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Articles 4141 - 4170 of 4223

Full-Text Articles in Systems Science

Algorithm For Tracking Position And Orientation Of Drug Delivery Capsules In Gastrointestinal Tract, Xudong Guo, Zhengping Lu, Qinfen Jiang, Shuyi Wang, Haipo Cui Jun 2018

Algorithm For Tracking Position And Orientation Of Drug Delivery Capsules In Gastrointestinal Tract, Xudong Guo, Zhengping Lu, Qinfen Jiang, Shuyi Wang, Haipo Cui

Journal of System Simulation

Abstract: To realize an accurate releasing by a drug-delivery capsule in the gastrointestinal tract, a method of magnetic vector detection with angle sensing has been presented to track the capsule in real time; and a prototype of the tracking system has been developed. Based on the fundamentals of spatial distribution of magnetic vector fields, a nonlinear model of tracking is established. An improved artificial bee colony algorithm is studied to solve the magnetic inverse problem. In the improved algorithm, a chaos operator is used to generate an initial population and a sort selection is used to prevent premature convergence. …


Design Of Mini Folding Electric Scooter Based On Relative Attitude Angle Control, Lijun Jiang, Zhanghong Wu, Shaohui Pan, Zhelin Li, Zhiyong Xiong, Yongqing Fu Jun 2018

Design Of Mini Folding Electric Scooter Based On Relative Attitude Angle Control, Lijun Jiang, Zhanghong Wu, Shaohui Pan, Zhelin Li, Zhiyong Xiong, Yongqing Fu

Journal of System Simulation

Abstract: To help people move conveniently after getting off the public transport in the city, anew mini electric scooter design is proposed. This new scooter uses a smart mobile phone to receive driving intention and owns more efficient, convenient and space-saving folding pattern. A kinematics model of scooter is set up and discussed. A control strategy based on the relative attitude angle, an attitude sensor data consolidation approach based on the complementary filter, a solution to the Euler angle jumping and an estimate method to the wrong operation are proposed. The design is made into a prototype based on …


Dynamic Blind Source Separation Method Of Bearing Fault Diagnosis Based On Ga-Aw-Pso, Tianqi Zhang, Baoze Ma, Xingzi Qiang, Shengrong Quan Jun 2018

Dynamic Blind Source Separation Method Of Bearing Fault Diagnosis Based On Ga-Aw-Pso, Tianqi Zhang, Baoze Ma, Xingzi Qiang, Shengrong Quan

Journal of System Simulation

Abstract: The adaptive particle swarm optimization based on genetic mechanism (GA-AW-PSO) is proposed, aiming at blind source separation for dynamic hybrid bearing signals. The negentropy of separated signal is regarded as an objective function. The inertia weight is adjusted adaptively to reduce the invalid iterations according to the fitness difference. The introduction of genetic mechanism can increase diversity and is helpful for dynamic signal processing. The parameterized representation of orthogonal matrices can reduce the complexity of the algorithm. The simulation results show that the proposed method is superior to traditional blind source separation for the dynamic mechanical hybrid analog signal. …


Event-Triggered Non-Fragile H∞ State Estimation For Fuzzy Time-Delay Neural Networks, Yanqin Wang, Weijian Ren Jun 2018

Event-Triggered Non-Fragile H∞ State Estimation For Fuzzy Time-Delay Neural Networks, Yanqin Wang, Weijian Ren

Journal of System Simulation

Abstract: For a class of fuzzy neural networks with randomly occurring time-varying delays and randomly data packet loss, an event-triggered non-fragile H∞ state estimator is designed. The event-triggered condition is introduced to determine whether the signal is transmitted or not, so as to reduce the occupation rate of network resource. Random variables of Gaussian distribution and the multiplicative gain uncertainties are adopted to construct the non-fragile state estimator with randomly occurring gain variations. By constructing Lyapunov function, and via stochastic computation and linear matrix inequality technique, the sufficient conditions for the existence of non-fragile estimators are obtained, which guarantee …


Emergency Condition Selection Based On Tcp-Nets, Weihong Liu, Zheng Xiao, Cheng Chen, Li Qiao Jun 2018

Emergency Condition Selection Based On Tcp-Nets, Weihong Liu, Zheng Xiao, Cheng Chen, Li Qiao

