• Title/Summary/Keyword: simulation functions

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The extension of the largest generalized-eigenvalue based distance metric Dij1) in arbitrary feature spaces to classify composite data points

  • Daoud, Mosaab
    • Genomics & Informatics
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    • v.17 no.4
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    • pp.39.1-39.20
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    • 2019
  • Analyzing patterns in data points embedded in linear and non-linear feature spaces is considered as one of the common research problems among different research areas, for example: data mining, machine learning, pattern recognition, and multivariate analysis. In this paper, data points are heterogeneous sets of biosequences (composite data points). A composite data point is a set of ordinary data points (e.g., set of feature vectors). We theoretically extend the derivation of the largest generalized eigenvalue-based distance metric Dij1) in any linear and non-linear feature spaces. We prove that Dij1) is a metric under any linear and non-linear feature transformation function. We show the sufficiency and efficiency of using the decision rule $\bar{{\delta}}_{{\Xi}i}$(i.e., mean of Dij1)) in classification of heterogeneous sets of biosequences compared with the decision rules min𝚵iand median𝚵i. We analyze the impact of linear and non-linear transformation functions on classifying/clustering collections of heterogeneous sets of biosequences. The impact of the length of a sequence in a heterogeneous sequence-set generated by simulation on the classification and clustering results in linear and non-linear feature spaces is empirically shown in this paper. We propose a new concept: the limiting dispersion map of the existing clusters in heterogeneous sets of biosequences embedded in linear and nonlinear feature spaces, which is based on the limiting distribution of nucleotide compositions estimated from real data sets. Finally, the empirical conclusions and the scientific evidences are deduced from the experiments to support the theoretical side stated in this paper.

What Do We Learn from Two-Dimensional Raman Spectra by Varying the Polarization Conditions?

  • Ma, Ao;Stratt, Richard M.
    • Bulletin of the Korean Chemical Society
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    • v.24 no.8
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    • pp.1126-1134
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    • 2003
  • The signals obtained from the $5^{th}$-order (two-dimensional) Raman spectrum of a liquid can depend dramatically on the polarizations of the various light beams, but to date there has been no evidence presented that different polarization conditions probe any fundamentally different aspects of liquid dynamics. In order to explore the molecular significance of polarization we have carried out a molecular dynamics simulation of the $5^{th}$-order spectrum of a dilute solution of CS₂ in liquid Xe, perhaps the simplest system capable of displaying a full range of polarization dependencies. By focusing on the 5 distinct rotational invariants revealed by the different polarizations and by comparing our results with those from liquid Xe, a liquid whose spectrum has no significant polarization dependence, we discovered that the polarization experiments do, in fact, yield valuable microscopic information. With different linear combinations of the experimental response functions one can separate the part of the signal derived from the purely interaction-induced part of the many-body polarizability from the portion with the largest contributions from single-molecule polarizabilities. This division does not directly address the underlying liquid dynamics, but it significantly simplifies the interpretation of the theoretical calculations which do address this issue. We find that the different linear combinations differ as well in whether they exhibit nodal lines. Despite the absence of nodes with the atomic liquid Xe, observing the resilience of our solution's nodes when we artificially remove the anisotropy of our solute leads us to conclude that there is no direct connection between nodes and specifically molecular degrees of freedom.

Estimation of Large Amplitude Motions and Wave Loads of a Ship Advancing in Transient Waves by Using a Three Dimensional Time-domain Approximate Body-exact Nonlinear 2nd-order BEM (3 차원 시간영역 근사비선형 2 차경계요소법에 의한 선체의 대진폭 운동 및 파랑하중 계산)

  • Hong, Do-Chun;Hong, Sa-Young;Sung, Hong-Gun
    • Journal of the Society of Naval Architects of Korea
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    • v.47 no.3
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    • pp.291-305
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    • 2010
  • A three-dimensional time-domain calculation method is of crucial importance in prediction of the motions and wave loads of a ship advancing in a severe irregular sea. The exact solution of the free surface wave-ship interaction problem is very complicated because of the essentially nonlinear boundary conditions. In this paper, an approximate body nonlinear approach based on the three-dimensional time-domain forward-speed free-surface Green function has been presented. The Froude-Krylov force and the hydrostatic restoring force are calculated over the instantaneous wetted surface of the ship while the forces due to the radiation and scattering potentials over the mean wetted surface. The time-domain radiation and scattering potentials have been obtained from a time invariant kernel of integral equations for the potentials which are discretized according to the second-order boundary element method (Hong and Hong 2008). The diffraction impulse-response functions of the Wigley seakeeping model advancing in transient head waves at various Froude numbers have been presented. A simulation of coupled heave-pitch motion of a long rectangular barge advancing in regular head waves of large amplitude has been carried out. Comparisons between the linear and the approximate body nonlinear numerical results of motions and wave loads of the barge at a nonzero Froude number have been made.

