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1

Configuration Issues of Cashier Staff in Supermarket Based on Queuing Theory  

Microsoft Academic Search

\\u000a Known that it is particularly important for a supermarket to reasonably employ cashier staff, reduce customers’ waiting time\\u000a and the operating costs of the supermarket and improve efficiency. In order to settle the problem that how to configure the\\u000a cashier staff in supermarket, this paper builds the mathematical model about service system based on queuing theory. Then\\u000a it analyzes and

Baofeng Li; Donghua Wang

2

Comparison of an AGV transportation system by using the queuing network theory  

Microsoft Academic Search

In this paper, we provide the comparison indicator of the AGV transportation systems. For this purpose, we propose an optimal design methodology for the AGV transportation system by using the queuing network theory. In this methodology, the queuing network theory and a simulation-based optimization method are integrated to obtain the optimal design parameters (i.e., these are the design solutions of

Satoshi HOSHINO; Jun OTA; Akiko SHINOZAKI; Hideki HASHIMOTO

2004-01-01

3

An Application of Queuing Theory to Waterfowl Migration  

Microsoft Academic Search

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

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

4

Stabilizing distributed queuing systems using feedback based on diversity  

Microsoft Academic Search

The Huberman-Hogg model of computational ecosystems is applied to resources with queues. The previous theoretical results indicate that instabilities, due to delayed information, can be controlled by adaptive mechanisms, particularly schemes which employ diverse past horizons. A stochastic learning automaton, with rewards based on queuing parameters, is implemented to test the theoretical results. The effects of the learning step size

Edward A. Billard

1997-01-01

5

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.

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

2014-01-01

6

A Framework for Differential Frame-Based Matching Algorithms in Input-Queued Switches  

Microsoft Academic Search

We propose a novel framework to solve the problem of scheduling packets in high-speed input-queued switches with frame-based control. Our approach is based on the application of game theory concepts. We define a flexible scheduling policy, named SSB (Slot Sell and Buy): the existence of a unique Nash equilibrium for the policy is proved, together with properties of convergence of

Andrea Bianco; Paolo Giaccone; Emilio Leonardi; Fabio Neri

2004-01-01

7

Genetic algorithm based optimization of an agent based queuing system  

Microsoft Academic Search

Queuing research and its applications have been studied extensively by concentrating mainly on design, performance and running of the service facility under study. In this paper we show how a simple behavioral queuing system can be modeled using a Cellular Automata; and then we show how a Genetic Algorithm can be used to optimize the behavioral properties of this agent

K. Sankaranarayanan; E. R. Larsen; A. van Ackere; C. A. Delgado

2010-01-01

8

Performance Analysis on Adaptive Modulation-based BLAST Systems with Queuing Model  

Microsoft Academic Search

In this paper, we analyze the performance of adaptive modulation-based Bell-labs layered space–time systems with finite-length\\u000a queuing model. Since the thresholds values for the adaptive modulation scheme should be optimized when the queuing model is\\u000a taken into account in the system, cross-layer performance analysis on the queuing behavior is necessary. The most important\\u000a contribution of our work is to express

Wei Zhao; Honglin Hu

9

GOD Queuing : A Novel Grid-based Resource Co-allocation Scheme in Distributed Multimedia System  

Microsoft Academic Search

In this paper, we firstly analyze all kinds of resource allocation schemes in distributed multimedia system, including QoS manager, SRT, GARA, and propose a novel distributed multimedia service grid architecture & multimedia service grid. Based on grid architecture, this paper introduces a novel resource allocation scheme & grid-based on-demand queuing, GOD queuing. We propose the function architecture of the scheme,

Lv Zhihui; Yiping Zhong; Weiming Fu; Shiyong Zhang

2005-01-01

10

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.

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

2013-01-01

11

Spreadsheet Analysis Of Queuing In A Computer Network  

NASA Technical Reports Server (NTRS)

Method of analyzing responses of computer network based on simple queuing-theory mathmatical models via spreadsheet program. Effects of variations in traffic, capacities of channels, and message protocols assessed.

Galant, David C.

1992-01-01

12

Modeling ad hoc network based on 802.11 DCF by queuing network analyzer  

NASA Astrophysics Data System (ADS)

In this paper, we present an analytic model for evaluating the average end-to-end delay and per-node throughput in an IEEE802.11MAC DCF based wireless network. By virtue of QNA and probability generation function, we model ad hoc network as open M/G/1 queuing networks and obtain the closed form expressions for average end-to-end delay. Simulations based on NS2 validate the accuracy of our model.

Zhang, Wenbin; Zhang, Zhongzhao

2007-11-01

13

Design of packet-fair queuing schedulers using a RAM-based searching engine  

Microsoft Academic Search

The implementation of packet-fair queuing (PFQ) schedulers, which aim at approximating the generalized processor sharing (GPS) policy, is a central issue for providing multimedia services with various quality-of-service (QoS) requirements in packet-switching networks. In the PFQ scheduler, packets are usually time stamped with a value based on some algorithm and are transmitted with an increasing order of the time-stamp values.

H. Jonathan Chao; Yau-Ren Jenq; Xiaolei Guo; Cheuk H. Lam

1999-01-01

14

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

NASA Astrophysics Data System (ADS)

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

Saichev, A.; Sornette, D.

2010-01-01

15

Perspectives for Practice Why queuing never vanishes  

Microsoft Academic Search

This tutorial aims to address and illustrate that queuing theory has a wider potential than generally perceived, while at the same time a variety of practical problems, both in daily-life and industry, are open for fundamental research. To this end, it will: (i) Highlight basic queuing insights for daily-life purposes. (ii) Provide exact and bounding results for queuing network applications.

Nico M. van Dijk

16

MQML-Message Queuing Markup Language  

Microsoft Academic Search

Message Queuing allows applications to use components that communicate with one another using queued messages. In this paper, we propose a Message Queuing Markup Language (MQML), which is an XML based markup language designed to describe e-business applications and enterprise integration. The MQML language is extensible. The detailed description of the MQML is presented in this paper. An research prototype

Min-hua Shi; De-ren Chen; Liang-jie Zhang; Rong-guo Wang

2002-01-01

17

Optimization of wind turbine vane manufacture based on queuing theory  

Microsoft Academic Search

Wind turbine vane is the key components of wind power generators effectively capture the wind. RTM is a manufacture technology of advanced composite materials, low cost, medium batch blade. Some random factors often lead to the production schedule can not be predetermined program normally. It can help reduce production costs that with the start-up costs were study of production scheduling

Qing-hui Dai; Sha Li

2011-01-01

18

Design and Implementation of High-Speed Input-Queued Switches Based on a Fair Scheduling Algorithm  

NASA Astrophysics Data System (ADS)

To increase both the capacity and the processing speed for input-queued (IQ) switches, we proposed a fair scalable scheduling architecture (FSSA). By employing FSSA comprised of several cascaded sub-schedulers, a large-scale high performance switches or routers can be realized without the capacity limitation of monolithic device. In this paper, we present a fair scheduling algorithm named FSSA_DI based on an improved FSSA where a distributed iteration scheme is employed, the scheduler performance can be improved and the processing time can be reduced as well. Simulation results show that FSSA_DI achieves better performance on average delay and throughput under heavy loads compared to other existing algorithms. Moreover, a practical 64 × 64 FSSA using FSSA_DI algorithm is implemented by four Xilinx Vertex-4 FPGAs. Measurement results show that the data rates of our solution can be up to 800Mbps and the tradeoff between performance and hardware complexity has been solved peacefully.

Hu, Qingsheng; Zhao, Hua-An

19

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

20

A Queuing-Theoretic and Optimization-Based Model for Radio Resource Management in IEEE 802.16 Broadband Wireless Networks  

Microsoft Academic Search

We present a queuing-theoretic and optimization-based model for radio resource management in IEEE 802.16-based multiservice broadband wireless access (BWA) networks considering both packet-level and connection-level quality-of-service (QoS) constraints. Specifically, we model and analyze two approaches, namely, the optimal and the iterative approaches, for joint bandwidth allocation (BA) and connection admission control (CAC). To limit the amount of bandwidth allocated to

Dusit Niyato; Ekram Hossain

2006-01-01

21

Capacity Utilization Study for Aviation Security Cargo Inspection Queuing System  

SciTech Connect

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

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

2010-01-01

22

Queuing register uses fluid logic elements  

NASA Technical Reports Server (NTRS)

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

1966-01-01

23

Randomized Parallel Scheduling Algorithm for Input Queued Crossbar Switches  

Microsoft Academic Search

A significant research effort has been devoted in recent years to the design of simple and efficient scheduling algorithms for input-queued packet switches. Among these algorithms, scheduling policies based on maximum weight matching (MWM) were proved to achieve 100% throughput under any admissible traffic load. However, MWM is impractical for its high computational complexity O(N3). In this paper, we propose

Yanfeng Zheng; Wen Gao

2005-01-01

24

Improving the Performance of Input-Queued ATM Packet Switches  

Microsoft Academic Search

The authors propose a single way to dramatically improve the performance of input-queued ATM packet switches beyond the 82% saturation point obtained in previous work. The method is an extension of the independent output-port schedulers technique and is based on the notion of recycled time slots, i.e. reusing time slots normally wasted due to scheduling conflicts. In contrast to previous

Mark J. Karol; Kai Y. Eng; Hitoshi Obara

1992-01-01

25

Queuing network modeling of the psychological refractory period (PRP).  

PubMed

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 for a variety of PRP phenomena; however, each also encounters at least 1 experimental counterexample to its predictions or modeling mechanisms. This article describes a queuing network-based mathematical model of PRP that is able to model various experimental findings in PRP with closed-form equations including all of the major counterexamples encountered by the existing models with fewer or equal numbers of free parameters. This modeling work also offers an alternative theoretical account for PRP and demonstrates the importance of the theoretical concepts of "queuing" and "hybrid cognitive networks" in understanding cognitive architecture and multitask performance. PMID:18954209

Wu, Changxu; Liu, Yili

2008-10-01

26

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

27

Using queuing theory to predict organizational metrics  

Microsoft Academic Search

Most existing organizational design processes focus on either the qualitative or domain-independent features of candidate designs. This paper demonstrates the significance of domain-specific features through an examination of an organizationally-driven information retrieval network. The behavior of a distributed search process and the consequences of hierarchical control are described. A model capable of predicting these characteristics is created in the ODML

Bryan Horling; Victor R. Lesser

2006-01-01

28

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

29

Fair Queuing and Other Probabilistic Allocation Methods  

Microsoft Academic Search

A server processes one job per unit of time and randomly schedules the jobs requested by a given set of users; each user may request a different number of jobs. Fair queuing (Shenker 1989) schedules jobs in successive round-robin fashion, where each agent receives one unit in each round until his demand is met and the ordering is random in

Herve Moulin; Richard Stong

2001-01-01

30

An implementable parallel scheduler for input-queued switches  

Microsoft Academic Search

The input-queued (IQ) switch architecture has received much attention in the research community and with implementers because it scales well with the line speed and the switch size. The main reason for this is that the memory bandwidth requirement for an input-queued switch is minimal, making it less expensive to implement compared to an output-queued or a shared-memory switch. To

Paolo Giaccone; Devavrat Shah; Balaji Prabhakar

2001-01-01

31

Fair queuing in wireless networks: issues and approaches  

Microsoft Academic Search

Fair queuing has long been a popular paradigm for providing bounded delay channel access and separation between flows in wireline networks. However, adapting fair queuing to the wireless domain is not a trivial task because of the unique problems in wireless channels such as location-dependent and bursty channel error. In this article we identify the key issues in wireless fair

VADUVUR BHARGHAVAN; Songwu Lu; THYAGARAJAN NANDAGOPAL

1999-01-01

32

Time-Varying Priority Queuing Models for Human Dynamics  

Microsoft Academic Search

Queuing models provide insight into the temporal inhomogeneity of human dynamics, characterized by the broad distribution of waiting times of individuals performing tasks. We study the queuing model of an agent trying to execute a task of interest, the priority of which may vary with time due to the agent's \\

Hang-Hyun Jo; Raj Kumar Pan; Kimmo Kaski

2011-01-01

33

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

34

Tracking the behavior of an ideal output queued switch using an input queued switch with unity speedup  

Microsoft Academic Search

We address the problem of fair scheduling of packets in Internet routers with input-queued (IQ) switches. We present new performance metrics for IQ switches with unity speedup. Scheduling in IQ switches is formulated as tracking the behavior of an ideal output-queued (OQ) switch that provides optimal performance. We introduce several performance metrics that measure the difference between the ideal performance

Amir Gourgy; Ted H. Szymanski

2004-01-01

35

Agent-Based Literacy Theory  

ERIC Educational Resources Information Center

The purpose of this theoretical essay is to explore the limits of traditional conceptualizations of reader and text and to propose a more general theory based on the concept of a literacy agent. The proposed theoretical perspective subsumes concepts from traditional theory and aims to account for literacy online. The agent-based literacy theory

McEneaney, John E.

2006-01-01

36

A multi-agent queuing model for resource allocations in a non-cooperative game  

Microsoft Academic Search

In this paper, we investigate a multi-agent non-cooperative game for resource allocations based on an M\\/D\\/1 queuing model. Specifically, agents with common goals to maximize individual utility are deployed to compete with each other to bid or bribe for quicker service provided by the server. Agents choose from one of three available strategies: random strategy, Nash equilibrium strategy and linear

Pinata Winoto; Tiffany Ya Tang

2002-01-01

37

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

38

Scheduling with Soft Deadlines for Input Queued Switches  

Microsoft Academic Search

We study the problem of deadline aware schedul- ing for input queued (IQ) switches. While most research on scheduler design for IQ switches has focused on maximizing throughput and optimizing switch performance for non-real- time traffic, packet deadlines are a key consideration in the context of real-time applications like multimedia streaming and video telephony. In this paper, we introduce the

Aditya Dua; Nicholas Bambos

2006-01-01

39

Scheduling Algorithms for Input Queued Switches Using Local Search Technique  

Microsoft Academic Search

Input Queued switches have been very well studied in the recent past. The Maximum Weight Matching (MWM) algorithm is known to deliver 100% throughput under any admissible traffic. However, MWM is not practical for its high computational complexity O(N3). In this paper, we study a class of ap- proximations to MWM from the point of view of local search. Firstly,

Yanfeng Zheng; Simin He; Shutao Sun; Wen Gao

2005-01-01

40

An Implementable Parallel Scheduler for Input-Queued Switches  

Microsoft Academic Search

The Apsara algorithm is an input-queued switch scheduler that uses limited parallelism to find a matching in a single iteration, as compared to the O(N3) iterations of the more common maximum-weight matching algorithm. The Apsara algorithm also achieves a throughput of up to 100 percent and has very good delay properties

Paolo Giaccone; Devavrat Shah; Balaji Prabhakar

2002-01-01

41

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

42

A Queuing Model of Price Determination in a Competitive Market  

Microsoft Academic Search

This paper addresses the question of how prices change in a competitive market if all agents are price takers. A queuing model of price determination is developed in which buyers and sellers face trade-offs between price and expected wait times. Sellers set prices but are competitive in the sense that they are \\

Michael Sattinger

1998-01-01

43

The Building of E-Commerce Transaction Network Based on Multi-agent and CAS Theory  

Microsoft Academic Search

In this paper, analyzed the characteristic of E-Commerce Transaction Network --indetermination, non- linearity, complexity, variety, discreteness, dynamic from the point of view of system, suggested that the modeling and simulation for E-Commerce Transaction Network would simulation for queuing, inventory and network. Complex adaptive system (CAS) theory is used to analyze the e-commerce system and the concept of e-commerce transaction network

Hao Xu; Duo-lin Liu; Zhi-jie Lu

2010-01-01

44

ENHANCING OBJECT-ORIENTED SIMULATION WITH RULE-BASED EXPERT SYSTEM  

Microsoft Academic Search

This paper describes our research in developing an intelligent simulation system by enhancing an object-oriented simulator with a rule-based expert system. Designing and implementing a simulation model for a particular problem requires extensive expertise in simulation techniques, computer languages and queuing theory. However, those who would like to use simulation to assist their decision making might not always be technically

Otto Lee; Hon Wai Chun

45

Agent-Based Negotiation Techniques for a Grid: The Prophet Agents  

Microsoft Academic Search

The aims of this research are to introduce a new transparent control paradigm and to consolidate Grid resources by a statistical approach based on Agents and on Queuing Theory. These goals are obtained through the creation of a new category of Agents called \\

Massimo Orazio Spata; Giuseppe Pappalardo; Salvatore Rinaudo; Tonio Biondi

2006-01-01

46

Queuing of concurrent movement plans by basal ganglia.  

PubMed

How the brain converts parallel representations of movement goals into sequential movements is not known. We tested the role of basal ganglia (BG) in the temporal control of movement sequences by a convergent approach involving inactivation of the BG by muscimol injections into the caudate nucleus of monkeys and assessing behavior of Parkinson's disease patients, performing a modified double-step saccade task. We tested a critical prediction of a class of competitive queuing models that explains serial behavior as the outcome of a selection of concurrently activated goals. In congruence with these models, we found that inactivation or impairment of the BG unmasked the parallel nature of goal representations such that a significantly greater extent of averaged saccades, curved saccades, and saccade sequence errors were observed. These results suggest that the BG perform a form of competitive queuing, holding the second movement plan in abeyance while the first movement is being executed, allowing the proper temporal control of movement sequences. PMID:23761894

Bhutani, Neha; Sureshbabu, Ramakrishnan; Farooqui, Ausaf A; Behari, Madhuri; Goyal, Vinay; Murthy, Aditya

2013-06-12

47

Time-varying priority queuing models for human dynamics  

NASA Astrophysics Data System (ADS)

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

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

2012-06-01

48

Time-varying priority queuing models for human dynamics.  

PubMed

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

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

2012-06-01

49

Fair scheduling in input-queued switches under inadmissible traffic  

Microsoft Academic Search

In recent years, several high-throughput low-delay scheduling algorithms have been designed for input-queued (IQ) switches, assuming admissible traffic. In this paper, we focus on queueing systems that violate admissibility criteria. We show that in a single-server system with multiple queues, the longest queue first (LQF) policy disallows a fair allocation of service rates. We also describe the duality shared by

Neha Kumar; Rong Pan; Devavrat Shah

2004-01-01

50

A deterministic parallel scheduling algorithm for input queued crossbar switches  

Microsoft Academic Search

Input-queued (IQ) switch architectures have become predominant in high-speed switching for the past decade. Maximum weight matching (MWM) algorithms are known to achieve 100% throughput under any admissible traffic. Unfortunately, MWM is impractical for its high computational complexity O(N3). In this paper, we study a new type of approximate algorithm to MWM using local search technique. Instead of using randomized

Yanfeng Zheng; Simin He; Shutao Sun; Wen Gao

2005-01-01

51

Queues allocation for multiple input-queued switches  

Microsoft Academic Search

To meet the increasing requirement for high speed switches, a multiple input-queued (MIQ) switch is explored. Rather than handling the scheduling problem heavily focused on by many researchers, a proposed dynamic queue allocation algorithm is used to handle non-uniform or hot-spot traffic. Although the performance of the original algorithm is analyzed by N.K. Sharma and M.R. Pinnu (see Parallel Computing,

Joe Shang-Chieh Wu; Raymond Miler; Tsern-Huei Lee; Ying-Dar Lin

2001-01-01

52

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

53

A queueing theory based model for business continuity in hospitals.  

PubMed

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

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

2013-01-01

54

ANALYSIS OF THE SALES CHECKOUT OPERATION IN ICA SUPERMARKET USING QUEUING SIMULATION  

Microsoft Academic Search

This paper contains the analysis of Queuing systems for the empirical data of supermarket checkout service unit as an example. One of the expected gains from studying queuing systems is to review the efficiency of the models in terms of utilization and waiting length, hence increasing the number of queues so customers will not have to wait longer when servers

Azmat Nafees

55

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

56

Modeling multi-lane traffic flow with queuing effects  

NASA Astrophysics Data System (ADS)

On the basis of assumptions about the behavior of driver-vehicle units concerning acceleration, deceleration, overtaking, and lane-changing maneuvers, a gas-kinetic traffic model for unidirectional multi-lane freeways is constructed. Queuing effects are explicitly taken into account in an overall manner. The resulting model is a generalization of Paveri-Fontana's Boltzmann-like traffic model and allows the derivation of macroscopic traffic equations for interacting lanes, including velocity equations. The related effective macroscopic traffic model for the total free-way cross-section is also derived. It provides corrections with respect to previous traffic models, but agrees with them in special cases.

Helbing, Dirk

1997-02-01

57

Closeness theory based fuzzy ART model  

Microsoft Academic Search

A fuzzy ART neural network model based on the closeness theory, called CBFART, is introduced in this paper. It incorporates two concepts of the fuzzy set theory, the closeness and closet principle with the adaptive resonance theory (ART), to form a new neural network model. The model is characterized with a matching-consigning cycle, and classification of patterns in the network

Zhang Dianzhi; Liu Wenhua; Lei Hongli

2000-01-01

58

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

59

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

SciTech Connect

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

Buckwalter, J

2005-09-28

60

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

NASA Astrophysics Data System (ADS)

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

Duan, Haoran

1997-12-01

61

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

62

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

63

StablePlus: A practical 100% throughput scheduling for input-queued switches  

Microsoft Academic Search

This paper proposes a practical stable packet scheduling algorithm for input-queued switches, called Sta- blePlus, which combines a stable matching with a heuristic matching. It not only achieves 100% throughput under any admissible traffic but also has good delay performance. Sta- blePlus can be implemented with today's technology for high line rates, e.g., 100Gbps, and a relatively large input-queued switch,

Yu Xia; H. Jonathan Chao

2011-01-01

64

Automata Theory Based on Quantum Logic. (I)  

Microsoft Academic Search

We present a basic framework of automata theory based on quantum logic. Inparticular, we introduce the orthomodular lattice-valued (quantum) predicate ofrecognizability and establish some of its fundamental properties.

Mingsheng Ying

2000-01-01

65

Generalized Information Theory Based on the Theory of Hints  

Microsoft Academic Search

\\u000a The aggregate uncertainty is the only known functional for Dempster-Shafer theory that generalizes the Shannon and Hartley measures and satisfies all\\u000a classical requirements for uncertainty measures, including subadditivity. Although being posed several times in the literature,\\u000a it is still an open problem whether the aggregate uncertainty is unique under these properties. This paper derives an uncertainty\\u000a measure based on the

Marc Pouly

66

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

67

Discontinuous Galerkin method based on peridynamic theory  

Microsoft Academic Search

In this study, a novel formulation of the discontinuous Galerkin method is derived based on peridynamic theory. Derivation of the proposed formulation is presented. Numerical analysis are performed for 2D problems, and results are compared to their respective known exact solutions. Numerical tests are performed at the incompressible limit. The proposed discontinuous Galerkin formulation is found to be robust and

H G Aksoy; E ?enocak

2010-01-01

68

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

69

Automata Theory Based on Quantum Logic II  

Microsoft Academic Search

We establish the pumping lemma in automata theory based on quantum logicunder certain conditions on implication, and discuss the recognizability by theproduct and union of orthomodular lattice-valued (quantum) automata. Inparticular, we show that the equivalence between the recognizabilty by the productof automata and the conjunction of the recognizabilities by the factor automatais equivalent to the distributivity of meet over union

Mingsheng Ying

2000-01-01

70

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.

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

2013-01-01

71

Modelling pedestrian travel time and the design of facilities: a queuing approach.  

PubMed

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

2013-01-01

72

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

73

Structure based statistical theory of intermittency  

SciTech Connect

A general statistical theory of the intermittency in turbulence based on short-lived coherent structures (instantons) is presented. The probability density functions (PDFs) of the flux R are shown to have an exponential scaling P(R){proportional_to}exp(-cR{sup s}) in the tails, with the exponent s=(n+1)/m. Here, n and m are the order of the highest nonlinear interaction term and moments for which the PDFs are computed, respectively; c is constant depending on spatial profile of the coherent structure. The results can have important implications for understanding the universality often observed in simulations and experiments.

Kim, Eun-jin; Anderson, Johan [Department of Applied Mathematics, University of Sheffield, Sheffield, S3 7RH (United Kingdom)

2008-11-15

74

An enhanced model for minimizing fuel consumption under block-queuing in a drive-through service system  

Microsoft Academic Search

We present a new model for determining the optimal block-size under block-queuing in a simple, single-channel queue at a drive-through service facility. With block-queuing, a queue is partitioned into an active section and a passive section, where drivers are asked to turn off their engines until the active section clears. Our model prescribes a block-size, i.e., a maximum number of

Charles H. Reilly; Jon Berglin

2004-01-01

75

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

76

Achieving stability in networks of input-queued switches using a local online scheduling policy  

Microsoft Academic Search

In recent years, several high-throughput low-delay scheduling algorithms have been designed for input-queued (IQ) switches. It has been shown however that scheduling policies such as maximum weight matching, that perform optimally for an isolated switch, fail to provide stability in a network of IQ switches (M. Andrews and L. Zhang, 2001). Although there exist algorithms that ensure stability in networks

Shubha U. Nabar; Neha Kumar; Mohsen Bayati; Abtin Keshavarzian

2005-01-01

77

Packet scheduling in a combined input and output queued switch using virtual time reference system  

Microsoft Academic Search

There is an increasing demand for Internet core nodes to have (1) quality-of-service (QoS) guarantees and (2) higher switching capacity. The combined input and output queued (CIOQ) switching has been shown to be a promising solution to meet such demand. However, many of the proposed scheduling algorithms for a CIOQ switch cannot be practically implemented due to problems from scalability

Yiwei Thomas Hou; Z.-L. Zhang; T. Hamada

2000-01-01

78

One-way queuing delay measurement and its application on detecting DDoS attack  

Microsoft Academic Search

This paper presents a novel approach to measure and estimate end-to-end one-way queuing delay in a network, which carries information about traffic characteristics and congestion properties. The measurement results can be used to describe the normal behavior of the network and detect distributed denial-of-service attacks (DDoS attacks). The measurement does not require any synchronization between the two measurement ends. Pairs

Wei-zhou Lu; Wei-xuan Gu; Shun-zheng Yu

2009-01-01

79

M\\/M\\/1 queuing model for adaptive cross-layer error protection in WLANs  

Microsoft Academic Search

An analytical model is employed to solve a cross-layer optimization problem in IEEE 802.11 wireless local area networks (WLANs). Closed-form expressions for the optimum retry limit, packet overflow drop rate and overall loss rate are derived using M\\/M\\/l queuing model, and subsequently an adaptive MAC retry limit scheme is studied. Furthermore simulation results (network simulator-2) will verify the accuracy of

Hossein Bobarshad; Mohammad Shikh-Bahaei

2009-01-01

80

Modelling tissue behaviour based on hyperelasticity theory.  

