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1

Queuing Theory  

E-print Network

Humans have practised gambling at all times. The archaeologists have made excavations in prehistoric sites and found large numbers of roughly dice-shaped bones. Different types of games, sports events, other types of events and gambling are connected because it has always been challenging to make bets on differ-ent outcomes of a game. Experiences and simple statistics used more or less unconsciously made in old times the basis for the gamblers and their betting. Until the 16th century the mathematics was not applied on gambling and proba-bility problems. This paper shows how gambling problems initiated the mathematical theory of probability and gives an overview of the establishment of the mathematical theory of probability. The lines are drawn from the mathematical theory of probability to the establish-ment of the queuing/teletraffic theory more than 200 years later. And the pioneers in developing the queu-ing / teletraffic theory were Agner Krarup Erlang and Tore Olaus Engset! (Stordahl, 2006) identified that The Gambler’s Ruin Problem was solved by using the same difference equations as for the M/M/1 queuing systems, only 200 years earlier. This paper investigates and explains the incitements for the development of the queuing/teletraffic theory which was mainly caused by introduction of telephone switching systems.

Kjell Stordahl Is

2

Waiting in line [queuing theory  

Microsoft Academic Search

Queuing phenomenon encompasses all activities of our lives. We have to wait in line whenever the number of servers or the service rate of the server does not match the rate at which the customers arrive in the queue. Queuing theory is the formal analysis of this phenomenon in search of finding the optimum solution to this problem so that

L. Tadj

1995-01-01

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

Using Queuing Theory to Model Streaming Applications  

E-print Network

is particularly interesting given the fact that we know, a priori, that the queu- ing models make several on modeling Mercury BLAST [2], [3], an accelerated BLAST that combines general-purpose processors and FPGAs. Mercury BLAST's three-stage pipeline is illus- trated in Figure 1. In the first FPGA stage, BLAST detects

Chamberlain, Roger

5

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 chose to develop the waiting line's problem on a level with landing on a runway. Among the different

Paris-Sud XI, Université de

6

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

7

On application of methods of Queuing Theory to scheduling in GRIDs  

NASA Astrophysics Data System (ADS)

Methods of Queuing Theory are applied to study and develop a scheduling algorithm for GRIDs. The problem of optimal scheduling is reduced to the one of linear programming, for which there exists an exact solution.

Bityukov, Serge S.

2004-11-01

8

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

9

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

10

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

11

Modeling Relief Demands in an Emergency Supply Chain System under Large-Scale Disasters Based on a Queuing Network  

PubMed Central

This paper presents a multiple-rescue model for an emergency supply chain system under uncertainties in large-scale affected area of disasters. The proposed methodology takes into consideration that the rescue demands caused by a large-scale disaster are scattered in several locations; the servers are arranged in multiple echelons (resource depots, distribution centers, and rescue center sites) located in different places but are coordinated within one emergency supply chain system; depending on the types of rescue demands, one or more distinct servers dispatch emergency resources in different vehicle routes, and emergency rescue services queue in multiple rescue-demand locations. This emergency system is modeled as a minimal queuing response time model of location and allocation. A solution to this complex mathematical problem is developed based on genetic algorithm. Finally, a case study of an emergency supply chain system operating in Shanghai is discussed. The results demonstrate the robustness and applicability of the proposed model. PMID:24688367

He, Xinhua

2014-01-01

12

Modeling relief demands in an emergency supply chain system under large-scale disasters based on a queuing network.  

PubMed

This paper presents a multiple-rescue model for an emergency supply chain system under uncertainties in large-scale affected area of disasters. The proposed methodology takes into consideration that the rescue demands caused by a large-scale disaster are scattered in several locations; the servers are arranged in multiple echelons (resource depots, distribution centers, and rescue center sites) located in different places but are coordinated within one emergency supply chain system; depending on the types of rescue demands, one or more distinct servers dispatch emergency resources in different vehicle routes, and emergency rescue services queue in multiple rescue-demand locations. This emergency system is modeled as a minimal queuing response time model of location and allocation. A solution to this complex mathematical problem is developed based on genetic algorithm. Finally, a case study of an emergency supply chain system operating in Shanghai is discussed. The results demonstrate the robustness and applicability of the proposed model. PMID:24688367

He, Xinhua; Hu, Wenfa

2014-01-01

13

Concatenating Packets in Variable-Length Input-Queued Packet Switches with Cell-Based and  

E-print Network

. There has been a growing interest in developing the design of Internet routers based variable-lenght packets in the Internet increased to process packets rapidly. These switches use then fixed-lengh packet internally and re-Based Scheduling Nabeel A. Al-Saber, Saurabh Oberoi, Roberto Rojas-Cessa, and Sotirios G. Ziavras Abstract--Internet

Rojas-Cessa, Roberto

14

A closed-form expression for queuing delay in Rayleigh fading channels using stochastic network calculus  

Microsoft Academic Search

Stochastic Network Calculus is a modern theory for studying the delay performance of a queuing system. So far, this theory proved very effective in studying QoS in the wireline transmission media. In fact, it provides an upper bound to the probability tail of the queuing delay and requires only the expression of an arrival curve, which models the traffic source,

Giacomo Verticale

2009-01-01

15

How fair is fair queuing  

Microsoft Academic Search

Fair Queuing is a novel queuing discipline with important applications to data networks that support variable-size packets and to systems where the cost of preempting jobs from service is high. The disciphne controls a single server shared by N job arrival streams with each stream allotted a separate queue. After every job completion, the server is assigned to serve, without

Albert G. Greenberg; Neal Madras

1992-01-01

16

Network Queuing System, Version 2.0  

NASA Technical Reports Server (NTRS)

Network Queuing System (NQS) computer program is versatile batch- and device-queuing facility for single UNIX computer or group of computers in network. User invokes NQS collection of user-space programs to move batch and device jobs freely among different computers in network. Provides facilities for remote queuing, request routing, remote status, queue-status controls, batch-request resource quota limits, and remote output return. Revision of NQS provides for creation, deletion, addition, and setting of complexes aiding in limiting number of requests handled at one time. Also has improved device-oriented queues along with some revision of displays. Written in C language.

Walter, Howard; Bridges, Mike; Carver, Terrie; Kingsbury, Brent

1993-01-01

17

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

18

A new technique to optimize the functions of fuzzy profit of queuing models: Application to a queuing model with publicity and renouncement  

Microsoft Academic Search

In this paper we model, using the Queuing Theory, the situation in which the manager of some facilities wishes to maximize the profit generated by the same. The manager tries to attract customers and the effectiveness of his publicity politic is measured in the fraction of customers who renounce. In this paper, unlike the classic models, we consider that the

María José Pardo; David de la Fuente

2009-01-01

19

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

20

Principles of Queued Service Observing at CFHT  

NASA Astrophysics Data System (ADS)

CFHT started to use Queued Service Observing in 2001, and is now operating in that mode over 95% of the time. Ten years later, the observations are now carried out by Remote Observers who are not present at the telescope (see the companion presentation "Remote Queued Service Observing at CFHT"). The next phase at CFHT will likley involve assisted or autonomous service observing (see the presentation "Artificial Intelligence in Autonomous Telescopes"), which would not be possible without first having a Queued observations system already in place. The advantages and disadvantages of QSO at CFHT will be reviewed. The principles of QSO at CFHT, which allow CFHT to complete 90-100% of the top 30-40% programs and often up to 80% of other accepted programs, will be presented, along with the strategic use of overfill programs, the method of agency balance, and the suite of planning, scheduling, analysis and data quality assessment tools available to Queue Coordinators and Remote Observers.

Manset, Nadine; Burdullis, T.; Devost, D.

2011-03-01

21

Is Your Queuing System ADA-Compliant?  

ERIC Educational Resources Information Center

Discusses the Americans with Disabilities (ADA) and Uniform Federal Accessibility Standards (UFAS) regulations regarding public facilities' crowd control stanchions and queuing systems. The major elements are protruding objects and wheelchair accessibility. Describes how to maintain compliance with the regulations and offers a list of additional…

Lawrence, David

2002-01-01

22

Stability of Maximal Size Matching Scheduling in Input-Queued Cell Switches  

E-print Network

organize input buffers in each line card into a set of queues where cells awaiting access to the switchingStability of Maximal Size Matching Scheduling in Input-Queued Cell Switches E.Leonardi, M.Mellia, M,mellia,ajmone,neri @mail.tlc.polito.it Abstract-- We consider cell-based switch architectures in which the speedup

23

The queuing theory based research of dispatching strategy for elevator group control system during up-peak  

Microsoft Academic Search

This paper discusses the result of research on the valid range of passenger arrival rate for dispatching method. During up-peak traffic, some rules of dispatching scheme in elevator-group under variant arrival rates are summarized on the basis of simulations of three different conventional dispatching methods including none-zoning method, two-fixed-zoning method and four-fixed-zoning method. Afterwards, the equation for the average journey

Qun Zong; Guansheng Xing; Donghang Chen; Shuhong Ya

2004-01-01

24

Improving hospital bed occupancy and resource utilization through queuing modeling and evolutionary computation.  

PubMed

Scarce healthcare resources require carefully made policies ensuring optimal bed allocation, quality healthcare service, and adequate financial support. This paper proposes a complex analysis of the resource allocation in a hospital department by integrating in the same framework a queuing system, a compartmental model, and an evolutionary-based optimization. The queuing system shapes the flow of patients through the hospital, the compartmental model offers a feasible structure of the hospital department in accordance to the queuing characteristics, and the evolutionary paradigm provides the means to optimize the bed-occupancy management and the resource utilization using a genetic algorithm approach. The paper also focuses on a "What-if analysis" providing a flexible tool to explore the effects on the outcomes of the queuing system and resource utilization through systematic changes in the input parameters. The methodology was illustrated using a simulation based on real data collected from a geriatric department of a hospital from London, UK. In addition, the paper explores the possibility of adapting the methodology to different medical departments (surgery, stroke, and mental illness). Moreover, the paper also focuses on the practical use of the model from the healthcare point of view, by presenting a simulated application. PMID:25433363

Belciug, Smaranda; Gorunescu, Florin

2015-02-01

25

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

26

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

27

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

28

NQS - NETWORK QUEUING SYSTEM, VERSION 2.0 (UNIX VERSION)  

NASA Technical Reports Server (NTRS)

The Network Queuing System, NQS, is a versatile batch and device queuing facility for a single Unix computer or a group of networked computers. With the Unix operating system as a common interface, the user can invoke the NQS collection of user-space programs to move batch and device jobs freely around the different computer hardware tied into the network. NQS provides facilities for remote queuing, request routing, remote status, queue status controls, batch request resource quota limits, and remote output return. This program was developed as part of an effort aimed at tying together diverse UNIX based machines into NASA's Numerical Aerodynamic Simulator Processing System Network. This revision of NQS allows for creating, deleting, adding and setting of complexes that aid in limiting the number of requests to be handled at one time. It also has improved device-oriented queues along with some revision of the displays. NQS was designed to meet the following goals: 1) Provide for the full support of both batch and device requests. 2) Support all of the resource quotas enforceable by the underlying UNIX kernel implementation that are relevant to any particular batch request and its corresponding batch queue. 3) Support remote queuing and routing of batch and device requests throughout the NQS network. 4) Support queue access restrictions through user and group access lists for all queues. 5) Enable networked output return of both output and error files to possibly remote machines. 6) Allow mapping of accounts across machine boundaries. 7) Provide friendly configuration and modification mechanisms for each installation. 8) Support status operations across the network, without requiring a user to log in on remote target machines. 9) Provide for file staging or copying of files for movement to the actual execution machine. To support batch and device requests, NQS v.2 implements three queue types--batch, device and pipe. Batch queues hold and prioritize batch requests; device queues hold and prioritize device requests; pipe queues transport both batch and device requests to other batch, device, or pipe queues at local or remote machines. Unique to batch queues are resource quota limits that restrict the amounts of different resources that a batch request can consume during execution. Unique to each device queue is a set of one or more devices, such as a line printer, to which requests can be sent for execution. Pipe queues have associated destinations to which they route and deliver requests. If the proper destination machine is down or unreachable, pipe queues are able to requeue the request and deliver it later when the destination is available. All NQS network conversations are performed using the Berkeley socket mechanism as ported into the respective vendor kernels. NQS is written in C language. The generic UNIX version (ARC-13179) has been successfully implemented on a variety of UNIX platforms, including Sun3 and Sun4 series computers, SGI IRIS computers running IRIX 3.3, DEC computers running ULTRIX 4.1, AMDAHL computers running UTS 1.3 and 2.1, platforms running BSD 4.3 UNIX. The IBM RS/6000 AIX version (COS-10042) is a vendor port. NQS 2.0 will also communicate with the Cray Research, Inc. and Convex, Inc. versions of NQS. The standard distribution medium for either machine version of NQS 2.0 is a 60Mb, QIC-24, .25 inch streaming magnetic tape cartridge in UNIX tar format. Upon request the generic UNIX version (ARC-13179) can be provided in UNIX tar format on alternate media. Please contact COSMIC to discuss the availability and cost of media to meet your specific needs. An electronic copy of the NQS 2.0 documentation is included on the program media. NQS 2.0 was released in 1991. The IBM RS/6000 port of NQS was developed in 1992. IRIX is a trademark of Silicon Graphics Inc. IRIS is a registered trademark of Silicon Graphics Inc. UNIX is a registered trademark of UNIX System Laboratories Inc. Sun3 and Sun4 are trademarks of Sun Microsystems Inc. DEC and ULTRIX are trademarks of Digital Equipment Corporation.

Walter, H.

1994-01-01

29

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

30

Field programmable port extender (FPX) for distributed routing and queuing  

Microsoft Academic Search

Field Programmable Gate Arrays (FPGAs) are being used to provide fast Internet Protocol (IP) packet routing and advanced queuing in a highly scalable network switch. A new module, called the Field-programmable Port Extender (FPX), is being built to augment the Washington University Gigabit Switch (WUGS) with reprogrammable logic.FPX modules reside at the edge of the WUGS switching fabric. Physically, the

John W. Lockwood; Jonathan S. Turner; David E. Taylor

2000-01-01

31

Core-stateless proportional fair queuing for AF traffic  

Microsoft Academic Search

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 committed rate or other service level agreement (SLA). It is of great importance in Differentiated Services (DiffServ) networks as well as other price incentive network services. In this paper, we propose a simple

Gang Cheng; Kai Xu; Ye Tian; Nirwan Ansari

2004-01-01

32

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 synchronous parallel jobs are submitted. In order to simplify the analysis, we assume constant length jobs In a (computational) Grid, clients submit their jobs to a job broker, who sends them to well chosen computing elements

Louchard, Guy

33

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

34

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

35

Captured-Frame Selection Schemes for Scalable Input-Queued Packet Switches  

E-print Network

-Cessa and Chuan-Bi Lin Abstract-- Input-queued (IQ) switches are attractive for the implementation of high are attractive because their memories work without the speedup requirement of an output- queued (OQ) switch/routers. The introduction of virtual output queues (VOQs), where one queue per output port is placed in an input port

Rojas-Cessa, Roberto

36

SCHEDULING MULTICAST CELLS IN AN INPUT-QUEUED SWITCH NICK MCKEOWN  

E-print Network

SCHEDULING MULTICAST CELLS IN AN INPUT-QUEUED SWITCH NICK MCKEOWN Departments of EE & CS Stanford@hplb.hpl.hp.com.edu. Abstract In this paper we consider policies for scheduling cells in an input-queued multicast switch. It is assumed that each input maintains a single queue for arriving multicast cells and that only the cell

McKeown, Nick

37

Mean starting potential fair queuing for high-speed packet networks  

Microsoft Academic Search

This paper proposes an efficient fair queuing algorithm, called mean starting potential fair queuing (MSPFQ), which has O(l) complexity for the virtual time computation while it has delay and fairness properties similar to starting-potential fair queueing (SPFQ). The key idea of MSPFQ algorithm is that it recalibrates the system virtual time to the mean value of the minimum possible virtual

Dong-Yong Kwak; Nam-Seok Ko; Hong-Shik Park

2003-01-01

38

A Quantitative Comparison of Scheduling Algorithms for InputQueued Switches \\Lambda  

E-print Network

A Quantitative Comparison of Scheduling Algorithms for Input­Queued Switches \\Lambda Nick Mc to the scheduling of cells in a high­ bandwidth input­queued ATM switch. In particular, we compare the performance complexity of SLIP is an order of magnitude less than for PIM, making it feasible to implement a 32x32 switch

Anderson, Tom

39

A Quantitative Comparison of Iterative Scheduling Algorithms for Input-Queued  

E-print Network

and switches, instead of via a shared medium, as in Ethernet 24 , or a ring, as in FDDI 4 . One reasonA Quantitative Comparison of Iterative Scheduling Algorithms for Input-Queued Switches Nick Mc for scheduling cells in a high-bandwidth input-queued ATM switch. In particular, we compare the performance

McKeown, Nick

40

Bluetooth energy-saving optimization: a queuing theory analysis  

Microsoft Academic Search

Bluetooth on mobile terminal can be used to scan the surroundings to discover other Bluetooth-enabled devices. However, with energy limitations, the scanning actions must be well arranged to reduce power consumption. In this paper we propose an energy-saving strategy that turns on and off the Bluetooth device at a configured time. The scenario of Bluetooth scanning is modeled as an

Yi-dong CUI; Zhi-qing XIAO; Xiao-yue WANG; Bao-xing YANG

2010-01-01

41

NAS Requirements Checklist for Job Queuing/Scheduling Software  

NASA Technical Reports Server (NTRS)

The increasing reliability of parallel systems and clusters of computers has resulted in these systems becoming more attractive for true production workloads. Today, the primary obstacle to production use of clusters of computers is the lack of a functional and robust Job Management System for parallel applications. This document provides a checklist of NAS requirements for job queuing and scheduling in order to make most efficient use of parallel systems and clusters for parallel applications. Future requirements are also identified to assist software vendors with design planning.

Jones, James Patton

1996-01-01

42

Theory-Based Evaluation: Reflections Ten Years On. Theory-Based Evaluation: Past, Present, and Future  

ERIC Educational Resources Information Center

This chapter begins with a brief introduction by Rogers, in which she highlights the continued salience of Carol Weiss's decade-old questions about theory-based evaluation. Theory-based evaluation has developed significantly since Carol Weiss's chapter was first published ten years ago. In 1997 Weiss pointed to theory-based evaluation being mostly…

Rogers, Patricia J.; Weiss, Carol H.

2007-01-01

43

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

44

Markovian Ants in a Queuing System  

NASA Astrophysics Data System (ADS)

The synthesis of memoryless Markovian systems and Ant based concept with memory characteristics of deposit pheromone is the basis for the presented artificial intelligence hybrid. Only the initial elements of the system are specified in this paper by illustrating the routes of two ants. The pheromone capacity was first modelled as an exponential-type random variable. The Ant Queueing System was formed. The pheromone capacity was then used to form two independent exponential random variables. The convolution of these variables induces significant quality and quantity changes, mainly the decrease in entropy. The study also provides a possible method for dealing with stationary queueing systems when we are familiar with the state probability and the arrival rate and service rate are unknown.

Tanackov, Ilija; Simi?, Dragan; Sremac, Siniša; Tepi?, Jovan; Koci?-Tanackov, Sun?ica

45

Evaluation of Job Queuing/Scheduling Software: Phase I Report  

NASA Technical Reports Server (NTRS)

The recent proliferation of high performance work stations and the increased reliability of parallel systems have illustrated the need for robust job management systems to support parallel applications. To address this issue, the national Aerodynamic Simulation (NAS) supercomputer facility compiled a requirements checklist for job queuing/scheduling software. Next, NAS began an evaluation of the leading job management system (JMS) software packages against the checklist. This report describes the three-phase evaluation process, and presents the results of Phase 1: Capabilities versus Requirements. We show that JMS support for running parallel applications on clusters of workstations and parallel systems is still insufficient, even in the leading JMS's. However, by ranking each JMS evaluated against the requirements, we provide data that will be useful to other sites in selecting a JMS.

Jones, James Patton

1996-01-01

46

Second Evaluation of Job Queuing/Scheduling Software. Phase 1  

NASA Technical Reports Server (NTRS)

The recent proliferation of high performance workstations and the increased reliability of parallel systems have illustrated the need for robust job management systems to support parallel applications. To address this issue, NAS compiled a requirements checklist for job queuing/scheduling software. Next, NAS evaluated the leading job management system (JMS) software packages against the checklist. A year has now elapsed since the first comparison was published, and NAS has repeated the evaluation. This report describes this second evaluation, and presents the results of Phase 1: Capabilities versus Requirements. We show that JMS support for running parallel applications on clusters of workstations and parallel systems is still lacking, however, definite progress has been made by the vendors to correct the deficiencies. This report is supplemented by a WWW interface to the data collected, to aid other sites in extracting the evaluation information on specific requirements of interest.

Jones, James Patton; Brickell, Cristy; Chancellor, Marisa (Technical Monitor)

1997-01-01

47

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

48

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

49

Evolutionary and competence-based theories of the firm  

Microsoft Academic Search

This essay explores evolutionary and competence-based theories of the firm. Evolutionary theories can be regarded as a subset of a wider class of theories, variously described as “capabilities”, “resource-based”, or “competence-basedtheories of the firm. These contrast with a different set of contractarian theories, emanating largely from the work of Coase. It is argued that the contractarian theories of the

Geoffrey M. Hodgson

1998-01-01

50

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

51

On the Relationship Between Queuing Delay and Spatial Degrees of Freedom in a MIMO Multiple Access Channel  

E-print Network

On the Relationship Between Queuing Delay and Spatial Degrees of Freedom in a MIMO Multiple Access, we study the relationship between queuing delay for a random packet arrival process and physical in a single antenna multiple access channel (MAC) in their seminal paper [3]. This paper effectively dispensed

Rajan, Dinesh

52

Modeling Psychological Refractory Period (PRP) and Practice Effect on PRP with Queuing Networks and Reinforcement Learning Algorithms  

E-print Network

Modeling Psychological Refractory Period (PRP) and Practice Effect on PRP with Queuing Networks, 48109 USA Abstract PRP (Psychological Refractory Period) is a basic but important form of human information processing in dual-task situations. This article describes a queuing network model of PRP

Wu, Changxu (Sean)

53

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

54

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

55

SENSITIVITY ANALYSIS ON A DYNAMIC PRICING PROBLEM OF AN M/M/c QUEUING SYSTEM  

E-print Network

(2000) work on the congestion dependent pricing by #12;considering a service provider of a communicationSENSITIVITY ANALYSIS ON A DYNAMIC PRICING PROBLEM OF AN M/M/c QUEUING SYSTEM Eren Baar Ã?il, Fikri dynamic pricing is employed as the control policy. In order to obtain the desired results, we first

Ã?rmeci, E. Lerzan

56

A Queuing Network Model with Blocking: Analysis of Congested Patient Flows in Mental Health Systems  

E-print Network

;2 A Queuing Network Model with Blocking: Analysis of Congested Patient Flows in Mental Health Systems ABSTRACT network model, Blocking, Single node decomposition method, Simulation, Mental health system #12;3 1. The Philadelphia mental health system has been the forefront of the movement [3]. Inflow and outflow of clients

Smith, Tony E.

57

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

58

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

59

Self-organized queuing and scale-free behavior in real escape panic  

Microsoft Academic Search

Numerical investigations of escape panic of confined pedestrians have revealed interesting dynamical features such as pedestrian arch formation around an exit, disruptive interference, self-organized queuing, and scale-free behavior. However, these predictions have remained unverified because escape panic experiments with real systems are difficult to perform. For mice escaping out of a water pool, we found that for a critical sampling

Caesar Saloma; Gay Jane Perez; Giovanni Tapang; May Lim; Cynthia Palmes-Saloma

2003-01-01

60

Fair Queuing with Service Envelopes (FQSE): a cousin-fair hierarchical scheduler for Ethernet PONs  

E-print Network

Fair Queuing with Service Envelopes (FQSE): a cousin-fair hierarchical scheduler for Ethernet PONs algorithms do not provide fairness among the end consumers. This study presents a novel hierarchical EPON scheduler, which guarantees fairness among all subscribers. ©2003 Optical Society of America OCIS codes

California at Davis, University of

61

Queuing Network Models for Multi-Channel P2P Live Streaming Systems  

E-print Network

Queuing Network Models for Multi-Channel P2P Live Streaming Systems Di Wu, Yong Liu, Keith W. Ross there have been several large-scale deployments of P2P live video systems. Existing and future P2P live video-channel P2P streaming systems. Our models capture essential aspects of multi-channel video systems

Liu, Yong

62

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

63

Queuing Network Modeling of the Psychological Refractory Period (PRP) Changxu Wu and Yili Liu  

E-print Network

Queuing Network Modeling of the Psychological Refractory Period (PRP) Changxu Wu and Yili Liu University of Michigan The psychological refractory period (PRP) is a basic but important form of dual-task information processing. Existing serial or parallel processing models of PRP have successfully accounted

Liu, Yili

64

Toward a Category Theory Design of Ontological Knowledge Bases  

E-print Network

I discuss (ontologies_and_ontological_knowledge_bases / formal_methods_and_theories) duality and its category theory extensions as a step toward a solution to Knowledge-Based Systems Theory. In particular I focus on the example of the design of elements of ontologies and ontological knowledge bases of next three electronic courses: Foundations of Research Activities, Virtual Modeling of Complex Systems and Introduction to String Theory.

Glazunov, Nikolaj

2009-01-01

65

Discrete-time Queuing Analysis of Opportunistic Spectrum Access: Single User Case  

NASA Astrophysics Data System (ADS)

This article studies the discrete-time queuing dynamics of opportunistic spectrum access (OSA) systems, in which the secondary user seeks spectrum vacancies between bursty transmissions of the primary user to communicate. Since spectrum sensing and data transmission can not be performed simultaneously, the secondary user employs a sensing-then-transmission strategy to detect the presence of the primary user before accessing the licensed channel. Consequently, the transmission of the secondary user is periodically suspended for spectrum sensing. To capture the discontinuous transmission nature of the secondary user, we introduce a discrete-time queuing subjected to bursty preemption to describe the behavior of the secondary user. Specifically, we derive some important metrics of the secondary user, including secondary spectrum utilization ratio, buffer length, packet delay and packet dropping ratio. Finally, simulation results validate the proposed theoretical model and reveal that the theoretical results fit the simulated results well.

Wang, Jin-long; Xu, Yu-hua; Gao, Zhan; Wu, Qi-hui

2011-11-01

66

Feature-Based Binding and Phase Theory  

ERIC Educational Resources Information Center

Current theories of binding cannot provide a uniform account for many facts associated with the distribution of anaphors, such as long-distance binding effects and the subject-orientation of monomorphemic anaphors. Further, traditional binding theory is incompatible with minimalist assumptions. In this dissertation I propose an analysis of…

Antonenko, Andrei

2012-01-01

67

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

68

Mechanism-based strain gradient plasticity— I. Theory  

Microsoft Academic Search

A mechanism-based theory of strain gradient plasticity (MSG) is proposed based on a multiscale framework linking the microscale notion of statistically stored and geometrically necessary dislocations to the mesoscale notion of plastic strain and strain gradient. This theory is motivated by our recent analysis of indentation experiments which strongly suggest a linear dependence of the square of plastic flow stress

H. Gao; Y. Huang; W. D. Nix; J. W. Hutchinson

1999-01-01

69

CONTINUING BONDS IN BEREAVEMENT: AN ATTACHMENT THEORY BASED PERSPECTIVE  

Microsoft Academic Search

An attachment theory based perspective on the continuing bond to the deceased (CB) is proposed. The value of attachment theory in specifying the normative course of CB expression and in identifying adaptive versus maladaptive variants of CB expression based on their deviation from this normative course is outlined. The role of individual differences in attachment security on effective versus ineffective

NIGEL P. FIELD; BERYL GAO; LISA PADERNA

2005-01-01

70

Continuing Bonds in Bereavement: An Attachment Theory Based Perspective  

ERIC Educational Resources Information Center

An attachment theory based perspective on the continuing bond to the deceased (CB) is proposed. The value of attachment theory in specifying the normative course of CB expression and in identifying adaptive versus maladaptive variants of CB expression based on their deviation from this normative course is outlined. The role of individual…

Field, Nigel P.; Gao, Beryl; Paderna, Lisa

2005-01-01

71

Scheme-Based Synthesis of Inductive Theories   

E-print Network

We describe an approach to automatically invent/explore new mathematical theories, with the goal of producing results comparable to those produced by humans, as represented, for example, in the libraries of the Isabelle ...

