• Title/Summary/Keyword: Combining Technique

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Exploring the Effect of Replacement Levels on Data Fusion Methods : A Monte Carlo Simulation Approach (자료융합방법의 성과에 대체수준이 미치는 영향에 관한 연구 : 몬테카를로 시뮬레이션 접근방법)

  • 김성호;조성빈;백승익
    • Korean Management Science Review
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    • v.19 no.1
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    • pp.129-142
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    • 2002
  • Data fusion Is a technique used for creating an Integrated database by combining two or more databases that include a different set of variables or attributes. This paper attempts to apply data fusion technique to customer relationships management (CRM), in that we can not only plan a database structure but also collect and manage customer data In a more efficient way In particular our study Is useful when no s1n91e database Is complete, i.e., each and every subject in the pre-integrated database contains somewhat missing observations. According to the way of treating the common variables, donors can be differently selected for the substitution of the missing attributes of recipients. One way is to find the donor that has the highest correlation coefficient with the recipient by. treating common variables metrically The other is based on the closest distance by the correspondence analysis in case of treating common variables nominally. The predictability of data fusion for CRM can be evaluated by measuring the correlation of the original database and the substituted one. A Monte Carlo Simulation analysis is used to examine the stability of the two substitution methods in building an integrated database.

Study of Supporting Location Optimization for a Structure under Non-uniform Load Using Genetic Algorithm (유전알고리즘을 이용한 비균일 하중을 받는 구조물의 지지 위치 최적화 연구)

  • Kim, G.H.;Lee, Y.S.;Kim, H.K.;Her, N.I.;Sa, J.W.;Yang, H.L.;Kim, B.C.;Bak, J.S.
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1322-1327
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    • 2003
  • It is important to determine supporting locations for structural stability of a structure under non-uniform load in space interfered by other parts. In this case, There are many local optima with discontinuous design space. Therefore, The traditional optimization methods based on derivative are not suitable. Whereas, Genetic algorithm(GA) based on stochastic search technique is a very robust and general method. This paper has been presented to determine supporting locations of the vertical supports for reducing stress of the KSTAR(Korea super Superconducting Tokamak Advanced Research) IVCC(In-vessel control coil) under non-uniform electromagnetic load and space interfered by other parts using genetic algorithm. For this study, we develop a program combining finite element analysis with a genetic algorithm to perform structural analysis of IVCC. In addition, this paper presents a technique to perform optimization with FEM when design variables are trapped in an incongruent design space.

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On the Mass Transfer Behaviors in Hollcw-Fiber Membrane Modules for $CO_2$ Separation (이산화탄소 분리를 위한 중공사막 모듈에서의 물질전달 거동)

  • 전명석;김영목;이규호
    • Proceedings of the Membrane Society of Korea Conference
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    • 1994.04a
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    • pp.51-52
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    • 1994
  • High permeability, selectivity and stability are the basic properties also required for membrane gas separations. The $CO_2$ separation by liquid membranes has been developed as a new technique to improve the permeability and selectivity of polymeric membranes. Sirkar et al.(1) have atlempted the hollow-fiber contained liquid membrane technique under four different operational modes, and permeation models have been proposed for all modes. Compared to a conventional liquid membrane, the diffusional resistance decreased by the work of Teramoto et al.(2), who referred to a moving liquid membrane. Recently, Shelekhin and Beckman (3) considered the possibility of combining absorption and membrane separation processes in one integrated system called a membrane absorber. Their analysis could be predicted effectively the performance of flat sheet membrane, however, there are restrictions for considering a flow effect. The gas absorption rate is determined by both an interfacial area and a mass transfer coefficient. It can be easily understood that although the mass transfer coefficients in hollow fiber modules are smaller than in conventional contactors, the substantial increase of the interfacial area can result in a more efficient absorber (4). In order to predict a performance in the general system of hollow-fiber membrane absorber, a gas-liquid mass transfor should be investigated inevitably. The influence of liquid velocity on both a mass transfer and a performance will be described, and then compared with experimental results. A present study is attempted to provide the fundamentals for understanding aspects of promising a hollow-fiber membrane absorber.