PubMed

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

Valenta, J; R?zicka, M; Cihák, R

1994-01-01

81

A goalkeeper strategy in robot soccer based on Danger Theory  

Microsoft Academic Search

Artificial Immune Systems (AIS) have been successfully modeled and implemented in several engineering applications. In this work, a goalkeeper strategy in robot soccer based on Danger Theory is proposed. Danger Theory is a recent immune theory which has not been widely applied so far. The proposed strategy is implemented and evaluated using middle league SIMUROSOT from FIRA. Experiments carried out

Camilo Eduardo Prieto; Fernando Niño; Gerardo Quintana

2008-01-01

82

Theory Based Approaches to Learning. Implications for Adult Educators.  

ERIC Educational Resources Information Center

This paper presents a codification of theory-based approaches that are applicable to adult learning situations. It also lists some general guidelines that can be used when selecting a particular approach or theory as a basis for planning instruction. Adult education's emphasis on practicality and the relationship between theory and practice is…

Bolton, Elizabeth B.; Jones, Edward V.

83

Information Security Risk Assessment Based on Artificial Immune Danger Theory  

Microsoft Academic Search

This paper puts forward an information security risk assessment model, which based on danger theory, and provides a risk calculation method based on this model. It aims at the problem of the strong subjectivity and improving the accuracy and real time performance of current information security risk assessment system, by reference to dynamic response characteristic of danger theory in immunology.

Yi Zhuang; Xiaorong Li; Bin Xu; Bo Zhou

2009-01-01

84

Towards a Resource-based Theory of Information Strategy  

Microsoft Academic Search

The central aim of this paper is to instigate the construction of a theory of information strategy based on th e Resource -based View (RBV) of the firm (Barney, 1986, 1991; Penrose, 1959; Wernerfelt, 1984). Therefore, an initial theoretical framework is proposed within which such a theory could be developed further. In essence, this theoretical framework sheds light on how

Onno Truijens

85

Theory-Based University Admissions Testing for a New Millennium  

ERIC Educational Resources Information Center

This article describes two projects based on Robert J. Sternberg's theory of successful intelligence and designed to provide theory-based testing for university admissions. The first, Rainbow Project, provided a supplementary test of analytical, practical, and creative skills to augment the SAT in predicting college performance. The Rainbow…

Sternberg, Robert J.

2004-01-01

86

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

87

Observational attachment theory-based parenting measures predict children's attachment narratives independently from social learning theory-based measures.  

PubMed

Conceptually and methodologically distinct models exist for assessing quality of parent-child relationships, but few studies contrast competing models or assess their overlap in predicting developmental outcomes. Using observational methodology, the current study examined the distinctiveness of attachment theory-based and social learning theory-based measures of parenting in predicting two key measures of child adjustment: security of attachment narratives and social acceptance in peer nominations. A total of 113 5-6-year-old children from ethnically diverse families participated. Parent-child relationships were rated using standard paradigms. Measures derived from attachment theory included sensitive responding and mutuality; measures derived from social learning theory included positive attending, directives, and criticism. Child outcomes were independently-rated attachment narrative representations and peer nominations. Results indicated that Attachment theory-based and Social Learning theory-based measures were modestly correlated; nonetheless, parent-child mutuality predicted secure child attachment narratives independently of social learning theory-based measures; in contrast, criticism predicted peer-nominated fighting independently of attachment theory-based measures. In young children, there is some evidence that attachment theory-based measures may be particularly predictive of attachment narratives; however, no single model of measuring parent-child relationships is likely to best predict multiple developmental outcomes. Assessment in research and applied settings may benefit from integration of different theoretical and methodological paradigms. PMID:24283669

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

2014-01-01

88

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

...2013-04-01 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?...

2013-04-01

89

A Theory-Based Computer Tutorial Model.  

ERIC Educational Resources Information Center

Because of the need for models to illustrate some possible answers to practical courseware development questions, a specific, three-section model incorporating the Corrective Feedback Paradigm (PCP) is advanced for applying theory to courseware. The model is reconstructed feature-by-feature against a framework of a hypothetical, one-to-one,…

Dixon, Robert C.; Clapp, Elizabeth J.

90

Recursive renormalization group theory based subgrid modeling  

NASA Technical Reports Server (NTRS)

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

Zhou, YE

1991-01-01

91

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

ERIC Educational Resources Information Center

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

Anil, Duygu

2008-01-01

92

Automata theory based on quantum logic: some characterizations  

Microsoft Academic Search

Automata theory based on quantum logic (abbr. l-valued automata theory) may be viewed as a logical approach of quantum computation. In this paper, we characterize some fundamental properties of l-valued automata theory, and discover that some properties of the truth-value lattices of the underlying logic are equivalent to certain properties of automata. More specifically (i) the transition relations of l-valued

Daowen Qiu

2004-01-01

93

A DFT Based Ligand Field Theory  

Microsoft Academic Search

A general and user-oriented ligand field (LF) theory – LFDFT with parameters adjusted to DFT energies of separate Slater Determinants (SD) of the partly filled dn shell [n=2(8), 3(7), 4(6) and 5] of transition metals (TM) complexes – is developed and tested using 22 well documented examples from the literature. These include CrIII, d3 and CoII d7 in octahedral and

M. Atanasov; C. Daul; C. Rauzy

94

Increasing Customer Satisfaction in Queuing Systems with Rapid Modelling  

Microsoft Academic Search

\\u000a Companies have to increase their customers’ satisfaction to keep their competitiveness. In services, waiting has great impact\\u000a on service level and customer satisfaction. Consequently, in time-based competition, one of the main objectives of service\\u000a companies is to minimize customer waiting. Waiting can be defined in several ways; however, the ultimate management objective\\u000a should be the maximization of customer satisfaction.\\u000a \\u000a \\u000a The

Noémi Kalló; Tamás Koltai

95

Evaluating Sensor Reliability in Classification Problems Based on Evidence Theory  

Microsoft Academic Search

This paper presents a new framework for sensor reliability evaluation in classification problems based on evidence theory (or the Dempster-Shafer theory of belief functions). The evaluation is treated as a two-stage training process. First, the authors assess the static reliability from a training set by comparing the sensor classification readings with the actual values of data, which are both represented

Huawei Guo; Wenkang Shi; Yong Deng

2006-01-01

96

Toward a Theory-Based Approach to Instructional Development.  

ERIC Educational Resources Information Center

Instructional development should be based on theory rather than raw empiricism. The dimensions and possible form of an instructional theory are outlined in three premises. It was presumed that a limited set of behavior categories exist and that all behaviors can be calssed into one or more of these categories. It was also presumed that for each…

Merrill, M. David

97

BDI and QDT: a comparison based on classical decision theory  

Microsoft Academic Search

In this paper we compare Beliefs-Desire-Intention sys- tems (BDI systems) with Qualitative Decision Theory (QDT). Our analysis based on classical decision theory illustrates several issues where one area may profit from research in the other area. BDI has studied how inten- tions link subsequent decisions, whereas QDT has stud- ied methods to calculate candidate goals from desires, and how to

Mehdi Dastani; Joris Hulstijn; Leendert van der Torre

2001-01-01

98

A Computer Forensics Model Based On Danger Theory  

Microsoft Academic Search

To effectively collect electronic evidences of computer crime, a novel danger theory based computer dynamic model (Demed) is proposed. With definitions of self, non-self and detector, the intrusion detection sub-model is given, which is composed of memory cell set, mature cells set, and immature cells set. Then, the danger theory based computer dynamic forensics sub-model is further given. Both the

Lingxi Peng; Zhengde Li; Jinquan Zeng; Jian Zhang; Caiming Liu; ChunLin Liang

2007-01-01

99

Ground reaction curve based upon block theory  

SciTech Connect

Discontinuities in a rock mass can intersect an excavation surface to form discrete blocks (keyblocks) which can be unstable. Once a potentially unstable block is identified, the forces affecting it can be calculated to assess its stability. The normal and shear stresses on each block face before displacement are calculated using elastic theory and are modified in a nonlinear way by discontinuity deformations as the keyblock displaces. The stresses are summed into resultant forces to evaluate block stability. Since the resultant forces change with displacement, successive increments of block movement are examined to see whether the block ultimately becomes stable or fails. Two-dimensional (2D) and three-dimensional (3D) analytic models for the stability of simple pyramidal keyblocks were evaluated. Calculated stability is greater for 3D analyses than for 2D analyses. Calculated keyblock stability increases with larger in situ stress magnitudes, larger lateral stress ratios, and larger shear strengths. Discontinuity stiffness controls blocks displacement more strongly than it does stability itself. Large keyblocks are less stable than small ones, and stability increases as blocks become more slender.

Yow, J.L. Jr.; Goodman, R.E.

1985-09-01

100

Local Rule-Based Theory of Virus Shell Assembly  

Microsoft Academic Search

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

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

1994-01-01

101

Kinetic energy decomposition scheme based on information theory.  

PubMed

We proposed a novel kinetic energy decomposition analysis based on information theory. Since the Hirshfeld partitioning for electron densities can be formulated in terms of Kullback-Leibler information deficiency in information theory, a similar partitioning for kinetic energy densities was newly proposed. The numerical assessments confirm that the current kinetic energy decomposition scheme provides reasonable chemical pictures for ionic and covalent molecules, and can also estimate atomic energies using a correction with viral ratios. PMID:24132810

Imamura, Yutaka; Suzuki, Jun; Nakai, Hiromi

2013-12-15

102

Knowledge set theory: a knowledge representation method based on extenics  

NASA Astrophysics Data System (ADS)

Researchers put forward many knowledge representation methods according to specific problems for different domain. These methods according to their respective domain problem has different characteristic, each has its own strong points, suitable for different questions. This paper is research on a knowledge representation method based on extenics. Through the analysis of organizational knowledge system, the paper puts forward the related theory of knowledge set, and with the extenics theory gives the extension representation and the correlation analysis of knowledge set.

Li, Haifeng

2013-07-01

103

Queuing model analysis of the Fujitsu VP2000 with dual scalar architecture  

SciTech Connect

This paper reports on a queuing model analysis which is given for the performance evaluation of a dual scalar processor (DSP), which is composed to two scalar units and one vector unit. The performance evaluation is the three different processor models with equivalent hardware capacity: homogeneous DSP (DSP1), heterogeneous DSP (DSP2), and multiprocessor (MP), with particular attention given to the case of short vector lengths. It is found that the performance of DSP1 is preferable to that of MP for most actual workloads, and in particular for the work-load of the Japan Atomic Energy Research Institute. The effect of the dual scalar capacity, that is, of attaching a secondary scalar unit, is also investigated. It is shown that the throughput of DSP1 is about 1.8 times that of the uniprocessor, for a vectorization ratio of 90%.

Ishiguro, M. (Faculty of Engineering, Ibaraki Univ., Naka-Narusawa 4-12-1, Hitachi (JP))

1991-01-01

104

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

105

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

106

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

PubMed Central

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

Nami, Mohammad Rahim

2013-01-01

107

Multiple k-NN Classifiers Fusion Based on Evidence Theory  

Microsoft Academic Search

Multiple classifiers fusion is a powerful solution to the difficult and complex classification problems, which can improve performance and generalization capability. This paper presents a multiple k-nearest neighbor classifiers fusion approach based on evidence theory. Independent k-NN classifiers are established based on heterogeneous features. The novel approach to generating mass functions of a given sample for each member classifiers are

Deqiang Han; Chongzhao Han; Yi Yang

2007-01-01

108

Measurement of lens aberration based on vector imaging theory  

NASA Astrophysics Data System (ADS)

Current aerial image based aberration measurement methods are all derived from the scalar imaging theory which is not applicable to hyper-NA lithography. Here we propose an aberration measurement method for the lithography system with an arbitrary NA based on the rigorous vector imaging theory. The retrieval error of the proposed method is clearly demonstrated by comparing with the method based on the scalar imaging theory for an immersion NA 1.35 projector using numerical results. The results show that the maximal retrieval error of our method is below 0:5 m?, while that of previous method is above 4 m?. In addition, the effect of practical aerial image metrology accuracy on the retrieval accuracy of proposed technique is analyzed. The results obtained demonstrate that the retrieval accuracy of our method is greatly improved, and the proposed technique is applicable to the retrieval of the wavefront aberration of a projector with hyper-NA.

Dong, Lisong; Li, Yanqiu; Guo, Xuejia; Liu, Hao; Liu, Ke

2014-05-01

109

The Hypercube Queuing Model: An Introduction To Its Structure and Utility. (Part of Study: Innovative Resource Planning in Urban Public Safety Systems).  

National Technical Information Service (NTIS)

The hypercube queuing model provides a quantitative framework for spatially redeploying or revising the dispatching procedures of emergency response units (such as those found in municipal police, fire, and ambulance services). The model computes a mixtur...

R. C. Larson

1975-01-01

110

Spectrum Sensing for Multiuser Network Based on Free Probability Theory  

NASA Astrophysics Data System (ADS)

Based on Free Probability Theory (FPT), which has become an important branch of Random Matrix Theory (RMT), a new scheme of frequency band sensing for Cognitive Radio (CR) in Direct-Sequence Code-Division Multiple-Access (DS-CDMA) multiuser network is proposed. Unlike previous studies in the field, the new scheme does not require the knowledge of the spreading sequences of users and is related to the behavior of the asymptotic free behavior of random matrices. Simulation results show that the asymptotic claims hold true even for a small number of observations (which makes it convenient for time-varying topologies) outperforming classical energy detection scheme and another scheme based on random matrix theory.

Wang, Lei; Zheng, Baoyu; Meng, Qingmin; Chen, Chao

111

Infrared small target detection based on Danger Theory  

Microsoft Academic Search

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

Jinhui Lan; Xiao Yang

2009-01-01

112

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

113

A Natural Teaching Method Based on Learning Theory.  

ERIC Educational Resources Information Center

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

Smilkstein, Rita

1991-01-01

114

DS Theory-Based Software Trustworthiness Classification Assessment  

Microsoft Academic Search

Software trustworthiness Evaluation has become a research focus nowadays. Referencing the TRUSTIE Software Trust Classification Specification and Trust Evidence Framework Specification, we proposed a software trustworthiness classification assessment method based on DS theory. In this method, the uncertainty and evidences combination which are important during the evaluation but rarely considered by existing studies are taken into account, and DS combination

Wang Ben; Zhou Xingshe; Yang Gang; Yang Yalei

2010-01-01

115

Instantaneous power theory based Unified Power Quality Conditioner (UPQC)  

Microsoft Academic Search

This paper presents a novel control strategy for the case of 3-phase 3-wire Unified Power-Quality Conditioner (UPQC) based on the concepts of instantaneous active and reactive Power theory. The UPQCs is one of the major custom power solutions capable of mitigating the effect of supply voltage sags \\/ swells, distortion, unbalance voltage at the point of common coupling (PCC) as

K. Palanisamy; J. S. Mishra; I. J. Raglend; D. P. Kothari

2010-01-01

116

Exposition of magnetostatics based on the special theory of relativity  

NASA Astrophysics Data System (ADS)

We present the division “Magnetostatics” in the course of general physics, with the treatment based on the deductions of the special theory of relativity, the invariance of the electric charge, Coulomb's law, and the superposition principle of fields. The exposition begins with the analysis of the interaction of two point electric charges with arbitrary orientations of their velocities.

Tuman'yan, Yu. A.

1985-04-01

117

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

118

An Improved Terminal Guidance Algorithm Based on Differential Game Theory  

Microsoft Academic Search

Two-side optimal problem of pursuit-evasion conflicts is studied in this paper, and a new missile guidance law for air defense missile intercepting maneuver target is developed. The guidance law could be called as Reduced Sensitivity Guidance Law (RSGL), which is based on the differential game theory and the capacity of target maneuver. The mathematical model of RSGL is solved by

Li Yi; Yang Yan; Gao Tian; Jing Zhanrong

2010-01-01

119

Iterative learning control synthesis based on 2-D system theory  

Microsoft Academic Search

An algorithm is presented for iterative learning of the control input for a linear discrete-time multivariable system. Necessary and sufficient conditions are stated for convergence of the proposed algorithm. The algorithm synthesis and analysis are based on two-dimensional (2-D) system theory. A numerical example is given

J. E. Kurek; M. B. Zaremba

1993-01-01

120

Travel time information service device based on fuzzy sets theory  

Microsoft Academic Search

Drivers on highways usually can obtain predicted travel time information through a traffic control system in Japan. Information processing for the proper description of the travel time is discussed. A device based on fuzzy set theory is considered to transform forecasted values into practical traffic information. Drivers perception concerned with an allowable gap between a real travel time and an

Takamasa Akiyama; Hirotake Yamanishi

1993-01-01

121

An information theory based learning paradigm for linear feature extraction  

Microsoft Academic Search

This paper presents a novel unsupervised learning paradigm for feature extraction in linear networks under the constraint that no information distortion occurs in the input-output map. Independent feature extraction is then accomplished by minimizing an appropriate information theory based measure of the statistical dependence between the output components. In the case of Gaussian input distribution, a learning rule which preserves

Dragan Obradovic; Gustavo Deco

1996-01-01

122

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

123

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

124

New Variational Perturbation Theory Based on q-Deformed Oscillator  

NASA Astrophysics Data System (ADS)

A new variational perturbation theory is developed based on the q-deformed oscillator. It is shown that the new variational perturbation method provides 200 and 10 times better accuracy for the ground state energy of anharmonic oscillator than the Gaussian and the post Gaussian approximation, respectively, for weak coupling.

Kim, Hyeong-Chan; Yee, Jae Hyung; Kim, Sang Pyo

2006-05-01

125

Study on pilot attention allocation model based on fuzzy theory  

Microsoft Academic Search

Quantitative research of pilot attention allocation mechanism is required in aircraft human-machine interface optimization design and pilot flight performance evaluation. After making a comprehensive consideration of several factors, including information importance, information visual coding, information processing depth and human errors, pilot attention allocation model based on fuzzy theory is built. In order to make verification of this model, a head-up

Xiaoru Wanyan; Hengyang Wei; Damin Zhuang

2010-01-01

126

Innovating Method of Existing Mechanical Product Based on TRIZ Theory  

NASA Astrophysics Data System (ADS)

Main way of product development is adaptive design and variant design based on existing product. In this paper, conceptual design frame and its flow model of innovating products is put forward through combining the methods of conceptual design and TRIZ theory. Process system model of innovating design that includes requirement analysis, total function analysis and decomposing, engineering problem analysis, finding solution of engineering problem and primarily design is constructed and this establishes the base for innovating design of existing product.

Zhao, Cunyou; Shi, Dongyan; Wu, Han

127

Per-stream loss behavior of Sigma MAP\\/M\\/1\\/K queuing system with a random early detection mechanism  

Microsoft Academic Search

In this paper, the matrix-analytic approach is applied to explore the per-stream loss behavior of the multimedia traffic under RED scheme. We constructed a ?MAP\\/M\\/1\\/K queuing model for the RED mechanism with multimedia traffic which follows a continuous-time Markovian arrival process (MAP). In addition to evaluating the long-term per-stream packet drop probabilities, we examine the bursty nature of per-stream packet

Yung-chung Wang; Chwan-lu Tseng; Ren-guey Chu; Fu-hsiang Tsai

2009-01-01

128

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

129

Local Rule-Based Theory of Virus Shell Assembly  

NASA Astrophysics Data System (ADS)

A local rule-based theory is developed which shows that the self-assembly of icosahedral virus shells may depend on only the lower-level interactions of a protein subunit with its neighbors-i.e., on local rules rather than on larger structural building blocks. The local rule theory provides a framework for understanding the assembly of icosahedral viruses. These include both viruses that fall in the quasiequivalence theory of Caspar and Klug and the polyoma virus structure, which violates quasi-equivalence and has puzzled researchers since it was first observed. Local rules are essentially templates for energetically favorable arrangements. The tolerance margins for these rules are investigated through computer simulations. When these tolerance margins are exceeded in a particular way, the result is a "spiraling" malformation that has been observed in nature.

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

1994-08-01

130

? 6 Mixed plate theories based on the Generalized Unified Formulation. Part III: Advanced mixed high order shear deformation theories  

Microsoft Academic Search

The Generalized Unified Formulation was introduced in Part I in the case of plate theories based upon Reissner’s Mixed Variational Theorem. Part II analyzed the case of layerwise theories.In this work (Part III) the Generalized Unified Formulation is applied, for the first time in the literature, to the case of mixed higher order shear deformation theories. The displacements ux, uy,

Luciano Demasi

2009-01-01

131

Infrared small target detection based on Danger Theory  

NASA Astrophysics Data System (ADS)

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

Lan, Jinhui; Yang, Xiao

2009-11-01

132

Danger theory based SYN flood attack detection in autonomic network  

Microsoft Academic Search

In the context of autonomic environment, we present a simple yet, effective Danger Theory based method to detect TCP SYN Flooding attack. An autonomous communication network consists of self-managed (i.e. self-configuring, self-awareness, self-optimization, self-healing and self-protection, collectively denoted as self-*) entities. These self-* properties ensure functioning of the network without or very minimum human intervention. In such an environment, security

Sanjay Rawat; Ashutosh Saxena

2009-01-01

133

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

134

Research on Capturing of Customer Requirements Based on Innovation Theory  

NASA Astrophysics Data System (ADS)

To exactly and effectively capture customer requirements information, a new customer requirements capturing modeling method was proposed. Based on the analysis of function requirement models of previous products and the application of technology system evolution laws of the Theory of Innovative Problem Solving (TRIZ), the customer requirements could be evolved from existing product designs, through modifying the functional requirement unit and confirming the direction of evolution design. Finally, a case study was provided to illustrate the feasibility of the proposed approach.

junwu, Ding; dongtao, Yang; zhenqiang, Bao

135

Pathogenesis of Chronic Pancreatitis: An Evidence-Based Review of Past Theories and Recent Developments  

Microsoft Academic Search

In the past several decades, four prominent theories of chronic pancreatitis pathogenesis have emerged: the toxic-metabolic theory, the oxidative stress hypothesis, the stone and duct obstruction theory, and the necrosis-fibrosis hypothesis. Although these traditional theories are formulated based on compelling scientific observations, substantial contradictory data also exist for each. Furthermore, the basic premises of some of these theories are directly

Tyler Stevens; Darwin L. Conwell; Gregory Zuccaro

2004-01-01

136

Uncertainty analysis of groundwater modeling based on information entropy theory  

NASA Astrophysics Data System (ADS)

Because of groundwater conceptualization uncertainty, multi-model methods are usually used and the corresponding uncertainties are estimated by integrating generalized likelihood uncertainty estimation (GLUE) and Bayesian model averaging (BMA) methods.As for uncertainty assessment, it is crucial to select appropriate theory to define and measure uncertainty. Generally, variance method is traditionally applied to measure the uncertainties of BMA prediction. The total variance of ensemble prediction is decomposed into within-model and between-model variances, which represent theuncertainties fromparameter and conceptual model, respectively. However, variance is not a perfect method for measuring the uncertainty of a probability distribution. Furthermore, the overlapped parameter uncertaintyderived from the combination of multi-model's predictions cannot be appropriatelyrepresented by variance method. A new measuring method based on information entropy theory is developed in this study.The information entropy is ageneral method for measuring the uncertainty of a predictive distribution, and the predictive uncertainty of BMA ensemble prediction is appropriately partitioned by this method. Based on a synthetical groundwater model, variance and information entropy methods are used to assess groundwater modeling uncertainties. The compared results indicate that information entropy method is more informative and authentic for measuring groundwater modeling uncertainty than variance method. Variance method is characterized by clear mechanism, easy computation, and easy understandable assessment result.Information entropy methodstrengths lie inreliable theory foundation and rational derivation to the partition of BMA predictive uncertainty.

Zeng, X.; Wu, J.

2013-12-01

137

A danger-theory-based immune network optimization algorithm.  

PubMed

Existing artificial immune optimization algorithms reflect a number of shortcomings, such as premature convergence and poor local search ability. This paper proposes a danger-theory-based immune network optimization algorithm, named dt-aiNet. The danger theory emphasizes that danger signals generated from changes of environments will guide different levels of immune responses, and the areas around danger signals are called danger zones. By defining the danger zone to calculate danger signals for each antibody, the algorithm adjusts antibodies' concentrations through its own danger signals and then triggers immune responses of self-regulation. So the population diversity can be maintained. Experimental results show that the algorithm has more advantages in the solution quality and diversity of the population. Compared with influential optimization algorithms, CLONALG, opt-aiNet, and dopt-aiNet, the algorithm has smaller error values and higher success rates and can find solutions to meet the accuracies within the specified function evaluation times. PMID:23483853

Zhang, Ruirui; Li, Tao; Xiao, Xin; Shi, Yuanquan

2013-01-01

138

Evaluating sensor reliability in classification problems based on evidence theory.  

PubMed

This paper presents a new framework for sensor reliability evaluation in classification problems based on evidence theory (or the Dempster-Shafer theory of belief functions). The evaluation is treated as a two-stage training process. First, the authors assess the static reliability from a training set by comparing the sensor classification readings with the actual values of data, which are both represented by belief functions. Information content contained in the actual values of each target is extracted to determine its influence on the evaluation. Next, considering the ability of the sensor to understand a dynamic working environment, the dynamic reliability is evaluated by measuring the degree of consensus among a group of sensors. Finally, the authors discuss why and how to combine these two kinds of reliabilities. A significant improvement using the authors' method is observed in numerical simulations as compared with the recently proposed method. PMID:17036806

Guo, Huawei; Shi, Wenkang; Deng, Yong

2006-10-01

139

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

140

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

141

A communication-theory based view on telemedical communication.  

PubMed

Communication theory based analysis sheds new light on the use of health telematics. This analysis of structures in electronic medical communication shows communicative structures with special features. Current and evolving telemedical applications are analyzed. The methodology of communicational theory (focusing on linguistic pragmatics) is used to compare it with its conventional counterpart. The semiotic model, the roles of partners, the respective message and their relation are discussed. Channels, sender, addressee, and other structural roles are analyzed for different types of electronic medical communication. The communicative processes are shown as mutual, rational action towards a common goal. The types of communication/texts are analyzed in general. Furthermore the basic communicative structures of medical education via internet are presented with their special features. The analysis shows that electronic medical communication has special features compared to everyday communication: A third participant role often is involved: the patient. Messages often are addressed to an unspecified partner or to an unspecified partner within a group. Addressing in this case is (at least partially) role-based. Communication and message often directly (rather than indirectly) influence actions of the participants. Communication often is heavily regulated including legal implications like liability, and more. The conclusion from the analysis is that the development of telemedical applications so far did not sufficiently take communicative structures into consideration. Based on these results recommendations for future developments of telemedical applications/services are given. PMID:15537236

Schall, Thomas; Roeckelein, Wolfgang; Mohr, Markus; Kampshoff, Joerg; Lange, Tim; Nerlich, Michael

2003-01-01

142

Enhancement of infrared image based on the Retinex theory.  