Montano-Rivas, O.; McCasland, R.; Dixon, L.; Bundy, Alan

2010-01-01

72

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

73

Toric bases for 6D F-theory models  

E-print Network

We find all smooth toric bases that support elliptically fibered Calabi-Yau threefolds, using the intersection structure of the irreducible effective divisors on the base. These bases can be used for F-theory constructions of six-dimensional quantum supergravity theories. There are 61,539 distinct possible toric bases. The associated 6D supergravity theories have a number of tensor multiplets ranging from 0 to 193. For each base an explicit Weierstrass parameterization can be determined in terms of the toric data. The toric counting of parameters matches with the gravitational anomaly constraint on massless fields. For bases associated with theories having a large number of tensor multiplets, there is a large non-Higgsable gauge group containing multiple irreducible gauge group factors, particularly those having algebras e_8, f_4 and (g_2 + su(2)) with minimal (non-Higgsable) matter.

David R. Morrison; Washington Taylor

2012-04-17

74

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

75

Heuristic classification of physical theories based on quantum correlations  

NASA Astrophysics Data System (ADS)

Taking quantum formalism as a point of reference and connection, we explore the various possibilities that arise in the construction of physical theories. Analyzing the distinct physical phenomena that each of them may describe, we introduce the different types of theories that correspond to these physical phenomena. A hierarchical classification of the offered theories, based on the degree of correlation between dichotomic observables in bipartite systems, as quantified by a Bell-type inequality, is finally proposed as a conclusion.

Ferrero, M.; Sánchez-Gómez, J. L.

2013-06-01

76

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

77

23 CFR 661.43 - Can other sources of funds be used to finance a queued project in advance of receipt of IRRBP funds?  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Can other sources of funds be used to finance a queued project in advance of receipt of IRRBP funds? 661...PROGRAM § 661.43 Can other sources of funds be used to finance a queued project in advance of receipt of IRRBP funds?...

2010-04-01

78

Spectrum Investment with Uncertainty Based on Prospect Theory  

E-print Network

Spectrum Investment with Uncertainty Based on Prospect Theory Junlin Yu, Man Hon Cheung, and Jianwei Huang Abstract--We study a secondary wireless operator's spectrum investment problem under spectrum supply uncertainty using prospect theory. In order to meet the demands of its users, the secondary

Huang, Jianwei

79

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§ University of California, Irvine, Irvine, California 92697-3975 DOI: 10.2514/1.37750 A highly efficient local-piston speeds. A steady mean flow solution is first obtained by an Euler method. The classical piston theory

Liu, Feng

80

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

81

Task-Based Language Teaching and Expansive Learning Theory  

ERIC Educational Resources Information Center

Task-Based Language Teaching (TBLT) has become increasingly recognized as an effective pedagogy, but its location in generalized sociocultural theories of learning has led to misunderstandings and criticism. The purpose of this article is to explain the congruence between TBLT and Expansive Learning Theory and the benefits of doing so. The merit…

Robertson, Margaret

2014-01-01

82

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

83

Optimization Online - Information Gap Decision Theory Based OPF ...  

E-print Network

Jan 3, 2015 ... Information Gap Decision Theory Based OPF With HVDC Connected Wind Farms ... of AC/DC power systems with high penetration of offshore wind farms. ... Category 1: Applications -- OR and Management Sciences.

rabiee abbas

2015-01-03

84

Automata Theory Based on Quantum Logic: Recognizability and Accessibility  

NASA Astrophysics Data System (ADS)

Inspired by Ying’s work on automata theory based on quantum logic and classical automata theory, we introduce the concepts of reversal, accessible, coaccessible and complete part of finite state automata based on quantum logic. Some properties of them are discussed. More importantly we investigate the recognizability and accessibility properties of these types on the framework of quantum logic by employing the approach of semantic analysis.

Liu, Jun; Mo, Zhi-Wen

2009-04-01

85

Unifying ecology and macroevolution with individual-based theory.  

PubMed

A contemporary goal in both ecology and evolutionary biology is to develop theory that transcends the boundary between the two disciplines, to understand phenomena that cannot be explained by either field in isolation. This is challenging because macroevolution typically uses lineage-based models, whereas ecology often focuses on individual organisms. Here, we develop a new parsimonious individual-based theory by adding mild selection to the neutral theory of biodiversity. We show that this model generates realistic phylogenies showing a slowdown in diversification and also improves on the ecological predictions of neutral theory by explaining the occurrence of very common species. Moreover, we find the distribution of individual fitness changes over time, with average fitness increasing at a pace that depends positively on community size. Consequently, large communities tend to produce fitter species than smaller communities. These findings have broad implications beyond biodiversity theory, potentially impacting, for example, invasion biology and paleontology. PMID:25818618

Rosindell, James; Harmon, Luke J; Etienne, Rampal S

2015-05-01

86

Unifying ecology and macroevolution with individual-based theory  

PubMed Central

A contemporary goal in both ecology and evolutionary biology is to develop theory that transcends the boundary between the two disciplines, to understand phenomena that cannot be explained by either field in isolation. This is challenging because macroevolution typically uses lineage-based models, whereas ecology often focuses on individual organisms. Here, we develop a new parsimonious individual-based theory by adding mild selection to the neutral theory of biodiversity. We show that this model generates realistic phylogenies showing a slowdown in diversification and also improves on the ecological predictions of neutral theory by explaining the occurrence of very common species. Moreover, we find the distribution of individual fitness changes over time, with average fitness increasing at a pace that depends positively on community size. Consequently, large communities tend to produce fitter species than smaller communities. These findings have broad implications beyond biodiversity theory, potentially impacting, for example, invasion biology and paleontology. PMID:25818618

Rosindell, James; Harmon, Luke J; Etienne, Rampal S

2015-01-01

87

Classifying bases for 6D F-theory models  

E-print Network

We classify six-dimensional F-theory compactifications in terms of simple features of the divisor structure of the base surface of the elliptic fibration. This structure controls the minimal spectrum of the theory. We determine all irreducible configurations of divisors ("clusters") that are required to carry nonabelian gauge group factors based on the intersections of the divisors with one another and with the canonical class of the base. All 6D F-theory models are built from combinations of these irreducible configurations. Physically, this geometric structure characterizes the gauge algebra and matter that can remain in a 6D theory after maximal Higgsing. These results suggest that all 6D supergravity theories realized in F-theory have a maximally Higgsed phase in which the gauge algebra is built out of summands of the types su(3), so(8), f_4, e_6, e_8, e_7, (g_2 + su(2)), and su(2) + so(7) + su(2), with minimal matter content charged only under the last three types of summands, corresponding to the non-Higgsable cluster types identified through F-theory geometry. Although we have identified all such geometric clusters, we have not proven that there cannot be an obstruction to Higgsing to the minimal gauge and matter configuration for any possible F-theory model. We also identify bounds on the number of tensor fields allowed in a theory with any fixed gauge algebra; we use this to bound the size of the gauge group (or algebra) in a simple class of F-theory bases.

David R. Morrison; Washington Taylor

2012-05-04

88

A simple framework for filtering queued SMTP mail (cyberwar countermeasures)  

Microsoft Academic Search

Pre-information age military battlefields are based on the traditional land, sea, air, and space paradigm. Global internetworking is causal to the creation of a dangerously real 5th dimension of warfare-cyberspace. This paper describes an Internet based assault, commonly referred to as e-mail spam, on the Langley AFB internetworking infrastructure. We discuss the cyber-attack, a framework for defending against the attack,

Tim Bass; G. Watt

1997-01-01

89

The bases of effective field theories  

NASA Astrophysics Data System (ADS)

With reference to the equivalence theorem, we discuss the selection of basis operators for effective field theories in general. The equivalence relation can be used to partition operators into equivalence classes, from which inequivalent basis operators are selected. These classes can also be identified as containing Potential-Tree-Generated (PTG) operators, Loop-Generated (LG) operators, or both, independently of the specific dynamics of the underlying extended models, so long as it is perturbatively decoupling. For an equivalence class containing both, we argue that the basis operator should be chosen from among the PTG operators, because they may have the largest coefficients. We apply this classification scheme to dimension-six operators in an illustrative Yukawa model as well in the Standard Model (SM). We show that the basis chosen by Grzadkowski et al. [5] for the SM satisfies this criterion. In this light, we also revisit and verify our earlier result [6] that the dimension-six corrections to the triple-gauge-boson couplings only arise from LG operators, so the magnitude of the coefficients should only be a few parts per thousand of the SM gauge coupling if BSM dynamics respects decoupling. The same is true of the quartic-gauge-boson couplings.

Einhorn, Martin B.; Wudka, José

2013-11-01

90

Outcomes-Based Education: Some Insights from Complexity Theory.  

ERIC Educational Resources Information Center

Describes a new outcomes-based teacher-education curriculum being introduced in South Africa, noting its compatibility with complexity theory, which advocates self-organization, unpredictability, and randomness. While outcomes-based education is criticized for being behavioristic, for its prescriptiveness, for its rejection of modernism's…

Claassen, C.

1998-01-01

91

Image Detection in real time based on Fuzzy Fractal theory  

E-print Network

Image Detection in real time based on Fuzzy Fractal theory Kya Abraham Berthe Yan Yan Soungalo China Abstract: Real time image detection is still a challenge in research. Several methods have been used, but all can be divide in two approaches: the first is based on image field estimation

Paris-Sud XI, Université de

92

Security Operation Center Design Based on DS Evidence Theory  

Microsoft Academic Search

With the widespread application of large and complicated network, network safety has become an important issue. In this paper, a security operation center (SOC) concept based on multi-sensor data fusion technology is presented from the viewpoint of the network security. A structure of a SOC system based on D-S evidence theory is proposed, and the detailed method of data fusion

Xuanzi Hu; Cunxi Xie

2006-01-01

93

A general resonance theory based on Mourre's inequality  

E-print Network

We study the perturbation of bound states embedded in the continuous spectrum which are unstable by the Fermi Golden Rule. The approach to resonance theory based on spectral deformation is extended to a more general class of quantum systems characterized by Mourre's inequality and smoothness of the resolvent. Within the framework of perturbation theory it is still possible to give a definite meaning to the notion of complex resonance energies and of corresponding metastable states. The main result is a quasi-exponential decay estimate up to a controlled error of higher order in perturbation theory.

L. Cattaneo; G. M. Graf; W. Hunziker

2005-07-25

94

Combined Field Integral Equation Based Theory of Characteristic Mode  

E-print Network

Conventional electric field integral equation based theory is susceptible to the spurious internal resonance problem when the characteristic modes of closed perfectly conducting objects are computed iteratively. In this paper, we present a combined field integral equation based theory to remove the difficulty of internal resonances in characteristic mode analysis. The electric and magnetic field integral operators are shown to share a common set of non-trivial characteristic pairs (values and modes), leading to a generalized eigenvalue problem which is immune to the internal resonance corruption. Numerical results are presented to validate the proposed formulation. This work may offer efficient solutions to characteristic mode analysis which involves electrically large closed surfaces.

Qi I. Dai; Qin S. Liu; Hui Gan; Weng Cho Chew

2015-03-04

95

Reasons for Enterprises' Abortive Application of Management Fashion: An Explanation Based on Game Theory and Rhetoric Theory  

Microsoft Academic Search

Based on game theory and rhetoric theory, this paper probes the reasons for enterprises' abortive application of management fashion. In view of the game theory, enterprises the applicate management fashion are aiming to minimize the losses rather than maximize the gains. While according to the rhetoric theory, the fact that rhetoric management fashion replaced technical management fashion leads to their

Ming Sun; Yuanyuan Wang; Ming Lin

2010-01-01

96

Instanton moduli spaces and bases in coset conformal field theory  

E-print Network

Recently proposed relation between conformal field theories in two dimensions and supersymmetric gauge theories in four dimensions predicts the existence of the distinguished basis in the space of local fields in CFT. This basis has a number of remarkable properties, one of them is the complete factorization of the coefficients of the operator product expansion. We consider a particular case of the U(r) gauge theory on C^2/Z_p which corresponds to a certain coset conformal field theory and describe the properties of this basis. We argue that in the case p=2, r=2 there exist different bases. We give an explicit construction of one of them. For another basis we propose the formula for matrix elements.

A. A. Belavin; M. A. Bershtein; B. L. Feigin; A. V. Litvinov; G. M. Tarnopolsky

2012-05-28

97

Instanton Moduli Spaces and Bases in Coset Conformal Field Theory  

NASA Astrophysics Data System (ADS)

The recently proposed relation between conformal field theories in two dimensions and supersymmetric gauge theories in four dimensions predicts the existence of the distinguished basis in the space of local fields in CFT. This basis has a number of remarkable properties: one of them is the complete factorization of the coefficients of the operator product expansion. We consider a particular case of the U(r) gauge theory on {{C}2/{Z}p} which corresponds to a certain coset conformal field theory and describe the properties of this basis. We argue that in the case p = 2, r = 2 there exist different bases. We give an explicit construction of one of them. For another basis we propose the formula for matrix elements.

Belavin, A. A.; Bershtein, M. A.; Feigin, B. L.; Litvinov, A. V.; Tarnopolsky, G. M.

2013-04-01

98

Voxel-based Surface Area Estimation: From Theory to Practice  

E-print Network

Voxel-based Surface Area Estimation: From Theory to Practice G. Windreich N. Kiryati Department of voxels. How can one estimate the (original, continuous) area of a region of interest on the surface, the surface area of a digital voxel world is generally very different than the area of the underlying

Kiryati, Nahum

99

An automotive lateral controller based on generalized predictive control theory  

Microsoft Academic Search

This paper proposes a new design method of a lane tracking control system based on Generalized Predictive Control theory. The proposed system realizes the preview control without the “perfect measurement” assumption. A series of computer simulations and frequency domain analyses were carried out to show the validity of the proposed control system. In comparison with a lane tracking system using

Shinichiro Horiuchi; Toshiyuki Tamatsukuri; Shinya Nohtomi

2000-01-01

100

CONCEPTS & THEORY Process-based models are required to manage  

E-print Network

CONCEPTS & THEORY Process-based models are required to manage ecological systems in a changing are required to manage ecological systems in a changing world. Ecosphere 4(2):20. http://dx.doi.org/10. 1890/ES management under global change a particular challenge: changes to relevant scales and processes, additional

Gerber, Leah R.

101

Theory-Based Considerations Influence the Interpretation of Generic Sentences  

ERIC Educational Resources Information Center

Under what circumstances do people agree that a kind-referring generic sentence (e.g., "Swans are beautiful") is true? We hypothesised that theory-based considerations are sufficient, independently of prevalence/frequency information, to lead to acceptance of a generic statement. To provide evidence for this general point, we focused on…

Cimpian, Andrei; Gelman, Susan A.; Brandone, Amanda C.

2010-01-01

102

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

103

Reasserting Theory in Professionally Based Initial Teacher Education  

ERIC Educational Resources Information Center

Conceptions of theory within initial teacher education in England are adjusting to new conditions where most learning how to teach is school-based. Student teachers on a programme situated primarily in an employing school were monitored within a practitioner enquiry by their university programme tutors according to how they progressively…

Hodson, Elaine; Smith, Kim; Brown, Tony

2012-01-01

104

An Analysis of Memory-Based Theories of Automaticity  

Microsoft Academic Search

Memory-based theories of automaticity predict that performance in a memory search task which is automatic will not require a representation of the memory set in working memory. The information contained in working memory was manipulated by inserting an interference task between the presentation of a memory set and a probe stimulus in a memory search task. The interference task prevented

David L. Strayer; Arthur F. Kramer

1990-01-01

105

Toward an Instructionally Oriented Theory of Example-Based Learning  

ERIC Educational Resources Information Center

Learning from examples is a very effective means of initial cognitive skill acquisition. There is an enormous body of research on the specifics of this learning method. This article presents an instructionally oriented theory of example-based learning that integrates theoretical assumptions and findings from three research areas: learning from…

Renkl, Alexander

2014-01-01

106

What Gets Recycled: An Information Theory Based Model for  

E-print Network

What Gets Recycled: An Information Theory Based Model for Product Recycling J E F F R E Y B . D A H focuses on developing a concise representation of the material recycling potential for products at end for the two different applications. Cost estimates for product recycling systems are developed using Shannon

Gutowski, Timothy

107

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

108

Accuracy analysis of SCARA industrial robot based on screw theory  

Microsoft Academic Search

Based on an analysis of error sources of industrial robots, we build a pose error model of industrial robots with screw theory, which overcomes the defect that the error on the y-axis could not be reflected by the classical D-H parameter method. Given the error sources which influence the end- executor's accuracy, we established a screw representation of the static

Zhao Liang; Su Meng; Diao Changkun

2011-01-01

109

Density Functional Theory-Based Database Development and CALPHAD Automation  

E-print Network

Density Functional Theory-Based Database Development and CALPHAD Automation YI WANG,1,2 SHUNLI, the integration of first-principles calculations, CALPHAD modeling, and the automation of phase diagram, and the automated calculation of a phase diagram for the Al- Mg system. INTRODUCTION In thermodynamics, a phase

Chen, Long-Qing

110

Decision Dynamics in Cooperative Search Based on Evolutionary Game Theory  

E-print Network

Decision Dynamics in Cooperative Search Based on Evolutionary Game Theory Mamoru Saito, Takeshi to periodic trajectories. The macro order is achieved by a probabilistic decision-making model called Win by the decision-making model, each robot determines a control input aiming at reduction of control energy. Finally

111

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

112

23 CFR 661.43 - Can other sources of funds be used to finance a queued project in advance of receipt of IRRBP funds?  

Code of Federal Regulations, 2014 CFR

...Section 661.43 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.43 Can other sources of funds be used to finance a queued...

2014-04-01

113

23 CFR 661.43 - Can other sources of funds be used to finance a queued project in advance of receipt of IRRBP funds?  

Code of Federal Regulations, 2012 CFR

...Section 661.43 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.43 Can other sources of funds be used to finance a queued...

2012-04-01

114

23 CFR 661.43 - Can other sources of funds be used to finance a queued project in advance of receipt of IRRBP funds?  

Code of Federal Regulations, 2013 CFR

...Section 661.43 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.43 Can other sources of funds be used to finance a queued...

2013-04-01

115

23 CFR 661.43 - Can other sources of funds be used to finance a queued project in advance of receipt of IRRBP funds?  

Code of Federal Regulations, 2011 CFR

...Section 661.43 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.43 Can other sources of funds be used to finance a queued...

2011-04-01

116

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

117

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

118

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

119

Research Paper: Queuing Theory to Guide the Implementation of a Heart Failure Inpatient Registry Program  

Microsoft Academic Search

ObjectiveThe 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

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

2009-01-01

120

An Integrated Model of Patient and Staff Satisfaction Using Queuing Theory  

E-print Network

and many more also affect staff job satisfaction in healthcare [43], [44]. The choice of service time, was influenced by the observations of the effects of waiting time targets that motivated the current research. Several inappropriate prac- tices have been... with a five point Likert scale. A subset of these questions were initially used but this only showed how satisfaction rose or fell with longer or shorter service times. Figure 4 summarizes the VOLUME 3, 2015 2200110 Komashie et al.: Integrated Model...

Komashie, Alexander; Mousavi, Ali; Clarkson, P. John; Young, Terry

2015-02-06

121

Evidence for an expectancy-based theory of avoidance behaviour.  

PubMed

In most studies on avoidance learning, participants receive an aversive unconditioned stimulus after a warning signal is presented, unless the participant performs a particular response. Lovibond (2006) recently proposed a cognitive theory of avoidance learning, according to which avoidance behaviour is a function of both Pavlovian and instrumental conditioning. In line with this theory, we found that avoidance behaviour was based on an integration of acquired knowledge about, on the one hand, the relation between stimuli and, on the other hand, the relation between behaviour and stimuli. PMID:18609382

Declercq, Mieke; De Houwer, Jan; Baeyens, Frank

2008-01-01

122

Two-scale mechanism-based theory of nonlinear viscoelasticity  

NASA Astrophysics Data System (ADS)

The paper presents a mechanism-based two-scale theory for a generalized nonlinear viscoelastic continuum. The continuum is labeled as generalized since it contains extra degrees of freedom typical of past high-order continuum theories, though a new formulation is presented here tailored to meet the needs of the physical description of the viscoelastic solid. The microstress that appears in the equations, often criticized for a lack of physical meaning, is assigned in this work to viscous free chains superimposed on a nonlinear elastic backbone composed of crosslinks and reinforcement. Mathematically, hyperelasticity is used to describe the equilibrium backbone (macroscale), and an improvement of tube models for reptation dynamics describes the free chain motion at the microscale. Inhomogeneous deformation is described by inclusion of a microstrain gradient into the formulation. Thus, the theory is nicely suited for materials with microstructure where localization of strains and inhomogeneous deformation occur in addition to viscoelastic damping mechanisms due to free chains. Besides the microstress, physical meaning of the additional boundary conditions arising in the general theory is also presented. Since the proposed material model is mechanism-based, macroscopic performances are functions of microstructural variables describing the polymer chemistry so that parametric material design concepts may be gleaned from the model. Several physical phenomena are captured through numerical simulation of the class of materials of interest: size effects, strain localization, and the fracture process. Results agree qualitatively with both experimental data and direct numerical simulation for filled elastomeric solids.

Tang, Shan; Steven Greene, M.; Liu, Wing Kam

2012-02-01

123

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

124

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

125

A theory for cursive handwriting based on the minimization principle  

Microsoft Academic Search

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

Yasuhiro Wada; Mitsuo Kawato

1995-01-01

126

Game-Theory based Multi-Robot Searching Approach  

Microsoft Academic Search

Two strategic searching approaches for a multi-robot system are proposed in this paper: utility greedy approach and game theory approach. It is assumed that a-priori probability of the target distribution is provided in a partially known dynamic environment. The proposed two approaches aim to optimize the searching task using a dynamic-programming based utility function. The pure Nash Equilibrium solution and

Yan Meng; Ke Cao

127

Rough set theory based robot stiffness tel-control  

Microsoft Academic Search

When the traditional robot stiffness control is applied into the internet environment, the uncertain time delay will bring a very austere problem of impact and stability to the system. So, a RST(rough set theory) based stiffness tel-controller was designed to solve the problem, and the result of experiment show that this controller can ensure the stability of the stiffness tel-control

Yunhong Lei; Jianxin Wang; Guanzhen Wu; Yongqing Zhou

2009-01-01

128

What Communication Theories Can Teach the Designer of Computer-Based Training.  

ERIC Educational Resources Information Center

Reviews characteristics of computer-based training (CBT) that make application of communication theories appropriate and presents principles from communication theory (e.g., general systems theory, symbolic interactionism, rule theories, and interpersonal communication theories) to illustrate how CBT developers can profitably apply them to…

Larsen, Ronald E.

1985-01-01

129

A Knowledge-Based Theory of the Firm?The Problem-Solving Perspective  

Microsoft Academic Search

n this paper we develop a knowledge-based theory of the firm. While existing knowledge-based theory focuses on the efficiency of hierarchy in economizing on knowledge exchange, we develop a theory of the firm that focuses on the efficiency of alternative organizational forms in generating knowledge or capability. Our theory begins with the problem as the basic unit of analysis, arguing

Jack A. Nickerson; Todd R. Zenger

2004-01-01

130

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

131

An intelligent diagnosis model based on rough set theory  

NASA Astrophysics Data System (ADS)

Along with the popularity of computer and rapid development of information technology, how to increase the accuracy of the agricultural diagnosis becomes a difficult problem of popularizing the agricultural expert system. Analyzing existing research, baseing on the knowledge acquisition technology of rough set theory, towards great sample data, we put forward a intelligent diagnosis model. Extract rough set decision table from the samples property, use decision table to categorize the inference relation, acquire property rules related to inference diagnosis, through the means of rough set knowledge reasoning algorithm to realize intelligent diagnosis. Finally, we validate this diagnosis model by experiments. Introduce the rough set theory to provide the agricultural expert system of great sample data a effective diagnosis model.

Li, Ze; Huang, Hong-Xing; Zheng, Ye-Lu; Wang, Zhou-Yuan

2013-03-01

132

Assessing Staffing Needs for a Software Maintenance Project through Queuing Simulation  

Microsoft Academic Search

Abstract We present an approach based on queueing theory and stochastic simulation to help planning, managing and controlling the project staffing and the resulting service level in distributed multi - phase maintenance processes Data from a Y2K massive maintenance intervention on a large COBOL\\/JCL financial software system were used to simulate and study different service center configurations for a geographically

Giuliano Antoniol; Aniello Cimitile; Giuseppe A. Di Lucca; Massimiliano Di Penta

2004-01-01

133

Workplace-based assessment: raters' performance theories and constructs.  

PubMed

Weaknesses in the nature of rater judgments are generally considered to compromise the utility of workplace-based assessment (WBA). In order to gain insight into the underpinnings of rater behaviours, we investigated how raters form impressions of and make judgments on trainee performance. Using theoretical frameworks of social cognition and person perception, we explored raters' implicit performance theories, use of task-specific performance schemas and the formation of person schemas during WBA. We used think-aloud procedures and verbal protocol analysis to investigate schema-based processing by experienced (N = 18) and inexperienced (N = 16) raters (supervisor-raters in general practice residency training). Qualitative data analysis was used to explore schema content and usage. We quantitatively assessed rater idiosyncrasy in the use of performance schemas and we investigated effects of rater expertise on the use of (task-specific) performance schemas. Raters used different schemas in judging trainee performance. We developed a normative performance theory comprising seventeen inter-related performance dimensions. Levels of rater idiosyncrasy were substantial and unrelated to rater expertise. Experienced raters made significantly more use of task-specific performance schemas compared to inexperienced raters, suggesting more differentiated performance schemas in experienced raters. Most raters started to develop person schemas the moment they began to observe trainee performance. The findings further our understanding of processes underpinning judgment and decision making in WBA. Raters make and justify judgments based on personal theories and performance constructs. Raters' information processing seems to be affected by differences in rater expertise. The results of this study can help to improve rater training, the design of assessment instruments and decision making in WBA. PMID:22592323

Govaerts, M J B; Van de Wiel, M W J; Schuwirth, L W T; Van der Vleuten, C P M; Muijtjens, A M M

2013-08-01

134

Dynamic Properties of Disk Brake Based on Thermoelastic Instability Theory  

Microsoft Academic Search

Based on the thermo-elastic instability (TEI) theory and direct thermal-structural coupling method, the temperature increment and deformation of disk brake during an emergency braking process are analyzed. The simulation results indicate that the disc brake, before running-in, takes 3.35sec to decelerate from the initial speed of 100km\\/h to 0km\\/h, with 207°C maximum temperature increment, 8.29m\\/s2 average deceleration, 0.624 braking torque

Xun Yang; Jixin Wang; Ying Liu

2010-01-01

135

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

136

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

137

Forewarning model for water pollution risk based on Bayes theory.  

