially characterizes the velocity of change of mechanical response of tissue in the course of its aging, was also defined. The coefficient of tissue aging is the further diagnostic parameter, which is independent of the rotationless strain tensor and expresses the relative change of mechanical response of tissue during the biological time. The corresponding constitutive equation of tissue depending on the biological time is also determined. On the base of the regression analysis the theoretical stress-strain curves for myocardium and blood vessels were determined. The numerical results reveal that the coefficient of aging progressively increases in hardening tissues (coronary artery, vena cava inferior) whereas at the softening tissues it has a relatively slow increase at the dependence on tissue aging. PMID:8000292

Valenta, J; R?zicka, M; Cihák, R

1994-01-01

77

A Queuing Analysis of Server Sharing Collectives for Content Distribution Daniel Villela Dan Rubenstein  

E-print Network

sharing its resources to a point where its ability to service its own clients is unsatisfactory. 1 of servers to closely meet client demand for the content objects it hosts. However, selecting the bestA Queuing Analysis of Server Sharing Collectives for Content Distribution Daniel Villela Dan

78

Comparing Java, C# and Ada monitors queuing policies: a case study and its Ada refinement  

Microsoft Academic Search

Learning concurrency paradigms is necessary but it is not sufficient since the choice of run-time semantics may introduce subtle programming errors. It is the aim of this paper to exemplify the importance of process queuing and awaking policies resulting from possible choices of the monitor concept implementation.The first part of the paper compares the behaviour of concurrent processes sharing a

Claude Kaiser; Jean-François Pradat-Peyre; Sami Évangelista; Pierre Rousseau

2006-01-01

79

Comparing Java, C# and Ada Monitors queuing policies : a case study and its Ada refinement  

Microsoft Academic Search

Abstract. Learning concurrency paradigms is necessary but it is not sufficient since the choice of run-time semantics may introduce subtle programming errors. It is the aim of this paper to exemplify the importance of process queuing and awaking policies resulting from possible choices of the monitor concept implementation.

Claude Kaiser; Pierre Rousseau; Cedric-cnam Paris

80

Introduction to Queuing Networks MATH 35800/M5800 Problem Sheet 4 Autumn 2014  

E-print Network

Introduction to Queuing Networks MATH 35800/M5800 Problem Sheet 4 Autumn 2014 Questions 3 and 4 are independent Exp(µ) random variables and where there is infinite waiting room. Assume jobs arrive at rate when process of rate µ. These two Poisson processes are independent of each other. There is infinite waiting

Collins, Sean

81

Introduction to Queuing Networks MATH 35800/M5800 Problem Sheet 2 Autumn 2014  

E-print Network

Introduction to Queuing Networks MATH 35800/M5800 Problem Sheet 2 Autumn 2014 Questions 3 and 5. Buses are infinitely large and there is only one route, so that when a bus arrives, everyone waiting at the bus stop gets on to it. (a) Let Xt denote the number of people waiting at the bus stop at time t

Collins, Sean

82

Introduction to Queuing Networks MATH 35800/M5800 Problem Sheet 3 Autumn 2014  

E-print Network

Introduction to Queuing Networks MATH 35800/M5800 Problem Sheet 3 Autumn 2014 Questions 4 and 5 waiting room. Let X(t) denote the number in the queue at time t. Write down the transition rates with rate and a single server. Assume that limits on the waiting room limit the number in the queue

Collins, Sean

83

The Distribution of Queuing Network States at Input and Output Instants  

Microsoft Academic Search

Queuing networks are studied at selected points in the steady state, namely, at the moments when jobs of a given class arrive into a given node (either from the outside or from other nodes) and at the moments when jobs of a given class leave a given node (either for the outside or for other nodes). The processes defined by

Kenneth C. Sevcik; Isi Mitrani

1981-01-01

84

Analysis of Aircraft Sortie Generation Process Using a Closed Queuing Network Model  

Microsoft Academic Search

Sortie generation rate (SGR) is a key factor of military aircraft's combat effectiveness. An approximate analytical method is presented to analyzing aircraft sortie generation process by modeling the process as a closed queuing network (CQN). Each station in the CQN provides a kind of service to aircraft. The service time of servers in a same station can be unequal. A

Xia Guoqing; Chen Hongzhao; Wang Yuanhui

2010-01-01

85

Self-Organizing Relays in LTE networks: Queuing analysis and algorithms  

E-print Network

Self-Organizing Relays in LTE networks: Queuing analysis and algorithms Richard Combes,Zwi Altman capacity and QoS all over the cell area. This paper develops a self-organizing network (SON) feature are evaluated analytically. Self-optimizing dynamic resource allocation is tackled using a Markov Decision

86

Minimizing Queuing Delays and Number of Messages in Mobile Phone Location  

Microsoft Academic Search

thispaper, we present an analysis of the delay and number of messages transmittedin different sequential and parallel search strategies, considering for the first timethe issue of queuing on radio paging channels. Our analysis shows that parallelsearch may not reduce the time to find a mobile phone if the parameters of thesystem are unfavorable. We also develop an efficient algorithm for

David J. Goodman; P. Krishnan; Binay Sugla

1996-01-01

87

Fuzzy Comprehensive Evaluation Model based on Rough Set Theory  

Microsoft Academic Search

Rough set theory was an effective tool in dealing with vague and uncertainty information. A new comprehensive evaluation model based on rough set theory was proposed in the paper, computation of weighting coefficient in evaluation model was transformed into importance of attributes in rough set theory, thus it effectively avoided subjectivity about weighting coefficient in fuzzy comprehensive evaluation, its evaluation

Yitian Xu; Laisheng Wangt

2006-01-01

88

AN INFORMATION SYSTEMS DESIGN THEORY FOR WEB-BASED EDUCATION  

Microsoft Academic Search

An Information Systems Design Theory (ISDT) is a prescriptive theory that offers theory-based principles that can guide practitioners in the design of effective Information Systems and set an agenda for on-going research. This paper introduces the origins of the ISDT concept and describes one ISDT for Web-based Education (WBE). The paper shows how this ISDT has, over the last seven

David Jones; Teresa Lynch; Rockhampton Australia

89

Evaluation of Enterprise Innovation Ability Based on Rough Set Theory  

Microsoft Academic Search

The creative ability index is quite important for enterprises. This paper proposes an evaluation method for enterprise innovation ability based on rough set theory. Firstly, an index reduction which effects the enterprises based on the rough set theory is carried out, then the major indexes of enterprise development ability is extracted. Secondly, the standardized processing of all kinds of index

Lei Yin; Xiaoxiang Liu; Weigang Jiang; Jianwen Xie

2009-01-01

90

Recursive renormalization group theory based subgrid modeling  

NASA Technical Reports Server (NTRS)

Advancing the knowledge and understanding of turbulence theory is addressed. Specific problems to be addressed will include studies of subgrid models to understand the effects of unresolved small scale dynamics on the large scale motion which, if successful, might substantially reduce the number of degrees of freedom that need to be computed in turbulence simulation.

Zhou, YE

1991-01-01

91

Zone plate theory based on holography.  

PubMed

A series representation developed from holography theory is used to determine the image distances and relative image intensities for three types of zone plates. The effect of nonlinearity in film reproduction on the hologram of a point object and the images produced by this hologram are discussed. PMID:20057745

Horman, M H; Chau, H H

1967-02-01

92

Embodied Symbol Emergence Based on Mimesis Theory  

Microsoft Academic Search

“Mimesis” theory focused in the cognitive science field and “mirror neurons” found in the biology field show that the behavior generation process is not independent of the behavior cognition process. The generation and cognition processes have a close relationship with each other. During the behavioral imitation period, a human being does not practice simple joint coordinate transformation, but will acknowledge

Tetsunari Inamura; Iwaki Toshima; Hiroaki Tanie; Yoshihiko Nakamura

2004-01-01

93

Current algebra based effective chiral theory of mesons and a new EW theory  

E-print Network

A current algebra based effective chiral theory of pseudoscalar, vector, axial-vector mesons is reviewed. A new mechanism generating the masses and guage fixing terms of gauge boson is revealed from this effective theory. A EW theory without Higgs is proposed. The masses and gauge fixing terms of W and Z are dynamically generated. Three heavy scalar fields are dynamically generated too. They are ghosts.

Bing An Li

2005-09-08

94

Maximum Entropy Principle Based Estimation of Performance Distribution in Queueing Theory  

PubMed Central

In related research on queuing systems, in order to determine the system state, there is a widespread practice to assume that the system is stable and that distributions of the customer arrival ratio and service ratio are known information. In this study, the queuing system is looked at as a black box without any assumptions on the distribution of the arrival and service ratios and only keeping the assumption on the stability of the queuing system. By applying the principle of maximum entropy, the performance distribution of queuing systems is derived from some easily accessible indexes, such as the capacity of the system, the mean number of customers in the system, and the mean utilization of the servers. Some special cases are modeled and their performance distributions are derived. Using the chi-square goodness of fit test, the accuracy and generality for practical purposes of the principle of maximum entropy approach is demonstrated. PMID:25207992

He, Dayi; Li, Ran; Huang, Qi; Lei, Ping

2014-01-01

95

Maximum entropy principle based estimation of performance distribution in queueing theory.  

PubMed

In related research on queuing systems, in order to determine the system state, there is a widespread practice to assume that the system is stable and that distributions of the customer arrival ratio and service ratio are known information. In this study, the queuing system is looked at as a black box without any assumptions on the distribution of the arrival and service ratios and only keeping the assumption on the stability of the queuing system. By applying the principle of maximum entropy, the performance distribution of queuing systems is derived from some easily accessible indexes, such as the capacity of the system, the mean number of customers in the system, and the mean utilization of the servers. Some special cases are modeled and their performance distributions are derived. Using the chi-square goodness of fit test, the accuracy and generality for practical purposes of the principle of maximum entropy approach is demonstrated. PMID:25207992

He, Dayi; Li, Ran; Huang, Qi; Lei, Ping

2014-01-01

96

A priority queuing model to reduce waiting times in emergency care.  

PubMed

Investigates the increased waiting time costs imposed on society due to inappropriate use of the emergency department by patients, seeking non-emergency or primary care. Proposes a simple economic model to illustrate the effect of this misuse at a public or not-for-profit hospital. Provides evidence that non-emergency patients contribute to lengthy delays in the ER for all classes of patients. Proposes a priority queuing model to reduce average waiting times. PMID:10162117

Siddharthan, K; Jones, W J; Johnson, J A

1996-01-01

97

Supersonic Flutter Analysis Based on a Local Piston Theory  

E-print Network

Supersonic Flutter Analysis Based on a Local Piston Theory Wei-Wei Zhang, Zheng-Yin Ye, and Chen loads and flutter predictions are compared with those obtained by the classical piston theory = reduced flutter speed V1 = freestream speed = angle of attack, torsion deflection 0 = airfoil steady

Liu, Feng

98

Supersymmetric Field Theory Based on Generalized Uncertainty Principle  

E-print Network

We construct a quantum theory of free fermion field based on the generalized uncertainty principle using supersymmetry as a guiding principle. A supersymmetric field theory with a real scalar field and a Majorana fermion field is given explicitly and we also find that the supersymmetry algebra is deformed from an usual one.

Yuuichirou Shibusa

2007-04-12

99

Evaluation Theory in Problem-Based Learning Approach.  

ERIC Educational Resources Information Center

The purpose of this paper is to review evaluation theories and techniques in both the medical and educational fields and to propose an evaluation theory to explain the condition variables, the method variables, and the outcome variables of student assessment in a problem-based learning (PBL) approach. The PBL definition and process are presented,…

Hsu, Yu-chen

100

Implementation of GIS Spatial Data Mining Based on Cloud Theory  

Microsoft Academic Search

The transforms between qualitative concepts and their quantitative expressions plan an important role in spatial data mining & knowledge discovery (SDMKD), the cloud theory is this kind of powerful tools. Based on the cloud model, this paper presents a expression method for uncertain direction by using two-dimensional normal cloud, builds a data mining pattern through combining cloud theory and rough

Wang Xiao hui; Xie Jiancang; Li Jianxun; Luo Jungang; Liu Fuchao

2006-01-01

101

Performance theory based outcome measurement in engineering education and training  

Microsoft Academic Search

An approach is presented to improve engineering education that is based on new concepts of systems performance and classic feedback theory. An important aspect is the use of general systems performance theory (GSPT) to provide a performance model of the educational system and as a basis for the key outcome metrics: the volumes of performance capacity envelopes of individual students.

William E. Dillon; George V. Kondraske; Louis J. Everett; Richard A. Volz

2000-01-01

102

Highway Traffic Safety Management System Based on the Theory of Dissipative Structures and Catastrophe Theory  

Microsoft Academic Search

Highway traffic safety management system is an open complex system, there are so many impact factors which influence highway safety, in this paper highway traffic safety management system is studied based on the theory of dissipative structure and catastrophe theory, it indicate that the highway safety management system will be stable or unstable under different disturbances, there are two different

Pan Xiaodong; Wang Xiang; Yang Zhen; Cong Haozhe

2009-01-01

103

The Prediction of Item Parameters Based on Classical Test Theory and Latent Trait Theory  

ERIC Educational Resources Information Center

In this study, the prediction power of the item characteristics based on the experts' predictions on conditions try-out practices cannot be applied was examined for item characteristics computed depending on classical test theory and two-parameters logistic model of latent trait theory. The study was carried out on 9914 randomly selected students…

Anil, Duygu

2008-01-01

104

Theory of friction based on brittle fracture  

USGS Publications Warehouse

A theory of friction is presented that may be more applicable to geologic materials than the classic Bowden and Tabor theory. In the model, surfaces touch at the peaks of asperities and sliding occurs when the asperities fail by brittle fracture. The coefficient of friction, ??, was calculated from the strength of asperities of certain ideal shapes; for cone-shaped asperities, ?? is about 0.1 and for wedge-shaped asperities, ?? is about 0.15. For actual situations which seem close to the ideal model, observed ?? was found to be very close to 0.1, even for materials such as quartz and calcite with widely differing strengths. If surface forces are present, the theory predicts that ?? should decrease with load and that it should be higher in a vacuum than in air. In the presence of a fluid film between sliding surfaces, ?? should depend on the area of the surfaces in contact. Both effects are observed. The character of wear particles produced during sliding and the way in which ?? depends on normal load, roughness, and environment lend further support to the model of friction presented here. ?? 1967 The American Institute of Physics.

Byerlee, J.D.

1967-01-01

105

An Improved Call Admission Control Mechanism with Prioritized Handoff Queuing Scheme for BWA Networks  

NASA Astrophysics Data System (ADS)

Nowadays, due to increased demand for using the Broadband Wireless Access (BWA) networks in a satisfactory manner a promised Quality of Service (QoS) is required to manage the seamless transmission of the heterogeneous handoff calls. To this end, this paper proposes an improved Call Admission Control (CAC) mechanism with prioritized handoff queuing scheme that aims to reduce dropping probability of handoff calls. Handoff calls are queued when no bandwidth is available even after the allowable bandwidth degradation of the ongoing calls and get admitted into the network when an ongoing call is terminated with a higher priority than the newly originated call. An analytical Markov model for the proposed CAC mechanism is developed to analyze various performance parameters. Analytical results show that our proposed CAC with handoff queuing scheme prioritizes the handoff calls effectively and reduces dropping probability of the system by 78.57% for real-time traffic without degrading the number of failed new call attempts. This results in the increased bandwidth utilization of the network.

Chowdhury, Prasun; Saha Misra, Iti

2014-10-01

106

Theory and practice of risk-based testing  

Microsoft Academic Search

This paper extends a theory of risk-based test planning that was outlined in a previous paper, introduces techniques to facilitate it, explains their practical application, and highlights opportunities for research to enquire into their feasibility and efficacy.

Felix Redmill

2005-01-01

107

Ramanujan’s theories of elliptic functions to alternative bases  

E-print Network

In his famous paper on modular equations and approximations to n, Ramanujan offers several series representations for X/n, which he claims are derived from "corresponding theories" in which the classical base q is replaced by one of three other bases. The formulas for \\fn were only recently proved by J. M. and P. B. Borwein in 1987, but these "corresponding theories" have never been heretofore developed. However, on six pages of his notebooks, Ramanujan gives approximately 50 results without proofs in these theories. The purpose of this paper is to prove all of these claims, and several further results are established as well.

Bruce C. Berndt; S. Bhargava; Frank G. Garvan

1995-01-01

108

Towards a Packet-based Control Theory -Part I: Stabilization Over a Packet-based Network  

E-print Network

Towards a Packet-based Control Theory - Part I: Stabilization Over a Packet-based Network Ling Shi classical information theory has several fundamental assumptions incompatible with control problems controllable and observable. The state information is transmitted to the controller over a packet- based

Murray, Richard M.

109

Understanding women's mammography intentions: a theory-based investigation.  

PubMed

The present study compared the utility of two models (the Theory of Planned Behavior and Protection Motivation Theory) in identifying factors associated with intentions to undertake screening mammography, before and after an intervention. The comparison was made between the unique components of the two models. The effect of including implementation intentions was also investigated. Two hundred and fifty-one women aged 37 to 69 years completed questionnaires at baseline and following the delivery of a standard (control) or a protection motivation theory-based informational intervention. Hierarchical multiple regressions indicated that theory of planned behavior variables were associated with mammography intentions. Results also showed that inclusion of implementation intention in the model significantly increased the association with mammography intentions. The findings suggest that future interventions aiming to increase screening mammography participation should focus on the theory of planned behavior variables and that implementation intention should also be targeted. PMID:19533505

Naito, Mikako; O'Callaghan, Frances V; Morrissey, Shirley

2009-01-01

110

Local Rule-Based Theory of Virus Shell Assembly  

Microsoft Academic Search

A local rule-based theory is developed which shows that the self-assembly of icosahedral virus shells may depend on only the lower-level interactions of a protein subunit with its neighbors-i.e., on local rules rather than on larger structural building blocks. The local rule theory provides a framework for understanding the assembly of icosahedral viruses. These include both viruses that fall in

Bonnie Berger; Peter W. Shor; Lisa Tucker-Kellogg; Jonathan King

1994-01-01

111

Evaluation of security investment based on blind number theory  

Microsoft Academic Search

In order to solve security investment evaluation with multi-factor, multi-variable and multi-level attributes, the blind number theory is applied to this paper. By introducing comprehensive faith degree and unascertained measure, multi-agent system based on the blind number theory can efficiently solve the problems such as uncertainty, fuzziness and randomness. The analysis of CNPC shows that the uncertain conclusion synthesis of

Min Wang; Ping Yang

2010-01-01

112

Invasion percolation and the time scaling behavior of a queuing model of human dynamics  

NASA Astrophysics Data System (ADS)

In this paper we study the properties of the Barabási model of queuing under the hypothesis that the number of tasks is steadily growing in time. We map this model exactly onto an invasion percolation dynamics on a Cayley tree. This allows us to recover the correct waiting time distribution PW(?)~?-3/2 at the stationary state (as observed in different realistic data) and also to characterize it as a sequence of causally and geometrically connected bursts of activity. We also find that the approach to stationarity is very slow.

Gabrielli, A.; Caldarelli, G.

2009-02-01

113

Aviation security cargo inspection queuing simulation model for material flow and accountability  

NASA Astrophysics Data System (ADS)

Beginning in 2010, the U.S. will require that all cargo loaded in passenger aircraft be inspected. This will require more efficient processing of cargo and will have a significant impact on the inspection protocols and business practices of government agencies and the airlines. In this paper, we develop an aviation security cargo inspection queuing simulation model for material flow and accountability that will allow cargo managers to conduct impact studies of current and proposed business practices as they relate to inspection procedures, material flow, and accountability.

Allgood, Glenn O.; Olama, Mohammed M.; Rose, Terri A.; Brumback, Daryl

2009-05-01

114

Aviation security cargo inspection queuing simulation model for material flow and accountability  

SciTech Connect

Beginning in 2010, the U.S. will require that all cargo loaded in passenger aircraft be inspected. This will require more efficient processing of cargo and will have a significant impact on the inspection protocols and business practices of government agencies and the airlines. In this paper, we develop an aviation security cargo inspection queuing simulation model for material flow and accountability that will allow cargo managers to conduct impact studies of current and proposed business practices as they relate to inspection procedures, material flow, and accountability.

Olama, Mohammed M [ORNL; Allgood, Glenn O [ORNL; Rose, Terri A [ORNL; Brumback, Daryl L [ORNL

2009-01-01

115

Optimising node selection probabilities in multi-hop M/D/1 queuing networks to reduce the latency of Tor  

E-print Network

is ?, and the waiting time (i.e., the total waiting time including queuing and service) for the kth hop is Wk. The problem can thus be expressed as a function optimisation. Minimise: E (W0 +W1 + ...+WN?1) =E(W0) + E(W1) + ...+ E(WN?1), (1) 1 It may... Optimising node selection probabilities in multi-hop M/D/1 queuing networks to reduce the latency of Tor S. J. Herbert, S. J. Murdoch and E. Punskaya This paper is a postprint of a paper submitted to and accepted...

Herbert, S. J.; Murdoch, S. J.; Punskaya, E.

2014-08-11

116

Static analysis of rectangular nanoplates using trigonometric shear deformation theory based on nonlocal elasticity theory.  

PubMed

In this article, a new higher order shear deformation theory based on trigonometric shear deformation theory is developed. In order to consider the size effects, the nonlocal elasticity theory is used. An analytical method is adopted to solve the governing equations for static analysis of simply supported nanoplates. In the present theory, the transverse shear stresses satisfy the traction free boundary conditions of the rectangular plates and these stresses can be calculated from the constitutive equations. The effects of different parameters such as nonlocal parameter and aspect ratio are investigated on both nondimensional deflections and deflection ratios. It may be important to mention that the present formulations are general and can be used for isotropic, orthotropic and anisotropic nanoplates. PMID:24455455

Nami, Mohammad Rahim; Janghorban, Maziar

2013-12-30

117

Density functional theory based effective fragment potential method  

NASA Astrophysics Data System (ADS)

The effective fragment potential (EFP) method, is a discrete method for the treatment of solvent effects, originally formulated using Hartree-Fock (HF) theory. Here, a density functional theory (DFT) based implementation of the EFP method is presented for water as a solvent. In developing the DFT based EFP method for water, all molecular properties (multipole moments, polarizability tensors, screening parameters, and fitting parameters for the exchange repulsion potential) are recalculated and optimized, using the B3LYP functional. Initial tests for water dimer, small water clusters, and the glycine-water system show good agreement with ab initio and DFT calculations. Several computed properties exhibit marked improvement relative to the Hartree-Fock based method, presumably because the DFT based method includes some dynamic electron correlation through the corresponding functional.

Adamovic, Ivana; Freitag, Mark A.; Gordon, Mark S.

2003-04-01

118

A Pedagogy of Blending Theory with Community-Based Research  

ERIC Educational Resources Information Center

Blending activity theory and community-based research educational applications describes the praxis achieved through the initial design, development, implementation, and assessment of one research methods course as a pedagogy to enhance and improve the outcomes of civic and community engagement for the university, its students, and the community.…

Brown, Kathleen Taylor

2011-01-01

119

A Memory-Based Theory of Verbal Cognition  

ERIC Educational Resources Information Center

The syntagmatic paradigmatic model is a distributed, memory-based account of verbal processing. Built on a Bayesian interpretation of string edit theory, it characterizes the control of verbal cognition as the retrieval of sets of syntagmatic and paradigmatic constraints from sequential and relational long-term memory and the resolution of these…

Dennis, Simon

2005-01-01

120

Method of Fuzzy Comprehensive Evaluation Based on Catastrophe Theory  

Microsoft Academic Search

Man-made objectivity always exits in traditional fuzzy comprehensive evaluation for the weights of the evaluation factors are setting by us. This paper introduces a new fuzzy comprehensive evaluation based on the catastrophe theory and factor analysis, which has just to consider the relative importance without computing the calculation details. So the final result is more compliance with objective facts. We

Yuanchao Yu; Sicong Guo

2011-01-01

121

Chemical Organization Theory as a Theoretical Base for Chemical Computing  

E-print Network

Chemical Organization Theory as a Theoretical Base for Chemical Computing NAOKI MATSUMARU, FLORIAN-07743 Jena, Germany http://www.minet.uni-jena.de/csb/ Submitted 14 November 2005 In chemical computing- gramming chemical systems a theoretical method to cope with that emergent behavior is desired

Dittrich, Peter

122

On a Quantitative Measure for Modularity Based on Information Theory  

E-print Network

for many questions in the field of Artificial Life research. However, there have not been many quantitativeOn a Quantitative Measure for Modularity Based on Information Theory Daniel Polani1 , Peter, the crossover oper- ator (which is construed by researchers of artificial evolution as to be preserving building

Polani, Daniel

123

A Natural Teaching Method Based on Learning Theory.  

ERIC Educational Resources Information Center

The natural teaching method is active and student-centered, based on schema and constructivist theories, and informed by research in neuroplasticity. A schema is a mental picture or understanding of something we have learned. Humans can have knowledge only to the degree to which they have constructed schemas from learning experiences and practice.…

Smilkstein, Rita

1991-01-01

124

Rational Exchange --A Formal Model Based on Game Theory ?  

E-print Network

Rational Exchange -- A Formal Model Based on Game Theory ? Levente Butty'an and Jean­Pierre Hubaux to give a formal definition for rational exchange relating it to the concept of Nash equilibrium in games. In addition, we study the relationship between rational exchange and fair exchange. We prove that fair

Bencsáth, Boldizsár

125

Qualitative model-based diagnosis using possibility theory  

NASA Technical Reports Server (NTRS)

The potential for the use of possibility in the qualitative model-based diagnosis of spacecraft systems is described. The first sections of the paper briefly introduce the Model-Based Diagnostic (MBD) approach to spacecraft fault diagnosis; Qualitative Modeling (QM) methodologies; and the concepts of possibilistic modeling in the context of Generalized Information Theory (GIT). Then the necessary conditions for the applicability of possibilistic methods to qualitative MBD, and a number of potential directions for such an application, are described.

Joslyn, Cliff

1994-01-01

126

Nano-resonator frequency response based on strain gradient theory  

NASA Astrophysics Data System (ADS)

This paper aims to explore the dynamic behaviour of a nano-resonator under ac and dc excitation using strain gradient theory. To achieve this goal, the partial differential equation of nano-beam vibration is first converted to an ordinary differential equation by the Galerkin projection method and the lumped model is derived. Lumped parameters of the nano-resonator, such as linear and nonlinear springs and damper coefficients, are compared with those of classical theory and it is demonstrated that beams with smaller thickness display greater deviation from classical parameters. Stable and unstable equilibrium points based on classic and non-classical theories are also compared. The results show that, regarding the applied dc voltage, the dynamic behaviours expected by classical and non-classical theories are significantly different, such that one theory predicts the un-deformed shape as the stable condition, while the other theory predicts that the beam will experience bi-stability. To obtain the frequency response of the nano-resonator, a general equation including cubic and quadratic nonlinearities in addition to parametric electrostatic excitation terms is derived, and the analytical solution is determined using a second-order multiple scales method. Based on frequency response analysis, the softening and hardening effects given by two theories are investigated and compared, and it is observed that neglecting the size effect can lead to two completely different predictions in the dynamic behaviour of the resonators. The findings of this article can be helpful in the design and characterization of the size-dependent dynamic behaviour of resonators on small scales.

Maani Miandoab, Ehsan; Yousefi-Koma, Aghil; Nejat Pishkenari, Hossein; Fathi, Mohammad

2014-09-01

127

Evolutionary game theory using agent-based methods  

E-print Network

Evolutionary game theory is a successful mathematical framework geared towards understanding the selective pressures that affect the evolution of the strategies of agents engaged in interactions with potential conflicts. While a mathematical treatment of the costs and benefits of decisions can predict the optimal strategy in simple settings, more realistic situations (finite populations, non-vanishing mutations rates, communication between agents, and spatial interactions) require agent-based methods where each agent is modeled as an individual, carries its own genes that determine its decisions, and where the evolutionary outcome can only be ascertained by evolving the population of agents forward in time. Here we discuss the use of agent-based methods in evolutionary game theory and contrast standard results to those obtainable by a mathematical treatment. We conclude that agent-based methods can predict evolutionary outcomes where purely mathematical treatments cannot tread, but that mathematics is crucial...

Adami, Christoph; Hintze, Arend

2014-01-01

128

Reducing Queuing Stalls Caused by Data Prefetching Rao Fu, Antonia Zhai, Pen-Chung Yew and Wei-Chung Hsu  

E-print Network

Reducing Queuing Stalls Caused by Data Prefetching Rao Fu, Antonia Zhai, Pen-Chung Yew and Wei of the prefetches generated by the compiler, recent architectures allow the selection of stalling or dropping of stall, queue full stall. Large percentage of queue full stall as high as 50% can be observed for SPEC

Minnesota, University of

129

Reduce fluctuations in capacity to improve the accessibility of radiotherapy treatment  

E-print Network

out to be the outpatient department (OPD). Next, based on queuing theory, waiting times were improved event simulation Á Queuing theory Á Radiotherapy department Á Variability Á Waiting lists P. E. Joustra is to find a cost-effective way to meet future throughput targets. A combination of queuing theory

Boucherie, Richard J.

130

Ensemble method: Community detection based on game theory  

NASA Astrophysics Data System (ADS)

Timely and cost-effective analytics over social network has emerged as a key ingredient for success in many businesses and government endeavors. Community detection is an active research area of relevance to analyze online social network. The problem of selecting a particular community detection algorithm is crucial if the aim is to unveil the community structure of a network. The choice of a given methodology could affect the outcome of the experiments because different algorithms have different advantages and depend on tuning specific parameters. In this paper, we propose a community division model based on the notion of game theory, which can combine advantages of previous algorithms effectively to get a better community classification result. By making experiments on some standard dataset, it verifies that our community detection model based on game theory is valid and better.

Zhang, Xia; Xia, Zhengyou; Xu, Shengwu; Wang, J. D.

2014-08-01

131

Infrared small target detection based on Danger Theory  

NASA Astrophysics Data System (ADS)

To solve the problem that traditional method can't detect the small objects whose local SNR is less than 2 in IR images, a Danger Theory-based model to detect infrared small target is presented in this paper. First, on the analog with immunology, the definition is given, in this paper, to such terms as dangerous signal, antigens, APC, antibodies. Besides, matching rule between antigen and antibody is improved. Prior to training the detection model and detecting the targets, the IR images are processed utilizing adaptive smooth filter to decrease the stochastic noise. Then at the training process, deleting rule, generating rule, crossover rule and the mutation rule are established after a large number of experiments in order to realize immediate convergence and obtain good antibodies. The Danger Theory-based model is built after the training process, and this model can detect the target whose local SNR is only 1.5.

Lan, Jinhui; Yang, Xiao

2009-11-01

132

Improved virtual queuing and dynamic EPD techniques for TCP over ATM  

SciTech Connect

It is known that TCP throughput can degrade significantly over UBR service in a congested ATM network, and the early packet discard (EPD) technique has been proposed to improve the performance. However, recent studies show that EPD cannot ensure fairness among competing VCs in a congested network, but the degree of fairness can be improved using various forms of fair buffer allocation techniques. The authors propose an improved scheme that utilizes only a single shared FIFO queue for all VCs and admits simple implementation for high speed ATM networks. The scheme achieves nearly perfect fairness and throughput among multiple TCP connections, comparable to the expensive per-VC queuing technique. Analytical and simulation results are presented to show the validity of this new scheme and significant improvement in performance as compared with existing fair buffer allocation techniques for TCP over ATM.

Wu, Y.; Siu, K.Y.; Ren, W.

1998-11-01

133

[Application of a calling and queuing system in blood sampling in the clinical laboratory].  

PubMed

This paper introduces the application of a calling and queuing system for blood sample collection in a large hospital in China. Besides the basic function, it has following functions. (a) A real name system: get the number according to the laboratory application form to prevent the phenomena of buying a number and an empty number. (b) Two times waiting: the patient should wait at the main hall, then at the blood sampling window so as to improve the work efficiency. (c) The flowchart for an outpatient blood testing is as following: getting the number --> waiting --> blood sampling --> getting the test information report. This system is capable of not only optimizing the work flow, but also improving the clinical environment. It shortens the patient's waiting time and raises the laboratory quality as well. PMID:18581883

Yang, Da-Gan; Guo, Xi-Chao; Xu, Gen-Yun; Chen, Yu

2008-03-01

134

Modeling Air Traffic Management Technologies with a Queuing Network Model of the National Airspace System  

NASA Technical Reports Server (NTRS)

This report describes an integrated model of air traffic management (ATM) tools under development in two National Aeronautics and Space Administration (NASA) programs -Terminal Area Productivity (TAP) and Advanced Air Transport Technologies (AATT). The model is made by adjusting parameters of LMINET, a queuing network model of the National Airspace System (NAS), which the Logistics Management Institute (LMI) developed for NASA. Operating LMINET with models of various combinations of TAP and AATT will give quantitative information about the effects of the tools on operations of the NAS. The costs of delays under different scenarios are calculated. An extension of Air Carrier Investment Model (ACIM) under ASAC developed by the Institute for NASA maps the technologies' impacts on NASA operations into cross-comparable benefits estimates for technologies and sets of technologies.

Long, Dou; Lee, David; Johnson, Jesse; Gaier, Eric; Kostiuk, Peter

1999-01-01

135

Quantum Game Theory Based on the Schmidt Decomposition  

E-print Network

We present a novel formulation of quantum game theory based on the Schmidt decomposition, which has the merit that the entanglement of quantum strategies is manifestly quantified. We apply this formulation to 2-player, 2-strategy symmetric games and obtain a complete set of quantum Nash equilibria. Apart from those available with the maximal entanglement, these quantum Nash equilibria are extensions of the Nash equilibria in classical game theory. The phase structure of the equilibria is determined for all values of entanglement, and thereby the possibility of resolving the dilemmas by entanglement in the game of Chicken, the Battle of the Sexes, the Prisoners' Dilemma, and the Stag Hunt, is examined. We find that entanglement transforms these dilemmas with each other but cannot resolve them, except in the Stag Hunt game where the dilemma can be alleviated to a certain degree.

Tsubasa Ichikawa; Izumi Tsutsui; Taksu Cheon

2013-01-30

136

Control theory based airfoil design using the Euler equations  

NASA Technical Reports Server (NTRS)

This paper describes the implementation of optimization techniques based on control theory for airfoil design. In our previous work it was shown that control theory could be employed to devise effective optimization procedures for two-dimensional profiles by using the potential flow equation with either a conformal mapping or a general coordinate system. The goal of our present work is to extend the development to treat the Euler equations in two-dimensions by procedures that can readily be generalized to treat complex shapes in three-dimensions. Therefore, we have developed methods which can address airfoil design through either an analytic mapping or an arbitrary grid perturbation method applied to a finite volume discretization of the Euler equations. Here the control law serves to provide computationally inexpensive gradient information to a standard numerical optimization method. Results are presented for both the inverse problem and drag minimization problem.

Jameson, Antony; Reuther, James

1994-01-01

137

Theory of networked minority games based on strategy pattern dynamics.  

PubMed

We formulate a theory of agent-based models in which agents compete to be in a winning group. The agents may be part of a network or not, and the winning group may be a minority group or not. An important feature of the present formalism is its focus on the dynamical pattern of strategy rankings, and its careful treatment of the strategy ties which arise during the system's temporal evolution. We apply it to the minority game with connected populations. Expressions for the mean success rate among the agents and for the mean success rate for agents with k neighbors are derived. We also use the theory to estimate the value of connectivity p above which the binary-agent-resource system with high resource levels makes the transition into the high-connectivity state. PMID:15600687

Lo, T S; Chan, H Y; Hui, P M; Johnson, N F

2004-11-01

138

A new lightning return stroke model based on antenna theory  

NASA Astrophysics Data System (ADS)

A new approach based on antenna theory is presented to describe the lightning return-stroke process. The lightning channel is approximated by a straight and vertical monopole antenna with distributed resistance (a so-called lossy antenna) above a perfectly conducting ground. The antenna is fed at its lower end by a voltage source such that the antenna input current, which represents the lightning return-stroke current at the lightning channel base, can be specified. An electric field integral equation (EFIE) in the time domain is employed to describe the electromagnetic behavior of this lossy monopole antenna. The numerical solution of EFIE by the method of moments (MOM) provides the time-space distribution of the current and line charge density along the antenna. This new antenna-theory (or electromagnetic) model with specified current at the channel base requires only two adjustable parameters: the return-stroke propagation speed for a nonresistive channel and the channel resistance per unit length, each assumed to be constant (independent of time and height). The new model is compared to four of the most commonly used ``engineering'' return-stroke models in terms of the temporal-spatial distribution of channel current, the line charge density distribution, and the predicted electromagnetic fields at different distances. A reasonably good agreement is found with the modified transmission line model with linear current decay with height (MTLL) and with the Diendorfer-Uman (DU) model.

Moini, Rouzbeh; Kordi, Behzad; Rafi, Gholamreza Z.; Rakov, Vladimir A.

139

Transportation Optimization with Fuzzy Trapezoidal Numbers Based on Possibility Theory  

PubMed Central

In this paper, a parametric method is introduced to solve fuzzy transportation problem. Considering that parameters of transportation problem have uncertainties, this paper develops a generalized fuzzy transportation problem with fuzzy supply, demand and cost. For simplicity, these parameters are assumed to be fuzzy trapezoidal numbers. Based on possibility theory and consistent with decision-makers' subjectiveness and practical requirements, the fuzzy transportation problem is transformed to a crisp linear transportation problem by defuzzifying fuzzy constraints and objectives with application of fractile and modality approach. Finally, a numerical example is provided to exemplify the application of fuzzy transportation programming and to verify the validity of the proposed methods. PMID:25137239

He, Dayi; Li, Ran; Huang, Qi; Lei, Ping

2014-01-01

140

Transportation optimization with fuzzy trapezoidal numbers based on possibility theory.  

PubMed

In this paper, a parametric method is introduced to solve fuzzy transportation problem. Considering that parameters of transportation problem have uncertainties, this paper develops a generalized fuzzy transportation problem with fuzzy supply, demand and cost. For simplicity, these parameters are assumed to be fuzzy trapezoidal numbers. Based on possibility theory and consistent with decision-makers' subjectiveness and practical requirements, the fuzzy transportation problem is transformed to a crisp linear transportation problem by defuzzifying fuzzy constraints and objectives with application of fractile and modality approach. Finally, a numerical example is provided to exemplify the application of fuzzy transportation programming and to verify the validity of the proposed methods. PMID:25137239

He, Dayi; Li, Ran; Huang, Qi; Lei, Ping

2014-01-01

141

Enhancement of infrared image based on the Retinex theory.  

PubMed

The infrared imaging technique can be used to image the temperature distribution of the body. It's hopeful to be applied to the diagnosis and prediction of many diseases. Image processing is necessary to enhance the original infrared images because of the blurring. In this paper, the image enhancement technique based on the Retinex theory is studied. The algorithms such as Frackle-McCann algorithm, McCann99 algorithm, single-scale Retinex algorithm and multi-scale Retinex algorithm are applied to the enhancement of gray infrared image. The acceptable results are obtained and compared. PMID:18002705

Li, Ying; Hou, Changzhi; Tian, Fu; Yu, Hongli; Guo, Lei; Xu, Guizhi; Shen, Xueqin; Yan, Weili

2007-01-01

142

Resource based view: a promising new theory for healthcare organizations  

PubMed Central

This commentary reviews a recent piece by Burton and Rycroft-Malone on the use of Resource Based View (RBV) in healthcare organizations. It first outlines the core content of their piece. It then discusses their attempts to extend RBV to the analysis of large scale quality improvement efforts in healthcare. Some critique is elaborated. The broader question of why RBV seems to be migrating into healthcare management research is considered. They conclude RBV is a promising new theory for healthcare organizations. PMID:25396211

Ferlie, Ewan

2014-01-01

143

Assessment of urban water security based on catastrophe theory.  