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A Study of the Evaluating Method for the Survivability of Aircraft during Mission Completion (임무수행 경과에 따른 항공기 생존성 평가기법 연구)

  • 윤봉수
    • Journal of the military operations research society of Korea
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    • v.22 no.2
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    • pp.166-181
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    • 1996
  • Aircraft survivability is determined by the susceptibility and the vulnerability. The aircraft susceptibility and vulnerability depend upon the hardware and software factors. Each of the hardware and software factors consisted of the qualitative and quantitative attributes varies according to the time of the mission. In order to establish the mathermatical model to analyze and evaluate the aircraft survivability, qualitative factors have to be transformed into quantitative factors. Even if many researches in the area of dynamic concept analysis and conversion of qualitative factors into the quantitative factors has been insufficient. This research enhances these insufficient area by developing a reliable aircarft survivability analysis method. The major areas of this research are as follows. First, a method for the conversion of the qualitative factors into the quantitative factors is developed by combining the Fuzzy Set Theory concept and the Delphi Technique. Second, by using the stochastic network diagram for the dynamic survivability analysis, the aircraft survivability and the probability of kill are calculated from the state probability for the situation during mission. The advantage of the analysis technique developed in this research includes ease of use and flexibility. In other words, in any given aircraft's mission execution under any variable probability density function, the developed computer program is able to analyze and evaluate the aircraft survivability.

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Combining Distributed Word Representation and Document Distance for Short Text Document Clustering

  • Kongwudhikunakorn, Supavit;Waiyamai, Kitsana
    • Journal of Information Processing Systems
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    • v.16 no.2
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    • pp.277-300
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    • 2020
  • This paper presents a method for clustering short text documents, such as news headlines, social media statuses, or instant messages. Due to the characteristics of these documents, which are usually short and sparse, an appropriate technique is required to discover hidden knowledge. The objective of this paper is to identify the combination of document representation, document distance, and document clustering that yields the best clustering quality. Document representations are expanded by external knowledge sources represented by a Distributed Representation. To cluster documents, a K-means partitioning-based clustering technique is applied, where the similarities of documents are measured by word mover's distance. To validate the effectiveness of the proposed method, experiments were conducted to compare the clustering quality against several leading methods. The proposed method produced clusters of documents that resulted in higher precision, recall, F1-score, and adjusted Rand index for both real-world and standard data sets. Furthermore, manual inspection of the clustering results was conducted to observe the efficacy of the proposed method. The topics of each document cluster are undoubtedly reflected by members in the cluster.

Probabilistic bearing capacity of strip footing on reinforced anisotropic soil slope

  • Halder, Koushik;Chakraborty, Debarghya
    • Geomechanics and Engineering
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    • v.23 no.1
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    • pp.15-30
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    • 2020
  • The probabilistic bearing capacity of a strip footing placed on the edge of a purely cohesive reinforced soil slope is computed by combining lower bound finite element limit analysis technique with random field method and Monte Carlo simulation technique. To simulate actual field condition, anisotropic random field model of undrained soil shear strength is generated by using the Cholesky-Decomposition method. With the inclusion of a single layer of reinforcement, dimensionless bearing capacity factor, N always increases in both deterministic and probabilistic analysis. As the coefficient of variation of the undrained soil shear strength increases, the mean N value in both unreinforced and reinforced slopes reduces for particular values of correlation length in horizontal and vertical directions. For smaller correlation lengths, the mean N value of unreinforced and reinforced slopes is always lower than the deterministic solutions. However, with the increment in the correlation lengths, this difference reduces and at a higher correlation length, both the deterministic and probabilistic mean values become almost equal. Providing reinforcement under footing subjected to eccentric load is found to be an efficient solution. However, both the deterministic and probabilistic bearing capacity for unreinforced and reinforced slopes reduces with the consideration of loading eccentricity.

Effect of Si on the Microstructure and Mechanical Properties of Ti-Al-Si-C-N Coatings (Si 함량에 따른 Ti-Al-Si-C-N 코팅막의 미세구조와 기계적 특성의 변화에 관한 연구)

  • Hong, Young-Su;Kwon, Se-Hun;Kim, Kwang-Ho
    • Journal of the Korean institute of surface engineering
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    • v.42 no.2
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    • pp.73-78
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    • 2009
  • Quinary Ti-Al-Si-C-N films were successfully synthesized on SUS 304 substrates and Si wafers by a hybrid coating system combining an arc ion plating technique and a DC reactive magnetron sputtering technique. In this work, the effect of Si content on the microstructure and mechanical properties of Ti-Al-C-N films were systematically investigated. It was revealed that the microstructure of Ti-Al-Si-C-N coatings changed from a columnar to a nano-composite by the Si addition. Due to the nanocomposite microstructure of Ti-Al-Si-C-N coatings, the microhardness of The Ti-Al-Si-C-N coatings significantly increased up to 56 GPa. In addition the average friction coefficients of Ti-Al-Si-C-N coatings were remarkably decreased with Si addition. Therefore, Ti-Al-Si-C-N coatings can be applicable as next-generation hard-coating materials due to their improved hybrid mechanical properties.