PubMed

In order to reduce the losses by water pollution, forewarning model for water pollution risk based on Bayes theory was studied. This model is built upon risk indexes in complex systems, proceeding from the whole structure and its components. In this study, the principal components analysis is used to screen out index systems. Hydrological model is employed to simulate index value according to the prediction principle. Bayes theory is adopted to obtain posterior distribution by prior distribution with sample information which can make samples' features preferably reflect and represent the totals to some extent. Forewarning level is judged on the maximum probability rule, and then local conditions for proposing management strategies that will have the effect of transforming heavy warnings to a lesser degree. This study takes Taihu Basin as an example. After forewarning model application and vertification for water pollution risk from 2000 to 2009 between the actual and simulated data, forewarning level in 2010 is given as a severe warning, which is well coincide with logistic curve. It is shown that the model is rigorous in theory with flexible method, reasonable in result with simple structure, and it has strong logic superiority and regional adaptability, providing a new way for warning water pollution risk. PMID:24194413

Zhao, Jun; Jin, Juliang; Guo, Qizhong; Chen, Yaqian; Lu, Mengxiong; Tinoco, Luis

2014-02-01

138

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

139

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

140

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

141

Frequency-domain direct waveform inversion based on perturbation theory  

NASA Astrophysics Data System (ADS)

A direct waveform inversion based on perturbation theory is proposed to delineate a subsurface velocity structure from seismic data. This technique can directly compute the difference between the actual subsurface velocity and an initial guess of the velocity, while full waveform inversion updates the velocity model in the directions of reducing the data residual. Unlike full waveform inversion using the steepest descent method, the direct waveform inversion does not require a proper step length to iteratively update the velocity model. We present an algorithm for the waveform inversion method in the frequency domain and numerical examples demonstrating how the inversion method can reconstruct subsurface velocity structures using surface seismic data. The time-domain seismograms synthesized in the inversion procedure match the corresponding shot-gather seismograms of field data.

Kwak, Sangmin; Kim, Youngseo; Shin, Changsoo

2014-05-01

142

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

143

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

144

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

145

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

146

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

147

Density functional theory based generalized effective fragment potential method  

SciTech Connect

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., E-mail: kiet.nguyen@wpafb.af.mil, E-mail: ruth.pachter@wpafb.af.mil [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); UES, Inc., Dayton, Ohio 45432 (United States); Pachter, Ruth, E-mail: kiet.nguyen@wpafb.af.mil, E-mail: ruth.pachter@wpafb.af.mil [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); Day, Paul N. [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); General Dynamics Information Technology, Inc., Dayton, Ohio 45431 (United States)

2014-06-28

148

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

149

IMMAN: free software for information theory-based chemometric analysis.  

PubMed

The features and theoretical background of a new and free computational program for chemometric analysis denominated IMMAN (acronym for Information theory-based CheMoMetrics ANalysis) are presented. This is multi-platform software developed in the Java programming language, designed with a remarkably user-friendly graphical interface for the computation of a collection of information-theoretic functions adapted for rank-based unsupervised and supervised feature selection tasks. A total of 20 feature selection parameters are presented, with the unsupervised and supervised frameworks represented by 10 approaches in each case. Several information-theoretic parameters traditionally used as molecular descriptors (MDs) are adapted for use as unsupervised rank-based feature selection methods. On the other hand, a generalization scheme for the previously defined differential Shannon's entropy is discussed, as well as the introduction of Jeffreys information measure for supervised feature selection. Moreover, well-known information-theoretic feature selection parameters, such as information gain, gain ratio, and symmetrical uncertainty are incorporated to the IMMAN software ( http://mobiosd-hub.com/imman-soft/ ), following an equal-interval discretization approach. IMMAN offers data pre-processing functionalities, such as missing values processing, dataset partitioning, and browsing. Moreover, single parameter or ensemble (multi-criteria) ranking options are provided. Consequently, this software is suitable for tasks like dimensionality reduction, feature ranking, as well as comparative diversity analysis of data matrices. Simple examples of applications performed with this program are presented. A comparative study between IMMAN and WEKA feature selection tools using the Arcene dataset was performed, demonstrating similar behavior. In addition, it is revealed that the use of IMMAN unsupervised feature selection methods improves the performance of both IMMAN and WEKA supervised algorithms. Graphic representation for Shannon's distribution of MD calculating software. PMID:25620721

Urias, Ricardo W Pino; Barigye, Stephen J; Marrero-Ponce, Yovani; García-Jacas, César R; Valdes-Martiní, José R; Perez-Gimenez, Facundo

2015-05-01

150

Density functional theory based generalized effective fragment potential method.  

PubMed

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. PMID:24985612

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

2014-06-28

151

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.

152

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

153

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 there is currently much interest in deriving a theory of quantum engineering as the foundation for a much anticipated

Gohm, Rolf

154

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

155

Manufacturing Capability Evaluation of E-HUB Based on Harmony Theory  

Microsoft Academic Search

Harmony theory summarizes and abstracts the mechanism of social economic development. Using harmony theory to analyze the harmoniousness of virtual enterprise, it can realize the co-adaptation degree more between enterprises which compose to a virtual enterprise set and improve its success probability. Based on the methods in manufacturing information theory, taking regional small and medium-sized enterprises as application background, the

Qingsheng Xie; Weijie Pan; Shaobo Li; Guanci Yang

2009-01-01

156

Algorithmic Decision Theory and Risk-based Decision Making in the  

E-print Network

1 Algorithmic Decision Theory and Risk-based Decision Making in the Maritime Environment Fred S. Roberts Director of CCICADA Rutgers University #12;2 Algorithmic Decision Theory ·Today's decision makers speeds and quantities 2 #12;3 Algorithmic Decision Theory ·These tools and resources will enable better

157

Mutation in Autocatalytic Reaction Networks An Analysis based on Perturbation Theory  

E-print Network

Mutation in Autocatalytic Reaction Networks An Analysis based on Perturbation Theory By Peter F 11 170 Bitnet: A8441DAM@AWIUNI11 #12; P.F.Stadler, P.Schuster: Perturbation Theory Page 1 Key words: Autocatalyis -- mutation -- perturbation theory -- -- qualitative analysis -- replication dynamics Abstract

Stadler, Peter F.

158

The Marketing Opportunity Theory and Empirical Research Based on Product Benefit Value  

Microsoft Academic Search

People's pursuit of benefits is the performance of demands in did. The current value theory was built on the basis of demand. In the context of economic restructuring, the concept of demands has gradually been replaced by value. This paper make a deep analysis of value theory, put forward the theory of product benefit value, based on this, developed the

Jingdong Chen; Long Cheng

2010-01-01

159

Scheduling for indoor visible light communication based on graph theory.  

PubMed

Visible light communication (VLC) has drawn much attention in the field of high-rate indoor wireless communication. While most existing works focused on point-to-point VLC technologies, few studies have concerned multiuser VLC, where multiple optical access points (APs) transmit data to multiple user receivers. In such scenarios, inter-user interference constitutes the major factor limiting the system performance. Therefore, a proper scheduling scheme has to be proposed to coordinate the interference and optimize the whole system performance. In this work, we aim to maximize the sum rate of the system while taking into account user fairness by appropriately assigning LED lamps to multiple users. The formulated scheduling problem turns out to be a maximum weighted independent set problem. We then propose a novel and efficient resource allocation method based on graph theory to achieve high sum rates. Moreover, we also introduce proportional fairness into our scheduling scheme to ensure the user fairness. Our proposed scheduling scheme can, with low complexity, achieve more multiplexing gains, higher sum rate, and better fairness than the existing works. PMID:25836136

Tao, Yuyang; Liang, Xiao; Wang, Jiaheng; Zhao, Chunming

2015-02-01

160

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

161

Couple stress based strain gradient theory for elasticity  

Microsoft Academic Search

The deformation behavior of materials in the micron scale has been experimentally shown to be size dependent. In the absence of stretch and dilatation gradients, the size dependence can be explained using classical couple stress theory in which the full curvature tensor is used as deformation measures in addition to the conventional strain measures. In the couple stress theory formulation,

F. Yang; A. C. M. Chong; D. C. C. Lam; P. Tong

2002-01-01

162

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

163

Theories of Medical Decision Making and Health: An Evidence Based Approach  

Microsoft Academic Search

In this special section of Medical Decision Making, 3 developers of evidence-based theories of medical decision making and health present their approaches: Fishbein (theory of reasoned action); Prochaska (transtheoretical model); and Reyna (fuzzy-trace theory). Spring, chair of the Evidence-Based Practice Committee of the Society for Behavioral Medicine, follows with a commentary on the 3 approaches and many other topics of

Valerie F. Reyna

2009-01-01

164

A theory-based transport model with comprehensive physics  

SciTech Connect

A new theory-based transport model with comprehensive physics (trapping, general toroidal geometry, fully electromagnetic, electron-ion collisions, impurity ions) has been developed. The core of the model is the new trapped-gyro-Landau-fluid (TGLF) equations, which provide a fast and accurate approximation to the linear eigenmodes for gyrokinetic drift-wave instabilities (trapped ion and electron modes, ion and electron temperature gradient modes, and kinetic ballooning modes). The new TGLF transport model is more accurate, and has an extended range of validity, compared to its predecessor GLF23. The TGLF model unifies trapped and passing particles in a single set of gyro-Landau-fluid equations. A model for the averaging of the Landau resonance by the trapped particles makes the equations work seamlessly over the whole drift-wave wave-number range from trapped ion modes to electron temperature gradient modes. A fast eigenmode solution method enables unrestricted magnetic geometry. The transport model uses the TGLF eigenmodes to compute quasilinear fluxes of energy and particles. A model for the saturated intensity of the turbulence completes the flux calculation. The intensity model is constructed to fit a large set of nonlinear gyrokinetic turbulence simulations with kinetic electrons. The TGLF model is valid in new physical regimes that GLF23 was not. These include the low aspect ratio spherical torus, which has both a high trapped fraction and strong shaping of magnetic flux surfaces. The TGLF model is also valid close to the magnetic separatrix so the transport physics of the H-mode pedestal region can be explored.

Staebler, G. M.; Kinsey, J. E.; Waltz, R. E. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Lehigh University, Bethlehem, Pennsylvania 18015 (United States); General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

2007-05-15

165

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

166

Data Mining Techniques Based on Grey System Theories for Time Sequence Data  

Microsoft Academic Search

Data mining is an interesting focus in computer science field now. This paper deals with data mining techniques based on Grey system theories for time sequence data. Firstly, thoughts of data mining with embedded knowledge are expatiated, and the status quo of Data mining techniques is presented briefly. Then, based on the above thoughts and the Grey system theories, data

Liu Bin; Zhang Hui; Liu Sifeng; Dang Yaoguo

2006-01-01

167

How Is a Science Lesson Developed and Implemented Based on Multiple Intelligences Theory?  

ERIC Educational Resources Information Center

The purpose of this study is to present the whole process step-by-step of how a science lesson can be planned and implemented based on Multiple Intelligences (MI) theory. First, it provides the potential of the MI theory for science teaching and learning. Then an MI science lesson that was developed based on a modified model in the literature and…

Kaya, Osman Nafiz

2008-01-01

168

A Theory-Driven Integrative Process/Outcome Evaluation of a Concept-Based Nursing Curriculum  

ERIC Educational Resources Information Center

The current trend in curriculum revision in nursing education is concept-based learning, but little research has been done on concept-based curricula in nursing education. The study used a theory-driven integrative process/outcome evaluation. Embedded in this theory-driven integrative process/outcome evaluation was a causal comparative…

Fromer, Rosemary F.

2013-01-01

169

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

170

Research on modern testing technique of optical system magnifying ratio based on CCD imaging theory  

Microsoft Academic Search

The paper discusses a new kind of modern testing method used in magnification of telescopic optical system, which applied the technique of photoelectric imaging creation automatically based on DLP theory and the technique of collecting image based on CCD imaging theory. This method simplifies customary measuring process, realizes objective and automatic measuring, and avoids subjective error which artificial factor leads

Lixia Shi; Chang Zeng

2005-01-01

171

Evaluating Case-based Decision Theory: Predicting Empirical Patterns of Human Classification Learning  

E-print Network

Evaluating Case-based Decision Theory: Predicting Empirical Patterns of Human Classification which calculates an agent's optimal behavior according to Case- based Decision Theory (Gilboa the efficacy of CBDT as an account of human decision-making on this set of problems. We find: (1) The choice

Tesfatsion, Leigh

172

A Game-based Learning System for Theory of Computation Using Lego NXT Robot  

Microsoft Academic Search

Finite state automata are in the core of theory of computation course and related courses such as discrete mathematics, formal languages, etc. This paper introduces a finite state automata simulator and a robot-based game associated with it for active learning in theory of computation related courses. The simulator is implemented in Java language and the automaton game based robot is

Mohamed Hamada; Sayota Sato

2011-01-01

173

DNA-BASED SELF-ASSEMBLY AND NANOROBOTICS: THEORY AND EXPERIMENTS  

E-print Network

DNA-BASED SELF-ASSEMBLY AND NANOROBOTICS: THEORY AND EXPERIMENTS by Sudheer Sahu Department School of Duke University 2007 #12;ABSTRACT DNA-BASED SELF-ASSEMBLY AND NANOROBOTICS: THEORY-assembly and nanorobotics: How to control errors in self-assembly? How to construct complex nanoscale objects in simpler

Reif, John H.

174

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

175

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

176

Theories  

NSDL National Science Digital Library

This activity will help the students understand that science theories change in the face of new evidence, but those changes can be slow in coming. Students will observe how scientific theories change over time, Be introduced to the sophistication of the geocentric model and the time it took to change the theory underpinning the heliocentric model, Compare the heliocentric model to the geocentric model.

2010-01-01

177

Prior Individual Training and Self-Organized Queuing during Group Emergency Escape of Mice from Water Pool.  

PubMed

We study the impact of prior individual training during group emergency evacuation using mice that escape from an enclosed water pool to a dry platform via any of two possible exits. Experimenting with mice avoids serious ethical and legal issues that arise when dealing with unwitting human participants while minimizing concerns regarding the reliability of results obtained from simulated experiments using 'actors'. First, mice were trained separately and their individual escape times measured over several trials. Mice learned quickly to swim towards an exit-they achieved their fastest escape times within the first four trials. The trained mice were then placed together in the pool and allowed to escape. No two mice were permitted in the pool beforehand and only one could pass through an exit opening at any given time. At first trial, groups of trained mice escaped seven and five times faster than their corresponding control groups of untrained mice at pool occupancy rate ? of 11.9% and 4%, respectively. Faster evacuation happened because trained mice: (a) had better recognition of the available pool space and took shorter escape routes to an exit, (b) were less likely to form arches that blocked an exit opening, and (c) utilized the two exits efficiently without preference. Trained groups achieved continuous egress without an apparent leader-coordinator (self-organized queuing)-a collective behavior not experienced during individual training. Queuing was unobserved in untrained groups where mice were prone to wall seeking, aimless swimming and/or blind copying that produced circuitous escape routes, biased exit use and clogging. The experiments also reveal that faster and less costly group training at ? = 4%, yielded an average individual escape time that is comparable with individualized training. However, group training in a more crowded pool (? = 11.9%) produced a longer average individual escape time. PMID:25693170

Saloma, Caesar; Perez, Gay Jane; Gavile, Catherine Ann; Ick-Joson, Jacqueline Judith; Palmes-Saloma, Cynthia

2015-01-01

178

Prior Individual Training and Self-Organized Queuing during Group Emergency Escape of Mice from Water Pool  

PubMed Central

We study the impact of prior individual training during group emergency evacuation using mice that escape from an enclosed water pool to a dry platform via any of two possible exits. Experimenting with mice avoids serious ethical and legal issues that arise when dealing with unwitting human participants while minimizing concerns regarding the reliability of results obtained from simulated experiments using ‘actors’. First, mice were trained separately and their individual escape times measured over several trials. Mice learned quickly to swim towards an exit–they achieved their fastest escape times within the first four trials. The trained mice were then placed together in the pool and allowed to escape. No two mice were permitted in the pool beforehand and only one could pass through an exit opening at any given time. At first trial, groups of trained mice escaped seven and five times faster than their corresponding control groups of untrained mice at pool occupancy rate ? of 11.9% and 4%, respectively. Faster evacuation happened because trained mice: (a) had better recognition of the available pool space and took shorter escape routes to an exit, (b) were less likely to form arches that blocked an exit opening, and (c) utilized the two exits efficiently without preference. Trained groups achieved continuous egress without an apparent leader-coordinator (self-organized queuing)—a collective behavior not experienced during individual training. Queuing was unobserved in untrained groups where mice were prone to wall seeking, aimless swimming and/or blind copying that produced circuitous escape routes, biased exit use and clogging. The experiments also reveal that faster and less costly group training at ? = 4%, yielded an average individual escape time that is comparable with individualized training. However, group training in a more crowded pool (? = 11.9%) produced a longer average individual escape time. PMID:25693170

Saloma, Caesar; Perez, Gay Jane; Gavile, Catherine Ann; Ick-Joson, Jacqueline Judith; Palmes-Saloma, Cynthia

2015-01-01

179

Quantum mechanical embedding theory based on a unique embedding potential  

SciTech Connect

We remove the nonuniqueness of the embedding potential that exists in most previous quantum mechanical embedding schemes by letting the environment and embedded region share a common embedding (interaction) potential. To efficiently solve for the embedding potential, an optimized effective potential method is derived. This embedding potential, which eschews use of approximate kinetic energy density functionals, is then used to describe the environment while a correlated wavefunction (CW) treatment of the embedded region is employed. We first demonstrate the accuracy of this new embedded CW (ECW) method by calculating the van der Waals binding energy curve between a hydrogen molecule and a hydrogen chain. We then examine the prototypical adsorption of CO on a metal surface, here the Cu(111) surface. In addition to obtaining proper site ordering (top site most stable) and binding energies within this theory, the ECW exhibits dramatic changes in the p-character of the CO 4{sigma} and 5{sigma} orbitals upon adsorption that agree very well with x-ray emission spectra, providing further validation of the theory. Finally, we generalize our embedding theory to spin-polarized quantum systems and discuss the connection between our theory and partition density functional theory.

Chen Huang [Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States); Pavone, Michele; Carter, Emily A. [Department of Mechanical and Aerospace Engineering, Program in Applied and Computational Mathematics, and the Andlinger Center for Energy and the Environment, Princeton University, Princeton, New Jersey 08544-5263 (United States)

2011-04-21

180

Capacity and delay estimation for roundabouts using conflict theory.  

PubMed

To estimate the capacity of roundabouts more accurately, the priority rank of each stream is determined through the classification technique given in the Highway Capacity Manual 2010 (HCM2010), which is based on macroscopical analysis of the relationship between entry flow and circulating flow. Then a conflict matrix is established using the additive conflict flow method and by considering the impacts of traffic characteristics and limited priority with high volume. Correspondingly, the conflict relationships of streams are built using probability theory. Furthermore, the entry capacity model of roundabouts is built, and sensitivity analysis is conducted on the model parameters. Finally, the entrance delay model is derived using queuing theory, and the proposed capacity model is compared with the model proposed by Wu and that in the HCM2010. The results show that the capacity calculated by the proposed model is lower than the others for an A-type roundabout, while it is basically consistent with the estimated values from HCM2010 for a B-type roundabout. PMID:24982982

Qu, Zhaowei; Duan, Yuzhou; Hu, Hongyu; Song, Xianmin

2014-01-01

181

Capacity and Delay Estimation for Roundabouts Using Conflict Theory  

PubMed Central

To estimate the capacity of roundabouts more accurately, the priority rank of each stream is determined through the classification technique given in the Highway Capacity Manual 2010 (HCM2010), which is based on macroscopical analysis of the relationship between entry flow and circulating flow. Then a conflict matrix is established using the additive conflict flow method and by considering the impacts of traffic characteristics and limited priority with high volume. Correspondingly, the conflict relationships of streams are built using probability theory. Furthermore, the entry capacity model of roundabouts is built, and sensitivity analysis is conducted on the model parameters. Finally, the entrance delay model is derived using queuing theory, and the proposed capacity model is compared with the model proposed by Wu and that in the HCM2010. The results show that the capacity calculated by the proposed model is lower than the others for an A-type roundabout, while it is basically consistent with the estimated values from HCM2010 for a B-type roundabout. PMID:24982982

Qu, Zhaowei; Duan, Yuzhou; Hu, Hongyu; Song, Xianmin

2014-01-01

182

A basic introduction to large deviations: Theory, applications, simulations  

E-print Network

The theory of large deviations deals with the probabilities of rare events (or fluctuations) that are exponentially small as a function of some parameter, e.g., the number of random components of a system, the time over which a stochastic system is observed, the amplitude of the noise perturbing a dynamical system or the temperature of a chemical reaction. The theory has applications in many different scientific fields, ranging from queuing theory to statistics and from finance to engineering. It is also increasingly used in statistical physics for studying both equilibrium and nonequilibrium systems. In this context, deep analogies can be made between familiar concepts of statistical physics, such as the entropy and the free energy, and concepts of large deviation theory having more technical names, such as the rate function and the scaled cumulant generating function. The first part of these notes introduces the basic elements of large deviation theory at a level appropriate for advanced undergraduate and graduate students in physics, engineering, chemistry, and mathematics. The focus there is on the simple but powerful ideas behind large deviation theory, stated in non-technical terms, and on the application of these ideas in simple stochastic processes, such as sums of independent and identically distributed random variables and Markov processes. Some physical applications of these processes are covered in exercises contained at the end of each section. In the second part, the problem of numerically evaluating large deviation probabilities is treated at a basic level. The fundamental idea of importance sampling is introduced there together with its sister idea, the exponential change of measure. Other numerical methods based on sample means and generating functions, with applications to Markov processes, are also covered.

Hugo Touchette

2012-02-29

183

Item Response Theory-Based Approaches for Computing Minimum Passing Scores from an Angoff-Based Standard-Setting Study  

ERIC Educational Resources Information Center

Even when the scoring of an examination is based on item response theory (IRT), standard-setting methods seldom use this information directly when determining the minimum passing score (MPS) for an examination from an Angoff-based standard-setting study. Often, when IRT scoring is used, the MPS value for a test is converted to an IRT-based theta…

Ferdous, Abdullah A.; Plake, Barbara S.

2008-01-01

184

Modeling Crowd Behavior Based on Social Comparison Theory: Extended Abstract  

E-print Network

or no verbal communication. Le Bon explains the homogeneous behavior of a crowd by two processes: (i) Imitation continuously #12;evolving since the 1950s. The key idea in this theory is that humans, lacking objective means cognitive model which, when executed individually by many agents, will cause them to behave as humans do

Kaminka, Gal A.

185

Renormalization group method based on the ionization energy theory  

NASA Astrophysics Data System (ADS)

Proofs are developed to explicitly show that the ionization energy theory is a renormalized theory, which mathematically exactly satisfies the renormalization group formalisms developed by Gell-Mann-Low, Shankar and Zinn-Justin. However, the cutoff parameter for the ionization energy theory relies on the energy-level spacing, instead of lattice point spacing in k-space. Subsequently, we apply the earlier proofs to prove that the mathematical structure of the ionization-energy dressed electron-electron screened Coulomb potential is exactly the same as the ionization-energy dressed electron-phonon interaction potential. The latter proof is proven by means of the second-order time-independent perturbation theory with the heavier effective mass condition, as required by the electron-electron screened Coulomb potential. The outcome of this proof is that we can derive the heat capacity and the Debye frequency as a function of ionization energy, which can be applied in strongly correlated matter and nanostructures.

Arulsamy, Andrew Das

2011-03-01

186

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

187

Toward a Suite of Performatives Based Upon Joint Intention Theory  

Microsoft Academic Search

Agent communication languages defined using joint intention theory have enjoyed a long research history. A number of performatives have been defined and refined in this literature with particular emphasis on the basic performatives of REQUEST and INFORM, which subsequently have many subtle versions. Even these less common performatives have been extended and refined multiple times. In many cases the underlying

Marcus J. Huber; Sanjeev Kumar; David Mcgee

2004-01-01

188

Course Management and Students' Expectations: Theory-Based Considerations  

ERIC Educational Resources Information Center

This paper proposes a theoretical, yet practical, framework for managing the formation process of students unrealistic expectations in a college course. Using relational contracting theory, alternative teacher interventions, aimed at effective management of students expectations about the course, are described. Also, the formation of the student…

Buckley, M. Ronald; Novicevic, Milorad M.; Halbesleben, Jonathon R. B.; Harvey, Michael

2004-01-01

189

Bulk Density of Meteoroids based on Single Body Theory  

Microsoft Academic Search

The mean bulk density of small meteoroids remains a poorly measured quantity. The bulk density for small meteoroids is an important proxy of the physical nature of the host parent body. As well, variations in bulk densities among meteoroids may reflect various evolutionary processes, such as sintering, thus providing some insight into the orbital evolution of individual meteoroids. The theory

Jean-Baptiste Kikwaya-Eluo; P. Brown; M. Campbell-Brown

2006-01-01

190

Artifact as theory-nexus: hermeneutics meets theory-based design  

Microsoft Academic Search

We suggest that HCI designs characteristically embody multiple, distinct psychological claims, that virtually every aspect of a system's usability is overdetermined by independent psychological rationales inherent in its design. These myriad claims cohere in being implemented together in a running system. Thus, HCI artifacts themselves are perhaps the most effective medium for theory development in HCI. We advance a framework

John M. Carroll; Wendy A. Kellogg

1989-01-01

191

The refined theory of deep rectangular beams based on general solutions of elasticity  

NASA Astrophysics Data System (ADS)

The problem of deducing one-dimensional theory from two-dimensional theory for a homogeneous isotropic beam is investigated. Based on elasticity theory, the refined theory of rectangular beams is derived by using Papkovich-Neuber solution and Lur’e method without ad hoc assumptions. It is shown that the displacements and stresses of the beam can be represented by the angle of rotation and the deflection of the neutral surface. Based on the refined beam theory, the exact equations for the beam without transverse surface loadings are derived and consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beam under transverse loadings are derived directly from the refined beam theory and are almost the same as the governing equations of Timoshenko beam theory. In two examples, it is shown that the new theory provides better results than Levinson’s beam theory when compared with those obtained from the linear theory of elasticity.

Gao, Yang; Wang, Minzhong

2006-06-01

192

Teachers' Private Theories and their Design of Technology-Based Learning  

ERIC Educational Resources Information Center

This study explores the private theories of four vocational education teachers in Singapore who have engaged in the design of technology-based learning for their own classes. The understanding of teachers' private theories is important in the context of contemporary educational reforms, which emphasise the shift towards student-centred practices…

Churchill, Daniel

2006-01-01

193

The Construction of Decision Model for Tourism Disaster Evacuation Based on GIS and Fuzzy Theory  

Microsoft Academic Search

Fuzzy theory provides a rigorous, flexible approach to the problem of defining and computing. Therefore, to facilitate decision-making in geographic information system (GIS), the graph layer indicator and the Takagi Sugeno (TS) fuzzy model have to be integrated. This study explains several versions of the TS fuzzy model based on fuzzy theory and fuzzy operation. An inference model is constructed

Chung-Hung Tsai; Wen-Ching Wang; Cheng-Wu Chen; Han-Lin Chen; Meng-Lung Lin

2009-01-01

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 problem with outcomes-based curricula in medical education: insights from educational theory  

Microsoft Academic Search

BACKGROUND Educators across the world are charged with the responsibility of producing core learning outcomes for medical curricula. However, much educational theory exists which deliberates the value of learning outcomes in education. AIMS This paper aims to discuss the problems sur- rounding outcomes-based curricula in medical edu- cation, using insights from educational theory. DISCUSSION The paper begins with a discussion

Charlotte E Rees

2004-01-01

196

Social Learning Theory Parenting Intervention Promotes Attachment-Based Caregiving in Young Children: Randomized Clinical Trial  

ERIC Educational Resources Information Center

Parenting programs for school-aged children are typically based on behavioral principles as applied in social learning theory. It is not yet clear if the benefits of these interventions extend beyond aspects of the parent-child relationship quality conceptualized by social learning theory. The current study examined the extent to which a social…

O'Connor, Thomas G.; Matias, Carla; Futh, Annabel; Tantam, Grace; Scott, Stephen

2013-01-01

197

Applying Ecological Theory to Advance the Science and Practice of School-Based Prejudice Reduction Interventions  

ERIC Educational Resources Information Center

Several school-based racial prejudice-reduction interventions have demonstrated some benefit. Ecological theory serves as a framework within which to understand the limits and to enhance the efficacy of prejudice-reduction interventions. Using ecological theory, this article examines three prejudice-reduction approaches, including social cognitive…

McKown, Clark

2005-01-01

198

Automated Detection of Local Coherence in Short Argumentative Essays Based on Centering Theory  

E-print Network

Automated Detection of Local Coherence in Short Argumentative Essays Based on Centering Theory local coherence in short argumentative essays. We use ideas from Centering Theory to measure local coherence of essays' paragraphs and compare it to human judgments on one analytical feature of essay quality

Rus, Vasile

199

Cooperative Learning: Improving University Instruction by Basing Practice on Validated Theory  

ERIC Educational Resources Information Center

Cooperative learning is an example of how theory validated by research may be applied to instructional practice. The major theoretical base for cooperative learning is social interdependence theory. It provides clear definitions of cooperative, competitive, and individualistic learning. Hundreds of research studies have validated its basic…

Johnson, David W.; Johnson, Roger T.; Smith, Karl A.