PubMed

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

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

2007-01-01

143

Quantum message authentication based on algebraic coding theory  

NASA Astrophysics Data System (ADS)

We present a new type of authentication scheme for quantum message based on algebraic coding theory and quantum computation operations between different quantum registers. The results are that if the pre-coding generator matrix in SN-S code is public, the quantum scheme is a public-key data integrity scheme; if it is secret, the quantum scheme is a hybrid data origin authentication scheme. The advantage of this scheme is that the public and secret keys are merely some classical data.

Yang, Li; Hu, Lei; Feng, Deng-Guo

2005-01-01

144

Quantum Hall transitions: An exact theory based on conformal restriction  

NASA Astrophysics Data System (ADS)

We revisit the problem of the plateau transition in the integer quantum Hall effect. Here we develop an analytical approach for this transition, and for other two-dimensional disordered systems, based on the theory of “conformal restriction.” This is a mathematical theory that was recently developed within the context of the Schramm-Loewner evolution which describes the “stochastic geometry” of fractal curves and other stochastic geometrical fractal objects in two-dimensional space. Observables elucidating the connection with the plateau transition include the so-called point-contact conductances (PCCs) between points on the boundary of the sample, described within the language of the Chalker-Coddington network model for the transition. We show that the disorder-averaged PCCs are characterized by a classical probability distribution for certain geometric objects in the plane (which we call pictures), occurring with positive statistical weights, that satisfy the crucial so-called restriction property with respect to changes in the shape of the sample with absorbing boundaries; physically, these are boundaries connected to ideal leads. At the transition point, these geometrical objects (pictures) become fractals. Upon combining this restriction property with the expected conformal invariance at the transition point, we employ the mathematical theory of “conformal restriction measures” to relate the disorder-averaged PCCs to correlation functions of (Virasoro) primary operators in a conformal field theory (of central charge c=0). We show how this can be used to calculate these functions in a number of geometries with various boundary conditions. Since our results employ only the conformal restriction property, they are equally applicable to a number of other critical disordered electronic systems in two spatial dimensions, including for example the spin quantum Hall effect, the thermal metal phase in symmetry class D, and classical diffusion in two dimensions in a perpendicular magnetic field. For most of these systems, we also predict exact values of critical exponents related to the spatial behavior of various disorder-averaged PCCs.

Bettelheim, E.; Gruzberg, I. A.; Ludwig, A. W. W.

2012-10-01

145

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

146

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

ERIC Educational Resources Information Center

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

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

2012-01-01

147

Theory based design and optimization of materials for spintronics applications  

NASA Astrophysics Data System (ADS)

The Spintronics industry has developed rapidly in the past decade. Finding the right material is very important for Spintronics applications, which requires good understanding of the physics behind specific phenomena. In this dissertation, we will focus on two types of perpendicular transport phenomena, the current-perpendicular-to-plane giant-magneto-resistance (CPP-GMR) phenomenon and the tunneling phenomenon in the magnetic tunnel junctions. The Valet-Fert model is a very useful semi-classical approach for understanding the transport and spin-flip process in CPP-GMR. We will present a finite element based implementation for the Valet-Fert model which enables a practical way to calculate the electron transport in real CPP-GMR spin valves. It is very important to find high spin polarized materials for CPP-GMR spin valves. The half-metal, due to its full spin polarization, is of interest. We will propose a rational way to find half-metals based on the gap theorem. Then we will focus on the high-MR TMR phenomenon. The tunneling theory of electron transport in mesoscopic systems will be covered. Then we will calculate the transport properties of certain junctions with the help of Green's function under the Landauer-Buttiker formalism, also known as the scattering formalism. The damping constant determines the switching rate of a device. We can calculate it using a method based on the Extended Huckel Tight-Binding theory (EHTB). The symmetry filtering effect is very helpful for finding materials for TMR junctions. Based upon which, we find a good candidate material, MnAl, for TMR applications.

Xu, Tianyi

148

Plato: A localised orbital based density functional theory code  

NASA Astrophysics Data System (ADS)

The Plato package allows both orthogonal and non-orthogonal tight-binding as well as density functional theory (DFT) calculations to be performed within a single framework. The package also provides extensive tools for analysing the results of simulations as well as a number of tools for creating input files. The code is based upon the ideas first discussed in Sankey and Niklewski (1989) [1] with extensions to allow high-quality DFT calculations to be performed. DFT calculations can utilise either the local density approximation or the generalised gradient approximation. Basis sets from minimal basis through to ones containing multiple radial functions per angular momenta and polarisation functions can be used. Illustrations of how the package has been employed are given along with instructions for its utilisation. Program summaryProgram title: Plato Catalogue identifier: AEFC_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFC_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 219 974 No. of bytes in distributed program, including test data, etc.: 1 821 493 Distribution format: tar.gz Programming language: C/MPI and PERL Computer: Apple Macintosh, PC, Unix machines Operating system: Unix, Linux and Mac OS X Has the code been vectorised or parallelised?: Yes, up to 256 processors tested RAM: Up to 2 Gbytes per processor Classification: 7.3 External routines: LAPACK, BLAS and optionally ScaLAPACK, BLACS, PBLAS, FFTW Nature of problem: Density functional theory study of electronic structure and total energies of molecules, crystals and surfaces. Solution method: Localised orbital based density functional theory. Restrictions: Tight-binding and density functional theory only, no exact exchange. Unusual features: Both atom centred and uniform meshes available. Can deal with arbitrary angular momenta for orbitals, whilst still retaining Slater-Koster tables for accuracy. Running time: Test cases will run in a few minutes, large calculations may run for several days.

Kenny, S. D.; Horsfield, A. P.

2009-12-01

149

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

NASA Astrophysics Data System (ADS)

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

Fardis, Fatemeh; Zandi, Afagh; Ghezavati, Vahidreza

2013-07-01

150

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

151

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.

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

2013-01-01

152

Development and evaluation of theory-based diabetes support services.  

PubMed

Technology-enabled support services for diabetes can fulfill patient demand to care for diabetes independently. Patients benefit from such services after greater adoption of the services in healthcare systems. Unfortunately, conventional service development fails to thoroughly understand patient care support, making it difficult to achieve the desired design, and posing substantial challenges in adopting these services. Thus, previously developed services in many cases are not as patients expected, as evidenced by their low acceptance among patients. To solve this problem, adequate strategies must be developed by incorporating theoretical knowledge as a solid foundation in order to improve service design. This study develops technology-enabled diabetes support services based on the self-care theory. A set of self-care service scenarios is also established and combined with theoretical concepts. The developed services consist of a nurse-led consultation service and a mobile application service. Additionally, user acceptance is confirmed by assessing patient perceptions of the diabetes support services in a group of patients with diabetes (N=27). Results of analysis reveal that patients respond favorably toward the services. Patient preference and perceived ease of use attest to their intention to use the services. Greater adoption of the services can be anticipated, owing to a higher levels of preference and higher perceived ease of use. This study demonstrated that the self-care theory can be linked to nursing informatics research and chronic care clinical practices. PMID:22968249

Guo, Sophie Huey-Ming; Lin, Yung-Hsiu; Chen, Rong-Rong; Kao, Shu-Fen; Chang, Her-Kun

2013-01-01

153

Laser image denoising technique based on multi-fractal theory  

NASA Astrophysics Data System (ADS)

The noise of laser images is complex, which includes additive noise and multiplicative noise. Considering the features of laser images, the basic processing capacity and defects of the common algorithm, this paper introduces the fractal theory into the research of laser image denoising. The research of laser image denoising is implemented mainly through the analysis of the singularity exponent of each pixel in fractal space and the feature of multi-fractal spectrum. According to the quantitative and qualitative evaluation of the processed image, the laser image processing technique based on fractal theory not only effectively removes the complicated noise of the laser images obtained by range-gated laser active imaging system, but can also maintains the detail information when implementing the image denoising processing. For different laser images, multi-fractal denoising technique can increase SNR of the laser image at least 1~2dB compared with other denoising techniques, which basically meet the needs of the laser image denoising technique.

Du, Lin; Sun, Huayan; Tian, Weiqing; Wang, Shuai

2014-02-01

154

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

ERIC Educational Resources Information Center

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

Amrein-Beardsley, A.; Haladyna, T.

2012-01-01

155

Learning Styles of Baccalaureate Nursing Students and Attitudes toward Theory-Based Nursing.  

ERIC Educational Resources Information Center

The personal and environmental factors related to undergraduate and post-RN nursing students' attitudes toward theory-based nursing from Kolb's experiential learning theory perspective were investigated. Learning style and environmental press perceptions were found to be related to attitudes toward theory-based nursing. (Author/MLW)

Laschinger, Heather K.; Boss, Marvin K.

1989-01-01

156

Quantum theory of a spaser-based nanolaser.  

PubMed

We present a quantum theory of a spaser-based nanolaser, under the bad-cavity approximation. We find first- and second-order correlation functions g(1)(?) and g(2)(?) below and above the generation threshold, and obtain the average number of plasmons in the cavity. The latter is shown to be of the order of unity near the generation threshold, where the spectral line narrows considerably. In this case the coherence is preserved in a state of active atoms in contradiction to the good-cavity lasers, where the coherence is preserved in a state of photons. The damped oscillations in g(2)(?) above the generation threshold indicate the unusual character of amplitude fluctuations of polarization and population, which become interconnected in this case. Obtained results allow to understand the fundamental principles of operation of nanolasers. PMID:24921561

Parfenyev, Vladimir M; Vergeles, Sergey S

2014-06-01

157

Theory for a gas composition sensor based on acoustic properties  

NASA Technical Reports Server (NTRS)

Sound travelling through a gas propagates at different speeds and its intensity attenuates to different degrees depending upon the composition of the gas. Theoretically, a real-time gaseous composition sensor could be based on measuring the sound speed and the acoustic attenuation. To this end, the speed of sound was modelled using standard relations, and the acoustic attenuation was modelled using the theory for vibrational relaxation of gas molecules. The concept for a gas composition sensor is demonstrated theoretically for nitrogen-methane-water and hydrogen-oxygen-water mixtures. For a three-component gas mixture, the measured sound speed and acoustic attenuation each define separate lines in the composition plane of two of the gases. The intersection of the two lines defines the gas composition. It should also be possible to use the concept for mixtures of more than three components, if the nature of the gas composition is known to some extent.

Phillips, Scott; Dain, Yefim; Lueptow, Richard M.

2003-01-01

158

The Theory of Individual Based Discrete-Time Processes  

NASA Astrophysics Data System (ADS)

A general theory is developed to study individual based models which are discrete in time. We begin by constructing a Markov chain model that converges to a one-dimensional map in the infinite population limit. Stochastic fluctuations are hence intrinsic to the system and can induce qualitative changes to the dynamics predicted from the deterministic map. From the Chapman-Kolmogorov equation for the discrete-time Markov process, we derive the analogues of the Fokker-Planck equation and the Langevin equation, which are routinely employed for continuous time processes. In particular, a stochastic difference equation is derived which accurately reproduces the results found from the Markov chain model. Stochastic corrections to the deterministic map can be quantified by linearizing the fluctuations around the attractor of the map. The proposed scheme is tested on stochastic models which have the logistic and Ricker maps as their deterministic limits.

Challenger, Joseph D.; Fanelli, Duccio; McKane, Alan J.

2014-04-01

159

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

160

Time-dependent density functional theory based Ehrenfest dynamics  

NASA Astrophysics Data System (ADS)

Time-dependent density functional theory based Ehrenfest dynamics with atom-centered basis functions is developed in present work. The equation of motion for electrons is formulated in terms of first-order reduced density matrix and an additional term arises due to the time-dependence of basis functions through their dependence on nuclear coordinates. This time-dependence of basis functions together with the imaginary part of density matrix leads to an additional term for nuclear force. The effects of the two additional terms are examined by studying the dynamics of H2 and C2H4, and it is concluded that the inclusion of these two terms is essential for correct electronic and nuclear dynamics.

Wang, Fan; Yam, Chi Yung; Hu, Lihong; Chen, Guanhua

2011-07-01

161

The Theory of Individual Based Discrete-Time Processes  

NASA Astrophysics Data System (ADS)

A general theory is developed to study individual based models which are discrete in time. We begin by constructing a Markov chain model that converges to a one-dimensional map in the infinite population limit. Stochastic fluctuations are hence intrinsic to the system and can induce qualitative changes to the dynamics predicted from the deterministic map. From the Chapman-Kolmogorov equation for the discrete-time Markov process, we derive the analogues of the Fokker-Planck equation and the Langevin equation, which are routinely employed for continuous time processes. In particular, a stochastic difference equation is derived which accurately reproduces the results found from the Markov chain model. Stochastic corrections to the deterministic map can be quantified by linearizing the fluctuations around the attractor of the map. The proposed scheme is tested on stochastic models which have the logistic and Ricker maps as their deterministic limits.

Challenger, Joseph D.; Fanelli, Duccio; McKane, Alan J.

2014-07-01

162

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

163

Unified theories for quarks and leptons based on Clifford algebras  

Microsoft Academic Search

The general standpoint is presented that unified theories arise from gauging of Clifford algebras describing the internal degrees of freedom (charge, color, generation, spin) of the fundamental fermions. The general formalism is presented and the ensuing theories for theories for color and charge (with extension to N colors), and for generations, are discussed. The possibility of further including the spin

R. Casalbuoni; R. Gatto

1980-01-01

164

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

ERIC Educational Resources Information Center

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

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

2012-01-01

165

Comparison of theory based transport models with ASDEX Upgrade data  

NASA Astrophysics Data System (ADS)

Heat transport in steady state ASDEX Upgrade discharges is compared with the predictions of four theory based models: the IFS/PPPL, Weiland and GLF23 models, based on ion temperature gradient (ITG) and trapped electron mode physics, and the current diffusive ballooning mode (CDBM) model. The discharges selected provide scans over heating power, density and plasma current, by varying these quantities separately. The ion temperature profiles are found to be stiff, with the same linear relation between the core and edge temperatures for all the scans considered. The ITG based models reproduce this behaviour well qualitatively and quantitatively, while the CDBM model fails to predict profile stiffness. The electron temperature, however, does change shape when the density is lowered. All models reproduce this feature qualitatively. The stored energy is well predicted by the IFS/PPPL and Weiland models. The GLF23 model is less good, showing a clear trend to underpredict the energy at higher temperatures. The predictions made with the CDBM model are rather poor.

Tardini, G.; Peeters, A. G.; Pereverzev, G. V.; Ryter, F.; Stober, J.; ASDEX Upgrade Team

2002-03-01

166

A theory of open systems based on stochastic differential equations  

NASA Astrophysics Data System (ADS)

For a model of an open quantum system—a concentrated ensemble consisting of similar atoms and interacting with a one-dimensional quantum vacuum environment with a zero photon density—quantum stochastic differential equations of a non-Wiener type of the general form have been obtained; based on the equations, kinetic equations describing a wide class of physical systems are derived. The distinctive feature of such systems is effects of suppression of collective spontaneous emission and stabilization of the excited state. For the open classical system exposed to the action of noise in the form of a Levy process of the general non-Gaussian kind, kinetic equations of the Fokker-Planck type with fractional derivatives have been obtained based on classical non-Wiener stochastic differential equations. This emphasizes the common base of the developed theory for different types of open systems, which is expressed in using the mathematical formalism of stochastic differential equations of the general non-Wiener type.

Basharov, A. M.

2014-04-01

167

Restructuring Lattice Theory: An Approach Based on Hierarchies of Concepts  

Microsoft Academic Search

Lattice theory today reflects the general Status of current mathematics: there is a rich production of theoretical concepts,\\u000a results, and developments, many of which are reached by elaborate mental gymnastics; on the other hand, the connections of\\u000a the theory to its surroundings are getting weaker and weaker, with the result that the theory and even many of its parts become

Rudolf Wille

2009-01-01

168

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

169

Speech Enhancement Based on Hilbert-Huang Transform Theory  

Microsoft Academic Search

Speech enhancement is effective in solving the problem of noisy speech. Hilbert-Huang transform (HHT) is efficient for describing the local features of dynamic signals and is a new and powerful theory for the time-frequency analysis. According to the theory of HHT, this text introduced a new method of speech enhancement to improve the speech quantity and the signal noise ratio

Xiaojie Zou; Xueyao Li; Rubo Zhang

2006-01-01

170

Towards an Empirically Based Curriculum Theory: A Guide for Research.  

ERIC Educational Resources Information Center

Theories are useful in predicting events and exploring alternatives only to the extent they accurately describe existing states of affairs. The development of a curriculum theory with predictive and exploratory power depends on accurately describing decision-making systems that result in curriculum -- however curriculum is defined. Three…

Vickery, Tom Rusk; Hudspeth, DeLayne R.

171

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

172

Security Situation Assessment Based on the DS Theory  

Microsoft Academic Search

A security situation assessment model is proposed in this paper. One of the math function and the rectification function are used to design the experience function in the theory of evidence. Then the theory of evidence is brought into the security situation assessment. From correlating and fusing the data which is provided by the sensors deployed in network to depicting

Feng Xuewei; Wang Dongxia; Ma Guoqing; Li Jin

2010-01-01

173

An improved Voronoi diagram model based on fuzzy interval theory  

NASA Astrophysics Data System (ADS)

Considering that the application of traditional Voronoi diagram in spatial division ignores the impact of road hierarchy, speed, road-block, one-way and some other influential factors on proximity, an improved Voronoi diagram model based on fuzzy interval theory is proposed in this paper by introducing different influential factors into the construction of Voronoi diagram in order to enhance the accuracy of spatial division and to meet application requirements. The idea of our improved Voronoi diagram model can be summarized as follows: Firstly, initial Voronoi diagram is built via point by point insertion algorithm. Secondly, fuzzy interval on all Voronoi edges is generated via geometric algorithm and is further used to represent each edge of Voronoi polygons. The size of fuzzy interval is determined by taking all influential factors into consideration. Thirdly, an improved Voronoi diagram with fuzzy boundaries is provided in which the proximity relationships between points in the fuzzy interval and the sites of Voronoi polygons which own a public edge are all proposed to be the nearest. Finally, the validity and performance of our improved Voronoi diagram is demonstrated through a typical application in emergency response system, in which the actual path distance is acted as influential factor. Experimental results show that with our improved Voronoi diagram optimal attendance station can be localized quickly and emergency response efficiency can be enhanced obviously. Besides, classification accuracy can be increased more than 20% compared with traditional Voronoi diagram.

Yan, Beibei; Shao, Zhenfeng; Zhou, Yang; Cheng, Qimin

2009-10-01

174

LSST Telescope Alignment Plan Based on Nodal Aberration Theory  

NASA Astrophysics Data System (ADS)

The optical alignment of the Large Synoptic Survey Telescope (LSST) is potentially challenging, due to its fast three-mirror optical design and its large 3.5° field of view (FOV). It is highly advantageous to align the three-mirror optical system prior to the integration of the complex science camera on the telescope, which corrects the FOV via three refractive elements and includes the operational wavefront sensors. A telescope alignment method based on nodal aberration theory (NAT) is presented here to address this challenge. Without the science camera installed on the telescope, the on-axis imaging performance of the telescope is diffraction-limited, but the field of view is not corrected. The nodal properties of the three-mirror telescope design have been analyzed and an alignment approach has been developed using the intrinsically linear nodal behavior, which is linked via sensitivities to the misalignment parameters. Since mirror figure errors will exist in any real application, a methodology to introduce primary-mirror figure errors into the analysis has been developed and is also presented.

Sebag, J.; Gressler, W.; Schmid, T.; Rolland, J. P.; Thompson, K. P.

2012-04-01

175

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.

176

Microscopic theory of semiconductor-based optoelectronic devices  

NASA Astrophysics Data System (ADS)

Since the seminal paper by Esaki and Tsu, semiconductor-based nanometric heterostructures have been the subject of impressive theoretical and experimental activity due to their high potential impact in both fundamental research and device technology. The steady scaling down of typical space and time scales in quantum optoelectronic systems inevitably leads to a regime in which the validity of the traditional Boltzmann transport theory cannot be taken for granted and a more general quantum-transport description is imperative. In this paper, we shall review state-of-the-art approaches used in the theoretical modelling, design and optimization of optoelectronic quantum devices. The primary goal is to provide a cohesive treatment of basic quantum-transport effects, able to explain and predict the performances of new-generation semiconductor devices. With this aim, we shall review and discuss a fully three-dimensional microscopic treatment of time-dependent as well as steady-state quantum-transport phenomena, based on the density matrix formalism. This will allow us to introduce in a quite natural way the separation between coherent and incoherent processes. Starting with this general theoretical framework, we shall analyse two different types of quantum devices, namely periodically repeated structures and quantum systems with open boundaries. For devices within the first class, we will show how a proper use of periodic boundary conditions allows us to reproduce and predict their current-voltage characteristics without resorting to phenomenological parameters. For the second class of devices, we will address the relevant issue of a quantum treatment of charge transport in systems with open boundaries (electrical contacts) when studying and simulating an at least two-terminal device.

Iotti, Rita C.; Rossi, Fausto

2005-11-01

177

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

178

Exact Kohn-Sham scheme based on perturbation theory  

Microsoft Academic Search

An exact formal Kohn-Sham scheme is derived with the help of perturbation theory. Through the introduction of a basis set this Kohn-Sham scheme can be used to perform, in principle, exact Kohn-Sham calculations. As a demonstration, only zeroth- and first-order terms in the underlying perturbation theory are considered. As a result an exact basis set ``exchange-only'' method is obtained. The

Andreas Görling; Mel Levy

1994-01-01

179

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.

Ishizu, Tomohiro; Zeki, Semir

2011-01-01

180

Design of traveling wave tubes based on field theory  

SciTech Connect

A method is described for the design of helix traveling wave tubes (TWT) which is based on the linear field analysis of the coupled beam-wave system. The dispersion relations are obtained by matching of radial admittances at boundaries instead of the individual field components. This approach provides flexibility in modeling various beam and circuit configurations with relative ease by choosing the appropriate admittance functions for each case. The method is illustrated for the case of a solid beam inside a sheath helix which is loaded externally by lossy dielectric material, a conducting cylinder, and axial vanes. Extension of the analysis to include a thin tape helix model is anticipated in the near future. The TWT model may be divided into axial regions to include velocity tapers, lossy materials and severs, with the helix geometry in each region varied arbitrarily. The relations between the ac velocities, current densities, and axial electric fields are used to derive a general expression for the new amplitudes of the three forward waves at each axial boundary. The sum of the fields for the three forward waves (two waves in a drift region) is followed to the circuit output. Numerical results of the field analysis are compared with the coupled-mode Pierce theory. A method is suggested for applying the field analysis to accurate design of practical TWT's that have a more complex circuit geometry, which starts with a simple measurement of the dispersion of the helix circuit. The field analysis may then be used to generate a circuit having properties very nearly equivalent to those of the actual circuit.

Vanderplaats, N.R.; Kodis, M.A. (Naval Research Lab., Washington, DC (United States). Vacuum Electronics Branch); Freund, H.P. (Science Applications International Corp., McLean, VA (United States))

1994-07-01

181

Predicting the Number of Public Computer Terminals Needed for an On-Line Catalog: A Queuing Theory Approach.  

ERIC Educational Resources Information Center

Describes a method for estimating the number of cathode ray tube terminals needed for public use of an online library catalog. Authors claim method could also be used to estimate needed numbers of microform readers for a computer output microform (COM) catalog. Formulae are included. (Author/JD)

Knox, A. Whitney; Miller, Bruce A.

1980-01-01

182

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

183

Sensitivity theory for reactor burnup analysis based on depletion perturbation theory  

Microsoft Academic Search

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

Wonsik

1989-01-01

184

Three-Level Anomaly Disposal System Model Based on Danger Theory  

Microsoft Academic Search

In order to improve the intrusion detection system based on traditional immune theory, a new three levels anomaly disposal system model based on danger theory was proposed in this paper. The data stream is treated with three levels anomaly disposal in the model, the first level is to recognize the danger and remove the data of non-danger which will not

Hai-Dong Fu; Gui-Feng Li

2008-01-01

185

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

ERIC Educational Resources Information Center

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

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

2007-01-01

186

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

187

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

188

Evaluating theory-based evaluation: information, norms, and adherence.  

PubMed

Programmatic social interventions attempt to produce appropriate social-norm-guided behavior in an open environment. A marriage of applicable psychological theory, appropriate program evaluation theory, and outcome of evaluations of specific social interventions assures the acquisition of cumulative theory and the production of successful social interventions--the marriage permits us to advance knowledge by making use of both success and failures. We briefly review well-established principles within the field of program evaluation, well-established processes involved in changing social norms and social-norm adherence, the outcome of several program evaluations focusing on smoking prevention, pro-environmental behavior, and rape prevention and, using the principle of learning from our failures, examine why these programs often do not perform as expected. Finally, we discuss the promise of learning from our collective experiences to develop a cumulative science of program evaluation and to improve the performance of extant and future interventions. PMID:22277114

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

2012-08-01

189

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.

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

2014-01-01

190

Trends in information theory-based chemical structure codification.  

PubMed

This report offers a chronological review of the most relevant applications of information theory in the codification of chemical structure information, through the so-called information indices. Basically, these are derived from the analysis of the statistical patterns of molecular structure representations, which include primitive global chemical formulae, chemical graphs, or matrix representations. Finally, new approaches that attempt to go "back to the roots" of information theory, in order to integrate other information-theoretic measures in chemical structure coding are discussed. PMID:24705993

Barigye, Stephen J; Marrero-Ponce, Yovani; Pérez-Giménez, Facundo; Bonchev, Danail

2014-08-01

191

Research on Danger Model Theory Based Artificial Immune Algorithm  

Microsoft Academic Search

Inspired from the experience of genetic and clone algorithm, propose an algorithm of danger model immune algorithm (DMIA) according to the danger model theory. It has a good performance in function optimization. From the simulation result, we can see that DMIA is valid, and also with higher efficiency than genetic algorithm.

Qingyang Xu; Xianyao Meng; Ning Wang; Chuang Zhang

2009-01-01

192

A Novel Intrusion Detection Model Based on Danger Theory  

Microsoft Academic Search

As the traditional negative selection, clonal selection algorithms predefine one part of antigens to be self (the training set) in intrusion detection applications, but in practice the self is difficult to define and can change over time. With the change of the self, error detection rate increases sharply. A recently developed hypothesis in immunology, the Danger Theory, states that our

Junmin Zhang; Yiwen Liang

2008-01-01

193

Effective Contraceptive Use: An Exploration of Theory-Based Influences  

ERIC Educational Resources Information Center

The purpose of this study was to explore factors that influence oral contraceptive (OC) use among women in Iran using the Theory of Planned Behavior (TPB) and concept of self-efficacy (SE). The study sample consisted of 360 married OC users, aged 18-49 years recruited at public health centers of Mashhad, 900 km east of Tehran. SE had the strongest…

Peyman, N.; Oakley, D.