PubMed

In this study, a model for assessing urban water security is developed using an evaluation method of catastrophe theory. To overcome the defects of the traditional catastrophe evaluation method, two aspects of improvement are assessed. One is expanding the scope of application of the traditional catastrophe approach, i.e., new normalization formulae for five lower level indicators contained in the index at the higher level is proposed in theory. The other is solving the problem that the synthetic values are generally high and the differences are not obvious based on the theories of Cramer's Rule and Vander monde determinant. The assessment results in Wuhan city are in good agreement with the actual situation. The comparison between the results of the improved method and a fuzzy comprehensive evaluation method verifies the science and reliability of the developed method. Consequently, it is concluded that the improved method can be an effective tool for assessment of urban water security and provide a valuable reference for improving inadequacies in urban water security. PMID:22744677

Yang, Fengshun; Shao, Dongguo; Xiao, Chun; Tan, Xuezhi

2012-01-01

144

Feature Selection with Neighborhood Entropy-Based Cooperative Game Theory  

PubMed Central

Feature selection plays an important role in machine learning and data mining. In recent years, various feature measurements have been proposed to select significant features from high-dimensional datasets. However, most traditional feature selection methods will ignore some features which have strong classification ability as a group but are weak as individuals. To deal with this problem, we redefine the redundancy, interdependence, and independence of features by using neighborhood entropy. Then the neighborhood entropy-based feature contribution is proposed under the framework of cooperative game. The evaluative criteria of features can be formalized as the product of contribution and other classical feature measures. Finally, the proposed method is tested on several UCI datasets. The results show that neighborhood entropy-based cooperative game theory model (NECGT) yield better performance than classical ones. PMID:25276120

Zeng, Kai; She, Kun; Niu, Xinzheng

2014-01-01

145

Embedding parameters in ab initio theory to develop well-controlled approximations based on molecular similarity  

E-print Network

Embedding parameters in ab initio theory to develop well- controlled approximations based Journal of Chemical Theory and Computation #12;1 Embedding parameters in ab initio theory to develop well-controlled on molecular similarity Journal: Journal of Chemical Theory and Computation Manuscript ID: Draft Manuscript

Yaron, David

146

Investigating the Learning-Theory Foundations of Game-Based Learning: A Meta-Analysis  

ERIC Educational Resources Information Center

Past studies on the issue of learning-theory foundations in game-based learning stressed the importance of establishing learning-theory foundation and provided an exploratory examination of established learning theories. However, we found research seldom addressed the development of the use or failure to use learning-theory foundations and…

Wu, W-H.; Hsiao, H-C.; Wu, P-L.; Lin, C-H.; Huang, S-H.

2012-01-01

147

SARA: A Text-Based and Reader-Based Theory of Signaling  

ERIC Educational Resources Information Center

We propose a two-component theory of text signaling devices. The first component is a text-based analysis that characterizes any signaling device along four dimensions: (a) the type of information it makes available, (b) its scope, (c) how it is realized in the text, and (d) its location with respect to the content it cues. The second component is…

Lemarie, Julie; Lorch, Robert F., Jr.; Eyrolle, Helene; Virbel, Jacques

2008-01-01

148

INTEGRATION OF BOUNDARY FINDING AND REGION BASED SEGMENTATION USING GAME THEORY  

E-print Network

INTEGRATION OF BOUNDARY FINDING AND REGION­ BASED SEGMENTATION USING GAME THEORY AMIT CHAKRABORTY and gradient based boundary finding using game theory in an effort to form a unified approach that is robust at best sub­optimal. One of the biggest advantages of using game theory is that it can dealing

Duncan, James S.

149

Validating a Theory-Based Survey to Evaluate Teaching Effectiveness in Higher Education  

ERIC Educational Resources Information Center

Surveys to evaluate instructor effectiveness are commonly used in higher education. Yet the survey items included are often drawn from other surveys without reference to a theory of adult learning. The authors present the results from a validation study of such a theory-based survey. They evidence that an evaluation survey based on a theory that…

Amrein-Beardsley, A.; Haladyna, T.

2012-01-01

150

A theory of individual-level predicates based on blind mandatory implicatures : constraint promotion for optimality theory  

E-print Network

Part I of this dissertation proposes an implicature-based theory of individual-level predicates. The idea is that we cannot say '#John is sometimes tall' because the sentence triggers the scalar implicature that the ...

Magri, Giorgio, 1975-

2009-01-01

151

A theory for cursive handwriting based on the minimization principle.  

PubMed

We propose a trajectory planning and control theory which provides explanations at the computation, algorithm, representation, and hardware levels for continuous movement such as connected cursive handwriting. The hardware is based on our previously proposed forward-inverse-relaxation neural network. Computationally, the optimization principle is the minimum torque-change criterion. At the representation level, hard constraints satisfied by a trajectory are represented as a set of via-points extracted from handwritten characters. Accordingly, we propose a via-point estimation algorithm that estimates via-points by repeating trajectory formation of a character and via-point extraction from the character. It is shown experimentally that for movements with a single via-point target, the via-point estimation algorithm can assign a point near the actual via-point target. Good quantitative agreement is found between human movement data and the trajectories generated by the proposed model. PMID:7654848

Wada, Y; Kawato, M

1995-06-01

152

Intelligent control based on fuzzy logic and neural net theory  

NASA Technical Reports Server (NTRS)

In the conception and design of intelligent systems, one promising direction involves the use of fuzzy logic and neural network theory to enhance such systems' capability to learn from experience and adapt to changes in an environment of uncertainty and imprecision. Here, an intelligent control scheme is explored by integrating these multidisciplinary techniques. A self-learning system is proposed as an intelligent controller for dynamical processes, employing a control policy which evolves and improves automatically. One key component of the intelligent system is a fuzzy logic-based system which emulates human decision making behavior. It is shown that the system can solve a fairly difficult control learning problem. Simulation results demonstrate that improved learning performance can be achieved in relation to previously described systems employing bang-bang control. The proposed system is relatively insensitive to variations in the parameters of the system environment.

Lee, Chuen-Chien

1991-01-01

153

Aaronistotle's poetics| A scholarship-based thought experiment constructing Aristotle's comedic theory.  

E-print Network

?? I like to describe this thesis as a scholarship-based thought experiment constructing Aristotle's comedic theory using post-Aristotelian plays and quasi-Aristotelian theory. In other words,… (more)

Penn, Aaron Nicholas

2012-01-01

154

Optimal floating and queuing strategies: consequences for density dependence and habitat loss.  

PubMed

Field studies of many vertebrates show that some individuals (floaters) do not defend territories even when there is space for them to do so. We show that the evolutionarily stable strategy (ESS) for the threshold territory quality at which floating takes place is that which maximizes the size of the floating population (but not the total population, breeding population, or reproductive output). The ESS is solved separately for two assumptions: whether individuals wait to occupy a single territory or multiple territories and whether queuing rules are strict or if all waiting individuals are equally likely to obtain the next territory. The four combinations of these assumptions all give the same evolutionarily stable population size of both floaters and breeders. At the ESS, only territories with expected lifetime reproductive success (LRS) exceeding 1 should be occupied, which introduces a limit to ideal habitat selection. The behavioral decision to float alters the shape of the density-dependent response, reduces the equilibrium population size, and affects the response of the population to habitat loss. Specifically, the floater: breeder ratio is directly related to average breeding habitat quality, and the floater population size will decrease more than the breeding population size if better than average quality habitat is lost. PMID:18811444

Kokko, H; Sutherland, W J

1998-09-01

155

Evaluating Theory-Based Evaluation: Information, Norms, and Adherence  

ERIC Educational Resources Information Center

Programmatic social interventions attempt to produce appropriate social-norm-guided behavior in an open environment. A marriage of applicable psychological theory, appropriate program evaluation theory, and outcome of evaluations of specific social interventions assures the acquisition of cumulative theory and the production of successful social…

Jacobs, W. Jake; Sisco, Melissa; Hill, Dawn; Malter, Frederic; Figueredo, Aurelio Jose

2012-01-01

156

An Architecturally-based Theory of Human Sentence Comprehension  

Microsoft Academic Search

Real-time language comprehension is an important area of fo- cus for a candidate unified theory of cognition. In his 1987 William James lectures, Allen Newell sketched the beginnings of a comprehension theory embedded in the Soar architecture. This theory, NL-Soar, has developed over the past few years into a detailed computational model that provides an account of a range of

Richard L. Lewis

1993-01-01

157

Image Integrity Authentication Scheme Based On Fixed Point Theory.  

PubMed

Based on the fixed point theory, this paper proposes a new scheme for image integrity authentication, which is very different from Digital Signature and Fragile Watermarking. By the new scheme, the sender transforms an original image into a fixed point image (very close to the original one) of a well chosen transform, and send the fixed point image (instead of the original one) to the receiver; using the same transform, the receiver checks the integrity of the received image by testing whether it is a fixed point image, and locate the tampered areas if the image has been modified during the transmission. A realization of the new scheme is based on a Gaussian Convolution and Deconvolution (GCD) transform, for which an existence theorem of fixed points is proved. The semi-fragility is analyzed via commutativity of transforms, and three commutativity theorems are found for the GCD transform. Three iterative algorithms are presented for finding a fixed point image with few numbers of iterations, and for the whole procedure of image integrity authentication; a fragile authentication system and a semi-fragile one are separately built. Experiments show that both systems have good performance in transparence, fragility, security and tampering localization. In particular, the semi-fragile system can perfectly resist the rotation by a multiple of 90o, flipping and brightness attacks. PMID:25420259

Li, Xu; Sun, Xingming; Liu, Quansheng

2014-11-20

158

Bowel anastomoses: The theory, the practice and the evidence base  

PubMed Central

Since the introduction of stapling instruments in the 1970s various studies have compared the results of sutured and stapled bowel anastomoses. A literature search was performed from 1960 to 2010 and articles relating to small bowel, colonic and colorectal anastomotic techniques were reviewed. References from these articles were also reviewed, and relevant articles obtained. Either a stapled or sutured gastrointestinal tract anastomosis is acceptable in most situations. The available evidence suggests that in the following situations, however, particular anastomotic techniques may result in fewer complications: A stapled side-to-side ileocolic anastomosis is preferable following a right hemicolectomy for cancer. A stapled side-to-side anastomosis is likely also preferable after an ileocolic resection for Crohn’s disease. Colorectal anastomoses can be sutured or stapled with similar results, although the incidence of strictures is higher following stapled anastomoses. Following reversal of loop ileostomy there is some evidence to suggest that a stapled side-to-side anastomosis or sutured enterotomy closure (rather than spout resection and sutured anastomosis) results in fewer complications. Non-randomised data has indicated that small bowel anastomoses are best sutured in the trauma patient. This article reviews the theory, practice and evidence base behind the various gastrointestinal anastomoses to help the practising general surgeon make evidence based operative decisions. PMID:23293735

Goulder, Frances

2012-01-01

159

Density functional theory based generalized effective fragment potential method  

NASA Astrophysics Data System (ADS)

We present a generalized Kohn-Sham (KS) density functional theory (DFT) based effective fragment potential (EFP2-DFT) method for the treatment of solvent effects. Similar to the original Hartree-Fock (HF) based potential with fitted parameters for water (EFP1) and the generalized HF based potential (EFP2-HF), EFP2-DFT includes electrostatic, exchange-repulsion, polarization, and dispersion potentials, which are generated for a chosen DFT functional for a given isolated molecule. The method does not have fitted parameters, except for implicit parameters within a chosen functional and the dispersion correction to the potential. The electrostatic potential is modeled with a multipolar expansion at each atomic center and bond midpoint using Stone's distributed multipolar analysis. The exchange-repulsion potential between two fragments is composed of the overlap and kinetic energy integrals and the nondiagonal KS matrices in the localized molecular orbital basis. The polarization potential is derived from the static molecular polarizability. The dispersion potential includes the intermolecular D3 dispersion correction of Grimme et al. [J. Chem. Phys. 132, 154104 (2010)]. The potential generated from the CAMB3LYP functional has mean unsigned errors (MUEs) with respect to results from coupled cluster singles, doubles, and perturbative triples with a complete basis set limit (CCSD(T)/CBS) extrapolation, of 1.7, 2.2, 2.0, and 0.5 kcal/mol, for the S22, water-benzene clusters, water clusters, and n-alkane dimers benchmark sets, respectively. The corresponding EFP2-HF errors for the respective benchmarks are 2.41, 3.1, 1.8, and 2.5 kcal/mol. Thus, the new EFP2-DFT-D3 method with the CAMB3LYP functional provides comparable or improved results at lower computational cost and, therefore, extends the range of applicability of EFP2 to larger system sizes.

Nguyen, Kiet A.; Pachter, Ruth; Day, Paul N.

2014-06-01

160

The Application of Carl Rogers' Person-Centered Learning Theory to Web-Based Instruction.  

ERIC Educational Resources Information Center

This paper provides a review of literature that relates research on Carl Rogers' person-centered learning theory to Web-based learning. Based on the review of the literature, a set of criteria is described that can be used to determine how closely a Web-based course matches the different components of Rogers' person-centered learning theory. Using…

Miller, Christopher T.

161

Enhancing Student Learning in Knowledge-Based Courses: Integrating Team-Based Learning in Mass Communication Theory Classes  

ERIC Educational Resources Information Center

This study explores the adoption of the team-based learning (TBL) method in knowledge-based and theory-oriented journalism and mass communication (J&MC) courses. It first reviews the origin and concept of TBL, the relevant theories, and then introduces the TBL method and implementation, including procedures and assessments, employed in an…

Han, Gang; Newell, Jay

2014-01-01

162

Quantum Control: Approach based on Scattering Theory for Non-commutative Markov  

E-print Network

Quantum Control: Approach based on Scattering Theory for Non-commutative Markov Chains Theory to problems in the rapidly developing in- terdisciplinary field of Quantum Control. The pro- posal these fields, and to combine them in a new way toward developing a systematic theory of quan- tum control. 1

Gohm, Rolf

163

The Development of an Attribution-Based Theory of Motivation: A History of Ideas  

ERIC Educational Resources Information Center

The history of ideas guiding the development of an attribution-based theory of motivation is presented. These influences include the search for a "grand" theory of motivation (from drive and expectancy/value theory), an attempt to represent how the past may influence the present and the future (as Thorndike accomplished), and the incorporation of…

Weiner, Bernard

2010-01-01

164

Cognitive performance modeling based on general systems performance theory.  

PubMed

General Systems Performance Theory (GSPT) was initially motivated by problems associated with quantifying different aspects of human performance. It has proved to be invaluable for measurement development and understanding quantitative relationships between human subsystem capacities and performance in complex tasks. It is now desired to bring focus to the application of GSPT to modeling of cognitive system performance. Previous studies involving two complex tasks (i.e., driving and performing laparoscopic surgery) and incorporating measures that are clearly related to cognitive performance (information processing speed and short-term memory capacity) were revisited. A GSPT-derived method of task analysis and performance prediction termed Nonlinear Causal Resource Analysis (NCRA) was employed to determine the demand on basic cognitive performance resources required to support different levels of complex task performance. This approach is presented as a means to determine a cognitive workload profile and the subsequent computation of a single number measure of cognitive workload (CW). Computation of CW may be a viable alternative to measuring it. Various possible "more basic" performance resources that contribute to cognitive system performance are discussed. It is concluded from this preliminary exploration that a GSPT-based approach can contribute to defining cognitive performance models that are useful for both individual subjects and specific groups (e.g., military pilots). PMID:21096046

Kondraske, George V

2010-01-01

165

Semi-supervised community detection based on discrete potential theory  

NASA Astrophysics Data System (ADS)

In recent studies of the complex network, most of the community detection methods only consider the network topological structure without background information. This leads to a relatively low accuracy. In this paper, a novel semi-supervised community detection algorithm is proposed based on the discrete potential theory. It effectively incorporates individual labels, the labels of corresponding communities, to guide the community detection process for achieving better accuracy. Specifically, a number of vertices with user-defined labels are first identified to act as unit elementary charges which can generate different electrostatic fields. Then, community detection can be translated into a potential transmission problem. By formulating the problem using combinational Dirichlet, labels of those unlabeled vertices can be determined by the labels for which the greatest potential is calculated. Finally, a better community partition can be obtained. Our extensive numerical experiments in both artificial and real networks lead to two key observations: first, individual labels play an important role in community detection; and second, our proposed semi-supervised community detection algorithm outperforms existing counterparts in both accuracy and time complexity, especially for obscure networks.

Liu, Dong; Liu, Xiao; Wang, Wenjun; Bai, Hongyu

2014-12-01

166

Experimental Energy Consumption of Frame Slotted ALOHA and Distributed Queuing for Data Collection Scenarios  

PubMed Central

Data collection is a key scenario for the Internet of Things because it enables gathering sensor data from distributed nodes that use low-power and long-range wireless technologies to communicate in a single-hop approach. In this kind of scenario, the network is composed of one coordinator that covers a particular area and a large number of nodes, typically hundreds or thousands, that transmit data to the coordinator upon request. Considering this scenario, in this paper we experimentally validate the energy consumption of two Medium Access Control (MAC) protocols, Frame Slotted ALOHA (FSA) and Distributed Queuing (DQ). We model both protocols as a state machine and conduct experiments to measure the average energy consumption in each state and the average number of times that a node has to be in each state in order to transmit a data packet to the coordinator. The results show that FSA is more energy efficient than DQ if the number of nodes is known a priori because the number of slots per frame can be adjusted accordingly. However, in such scenarios the number of nodes cannot be easily anticipated, leading to additional packet collisions and a higher energy consumption due to retransmissions. Contrarily, DQ does not require to know the number of nodes in advance because it is able to efficiently construct an ad hoc network schedule for each collection round. This kind of a schedule ensures that there are no packet collisions during data transmission, thus leading to an energy consumption reduction above 10% compared to FSA. PMID:25061839

Tuset-Peiro, Pere; Vazquez-Gallego, Francisco; Alonso-Zarate, Jesus; Alonso, Luis; Vilajosana, Xavier

2014-01-01

167

Experimental energy consumption of Frame Slotted ALOHA and Distributed Queuing for data collection scenarios.  

PubMed

Data collection is a key scenario for the Internet of Things because it enables gathering sensor data from distributed nodes that use low-power and long-range wireless technologies to communicate in a single-hop approach. In this kind of scenario, the network is composed of one coordinator that covers a particular area and a large number of nodes, typically hundreds or thousands, that transmit data to the coordinator upon request. Considering this scenario, in this paper we experimentally validate the energy consumption of two Medium Access Control (MAC) protocols, Frame Slotted ALOHA (FSA) and Distributed Queuing (DQ). We model both protocols as a state machine and conduct experiments to measure the average energy consumption in each state and the average number of times that a node has to be in each state in order to transmit a data packet to the coordinator. The results show that FSA is more energy efficient than DQ if the number of nodes is known a priori because the number of slots per frame can be adjusted accordingly. However, in such scenarios the number of nodes cannot be easily anticipated, leading to additional packet collisions and a higher energy consumption due to retransmissions. Contrarily, DQ does not require to know the number of nodes in advance because it is able to efficiently construct an ad hoc network schedule for each collection round. This kind of a schedule ensures that there are no packet collisions during data transmission, thus leading to an energy consumption reduction above 10% compared to FSA. PMID:25061839

Tuset-Peiro, Pere; Vazquez-Gallego, Francisco; Alonso-Zarate, Jesus; Alonso, Luis; Vilajosana, Xavier

2014-01-01

168

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 1 A Virtual Queuing based Algorithm for Delays  

E-print Network

) is presented. Switched-Ethernet with Client/Server protocol is considered for communication. As a result/Server Protocol, Switched Ethernet, Delays Evaluation, Virtual Queue I. INTRODUCTION OWADAYS, the industrial communication protocols were developed for this purpose [1], [2], [3], [4]. The other approach is to firstly

Paris-Sud XI, Université de

169

Optimisation of a honeybee-colony's energetics via social learning based on queuing delays  

NASA Astrophysics Data System (ADS)

Natural selection shaped the foraging-related processes of honeybees in such a way that a colony can react to changing environmental conditions optimally. To investigate this complex dynamic social system, we developed a multi-agent model of the nectar flow inside and outside of a honeybee colony. In a honeybee colony, a temporal caste collects nectar in the environment. These foragers bring their harvest into the colony, where they unload their nectar loads to one or more storer bees. Our model predicts that a cohort of foragers, collecting nectar from a single nectar source, is able to detect changes in quality in other food sources they have never visited, via the nectar processing system of the colony. We identified two novel pathways of forager-to-forager communication. Foragers can gain information about changes in the nectar flow in the environment via changes in their mean waiting time for unloadings and the number of experienced multiple unloadings. This way two distinct groups of foragers that forage on different nectar sources and that never communicate directly can share information via a third cohort of worker bees. We show that this noisy and loosely knotted social network allows a colony to perform collective information processing, so that a single forager has all necessary information available to be able to 'tune' its social behaviour, like dancing or dance-following. This way the net nectar gain of the colony is increased.

Thenius, Ronald; Schmickl, Thomas; Crailsheim, Karl

2008-06-01

170

Stochastic extension of cellular manufacturing systems: a queuing-based analysis  

NASA Astrophysics Data System (ADS)

Clustering parts and machines into part families and machine cells is a major decision in the design of cellular manufacturing systems which is defined as cell formation. This paper presents a non-linear mixed integer programming model to design cellular manufacturing systems which assumes that the arrival rate of parts into cells and machine service rate are stochastic parameters and described by exponential distribution. Uncertain situations may create a queue behind each machine; therefore, we will consider the average waiting time of parts behind each machine in order to have an efficient system. The objective function will minimize summation of idleness cost of machines, sub-contracting cost for exceptional parts, non-utilizing machine cost, and holding cost of parts in the cells. Finally, the linearized model will be solved by the Cplex solver of GAMS, and sensitivity analysis will be performed to illustrate the effectiveness of the parameters.

Fardis, Fatemeh; Zandi, Afagh; Ghezavati, Vahidreza

2013-07-01

171

Input-queued router architectures exploiting cell-based switching fabrics  

E-print Network

. Bianco, P. Giaccone, E. Leonardi, F. Neri Dipartimento di Elettronica, Politecnico di Torino, Corso Duca. Bianco), giaccone@polito.it (P. Giac- cone), leonardi@polito.it (E. Leonardi), neri@polito.it (F. Neri

172

Internal variable theory of plasticity based on dislocation mechanics  

Microsoft Academic Search

Using the internal variable theory of material behavior, a theory of plasticity for polycrystalline solids has been developed. Assuming that the motion of a dislocation flux is the primary cause of plastic flow, the average mobile and immobile dislocation density tensors and the dislocation velocity vector are chosen as the internal variables. By decomposing the deformation gradient into its elastic

Werne

1976-01-01

173

Hopelessness Depression: A Theory-Based Subtype of Depression  

Microsoft Academic Search

We present a revision of the 1978 reformulated theory of helplessness and depression and call it the hopelessness theory of depression. Although the 1978 reformulation has generated a vast amount of empirical work on depression over the past 10 years and recently has been evaluated as a model of depression, we do not think that it presents a clearly articulated

Lyn Y. Abramson; Gerald I. Metalsky; Lauren B. Alloy

1989-01-01

174

Seismic site-response analysis based on random vibration theory  

NASA Astrophysics Data System (ADS)

Local geology influences earthquake ground motions, which is of importance in specifying ground motion levels for seismic design in practice. This effect is quantified through site response analysis, which involves the propagation of seismic waves from bedrock to the free surface through soft layers. Site response analysis provides a set or several sets of scale factors given as function of frequency at the surface. Empirical characterization of site response requires a large data set over a wide range of magnitudes and distances of events. In reality, especially in low to moderate seismicity regions such as the Korean Peninsula, empirical characterization of site response is not plausible. Thus numerical modeling is only a viable tool for site response in those regions. On the other hand, most of conventional modeling procedures include a step for developing some appropriate synthetic waveforms as input motions to be used in site response analyses. The waveforms are typically synthesized by matching the spectrum, such as uniform hazard response spectrum, on basement rock obtained from the seismic hazard analysis. However, these synthetics are fundamentally problematic in spite of spectral matching because it is based on the amplitude spectrum only without phase information. As an alternative, an approach based on random vibration theory (RVT) is introduced without the need of waveform generations. RVT explains that a given response spectrum can be converted into a power spectrum density function. It is performed in the frequency domain and deals with the statistical representation of responses. It requires the transfer function for the velocity profile of a site. The transfer function is initially developed by computations of receiver functions using the reflectivity method assuming no attenuation for the profile under consideration of various incidence angles. Then the transfer function is iteratively updated with varying attenuation until the results are compatible with the observed modulus and damping which can be obtained through the in-situ or lab tests for the profile. After the final iteration on the transfer function, the maximum amplification responses can be obtained with the extreme values of shear stress and strain on the profile. Thus this approach combines the observational results of material properties with the analytical results based on the reflectivity calculations of a layered structure, which makes it able to estimate site response in reducing unphysical manipulations.

Kang, T.; Jang, H.

2013-12-01

175

Toward A Brain-Based Theory of Beauty  

PubMed Central

We wanted to learn whether activity in the same area(s) of the brain correlate with the experience of beauty derived from different sources. 21 subjects took part in a brain-scanning experiment using functional magnetic resonance imaging. Prior to the experiment, they viewed pictures of paintings and listened to musical excerpts, both of which they rated on a scale of 1–9, with 9 being the most beautiful. This allowed us to select three sets of stimuli–beautiful, indifferent and ugly–which subjects viewed and heard in the scanner, and rated at the end of each presentation. The results of a conjunction analysis of brain activity showed that, of the several areas that were active with each type of stimulus, only one cortical area, located in the medial orbito-frontal cortex (mOFC), was active during the experience of musical and visual beauty, with the activity produced by the experience of beauty derived from either source overlapping almost completely within it. The strength of activation in this part of the mOFC was proportional to the strength of the declared intensity of the experience of beauty. We conclude that, as far as activity in the brain is concerned, there is a faculty of beauty that is not dependent on the modality through which it is conveyed but which can be activated by at least two sources–musical and visual–and probably by other sources as well. This has led us to formulate a brain-based theory of beauty. PMID:21755004

Ishizu, Tomohiro; Zeki, Semir

2011-01-01

176

Lyapunov-based Controller using Singular Perturbation Theory: An Application on a mini-UAV  

E-print Network

Lyapunov-based Controller using Singular Perturbation Theory: An Application on a mini-UAV Gerardo Flores and R. Lozano Abstract-- In this paper, a Lyapunov-based control using singular perturbation theory is proposed and applied on dy- namics of a miniature unmanned aerial vehicle (MAV

Paris-Sud XI, Université de

177

Theory based ecology (OUP Book Proposal) Page 1 OUP BOOK PROPOSAL  

E-print Network

Theory based ecology (OUP Book Proposal) Page 1 OUP BOOK PROPOSAL Theory based Ecology a Darwinian change) Loránd Eötvös University, Budapest Rationale More than ever before, ecology is in a challenging ecology on first principles or laws, many others question even the feasibility of a general ecological

Meszéna, Géza

178

Development and Evaluation of a Theory-Based Physical Activity Guidebook for Breast Cancer Survivors  

ERIC Educational Resources Information Center

This study's objective was to develop and evaluate the suitability and appropriateness of a theory-based physical activity (PA) guidebook for breast cancer survivors. Guidebook content was constructed based on the theory of planned behavior (TPB) using salient exercise beliefs identified by breast cancer survivors in previous research. Expert…

Vallance, Jeffrey K.; Courneya, Kerry S.; Taylor, Lorian M.; Plotnikoff, Ronald C.; Mackey, John R.

2008-01-01

179

Structural theory of elastomeric composites based on fiber systems — Invariant description  

Microsoft Academic Search

A three-dimensional theory of elastomeric composites with elastomeric matrices reinforced by systems of fibers is presented. The theory is based on a structural approach in which the matrix and the reinforcement of the composite are considered separately without reduction to a medium having continuously changing characteristics. The approach is based on the idea of a vector field of macroscopic displacements

V. M. Akhundov

1996-01-01

180

Rough set theory based on genetic algorithm in radar equipment damage evaluation method  

Microsoft Academic Search

Damage evaluation is a very important work to effect-based operation. In the paper, a damage evaluation method for radar equipment by using rough set theory is presented, the principle of rough set theory is introduced, a damage evaluation procedure based on reduction at tributes with discrimination matrix is given, and applying the approach, an example is also given to realize

Pan Wei; Xia Huabing; San Ye

2008-01-01

181

Theory-Based Evaluation of a Comprehensive Latino Education Initiative: An Interactive Evaluation Approach  

ERIC Educational Resources Information Center

Latino student access to higher education has received significant national attention in recent years. This article describes a theory-based evaluation approach used with ENLACE of Hillsborough, a 5-year project funded by the W.K. Kellogg Foundation for the purpose of increasing Latino student graduation from high school and college. Theory-based…

Nesman, Teresa M.; Batsche, Catherine; Hernandez, Mario

2007-01-01

182

Theory of mind and rule-based reasoning  

Microsoft Academic Search

The hypothesis is tested that during the preschool period a particular form of reasoning is applied to theory of mind and a set of problems that do not require the understanding of mental states. Three experiments each provided a different piece of support for this hypothesis. Experiment 1 found similar age-related changes between three standard theory-of-mind tasks (false belief, appearance-reality

Tibor Palfai; P. D. Zelazo

1995-01-01

183

A discrete event simulation model for evaluating the performances of an m/g/c/c state dependent queuing system.  

PubMed

M/G/C/C state dependent queuing networks consider service rates as a function of the number of residing entities (e.g., pedestrians, vehicles, and products). However, modeling such dynamic rates is not supported in modern Discrete Simulation System (DES) software. We designed an approach to cater this limitation and used it to construct the M/G/C/C state-dependent queuing model in Arena software. Using the model, we have evaluated and analyzed the impacts of various arrival rates to the throughput, the blocking probability, the expected service time and the expected number of entities in a complex network topology. Results indicated that there is a range of arrival rates for each network where the simulation results fluctuate drastically across replications and this causes the simulation results and analytical results exhibit discrepancies. Detail results that show how tally the simulation results and the analytical results in both abstract and graphical forms and some scientific justifications for these have been documented and discussed. PMID:23560037

Khalid, Ruzelan; Nawawi, Mohd Kamal M; Kawsar, Luthful A; Ghani, Noraida A; Kamil, Anton A; Mustafa, Adli

2013-01-01

184

A Discrete Event Simulation Model for Evaluating the Performances of an M/G/C/C State Dependent Queuing System  

PubMed Central

M/G/C/C state dependent queuing networks consider service rates as a function of the number of residing entities (e.g., pedestrians, vehicles, and products). However, modeling such dynamic rates is not supported in modern Discrete Simulation System (DES) software. We designed an approach to cater this limitation and used it to construct the M/G/C/C state-dependent queuing model in Arena software. Using the model, we have evaluated and analyzed the impacts of various arrival rates to the throughput, the blocking probability, the expected service time and the expected number of entities in a complex network topology. Results indicated that there is a range of arrival rates for each network where the simulation results fluctuate drastically across replications and this causes the simulation results and analytical results exhibit discrepancies. Detail results that show how tally the simulation results and the analytical results in both abstract and graphical forms and some scientific justifications for these have been documented and discussed. PMID:23560037

Khalid, Ruzelan; M. Nawawi, Mohd Kamal; Kawsar, Luthful A.; Ghani, Noraida A.; Kamil, Anton A.; Mustafa, Adli

2013-01-01

185

The three dimensional theory of gravitation based on a temporal scalar field in Riemanian geometry  

E-print Network

A new approach to the model of the universe based on work by Rippl, Romero, Tavakol is presented. We have used the scheme for relating the vacuum (D + 1) dimensional theories to D dimensional theories for setting up a correspondence between vacuum 4-dimensional Einstein theory with 3-dimensional gravity theory with temporal scalar field. These ideas we continued by using the 3-dimensional analog of Jordan, Brans-Dicke theory with temporal scalar field. As the result space and time are treated in completely different ways. For the case of a static spherically symmetric field new vacuum static solutions are found.

S. Kozyrev

2004-06-21

186

Theories  

NSDL National Science Digital Library

This activity is designed to help building student understanding of how scientific theories can change over time. Science theories change in the face of new evidence. However, when new explanatory frameworks, or theories, are proposed to explain scientific phenomena, there is often a lengthy period during which groups of scientists use different competing theories to explain the same phenomena. During the activity, students are introduced to the geocentric and heliocentric models, students compare the two models, and then observe the time it took to change the theory underpinning the heliocentric model. This activity is part of the "Swift: Eyes through Time" collection that is available on the Teacher's Domain website.

187

Queuing for Union Jobs and the Social Return to Schooling. Institute for Research on Poverty Discussion Papers. Report 360-76.  

ERIC Educational Resources Information Center

An analysis of the argument that a market imperfection (wage differentials and queuing caused by unions) raises the marginal social product (MSP) of college education above the average before-tax private wage premium (APP) for college (this discrepancy is called a union-Q-nality) focuses on verifying five hypotheses: (1) Workers with identical…

Bishop, John

188

Cognitive performance modeling based on general systems performance theory  

Microsoft Academic Search

General Systems Performance Theory (GSPT) was initially motivated by problems associated with quantifying different aspects of human performance. It has proved to be invaluable for measurement development and understanding quantitative relationships between human subsystem capacities and performance in complex tasks. It is now desired to bring focus to the application of GSPT to modeling of cognitive system performance. Previous studies

George V. Kondraske

2010-01-01

189

Theory-Based Negotiation Frameworks for Supporting Group Work  

Microsoft Academic Search

In this paper we begin by presenting a taxonomy of impasses in group work situations. The taxonomy includes factors such as goal conflicts and resource limitations. We then present a prescriptive theoretical framework designed to support negotiation during these impasses. We also describe NegotiationLens, a system which embodies the framework by supporting the actions prescribed by the theory. We then

Beth Adelson

1993-01-01

190

PDAs as Lifelong Learning Tools: An Activity Theory Based Analysis  

ERIC Educational Resources Information Center

This paper describes the use of an activity theory (AT) framework to analyze the ways that distance part time learners and mobile workers adapted and appropriated mobile devices for their activities and in turn how their use of these new tools changed the ways that they carried out their learning or their work. It is argued that there are two key…

Waycott, Jenny; Jones, Ann; Scanlon, Eileen

2005-01-01

191

Sensitivity theory for reactor burnup analysis based on depletion perturbation theory  

Microsoft Academic Search

The large computational effort involved in the design and analysis of advanced reactor configurations motivated the development of Depletion Perturbation Theory (DPT) for general fuel cycle analysis. The work here focused on two important advances in the current methods. First, the adjoint equations were developed for using the efficient linear flux approximation to decouple the neutron\\/nuclide field equations. And second,

Wonsik

1989-01-01

192

[Systematic view on medicinal property theory based on self-similarity principle].  

PubMed

Studies on the prescription combination regularity based on medicinal tastes focus on the internal relations between the structure and hierarchy of the prescription combination system. In this paper, with the systematic and scientific self-similarity theory as the core ideology, authors systematically interpreted the self-similarity theory of medicinal properties, defined the self-similarity of prescriptions with identical or similar medicinal properties, and built the systematic view of medicinal property theory based on the prescription combination based on the entity grammar system. As a result, the system was conducive to integrating traditional Chinese medicinal knowledge of syndromes, therapeutic principles, efficacies, medicinal properties and tastes and achieving the automatic design and optimization process from symptoms to prescriptions, and providing scientific and feasible methods and technical systems for the application of the medicinal property theory, with a guiding significance to the technology, methodology and theory of decoction pieces compatibility, component compatibility and compound medicine design. PMID:25276944

Yuan, Bin; Zhang, Yan-Ling; Wang, Yun; Qiao, Yan-Jiang

2014-07-01

193

Strategies that Students Use to Trace Code: An Analysis Based in Grounded Theory  

E-print Network

Theory. Keywords Grounded Theory, Problem Solving, Strategies, Multiple Choice Questions (MCQs), Multi multiple choice questions (MCQs) featuring arrays and loops [15]. The working group, itself a follow used in answering code-based MCQs. This is an exploratory study, utilizing the set of 37 transcripts

Simon, Beth

194

A Web-based Resource for Design Theory 1 Description of the project  

E-print Network

A Web-based Resource for Design Theory 1 Description of the project We believe it is important and timely to create a comprensive world-wide-web resource for Design Theory, covering combinatorial this software to publish a database of designs on the world-wide-web, as well as publishing theoretical advances

Cameron, Peter

195

The TEACH Method: An Interactive Approach for Teaching the Needs-Based Theories Of Motivation  

ERIC Educational Resources Information Center

This paper describes an interactive approach for explaining and teaching the Needs-Based Theories of Motivation. The acronym TEACH stands for Theory, Example, Application, Collaboration, and Having Discussion. This method can help business students to better understand and distinguish the implications of Maslow's Hierarchy of Needs,…

Moorer, Cleamon, Jr.

2014-01-01

196

Control Theory Based Airfoil Design for Potential Flow and a Finite Volume Discretization u  

Microsoft Academic Search

This paper describes the implementation of opti- mization techniques based on control theory for air- foil design. In previous studies (6, 71 it was shown that control theory could be used to devise an ef- fective optimization procedure for two-dimensional profiles in which the shape is determined by a con- formal transformation from a unit circle, and the control is

J. Reuther; A. Jamesont

197

Local control theory in trajectory-based nonadiabatic dynamics  

SciTech Connect

In this paper, we extend the implementation of nonadiabatic molecular dynamics within the framework of time-dependent density-functional theory in an external field described in Tavernelli et al.[Phys. Rev. A 81, 052508 (2010)] by calculating on-the-fly pulses to control the population transfer between electronic states using local control theory. Using Tully's fewest switches trajectory surface hopping method, we perform MD to control the photoexcitation of LiF and compare the results to quantum dynamics (QD) calculations performed within the Heidelberg multiconfiguration time-dependent Hartree package. We show that this approach is able to calculate a field that controls the population transfer between electronic states. The calculated field is in good agreement with that obtained from QD, and the differences that arise are discussed in detail.

Curchod, Basile F. E.; Penfold, Thomas J.; Rothlisberger, Ursula; Tavernelli, Ivano [Laboratory of Computational Chemistry and Biochemistry, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Laboratory of Computational Chemistry and Biochemistry, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne, Switzerland, (Switzerland); Ecole Polytechnique Federale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC, FSB-BSP, CH-1015 Lausanne, Switzerland, (Switzerland); SwissFEL, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); Laboratory of Computational Chemistry and Biochemistry, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland)

2011-10-15

198

A labor market based theory of regional economic development  

Microsoft Academic Search

.   The Borts and Stein (1964) theory of regional economic growth and development has been widely accepted and discussed in regional\\u000a economic development literature. Given their assumption that labor demand conditions are invariant between regions and that\\u000a the labor demand is highly wage elastic, they conclude that regional growth is primarily supply driven and differences in\\u000a growth among regions arise

Vijay K. Mathur; Frank M. Song

2000-01-01

199

Circuit theory and model-based inference for landscape connectivity  

USGS Publications Warehouse

Circuit theory has seen extensive recent use in the field of ecology, where it is often applied to study functional connectivity. The landscape is typically represented by a network of nodes and resistors, with the resistance between nodes a function of landscape characteristics. The effective distance between two locations on a landscape is represented by the resistance distance between the nodes in the network. Circuit theory has been applied to many other scientific fields for exploratory analyses, but parametric models for circuits are not common in the scientific literature. To model circuits explicitly, we demonstrate a link between Gaussian Markov random fields and contemporary circuit theory using a covariance structure that induces the necessary resistance distance. This provides a parametric model for second-order observations from such a system. In the landscape ecology setting, the proposed model provides a simple framework where inference can be obtained for effects that landscape features have on functional connectivity. We illustrate the approach through a landscape genetics study linking gene flow in alpine chamois (Rupicapra rupicapra) to the underlying landscape.