2014-01-01

200

Towards a Logic of Feature-Based Semantic Science Theories David Poole  

E-print Network

Towards a Logic of Feature-Based Semantic Science Theories David Poole Dept of Computer Science (Poole, Smyth, and Sharma 2008) is: · Information is published using well defined ontologies (Smith 2003 that will distinguish the theories. · To make a prediction for a new case (e.g., predict the ef- fect of treatment

Poole, David

201

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

202

Group Decision-Making Model Based on Rough Set and Evidence Theory  

Microsoft Academic Search

In this paper, rough set and evidence theory are applied to the research on the evaluation of group decision making. Focal element increases rapidly while applying the evidence theory. A feature reduction algorithm based on rough set is used when classification result is almost invariable. On one hand, in order to reduce the interdependence between evidences, we adopt a little

Ruixia Yan; Hualing Liu

2010-01-01

203

A Nelson-Oppen based Proof System using Theory Specific Proof Systems  

E-print Network

A Nelson-Oppen based Proof System using Theory Specific Proof Systems Fr´ed´eric Besson, Pierre systems that are combined using the Nelson-Oppen proof scheme. We propose specific proof systems reasoning. Each multi-theory proof is itself decomposed (using the Nelson-Oppen proof scheme) into mono

Paris-Sud XI, Université de

204

Capturing Landscape Visual Character Using Indicators: Touching Base with Landscape Aesthetic Theory  

Microsoft Academic Search

This paper presents one way that landscape visual character can be captured using indicators derived from nine theory-based concepts related to landscape perception. The paper aims to establish links between landscape aesthetic theory and visual indicators, thus exploring what landscape indicators are really indicating. The steps from abstract visual concepts to measurable visual indicators are described, and links are made

Åsa Ode; Mari S. Tveit; Gary Fry

2008-01-01

205

Ground Movement Analysis Based on Stochastic Medium Theory  

PubMed Central

In order to calculate the ground movement induced by displacement piles driven into horizontal layered strata, an axisymmetric model was built and then the vertical and horizontal ground movement functions were deduced using stochastic medium theory. Results show that the vertical ground movement obeys normal distribution function, while the horizontal ground movement is an exponential function. Utilizing field measured data, parameters of these functions can be obtained by back analysis, and an example was employed to verify this model. Result shows that stochastic medium theory is suitable for calculating the ground movement in pile driving, and there is no need to consider the constitutive model of soil or contact between pile and soil. This method is applicable in practice. PMID:24701184

Fei, Meng; Li-chun, Wu; Jia-sheng, Zhang; Guo-dong, Deng; Zhi-hui, Ni

2014-01-01

206

GROUP THEORY BASED DESIGN OF ISOTROPIC NEGATIVE REFRACTIVE INDEX METAMATERIALS  

Microsoft Academic Search

Abstract—Novel isotropic planar and three-dimensional negative refractive index (NRI) metamaterial (MTM) designs consisting of periodically arranged cross structures are developed in the terahertz (THz) frequency regime using group theory. The novel designs not only avoid magnetoelectric coupling but also enable a simplified fabrication process. Using Finite-difference Time-Domain (FDTD) simulations, the design exhibits an NRI passband which is in good agreement

N. Wongkasemand; A. Akyurtlu; K. A. Marx

2006-01-01

207

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

208

A reactive mobile robot based on a formal theory of action  

SciTech Connect

One of the agenda behind research in reasoning about actions is to develop autonomous agents (robots) that can act in a dynamic world. The early attempts to use theories of reasoning about actions and planning to formulate a robot control architecture were not successful for several reasons: The early theories based on STRIPS and its extensions allowed only observations about the initial state. A robot control architecture using these theories was usually of the form: (i) make observations (ii) Use the action theory to construct a plan to achieve the goal, and (iii) execute the plan.

Baral, C. Floriano, L.; Gabaldon, A. [Univ. of Texas, El Paso, TX (United States)] [and others

1996-12-31

209

Testing Expectancy Theory Predictions Using Behaviorally Based Measures of Motivational Effort for Engineers  

ERIC Educational Resources Information Center

Expectancy theory predictions were tested using a sample of engineers who had been rated on dimensions of work motivation or effort (in contrast to performance) using the behaviorally based rating scales designed by Landy and Guion (1970). (Author)

Arvey, Richard D.; Neel, C. Warren

1974-01-01

210

Photoelectron properties of DNA and RNA bases from many-body perturbation theory  

E-print Network

The photoelectron properties of DNA and RNA bases are studied using many-body perturbation theory within the GW approximation, together with a recently developed Lanczos-chain approach. Calculated vertical ionization ...

Umari, Paolo

211

An Anti-attack Model Based on Complex Network Theory in P2P networks  

E-print Network

Complex network theory is a useful way to study many real systems. In this paper, an anti-attack model based on complex network theory is introduced. The mechanism of this model is based on dynamic compensation process and reverse percolation process in P2P networks. The main purpose of the paper is: (i) a dynamic compensation process can turn an attacked P2P network into a power-law (PL) network with exponential cutoff; (ii) a local healing process can restore the maximum degree of peers in an attacked P2P network to a normal level; (iii) a restoring process based on reverse percolation theory connects the fragmentary peers of an attacked P2P network together into a giant connected component. In this way, the model based on complex network theory can be effectively utilized for anti-attack and protection purposes in P2P networks.

Peng, Hao; Zhao, Dandan; Zhang, Aixin; Li, Jianhua

2011-01-01

212

Obtaining Closure for Fin-and-Tube Heat Exchanger Modeling Based on Volume Averaging Theory (VAT)  

E-print Network

in fin-and-tube heat exchangers for design and optimizationtube heat exchangers based on volume averaging theory with the help of designdesign of experiments (DOE), the performance of a fin-and-tube heat exchanger

Zhou, Feng; Hansen, Nicholas E; Geb, David J; Catton, Ivan

2011-01-01

213

An anti-attack model based on complex network theory in P2P networks  

NASA Astrophysics Data System (ADS)

Complex network theory is a useful way to study many real systems. In this paper, an anti-attack model based on complex network theory is introduced. The mechanism of this model is based on a dynamic compensation process and a reverse percolation process in P2P networks. The main purpose of the paper is: (i) a dynamic compensation process can turn an attacked P2P network into a power-law (PL) network with exponential cutoff; (ii) a local healing process can restore the maximum degree of peers in an attacked P2P network to a normal level; (iii) a restoring process based on reverse percolation theory connects the fragmentary peers of an attacked P2P network together into a giant connected component. In this way, the model based on complex network theory can be effectively utilized for anti-attack and protection purposes in P2P networks.

Peng, Hao; Lu, Songnian; Zhao, Dandan; Zhang, Aixin; Li, Jianhua

2012-04-01

214

A game theory based highway cost allocation method with non-denumerable vehicle passage  

E-print Network

A GAME THEORY BASED HIGHWAY COST ALLOCATION METHOD WITH NON-DENUMERABLE VEHICLE PASSAGE A Thesis by ALBERTO CASTANO-PARDO Submitted to the Office of Graduate Studies of Texas A&M TJniversity in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 1992 Major Subject: Industrial Engineering A GAME THEORY BASED HIGHWAY COST ALLOCATION METHOD WITH NON-DENUMERABLE VEHICLE PASSAGE A Thesis by ALBERTO CASTANO-PARDO Approved as to style and content by: A...

Castano-Pardo, Alberto

1992-01-01

215

Theory of Spike Timing-Based Neural Classifiers  

NASA Astrophysics Data System (ADS)

We study the computational capacity of a model neuron, the tempotron, which classifies sequences of spikes by linear-threshold operations. We use statistical mechanics and extreme value theory to derive the capacity of the system in random classification tasks. In contrast with its static analog, the perceptron, the tempotron’s solutions space consists of a large number of small clusters of weight vectors. The capacity of the system per synapse is finite in the large size limit and weakly diverges with the stimulus duration relative to the membrane and synaptic time constants.

Rubin, Ran; Monasson, Rémi; Sompolinsky, Haim

2010-11-01

216

Changes in regulatory theory: Market-based pricing  

SciTech Connect

With the introduction of competition and diversification into retail utility services, rate-making methods are being rethought. Rates that are strictly cost-based may be too slow in responding to changes within the utility industry. And the advent of independent power production as a significant source of energy calls for greater flexibility in pricing of wholesale utility services as well. Various deregulation or reregulation plans have been formulated, including both price cap and price floor proposals. Some regulatory authorities have embraced market-based pricing over cost-based methods as the best solution to pricing problems. This article addresses Federal Energy Regulatory Commission response to market-based rates.

Sponseller, D.

1990-11-08

217

Hyperbolic Models for Large Supply Chains Christian Ringhofer (Arizona State University)  

E-print Network

Clearing functions: Quasi - steady state models - queueing theory. First principle models for non in Progress'. Derived from steady state queuing theory. Yields a formula for the velocity of an item through speeds can have both signs. Problem: Queuing theory models are based on quasi - steady state regime

Ringhofer, Christian

218

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

219

A model for renal arterial branching based on graph theory.  

PubMed

The kidney is one of the most complicated organs in terms of structure and physiology, in part because it is highly vascularized. The renal vascular development occurs through two mechanisms that sometimes overlap: vasculogenesis and angiogenesis. Here, we consider angiogenesis to model the renal arterial tree with the two processes of vascular angiogenesis: sprouting and splitting. We recognize the vessels are not tubes with ends that get glued but physiological factors are relevant into the vascular development. Our contribution integrates the graph theory and physiological information to derive a quantitative model for the vascular tree in the sense that the vertices and edges represent, respectively, a branching point and a vessel. From such a premise, development of the arterial vascular tree of the kidney is mathematically expressed, including physiological processes as the effect of the vascular endothelial growth factor (VEGF) on the vessel length. A definition of the graph is used to visualize the topology of vascular tree in kidney providing physiological information into the edges. Thus, renal arterial branching is modeled as a graph where edges are labeled and oriented. PMID:20109473

Espinoza-Valdez, Aurora; Femat, Ricardo; Ordaz-Salazar, Francisco C

2010-05-01

220

Treatment motivation in drug users: a theory-based analysis.  

PubMed

Motivation for drug use treatment is widely regarded as crucial to a client's engagement in treatment and success in quitting drug use. Motivation is typically measured with items reflecting high treatment readiness (e.g., perceived need for treatment and commitment to participate) and low treatment resistance (e.g., skepticism regarding benefits of treatment). Building upon reactance theory and the psychotherapeutic construct of resistance, we conceptualized these two aspects of treatment motivation - readiness and resistance - as distinct constructs and examined their predictive power in a sample of 1295 drug-using offenders referred to treatment while on probation. The sample was 60.7% African Americans, 33.5% non-Hispanic Whites, and 21.2% women; their ages ranged from 16 to 63 years old. Interviews occurred at treatment entry and 6 months later. Readiness (but not resistance) predicted treatment retention during the 6-month period. Resistance (but not readiness) predicted drug use, especially among offenders for whom the treatment referral was coercive. These findings suggest that readiness and resistance should both be assessed among clients entering treatment, especially when the referral is coercive. Intake and counseling protocols should address readiness and resistance separately. PMID:16051447

Longshore, Douglas; Teruya, Cheryl

2006-02-01

221

Models, strategies, and tools. Theory in implementing evidence-based findings into health care practice.  

PubMed

This paper presents a case for careful consideration of theory in planning to implement evidence-based practices into clinical care. As described, theory should be tightly linked to strategic planning through careful choice or creation of an implementation framework. Strategies should be linked to specific interventions and/or intervention components to be implemented, and the choice of tools should match the interventions and overall strategy, linking back to the original theory and framework. The thesis advanced is that in most studies where there is an attempt to implement planned change in clinical processes, theory is used loosely. An example of linking theory to intervention design is presented from a Mental Health Quality Enhancement Research Initiative effort to increase appropriate use of antipsychotic medication among patients with schizophrenia in the Veterans Health Administration. PMID:16637960

Sales, Anne; Smith, Jeffrey; Curran, Geoffrey; Kochevar, Laura

2006-02-01

222

Conflict resolution for collaborative design based on rough set theory  

Microsoft Academic Search

Due to the design knowledge discrepancy during collaborative design, conflicts can be revealed from the process of collaborative design decision. A critical element of collaborative design would be conflict resolution. The conflict resolution is correlative with both of the knowledge granulation and specific method provided. In this paper, granularity is used to describe rules acquainted based on the concept of

Jun Ma; Tian-Yuan Xiao; Jian-chao Zeng; Ma Hao

2008-01-01

223

University Campus Planning Research Based on Theories of Industrial Engineering  

Microsoft Academic Search

The revision of the planning for a college is introduced and summarized in this paper. Industrial engineering based principles and methods for facilities planning were applied and experimented in the planning. Suggestions and cautions according to the ubiquitous problems were given for future campus planning: paying attention to people-oriented spirit, regarding it as system engineering and proper application of industrial

Pang Yucheng; Shi Li; Zhang Feng

2008-01-01

224

Research on Maintainability Evaluation Model Based on Fuzzy Theory  

Microsoft Academic Search

Maintainability influencing attributes are analyzed, their weight and value calculating methods are given, and the maintainability fuzzy evaluation method is proposed based on the relative closeness. According to the maintenance task simulation operated in virtual environment, the maintainability virtual evaluation model is built by analyzing the maintenance task for each replaceable unit of product. At last, a case study is

Lu Zhong; Sun Youchao

2007-01-01

225

A Labour-Based Theory of International Trade  

Microsoft Academic Search

This new model of international trade patterns is based on differing relative labor costs derived from differing endowments of skilled and unskilled labor, when labor is in elastic supply because of social support systems. All factors other than labor are assumed to be mobile across frontiers; constant returns to scale prevail. The model predicts that (1) high wage countries will

Patrick Minford

1988-01-01

226

Executive Cognitive Control in Communication: Extending Plan-Based Theory.  

ERIC Educational Resources Information Center

Explores role of cognitive efficiency in interaction planning and plan performance of undergraduate students--one study explicated the concept of cognitive efficiency relating to communication processes; two others aimed at extending existing plan-based theorizing. Suggests cognitive efficiency and interaction experience are at the root of…

Jordan, Jerry Monroe

1998-01-01

227

Content Based Image Retrieval and Information Theory: A General Approach.  

ERIC Educational Resources Information Center

Proposes an alternative real valued representation of color based on the information theoretic concept of entropy. A theoretical presentation of image entropy is accompanied by a practical description of the merits and limitations of image entropy compared to color histograms. Results suggest that image entropy is a promising approach to image…

Zachary, John; Iyengar, S. S.; Barhen, Jacob

2001-01-01

228

A homogenization-based theory for anisotropic beams with accurate through-section stress and strain prediction  

E-print Network

A homogenization-based theory for anisotropic beams with accurate through-section stress and strain Engineering, Ann Arbor, MI 48109 Abstract This paper presents a homogenization-based theory for three-dimensional anisotropic beams. The proposed beam theory uses a hierarchy of solutions to carefully-chosen beam problems

Papalambros, Panos

229

The Cultures of Contemporary Instructional Design Scholarship, Part Two: Developments Based on Constructivist and Critical Theory Foundations  

ERIC Educational Resources Information Center

This article is the second in a series (see Willis, 2011) that looks at the current status of instructional design scholarship and theory. In this concluding article, the focus is on two cultures of ID work, one based on constructivist and interpretivist theory and the other based on critical theory and critical pedagogy. There are distinct…

Willis, Jerry

2011-01-01

230

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

231

Theory Presentation and Assessment in a Problem-based Learning Group.  

ERIC Educational Resources Information Center

Examines the discourse of a problem-based learning group in medicine. Identifies ethnomethodological conversation analysis to analyze a segment of interaction in a problem-based learning (PBL) meeting. Observes that the presentation of a theory makes relevant a variety of sequential activities through which participants in this instructional…

Glenn, Phillip J.; Koschmann, Timothy; Conlee, Melinda

1999-01-01

232

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

233

Negative index of refraction microwave frequency structures based on high permittivity inclusions and effective medium theory  

Microsoft Academic Search

A metamaterial designed to have simultaneous negative permittivity and permeability may be built from a cubic lattice of spheres and a three dimensional wire grid embedded in a host medium. Based on reported theory, the spheres must have higher permittivity than the surrounding medium and be smaller than the wavelength of the electromagnetic radiation in the host medium. Metamaterials based

James M. L. Cramer; Andrew J. Gatesman; Robert H. Giles; William E. Nixon

2008-01-01

234

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.

235

A Kind of Spatial Data Storage System Based on Global Subdivision Theory for Mobile GIS  

Microsoft Academic Search

In order to better solve unified reference and multiscale framework of storage, organization and service of spatial data, aiming at deficiencies of organization and scheduling methods of spatial data in the mobile GIS service, a kind of new cluster storage management technology based on global subdivision theory is presented in this paper. The main characteristic of this technology is space-based

Xuefeng Lv; Chengqi Cheng; Guoliang Pu; Li Guan

2009-01-01

236

Evaluating the Importance of Service Quality Factors in PMR Based on Grey Relational Theory  

Microsoft Academic Search

Based on the grey relation theory, the paper presented a grey relational assessment model to evaluate the importance of various quality factors in property management of residence (PMR). First, this study found out twenty main service quality factors that influence overall service quality of property management of residence (SQPMR) based on SERVQUAL instrument and interview with experts and literature review,

Chen Yongqing; Huang Jiatao

2009-01-01

237

Nonlinear finite element analysis based on a large strain deformation theory of plasticity  

Microsoft Academic Search

The present paper is concerned with an efficient framework for a nonlinear finite element procedure for the numerical analysis of finite deformation elastic–plastic problems, based on a deformation theory of plasticity. Stress measures are related to Green’s strains via a hyperelastic constitutive law based on a free energy potential function, whereas the plastic behavior is described using a von Mises

M. Brünig

1998-01-01

238

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 L control algorithms are described. First, a model­based adaptive robot force control algorithm is reviewed. Second, a new experimental robot system for the testing of these new force control algorithms is de

Whitcomb, Louis L.

239

Vein Power Plane for Printed Circuit Board Based on Constructal Theory  

Microsoft Academic Search

In this paper, a novel vein power tree design tech- nique based on constructal theory is introduced for optimal direct current performance. The designed vein tree has multifunctions of low electrical resistance, equidistribution, and compactness. In the meantime, a vein power plane based on the vein tree is de- veloped for printed circuit board. The designed vein power plane example

Hui-Fen Huang; Wei-Guo; Qing-Xin Chu

2011-01-01

240

Score Reliability of a Test Composed of Passage-Based Testlets: A Generalizability Theory Perspective.  

ERIC Educational Resources Information Center

The purpose of this study was to investigate the impact of local item dependence (LID) in passage-based testlets on the test score reliability of an English as a Foreign Language (EFL) reading comprehension test from the perspective of generalizability (G) theory. Definitions and causes of LID in passage-based testlets are reviewed within the…

Lee, Yong-Won

241

A Proxy Signature Scheme Based on Coding Theory  

NASA Astrophysics Data System (ADS)

Proxy signature helps the proxy signer to sign messages on behalf of the original signer. This signature is used when the original signer is not available to sign a specific document. In this paper, we introduce a new proxy signature scheme based on Stern's identification scheme whose security depends on syndrome decoding problem. The proposed scheme is the first code-based proxy signature and can be used in a quantum computer. In this scheme, the operations to perform are linear and very simple thus the signature is performed quickly and can be implemented using smart card in a quite efficient way. The proposed scheme also satisfies unforgeability, undeniability, non-transferability and distinguishability properties which are the security requirements for a proxy signature.

Jannati, Hoda; Falahati, Abolfazl

242

The boundaries of instance-based learning theory for explaining decisions from experience.  

PubMed

Most demonstrations of how people make decisions in risky situations rely on decisions from description, where outcomes and their probabilities are explicitly stated. But recently, more attention has been given to decisions from experience where people discover these outcomes and probabilities through exploration. More importantly, risky behavior depends on how decisions are made (from description or experience), and although prospect theory explains decisions from description, a comprehensive model of decisions from experience is yet to be found. Instance-based learning theory (IBLT) explains how decisions are made from experience through interactions with dynamic environments (Gonzalez et al., 2003). The theory has shown robust explanations of behavior across multiple tasks and contexts, but it is becoming unclear what the theory is able to explain and what it does not. The goal of this chapter is to start addressing this problem. I will introduce IBLT and a recent cognitive model based on this theory: the IBL model of repeated binary choice; then I will discuss the phenomena that the IBL model explains and those that the model does not. The argument is for the theory's robustness but also for clarity in terms of concrete effects that the theory can or cannot account for. PMID:23317827

Gonzalez, Cleotilde

2013-01-01

243

Sensor-Based Collision Avoidance: Theory and Experiments  

NASA Technical Reports Server (NTRS)

A new on-line control strategy for sensor-based collision avoidance of manipulators and supporting experimental results are presented in this article. This control strategy is based on nullification of virtual forces applied to the end-effector by a hypothetical spring-plus-damper attached to the object's surface. In the proposed approach, the real-time arm control software continuously monitors the object distance measured by the arm-mounted proximity sensors. When this distance is less than a preset threshold, the collision avoidance control action is initiated to inhibit motion toward the object and thus prevent collision. This is accomplished by employing an outer feedback loop to perturb the end-effector nominal motion trajectory in real-time based on the sensory data. The perturbation is generated by a proportional-plus-integral (PI) collision avoidance controller acting on the difference between the sensed distance and the preset threshold. This approach is computationally very fast, requires minimal modification to the existing manipulator positioning system, and provides the manipulator with an on-line collision avoidance capability to react autonomously and intelligently. A dexterous RRC robotic arm is instrumented with infrared proximity sensors and is operated under the proposed collision avoidance strategy. Experimental results are presented to demonstrate end-effector collision avoidance both with an approaching object and while reaching inside a constricted opening.

Seraji, Homayoun; Steele, Robert; Ivlev, Robert

1996-01-01

244

Multi-attribute Decision-Making Model Based on Grey Game Theory with Mixed Strategy  

Microsoft Academic Search

As for the multi-attribute decision-making problem, most common methods used based on AHP are imprecise and complicated for taking weights of indices into account. The paper introduces game theory avoiding the discussion of weights which are inevitable in the normal decision-making model like AHP, DEA, and ANP, FUZZY and so on. Then it combines grey theory to establish a grey

Chen Wang; Jun Chen

2009-01-01

245

Creep behavior of beams using the viscoplasticity theory based on total strain and overstress  

Microsoft Academic Search

The viscoplasticity theory based on total strain and overstress can reproduce rate-dependent inelastic deformation without distinction between plastic and creep strain using two material functions. A viscosity function and an equilibrium stress-strain curve characterize rate-dependency and work hardening, respectively. The theory is used to analyze the creep behavior of a beam subjected to a linearly increasing moment which is subsequently

T. Hiroe; E. Krempl

1982-01-01

246

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

247

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

248

Safety models incorporating graph theory based transit indicators.  

PubMed

There is a considerable need for tools to enable the evaluation of the safety of transit networks at the planning stage. One interesting approach for the planning of public transportation systems is the study of networks. Network techniques involve the analysis of systems by viewing them as a graph composed of a set of vertices (nodes) and edges (links). Once the transport system is visualized as a graph, various network properties can be evaluated based on the relationships between the network elements. Several indicators can be calculated including connectivity, coverage, directness and complexity, among others. The main objective of this study is to investigate the relationship between network-based transit indicators and safety. The study develops macro-level collision prediction models that explicitly incorporate transit physical and operational elements and transit network indicators as explanatory variables. Several macro-level (zonal) collision prediction models were developed using a generalized linear regression technique, assuming a negative binomial error structure. The models were grouped into four main themes: transit infrastructure, transit network topology, transit route design, and transit performance and operations. The safety models showed that collisions were significantly associated with transit network properties such as: connectivity, coverage, overlapping degree and the Local Index of Transit Availability. As well, the models showed a significant relationship between collisions and some transit physical and operational attributes such as the number of routes, frequency of routes, bus density, length of bus and 3+ priority lanes. PMID:22831497

Quintero, Liliana; Sayed, Tarek; Wahba, Mohamed M

2013-01-01

249

Generalized perturbation theory based on the method of cyclic characteristics  

SciTech Connect

A GPT algorithm for estimation of eigenvalues and reaction-rate ratios is developed for the neutron transport problems in 2D fuel assemblies with isotropic scattering. In our study the GPT formulation is based on the integral transport equations. The mathematical relationship between the generalized flux importance and generalized source importance functions is applied to transform the generalized flux importance transport equations into the integro-differential forms. The resulting adjoint and generalized adjoint transport equations are then solved using the method of cyclic characteristics (MOCC). Because of the presence of negative adjoint sources, a biasing/decontamination scheme is applied to make the generalized adjoint functions positive in such a way that it can be used for the multigroup re-balance technique. To demonstrate the efficiency of the algorithms, perturbative calculations are performed on a 17 x 17 PWR lattice. (authors)

Assawaroongruengchot, M.; Marleau, G. [Institut de Genie Nucleaire, Departement de Genie Physique, Ecole Polytechnique de Montreal, 2900 Boul. Edouard-Montpetit, Montreal, Que. H3T 1J4 (Canada)

2006-07-01

250

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

251

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. PMID:25699107

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

2015-01-01

252

Enhancing quality of practice through theory of change-based evaluation: science or practice?  

PubMed

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 that the current conceptualization of community science pays scant attention to community practice. This paper concludes by suggesting that the current conceptualization of community science be modified to recognize the importance of community practice as an equal aspiration for community psychologists. PMID:15909792

Julian, David A

2005-06-01

253

General biorthogonal projected bases as applied to second-order Møller-Plesset perturbation theory  

NASA Astrophysics Data System (ADS)

With low-order scaling correlated wave function theories in mind, we present second quantization formalism as well as biorthonormalization procedures for general—singular or nonsingular—bases. Of particular interest are the so-called projected atomic orbital bases, which are obtained from a set of atom-centered functions and feature a separation of occupied and virtual spaces. We demonstrate the formalism by deriving and implementing second-order Møller-Plesset perturbation theory in it, and discuss the convergence and preconditioning of the iterative amplitude equations in detail.

Weijo, Ville; Manninen, Pekka; Jørgensen, Poul; Christiansen, Ove; Olsen, Jeppe

2007-08-01

254

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

255

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

256

Microfluidic, Bead-Based Assay: Theory and Experiments  

PubMed Central

Microbeads are frequently used as a solid support for biomolecules such as proteins and nucleic acids in heterogeneous microfluidic assays. However, relatively few studies investigate the binding kinetics on modified bead surfaces in a microfluidics context. In this study, a customized hot embossing technique is used to stamp microwells in a thin plastic substrate where streptavidin-coated agarose beads are selectively placed and subsequently immobilized within a conduit. Biotinylated quantum dots are used as a label to monitor target analyte binding to the bead's surface. Three-dimensional finite element simulations are carried out to model the binding kinetics on the bead's surface. The model accounts for surface exclusion effects resulting from a single quantum dot occluding multiple receptor sites. The theoretical predictions are compared and favorably agree with experimental observations. The theoretical simulations provide a useful tool to predict how varying parameters affect microbead reaction kinetics and sensor performance. This study enhances our understanding of bead-based microfluidic assays and provides a design tool for developers of point-of-care, lab-on-chip devices for medical diagnosis, food and water quality inspection, and environmental monitoring. PMID:19766545

Thompson, Jason A.; Bau, Haim H.