2009-01-01

194

A Hierarchical Classification System Based on Adaptive Resonance Theory  

Microsoft Academic Search

In this study, we propose a hierarchical classification system, which emulates the eye-brain channel in two hierarchical layers. In the first layer, a set of classifiers are trained by using low level, low dimensional features. In the second layer, the recognition results of the first layer are fed to the Fuzzy ARTMAP (FAM) classifier which implements the Adaptive Resonance Theory.

Mutlu Uysal; Emre Akbas; Fatos T. Yarman-vural

2006-01-01

195

THEORY OF CYBERNETIC AND INTELLIGENT MACHINE BASED ON LIE COMMUTATORS  

Microsoft Academic Search

Many attempts have been made to overcome the limit imposed by the Turing Machine to realise general mathematical functions and models of (physical) phenomena.They center around the notion of computability.In this paper we propose a new definition of computability which lays the foundations for a theory of cybernetic and intelligent machines in which the classical limits imposed by discrete algorithmic

H. A. FATMI; P. J. MARCER; M. JESSEL; G. RESCONI

1990-01-01

196

Towards a Language-Based Theory of Learning  

Microsoft Academic Search

Despite the fact that educational knowledge is massively dependent on verbal learn- ing, theories of learning have not been specifically derived from observations of children's language development. But language development is learning how to mean; and because human beings are quintessentially creatures who mean (i.e., who engage in semiotic processes, with natural language as prototypical), all human learning is essentially

M. A. K. HALLIDAY

1994-01-01

197

Relativistic theory of gravitation based on the constant curvature space.  

National Technical Information Service (NTIS)

This paper expounds the basic postulates of the relativistic theory of gravitation on the basis of the constant curvature space, which make it possible to find uniquely the complete system of the equations for gravitational field having a nonzero rest mas...

A. A. Logunov, M. A. Mestvirishvili, Y. Chugreev

1990-01-01

198

Stability Analysis for Car Following Model Based on Control Theory  

NASA Astrophysics Data System (ADS)

Stability analysis is one of the key issues in car-following theory. The stability analysis with Lyapunov function for the two velocity difference car-following model (for short, TVDM) is conducted and the control method to suppress traffic congestion is introduced. Numerical simulations are given and results are consistent with the theoretical analysis.

Meng, Xiang-Pei; Li, Zhi-Peng; Ge, Hong-Xia

2014-05-01

199

Thermodynamically consistent residual-based gradient plasticity theory and comparisons  

Microsoft Academic Search

A gradient plasticity theory for small deformations is presented within the framework of nonlocal continuum thermodynamics. The second principle (Clausius-Duhem inequality), enriched by an additional term named energy residual, is employed in conjunction with the concepts of insulation condition and locality recovery condition, in order to derive all the pertinent restrictions upon the constitutive equations. These include the expressions of

G. Borino; C. Polizzotto

2007-01-01

200

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

201

A theory of computation based on quantum logic (I)  

Microsoft Academic Search

Summary form only given. The (meta) logic underlying classical theory of computation is Boolean (two-valued) logic. Quantum logic was proposed by Birkhoff and von Neumann as a logic of quantum mechanics. It is currently understood as a logic whose truth values are taken from an orthomodular lattice. The major difference between Boolean logic and quantum logic is that the latter

Mingsheng Ying

2005-01-01

202

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

Microsoft Academic Search

Based on ideas proposed by Massoudi and Rajagopal M-R, we develop a model for blood using;\\u000athe theory of interacting continua, that is, the mixture theory. We first provide a brief review;\\u000aof mixture theory, and then discuss certain issues in constitutive modeling of a two-component;\\u000amixture. In the present formulation, we ignore the biochemistry of blood and assume that

Mehrdad Massoudi; James F. Antaki

2008-01-01

203

Ground movement analysis based on stochastic medium theory.  

PubMed

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

2014-01-01

204

Fragment-based time-dependent density functional theory.  

PubMed

Using the Runge-Gross theorem that establishes the foundation of time-dependent density functional theory, we prove that for a given electronic Hamiltonian, choice of initial state, and choice of fragmentation, there is a unique single-particle potential (dubbed time-dependent partition potential) which, when added to each of the preselected fragment potentials, forces the fragment densities to evolve in such a way that their sum equals the exact molecular density at all times. This uniqueness theorem suggests new ways of computing the time-dependent properties of electronic systems via fragment-time-dependent density functional theory calculations. We derive a formally exact relationship between the partition potential and the total density, and illustrate our approach on a simple model system for binary fragmentation in a laser field. PMID:23889390

Mosquera, Martín A; Jensen, Daniel; Wasserman, Adam

2013-07-12

205

Gravitational Cherenkov Losses in Theories Based on Modified Newtonian Dynamics  

NASA Astrophysics Data System (ADS)

Survival of high-energy cosmic rays (HECRs) against gravitational Cherenkov losses is shown not to cast strong constraints on modified Newtonian dynamics (MOND) theories that are compatible with general relativity (GR): theories that coincide with GR for accelerations ?a0 (a0 is the MOND constant). The energy-loss rate, E?, is many orders smaller than those derived in the literature for theories with no extra scale. Modification to GR, which underlies E?, enters only beyond the MOND radius of the particle: rM=(Gp/ca0)1/2. The spectral cutoff, entering E? quadratically, is thus rM-1, not kdB=p/?. Thus, E? is smaller than published rates, which use kdB, by a factor ˜(rMkdB)2?1039(cp/3×1011Gev)3. Losses are important only beyond Dloss?q?M, where q is a dimensionless factor, and ?M=c2/a0 is the MOND length, which is ?2? times the Hubble distance.

Milgrom, Mordehai

2011-03-01

206

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

207

Gravitational Cherenkov losses in theories based on modified Newtonian dynamics.  

PubMed

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

Milgrom, Mordehai

2011-03-18

208

A Layered Multi-Agent Detection Model for Abnormal Intrusion Based on Danger Theory  

Microsoft Academic Search

A layered multi-agent detection model for abnormal intrusion, based on danger theory, is presented according to the research on the danger theory and artificial immunity. The model, with three layers in the frame, conducts the real time monitoring and danger judgment on the host computer and network resource before it recognizes the nonself, and then the danger signal activates the

Xiao TaoHuang; Sha Li; Li QunHuang

2010-01-01

209

Research on AMU fault detection algorithm based on immune danger theory  

Microsoft Academic Search

From danger theory of the biological immunology , a new kind of AMU fault detection algorithm based on immune danger theory was presented. In this paper of the new algorithm, System only respond to danger signal and analyze whether there is the existence of fault signal by analysis of the danger extent . The result of the experiment shows that

Zhou Dexin; Fan Zhicheng; Zhang Wenlin

2011-01-01

210

Web-Support for Activating Use of Theory in Group-Based Learning.  

ERIC Educational Resources Information Center

This paper describes a series of experiments conducted within the context of a course on organizational theory that is taught at the Department of Management Sciences at the University of Twente (Netherlands). In 1997, a group-based learning approach was adopted, but after the first year it was apparent that acquisition and application of theory

van der Veen, Jan; van Riemsdijk, Maarten; Laagland, Eelco; Gommer, Lisa; Jones, Val

211

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

212

Design theory of wireless power transfer system based on magnetically coupled resonators  

Microsoft Academic Search

A wireless power transfer system based on magnetically coupled two resonators is analysed using the filter theory. Design equations for each lumped parameter circuit components are derived. As a result, change of coupling coefficient between the resonators and\\/or change of load resistance are easily responded. Effect of circuit loss to the design theory is also addressed.

I. Awai

2010-01-01

213

Thermal buckling of functionally graded circular plates based on higher order shear deformation plate theory  

Microsoft Academic Search

In this research, thermal buckling of circular plates compose of functionally graded material (FGM) is considered. Equilibrium and stability equations of a FGM circular plate under thermal loads are derived, based on the higher order shear deformation plate theory (3rd order plate theory). Assuming that the material properties vary as a power form of the thickness coordinate variable z and

M. M. Najafizadeh; H. R. Heydari

2004-01-01

214

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

215

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

216

Dislocation theory based short crack model and its application for aircraft aluminum alloys  

Microsoft Academic Search

This paper presents a study on dislocation theory based short\\/small crack modeling, and its application for short crack growth life analysis on 2024-T351 aluminum specimens. The dislocation theory was applied to determine the crack tip opening displacement (CTOD) of a microstructurally short crack by taking into account the effects of microstructural features, such as grain size, orientation, and grain boundary.

Min Liao

2010-01-01

217

Competence-based management and corporate culture: Two theories with common flaws?  

Microsoft Academic Search

There are a number of issues that researchers in the newly emerging perspective of competence-based management (CBM) could consider from the experiences of culture theory, which was hailed in the 1980s as the definitive answer to managing strategically. However, for three main reasons, culture theory is not as useful to practising managers as the hype in the early 1980s led

Dianne Lewis

1998-01-01

218

Theory-based Evaluation: Gaining a Shared Understanding between School Staff and Evaluators.  

ERIC Educational Resources Information Center

Explores how theory-based evaluation can be used to help conduct formative, reflective evaluation in educational settings. Program theory evaluation identifies links between planned activities and anticipated outcomes. This model helps schools clarify program goals, and builds cooperation and buy-in an evaluation as it encourages reflective…

Heubner, Tracy A.

2000-01-01

219

Model system design for small-size unmanned helicopter based on moment theory, blade element theory and FlightLab software  

Microsoft Academic Search

Model system based on moment theory, blade element theory and FlightLab software is designed for small-size unmanned helicopter. The system includes three models of helicopter, moment theory model (MTM), blade element theory model (BETM) and FlightLab model (FLM). MTM is used mainly for performance analysis, BETM for control system design and FLM for nonlinear real-time simulation. Then a high-reliable model

Wang Xiaoqing; Huang Yimin

2008-01-01

220

Clarification of Onsager reciprocal relations based on thermomass theory  

NASA Astrophysics Data System (ADS)

The fluxes in transport processes expressed as a time derivative of state variables is a crucial requirement in Onsager's proof of his reciprocal relations, which is a much debated question existing in nonequilibrium thermodynamics. Thermomass theory is used to show that the linear decay of the fluctuation is a balance between the inertial forces and resistant force. Therefore, products of the drift velocities and relaxation times, namely, the displacements from equilibrium, can be used as the state variables, whose time derivatives give the transport fluxes. The Onsager reciprocal relations can be macroscopically derived from the principle that every action has an equal and opposite reaction, applicable in steady nonequilibrium systems and nonlinear couplings.

Dong, Yuan

2012-12-01

221

Cis control of gene expression in E.coli by ribosome queuing at an inefficient translational stop signal  

PubMed Central

An UGA stop codon context which is inefficient because of the 3?-flanking context and the last two amino acids in the gene protein product has a negative effect on gene expression, as shown using a model protein A? gene. This is particularly true at low mRNA levels, corresponding to a high intracellular ribosome/mRNA ratio. The negative effect is smaller if this ratio is decreased, or if the distance between the initiation and termination signals is increased. The results suggest that an inefficient termination codon can cause ribosomal pausing and queuing along the upstream mRNA region, thus blocking translation initiation of short genes. This cis control effect is dependent on the stop codon context, including the C-terminal amino acids in the gene product, the translation initiation signal strength, the ribosome/mRNA ratio and the size of the mRNA coding region. A large proportion of poorly expressed natural Escherichia coli genes are small, and the weak termination codon UGA is under-represented in small, highly expressed E.coli genes as compared with the efficient stop codon UAA.

Jin, Haining; Bjornsson, Asgeir; Isaksson, Leif A.

2002-01-01

222

Popov Theory Based Survey on Digital Control of Infinite-Dimensional Systems with Unboundedness.  

National Technical Information Service (NTIS)

The paper represents a Popov theory based assessment of the current status of the digital control of infinite-dimensional systems with certain unboundedness in control and/or observation, summarizing some results and indicating, what would be, from their ...

F. D. Barb V. Ionescu W. de Koning

1994-01-01

223

Planetary Boundary Layer Parameterization for Tropical Cyclones Based on Generalized Similarity Theory.  

National Technical Information Service (NTIS)

A planetary boundary layer (PBL) parameterization based on the generalized similarity theory (GST) was developed for tropical cyclone models. This parameterization, with only one layer, is necessary in modeling tropical cyclones for computational speed. T...

S. W. Chang R. V. Madala

1980-01-01

224

Core Design and Operation Optimization Methods Based on Time-Dependent Perturbation Theory.  

National Technical Information Service (NTIS)

A general approach for the optimization of nuclear reactor core design and operation is outlined; it is based on two cornerstones: a newly developed time-dependent (or burnup-dependent) perturbation theory for nonlinear problems and a succesive iteration ...

E. Greenspan

1983-01-01

225

A joint signature encryption and error correction public-key cryptosystem based on algebraic coding theory  

Microsoft Academic Search

A joint signature, entyption and error correction public-key cryptosystem is presented based on an NP-completeness problem—the\\u000a decoding problem of general linear codes in algebraic coding theory.

Li Yuanxing; Cheng Jian; Wang Xinmei

1992-01-01

226

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

227

Developing a Methodology Information Base for Administrative and Organization Theory: An Initial Bibliography and Comment  

ERIC Educational Resources Information Center

There is a need to develop an interdisciplinary information base of publications related specifically to theory methodology and construction. Existing information sources focus primarily on the dissemination of ccompleted research project results. (Author/WM)

Van Meter, Eddy J.

1974-01-01

228

Theory of Deformation Processes and Lifetime of Wood Based on Deformation Kinetics,  

National Technical Information Service (NTIS)

As part of a research and development program for timber of the European Economical Community, a lifetime theory will be investigated based on chemical reaction kinetics of bond breaking. For wood the approach is complicated by the complex structure, thro...

T. A. C. M. van der Put

1985-01-01

229

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

230

Cyclic Voltammetric Analysis of Ferrocene Alkanethiol Monolayer Electrode Kinetics Based on Marcus Theory.  

National Technical Information Service (NTIS)

Theory for electrode kinetics of surface-immobilized monolayers in cyclic voltammetry is developed based on the Marcus free energy-rate relation. Numerical calculations show that when the applied over-potential exceeds ca. 30% of the reorganizational ener...

L. Tender M. T. Carter R. W. Murray

1994-01-01

231

Is abstinence education theory based? The underlying logic of abstinence education programs in Texas.  

PubMed

Authors examined the logic (or the implicit theory) underlying 16 abstinence-only-until-marriage programs in Texas (50% of all programs funded under the federal welfare reform legislation during 2001 and 2002). Defined as a set of propositions regarding the relationship between program activities and their intended outcomes, program staff's implicit theories were summarized and compared to (a) data from studies on adolescent sexual behavior, (b) a theory-based model of youth abstinent behavior, and (c) preliminary findings from the national evaluation of Title V programs. Authors interviewed 62 program directors and instructors and employed selected principles of grounded theory to analyze interview data. Findings indicated that abstinence education staff could clearly articulate the logic guiding program activity choices. Comparisons between interview data and a theory-based model of adolescent sexual behavior revealed striking similarities. Implications of these findings for conceptualizing and evaluating abstinence-only-until-marriage (or similar) programs are examined. PMID:16531516

Goodson, Patricia; Pruitt, B E; Suther, Sandy; Wilson, Kelly; Buhi, Eric

2006-04-01

232

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

233

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

Microsoft Academic Search

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

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

2008-01-01

234

Efficient Color-theory-based Dynamic Localization for Mobile Wireless Sensor Networks  

Microsoft Academic Search

Location information is critical to mobile wireless sensor networks (WSN) applications. With the help of location information,\\u000a for example, routing can be performed more efficiently. In this paper, we propose a novel localization approach, Color-theory based Dynamic Localization (CDL), which is based on color theory to exploit localization in mobile WSNs. CDL makes use of the broadcast information, such as

Shen-Hai Shee; Tzu-Chien Chang; Kuochen Wang; Yi-Ling Hsieh

2011-01-01

235

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

Microsoft Academic Search

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

Vincenzo Fiorentini; Alessio Filippetti

2006-01-01

236

Molar conductivity calculation of Li-ion battery electrolyte based on mode coupling theory.  

PubMed

A method is proposed to calculate molar conductivity based on mode coupling theory in which the ion transference number is introduced into the theory. The molar conductivities of LiPF6, LiClO4, LiBF4, LiAsF6 in PC (propylene carbonate) are calculated based on this method. The results fit well to the literature data. This presents a potential way to calculate the conductivities of Li-ion battery electrolytes. PMID:16392907

Pu, Weihua; He, Xiangming; Lu, Jiufang; Jiang, Changyin; Wan, Chunrong

2005-12-15

237

Research on remote controlled robot motion control system based on agent theory  

Microsoft Academic Search

This paper introduces remote controlled robot motion control system based on agent theory. Task planning and reactive behavior control are discussed and implemented. This paper describes design of manager agent and motion control agent in detail. Agent theory are implemented in the robot control system to realize distributed intelligence based on M\\/A\\/R(Man\\/Agent\\/Robot) architecture. Thereby autonomy, reliability and real-time operation are

Jijin Xia; Wenbin Wan; Kai Fang; Wei Qian; Zhenshu Ma; Xihui Mu; Qinshu Ang; Jing Fang

2004-01-01

238

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

NASA Technical Reports Server (NTRS)

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

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

2010-01-01

239

Towards Enterprise Integration Performance Assessment based on Category Theory  

NASA Astrophysics Data System (ADS)

A major difference between what we refer to as a "well-developed" science, such as civil engineering, and sciences which are less so, like enterprise engineering, is the degree to which nonfunctional requirements, such as performance, are integrated into the design and development process, and satisfaction of those requirements is controlled by theoretically valid measurement procedures. This paper introduces the preliminary results, which are aimed at developing a concise formal framework for enterprise performance modeling, measurement, and control during enterprise integration activities. The novelty of this research consists in employing the mathematical category theory for modeling purposes, an approach that is broad enough to formally capture heterogeneous (structural, functional and nonfunctional) requirements, by, for example, using the constructs from the graphical categorical formal language.

Mikhnovsky, Victoria; Ormandjieva, Olga

240

The Role of Culture Theory in Cross-Cultural Training: A Multimethod Study of Culture-Specific, Culture-General, and Culture Theory-Based Assimilators.  

ERIC Educational Resources Information Center

In a multimethod evaluation of cross-cultural training tools involving 102 exchange students at a midwestern university, a theory-based individualism and collectivism assimilator tool had significant advantages over culture-specific and culture-general assimilators and a control condition. Results support theory-based culture assimilators. (SLD)

Bhawuk, Dharm P. S.

1998-01-01

241

Export base theory and multiplier estimation: A critique  

Microsoft Academic Search

In recent years export-base related models have come under increasing criticism by regional economists. At the same time, the framework is being used implicitly in the great many studies including most socioeconomic environmental impact studies. The paper shows that the various alternatives commonly used at each step in the process of an export-base analysis (i.e., that is to specify one

W. Cris Lewis

1976-01-01

242

Topological analysis of metabolic networks based on petri net theory.  

PubMed

Petri net concepts provide additional tools for the modelling of metabolic networks. Here, the similarities between the counterparts in traditional biochemical modelling and Petri net theory are discussed. For example the stoichiometry matrix of a metabolic network corresponds to the incidence matrix of the Petri net. The flux modes and conservation relations have the T-invariants, respectively, P-invariants as counterparts. We reveal the biological meaning of some notions specific to the Petri net framework (traps, siphons, deadlocks, liveness). We focus on the topological analysis rather than on the analysis of the dynamic behaviour. The treatment of external metabolites is discussed. Some simple theoretical examples are presented for illustration. Also the Petri nets corresponding to some biochemical networks are built to support our results. For example, the role of triose phosphate isomerase (TPI) in Trypanosoma brucei metabolism is evaluated by detecting siphons and traps. All Petri net properties treated in this contribution are exemplified on a system extracted from nucleotide metabolism. PMID:21685562

Zevedei-Oancea, Ionela; Schuster, Stefan

2011-01-01

243

Seismic data reconstruction based on CS and Fourier theory  

NASA Astrophysics Data System (ADS)

Traditional seismic data sampling follows the Nyquist sampling theorem. In this paper, we introduce the theory of compressive sensing (CS), breaking through the limitations of the traditional Nyquist sampling theorem, rendering the coherent aliases of regular undersampling into harmless incoherent random noise using random undersampling, and effectively turning the reconstruction problem into a much simpler denoising problem. We introduce the projections onto convex sets (POCS) algorithm in the data reconstruction process, apply the exponential decay threshold parameter in the iterations, and modify the traditional reconstruction process that performs forward and reverse transforms in the time and space domain. We propose a new method that uses forward and reverse transforms in the space domain. The proposed method uses less computer memory and improves computational speed. We also analyze the antinoise and anti-aliasing ability of the proposed method, and compare the 2D and 3D data reconstruction. Theoretical models and real data show that the proposed method is effective and of practical importance, as it can reconstruct missing traces and reduce the exploration cost of complex data acquisition.

Zhang, Hua; Chen, Xiao-Hong; Wu, Xin-Min

2013-06-01

244

An open-shell restricted Hartree-Fock perturbation theory based on symmetric spin orbitals  

NASA Technical Reports Server (NTRS)

A new open-shell perturbation theory is formulated in terms of symmetric spin orbitals. Only one set of spatial orbitals is required, thereby reducing the number of independent coefficients in the perturbed wavefunctions. For second order, the computational cost is shown to be similar to a closed-shell calculation. This formalism is therefore more efficient than the recently developed RMP, ROMP or RMP-MBPT theories. The perturbation theory described herein was designed to have a close correspondence with our recently proposed coupled-cluster theory based on symmetric spin orbitals. The first-order wavefunction contains contributions from only doubly excited determinants. Equilibrium structures and vibrational frequencies determined from second-order perturbation theory are presented for OH, NH, CH, 02, NH2 and CH2.

Lee, Timothy J.; Jayatilaka, Dylan

1993-01-01

245

The theory of shell-based Q-mappings in geometric function theory  

NASA Astrophysics Data System (ADS)

Open, discrete Q-mappings in {\\mathbb R}^n, n\\ge2, Q\\in L^1_{\\mathrm{loc}}, are proved to be absolutely continuous on lines, to belong to the Sobolev class W_{\\mathrm{loc}}^{1,1}, to be differentiable almost everywhere and to have the N^{-1}-property (converse to the Luzin N-property). It is shown that a family of open, discrete shell-based Q-mappings leaving out a subset of positive capacity is normal, provided that either Q has finite mean oscillation at each point or Q has only logarithmic singularities of order at most n-1. Under the same assumptions on Q it is proved that an isolated singularity x_0\\in D of an open discrete shell-based Q-map f\\colon D\\setminus\\{x_0\\}\\to\\overline{\\mathbb R}{}^n is removable; moreover, the extended map is open and discrete. On the basis of these results analogues of the well-known Liouville, Sokhotskii-Weierstrass and Picard theorems are obtained. Bibliography: 34 titles.

Salimov, Ruslan R.; Sevost'yanov, Evgenii A.

2010-08-01

246

A Conceptual Framework Based on Activity Theory for Mobile CSCL  

ERIC Educational Resources Information Center

There is a need for collaborative group activities that promote student social interaction in the classroom. Handheld computers interconnected by a wireless network allow people who work on a common task to interact face to face while maintaining the mediation afforded by a technology-based system. Wirelessly interconnected handhelds open up new…

Zurita, Gustavo; Nussbaum, Miguel

2007-01-01

247

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

248

VSS Theory Based Training of a Fuzzy Motion Control System  

Microsoft Academic Search

This paper presents a novel training algorithm for adaptive neuro-fuzzy inference systems. The algorithm combines the error backpropagation algorithm with variable structure systems approach. Expressing the parameter update rule as a dynamic system in continuous time and applying sliding mode control (SMC) method to the dynamic model of the gradient based training procedure results in the parameter stabilizing part of

M. Onder Efe; A. Murat Fiskiran; Okyay Kaynak; Imre J. Rudas

249

Exploring the Theory and Paradigm Base for Wraparound  

Microsoft Academic Search

Until recently, family-centered policy and practice used expert models which defined families of children with serious emotional disturbance as dysfunctional A collaborative model, called wraparound, is emerging which engages these families as decision making participants, using naturally occurring strengths to wrap individualized supports around the child and family. However, because wraparound has been defined only through value-based principles, the fidelity

Rosalyn Malysiak

1997-01-01

250

Integrated Models of School-Based Prevention: Logic and Theory  

ERIC Educational Resources Information Center

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

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

2010-01-01

251

Learning Trajectory Based Instruction: Toward a Theory of Teaching  

ERIC Educational Resources Information Center

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

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

2012-01-01

252

System failure analysis based on complex network theory  

Microsoft Academic Search

In this paper, we have introduced a novel method for failure analysis of complex systems in the chemical process industry based on recent advances in complex networks. We model the engineering system as a large, complex network and choose to investigate failure from the topological perspective. Then, we introduce a model incorporating the load of nodes and the efficiency to

Hongquan Jiang; Jianmin Gao; Fumin Chen

2009-01-01

253

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

PubMed

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

Otal, Begonya; Alonso, Luis; Verikoukis, Christos

2011-01-01

254

Microscopic theory of anomalous diffusion based on particle interactions  

NASA Astrophysics Data System (ADS)

We present a master equation formulation based on a Markovian random walk model that exhibits subdiffusion, classical diffusion, and superdiffusion as a function of a single parameter. The nonclassical diffusive behavior is generated by allowing for interactions between a population of walkers. At the macroscopic level, this gives rise to a nonlinear Fokker-Planck equation. The diffusive behavior is reflected not only in the mean squared displacement [˜t? with 0based on the master equation are shown to be in agreement with the analytical solutions of the nonlinear Fokker-Planck equation in all three diffusion regimes.

Lutsko, James F.; Boon, Jean Pierre

2013-08-01

255

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

256

Transient response of lattice structures based on exact member theory  

NASA Technical Reports Server (NTRS)

The computer program BUNVIS-RG, which treats vibration and buckling of lattice structures using exact member stiffness matrices, has been extended to calculate the exact modal mass and stiffness quantities that can be used in a conventional transient response analysis based on modes. The exact nature of the development allows inclusion of local member response without introduction of any interior member nodes. Results are given for several problems in which significant interaction between local and global response occurs.

Anderson, Melvin S.

1989-01-01

257

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

258

Phase-field model during static recrystallization based on crystal-plasticity theory  

Microsoft Academic Search

A numerical model and computational procedure for static recrystallization are developed using a phase-field method coupled\\u000a with crystal-plasticity theory. In this model, first, the microstructure and dislocation density during the deformation process\\u000a of a polycrystalline metal are simulated using a finite element method based on strain-gradient crystal-plasticity theory.\\u000a Second, the calculated data are mapped onto the regular grids used in

T. Takaki; A. Yamanaka; Y. Higa; Y. Tomita

2007-01-01

259

Research on multi-Agent cooperation mechanism based on game theory  

Microsoft Academic Search

Aiming at the cooperation of Agent in multi-Agent system, the game theory was introduced to the cooperation of Agent, and the multi-Agent cooperation mechanism based on game theory was established. The common multi-Agent cooperation model was analyzed, and an improved benevolent function was given, as well as the specific process of cooperation strategies and cooperation algorithms. At last, the cooperation

Zhang Lieping; Cheng Dafang; Zhang Yunsheng

2010-01-01

260

The Effect Of The Materials Based On Multiple Intelligence Theory Upon The Intelligence Groups' Learning Process  

NASA Astrophysics Data System (ADS)

The aim of this study is to find out the effect of the course materials based on Multiple Intelligence Theory upon the intelligence groups' learning process. In conclusion, the results proved that the materials prepared according to Multiple Intelligence Theory have a considerable effect on the students' learning process. This effect was particularly seen on the student groups of the musical-rhythmic, verbal-linguistic, interpersonal-social and naturalist intelligence.