Hanks, Ephraim M.; Hooten, Mevin B.

2013-01-01

200

Gravitational Cherenkov losses in theories based on modified Newtonian dynamics.  

PubMed

Survival of high-energy cosmic rays (HECRs) against gravitational Cherenkov losses is shown not to cast strong constraints on modified Newtonian dynamics (MOND) theories that are compatible with general relativity (GR): theories that coincide with GR for accelerations ?a(0) (a(0) is the MOND constant). The energy-loss rate, E, is many orders smaller than those derived in the literature for theories with no extra scale. Modification to GR, which underlies E, enters only beyond the MOND radius of the particle: r(M)=(Gp/ca(0))(1/2). The spectral cutoff, entering E quadratically, is thus r(M)(-1), not k(dB)=p/?. Thus, E is smaller than published rates, which use k(dB), by a factor ?(r(M)k(dB))(2)?10(39)(cp/3×10(11)??Gev)(3). Losses are important only beyond D(loss)?q?(M), where q is a dimensionless factor, and ?(M)=c(2)/a(0) is the MOND length, which is ?2? times the Hubble distance. PMID:21469855

Milgrom, Mordehai

2011-03-18

201

Enhancing Quality of Practice Through Theory of Change-Based Evaluation: Science or Practice?  

Microsoft Academic Search

This paper describes the evaluation component of Partnerships for Success (PfS), a comprehensive community effort designed to address youth development issues. The evaluation component is referred to as “theory of change-based evaluation.” The author considers the implications of applying community practice tools such as theory of change-based evaluation to the current conceptualization of community science. More specifically, the author argues

David A. Julian

2005-01-01

202

Regime recognition of two-phase pipe flow based on DS evidence theory  

Microsoft Academic Search

Flow regime recognition plays a fundamental role in two-phase flow measurement. Based on the characters information provided by dual-plane electrical resistance tomography (ERT) system, a method of flow regime recognition in horizontal pipe based on D-S evidence theory is brought forward. A particular way to acquire the basic probability assignment function in D-S evidence theory is introduced. Every single plane

Fu-Sheng Zhang; Feng Dong; Chao Tan; Dong Liu

2008-01-01

203

A band theory for magnetic cuprates based on self-interaction free local density approximation  

Microsoft Academic Search

The pseudo-SIC approach is based on an approximate form of self-interaction corrected (SIC) Kohn-Sham Equations. We overview the functionalities of this method applied to cuprates, which are prototypes of difficult materials for standard local-spin density functional theories such as LSDA (or even GGA). Indeed, theories based on local exchange-correlation potentials fail to predict the correct spin-polarized ground-state solution expected for

Vincenzo Fiorentini; Alessio Filippetti

2006-01-01

204

Benchmarks for electronically excited states: Time-dependent density functional theory and density functional theory based multireference configuration interaction  

Microsoft Academic Search

Time-dependent density functional theory (TD-DFT) and DFT-based multireference configuration interaction (DFT\\/MRCI) calculations are reported for a recently proposed benchmark set of 28 medium-sized organic molecules. Vertical excitation energies, oscillator strengths, and excited-state dipole moments are computed using the same geometries (MP2\\/6-31G*) and basis set (TZVP) as in our previous ab initio benchmark study on electronically excited states. The results from

Mario R. Silva-Junior; Marko Schreiber; Stephan P. A. Sauer; Walter Thiel

2008-01-01

205

Benchmarks for electronically excited states: Time-dependent density functional theory and density functional theory based multireference configuration interaction  

Microsoft Academic Search

Time-dependent density functional theory (TD-DFT) and DFT-based multireference configuration interaction (DFT\\/MRCI) calculations are reported for a recently proposed benchmark set of 28 medium-sized organic molecules. Vertical excitation energies, oscillator strengths, and excited-state dipole moments are computed using the same geometries (MP2\\/6-31G*) and basis set (TZVP) as in our previous ab initio benchmark study on electronically excited states. The results from

Mario R. Silva-Junior; Marko Schreiber; Stephan P. A. Sauer; Walter Thiel

2008-01-01

206

Invited commentary: agent-based models for causal inference-reweighting data and theory in epidemiology.  

PubMed

The relative weights of empirical facts (data) and assumptions (theory) in causal inference vary across disciplines. Typically, disciplines that ask more complex questions tend to better tolerate a greater role of theory and modeling in causal inference. As epidemiologists move toward increasingly complex questions, Marshall and Galea () support a reweighting of data and theory in epidemiologic research via the use of agent-based modeling. The parametric g-formula can be viewed as an intermediate step between traditional epidemiologic methods and agent-based modeling and therefore is a method that can ease the transition toward epidemiologic methods that rely heavily on modeling. PMID:25480820

Hernán, Miguel A

2015-01-15

207

Interlaminar Stresses by Refined Beam Theories and the Sinc Method Based on Interpolation of Highest Derivative  

NASA Technical Reports Server (NTRS)

Computation of interlaminar stresses from the higher-order shear and normal deformable beam theory and the refined zigzag theory was performed using the Sinc method based on Interpolation of Highest Derivative. The Sinc method based on Interpolation of Highest Derivative was proposed as an efficient method for determining through-the-thickness variations of interlaminar stresses from one- and two-dimensional analysis by integration of the equilibrium equations of three-dimensional elasticity. However, the use of traditional equivalent single layer theories often results in inaccuracies near the boundaries and when the lamina have extremely large differences in material properties. Interlaminar stresses in symmetric cross-ply laminated beams were obtained by solving the higher-order shear and normal deformable beam theory and the refined zigzag theory with the Sinc method based on Interpolation of Highest Derivative. Interlaminar stresses and bending stresses from the present approach were compared with a detailed finite element solution obtained by ABAQUS/Standard. The results illustrate the ease with which the Sinc method based on Interpolation of Highest Derivative can be used to obtain the through-the-thickness distributions of interlaminar stresses from the beam theories. Moreover, the results indicate that the refined zigzag theory is a substantial improvement over the Timoshenko beam theory due to the piecewise continuous displacement field which more accurately represents interlaminar discontinuities in the strain field. The higher-order shear and normal deformable beam theory more accurately captures the interlaminar stresses at the ends of the beam because it allows transverse normal strain. However, the continuous nature of the displacement field requires a large number of monomial terms before the interlaminar stresses are computed as accurately as the refined zigzag theory.

Slemp, Wesley C. H.; Kapania, Rakesh K.; Tessler, Alexander

2010-01-01

208

Theory and Applications of the Double-Base Number System  

Microsoft Academic Search

In this paper we analyze some of the main properties of a double base number system, using bases 2 and 3; in particular we emphasize the sparseness of the representation. A simple geometric interpretation allows an efficient implementation of the basic arithmetic operations and we introduce an index calculus for logarithmic-like arithmetic with consid- erable hardware reductions in look-up table

Vassil S. Dimitrov; Graham A. Jullien; William C. Miller

1999-01-01

209

Theory and applications for a double-base number system  

Microsoft Academic Search

In this paper we present a rigorous theoretical analysis of the main properties of a double base number system, using bases 2 and 3; in particular we emphasize the sparseness of the representation. A simple geometric interpretation allows an efficient implementation of the basic arithmetic operations and we introduce an index calculus for loga- rithmic-like arithmetic with considerable hardware reduc-

Vassil S. Dimitrov; Graham A. Jullien; William C. Miller

1997-01-01

210

The fuzzy clustering analysis based on AFS theory.  

PubMed

In the framework of axiomatic fuzzy sets theory, we first study how to impersonally and automatically determine the membership functions for fuzzy sets according to original data and facts, and a new algorithmic framework of determining membership functions and their logic operations for fuzzy sets has been proposed. Then, we apply the proposed algorithmic framework to give a new clustering algorithm and show that the algorithm is feasible. A number of illustrative examples show that this approach offers a far more flexible and effective means for the intelligent systems in real-world applications. Compared with popular fuzzy clustering algorithms, such as c-means fuzzy algorithm and k-nearest-neighbor fuzzy algorithm, the new fuzzy clustering algorithm is more simple and understandable, the data types of the attributes can be various data types or subpreference relations, even descriptions of human intuition, and the distance function and the class number need not be given beforehand. PMID:16240775

Liu, Xiaodong; Wang, Wei; Chai, Tianyou

2005-10-01

211

Determination of the Sediment Carrying Capacity Based on Perturbed Theory  

PubMed Central

According to the previous studies of sediment carrying capacity, a new method of sediment carrying capacity on perturbed theory was proposed. By taking into account the average water depth, average flow velocity, settling velocity, and other influencing factors and introducing the median grain size as one main influencing factor in deriving the new formula, we established a new sediment carrying capacity formula. The coefficients were determined by the principle of dimensional analysis, multiple linear regression method, and the least square method. After that, the new formula was verified through measuring data of natural rivers and flume tests and comparing the verified results calculated by Cao Formula, Zhang Formula, Li Formula, Engelung-Hansen Formula, Ackers-White Formula, and Yang Formula. According to the compared results, it can be seen that the new method is of high accuracy. It could be a useful reference for the determination of sediment carrying capacity. PMID:25136652

Ni, Zhi-hui; Zeng, Qiang; Li-chun, Wu

2014-01-01

212

Feedback Control-Based QoS Guarantees in Web Application Servers  

Microsoft Academic Search

This paper considers providing two types of QoS guarantees, proportional delay differentiation (PDD) and absolute delay guarantee (ADG), in the database connection pool (DBCP) for Web application servers using the classical feedback control theory. PDD aims to maintain the average queuing delay ratio between different classes of requests according to pre-specified parameters, and ADG aims to ensure the average queueing

Wenping Pan; Dejun Mu; Hangxing Wu; Lei Yao

2008-01-01

213

Learning Trajectory Based Instruction: Toward a Theory of Teaching  

ERIC Educational Resources Information Center

In this article, we propose a theoretical connection between research on learning and research on teaching through recent research on students' learning trajectories (LTs). We define learning trajectory based instruction (LTBI) as teaching that uses students' LTs as the basis for instructional decisions. We use mathematics as the context for our…

Sztajn, Paola; Confrey, Jere; Wilson, P. Holt; Edgington, Cynthia

2012-01-01

214

Integrated Models of School-Based Prevention: Logic and Theory  

ERIC Educational Resources Information Center

School-based prevention programs can positively impact a range of social, emotional, and behavioral outcomes. Yet the current climate of accountability pressures schools to restrict activities that are not perceived as part of the core curriculum. Building on models from public health and prevention science, we describe an integrated approach to…

Domitrovich, Celene E.; Bradshaw, Catherine P.; Greenberg, Mark T.; Embry, Dennis; Poduska, Jeanne M.; Ialongo, Nicholas S.

2010-01-01

215

Content Based Medical Image Retrieval: Theory, Gaps and Future Directions  

Microsoft Academic Search

Content-based image retrieval (CBIR) has been one the most vivid research areas in the field of computer vision, and substantial progress have been made over the last years. CBIR has a potential for making a strong impact in diagnostics, research, and education. CBIR is a promising technology to enrich the core functionality of picture archiving and communication systems (PACS). Even

Preeti Aggarwal; H. K. Sardana; Gagandeep Jindal

2009-01-01

216

Cryptography based on operator theory (I): quantum no-key protocols  

E-print Network

We study cryptography based on operator theory, and propose quantum no-key (QNK) protocols from the perspective of operator theory, then present a framework of QNK protocols. The framework is expressed in two forms: trace-preserving quantum operators and natural presentations. Then we defined the information-theoretical security of QNK protocols and the security of identification keys. Two kinds of QNK protocols are also proposed. The first scheme is constructed based on unitary transformation, and the other is constructed based on two multiplicative commutative sets.

Li Yang; Min Liang

2012-10-31

217

arXiv:quant-ph/0702167v116Feb2007 Quantum Game Theory Based on the Schmidt Decomposition  

E-print Network

arXiv:quant-ph/0702167v116Feb2007 Quantum Game Theory Based on the Schmidt Decomposition: Can formulation of quantum game theory based on the Schmidt de- composition, which has the merit game theory. The phase structure of the equilibria is determined for all values of entanglement

Tsutsui, Izumi

218

High Performance Adaptive ModelBased Force Control of Robot Arms: Theory and Practice  

E-print Network

High Performance Adaptive Model­Based Force Control of Robot Arms: Theory and Practice Louis L­based adaptive force control algorithms for simultaneous posi­ tion and force trajectory tracking of a robot arm and Mechanical Research Laboratory Research and Development Center, Toshiba Corporation 4­1 Ukishima

Whitcomb, Louis L.

219

A Consumption Base Theory of Development: An Application to the Rural Cultural Economy  

Microsoft Academic Search

Export base theory, which posits that overall regional growth is a function of external sales of locally produced goods and services, dominates economic development practice. But the consumption base can also serve as a growth driver, especially in small towns and rural areas. Local investments may induce residents to divert expenditures into local purchases, attract new and footloose residents and

Ann Markusen

2007-01-01

220

Applying Item Response Theory Methods to Design a Learning Progression-Based Science Assessment  

ERIC Educational Resources Information Center

Learning progressions are used to describe how students' understanding of a topic progresses over time and to classify the progress of students into steps or levels. This study applies Item Response Theory (IRT) based methods to investigate how to design learning progression-based science assessments. The research questions of this study are: (1)…

Chen, Jing

2012-01-01

221

Development of a Brief Measure of Career Development Influences Based on the Systems Theory Framework  

ERIC Educational Resources Information Center

This paper documents the initial development and validation of a brief quantitative measure of career development influences based on the Systems Theory Framework (STF) of career development (McMahon & Patton, 1995; Patton & McMahon, 1997, 1999, 2006). Initial exploratory factor analyses of pilot study data revealed a six-factor structure based on…

Bridgstock, Ruth

2007-01-01

222

Lung Sound Recognition Using Model-Theory Based Feature Selection and Fusion  

E-print Network

Lung Sound Recognition Using Model-Theory Based Feature Selection and Fusion Zbigniew Korona recognition methodology to the recognition of lung sounds. Two main features of this method- ology are features using an entropy-based criterion. To evaluate the methodology we used both normal lung sounds

Kokar, Mieczyslaw M.

223

A Comparison of Measurement Equivalence Methods Based on Confirmatory Factor Analysis and Item Response Theory.  

ERIC Educational Resources Information Center

Current interest in the assessment of measurement equivalence emphasizes two methods of analysis, linear, and nonlinear procedures. This study simulated data using the graded response model to examine the performance of linear (confirmatory factor analysis or CFA) and nonlinear (item-response-theory-based differential item function or IRT-Based…

Flowers, Claudia P.; Raju, Nambury S.; Oshima, T. C.

224

Solar Activity Predictions Based on Solar Dynamo Theories  

NASA Astrophysics Data System (ADS)

We review solar activity prediction methods, statistical, precursor, and recently the Dikpati and the Choudhury groups’ use of numerical flux-dynamo methods. Outlining various methods, we compare precursor techniques with weather forecasting. Precursors involve events prior to a solar cycle. First started by the Russian geomagnetician Ohl, and then Brown and Williams; the Earth's field variations near solar minimum was used to predict the next solar cycle, with a correlation of 0.95. From the standpoint of causality, as well as energetically, these relationships were somewhat bizarre. One index used was the "number of anomalous quiet days,” an antiquated, subjective index. Scientific progress cannot be made without some suspension of disbelief; otherwise old paradigms become tautologies. So, with youthful naïveté, Svalgaard, Scherrer, Wilcox and I viewed the results through rose-colored glasses and pressed ahead searching for understanding. We eventually fumbled our way to explaining how the Sun could broadcast the state of its internal dynamo to Earth. We noted one key aspect of the Babcock-Leighton Flux Dynamo theory: the polar field at the end of a cycle serves as a seed for the next cycle's growth. Near solar minimum this field usually bathes the Earth, and thereby affects geomagnetic indices then. We found support by examining 8 previous solar cycles. Using our solar precursor technique we successfully predicted cycles 21, 22 and 23 using WSO and MWSO data. Pesnell and I improved the method using a SODA (SOlar Dynamo Amplitude) Index. In 2005, nearing cycle 23's minimum, Svalgaard and I noted an unusually weak polar field, and forecasted a small cycle 24. We discuss future advances: the flux-dynamo methods. As far as future solar activity, I shall let the Sun decide; it will do so anyhow.

Schatten, Kenneth H.

2009-05-01

225

Multiple object image segmentation algorithm based on wavelet theory  

NASA Astrophysics Data System (ADS)

The colony characteristics are used for evaluating the quality of water and food. Auto-detecting colony in an image is a hard task. This paper proposes a new multi-scale segmentation technique based on wavelet decompositions and watersheds. Firstly, we dispose the tiny colonies by using a wavelet domain median filter. Secondly, wavelet transform is used to create multi-resolution images. Then watershed segmentation algorithm is applied to segment the lowestresolution image and obtain the initial watershed segmentation result. Finally, we do segmentation on the high-resolution image based on the low-resolution image. Experiments results show that the colony images can be well segmented by using the new algorithm.

Wang, W.; Wang, Z.

2009-06-01

226

Theory of regular M-band wavelet bases  

Microsoft Academic Search

Orthonormal M-band wavelet bases have been constructed and applied by several authors. This paper makes three main contributions. First, it generalizes the minimal length K-regular 2-band wavelets of Daubechies (1988) to the M-band case by deriving explicit formulas for K-regular M-band scaling filters. Several equivalent characterizations of K-regularity are given and their significance explained. Second, two approaches to the construction

Peter Steffen; Peter N. Heller; Ramesh A. Gopinath; C. Sidney Burms

1993-01-01

227

Research on e-learning services based on ontology theory  

NASA Astrophysics Data System (ADS)

E-learning services can realize network learning resource sharing and interoperability, but they can't realize automatic discovery, implementation and integration of services. This paper proposes a framework of e-learning services based on ontology, the ontology technology is applied to the publication and discovery process of e-learning services, in order to realize accurate and efficient retrieval and utilization of e-learning services.

Liu, Rui

2013-07-01

228

Generalized projection based M-estimator: Theory and applications  

Microsoft Academic Search

We introduce a robust estimator called generalized projection based M-estimator (gpbM) which does not require the user to specify any scale parameters. For multiple inlier structures, with different noise covariances, the estimator iteratively determines one inlier structure at a time. Unlike pbM, where the scale of the inlier noise is estimated simultaneously with the model parameters, gpbM has three distinct

Sushil Mittal; Saket Anand; Peter Meer

2011-01-01

229

A web exercise in evidence-based medicine using cognitive theory  

Microsoft Academic Search

Our aim was to improve clinical reasoning skills by applying an established theory of memory, cognition, and decision making\\u000a (fuzzy-trace theory) to instruction in evidence-based medicine. Decision-making tasks concerning chest pain evaluation in\\u000a women were developed for medical students and internal medicine residents. The fuzzy-trace theory guided the selection of\\u000a online sources (e.g., target articles) and decision-making tasks. Twelve students

Farrell J. Lloyd; Valerie F. Reyna

2001-01-01

230

Microstructure-dependent piezoelectric beam based on modified strain gradient theory  

NASA Astrophysics Data System (ADS)

A microstructure-dependent piezoelectric beam model was developed using a variational formulation, which is based on the modified strain gradient theory and the Timoshenko beam theory. The new model contains three material length scale parameters and can capture the size effect, unlike the classical beam theory. To illustrate the new piezoelectric beam model, the static bending and the free vibration problems of a simply supported beam are numerically solved. These results may be useful in the analysis and design of smart structures that are constructed from piezoelectric materials.

Li, Y. S.; Feng, W. J.

2014-09-01

231

Kinematics and dynamics of deployable structures with scissor-like-elements based on screw theory  

NASA Astrophysics Data System (ADS)

Because the deployable structures are complex multi-loop structures and methods of derivation which lead to simpler kinematic and dynamic equations of motion are the subject of research effort, the kinematics and dynamics of deployable structures with scissor-like-elements are presented based on screw theory and the principle of virtual work respectively. According to the geometric characteristic of the deployable structure examined, the basic structural unit is the common scissor-like-element(SLE). First, a spatial deployable structure, comprised of three SLEs, is defined, and the constraint topology graph is obtained. The equations of motion are then derived based on screw theory and the geometric nature of scissor elements. Second, to develop the dynamics of the whole deployable structure, the local coordinates of the SLEs and the Jacobian matrices of the center of mass of the deployable structure are derived. Then, the equivalent forces are assembled and added in the equations of motion based on the principle of virtual work. Finally, dynamic behavior and unfolded process of the deployable structure are simulated. Its figures of velocity, acceleration and input torque are obtained based on the simulate results. Screw theory not only provides an efficient solution formulation and theory guidance for complex multi-closed loop deployable structures, but also extends the method to solve dynamics of deployable structures. As an efficient mathematical tool, the simper equations of motion are derived based on screw theory.

Sun, Yuantao; Wang, Sanmin; Mills, James K.; Zhi, Changjian

2014-07-01

232

Community-based Practices: Integrating Dissemination Theory with Critical Theories of Power and Justice  

Microsoft Academic Search

This paper critically reviews two diverse intellectual traditions concerned with community-based interventions: the literature\\u000a on dissemination of community interventions and the critical psychology literature that is concerned with systemic power inequalities\\u000a and structural injustice. The dominant dissemination-of-innovations framework has shifted toward an emphasis on community,\\u000a yet it does not generally take into account issues of power and inequality within the

Jen Sandler

2007-01-01

233

Venture Capital Investment Base on Grey Relational Theory  

NASA Astrophysics Data System (ADS)

This paper builds a venture capital investment projects selection evaluation model base on risk-weight investment return using grey relational analysis. The risk and return in venture capital investment projects selection process is analyses. These risk and return mainly constricted in management ability, operation ability, market ability, exit obtain and investment cost. The 18 sub-indicators are the impact factors contributed to these five evaluation aspects. Grey relation analysis is use to evaluate the venture capital investment selection. Get the optimal solution of risk-weight double objective investment selection evaluation model. An example is used to demonstrate the model in this paper.

Zhang, Xubo

234

Tire grip identification based on strain information: Theory and simulations  

NASA Astrophysics Data System (ADS)

A novel technique for the identification of the tire-road grip conditions is presented. This is based on the use of strain information inside the tire, from which relevant characteristics of the tire-road contact can be extracted also through a factor named area slip ratio. This process forms the basis of a technology for grip identification that requires a new model of the tire dynamics. The model permits to determine closed form analytical relationships between the measured strain and the area slip ratio. On this basis, a procedure that can extract the contact kinematic parameter from the time history of the internal strain of the rolling tire is presented. Numerical simulations offer the chance to validate the identification algorithm.

Carcaterra, A.; Roveri, N.

2013-12-01

235

Improvement of Priority Computation in Exemplar-Based Image Inpainting Base on DS Evidence Theory and TV Model  

Microsoft Academic Search

As the quality of the repaired image is significantly influenced by the filling order of the boundary pixels, it tries to compute priority to improve the exemplar-based algorithm by means of fusion the D-S evidence theory and TV model, according to analyzing the pixel's surrounding image features. The experimental results of the algorithm is given and proved to be effective

Wang Shu-wen; Xu Yong-sheng

2009-01-01

236

Theory in Practice instead of Theory versus Practice – Curricular design for Task-based Learning within a competency oriented Curriculum  

PubMed Central

Objective: Already during their studies, medical students should intensively train their clinical thinking and practice skills, enhancing their clinical expertise in theoretical and practical terms. Methods: Based on the findings of educational research, a new curriculum for clinical training was developed at Duesseldorf University, focussing on workplace-based teaching, learning and assessment. Results: For students in their 3rd, 4th and 5th year of study, our curriculum is based on learning with patient complaint items in regard to multidisciplinary areas of outpatient and inpatient care. For this educational format, 123 complaint items were defined and their compatibility with diseases from various disciplines was tested. Based on the complaint of a specific case, students locate the underlying disease pattern, the differential diagnostic and therapeutical procedures and thereby deepen the required knowledge in the basic subjects. Study books have been created by the clinical departments to support this process. Learning is integrated in competence-oriented and workplace-based learning and assessment, offering a close-knit contact between students and doctors. Conclusion: The concept allows the integration of theory into practice and the integration of knowledge from the basic, clinical-theoretical and clinical subjects into clinical thinking and action.

Rotthoff, Thomas; Schneider, Matthias; Ritz-Timme, Stefanie; Windolf, Joachim

2015-01-01

237

Theory of normal and superconducting properties of fullerene-based solids  

SciTech Connect

Recent experiments on the normal-state and superconducting properties of fullerene-based solids are used to constrain the proposal theories of the electronic nature of these materials. In general, models of superconductivity based on electron pairing induced by phonons are consistent with electronic band theory. The latter experiments also yield estimates of the parameters characterizing these type H superconductors. It is argued that, at this point, a ``standard model`` of phonons interacting with itinerant electrons may be a good first approximation for explaining the properties of the metallic fullerenes.

Cohen, M.L.

1992-10-01

238

Theory of normal and superconducting properties of fullerene-based solids  

SciTech Connect

Recent experiments on the normal-state and superconducting properties of fullerene-based solids are used to constrain the proposal theories of the electronic nature of these materials. In general, models of superconductivity based on electron pairing induced by phonons are consistent with electronic band theory. The latter experiments also yield estimates of the parameters characterizing these type H superconductors. It is argued that, at this point, a standard model'' of phonons interacting with itinerant electrons may be a good first approximation for explaining the properties of the metallic fullerenes.

Cohen, M.L.

1992-10-01

239

[Modeling continuous scaling of NDVI based on fractal theory].  

PubMed

Scale effect was one of the very important scientific problems of remote sensing. The scale effect of quantitative remote sensing can be used to study retrievals' relationship between different-resolution images, and its research became an effective way to confront the challenges, such as validation of quantitative remote sensing products et al. Traditional up-scaling methods cannot describe scale changing features of retrievals on entire series of scales; meanwhile, they are faced with serious parameters correction issues because of imaging parameters' variation of different sensors, such as geometrical correction, spectral correction, etc. Utilizing single sensor image, fractal methodology was utilized to solve these problems. Taking NDVI (computed by land surface radiance) as example and based on Enhanced Thematic Mapper Plus (ETM+) image, a scheme was proposed to model continuous scaling of retrievals. Then the experimental results indicated that: (a) For NDVI, scale effect existed, and it could be described by fractal model of continuous scaling; (2) The fractal method was suitable for validation of NDVI. All of these proved that fractal was an effective methodology of studying scaling of quantitative remote sensing. PMID:24059189

Luan, Hai-Jun; Tian, Qing-Jiu; Yu, Tao; Hu, Xin-Li; Huang, Yan; Du, Ling-Tong; Zhao, Li-Min; Wei, Xi; Han, Jie; Zhang, Zhou-Wei; Li, Shao-Peng

2013-07-01

240

Research on Prediction Model of Time Series Based on Fuzzy Theory and Genetic Algorithm  

NASA Astrophysics Data System (ADS)

Fuzzy theory is one of the newly adduced self-adaptive strategies,which is applied to dynamically adjust the parameters o genetic algorithms for the purpose of enhancing the performance.In this paper, the financial time series analysis and forecasting as the main case study to the theory of soft computing technology framework that focuses on the fuzzy theory and genetic algorithms(FGA) as a method of integration. the financial time series forecasting model based on fuzzy theory and genetic algorithms was built. the ShangZheng index cards as an example. The experimental results show that FGA perform s much better than BP neural network, not only in the precision, but also in the searching speed.The hybrid algorithm has a strong feasibility and superiority.

Xiao-qin, Wu

241

Comments on observables for identity-based marginal solutions in Berkovits' superstring field theory  

NASA Astrophysics Data System (ADS)

We construct an analytic solution for tachyon condensation around identity-based marginal solutions in Berkovits' WZW-like open superstring field theory. Using this, which is a kind of wedge-based solution, the gauge invariant overlaps for the identity-based marginal solutions can be calculated analytically. This is a straightforward extension of a method in bosonic string field theory, which has been elaborated by the authors, to superstring. We also comment on a gauge equivalence relation between the tachyon vacuum solution and its marginally deformed one. From this viewpoint, we can find the vacuum energy of the identity-based marginal solutions to be zero, which agrees with the previous result as a consequence of ? zero mode counting.

Kishimoto, Isao; Takahashi, Tomohiko

2014-07-01

242

Towards a Packet-based Control Theory -Part II: Rate Issues Ling Shi and Richard M. Murray  

E-print Network

Towards a Packet-based Control Theory - Part II: Rate Issues Ling Shi and Richard M. Murray networked control structure. For details of classical information theory, readers are referred to [14], [4], [6] and for details of classical control theory, readers are referred to [10], [17], [3]. Networked

Murray, Richard M.

243

Portuguese Public University Student Satisfaction: A Stakeholder Theory-Based Approach  

ERIC Educational Resources Information Center

In accordance with the importance of the student stakeholder to universities, the objective of this research project was to evaluate student satisfaction at Portuguese public universities as regards their self-expressed core expectations. The research was based both on stakeholder theory itself and on previous studies of university stakeholders.…

Mainardes, Emerson; Alves, Helena; Raposo, Mario

2013-01-01

244

A Practice-Based Theory of Professional Education: Teach For America's Professional Development Model  

ERIC Educational Resources Information Center

In 1999, Ball and Cohen proposed a practice-based theory of professional education, which would end inadequate professional development efforts with a more comprehensive approach. Their work has been referenced over the past decade, yet there have been limited attempts to actualize their ideals and research their implications. In this article, I…

Gabriel, Rachael

2011-01-01

245

Explaining Virtual Community User Knowledge Sharing Based on Social Cognitive Theory  

Microsoft Academic Search

User active knowledge contribution is crucial for virtual community development. Social cognitive theory (SCT) argues that individual behavior is influenced by both environment and personal cognition. Based on SCT, this paper analyzed the effect of trust as an environmental factor and self-efficacy, community-related outcome expectation and personal outcome expectation as personal cognitive factors on user knowledge sharing. We collected 250

Tao Zhou

2008-01-01

246

An Improved Motivation Model for People Behaviors Change in Virtual Communities Based on Social Cognitive Theory  

Microsoft Academic Search

In virtual communities, people are easier to transform their potential behavioral tendencies into actual behavior. To explain this phenomeno, we analyze the self-efficacy of agents using social cognitive theory (SCT). Based on the analysis, we propose structural capital as a new construment and offer an improved motivation model for people behaviors change in virtual communities. The improved model can suit

Siwei Dong; Xiaoping Yang

2009-01-01

247

Assessing Instructional Reform in San Diego: A Theory-Based Approach  

ERIC Educational Resources Information Center

This article provides an overview of the approach, methodology, and key findings from a theory-based evaluation of the district-led instructional reform effort in San Diego City Schools, under the leadership of Alan Bersin and Anthony Alvarado, that began in 1998. Beginning with an analysis of the achievement trends in San Diego relative to other…

O'Day, Jennifer; Quick, Heather E.

2009-01-01

248

A discourse model for interaction design based on theories of human communication  

Microsoft Academic Search

Most current models of interaction design build on scenarios and task analysis. We think that interaction design should be more along the lines of communication between humans. With this motivation, our paper presents a new approach to modeling interaction design based on insights from theories of human communication. From such discourse models, we aim for automated generation of user interfaces.

Jürgen Falb; Hermann Kaindl; Helmut Horacek; Cristian Bogdan; Roman Popp; Edin Arnautovic

2006-01-01

249

Schema Theory-Based Pre-Reading Tasks: A Neglected Essential in the ESL Reading Class.  

ERIC Educational Resources Information Center

Describes a study in which an English-as-a-Second-Language reading instructor worked with a group of intermediate students that focused on schema theory-based pre-reading activities. Highlights the students' impressions on the strategies covered during the term. (Author/VWL)

Ajideh, Parviz

2003-01-01

250

Coping with Drought: Towards a Multilevel Understanding Based on Conservation of Resources Theory  

Microsoft Academic Search

There is substantial research on psychological consequences of disasters. However, most disaster studies to date have focused on acute disasters, ignoring slow-onset chronic hazards, such as extreme climate conditions and pollution. Using a multilevel theoretical framework based on the Conservation of Resources theory (S. E. Hobfoll, The Ecology of Stress, Hemisphere, New York, 1988; Stress, Culture, and Community: The Psychology

Gh. H. Zamani; Marjan J. Gorgievski-Duijvesteijn; Kiumars Zarafshani

2006-01-01

251

James Clerk Maxwell and the Kinetic Theory of Gases: A Review Based on Recent Historical Studies  

Microsoft Academic Search

Maxwell's four major papers and some shorter publications relating to kinetic theory and statistical mechanics are discussed in the light of subsequent research in those subjects. Further information about the origin and development of Maxwell's ideas, based on study of unpublished materials and closer examination of less well-known articles, is reviewed, with reference to topics such as the velocity distribution

Stephen G. Brush

1971-01-01

252

Theory-Based MJO Diagnostics David J. Raymond, Sharon Sessions, Carlos Lpez Carrillo  

E-print Network

Theory-Based MJO Diagnostics 1 David J. Raymond, Sharon Sessions, Carlos López Carrillo New Mexico radiative entropy sink, surface evaporation rate, precipitation rate #12;Gross moist stability (Raymond et al. 2009) Normalized gross moist stability: = - TR · [sv] L · [rv] = - TR ([v · s] + [(s/p)]) L

Raymond, David J.

253

Transdiagnostic Theory and Application of Family-Based Treatment for Youth with Eating Disorders  

ERIC Educational Resources Information Center

This paper describes the transdiagnostic theory and application of family-based treatment (FBT) for children and adolescents with eating disorders. We review the fundamentals of FBT, a transdiagnostic theoretical model of FBT and the literature supporting its clinical application, adaptations across developmental stages and the diagnostic spectrum…

Loeb, Katharine L.; Lock, James; Greif, Rebecca; le Grange, Daniel

2012-01-01

254

Time-dependent self-consistent-field dynamics based on a reaction path Hamiltonian. I. Theory  

E-print Network

Time-dependent self-consistent-field dynamics based on a reaction path Hamiltonian. I. Theory Jian the time-dependent self-consistent-field TDSCF method with the reaction path Hamiltonian RPH derived the calculation of the real-time quantum dynamics of chemical reactions involving polyatomic molecules. When both

Hammes-Schiffer, Sharon

255

Author's personal copy Unified nano-mechanics based probabilistic theory of quasibrittle  

E-print Network

Author's personal copy Unified nano-mechanics based probabilistic theory of quasibrittle. Examples include concrete, fiber composites, coarse- grained or toughened ceramics, rocks, sea ice, rigid foams and bone, as well as many materials used in nano- and microscale devices. This study presents

Bazant, Martin Z.

256

Kinetic theory based CFD simulation of turbulent fluidization of FCC particles in a riser  

Microsoft Academic Search

The turbulent fluidization regime is characterized by the co-existence of a dense, bottom region and a dilute, top bed. A kinetic theory based CFD code with a drag corrected for clusters captured the basic features of this flow regime: the dilute and dense regions, high dispersion coefficients and a strong anisotropy. The computed energy spectrum captures the observed gravity wave

Veeraya Jiradilok; Dimitri Gidaspow; Somsak Damronglerd; William J. Koves; Reza Mostofi

2006-01-01

257

Image coding based on a fractal theory of iterated contractive image transformations  

Microsoft Academic Search

The author proposes an independent and novel approach to image coding, based on a fractal theory of iterated transformations. The main characteristics of this approach are that (i) it relies on the assumption that image redundancy can be efficiently exploited through self-transformability on a block-wise basis, and (ii) it approximates an original image by a fractal image. The author refers

Arnaud E. Jacquin

1992-01-01

258

Assessment of Prevalence of Persons with Down Syndrome: A Theory-Based Demographic Model  

ERIC Educational Resources Information Center

Background: The Netherlands are lacking reliable empirical data in relation to the development of birth and population prevalence of Down syndrome. For the UK and Ireland there are more historical empirical data available. A theory-based model is developed for predicting Down syndrome prevalence in the Netherlands from the 1950s onwards. It is…

de Graaf, Gert; Vis, Jeroen C.; Haveman, Meindert; van Hove, Geert; de Graaf, Erik A. B.; Tijssen, Jan G. P.; Mulder, Barbara J. M.

2011-01-01

259

A game theory-based analysis of search engine non-neutral behavior  

E-print Network

A game theory-based analysis of search engine non-neutral behavior Luis Guijarro, Vicent Pla, Bruno the policy of major search engines, and more specifically about their ranking in so-called organic results: the payment by content providers to the search engine in order to improve the chances to be located

Paris-Sud XI, Université de

260

Theory and Utility-Key Themes in Evidence-Based Assessment: Comment on the Special Section  

ERIC Educational Resources Information Center

This article focuses on two key themes in the four featured reviews on evidence-based assessment. The first theme is the essential role of theory in psychological assessment. An overview of this complex, multilayered role is presented. The second theme is the need for a common metric with which to gauge the utility of specific psychological tests…

McFall, Richard M.

2005-01-01

261

Knowledge management performance evaluation based on triangular fuzzy number and the theory of knowledge cycle  

Microsoft Academic Search

In order to express the differences between subjective judgments and real results and reflect the dynamic process of knowledge management performance evaluation, the paper bases on the triangular fuzzy number and knowledge cycle theory to construct a knowledge management performance evaluation index system, with knowledge acquisition, knowledge sharing, knowledge utilization and knowledge innovation as its foundation. The paper summarizes the

Xi Wang; Xia Cao; Xiu-hua Zhang

2011-01-01

262

Poverty Lines Based on Fuzzy Sets Theory and Its Application to Malaysian Data  

ERIC Educational Resources Information Center

Defining the poverty line has been acknowledged as being highly variable by the majority of published literature. Despite long discussions and successes, poverty line has a number of problems due to its arbitrary nature. This paper proposes three measurements of poverty lines using membership functions based on fuzzy set theory. The three…

Abdullah, Lazim

2011-01-01

263

A reexamination of information theory-based methods for DNA-binding site identification  

Microsoft Academic Search

BACKGROUND: Searching for transcription factor binding sites in genome sequences is still an open problem in bioinformatics. Despite substantial progress, search methods based on information theory remain a standard in the field, even though the full validity of their underlying assumptions has only been tested in artificial settings. Here we use newly available data on transcription factors from different bacterial

Ivan Erill; Michael C. O'neill

2009-01-01

264

Real-time estimation of transmission line impedance based on modal analysis theory  

Microsoft Academic Search

1 Abstract--The objective of this paper is to show a methodology to estimate the longitudinal parameters of transmission lines. The method is based on the modal analysis theory and developed from the currents and voltages measured at the sending and receiving ends of the line. Another proposal is to estimate the line impedance in function of the real-time load apparent

G. A. Asti; S. Kurokawa; E. C. M. Costa; J. Pissolato

2011-01-01

265

Strategies for third party logistics enterprises based on theory of Ecological Niche  

Microsoft Academic Search

Based on the theory of ecological niche, this paper discusses the various types of third party logistics (TPL) enterprises, and the four relationships between them, including competition, differentiation, and cooperation, as well as shift. Finally, four important strategies, such as discrepant operation strategy, value innovation strategy, resources expansion strategy, and Blue Ocean strategy were put forward to strengthen core competencies,

Shen Cheng lin; Zhang Xinxin

2008-01-01

266

Using relationship styles based on attachment theory to improve understanding of specialty choice in medicine  

Microsoft Academic Search

BACKGROUND: Patient-provider relationships in primary care are characterized by greater continuity and depth than in non-primary care specialties. We hypothesized that relationship styles of medical students based on attachment theory are associated with specialty choice factors and that such factors will mediate the association between relationship style and ultimately matching in a primary care specialty. METHODS: We determined the relationship

Paul S Ciechanowski; Linda LM Worley; Joan E Russo; Wayne J Katon

2006-01-01

267

Number Theory Based Image Compression Encryption and Application to Image Multiplexing  

Microsoft Academic Search

Image compression and image encryption are pivotal to proper storage and transmission of images. Simultaneous image compression and encryption aims at achieving enhanced bandwidth utilization and security at the same time. The proposed number theory based image compression encryption (NTICE) algorithm employs number theoretic paradigm-Chinese remainder theorem, to solve congruencies and hence realize the twin ideals of compression and encryption

V. Jagannathan; A. Mahadevan; R. Hariharan; S. Srinivasan

2007-01-01

268

Assessment the connecting style of power distribution network based on fuzzy and blind number theory  

Microsoft Academic Search

The selection of the distribution network connection mode is the precondition and key base work for improving the technical and economic of the distribution system. To take into account the influence of uncertainties in power network expansion planning, the fuzzy and blind number theory is deduced and used for measurement and calculation of uncertain information which influence the final decision.