Journal of System Simulation

Abstract: The representative or relative important emergency conditions need to be selected for making well-directed emergency plans. The quantitative method is normally used to select emergency conditions, but it requires users to specify the weight of every attribute, which does not conform to the users' habit. A qualitative method for emergency condition selection is put forward which includes two steps: for the first step, TCP-nets is adopted to describe users' requirements; and for the second step, the most important emergency conditions are selected based on TCP-nets. The effectiveness of the method is proved, and the efficiency is verified by experiments …


Test Data Compression Scheme For Fast Search Best Rational Approximate Fraction, Haifeng Wu, Wenfa Zhan, Yifei Cheng Jun 2018

Test Data Compression Scheme For Fast Search Best Rational Approximate Fraction, Haifeng Wu, Wenfa Zhan, Yifei Cheng

Journal of System Simulation

Abstract: Rapid growth of test data volume becomes a major factor for test time and manufacturing cost increasing. To reduce test data volume, a code-based compression scheme with fast search best rational approximate fraction is presented. The run-length data is converted into floating point numbers; and the equal best rational approximate fractions of floating point numbers is searched quickly; the appearing law of run-length data in the form of integer numerator and integer denominator is stored instead of storing run-length data directly. This scheme is compatible with traditional code-based methods. It also has simple compression and decompression protocol, good compression …


Imu Single-Axis Rotation Method And Error Analysis Of Modulation Inertial Navigation System, Sun Wei, Ruibao Li, Zhang Yuan, Yang Dan Jun 2018

Imu Single-Axis Rotation Method And Error Analysis Of Modulation Inertial Navigation System, Sun Wei, Ruibao Li, Zhang Yuan, Yang Dan

Journal of System Simulation

Abstract: Aiming at the problem that inertial device bias has an influence on the improvement of system precision, a single axis error modulation scheme whose sensitive axis is misalignment with rotation axis which can continuously rotate in clockwise and counterclockwise is proposed. Based on the same level precision of inertial components in IMU, the IMU is installed on rotation mechanism with non-coincidence. The symmetric part of inertial device deviation can be compensated by the positive and negative cancellation of the device deviation in the rotation axis direction and the rotation modulation in the vertical plane of the rotary axis. The …


Eye Gaze Tracking In 3d Immersive Environments, Xincan Zhao, Shihao Pan, Yaping Wang, Tie Yun Jun 2018

Eye Gaze Tracking In 3d Immersive Environments, Xincan Zhao, Shihao Pan, Yaping Wang, Tie Yun

Journal of System Simulation

Abstract: Aiming at the problem that human-computer interaction in immersive environments is entirely dependent on the body movement with low operational efficiency,a 3D eye gaze tracking method is proposed to gain the 3D gaze point of the user. Thus the interactive operation could be achieved, which provides a natural and bidirectional way for interaction. The Leap Motion controller is innovatively used to track the coordinates of eyes and the head position is tracked with the motion capture device. The gaze point under free movement can be estimated based on the mapping equation that is obtained in the initial …


Identification Of Closed Loop Projection Subspace For Motor Based On Hankel Correlation Function, Minghong She Jun 2018

Identification Of Closed Loop Projection Subspace For Motor Based On Hankel Correlation Function, Minghong She

Journal of System Simulation

Abstract: To solve estimation deviation problem of model parameter in the closed-loop system identification, the subspace identification model and state space model based on the estimation of the correlation function are presented, and through the correlation function estimation and zero space followed by projection, the block Hankel matrix of identification framework was filled so as to obtain the scope of the extended observability matrix; on the basis of the same projection on the time offset set of related data, the RQ decomposition of the projection is calculated by numerical calculation, and the dynamic estimation of the system model is obtained. …


High Frequency Blend Clips Matching Based Fire Sound Synthesis, Yin Qiang, Shiguang Liu Jun 2018

High Frequency Blend Clips Matching Based Fire Sound Synthesis, Yin Qiang, Shiguang Liu

Journal of System Simulation

Abstract: Aimed at the problem which generated by fire sound simulation in virtual reality field, a new fire sound synthesis method was proposed. Most of the sound synthesis methods currently separate the fire sound into low and high frequencies for synthesizing. The influence of low frequency fire sound models was considered and the low frequency signal was synthesized based on the physical visual fire model data. The high frequency sound signal was synthesized based on high frequency blend clips matching method. According to the characteristics of the fire's high frequency, the different frequency bands of high noise signal …