Oral, I.; Dogan, O.

2007-04-01

261

A finite-deformation-based phenomenological theory for shape-memory alloys  

Microsoft Academic Search

In this work we develop a finite-deformation-based, thermo-mechanically-coupled and non-local phenomenological theory for polycrystalline shape-memory alloys (SMAs) capable of undergoing austenite ? martensite phase transformations. The constitutive model is developed in the isotropic plasticity setting using standard balance laws, thermodynamic laws and the theory of micro-force balance (Fried and Gurtin, 1994). The constitutive model is then implemented in the ABAQUS\\/Explicit

P. Thamburaja

2010-01-01

262

Method for PE Pipes Fusion Jointing Based on TRIZ Contradictions Theory  

NASA Astrophysics Data System (ADS)

The core of the TRIZ theories is the contradiction detection and solution. TRIZ provided various methods for the contradiction solution, but all that is not systematized. Combined with the technique system conception, this paper summarizes an integration solution method for contradiction solution based on the TRIZ contradiction theory. According to the method, a flowchart of integration solution method for contradiction is given. As a casestudy, method of fusion jointing PE pipe is analysised.

Sun, Jianguang; Tan, Runhua; Gao, Jinyong; Wei, Zihui

263

Gauge Theory of Supergravity Based Only on a Self-Dual Spin Connection  

NASA Astrophysics Data System (ADS)

A gauge theory of supergravity is constructed based only on the supersymmetric self-dual spin connection associated to the supergroup OSp \\(1 \\| 4\\). We show that Jacobson's supergravity action arises naturally from our proposed action. It is formulated by taking the self-dual part of the MacDowell-Mansouri gauge theory of supergravity. In this sense, our quadratic action in the supersymmetric self-dual curvature tensor provides a relation between these two important previous extensions of supergravity.

Nieto, J. A.; Socorro, J.; Obregón, O.

1996-05-01

264

An information fusion method for reliability based on DS evidential theory  

Microsoft Academic Search

The multi-source reliability information fusion method based on D-S evidential theory is presented in this paper to solve the complex system reliability assessment problems. Aimed to the multi-source reliability information, the method in this paper established basic probability assignment firstly. Then, the reliability information is fused using D-S evidential theory. After that, the fused basic probability assignment is translated into

Jun-bo Wan; Tong-min Jiang; Xiao-yang Li; Yu Fan

2010-01-01

265

Agent-Based Immunity for Computer Virus: Abstraction from Dendritic Cell Algorithm with Danger Theory  

Microsoft Academic Search

\\u000a Biologically-inspired artificial immune systems (AIS) have been applied to computer virus detection systems (CVDS). An agent-based\\u000a CVDS based on danger theory of human immune system is proposed. The intelligence behind such system is based on the functionality\\u000a of dendritic cells in human immune systems. This paper embeds multiple agents into AIS-based virus detection system, where\\u000a each agent coordinates one another

Chung-Ming Ou; Chung-Ren Ou

2010-01-01

266

AHP for Risk Management Based on Expected Utility Theory  

NASA Astrophysics Data System (ADS)

This paper presents a model of decision-making considering the risk assessment. The conventional evaluation in AHP is considered to be a kind of utility. When dealing with the risk, however, it is necessary to consider the probability of damage. In order to take risk into decision-making problem, we construct AHP based on expected utility. The risk is considered as a related element of criterion rather than criterion itself. The expected utility is integrated, considering that satisfaction is positive utility and damage by risk is negative utility. Then, evaluation in AHP is executed using the expected utility.

Azuma, Rumiko; Miyagi, Hayao

267

Design of a Four-Layer IDS Model Based on Immune Danger Theory  

Microsoft Academic Search

Owing to the similarity between biological immune system and intrusion detection system, a four-layer model for network intrusion detection system based on Dendritic cells (DC) in danger theory is constructed . DC detectors are introduced and a DC-based algorithm is proposed in this model. It involves comprehensive evaluation and improves the detection ability of undefined intrusion.

Song Yuan; Qi-juan Chen; Peng Li

2009-01-01

268

Study on fault diagnosis algorithm based on artificiall immune danger theory  

Microsoft Academic Search

In order to improve precision of fault diagnosis which based on artificial immune system, a kind of fault diagnosis algorithm based on immune danger theory was presented. The algorithm can make judgment according to whether existing danger signals and reduce false rate. The algorithm also can adjust databases online. The algorithm was applied to automobile axle driving fault diagnosis. the

Qinghua Meng; Wenli Zhao

2010-01-01

269

Data reduction for multispectral and hyperspectral imagery based on application of catastrophe theory  

Microsoft Academic Search

In this paper, we discuss a novel method, for multispectral and hyperspectral imagery data reduction. This method is based on singularity representation and integrates a rotational invariant visual object extraction and understanding technique based on the application of differential mapping to image processing. This new compression method applies Arnold's Differential Mapping Singularities Theory in the context of three-dimensional (3D) terrain

Igor V. Ternovskiy; Tomasz M. Jannson

2000-01-01

270

Increasing Screening Mammography in Asymptomatic Women: Evaluation of a Second-Generation, Theory-Based Program  

Microsoft Academic Search

Two theory-based programs to increase mammography screening rates among asymptomatic women were implemented and evaluated in the community. One program (E) was based on the Health Belief Model (HBM); the second program (EP) added exercises adapted from the social psychology of compliance. Program impact on screening among 295 primarily Caucasian, middle-class women was evaluated against untreated controls (C) over a

Leona S. Aiken; Stephen G. West; Claudia K. Woodward; Raymond R. Reno; Kim D. Reynolds

1994-01-01

271

Using Game Theory and Competition-Based Learning to Stimulate Student Motivation and Performance  

ERIC Educational Resources Information Center

This paper introduces a framework for using Game Theory tournaments as a base to implement Competition-based Learning (CnBL), together with other classical learning techniques, to motivate the students and increase their learning performance. The paper also presents a description of the learning activities performed along the past ten years of a…

Burguillo, Juan C.

2010-01-01

272

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

ERIC Educational Resources Information Center

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

Bridgstock, Ruth

2007-01-01

273

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

274

Theory, Theory  

NSDL National Science Digital Library

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

Kimmel, Michael

2007-12-12

275

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

276

Mindfulness-based cognitive therapy: theory and practice.  

PubMed

Mindfulness-based cognitive therapy (MBCT) incorporates elements of cognitive-behavioural therapy with mindfulness-based stress reduction into an 8-session group program. Initially conceived as an intervention for relapse prevention in people with recurrent depression, it has since been applied to various psychiatric conditions. Our paper aims to briefly describe MBCT and its putative mechanisms of action, and to review the current findings about the use of MBCT in people with mood and anxiety disorders. The therapeutic stance of MBCT focuses on encouraging patients to adopt a new way of being and relating to their thoughts and feelings, while placing little emphasis on altering or challenging specific cognitions. Preliminary functional neuroimaging studies are consistent with an account of mindfulness improving emotional regulation by enhancing cortical regulation of limbic circuits and attentional control. Research findings from several randomized controlled trials suggest that MBCT is a useful intervention for relapse prevention in patients with recurrent depression, with efficacy that may be similar to maintenance antidepressants. Preliminary studies indicate MBCT also shows promise in the treatment of active depression, including treatment-resistant depression. Pilot studies have also evaluated MBCT in bipolar disorder and anxiety disorders. Patient and clinician resources for further information on mindfulness and MBCT are provided. PMID:22340145

Sipe, Walter E B; Eisendrath, Stuart J

2012-02-01

277

Theory-based ability measurement: the learning abilities measurement program.  

PubMed

This paper briefly describes the U.S. Air Force Learning Abilities Measurement Program (LAMP), which is devoted to the development of a science-based system of ability measurement. A short history is given of ability testing and research in the military services, along with a statement of the value of ability testing for making personnel selection and classification decisions. Although few advances in ability measurement have been made in the last two decades, the present availability of micro-computers and recent progress in our understanding of human cognition create possibilities for a major breakthrough in the state-of-the-art. Examples are provided of recent LAMP studies on processing speed and processing capacity which hold promise for forecasting individual differences in learning efficiency, performance capabilities, and susceptibility to information overload. Also discussed is a program which encourages university scientists working toward the same goals to make use of U.S. Air Force subjects and testing facilities. PMID:3060094

Christal, R E

1988-11-01

278

[The Chinese urban metabolisms based on the emergy theory].  

PubMed

By using emergy indices of urban metabolisms, this paper analyzed 31 Chinese urban metabolisms' systematic structures and characteristics in 2000 and 2010. The results showed that Chinese urban metabolisms were characterized as resource consumption and coastal external dependency. Non-renewable resource emergy accounted for a higher proportion of the total emergy in the inland cities' urban metabolisms. The emergy of imports and exports accounted for the vast majority of urban metabolic systems in metropolises and coastal cities such as Beijing and Shanghai, showing a significant externally-oriented metabolic characteristic. Based on that, the related policies were put forward: to develop the renewable resource and energy industry; to improve the non-renewable resource and energy utilization efficiencies; to optimize the import and export structure of services, cargo and fuel; and to establish the flexible management mechanism of urban metabolisms. PMID:25011303

Song, Tao; Cai, Jian-Ming; Ni, Pan; Yang, Zhen-Shan

2014-04-01

279

The iSLIP scheduling algorithm for input-queued switches  

Microsoft Academic Search

An increasing number of high performance inter- networking protocol routers, LAN and asynchronous transfer mode (ATM) switches use a switched backplane based on a crossbar switch. Most often, these systems use input queues to hold packets waiting to traverse the switching fabric. It is well known that if simple first in first out (FIFO) input queues are used to hold

Nick McKeown

1999-01-01

280

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

PubMed

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

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

2013-07-01

281

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.

Thompson, Jason A.; Bau, Haim H.

2009-01-01

282

Derivative Trade Optimizing Model Utilizing GP Based on Behavioral Finance Theory  

NASA Astrophysics Data System (ADS)

This paper proposed a new technique which makes the strategy trees for the derivative (option) trading investment decision based on the behavioral finance theory and optimizes it using evolutionary computation, in order to achieve high profitability. The strategy tree uses a technical analysis based on a statistical, experienced technique for the investment decision. The trading model is represented by various technical indexes, and the strategy tree is optimized by the genetic programming(GP) which is one of the evolutionary computations. Moreover, this paper proposed a method using the prospect theory based on the behavioral finance theory to set psychological bias for profit and deficit and attempted to select the appropriate strike price of option for the higher investment efficiency. As a result, this technique produced a good result and found the effectiveness of this trading model by the optimized dealings strategy.

Matsumura, Koki; Kawamoto, Masaru

283

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

284

Social learning theory parenting intervention promotes attachment-based caregiving in young children: randomized clinical trial.  

PubMed

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 learning theory-based treatment promoted change in qualities of parent-child relationship derived from attachment theory. A randomized clinical trial of 174 four- to six-year-olds selected from a high-need urban area and stratified by conduct problems were assigned to a parenting program plus a reading intervention (n = 88) or nonintervention condition (n = 86). In-home observations of parent-child interactions were assessed in three tasks: (a) free play, (b) challenge task, and (c) tidy up. Parenting behavior was coded according to behavior theory using standard count measures of positive and negative parenting, and for attachment theory using measures of sensitive responding and mutuality; children's attachment narratives were also assessed. Compared to the parents in the nonintervention group, parents allocated to the intervention showed increases in the positive behavioral counts and sensitive responding; change in behavioral count measures overlapped modestly with change in attachment-based changes. There was no reliable change in children's attachment narratives associated with the intervention. The findings demonstrate that standard social learning theory-based parenting interventions can change broader aspects of parent-child relationship quality and raise clinical and conceptual questions about the distinctiveness of existing treatment models in parenting research. PMID:23020146

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

2013-01-01

285

A Queuing Theoretic Approach to Processor Power Adaptation for Video Decoding Systems  

Microsoft Academic Search

Video decoding applications must often cope with highly time-varying workload demands, while meeting stringent display deadlines. Voltage\\/frequency scalable processors are highly attractive for video decoding on resource-constrained systems, since significant energy savings can be achieved by dynamically adapting the processor speed based on the changing workload demand. Previous works on video-related voltage scaling algorithms are often limited by the lack

Brian Foo; Mihaela Van Der Schaar

2008-01-01

286

The use of density functional theory-based reactivity descriptors in molecular similarity calculations  

NASA Astrophysics Data System (ADS)

Molecular similarity is studied via density functional theory-based similarity indices using a numerical integration method. Complementary to the existing similarity indices, we introduce a reactivity-related similarity index based on the local softness. After a study of some test systems, a series of peptide isosteres is studied in view of their importance in pharmacology. The whole of the present work illustrates the importance of the study of molecular similarity based on both shape and reactivity.

Boon, Greet; De Proft, Frank; Langenaeker, Wilfried; Geerlings, Paul

1998-10-01

287

Ground and Excited States of Retinal Schiff Base Chromophores by Multiconfigurational Perturbation Theory  

PubMed Central

We have studied the wavelength dependence of retinal Schiff base absorbencies on the protonation state of the chromophore at the multiconfigurational level of theory using second order perturbation theory (CASPT2) within an atomic natural orbital basis set on MP2 optimized geometries. Quantitative agreement between calculated and experimental absorption maxima was obtained for protonated and deprotonated Schiff bases of all-trans- and 11-cis-retinal and intermediate states covering a wavelength range from 610 to 353 nm. These data will be useful as reference points for the calibration of more approximate schemes.

Sekharan, Sivakumar; Weingart, Oliver; Buss, Volker

2006-01-01

288

Theory of concave gratings based on a recursive definition of facet positions.  

PubMed

A general theory for concave gratings is presented that is based on a recursion formula for the facet positions and that differs from previous theories that are based on a power-series expansion of the light path function. In the recursion formula approach the facet positions are determined from a numerical solution for the roots of two constraint functions. Facet positions are determined in sequence, starting from the grating pole. One constraint function may be chosen to give a stigmatic point. A variety of grating designs are discussed, including a design that cannot be generated with the power-series approach. PMID:21127601

McGreer, K A

1996-10-20

289

Calculations of the evolution of the upper ocean based on the similarity theory  

NASA Astrophysics Data System (ADS)

Several schemes of turbulent mixing in the upper ocean are considered, including a modified scheme based on the modified Monin-Obukhov similarity theory. The schemes have been used for the calculation of the evolution of the upper ocean. The results are compared with the data of automated buoys. It is shown that the scheme based on the similarity theory gives a result not worse than the commonly used ones and has several advantages, which makes it the most appropriate for including in the ocean circulation models and climate models.

Bulgakov, K. Yu.

2012-05-01

290

Theory of concave gratings based on a recursive definition of facet positions  

NASA Astrophysics Data System (ADS)

A general theory for concave gratings is presented that is based on a recursion formula for the facet positions and that differs from previous theories that are based on a power-series expansion of the light path function. In the recursion formula approach the facet positions are determined from a numerical solution for the roots of two constraint functions. Facet positions are determined in sequence, starting from the grating pole. One constraint function may be chosen to give a stigmatic point. A variety of grating designs are discussed, including a design that cannot be generated with the power-series approach.

McGreer, K. A.

1996-10-01

291

Performance evaluation of an optical hybrid switch with circuit queued reservations and circuit priority preemption  

NASA Astrophysics Data System (ADS)

We provide here a new loss model for an optical hybrid switch that can function as an optical burst switch and/or optical circuit switch. Our model is general as it considers an implementation whereby some of the circuits have preemptive priority over bursts and others are allowed to queue their reservations. We first present an analysis based on a 3-dimension state-space Markov chain that provides exact results for the blocking probabilities of bursts and circuits, the proportion of circuits that are delayed and the mean delay of the circuits that are delayed. Because it is difficult to exactly compute the blocking probability in realistic scenarios with a large number of wavelengths, we derive computationally a scalable and accurate approximations based on reducing the 3-dimension state space into a single dimension. These scalable approximations that can produce performance results in a fraction of a second can readily enable switch dimensioning. Extensive numerical results are presented to demonstrate the accuracy and the use of the new approximations.

Wong, Eric W. M.; Zukerman, Moshe

2006-11-01

292

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

293

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

294

Theory-based predictors of multiple clinician behaviors in the management of diabetes.  

PubMed

Behavioral theory is often tested on one behavior in isolation from other behaviors and theories. We aimed to test the predictive validity of constructs from motivation and action theories of behavior across six diabetes-related clinician behaviors, within the same sample of primary care clinicians. Physicians and nurses (n = 427 from 99 practices in the United Kingdom) completed questionnaires at baseline and 12 months. Primary outcomes: six self-reported clinician behaviors related to advising, prescribing and examining measured at 12 months; secondary outcomes: baseline intention and patient-scenario-based simulated behavior. Across six behaviors, each theory accounted for a medium amount of variance for 12-month behavior (median R adj (2)  = 0.15), large and medium amount of variance for two intention measures (median R adj (2)  = 0.66; 0.34), and small amount of variance for simulated behavior (median R adj (2)  = 0.05). Intention/proximal goals, self-efficacy, and habit predicted all behaviors. Constructs from social cognitive theory (self-efficacy), learning theory (habit) and action and coping planning consistently predicted multiple clinician behaviors and should be targeted by quality improvement interventions. PMID:23670643

Presseau, Justin; Johnston, Marie; Francis, Jill J; Hrisos, Susan; Stamp, Elaine; Steen, Nick; Hawthorne, Gillian; Grimshaw, Jeremy M; Elovainio, Marko; Hunter, Margaret; Eccles, Martin P

2014-08-01

295

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.

Cowin, Stephen C.; Cardoso, Luis

2011-01-01

296

Nursing students' immediate responses to distressed clients based on Orlando's theory  

PubMed Central

BACKGROUND: Nowadays, problem solving skills, clinical decision making ability and making a proper relationship to clients are essential necessities for nursing graduates; however there are few studies which investigated nursing students’ responses to clients with problematic situations based on nursing theories addressing interactions. The purpose of this study was to analyze the nursing students’ immediate responses to distressed clients’ behaviors focusing on collaborative Orlando’s theory. METHODS: This exploratory study was assessed 60 nursing students’ responses to a simulated clients’ questionnaire based on Orlando’s theory in 2008. All of the students were enrolled in bachelor degree of nursing. The data were analyzed by dimensional content analysis to specify the key categories, according to concepts of Orlando’s theory. RESULTS: According to Orlando’s theory, students’ immediate responses to physical and mental problems of distressed clients were classified into 6 main categories: physical caring, uncertainty, assuring, recommending, asking information and explaining. The most frequent responses to clients’ behaviors were physical caring, assuring and recommending and most of the students were unable to respond to mental problems. CONCLUSIONS: Nursing students responded to clients’ needs automatically and they did not consider clients’ ability in decision making. Medical diagnosis, physical caring and assuring were their main concerns and they were confused in responding to mental problems. Orlando’s theory emphasizes on nurse-client interactions and considers nurses’ perceptions, thoughts, and feelings. It views clients as a participant in care giving, so teaching this theory can enhance students’ communication skills and improve quality of nursing care.

Abdoli, Samereh; Safavi, Shadi Satat

2010-01-01

297

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

298

Design of a Dendritic Cells inspired Model Based on Danger Theory for Intrusion Detection System  

Microsoft Academic Search

The research into intrusion detection system (IDS) based on immunology has shifted from the negative selection algorithm to a novel concept, the danger theory (DT). Dendritic cells (DCs) are professional antigen presenting cells in innate immunity that perform the central role of sensing infection situation and coordinating T cells behavior. DCs play an integral part in incorporation of DT into

Xue Li; Haidong Fu; Siliang Huang

2008-01-01

299

Research on the Method of Opinion Mining Based on Danger Theory  

Microsoft Academic Search

Kinds of text opinion on the Internet are very important to the development of companies, however, methods of opinion mining is very limited, because there always need to deal with many meaning analysis, so this paper presents a new method on opinion mining based on danger theory. Using this method, companies can make decision easier.

Dan Liu; Shi-xia Ma; Zu-hua Guo

2010-01-01

300

Quality Control Model for Complex Manufacturing System Based on Danger Theory of Biological Immune System  

Microsoft Academic Search

In this article we introduce a new quality control model for complex manufacturing system which has the potential to enable enterprise to protect itself from harmful non-conformance in a way like biological system. The model is based on danger theory. In the proposed quality control model, a co-stimulation is necessary to confirm the danger implied by the presence of a

Genbao Zhang; Haifeng Zeng; Guoqiang Wang; Gengbao Huang

2009-01-01

301

Interpretation-Based Processing: A Unified Theory of Semantic Sentence Comprehension  

ERIC Educational Resources Information Center

We present interpretation-based processing--a theory of sentence processing that builds a syntactic and a semantic representation for a sentence and assigns an interpretation to the sentence as soon as possible. That interpretation can further participate in comprehension and in lexical processing and is vital for relating the sentence to the…

Budiu, Raluca; Anderson, John R.

2004-01-01

302

Motivational Strategies in Computer-Based Instruction: Some Lessons from Theories and Models of Motivation.  

ERIC Educational Resources Information Center

This paper proposes strategies of motivation in computer based instruction (CBI) derived from motivational foundations of cognitive, affective, and social learning theories. The assumption made here is that motivation and achievement interact in ways that warrant a "holistic" examination of strategies incorporated into CBI. Thus motivation in CBI…

Relan, Anju

303

Reverberation Chamber Modeling Based on Image Theory: Investigation in the Pulse Regime  

Microsoft Academic Search

In this paper, we propose a straightforward 3-D time-domain model of a reverberation chamber (RC) based on image theory. This model allows one to describe the earliest moments of an arbitrary waveform in an RC. Time domain and frequency domain results from this model are analyzed and compared with measurements conducted in a RC.

Emmanuel Amador; Christophe Lemoine; Philippe Besnier; A. Laisne?

2010-01-01

304

Low Level Fusion of Imagery Based on Dempster-Shafer Theory  

Microsoft Academic Search

An approach to fuse multiple images based on Dempster-Shafer evidential reasoning is proposed in this article. Dempster-Shafer theory provides a com- plete framework for combining weak evidences from multiple sources. Such situations typically arise in the image fusion problems, where a 'real scene' image has to be estimated from incomplete and unreliable observa- tions. By converting images from their spatial

Xiaohui Yuan; Jian Zhang; Xiaojing Yuan; Bill P. Buckles

2003-01-01

305

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

306

A New Method for Evaluating Node Importance in Complex Networks Based on Data Field Theory  

Microsoft Academic Search

Estimating of the node importance in complex networks will help us research the core issues of real networks. Evaluating node importance with a single metric is incomplete and limited. This paper proposed a new measure of evaluating node importance. Its basic idea is sequencing the topology potential of node which is based on data field theory and combined with node-degree

Lv Le; Yu Hewei

2010-01-01

307

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

308

A graphical unitary group approach-based hybrid density functional theory multireference configuration interaction method  

Microsoft Academic Search

A hybrid density functional theory multireference configuration interaction hybrid model (DFT\\/MRCI) method for computing electronic excitation energies in heavy-element atomic and molecular systems has been developed within a graphical unitary group approach (GUGA) based configuration interaction framework. Implemented in the COLUMBUS suite of programs, the method advances several new capabilities for evaluating systems involving several electronic spin states, relativistic effects

Eric V. Beck; Eric A. Stahlberg; Larry W. Burggraf; Jean-Philippe Blaudeau

2008-01-01

309

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

310

Bending analysis of a functionally graded rotating disk based on the first order shear deformation theory  

Microsoft Academic Search

The theoretical formulation for bending analysis of functionally graded (FG) rotating disks based on first order shear deformation theory (FSDT) is presented. The material properties of the disk are assumed to be graded in the radial direction by a power law distribution of volume fractions of the constituents. New set of equilibrium equations with small deflections are developed. A semi-analytical

M. Bayat; B. B. Sahari; M. Saleem; Aidy Ali; S. V. Wong

2009-01-01

311

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

312

Tour routes optimization based on Graph theory for improving instruction services in scenic spots  

Microsoft Academic Search

In order to settle many problems caused by misled tourists in tourism spots it is necessary to help the operators to provide better instruction services based on careful tour rout optimization, thus improving both the customers' travel experiences and operator's services efficiency. The paper aims to deal with this issue by applying Graph theory to optimize tour path and tour

Jue Chen; Daijian Tang

2011-01-01

313

A micro scale Timoshenko beam model based on strain gradient elasticity theory  

Microsoft Academic Search

A micro scale Timoshenko beam model is developed based on strain gradient elasticity theory. Governing equations, initial conditions and boundary conditions are derived simultaneously by using Hamilton's principle. The new model incorporated with Poisson effect contains three material length scale parameters and can consequently capture the size effect. This model can degenerate into the modified couple stress Timoshenko beam model

Binglei Wang; Junfeng Zhao; Shenjie Zhou

2010-01-01

314

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

315

Theory-Based Development and Testing of an Adolescent Tobacco-Use Awareness Program.  