2009-01-01

257

Application of Monte Carlo simulation to cavity theory based on the virtual electron source concept  

NASA Astrophysics Data System (ADS)

A cavity theory based on the application of the electron transport equation in the cavity and the surrounding medium, referred to as L-L cavity theory in this paper, is discussed. The L-L cavity theory is a very detailed theory that considers electron production in the cavity as well as in the wall, and is applicable to all cavity sizes. The main idea of this cavity theory is that the effect of the cavity on the energy deposition of electrons inside it can be attributed to a virtual electron source uniformly distributed in the cavity. Monte Carlo calculations have been used to determine the effect of the virtual electron source on the relative ionization density in the cavity. In particular, the Monte Carlo method has been used to compute the parameter k(E, a), which is the fraction of the energy deposited in the cavity relative to the initial energy of electrons, given an electron source uniformly distributed in the cavity. The total energy deposition of the virtual electron source in the cavity may also be obtained. The calculated results agree well with the experimental results from Attix et al (Attix F H, Vergne L D and Ritz V H 1958 J. Res. NBS 60 235-43) and show that the L-L cavity theory gives a more accurate prediction of the cavity response at low energies than do other cavity theories.

Fu, Yuchuan; Luo, Zhengming

2002-09-01

258

Application of Monte Carlo simulation to cavity theory based on the virtual electron source concept.  

PubMed

A cavity theory based on the application of the electron transport equation in the cavity and the surrounding medium, referred to as L-L cavity theory in this paper, is discussed. The L-L cavity theory is a very detailed theory that considers electron production in the cavity as well as in the wall, and is applicable to all cavity sizes. The main idea of this cavity theory is that the effect of the cavity on the energy deposition of electrons inside it can be attributed to a virtual electron source uniformly distributed in the cavity. Monte Carlo calculations have been used to determine the effect of the virtual electron source on the relative ionization density in the cavity. In particular, the Monte Carlo method has been used to compute the parameter k(E, a), which is the fraction of the energy deposited in the cavity relative to the initial energy of electrons, given an electron source uniformly distributed in the cavity. The total energy deposition of the virtual electron source in the cavity may also be obtained. The calculated results agree well with the experimental results from Attix et al (Attix F H, Vergne L D and Ritz V H 1958 J. Res. NBS 60 235-43) and show that the L-L cavity theory gives a more accurate prediction of the cavity response at low energies than do other cavity theories. PMID:12361222

Fu, Yuchuan; Luo, Zhengming

2002-09-01

259

An approach for leukemia classification based on cooperative game theory.  

PubMed

Hematological malignancies are the types of cancer that affect blood, bone marrow and lymph nodes. As these tissues are naturally connected through the immune system, a disease affecting one of them will often affect the others as well. The hematological malignancies include; Leukemia, Lymphoma, Multiple myeloma. Among them, leukemia is a serious malignancy that starts in blood tissues especially the bone marrow, where the blood is made. Researches show, leukemia is one of the common cancers in the world. So, the emphasis on diagnostic techniques and best treatments would be able to provide better prognosis and survival for patients. In this paper, an automatic diagnosis recommender system for classifying leukemia based on cooperative game is presented. Through out this research, we analyze the flow cytometry data toward the classification of leukemia into eight classes. We work on real data set from different types of leukemia that have been collected at Iran Blood Transfusion Organization (IBTO). Generally, the data set contains 400 samples taken from human leukemic bone marrow. This study deals with cooperative game used for classification according to different weights assigned to the markers. The proposed method is versatile as there are no constraints to what the input or output represent. This means that it can be used to classify a population according to their contributions. In other words, it applies equally to other groups of data. The experimental results show the accuracy rate of 93.12%, for classification and compared to decision tree (C4.5) with (90.16%) in accuracy. The result demonstrates that cooperative game is very promising to be used directly for classification of leukemia as a part of Active Medical decision support system for interpretation of flow cytometry readout. This system could assist clinical hematologists to properly recognize different kinds of leukemia by preparing suggestions and this could improve the treatment of leukemic patients. PMID:21988887

Torkaman, Atefeh; Charkari, Nasrollah Moghaddam; Aghaeipour, Mahnaz

2011-01-01

260

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

261

Relationships between axisymmetric bending and buckling solutions of FGM circular plates based on third-order plate theory and classical plate theory  

Microsoft Academic Search

The third-order shear deformation plate theory (TPT) is employed to solve the axisymmetric bending and buckling problems of functionally graded circular plates. Relationships between the TPT solutions of axisymmetric bending and buckling of functionally graded circular plates and those of isotropic circular plates based on the classical plate theory (CPT) are presented, from which one can easily obtain the TPT

L. S. Ma; T. J. Wang

2004-01-01

262

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

263

An anisotropic constitutive equation for the stress tensor of blood based on mixture theory  

SciTech Connect

Based on ideas proposed by Massoudi and Rajagopal (M-R), we develop a model for blood using the theory of interacting continua, that is, the mixture theory. We first provide a brief review of mixture theory, and then discuss certain issues in constitutive modeling of a two-component mixture. In the present formulation, we ignore the biochemistry of blood and assume that blood is composed of red blood cells (RBCs) suspended in plasma, where the plasma behaves as a linearly viscous fluid and the RBCs are modeled as an anisotropic nonlinear density-gradient-type fluid. We obtain a constitutive relation for blood, based on the simplified constitutive relations derived for plasma and RBCs. A simple shear flow is discussed, and an exact solution is obtained for a very special case; for more general cases, it is necessary to solve the nonlinear coupled equations numerically.

Massoudi, Mehrdad; Antaki, J.F.

2008-09-12

264

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

265

Comments on Observables for Identity-Based Marginal Solutions in Berkovits' Superstring Field Theory  

E-print Network

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 $\\xi$ zero mode counting.

Isao Kishimoto; Tomohiko Takahashi

2014-04-17

266

Benefits and uncertainties of performance-based contracting in manufacturing industries : An agency theory perspective  

Microsoft Academic Search

Purpose – In view of a lack of understanding of the consequences of performance-based contracting (PBC), this paper aims to reveal deeper insights into the mechanisms inherent to PBC and explore which benefits and uncertainties may result for providers and customers. Design\\/methodology\\/approach – Conducting a comprehensive literature review and drawing on insights from agency theory as a framework, the auhtors

Phillipp Hypko; Meike Tilebein; Ronald Gleich

2010-01-01

267

The Contribution of Genre Theory to Theme-Based EAP: Navigating Foreign Fiords.  

ERIC Educational Resources Information Center

Utilizes genre theory to illuminate issues of debate in theme-based English for Academic Purposes (EAP) pedagogy, including program goals and course design and content. The article argues that EAP instructors cannot teach students skills required for all their future content courses, but can impart strategies to cope with community expectations.…

Meyer, Lisa

1996-01-01

268

Implications and Applications of Modern Test Theory in the Context of Outcomes Based Education.  

ERIC Educational Resources Information Center

Uses a framework previously developed to relate outcomes based education and B. Bloom's "Taxonomy of Educational Objectives" to consider ways in which modern test theory can be used to connect aspects of assessment to the curriculum framework and to consider insights this connection might provide. (SLD)

Andrich, David

2002-01-01

269

What is justice in education? Sketch of answer based on theories of justice and economics'  

E-print Network

Page 1 What is justice in education? Sketch of answer based on theories of justice and economics inputs or educational outcomes are just or not? How should a society distribute its educational resources whether given distributions of educational inputs or educational outcomes are just or not? How should

Paris-Sud XI, Université de

270

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

271

Defects detecting method of copper interconnects based on signal reflection theory  

Microsoft Academic Search

Based on the signal reflection theory, this paper investigates the diction method of loss object defects in copper interconnects. The signal is reflected at the edge of impedance discontinuity, which is caused by the defects in interconnects. The reflection results of defects with different size and with different signal rise time are investigated. The results show that signal reflection caused

Wen Zhou; Hongxia Liu; Jianjun Wei; Qianwei Kuang

2009-01-01

272

Internal impedance of battery detection based on theory of chaotic Oscillator  

Microsoft Academic Search

Present a method with the chaotic oscillator to detect the battery internal impedance. Chaotic oscillator is sensitive to certain signal and immune to noise, so based on chaotic detection principle, and association the theory of AC internal impedance detection method, a new battery internal impedance detection method is presented. The on-line detection the battery internal impedance will be achieved. And

Yin Cheng-que; Sun Yue; Huang Yi-ran

2008-01-01

273

Effects of Guided Writing Strategies on Students' Writing Attitudes Based on Media Richness Theory  

ERIC Educational Resources Information Center

The purpose of this paper is to develop different guided writing strategies based on media richness theory and further evaluate the effects of these writing strategies on younger students' writing attitudes in terms of motivation, enjoyment and anxiety. A total of 66 sixth-grade elementary students with an average age of twelve were invited to…

Lan, Yu-Feng; Hung, Chun-Ling; Hsu, Hung-Ju

2011-01-01

274

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

275

Leadership with inner meaning: A contingency theory of leadership based on the worldviews of five religions  

Microsoft Academic Search

The purpose of this article is to create the foundation for a contingency theory of leadership based on the inner values and worldviews of five major religious traditions: Islam, Christianity, Judaism, Hinduism and Buddhism. The article identifies similarities and differences in the implicit leadership models among these five religious traditions. It further explores the implications of this model for organizational

Mark Kriger; Yvonne Seng

2005-01-01

276

preprint --preprint --preprint --preprint --preprint A limiter based on kinetic theory  

E-print Network

preprint -- preprint -- preprint -- preprint -- preprint A limiter based on kinetic theory Mapundi for the incompressible Euler equation is derived. In section 4 we concentrate on the derivation of the discretization will not specify the complete structure of the collision operator J(f). Only those properties which are important

Junk, Michael

277

Revisiting Transactional Distance Theory in a Context of Web-Based High-School Distance Education  

ERIC Educational Resources Information Center

The purpose of this paper is to report on a study that provided an opportunity to consider Transactional Distance Theory (TDT) in a current technology context of web-based learning in distance education (DE), high-school classrooms. Data collection relied on semi-structured interviews conducted with 22 e-teachers and managers in Newfoundland and…

Murphy, Elizabeth Anne; Rodriguez-Manzanares, Maria Angeles

2008-01-01

278

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

279

Evidence-Based Practice in Kinesiology: The Theory to Practice Gap Revisited  

ERIC Educational Resources Information Center

As evidence-based practice sweeps the applied health professions, it is a good time to evaluate the generation of knowledge in Kinesiology and its transmission to professionals and the public. Knowledge transmission has been debated in the past from the perspectives of the theory-to-practice gap and the discipline versus profession emphasis.…

Knudson, Duane

2005-01-01

280

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

281

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

282

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

283

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

284

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

285

Evaluating of TRB stamping process plans based on theory of fuzzy set barycenter  

Microsoft Academic Search

Generalizing tailor rolled blank applied in panels is one of efficient approach for automobile realizing lightweight, the stamping process plans based on general blank are affirmed even depending on experience, the uncertainty of plans decision making must greatly boost up if TRB will be applied in panels. Theory of fuzzy set barycenter was put forward to decision make plans in

Jitao Du; Yanhua Li; Hongbin Fei

2009-01-01

286

From Theory to Practice: Concept-Based Inquiry in a High School Art Classroom  

ERIC Educational Resources Information Center

This study examines what an emerging educational theory looks like when put into practice in an art classroom. It explores the teaching methodology of a high school art teacher who has utilized concept-based inquiry in the classroom to engage his students in artmaking and analyzes the influence this methodology has had on his adolescent students.…

Walker, Margaret A.

2014-01-01

287

Enhancing Student Motivation: A Longitudinal Intervention Study Based on Future Time Perspective Theory  

ERIC Educational Resources Information Center

The authors investigated the effects of an intervention developed to enhance student motivation in the first years of secondary education. The intervention, based on future time perspective (FTP) theory, has been found to be effective in prevocational secondary education (T. T. D. Peetsma & I. Van der Veen, 2008, 2009). The authors extend the…

Schuitema, Jaap; Peetsma, Thea; van der Veen, Ineke

2014-01-01

288

Nonlinear scattering based imaging in elastic media: Theory, theorems, and imaging conditions  

E-print Network

Nonlinear scattering based imaging in elastic media: Theory, theorems, and imaging conditions recording devices in land and marine ocean-bottom seismic ac- quisition, elastic imaging may become mainstream in coming years. We have derived new, nonlinear, elastic imaging condi- tions. A correlation

289

On Robustness of the Normal-Theory Based Asymptotic Distributions of Three Reliability Coefficient Estimates.  

ERIC Educational Resources Information Center

Examined the asymptotic distributions of three reliability coefficient estimates: (1) sample coefficient alpha; (2) reliability estimate of a composite score following factor analysis; and (3) maximal reliability of a linear combination of item scores after factor analysis. Findings show that normal theory based asymptotic distributions for these…

Yuan, Ke-Hai; Bentler, Peter M.

2002-01-01

290

Examining Instruction in MIDI-Based Composition through a Critical Theory Lens  

ERIC Educational Resources Information Center

This paper considers the issue of computer-assisted composition in formal music education settings from the perspective of critical theory. The author examines the case of MIDI-based software applications and suggests that the greatest danger from the standpoint of ideology critique is not the potential for circumventing a traditional…

Louth, Paul

2013-01-01

291

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

292

Nonlinear disturbance attenuation excitation control of structure preserving power systems based on Hamiltonian theory  

Microsoft Academic Search

A novel nonlinear disturbance attenuation control scheme based on Hamiltonian theory for the solution of structure preserving multi-machine power systems is proposed in this paper. The dissipative Hamiltonian realization of structure preserving power system is completed using the singular perturbation approach in which the algebraic equations are treated as a limit of fast dynamics; moreover, a nonlinear disturbance attenuation excitation

Jin Hao; Libao Shi; Jie Wang; Chen Chen

2005-01-01

293

Pattern memory analysis based on stability theory of cellular neural networks  

E-print Network

Pattern memory analysis based on stability theory of cellular neural networks Zhigang Zeng a,*, De-dimensional cellular neural network can have even (62n ) memory patterns. In addition, the estimations of attractive rights reserved. Keywords: Stability; Pattern memory; Cellular neural networks; Isolated equilibrium

Hefei Institute of Intelligent Machines

294

Preparing Students for Education, Work, and Community: Activity Theory in Task-Based Curriculum Design  

ERIC Educational Resources Information Center

This case study describes how sociocultural and activity theory were applied in the design of a publicly funded, Canadian Language Benchmark (CLB)-based English as a Second Language (ESL) credential program and curriculum for immigrant and international students in postsecondary institutions in British Columbia, Canada. The ESL Pathways Project…

Campbell, Chris; MacPherson, Seonaigh; Sawkins, Tanis

2014-01-01

295

Applying Unidimensional and Multidimensional Item Response Theory Models in Testlet-Based Reading Assessment  

ERIC Educational Resources Information Center

This study examined the relative effectiveness of the multidimensional bi-factor model and multidimensional testlet response theory (TRT) model in accommodating local dependence in testlet-based reading assessment with both dichotomously and polytomously scored items. The data used were 14,089 test-takers' item-level responses to the…

Min, Shangchao; He, Lianzhen

2014-01-01

296

Fuzzy Group Decision Making Model Based on Credibility Theory and Gray Relative Degree  

Microsoft Academic Search

In this paper, the problems of fuzzy multi-attribute group decision making in which the attribute values are given in the form of linguistic fuzzy numbers are studied. First of all, a new method called fuzzy dominance is given for ranking trapezoidal fuzzy numbers based on the credibility theory. Then the TOWA operator is presented to aggregate the trapezoidal fuzzy numbers.

Congjun Rao; Jin Peng

2009-01-01

297

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

298

Cascaded Multilevel Converter based DSTATCOM using p-q theory with DC link voltage balancing  

Microsoft Academic Search

This paper presents the p-q theory based DSTATCOM for reactive power management to control the power factor in a distribution system which serves resistance-reactance loads. Power factor which is one of the measures of power quality in a distribution system plays an important role in the optimal operation of the power system. The active management of reactive power proposed here

K. Anuradha; B. P. Muni; A. D. Raj Kumar

2011-01-01

299

Facial Expression Recognition Based on The Belief Theory: Comparison With Different Classifiers  

E-print Network

Facial Expression Recognition Based on The Belief Theory: Comparison With Different Classifiers Z of facial expression recognition, its performances are compared with those of more classical approaches is analysed for recognition of facial expressions. First, the contours of facial features are automatically

Dupont, Stéphane

300

A Case Study of Institutional Reform Based on Innovation Diffusion Theory through Instructional Technology.  

ERIC Educational Resources Information Center

Explains the Training, Infrastructure and Empowerment System (TIES), a theory-based system of educational reform through instructional technology, and discusses results of a study at a Canadian university that investigated the vision for instructional technology, learning technologies and alternative delivery systems, and adoption of innovation.…

Szabo, Michael; Sobon, Sonia A.

2003-01-01

301

Globally convergent approach based on chaotic theory for underwater robot motor optimization  

Microsoft Academic Search

Based on the property analysis of chaotic theory, an chaos optimization algorithm is proposed to solve nonlinear constraint optimization design of underwater robot motor by the use of properties of ergodicity, randomicity and regularity of chaotic motion, which can enhance the speed of global convergence and improve the accuracy of solution. The mathematical model of robot motor is set up.

Chen Zhifei; Shi Hongyan; An Yuejun; Sun Changzhi

2003-01-01

302

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

303

The Idea of National HRD: An Analysis Based on Economics and Theory Development Methodology  

ERIC Educational Resources Information Center

Recent human resource development (HRD) literature focuses attention on national HRD (NHRD) research and represents problems in both HRD identity and research methodology. Based on a review of development economics and international development literature, this study analyzes the existing NHRD literature with respect to the theory development…

Wang, Greg G.; Swanson, Richard A.

2008-01-01

304

Research on Web2.0 System Design Based on CAS Theory  

NASA Astrophysics Data System (ADS)

According to complexity theory, this paper analyses several characteristics of some present Web2.0 systems, such as Blog, Wiki, SNS and social tags. It also summarizes the disadvantages of current information system design methods and finally re-designs it based on CAS and DSDM.

Chen, Kai; Wang, Hengshan

305

SVM based Identification and Classification Schizophrenia from EEG using Graph Theory  

Microsoft Academic Search

Electroencephalogram is a reliable reflection of many physiological factors modulating the brain. Schizophrenia is a universal brain disorder with largely genetic aetiology. Schizophrenia being a networking problem with in brain requires a network based approach for analysis and identification. In this work, graph theory approach is used to get parameters like connection density, complexity, characteristic path length, cluster index are

M. Kiran Kumar; D. Narayana Dutt

306

Item Response Theory with Estimation of the Latent Population Distribution Using Spline-Based Densities  

ERIC Educational Resources Information Center

The purpose of this paper is to introduce a new method for fitting item response theory models with the latent population distribution estimated from the data using splines. A spline-based density estimation system provides a flexible alternative to existing procedures that use a normal distribution, or a different functional form, for the…

Woods, Carol M.; Thissen, David

2006-01-01

307

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.

308

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

309

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

310

Supporting Self-Regulated Personalised Learning through Competence-Based Knowledge Space Theory  

ERIC Educational Resources Information Center

This article presents two current research trends in e-learning that at first sight appear to compete. Competence-Based Knowledge Space Theory (CBKST) provides a knowledge representation framework which, since its invention by Doignon & Falmagne, has been successfully applied in various e-learning systems (for example, Adaptive Learning with…

Steiner, Christina M.; Nussbaumer, Alexander; Albert, Dietrich

2009-01-01

311

Flocking task research for multiple mobile robots based on game theory  

Microsoft Academic Search

It established multi-objective optimal mathematic model and did research on solving methods based on game theory. First, n robots specified n players. Second, it decomposed the design variables set and took the design variables set of paths which belonged to each robot as strategy space of the corresponding players. Third, it established mapping relationships between payoff functions and objective functions

Yuwan Cen; Ye Ye; Nenggang Xie; Jiahan Bao; Chongzhi Song

2008-01-01

312

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

313

Glacier mapping based on rough set theory in the Manas River watershed  

NASA Astrophysics Data System (ADS)

Precise glacier information is important for assessing climate change in remote mountain areas. To obtain more accurate glacier mapping, rough set theory, which can deal with vague and uncertainty information, was introduced to obtain optimal knowledge rules for glacier mapping. Optical images, thermal infrared band data, texture information and morphometric parameters were combined to build a decision table used in our proposed rough set theory method. After discretizing the real value attributes, decision rules were calculated through the decision rule generation algorithm for glacier mapping. A decision classifier based on the generated rules classified the multispectral image into glacier and non-glacier areas. The result of maximum likelihood classification (MLC) was used to compare with the result of the classification based on the rough set theory. Confusion matrix and visual interpretation were used to evaluate the overall accuracy of the results of the two methods. The accuracies of the rough set method and maximum likelihood classification were compared, yielding overall accuracies of 94.15% and 93.88%, respectively. It showed the area difference based on rough set was smaller by comparing the glacier areas of the rough set method and MLC with visual interpreter, respectively. The high accuracy for glacier mapping and the small area difference for glacier based on rough set theory demonstrated that this method was effective and promising for glacier mapping.

Yan, Lili; Wang, Jian; Hao, Xiaohua; Tang, Zhiguang

2014-04-01

314

Trajectory generation for aircraft based on differential flatness and spline theory  

Microsoft Academic Search

An efficient approach based on differential flatness and spline theory for the aircraft trajectory generation in the target area is proposed. It is well known that the traditional feedback control approach frequently fails for a large class of nonlinear mechanical systems with constraints. The aircraft dynamics system is a nonlinear system restrained by the nonholonomic constraints, dynamic constraints, etc., where

Chaojie Zhang; Nan Wang; Jing Chen

2010-01-01

315

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

316

The Resource-Based Theory of the Firm and Firm Survival  

Microsoft Academic Search

This paper examines the determinants of firm survival. We use hazard models to test a number of hypotheses mainly drawn from\\u000a the Resource-Based Theory of the Firm. According to the Resource-Based View the ability of a firm to develop distinct capabilities\\u000a enhances its ability to adapt to the changing competitive environment and improves its survival prospects. The results confirm\\u000a that

Silviano Esteve-Pérez; Juan A. Mañez-Castillejo

2008-01-01

317

Stamping process modeling of auto-body panel based on hierarchical polychromatic sets theory  

Microsoft Academic Search

Based on analysis of auto-body panelpsilas stamping process characteristics and feature classification, a stamping process information model of auto-body panel is established by using hierarchical polychromatic sets theory. The complex process information of auto-body panel can be described formally in the model. Based on the model, the system framework and flow of stamping CAPP for auto-body panel are presented.

Zhao Liping; Liu Chuanwei; Li Zongbin; Yao Yiyong

2008-01-01

318

A Decision Making Model Based on Dempster-Shafer Theory and Linguistic Hybrid Aggregation Operators  

Microsoft Academic Search

The solving processes for decision making problems based on the use of the Dempster-Shafer (D-S) theory can be accomplished in different ways according to the necessities of each single problem. In this contribution we present a decision making scheme based on the D-S defined in a linguistic framework and then, we propose the use of an hybrid averaging operator (2-THA)

José M. Merigó; Montserrat Casanovas; Luis Martínez

2008-01-01

319

Testbed for wireless vehicle communication: a simulation approach based on three-phase traffic theory  

Microsoft Academic Search

A testbed for wireless vehicle communication based on a microscopic model in the framework of three-phase traffic theory is presented. In this testbed, vehicle motion in traffic flow and analyses of a vehicle communication channel access based on IEEE 802.11e mechanisms, radio propagation modeling, message reception characteristics as well as all other effects associated with ad-hoc networks are integrated into

B. S. Kerner; S. L. Klenov; A. Brakemeier

2008-01-01

320

Testbed for Wireless Vehicle Communication: a Simulation Approach based on Three-Phase Traffic Theory  

Microsoft Academic Search

A testbed for wireless vehicle communication based on a microscopic model in the framework of three-phase traffic theory is presented. In this testbed, vehicle motion in traffic flow and analyses of a vehicle communication channel access based on IEEE 802.11e mechanisms, radio propagation modeling, message reception characteristics as well as all other effects associated with ad-hoc networks are integrated into

B. S. Kerner; S. L. Klenov; A. Brakemeier

2007-01-01

321

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

PubMed

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

2012-01-01

322

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

323

Technical Report: Efficient Buffering and Scheduling for a Single-Chip Crosspoint-Queued Switch  

E-print Network

-based services such as social networking and video streaming have brought about a continuous, exponential growth in Internet traffic. The boom in smartphones, tablets and other portable electronic devices has made all

Panwar, Shivendra S.

324

Efficient Buffering and Scheduling for a Single-Chip Crosspoint-Queued Switch  

E-print Network

In the past decade, modern Internet-based services such as social networking, video streaming and cloud in smartphones, tablets and other portable electronic de- vices has made all these remote services more

Panwar, Shivendra S.

325

ACM INTERNET MEASUREMENT CONFERENCE 2004 1 Constraint-Based Geolocation of Internet Hosts  

E-print Network

of adopted landmarks. In contrast, we propose Constraint- Based Geolocation (CBG), which infers- cluding queuing delays and the absence of great-circle paths between hosts. CBG accurately transforms the geolocation of the target host. Our experimental results show that CBG outperforms the pre- vious measurement

Crovella, Mark

326

Performance Characterization of IP Network-based Control Methodologies for DC Motor Applications Part I  

E-print Network

scheduling middleware (GSM), optimal stochastic methodology, queuing methodology, and robust controlPerformance Characterization of IP Network-based Control Methodologies for DC Motor Applications ­ Part I Tyler Richards Mo-Yuen Chow Advanced Diagnosis Automation and Control Lab Advanced Diagnosis

Chow, Mo-Yuen

327

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

328

A method for calculating strain energy release rate based on beam theory  

NASA Technical Reports Server (NTRS)

The Timoshenko beam theory was used to model cracked beams and to calculate the total strain energy release rate. The root rotation of the beam segments at the crack tip were estimated based on an approximate 2D elasticity solution. By including the strain energy released due to the root rotations of the beams during crack extension, the strain energy release rate obtained using beam theory agrees very well with the 2D finite element solution. Numerical examples were given for various beam geometries and loading conditions. Comparisons with existing beam models were also given.

Sun, C. T.; Pandey, R. K.

1993-01-01

329

Improved method for calculating strain energy release rate based on beam theory  

NASA Technical Reports Server (NTRS)

The Timoshenko beam theory was used to model cracked beams and to calculate the total strain-energy release rate. The root rotations of the beam segments at the crack tip were estimated based on an approximate two-dimensional elasticity solution. By including the strain energy released due to the root rotations of the beams during crack extension, the strain-energy release rate obtained using beam theory agrees very well with the two-dimensional finite element solution. Numerical examples were given for various beam geometries and loading conditions. Comparisons with existing beam models were also given.

Sun, C. T.; Pandey, R. K.

1994-01-01

330

Learning control system design based on 2-D theory - An application to parallel link manipulator  

NASA Technical Reports Server (NTRS)

An approach to iterative learning control system design based on two-dimensional system theory is presented. A two-dimensional model for the iterative learning control system which reveals the connections between learning control systems and two-dimensional system theory is established. A learning control algorithm is proposed, and the convergence of learning using this algorithm is guaranteed by two-dimensional stability. The learning algorithm is applied successfully to the trajectory tracking control problem for a parallel link robot manipulator. The excellent performance of this learning algorithm is demonstrated by the computer simulation results.

Geng, Z.; Carroll, R. L.; Lee, J. D.; Haynes, L. H.