Physically-Based Dynamic Algorithms For Time-Varying Of Flowers And Leaves, Jiao Di, Yang Meng, Yang Gang Jun 2018

Physically-Based Dynamic Algorithms For Time-Varying Of Flowers And Leaves, Jiao Di, Yang Meng, Yang Gang

Journal of System Simulation

Abstract: This paper presents physically-based simulations of dynamic algorithms of the blossom and fading of flowers as well as the time-varying leaves following the seasons. The models of the flowers are constructed according to the previously collected primary biological data of organs of flowers. The dynamic simulation is presented by two phases: the process of blooming and the process of fading. To simulate the former, the curved surfaces of petals are controlled by controlling the points on the Bezier surface; for realizing the simulation of the latter, the physical method is used. The dynamic effects of colors of leaves according …


Combination Forecasting Of Stock Index Time Series Based On Cooperative Game Theory, Luo Wei Jun 2018

Combination Forecasting Of Stock Index Time Series Based On Cooperative Game Theory, Luo Wei

Journal of System Simulation

Abstract: In view of the characteristics of nonlinear, large amplitude, frequent fluctuations in China's stock market, a prediction method of intelligent composite stock index time series based on the cooperative game is presented. The prediction model of stock index time series is established by using neural network method based on the correlations among the various economic indicators, and the development trend and laws of stock index time series are established by using the improved ARIMA method. The two methods are combined by importing cooperative game method. Simulation results show that the prediction accuracy of the presented method is controlled …


Temperature Characteristics Of Contact Wire Under Different Driving Intervals, Hongwei Wang, Zhang Kai, Zhiyong Wang, Fengyi Guo, Liu Shuai, Zhang Qiong Jun 2018

Temperature Characteristics Of Contact Wire Under Different Driving Intervals, Hongwei Wang, Zhang Kai, Zhiyong Wang, Fengyi Guo, Liu Shuai, Zhang Qiong

Journal of System Simulation

Abstract: To reduce the wear of pantograph and catenary system while decreasing the headway, the temperature field of the contact wire is studied. A simulation model is established by using the COMSOL Multiphysics software. The effectiveness of the model is verified with temperature experiments. Temperature field of the contact wire of freight locomotive and passenger locomotive in different intervals is studied by simulation. The smaller the headway of trains, the higher the temperature value, and the shorter the balance process. Under the constraint of temperature field, the headway of freight locomotive couldn't be less than 180s under long term operation. …


A Proposed Taxonomy For The Systems Statistical Engineering Body Of Knowledge, Teddy Steven Cotter Jan 2018

A Proposed Taxonomy For The Systems Statistical Engineering Body Of Knowledge, Teddy Steven Cotter

Engineering Management & Systems Engineering Faculty Publications

In the ASEM-IAC 2012, Cotter (2012) identified the gaps in knowledge that statistical engineering needs to address, explored additional gaps in knowledge not addressed in the prior works, and set forth a working definition of and body of knowledge for statistical engineering. In the ASEM-IAC 2015, Cotter (2015) proposed a systemic causal Bayesian hierarchical model that addressed the knowledge gap needed to integrate deterministic mathematical engineering causal models within a stochastic framework. Missing, however, is the framework for specifying the hierarchical qualitative systems structures necessary and sufficient for specifying systemic causal Bayesian hierarchical models. In the ASEM-IAC 2016, Cotter (2016) …


Systems Statistical Engineering – Systems Hierarchical Constraint Propagation, Teddy Steven Cotter, Peggy A. Quigley Jan 2018

Systems Statistical Engineering – Systems Hierarchical Constraint Propagation, Teddy Steven Cotter, Peggy A. Quigley

Engineering Management & Systems Engineering Faculty Publications

Cotter (ASEM-IAC 2012, 2015, 2016, 2017): (1) identified the gaps in knowledge that statistical engineering needed to address and set forth a working definition of and body of knowledge for statistical engineering; (2) proposed a systemic causal Bayesian hierarchical model that addressed the knowledge gap needed to integrate deterministic mathematical engineering causal models within a stochastic framework; (3) specified the modeling methodology through which statistical engineering models could be developed, diagnosed, and applied to predict systemic mission performance; and (4) proposed revisions to and integration of IDEF0 as the framework for developing hierarchical qualitative systems models. In the last work, …