ERIC Educational Resources Information Center

The Adolescent Tobacco Use Awareness and Cessation Program trial, based on social cognitive theory and transtheoretical model, was designed to develop, evaluate, and disseminate effective cessation programming related to Texas legislation. Data from participants and site facilitators indicated that significantly more participants were in the…

Smith, Dennis W.; Colwell, Brian; Zhang, James J.; Brimer, Jennifer; McMillan, Catherine; Stevens, Stacey

2002-01-01

316

Instantaneous Symmetrical Component Theory Based Voltage and Frequency Controller for Isolated Small Hydropower Generation  

Microsoft Academic Search

This article deals with the design and implementation of an instantaneous sequence component theory based integrated voltage and frequency controller for an isolated asynchronous generator, which is used in constant power small hydropower generation for feeding three-phase four-wire consumer loads. The proposed integrated voltage and frequency controller is used to control the voltage and frequency of an isolated asynchronous generator

V. Rajagopal; Bhim Singh

2011-01-01

317

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

SciTech Connect

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

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

2010-07-15

318

Natural Resource-Based Communities, Risk, and Disaster: An Intersection of Theories  

Microsoft Academic Search

Natural resource-based communities are often theoretically assumed to be vulnerable to the negative effects of environmental and social change. Such communities are also seen as being especially vulnerable to risks and disasters. Disaster research perspectives echo this in their emphasis on environmental and social vulnerability. Also, theories of risk largely fail to illuminate community level experiences. To address this gap,

COURTNEY G. FLINT; A. E. LULOFF

2005-01-01

319

Regulation Framework of Data Service Market Based on Two-sided Market Theory  

Microsoft Academic Search

Based on emerging two-sided marked theory, this paper builds a bridge between data service market and securities market, and constructs the regulation framework of data service market combining the experience in securities market. It is shown that the role of operators as regulatory agency should be established in law and a reasonable division between the functions of telecoms regulator and

Zhenzhong Zhu; Fuxing Duan

2006-01-01

320

PPS-metal adhesion: a density functional theory-based study  

Microsoft Academic Search

We investigate the adhesion of poly(phenylene sulfide) (PPS) on aluminum, copper, silver and gold through simulations involving PPS monomers and single metal atoms. Density functional theory based-total energy calculation results show that PPS binds best to aluminum through the sulfur end of the monomer. Although adhesion to copper is strongest in the other two schemes examined, the energy curves suggest

Tanglaw Roman; Wilson Agerico Diño; Hiroshi Nakanishi; Hideaki Kasai; Yoshihito Miyako; Masanori Naritomi

2004-01-01

321

Science Teaching Based on Cognitive Load Theory: Engaged Students, but Cognitive Deficiencies  

ERIC Educational Resources Information Center

To improve science learning under demanding conditions, we designed an out-of-school lesson in compliance with cognitive load theory (CLT). We extracted student clusters based on individual effectiveness, and compared instructional efficiency, mental effort, and persistence of learning. The present study analyses students' engagement. 50.0% of our…

Meissner, Barbara; Bogner, Franz X.

2012-01-01

322

Applications of Cognitive Load Theory to Multimedia-Based Foreign Language Learning: An Overview  

ERIC Educational Resources Information Center

This article reviews the multimedia instructional design literature based on cognitive load theory (CLT) in the context of foreign language learning. Multimedia are of particular importance in language learning materials because they incorporate text, image, and sound, thus offering an integrated learning experience of the four language skills…

Chen, I-Jung; Chang, Chi-Cheng; Lee, Yen-Chang

2009-01-01

323

Creating and Capturing Value: Strategic Corporate Social Responsibility, Resource-Based Theory, and Sustainable Competitive Advantage  

Microsoft Academic Search

The authors analyze the creation and capture of private and social value by firms that adopt corporate social responsibility (CSR) strategies. Strategic CSR is defined as any “responsible” activity that allows a firm to achieve a sustainable competitive advantage, regardless of motive. To provide a roadmap for managers to accomplish this objective, the authors integrate the resource-based theory (RBT) framework

Abagail McWilliams; Donald S. Siegel

2011-01-01

324

Effectiveness of theory-based invitations to improve attendance at cardiac rehabilitation: A randomized controlled trial.  

PubMed

Background: Despite well-established evidence of benefit from cardiac rehabilitation, typically fewer than 35% of eligible patients attend. Objective: The purpose of this study was to evaluate whether theory-based invitations increase attendance at cardiac rehabilitation. Method: The study was a randomized controlled trial (RCT) with two by two factorial design. A total of 375 participants with acute myocardial infarction or coronary revascularization was recruited from medical and surgical cardiac wards at Aberdeen Royal Infirmary (ARI). They were randomly assigned to receive either the standard invitation letter or a letter with wording based on the 'theory of planned behavior (TPB)' and the 'common sense model of illness perception', and either a supportive leaflet with motivational messages or not. The primary outcome was one or more attendances at cardiac rehabilitation. Results: The theory-based letter increased attendance at cardiac rehabilitation compared to the standard letter (84% versus 74%, odds ratio (OR) 2.93, 95% confidence interval (CI) 1.54-5.56), independent of age, gender, working status, hypertension, identity and TPB constructs. The number needed to treat (NNT) was 9 (95% CI 7-12). The motivational leaflet had no significant effect on attendance at rehabilitation (OR 1.02, 95% CI 0.57-1.83). Conclusions: The use of theory-based wording in invitation letters is a simple method to improve attendance at cardiac rehabilitation. Our letter, reproduced in this paper, could provide a template for practitioners and researchers. PMID:23733348

Mosleh, Sultan M; Bond, Christine M; Lee, Amanda J; Kiger, Alice; Campbell, Neil C

2014-06-01

325

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

326

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

327

Deterministic Material-Based Averaging Theory Model of Collagen Gel Micromechanics  

Microsoft Academic Search

Mechanics of collagen gels, like that of many tissues, is governed by events occurring on a length scale much smaller than the functional scale of the material. To deal with the challenge of incorporating deterministic micromechanics into a continuous macroscopic model, we have developed an averaging-theory-based modeling framework for collagen gels. The averaging volume, which is constructed around each integration

Preethi L. Chandran; Victor H. Barocas

2007-01-01

328

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

329

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

Microsoft Academic Search

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

K. Ohyama; T. Nakashima

2010-01-01

330

Information-theory-based band selection and utility evaluation for reflective spectral systems  

Microsoft Academic Search

We have developed a methodology for wavelength band selection. This methodology can be used in system design studies to provide an optimal sensor cost, data reduction, and data utility trade-off relative to a specific application. The methodology combines an information theory- based criterion for band selection with a genetic algorithm to search for a near-optimal solution. We have applied this

Sylvia S. Shen; Edward M. Bassett

2002-01-01

331

Issues in Inquiry-Based Science Education Seen through Dewey's Theory of Inquiry  

ERIC Educational Resources Information Center

To understand the issues of inquiry-based education, I adopted John Dewey's theory of inquiry as the analytical framework to examine science learning activities, students' interactions, and education standards. Educators have tried to engage students in meaningful learning, but the analysis revealed that the meaning of inquiry was diverse:…

Won, Mihye

2009-01-01

332

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

333

A progressive failure theory for woven polymer-based composites subjected to dynamic loading  

Microsoft Academic Search

A progressive failure approach, applicable to woven polymer-based composites is developed and validated with experiments. Constitutive equations are formulated to characterize the mechanical response for fully non-linear, rate dependent, anisotropic behavior under dynamic loading. A mechanistic fiber failure theory is implemented, while a degradation model describes the stiffness reductions after failure. The approach is implemented in the Abaqus finite element

David R. Hufner; Michael L. Accorsi

2009-01-01

334

The study of milling online detecting intelligent optimization and control methods based on stability theory  

Microsoft Academic Search

Stability intelligent optimization and control theory in machining is one of the key technologies to ensure high precision and efficiency. Based on the MDOF dynamic model of tool-workpiece milling regenerative chatter, the MDOF coupling effect to stability is analyzed. The average milling force methods and second order response surface methods to obtain time varying milling force coefficient is studied to

Jiang Yongxiang; Du Bing; Wang Taiyong; Jiang Da yong

2010-01-01

335

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

336

Analytical solution on Magnus wind turbine power performance based on the blade element momentum theory  

Microsoft Academic Search

Instead of using conventional horizontal axis wind turbine blades, a Magnus wind turbine is equipped with rotating cylinders, which rotate around their own axes according to the principle of the Magnus effect. Based on the blade element momentum (or BEM) theory, an analytical analysis of the Magnus wind turbine power performance is conducted and its expression of power coefficient has

Dahai Luo; Diangui Huang; Guoqing Wu

2011-01-01

337

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

338

Model and application of risk evaluation for construction project based on fuzzy theory  

Microsoft Academic Search

Any project is attached with risks, and same case with construction projects, whose risk is rather complicated. Finding out the risk factors of construction project is of great realistic significance and scientific value for scientific risk evaluation and accomplishment of construction project. Fuzzy mathematics theory for solving risk evaluation is put forward based on the complexity and nonlinearity of risk

Aifang Liu; Shandong Zibo

2010-01-01

339

Research of nonlinear control strategy for VSC-HVDC system based on Lyapunov stability theory  

Microsoft Academic Search

A nonlinear control strategy based on Lyapunov stability theory is proposed to satisfy stability requirements under the external interference of the uncertainty condition. Due to the nonlinear of the DC voltage differential equation for VSC-HVDC, the control of DC voltage is transformed to the control of the q-axis component of AC current fundamental component. Suitable Lyapunov functions are adopted according

Guangkai Li; Guopeng Ma; Chengyong Zhao; Gengyin Li

2008-01-01

340

General theory based on fluctuational electrodynamics for van der Waals interactions in colloidal systems  

Microsoft Academic Search

A rigorous theory for the determination of the van der Waals interactions in colloidal systems is presented. The method is based on fluctuational electrodynamics and a multiple-scattering method which provides the electromagnetic Green's tensor. In particular, expressions for the Green's tensor are presented for arbitrary, finite collections of colloidal particles, for infinitely periodic or defected crystals, as well as for

Yannopapas; Vassilios

2007-01-01

341

A general theory for the van der Waals interactions in colloidal systems based on fluctuational electrodynamics  

Microsoft Academic Search

A rigourous theory for the determination of the van der Waals interactions in colloidal systems is presented. The method is based on fluctuational electrodynamics and a multiple-scattering method which provides the electromagnetic Green's tensor. In particular, expressions for the Green's tensor are presented for arbitrary, finite, collections of colloidal particles, for infinitely periodic or defected crystals as well as for

Vassilios Yannopapas

2007-01-01

342

An intervention for delirium superimposed on dementia based on cognitive reserve theory  

Microsoft Academic Search

Delirium superimposed on dementia (DSD) accelerates the trajectory of functional decline and results in prolonged hospitalization, re-hospitalization, premature nursing home placement, and death. In this article we propose a theory-based intervention for DSD that is derived from the literature on cognitive reserve and neuroplasticity. We begin by defining cognitive reserve, the guiding framework for our hypothesis. We review the pathophysiology

Ann M. Kolanowski; Donna M. Fick; Linda Clare; Barbara Therrien; David J. Gill

2010-01-01

343

English Vocabulary Learning System Based on Theory of Depths of Processing  

Microsoft Academic Search

English learning involves memorization and practice of vocabularies. It is widely known that English learning should pay great attention to vocabulary learning, and what's more, the vocabulary learning is considered to be a key issue for English learning because vocabularies are fundamental in an English sentence. This study proposes a study system of English vocabulary learning based on theory of

Zheng Hongyan; Wang Xiaohui; Han Liyang

2009-01-01

344

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

345

Capacity evaluation for dynamic route based on maximum flow in network theory  

Microsoft Academic Search

This paper has researched the capacity evaluation of dynamic route. In the evaluation process, take the original routes as a factor and establish the capacity evaluation model for dynamic route based on maximum flow in network theory. Finally, a example proves that the model is reasonable and availability. The research result shows that the capacity of dynamic route will be

Yang Guohui; Dai Fuqing

2011-01-01

346

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

347

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

348

Evaluation of Automatic Text Summarization Methods Based on Rhetorical Structure Theory  

Microsoft Academic Search

Motivated by governmental, commercial and academic interests, automatic text summarization area has experienced an increasing number of researches and products, which led to a countless number of summarization methods. In this paper, we present a comprehensive comparative evaluation of the main automatic text summarization methods based on rhetorical structure theory (RST), claimed to be among the best ones. We also

Vinícius Rodrigues Uzêda; Thiago Alexandre Salgueiro Pardo; Maria Das Graças Nunes

2008-01-01

349

National Critical Infrastructure Modeling and Analysis Based on Complex System Theory  

Microsoft Academic Search

National critical infrastructure is a typical complex system with the characteristics of self-organized criticality. In this paper, we firstly analyze the basic concepts of national critical infrastructure and the associated complex system characteristics, and then construct the model of national critical infrastructure based on complex system theory. This model abstracts the nodes of national critical infrastructure network and their connectivity

Wang Chunlei; Fang Lan; Dai Yiqi

2011-01-01

350

Ninter-Networked Interaction: Theory-based Cases in Teaching and Learning.  

ERIC Educational Resources Information Center

Describes the pedagogical framework of an interdisciplinary, international project entitled NINTER (Networked Interaction: Theory-Based Cases in Teaching and Learning). Discusses a pedagogical model for teacher and staff development programs in a networked environment; distributed cognition; cognitive apprenticeship; challenges for educational…

Saarenkunnas, Maarit; Jarvela, Sanna; Hakkinen, Paivi; Kuure, Leena; Taalas, Peppi; Kunelius, Esa

2000-01-01

351

A thermodynamic based higher-order gradient theory for size dependent plasticity  

Microsoft Academic Search

A physically motivated and thermodynamically consistent formulation of small strain higher-order gradient plasticity theory is presented. Based on dislocation mechanics interpretations, gradients of variables associated with kinematic and isotropic hardenings are introduced. This framework is a two non-local parameter framework that takes into consideration large variations in the plastic strain tensor and large variations in the plasticity history variable; the

Rashid K. Abu Al-Rub; George Z. Voyiadjis; Douglas J. Bammann

2007-01-01

352

A finite element formulation based on an enhanced first order shear deformation theory for composite and sandwich structures  

Microsoft Academic Search

A finite element formulation based on an enhanced first order shear deformation theory is developed to accurately and efficiently\\u000a predict the behavior of laminated composite and sandwich structures. An enhanced first order shear deformation theory is systematically\\u000a derived by minimizing the least-squared energy error between the first order shear deformable plate theory and a higher order\\u000a shear deformable plate theory.

Jinho Oh; Maenghyo Cho; Jun-Sik Kim; Michel Grédiac

2008-01-01

353

Design of a Four-Layer Model Based on Danger Theory and AIS for IDS  

Microsoft Academic Search

After a decade of research into the classical self-non-self model for immune-based intrusion detection system (IDS), a new idea has been developed by immunologists recently, which is called danger theory. Based on this new viewpoint, we present a four-layer model of artificial immune system (AIS) . Also, a mechanism of reasoning with uncertainty is proposed to increase the detection accuracy.

Haidong Fu; Xiguo Yuan; Liping Hu

2007-01-01

354

Multiagent-based computer virus detection systems: abstraction from dendritic cell algorithm with danger theory  

Microsoft Academic Search

Biologically-inspired artificial immune systems (AIS) have been applied to computer virus detection systems (CVDS). A multiagent-based\\u000a CVDS (ABCVDS) inspired by the danger theory of human immune system is proposed. The intelligence behind ABCVDS is based on\\u000a the functionalities of dendritic cells in human immune systems. Multiple agents are embedded to this virus detection system,\\u000a where agents coordinate one another to

Chung-Ming Ou

355

Evaluation of transverse thermal stresses in composite plates based on first-order shear deformation theory  

Microsoft Academic Search

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

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

1998-01-01

356

A finite temperature continuum theory based on interatomic potential in crystalline solids  

Microsoft Academic Search

A finite temperature continuum theory of crystalline solid based on an approximate Helmholtz free energy expression is proposed.\\u000a The free energy expression is specifically derived for simple implementation in atomistic-based continuum methods (i.e. quasicontinuum\\u000a method) via the Cauchy–Born rule at finite temperature. It is obtained by the method of statistical moments via the quasi-harmonic\\u000a approximation together with Taylor series expansion

Albert C. To; Wing Kam Liu; Adrian Kopacz

2008-01-01

357

towards a theory-based multi-dimensional framework for assessment in mathematics: The "SEA" framework  

NASA Astrophysics Data System (ADS)

Using the reform documents of the National Council of Teachers of Mathematics (NCTM) (NCTM, 1989, 1991, 1995), a theory-based multi-dimensional assessment framework (the "SEA" framework) which should help expand the scope of assessment in mathematics is proposed. This framework uses a context based on mathematical reasoning and has components that comprise mathematical concepts, mathematical procedures, mathematical communication, mathematical problem solving, and mathematical disposition.

Anku, Sitsofe E.

1997-09-01

358

Complexity theory and collaboration: An agent-based simulator for a space mission design team  

Microsoft Academic Search

In this paper, we investigate how complexity theory can benefit collaboration by applying an agent-based computer simulation\\u000a approach to a new form of synchronous real-time collaborative engineering design. Fieldwork was conducted with a space mission\\u000a design team during their actual design sessions, to collect data on their group conversations, team interdependencies, and\\u000a error monitoring and recovery practices. Based on the

Narjès Bellamine-Ben Saoud; Gloria Mark

2007-01-01

359

Interval-Based Real-Time Transmission Control  

Microsoft Academic Search

Existing cell switched and packet switched transmission systems have difficulties to support real-time data transfe r because the queuing characteristics and load variations in the network nodes are a handicap for it. With our interval-based transmission control method the data stream behavior is regulated in each network node and a data stream dependent time parameter adjustment is per- formed in

Christian Dünkel; Dietrich Reschke

1996-01-01

360

Risk Assessment of Communication Network of Power Company Based on Rough Set Theory and Multiclass SVM  

NASA Astrophysics Data System (ADS)

This paper proposes a new risk assessment method based on the attribute reduction theory of rough set and multiclass SVM classification. Rough set theory is introduced for data attribute reduction and multiclass SVM is used for automatic assessment of risk levels. Redundant features of data are deleted that can reduce the computation complexity of multiclass SVM and improve the learning and the generalization ability. Multiclass SVM trained with the empirical data can predict the risk level. Experiment shows that the predict result has relatively high precision, and the method is validity for power network risk assessment.

He, Xi; Wang, Wei; Liu, Xinyu; Ji, Yong

361

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

362

An electrification mechanism of sand grains based on the diffuse double layer and Hertz contact theory  

NASA Astrophysics Data System (ADS)

The electrification of sand grains lifting off from sand bed is investigated experimentally. It was found that sand grains were able to carry charges, which is comparable in magnitude with the experimental results and is related to grain sizes, pH of soil, relative humidity, and electric field. Based on the theory of diffuse double layer (DDL) and Hertz contact theory, an electrification mechanism due to the break of DDLs of sand grains is presented and a formula which takes environmental conditions and grain parameters into consideration is obtained to calculate the charge-mass ratio of lift-off sand grains.

Xie, Li; Han, Kui; Ma, Yanping; Zhou, Jùn

2013-09-01

363

Finite element for composite plate bending based on efficient higher order theory  

NASA Astrophysics Data System (ADS)

A triangular bending element based on an efficient higher order plate theory is developed for symmetric laminated composites. This nonconforming element has five degrees of freedom in each node. It passes proper bending and shear patch tests in arbitrary meshes in isotropic materials. Thus it converges to the exact solution. To demonstrate the element and compare with other theories, finite element solutions are obtained for a static bending problem under sinusoidal loading. The present finite element results give deflections and stresses that are in good agreement with three-dimensional elasticity solutions. Thus this element provides an efficient and accurate tool for the analysis of symmetric multilayered composite plates.

Cho, Maenghyo; Parmerter, Reid

1994-11-01

364

Theory-based scaling of the SOL width in circular limited tokamak plasmas  

NASA Astrophysics Data System (ADS)

A theory-based scaling for the characteristic length of a circular, limited tokamak scrape-off layer (SOL) is obtained by considering the balance between parallel losses and non-linearly saturated resistive ballooning mode turbulence driving anomalous perpendicular transport. The SOL size increases with plasma size, resistivity, and safety factor q. The scaling is verified against flux-driven non-linear turbulence simulations, which reveal good agreement within a wide range of dimensionless parameters, including parameters closely matching the TCV tokamak. An initial comparison of the theory against experimental data from several tokamaks also yields good agreement.

Halpern, F. D.; Ricci, P.; Labit, B.; Furno, I.; Jolliet, S.; Loizu, J.; Mosetto, A.; Arnoux, G.; Gunn, J. P.; Horacek, J.; Ko?an, M.; LaBombard, B.; Silva, C.; Contributors, JET-EFDA

2013-12-01

365

A symmetry-adapted perturbation theory based on density functional description of monomers  

NASA Astrophysics Data System (ADS)

The accurate and efficient calculation of the intermolecular interaction energy between large molecules---particularly those of biological interest---is of significant importance. However, existing ab initio techniques of sufficient accuracy can be used to calculate the interaction energy between molecules of about 10 atoms only. We provide a method based on density-functional theory and symmetry-adapted perturbation theory, termed SAPT(DFT), with which the interaction energy between larger molecules, perhaps as large as 40 atoms each, is calculable to high accuracy.

Misquitta, Alston Jude

366

Scheduling framework for queuing and advanced reservation using TBRA in grid computing environments: Trust based resource agent  

Microsoft Academic Search

The term Grid computing refers to multiple clusters of resource linked together in order to achieve a common objective. The power of grid computing lies in its capacity to aggregate widely distributed heterogeneous resources, and provide non-trivial services to users. Task management or workload management is a key issue that must be solved in grid computing, and a better scheduling

R. Venkatesan; K. Ramalakshmi; J. Isaac Victor Bhasme; K. Thanushkodi

2011-01-01

367

A closure for meso-scale eddy fluxes based on linear instability theory  

NASA Astrophysics Data System (ADS)

Linear instability theory is used to predict the lateral diffusivity K for eddy buoyancy fluxes in an idealized channel model, following a suggestion by Killworth (1997). The vertical structure and magnitude of K agree approximately with the non-linear model results. The lateral structure of K from linear theory lacks minima within eddy-driven zonal jets, pointing towards a non-linear mechanism for mixing barriers in the channel model. This effect can be accounted for by a modification of K from linear theory by the kinematic effect of the background flow following a recent suggestion by Ferrari and Nikurashin (2010). Implementation of this closure for K in an eddy mixing framework based on potential vorticity mixing in a zonally averaged model version yields approximate agreement with the zonally resolved version over a certain range of external parameters, in particular with respect to the reproduction of eddy-driven zonal jets.

Eden, Carsten

368

Analysis and synthesis of phase shifting algorithms based on linear systems theory  

NASA Astrophysics Data System (ADS)

We review and update a recently published formalism for the theory of linear Phase Shifting Algorithms (PSAs) based on linear filtering (systems) theory, mainly using the Frequency Transfer Function (FTF). The FTF has been for decades the standard tool in Electrical Engineering to analyze and synthesize their linear systems. Given the well defined FTF approach (matured over the last century), it clarifies, in our view, many not fully understood properties of PSAs. We present easy formulae for the spectra of the PSAs (the FTF magnitude), their Signal to Noise (S/N) power-ratio gain, their detuning robustness, and their harmonic rejection in terms of the FTF. This paper has more practical appeal than previous publications by the same authors, hoping to enrich the understanding of this PSA's theory as applied to the analysis and synthesis of temporal interferometry algorithms in Optical Metrology.

Servin, M.; Estrada, J. C.

2012-08-01

369

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.

Liu, Mengying; Sun, Peihua

2014-01-01

370

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

371

Evaluating clinical simulations for learning procedural skills: a theory-based approach.  

PubMed

Simulation-based learning is becoming widely established within medical education. It offers obvious benefits to novices learning invasive procedural skills, especially in a climate of decreasing clinical exposure. However, simulations are often accepted uncritically, with undue emphasis being placed on technological sophistication at the expense of theory-based design. The author proposes four key areas that underpin simulation-based learning, and summarizes the theoretical grounding for each. These are (1) gaining technical proficiency (psychomotor skills and learning theory, the importance of repeated practice and regular reinforcement), (2) the place of expert assistance (a Vygotskian interpretation of tutor support, where assistance is tailored to each learner's needs), (3) learning within a professional context (situated learning and contemporary apprenticeship theory), and (4) the affective component of learning (the effect of emotion on learning). The author then offers four criteria for critically evaluating new or existing simulations, based on the theoretical framework outlined above. These are: (1) Simulations should allow for sustained, deliberate practice within a safe environment, ensuring that recently-acquired skills are consolidated within a defined curriculum which assures regular reinforcement; (2) simulations should provide access to expert tutors when appropriate, ensuring that such support fades when no longer needed; (3) simulations should map onto real-life clinical experience, ensuring that learning supports the experience gained within communities of actual practice; and (4) simulation-based learning environments should provide a supportive, motivational, and learner-centered milieu which is conducive to learning. PMID:15917357

Kneebone, Roger

2005-06-01

372

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.

van Kampen, Dirk

2009-01-01

373

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

374

A Measurement-Based Prioritization Scheme for Handovers in Mobile Cellular Networks  

Microsoft Academic Search

A method of improving the quality of service in mobile cellular systems based on prioritization of handover requests is presented. The objective is to improve perceived quality of cellular service by minimizing both the probability of forced termination of ongoing calls due to handover failures and the degradation in spectrum utilization. A model based on a multiple-priority nonpreemptive queuing discipline

Sirin Tekinay; Bijan Jabbari

1992-01-01

375

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

PubMed

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

Laughlin, Daniel C

2014-07-01

376

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

PubMed Central

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.

Kiani, Mehdi; Ghovanloo, Maysam

2014-01-01

377

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

PubMed Central

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

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

2008-01-01

378

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.

Lazik, Detlef

2014-01-01

379

Using company web sites to e-recruit qualified applicants: A job marketing based review of theory-based research  

Microsoft Academic Search

In their rapidly expanding attempts to use company web sites to e-recruit job applicants in a world-wide labor market, employers have often found their hiring systems to be unexpectedly overwhelmed by large numbers of applications from poorly qualified individuals. To both limit and understand this phenomenon, this article employs a job marketing perspective to organize and review contemporary theory-based studies

Steven D. Maurer; David P. Cook

2011-01-01

380

Cattell-Horn-Carroll (CHC) theory-based assessment with deaf and hard of hearing children in the school setting.  

PubMed

The general purpose of the present article is to emphasize contemporary research-based and theory-based assessment, specifically Cattell-Horn-Carroll (CHC) theory-based assessment (Carroll, 1993, 1997; Horn & Noll, 1997), in work with deaf and hard of hearing students in the school setting. The article focuses on the history of cognitive ability theory and test development and interpretation, as well as contemporary perspectives, including recent applications of CHC-based assessment useful with deaf and hard of hearing students in school-based evaluations. Implications for future research and educational practice are discussed. PMID:18488534

Miller, Bryan D

2008-01-01

381

Ionic limiting molar conductivity calculation of Li-ion battery electrolyte based on mode coupling theory.  

PubMed

A method is proposed based on mode coupling theory in which the ion transference number is introduced into the theory. The ionic limiting molar conductivities of LiPF6, LiClO4, LiBF4, LiCF3SO3, Li(CF3SO3)2N, LiC4F9SO3, and LiAsF6 in PC(propylene carbonate), GBL(gamma-butyrolactone), PC(propylene carbonate)/EMC(ethylmethyl carbonate), and PC(propylene carbonate)/DME(dimethoxyethane) are calculated based on this method, which does not involve any adjustable parameter. The results fit well to the literature data which are calculated by an empirically adjusted formula. This presents a potential way to calculate the conductivities of Li-ion battery electrolytes. PMID:16375275

He, Xiangming; Pu, Weihua; Han, Jingli; Chen, Jian; Lu, Jiufang; Jiang, Changyin; Wan, Chunrong

2005-12-15

382

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

PubMed

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

2014-04-01

383

Design of Flexure-based Precision Transmission Mechanisms using Screw Theory  

SciTech Connect

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

Hopkins, J B; Panas, R M

2011-02-07

384

In-medium ?' mass and ?'N interaction based on chiral effective theory  

NASA Astrophysics Data System (ADS)

The in-medium ?' mass and the ?'N interaction are investigated in an effective theory based on the linear realization of the SU(3) chiral symmetry. We find that a large part of the ?' mass is generated by the spontaneous breaking of chiral symmetry through the UA(1) anomaly. As a consequence of this observation, the ?' mass is reduced in nuclear matter where chiral symmetry is partially restored. In our model, the mass reduction is found to be 80 MeV at the saturation density. Estimating the ?'N interaction based on the same effective theory, we find that the ?'N interaction in the scalar channel is attractive sufficiently to form a bound state in the ?'N system with a several MeV binding energy. We discuss the origin of attraction by emphasizing the special role of the ? meson in the linear sigma model for the mass generation of ?' and N.