An End-to-End Mobility Support Mechanism based on mSCTP (mSCTP를 이용한 종단간 이동성 지원 방안)

  • 장문정;이미정;고석주
    • Journal of KIISE:Information Networking
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    • v.31 no.4
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    • pp.393-404
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    • 2004
  • Recently, mSCTP (Mobile SCTP) has been proposed as a transport layer approach for supporting mobility. mSCTP is based on the ‘multi-homing’ feature of Stream Control Transmission Protocol(SCTP), and utilize the functions to dynamically add or delete IP addresses of end points to or from the existing connectionin order to support mobility. In this paper, we propose a mechanism to determine when to add or delete an W address, utilizing the link layer radio signal strength information in order to enhance the performance of mSCTP We also propose a mechanism for a mobile node to initiate the change of data delivery path based on link layer radio signal strength information. In addition, if it takes long time to acquire new data path, we propose an approach for reducing handover latency. The simulation results show that the performance of proposed transport layer mobility support mechanism is competitive compared to the traditional network layer mobility supporting approach. Especially, when the moving speed of mobile node is fast, it shows better performance than the traditional network layer approaches.

A Study on a Control Language for the Configuration of Process Controllers (공정 제어기 구성을 위한 제어 언어에 관한 연구)

  • Seo, Chang-Jun;Kim, Byung-Kook
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.11
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    • pp.36-44
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    • 1994
  • In this paper, a high-level process control language is developed to construct multi-loop controllers for large scale process control systems. Function locks are defined which are basic functions necessary to configure a multi-loop controller. Each block is presented to the function code which is a line of ASCII codes and has the characteristics to be simple and to be easily understood. A control algorithm for a process is attained by means of the arrangement of function codes with order. In order to be used to various environments of target hardwares, a transformation program is prepared that transfers a control program configured by function codes to a C-language program. The proposed control language is easy and simple to use, possible to expend, and able to apply to various control systems. Simulation results are included to show the availability for the usage of the proposed control language in real world.

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Implementation of efficient DNA Sequence Generate System with Genetic Algorithm (유전자 알고리즘을 이용한 DNA 서열 생성 시스템의 효율적인 구현에 대한 연구)

  • Lee Eun-Kyung;Lee Seung-Ryeol;Kim Dong-Soon;Chung Duck-Jin
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.43 no.5 s.311
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    • pp.44-59
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    • 2006
  • This paper describes the efficient implementation of DNA sequence generate system with genetic algorithm for reducing computation time of NACST. The proposed processor is based on genetic algerian with fitness functions which would suit the point of reference for generated sequences. In order to implement efficient hardware structure, we used the pipelined structure. In addition our design was applied the parallelism to achieve even better simulation time than the sequence generator system which is designed on software. In this paper, our hardware is implemented on the FPGA board with xc2v6000 devices. Through experiment, the proposed hardware achieves 467 times speed-up over software on a PC and sequence generate performance of hardware is same with software.

Studies of Communicational Education Suitable for Security Environment (안보환경에 적합한 해군부사관과의 의사소통 교육방안 연구 - 맥락적 의사소통을 중심으로)

  • Yu, Yong-tae
    • Convergence Security Journal
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    • v.16 no.3_1
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    • pp.47-56
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    • 2016
  • This study's goal is to consider deeper about the Context-Communication Study on candidates of future petty officers in community colleagues, therefore the study uses theoretical approaches of the communications based on literature research. The petty officer majors in community colleagues need to set a curriculum to achieve the goal of the Context-Communication Study. The class, which is a continuous class from freshman to sophomore year, needs to be designed as a combination class of command/discipline major classes and communication studies. This study shows the detail ways of the Context-Communication Study to bring student's interests by using simulation studies with writing papers, training interviews, and presentations which all will be checked by their instructors. Instructors will get students to the point that they have upscale communication abilities and language abilities. Finally, this study shows limitations of the Context-Communication Study and suggests the further direction of research.