A Method For Identification, Representation, And Assessment Of Complex System Pathologies In Acquisition Programs, Charles B. Keating, Polinpapilinho F. Katina, Keith F. Joiner, Joseph M. Bradley, Raed M. Jaradat Jan 2018

A Method For Identification, Representation, And Assessment Of Complex System Pathologies In Acquisition Programs, Charles B. Keating, Polinpapilinho F. Katina, Keith F. Joiner, Joseph M. Bradley, Raed M. Jaradat

Engineering Management & Systems Engineering Faculty Publications

Acquisition programs continue to struggle with increasing complexity. High degrees of emergence, interconnectedness, and uncertainty are the norm rather than exception. The purpose of this research is to explore extension of ongoing research in complex system pathologies for acquisition programs. Significant advances have been made in development of deeper understanding of the nature of pathologies (deviations from healthy system function) and their implications for performance of complex systems. Complex system pathologies represent violations of underlying system principles. These violations negatively affect system governance functions (control, oversight, accountability) resulting in degradation of system performance. Greater understanding of complex system pathologies offers …


A Systems Theory Based Examination Of Failure In Acquisition System Reform, Charles B. Keating, Joseph M. Bradley, Polinpapilinho F. Katina, Craig Arndt Jan 2018

A Systems Theory Based Examination Of Failure In Acquisition System Reform, Charles B. Keating, Joseph M. Bradley, Polinpapilinho F. Katina, Craig Arndt

Engineering Management & Systems Engineering Faculty Publications

The defense acquisition system has been the source of intense scrutiny and calls for reform for over four decades. This research is to examine the contributions of Systems Theory to enhance prospects related to acquisition reform. Systems Theory offers a set of principles, laws, and concepts that explain the behavior of complex systems. Although the acquisition system and constituent programs have been critiqued and examined from multiple perspectives, they have never been the subject of exploration from Systems Theory. Recent advances in Systems Theory have identified 83 different potential system pathologies that can result in degraded system performance or outright …


Adaptation Of Legacy Computer Science Complexity Metrics To Sysml Diagrams, Victor Lopez Oct 2017

Adaptation Of Legacy Computer Science Complexity Metrics To Sysml Diagrams, Victor Lopez

Von Braun Symposium Student Posters

No abstract provided.


Internet Of Vehicles: Architecture, Applications, And Security Requirements Of Cognitive Radio Adhoc Vehicular Network, Sachin Sharma Aug 2017

Internet Of Vehicles: Architecture, Applications, And Security Requirements Of Cognitive Radio Adhoc Vehicular Network, Sachin Sharma

Theses and Dissertations

In recent years, the demand for spectrum has increased exponentially. Cognitive radio (CR) technology provides the capability to dynamically sense the spectrum for available channels, estimate them and select a good channel. This thesis introduces the concept of dynamic spectrum leasing methodology (DSLM), a paradigm based on game theoretic concepts. DSLM takes into account the demand for spectrum by secondary users and the willingness of primary users to relinquish spectrum in a restricted manner, making possible spectrum leasing as a long-term commercially viable concept. This thesis also introduces the notion of a Cognitive Radio Network Service Provider (CRNSP) and the …


Protecting Non-Public Information In Community Banks: A Study For Implementing Risk Based Framework For Protecting Non Public Personal Information, Bruce Lee Upton Aug 2017

Protecting Non-Public Information In Community Banks: A Study For Implementing Risk Based Framework For Protecting Non Public Personal Information, Bruce Lee Upton

Theses and Dissertations

In today’s world it seems that cyber hackers, cyber terrorists, and cyber activists make headlines almost every day. Information security has become a major concern for bankers from both a reputation and regulatory examination standpoint. Bank management is tasked to answer a litany of questions. Is my bank secure? What impact does this security have on productivity? What solutions are cost effective? What impact will a security breach have on my bank and respective customer base? Additionally, many bankers don’t have on-staff expertise to answer these questions. Having a framework where bankers can know how likely it is they will …


Investment Plan Against Malicious Attacks On Power Networks: Multilevel Game-Theoretic Models With Shared Cognition, Hamzeh Davarikia Aug 2017

