• Proceedings of the Korean Information Science Society Conference
• /
• 2011.06b
• /
• pp.33-36
• /
• 2011

본 논문에서는 SMART(Self-Monitoring Analysis and Reporting Technology)를 기반으로 SSD(Solid State Drives) 저장 장치의 신뢰성을 분석할 수 있는 방법론과 도구를 제안한다. 방법론은 SSD를 구성하는 플래시 메모리의 결함 종류, 결함들을 효과적으로 모니터링 할 수 있는 SMART 속성과 임계값, 그리고 이를 기반으로 SSD의 신뢰성을 예측할 수 있는 모델로 구성된다. 이 방법론은 신뢰성 분석 도구로 구현 되었으며, 이 도구는 Workload generator, SMART monitor, Dependability analyzer, 그리고 GUI viewer로 구성된다. 실제 두 회사에서 생산한 6개의 SSD를 이용하여 실험한 결과, SMART를 기반으로 SSD의 고장 예측이 가능하며, 여러 속성들을 동시에 고려하였을 때 예측의 정확도가 높아짐을 발견하였다.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.7
• /
• pp.151-157
• /
• 1999

Vibrations in machine tools make many problems in precision, production efficiency, and machine performance. The relative vibration between a workpiece and a tool is very complicated due to many sources. In this study, the dynamic characteristics of a newly developed CNC lathe were analyzed and its chatter characteristics were predicted by a chatter analysis method using finite element analysis and 3 dimensional cutting dynamics. The simulated results showed very complex characteristics of chatter vibration and the borderline of limiting depth of cut was used as the stability limit. To check the validity of this method, cutting tests were done in the CNC lathe using a boring bar as a tool because boring process is very weak due to long overhang . The experimental results showed that the simplified borderline was to be considered as limiting depth of cut at which the chatter vibration starts and the stability limits depended on various cutting parameters such as cutting speed, feed and nose radius of tool.

• Korean Journal of Psychosomatic Medicine
• /
• v.10 no.2
• /
• pp.176-180
• /
• 2002

Hypnosis as a traditional healing method, in its recent development, has generated a multitude of techniques. These serve as practical tools which can be combined with other therapy techniques for the treatment of a variety of psychiatric and medical conditions. The empirical evidence for the effectiveness of hypnosis is considerable and proves its clinical impact in various areas of application. This case review describes the integration of hypnotherapeutic methods into the continuum of psychiatric encounters in a general practice. Guidelines for the application of hypnosis in approaching and treating each patients with headache, sexual dysfunction and bronchial asthma were illustrated. As hypotheses mechanism of effectiveness in psychosomatic disorders has been formulated. Training in hypnotherapy provides the psychiatrist with skills needed to address psychophysiological disorders. Emphasis is placed on the necessity and opportunity for research on the efficacy and specific technique of hypnosis in the psychosomatic disorders.

• Fisheries and Aquatic Sciences
• /
• v.14 no.2
• /
• pp.138-147
• /
• 2011

Modeling fishing-gear systems is essential to better understand the factors affecting their movement and for devising strategies to control movement. In this study, we present a generalized mathematical modeling methodology to analyze fishing gear and its various components. Fishing gear can be divided into a finite number of elements that are connected with flexible lines. We use an algorithm to develop a numerical method that calculates precisely the shape and movement of the gear. Fishinggear mathematical models have been used to develop software tools that can design and simulate dynamic movement of novel fishing-gear systems. The tool allowed us to predict the shape and motion of the gear based on changes in operation and gear design parameters. Furthermore, the tool accurately calculated the swept volume of towed gear and the surrounding volume of purse-seine gear. We analyzed the fished volume for trawl and purse-seine gear and proposed a new definition of fishing effort, incorporating the concept of fished space. This method may be useful for quantitative fishery research, which requires a good understanding of the selectivity and efficiency of fishing gear used in surveys.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.6 no.4
• /
• pp.22-27
• /
• 2007

This study aims to find the optimal cutting conditions, when ellipse mirrors consisted Aluminum alloy were made it the Millimeter-Wave Interferometer System mirror with several tools on the High-Speed Machine. Machining technique for precision machining characteristics of ellipse mirrors consisted Al6061 matter by Ball endmill is reported in this paper., Results of machining on the High-Speed Machine(using NCD(Natural Crystalline diamond), WC and coated TiAlN ${\phi}6mm$ ball endmill tool) had measurement of surface roughness and form accuracy with cutting conditions(the Feed rate, the Depth of cut and the Cutting speed). the Millimeter-Wave Interferometer System ellipse mirror had been machined foundational precision machining characteristics of aluminum.