Yong-Xiu He; Wei Wang; Liang-Qi Wu; Fu-Rong Li

2008-01-01

269

Unified interpretation for second-order subwavelength interference based on Feynman's path-integral theory  

SciTech Connect

The second-order spatial subwavelength interference pattern is observed in a modified Michelson interferometer with single-mode continuous-wave laser beams. By analyzing our subwavelength interference experiment based on Feynman's path integral theory, a unified interpretation for all the second-order subwavelength interference is suggested.

Liu Jianbin; Zhang Guoquan [MOE Key Laboratory of Weak Light Nonlinear Photonics, Nankai University, Tianjin 300457 (China) and Photonics Center, School of Physics, Nankai University, Tianjin 300071 (China)

2010-07-15

270

English Textbooks Based on Research and Theory--A Possible Dream.  

ERIC Educational Resources Information Center

Research based text materials will probably never dominate the textbook market. To begin with, translating theory and research into practice is a chancy business. There are also creative problems such as the inherent oversimplification involved in textbook writing. Every textbook writer who has been a classroom teacher will acknowledge that such…

Suhor, Charles

1984-01-01

271

Application of multi-sensor data fusion in defects evaluation based on Dempster-Shafer theory  

Microsoft Academic Search

Ultrasonic testing (UT) and eddy current testing (ECT) are the effective nondestructive testing methods which are widely used in many practical fields, such as machinery, power system, airplane and petrochemical industries. Each method has its advantages and disadvantages in the practical application. We use data fusion method that is based on the Dempster-Shafer evidence theory and the fuzzy inference and

Li Guohou; Huang Pingjie; Chen Peihua; Hou Dibo; Zhang Guangxin; Zhou Zekui

2011-01-01

272

Adaptive control the fractional unified chaotic system based on the estimated eigenvalue theory  

NASA Astrophysics Data System (ADS)

A simple but efficient method for controlling a fractional chaotic system is proposed based on the estimated eigenvalue theory. Using the new method, the fractional chaotic system with known or unknown parameters can be controlled. Numerical simulation results are presented to show the effectiveness of the proposed scheme.

Hu, J.-B.; Han, Y.; Zhao, L.-D.

2008-02-01

273

Investigating Acceptance toward Mobile Learning to Assist Individual Knowledge Management: Based on Activity Theory Approach  

ERIC Educational Resources Information Center

Mobile devices could facilitate human interaction and access to knowledge resources anytime and anywhere. With respect to wide application possibilities of mobile learning, investigating learners' acceptance towards it is an essential issue. Based on activity theory approach, this research explores positive factors for the acceptance of m-learning…

Liaw, Shu-Sheng; Hatala, Marek; Huang, Hsiu-Mei

2010-01-01

274

Authentic Leadership: Development and Validation of a Theory-Based Measure†  

Microsoft Academic Search

This study developed and tested a theory-based measure of authentic leadership using five separate samples obtained from China, Kenya, and the United States. Confirmatory factor analyses supported a higher order, multidimensional model of the authentic leadership construct (the Authentic Leadership Questionnaire [ALQ]) comprising leader self-awareness, relational transparency, internalized moral perspective, and balanced processing. Structural equation modeling (SEM) demonstrated the predictive

Fred O. Walumbwa; Bruce J. Avolio; William L. Gardner; Tara S. Wernsing; Suzanne J. Peterson

2008-01-01

275

Two Prophecy Formulas for Assessing the Reliability of Item Response Theory-Based Ability Estimates  

ERIC Educational Resources Information Center

Two new prophecy formulas for estimating item response theory (IRT)-based reliability of a shortened or lengthened test are proposed. Some of the relationships between the two formulas, one of which is identical to the well-known Spearman-Brown prophecy formula, are examined and illustrated. The major assumptions underlying these formulas are…

Raju, Nambury S.; Oshima, T.C.

2005-01-01

276

Portfolio Theory-Based Resource Assignment in a Cloud Computing System  

E-print Network

Portfolio Theory-Based Resource Assignment in a Cloud Computing System Inkwon Hwang and Massoud-- The focus of this paper is on energy-aware resource management in a cloud computing system. Much. Keywords- Cloud computing; portfolio effect; bin-packing; resource allocation I. INTRODUCTION Cloud

Pedram, Massoud

277

Human errors reliability analysis in coal mine accidents based on Gray Relational Theory  

Microsoft Academic Search

Human errors which have been affecting safety accidents are one of the main reasons in coal mine. So these Accidents can be pre vented and reduced through analyzing human errors affecting factors. This paper has made elaborate analysis of the relative affecting factors which cause human errors through applying the Gray Relational Theory in coal mine accidents. Based upon this

Jianyi Lan; Meiying Qiao

2010-01-01

278

Magnetometer Bias Calibration Based on Relative Angular Position: Theory and Experimental Comparative Evaluation  

E-print Network

Magnetometer Bias Calibration Based on Relative Angular Position: Theory and Experimental for esti- mating the sensor bias of three-axis magnetometers (or any other field sensor). Our approach employs relative angular position measurements to estimate the three-axis magnetometer measurement bias

Eustice, Ryan

279

Wind turbine emulator using wind turbine model based on blade element momentum theory  

Microsoft Academic Search

This paper presents the wind turbine emulator using the wind turbine model based on blade element momentum theory. The lift coefficient cl and drag coefficient cd of designed blade shape are calculated with the fluid analysis. Therefore the proposed wind turbine emulator can emulate the new designed windmill without manufacturing. Also the wind turbine model considers the mechanical model and

K. Ohyama; T. Nakashima

2010-01-01

280

Non-Rational Discrete Choice Based On Q-Learning And The Prospect Theory  

E-print Network

Non-Rational Discrete Choice Based On Q-Learning And The Prospect Theory Gustavo Kuhn Andriotti the standard ap- proach is to adopt the rational model. This has been shown, however, to fail systematically on the rational choice defined by Bernoulli principle and von Neumann's axioms. Then to cope with a non-rational

Taylor, Matthew

281

Using instructional theory to facilitate communication in Web-based courses  

Microsoft Academic Search

This articles examines the role of computer-mediated communication as well as broader interpretations of communication in Web-based instruction. Overviews of cognitive processing and cognitive constructivist paradigms are presented to illustrate their relevance for guiding development of Web-based courses. Instructional goals and communication strategies associated with these paradigms are identified. We conclude that developers should use instructional theories to guide choices

Susan M. Miller; Kenneth L. Miller

1999-01-01

282

A Christian Faith-Based Recovery Theory: Understanding God as Sponsor  

Microsoft Academic Search

This article reports the development of a substantive theory to explain an evangelical Christian-based process of recovery\\u000a from addiction. Faith-based, 12-step, mutual aid programs can improve drug abstinence by offering: (a) an intervention option\\u000a alone and\\/or in conjunction with secular programs and (b) an opportunity for religious involvement. Although literature on\\u000a religion, spirituality, and addiction is voluminous, traditional 12-step programs

Shirley M. Timmons

283

Modeling and Performance Analysis of Communication Networks  

E-print Network

. The underlying principles of computer systems analysis (which are based on queuing theory) will be studied. Analytical methods based on queuing theory will be used to study the behavior of communication networks, for example, the time spent by a packet waiting to be transmitted on a given link or through a whole network

Xie,Jiang (Linda)

284

Mixture theory-based poroelasticity as a model of interstitial tissue growth  

PubMed Central

This contribution presents an alternative approach to mixture theory-based poroelasticity by transferring some poroelastic concepts developed by Maurice Biot to mixture theory. These concepts are a larger RVE and the subRVE-RVE velocity average tensor, which Biot called the micro-macro velocity average tensor. This velocity average tensor is assumed here to depend upon the pore structure fabric. The formulation of mixture theory presented is directed toward the modeling of interstitial growth, that is to say changing mass and changing density of an organism. Traditional mixture theory considers constituents to be open systems, but the entire mixture is a closed system. In this development the mixture is also considered to be an open system as an alternative method of modeling growth. Growth is slow and accelerations are neglected in the applications. The velocity of a solid constituent is employed as the main reference velocity in preference to the mean velocity concept from the original formulation of mixture theory. The standard development of statements of the conservation principles and entropy inequality employed in mixture theory are modified to account for these kinematic changes and to allow for supplies of mass, momentum and energy to each constituent and to the mixture as a whole. The objective is to establish a basis for the development of constitutive equations for growth of tissues. PMID:22184481

Cowin, Stephen C.; Cardoso, Luis

2011-01-01

285

A novel trust evaluation method for Ubiquitous Healthcare based on cloud computational theory.  

PubMed

The notion of trust is considered to be the cornerstone on patient-psychiatrist relationship. Thus, a trustfully background is fundamental requirement for provision of effective Ubiquitous Healthcare (UH) service. In this paper, the issue of Trust Evaluation of UH Providers when register UH environment is addressed. For that purpose a novel trust evaluation method is proposed, based on cloud theory, exploiting User Profile attributes. This theory mimics human thinking, regarding trust evaluation and captures fuzziness and randomness of this uncertain reasoning. Two case studies are investigated through simulation in MATLAB software, in order to verify the effectiveness of this novel method. PMID:25570992

Athanasiou, Georgia; Fengou, Maria-Anna; Beis, Antonios; Lymberopoulos, Dimitrios

2014-08-01

286

Non-relativistic M-Theory solutions based on Kaehler-Einstein spaces  

E-print Network

We present new families of non-supersymmetric solutions of D=11 supergravity with non-relativistic symmetry, based on six-dimensional Kaehler-Einstein manifolds. In constructing these solutions, we make use of a consistent reduction to a five-dimensional gravity theory coupled to a massive scalar and vector field. This theory admits a non-relativistic CFT dual with dynamical exponent z=4, which may be uplifted to D=11 supergravity. Finally, we generalise this solution and find new solutions with various z, including z=2.

Eoin 'O Colgain; Oscar Varela; Hossein Yavartanoo

2009-07-21

287

Gravitational Wave Spectrums from Pole-like Inflations based on Generalized Gravity Theories  

E-print Network

We present a general and unified formulation which can handle the classical evolution and quantum generation processes of the cosmological gravitational wave in a broad class of generalized gravity theories. Applications are made in several inflation models based on the scalar-tensor theory, the induced gravity, and the low energy effective action of string theory. The gravitational wave power spectrums based on the vacuum expectation value of the quantized fluctuating metric during the pole-like inflation stages are derived in analytic forms. Assuming that the gravity theory transits to Einstein one while the relevant scales remain in the superhorizon scale, we derive the consequent power spectrums and the directional fluctuations of the relic radiation produced by the gravitational wave. The spectrums seeded by the vacuum fluctuations in the pole-like inflation models based on the generalized gravity show a distinguished common feature which differs from the scale invariant spectrum generated in an exponential inflation in Einstein gravity which is supported by observations.

J. Hwang

1997-10-10

288

Efficacy of theory-based interventions to promote physical activity. A meta-analysis of randomised controlled trials.  

PubMed

Implementing theory-based interventions is an effective way to influence physical activity (PA) behaviour in the population. This meta-analysis aimed to (a) determine the global effect of theory-based randomised controlled trials (RCTs) dedicated to the promotion of PA among adults, (b) measure the actual efficacy of interventions against their theoretical objectives, and (c) compare the efficacy of single- versus combined-theory interventions. A systematic search through databases and review articles was carried out. Our results show that theory-based interventions (k = 82) significantly impact the PA behaviour of participants (d = 0.31, 95% CI [0.24, 0.37]). While moderation analyses revealed no efficacy difference between theories, interventions based on a single theory (d = 0.35; 95% CI [0.26, 0.43]) reported a higher impact on PA behaviour than those based on a combination of theories (d = 0.21; 95% CI [0.11, 0.32]). In spite of the global positive effect of theory-based interventions on PA behaviour, further research is required to better identify the specificities, overlaps or complementarities of the components of interventions based on relevant theories. PMID:25402606

Gourlan, M; Bernard, P; Bortholon, C; Romain, Aj; Lareyre, O; Carayol, M; Ninot, G; Boiché, J

2014-11-17

289

The Scientific Value of Cognitive Load Theory: A Research Agenda Based on the Structuralist View of Theories  

ERIC Educational Resources Information Center

In this paper, two methodological perspectives are used to elaborate on the value of cognitive load theory (CLT) as a scientific theory. According to the more traditional critical rationalism of Karl Popper, CLT cannot be considered a scientific theory because some of its fundamental assumptions cannot be tested empirically and are thus not…

Gerjets, Peter; Scheiter, Katharina; Cierniak, Gabriele

2009-01-01

290

A comparison of design variables for control theory based airfoil optimization  

NASA Technical Reports Server (NTRS)

This paper describes the implementation of optimization techniques based on control theory for airfoil design. In our previous work in the area it was shown that control theory could be employed to devise effective optimization procedures for two-dimensional profiles by using either the potential flow or the Euler equations with either a conformal mapping or a general coordinate system. We have also explored three-dimensional extensions of these formulations recently. The goal of our present work is to demonstrate the versatility of the control theory approach by designing airfoils using both Hicks-Henne functions and B-spline control points as design variables. The research also demonstrates that the parameterization of the design space is an open question in aerodynamic design.

Reuther, James; Jameson, Antony

1995-01-01

291

Robust Stabilization Control Based on Guardian Maps Theory for a Longitudinal Model of Hypersonic Vehicle  

PubMed Central

A typical model of hypersonic vehicle has the complicated dynamics such as the unstable states, the nonminimum phases, and the strong coupling input-output relations. As a result, designing a robust stabilization controller is essential to implement the anticipated tasks. This paper presents a robust stabilization controller based on the guardian maps theory for hypersonic vehicle. First, the guardian maps theories are provided to explain the constraint relations between the open subsets of complex plane and the eigenvalues of the state matrix of closed-loop control system. Then, a general control structure in relation to the guardian maps theories is proposed to achieve the respected design demands. Furthermore, the robust stabilization control law depending on the given general control structure is designed for the longitudinal model of hypersonic vehicle. Finally, a simulation example is provided to verify the effectiveness of the proposed methods. PMID:24795535

Liu, Mengying; Sun, Peihua

2014-01-01

292

An automated integration-free path-integral method based on Kleinert's variational perturbation theory  

NASA Astrophysics Data System (ADS)

Based on Kleinert's variational perturbation (KP) theory [Path Integrals in Quantum Mechanics, Statistics, Polymer Physics, and Financial Markets, 3rd ed. (World Scientific, Singapore, 2004)], we present an analytic path-integral approach for computing the effective centroid potential. The approach enables the KP theory to be applied to any realistic systems beyond the first-order perturbation (i.e., the original Feynman-Kleinert [Phys. Rev. A 34, 5080 (1986)] variational method). Accurate values are obtained for several systems in which exact quantum results are known. Furthermore, the computed kinetic isotope effects for a series of proton transfer reactions, in which the potential energy surfaces are evaluated by density-functional theory, are in good accordance with experiments. We hope that our method could be used by non-path-integral experts or experimentalists as a "black box" for any given system.

Wong, Kin-Yiu; Gao, Jiali

2007-12-01

293

Robust stabilization control based on guardian maps theory for a longitudinal model of hypersonic vehicle.  

PubMed

A typical model of hypersonic vehicle has the complicated dynamics such as the unstable states, the nonminimum phases, and the strong coupling input-output relations. As a result, designing a robust stabilization controller is essential to implement the anticipated tasks. This paper presents a robust stabilization controller based on the guardian maps theory for hypersonic vehicle. First, the guardian maps theories are provided to explain the constraint relations between the open subsets of complex plane and the eigenvalues of the state matrix of closed-loop control system. Then, a general control structure in relation to the guardian maps theories is proposed to achieve the respected design demands. Furthermore, the robust stabilization control law depending on the given general control structure is designed for the longitudinal model of hypersonic vehicle. Finally, a simulation example is provided to verify the effectiveness of the proposed methods. PMID:24795535

Liu, Yanbin; Liu, Mengying; Sun, Peihua

2014-01-01

294

Calculation of the Ultimate Bearing Capacity of Soil Slope Based on the Unified Strength Theory  

NASA Astrophysics Data System (ADS)

At present, the failure criteria used in calculating the ultimate bearing capacity of soil slope are the Tresca and Mohr-Coulomb criteria. But the results are conservative and the potential strength of soil mass cannot be utilized sufficiently because these two criteria do not take into account the effect of the intermediate principal stress. In this paper the unified strength theory was used to analyze the ultimate bearing capacity of soil slope. The formula for calculating the ultimate bearing capacity of soil slope using the unified strength theory was established. At the end, a case history was analyzed and it indicated that the result of the unified strength theory is larger than that of the Mohr-Coulomb criterion. This indicates that calculation of ultimate bearing capacity of soil slope with the unified strength theory can sufficiently exploit the strength of material. Therefore, the calculation of ultimate bearing capacity of the soil slope based on the unified strength theory will be of great significance in future applications.

Liao, Hongjian; Ma, Zongyuan; Su, Lijun

295

Personality and Psychopathology: a Theory-Based Revision of Eysenck’s PEN Model  

PubMed Central

The principal aim of this paper is to investigate whether it is possible to create a personality taxonomy of clinical relevance out of Eysenck’s original PEN model by repairing the various shortcomings that can be noted in Eysenck’s personality theory, particularly in relation to P or Psychoticism. Addressing three approaches that have been followed to answer the question ‘which personality factors are basic?’, arguments are listed to show that particularly the theory-informed approach, originally defended by Eysenck, may lead to scientific progress. However, also noting the many deficiencies in the nomological network surrounding P, the peculiar situation arises that we adhere to Eysenck’s theory-informed methodology, but criticize his theory. These arguments and criticisms led to the replacement of P by three orthogonal and theory-based factors, Insensitivity (S), Orderliness (G), and Absorption (A), that together with the dimensions E or Extraversion and N or Neuroticism, that were retained from Eysenck’s PEN model, appear to give a comprehensive account of the main vulnerability factors in schizophrenia and affective disorders, as well as in other psychopathological conditions. PMID:20498694

van Kampen, Dirk

2009-01-01

296

Membrane-Based Characterization of a Gas Component — A Transient Sensor Theory  

PubMed Central

Based on a multi-gas solution-diffusion problem for a dense symmetrical membrane this paper presents a transient theory of a planar, membrane-based sensor cell for measuring gas from both initial conditions: dynamic and thermodynamic equilibrium. Using this theory, the ranges for which previously developed, simpler approaches are valid will be discussed; these approaches are of vital interest for membrane-based gas sensor applications. Finally, a new theoretical approach is introduced to identify varying gas components by arranging sensor cell pairs resulting in a concentration independent gas-specific critical time. Literature data for the N2, O2, Ar, CH4, CO2, H2 and C4H10 diffusion coefficients and solubilities for a polydimethylsiloxane membrane were used to simulate gas specific sensor responses. The results demonstrate the influence of (i) the operational mode; (ii) sensor geometry and (iii) gas matrices (air, Ar) on that critical time. Based on the developed theory the case-specific suitable membrane materials can be determined and both operation and design options for these sensors can be optimized for individual applications. The results of mixing experiments for different gases (O2, CO2) in a gas matrix of air confirmed the theoretical predictions. PMID:24608004

Lazik, Detlef

2014-01-01

297

Applying trait-based models to achieve functional targets for theory-driven ecological restoration.  

PubMed

Manipulating community assemblages to achieve functional targets is a key component of restoring degraded ecosystems. The response-and-effect trait framework provides a conceptual foundation for translating restoration goals into functional trait targets, but a quantitative framework has been lacking for translating trait targets into assemblages of species that practitioners can actually manipulate. This study describes new trait-based models that can be used to generate ranges of species abundances to test theories about which traits, which trait values and which species assemblages are most effective for achieving functional outcomes. These models are generalisable, flexible tools that can be widely applied across many terrestrial ecosystems. Examples illustrate how the framework generates assemblages of indigenous species to (1) achieve desired community responses by applying the theories of environmental filtering, limiting similarity and competitive hierarchies, or (2) achieve desired effects on ecosystem functions by applying the theories of mass ratios and niche complementarity. Experimental applications of this framework will advance our understanding of how to set functional trait targets to achieve the desired restoration goals. A trait-based framework provides restoration ecology with a robust scaffold on which to apply fundamental ecological theory to maintain resilient and functioning ecosystems in a rapidly changing world. PMID:24766299

Laughlin, Daniel C

2014-07-01

298

Energy-Efficiency Analysis of a Distributed Queuing Medium Access Control Protocol for Biomedical Wireless Sensor Networks in Saturation Conditions  

PubMed Central

The aging population and the high quality of life expectations in our society lead to the need of more efficient and affordable healthcare solutions. For this reason, this paper aims for the optimization of Medium Access Control (MAC) protocols for biomedical wireless sensor networks or wireless Body Sensor Networks (BSNs). The hereby presented schemes always have in mind the efficient management of channel resources and the overall minimization of sensors’ energy consumption in order to prolong sensors’ battery life. The fact that the IEEE 802.15.4 MAC does not fully satisfy BSN requirements highlights the need for the design of new scalable MAC solutions, which guarantee low-power consumption to the maximum number of body sensors in high density areas (i.e., in saturation conditions). In order to emphasize IEEE 802.15.4 MAC limitations, this article presents a detailed overview of this de facto standard for Wireless Sensor Networks (WSNs), which serves as a link for the introduction and initial description of our here proposed Distributed Queuing (DQ) MAC protocol for BSN scenarios. Within this framework, an extensive DQ MAC energy-consumption analysis in saturation conditions is presented to be able to evaluate its performance in relation to IEEE 802.5.4 MAC in highly dense BSNs. The obtained results show that the proposed scheme outperforms IEEE 802.15.4 MAC in average energy consumption per information bit, thus providing a better overall performance that scales appropriately to BSNs under high traffic conditions. These benefits are obtained by eliminating back-off periods and collisions in data packet transmissions, while minimizing the control overhead. PMID:22319351

Otal, Begonya; Alonso, Luis; Verikoukis, Christos

2011-01-01

299

Energy-efficiency analysis of a distributed queuing medium access control protocol for biomedical wireless sensor networks in saturation conditions.  

PubMed

The aging population and the high quality of life expectations in our society lead to the need of more efficient and affordable healthcare solutions. For this reason, this paper aims for the optimization of Medium Access Control (MAC) protocols for biomedical wireless sensor networks or wireless Body Sensor Networks (BSNs). The hereby presented schemes always have in mind the efficient management of channel resources and the overall minimization of sensors' energy consumption in order to prolong sensors' battery life. The fact that the IEEE 802.15.4 MAC does not fully satisfy BSN requirements highlights the need for the design of new scalable MAC solutions, which guarantee low-power consumption to the maximum number of body sensors in high density areas (i.e., in saturation conditions). In order to emphasize IEEE 802.15.4 MAC limitations, this article presents a detailed overview of this de facto standard for Wireless Sensor Networks (WSNs), which serves as a link for the introduction and initial description of our here proposed Distributed Queuing (DQ) MAC protocol for BSN scenarios. Within this framework, an extensive DQ MAC energy-consumption analysis in saturation conditions is presented to be able to evaluate its performance in relation to IEEE 802.5.4 MAC in highly dense BSNs. The obtained results show that the proposed scheme outperforms IEEE 802.15.4 MAC in average energy consumption per information bit, thus providing a better overall performance that scales appropriately to BSNs under high traffic conditions. These benefits are obtained by eliminating back-off periods and collisions in data packet transmissions, while minimizing the control overhead. PMID:22319351

Otal, Begonya; Alonso, Luis; Verikoukis, Christos

2011-01-01

300

Simple Models for Airport Delays During Transition to a Trajectory-Based Air Traffic System  

NASA Astrophysics Data System (ADS)

It is now widely recognised that a paradigm shift in air traffic control concepts is needed. This requires state-of-the-art innovative technologies, making much better use of the information in the air traffic management (ATM) system. These paradigm shifts go under the names of NextGen in the USA and SESAR in Europe, which inter alia will make dramatic changes to the nature of airport operations. A vital part of moving from an existing system to a new paradigm is the operational implications of the transition process. There would be business incentives for early aircraft fitment, it is generally safer to introduce new technologies gradually, and researchers are already proposing potential transition steps to the new system. Simple queuing theory models are used to establish rough quantitative estimates of the impact of the transition to a more efficient time-based navigational and ATM system. Such models are approximate, but they do offer insight into the broad implications of system change and its significant features. 4D-equipped aircraft in essence have a contract with the airport runway and, in return, they would get priority over any other aircraft waiting for use of the runway. The main operational feature examined here is the queuing delays affecting non-4D-equipped arrivals. These get a reasonable service if the proportion of 4D-equipped aircraft is low, but this can deteriorate markedly for high proportions, and be economically unviable. Preventative measures would be to limit the additional growth of 4D-equipped flights and/or to modify their contracts to provide sufficient space for the non-4D-equipped flights to operate without excessive delays. There is a potential for non-Poisson models, for which there is little in the literature, and for more complex models, e.g. grouping a succession of 4D-equipped aircraft as a batch.

Brooker, Peter

301

Design of Flexure-based Precision Transmission Mechanisms using Screw Theory  

SciTech Connect

This paper enables the synthesis of flexure-based transmission mechanisms that possess multiple decoupled inputs and outputs of any type (e.g. rotations, translations, and/or screw motions), which are linked by designer-specified transmission ratios. A comprehensive library of geometric shapes is utilized from which every feasible concept that possesses the desired transmission characteristics may be rapidly conceptualized and compared before an optimal concept is selected. These geometric shapes represent the rigorous mathematics of screw theory and uniquely link a body's desired motions to the flexible constraints that enable those motions. This paper's impact is most significant to the design of nano-positioners, microscopy stages, optical mounts, and sensors. A flexure-based microscopy stage was designed, fabricated, and tested to demonstrate the utility of the theory.

Hopkins, J B; Panas, R M

2011-02-07

302

Finding theory- and evidence-based alternatives to fear appeals: Intervention Mapping  

PubMed Central

Fear arousal—vividly showing people the negative health consequences of life-endangering behaviors—is popular as a method to raise awareness of risk behaviors and to change them into health-promoting behaviors. However, most data suggest that, under conditions of low efficacy, the resulting reaction will be defensive. Instead of applying fear appeals, health promoters should identify effective alternatives to fear arousal by carefully developing theory- and evidence-based programs. The Intervention Mapping (IM) protocol helps program planners to optimize chances for effectiveness. IM describes the intervention development process in six steps: (1) assessing the problem and community capacities, (2) specifying program objectives, (3) selecting theory-based intervention methods and practical applications, (4) designing and organizing the program, (5) planning, adoption, and implementation, and (6) developing an evaluation plan. Authors who used IM indicated that it helped in bringing the development of interventions to a higher level. PMID:24811880

Kok, Gerjo; Bartholomew, L Kay; Parcel, Guy S; Gottlieb, Nell H; Fernández, María E

2014-01-01

303

Comparison of inlet suppressor data with approximate theory based on cutoff ratio  

NASA Technical Reports Server (NTRS)

Inlet suppressor far-field directivity suppression was quantitatively compared with that predicted using an approximate linear design and evaluation method based upon mode cutoff ratio. The experimental data was obtained using a series of cylindrical point-reacting inlet liners on a YF102 engine. The theoretical prediction program is based upon simplified sound propagation concepts derived from exact calculations. These indicate that all of the controlling phenomenon can be approximately correlated with mode cutoff ratio which itself is intimately related to the angles of propagation within the duct. The theory-data comparisons are intended to point out possible deficiencies in the approximate theory which may be corrected. After all theoretical refinements are made, then empirical corrections can be applied.

Rice, E. J.; Heidelberg, L. J.

1979-01-01

304

Using importance sampling to simulate queuing networks with heavy-tailed service time distributions  

E-print Network

Characterization of steady-state queue length distributions using direct simulation is generally computationally prohibitive. We develop a fast simulation method by using an importance sampling approach based on a change ...

Liman-Tinguiri, Karim

2011-01-01

305

Web-Based Learning Environment: A Theory-Based Design Process for Development and Evaluation  

ERIC Educational Resources Information Center

Web-based courses and programs have increasingly been developed by many academic institutions, organizations, and companies worldwide due to their benefits for both learners and educators. However, many of the developmental approaches lack two important considerations needed for implementing Web-based learning applications: (1) integration of the…

Nam, Chang S.; Smith-Jackson, Tonya L.

2007-01-01

306

Are node-based and stem-based clades equivalent? Insights from graph theory  

E-print Network

mathematical models used to portray phylogenetic relationships among species and higher taxa: stem-based trees and node-based trees. Each model is a tree in the sense that is commonly used in mathematics; the difference between them lies in the biological...

Martin, Jeremy L.; Blackburn, David C.; Wiley, Edward O.

2010-11-08

307

Healthcare professionals' intentions and behaviours: A systematic review of studies based on social cognitive theories  

PubMed Central

Background There is an important gap between the implications of clinical research evidence and the routine clinical practice of healthcare professionals. Because individual decisions are often central to adoption of a clinical-related behaviour, more information about the cognitive mechanisms underlying behaviours is needed to improve behaviour change interventions targeting healthcare professionals. The aim of this study was to systematically review the published scientific literature about factors influencing health professionals' behaviours based on social cognitive theories. These theories refer to theories where individual cognitions/thoughts are viewed as processes intervening between observable stimuli and responses in real world situations. Methods We searched psycINFO, MEDLINE, EMBASE, CIHNAL, Index to theses, PROQUEST dissertations and theses and Current Contents for articles published in English only. We included studies that aimed to predict healthcare professionals' intentions and behaviours with a clear specification of relying on a social cognitive theory. Information on percent of explained variance (R2) was used to compute the overall frequency-weighted mean R2 to evaluate the efficacy of prediction in several contexts and according to different methodological aspects. The cognitive factors most consistently associated with prediction of healthcare professionals' intention and behaviours were documented. Results Seventy eight studies met the inclusion criteria. Among these studies, 72 provided information on the determinants of intention and 16 prospective studies provided information on the determinants of behaviour. The theory most often used as reference was the Theory of Reasoned Action (TRA) or its extension the Theory of Planned Behaviour (TPB). An overall frequency-weighted mean R2 of 0.31 was observed for the prediction of behaviour; 0.59 for the prediction of intention. A number of moderators influenced the efficacy of prediction; frequency-weighted mean R2 varied from 0.001 to 0.58 for behaviour and 0.19 to 0.81 for intention. Conclusion Our results suggest that the TPB appears to be an appropriate theory to predict behaviour whereas other theories better capture the dynamic underlying intention. In addition, given the variations in efficacy of prediction, special care should be given to methodological issues, especially to better define the context of behaviour performance. PMID:18631386

Godin, Gaston; Bélanger-Gravel, Ariane; Eccles, Martin; Grimshaw, Jeremy

2008-01-01

308

The puzzling Hg family revisited: a comprehensive study based on density functional theory  

Microsoft Academic Search

We review theoretical investigations of high-temperature superconductors which have been performed by density functional theory. The main subject of our study is the Hg-based family of the superconducting cuprates, which demonstrates unusual and still puzzling properties. We show that the first-principles approach is able to describe the effects of chemical doping and pressure on the structural properties, the band structure,

C Ambrosch-Draxl

309

Ultrasonic Field Computation into Multilayered Composite Materials Using a Homogenization Method Based on Ray Theory  

NASA Astrophysics Data System (ADS)

The simulation of ultrasonic NDT of carbon-fiber-reinforced epoxy composites (CFRP) is an important challenge for the aircraft industry. In a previous article, we proposed to evaluate the field radiated into such components by means of a homogenization method coupled to the pencil model implemented in CIVA software. Following the same goals, an improvement is proposed here through the development of an original homogenization procedure based on ray theory.

Deydier, S.; Gengembre, N.; Calmon, P.; Mengeling, V.; Pétillon, O.

2005-04-01

310

A Validation-Structure-Based Theory of Plan Modification and Reuse  

Microsoft Academic Search

Kambhampati, S. and J.A. Hendler, A validation-structure-based theory of plan modifica- tion and reuse, Artificial Intelligence 55 (1992) 193-258. The ability to modify existing plans to accommodate a variety of externally imposed constraints (such as changes in the problem specification, the expected world state, or the structure of the plan) is a valuable tool for improving efficiency of planning by

Subbarao Kambhampati; James A. Hendler

1992-01-01

311

Design of Coaxial Adaptor based on Discontinuity Theory using 3D Simulator  

Microsoft Academic Search

We present the design approach, realization and test results of the Q-band precision subminiature coaxial adaptor. Coaxial adaptor based on transmission line theory using multi-step impedance and coaxial discontinuities to increase its cutoff frequency. The return-loss increments due to the hooked structure and multi air-holes are minimized to 2 dB and 1.5 dB, respectively. VSWR of < 1.2 is obtained

Won-Yong Cho; G. I. Kyung; D.-Y. Yoon; Eun-Soo Kim; B. Shrestha; Nam-Young Kim

2007-01-01

312

Risk analysis on groundwater resources carrying capacity based on blind number theory  

Microsoft Academic Search

Blind numbers of evaluation indices about groundwater resources carrying capacity are defined from the concomitancy of randomness,\\u000a fuzziness, grey property and unascertainment of groundwater system. Based on fuzzy theory, a comprehensive evaluation model\\u000a on groundwater resources carrying capacity is constructed with blind information. Then a risk assessment model of surcharge\\u000a about groundwater resources carrying capacity is established on blind reliability

Ji Zhang; Sujun Yu

2007-01-01

313

Attribute Reduction for Massive Data Based on Rough Set Theory and MapReduce  

Microsoft Academic Search

\\u000a Data processing and knowledge discovery for massive data is always a hot topic in data mining, along with the era of cloud\\u000a computing is coming, data mining for massive data is becoming a highlight research topic. In this paper, attribute reduction\\u000a for massive data based on rough set theory is studied. The parallel programming mode of MapReduce is introduced and

Yong Yang; Zhengrong Chen; Zhu Liang; Guoyin Wang

2010-01-01

314

Characterizations of MV-Algebras Based on the Theory of Falling Shadows  

PubMed Central

Based on the falling shadow theory, the concept of falling fuzzy (implicative) ideals as a generalization of that of a T ?-fuzzy (implicative) ideal is proposed in MV-algebras. The relationships between falling fuzzy (implicative) ideals and T-fuzzy (implicative) ideals are discussed, and conditions for a falling fuzzy (implicative) ideal to be a T ?-fuzzy (implicative) ideal are provided. Some characterizations of falling fuzzy (implicative) ideals are presented by studying proprieties of them. The product ? and the up product ? operations on falling shadows and the upset of a falling shadow are established, by which T-fuzzy ideals are investigated based on probability spaces. PMID:25258743

Yang, Yongwei; Xin, Xiaolong; He, Pengfei

2014-01-01

315

On the stability of input-queued switches with speed-up  

Microsoft Academic Search

We consider cell-based switch and router architec- tures whose internal switching matrix does not provide enough speed to avoid input buffering. These architectures require a sched- uling algorithm to select at each slot a subset of input buffered cells which can be transferred toward output ports. In this paper, we propose several classes of scheduling algorithms whose stability properties are

Emilio Leonardi; Marco Mellia; Fabio Neri; Marco Ajmone Marsan

2001-01-01

316

Testing a Theory-Based Mobility Monitoring Protocol Using In-Home Sensors: A Feasibility Study  

PubMed Central

Mobility is a key factor in the performance of many everyday tasks required for independent living as a person grows older. The purpose of this mixed methods study was to test a theory-based mobility monitoring protocol by comparing sensor-based measures to self-report measures of mobility and assessing the acceptability of in-home sensors with older adults. Standardized instruments to measure physical, psychosocial and cognitive parameters were administered to 8 community-dwelling older adults at baseline, 3 month and 6 month visits (examples: FES, GDS-SF, Mini-cog). Semi-structured interviews to characterize acceptability of the technology were conducted at 3 month and 6 month visits. Technical issues prevented comparison of sensor-based measures with self-report measures. In-home sensor technology for monitoring mobility is acceptable to older adults. Implementing our theory-based mobility monitoring protocol in a field study in the homes of older adults is a feasible undertaking but requires more robust technology for sensor-based measure validation. PMID:23938159

Reeder, Blaine; Chung, Jane; Lazar, Amanda; Joe, Jonathan; Demiris, George; Thompson, Hilaire J.

2014-01-01

317

The theory of community based health and safety programs: a critical examination  

PubMed Central

This paper examines the theoretical underpinning of the community based approach to health and safety programs. Drawing upon the literature, a theory is constructed by elucidating assumptions of community based programs. The theory is then put to test by analyzing the extent to which the assumptions are supported by empirical evidence and the extent to which the assumptions have been applied in community based injury prevention practice. Seven principles representing key assumptions of the community based approach to health and safety programs are identified. The analysis suggests that some of the principles may have important shortcomings. Programs overwhelmingly define geographical or geopolitical units as communities, which is problematic considering that these entities can be heterogeneous and characterized by a weak sense of community. This may yield insufficient community mobilization and inadequate program reach. At the same time, none of the principles identified as most plausible appears to be widely or fully applied in program practice. The implication is that many community based health and safety programs do not function at an optimum level, which could explain some of the difficulties in demonstrating effectiveness seen with many of these programs. PMID:16751442

Nilsen, P

2006-01-01

318

Game Theory Based Dynamic Bit-Rate Adaptation for H.264 Scalable Video Transmission in 4G  

E-print Network

Game Theory Based Dynamic Bit-Rate Adaptation for H.264 Scalable Video Transmission in 4G Wireless adaptation game based on the quasi-concavity of the net video utility function. Existence of Nash equilibrium based services such as video conferencing, interactive gaming and subscription based broadcast

Jagannatham, Aditya K.

319

Theory of plasma contactors in ground-based experiments and low Earth orbit  

NASA Technical Reports Server (NTRS)

Previous theoretical work on plasma contactors as current collectors has fallen into two categories: collisionless double layer theory (describing space charge limited contactor clouds) and collisional quasineutral theory. Ground based experiments at low current are well explained by double layer theory, but this theory does not scale well to power generation by electrodynamic tethers in space, since very high anode potentials are needed to draw a substantial ambient electron current across the magnetic field in the absence of collisions (or effective collisions due to turbulence). Isotropic quasineutral models of contactor clouds, extending over a region where the effective collision frequency upsilon sub e exceeds the electron cyclotron frequency omega sub ce, have low anode potentials, but would collect very little ambient electron current, much less than the emitted ion current. A new model is presented, for an anisotropic contactor cloud oriented along the magnetic field, with upsilon sub e less than omega sub ce. The electron motion along the magnetic field is nearly collisionless, forming double layers in that direction, while across the magnetic field the electrons diffuse collisionally and the potential profile is determined by quasineutrality. Using a simplified expression for upsilon sub e due to ion acoustic turbulence, an analytic solution has been found for this model, which should be applicable to current collection in space. The anode potential is low and the collected ambient electron current can be several times the emitted ion current.