Investment Plan Against Malicious Attacks On Power Networks: Multilevel Game-Theoretic Models With Shared Cognition, Hamzeh Davarikia

Theses and Dissertations

The work reported in this thesis aims at developing a practical tool for utility transmission planners to protect power network from potential attacks. To efficiently address the problem, we propose a new formulation for defender which has a promising result than its counterpart. Moreover, the optimum defending strategy in power network is modeled which return the best protecting strategy based on the defender resources. Going beyond the common approaches in literature, defender deception is mathematically formulated by releasing misinformation about his plan in the shared cognition based model. The problems are formulated as tri-level mixed-integer non-linear programming and exact linearization …


Integrating Idef0 Into A Systems Framework For Statistical Engineering, Teddy Steven Cotter Jan 2017

Integrating Idef0 Into A Systems Framework For Statistical Engineering, Teddy Steven Cotter

Engineering Management & Systems Engineering Faculty Publications

Driven by a growing requirement during the 21st century for the integration of rigorous statistical analyses in engineering research, there has been a movement within the statistics and quality communities to evolve a unified statistical engineering body of knowledge (Horel and Snee, 2010; Anderson-Cook, 2012). Outside of the 2014 Statistical Engineering Agreement among the ASQ Statistics Division, DOT&E, NASA, and IDA, there has been little formal progress toward this goal since the May 2011 NASA Symposium on Statistical Engineering in Williamsburg Virginia. In the ASEM-IAC 2012, Cotter (2012) identified the gaps in knowledge that statistical engineering needs to address, explored …


Cockpit In The Systems Engineering Lenses, Aysen K. Taylor, Charles B. Keating, T. Steven Cotter Jan 2017

Cockpit In The Systems Engineering Lenses, Aysen K. Taylor, Charles B. Keating, T. Steven Cotter

Engineering Management & Systems Engineering Faculty Publications

The commercial transport aircraft of today vary greatly from early aircraft in regards to how they are controlled and the feedback provided from the machine to the human operator. Automation has improved operational precision and efficiency but at the cost of providing less feedback. Pilots are the last line of defense and current technology cannot provide the human ability to solve novel problems for which no computer logic can be written. The automated cockpits of today have may sub-components that interact in a manner often opaque and unpredictable when a sensor or sub-component fails or even in situations where no …


A Systems Theoretic-Based Framework To Discover Pathologies In Acquisition System Governance, Charles B. Keating, Joseph M. Bradley, Polinpapilinho F. Katina, Ra'ed M. Jaradat Jan 2017

A Systems Theoretic-Based Framework To Discover Pathologies In Acquisition System Governance, Charles B. Keating, Joseph M. Bradley, Polinpapilinho F. Katina, Ra'ed M. Jaradat

Engineering Management & Systems Engineering Faculty Publications

The acquisition field continues to face increasing pressures to perform under conditions of escalating complexity, uncertainty, and ambiguity. These conditions suggest that traditional approaches, practices, and acquisition technologies might be incongruent with support demands for acquisition practitioners. This research is focused on exploiting and extending recent developments in Complex System Governance (CSG) to advance the acquisition field. CSG is focused on the design, execution, and evolution of fundamental system functions necessary for control, communications, coordination, and integration of complex systems (e.g., acquisition). CSG is based in Systems Theory (fundamental laws governing complex systems), Management Cybernetics (the science of effective system …


Systemic Intervention For Complex System Governance Development, Charles B. Keating, Polinpapilinho F. Katina,, John C. Pyne, Ra’Ed M. Jaradat Jan 2017

Systemic Intervention For Complex System Governance Development, Charles B. Keating, Polinpapilinho F. Katina,, John C. Pyne, Ra’Ed M. Jaradat

Engineering Management & Systems Engineering Faculty Publications

This paper explores the issues related to systemic intervention for Complex System Governance (CSG) development. Systemic intervention seeks to intentionally engage a system to influence trajectory or outcomes. CSG is an emerging field focused on the design, execution, and evolution of the functions necessary to provide continued system performance (stability) in the midst of incessant turbulence and increasing complexity. Integral to this field is the necessity to ‘intervene’ in a complex system to enhance system behavior, structure, or performance. Arguably, system interventions have an unremarkable record of success, ranging from declared success in improving a situation (system) to abysmal failure …