1990-01-01

331

FKWC-bases and geometrical identities for classical and quantum field theories in curved spacetime  

E-print Network

Fulling, King, Wybourne and Cummings (FKWC) have proposed to expand systematically the Riemann polynomials encountered in the context of field theories in curved spacetime on standard bases constructed from group theoretical considerations. They have also displayed such bases for scalar Riemann polynomials of order eight or less in the derivatives of the metric tensor and for tensorial Riemann polynomials of order six or less. Here we provide a slightly modified version of the FKWC-bases as well as an important list of geometrical relations we have used in recent works. These relations are independent of the dimension of spacetime. In our opinion, they are helpful to achieve quickly and easily, by hand, very tedious calculations as well as, of course, to provide irreducible expressions for all the results obtained. They could be very helpful to people working in gravitational physics and more particularly (i) to treat some aspects of the classical theory of gravitational waves such as the radiation reaction problem and (ii) to deal with regularization and renormalization of quantum field theories, of stochastic semiclassical gravity and of higher-order theories of gravity.

Yves Décanini; Antoine Folacci

2008-05-12

332

Comment on the consistency of truncated nonlinear integral equation based theories of freezing  

SciTech Connect

We report the results of two studies of aspects of the consistency of truncated nonlinear integral equation based theories of freezing: (i) We show that the self-consistent solutions to these nonlinear equations are unfortunately sensitive to the level of truncation. For the hard sphere system, if the Wertheim--Thiele representation of the pair direct correlation function is used, the inclusion of part but not all of the triplet direct correlation function contribution, as has been common, worsens the predictions considerably. We also show that the convergence of the solutions found, with respect to number of reciprocal lattice vectors kept in the Fourier expansion of the crystal singlet density, is slow. These conclusions imply great sensitivity to the quality of the pair direct correlation function employed in the theory. (ii) We show the direct correlation function based and the pair correlation function based theories of freezing can be cast into a form which requires solution of isomorphous nonlinear integral equations. However, in the pair correlation function theory the usual neglect of the influence of inhomogeneity of the density distribution on the pair correlation function is shown to be inconsistent to the lowest order in the change of density on freezing, and to lead to erroneous predictions.

Cerjan, C.; Bagchi, B.; Rice, S.A.

1985-09-01

333

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

334

Steady-state crack growth and fracture work based on the theory of mechanism-based strain gradient plasticity  

Microsoft Academic Search

Mode I steady-state crack growth is analyzed under plane strain conditions in small scale yielding. The elastic–plastic solid is characterized by the mechanism-based strain gradient (MSG) plasticity theory [J. Mech. Phys. Solids 47 (1999) 1239, J. Mech. Phys. Solids 48 (2000) 99]. The distributions of the normal separation stress and the effective stress along the plane ahead of the crack

Y. Wei; X. Qiu; K. C. Hwang

2004-01-01

335

Reference Frame Fields based on Quantum Theory Representations of Real and Complex Numbers  

E-print Network

A quantum theory representations of real (R) and complex (C) numbers is given that is based on states of single, finite strings of qukits for any base k > 1. Both unary representations and the possibility that qukits with k a prime number are elementary and the rest composite are discussed. Cauchy sequences of qukit string states are defined from the arithmetic properties. The representations of R and C, as equivalence classes of these sequences, differ from classical kit string state representations in two ways: the freedom of choice of basis states, and the fact that each quantum theory representation is part of a mathematical structure that is itself based on the real and complex numbers. These aspects enable the description of 3 dimensional frame fields labeled by different k values, different basis or gauge choices, and different iteration stages. The reference frames in the field are based on each R and C representation where each frame contains representations of all physical theories as mathematical structures based on the R and C representation. Approaches to integrating this with physics are described. It is observed that R and C values of physical quantities, matrix elements, etc. which are viewed in a frame as elementary and featureless, are seen in a parent frame as equivalence classes of Cauchy sequences of qukit string states.

Paul Benioff

2008-03-05

336

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

337

A Theory-based Approach to the Measurement of Foreign Language Learning Ability: The CANAL-F Theory and Test.  

ERIC Educational Resources Information Center

Presents a rationale, description, and partial construct validation of a new theory of foreign language aptitude: CANAL-F--Cognitive Ability for Novelty in Acquisition of Language (foreign). The theory was applied and implemented in a test of foreign language aptitude (CANAL-FT). Outlines the CANAL-F theory and details of its instrumentation…

Grigorenko, Elena L.; Sternberg, Robert J.; Ehrman, Madeline E.

2000-01-01

338

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

339

Forcing a unitary transformation by an external field: comparing two approaches based on optimal control theory  

E-print Network

A quantum gate is realized by specific unitary transformations operating on states representing qubits. Considering a quantum system employed as an element in a quantum computing scheme, the task is therefore to enforce the pre-specified unitary transformation. This task is carried out by an external time dependent field. Optimal control theory has been suggested as a method to compute the external field which alters the evolution of the system such that it performs the desire unitary transformation. This study compares two recent implementations of optimal control theory to find the field that induces a quantum gate. The first approach is based on the equation of motion of the unitary transformation. The second approach generalizes the state to state formulation of optimal control theory. This work highlight the formal relation between the two approaches.

Jose P. Palao; Ronnie Kosloff

2002-08-24

340

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

341

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

342

Testbed for Wireless Vehicle Communication: a Simulation Approach based on Three-Phase Traffic Theory  

E-print Network

A testbed for wireless vehicle communication based on a microscopic model in the framework of three-phase traffic theory is presented. In this testbed, vehicle motion in traffic flow and analyses of a vehicle communication channel access based on IEEE 802.11e mechanisms, radio propagation modeling, message reception characteristics as well as all other effects associated with ad-hoc networks are integrated into a three-phase traffic flow model. Based on simulations of this testbed, some statistical features of ad-hoc vehicle networks as well as the effect of C2C communication on increase in the efficiency and safety of traffic are studied.

Kerner, B S; Brakemeier, A

2007-01-01

343

Employee Communication at a University-Based R & D Center: An Analysis Using Grunig's Theory of Communication Behavior.  

ERIC Educational Resources Information Center

About 80% of the 282 employees at a university-based educational research and development center completed questionnaires based on J.E. Grunig's theory of communication behavior in a study to define communication types, discover communication patterns, and make recommendations for improving the center's communication program. Grunig's theory

Schneider, Larissa J.

344

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

Microsoft Academic Search

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

Joyce H Keyak; Stephen A Rossi

2000-01-01

345

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

346

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

347

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

348

Buckling analysis of functionally graded nanobeams based on a nonlocal third-order shear deformation theory  

NASA Astrophysics Data System (ADS)

In this paper, a general third-order beam theory that accounts for nanostructure-dependent size effects and two-constituent material variation through the nanobeam thickness, i.e., functionally graded material (FGM) beam is presented. The material properties of FG nanobeams are assumed to vary through the thickness according to the power law. A detailed derivation of the equations of motion based on Eringen nonlocal theory using Hamilton's principle is presented, and a closed-form solution is derived for buckling behavior of the new model with various boundary conditions. The nonlocal elasticity theory includes a material length scale parameter that can capture the size effect in a functionally graded material. The proposed model is efficient in predicting the shear effect in FG nanobeams by applying third-order shear deformation theory. The proposed approach is validated by comparing the obtained results with benchmark results available in the literature. In the following, a parametric study is conducted to investigate the influences of the length scale parameter, gradient index, and length-to-thickness ratio on the buckling of FG nanobeams and the improvement on nonlocal third-order shear deformation theory comparing with the classical (local) beam model has been shown. It is found out that length scale parameter is crucial in studying the stability behavior of the nanobeams.

Rahmani, O.; Jandaghian, A. A.

2015-03-01

349

NAP: An Agent-based Scheme on Reducing Churn-Induced Delays for P2P Live Fei Huang, Binoy Ravindran, Maleq Khan  

E-print Network

NAP: An Agent-based Scheme on Reducing Churn-Induced Delays for P2P Live Streaming Fei Huang, Binoy-based P2P streaming scheme, called NAP, which reduces churn-induced delays. We first formulate methodology of NAP. In addition, we develop a queuing model for the P2P streaming scenario and analyze

Ravindran, Binoy

350

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

351

On the Foundations of the Theory of a new Collatz Based Number System  

E-print Network

Set out here are some fundamental theories that may be regarded as newly discovered metamathematics of the odd integers in relation to the Collatz conjecture (also called the 3x+1 problem). Originally motivated by the requirement to invent a new optimised integer factorisation method, this foundational paper primarily focuses on the foundation, formalisation and presentation of a new theoretical framework (schema or blueprint) of a Collatz based number system. The proposed framework is based on metamathematical theories meticulously derived through iterative analyses and reverse engineering (i.e., by hand and mathematical computations) of many large subsets of integers. A collation of the fundamental results from these analytical attempts has led to the establishment of a completely deterministic model of a generalised Collatz based number system that is fundamentally and strangely associated with nonchaotic patterns. The proposed Collatz based number schema comprises of both visual and theoretical representations of many hidden patterns in Collatz sequences yet to be reported in literature. This novel theoretical approach may be viewed as a new method to contemporary Collatz conjecture research which may be connected to the proofs of many other mathematical theorems in number theory and discrete mathematics.

Michael A. Idowu

2015-03-18

352

On the Foundations of the Theory of a new Collatz Based Number System  

E-print Network

Set out here are some fundamental theories that may be regarded as newly discovered metamathematics of the odd integers in relation to the Collatz conjecture (also called the 3x+1 problem). Originally motivated by the requirement to invent a new optimised integer factorisation method, this foundational paper primarily focuses on the foundation, formalisation and presentation of a new theoretical framework (schema or blueprint) of a Collatz based number system. The proposed framework is based on metamathematical theories meticulously derived through iterative analyses and reverse engineering (i.e., by hand and mathematical computations) of many large subsets of integers. A collation of the fundamental results from these analytical attempts has led to the establishment of a completely deterministic model of a generalised Collatz based number system that is fundamentally and strangely associated with nonchaotic patterns. The proposed Collatz based number schema comprises of both visual and theoretical representations of many hidden patterns in Collatz sequences yet to be reported in literature. This novel theoretical approach may be viewed as a new method to contemporary Collatz conjecture research which may be connected to the proofs of many other mathematical theorems in number theory and discrete mathematics.

Michael A. Idowu

2015-03-12

353

The Circuit Theory Behind Coupled-Mode Magnetic Resonance-Based Wireless Power Transmission.  

PubMed

Inductive coupling is a viable scheme to wirelessly energize devices with a wide range of power requirements from nanowatts in radio frequency identification tags to milliwatts in implantable microelectronic devices, watts in mobile electronics, and kilowatts in electric cars. Several analytical methods for estimating the power transfer efficiency (PTE) across inductive power transmission links have been devised based on circuit and electromagnetic theories by electrical engineers and physicists, respectively. However, a direct side-by-side comparison between these two approaches is lacking. Here, we have analyzed the PTE of a pair of capacitively loaded inductors via reflected load theory (RLT) and compared it with a method known as coupled-mode theory (CMT). We have also derived PTE equations for multiple capacitively loaded inductors based on both RLT and CMT. We have proven that both methods basically result in the same set of equations in steady state and either method can be applied for short- or midrange coupling conditions. We have verified the accuracy of both methods through measurements, and also analyzed the transient response of a pair of capacitively loaded inductors. Our analysis shows that the CMT is only applicable to coils with high quality factor (Q) and large coupling distance. It simplifies the analysis by reducing the order of the differential equations by half compared to the circuit theory. PMID:24683368

Kiani, Mehdi; Ghovanloo, Maysam

2012-09-01

354

Query Shifting Based on Bayesian Decision Theory for Content-Based Image Retrieval  

Microsoft Academic Search

Despite the efforts to reduce the so-called semantic gap between the user s perception of image similarity and feature-based representation of images, the interaction with the user remains fundamental to improve performances of content-based image retrieval systems. To this end, relevance feedback mechanisms are adopted to refine image-based queries by asking users to mark the set of images retrieved in

Giorgio Giacinto; Fabio Roli

2002-01-01

355

Agent-based modeling: a new approach for theory building in social psychology.  

PubMed

Most social and psychological phenomena occur not as the result of isolated decisions by individuals but rather as the result of repeated interactions between multiple individuals over time. Yet the theory-building and modeling techniques most commonly used in social psychology are less than ideal for understanding such dynamic and interactive processes. This article describes an alternative approach to theory building, agent-based modeling (ABM), which involves simulation of large numbers of autonomous agents that interact with each other and with a simulated environment and the observation of emergent patterns from their interactions. The authors believe that the ABM approach is better able than prevailing approaches in the field, variable-based modeling (VBM) techniques such as causal modeling, to capture types of complex, dynamic, interactive processes so important in the social world. The article elaborates several important contrasts between ABM and VBM and offers specific recommendations for learning more and applying the ABM approach. PMID:18453457

Smith, Eliot R; Conrey, Frederica R

2007-02-01

356

A theory-based logic model for innovation policy and evaluation.  

SciTech Connect

Current policy and program rationale, objectives, and evaluation use a fragmented picture of the innovation process. This presents a challenge since in the United States officials in both the executive and legislative branches of government see innovation, whether that be new products or processes or business models, as the solution to many of the problems the country faces. The logic model is a popular tool for developing and describing the rationale for a policy or program and its context. This article sets out to describe generic logic models of both the R&D process and the diffusion process, building on existing theory-based frameworks. Then a combined, theory-based logic model for the innovation process is presented. Examples of the elements of the logic, each a possible leverage point or intervention, are provided, along with a discussion of how this comprehensive but simple model might be useful for both evaluation and policy development.

Jordan, Gretchen B.

2010-04-01

357

Attachment-based family therapy for depressed and suicidal adolescents: theory, clinical model and empirical support.  

PubMed

Attachment-Based Family Therapy (ABFT) is a manualized family-based intervention designed for working with depressed adolescents, including those at risk for suicide, and their families. It is an empirically informed and supported treatment. ABFT has its theoretical underpinnings in attachment theory and clinical roots in structural family therapy and emotion focused therapies. ABFT relies on a transactional model that aims to transform the quality of adolescent-parent attachment, as a means of providing the adolescent with a more secure relationship that can support them during challenging times generally, and the crises related to suicidal thinking and behavior, specifically. This article reviews: (1) the theoretical foundations of ABFT (attachment theory, models of emotional development); (2) the ABFT clinical model, including training and supervision factors; and (3) empirical support. PMID:25778674

Ewing, E Stephanie Krauthamer; Diamond, Guy; Levy, Suzanne

2015-04-01

358

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

359

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

360

Dynamic stability of laminated FGM plates based on higher-order shear deformation theory  

Microsoft Academic Search

This paper conducts a dynamic stability analysis of symmetrically laminated FGM rectangular plates with general out-of-plane supporting conditions, subjected to a uniaxial periodic in-plane load and undergoing uniform temperature change. Theoretical formulations are based on Reddy’s third-order shear deformation plate theory, and account for the temperature dependence of material properties. A semi-analytical Galerkin-differential quadrature approach is employed to convert the

J. Yang; K. M. Liew; S. Kitipornchai

2004-01-01

361

An optimization of frame structures with exact dynamic constraints based on Timoshenko beam theory  

NASA Astrophysics Data System (ADS)

Sensitivity analyses of eigensolutions and eigenfunctions of 3-D frame structures using the exact frequency equation from the transfer dynamic stiffness matrix that was derived on Timoshenko beam theory were developed in this paper. Based on the sensitivity data of frame structures, the minimum weight design with an exact frequency constraint can be carried out efficiently. Three examples that demonstrated the results obtained by the proposed method, are in good agreement with those computed by ANSYS.

Yu, Jen-Fang; Wang, B. P.

2004-01-01

362

A tennis serve and upswing learning robot based on bi-directional theory  

Microsoft Academic Search

We experimented on task-level robot learning based on bi-directional theory. The via-point representation was used for 'learning by watching'. In our previous work, we had a robot learn kendama (a Japanese game) in order to demonstrate a single simple task. Our approach can be applied to a wide variety of motor behavior. However, some difficulties still remain. In this paper,

Hiroyuki Miyamoto; Mitsuo Kawato

1998-01-01

363

Gradient and fracture energy-based plasticity theory for quasi-brittle materials like concrete  

Microsoft Academic Search

In this work a thermodynamically consistent non-local gradient and fracture energy-based plasticity theory is proposed to simulate the failure behavior of concrete. The model incorporates two characteristic lengths, one due to the microcrack opening process and the other due to the non-local degradation process of the continuum in between cracks. The failure behavior of quasi-brittle materials like concrete is controlled

S. M. Vrech; G. Etse

2009-01-01

364

Accumulation characteristics of heavy metal Pb, Cu, Zn in Wanggang tidal flat based on Renyi theory  

Microsoft Academic Search

The vertical accumulation of heavy metals and the pollution status in Wanggang China tidal flat were studied. The base value of 210Pb in Wanggang area was obtained as 1.16 dpm\\/g. The fractal theories were led into the quantitative study of pollution issues. The modern average deposition rate in Wanggang area is 4.13 cm\\/a, according to the 210Pb analysis. Through the

Wenjin Yu; Xinqing Zou; Dakui Zhu

2007-01-01

365

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

366

A thermomechanical analysis of laminated metal matrix composites using the viscoplasticity theory based on overstress  

Microsoft Academic Search

The present use of the vanishing fiber-diameter model and the unified theory of thermoviscoplasticity based on overstress to analyze the thermomechanical behavior of angle-ply composite laminates assumes that the fiber and matrix are stress-free at the manufacturing temperature, and that they remain perfectly bonded during cooldown. This assumption allows the model to calculate residual stresses between fiber and matrix that

Nan-Ming Yeh; Erhard Krempl

1991-01-01

367

Local Realistic Theory for PDC Experiments Based on the Wigner Formalism  

E-print Network

In this article we present a local hidden variables model for all experiments involving photon pairs produced in parametric down conversion, based on the Wigner representation of the radiation field. A modification of the standard quantum theory of detection is made in order to give a local realist explanation of the counting rates in photodetectors. This model involves the existence of a real zeropoint field, such that the vacumm level of radiation lies below the threshold of the detectors.

Casado, A; Santos, E; Casado, Alberto; Risco-Delgado, Ramon; Santos, Emilio

2001-01-01

368

Local Realistic Theory for PDC Experiments Based on the Wigner Formalism  

E-print Network

In this article we present a local hidden variables model for all experiments involving photon pairs produced in parametric down conversion, based on the Wigner representation of the radiation field. A modification of the standard quantum theory of detection is made in order to give a local realist explanation of the counting rates in photodetectors. This model involves the existence of a real zeropoint field, such that the vacumm level of radiation lies below the threshold of the detectors.

Alberto Casado; Ramon Risco-Delgado; Emilio Santos

2001-03-09

369

Generalized constitutive relations for metamaterials based on the quasi-static Lorentz theory  

Microsoft Academic Search

This paper presents a method of calculating the elements of the generalized matrix representation of the macroscopic constitutive relations for a three-dimensional (3-D) array of non-magnetic inclusions with arbitrary shape. The derivation is based on the quasi-static Lorentz theory and the inclusions are represented by electric and magnetic dipole moments. The 6×6 constitutive relation matrix is expressed in terms of

Akira Ishimaru; Seung-Woo Lee; Yasuo Kuga; Vikram Jandhyala

2003-01-01

370

E-learning adoption intention and its key influence factors based on innovation adoption theory  

Microsoft Academic Search

This paper, from innovation adoption perspective, investigates people’s perceptions and attitudes toward adopting e-learning to explore the key factors affecting the e-learning adoption behavior in China. Based on Rogers’ innovation adoption theory, 33 factors of perceived innovative attributes will be quantificationally analysed to test the relationship between the perceived innovative attributes and adoption intention of e-learning by an analytic hierarchy

Lingxian Zhang; Haojie Wen; Daoliang Li; Zetian Fu; Shuang Cui

2010-01-01

371

An improved game theory based approach to one type of H-infinity optimal control problems  

Microsoft Academic Search

In this paper we convert H-infinity optimal control problems with linear quadratic objective functions to a regular optimal regulator problem by improving a game theory based approach (Basar and Bernhard, 1991), in which the critical lambdainfin* plays a key role. An alternative and optimal-control-related method of theoretically defining lambdacirc is presented. Instead of solving the H-infinity problem, we solve a

Dan Shen

2006-01-01

372

A fast algorithm for attribute reduction based on Trie tree and rough set theory  

NASA Astrophysics Data System (ADS)

Attribute reduction is an important issue in rough set theory. Many efficient algorithms have been proposed, however, few of them can process huge data sets quickly. In this paper, combining the Trie tree, the algorithms for computing positive region of decision table are proposed. After that, a new algorithm for attribute reduction based on Trie tree is developed, which can be used to process the attribute reduction of large data sets quickly. Experiment results show its high efficiency.

Hu, Feng; Wang, Xiao-yan; Luo, Chuan-jiang

2013-03-01

373

Towards an evidence base of theory-driven evaluations: Some questions for proponents of theory-driven evaluation  

Microsoft Academic Search

This article discusses the further development of theory-driven evaluation approaches that are informed by contribution analysis. Using an illustrative example of an ongoing dance\\/physical activity programme for health promotion, a number of challenges are identified when applying a theory-driven evaluation approach. These challenges are reformulated as questions that need to be answered to make further progress with theory-driven evaluation including

Sanjeev Sridharan; April Nakaima

2012-01-01

374

Noise theory of dc nano-SQUIDs based on Dayem nanobridges  

NASA Astrophysics Data System (ADS)

In the recent years, nanoscale superconducting quantum interference devices (nano-SQUIDs) played a fundamental role in the study of small spin systems. Nano-SQUIDs typically employ nano-Dayem bridges having dimensions (length L and/or width W) greater than coherence length ? of the superconducting film. They exhibit characteristics different from those of standard SQUIDs because the current-phase relationship (CPR) is nonsinusoidal, rendering most of the theoretical predictions based on the standard SQUID theory usually unreliable. Here, we present a noise theory of dc nano-SQUIDs based on Dayem nanobridges. We have computed the main characteristics of this quantum device including current-voltage and voltage-magnetic flux characteristics, magnetic flux-to-voltage transfer factor, and spectral densities of voltage and magnetic flux noise for L/? ratios ranging from 1 (sinusoidal limit) to 3.5 (hysteretic limit). The CPRs have been computed by using the theory of Josephson weak links based on the Ginzburg-Landau equation. The results show a dependence of the magnetic flux noise spectral density on (L/?)4/3 involving a degradation of about a factor of five between the two extreme cases and are consistent with experimentally measured magnetic flux noises reported in the literature. These results provide useful information for both device physics and their applications.

Granata, C.; Vettoliere, A.; Russo, M.; Ruggiero, B.

2011-12-01

375

A basic introduction to large deviations: Theory, applications, simulations  

E-print Network

The theory of large deviations deals with the probabilities of rare events (or fluctuations) that are exponentially small as a function of some parameter, e.g., the number of random components of a system, the time over which a stochastic system is observed, the amplitude of the noise perturbing a dynamical system or the temperature of a chemical reaction. The theory has applications in many different scientific fields, ranging from queuing theory to statistics and from finance to engineering. It is also increasingly used in statistical physics for studying both equilibrium and nonequilibrium systems. In this context, deep analogies can be made between familiar concepts of statistical physics, such as the entropy and the free energy, and concepts of large deviation theory having more technical names, such as the rate function and the scaled cumulant generating function. The first part of these notes introduce the basic elements of large deviation theory at a level appropriate for advanced undergraduate and gr...

Touchette, Hugo

2011-01-01

376

A Research of Weapon System Storage Reliability Simulation Method Based on Fuzzy Theory  

NASA Astrophysics Data System (ADS)

Aimed at the problem of the new, complicated weapon equipment system storage reliability analyze, the paper researched on the methods of fuzzy fault tree analysis and fuzzy system storage reliability simulation, discussed the path that regarded weapon system as fuzzy system, and researched the storage reliability of weapon system based on fuzzy theory, provided a method of storage reliability research for the new, complicated weapon equipment system. As an example, built up the fuzzy fault tree of one type missile control instrument based on function analysis, and used the method of fuzzy system storage reliability simulation to analyze storage reliability index of control instrument.

Shi, Yonggang; Wu, Xuguang; Chen, Haijian; Xu, Tingxue

377

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

378

Value-at-risk estimation with wavelet-based extreme value theory: Evidence from emerging markets  

NASA Astrophysics Data System (ADS)

This paper introduces wavelet-based extreme value theory (EVT) for univariate value-at-risk estimation. Wavelets and EVT are combined for volatility forecasting to estimate a hybrid model. In the first stage, wavelets are used as a threshold in generalized Pareto distribution, and in the second stage, EVT is applied with a wavelet-based threshold. This new model is applied to two major emerging stock markets: the Istanbul Stock Exchange (ISE) and the Budapest Stock Exchange (BUX). The relative performance of wavelet-based EVT is benchmarked against the Riskmetrics-EWMA, ARMA-GARCH, generalized Pareto distribution, and conditional generalized Pareto distribution models. The empirical results show that the wavelet-based extreme value theory increases predictive performance of financial forecasting according to number of violations and tail-loss tests. The superior forecasting performance of the wavelet-based EVT model is also consistent with Basel II requirements, and this new model can be used by financial institutions as well.

Cifter, Atilla

2011-06-01

379

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

380

Development and exploratory cluster-randomised opportunistic trial of a theory-based intervention to enhance physical activity among adolescents  

Microsoft Academic Search

This article reports the development and exploratory testing of a school-based intervention programme designed to enhance levels of physical activity in adolescents. The intervention is based on social cognitive theory (SCT), self-regulation theory (SRT) and planning as evidence-based mediators of physical activity changes. Two classes, paired on socio-economic variables, were selected from each of eight Portuguese schools and randomly assigned

Vera Araújo-Soares; Teresa McIntyre; Graeme MacLennan; Falko F. Sniehotta

2009-01-01

381

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.

382

A Monte Carlo Comparison of Item and Person Statistics Based on Item Response Theory versus Classical Test Theory.  

ERIC Educational Resources Information Center

Examined the behavior of item and person statistics from item response theory and classical test theory frameworks through Monte Carlo methods with simulated test data. Findings suggest that item difficulty and person ability estimates are highly comparable for both approaches. (SLD)

MacDonald, Paul; Paunonen, Sampo V.

2002-01-01

383

Distinguishing Topical and Social Groups Based on Common Identity and Bond Theory  

E-print Network

Social groups play a crucial role in social media platforms because they form the basis for user participation and engagement. Groups are created explicitly by members of the community, but also form organically as members interact. Due to their importance, they have been studied widely (e.g., community detection, evolution, activity, etc.). One of the key questions for understanding how such groups evolve is whether there are different types of groups and how they differ. In Sociology, theories have been proposed to help explain how such groups form. In particular, the common identity and common bond theory states that people join groups based on identity (i.e., interest in the topics discussed) or bond attachment (i.e., social relationships). The theory has been applied qualitatively to small groups to classify them as either topical or social. We use the identity and bond theory to define a set of features to classify groups into those two categories. Using a dataset from Flickr, we extract user-defined gr...

Grabowicz, Przemyslaw A; Eguíluz, Víctor M; Jaimes, Alejandro

2013-01-01

384

Energy decomposition analysis based on a block-localized wavefunction and multistate density functional theory  

PubMed Central

An interaction energy decomposition analysis method based on the block-localized wavefunction (BLW-ED) approach is described. The first main feature of the BLW-ED method is that it combines concepts of valence bond and molecular orbital theories such that the intermediate and physically intuitive electron-localized states are variationally optimized by self-consistent field calculations. Furthermore, the block-localization scheme can be used both in wave function theory and in density functional theory, providing a useful tool to gain insights on intermolecular interactions that would otherwise be difficult to obtain using the delocalized Kohn–Sham DFT. These features allow broad applications of the BLW method to energy decomposition (BLW-ED) analysis for intermolecular interactions. In this perspective, we outline theoretical aspects of the BLW-ED method, and illustrate its applications in hydrogen-bonding and ?–cation intermolecular interactions as well as metal–carbonyl complexes. Future prospects on the development of a multistate density functional theory (MSDFT) are presented, making use of block-localized electronic states as the basis configurations. PMID:21369567

Bao, Peng

2013-01-01

385

A theory-based approach to understanding suicide risk in shelter-seeking women.  