Gerver, M. J.; Hastings, Daniel E.; Oberhardt, M. R.

1990-01-01

320

Adolescent decision making: a broadly based theory and its application to the prevention of early pregnancy.  

PubMed

The purpose of this paper is to present a broadly based theory of adolescent decision making including all the necessary components of the subject: cognitive development, social and psychological factors, and, perhaps most importantly, cultural and societal influences. Previous theories and applications have often focused on only one or two aspects. This theory is then applied to the problem of prevention of early pregnancy at an inner-city high school. Use of this theory, combined with an open-ended data-gathering format made possible some of the unexpected findings of this study: most of the young women at this school desire their pregnancies; many of them prefer single parenthood to traditional family structure; and low academic skills and poverty often result in pregnancy, rather than pregnancy causing high school dropouts and a life of poverty. Prevention programs will necessarily differ for sexually active adolescents who do and do not want pregnancy and for younger versus older adolescents. In designing such programs, we need to focus on pregnancy as the problem rather than on adolescent sexuality. PMID:8874604

Gordon, C P

1996-01-01

321

Analysis of dislocation pile-ups using a dislocation-based continuum theory  

NASA Astrophysics Data System (ADS)

The increasing demand for materials with well-defined microstructure, accompanied by the advancing miniaturization of devices, is the reason for the growing interest in physically motivated, dislocation-based continuum theories of plasticity. In recent years, various advanced continuum theories have been introduced, which are able to described the motion of straight and curved dislocation lines. The focus of this paper is the question of how to include fundamental properties of discrete dislocations during their motion and interaction in a continuum dislocation dynamics (CDD) theory. In our CDD model, we obtain elastic interaction stresses for the bundles of dislocations by a mean-field stress, which represents long-range stress components, and a short range corrective stress component, which represents the gradients of the local dislocation density. The attracting and repelling behavior of bundles of straight dislocations of the same and opposite sign are analyzed. Furthermore, considering different dislocation pile-up systems, we show that the CDD formulation can solve various fundamental problems of micro-plasticity. To obtain a mesh size independent formulation (which is a prerequisite for further application of the theory to more complex situations), we propose a discretization dependent scaling of the short range interaction stress. CDD results are compared to analytical solutions and benchmark data obtained from discrete dislocation simulations.

Schulz, K.; Dickel, D.; Schmitt, S.; Sandfeld, S.; Weygand, D.; Gumbsch, P.

2014-03-01

322

Adapting SAFT-? perturbation theory to site-based molecular dynamics simulation. I. Homogeneous fluids.  

PubMed

In this work, we aim to develop a version of the Statistical Associating Fluid Theory (SAFT)-? equation of state (EOS) that is compatible with united-atom force fields, rather than experimental data. We rely on the accuracy of the force fields to provide the relation to experimental data. Although, our objective is a transferable theory of interfacial properties for soft and fused heteronuclear chains, we first clarify the details of the SAFT-? approach in terms of site-based simulations for homogeneous fluids. We show that a direct comparison of Helmholtz free energy to molecular simulation, in the framework of a third order Weeks-Chandler-Andersen perturbation theory, leads to an EOS that takes force field parameters as input and reproduces simulation results for Vapor-Liquid Equilibria (VLE) calculations. For example, saturated liquid density and vapor pressure of n-alkanes ranging from methane to dodecane deviate from those of the Transferable Potential for Phase Equilibria (TraPPE) force field by about 0.8% and 4%, respectively. Similar agreement between simulation and theory is obtained for critical properties and second virial coefficient. The EOS also reproduces simulation data of mixtures with about 5% deviation in bubble point pressure. Extension to inhomogeneous systems and united-atom site types beyond those used in description of n-alkanes will be addressed in succeeding papers. PMID:24359349

Ghobadi, Ahmadreza F; Elliott, J Richard

2013-12-21

323

Adapting SAFT-? perturbation theory to site-based molecular dynamics simulation. I. Homogeneous fluids  

SciTech Connect

In this work, we aim to develop a version of the Statistical Associating Fluid Theory (SAFT)-? equation of state (EOS) that is compatible with united-atom force fields, rather than experimental data. We rely on the accuracy of the force fields to provide the relation to experimental data. Although, our objective is a transferable theory of interfacial properties for soft and fused heteronuclear chains, we first clarify the details of the SAFT-? approach in terms of site-based simulations for homogeneous fluids. We show that a direct comparison of Helmholtz free energy to molecular simulation, in the framework of a third order Weeks-Chandler-Andersen perturbation theory, leads to an EOS that takes force field parameters as input and reproduces simulation results for Vapor-Liquid Equilibria (VLE) calculations. For example, saturated liquid density and vapor pressure of n-alkanes ranging from methane to dodecane deviate from those of the Transferable Potential for Phase Equilibria (TraPPE) force field by about 0.8% and 4%, respectively. Similar agreement between simulation and theory is obtained for critical properties and second virial coefficient. The EOS also reproduces simulation data of mixtures with about 5% deviation in bubble point pressure. Extension to inhomogeneous systems and united-atom site types beyond those used in description of n-alkanes will be addressed in succeeding papers.

Ghobadi, Ahmadreza F.; Elliott, J. Richard, E-mail: elliot1@uakron.edu [Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, Ohio 44325 (United States)

2013-12-21

324

Perturbation theory based on the Variational Nodal Transport method in X-Y-Z geometry  

SciTech Connect

A perturbation method based on the Variational Nodal Method (VNM) of solving the neutron transport equation is developed for three-dimensional Cartesian geometry. The method utilizes the solution of the corresponding adjoint transport equation to calculate changes in the critical eigenvalue due to changes in cross sections. Both first order and exact perturbation theory expressions are derived. The adjoint solution algorithm has been formulated and incorporated into the VNM option of the Argonne National Laboratory DEF3D production code. The perturbation method is currently implemented as a post-processor to the VNM option of the DIF3D code. To demonstrate the efficacy of the method, example perturbations are applied to the Takeda Benchmark Model 1. In the first perturbation example, the thermal capture cross section is increased within the core region. For the second perturbation example, the increase in the thermal capture cross section is applied in the control rod region. The resulting changes in the critical eigenvalue are obtained by direct calculation in the VNM and compared to the change approximated by the first order and exact theory expressions from the perturbation method. Exact perturbation theory results are inexcellent agreement with the actual eigenvalue differences calculated in the VNM. First order theory holds well for sufficiently small perturbations.

Laurin-Kovitz, K.F.; Lewis, E.E. [Northwestern Univ., Evanston, IL (United States). Dept. of Mechanical Engineering

1995-07-01

325

Improved prediction of tacrolimus concentrations early after kidney transplantation using theory-based pharmacokinetic modelling  

PubMed Central

Aims The aim was to develop a theory-based population pharmacokinetic model of tacrolimus in adult kidney transplant recipients and to externally evaluate this model and two previous empirical models. Methods Data were obtained from 242 patients with 3100 tacrolimus whole blood concentrations. External evaluation was performed by examining model predictive performance using Bayesian forecasting. Results Pharmacokinetic disposition parameters were estimated based on tacrolimus plasma concentrations, predicted from whole blood concentrations, haematocrit and literature values for tacrolimus binding to red blood cells. Disposition parameters were allometrically scaled to fat free mass. Tacrolimus whole blood clearance/bioavailability standardized to haematocrit of 45% and fat free mass of 60 kg was estimated to be 16.1 l h?1 [95% CI 12.6, 18.0 l h?1]. Tacrolimus clearance was 30% higher (95% CI 13, 46%) and bioavailability 18% lower (95% CI 2, 29%) in CYP3A5 expressers compared with non-expressers. An Emax model described decreasing tacrolimus bioavailability with increasing prednisolone dose. The theory-based model was superior to the empirical models during external evaluation displaying a median prediction error of ?1.2% (95% CI ?3.0, 0.1%). Based on simulation, Bayesian forecasting led to 65% (95% CI 62, 68%) of patients achieving a tacrolimus average steady-state concentration within a suggested acceptable range. Conclusion A theory-based population pharmacokinetic model was superior to two empirical models for prediction of tacrolimus concentrations and seemed suitable for Bayesian prediction of tacrolimus doses early after kidney transplantation. PMID:25279405

Størset, Elisabet; Holford, Nick; Hennig, Stefanie; Bergmann, Troels K; Bergan, Stein; Bremer, Sara; Åsberg, Anders; Midtvedt, Karsten; Staatz, Christine E

2014-01-01

326

Impact of an evidence-based medicine curriculum based on adult learning theory  

Microsoft Academic Search

Objective  To develop and implement an evidence-based medicine (EBM) curriculum and determine its effectiveness in improving residents’\\u000a EBM behaviors and skills.\\u000a \\u000a \\u000a \\u000a Design  Description of the curriculum and a multifaceted evaluation, including a pretest-posttest controlled trial.\\u000a \\u000a \\u000a \\u000a Setting  University-based primary care internal medicine residency program.\\u000a \\u000a \\u000a \\u000a Participants  Second-and third-year internal medicine residents (N=34).\\u000a \\u000a \\u000a \\u000a Interventions  A 7-week EBM curriculum in which residents work through the steps of evidence-based decisions

Michael L. Green; Peter J. Ellis

1997-01-01

327

Paying for Express Checkout: Competition and Price Discrimination in Multi-Server Queuing Systems  

PubMed Central

We model competition between two firms selling identical goods to customers who arrive in the market stochastically. Shoppers choose where to purchase based upon both price and the time cost associated with waiting for service. One seller provides two separate queues, each with its own server, while the other seller has a single queue and server. We explore the market impact of the multi-server seller engaging in waiting cost-based-price discrimination by charging a premium for express checkout. Specifically, we analyze this situation computationally and through the use of controlled laboratory experiments. We find that this form of price discrimination is harmful to sellers and beneficial to consumers. When the two-queue seller offers express checkout for impatient customers, the single queue seller focuses on the patient shoppers thereby driving down prices and profits while increasing consumer surplus. PMID:24667809

Deck, Cary; Kimbrough, Erik O.; Mongrain, Steeve

2014-01-01

328

Paying for express checkout: competition and price discrimination in multi-server queuing systems.  

PubMed

We model competition between two firms selling identical goods to customers who arrive in the market stochastically. Shoppers choose where to purchase based upon both price and the time cost associated with waiting for service. One seller provides two separate queues, each with its own server, while the other seller has a single queue and server. We explore the market impact of the multi-server seller engaging in waiting cost-based-price discrimination by charging a premium for express checkout. Specifically, we analyze this situation computationally and through the use of controlled laboratory experiments. We find that this form of price discrimination is harmful to sellers and beneficial to consumers. When the two-queue seller offers express checkout for impatient customers, the single queue seller focuses on the patient shoppers thereby driving down prices and profits while increasing consumer surplus. PMID:24667809

Deck, Cary; Kimbrough, Erik O; Mongrain, Steeve

2014-01-01

329

Theory, Theory  

NSDL National Science Digital Library

This lesson includes a theory-evaluation activity. A set of five scenarios (theories for how diverse life came into existence on Earth) is divided evenly throughout the class, so each student is asked to evaluate one theory. Students then come together in groups of five, so that all theories are represented in each group, where they are compared and evaluated. Each group reports to the entire class for further discussion and clarifications.

Kimmel, Michael

330

SPN model-based performance evaluation of job scheduling plans for distributed rendering environment  

Microsoft Academic Search

Based on the workflow of jobs under DRE (distributed rendering environment), mathematical modeling and performance evaluation were used to investigate different job scheduling plans. Firstly, a SPN (Stochastic Petri Nets) model for job scheduling with different priorities was constructed. Furthermore, using methodologies of SPN model and queuing one, effect of rendering rate, job priority on average completion time was conducted

Zhiguo Hong; Yongbin Wang; Minyong Shi

2011-01-01

331

AN AGENT-BASED APPROACH TO IMPROVING RESOURCE ALLOCATION IN THE DUTCH YOUTH HEALTH CARE  

E-print Network

AN AGENT-BASED APPROACH TO IMPROVING RESOURCE ALLOCATION IN THE DUTCH YOUTH HEALTH CARE SECTOR is used for analyzing different queuing strategies in the youth health care sector. The simulation model-stationary Poisson arrival process, and a preference algorithm to include a care provider's case preference

Ketter, Wolfgang

332

Theory of magnetoresistance based on variable-range hopping in the presence of Hubbard interaction and spin-dynamics  

E-print Network

We develop a theory of magnetoresistance based on variable-range hopping. An exponentially large, low-field and necessarily positive magnetoresistance effect is predicted in the presence of Hubbard interaction and spin-dynamics under certain conditions. The theory was developed with the recently discovered organic magnetoresistance in mind. To account for the experimental observation that the organic magnetoresistance effect can also be negative, we tentatively amend the theory with a mechanism of bipolaron formation.

M. Wohlgenannt

2006-09-22

333

Compressed sensing theory-based channel estimation for optical orthogonal frequency division multiplexing communication system  

NASA Astrophysics Data System (ADS)

Due to the spare multipath property of the channel, a channel estimation method, which is based on partial superimposed training sequence and compressed sensing theory, is proposed for line of sight optical orthogonal frequency division multiplexing communication systems. First, a continuous training sequence is added at variable power ratio to the cyclic prefix of orthogonal frequency division multiplexing symbols at the transmitter prior to transmission. Then the observation matrix of compressed sensing theory is structured by the use of the training symbols at receiver. Finally, channel state information is estimated using sparse signal reconstruction algorithm. Compared to traditional training sequences, the proposed partial superimposed training sequence not only improves the spectral efficiency, but also reduces the influence to information symbols. In addition, compared with classical least squares and linear minimum mean square error methods, the proposed compressed sensing theory based channel estimation method can improve both the estimation accuracy and the system performance. Simulation results are given to demonstrate the performance of the proposed method.

Zhao, Hui; Li, Minghui; Wang, Ruyan; Liu, Yuanni; Song, Daiping

2014-09-01

334

Sophisticated design of PVC membrane ion-selective electrodes based on the mixed potential theory.  

PubMed

The mixed potential (MP) theory was successfully utilized to design an ionophore-based polyvinyl chloride (PVC) membrane K(+) ion-selective electrode (ISE). Prior to the application of the MP theory, the transfer of K(+) and interfering ions (Na(+), Li(+), and H(+)) facilitated by bis(benzo-15-crown-5) (BB15C5) or dibenzo-18-crown-6 (DB18C6) at a micro PVC membrane/water interface was studied by ion-transfer voltammetry (ITV). The reversible half-wave potentials were then obtained for the facilitated transfer of the ions. Using such voltammetric data and the literature data about diffusion coefficients of ions, we could well-predict the potential responses of the BB15C5- or DB18C6-based K(+) ISE, as the function of the concentrations of primary and interfering ions, and also of the counterion for K(+) [e.g., tetrakis(4-chlorophenyl)borate] added to the membrane. Thus, the MP theory has been proven to be useful to optimize the membrane composition for a higher ion selectivity and a lower detection limit. It has also been found that the leaching of ions from an inner solution is too small to affect the detection limit, at least for the designed PVC membrane ISE. PMID:23594104

Imoto, Maya; Sakaki, Toru; Osakai, Toshiyuki

2013-05-01

335

Slender-Body Theory Based On Approximate Solution of the Transonic Flow Equation  

NASA Technical Reports Server (NTRS)

Approximate solution of the nonlinear equations of the small disturbance theory of transonic flow are found for the pressure distribution on pointed slender bodies of revolution for flows with free-stream, Mach number 1, and for flows that are either purely subsonic or purely supersonic. These results are obtained by application of a method based on local linearization that was introduced recently in the analysis of similar problems in two-dimensional flows. The theory is developed for bodies of arbitrary shape, and specific results are given for cone-cylinders and for parabolic-arc bodies at zero angle of attack. All results are compared either with existing theoretical results or with experimental data.

Spreiter, John R.; Alksne, Alberta Y.

1959-01-01

336

A continuum thermal stress theory for crystals based on interatomic potentials  

NASA Astrophysics Data System (ADS)

This paper presents a new continuum thermal stress theory for crystals based on interatomic potentials. The effect of finite temperature is taken into account via a harmonic model. An EAM potential for copper is adopted in this paper and verified by computing the effect of the temperature on the specific heat, coefficient of thermal expansion and lattice constant. Then we calculate the elastic constants of copper at finite temperature. The calculation results are in good agreement with experimental data. The thermal stress theory is applied to an anisotropic crystal graphite, in which the Brenner potential is employed. Temperature dependence of the thermodynamic properties, lattice constants and thermal strains for graphite is calculated. The calculation results are also in good agreement with experimental data.

Liu, XiaoLei; Tang, QiHeng; Wang, TzuChiang

2014-01-01

337

Formula for the rms blur circle radius of Wolter telescope based on aberration theory  

NASA Technical Reports Server (NTRS)

A formula for the rms blur circle for Wolter telescopes has been derived using the transverse ray aberration expressions of Saha (1985), Saha (1984), and Saha (1986). The resulting formula for the rms blur circle radius over an image plane and a formula for the surface of best focus based on third-, fifth-, and seventh-order aberration theory predict results in good agreement with exact ray tracing. It has also been shown that one of the two terms in the empirical formula of VanSpeybroeck and Chase (1972), for the rms blur circle radius of a Wolter I telescope can be justified by the aberration theory results. Numerical results are given comparing the rms blur radius and the surface of best focus vs the half-field angle computed by skew ray tracing and from analytical formulas for grazing incidence Wolter I-II telescopes and a normal incidence Cassegrain telescope.

Shealy, David L.; Saha, Timo T.

1990-01-01

338

Control theory based airfoil design for potential flow and a finite volume discretization  

NASA Technical Reports Server (NTRS)

This paper describes the implementation of optimization techniques based on control theory for airfoil design. In previous studies it was shown that control theory could be used to devise an effective optimization procedure for two-dimensional profiles in which the shape is determined by a conformal transformation from a unit circle, and the control is the mapping function. The goal of our present work is to develop a method which does not depend on conformal mapping, so that it can be extended to treat three-dimensional problems. Therefore, we have developed a method which can address arbitrary geometric shapes through the use of a finite volume method to discretize the potential flow equation. Here the control law serves to provide computationally inexpensive gradient information to a standard numerical optimization method. Results are presented, where both target speed distributions and minimum drag are used as objective functions.

Reuther, J.; Jameson, A.

1994-01-01

339

Scale effects on information theory-based measures applied to streamflow patterns in two rural watersheds  

NASA Astrophysics Data System (ADS)

SummaryUnderstanding streamflow patterns in space and time is important for improving flood and drought forecasting, water resources management, and predictions of ecological changes. Objectives of this work include (a) to characterize the spatial and temporal patterns of streamflow using information theory-based measures at two thoroughly-monitored agricultural watersheds located in different hydroclimatic zones with similar land use, and (b) to elucidate and quantify temporal and spatial scale effects on those measures. We selected two USDA experimental watersheds to serve as case study examples, including the Little River experimental watershed (LREW) in Tifton, Georgia and the Sleepers River experimental watershed (SREW) in North Danville, Vermont. Both watersheds possess several nested sub-watersheds and more than 30 years of continuous data records of precipitation and streamflow. Information content measures (metric entropy and mean information gain) and complexity measures (effective measure complexity and fluctuation complexity) were computed based on the binary encoding of 5-year streamflow and precipitation time series data. We quantified patterns of streamflow using probabilities of joint or sequential appearances of the binary symbol sequences. Results of our analysis illustrate that information content measures of streamflow time series are much smaller than those for precipitation data, and the streamflow data also exhibit higher complexity, suggesting that the watersheds effectively act as filters of the precipitation information that leads to the observed additional complexity in streamflow measures. Correlation coefficients between the information-theory-based measures and time intervals are close to 0.9, demonstrating the significance of temporal scale effects on streamflow patterns. Moderate spatial scale effects on streamflow patterns are observed with absolute values of correlation coefficients between the measures and sub-watershed area varying from 0.2 to 0.6 in the two watersheds. We conclude that temporal effects must be evaluated and accounted for when the information theory-based methods are used for performance evaluation and comparison of hydrological models.

Pan, Feng; Pachepsky, Yakov A.; Guber, Andrey K.; McPherson, Brian J.; Hill, Robert L.

2012-01-01

340

Mapping edge-based traffic measurements onto the internal links in MPLS network  

NASA Astrophysics Data System (ADS)

Applying multi-protocol label switching techniques to IP-based backbone for traffic engineering goals has shown advantageous. Obtaining a volume of load on each internal link of the network is crucial for traffic engineering applying. Though collecting can be available for each link, such as applying traditional SNMP scheme, the approach may cause heavy processing load and sharply degrade the throughput of the core routers. Then monitoring merely at the edge of the network and mapping the measurements onto the core provides a good alternative way. In this paper, we explore a scheme for traffic mapping with edge-based measurements in MPLS network. It is supposed that the volume of traffic on each internal link over the domain would be mapped onto by measurements available only at ingress nodes. We apply path-based measurements at ingress nodes without enabling measurements in the core of the network. We propose a method that can infer a path from the ingress to the egress node using label distribution protocol without collecting routing data from core routers. Based on flow theory and queuing theory, we prove that our approach is effective and present the algorithm for traffic mapping. We also show performance simulation results that indicate potential of our approach.

Zhao, Guofeng; Tang, Hong; Zhang, Yi

2004-09-01

341

Consistent propagator theory based on the extended coupled-cluster parametrization of the ground state  

NASA Astrophysics Data System (ADS)

We develop in this paper a consistent superoperator-resolvent-based propagator theory using the extended coupled-cluster (CC) parametrization [Phys. Rev. A 36, 2519 (1987); Ann. Phys. 151, 311 (1983)] of the ground state. The method exploits the underlying non-Hermitian nature of the transformed Hamiltonian appearing in the extended coupled-cluster method. In this method, we obtain finite expressions in powers of cluster coefficients for both the transition amplitudes as the residues and the elements of the effective matrix contributing to the poles of the propagator. There is a natural ``resolution of identity'' involving consistent basis constructed by us, which leads to the biorthogonal sets of ket and bra functions used in the representation of the intermediate states in the inner projection of the propagator. The manifold of operators generating these states satisfies the ``vacuum-annihilation condition'' on the ground state and is thus consistent. There is a natural decoupling of the forward and backward components of the propagator even under the uneven truncation of the CC expansion of the ground state and the operator basis, which should be convenient for practical applications. We have discussed in detail the realization of the consistent representation of the ionized or excited states by taking as illustrative examples the case of one-electron and polarization propagators and have suggested practical truncation schemes for their implementation. An order-by-order perturbative analysis has been made to indicate the relation of our formalism to some of the more recent theories. We have also shown that the now established coupled-cluster-based linear-response theory can be viewed as an approximate version of the consistent propagator theory, which furnishes the same poles as the latter but nonconsistent residues.

Datta, Barnali; Mukhopadhyay, Debasis; Mukherjee, Debashis

1993-05-01

342

Simulating Single Word Processing in the Classic Aphasia Syndromes Based on the Wernicke-Lichtheim-Geschwind Theory  

ERIC Educational Resources Information Center

The Wernicke-Lichtheim-Geschwind (WLG) theory of the neurobiological basis of language is of great historical importance, and it continues to exert a substantial influence on most contemporary theories of language in spite of its widely recognized limitations. Here, we suggest that neurobiologically grounded computational models based on the WLG…

Weems, Scott A.; Reggia, James A.

2006-01-01

343

An Alienation-Based Framework for Student Experience in Higher Education: New Interpretations of Past Observations in Student Learning Theory  

ERIC Educational Resources Information Center

This article orients a recently proposed alienation-based framework for student learning theory (SLT) to the empirical basis of the approaches to learning perspective. The proposed framework makes new macro-level interpretations of an established micro-level theory, across three levels of interpretation: (1) a context-free psychological state…

Barnhardt, Bradford; Ginns, Paul

2014-01-01

344

The Conceptual Mechanism for Viable Organizational Learning Based on Complex System Theory and the Viable System Model  

ERIC Educational Resources Information Center

The purpose of this research is to explore the possibility of viable learning organizations based on identifying viable organizational learning mechanisms. Two theoretical foundations, complex system theory and viable system theory, have been integrated to provide the rationale for building the sustainable organizational learning mechanism. The…

Sung, Dia; You, Yeongmahn; Song, Ji Hoon

2008-01-01

345

A sampling-based computational strategy for the representation of epistemic uncertainty in model predictions with evidence theory.  

SciTech Connect

Evidence theory provides an alternative to probability theory for the representation of epistemic uncertainty in model predictions that derives from epistemic uncertainty in model inputs, where the descriptor epistemic is used to indicate uncertainty that derives from a lack of knowledge with respect to the appropriate values to use for various inputs to the model. The potential benefit, and hence appeal, of evidence theory is that it allows a less restrictive specification of uncertainty than is possible within the axiomatic structure on which probability theory is based. Unfortunately, the propagation of an evidence theory representation for uncertainty through a model is more computationally demanding than the propagation of a probabilistic representation for uncertainty, with this difficulty constituting a serious obstacle to the use of evidence theory in the representation of uncertainty in predictions obtained from computationally intensive models. This presentation describes and illustrates a sampling-based computational strategy for the representation of epistemic uncertainty in model predictions with evidence theory. Preliminary trials indicate that the presented strategy can be used to propagate uncertainty representations based on evidence theory in analysis situations where naive sampling-based (i.e., unsophisticated Monte Carlo) procedures are impracticable due to computational cost.

Johnson, J. D. (Prostat, Mesa, AZ); Oberkampf, William Louis; Helton, Jon Craig (Arizona State University, Tempe, AZ); Storlie, Curtis B. (North Carolina State University, Raleigh, NC)

2006-10-01

346

Volume Averaging Theory (VAT) based modeling and closure evaluation for fin-and-tube heat exchangers  

NASA Astrophysics Data System (ADS)

A fin-and-tube heat exchanger was modeled based on Volume Averaging Theory (VAT) in such a way that the details of the original structure was replaced by their averaged counterparts, so that the VAT based governing equations can be efficiently solved for a wide range of parameters. To complete the VAT based model, proper closure is needed, which is related to a local friction factor and a heat transfer coefficient of a Representative Elementary Volume (REV). The terms in the closure expressions are complex and sometimes relating experimental data to the closure terms is difficult. In this work we use CFD to evaluate the rigorously derived closure terms over one of the selected REVs. The objective is to show how heat exchangers can be modeled as a porous media and how CFD can be used in place of a detailed, often formidable, experimental effort to obtain closure for the model.

Zhou, Feng; Catton, Ivan

2012-10-01

347

Vervet monkeys solve a multiplayer "forbidden circle game" by queuing to learn restraint.  

PubMed

In social dilemmas, the ability of individuals to coordinate their actions is crucial to reach group optima. Unless exacted by power or force, coordination in humans relies on a common understanding of the problem, which is greatly facilitated by communication. The lack of means of consultation about the nature of the problem and how to solve it may explain why multiagent coordination in nonhuman vertebrates has commonly been observed only when multiple individuals react instantaneously to a single stimulus, either natural or experimentally simulated, for example a predator, a prey, or a neighboring group. Here we report how vervet monkeys solved an experimentally induced coordination problem. In each of three groups, we trained a low-ranking female, the "provider," to open a container holding a large amount of food, which the providers only opened when all individuals dominant to them ("dominants") stayed outside an imaginary "forbidden circle" around it. Without any human guidance, the dominants learned restraint one by one, in hierarchical order from high to low. Once all dominants showed restraint immediately at the start of the trial, the providers opened the container almost instantly, saving all individuals opportunity costs due to lost foraging time. Solving this game required trial-and-error learning based on individual feedback from the provider to each dominant, and all dominants being patient enough to wait outside the circle while others learned restraint. Communication, social learning, and policing by high-ranking animals played no perceptible role. PMID:23541727

Fruteau, Cécile; van Damme, Eric; Noë, Ronald

2013-04-22

348

Allport's Intergroup Contact Theory as a theoretical base for impacting student attitudes in interprofessional education.  

PubMed

Interprofessional education has been defined as "members or students of two or more professionals associated with health or social care, engaged in learning with, from and about each other". Ideally, students trained using interprofessional education paradigms become interprofessional team members who gain respect and improve their attitudes about each other, and ultimately improve patient outcomes. However, it has been stated that before interprofessional education can claim its importance and successes, its impact must be critically evaluated. What theory can explain the impact that interprofessional education seems to have on changing students' attitudes of other professionals and positively affecting their performance as interprofessional healthcare team members? The authors of this paper suggest conditions identified in Gordon Allport's Contact Theory may be used as a theoretical base in interprofessional education to positively impact attitudinal change of students towards working as an interprofessional team member. For the purpose of this paper, equal status and common goals will be the two conditions highlighted as a theoretical base in interprofessional education. The premise to be explored in this paper is that utilizing a sound theoretical base in interprofessional education may positively impact students' attitudes towards working in interprofessional teams. PMID:20216998

Bridges, Diane R; Tomkowiak, John

2010-01-01

349

color prediction for print based on kubelka-munk theory and under ink penetration  

NASA Astrophysics Data System (ADS)

In 1931, Kubelka and Munk introduced two-flux Kubelka-Munk model based on radiative transfer theory[1]. But the model has lots of strict conditions. In 1942, Saunderson introduced revised method, for there would occur multiple inside reflection in the interface of print, and it would induce density increase in the ink layer, and influenced prediction precision. Dot gain is always the difficult problem in print, it includes physics gain and optical gain. Kubelka-Munk model didn't consider dot gain's effect, especially optical gain. There are many methods to calculate dot gain. Many of them are based on point spread function principle[5]. Recently, Yang Li corrects the scattering coefficient S and absorption coefficient K in the Kubelka-Munk model based on statistical physics theory[2][3][4]. This makes the model has more widely applications. This article, taking into account of oil layer, oil penetration layer and paper layer respectively, thinking over multiple reflection and optical dot gain, builds a new halftone color prediction model.

Shi, Guoyun; Dong, Na; Zhang, Yixin

2009-01-01

350

A Feature Extraction Method Based on Information Theory for Fault Diagnosis of Reciprocating Machinery  

PubMed Central

This paper proposes a feature extraction method based on information theory for fault diagnosis of reciprocating machinery. A method to obtain symptom parameter waves is defined in the time domain using the vibration signals, and an information wave is presented based on information theory, using the symptom parameter waves. A new way to determine the difference spectrum of envelope information waves is also derived, by which the feature spectrum can be extracted clearly and machine faults can be effectively differentiated. This paper also compares the proposed method with the conventional Hilbert-transform-based envelope detection and with a wavelet analysis technique. Practical examples of diagnosis for a rolling element bearing used in a diesel engine are provided to verify the effectiveness of the proposed method. The verification results show that the bearing faults that typically occur in rolling element bearings, such as outer-race, inner-race, and roller defects, can be effectively identified by the proposed method, while these bearing faults are difficult to detect using either of the other techniques it was compared to. PMID:22574021

Wang, Huaqing; Chen, Peng

2009-01-01

351

Can Directors Impact Performance? A case-based test of three theories of corporate governance  

Microsoft Academic Search

We examine hypothesised links between the board of directors and firm performance as predicted by the three predominant theories in corporate governance research, namely agency theory, stewardship theory and resource dependence theory. By employing a pattern matching analysis of seven cases, we are able to examine the hypothesised link between board demography and firm performance expected under each theory. We

Gavin J. Nicholson; Geoffrey C. Kiel

2007-01-01

352

An Implicational View of Self-Healing and Personality Change Based on Gendlin's Theory of Experiencing.  

ERIC Educational Resources Information Center

There is relatively little theory on how psychotherapy clients self-heal since most theories of therapy stress the magic of the therapist's interventions. Of the theories that exist, this paper briefly discusses Carl Rogers' theory of self-actualization; and the dialectical theories of Greenberg and his colleagues, Jenkins, and Rychlak. Gendlin's…

Bohart, Arthur C.

353

Spatial registration of digital brain atlases based on fuzzy set theory.  

PubMed

We present a semiautomatic method based on fuzzy set theory for adjusting a computerized brain atlas to magnetic resonance images (MRIs) of the human cerebral cortex. The atlas was registered to three-dimensional MRI data sets of 10 healthy volunteers. After a global matching using the external contour of the brain, several local procedures were performed regarding selected primary furrows and cytoarchitectonic areas. The final transformation matrix was calculated with respect to these anatomical structures and to their local matrices. Evaluation revealed an increase in accuracy as expressed by a reduction of the visible mismatch with respect to the registration of cortical and subcortical brain structures. PMID:11120403

Berks, G; Ghassemi, A; von Keyserlingk, D G

2001-01-01

354

System for absolute measurement of electrolytic conductivity in aqueous solutions based on van der Pauw's theory  

NASA Astrophysics Data System (ADS)

Based on an innovative application of van der Pauw's theory, a system was developed for the absolute measurement of electrolytic conductivity in aqueous solutions. An electrolytic conductivity meter was designed that uses a four-electrode system with an axial-radial two-dimensional adjustment structure coupled to an ac voltage excitation source and signal collecting circuit. The measurement accuracy, resolution and repeatability of the measurement system were examined through a series of experiments. Moreover, the measurement system and a high-precision electrolytic conductivity meter were compared using some actual water samples.

Zhang, Bing; Lin, Zhen; Zhang, Xiao; Yu, Xiang; Wei, Jiali; Wang, Xiaoping

2014-05-01

355

A rapid, universal TI-59 model-independent pharmacokinetic analysis program based on statistical moment theory.  

PubMed

A model-independent program for pharmacokinetic analyses based on statistical moment theory is presented and demonstrated. The program uses an inexpensive and portable TI-59; a PC-100A printer adds convenience but is optional. The program may be used in analysis of blood, serum, or plasma concentration vs. time curves originating from iv, im, po, sl, or sc administration. Drug input can be zero or first order; both single-dose and multiple-dose steady-state conditions can be evaluated. A comparison between results generated using moment analysis and traditional two-compartment nonlinear regression showed excellent agreement. PMID:3838276

Reitberg, D P; Smith, I L; Love, S J; Lewin, H M; Schentag, J J

1985-02-01

356

Risk Evaluation of Bogie System Based on Extension Theory and Entropy Weight Method  

PubMed Central

A bogie system is the key equipment of railway vehicles. Rigorous practical evaluation of bogies is still a challenge. Presently, there is overreliance on part-specific experiments in practice. In the present work, a risk evaluation index system of a bogie system has been established based on the inspection data and experts' evaluation. Then, considering quantitative and qualitative aspects, the risk state of a bogie system has been evaluated using an extension theory and an entropy weight method. Finally, the method has been used to assess the bogie system of four different samples. Results show that this method can assess the risk state of a bogie system exactly. PMID:25574159

Du, Yanping; Zhang, Yuan; Zhao, Xiaogang; Wang, Xiaohui

2014-01-01

357

Unique laminar-flow stability limit based shallow-water theory  

USGS Publications Warehouse

Two approaches are generally taken in deriving the stability limit for the Froude member (Fs) for laminar sheet flow. The first approach used the Orr-Sommerfeld equation, while the second uses the cross-section-averaged equations of continuity and motion. Because both approaches are based on shallow-water theory, the values of Fs obtained from both approaches should be identical, yet in the literature they are not. This suggests that a defect exists in at least one of the two approaches. After examining the governing equations used in both approaches, one finds that the existing cross-section -averaged equation of motion is dependent on the frame of reference.

Chen, Cheng-lung

1993-01-01

358

An ISAR imaging algorithm for the space satellite based on empirical mode decomposition theory  

NASA Astrophysics Data System (ADS)

Currently, high resolution imaging of the space satellite is a popular topic in the field of radar technology. In contrast with regular targets, the satellite target often moves along with its trajectory and simultaneously its solar panel substrate changes the direction toward the sun to obtain energy. Aiming at the imaging problem, a signal separating and imaging approach based on the empirical mode decomposition (EMD) theory is proposed, and the approach can realize separating the signal of two parts in the satellite target, the main body and the solar panel substrate and imaging for the target. The simulation experimentation can demonstrate the validity of the proposed method.

Zhao, Tao; Dong, Chun-zhu

2014-11-01

359

Development of new tip-loss corrections based on vortex theory and vortex methods  

NASA Astrophysics Data System (ADS)

A new analytical formulation of the tip-loss factor is established based on helical vortex filament solutions. The derived tip-loss factor can be applied to wind-turbines, propellers or other rotary wings. Similar numerical formulations are used to assess the influence of wake expansion on tip-losses. Theodorsen's theory is successfully applied for the first time to assess the wake expansion behind a wind turbine. The tip-loss corrections obtained are compared with the ones from Prandtl and Glauert and implemented within a new Blade Element Momentum(BEM) code. Wake expansion is seen to reduce tip-losses and have a greater influence than wake distortion.

Branlard, Emmanuel; Gaunaa, Mac

2014-12-01

360

Building a multiple modality, theory-based physical activity intervention: The development of CardiACTION!  

PubMed

OBJECTIVES: Despite the widely acknowledged benefits of regular physical activity (PA), specific goals for increased population levels of PA, and strongly recommended strategies to promote PA, there is no evidence suggesting that the prevalence of PA is improving. If PA intervention research is to be improved, theory should be used as the basis for intervention development, participant context or environment should be considered in the process, and intervention characteristics that will heighten the likelihood of translation into practice should be implemented (e.g., ease of implementation, low human resource costs). The purpose of this paper is to describe the implementation of the aforementioned concepts within the intervention development process associated with CardiACTION an ongoing randomized 2 × 2 factorial trial. METHODS: The Ecological Model of Physical Activity integrated with Protection Motivation Theory was used to inform the design of the interventions. This integrated model was selected to allow for the development of theory-based individual, environmental, and individually + environmentally targeted physical activity interventions. All intervention strategies were matched to proposed mediators of behavior change. Strategies were then matched to the most appropriate interactive technology (i.e., interactive computer session, automated telephone counseling, and tailored mailings) delivery channel. CONCLUSIONS: The potential implications of this study include determining the independent and combined influence of individual and environment mechanisms of behavior change on intervention effectiveness. In addition, all intervention models are developed to be scalable and disseminable to a broad audience at a low cost. PMID:22473308

Estabrooks, Paul A; Glasgow, Russ E; Xu, Stan; Dzewaltowski, David A; Lee, Rebecca E; Thomas, Deborah; Almeida, Fabio A; Thayer, Amy N; Smith-Ray, Renae L

2011-01-01

361

Brillouin{endash}Wigner based multi-reference perturbation theory for electronic correlation effects  

SciTech Connect

We investigate basis set reduction (BSR), a configuration-based multi-reference perturbation theory using an implicit effective Hamiltonian motivated by Brillouin-Wigner perturbation theory. This approach avoids the intruder-state and level-crossing problems by construction and yields a rapidly converging perturbation expansion. Formulated to systematically approximate multi-reference configuration interaction, BSR yields accurate results in second order, because it includes relaxation effects of the primary space wavefunction in the presence of the perturbation. We benchmark the method for molecules (CH{sub 2},O{sub 3}) in which both dynamical and non-dynamical correlation effects are known to be important, obtaining accuracies of the order of 1 kcal/mol across the potential energy surface in second-order perturbation theory. We address the critical issues of perturbative orbital optimization for the primary orbital space, the choice of the secondary orbital space and the effects of single excitations. {copyright} {ital 1998 American Institute of Physics.}

Wenzel, W. [Theoretical Physics I, Dortmund University, D-44221 Dortmund (Germany)] [Theoretical Physics I, Dortmund University, D-44221 Dortmund (Germany); Steiner, M.M. [Department of Physics, Ohio State University, 174 W 19th Ave, Columbus, Ohio 43210 (United States)] [Department of Physics, Ohio State University, 174 W 19th Ave, Columbus, Ohio 43210 (United States)

1998-03-01

362

Toward a limited realism for psychiatric nosology based on the coherence theory of truth.  