Girl’S Cybersecurity Camp, Sarah Cunha, Dale Rowe Jan 2016

Girl’S Cybersecurity Camp, Sarah Cunha, Dale Rowe

Journal of Undergraduate Research

In 2015, the BYU Cybersecurity Research Lab (CSRL) held its first annual summer camp for Girls aged 14-18. A total of 38 girls attended the week’s activities and workshops. While over 75% of girls indicated they had taken a computing-related class, only 40% reported any significant interest in cybersecurity prior to the summercamp with 10% believing they had some experience in the field. At the conclusion of the camp, 80% of attendees reported a significant interest in the field with 100% of attendees interested in attending a similar event again.


Systemic Analysis Of Complex System Governance For Acquisition, Charles B. Keating, Joseph M. Bradley, Polinpapilinho F. Katina Jan 2016

Systemic Analysis Of Complex System Governance For Acquisition, Charles B. Keating, Joseph M. Bradley, Polinpapilinho F. Katina

Engineering Management & Systems Engineering Faculty Publications

The purpose of this paper is to explore Complex System Governance (CSG) issues related to systemic analysis of acquisition systems. CSG is an emerging field focused on the design, execution, and evolution of the functions necessary to provide continued system performance (stability) in the midst of incessant turbulence and increasing complexity. Integral to this field is the necessity to engage systems to address behavior or performance that is inconsistent with that which is desired. Systemic analysis for CSG serves to examine a system to discover fundamental system issues (e.g. acquisition). Arguably, system acquisition has an unremarkable record of success, ranging …


Cyber-Physical Systems: Complex System Governance As An Integrating Construct, Polinpapilinho F. Katina, Charles B. Keating, Adrian V. Gheorghe Jan 2016

Cyber-Physical Systems: Complex System Governance As An Integrating Construct, Polinpapilinho F. Katina, Charles B. Keating, Adrian V. Gheorghe

Engineering Management & Systems Engineering Faculty Publications

This paper examines contributions of Complex System Governance (CSG) as an integrating construct for the emerging fields of critical cyber-physical systems (CPS). CPS is concerned with physical entities that are controlled by computational elements. The field is relatively new, emerging, and also somewhat fragmented in development. There are multiple agencies, entities, and activities being undertaken to address a nexus of emerging issues (e.g., cybersecurity) in critical infrastructures. However, the development of critical CPS, as a field, albeit with good intentions and efforts, appears to be largely ‘self-organizing.’ In response, we suggest CSG as an organizing construct capable of provided a …


The Role Of 'Metasystem' In Engineering A System Of Systems, Polinpapilinho F. Katina, Charles B. Keating, Joseph M. Bradley Jan 2016

The Role Of 'Metasystem' In Engineering A System Of Systems, Polinpapilinho F. Katina, Charles B. Keating, Joseph M. Bradley

Engineering Management & Systems Engineering Faculty Publications

Fundamentally, a system of systems is characterized by operational independence, managerial independence, evolutionary development, emergent behavior, and geographical distribution. However, value-wise, a system of systems should provide greater capability beyond that which individual systems can provide. Enabling this greater capability has to be purposely designed for and managed. In this paper, we argue that this is the primary role of the metasystem structure and its execution. A metasystem is a governing structure that provides coordination and integration of multiple systems, brought together to achieve overarching missions and functions beyond those of the constituent systems. This paper articulates the differences between …


Complex System Governance For Acquisition, Joseph Bradley, Polinpapilinho Katina, Charles Keating Jan 2016

Complex System Governance For Acquisition, Joseph Bradley, Polinpapilinho Katina, Charles Keating

Engineering Management & Systems Engineering Faculty Publications

As acquisition processes have become more complex, they appear to no longer be governable by traditional approaches. Missed budgets, delayed deliveries, and expensive canceled systems appear to becoming more prevalent. Numerous investigations have been conducted attempting to elicit the factors that prevented success. Those systems that succeed in terms of usability, budget, and delivery schedule are the rarity and often become case studies themselves as we try to extract the characteristics that differentiate success from failure. A different viewpoint is to look at the acquisition system from the perspective of Complex Systems Governance (CSG). Recent developments in the field of …