Development of Field Programmable Gate Array-based Reactor Trip Functions Using Systems Engineering Approach

  • Jung, Jaecheon;Ahmed, Ibrahim
    • Nuclear Engineering and Technology
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    • v.48 no.4
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    • pp.1047-1057
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    • 2016
  • Design engineering process for field programmable gate array (FPGA)-based reactor trip functions are developed in this work. The process discussed in this work is based on the systems engineering approach. The overall design process is effectively implemented by combining with design and implementation processes. It transforms its overall development process from traditional V-model to Y-model. This approach gives the benefit of concurrent engineering of design work with software implementation. As a result, it reduces development time and effort. The design engineering process consisted of five activities, which are performed and discussed: needs/systems analysis; requirement analysis; functional analysis; design synthesis; and design verification and validation. Those activities are used to develop FPGA-based reactor bistable trip functions that trigger reactor trip when the process input value exceeds the setpoint. To implement design synthesis effectively, a model-based design technique is implied. The finite-state machine with data path structural modeling technique together with very high speed integrated circuit hardware description language and the Aldec Active-HDL tool are used to design, model, and verify the reactor bistable trip functions for nuclear power plants.

The Study of Total Body Modification (TBM) Technique System (Total Body Modification(TBM) 기법에 관한 고찰)

  • Shin, Byung-Cheul;Woo, Young-Min
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.1 no.1
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    • pp.61-71
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    • 2006
  • Objectives : To introduce Total Body Modification(TBM) technique system developed by Dr. Victor Frank DC, DO, ND through combining chiropractic manipulation with osteopathy, acupuncture meridian system, and naturopathy based on his long-time clinical experiences and insights. Methods : After investigating the art, philosophy and science of TBM thechnique, and applying TBM practice under private clinical situation, we compared It with Chuna Korean manual medicine and oriental medicine system. Results : This system deals with correcting human body's functional physiology to potentiate in a favorable manner. TBM uses a neuromuscular reflex test and body access meridian points to tap into the body's biocomputer and read functional programs. Corrections are usually made by means of special respiratory spinal adjustment, cranial, soft tissue, or specific joint manipulation. Conclusions : We found similarities between TBM and Chuna system in the view of Korean Traditional meridian concept. The special combinations and sequences of various alarm points and associated points have clinical effects on the treatment of chronic spinal subluxation pattern. This suggests TBM has significance In the point of the future evolution of Chuna manual medicine in Korea.

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Applications of Scanning Electrochemical Microscopy (SECM) Coupled to Atomic Force Microscopy with Sub-Micrometer Spatial Resolution to the Development and Discovery of Electrocatalysts

  • Park, Hyun S.;Jang, Jong Hyun
    • Journal of Electrochemical Science and Technology
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    • v.7 no.4
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    • pp.316-326
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    • 2016
  • Development and discovery of efficient, cost-effective, and robust electrocatalysts are imperative for practical and widespread implementation of water electrolysis and fuel cell techniques in the anticipated hydrogen economy. The electrochemical reactions involved in water electrolysis, i.e., hydrogen and oxygen evolution reactions, are complex inner-sphere reactions with slow multi-electron transfer kinetics. To develop active electrocatalysts for water electrolysis, the physicochemical properties of the electrode surfaces in electrolyte solutions should be investigated and understood in detail. When electrocatalysis is conducted using nanoparticles with large surface areas and active surface states, analytical techniques with sub-nanometer resolution are required, along with material development. Scanning electrochemical microscopy (SECM) is an electrochemical technique for studying the surface reactions and properties of various types of electrodes using a very small tip electrode. Recently, the morphological and chemical characteristics of single nanoparticles and bio-enzymes for catalytic reactions were studied with nanometer resolution by combining SECM with atomic force microscopy (AFM). Herein, SECM techniques are briefly reviewed, including the AFM-SECM technique, to facilitate further development and discovery of highly active, cost-effective, and robust electrode materials for efficient electrolysis and photolysis.