PubMed

A fundamental debate in the philosophy of science is whether our central concepts are true or only useful instruments to help predict and manipulate the world. The first position is termed 'realism' and the second 'instrumentalism'. Strong support for the instrumentalist position comes from the 'pessimistic induction' (PI) argument. Given that many key scientific concepts once considered true (e.g. humors, ether, epicycles, phlogiston) are now considered false, how, the argument goes, can we assert that our current concepts are true? The PI argument applies strongly to psychiatric diagnoses. Given our long history of abandoned diagnoses, arguments that we have finally 'gotten it right' and developed definitive psychiatric categories that correspond to observer-independent reality are difficult to defend. For our current diagnostic categories, we should settle for a less ambitious vision of truth. For this, the coherence theory, which postulates that something is true when it fits well with the other things we confidently know about the world, can serve us well. Using the coherence theory, a diagnosis is real to the extent that it is well integrated into our accumulating scientific data base. Furthermore, the coherence theory establishes a framework for us to evaluate our diagnostic categories and can provide a set of criteria, closely related to our concept of validators, for deciding when they are getting better. Finally, we need be much less skeptical about the truth status of the aggregate concept of psychiatric illness than we are regarding the specific categories in our current nosology. PMID:25181016

Kendler, K S

2014-09-01

363

A density functional theory and time-dependent density functional theory investigation on the anchor comparison of triarylamine-based dyes  

Microsoft Academic Search

To understand the effects of the anchor part in organic dyes on the energy conversion efficiency of dye-sensitized solar cells (DSCs), two different anchor groups used in metal-free triphenylamine (TPA)-based organic dyes for DSCs have been theoretically compared. Density functional theory (DFT) and time-dependent DFT (TDDFT) study of geometry properties, excitations, and electronic structures of triarylamine-based dyes (TC1 and TPAR1)

Bo Peng; Siqi Yang; Lanlan Li; Fangyi Cheng; Jun Chen

2010-01-01

364

Unit Template Synchronous Reference Frame Theory Based Control Algorithm for DSTATCOM  

NASA Astrophysics Data System (ADS)

This article proposes new and simplified unit templates instead of standard phase locked loop (PLL) for Synchronous Reference Frame Theory Control Algorithm (SRFT). The extraction of synchronizing components (sin? and cos?) for parks and inverse parks transformation using standard PLL takes more execution time. This execution time in control algorithm delays the extraction of reference source current generation. The standard PLL not only takes more execution time but also increases the reactive power burden on the Distributed Static Compensator (DSTATCOM). This work proposes a unit template based SRFT control algorithm for four-leg insulated gate bipolar transistor based voltage source converter for DSTATCOM in distribution systems. This will reduce the execution time and reactive power burden on the DSTATCOM. The proposed DSTATCOM suppress harmonics, regulates the terminal voltage along with neutral current compensation. The DSTATCOM in distribution systems with proposed control algorithm is modeled and simulated using MATLAB using SIMULINK and Simpower systems toolboxes.

Bangarraju, J.; Rajagopal, V.; Jayalaxmi, A.

2014-04-01

365

Can functionalized cucurbituril bind actinyl cations efficiently? A density functional theory based investigation.  

PubMed

The feasibility of using cucurbituril host molecule as a probable actinyl cation binders candidate is investigated through density functional theory based calculations. Various possible binding sites of the cucurbit[5]uril host molecule to uranyl are analyzed and based on the binding energy evaluations, ?(5)-binding is predicted to be favored. For this coordination, the structure, vibrational spectra, and binding energies are evaluated for the binding of three actinyls in hexa-valent and penta-valent oxidation states with functionalized cucurbiturils. Functionalizing cucurbituril with methyl and cyclohexyl groups increases the binding affinities of actinyls, whereas fluorination decreases the binding affinities as compared to the native host molecule. Surprisingly hydroxylation of the host molecule does not distinguish the oxidation state of the three actinyls. PMID:22471316

Sundararajan, Mahesh; Sinha, Vivek; Bandyopadhyay, Tusar; Ghosh, Swapan K

2012-05-01

366

Buckling Analysis for Stiffened Anisotropic Circular Cylinders Based on Sanders Nonlinear Shell Theory  

NASA Technical Reports Server (NTRS)

Nonlinear and bifurcation buckling equations for elastic, stiffened, geometrically perfect, right-circular cylindrical, anisotropic shells subjected to combined loads are presented that are based on Sanders' shell theory. Based on these equations, a three-parameter approximate Rayleigh-Ritz solution and a classical solution to the buckling problem are presented for cylinders with simply supported edges. Extensive comparisons of results obtained from these solutions with published results are also presented for a wide range of cylinder constructions. These comparisons include laminated-composite cylinders with a wide variety of shell-wall orthotropies and anisotropies. Numerous results are also given that show the discrepancies between the results obtained by using Donnell's equations and variants of Sanders' equations. For some cases, nondimensional parameters are identified and "master" curves are presented that facilitate the concise representation of results.

Nemeth, Michael P.

2014-01-01

367

Evaluation of Transverse Thermal Stresses in Composite Plates Based on First-Order Shear Deformation Theory  

NASA Technical Reports Server (NTRS)

A postprocessing procedure is presented for the evaluation of the transverse thermal stresses in laminated plates. The analytical formulation is based on the first-order shear deformation theory and the plate is discretized by using a single-field displacement finite element model. The procedure is based on neglecting the derivatives of the in-plane forces and the twisting moments, as well as the mixed derivatives of the bending moments, with respect to the in-plane coordinates. The calculated transverse shear stiffnesses reflect the actual stacking sequence of the composite plate. The distributions of the transverse stresses through-the-thickness are evaluated by using only the transverse shear forces and the thermal effects resulting from the finite element analysis. The procedure is implemented into a postprocessing routine which can be easily incorporated into existing commercial finite element codes. Numerical results are presented for four- and ten-layer cross-ply laminates subjected to mechanical and thermal loads.

Rolfes, R.; Noor, A. K.; Sparr, H.

1998-01-01

368

Optimization of a photovoltaic pumping system based on the optimal control theory  

SciTech Connect

This paper suggests how an optimal operation of a photovoltaic pumping system based on an induction motor driving a centrifugal pump can be realized. The optimization problem consists in maximizing the daily pumped water quantity via the optimization of the motor efficiency for every operation point. The proposed structure allows at the same time the minimization the machine losses, the field oriented control and the maximum power tracking of the photovoltaic array. This will be attained based on multi-input and multi-output optimal regulator theory. The effectiveness of the proposed algorithm is described by simulation and the obtained results are compared to those of a system working with a constant air gap flux. (author)

Betka, A.; Attali, A. [Laboratoire de Genie Electrique de Biskra (LGEB), Electrical Engineering Department, University of Biskra (Algeria)

2010-07-15

369

Research on the alternatives in a strategic environmental assessment based on the extension theory.  

PubMed

The main purpose of a strategic environmental assessment (SEA) is to facilitate the early consideration of potential environmental impacts in decision-making processes. SEA alternative identification is a core issue within the SEA framework. However, the current methods of SEA alternative formulation and selection are constrained by the limited setting range and lack of scientific evaluation. Thus, the current paper attempts to provide a new methodology based on the extension theory to identify a range of alternatives and screen the best one. Extension planning is applied to formulate a set of alternatives that satisfy the reasonable interests of the stakeholders. Extension priority evaluation is used to assess and optimize the alternatives and present a scientific methodology for the SEA alternative study. Thereafter, the urban traffic plan of Dalian City is used as an example to demonstrate the feasibility of the new method. The traffic planning scheme and the environmental protection scheme are organically combined based on the extension theory, and the reliability and practicality of this approach are examined. PMID:21960364

Du, Jing; Yang, Yang; Xu, Ling; Zhang, Shushen; Yang, Fenglin

2012-09-01

370

A Protection Motivation Theory-Based Scale for Tobacco Research among Chinese Youth.  

PubMed

Rates of tobacco use among adolescents in China and other lower and middle-income countries remain high despite notable prevention and intervention programs. One reason for this may be the lack of theory-based research in tobacco use prevention in these countries. In the current study, a culturally appropriate 21-item measurement scale for cigarette smoking was developed based on the core constructs of Protection Motivation Theory (PMT). The scale was assessed among a sample of 553 Chinese vocational high school students. Results from correlational and measurement modeling analysis indicated adequate measurement reliability for the proposed PMT scale structure. The two PMT Pathways and the seven PMT constructs were significantly correlated with adolescent intention to smoke and actual smoking behavior. This study is the first to evaluate a PMT scale for cigarette smoking among Chinese adolescents. The scale provides a potential tool for assessing social cognitive processes underlying tobacco use. This is essential for understanding smoking behavior among Chinese youth and to support more effective tobacco use prevention efforts. Additional studies are needed to assess its utility for use with Chinese youth in other settings. PMID:24478933

Macdonell, Karen; Chen, Xinguang; Yan, Yaqiong; Li, Fang; Gong, Jie; Sun, Huiling; Li, Xiaoming; Stanton, Bonita

2013-07-01

371

A Protection Motivation Theory-Based Scale for Tobacco Research among Chinese Youth  

PubMed Central

Rates of tobacco use among adolescents in China and other lower and middle-income countries remain high despite notable prevention and intervention programs. One reason for this may be the lack of theory-based research in tobacco use prevention in these countries. In the current study, a culturally appropriate 21-item measurement scale for cigarette smoking was developed based on the core constructs of Protection Motivation Theory (PMT). The scale was assessed among a sample of 553 Chinese vocational high school students. Results from correlational and measurement modeling analysis indicated adequate measurement reliability for the proposed PMT scale structure. The two PMT Pathways and the seven PMT constructs were significantly correlated with adolescent intention to smoke and actual smoking behavior. This study is the first to evaluate a PMT scale for cigarette smoking among Chinese adolescents. The scale provides a potential tool for assessing social cognitive processes underlying tobacco use. This is essential for understanding smoking behavior among Chinese youth and to support more effective tobacco use prevention efforts. Additional studies are needed to assess its utility for use with Chinese youth in other settings. PMID:24478933

MacDonell, Karen; Chen, Xinguang; Yan, Yaqiong; Li, Fang; Gong, Jie; Sun, Huiling; Li, Xiaoming; Stanton, Bonita

2014-01-01

372

A Massive Yang-Mills Theory based on the Nonlinearly Realized Gauge Group  

E-print Network

We propose a subtraction scheme for a massive Yang-Mills theory realized via a nonlinear representation of the gauge group (here SU(2)). It is based on the subtraction of the poles in D-4 of the amplitudes, in dimensional regularization, after a suitable normalization has been performed. Perturbation theory is in the number of loops and the procedure is stable under iterative subtraction of the poles. The unphysical Goldstone bosons, the Faddeev-Popov ghosts and the unphysical mode of the gauge field are expected to cancel out in the unitarity equation. The spontaneous symmetry breaking parameter is not a physical variable. We use the tools already tested in the nonlinear sigma model: hierarchy in the number of Goldstone boson legs and weak power-counting property (finite number of independent divergent amplitudes at each order). It is intriguing that the model is naturally based on the symmetry SU(2)_L local times SU(2)_R global. By construction the physical amplitudes depend on the mass and on the self-coupling constant of the gauge particle and moreover on the scale parameter of the radiative corrections. The Feynman rules are in the Landau gauge.

Daniele Bettinelli; Ruggero Ferrari; Andrea Quadri

2007-05-16

373

Massive Yang-Mills theory based on the nonlinearly realized gauge group  

SciTech Connect

We propose a subtraction scheme for a massive Yang-Mills theory realized via a nonlinear representation of the gauge group [here SU(2)]. It is based on the subtraction of the poles in D-4 of the amplitudes, in dimensional regularization, after a suitable normalization has been performed. Perturbation theory is in the number of loops, and the procedure is stable under iterative subtraction of the poles. The unphysical Goldstone bosons, the Faddeev-Popov ghosts, and the unphysical mode of the gauge field are expected to cancel out in the unitarity equation. The spontaneous symmetry breaking parameter is not a physical variable. We use the tools already tested in the nonlinear sigma model: hierarchy in the number of Goldstone boson legs and weak-power-counting property (finite number of independent divergent amplitudes at each order). It is intriguing that the model is naturally based on the symmetry SU(2){sub L} local x SU(2){sub R} global. By construction the physical amplitudes depend on the mass and on the self-coupling constant of the gauge particle and moreover on the scale parameter of the radiative corrections. The Feynman rules are in the Landau gauge.

Bettinelli, D.; Ferrari, R.; Quadri, A. [Dipartimento di Fisica, Universita degli Studi di Milano and INFN, Sezione di Milano via Celoria 16, I-20133 Milan (Italy)

2008-02-15

374

Risk assessment and hierarchical risk management of enterprises in chemical industrial parks based on catastrophe theory.  

PubMed

According to risk systems theory and the characteristics of the chemical industry, an index system was established for risk assessment of enterprises in chemical industrial parks (CIPs) based on the inherent risk of the source, effectiveness of the prevention and control mechanism, and vulnerability of the receptor. A comprehensive risk assessment method based on catastrophe theory was then proposed and used to analyze the risk levels of ten major chemical enterprises in the Songmu Island CIP, China. According to the principle of equal distribution function, the chemical enterprise risk level was divided into the following five levels: 1.0 (very safe), 0.8 (safe), 0.6 (generally recognized as safe, GRAS), 0.4 (unsafe), 0.2 (very unsafe). The results revealed five enterprises (50%) with an unsafe risk level, and another five enterprises (50%) at the generally recognized as safe risk level. This method solves the multi-objective evaluation and decision-making problem. Additionally, this method involves simple calculations and provides an effective technique for risk assessment and hierarchical risk management of enterprises in CIPs. PMID:23208298

Chen, Yu; Song, Guobao; Yang, Fenglin; Zhang, Shushen; Zhang, Yun; Liu, Zhenyu

2012-12-01

375

Describing excited state intramolecular proton transfer in dual emissive systems: a density functional theory based analysis.  

PubMed

The excited state intramolecular proton transfer (ESIPT) reaction taking place within 2-(2-hydroxyphenyl)benzoxazole (HBT) and two recently experimentally characterized napthalimide derivatives-known as N-1 and N-4-has been investigated in order to identify and test a possible protocol for the description and complete mechanistic and electronic characterization of the reaction at the excited state. This protocol is based on density functional theory, time-dependent density functional theory, and a recently proposed electron density based index (DCT). This method is able to identify all stable species involved in the reaction, discriminate between possible reaction pathways over potential energy surfaces (PES), which are intrinsically very flat and difficult to characterize, and quantitatively measure the excited state charge transfer character throughout the reaction. The photophysical properties of the molecules (i.e., absorption and emission wavelength) are also quantitatively determined via the implicit inclusion of solvent effects in the case of toluene and, the more polar, tetrahydrofuran. The accuracy obtained with this protocol then opens up the possibility of the ab initio design of molecules exhibiting ESIPT for tailored applications such as highly selective molecular sensors. PMID:25208048

Wilbraham, Liam; Savarese, Marika; Rega, Nadia; Adamo, Carlo; Ciofini, Ilaria

2015-02-12

376

Carbon nanotube-reinforced composites: frequency analysis theories based on the matrix stiffness  

NASA Astrophysics Data System (ADS)

Strong and versatile carbon nanotubes are finding new applications in improving conventional polymer-based fibers and films. This paper studies the influence of matrix stiffness and the intertube radial displacements on free vibration of an individual double-walled carbon nanotube (DWNT). For this, a double elastic beam model is presented for frequency analysis in a DWNT embedded in an elastic matrix. The analysis is based on both Euler-Bernoulli and Timoshenko beam theories which considers shear deformation and rotary inertia and for both concentric and non-concentric assumptions considering intertube radial displacements and the related internal degrees of freedom. New intertube resonant frequencies and the associated non-coaxial vibrational modes are calculated. Detailed results are demonstrated for the dependence of resonant frequencies and mode shapes on the matrix stiffness. The results indicate that internal radial displacement and surrounding matrix stiffness could substantially affect resonant frequencies especially for longer double-walled carbon nanotubes of larger innermost radius at higher resonant frequencies, and thus the latter does not keep the otherwise concentric structure at ultrahigh frequencies. Therefore, depending on the matrix stiffness, for carbon nanotubes reinforced composites, different analysis techniques should be used while the aspect ratio of carbon nanotubes has a little effect on the analysis theory which should be selected.

Amin, Sara Shayan; Dalir, Hamid; Farshidianfar, Anooshirvan

2009-03-01

377

A modified warping operator based on BDRM theory in homogeneous shallow water  

NASA Astrophysics Data System (ADS)

In this paper, a modified warping operator for homogeneous shallow water based on the Beam-Displacement Ray-Mode (BDRM) theory is presented. According to the BDRM theory, the contribution of the beam displacement and the time delay to the group velocity can be easily considered in a shallow water waveguide. A more accurate dispersion formula is derived by using the cycle distance formula to calculate the group velocity of normal modes. The derived dispersion formula can be applied to the homogeneous shallow water waveguide. Theoretically, the formula is related to the phase of the reflection coefficient and suitable for various bottom models. Furthermore, based on the derived dispersion relation, the modified warping operator is developed to obtain linear modal structures. For the Pekeris model, the formulae for the phase of the reflection coefficient are derived in this work. By taking account of the effect of the bottom attenuation on the reflection coefficient, the formula for the phase of the reflection coefficient including the bottom attenuation is obtained for the Pekeris model with a lossy bottom. Performance and accuracy of different formulae are evaluated and compared. The numerical simulations indicate that the derived dispersion formulae and the modified warping operator are more accurate.

Niu, HaiQiang; Zhang, RenHe; Li, ZhengLin

2014-03-01

378

A band theory for magnetic cuprates based on self-interaction free local density approximation  

NASA Astrophysics Data System (ADS)

The pseudo-SIC approach is based on an approximate form of self-interaction corrected (SIC) Kohn-Sham Equations. We overview the functionalities of this method applied to cuprates, which are prototypes of difficult materials for standard local-spin density functional theories such as LSDA (or even GGA). Indeed, theories based on local exchange-correlation potentials fail to predict the correct spin-polarized ground-state solution expected for the low-magnetization state (S=1/2) of the Cu(I) ions, thus describing these systems as metallic and nonmagnetic. Here we present our results for a series of relevant cases, including CuO, Cu2O, CuGeO3, and YBa2Cu3O6+x, showing that the pseudo-SIC is capable to correct the gross failures of LSDA, restoring the expected S=1/2 electronic ground state and an overall satisfying description of the chemistry and the electronic and magnetic properties of these systems. Furthermore, since the pseudo-SIC is designed to work for metals as well as for insulators we can approach the challenging task of studying by first-principles the insulating-metal transition in doped Mott insulators. We will consider the example of Mn-doped CuO, where Mn-doping induces a simultaneous insulating-to-metal and antiferromagnetic-to-ferromagnetic phase transition.

Fiorentini, Vincenzo; Filippetti, Alessio

2006-03-01

379

Risk Assessment and Hierarchical Risk Management of Enterprises in Chemical Industrial Parks Based on Catastrophe Theory  

PubMed Central

According to risk systems theory and the characteristics of the chemical industry, an index system was established for risk assessment of enterprises in chemical industrial parks (CIPs) based on the inherent risk of the source, effectiveness of the prevention and control mechanism, and vulnerability of the receptor. A comprehensive risk assessment method based on catastrophe theory was then proposed and used to analyze the risk levels of ten major chemical enterprises in the Songmu Island CIP, China. According to the principle of equal distribution function, the chemical enterprise risk level was divided into the following five levels: 1.0 (very safe), 0.8 (safe), 0.6 (generally recognized as safe, GRAS), 0.4 (unsafe), 0.2 (very unsafe). The results revealed five enterprises (50%) with an unsafe risk level, and another five enterprises (50%) at the generally recognized as safe risk level. This method solves the multi-objective evaluation and decision-making problem. Additionally, this method involves simple calculations and provides an effective technique for risk assessment and hierarchical risk management of enterprises in CIPs. PMID:23208298

Chen, Yu; Song, Guobao; Yang, Fenglin; Zhang, Shushen; Zhang, Yun; Liu, Zhenyu

2012-01-01

380

Adapting evidence-based interventions using a common theory, practices, and principles.  

PubMed

Hundreds of validated evidence-based intervention programs (EBIP) aim to improve families' well-being; however, most are not broadly adopted. As an alternative diffusion strategy, we created wellness centers to reach families' everyday lives with a prevention framework. At two wellness centers, one in a middle-class neighborhood and one in a low-income neighborhood, popular local activity leaders (instructors of martial arts, yoga, sports, music, dancing, Zumba), and motivated parents were trained to be Family Mentors. Trainings focused on a framework that taught synthesized, foundational prevention science theory, practice elements, and principles, applied to specific content areas (parenting, social skills, and obesity). Family Mentors were then allowed to adapt scripts and activities based on their cultural experiences but were closely monitored and supervised over time. The framework was implemented in a range of activities (summer camps, coaching) aimed at improving social, emotional, and behavioral outcomes. Successes and challenges are discussed for (a) engaging parents and communities; (b) identifying and training Family Mentors to promote children and families' well-being; and (c) gathering data for supervision, outcome evaluation, and continuous quality improvement. To broadly diffuse prevention to families, far more experimentation is needed with alternative and engaging implementation strategies that are enhanced with knowledge harvested from researchers' past 30 years of experience creating EBIP. One strategy is to train local parents and popular activity leaders in applying robust prevention science theory, common practice elements, and principles of EBIP. More systematic evaluation of such innovations is needed. PMID:24079747

Rotheram-Borus, Mary Jane; Swendeman, Dallas; Becker, Kimberly D

2014-01-01

381

Theory of chemical kinetics and charge transfer based on nonequilibrium thermodynamics.  

PubMed

Advances in the fields of catalysis and electrochemical energy conversion often involve nanoparticles, which can have kinetics surprisingly different from the bulk material. Classical theories of chemical kinetics assume independent reactions in dilute solutions, whose rates are determined by mean concentrations. In condensed matter, strong interactions alter chemical activities and create variations that can dramatically affect the reaction rate. The extreme case is that of a reaction coupled to a phase transformation, whose kinetics must depend not only on the order parameter but also on its gradients at phase boundaries. Reaction-driven phase transformations are common in electrochemistry, when charge transfer is accompanied by ion intercalation or deposition in a solid phase. Examples abound in Li-ion, metal-air, and lead-acid batteries, as well as metal electrodeposition-dissolution. Despite complex thermodynamics, however, the standard kinetic model is the Butler-Volmer equation, based on a dilute solution approximation. The Marcus theory of charge transfer likewise considers isolated reactants and neglects elastic stress, configurational entropy, and other nonidealities in condensed phases. The limitations of existing theories recently became apparent for the Li-ion battery material LixFePO4 (LFP). It has a strong tendency to separate into Li-rich and Li-poor solid phases, which scientists believe limits its performance. Chemists first modeled phase separation in LFP as an isotropic "shrinking core" within each particle, but experiments later revealed striped phase boundaries on the active crystal facet. This raised the question: What is the reaction rate at a surface undergoing a phase transformation? Meanwhile, dramatic rate enhancement was attained with LFP nanoparticles, and classical battery models could not predict the roles of phase separation and surface modification. In this Account, I present a general theory of chemical kinetics, developed over the past 7 years, which is capable of answering these questions. The reaction rate is a nonlinear function of the thermodynamic driving force, the free energy of reaction, expressed in terms of variational chemical potentials. The theory unifies and extends the Cahn-Hilliard and Allen-Cahn equations through a master equation for nonequilibrium chemical thermodynamics. For electrochemistry, I have also generalized both Marcus and Butler-Volmer kinetics for concentrated solutions and ionic solids. This new theory provides a quantitative description of LFP phase behavior. Concentration gradients and elastic coherency strain enhance the intercalation rate. At low currents, the charge-transfer rate is focused on exposed phase boundaries, which propagate as "intercalation waves", nucleated by surface wetting. Unexpectedly, homogeneous reactions are favored above a critical current and below a critical size, which helps to explain the rate capability of LFP nanoparticles. Contrary to other mechanisms, elevated temperatures and currents may enhance battery performance and lifetime by suppressing phase separation. The theory has also been extended to porous electrodes and could be used for battery engineering with multiphase active materials. More broadly, the theory describes nonequilibrium chemical systems at mesoscopic length and time scales, beyond the reach of molecular simulations and bulk continuum models. The reaction rate is consistently defined for inhomogeneous, nonequilibrium states, for example, with phase separation, large electric fields, or mechanical stresses. This research is also potentially applicable to fluid extraction from nanoporous solids, pattern formation in electrophoretic deposition, and electrochemical dynamics in biological cells. PMID:23520980

Bazant, Martin Z

2013-05-21

382

Prediction of femoral fracture load using finite element models: an examination of stress- and strain-based failure theories.  

PubMed

Finite element (FE) models are often used to model bone failure. However, no failure theory for bone has been validated at this time. In this study, we examined the performance of nine stress- and strain-based failure theories, six of which could account for differences in tensile and compressive material strengths. The distortion energy, Hoffman and a strain-based Hoffman analog, maximum normal stress, maximum normal strain, maximum shear strain, maximum shear stress (tau(max)), Coulomb-Mohr, and modified Mohr failure theories were evaluated using automatically generated, computed tomographic scan-based FE models of the femur. Eighteen matched pairs of proximal femora were examined in two load configurations, one approximating joint loading during single-limb stance and one simulating impact from a fall. Mechanical testing was performed to assess model and failure theory performance in the context of predicting femoral fracture load. Measured and FE-computed fracture load were significantly correlated for both loading conditions and all failure criteria (p < or = 0.001). The distortion energy and tau(max) failure theories were the most robust of those examined, providing the most consistently strong FE model performance for two very different loading conditions. The more complex failure theories and the strain-based theories examined did not improve performance over the simpler distortion energy and tau(max) theories, and often degraded performance, even when differences between tensile and compressive failure properties were represented. The relatively strong performance of the distortion energy and tau(max) theories supports the hypothesis that shear/distortion is an important failure mode during femoral fracture. PMID:10653034

Keyak, J H; Rossi, S A

2000-02-01

383

Queuing the Wrong U?  

NASA Astrophysics Data System (ADS)

Just as there are many different types of uncertainty, there are many different types of models. The best technique for quantifying and communicating uncertainty will depend on the nature of that uncertainty: is it mere imprecision in a well-defined number (as with the square-root of two), intractability (as when we know how to compute the answer, but have not yet been able to carry out the calculation), indeterminacy (as when there is no well-defined target about which to be imprecise) or other. The relevance of UQ to a decision maker or scientist will also depend on the type of quantitative model that is considered: is the model intended to explain, or to forecast, or to provide a quantitative analysis of the past? When a perfect model is available, many of these distinctions collapse. In practice, attempting to quantify one type of uncertainty via a model which may not even display that kind of uncertainty is a nonsense. One must be careful not to confuse the diversity of our models for the uncertainty in our future. Or a well-defined probability forecast for what the next model simulation will report, with a probability forecast for the world. How is UQ to recognize the line between sensitivity analysis and probability forecasting? These questions will be addressed in the context of climate science, and more broadly that of science in support of decision making. The ways and means of UQ are shown to vary with type of model considered, the extent to which that model class is deemed adequate for purpose in a specific application, and whether or not the relevant dominant uncertainty (known from the science, but perhaps absent from the models) has been considered. Uncertainty Quantification may prove to be a very wide field, extending well beyond the bounds of the probability calculus.

Smith, L. A.

2012-12-01

384

A new theory-based social classification in Japan and its validation using historically collected information.  

PubMed

Studies of health inequalities in Japan have increased since the millennium. However, there remains a lack of an accepted theory-based classification to measure occupation-related social position for Japan. This study attempts to derive such a classification based on the National Statistics Socio-economic Classification in the UK. Using routinely collected data from the nationally representative Comprehensive Survey of the Living Conditions of People on Health and Welfare, the Japanese Socioeconomic Classification was derived using two variables - occupational group and employment status. Validation analyses were conducted using household income, home ownership, self-rated good or poor health, and Kessler 6 psychological distress (n ? 36,000). After adjustment for age, marital status, and area (prefecture), one step lower social class was associated with mean 16% (p < 0.001) lower income, and a risk ratio of 0.93 (p < 0.001) for home ownership. The probability of good health showed a trend in men and women (risk ratio 0.94 and 0.93, respectively, for one step lower social class, p < 0.001). The trend for poor health was significant in women (odds ratio 1.12, p < 0.001) but not in men. Kessler 6 psychological distress showed significant trends in men (risk ratio 1.03, p = 0.044) and in women (1.05, p = 0.004). We propose the Japanese Socioeconomic Classification, derived from basic occupational and employment status information, as a meaningful, theory-based and standard classification system suitable for monitoring occupation-related health inequalities in Japan. PMID:23631782

Hiyoshi, Ayako; Fukuda, Yoshiharu; Shipley, Martin J; Bartley, Mel; Brunner, Eric J

2013-06-01

385

Contextualization and standardization of the supportive leadership behavior questionnaire based on socio- cognitive theory in Iran  

PubMed Central

Background: Effective leadership is of prime importance in any organization and it goes through changes based on accepted health promotion and behavior change theory. Although there are many leadership styles, transformational leadership, which emphasizes supportive leadership behaviors, seems to be an appropriate style in many settings particularly in the health care and educational sectors which are pressured by high turnover and safety demands. Iran has been moving rapidly forward and its authorities have understood and recognized the importance of matching leadership styles with effective and competent care for success in health care organizations. This study aimed to develop the Supportive Leadership Behaviors Scale based on accepted health and educational theories and to psychometrically test it in the Iranian context. Methods: The instrument was based on items from established questionnaires. A pilot study validated the instrument which was also cross-validated via re-translation. After validation, 731 participants answered the questionnaire. Results: The instrument was finalized and resulted in a 20-item questionnaire using the exploratory factor analysis, which yielded four factors of support for development, integrity, sincerity and recognition and explaining the supportive leadership behaviors (all above 0.6). Mapping these four measures of leadership behaviors can be beneficial to determine whether effective leadership could support innovation and improvements in medical education and health care organizations on the national level. The reliability measured as Cronbach’s alpha was 0.84. Conclusion: This new instrument yielded four factors of support for development, integrity, sincerity and recognition and explaining the supportive leadership behaviors which are applicable in health and educational settings and are helpful in improving self –efficacy among health and academic staff.

Shirazi, Mandana; Emami, Amir Hosein; Mirmoosavi, ,Seyed Jamal; Alavinia, Seyed Mohammad; Zamanian, Hadi; Fathollahbeigi, Faezeh; Masiello, Italo

2014-01-01

386

Motivational cues predict the defensive system in team handball: A model based on regulatory focus theory.  

PubMed

This study was based on the naturalistic decision-making paradigm and regulatory focus theory. Its aim was to model coaches' decision-making processes for handball teams' defensive systems based on relevant cues of the reward structure, and to determine the weight of each of these cues. We collected raw data by video-recording 41 games that were selected using a simple random method. We considered the defensive strategy (DEF: aligned or staged) to be the dependent variable, and the three independent variables were (a) numerical difference between the teams; (b) score difference between the teams; and (c) game periods. We used a logistic regression design (logit model) and a multivariate logistic model to explain the link between DEF and the three category independent variables. Each factor was weighted differently during the decision-making process to select the defensive system, and combining these variables increased the impact on this process; for instance, a staged defense is 43 times more likely to be chosen during the final period in an unfavorable situation and in a man advantage. Finally, this shows that the coach's decision-making process could be based on a simple match or could require a diagnosis of the situation based on the relevant cues. PMID:25262855

Debanne, T; Laffaye, G

2014-09-28

387

Where are family theories in family-based obesity treatment?: conceptualizing the study of families in pediatric weight management  

PubMed Central

Family-based approaches to pediatric obesity treatment are considered the ‘gold-standard,’ and are recommended for facilitating behavior change to improve child weight status and health. If family-based approaches are to be truly rooted in the family, clinicians and researchers must consider family process and function in designing effective interventions. To bring a better understanding of family complexities to family-based treatment, two relevant reviews were conducted and are presented: (1) a review of prominent and established theories of the family that may provide a more comprehensive and in-depth approach for addressing pediatric obesity; and (2) a systematic review of the literature to identify the use of prominent family theories in pediatric obesity research, which found little use of theories in intervention studies. Overlapping concepts across theories include: families are a system, with interdependence of units; the idea that families are goal-directed and seek balance; and the physical and social environment imposes demands on families. Family-focused theories provide valuable insight into the complexities of families. Increased use of these theories in both research and practice may identify key leverage points in family process and function to prevent the development of or more effectively treat obesity. The field of family studies provides an innovative approach to the difficult problem of pediatric obesity, building on the long-established approach of family-based treatment. PMID:22531090

Skelton, JA; Buehler, C; Irby, MB; Grzywacz, JG

2014-01-01

388

The Psychobiological Model: Towards a New Theory of Computer-Mediated Communication Based on Darwinian Evolution  

Microsoft Academic Search

his article reviews theories of organizational communication with a special emphasis on theories that have been used to explain computer-mediated communication phenomena. Among the theories reviewed, two—social presence and media richness—are identified as problematic and as posing obstacles to future theoretical development. While shortcomings of these theories have been identified in the past, some of these theories' predictions have been

Ned Kock

2004-01-01

389

S E L F -A D A P T I V E S O F T W A R E Control Theory-Based  

E-print Network

S E L F - A D A P T I V E S O F T W A R E Control Theory-Based Foundations of Self- Controlling- trol model. Control theory generally concerns systems that repeatedly interact with the world through-dispatch-handle loop of THE AUTHORS' CONTROL THEORY-BASED PARADIGM GIVES A FRAMEWORK FOR SPECIFYING AND DESIGNING

Kokar, Mieczyslaw M.

390

Kinetic theory of semiconductor cascade laser based on quantum wells and wires V. F. Elesin and A. V. Krasheninnikov  

E-print Network

Kinetic theory of semiconductor cascade laser based on quantum wells and wires V. F. Elesin and A cascade lasers based on quantum wells and wires. For the case of quantum wells, we propose an analytical quantum cascade laser proposed in the original publications by Kazarinov and Suris1 has been implemented

Krasheninnikov, Arkady V.

391

An Organizational Model to Distinguish between and Integrate Research and Evaluation Activities in a Theory Based Evaluation  

ERIC Educational Resources Information Center

Theory-based evaluation (TBE) is an evaluation method that shows how a program will work under certain conditions and has been supported as a viable, evidence-based option in cases where randomized trials or high-quality quasi-experiments are not feasible. Despite the model's widely accepted theoretical appeal there are few examples of its…

Sample McMeeking, Laura B.; Basile, Carole; Cobb, R. Brian

2012-01-01

392

Parametric study of cylindrical converging shock waves generated based on shock dynamics theory  

NASA Astrophysics Data System (ADS)

In our previous work, the technique of generating cylindrical converging shock waves based on shock dynamics theory was proposed. In the present work, a further study is carried out to assess the influence of several parameters including the converging angle ?0, the incident planar shock Mach number M0, and the shock tube height h on the wall profile and the converging shock wave. Combining the high-speed schlieren photography and the numerical simulation with the shock dynamics theory, the characteristics of wall profiles, cylindrical converging shock waves, and thermodynamic properties for different controllable parameters are analyzed. It is found that these parameters have great effects on shapes of the wall profile and experimental investigation favors large values of M0 and h and moderate ?0. The experimental sequences of schlieren images indicate that the shocks moving in the converging part are of circular shapes, which further verifies the method in our previous work. In addition, the changes of the shock Mach number, pressure, temperature, and density are obtained quantitatively. The results show that higher pressure and temperature can be reached in the converging part at the same distance to the center of convergence for larger incident shock Mach numbers, larger shock tube heights, or smaller converging angles. All the database will be useful for understanding the shock focusing and further investigating the Richtmyer-Meshkov instability induced by the converging shock waves.

Zhai, Zhigang; Si, Ting; Luo, Xisheng; Yang, Jiming; Liu, Cangli; Tan, Duowang; Zou, Liyong

2012-02-01

393

Investigations into Generalization of Constraint-Based Scheduling Theories with Applications to Space Telescope Observation Scheduling  

NASA Technical Reports Server (NTRS)

This final report summarizes research performed under NASA contract NCC 2-531 toward generalization of constraint-based scheduling theories and techniques for application to space telescope observation scheduling problems. Our work into theories and techniques for solution of this class of problems has led to the development of the Heuristic Scheduling Testbed System (HSTS), a software system for integrated planning and scheduling. Within HSTS, planning and scheduling are treated as two complementary aspects of the more general process of constructing a feasible set of behaviors of a target system. We have validated the HSTS approach by applying it to the generation of observation schedules for the Hubble Space Telescope. This report summarizes the HSTS framework and its application to the Hubble Space Telescope domain. First, the HSTS software architecture is described, indicating (1) how the structure and dynamics of a system is modeled in HSTS, (2) how schedules are represented at multiple levels of abstraction, and (3) the problem solving machinery that is provided. Next, the specific scheduler developed within this software architecture for detailed management of Hubble Space Telescope operations is presented. Finally, experimental performance results are given that confirm the utility and practicality of the approach.

Muscettola, Nicola; Smith, Steven S.

1996-01-01

394

Cartographic generalization of urban street networks based on gravitational field theory  

NASA Astrophysics Data System (ADS)

The automatic generalization of urban street networks is a constant and important aspect of geographical information science. Previous studies show that the dual graph for street-street relationships more accurately reflects the overall morphological properties and importance of streets than do other methods. In this study, we construct a dual graph to represent street-street relationship and propose an approach to generalize street networks based on gravitational field theory. We retain the global structural properties and topological connectivity of an original street network and borrow from gravitational field theory to define the gravitational force between nodes. The concept of multi-order neighbors is introduced and the gravitational force is taken as the measure of the importance contribution between nodes. The importance of a node is defined as the result of the interaction between a given node and its multi-order neighbors. Degree distribution is used to evaluate the level of maintaining the global structure and topological characteristics of a street network and to illustrate the efficiency of the suggested method. Experimental results indicate that the proposed approach can be used in generalizing street networks and retaining their density characteristics, connectivity and global structure.

Liu, Gang; Li, Yongshu; Li, Zheng; Guo, Jiawei

2014-05-01

395

[Prediction of regional soil quality based on mutual information theory integrated with decision tree algorithm].  

PubMed

In this paper, some main factors such as soil type, land use pattern, lithology type, topography, road, and industry type that affect soil quality were used to precisely obtain the spatial distribution characteristics of regional soil quality, mutual information theory was adopted to select the main environmental factors, and decision tree algorithm See 5.0 was applied to predict the grade of regional soil quality. The main factors affecting regional soil quality were soil type, land use, lithology type, distance to town, distance to water area, altitude, distance to road, and distance to industrial land. The prediction accuracy of the decision tree model with the variables selected by mutual information was obviously higher than that of the model with all variables, and, for the former model, whether of decision tree or of decision rule, its prediction accuracy was all higher than 80%. Based on the continuous and categorical data, the method of mutual information theory integrated with decision tree could not only reduce the number of input parameters for decision tree algorithm, but also predict and assess regional soil quality effectively. PMID:22586972

Lin, Fen-Fang; Wang, Ke; Yang, Ning; Yan, Shi-Guang; Zheng, Xin-Yu

2012-02-01

396

The use of theory based semistructured elicitation questionnaires: formative research for CDC's Prevention Marketing Initiative.  