• International Journal of Precision Engineering and Manufacturing
• /
• v.6 no.3
• /
• pp.45-50
• /
• 2005

This paper proposed an efficient manufacturing system using the OMM (on-machine measurement) system. The OMM system is software-based 3D modeler for inspection on machine, and it is interfaced with machine tools via RS232C. The software is composed of two inspection modules; one is touch probe operating module, and the other is laser displacement sensor operating module. The module for touch probe needs the inspection feature extracted from CAD data. The touch probe moves to workpiece by three operating modes as follows: manual, general and automatic mode. The operating module of the laser displacement sensor is used to inspect profiles and very small holes. An advantage of this inspection method is the ability to execute on-line inspection during machining or afterward. The efficiency of proposed system which can predict and define the machining errors of each process was verified, so the developed system was applied to inspect a mold-base (cavity, core).

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.29 no.6 s.237
• /
• pp.763-771
• /
• 2005

This paper is an experimental study on the performance according to a capillary tube diameter and length in a domestic small multi refrigerator[kimchi refrigerator]. Pressure drop in a capillary tube is predicted by theoretical analysis and experimental method as the reduction of capillary tube diameter from 0.74 to 0.6 mm. The differences between experimental results and analytical results are mainly caused by friction factor in a capillary tube. Because there are no adequate equations used to calculate pressure drop of capillary tube diameter under 1.0mm. The empirical equations necessary for interpretation of capillary tube were derived from capillary tube test results data using curve fitting method. This study shows that the optimized designs of system, which is capillary tube length and refrigerant charge amount, are 2000mm, 83g at the capillary tube diameter 0.6mm and 3000mm, 73g at the capillary tube diameter 0.74mm. And capillary design tools and system matching techniques necessary for development of the kimchi refrigerator were also developed through this study.

• Journal of the Korean Society for Precision Engineering
• /
• v.26 no.1
• /
• pp.120-129
• /
• 2009

An internal lobe pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other various applications. In particular, the pump is an essential machine element of an automotive engine to feed lubricant oil. The subject of this paper is the theoretical analysis of internal lobe pump whose the main components are the rotors: usually the outer one is characterized by lobes with elliptical shape, while the inner rotor profile is determined as conjugate to the other. And the integrated system which is composed of three main modules has been developed through AutoLISP under AutoCAD circumstance. It generates new lobe profile and calculates automatically the flow rate and flow rate irregularity according to the lobe profile generated. Results obtained from the analysis enable the designer and manufacturer of oil pump to be more efficient in this field.

• Bulletin of the Korean Mathematical Society
• /
• v.33 no.1
• /
• pp.119-126
• /
• 1996

In this paper we study the asymptotic behavior of the edge independence number of a random (n,n)-tree. The tools we use include the matrix-tree theorem, the probabilistic method and Hall's theorem. We begin with some definitions. An (n,n)_tree T is a connected, acyclic, bipartite graph with n light and n dark vertices (see [Pa92]). A subset M of edges of a graph is called independent(or matching) if no two edges of M are adfacent. A subset S of vertices of a graph is called independent if no two vertices of S are adjacent. The edge independence number of a graph T is the number $\beta_1(T)$ of edges in any largest independent subset of edges of T. Let $\Gamma(n,n)$ denote the set of all (n,n)-tree with n light vertices labeled 1, $\ldots$, n and n dark vertices labeled 1, $\ldots$, n. We give $\Gamma(n,n)$ the uniform probability distribution. Our aim in this paper is to find bounds on $\beta_1$(T) for a random (n,n)-tree T is $\Gamma(n,n)$.

• Proceedings of the KIEE Conference
• /
• 1999.11b
• /
• pp.219-221
• /
• 1999

HVDC(High Voltage Direct Current) transmission system was constructed between Cheju island and mainland Haenam and has been operating commercially since 1998. But research activities in this area are not so much. That is caused by the facts that HVDC is large scale system and it is not so easy to implement and to test. Though such simulation tools as RTDS(Real Time Digital Simulator) and EMTDC can be useful, these have limitations for actual control and protective system design. Therefore scaled-down HVDC model was developed for the purpose of researches at operating technique, control and protection methods. The design of this model was based on real Cheju-Haenam HVDC system. And additionally faults simulator such as ground fault, short-circuit and change of impedance in transmission line is equipped for analysis of these faults. Control system of the model was implemented fully digitally. So it is very easy for the researchers to develope control and protection algorithm and to test the performance.