Sakai, Shuntaro; Jido, Daisuke

2013-12-01

385

A Danger-Theory-Based Abnormal Traffic Detection Model in Local Network  

Microsoft Academic Search

To solve the problem that abnormal traffic including Internet worm and P2P downloading has occupied the LANpsilas bandwidth, a danger-theory-based model to detect anomaly traffic in LAN is presented in this paper. The definition is given, in this paper, to such terms as dangerous signal, antigens, antibodies and memory antibodies. Besides, matching rule between antigen and antibody is improved. Experiments

Wang Xiuying; Xiao Lizhong; Shao Zhiqing

2008-01-01

386

Research of DoS Intrusion Real-time Detection Based on Danger Theory  

Microsoft Academic Search

Denial of Service (DoS) attack is one of the most common network attacks on network in the present. Usually DoS attack is often executed in fraudulent way, so they have the characteristic of fraudulence and danger. A new method of DoS intrusion detection based on the immune danger theory is presented in the paper, according to the characteristic of DoS

Chun Xu; Xing-shu Chen; Hui Zhao; Yu-ming Jiang; Nian Liu; Tie-fang Wang

2007-01-01

387

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

388

Theoretical Photochemistry of the Photochromic Molecules Based on Density Functional Theory Methods  

Microsoft Academic Search

Mechanism of photoswitching in diarylethenes involves the light-initiated symmetry-allowed disrotatory electrocyclic reaction.\\u000a Here we propose a computationally inexpensive Density Functional Theory (DFT) based method that is able to produce accurate\\u000a potential surfaces for the excited states. The method includes constrained optimization of the geometry for the ground and\\u000a two excited singlet states along the ring-closing reaction coordinate using the Slater

Ivan A. Mikhailov; Artëm E. Masunov

2009-01-01

389

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

390

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

391

Testing a self-determination theory-based teaching style intervention in the exercise domain  

Microsoft Academic Search

Drawing from self-determination theory (SDT), this study examined the effect of an autonomy supportive, well structured and interpersonally involving teaching style on exercise class participants' psychological need satisfaction, motivational regulations, exercise behaviour, behavioural intention and affect. Female exercise class participants enrolled in a 10-week exercise program were exposed to an SDT-based (i.e. SDTc; n ¼ 25) or typical (i.e. control

Jemma Edmunds; Nikos Ntoumanis; Joan L Duda

2008-01-01

392

Numerical modelling of a coupled cavity travelling wave tube based on non-stationary discrwete theory  

Microsoft Academic Search

We present the results of numerical modeling of a coupled cavity traveling wave tube (TWT) amplifier based on the non-stationary discrete theory of excitation of a periodic waveguide. The code developed is applicable for solution of various practical problems, including simulation of amplification of multi-frequency signals, self-modulation and chaos generation, parasitic self-excitation of amplifiers, and short pulses amplification or generation.

V. N. Titov; N. M. Ryskin; A. V. Yakovlev

2008-01-01

393

A vehicle traveling time prediction method based on grey theory and linear regression analysis  

Microsoft Academic Search

Vehicle traveling time prediction is an important part of the research of intelligent transportation system. By now, there\\u000a have been various kinds of methods for vehicle traveling time prediction. But few consider both aspects of time and space.\\u000a In this paper, a vehicle traveling time prediction method based on grey theory (GT) and linear regression analysis (LRA) is\\u000a presented. In

Jun Tu; Yan-ming Li; Cheng-liang Liu

2009-01-01

394

The Dynamic Character Curve Adjusting Model of Electric Load Based on Data Mining Theory  

Microsoft Academic Search

\\u000a There are a number of dirty data in the load database produced by SCADA system. Consequently, the data must be adjusted carefully\\u000a and reasonably before being used for electric load forecasting or power system analysis. This paper proposes a dynamic and\\u000a intelligent curve adjusting model based on data mining theory. Firstly the Kohonen neural network is meliorated according\\u000a to fuzzy

Xiaoxing Zhang; Haijun Ren; Yuming Liu; Qiyun Cheng; Caixin Sun

2005-01-01

395

Likelihood-Based Item-Fit Indices for Dichotomous Item Response Theory Models  

Microsoft Academic Search

New goodness-of-fit indices are introduced for dichotomous item response theory (IRT) models. These indices are based on the likelihoods of number-correct scores derived from the IRT model, and they provide a direct comparison of the modeled and observed frequencies for correct and incorrect responses for each number-correct score. The behavior of Pearson’s X2 (S-X2) and the likelihood ratio G2 (S-G2)

Maria Orlando; David Thissen

2000-01-01

396

Three-dimensional theory of quantum memories based on Lambda-type atomic ensembles  

Microsoft Academic Search

We develop a three-dimensional theory for quantum memories based on light storage in ensembles of Lambda-type atoms, where two long-lived atomic ground states are employed. We consider light storage in an ensemble of finite spatial extent and we show that within the paraxial approximation the Fresnel number of the atomic ensemble and the optical depth are the only important physical

Emil Zeuthen; Anna Grodecka-Grad; Anders S. Sørensen

2011-01-01

397

Reference Generation for Shunt Active Power Filters Based on Optimum Filtering Theory  

Microsoft Academic Search

This paper proposes methods for current reference generation for shunt active power filter based on optimum filtering theory. These methods incorporate possible frequency deviation of the fundamental grid frequency. The proposed methods are an extension of a recently proposed synchronization method named Kalman Filter-PLL (KF-PLL). In this paper it is shown that the KF-PLL can also be used to provide

Rafael Cardoso; JoMarcos Kanieski; Humberto Pinheiro; H. A. Grundling

2007-01-01

398

Electric power system load forecast model based on State Space time-varying parameter theory  

Microsoft Academic Search

Putting forward a new method of power system medium-long term load forecast model establishment based on state space time-varying parameter equation theory, this work brings state variable into model observable for solution, which reflects the varying rules of equilibrium relation of variables and enhances the veracity for model forecast. The State Space time-varying parameter model describes the variational regular of

Xiang Li; Hao Chen; Shan Gao

2010-01-01

399

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

400

Data reduction for multispectral and hyperspectral imagery based on application of catastrophe theory  

NASA Astrophysics Data System (ADS)

In this paper, we discuss a novel method, for multispectral and hyperspectral imagery data reduction. This method is based on singularity representation and integrates a rotational invariant visual object extraction and understanding technique based on the application of differential mapping to image processing. This new compression method applies Arnold's Differential Mapping Singularities Theory in the context of three-dimensional (3D) terrain and objects projection onto the two-dimensional (2D) image plane. It takes advantage of the fact that terrain features (particularly edges and singular points) and can be interpreted in terms of mapping singularities, which can be described by simple polynomials. We discuss the relationship between traditional approaches, including spatial and spectral decorrelation, and differential mapping singularities theory, or Catastrophe Theory (CT), in the context of multispectral image understanding and data reduction. CT maps 3D surfaces with exact results to construct a multispectral image-compression algorithm based on a finite set of singularities. This approach permits the rigorous mathematical description of a full set of singularities that describes the edges and other specific points of objects. The edges and specific points (degenerate critical points) are the products of mapping smooth 3D surfaces, which can be described by a simple set of polynomials that is suitable for image compression and automatic target recognition. The spectral signature for each extracted object was refined, and its dynamic diapason was compared with traditional methods.

Ternovskiy, Igor V.; Jannson, Tomasz M.

2000-10-01

401

Galloping of iced quad-conductors bundles based on curved beam theory  

NASA Astrophysics Data System (ADS)

Galloping refers to wind-induced, low-frequency, large-amplitude oscillations that have been more frequently observed for a bundle conductor than for a single conductor. In the present work two different models are built to investigate the galloping of a bundle conductor: (1) a finite curved beam element method and (2) a hybrid model based on curved beam element theory. The finite curved beam element model is effective in dealing with the spacers between the bundled conductors and the joint between the conductors and spacers that can be simulated as a rigid joint or a hinge. Furthermore, the finite curved beam element model can be used to deal with large deformation. The hybrid model invokes the small deformation hypothesis and has a high computational efficiency. A hybrid model based on conventional cable element theory is also programmed to be compared with the aforementioned models based on curved beam element theory. Numerical examples are presented to assess the accuracy of the different models in predicting the equilibrium conductor position, natural frequencies and galloping amplitude. The results show that the curved beam element models, involving more degrees of freedom and coupling of translational and torsional motion, are more accurate at simulating the static and dynamic characters of an iced quad-conductor bundle. The use of hinges, rather than rigid connections, reduces the structural response amplitudes of a galloping conductor bundle.

Yan, Zhitao; Savory, Eric; Li, Zhengliang; Lin, William E.

2014-03-01

402

Investigating Bulk Waves in Orthotropic Rectangular Nanoplates Based on Three Dimensional Elasticity Theory and Nonlocal Elasticity Theory  

NASA Astrophysics Data System (ADS)

The propagation of bulk waves in rectangular nanoplates is studied on the basis of nonlocal three-dimensional elasticity theory. The nonlocal theory applies to both thin and thick rectangular orthotropic nanoplates. The dispersion relation for the waves is derived analytically. Our results are checked against data for macroplates. The influence of nonlocality and other parameters on the wave frequency and phase velocity is discussed.

Nami, Mohammad Rahim; Janghorban, Maziar

2014-06-01

403

Coherent reverberation model based on adiabatic normal mode theory in a range dependent shallow water environment  

NASA Astrophysics Data System (ADS)

Ocean reverberation in shallow water is often the predominant background interference in active sonar applications. It is still an open problem in underwater acoustics. In recent years, an oscillation phenomenon of the reverberation intensity, due to the interference of the normal modes, has been observed in many experiments. A coherent reverberation theory has been developed and used to explain this oscillation phenomenon [F. Li et al., Journal of Sound and Vibration, 252(3), 457-468, 2002]. However, the published coherent reverberation theory is for the range independent environment. Following the derivations by F. Li and Ellis [D. D. Ellis, J. Acoust. Soc. Am., 97(5), 2804-2814, 1995], a general reverberation model based on the adiabatic normal mode theory in a range dependent shallow water environment is presented. From this theory the coherent or incoherent reverberation field caused by sediment inhomogeneity and surface roughness can be predicted. Observations of reverberation from the 2001 Asian Sea International Acoustic Experiment (ASIAEX) in the East China Sea are used to test the model. Model/data comparison shows that the coherent reverberation model can predict the experimental oscillation phenomenon of reverberation intensity and the vertical correlation of reverberation very well.

Li, Zhenglin; Zhang, Renhe; Li, Fenghua

2010-09-01

404

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

NASA Astrophysics Data System (ADS)

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

2013-12-01

405

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

PubMed

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

Ghobadi, Ahmadreza F; Elliott, J Richard

2013-12-21

406

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

407

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

408

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.

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

2014-01-01

409

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

410

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

411

An optimization program based on the method of feasible directions: Theory and users guide  

NASA Technical Reports Server (NTRS)

The theory and user instructions for an optimization code based on the method of feasible directions are presented. The code was written for wide distribution and ease of attachment to other simulation software. Although the theory of the method of feasible direction was developed in the 1960's, many considerations are involved in its actual implementation as a computer code. Included in the code are a number of features to improve robustness in optimization. The search direction is obtained by solving a quadratic program using an interior method based on Karmarkar's algorithm. The theory is discussed focusing on the important and often overlooked role played by the various parameters guiding the iterations within the program. Also discussed is a robust approach for handling infeasible starting points. The code was validated by solving a variety of structural optimization test problems that have known solutions obtained by other optimization codes. It has been observed that this code is robust: it has solved a variety of problems from different starting points. However, the code is inefficient in that it takes considerable CPU time as compared with certain other available codes. Further work is required to improve its efficiency while retaining its robustness.

Belegundu, Ashok D.; Berke, Laszlo; Patnaik, Surya N.

1994-01-01

412

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

ERIC Educational Resources Information Center

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

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

2007-01-01

413

A continuum thermal stress theory for crystals based on interatomic potentials  

NASA Astrophysics Data System (ADS)

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

Liu, XiaoLei; Tang, QiHeng; Wang, TzuChiang

2014-01-01

414

A 3-D elasticity theory based model for acoustic radiation from multilayered anisotropic plates.  

PubMed

A theoretical model built upon three-dimensional elasticity theory is developed to investigate the acoustic radiation from multilayered anisotropic plates subjected to a harmonic point force excitation. Fourier transform technique and stationary phase method are combined to predict the far-field radiated sound pressure of one-side water immersed plate. Compared to equivalent single-layer plate models, the present model based on elasticity theory can differentiate radiated sound pressure between dry-side and wet-side excited cases, as well as discrepancies induced by different layer sequences for multilayered anisotropic plates. These results highlight the superiority of the present theoretical model especially for handling multilayered anisotropic structures. PMID:24815294

Shen, C; Xin, F X; Lu, T J

2014-05-01

415

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

416

Theory of energy transfer interactions near sphere and nanoshell based plasmonic nanostructures  

NASA Astrophysics Data System (ADS)

Theory of energy transfer interactions between a pair of two level molecules in the molecular nanojunction including surface plasmon (SP) dressed interaction of plasmonic nanostructure, replicating metallic leads is presented. Results on the modification of bare dipolar interaction, known to be responsible for molecular energy transfer processes, in the proximity of metallic nanosystem are presented. Specifically, the manuscript includes theoretical investigation of nanosphere (NSP) monomer, nanoshell (NSH) monomer, and coupled nanosphere pair (dimer) based nanosystems. Closed form analytical expressions for NSP and NSH structures tailored for molecular nanojunction geometry are derived in the theoretical framework of multipole spectral expansion (MSE) method, which is straightforwardly extendible to dimers and multimers. The role of size and dielectric environment on energy transfer is investigated and interpreted. Theory predicts that the monomer and dimer both enhance the dipolar interaction, yet, dimer geometry is favorable due to its spectral tuning potential originated from plasmon hybridization and true resemblance with typical molecular nanojunctions.

Shishodia, Manmohan S.; Fainberg, Boris D.; Nitzan, Abraham

2011-09-01

417

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

418

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

419

Density functional theory based calculation of small-polaron mobility in hematite  

NASA Astrophysics Data System (ADS)

The mobility of electron small polarons in hematite, ?-Fe2O3, is calculated by density functional theory within the generalized gradient approximation including Hubbard U corrections. Our work goes beyond previous computational investigations of this system by computing both the prefactor and activation energies for adiabatic polaron transport. The results obtained using a Hubbard U value of 4.3 eV yield a calculated value of the room-temperature basal plane mobility of 0.009 S*cm2/s, which compares to within an order of magnitude with experimental measurements. Further, the values of the electronic-coupling parameter in the Marcus theory for small-polaron transport are estimated from DFT+U calculations of the defect energy levels in the stable and saddle-point configurations. Our results predict an adiabatic polaron transfer, in good agreement with previous wave function based calculations.

Adelstein, Nicole; Neaton, Jeffrey B.; Asta, Mark; De Jonghe, Lutgard C.

2014-06-01

420

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

NASA Technical Reports Server (NTRS)

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

Shealy, David L.; Saha, Timo T.

1990-01-01

421

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

422

An Interpretation of Non-Accidental Traffic Congestion Based on a Hybrid Phenomenological Theory  

NASA Astrophysics Data System (ADS)

A hybrid phenomenological theory based on the fundamental elastic and hydrodynamic theories is developed to interpret common traffic phenomena of non-accidental vehicle congestion. Compressional (longitudinal) waves propagating through a hyperspace and their hypothetical mapping onto the real configurational space are employed to prescribe the established traffic flow pattern. The continuity equation is solved for the density distribution function of the traffic subject to the derived group velocity and particular boundary and initial or final conditions. All desired quantities of the traffic flow can then be calculated with this distribution function. Possible applications of this work can be achieved by utilizing the concept of sinks and sources. One can predict the traffic flow through appropriate exits and entrances of the highway section where traffic jams often occur.

Chu, Kwo-Sun; Richards, Bernard L.; Davis, George W.

2001-10-01

423

Hybrid framework based on evidence theory for blood cell image segmentation  

NASA Astrophysics Data System (ADS)

The segmentation of microscopic images is an important issue in biomedical image processing. Many works can be found in the literature; however, there is not a gold standard method that is able to provide good results for all kinds of microscopic images. Then, authors propose methods for a given kind of microscopic images. This paper deals with new segmentation framework based on evidence theory, called ESA (Evidential Segmentation Algorithm) to segment blood cell images. The proposed algorithm allows solving the segmentation problem of blood cell images. Herein, our goal is to extract the components of a given cell image by using evidence theory, that allows more flexibility to classify the pixels. The obtained results showed the efficiency of the proposed algorithm compared to other competing methods.

Baghli, Ismahan; Nakib, Amir; Sellam, Elie; Benazzouz, Mourtada; Chikh, Amine; Petit, Eric

2014-03-01

424

Applying adult behavior change theory to support mediator-based intervention implementation.  

PubMed

A majority of evidence-based interventions in schools are delivered through consultation models and are implemented by a mediator, such as a teacher. Research indicates that mediators do not always adequately implement adopted evidence-based interventions, limiting their effectiveness in transforming student outcomes. We propose that to transform student outcomes through evidence-based practice, conceptualization of mediators' intervention implementation must move beyond quantification of discrete intervention steps implemented. Intervention implementation requires behavior change and thus can be conceptualized as an adult behavior change process. The purpose of this article is to illustrate how adult behavior change theory may inform how intervention implementation is conceptualized, facilitated, and supported. An empirically supported theory of adult behavior change from health psychology, the Health Action Process Approach, and how it has informed development of PRIME (Planning Realistic Intervention Implementation and Maintenance by Educators), a system of supports to facilitate mediators' implementation of school-based interventions, are introduced. A case study demonstrating the application of PRIME with a public school teacher implementing a behavior support plan is presented. Implications for future research are discussed. PMID:23398150

Sanetti, Lisa M H; Kratochwill, Thomas R; Long, Anna C J

2013-03-01

425

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.

426

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

Microsoft Academic Search

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

Gavin J. Nicholson; Geoffrey C. Kiel

2007-01-01

427

Research on Layout of Airport Logistics Park Based on Graph Theory: An Empirical Study of Ningbo Airport Logistics Park  

Microsoft Academic Search

In this paper, we propose graph theory model to the layout planning of airport logistics park. First, several commonly used facilities layout methods were introduced and a comparative analysis was made out respectively. Secondly, an empirical study of Ningbo airport logistics park was carried out based on graph theory to the layout planning of core facilities for this park. Finally,

Changbing Jiang; Lijun Bai; Wenwen Zheng

2010-01-01

428

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.

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

429

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

NASA Astrophysics Data System (ADS)

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

Zhou, Feng; Catton, Ivan

2012-10-01

430

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

431

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

432

Fluid substitution in carbonate rocks based on the Gassmann equation and Eshelby-Walsh theory  

NASA Astrophysics Data System (ADS)

Fluid substitution in carbonate rocks is more difficult than it is in clastic rocks for two reasons. Firstly, the rock physics modeling uncertainties in carbonate rocks, this is due to the difficulty of accurately acquiring the moduli of carbonate rocks' solid matrix because the experimental data on carbonate rocks have not been as thoroughly studied as silici-clastic sedimentary rocks. Secondly, due to the complex pore systems of carbonate rocks, it is very difficult to model pore geometry of carbonates, and hence hard to assess how the elastic properties change as fluid saturation changes based on the traditional Biot and Gassmann theories. In order to solve these problems, we present a new fluid substitution equation of carbonate rocks using the Gassmann equation and Eshelby-Walsh theory (GEW) in this paper. Then, the specific procedures of how to calculate the moduli of carbonate rocks' solid matrix and how to measure the effect of pore geometry in fluid substitution based on the new fluid substation equation were illustrated by experimental testing about 12 carbonate rock samples in different fluid saturation scenarios and logging data. Finally, we further compared the new fluid substitution method with the conventional Gassmann fluid substitution based on the experimental data. The results verified that the new method is more accurate and reliable in the fluid substitution of complex carbonate rocks.

Feng, Quanxiong; Jiang, Lian; Liu, Mingquan; Wan, Huan; Chen, Li; Xiao, Wei

2014-07-01

433

Comparison of ITER performance predicted by semi-empirical and theory-based transport models  

NASA Astrophysics Data System (ADS)

The values of Q = (fusion power)/(auxiliary heating power) predicted for ITER by three different methods are compared. The first method utilizes an empirical confinement-time scaling and prescribed radial profiles of transport coefficients; the second approach extrapolates from specially designed ITER similarity experiments, and the third approach is based on partly theory-based transport models. The energy confinement time given by the ITERH-98(y, 2) scaling for an inductive scenario with a plasma current of 15 MA and a plasma density 15% below the Greenwald density is 3.7 s with one estimated technical standard deviation of +/-14%. This translates, in the first approach, for levels of helium removal, and impurity concentration, that, albeit rather stringent, are expected to be attainable, into an interval for Q of [6-15] at the auxiliary heating power, Paux = 40 MW, and [6-30] at the minimum heating power satisfying a good confinement ELMy H-mode. All theoretical transport-model calculations have been performed for the plasma core only, whereas the pedestal temperatures were taken as estimated from empirical scalings. Predictions of similarity experiments from JET and of theory-based transport models that we have considered—Weiland, MMM, and IFS/PPPL—overlap with the prediction using the empirical confinement-time scaling within its estimated margin of uncertainty.

Mukhovatov, V.; Shimomura, Y.; Polevoi, A.; Shimada, M.; Sugihara, M.; Bateman, G.; Cordey, J. G.; Kardaun, O.; Pereverzev, G.; Voitsekhovich, I.; Weiland, J.; Zolotukhin, O.; Chudnovskiy, A.; Kritz, A. H.; Kukushkin, A.; Onjun, T.; Pankin, A.; Perkins, F. W.

2003-09-01

434

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.

Wang, Huaqing; Chen, Peng

2009-01-01

435

Suppressing Chaos of Warship Power System Based on the Quantum Mechanics Theory  

NASA Astrophysics Data System (ADS)

Chaos control of marine power system is investigated by adding the Gaussian white noise to the system. The top Lyapunov exponent is computed to detect whether the classical system chaos or not, also the phase portraits are plotted to further verify the obtained results. The classical control of chaos and its quantum counterpart of the marine power system are investigated. The Hamiltonian of the controlled system is given to analyze the quantum counterpart of the classical system, which is based on the quantum mechanics theory.

Cong, Xinrong; Li, Longsuo

2014-03-01

436

Nonparametric method for extraction of region of interest based on information theory  

NASA Astrophysics Data System (ADS)

We propose a nonparametric method for extraction of region of interest (ROI) based on information theory. A polygonal active contour, whose energy function is defined by Jensen-Shannon divergence, is used to drive the curve to match the boundaries of the ROI. Then, our method is able to solve problems involving arbitrary probability densities for the region intensity. We use this method to extract the ROI of synthesized, aerial and natural images and compare with classical statistical snake. Experimental results demonstrate the power of the proposed extraction method for ROI.

Zhang, Xiaodong; Zhao, Jianhua; Zhang, Yu; Zhong, Kaiwen

2007-11-01

437

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

438

Comparison of theory-based and semi-empirical transport modelling in JET plasmas with ITBs  

NASA Astrophysics Data System (ADS)

The theory-based Weiland transport model has been applied to JET discharges with internal transport barriers (ITBs) for the first time. The agreement of the modelling results with the experiments has been found to be comparable with the agreement of the modelling results produced by the semi-empirical Bohm/gyro-Bohm transport model. Weiland model overestimates the width of the ITB and the electron temperature. There is evidence that the density gradient in the Weiland model plays a more important role in governing the ITB formation dynamics for JET discharges than the suppression of turbulence by the ?E×B flow shearing rate.

Tala, T. J. J.; Parail, V. V.; Becoulet, A.; Corrigan, G.; Heading, D. J.; Mantsinen, M. J.; Strand, P. I.; EFDA-JET Workprogramme, contributors to the

2002-05-01

439

A description of the mechanical behavior of composite solid propellants based on molecular theory  

NASA Technical Reports Server (NTRS)

Both the investigation and the representation of the stress-strain response (including rupture) of gum and filled elastomers can be based on a simple functional statement. Internally consistent experiments are used to sort out the effects of time, temperature, strain and crosslink density on gum rubbers. All effects are readily correlated and shown to be essentially independent of the elastomer when considered in terms of non-dimensionalized stress, strain and time. A semiquantitative molecular theory is developed to explain this result. The introduction of fillers modifies the response, but, guided by the framework thus provided, their effects can be readily accounted for.

Landel, R. F.

1976-01-01

440

The Experimental Research on E-Learning Instructional Design Model Based on Cognitive Flexibility Theory  

NASA Astrophysics Data System (ADS)

The paper reports an educational experiment on the e-Learning instructional design model based on Cognitive Flexibility Theory, the experiment were made to explore the feasibility and effectiveness of the model in promoting the learning quality in ill-structured domain. The study performed the experiment on two groups of students: one group learned through the system designed by the model and the other learned by the traditional method. The results of the experiment indicate that the e-Learning designed through the model is helpful to promote the intrinsic motivation, learning quality in ill-structured domains, ability to resolve ill-structured problem and creative thinking ability of the students.

Cao, Xianzhong; Wang, Feng; Zheng, Zhongmei

441

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

442

Data Collection Method for Mobile Sensor Networks Based on the Theory of Thermal Fields  

PubMed Central

Many sensor applications are aimed for mobile objects, where conventional routing approaches of data delivery might fail. Such applications are habitat monitoring, human probes or vehicular sensing systems. This paper targets such applications and proposes lightweight proactive distributed data collection scheme for Mobile Sensor Networks (MSN) based on the theory of thermal fields. By proper mapping, we create distribution function which allows considering characteristics of a sensor node. We show the functionality of our proposed forwarding method when adapted to the energy of sensor node. We also propose enhancement in order to maximize lifetime of the sensor nodes. We thoroughly evaluate proposed solution and discuss the tradeoffs.