PubMed

Through one of its many HIV prevention programs, the Prevention Marketing Initiative, the Centers for Disease Control and Prevention promotes a multifaceted strategy for preventing the sexual transmission of HIV/AIDS among people less than 25 years of age. The Prevention Marketing Initiative is an application of marketing and consumer-oriented technologies that rely heavily on behavioral research and behavior change theories to bring the behavioral and social sciences to bear on practical program planning decisions. One objective of the Prevention Marketing Initiative is to encourage consistent and correct condom use among sexually active young adults. Qualitative formative research is being conducted in several segments of the population of heterosexually active, unmarried young adults between 18 and 25 using a semistructured elicitation procedure to identify and understand underlying behavioral determinants of consistent condom use. The purpose of this paper is to illustrate the use of this type of qualitative research methodology in designing effective theory-based behavior change interventions. Issues of research design and data collection and analysis are discussed. To illustrate the methodology, results of content analyses of selected responses to open-ended questions on consistent condom use are presented by gender (male, female), ethnic group (white, African American), and consistency of condom use (always, sometimes). This type of formative research can be applied immediately to designing programs and is invaluable for valid and relevant larger-scale quantitative research. PMID:8862153

Middlestadt, S E; Bhattacharyya, K; Rosenbaum, J; Fishbein, M; Shepherd, M

1996-01-01

397

New Approach to Optimize the Apfs Placement Based on Instantaneous Reactive Power Theory by Genetic Algorithm  

NASA Astrophysics Data System (ADS)

In electrical distribution systems, a great amount of power are wasting across the lines, also nowadays power factors, voltage profiles and total harmonic distortions (THDs) of most loads are not as would be desired. So these important parameters of a system play highly important role in wasting money and energy, and besides both consumers and sources are suffering from a high rate of distortions and even instabilities. Active power filters (APFs) are innovative ideas for solving of this adversity which have recently used instantaneous reactive power theory. In this paper, a novel method is proposed to optimize the allocation of APFs. The introduced method is based on the instantaneous reactive power theory in vectorial representation. By use of this representation, it is possible to asses different compensation strategies. Also, APFs proper placement in the system plays a crucial role in either reducing the losses costs and power quality improvement. To optimize the APFs placement, a new objective function has been defined on the basis of five terms: total losses, power factor, voltage profile, THD and cost. Genetic algorithm has been used to solve the optimization problem. The results of applying this method to a distribution network illustrate the method advantages.

Hashemi-Dezaki, Hamed; Mohammadalizadeh-Shabestary, Masoud; Askarian-Abyaneh, Hossein; Rezaei-Jegarluei, Mohammad

2014-01-01

398

Physical implication of two problems in transition prediction of boundary layers based on linear stability theory  

NASA Astrophysics Data System (ADS)

Up to now, the most widely used method for transition prediction is the one based on linear stability theory. When it is applied to three-dimensional boundary layers, one has to choose the direction, or path, along which the growth rate of the disturbance is to be integrated. The direction given by using saddle point method in the theory of complex variable function is seen as mathematically most reasonable. However, unlike the saddle point method applied to water waves, here its physical meaning is not so obvious, as the frequency and wave number may be complex. And on some occasions, in advancing the integration of the growth rate of the disturbance, up to a certain location, one may not be able to continue the integration, because the condition for specifying the direction set by the saddle point method can no longer be satisfied on the basis of continuously varying wave number. In this paper, these two problems are discussed, and suggestions for how to do transition prediction under the latter condition are provided.

Su, CaiHong

2014-05-01

399

Toward a new modeling of international economics: An attempt to reformulate an international trade model based on real option theory  

NASA Astrophysics Data System (ADS)

Reformulation of economics by physics has been carried out intensively to reveal many features of the asset market, which were missed in the classical economic theories. The present paper attempts to shed new light on this field. That is, this paper aims at reformulating the international trade model by making use of the real option theory. Based on such a stochastic dynamic model, we examine how the fluctuation of the foreign exchange rate makes effect on the welfare of the exporting country.

Fujita, Yasunori

2007-09-01

400

Control of a Flexible Space Antenna: A Finite Dimensional Perspective Based on Distributed Parameter Theory  

NASA Technical Reports Server (NTRS)

The methods presented are based on results from infinite dimensional control theory, but they can be described and used in a finite dimensional context. This blend leads to an approach which employs powerful ideas on convergence, and is also quite practical for systems of realistic complexity. Appropriate reduced order models are generated simultaneously with the development of the compensator. The required models change as a function of changes in the performance demanded, sensor and actuator location, inherent damping, disturbances, etc. Thus they are driven by the control and estimation problems at hand. The compensators which emerge are very close to the ideal compensators which would be obtained with a very large order model. However, some simplification is frequently possible. The method of balanced realizations was found to be effective for this purpose.

Mingori, D. L.; Gibson, J. S.; Blelloch, P.; Adamian, A.

1985-01-01

401

Suicide prevention by online support groups: an action theory-based model of emotional first aid.  

PubMed

In the last two decades, online support groups have become a valuable source of help for individuals in suicidal crisis. Their attractiveness is attributed to features that enhance help-seeking and self-disclosure such as availability, anonymity, and use of written communication. However, online support groups also suffer from limitations and potential risks as agents of suicide prevention. The Israeli Association for Emotional First Aid (ERAN) has developed a practical model that seeks to maximize the benefits and minimize the risks of online suicide prevention. The model applies the Action Theory concepts whereby individuals shape their own environment. The present paper presents the model, which is based on an online support group combined with personal chat and a telephonic help line. The online support group is moderated by paraprofessionals who function as both process regulators and support providers. The principles and practice of the model are described, the theoretical rationale is presented, and directions for future research are suggested. PMID:19123109

Gilat, Itzhak; Shahar, Golan

2009-01-01

402

Simulation of the Electrical Properties of ZnO-BASED Ceramic Varistors Using Continuum Theory  

NASA Astrophysics Data System (ADS)

A continuum field model describing the electrical characteristics of polycrystalline semiconductors ceramics is suggested. Taking into account the continuum theory, a static differential equation about electron level on the base of Poisson equation is established. The one-dimensional calculation is carried out using the Runge-Kutta method. The effect of grain size, temperature and donor concentration on the current-voltage characteristic and specific capacitance of the material is calculated quantitatively using ZnO ceramics as an example. The results pointed out that current and voltage characteristics divide into three regions: Linear region before breakdown field, nonlinear region near breakdown field and upturn region after breakdown field. As the applied voltage increases, the grain boundary barrier and the grain boundary capacitance in the nonlinear zone drop drastically. The results are compared with experimental data. An interesting phenomenon is that the Schottky barrier has a small offset along the direction of the applied electric field.

Fang, Chao; Zhou, Dongxiang

2012-07-01

403

Study on corporate social responsibility evaluation system based on stakeholder theory  

NASA Astrophysics Data System (ADS)

The issue of Corporate Social Responsibility (CSR) has been attracting the attention from many disciplines such as economics, management, laws, sociality and philosophy since last century. The purpose of this study is to explore the impact of CSR on performance and develop a CSR evaluation system. Building on the definition of CSR and Stakeholder theory, this article built a path-relationship model of CSR and business operation performance. The paper also constructed CSR evaluation system based on KLD index, GRJ report, CSR accounting account, SA8000, ISO14000 etc. The research provides a basis for future studies about the relationship between CSR and business performance and shed some light on the evaluation of CSR practices.

Ma, J.; Deng, Liming

2011-10-01

404

Grey Situation Group Decision-Making Method Based on Prospect Theory  

PubMed Central

This paper puts forward a grey situation group decision-making method on the basis of prospect theory, in view of the grey situation group decision-making problems that decisions are often made by multiple decision experts and those experts have risk preferences. The method takes the positive and negative ideal situation distance as reference points, defines positive and negative prospect value function, and introduces decision experts' risk preference into grey situation decision-making to make the final decision be more in line with decision experts' psychological behavior. Based on TOPSIS method, this paper determines the weight of each decision expert, sets up comprehensive prospect value matrix for decision experts' evaluation, and finally determines the optimal situation. At last, this paper verifies the effectiveness and feasibility of the method by means of a specific example. PMID:25197706

Zhang, Na; Fang, Zhigeng; Liu, Xiaqing

2014-01-01

405

Interatomic potentials for hydrogen in ? -iron based on density functional theory  

NASA Astrophysics Data System (ADS)

We present two interatomic potentials for hydrogen in ? -iron based on the embedded atom method potentials for iron developed by Mendelev [Philos. Mag. 83, 3977 (2003)] and Ackland [J. Phys.: Condens. Matter 16, S2629 (2004)]. Since these latter potentials are unique among existing iron potentials in their ability to produce the same core structure for screw dislocations as density functional theory (DFT) calculations, our interatomic potentials for hydrogen in iron also inherit this important feature. We use an extensive database of energies and atomic configurations from DFT calculations to fit the cross interaction of hydrogen with iron. Detailed tests on the dissolution and diffusion of hydrogen in bulk ? -iron, as well as the binding of H to vacancies, free surfaces, and dislocations, indicate that our potentials are in excellent overall agreement with DFT calculations.

Ramasubramaniam, Ashwin; Itakura, Mitsuhiro; Carter, Emily A.

2009-05-01

406

Wave propagation analysis in nonlinear curved single-walled carbon nanotubes based on nonlocal elasticity theory  

NASA Astrophysics Data System (ADS)

Theoretical predictions are presented for wave propagation in nonlinear curved single-walled carbon nanotubes (SWCNTs). Based on the nonlocal theory of elasticity, the computational model is established, combined with the effects of geometrical nonlinearity and imperfection. In order to use the wave analysis method on this topic, a linearization method is employed. Thus, the analytical expresses of the shear frequency and flexural frequency are obtained. The effects of the geometrical nonlinearity, the initial geometrical imperfection, temperature change and magnetic field on the flexural and shear wave frequencies are investigated. Numerical results indicate that the contribution of the higher-order small scale effect on the shear deformation and the rotary inertia can lead to a reduction in the frequencies compared with results reported in the published literature. The theoretical model derived in this study should be useful for characterizing the mechanical properties of carbon nanotubes and applications of nano-devices.

Wang, Bo; Deng, Zichen; Ouyang, Huajiang; Zhou, Jiaxi

2015-02-01

407

Convergence analysis of a CMFD method based on generalized equivalence theory  

SciTech Connect

CMFD acceleration methods have been successful in reducing the computational burden for steady-state and transient reactor calculations. However, recent work on a complex coupled code BWR ATWS event has exposed possible issues with the stability of the CMFD method when standard CMFD methods are used. During the simulation of the ATWS boron injection event in the BWR, the PARCS code failed to converge with the existing CMFD method. A new CMFD method based on generalized equivalence theory was developed and the PARCS solution converged for the same ATWS event. This paper presents the new method and a detailed analytic and numerical convergence analysis. The results show that the new CMFD converges for all possible cross sections combinations anticipated in Light Water Reactor simulation and unlike existing CMFD methods, it is very robust even when the initial guess is far from final true solution. (authors)

Xu, Y. [Argonne National Laboratory, Bldg. 208, 9700 South Case Ave., Argonne, IL 60439 (United States); Downar, T. [Dept. of Nuclear Engineering and Radiological Sciences, Univ. of Michigan, 2355 Bonisteel Blvd, Ann Arbor, MI 48109-2104 (United States)

2012-07-01

408

Predicting Substance Abuse Treatment Completion using a New Scale Based on the Theory of Planned Behavior  

PubMed Central

We examined whether a 9-item scale based on the theory of planned behavior (TPB) predicted substance abuse treatment completion. Data were collected at a public, outpatient program among clients initiating treatment (N=200). Baseline surveys included measures of treatment-related attitudes, norms, perceived control, and intention; discharge status was collected from program records. As expected, TPB attitude and control components independently predicted intention (model R-squared=.56), and intention was positively associated with treatment completion even including clinical and demographic covariates (model R-squared=.24). TPB components were generally associated with the alternative readiness scales as expected, and the TPB remained predictive at higher levels of coercion. Meanwhile, none of the standard measures of readiness (e.g., the URICA and TREAT) or treatment coercion were positively associated with treatment participation. Results suggest promise for application of the TPB to treatment completion and support use of the intention component as a screener, though some refinements are suggested. PMID:23953167

Zemore, Sarah E.; Ajzen, Icek

2013-01-01

409

A Study of Crude Oil Price Behavior Based on Fictitious Economy Theory  

NASA Astrophysics Data System (ADS)

The over fluctuating of international crude oil price has aroused wide concern in the society and the academics. Based on the theory of fictitious economy, this paper has studied and explained the crude oil price behavior from Jan 1946 to Dec 2008. It concludes that the long term prices of crude oil are subject to mean reversion in accordance with the decisive law of value, which is fluctuating around the long term marginal opportunity cost. However, at the same time the prices also appeared to deviate far from long term marginal opportunity cost for several relatively long periods. This paper highlights four aspects of this issue: the diversification of international crude oil market participants, the structural changes of the participants, the evolution of pricing mechanism, and the periodic change of world economy.

He, Xiaoming; Cheng, Siwei; Wang, Shouyang

410

A second-order accurate kinetic-theory-based method for inviscid compressible flows  

NASA Technical Reports Server (NTRS)

An upwind method for the numerical solution of the Euler equations is presented. This method, called the kinetic numerical method (KNM), is based on the fact that the Euler equations are moments of the Boltzmann equation of the kinetic theory of gases when the distribution function is Maxwellian. The KNM consists of two phases, the convection phase and the collision phase. The method is unconditionally stable and explicit. It is highly vectorizable and can be easily made total variation diminishing for the distribution function by a suitable choice of the interpolation strategy. The method is applied to a one-dimensional shock-propagation problem and to a two-dimensional shock-reflection problem.

Deshpande, Suresh M.

1986-01-01

411

Mathematical definition of general systems based on semiotics and set theory (part of statics)  

E-print Network

According to the relation between objects and time, our category of general systems theory was divided into three parts: statics, kinematics, and dynamics. In this part, beginning with clarifying fundamental in epistemology and semiotics, we gave the connections of measurements, partitions and functions. And conforming to customs, we defined the terms of quantity and value by our understanding of functions. Then the concept of relation quantity was coined to describe the relationship like distance and force. Farther more, we discussed correspondences established between two quantities, and the definitions and theorems of complete set based on it. Finally, we present the structure which can afford the obligation of general system, and also the definitions of subsystem and isomorphism.

Zou, D D

2009-01-01

412

Formulation of thermo-hydro-mechanical coupling behavior of unsaturated soils based on hybrid mixture theory  

NASA Astrophysics Data System (ADS)

Thermo-Hydro-Mechanical (THM) coupling processes in unsaturated soils are very important in both theoretical researches and engineering applications. A coupled formulation based on hybrid mixture theory is derived to model the THM coupling behavior of unsaturated soils. The free-energy and dissipative functions for different phases are derived from Taylor's series expansions. Constitutive relations for THM coupled behaviors of unsaturated soils, which include deformation, entropy change, fluid flow, heat conduction, and dynamic compatibility conditions on the interfaces, are then established. The number of field equations is shown to be equal to the number of unknown variables; thus, a closure of this coupling problem is established. In addition to modifications of the physical conservation equations with coupling effect terms, the constitutive equations, which consider the coupling between elastoplastic deformation of the soil skeleton, fluid flow, and heat transfer, are also derived.

Cai, Guo-Qing; Zhao, Cheng-Gang; Sheng, Dai-Chao; Zhou, An-Nan

2014-08-01

413

A Method of Incorporating Matrix Theory to Create Mathematical Function-Based Music  

E-print Network

This paper attempts to look for a mathematical method of composing music by incorporating Schonbergs idea of tone rows and matrix theory from linear algebra. The elements of a note set S are considered as the integer values for the natural notes based on the C Major Scale and rational numbers for semitones. The elements of S are effectively mapped by a polynomial function to another note set T. To accomplish this, S is treated as a column vector, applied to the matrix equation Ax equals b, where x denotes the vector S, b denotes the resulting set T, and A represents a square matrix. This method yields functions capable of mapping input note sets to others, thereby creating collections of sets that can be permuted in any order to form musical harmonies.

Sidarth Jayadev

2014-09-28

414

A High Precision Feature Based on LBP and Gabor Theory for Face Recognition  

PubMed Central

How to describe an image accurately with the most useful information but at the same time the least useless information is a basic problem in the recognition field. In this paper, a novel and high precision feature called BG2D2LRP is proposed, accompanied with a corresponding face recognition system. The feature contains both static texture differences and dynamic contour trends. It is based on Gabor and LBP theory, operated by various kinds of transformations such as block, second derivative, direct orientation, layer and finally fusion in a particular way. Seven well-known face databases such as FRGC, AR, FERET and so on are used to evaluate the veracity and robustness of the proposed feature. A maximum improvement of 29.41% is achieved comparing with other methods. Besides, the ROC curve provides a satisfactory figure. Those experimental results strongly demonstrate the feasibility and superiority of the new feature and method. PMID:23552103

Xia, Wei; Yin, Shouyi; Ouyang, Peng

2013-01-01

415

Density functional theory based study of graphene and dielectric oxide interfaces.  

PubMed

We study the effects of insulating oxides in their crystalline forms on the energy band structure of monolayer and bilayer graphene using a first principles density functional theory based electronic structure method and a local density approximation. We consider the dielectric oxides SiO(2) (?-quartz) and Al(2)O(3) (alumina or ?-sapphire), each with two surface terminations. Our study suggests that atomic relaxations and resulting equilibrium separations play a critical role in perturbing the linear band structure of graphene in contrast to the less critical role played by dangling bonds that result from cleaving the crystal in a particular direction. For Si-terminated quartz a Dirac cone is retained while it is restored on adding a second graphene layer for O-terminated quartz. Alumina needs more than two graphene layers to preserve the Dirac cone. Our results are, at best, semi-quantitative for the common amorphous forms of the oxides considered. PMID:22119858

Jadaun, Priyamvada; Banerjee, Sanjay K; Register, Leonard F; Sahu, Bhagawan

2011-12-21

416

Mechanisms of ultrasonic modulation of multiply scattered incoherent light based on diffusion theory  

NASA Astrophysics Data System (ADS)

An analytic equation interpreting the intensity of ultrasound-modulated scattering light is derived, based on diffusion theory and previous explanations of the intensity modulation mechanism. Furthermore, an experiment of ultrasonic modulation of incoherent light in a scattering medium is developed. This analytical model agrees well with experimental results, which confirms the validity of the proposed intensity modulation mechanism. The model supplements the existing research on the ultrasonic modulation mechanism of scattering light. Project supported by the National Natural Science Foundation of China (Grant No. 61178089), the Key Program of Science and Technology of Fujian Province, China (Grant No. 2011Y0019), and the Educational Department of Fujian Province, China (Grant No. JA13074).

Zhu, Li-Li; Li, Hui

2015-01-01

417

Nanobatteries in redox-based resistive switches require extension of memristor theory  

PubMed Central

Redox-based nanoionic resistive memory cells are one of the most promising emerging nanodevices for future information technology with applications for memory, logic and neuromorphic computing. Recently, the serendipitous discovery of the link between redox-based nanoionic-resistive memory cells and memristors and memristive devices has further intensified the research in this field. Here we show on both a theoretical and an experimental level that nanoionic-type memristive elements are inherently controlled by non-equilibrium states resulting in a nanobattery. As a result, the memristor theory must be extended to fit the observed non-zero-crossing I–V characteristics. The initial electromotive force of the nanobattery depends on the chemistry and the transport properties of the materials system but can also be introduced during redox-based nanoionic-resistive memory cell operations. The emf has a strong impact on the dynamic behaviour of nanoscale memories, and thus, its control is one of the key factors for future device development and accurate modelling. PMID:23612312

Valov, I.; Linn, E.; Tappertzhofen, S.; Schmelzer, S.; van den Hurk, J.; Lentz, F.; Waser, R.

2013-01-01

418

Nanobatteries in redox-based resistive switches require extension of memristor theory.  

PubMed

Redox-based nanoionic resistive memory cells are one of the most promising emerging nanodevices for future information technology with applications for memory, logic and neuromorphic computing. Recently, the serendipitous discovery of the link between redox-based nanoionic-resistive memory cells and memristors and memristive devices has further intensified the research in this field. Here we show on both a theoretical and an experimental level that nanoionic-type memristive elements are inherently controlled by non-equilibrium states resulting in a nanobattery. As a result, the memristor theory must be extended to fit the observed non-zero-crossing I-V characteristics. The initial electromotive force of the nanobattery depends on the chemistry and the transport properties of the materials system but can also be introduced during redox-based nanoionic-resistive memory cell operations. The emf has a strong impact on the dynamic behaviour of nanoscale memories, and thus, its control is one of the key factors for future device development and accurate modelling. PMID:23612312

Valov, I; Linn, E; Tappertzhofen, S; Schmelzer, S; van den Hurk, J; Lentz, F; Waser, R

2013-01-01

419

Nanobatteries in redox-based resistive switches require extension of memristor theory  

NASA Astrophysics Data System (ADS)

Redox-based nanoionic resistive memory cells are one of the most promising emerging nanodevices for future information technology with applications for memory, logic and neuromorphic computing. Recently, the serendipitous discovery of the link between redox-based nanoionic-resistive memory cells and memristors and memristive devices has further intensified the research in this field. Here we show on both a theoretical and an experimental level that nanoionic-type memristive elements are inherently controlled by non-equilibrium states resulting in a nanobattery. As a result, the memristor theory must be extended to fit the observed non-zero-crossing I-V characteristics. The initial electromotive force of the nanobattery depends on the chemistry and the transport properties of the materials system but can also be introduced during redox-based nanoionic-resistive memory cell operations. The emf has a strong impact on the dynamic behaviour of nanoscale memories, and thus, its control is one of the key factors for future device development and accurate modelling.

Valov, I.; Linn, E.; Tappertzhofen, S.; Schmelzer, S.; van den Hurk, J.; Lentz, F.; Waser, R.

2013-04-01

420

A Game Theory-Based Obstacle Avoidance Routing Protocol for Wireless Sensor Networks  

PubMed Central

The obstacle avoidance problem in geographic forwarding is an important issue for location-based routing in wireless sensor networks. The presence of an obstacle leads to several geographic routing problems such as excessive energy consumption and data congestion. Obstacles are hard to avoid in realistic environments. To bypass obstacles, most routing protocols tend to forward packets along the obstacle boundaries. This leads to a situation where the nodes at the boundaries exhaust their energy rapidly and the obstacle area is diffused. In this paper, we introduce a novel routing algorithm to solve the obstacle problem in wireless sensor networks based on a game-theory model. Our algorithm forms a concave region that cannot forward packets to achieve the aim of improving the transmission success rate and decreasing packet transmission delays. We consider the residual energy, out-degree and forwarding angle to determine the forwarding probability and payoff function of forwarding candidates. This achieves the aim of load balance and reduces network energy consumption. Simulation results show that based on the average delivery delay, energy consumption and packet delivery ratio performances our protocol is superior to other traditional schemes. PMID:22163698

Guan, Xin; Wu, Huayang; Bi, Shujun

2011-01-01

421

Identifying subcellular localizations of mammalian protein complexes based on graph theory with a random forest algorithm.  

PubMed

In the post-genome era, one of the most important and challenging tasks is to identify the subcellular localizations of protein complexes, and further elucidate their functions in human health with applications to understand disease mechanisms, diagnosis and therapy. Although various experimental approaches have been developed and employed to identify the subcellular localizations of protein complexes, the laboratory technologies fall far behind the rapid accumulation of protein complexes. Therefore, it is highly desirable to develop a computational method to rapidly and reliably identify the subcellular localizations of protein complexes. In this study, a novel method is proposed for predicting subcellular localizations of mammalian protein complexes based on graph theory with a random forest algorithm. Protein complexes are modeled as weighted graphs containing nodes and edges, where nodes represent proteins, edges represent protein-protein interactions and weights are descriptors of protein primary structures. Some topological structure features are proposed and adopted to characterize protein complexes based on graph theory. Random forest is employed to construct a model and predict subcellular localizations of protein complexes. Accuracies on a training set by a 10-fold cross-validation test for predicting plasma membrane/membrane attached, cytoplasm and nucleus are 84.78%, 71.30%, and 82.00%, respectively. And accuracies for the independent test set are 81.31%, 69.95% and 81.00%, respectively. These high prediction accuracies exhibit the state-of-the-art performance of the current method. It is anticipated that the proposed method may become a useful high-throughput tool and plays a complementary role to the existing experimental techniques in identifying subcellular localizations of mammalian protein complexes. The source code of Matlab and the dataset can be obtained freely on request from the authors. PMID:23429850

Li, Zhan-Chao; Lai, Yan-Hua; Chen, Li-Li; Chen, Chao; Xie, Yun; Dai, Zong; Zou, Xiao-Yong

2013-04-01

422

Numerically-based ducted propeller design using vortex lattice lifting line theory  

E-print Network

This thesis used vortex lattice lifting line theory to model an axisymmetrical-ducted propeller with no gap between the duct and the propeller. The theory required to model the duct and its interaction with the propeller ...

Stubblefield, John M

2008-01-01

423

The Model-Based View of Scientific Theories and the Structuring of School Science Programmes  

ERIC Educational Resources Information Center

Model theory in contemporary philosophy of science interprets scientific theories as sets of models, and contributes significantly to the understanding of the relation between theories, models, and the real world. The clarification of this relation is fundamental for the understanding of the nature of scientific methods and scientific knowledge…

Develaki, Maria

2007-01-01

424

Turbulence and refractivity changes and their sensing based upon the wave mechanics theory  

Microsoft Academic Search

After a brief review of the fundamental concepts of quantum theory, the writer discusses briefly some methods of quantum field theory in statistical physics, particularly with a view to applying them to a Bose fluid type of medium. Next follows an application of wave mechanics theory (the Schroedinger equation) to a spatial domain in a turbulent field. Next the problem

M. Z. V. Krzywoblocki

1974-01-01

425

The Role of Social Cognitive Career Theory in The Role of Social Cognitive Career Theory in Information Technology based Academic Information Technology based Academic Performance Performance  

Microsoft Academic Search

Positive academic efficacy beliefs elevate educational expectations that lead to academic success (Bandura, 1997; Lent, Brown, & Hackett, 1994). The purpose of this study was to explore the relationship of the variables: past performance, computer self-efficacy, outcome expectations, academic grade goal, and academic performance within social cognitive career theory's model of performance (Lent, Brown, & Hackett, 1994). The study focused

Sheila M. Smith

426

Thermo-Elastic Triangular Sandwich Element for the Complete Stress Field Based on a Single-Layer Theory  

NASA Technical Reports Server (NTRS)

This study presents a new triangular finite element for modeling thick sandwich panels, subjected to thermo-mechanical loading, based on a {3,2}-order single-layer plate theory. A hybrid energy functional is employed in the derivation of the element because of a C interelement continuity requirement. The single-layer theory is based on five weighted-average field variables arising from the cubic and quadratic representations of the in-plane and transverse displacement fields, respectively. The variations of temperature and distributed loading acting on the top and bottom surfaces are non-uniform. The temperature varies linearly through the thickness.

Das, M.; Barut, A.; Madenci, E.; Ambur, D. R.

2004-01-01

427

Theory analysis of mode coupling in tilted long period fiber grating based on the full vector complex coupled mode theory  

NASA Astrophysics Data System (ADS)

The mode coupling in the tilted long period fiber grating (TLPG) is analyzed by using the full vector complex coupled mode theory (FV-CCMT). Compared with the non-tilted LPG, new resonance bands corresponding to the LP1m cladding modes are observed in the transmission spectrum of the TLPG. The coupling to LP1m cladding modes is the combination of the coupling to degenerate vector modes TE0m, TM0m and HE2m with different propagation constants. The maximum coupling between LP01 and LP1m modes occurs at a tilt angle of ˜87°. Numerical results show that the state of polarization (SOP) of the input light would induce the shift of the new resonance wavelength. Also, the RI sensitivity of the new resonance wavelength is much higher than that of the normal resonance wavelength corresponding to the LP0m cladding modes. Such TLPG would find application in chemical and biological sensing fields.

Yin, Guolu; Lou, Shuqin; Li, Qi; Zou, Hui

2013-06-01

428

Analysis of creep behavior in thermoplastics based on visco-elastic theory  

NASA Astrophysics Data System (ADS)

Plastics and fiber-reinforced plastics (FRP) are used in the aerospace industry because of their mechanical properties. However, despite their excellent high-temperature mechanical properties, plastics and FRP eventually deform visco-elastically at high temperatures. Most of the research has focused on the creep behavior of FRPs, but few studies have investigated the linear visco-elastic behavior. Linear visco-elastic behavior and non-linear visco-elastic behavior occur with physical aging in these plastics. In this study, the non-linear visco-elastic behavior of plastics and FRP was investigated based on the bending creep deformation of polycarbonate (PC) and polyoxymethylene (POM). Moreover, the effects of the fiber volume fraction on the creep characteristics were investigated using glass fiber-reinforced polycarbonate (GFRPC). The creep deformation was calculated using the linear visco-elastic theory based on these effects, and comparison between experimental and estimated data showed that the creep analysis sufficiently predicted the creep behavior.

Sakai, Takenobu; Somiya, Satoshi

2011-08-01

429

Small scale effects on the mechanical behaviors of protein microtubules based on the nonlocal elasticity theory  

SciTech Connect

Based on the nonlocal elastic theory, small scale effects are considered in the investigation of the mechanical properties of protein microtubules. A new prediction formula for the persistence lengths of microtubules with the consideration of the small scale effect is presented. Subsequently, the buckling of microtubules is studied based on a nonlocal elastic beam model. The predicted results of our model indicate that the length-dependence of persistence length is related not only to the shear terms, but also to the small scale effect. The Eular beam model, which is always considered unable to explain the length-dependence of microtubules, can capture the length-dependence of the persistence length of microtubules with the consideration of the small scale effect. The elastic buckling behaviors of microtubules in viscoelastic surrounding cytoplasm are also considered using the nonlocal Timoshenko beam model in this paper, and the results indicate that the small scale effect of microtubules also plays an important role in the buckling of microtubules.

Gao, Yuanwen, E-mail: ywgao@lzu.edu.cn [Key Laboratory of Mechanics on Western Disaster and Environment, Ministry of Education, Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000 (China)] [Key Laboratory of Mechanics on Western Disaster and Environment, Ministry of Education, Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000 (China); Lei, Fang-Ming [Key Laboratory of Mechanics on Western Disaster and Environment, Ministry of Education, Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000 (China)] [Key Laboratory of Mechanics on Western Disaster and Environment, Ministry of Education, Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000 (China)

2009-09-25

430

Development of theory-based health messages: three-phase programme of formative research.  

PubMed

Online health behaviour interventions have great potential but their effectiveness may be hindered by a lack of formative and theoretical work. This paper describes the process of formative research to develop theoretically and empirically based health messages that are culturally relevant and can be used in an online intervention to promote healthy lifestyle behaviours among new university students. Drawing on the Theory of Planned Behaviour, a three-phase programme of formative research was conducted with prospective and current undergraduate students to identify (i) modal salient beliefs (the most commonly held beliefs) about fruit and vegetable intake, physical activity, binge drinking and smoking, (ii) which beliefs predicted intentions/behaviour and (iii) reasons underlying each of the beliefs that could be targeted in health messages. Phase 1, conducted with 96 pre-university college students, elicited 56 beliefs about the behaviours. Phase 2, conducted with 3026 incoming university students, identified 32 of these beliefs that predicted intentions/behaviour. Phase 3, conducted with 627 current university students, elicited 102 reasons underlying the 32 beliefs to be used to construct health messages to bolster or challenge these beliefs. The three-phase programme of formative research provides researchers with an example of how to develop health messages with a strong theoretical- and empirical base for use in health behaviour change interventions. PMID:24504361

Epton, Tracy; Norman, Paul; Harris, Peter; Webb, Thomas; Snowsill, F Alexandra; Sheeran, Paschal

2014-02-01

431

Reallocation of water in the state of New Mexico based on cooperative game theory  

NASA Astrophysics Data System (ADS)

Water allocation models often aim to maximize net benefits in the river basin based on the water rights, thus there is no motivation to use water efficiently by the users with lower marginal value for water. Water markets not only could help increase the net benefits over the basin but also will encourage the stakeholders to save the water and use it in transfer markets and increase their income. This issue can be viewed as a game in which stakeholders can play non-cooperatively and try to increase their own benefits using the amount of water assigned to them or they could cooperate and make coalitions in order to increase the total benefits in the coalition and the whole basin. The aim of this study is to reallocate the water based on cooperation among different stakeholders, namely agricultural, municipal and industrial and environmental, in the Upper Rio Grande river basin in the state of New Mexico in order to increase efficiency, sustainability and equity of water distribution in the basin using different game theory schemes such as Nucleolus and the Shapley Value.

Rouhi Rad, M.

2011-12-01

432

A cDNA microarray gene expression data classifier for clinical diagnostics based on graph theory.  

PubMed

Despite great advances in discovering cancer molecular profiles, the proper application of microarray technology to routine clinical diagnostics is still a challenge. Current practices in the classification of microarrays' data show two main limitations: the reliability of the training data sets used to build the classifiers, and the classifiers' performances, especially when the sample to be classified does not belong to any of the available classes. In this case, state-of-the-art algorithms usually produce a high rate of false positives that, in real diagnostic applications, are unacceptable. To address this problem, this paper presents a new cDNA microarray data classification algorithm based on graph theory and is able to overcome most of the limitations of known classification methodologies. The classifier works by analyzing gene expression data organized in an innovative data structure based on graphs, where vertices correspond to genes and edges to gene expression relationships. To demonstrate the novelty of the proposed approach, the authors present an experimental performance comparison between the proposed classifier and several state-of-the-art classification algorithms. PMID:20855919

Benso, Alfredo; Di Carlo, Stefano; Politano, Gianfranco

2011-01-01

433

Innovative group-decoupling design of a segment erector based on G F set theory  

NASA Astrophysics Data System (ADS)

The segment erector is a key part of the shield machines for tunnel engineering. The available segment erectors are all of serial configuration which is suffering from the problems of low rigidity and accumulative motion errors. The current research mainly focuses on improving assembly accuracy and control performance of serial segment erectors. An innovative design method is proposed featuring motion group-decoupling, based on which a new type of segment erector is developed and investigated. Firstly, the segment installation manipulation is analyzed and decomposed into three motion groups that are decoupled. Then the type synthesis for the 4-DOF motion group is performed based on the general function( G F ) set theory and a new configuration of (1T?1R?1PS&3UPS) is attained according to the segment manipulation requirements. Consequently, the kinematic models are built and the reducibility and accuracy are analyzed. The dexterity is verified though numerical simulation and no singular points appear in the workspace. Finally, a positioning experiment is carried out by using the prototype developed in the lab that demonstrates a 13.1% improvement of positioning accuracy and the feasibility of the new segment erector. The presented group-decoupling design method is able to invent new type of hybrid segment erectors that avoid the accumulative motion error of erecting.

Guo, Wentao; Guo, Weizhong; Gao, Feng; Mo, Pinxi

2013-03-01

434

Form of the effective interaction in harmonic-oscillator-based effective theory  

NASA Astrophysics Data System (ADS)

I explore the form of the effective interaction in harmonic-oscillator-based effective theory (HOBET) in leading order (LO) through next-to-next-to-next-to-leading order (NLO3). Because the included space in a HOBET (as in the shell model) is defined by the oscillator energy, both long-distance (low-momentum) and short-distance (high-momentum) degrees of freedom reside in the high-energy excluded space. A HOBET effective interaction is developed in which a short-range contact-gradient expansion, free of operator mixing and corresponding to a systematic expansion in nodal quantum numbers, is combined with an exact summation of the relative kinetic energy. By this means the very strong coupling of the included (P) and excluded (Q) spaces by the kinetic energy is removed. One finds a simple and rather surprising result, that the interplay of QT and QV is governed by a single parameter ?, the ratio of an observable, the binding energy |E|, to a parameter in the effective theory, the oscillator energy ??. Once the functional dependence on ? is identified, the remaining order-by-order subtraction of the short-range physics residing in Q becomes systematic and rapidly converging. Numerical calculations are used to demonstrate how well the resulting expansion reproduces the running of Heff from high scales to a typical shell-model scale of 8??. At NLO3 various global properties of Heff are reproduced to a typical accuracy of 0.01%, or about 1 keV, at 8??. Channel-by-channel variations in convergence rates are similar to those found in effective field theory approaches. The state dependence of the effective interaction has been a troubling problem in nuclear physics and is embodied in the energy dependence of Heff(|E|) in the Bloch-Horowitz formalism. It is shown that almost all of this state dependence is also extracted in the procedures followed here, isolated in the analytic dependence of Heff on ?. Thus there exists a simple, Hermitian Heff that can be use in spectral calculations. The existence of a systematic operator expansion for Heff, depending on a series of short-range constants augmented by ?, will be important to future efforts to determine the HOBET interaction directly from experiment, rather than from an underlying NN potential.

Haxton, W. C.

2008-03-01

435

Diffuse reflectance relations based on diffusion dipole theory for large absorption and reduced scattering  

NASA Astrophysics Data System (ADS)

Diffuse reflectance spectra are used to determine the optical properties of biological samples. In medicine and forensic science, the turbid objects under study often possess large absorption and/or scattering properties. However, data analysis is frequently based on the diffusion approximation to the radiative transfer equation, implying that it is limited to tissues where the reduced scattering coefficient dominates over the absorption coefficient. Nevertheless, up to absorption coefficients of 20 m at reduced scattering coefficients of 1 and 11.5 mm-1, we observed excellent agreement (r2=0.994) between reflectance measurements of phantoms and the diffuse reflectance equation proposed by Zonios et al. [Appl. Opt. 38, 6628-6637 (1999)], derived as an approximation to one of the diffusion dipole equations of Farrell et al. [Med. Phys. 19, 879-888 (1992)]. However, two parameters were fitted to all phantom experiments, including strongly absorbing samples, implying that the reflectance equation differs from diffusion theory. Yet, the exact diffusion dipole approximation at high reduced scattering and absorption also showed agreement with the phantom measurements. The mathematical structure of the diffuse reflectance relation used, derived by Zonios et al. [Appl. Opt. 38, 6628-6637 (1999)], explains this observation. In conclusion, diffuse reflectance relations derived as an approximation to the diffusion dipole theory of Farrell et al. can analyze reflectance ratios accurately, even for much larger absorption than reduced scattering coefficients. This allows calibration of fiber-probe set-ups so that the object's diffuse reflectance can be related to its absorption even when large. These findings will greatly expand the application of diffuse reflection spectroscopy. In medicine, it may allow the use of blue/green wavelengths and measurements on whole blood, and in forensic science, it may allow inclusion of objects such as blood stains and cloth at crime scenes.

Bremmer, Rolf H.; van Gemert, Martin J. C.; Faber, Dirk J.; van Leeuwen, Ton G.; Aalders, Maurice C. G.

2013-08-01

436

Application of the Hard and Soft, Acids and Bases (HSAB) theory to toxicant--target interactions.  