PubMed

Women seeking shelter from intimate partner violence are at an increased risk for suicide ideation and attempts compared to women in the general population. Control-based violence, which is common among shelter-seeking women, may play a pivotal role in the development of suicide ideation and attempts. Current risk assessment and management practices for shelter-seeking women are limited by the lack of an empirically grounded understanding of increased risk in this population. We argue that in order to more effectively promote risk assessment and management, an empirically supported theory that is sensitive to the experiences of shelter-seeking women is needed. Such a theory-driven approach has the benefits of identifying and prioritizing targetable areas for intervention. Here, we review the evidence for the link between coercive control and suicide ideation and attempts from the perspective of Baumeister's escape theory of suicide. This theory has the potential to explain the role of coercive control in the development of suicide ideation and eventual attempts in shelter-seeking women. Implications for suicide risk assessment and prevention in domestic violence shelters are discussed. PMID:24415137

Wolford-Clevenger, Caitlin; Smith, Phillip N

2015-04-01

386

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

387

Three new branched chain equations of state based on Wertheim's perturbation theory  

NASA Astrophysics Data System (ADS)

In this work, we present three new branched chain equations of state (EOS) based on Wertheim's perturbation theory. The first represents a slightly approximate general branched chain solution of Wertheim's second order perturbation theory (TPT2) for athermal hard chains, and the second represents the extension of first order perturbation theory with a dimer reference fluid (TPT1-D) to branched athermal hard chain molecules. Each athermal branched chain EOS was shown to give improved results over their linear counterparts when compared to simulation data for branched chain molecules with the branched TPT1-D EOS being the most accurate. Further, it is shown that the branched TPT1-D EOS can be extended to a Lennard-Jones dimer reference system to obtain an equation of state for branched Lennard-Jones chains. The theory is shown to accurately predict the change in phase diagram and vapor pressure which results from branching as compared to experimental data for n-octane and corresponding branched isomers.

Marshall, Bennett D.; Chapman, Walter G.

2013-05-01

388

Creep behavior of beams using the viscoplasticity theory based on total strain and overstress  

SciTech Connect

The viscoplasticity theory based on total strain and overstress can reproduce rate-dependent inelastic deformation without distinction between plastic and creep strain using two material functions. A viscosity function and an equilibrium stress-strain curve characterize rate-dependency and work hardening, respectively. The theory is used to analyze the creep behavior of a beam subjected to a linearly increasing moment which is subsequently held constant. The analysis shows the existence of two possible states of equilibrium: termination of primary creep or secondary creep. They occur when the equilibrium stress-strain curve has positive or zero slope in the plastic strain range. The numerical experiments illustrate that the stress distribution at the end of the moment increase depends on the moment rate. The rate effects disappear with time when stress is redistributed. The equilibrium solution is obtained before 10/sup 7/ sec, when the material functions representing AISI Type 304 Stainless Steel at room temperature are used. The other equilibrium solution (secondary creep) is reached after primary creep when the constant moment is above the limiting equilibrium moment which corresponds to the plastic hinge moment of plasticity theory. The stress distribution during stationary creep is shown to be the solution corresponding to the Norton Law of creep theory.

Hiroe, T.; Krempl, E.

1982-01-01

389

Eight myths on motivating social services workers: theory-based perspectives.  

PubMed

A combination of factors has made formal motivational and reward systems rare in human service organizations generally and virtually non-existent in social service agencies. The author reviews eight of these myths by reference to eight motivational theories which refute them: need theory, expectancy theory, feedback theory, equity theory, reinforcement theory, cognitive evaluation theory, goal setting theory, and social influence theory. Although most of these theories have been developed and applied in the private sector, relevant research has also been conducted in social service agencies. The author concludes with a summary of guidelines suggested by the eight theories for motivating human service workers. PMID:10114292

Latting, J K

1991-01-01

390

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

391

A Spatial Load Forecasting Method Based on the Theory of Clustering Analysis  

NASA Astrophysics Data System (ADS)

The spatial load forecasting method based on time series analysis usually divides predictive zone into cellules, and then forecast the load of each cell based on time series analysis, to predict the whole spatial load. Now there are many prediction models based on time series analysis, but it is hard to realize the minimum of the prediction error for each cell, namely not guarantee the accuracy of results of spatial load forecasting. Thus, the spatial load forecasting method based on the theory of clustering analysis is proposed there. Firstly this method analyzes the results and the relative prediction error of each cell with different load forecasting model. Second, according to the best forecast models, cluster all cellules, which cellules in the same cluster use the same prediction model to forecast the load of cellules of the target year. The results of a practical example show that our method is correct and effective.

Bai, Xiao; Peng-wei, Guo; Gang, Mu; Gan-gui, Yan; Ping, Li; Hong-wei, Cheng; Jie-fu, Li; Yang, Bai

392

A methodology for computing uncertainty bounds of multivariable systems based on sector stability theory concepts  

NASA Technical Reports Server (NTRS)

The application of a sector-based stability theory approach to the formulation of useful uncertainty descriptions for linear, time-invariant, multivariable systems is explored. A review of basic sector properties and sector-based approach are presented first. The sector-based approach is then applied to several general forms of parameter uncertainty to investigate its advantages and limitations. The results indicate that the sector uncertainty bound can be used effectively to evaluate the impact of parameter uncertainties on the frequency response of the design model. Inherent conservatism is a potential limitation of the sector-based approach, especially for highly dependent uncertain parameters. In addition, the representation of the system dynamics can affect the amount of conservatism reflected in the sector bound. Careful application of the model can help to reduce this conservatism, however, and the solution approach has some degrees of freedom that may be further exploited to reduce the conservatism.

Waszak, Martin R.

1992-01-01

393

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.

Michael Kimmel

2007-12-12

394

Doubly special relativity theories as different bases of kappa-Poincaré algebra  

Microsoft Academic Search

Doubly Special Relativity (DSR) theory is a theory with two observer-independent scales, of velocity and mass (or length). Such a theory has been proposed by Amelino-Camelia as a kinematic structure which may underline quantum theory of relativity. Recently another theory of this kind has been proposed by Magueijo and Smolin. In this Letter we show that both these theories can

J. Kowalski-Glikmanand; S. Nowak

2002-01-01

395

What Does Endogenous Growth Theory Tell about Regional Economies? Empirics of R&D Worker-based Productivity Growth  

Microsoft Academic Search

Izushi H. What does endogenous growth theory tell about regional economies? Empirics of R&D worker-based productivity growth, Regional Studies. Endogenous growth theory emerged in the 1990s as ‘new growth theory’ accounting for technical progress in the growth process. This paper examines the role of research and development (R&D) workers underlying the Romer model (1990) and its subsequent modifications, and compares

Hiro Izushi

2008-01-01

396

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

397

Transient Heat Conduction in a Functionally Graded Cylindrical Panel Based on the Dual Phase Lag Theory  

NASA Astrophysics Data System (ADS)

The transient heat conduction in a functionally graded cylindrical panel is investigated based on the dual phase lag (DPL) theory in this article. Except for the phase lags which are assumed to be constant, all the other material properties of the panel are assumed to change continuously along the radial direction according to a power-law formulation with different non-homogeneity indices. The heat conduction equations based on the DPL theory in the cylindrical coordinate system are written in a general form which are then used for the analyses of four different geometries: (1) a hollow cylinder of an infinite length; (2) a hollow cylinder of a finite length; (3) a cylindrical panel of an infinite length; and (4) a cylindrical panel of a finite length. Using the Laplace transform, the analytical solutions for temperature and heat flux are obtained in the Laplace domain. The solutions are then converted into the time domain by employing the fast Laplace inversion technique. The exact expressions for the radial thermal wave speed are obtained for the four different geometries. The numerical results are displayed to reveal the effect of different approximations of the DPL theory on the temperature distribution for various non-homogeneity indices. The results are verified with those reported in the literature.

Akbarzadeh, A. H.; Chen, Z. T.

2012-06-01

398

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

399

Lattice Boltzmann method for Lennard-Jones fluids based on the gradient theory of interfaces.  

PubMed

In the present study we propose a lattice Boltzmann equation (LBE) model derived from density gradient expansions of the discrete BBGKY evolution equations. The model is based on the mechanical approach of the gradient theory of interfaces. The basic input is the radial distribution function, which is related exclusively to the molecular interaction potential, rather than semiempirical equations of state used in previous LBE models. This function can be provided from independent molecular simulations or from approximate theories. Evidently the accuracy of the interaction potential, and thus the radial distribution function, reflects on the accuracy of the thermodynamic properties and consistency of the derived LBE model. We have applied the proposed model to obtain equilibrium bulk and interfacial properties of a Lennard-Jones fluid at different temperatures, T, close to critical, T(c). The results demonstrate that the LBE model is in excellent agreement with gradient theory as well as with independent literature results based on different molecular simulation approaches. Hence the proposed LBE model can recover accurately bulk and interfacial thermodynamics for a Lennard Jones fluid at T/T(c)>0.9. PMID:21230617

Kikkinides, E S; Kainourgiakis, M E; Yiotis, A G; Stubos, A K

2010-11-01

400

Randomised controlled trial of a brief theory-based intervention promoting breakfast consumption.  

PubMed

The present study sought to test the efficacy of a brief theory-based intervention to promote regular consumption of breakfast, and to expand previous results suggesting that the theory of planned behaviour (TPB) can be meaningfully applied to breakfast consumption. A four-armed randomised controlled trial was conducted. Participants (n=349) were allocated to receive either a (1) positively framed attitude intervention, (2) negatively framed attitude intervention, (3) Perceived Behavioural Control (PBC) intervention, or (4) control task. Attitude, subjective norm, PBC and behaviour were measured at baseline and 4-week follow-up. All three interventions employed persuasive communication and an implementation intention task. The intervention did not result in expected increases in breakfast consumption, or in changes in attitude, subjective norm or PBC. However, baseline attitude, subjective norm and PBC predicted 39.3% of baseline intention. Baseline intention in turn predicted 33% of breakfast consumption at 4 weeks. Change in breakfast consumption was predicted by change in attitude, subjective norm, and PBC between baseline and follow-up. Despite a lack of intervention effects, the TPB provided a good model of breakfast consumption over the four-week follow-up period. By expanding on previous work investigating breakfast consumption using the TPB, this study provides further support for the argument that that theory based interventions could result in meaningful increases in breakfast consumption. PMID:21163311

Kothe, Emily J; Mullan, Barbara A; Amaratunga, Rajith

2011-02-01

401

Nonlinear vibration of double layered viscoelastic nanoplates based on nonlocal theory  

NASA Astrophysics Data System (ADS)

The nonlinear flexural vibration properties of double layered viscoelastic nanoplates are investigated based on nonlocal continuum theory. The von Kámán strain-displacement relation is employed to model the geometrical nonlinearity. Based on the classical plate theory, the formulations are derived by the Hamilton's principle in conjunction with Eringen's nonlocal elasticity theory, and are further discretized by the Galerkin's method. The coordinate transformation is adopted to obtain the nonlinear governing equations of motion in the modal coordinate system. On the basis of these equations, the frequency responses of double layered nanoplates with simply supported and clamped boundary conditions are derived by the method of multiple scales. The influences of small scale and other structural parameters (e.g. the aspect ratio of the plate, van der Walls (vdW) interaction and the viscidity of the plate) on the nonlinear vibration characteristics are discussed. From the result, the vdW interaction has obvious effects on the nonlinear frequency corresponding to the second nonlinear normal mode (NNM). The nonexistence of the internal resonance is also induced from the vdW forces between the plates. The influence of the elastic matrix is also discussed. The hardening nonlinearity is observed for the primary resonance. Additionally, some interesting phenomena different from the linear vibration are observed.

Wang, Yu; Li, Feng-Ming; Wang, Yi-Ze

2015-03-01

402

Density functional theory based quantitative structure-property relationship studies on coumarin-based prodrugs.  

PubMed

A coumarin-based prodrug system plays a significant role in preparing esterase-sensitive prodrugs of amines and peptides. The electronic structures of 27 coumarin-based prodrugs developed in our lab were calculated at a B3LYP/6-31+G (d,p) level with a Gaussian 03 program. The calculated structural parameters were taken as theoretical descriptors to establish five novel QSPR models. The SMLR linear model (q² = 0.427, r² = 0.516) and the PLS linear model (q² = 0.584, r² = 0.663) were developed with descriptors selected by an Unsupervised Forward Selection method. Another three nonlinear QSPR models were established by a Polynomial Neural Network (PNN) Simulation method (q² = 0.692, 0.675, 0.663; r² = 0.700, 0.688, 0.672). We suggest that the QSPR models derived here, especially the PNN models, can be used to predict the release kinetics of coumarin-based prodrugs as well as design new derivatives of coumarin-based prodrug candidates. PMID:23229116

Yang, Xinying; Hou, Xuben; Wang, Binghe; Li, Minyong; Fang, Hao

2012-10-01

403

Creating a Technology-Based Entrepreneurial Economy: A Resource Based Theory Perspective  

Microsoft Academic Search

Academic research has identified a broad array of resources that exist in communities that have an established technology-based entrepreneurial venture population. These studies have focused upon well-known areas such as the Silicon Valley, the 128 loop in Boston and Austin, Texas. Yet even in these relatively homogeneous environments the studies have been highly inconsistent in their findings as to what

G. Page West III; Charles E. Bamford

2005-01-01

404

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

405

On projective synchronization of hyperchaotic complex nonlinear systems based on passive theory for secure communications  

NASA Astrophysics Data System (ADS)

In this paper we deal with the projective synchronization (PS) of hyperchaotic complex nonlinear systems and its application in secure communications based on passive theory. The unpredictability of the scaling factor in PS can additionally enhance the security of communications. In this paper, a scheme for secure message transmission is proposed, and we try to transmit more than one large or bounded message from the transmitter to the receiver. The new hyperchaotic complex Lorenz system is employed to encrypt these messages. In the transmitter, the original messages are modulated into its parameter. In the receiver, we assume that the parameter of the receiver system is uncertain. The controllers and corresponding parameter update law are constructed to achieve PS between the transmitter and receiver system with an uncertain parameter, and identify the unknown parameter via passive theory. The original messages can be recovered successfully through some simple operations by the estimated parameter. Numerical results have verified the effectiveness and feasibility of the presented method.

Mahmoud, Gamal M.; Mahmoud, Emad E.; Arafa, Ayman A.

2013-05-01

406

A second order analytical atmospheric drag theory based on the TD88 thermospheric density model  

NASA Astrophysics Data System (ADS)

A second order atmospheric drag theory based on the usage of TD88 model is constructed. It is developed to the second order in terms of TD88 small parameters K n, j . The short periodic perturbations, of all orbital elements, are evaluated. The secular perturbations of the semi-major axis and of the eccentricity are obtained. The theory is applied to determine the lifetime of the satellites ROHINI (1980 62A), and to predict the lifetime of the microsatellite MIMOSA. The secular perturbations of the nodal longitude and of the argument of perigee due to the Earth’s gravity are taken into account up to the second order in Earth’s oblateness.

El-Salam, F. A. Abd.; Sehnal, L.

2004-11-01

407

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

408

A preliminary study on atrial epicardial mapping signals based on Graph Theory.  

PubMed

In order to get a better understanding of atrial fibrillation, we introduced a method based on Graph Theory to interpret the relations of different parts of the atria. Atrial electrograms under sinus rhythm and atrial fibrillation were collected from eight living mongrel dogs with cholinergic AF model. These epicardial signals were acquired from 95 unipolar electrodes attached to the surface of the atria and four pulmonary veins. Then, we analyzed the electrode correlations using Graph Theory. The topology, the connectivity and the parameters of graphs during different rhythms were studied. Our results showed that the connectivity of graphs varied from sinus rhythm to atrial fibrillation and there were parameter gradients in various parts of the atria. The results provide spatial insight into the interaction between different parts of the atria and the method may have its potential for studying atrial fibrillation. PMID:24768086

Sun, Liqian; Yang, Cuiwei; Zhang, Lin; Chen, Ying; Wu, Zhong; Shao, Jun

2014-07-01

409

An English Vocabulary Learning System Based on Fuzzy Theory and Memory Cycle  

NASA Astrophysics Data System (ADS)

This paper proposes an English Vocabulary Learning System based on the Fuzzy Theory and the Memory Cycle Theory to help a learner to memorize vocabularies easily. By using fuzzy inferences and personal memory cycles, it is possible to find an article that best suits a learner. After reading an article, a quiz is provided for the learner to improve his/her memory of the vocabulary in the article. Early researches use just explicit response (ex. quiz exam) to update memory cycles of newly learned vocabulary; apart from that approach, this paper proposes a methodology that also modify implicitly the memory cycles of learned word. By intensive reading of articles recommended by our approach, a learner learns new words quickly and reviews learned words implicitly as well, and by which the vocabulary ability of the learner improves efficiently.

Wang, Tzone I.; Chiu, Ti Kai; Huang, Liang Jun; Fu, Ru Xuan; Hsieh, Tung-Cheng

410

Social judgment theory based model on opinion formation, polarization and evolution  

NASA Astrophysics Data System (ADS)

The dynamical origin of opinion polarization in the real world is an interesting topic that physical scientists may help to understand. To properly model the dynamics, the theory must be fully compatible with findings by social psychologists on microscopic opinion change. Here we introduce a generic model of opinion formation with homogeneous agents based on the well-known social judgment theory in social psychology by extending a similar model proposed by Jager and Amblard. The agents’ opinions will eventually cluster around extreme and/or moderate opinions forming three phases in a two-dimensional parameter space that describes the microscopic opinion response of the agents. The dynamics of this model can be qualitatively understood by mean-field analysis. More importantly, first-order phase transition in opinion distribution is observed by evolving the system under a slow change in the system parameters, showing that punctuated equilibria in public opinion can occur even in a fully connected social network.

Chau, H. F.; Wong, C. Y.; Chow, F. K.; Fung, Chi-Hang Fred

2014-12-01

411

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

412

Simulation of Ultrasound in Tomographic Imaging: Theory and Methods Based on Geometrical Acoustics.  

NASA Astrophysics Data System (ADS)

Imaging based upon ultrasound has found extensive application both in medicine for non-invasive diagnosis and in industry for the nondestructive testing of materials. Present commercially available devices are capable of producing images primarily of the geometry of objects (internal shapes and boundaries). A goal for the next generation of ultrasonic imaging devices is the additional capability of depicting, quantitatively, mechanical properties of the tissue or materials under investigation. To achieve this goal, researchers must: (i) identify measurable acoustic parameters capable of characterizing meaningful mechanical properties; and (ii) develop methods for producing quantitative images based upon these parameters. A major stumbling block in quantitative imaging is incomplete understanding of the interaction between imaging methods and the physics of acoustic propagation and measurement. The goal of this thesis is the development of theory and methods for studying this interaction. To study this interaction, methods are developed for simulating the measurements associated with computed ultrasonic transmission tomography based on ultrasonic attenuation. Modern geometrical acoustics theory is applied and novel simulation methods are developed. In conjunction with this, a general theory of discontinuities in partial differential equations is developed. The result is a novel set of rules for transforming first-order linear partial differential equations into corresponding sets of constraints on the surface of the discontinuity. Both the accuracy and the limitations of the method for simulation of measurements of ultrasonic attenuation are demonstrated by comparison with experiment. The simulation is then used to investigate the effects of inhomogeneities on ultrasound measurements. Such results would be difficult to achieve experimentally. Various sources of error in ultrasonic imaging are assessed, and are rank ordered according to their severity. These methods and results are both new and potentially useful in the future development of quantitative ultrasonic imaging based on tissue or materials characterization.

Brandenburger, Gary H.

413

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

414

A Bifactor Multidimensional Item Response Theory Model for Differential Item Functioning Analysis on Testlet-Based Items  

ERIC Educational Resources Information Center

A differential item functioning (DIF) detection method for testlet-based data was proposed and evaluated in this study. The proposed DIF model is an extension of a bifactor multidimensional item response theory (MIRT) model for testlets. Unlike traditional item response theory (IRT) DIF models, the proposed model takes testlet effects into…

Fukuhara, Hirotaka; Kamata, Akihito

2011-01-01

415

Motivational Measure of the Instruction Compared: Instruction Based on the ARCS Motivation Theory vs Traditional Instruction in Blended Courses  

ERIC Educational Resources Information Center

The ARCS Motivation Theory was proposed to guide instructional designers and teachers who develop their own instruction to integrate motivational design strategies into the instruction. There is a lack of literature supporting the idea that instruction for blended courses if designed based on the ARCS Motivation Theory provides different…

Colakoglu, Ozgur M.; Akdemir, Omur

2012-01-01

416

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

417

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

418

Theory-Guided Design of a Rating Scale for Program Evaluation in Problem-Based Medical Curricula.  

ERIC Educational Resources Information Center

The design and evaluation of a rating scale for program evaluation in problem-based medical curricula are described. The design process was guided by a theory of how students learn in problem-based learning as modeled by W. H. Gijselaers and H. G. Schmidt (1988). The rating scale was used in an evaluation of a new problem-based, community-oriented…

Des Marchais, Jacques E.; And Others

419

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.

420

Genome-based versus gene-based theory of cancer: possible implications for clinical practice.  

PubMed

The current state in oncology research indicates that the attempts to explain such complex process as cancerogenesis by a single or several genetic mutations were not successful enough. On the other hand, chromosomal/genomic instability--almost universal features of malignant tumours which influence a global pattern of gene expression and, subsequently, many oncogenic pathways--were often disregarded and considered nonessential to clinical application. However, a new arising field of system biology including 'new forms' of genome diversity such as copy number variations (CNV) and high-throughput oncogene mutation profiling now reveal all the complexity of cancer and provide the final explanation of the oncogenic pathways, based on stochastic (onco)genomic variation rather than on (onco)genic concepts. PMID:21857118

Todorovic-Rakovic, Natasa

2011-09-01

421

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

422

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

423

The Stability Analysis for an Extended Car Following Model Based on Control Theory  

NASA Astrophysics Data System (ADS)

A new method is proposed to study the stability of the car-following model considering traffic interruption probability. The stability condition for the extended car-following model is obtained by using the Lyapunov function and the condition for no traffic jam is also given based on the control theory. Numerical simulations are conducted to demonstrate and verify the analytical results. Moreover, numerical simulations show that the traffic interruption probability has an influence on driving behavior and confirm the effectiveness of the method on the stability of traffic flow.

Ge, Hong-Xia; Meng, Xiang-Pei; Zhu, Ke-Qiang; Cheng, Rong-Jun

2014-08-01

424

Risk evaluation of bogie system based on extension theory and entropy weight method.  

PubMed

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

425

Low-contrast small target image enhancement based on rough set theory  

NASA Astrophysics Data System (ADS)

Contrast enhancement is important for small target detection and tracking. Conventional contrast enhancement techniques often fail to produce satisfactory results for images expressing unimodal intensity histograms. This paper presents a new contrast enhancement method based on rough set theory which is especially suitable for such images. The method uses the max of between-class mean to partition the image into two sub-images, the denoised target region and the denoised background region. Then the target region is enhanced by extend histogram. Experimental results indicate the new enhancement method is more suitable than traditional methods for handling the enhancement problems of low contrast small target images.

Yong, Yang; Wang, Bingxue; Zhang, Wenhua; Peng, Zhenming

2008-03-01

426

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

427

Constraints on neutron star radii based on chiral effective field theory interactions.  

PubMed

We show that microscopic calculations based on chiral effective field theory interactions constrain the properties of neutron-rich matter below nuclear densities to a much higher degree than is reflected in commonly used equations of state. Combined with observed neutron star masses, our results lead to a radius R=9.7-13.9??km for a 1.4M? star, where the theoretical range is due, in about equal amounts, to uncertainties in many-body forces and to the extrapolation to high densities. PMID:21230959

Hebeler, K; Lattimer, J M; Pethick, C J; Schwenk, A

2010-10-15

428

Transmission Line Theory Based Two Layer Model for Determining Soil Moisture  

NASA Astrophysics Data System (ADS)

Present paper deals with the task of estimating soil moisture under vegetation cover by using transmission line theory based two layer model. The two layer model measures the impedance of both the layers namely, soil and vegetation. This impedance is the function of dielectric constant and thickness of both the layers. For known dielectric constant and height of vegetation layer, dielectric constant of soil was determined for certain thickness of soil layer using genetic algorithm (GA). The soil moisture value was retrieved from dielectric constant of soil by using Topp et al., (1980) relationship. Retrieved soil moisture values were in good agreement with observed values.

Mishra, P.; Singh, D.

2013-05-01

429

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

430

An efficient FE model based on combined theory for the analysis of soft core sandwich plate  

NASA Astrophysics Data System (ADS)

An efficient C0 continuous finite element (FE) model is developed based on combined theory (refine higher order shear deformation theory (RHSDT) and least square error (LSE) method) for the static analysis of soft core sandwich plate. In this (RHSDT) theory, the in-plane displacement field for the face sheets and the core is obtained by superposing a global cubically varying displacement field on a zig-zag linearly varying displacement field with a different slope in each layer. The transverse displacement assumes to have a quadratic variation within the core and it remains constant in the faces beyond the core. The proposed model satisfies the condition of transverse shear stress continuity at the layer interfaces and the zero transverse shear stress condition at the top and bottom of the sandwich plate. The nodal field variables are chosen in an efficient manner to circumvent the problem of C1 continuity requirement of the transverse displacements. In order to calculate the accurate through thickness transverse stresses variation, LSE method has been used at the post processing stage. The proposed combine model (RHSDT and LSE) is implemented to analyze the laminated composites and sandwich plates. Many new results are also presented which should be useful for future research.

Khandelwal, Ravi Prakash; Chakrabarti, Anupam; Bhargava, Pradeep

2013-05-01

431

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

PubMed Central

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.

2010-01-01

432

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

2015-04-01

433

On a consistent finite-strain plate theory based on 3-D energy principle  

E-print Network

This paper derives a finite-strain plate theory consistent with the principle of stationary three-dimensional (3-D) potential energy under general loadings with a third-order error. Staring from the 3-D nonlinear elasticity (with both geometrical and material nonlinearity) and by a series expansion, we deduce a vector plate equation with three unknowns, which exhibits the local force-balance structure. The success relies on using the 3-D field equations and bottom traction condition to derive exact recursion relations for the coefficients. Associated weak formulations are considered, leading to a 2-D virtual work principle. An alternative approach based on a 2-D truncated energy is also provided, which is less consistent than the first plate theory but has the advantage of the existence of a 2-D energy function. As an example, we consider the pure bending problem of a hyperelastic block. The comparison between the analytical plate solution and available exact one shows that the plate theory gives second-order...

Dai, Hui-Hui

2014-01-01

434

A simple laminate theory using the orthotropic viscoplasticity theory based on overstress. I - In-plane stress-strain relationships for metal matrix composites  

NASA Technical Reports Server (NTRS)

A macromechanics analysis is presented for the in-plane, anisotropic time-dependent behavior of metal matrix laminates. The small deformation, orthotropic viscoplasticity theory based on overstress represents lamina behavior in a modified simple laminate theory. Material functions and constants can be identified in principle from experiments with laminae. Orthotropic invariants can be repositories for tension-compression asymmetry and for linear elasticity in one direction while the other directions behave in a viscoplastic manner. Computer programs are generated and tested for either unidirectional or symmetric laminates under in-plane loading. Correlations with the experimental results on metal matrix composites are presented.

Krempl, Erhard; Hong, Bor Zen

1989-01-01

435

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

436

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

437

Study on the salary system for IT enterprise based on double factor motivation theory  

NASA Astrophysics Data System (ADS)

To improve the fact that the IT enterprise's salary & compensation system can not motivate a company's staff efficiently, the salary system based on Hertzberg's double factor motivation theory and the enterprise characteristics is presented. The salary system includes a salary model, an assessment model and a performance model. The system is connected with a cash incentive based on the staff's performance and emphasizes that the salary alone is not a motivating factor. Health care, for example, may also play a positive role on the motivation factor. According to this system, a scientific and reasonable salary & compensation management system was established and applied in an IT enterprise. It was found to promote the enterprise's overall performance and competitive power.