Macuha, Martin; Tariq, Muhammad; Sato, Takuro

2011-01-01

443

Separation prevention as an indirect problem based on the triple deck theory  

NASA Astrophysics Data System (ADS)

Streamlining as a means of preventing small-bubble separation is examined as an indirect problem based on the triple deck theory, and a numerical scheme to take care of this problem with accuracy and speed is formulated. This methodology is utilized to design an augmented compression corner that produces attached flow. A number of methods of boundary layer control are designed and employed, including suction, acceleration, and streamlining. These methods not only prevent separation but they also have a stabilizing effect which tends to delay the transition of a laminar boundary layer to a turbulent one. Therefore, additional drag reduction and energy savings are realized.

El-Mistikawy, Tarek M. A.

444

General theory based on fluctuational electrodynamics for van der Waals interactions in colloidal systems  

SciTech Connect

A rigorous theory for the determination of the van der Waals interactions in colloidal systems is presented. The method is based on fluctuational electrodynamics and a multiple-scattering method which provides the electromagnetic Green's tensor. In particular, expressions for the Green's tensor are presented for arbitrary, finite collections of colloidal particles, for infinitely periodic or defected crystals, as well as for finite slabs of crystals. The presented formalism allows for ab initio calculations of the van der Waals interactions in colloidal systems since it takes fully into account retardation, many-body, multipolar, and near-field effects.

Yannopapas, Vassilios [Department of Materials Science, University of Patras, GR-26504 Patras (Greece)

2007-12-15

445

Third-order theory of the Risley-prism-based beam steering system.  

PubMed

Nonparaxial ray tracing is performed to investigate the field scanned out by a single beam through two rotatable thick prisms with different parameters, and a general solution is obtained and then expanded into a power series to establish the third-order theory for Risley prisms that paves the way to investigate topics of interest such as optical distortions in the scan pattern and an analytical solution of the inverse problem of a Risley-prism-based laser beam steering system; i.e., the problem is concerned with how to direct a laser beam to any specified direction within the angular range of the system. PMID:21343989

Li, Yajun

2011-02-10

446

A Proposed Alternative Low Energy Quantum Field Theory of Gravity Based on a Bose-Einstein Condensate Effect  

Microsoft Academic Search

An alternative quantum field theory for gravity is proposed for low energies based on an attractive effect between contaminants in a Bose-Einstein Condensate rather than on particle exchange. In the ``contaminant in condensate effect,\\

Alexander Oshmyansky

2007-01-01

447

Theory of tunneling across hydrogen-bonded base pairs for DNA recognition and sequencing  

NASA Astrophysics Data System (ADS)

We present the results of first-principles calculations for the electron tunnel current through hydrogen-bonded DNA base pairs and for (deoxy)nucleoside-nucleobase pairs. Electron current signals either through a base pair or through a deoxynucleoside-nucleobase pair are a potential mechanism for recognition or identification of the DNA base on a single-stranded DNA polymer. Four hydrogen-bonded complexes are considered: guanine-cytosine, diaminoadenine-thymine, adenine-thymine, and guanine-thymine. First, the electron tunneling properties are examined through their complex band structure (CBS) and the metal contact’s Fermi-level alignment. For gold contacts, the metal Fermi level lies near the highest occupied molecular orbital for all DNA base pairs. The decay constant determined by the complex band structure at the gold Fermi level shows that tunnel current decays more slowly for base pairs with three hydrogen bonds (guanine-cytosine and diaminoadenine-thymine) than for base pairs with two hydrogen bonds (adenine-thymine and guanine-thymine). The decay length and its dependence on hydrogen-bond length are examined. Second, the conductance is computed using density functional theory Green’s-function scattering methods and these results agree with estimates made from the tunneling decay constant obtained from the CBS. Changing from a base pair to a deoxynucleoside-nucleobase complex shows a significant decrease in conductance. It also becomes difficult to distinguish the current signal by only the number of hydrogen bonds.

Lee, Myeong H.; Sankey, Otto F.

2009-05-01

448

Universal calculational recipe for solvent-mediated potential: based on a combination of integral equation theory and density functional theory  

Microsoft Academic Search

A universal formalism, which enables calculation of solvent-mediated potential (SMP) between two equal or non-equal solute particles with any shape immersed in solvent reservior consisting of atomic particle and\\/or polymer chain or their mixture, is proposed by importing a density functional theory externally into OZ equation systems. Only if size asymmetry of the solvent bath components is moderate, the present

Shiqi Zhou

2004-01-01

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

Theory-based research of high fidelity simulation use in nursing education: a review of the literature.  

PubMed

In this article, we explore the extent to which theory-based research is informing our understanding of high-fidelity simulation use in nursing education. We reviewed the primary literature archived in the Cumulative Index of Nursing and Applied Health Literature (CINAHL) and Proquest Dissertation and Theses for empirical reports using the key terms high-fidelity simulation and nursing from the years 1989 to 2009. Of the articles that matched our inclusion criteria: 45% made no use of theory; 45% made minimal use; and 10% made adequate use. We argue that theory-based research could bring coherence and external validity to this domain. PMID:20361859

Rourke, Liam; Schmidt, Megan; Garga, Neera

2010-01-01

451

A general theory of evolution based on energy efficiency: its implications for diseases.  

PubMed

We propose a general theory of evolution based on energy efficiency. Life represents an emergent property of energy. The earth receives energy from cosmic sources such as the sun. Biologic life can be characterized by the conversion of available energy into complex systems. Direct energy converters such as photosynthetic microorganisms and plants transform light energy into high-energy phosphate bonds that fuel biochemical work. Indirect converters such as herbivores and carnivores predominantly feed off the food chain supplied by these direct converters. Improving energy efficiency confers competitive advantage in the contest among organisms for energy. We introduce a term, return on energy (ROE), as a measure of energy efficiency. We define ROE as a ratio of the amount of energy acquired by a system to the amount of energy consumed to generate that gain. Life-death cycling represents a tactic to sample the environment for innovations that allow increases in ROE to develop over generations rather than an individual lifespan. However, the variation-selection strategem of Darwinian evolution may define a particular tactic rather than an overarching biological paradigm. A theory of evolution based on competition for energy and driven by improvements in ROE both encompasses prior notions of evolution and portends post-Darwinian mechanisms. Such processes may involve the exchange of non-genetic traits that improve ROE, as exemplified by cognitive adaptations or memes. Under these circumstances, indefinite persistence may become favored over life-death cycling, as increases in ROE may then occur more efficiently within a single lifespan rather than over multiple generations. The key to this transition may involve novel methods to address the promotion of health and cognitive plasticity. We describe the implications of this theory for human diseases. PMID:16122878

Yun, Anthony J; Lee, Patrick Y; Doux, John D; Conley, Buford R

2006-01-01

452

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

453

Learning of veterinary professionals in communities : using the theory of critically reflective work behaviour with regard to evidence based practice  

Microsoft Academic Search

Veterinary professionals are required to continue learning, and need to practice increasingly in an evidence-based manner. We investigate how continued learning takes place in communities, and explore how participation in communities might at the same time support the transition to evidence based practice. Based on social constructivist theories we assume that critically reflective work behaviour (CRWB) is essential for learning

E. de Groot

2012-01-01

454

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

SciTech Connect

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

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

2008-02-15

455

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

NASA Astrophysics Data System (ADS)

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

Fiorentini, Vincenzo; Filippetti, Alessio

2006-03-01

456

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

PubMed

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

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

2012-12-01

457

Parameterization of homogeneous ice nucleation for cloud and climate models based on classical nucleation theory  

NASA Astrophysics Data System (ADS)

A new analytical parameterization of homogeneous ice nucleation is developed based on extended classical nucleation theory including new equations for the critical radii of the ice germs, free energies and nucleation rates as the functions of the temperature and water saturation ratio simultaneously. By representing these quantities as separable products of the analytical functions of the temperature and supersaturation, analytical solutions are found for the integral-differential supersaturation equation and concentration of nucleated crystals. Parcel model simulations are used to illustrate the general behavior of various nucleation properties under various conditions, for justifications of the further key analytical simplifications, and for verification of the resulting parameterization. The final parameterization is based upon the values of the supersaturation that determines the current or maximum concentrations of the nucleated ice crystals. The crystal concentration is analytically expressed as a function of time and can be used for parameterization of homogeneous ice nucleation both in the models with small time steps and for substep parameterization in the models with large time steps. The crystal concentration is expressed analytically via the error functions or elementary functions and depends only on the fundamental atmospheric parameters and parameters of classical nucleation theory. The diffusion and kinetic limits of the new parameterization agree with previous semi-empirical parameterizations.

Khvorostyanov, V. I.; Curry, J. A.

2012-03-01

458

Parameterization of homogeneous ice nucleation for cloud and climate models based on classical nucleation theory  

NASA Astrophysics Data System (ADS)

A new analytical parameterization of homogeneous ice nucleation is developed based on extended classical nucleation theory including new equations for the critical radii of the ice germs, free energies and nucleation rates as simultaneous functions of temperature and water saturation ratio. By representing these quantities as separable products of the analytical functions of temperature and supersaturation, analytical solutions are found for the integral-differential supersaturation equation and concentration of nucleated crystals. Parcel model simulations are used to illustrate the general behavior of various nucleation properties under various conditions, for justifications of the further key analytical simplifications, and for verification of the resulting parameterization. The final parameterization is based upon the values of the supersaturation that determines the current or maximum concentrations of the nucleated ice crystals. The crystal concentration is analytically expressed as a function of time and can be used for parameterization of homogeneous ice nucleation both in the models with small time steps and for substep parameterization in the models with large time steps. The crystal concentration is expressed analytically via the error functions or elementary functions and depends only on the fundamental atmospheric parameters and parameters of classical nucleation theory. The diffusion and kinetic limits of the new parameterization agree with previous semi-empirical parameterizations.

Khvorostyanov, V. I.; Curry, J. A.

2012-10-01

459

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

460

Predictive models based on sensitivity theory and their application to practical shielding problems  

SciTech Connect

Two new calculational models based on the use of cross-section sensitivity coefficients have been devised for calculating radiation transport in relatively simple shields. The two models, one an exponential model and the other a power model, have been applied, together with the traditional linear model, to 1- and 2-m-thick concrete-slab problems in which the water content, reinforcing-steel content, or composition of the concrete was varied. Comparing the results obtained with the three models with those obtained from exact one-dimensional discrete-ordinates transport calculations indicates that the exponential model, named the BEST model (for basic exponential shielding trend), is a particularly promising predictive tool for shielding problems dominated by exponential attenuation. When applied to a deep-penetration sodium problem, the BEST model also yields better results than do calculations based on second-order sensitivity theory.

Bhuiyan, S.I.; Roussin, R.W.; Lucius, J.L.; Bartine, D.E.

1983-01-01

461

Combinatorial density functional theory-based screening of surface alloys for the oxygen reduction reaction.  

SciTech Connect

A density functional theory (DFT) -based, combinatorial search for improved oxygen reduction reaction (ORR) catalysts is presented. A descriptor-based approach to estimate the ORR activity of binary surface alloys, wherein alloying occurs only in the surface layer, is described, and rigorous, potential-dependent computational tests of the stability of these alloys in aqueous, acidic environments are presented. These activity and stability criteria are applied to a database of DFT calculations on nearly 750 binary transition metal surface alloys; of these, many are predicted to be active for the ORR but, with few exceptions, they are found to be thermodynamically unstable in the acidic environments typical of low-temperature fuel cells. The results suggest that, absent other thermodynamic or kinetic mechanisms to stabilize the alloys, surface alloys are unlikely to serve as useful ORR catalysts over extended periods of operation.

Greeley, J.; Norskov, J.; Center for Nanoscale Materials; Technical Univ. of Denmark

2009-03-26

462

New model for the correlation of the surface tension based on friction theory.  

PubMed

A new correlation method for the surface tension of fluids is proposed, which is based on friction theory applied to the interface of a two-phase system. The substance properties enter the model by a regular equation of state. Here we derive the method and test it with the Lennard-Jones 12-6 fluid as the reference system using molecular dynamics simulations of the vapor-liquid interface in combination with a new Lennard-Jones 12-6 equation of state. Further correlations of experimental surface tension data based on the Peng-Robinson and the PC-SAFT equations of state are presented. As a result, we find that the method allows an accurate correlation of the surface tension of pure fluids. PMID:19236013

Quiñones-Cisneros, S E; Deiters, U K; Rozas, R E; Kraska, T

2009-03-19

463

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

464

Discovering pair-wise genetic interactions: an information theory-based approach.  

PubMed

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

465

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

466

Paraprofessional delivery of a theory based HIV prevention counseling intervention for women.  

PubMed Central

This report describes a mid-course process evaluation of an HIV risk-reduction counseling intervention delivered by specially trained peer paraprofessionals. One of the key questions addressed is whether paraprofessionals can successfully implement a theory-based counseling intervention. The project, known as Project CARES, is a 5-year demonstration research project to prevent HIV infection and unplanned pregnancies in women at risk for HIV infection and transmission who were recruited from homeless shelters, drug treatment facilities, and hospital-based service settings for HIV-infected women. Project CARES uses an enhanced counseling intervention based on the Transtheoretical Model, also known as the Stages of Change model, to promote condom and other contraceptive use for women who wish to avoid pregnancy, condom use for disease prevention, and reproductive health service use. Peer paraprofessionals, called advocates, provide stage-tailored counseling using a structured manual which guides them in the selection of specific counseling activities appropriate to a woman's level of readiness to change her behavior. Data from process evaluation forms completed by advocates in Philadelphia and Baltimore document that the delivery of the intervention is consistent with the theoretical model upon which it was based. Paraprofessionals can become skilled in the delivery of a stage-based counseling intervention in health and social service settings. The use of paraprofessionals in HIV prevention service delivery may be a cost-effective way to enhance and extend services for women.

Cabral, R J; Galavotti, C; Gargiullo, P M; Armstrong, K; Cohen, A; Gielen, A C; Watkinson, L

1996-01-01

467

Surface collision theory for suspension-based cleaning of particle-contaminated solid substrates  

NASA Astrophysics Data System (ADS)

To quantify removal kinetics of contaminant particles on solid surfaces, we study collisions between nonspherical particles when one particle is suspended in laminar shear flow while the second is adhered to a solid surface. Based on kinetic theory of rigid nonspherical particles, we outline a theoretical framework for our previously developed binary-collision contaminant-removal model. We show that a distribution of adhered contaminant particles over orientation, size, and shape results in multiexponential decay of surface concentration of particles with time, in agreement with experimental findings [Andreev et al., J. Electrochem. Soc. 158, H55 (2011)]. Theory predicts a linear increase of removal rate constant with shear rate and with suspended solids concentration near the substrate surface, also in agreement with experiment [Andreev et al., J. Electrochem. Soc. 158, H55 (2011); Ind. Eng. Chem. Res. 49, 12461 (2010)]. To reveal the effect of geometry and size of colliding entrained particles on removal rates, an approximate singlet distribution function is derived for particles in flow at the level of the Smoluchowski theory for orthocoagulation. Two shapes of flow-suspended particles are considered: spheres and cuboids with high aspect ratio, while contaminant particles on the surface are small and spherical. Removal kinetic rate constants scale with contaminant particle size, aA, as aA3/2 for spheres and as aA for cuboids. Thus, rectangular platelet particles are effective for removal of small contaminant particles, confirming experimental observation [Andreev et al., J. Electrochem. Soc. 158, H55 (2011)]. The influence of platelet aspect ratio on removal rates is analyzed. Due to interplay between solids velocity and collision cross section, small aspect ratios improve cleaning efficiency when the size ratio of the entrained to contaminant particles is large.

Andreev, V. A.; Prausnitz, J. M.; Radke, C. J.

2011-03-01

468

A Neurosemantic Theory of Concrete Noun Representation Based on the Underlying Brain Codes  

PubMed Central

This article describes the discovery of a set of biologically-driven semantic dimensions underlying the neural representation of concrete nouns, and then demonstrates how a resulting theory of noun representation can be used to identify simple thoughts through their fMRI patterns. We use factor analysis of fMRI brain imaging data to reveal the biological representation of individual concrete nouns like apple, in the absence of any pictorial stimuli. From this analysis emerge three main semantic factors underpinning the neural representation of nouns naming physical objects, which we label manipulation, shelter, and eating. Each factor is neurally represented in 3–4 different brain locations that correspond to a cortical network that co-activates in non-linguistic tasks, such as tool use pantomime for the manipulation factor. Several converging methods, such as the use of behavioral ratings of word meaning and text corpus characteristics, provide independent evidence of the centrality of these factors to the representations. The factors are then used with machine learning classifier techniques to show that the fMRI-measured brain representation of an individual concrete noun like apple can be identified with good accuracy from among 60 candidate words, using only the fMRI activity in the 16 locations associated with these factors. To further demonstrate the generativity of the proposed account, a theory-based model is developed to predict the brain activation patterns for words to which the algorithm has not been previously exposed. The methods, findings, and theory constitute a new approach of using brain activity for understanding how object concepts are represented in the mind.

Just, Marcel Adam; Cherkassky, Vladimir L.; Aryal, Sandesh; Mitchell, Tom M.

2010-01-01

469

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.

2013-01-01

470

Coverage of dynamic correlation effects by density functional theory functionals: density-based analysis for neon.  

PubMed

The problem of linking the dynamic electron correlation effects defined in traditional ab initio methods [or wave function theories (WFTs)] with the structure of the individual density functional theory (DFT) exchange and correlation functionals has been analyzed for the Ne atom, for which nondynamic correlation effects play a negligible role. A density-based approach directly hinged on difference radial-density (DRD) distributions defined with respect the Hartree-Fock radial density has been employed for analyzing the impact of dynamic correlation effects on the density. Attention has been paid to the elimination of basis-set incompleteness errors. The DRD distributions calculated by several ab initio methods have been compared to their DFT counterparts generated for representatives of several generations of broadly used exchange-correlation functionals and for the recently developed orbital-dependent OEP2 exchange-correlation functional [Bartlett et al., J. Chem. Phys. 122, 034104 (2005)]. For the local, generalized-gradient, and hybrid functionals it has been found that the dynamic correlation effects are to a large extend accounted for by densities resulting from exchange-only calculations. Additional calculations with self-interaction corrected exchange potentials indicate that this finding cannot be explained as an artifact caused by the self-interaction error. It has been demonstrated that the VWN5 and LYP correlation functionals do not represent any substantial dynamical correlation effects on the electron density, whereas these effects are well represented by the orbital-dependent OEP2 correlation functional. Critical comparison of the present results with their counterparts reported in literature has been made. Some attention has been paid to demonstrating the differences between the energy- and density-based perspectives. They indicate the usefulness of density-based criteria for developing new exchange-correlation functionals. PMID:19405556

Jankowski, K; Nowakowski, K; Grabowski, I; Wasilewski, J

2009-04-28

471

Coverage of dynamic correlation effects by density functional theory functionals: Density-based analysis for neon  

NASA Astrophysics Data System (ADS)

The problem of linking the dynamic electron correlation effects defined in traditional ab initio methods [or wave function theories (WFTs)] with the structure of the individual density functional theory (DFT) exchange and correlation functionals has been analyzed for the Ne atom, for which nondynamic correlation effects play a negligible role. A density-based approach directly hinged on difference radial-density (DRD) distributions defined with respect the Hartree-Fock radial density has been employed for analyzing the impact of dynamic correlation effects on the density. Attention has been paid to the elimination of basis-set incompleteness errors. The DRD distributions calculated by several ab initio methods have been compared to their DFT counterparts generated for representatives of several generations of broadly used exchange-correlation functionals and for the recently developed orbital-dependent OEP2 exchange-correlation functional [Bartlett et al., J. Chem. Phys. 122, 034104 (2005)]. For the local, generalized-gradient, and hybrid functionals it has been found that the dynamic correlation effects are to a large extend accounted for by densities resulting from exchange-only calculations. Additional calculations with self-interaction corrected exchange potentials indicate that this finding cannot be explained as an artifact caused by the self-interaction error. It has been demonstrated that the VWN5 and LYP correlation functionals do not represent any substantial dynamical correlation effects on the electron density, whereas these effects are well represented by the orbital-dependent OEP2 correlation functional. Critical comparison of the present results with their counterparts reported in literature has been made. Some attention has been paid to demonstrating the differences between the energy- and density-based perspectives. They indicate the usefulness of density-based criteria for developing new exchange-correlation functionals.

Jankowski, K.; Nowakowski, K.; Grabowski, I.; Wasilewski, J.

2009-04-01

472

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.

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

2014-01-01

473

Theory analysis of mode coupling in tilted long period fiber grating based on the full vector complex coupled mode theory  

NASA Astrophysics Data System (ADS)

The mode coupling in the tilted long period fiber grating (TLPG) is analyzed by using the full vector complex coupled mode theory (FV-CCMT). Compared with the non-tilted LPG, new resonance bands corresponding to the LP1m cladding modes are observed in the transmission spectrum of the TLPG. The coupling to LP1m cladding modes is the combination of the coupling to degenerate vector modes TE0m, TM0m and HE2m with different propagation constants. The maximum coupling between LP01 and LP1m modes occurs at a tilt angle of ˜87°. Numerical results show that the state of polarization (SOP) of the input light would induce the shift of the new resonance wavelength. Also, the RI sensitivity of the new resonance wavelength is much higher than that of the normal resonance wavelength corresponding to the LP0m cladding modes. Such TLPG would find application in chemical and biological sensing fields.

Yin, Guolu; Lou, Shuqin; Li, Qi; Zou, Hui

2013-06-01

474

Robust method for infrared small-target detection based on Boolean map visual theory.  

PubMed

In this paper, we present an infrared small target detection method based on Boolean map visual theory. The scheme is inspired by the phenomenon that small targets can often attract human attention due to two characteristics: brightness and Gaussian-like shape in the local context area. Motivated by this observation, we perform the task under a visual attention framework with Boolean map theory, which reveals that an observer's visual awareness corresponds to one Boolean map via a selected feature at any given instant. Formally, the infrared image is separated into two feature channels, including a color channel with the original gray intensity map and an orientation channel with the orientation texture maps produced by a designed second order directional derivative filter. For each feature map, Boolean maps delineating targets are computed from hierarchical segmentations. Small targets are then extracted from the target enhanced map, which is obtained by fusing the weighted Boolean maps of the two channels. In experiments, a set of real infrared images covering typical backgrounds with sky, sea, and ground clutters are tested to verify the effectiveness of our method. The results demonstrate that it outperforms the state-of-the-art methods with good performance. PMID:24979425

Qi, Shengxiang; Ming, Delie; Ma, Jie; Sun, Xiao; Tian, Jinwen

2014-06-20

475

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

476

Closure-based density functional theory applied to interfacial colloidal fluids.  

PubMed

The behavior of dense colloidal fluids near surfaces can now be probed in great detail with experimental techniques like confocal microscopy. In fact, we are approaching a point where quantitative comparisons of experiment with particle-level theory, such as classical density functional theory (DFT), are appropriate. In a forward sense, we may use a known surface potential to predict a particle density distribution function from DFT; in an inverse sense, we may use an experimentally measured particle density distribution function to predict the underlying surface potential from DFT. In this paper, we tested the ability of the closure-based DFT of Zhou and Ruckenstein (J. Chem. Phys. 2000, 112, 8079-8082) to perform forward and inverse calculations on potential models commonly employed for colloidal particles and surfaces. To reduce sources of uncertainty in this initial study, Monte Carlo simulation results played the role of experimental data. The combination of Rogers-Young and modified-Verlet closures consistently performed well across the different potential models. For a reasonable range of choices of the density, temperature, and potential parameters, the inversion procedure yielded particle-surface potentials to an accuracy on the order of 0.1kT. PMID:17973405

Lu, Mingqing; Bevan, Michael A; Ford, David M

2007-12-01

477

General Formalism of Decision Making Based on Theory of Open Quantum Systems  

NASA Astrophysics Data System (ADS)

We present the general formalism of decision making which is based on the theory of open quantum systems. A person (decision maker), say Alice, is considered as a quantum-like system, i.e., a system which information processing follows the laws of quantum information theory. To make decision, Alice interacts with a huge mental bath. Depending on context of decision making this bath can include her social environment, mass media (TV, newspapers, INTERNET), and memory. Dynamics of an ensemble of such Alices is described by Gorini-Kossakowski-Sudarshan-Lindblad (GKSL) equation. We speculate that in the processes of evolution biosystems (especially human beings) designed such "mental Hamiltonians" and GKSL-operators that any solution of the corresponding GKSL-equation stabilizes to a diagonal density operator (In the basis of decision making.) This limiting density operator describes population in which all superpositions of possible decisions has already been resolved. In principle, this approach can be used for the prediction of the distribution of possible decisions in human populations.

Asano, M.; Ohya, M.; Basieva, I.; Khrennikov, A.

2013-01-01

478

A linear viscoelastic biphasic model for soft tissues based on the Theory of Porous Media.  

PubMed

Based on the Theory of Porous Media (mixture theories extended by the concept of volume fractions), a model describing the mechanical behavior of hydrated soft tissues such as articular cartilage is presented. As usual, the tissue will be modeled as a materially incompressible binary medium of one linear viscoelastic porous solid skeleton saturated by a single viscous pore-fluid. The contribution of this paper is to combine a descriptive representation of the linear viscoelasticity law for the organic solid matrix with an efficient numerical treatment of the strongly coupled solid-fluid problem. Furthermore, deformation-dependent permeability effects are considered. Within the finite element method (FEM), the weak forms of the governing model equations are set up in a system of differential algebraic equations (DAE) in time. Thus, appropriate embedded error-controlled time integration methods can be applied that allow for a reliable and efficient numerical treatment of complex initial boundary-value problems. The applicability and the efficiency of the presented model are demonstrated within canonical, numerical examples, which reveal the influence of the intrinsic dissipation on the general behavior of hydrated soft tissues, exemplarily on articular cartilage. PMID:11601726

Ehlers, W; Markert, B

2001-10-01

479

Filtering method based on wavelet packets theory applied to target tracking  

NASA Astrophysics Data System (ADS)

In this paper, we derive a filtering method that is based on wavelet packets theory. With the theory we can decompose a length of measurement data into two parts in different resolution levels. One is the low frequency component, the other is the high frequency component. We can detect the target maneuvering respectively in the two components according to different criteria because characteristics of the maneuver information in the two components are not the same. The temporal and spatial location of the target maneuvering can be derived by an 'AND' operation between those of the components. On the other hand, we can also reconstruct the signal with the decomposed components. When in signal reconstruction, we can deliberately filter or even discard some subspaces of the wavelet packets. The reconstruction can be done in certain resolution levels. Thus, by means of subspace selection and reconstruction, we can design a wavelet packets filter with some characteristics, such as the characteristics of lowpass filtering or highpass filtering. With the wavelet packets decomposition and reconstruction, we can not only detect the target maneuver in different resolution level, but we can also attenuate the noise component with little or without attenuation of the target's location and tracking information and maneuver information, providing a 'better' data for the later Kalman filter bank.

Cheng, Hongwei; Sun, Zhongkang

1997-06-01

480

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

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