PubMed

Many chemical toxicants and/or their active metabolites are electrophiles that cause cell injury by forming covalent bonds with nucleophilic targets on biological macromolecules. Covalent reactions between nucleophilic and electrophilic reagents are, however, discriminatory since there is a significant degree of selectivity associated with these interactions. Over the course of the past few decades, the theory of Hard and Soft, Acids and Bases (HSAB) has proven to be a useful tool in predicting the outcome of such reactions. This concept utilizes the inherent electronic characteristic of polarizability to define, for example, reacting electrophiles and nucleophiles as either hard or soft. These HSAB definitions have been successfully applied to chemical-induced toxicity in biological systems. Thus, according to this principle, a toxic electrophile reacts preferentially with biological targets of similar hardness or softness. The soft/hard classification of a xenobiotic electrophile has obvious utility in discerning plausible biological targets and molecular mechanisms of toxicity. The purpose of this perspective is to discuss the HSAB theory of electrophiles and nucleophiles within a toxicological framework. In principle, covalent bond formation can be described by using the properties of their outermost or frontier orbitals. Because these orbital energies for most chemicals can be calculated using quantum mechanical models, it is possible to quantify the relative softness (?) or hardness (?) of electrophiles or nucleophiles and to subsequently convert this information into useful indices of reactivity. This atomic level information can provide insight into the design of corroborative laboratory research and thereby help investigators discern corresponding molecular sites and mechanisms of toxicant action. The use of HSAB parameters has also been instrumental in the development and identification of potential nucleophilic cytoprotectants that can scavenge toxic electrophiles. Clearly, the difficult task of delineating molecular sites and mechanisms of toxicant action can be facilitated by the application of this quantitative approach. PMID:22053936

Lopachin, Richard M; Gavin, Terrence; Decaprio, Anthony; Barber, David S

2012-02-20

437

APPLICATION OF THE HARD AND SOFT, ACIDS AND BASES (HSAB) THEORY TO TOXICANT-TARGET INTERACTIONS  

PubMed Central

Many chemical toxicants and/or their active metabolites are electrophiles that cause cell injury by forming covalent bonds with nucleophilic targets on biological macromolecules. Covalent reactions between nucleophilic and electrophilic reagents are however discriminatory, since there is a significant degree of selectivity associated with these interactions. Over the course of the past few decades, the theory of Hard and Soft, Acid and Bases (HSAB) has proven to be a useful tool in predicting the outcome of such reactions. This concept utilizes the inherent electronic characteristic of polarizability to define, for example, reacting electrophiles and nucleophiles as either hard or soft. These HSAB definitions have been successfully applied to chemical-induced toxicity in biological systems. Thus, according to this principle, a toxic electrophile reacts preferentially with biological targets of similar hardness or softness. The soft/hard classification of a xenobiotic electrophile has obvious utility in discerning plausible biological targets and molecular mechanisms of toxicity. The purpose of this Perspective is to discuss the HSAB theory of electrophiles and nucleophiles within a toxicological framework. In principle, covalent bond formation can be described by using the properties of their outermost or frontier orbitals. Because these orbital energies for most chemicals can be calculated using quantum mechanical models, it is possible to quantify the relative softness (?) or hardness (?) of electrophiles or nucleophiles and to subsequently convert this information into useful indices of reactivity. This atomic level information can provide insight into the design of corroborative laboratory research and thereby help investigators discern corresponding molecular sites and mechanisms of toxicant action. The use of HSAB parameters has also been instrumental in the development and identification of potential nucleophilic cytoprotectants that can scavenge toxic electrophiles. Clearly, the difficult task of delineating molecular sites and mechanisms of toxicant action can be facilitated by the application of this quantitative approach. PMID:22053936

LoPachin, Richard M.; Gavin, Terrence; DeCaprio, Anthony; Barber, David S.

2011-01-01

438

Making psychological theory useful for implementing evidence based practice: a consensus approach  

PubMed Central

Background: Evidence-based guidelines are often not implemented effectively with the result that best health outcomes are not achieved. This may be due to a lack of theoretical understanding of the processes involved in changing the behaviour of healthcare professionals. This paper reports the development of a consensus on a theoretical framework that could be used in implementation research. The objectives were to identify an agreed set of key theoretical constructs for use in (1) studying the implementation of evidence based practice and (2) developing strategies for effective implementation, and to communicate these constructs to an interdisciplinary audience. Methods: Six phases of work were conducted to develop a consensus: (1) identifying theoretical constructs; (2) simplifying into construct domains; (3) evaluating the importance of the construct domains; (4) interdisciplinary evaluation; (5) validating the domain list; and (6) piloting interview questions. The contributors were a "psychological theory" group (n = 18), a "health services research" group (n = 13), and a "health psychology" group (n = 30). Results: Twelve domains were identified to explain behaviour change: (1) knowledge, (2) skills, (3) social/professional role and identity, (4) beliefs about capabilities, (5) beliefs about consequences, (6) motivation and goals, (7) memory, attention and decision processes, (8) environmental context and resources, (9) social influences, (10) emotion regulation, (11) behavioural regulation, and (12) nature of the behaviour. Conclusions: A set of behaviour change domains agreed by a consensus of experts is available for use in implementation research. Applications of this domain list will enhance understanding of the behaviour change processes inherent in implementation of evidence-based practice and will also test the validity of these proposed domains. PMID:15692000

Michie, S; Johnston, M; Abraham, C; Lawton, R; Parker, D; Walker, A; on, b

2005-01-01

439

A decision support system prototype including human factors based on the TOGA meta-theory approach  

SciTech Connect

The human contribution to the risk of operation of complex technological systems is often not negligible and sometimes tends to become significant, as shown by many reports on incidents and accidents occurred in the past inside Nuclear Power Plants (NPPs). An error of a human operator of a NPP can derive by both omission and commission. For instance, complex commission errors can also lead to significant catastrophic technological accidents, as for the case of the Three Mile Island accident. Typically, the problem is analyzed by focusing on the single event chain that has provoked the incident or accident. What is needed is a general framework able to include as many parameters as possible, i.e. both technological and human factors. Such a general model could allow to envisage an omission or commission error before it can happen or, alternatively, suggest preferred actions to do in order to take countermeasures to neutralize the effect of the error before it becomes critical. In this paper, a preliminary Decision Support System (DSS) based on the so-called (-) TOGA meta-theory approach is presented. The application of such a theory to the management of nuclear power plants has been presented in the previous ICAPP 2011. Here, a human factor simulator prototype is proposed in order to include the effect of human errors in the decision path. The DSS has been developed using a TRIGA research reactor as reference plant, and implemented using the LabVIEW programming environment and the Finite State Machine (FSM) model The proposed DSS shows how to apply the Universal Reasoning Paradigm (URP) and the Universal Management Paradigm (UMP) to a real plant context. The DSS receives inputs from instrumentation data and gives as output a suggested decision. It is obtained as the result of an internal elaborating process based on a performance function. The latter, describes the degree of satisfaction and efficiency, which are dependent on the level of responsibility related to each professional role. As an application, we present the simulation of the discussed error, e.g. the unchecked extraction of the control rods during a power variation maneuver and we show how the effect of human errors can affect the performance function, giving rise to different countermeasures which could call different operator figures into play, potentially not envisaged in the standard procedure. (authors)

Cappelli, M.; Memmi, F. [UTFISST, ENEA Casaccia, via Anguillarese 301, Rome (Italy); Gadomski, A. M. [ECONA, Centro Interuniv. Elaborazione Cognitiva Sistemi Naturali e Artificiali, via dei Marsi 47, Rome (Italy); Sepielli, M. [UTFISST, ENEA Casaccia, via Anguillarese 301, Rome (Italy)

2012-07-01

440

Einstein Critical-Slowing-Down is Siegel CyberWar Denial-of-Access Queuing/Pinning/ Jamming/Aikido Via Siegel DIGIT-Physics BEC ``Intersection''-BECOME-UNION Barabasi Network/GRAPH-Physics BEC: Strutt/Rayleigh-Siegel Percolation GLOBALITY--to-LOCALITY Phase-Transition Critical-Phenomenon  

NASA Astrophysics Data System (ADS)

Einstein[Dover(03)] critical-slowing-down(CSD)[Pais, Subtle in The Lord; Life & Sci. of Albert Einstein(81)] is Siegel CyberWar denial-of-access(DOA) operations-research queuing theory/pinning/jamming//Read [Aikido, Aikibojitsu & Natural-Law(90)]/Aikido(!!!) phase-transition critical-phenomenon via Siegel DIGIT-Physics (Newcomb[Am.J.Math. 4,39(1881)]-Planck[(1901)]-Einstein[(1905)])-Poincare[Calcul Probabilités(12)-p.313]-Weyl [Goett.Nachr.(14); Math.Ann.77,313 (16)]-Bose[(24)-Einstein[(25)]-Fermi[(27)]-Dirac[(1927)]-``Benford''[Proc.Am.Phil.Soc. 78,4,551 (38)]-Kac[Maths.Stat.-Reasoning(55)]-Raimi[Sci.Am. 221,109 (69);]-Jech[preprint, PSU(95)]-Hill[Proc.AMS 123,3,887(95)]-Browne[NYT(8/98)]-Antonoff-Smith-Siegel[AMS Joint-Mtg.,S.-D.(02)] algebraic-inversion to yield ONLY BOSE-EINSTEIN QUANTUM-statistics (BEQS) with ZERO-digit Bose-Einstein CONDENSATION(BEC) ``INTERSECTION''-BECOME-UNION to Barabasi[PRL 876,5632(01); Rev.Mod.Phys.74,47(02);] Network /Net/GRAPH(!!!)-physics BEC: Strutt/Rayleigh(1881)-Polya(21)-``Anderson''(58)-Siegel[J.Non-crystalline-Sol.40,453(80);

Buick, Otto; Falcon, Pat; Alexander, G. K.; Carl-Ludwig Siegel, Edward

2013-03-01

441

A Theory of Impedance Control based on Internal Model Uncertainty Djordje Mitrovic, Stefan Klanke, Adrian Haith and Sethu Vijayakumar  

E-print Network

A Theory of Impedance Control based on Internal Model Uncertainty Djordje Mitrovic, Stefan Klanke with learned dynamics (OFC-LD) updates the internal dynamics model from plant data during control, it can, University of Edinburgh Efficient human motor control is characterised by an extensive use of joint impedance

Vijayakumar, Sethu

442

Fuzzy soil mapping based on prototype category theory Feng Qi a,, A-Xing Zhu b,c  

E-print Network

Fuzzy soil mapping based on prototype category theory Feng Qi a,, A-Xing Zhu b,c , Mark Harrower c component of soil mapping is classification, a process of assigning spatial soil entities to predefined categories (classes). However, by their nature soils exist as a continuum both in the spatial and attribute

Zhu, A-Xing

443

Lax–Hopf Based Incorporation of Internal Boundary Conditions Into Hamilton–Jacobi Equation. Part I: Theory  

Microsoft Academic Search

This article proposes a new approach for computing a semi-explicit form of the solution to a class of Hamilton-Jacobi (HJ) partial differential equations (PDEs), using control techniques based on viability theory. We characterize the epigraph of the value function solving the HJ PDE as a capture basin of a target through an auxiliary dynamical system, called ??characteristic system??. The properties

Christian G. Claudel; Alexandre M. Bayen

2010-01-01

444

A Process-Based Model of New Venture Creation: Toward Modelling a Practical Application of Extant Theory using SADT Diagrams  

E-print Network

A Process-Based Model of New Venture Creation: Toward Modelling a Practical Application of Extant of new ventures from an array of theoretical perspectives, the answer to the critical question regarding with uncertainties in a systematic and comprehensive way. Keywords: Venture Creation Process, Theory, Models

Paris-Sud XI, Université de

445

Testing a Theoretical Model Based on Social Cognitive Theory for Media Influences on Suicidal Ideation: Results from a Panel Study  

Microsoft Academic Search

The influence of media representations of suicides on the subsequent increase of suicide rate has been researched for decades. Yet the underlying psychological mechanism of such media influences on individual's suicidality remains uncertain. Based on the conceptual framework of social cognitive theory, this article discusses the operationalization of media influences on suicidal ideation by using a psychometric approach. It then

King-Wa Fu; Yuen-Ying Chan; Paul S. F. Yip

2009-01-01

446

The Impact of a Social Cognitive Theory-Based Intervention on Physical Education Teacher Self-Efficacy  

ERIC Educational Resources Information Center

Adolescents are physically inactive and non-Caucasian adolescents achieve the least amount of physical activity. Hence, supporting teachers' efforts to increase their students' physical activity during physical education is important. We examined the influence of a social cognitive theory-based intervention on teachers' efficacy to teach…

Martin, Jeffrey J.; McCaughtry, Nate; Kulinna, Pamela Hodges; Cothran, Donetta

2009-01-01

447

Presentation-Practice-Production and Task-Based Learning in the Light of Second Language Learning Theories.  

ERIC Educational Resources Information Center

Features of presentation-practice-production (PPP) and task-based learning (TBL) models for language teaching are discussed with reference to language learning theories. Pre-selection of target structures, use of controlled repetition, and explicit grammar instruction in a PPP lesson are given. Suggests TBL approaches afford greater learning…

Ritchie, Graeme

2003-01-01

448

Patient assessment based on a theory of visual attention (TVA): subtle deficits after a right frontal-subcortical lesion  

Microsoft Academic Search

We report on a patient who complained of reduced awareness in the left visual field, but showed no visual neglect or extinction in clinical testing. By MR scanning, the brain damage was localized to the right basal ganglia, also involving structures in right frontal cortex. Using psychophysical testing and mathematical modeling based on Bundesen’s theory of visual attention [TVA; Psychol.

Thomas Habekost; Claus Bundesen

2003-01-01

449

Investigation of the Interactive, Intimidating Relation Between Urbanization and the Environment in an Arid Area Based on Grey System Theory  

Microsoft Academic Search

Taking the Hexi Corridor in western China as an example, this paper studies the interactive intimate i relation between urbanization and the environment in arid areas based on the grey system theory. The results show that the grey relational degree between urbanization and the environment is low in the agriculture-oriented cities, modest in the tourism-oriented cities and great in the

Biao QIAO; Chuang-lin FANG; Mao-sheng BAN

2006-01-01

450

Predicting Teachers' Intentions to Implement School-Based Assessment Using the Theory of Planned Behaviour  

ERIC Educational Resources Information Center

The theory of planned behaviour (TPB) was used to explore the Hong Kong teachers' intentions to implement school-based assessment (SBA) and the predictors of those intentions. A total of 280 teachers from Hong Kong secondary schools who had been involved in SBA were surveyed. Rasch-calibrated teacher measures were calculated for each of the 6…

Yan, Zi

2014-01-01

451

Understanding Women's Risk for HIV Infection Using Social Dominance Theory and the Four Bases of Gendered Power  

ERIC Educational Resources Information Center

Theoretical models to date have fallen short of accounting for the alarming worldwide rates of HIV infection in women through heterosexual contact. In this article, social dominance theory and the four bases of gendered power--force, resource control, social obligations, and consensual ideologies--are used to organize and explain international…

Rosenthal, Lisa; Levy, Sheri R.

2010-01-01

452

Social Ecology of Asthma: Engaging Stakeholders in Integrating Health Behavior Theories and Practice-Based Evidence through Systems Mapping  

ERIC Educational Resources Information Center

This article describes a process for integrating health behavior and social science theories with practice-based insights using participatory systems thinking and diagramming methods largely inspired by system dynamics methods. This integration can help close the gap between research and practice in health education and health behavior by offering…

Gillen, Emily M.; Hassmiller Lich, Kristen; Yeatts, Karin B.; Hernandez, Michelle L.; Smith, Timothy W.; Lewis, Megan A.

2014-01-01

453

Developing the Therapeutic Potential of Embodied Cognition and Metaphors in Nature-Based Therapy: Lessons from Theory to Practice  

ERIC Educational Resources Information Center

This paper theoretically examines the interplay between cognition and bodily involvement in relation to nature-based therapy and proposes implications for practice. With support from theory within embodied cognition and neuroscientific studies, it is argued that explicit learning is actively supported by bodily involvement with the environment.…

Corazon, Sus S.; Schilhab, Theresa S. S.; Stigsdotter, Ulrika K.

2011-01-01

454

Data Processing Inequalities Based on a Certain Structured Class of Information Measures with Application to Estimation Theory  

E-print Network

an arbitrary number of such replicas. We apply the data processing inequality induced by this information the stage for the separation theorem of Information Theory: When a source with rate­distortion function RData Processing Inequalities Based on a Certain Structured Class of Information Measures

Merhav, Neri

455

Comparison of Multiple-Indicators, Multiple-Causes--and Item Response Theory-Based Analyses of Subgroup Differences  

ERIC Educational Resources Information Center

This research provides a direct comparison of effect size estimates based on structural equation modeling (SEM), item response theory (IRT), and raw scores. Differences between the SEM, IRT, and raw score approaches are examined under a variety of data conditions (IRT models underlying the data, test lengths, magnitude of group differences, and…

Willse, John T.; Goodman, Joshua T.

2008-01-01

456

Nonlinear Decentralized Disturbance Attenuation Excitation Control for Power Systems With Nonlinear Loads Based on the Hamiltonian Theory  

Microsoft Academic Search

A novel nonlinear control scheme for disturbance attenuation of structure preserving multimachine power systems based on Hamiltonian theory is proposed in this paper. The proposed control scheme includes two steps: first, the dissipative Hamiltonian realization of structure preserving power system is completed using the singular perturbation approach in which the algebraic equations are considered as a limit of fast dynamics;

Jin Hao; Chen Chen; Libao Shi; Jie Wang

2007-01-01

457

Introducing Agent Based Implementation of the Theory of Reasoned Action: A Case Study in User Acceptance of  

E-print Network

to account for the changes in data between successive time intervals. Our implementation is cost effective other and another in which agents are connected to each other through social links. It is cost effective of the theory of reasoned action model. Our agent-based implementation simulates continuous data compared

Hexmoor, Henry

458

A Program Based on the Pragmatic Theory to Develop Grammatical Structure Comprehension Skills for Foreign Learners of Arabic  

ERIC Educational Resources Information Center

This study aimed at designing a program based on the Pragmatic theory to develop grammatical structure comprehension skills for foreign learners of Arabic and examining its effectiveness. Hence, the problem of the study has been summarized in the weakness of grammatical structure comprehension skills for foreign learners of Arabic and in the need…

Elsamman, Marwan

2014-01-01

459

A little logic goes a long way: basing experiment on semantic theory in the cognitive science of  

E-print Network

A little logic goes a long way: basing experiment on semantic theory in the cognitive science as the basis for a variety of anti-logical approaches to the study of human reasoning. Two examples. The program is motivated by a reaction against `logical' accounts of reasoning which are held

van Lambalgen, Michiel

460

Leveraging Genre Theory: A Genre-Based Interactive Model for the Era of the Common Core State Standards  

ERIC Educational Resources Information Center

Recent educational standards have refocused the goals of foreign language (FL) instruction on "the purpose of communication" (ACTFL, 2012, p. 1) across the three modes of communication (interpersonal, interpretive, and presentational). To this end, this article considers a linguistically based genre theory as a means of enhancing…

Troyan, Francis J.

2014-01-01

461

Using Web-Based Instruction to Teach Music Theory in the Piano Studio: Defining, Designing, and Implementing an Integrative Approach  

ERIC Educational Resources Information Center

This dissertation rationalizes the best use of Web-based instruction (WBI) for teaching music theory to private piano students in the later primary grades. It uses an integrative research methodology for defining, designing, and implementing a curriculum that includes WBI. Research from the fields of music education, educational technology,…

Carney, Robert D.

2010-01-01

462

Integrating Program Theory and Systems-Based Procedures in Program Evaluation: A Dynamic Approach to Evaluate Educational Programs  

ERIC Educational Resources Information Center

The current study attempts to integrate parts of program theory and systems-based procedures in educational program evaluation. The educational program that was implemented, called the "Early Steps" project, proposed that physical education can contribute to various educational goals apart from the usual motor skills improvement. Basic elements of…

Grammatikopoulos, Vasilis

2012-01-01

463

A Comprehensive Test of General Strain Theory: Key Strains, Situational- and Trait-Based Negative Emotions, Conditioning Factors, and Delinquency  

ERIC Educational Resources Information Center

Using longitudinal data on South Korean youth, the authors addressed limitations of previous tests of general strain theory (GST), focusing on the relationships among key strains, situational- and trait-based negative emotions, conditioning factors, and delinquency. Eight types of strain previously shown most likely to result in delinquency,…

Moon, Byongook; Morash, Merry; McCluskey, Cynthia Perez; Hwang, Hye-Won

2009-01-01

464

To have or to be? A comparison of materialism-based theories and self-determination theory as explanatory frameworks of prejudice.  

PubMed

The present study aimed to delineate the psychological structure of materialism and intrinsic and extrinsic value pursuit. Moreover, we compared models based on self-determination theory (SDT), Fromm's marketing character, and Inglehart's theory of social change to account for racial prejudice. In a sample of undergraduate students (n=131) and adults (n=176) it was revealed that the extrinsic value pursuit Financial Success/Materialism could be distinguished from the extrinsic value scales Physical Appeal and Social Recognition, and Community Concern could be distinguished from the intrinsic value pursuit scales Self-acceptance and Affiliation. Moreover, Financial Success/Materialism and Community Concern were consistently and significantly related to prejudice, whereas the other SDT facet scales yielded weaker relationships with prejudice. Structural models based on SDT and Inglehart were not corroborated, but instead the present data supported a mediation model based on Fromm's work in which the effect of Community Concern was mediated by Financial Success/Materialism. Broader implications for SDT are critically assessed. PMID:20573135

Van Hiel, Alain; Cornelis, Ilse; Roets, Arne

2010-06-01

465

Spiritually Based Intervention to Increase Colorectal Cancer Screening among African Americans: Screening and Theory-Based Outcomes from a Randomized Trial  

ERIC Educational Resources Information Center

Colorectal cancer screening has clear benefits in terms of mortality reduction; however, it is still underutilized and especially among medically underserved populations, including African Americans, who also suffer a disproportionate colorectal cancer burden. This study consisted of a theory-driven (health belief model) spiritually based…

Holt, Cheryl L.; Litaker, Mark S.; Scarinci, Isabel C.; Debnam, Katrina J.; McDavid, Chastity; McNeal, Sandre F.; Eloubeidi, Mohamad A.; Crowther, Martha; Bolland, John; Martin, Michelle Y.

2013-01-01

466

Theory of reasoned action and theory of planned behavior-based dietary interventions in adolescents and young adults: a systematic review  

PubMed Central

Background Childhood obesity has reached epidemic proportions in many nations around the world. The theory of planned behavior (TPB) and the theory of reasoned action (TRA) have been used to successfully plan and evaluate numerous interventions for many different behaviors. The aim of this study was to systematically review and synthesize TPB and TRA-based dietary behavior interventions targeting adolescents and young adults. Methods The following databases were systematically searched to find articles for this review: Academic Search Premier; Cumulative Index to Nursing and Allied Health (CINAHL); Education Resources Information Center (ERIC); Health Source: Nursing/Academic Edition; Cochrane Central Register of Controlled Trials (CENTRAL); and MEDLINE. Inclusion criteria for articles were: 1) primary or secondary interventions, 2) with any quantitative design, 3) published in the English language, 4) between January 2003 and March 2014, 5) that targeted adolescents or young adults, 6) which included dietary change behavior as the outcome, and 7) utilized TPB or TRA. Results Of the eleven intervention studies evaluated, nine resulted in dietary behavior change that was attributed to the treatment. Additionally, all but one study found there to be a change in at least one construct of TRA or TPB, while one study did not measure constructs. All of the studies utilized some type of quantitative design, with two employing quasi-experimental, and eight employing randomized control trial design. Among the studies, four utilized technology including emails, social media posts, information on school websites, web-based activities, audio messages in classrooms, interactive DVDs, and health-related websites. Two studies incorporated goal setting and four employed persuasive communication. Conclusion Interventions directed toward changing dietary behaviors in adolescents should aim to incorporate multi-faceted, theory-based approaches. Future studies should consider utilizing randomized control trial design and operationalize variables. More research is needed to identify the optimal TPB and TRA modalities to modify dietary behaviors. PMID:24966710

Hackman, Christine L; Knowlden, Adam P

2014-01-01

467

A new design of Prolog-based bottom-up parsing system with government-binding theory  

Microsoft Academic Search

This paper addresses the problems of movement transformation in Prolog-based bottom-up parsing system. Three principles of Government-Binding theory are employed to deal with these problems. They are Empty Category Principle, C-command Principle, and Subjacency Principle. A formalism based upon them is proposed. Translation algorithms are given to add these linguistic principles to the general grammar rules, the leftward movement grammar

Hsin-Hsi Chen; I-Peng Lin; Chien-Ping Wu

1988-01-01

468

Prognostics of lithium-ion batteries based on Dempster–Shafer theory and the Bayesian Monte Carlo method  

Microsoft Academic Search

A new method for state of health (SOH) and remaining useful life (RUL) estimations for lithium-ion batteries using Dempster–Shafer theory (DST) and the Bayesian Monte Carlo (BMC) method is proposed. In this work, an empirical model based on the physical degradation behavior of lithium-ion batteries is developed. Model parameters are initialized by combining sets of training data based on DST.

Wei He; Nicholas Williard; Michael Osterman; Michael Pecht

2011-01-01

469

Nonempirical Anharmonic Vibrational Perturbation Theory Applied to Biomolecules: Free-Base Porphin.  

PubMed

Anharmonic vibrational frequencies and intensities (infrared and Raman) of an isolated free-base porphin molecule are predicted from the quantum mechanical (QM) geometry, the "semi-diagonal" quartic force field, and dipole moment and polarizability surfaces. The second-order vibrational perturbation theory plus the numerical diagonalization of the Hamiltonian matrix containing off-diagonal Fermi and Darling-Dennison resonance couplings (VPT2+WK) was used. The QM calculations were carried out with the Becke-Lee-Yang-Parr composite exchange-correlation functional (B3LYP) and with the 6-31+G(d,p) basis set. The harmonic force field for the equilibrium configuration was transformed into nonredundant local symmetry internal coordinates, and normal coordinates were defined. The semi-diagonal quartic rectilinear normal coordinate potential energy surface (PES), as well as the cubic surfaces of dipole moment (p) and polarizability (?) components, needed for the VPT2+WK calculation, were constructed by a five-point finite differentiation of Hessians (for PES) and of the values and first derivatives of p and ?. They were obtained at the point of equilibrium and for 432 displaced configurations. This theoretical approach provides very good agreement between the predicted and experimental frequencies and intensities. However, the favorable result can be partly attributed to error cancellation within the B3LYP/6-31+G(d,p) QM model, as observed in earlier studies. Reassignments of some observed bands are proposed. PMID:25360995

Krasnoshchekov, Sergey V; Stepanov, Nikolay F

2014-11-18

470

Acceptability of a theory of planned behaviour email-based nutrition intervention.  

PubMed

This study investigated feasibility and acceptability of a new email-delivered intervention promoting fruit and vegetable consumption in a university-based population of Australian young adults. The study explored whether there are differences in the reported feasibility and acceptability between demographic groups within the population of interest and at three levels of intervention intensity. The email-delivered intervention program consists of an implementation intention 'planning task' and between 3 and 15 short email messages over a 15-day study period. The intervention program was developed using the Theory of Planned Behaviour and was designed to modify perceived behavioural control. One hundred and ten participants (mean age = 19.21 years, 25.6% male) completed the feasibility and acceptability questionnaire at Day 15. This questionnaire contained items about all intervention components. High acceptability and feasibility scores were found for all intervention parts and at all levels of intervention intensity. There were few significant differences in the reported acceptability of items between key demographic sub-groups, and no differences in reported acceptability at different levels of intervention intensity. These results suggest that this email-delivered intervention is an acceptable and feasible tool for promoting fruit and vegetable consumption for participants in the target population. PMID:22942273

Kothe, E J; Mullan, B A

2014-03-01

471

Actinide electronic structure based on the Dirac equation and density functional theory  

NASA Astrophysics Data System (ADS)

Density functional theory (DFT) provides a formally predictive basis for predicting the structural properties of actinides. Although available approximations to the exchange/correlation functional provide accurate predictions for many materials, they fail qualitatively and sometimes quantitatively when applied to actinides. Major contributors to this deficiency are an inadequate treatment of confinement physics and an incomplete treatment of relativity in the underlying equations. The development of a functional correctly incorporating confinement physics with a proper treatment of relativity would provide definitive, internally consistent predictions of actinide properties. To enable the development of such a functional and quantify the predictions of currently available functionals, we have developed an efficient first-principles electronic structure method based on the Dirac equation. Results are compared with current methods, and the implications for relativistic density functionals discussed. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Wills, John M.; Mattsson, Ann E.

2013-03-01

472

An enhanced version of a bone-remodelling model based on the continuum damage mechanics theory.  

PubMed

The purpose of this work was to propose an enhancement of Doblaré and García's internal bone remodelling model based on the continuum damage mechanics (CDM) theory. In their paper, they stated that the evolution of the internal variables of the bone microstructure, and its incidence on the modification of the elastic constitutive parameters, may be formulated following the principles of CDM, although no actual damage was considered. The resorption and apposition criteria (similar to the damage criterion) were expressed in terms of a mechanical stimulus. However, the resorption criterion is lacking a dimensional consistency with the remodelling rate. We propose here an enhancement to this resorption criterion, insuring the dimensional consistency while retaining the physical properties of the original remodelling model. We then analyse the change in the resorption criterion hypersurface in the stress space for a two-dimensional (2D) analysis. We finally apply the new formulation to analyse the structural evolution of a 2D femur. This analysis gives results consistent with the original model but with a faster and more stable convergence rate. PMID:24697274

Mengoni, M; Ponthot, J P

2015-09-01

473

Optical color image encryption based on computer generated hologram and chaotic theory  

NASA Astrophysics Data System (ADS)

A novel technique of optical color image encryption and decryption based on computer generated hologram (CGH) and chaotic theory is proposed. The tri-color separated images of an image to be encrypted are encoded with three random phase arrays constructed by a chaotic sequence of the deterministic non-linear system, respectively. Then Burch's encoding method using the modified off-axis reference beam is adopted to fabricate the CGH as the encryption image. A clear original color image can be reconstructed as long as the correct initial value of chaotic sequence and the correct system parameters are given. The initial value of chaotic function with a very small change will lead to the generation of an entirely different chaotic sequences. As a result, the random phase array changes dramatically and the original image cannot be recovered rightly. Serving as the secret keys, the initial values of chaotic sequence and system parameters reduce the amount of the key data. And the digital encryption image is also more favorable to be stored and transmitted. The feasibility and its robustness against occlusion and noise attacks are verified by numerical simulations.

Liu, Jian; Jin, Hongzhen; Ma, Lihong; Li, Yong; Jin, Weimin

2013-10-01

474

Precise segmentation of multiple organs in CT volumes using learning-based approach and information theory.  

PubMed

In this paper, we present a novel method by incorporating information theory into the learning-based approach for automatic and accurate pelvic organ segmentation (including the prostate, bladder and rectum). We target 3D CT volumes that are generated using different scanning protocols (e.g., contrast and non-contrast, with and without implant in the prostate, various resolution and position), and the volumes come from largely diverse sources (e.g., diseased in different organs). Three key ingredients are combined to solve this challenging segmentation problem. First, marginal space learning (MSL) is applied to efficiently and effectively localize the multiple organs in the largely diverse CT volumes. Second, learning techniques, steerable features, are applied for robust boundary detection. This enables handling of highly heterogeneous texture pattern. Third, a novel information theoretic scheme is incorporated into the boundary inference process. The incorporation of the Jensen-Shannon divergence further drives the mesh to the best fit of the image, thus improves the segmentation performance. The proposed approach is tested on a challenging dataset containing 188 volumes from diverse sources. Our approach not only produces excellent segmentation accuracy, but also runs about eighty times faster than previous state-of-the-art solutions. The proposed method can be applied to CT images to provide visual guidance to physicians during the computer-aided diagnosis, treatment planning and image-guided radiotherapy to treat cancers in pelvic region. PMID:23286081

Lu, Chao; Zheng, Yefeng; Birkbeck, Neil; Zhang, Jingdan; Kohlberger, Timo; Tietjen, Christian; Boettger, Thomas; Duncan, James S; Zhou, S Kevin

2012-01-01

475

[Reliability theory based on quality risk network analysis for Chinese medicine injection].  

PubMed

A new risk analysis method based upon reliability theory was introduced in this paper for the quality risk management of Chinese medicine injection manufacturing plants. The risk events including both cause and effect ones were derived in the framework as nodes with a Bayesian network analysis approach. It thus transforms the risk analysis results from failure mode and effect analysis (FMEA) into a Bayesian network platform. With its structure and parameters determined, the network can be used to evaluate the system reliability quantitatively with probabilistic analytical appraoches. Using network analysis tools such as GeNie and AgenaRisk, we are able to find the nodes that are most critical to influence the system reliability. The importance of each node to the system can be quantitatively evaluated by calculating the effect of the node on the overall risk, and minimization plan can be determined accordingly to reduce their influences and improve the system reliability. Using the Shengmai injection manufacturing plant of SZYY Ltd as a user case, we analyzed the quality risk with both static FMEA analysis and dynamic Bayesian Network analysis. The potential risk factors for the quality of Shengmai injection manufacturing were identified with the network analysis platform. Quality assurance actions were further defined to reduce the risk and improve the product quality. PMID:25509315

Li, Zheng; Kang, Li-Yuan; Fan, Xiao-Hui

2014-08-01

476

A new approach to preserve privacy data mining based on fuzzy theory in numerical database  

NASA Astrophysics Data System (ADS)

With the rapid development of information techniques, data mining approaches have become one of the most important tools to discover the in-deep associations of tuples in large-scale database. Hence how to protect the private information is quite a huge challenge, especially during the data mining procedure. In this paper, a new method is proposed for privacy protection which is based on fuzzy theory. The traditional fuzzy approach in this area will apply fuzzification to the data without considering its readability. A new style of obscured data expression is introduced to provide more details of the subsets without reducing the readability. Also we adopt a balance approach between the privacy level and utility when to achieve the suitable subgroups. An experiment is provided to show that this approach is suitable for the classification without a lower accuracy. In the future, this approach can be adapted to the data stream as the low computation complexity of the fuzzy function with a suitable modification.

Cui, Run; Kim, Hyoung Joong

2014-01-01

477

Systematic development and validation of a theory-based questionnaire to assess toddler feeding.  

PubMed

This paper describes the development and validation of a 27-item caregiver-reported questionnaire on toddler feeding. The development of the Toddler Feeding Behavior Questionnaire was based on a theory of interactive feeding that incorporates caregivers' responses to concerns about their children's dietary intake, appetite, size, and behaviors rather than relying exclusively on caregiver actions. Content validity included review by an expert panel (n = 7) and testing in a pilot sample (n = 105) of low-income mothers of toddlers. Construct validity and reliability were assessed among a second sample of low-income mothers of predominately African-American (70%) toddlers aged 12-32 mo (n = 297) participating in the baseline evaluation of a toddler overweight prevention study. Internal consistency (Cronbach's ?: 0.64-0.87) and test-retest (0.57-0.88) reliability were acceptable for most constructs. Exploratory and confirmatory factor analyses revealed 5 theoretically derived constructs of feeding: responsive, forceful/pressuring, restrictive, indulgent, and uninvolved (root mean square error of approximation = 0.047, comparative fit index = 0.90, standardized root mean square residual = 0.06). Statistically significant (P < 0.05) convergent validity results further validated the scale, confirming established relations between feeding behaviors, toddler overweight status, perceived toddler fussiness, and maternal mental health. The Toddler Feeding Behavior Questionnaire adds to the field by providing a brief instrument that can be administered in 5 min to examine how caregiver-reported feeding behaviors relate to toddler health and behavior. PMID:24068792

Hurley, Kristen M; Pepper, M Reese; Candelaria, Margo; Wang, Yan; Caulfield, Laura E; Latta, Laura; Hager, Erin R; Black, Maureen M

2013-12-01

478

Parallel implementation of multireference coupled-cluster theories based on the reference-level parallelism  

SciTech Connect

A novel algorithm for implementing general type of multireference coupled-cluster (MRCC) theory based on the Jeziorski-Monkhorst exponential Ansatz [B. Jeziorski, H.J. Monkhorst, Phys. Rev. A 24, 1668 (1981)] is introduced. The proposed algorithm utilizes processor groups to calculate the equations for the MRCC amplitudes. In the basic formulation each processor group constructs the equations related to a specific subset of references. By flexible choice of processor groups and subset of reference-specific sufficiency conditions designated to a given group one can assure optimum utilization of available computing resources. The performance of this algorithm is illustrated on the examples of the Brillouin-Wigner and Mukherjee MRCC methods with singles and doubles (BW-MRCCSD and Mk-MRCCSD). A significant improvement in scalability and in reduction of time to solution is reported with respect to recently reported parallel implementation of the BW-MRCCSD formalism [J.Brabec, H.J.J. van Dam, K. Kowalski, J. Pittner, Chem. Phys. Lett. 514, 347 (2011)].

Brabec, Jiri; Pittner, Jiri; van Dam, Hubertus JJ; Apra, Edoardo; Kowalski, Karol

2012-02-01

479

Ethnic Differences and Motivation Based on Maslow’s Theory on Iranian Employees  

PubMed Central

Background The aim of this study was to assess the levels of Maslow’s hierarchy of needs theory had been fulfilled and to compare the Maslow’s hierarchy of needs among Iranian different ethnic groups at Tehran University of Medical Sciences (TUMS). Methods: This research was a descriptive-analytical study which conducted among administrative employees of Tehran University of Medical Sciences; Tehran, Iran. The structured questionnaire consisted of 20 questions and demographic details. Each question had 4 parts to measure Maslow’s hierarchy of needs. The questionnaire was distributed randomly among 133 employees to fill-up the demographic details and the other questions. Data was collected and analyzed by SPSS software, and One Way ANOVA, T-test, Spearman and Mann Whitney statistical methods. Results: TUMS ethnic groups of the employees placed most importance on Basic, Self-esteem and Self-actualization. In addition, we found that Persians, Mazandaranians, and Turks ethnic groups, scored the most mean for Maslow’s hierarchical needs compared to the other ethnic groups. Conclusion: Basic needs and safety needs is available amongst the different ethnic groups in Iran. As though, self-actualization needs are ultimate human goal, Iranian employees’ ethnic groups pay emphasis on these needs. We believe that new structures and work practices such as prevailing cultural values and beliefs of the society or the organizations must be explored if Iranian-based organizations want to remain responsive to the needs of the workplace. PMID:23802110

MOUSAVI, Seyed Hadi; DARGAHI, Hossein

2013-01-01

480

Three-dimensional theory of quantum memories based on {Lambda}-type atomic ensembles  

SciTech Connect

We develop a three-dimensional theory for quantum memories based on light storage in ensembles of {Lambda}-type atoms, where two long-lived atomic ground states are employed. We consider light storage in an ensemble of finite spatial extent and we show that within the paraxial approximation the Fresnel number of the atomic ensemble and the optical depth are the only important physical parameters determining the quality of the quantum memory. We analyze the influence of these parameters on the storage of light followed by either forward or backward read-out from the quantum memory. We show that for small Fresnel numbers the forward memory provides higher efficiencies, whereas for large Fresnel numbers the backward memory is advantageous. The optimal light modes to store in the memory are presented together with the corresponding spin waves and outcoming light modes. We show that for high optical depths such {Lambda}-type atomic ensembles allow for highly efficient backward and forward memories even for small Fresnel numbers F(greater-or-similar sign)0.1.

Zeuthen, Emil; Grodecka-Grad, Anna; Soerensen, Anders S. [QUANTOP, Danish National Research Foundation Center for Quantum Optics, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen O (Denmark)

2011-10-15

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