The System Dynamics Model for Assessment of Organizational and Human Factor in Nuclear Power Plant (시스템 다이나믹스를 활용한 원전 조직 및 인적인자 평가)

  • 안남성;곽상만;유재국
    • Proceedings of the Korean System Dynamics Society
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    • 2002.02a
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    • pp.19-40
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    • 2002
  • The intent of this study is to develop system dynamics model for assessment of organizational and human factors in nuclear power plant which can contribute to secure the nuclear safety. Previous studies are classified into two major approaches. One is engineering approach such as ergonomics and probability safety assessment(PSA). The other is social science approach such like sociology, organization theory and psychology. Both have contributed to find organization and human factors and to present guideline to lessen human error in NPP. But, since these methodologies assume that relationship among factors is independent they don't explain the interactions among factors or variables in NPP. To overcome these limits, we have developed system dynamics model which can show cause and effect among factors and quantify organizational and human factors. The model we developed is composed of 16 functions of job process in nuclear power, and shows interactions among various factors which affects employees' productivity and job quality. Handling variables such like degree of leadership, adjustment of number of employee, and workload in each department, users can simulate various situations in nuclear power plant in the organization side. Through simulation, user can get insight to improve safety in plants and to find managerial tools in the organization and human side. Analyzing pattern of variables, users can get knowledge of their organization structure, and understand stands of other departments or employees. Ultimately they can build learning organization to secure optimal safety in nuclear power plant.

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GA-BASED PID AND FUZZY LOGIC CONTROL FOR ACTIVE VEHICLE SUSPENSION SYSTEM

  • Feng, J.-Z.;Li, J.;Yu, F.
    • International Journal of Automotive Technology
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    • v.4 no.4
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    • pp.181-191
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    • 2003
  • Since the nonlinearity and uncertainties which inherently exist in vehicle system need to be considered in active suspension control law design, this paper proposes a new control strategy for active vehicle suspension systems by using a combined control scheme, i.e., respectively using a genetic algorithm (GA) based self-tuning PID controller and a fuzzy logic controller in two loops. In the control scheme, the PID controller is used to minimize vehicle body vertical acceleration, the fuzzy logic controller is to minimize pitch acceleration and meanwhile to attenuate vehicle body vertical acceleration further by tuning weighting factors. In order to improve the adaptability to the changes of plant parameters, based on the defined objectives, a genetic algorithm is introduced to tune the parameters of PID controller, the scaling factors, the gain values and the membership functions of fuzzy logic controller on-line. Taking a four degree-of-freedom nonlinear vehicle model as example, the proposed control scheme is applied and the simulations are carried out in different road disturbance input conditions. Simulation results show that the present control scheme is very effective in reducing peak values of vehicle body accelerations, especially within the most sensitive frequency range of human response, and in attenuating the excessive dynamic tire load to enhance road holding performance. The stability and adaptability are also showed even when the system is subject to severe road conditions, such as a pothole, an obstacle or a step input. Compared with conventional passive suspensions and the active vehicle suspension systems by using, e.g., linear fuzzy logic control, the combined PID and fuzzy control without parameters self-tuning, the new proposed control system with GA-based self-learning ability can improve vehicle ride comfort performance significantly and offer better system robustness.

Fair Bandwidth Allocation in Core-Stateless Networks (Core-Stateless망에서의 공정한 대역폭 할당 방식)

  • Kim Mun-Kyung;Park Seung-Seob
    • The KIPS Transactions:PartC
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    • v.12C no.5 s.101
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    • pp.695-700
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    • 2005
  • To provide the fair rate and achieve the fair bandwidth allocation, many per-flow scheduling algorithms have been proposed such as fair queueing algorithm for congestion control. But these algorithms need to maintain the state, manage buffer and schedule packets on a per-flow basis; the complexity of these functions may prevent them from being cost-effectively implemented. In this paper, therefore, to acquire cost-effectively for implementation, we propose a CS-FNE(Core Stateless FNE) algorithm that is based on FM(Flow Number Estimation), and evaluated CS-FNE scheme together with CSFQ(Core Stateless Fair Queueing), FRED(Fair Random Early Detection), RED(Random Early Detection), and DRR(Dynamic Round Robin) in several different configurations and traffic sources. Through the simulation results, we showed that CS-FNE algorithm can allocate fair bandwidth approximately than other algorithms, and CS-FNE is simpler than many per-flow basis queueing mechanisms and it can be easily implemented.