Zhuang, Chen; Qian, Wu

2005-12-01

438

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

439

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

440

Discovering Pair-Wise Genetic Interactions: An Information Theory-Based Approach  

PubMed Central

Phenotypic variation, including that which underlies health and disease in humans, results in part from multiple interactions among both genetic variation and environmental factors. While diseases or phenotypes caused by single gene variants can be identified by established association methods and family-based approaches, complex phenotypic traits resulting from multi-gene interactions remain very difficult to characterize. Here we describe a new method based on information theory, and demonstrate how it improves on previous approaches to identifying genetic interactions, including both synthetic and modifier kinds of interactions. We apply our measure, called interaction distance, to previously analyzed data sets of yeast sporulation efficiency, lipid related mouse data and several human disease models to characterize the method. We show how the interaction distance can reveal novel gene interaction candidates in experimental and simulated data sets, and outperforms other measures in several circumstances. The method also allows us to optimize case/control sample composition for clinical studies. PMID:24670935

Ignac, Tomasz M.; Skupin, Alexander; Sakhanenko, Nikita A.; Galas, David J.

2014-01-01

441

Gas-Kinetic Theory Based Flux Splitting Method for Ideal Magnetohydrodynamics  

NASA Technical Reports Server (NTRS)

A gas-kinetic solver is developed for the ideal magnetohydrodynamics (MHD) equations. The new scheme is based on the direct splitting of the flux function of the MHD equations with the inclusion of "particle" collisions in the transport process. Consequently, the artificial dissipation in the new scheme is much reduced in comparison with the MHD Flux Vector Splitting Scheme. At the same time, the new scheme is compared with the well-developed Roe-type MHD solver. It is concluded that the kinetic MHD scheme is more robust and efficient than the Roe- type method, and the accuracy is competitive. In this paper the general principle of splitting the macroscopic flux function based on the gas-kinetic theory is presented. The flux construction strategy may shed some light on the possible modification of AUSM- and CUSP-type schemes for the compressible Euler equations, as well as to the development of new schemes for a non-strictly hyperbolic system.

Xu, Kun

1998-01-01

442

Low-complexity video compression for capsule endoscope based on compressed sensing theory.  

PubMed

Recently, the notions of Compressed Sensing (CS) have attracted attention as an innovative concept in signal processing. In this exploratory paper, a CS-based video compression approach suitable for wireless capsule endoscopy is proposed. In general, the amount of video data generated by capsule endoscopy is so large that video compression is the best way to lower the communication bandwidth and save the RF transmitting power. However, due to power limitation and small size conditions, traditional video compression techniques are not appropriate. Applying state-of-the-art CS theory may significantly reduce power consumption and memory of video compressor, thanks to its low computational complexity. The proposed approach is based on YUV color space conversion, blocking, zigzag scan and CS measuring. Experimental results show the feasibility of the proposed idea and that future improving works are necessary. PMID:19965013

Wu, Jing; Li, Ye

2009-01-01

443

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

444

Looking to the future of new media in health marketing: deriving propositions based on traditional theories.  

PubMed

Market trend data show that the media marketplace continues to rapidly evolve. Recent research shows that substantial portions of the U.S. media population are "new media" users. Today, more than ever before, media consumers are exposed to multiple media at the same point in time, encouraged to participate in media content generation, and challenged to learn, access, and use the new media that are continually entering the market. These media trends have strong implications for how consumers of health information access, process, and retain health-related knowledge. In this article we review traditional information processing models and theories of interpersonal and mass media access and consumption. We make several theory-based propositions for how traditional information processing and media consumption concepts will function as new media usage continues to increase. These propositions are supported by new media usage data from the Centers for Disease Control and Prevention's entry into the new media market (e.g., podcasting, virtual events, blogging, and webinars). Based on these propositions, we conclude by presenting both opportunities and challenges that public health communicators and marketers will face in the future. PMID:18935883

Della, Lindsay J; Eroglu, Dogan; Bernhardt, Jay M; Edgerton, Erin; Nall, Janice

2008-01-01

445

Analysis of non-equilibrium multi-species mixing based on Boltzmann kinetic theory  

NASA Astrophysics Data System (ADS)

In many applications of non-equilibrium flows relevant to design of micro-fluidic devices and spacecraft propulsion systems, where standard continuum field descriptions of multi-species mixing break down (when Knudsen number is not negligible), descriptions based on fundamental kinetic theory can be insightful. We use Boltzmann kinetic theory to obtain a statistical description of macroscopic system properties of multi-species mixing, using particle distribution functions for each species, which are governed by a system of coupled, nonlinear, integro-differential Boltzmann equations involving full collision operators. Formidable challenges involved in the computational treatment of full collision operators, consisting of multi-dimensional integrals, are addressed through an efficient quadrature-based moment method which not only preserves collision invariants but is also capable of describing general far-from equilibrium behavior. In this method, discrete representations of the particle distribution functions for each species are sought by accounting for generalized moment contributions due to full collision operators, which can be evaluated analytically via multinomial expansions. Fundamental behavior relevant to exchange of momentum, energy and generalized stresses among inert multiple species undergoing mixing, with and without the presence of spatial inhomogeneities, will be analyzed using this method.

Vedula, Prakash; Fox, Rodney O.

2008-11-01

446

Coding theory based models for protein translation initiation in prokaryotic organisms.  

SciTech Connect

Our research explores the feasibility of using communication theory, error control (EC) coding theory specifically, for quantitatively modeling the protein translation initiation mechanism. The messenger RNA (mRNA) of Escherichia coli K-12 is modeled as a noisy (errored), encoded signal and the ribosome as a minimum Hamming distance decoder, where the 16S ribosomal RNA (rRNA) serves as a template for generating a set of valid codewords (the codebook). We tested the E. coli based coding models on 5' untranslated leader sequences of prokaryotic organisms of varying taxonomical relation to E. coli including: Salmonella typhimurium LT2, Bacillus subtilis, and Staphylococcus aureus Mu50. The model identified regions on the 5' untranslated leader where the minimum Hamming distance values of translated mRNA sub-sequences and non-translated genomic sequences differ the most. These regions correspond to the Shine-Dalgarno domain and the non-random domain. Applying the EC coding-based models to B. subtilis, and S. aureus Mu50 yielded results similar to those for E. coli K-12. Contrary to our expectations, the behavior of S. typhimurium LT2, the more taxonomically related to E. coli, resembled that of the non-translated sequence group.

May, Elebeoba Eni; Bitzer, Donald L. (North Carolina State University, Raleigh, NC); Rosnick, David I. (North Carolina State University, Raleigh, NC); Vouk, Mladen A. (North Carolina State University, Raleigh, NC)

2003-03-01

447

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

448

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

449

A curvature-dependent interfacial energy-based interface stress theory and its applications to nano-structured materials: (I) General theory  

NASA Astrophysics Data System (ADS)

Experimental observations have shown the size-dependent residual surface stresses on spherical nanoparticles and their influence on the effective modulus of heterogeneous nanostructures. Based on these experimental findings, this paper proposes a new interface stress theory that considers the curvature effect on the interfacial energy. To investigate this curvature-dependent interfacial energy, we use the Green elasticity theory to describe the nonlinear constitutive relation of the interface at finite deformation, thus explicitly demonstrating the curvature-dependent nature of the interface stress and bending moment. By introducing a fictitious stress-free configuration, we then propose a new energy functional for heterogeneous hyperelastic solids with interfaces. For the first time, both the Lagrangian and Eulerian descriptions of the generalized Young-Laplace equation, which describes the intrinsic flexural resistance of the interface, are derived from the newly developed energy functional. This new interface stress theory is then used to investigate the residual elastic field in a heterogeneous hyperelastic solid containing interfaces. The present theory differs from the existing theories in that it takes fully into account both the curvature-dependence of the interfacial energy and the interfacial energy-induced residual elastic field in the bulk solid. Furthermore, the fundamental equations of the interface are given in Lagrangian description, which are preferable when considering the effects of residual interface stress, residual interface bending moment and interface elasticity. Finally, two examples are presented to shed light on the significance of this new interface stress theory. A more detailed analysis and applications of the new theory will be presented in Part (II) of this paper.

Gao, Xiang; Huang, Zhuping; Qu, Jianmin; Fang, Daining

2014-05-01

450

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. PMID:25679004

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

2014-01-01

451

Programmatic assessment of competency-based workplace learning: when theory meets practice  

PubMed Central

Background In competency-based medical education emphasis has shifted towards outcomes, capabilities, and learner-centeredness. Together with a focus on sustained evidence of professional competence this calls for new methods of teaching and assessment. Recently, medical educators advocated the use of a holistic, programmatic approach towards assessment. Besides maximum facilitation of learning it should improve the validity and reliability of measurements and documentation of competence development. We explored how, in a competency-based curriculum, current theories on programmatic assessment interacted with educational practice. Methods In a development study including evaluation, we investigated the implementation of a theory-based programme of assessment. Between April 2011 and May 2012 quantitative evaluation data were collected and used to guide group interviews that explored the experiences of students and clinical supervisors with the assessment programme. We coded the transcripts and emerging topics were organised into a list of lessons learned. Results The programme mainly focuses on the integration of learning and assessment by motivating and supporting students to seek and accumulate feedback. The assessment instruments were aligned to cover predefined competencies to enable aggregation of information in a structured and meaningful way. Assessments that were designed as formative learning experiences were increasingly perceived as summative by students. Peer feedback was experienced as a valuable method for formative feedback. Social interaction and external guidance seemed to be of crucial importance to scaffold self-directed learning. Aggregating data from individual assessments into a holistic portfolio judgement required expertise and extensive training and supervision of judges. Conclusions A programme of assessment with low-stakes assessments providing simultaneously formative feedback and input for summative decisions proved not easy to implement. Careful preparation and guidance of the implementation process was crucial. Assessment for learning requires meaningful feedback with each assessment. Special attention should be paid to the quality of feedback at individual assessment moments. Comprehensive attention for faculty development and training for students is essential for the successful implementation of an assessment programme. PMID:24020944

2013-01-01

452

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

453

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

454

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

455

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

456

RCR online course: build an online course to augment RCR training using evidenced-based learning theory.  

PubMed

This article demonstrates how to apply evidenced-based instructional design principles to develop a supplemental, online Responsible Conduct of Research (RCR) course. The supplement RCR course may serve to appropriately augment the National Institutes of Health (NIH) required RCR training. The way to ensure that an online RCR course is effective is to incorporate evidence-based learning theories into the development of the course content. This article specifically demonstrates application of Bloom's taxonomy and Gagne's Nine Instructional Events to a research misconduct course. At the conclusion, the reader will be able to apply evidence-based learning theories to the development of any online course. PMID:22861181

Ratliff, Mary; Masen, Nicole; Sullivan, Stephen; Fleming, Michael F; Carney, Paula

2012-01-01

457

Consensus-Based Course Design and Implementation of Constructive Alignment Theory in a Power System Analysis Course  

ERIC Educational Resources Information Center

This article presents the implementation of the constructive alignment theory (CAT) in a power system analysis course through a consensus-based course design process. The consensus-based design process involves both the instructor and graduate-level students and it aims to develop the CAT framework in a holistic manner with the goal of including…

Vanfretti, Luigi; Farrokhabadi, Mostafa

2015-01-01

458

Selection of gas sensing materials using the Hard Soft Acid Base theory; application to Surface Acoustic Wave CO2 detection  

Microsoft Academic Search

The Hard Soft Acid Base (HSAB) theory is introduced as a new tool to select or design sensitive materials for carbon dioxide detection with SAW-BAW (Surface Acoustic Waves - Bulk Acoustic Waves) devices. According to HSAB, CO2 is hard acid, thus small organic or inorganic molecules, or polymers which can act as hard bases could be suitable candidates as sensing

B. Serban; A. K. Sarin Kumar; C. Cobianu; O. Buiu; S. Costea; C. Bostan; N. Varachiu

2010-01-01

459

RCR Online Course: Build an Online Course to Augment RCR Training Using Evidenced-Based Learning Theory  

Microsoft Academic Search

This article demonstrates how to apply evidenced-based instructional design principles to develop a supplemental, online Responsible Conduct of Research (RCR) course. The supplement RCR course may serve to appropriately augment the National Institutes of Health (NIH) required RCR training. The way to ensure that an online RCR course is effective is to incorporate evidence-based learning theories into the development of

Mary Ratliff; Nicole Masen; Stephen Sullivan; Michael F. Fleming; Paula Carney

2012-01-01

460

Using the Dynamic Model to Develop an Evidence-Based and Theory-Driven Approach to School Improvement  

ERIC Educational Resources Information Center

This paper refers to a dynamic perspective of educational effectiveness and improvement stressing the importance of using an evidence-based and theory-driven approach. Specifically, an approach to school improvement based on the dynamic model of educational effectiveness is offered. The recommended approach to school improvement gives emphasis to…

Creemers, B. P. M.; Kyriakides, Leonidas

2010-01-01

461

Implementing shared decision-making in nutrition clinical practice: A theory-based approach and feasibility study  

Microsoft Academic Search

BACKGROUND: There are a growing number of dietary treatment options to choose from for the management of many chronic diseases. Shared decision making represents a promising approach to improve the quality of the decision making process needed for dietary choices that are informed by the best evidence and value-based. However, there are no studies reporting on theory-based approaches that foster

Sophie Desroches; Marie-Pierre Gagnon; Sylvie Tapp

2008-01-01

462

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

463

Design of a PD Position Control based on the Lyapunov Theory for a Robot Manipulator Flexible-Link  

Microsoft Academic Search

We propose the design of a PD position control for a one link flexible manipulator. This paper is based in development the scheme control using the theory Lyapunov, where the existence, unicity and asymptotic behavior of the equilibrium point is defined inside workspace of the robot manipulator, furthermore we are presenting a detailed mathematical development based in the dynamics of

C. Murrugarra; J. Grieco; G. Fernandez; O. De Castro

2006-01-01

464

The ?3 model of acids and bases: extending the Lewis theory to intermetallics.  

PubMed

A central challenge in the design of new metallic materials is the elucidation of the chemical factors underlying the structures of intermetallic compounds. Analogies to molecular bonding phenomena, such as the Zintl concept, have proven very productive in approaching this goal. In this Article, we extend a foundational concept of molecular chemistry to intermetallics: the Lewis theory of acids and bases. The connection is developed through the method of moments, as applied to DFT-calibrated Hückel calculations. We begin by illustrating that the third and fourth moments (?(3) and ?(4)) of the electronic density of states (DOS) distribution tune the properties of a pseudogap. ?(3) controls the balance of states above and below the DOS minimum, with ?(4) then determining the minimum's depth. In this way, ?(3) predicts an ideal occupancy for the DOS distribution. The ?(3)-ideal electron count is used to forge a link between the reactivity of transition metals toward intermetallic phase formation, and that of Lewis acids and bases toward adduct formation. This is accomplished through a moments-based definition of acidity which classifies systems that are electron-poor relative to the ?(3)-ideal as ?(3)-acidic, and those that are electron-rich as ?(3)-basic. The reaction of ?(3) acids and bases, whether in the formation of a Lewis acid/base adduct or an intermetallic phase, tends to neutralize the ?(3) acidity or basicity of the reactants. This ?(3)-neutralization is traced to the influence of electronegativity differences at heteroatomic contacts on the projected DOS curves of the atoms involved. The role of ?(3)-acid/base interactions in intermetallic phases is demonstrated through the examination of 23 binary phases forming between 3d metals, the stability range of the CsCl type, and structural trends within the Ti-Ni system. PMID:22420716

Stacey, Timothy E; Fredrickson, Daniel C

2012-04-01

465

Competitive effects between stationary chemical reaction centres: A theory based on off-center monopoles  

NASA Astrophysics Data System (ADS)

The subject of this paper is competitive effects between multiple reaction sinks. A theory based on off-center monopoles is developed for the steady-state diffusion equation and for the convection-diffusion equation with a constant flow field. The dipolar approximation for the diffusion equation with two equal reaction centres is compared with the exact solution. The former turns out to be remarkably accurate, even for two touching spheres. Numerical evidence is presented to show that the same holds for larger clusters (with more than two spheres). The theory is extended to the convection-diffusion equation with a constant flow field. As one increases the convective velocity, the competitive effects between the reactive centres gradually become less significant. This is demonstrated for a number of cluster configurations. At high flow velocities, the current methodology breaks down. Fixing this problem will be the subject of future research. The current method is useful as an easy-to-use tool for the calibration of other more complicated models in mass and/or heat transfer.

Biello, Joseph A.; Samson, René

2015-03-01

466

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

467

Optical surface measurement using phase retrieval hybrid algorithm based on diffraction angular spectrum theory  

NASA Astrophysics Data System (ADS)

In order to test the high dynamic range error beyond one wavelength after the rough polish process, we design a phase retrieval hybrid algorithm based on diffraction angular spectrum theory. Phase retrieval is a wave front sensing method that uses the intensity distribution to reconstruct the phase distribution of optical field. Phase retrieval is established on the model of diffractive propagation and approach the real intensity distribution gradually. In this paper, we introduce the basic principle and challenges of optical surface measurement using phase retrieval, then discuss the major parts of phase retrieval: diffractive propagation and hybrid algorithm. The angular spectrum theory describes the diffractive propagation in the frequency domain instead of spatial domain, which simplifies the computation greatly. Through the theoretical analysis, the angular spectrum in discrete form is more effective when the high frequency part values less and the diffractive distance isn't far. The phase retrieval hybrid algorithm derives from modified GS algorithm and conjugate gradient method, aiming to solve the problem of phase wrapping caused by the high dynamic range error. In the algorithm, phase distribution is described by Zernike polynomials and the coefficients of Zernike polynomials are optimized by the hybrid algorithm. Simulation results show that the retrieved phase distribution and real phase distribution are quite contiguous for the high dynamic range error beyond ?.

Feng, Liang; Zeng, Zhi-ge; Wu, Yong-qian

2013-08-01

468

Competitive effects between stationary chemical reaction centres: A theory based on off-center monopoles.  

PubMed

The subject of this paper is competitive effects between multiple reaction sinks. A theory based on off-center monopoles is developed for the steady-state diffusion equation and for the convection-diffusion equation with a constant flow field. The dipolar approximation for the diffusion equation with two equal reaction centres is compared with the exact solution. The former turns out to be remarkably accurate, even for two touching spheres. Numerical evidence is presented to show that the same holds for larger clusters (with more than two spheres). The theory is extended to the convection-diffusion equation with a constant flow field. As one increases the convective velocity, the competitive effects between the reactive centres gradually become less significant. This is demonstrated for a number of cluster configurations. At high flow velocities, the current methodology breaks down. Fixing this problem will be the subject of future research. The current method is useful as an easy-to-use tool for the calibration of other more complicated models in mass and/or heat transfer. PMID:25747063

Biello, Joseph A; Samson, René

2015-03-01

469

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

470

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

471

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

472

A Social Marketing Theory?Based Diet-Education Program for Women Ages 54 to 83 Years Improved Dietary Status  

Microsoft Academic Search

Social Marketing Theory is a comprehensive approach of program development encompassing the needs and preferences of the intended audience. It was hypothesized a Social Marketing Theory?based, registered dietitian–led, in-home, cardiovascular disease?targeted diet-education program would improve the dietary status of community-residing older women. Using a randomized control group design, this 90-day program in two North Carolina counties included 58 women (30

Sarah L. Francis; Martha L. Taylor

2009-01-01

473

[A new method for small displacement test and measurement based on the light reflection theory].  

PubMed

A new idea for small displacement test and measurement system based on light reflection is presented in this paper. Some theoretical researches using the method and experiments in practice were carried out. The results proved that the theory is feasible and efficient. Compared with the traditional small displacement test and measurement system, such as mechanical displacement magnifier; resistance strain test and measurement method; piezoelectric material strain test and measurement system and so on, this method has the following advantages: it creates little disturbance of the test and measurement system; the displacement magnification coefficient is high and is convenient for user to adjust; the test and measurement precision is high and is very easy for its realization; and the cost is low. It fits a lot of test and measurement situations. PMID:15768967

Chen, Ren-wen; Sun, Ya-fei; Chen, Yong

2004-01-01

474

Dynamic behavior of double-walled carbon nanotubes conveying viscous fluid based on nonlocal elastic theory  

NASA Astrophysics Data System (ADS)

In this paper, the dynamic behavior of a fixed-fixed double-walled carbon nanotube (DWCNT) conveying fluid is studied based on Euler-Bernoulli beam theory. The viscosity of the fluid and the nonlocal effect are incorporated in the formulation, and the Galerkin discretization method is used to solve the coupled equations of motions. The critical flow velocity of the fluid is obtained. Numerical simulations show that the van der Waals (vdW) interactions and the internal moving fluid play significant roles in the natural frequencies and the instability of DWCNTs. Also, the influences of the viscosity, nonlocal effect, aspect ratio and the surrounding elastic medium on the dynamic behavior of the double-walled carbon nanotube is studied in detail. It is found that a higher viscous-fluid-conveying DWCNT embedded in a stiff matrix with a larger aspect ratio make the induced instability vibration occur until a higher flow velocity.

Zhen, Yaxin; Fang, Bo; Wang, Liguo

2010-04-01

475

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

476

Detection and control of combustion instability based on the concept of dynamical system theory  

NASA Astrophysics Data System (ADS)

We propose an online method of detecting combustion instability based on the concept of dynamical system theory, including the characterization of the dynamic behavior of combustion instability. As an important case study relevant to combustion instability encountered in fundamental and practical combustion systems, we deal with the combustion dynamics close to lean blowout (LBO) in a premixed gas-turbine model combustor. The relatively regular pressure fluctuations generated by thermoacoustic oscillations transit to low-dimensional intermittent chaos owing to the intermittent appearance of burst with decreasing equivalence ratio. The translation error, which is characterized by quantifying the degree of parallelism of trajectories in the phase space, can be used as a control variable to prevent LBO.

Gotoda, Hiroshi; Shinoda, Yuta; Kobayashi, Masaki; Okuno, Yuta; Tachibana, Shigeru

2014-02-01

477

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

478

Nonlinear diffusion in two-dimensional ordered porous media based on a free volume theory  

NASA Astrophysics Data System (ADS)

A continuum nonlinear diffusion model is developed to describe molecular transport in ordered porous media. An existing generic van der Waals equation of state based free volume theory of binary diffusion coefficients is modified and introduced into the two-dimensional diffusion equation. The resulting diffusion equation is solved numerically with the alternating-direction fully implicit method under Neumann boundary conditions. Two types of pore structure symmetries are considered, hexagonal and cubic. The former is modeled as parallel channels while in case of the latter equal-sized channels are placed perpendicularly thus creating an interconnected network. First, general features of transport in both systems are explored, followed by the analysis of the impact of molecular properties on diffusion inside and out of the porous matrix. The influence of pore size on the diffusion-controlled release kinetics is assessed and the findings used to comment recent experimental studies of drug release profiles from ordered mesoporous silicates.

Godec, A.; Gaberscek, M.; Jamnik, J.; Merzel, F.

2009-12-01

479

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

480

Nonlinear vibration of embedded SWBNNTs based on nonlocal Timoshenko beam theory using DQ method  

NASA Astrophysics Data System (ADS)

In the present work, effect of von Kàrmàn geometric nonlinearity on the vibration behavior of a single-walled boron nitride nanotube (SWBNNT) is investigated based on nonlocal piezoelasticity theory. The SWBNNT is considered as a nanobeam within the framework of Timoshenko beam (TB). Loading is composed of a temperature change and an imposed axially electric potential throughout the SWBNNT. The interactions between the SWBNNT and its surrounding elastic medium are simulated by Winkler and Pasternak foundation models. The higher order governing equations of motion are derived using Hamilton's principle and the numerical solution of equations is obtained using Differential Quadrature (DQ) method. The effects of geometric nonlinearity, elastic foundation modulus, electric potential field, temperature change and nonlocal parameter on the frequency of the SWBNNT are studied in detail.

Ghorbanpour Arani, A.; Atabakhshian, V.; Loghman, A.; Shajari, A. R.; Amir, S.

2012-07-01

481

A resource management architecture based on complex network theory in cloud computing federation  

NASA Astrophysics Data System (ADS)

Cloud Computing Federation is a main trend of Cloud Computing. Resource Management has significant effect on the design, realization, and efficiency of Cloud Computing Federation. Cloud Computing Federation has the typical characteristic of the Complex System, therefore, we propose a resource management architecture based on complex network theory for Cloud Computing Federation (abbreviated as RMABC) in this paper, with the detailed design of the resource discovery and resource announcement mechanisms. Compare with the existing resource management mechanisms in distributed computing systems, a Task Manager in RMABC can use the historical information and current state data get from other Task Managers for the evolution of the complex network which is composed of Task Managers, thus has the advantages in resource discovery speed, fault tolerance and adaptive ability. The result of the model experiment confirmed the advantage of RMABC in resource discovery performance.

Zhang, Zehua; Zhang, Xuejie

2011-10-01

482

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

483

AAA gunnermodel based on observer theory. [predicting a gunner's tracking response  

NASA Technical Reports Server (NTRS)

The Luenberger observer theory is used to develop a predictive model of a gunner's tracking response in antiaircraft artillery systems. This model is composed of an observer, a feedback controller and a remnant element. An important feature of the model is that the structure is simple, hence a computer simulation requires only a short execution time. A parameter identification program based on the least squares curve fitting method and the Gauss Newton gradient algorithm is developed to determine the parameter values of the gunner model. Thus, a systematic procedure exists for identifying model parameters for a given antiaircraft tracking task. Model predictions of tracking errors are compared with human tracking data obtained from manned simulation experiments. Model predictions are in excellent agreement with the empirical data for several flyby and maneuvering target trajectories.

Kou, R. S.; Glass, B. C.; Day, C. N.; Vikmanis, M. M.

1978-01-01

484

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

485

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

486

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

487

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

488

Detection and control of combustion instability based on the concept of dynamical system theory.  

PubMed

We propose an online method of detecting combustion instability based on the concept of dynamical system theory, including the characterization of the dynamic behavior of combustion instability. As an important case study relevant to combustion instability encountered in fundamental and practical combustion systems, we deal with the combustion dynamics close to lean blowout (LBO) in a premixed gas-turbine model combustor. The relatively regular pressure fluctuations generated by thermoacoustic oscillations transit to low-dimensional intermittent chaos owing to the intermittent appearance of burst with decreasing equivalence ratio. The translation error, which is characterized by quantifying the degree of parallelism of trajectories in the phase space, can be used as a control variable to prevent LBO. PMID:25353548

Gotoda, Hiroshi; Shinoda, Yuta; Kobayashi, Masaki; Okuno, Yuta; Tachibana, Shigeru

2014-02-01

489

Z curve theory-based analysis of the dynamic nature of nucleosome positioning in Saccharomyces cerevisiae.  

PubMed

Nucleosome is the elementary structural unit of eukaryotic chromatin. Instability of nucleosome positioning plays critical roles in chromatin remodeling in differentiation and disease. In this study, we investigated nucleosome dynamics in the Saccharomyces cerevisiae genome using a geometric model based on Z curve theory. We identified 52,941 stable nucleosomes and 7607 dynamic nucleosomes, compiling them into a genome-wide nucleosome dynamic positioning map and constructing a user-friendly visualization platform (http://bioinfo.hrbmu.edu.cn/nucleosome). Our approach achieved a sensitivity of 90.31% and a specificity of 87.76% for S. cerevisiae. Analysis revealed transcription factor binding sites (TFBSs) were enriched in linkers. And among the sparse nucleosomes around TFBSs, dynamic nucleosomes were slightly preferred. Gene Ontology (GO) enrichment analysis indicated that stable and dynamic nucleosomes were enriched on genes involved in different biological processes and functions. This study provides an approach for comprehending chromatin remodeling and transcriptional regulation of genes. PMID:23958656

Wu, Xueting; Liu, Hui; Liu, Hongbo; Su, Jianzhong; Lv, Jie; Cui, Ying; Wang, Fang; Zhang, Yan

2013-11-01

490

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

491

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

492

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 app