• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.6
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• pp.655-660
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• 2003

In general, Support Vector Machine has a good performance in binary classification, but it has the limitation on multi-pattern classification. So, we proposed an Import Vector Voting model for two or more labels classification. This model applied kernel bagging strategy to Import Vector Machine by Zhu. The proposed model used a voting strategy which averaged optimal kernel function from many kernel functions. In experiments, not only binary but multi-pattern classification problems, our proposed Import Vector Voting model showed good performance for given machine learning data.

• Journal of Digital Convergence
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• v.12 no.3
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• pp.69-77
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• 2014

Because smart televisions (TVs) have various and innovative functions that are different from traditional TVs, consumers are front with a complex decision-making problem when they want to buy a best TV among alternatives made by many TV makers. TV manufactures have developed and announced different types of smart TV models and they need a comparative study for evaluating their characteristics. In this paper, we suggest the Analytic Hierarchy Process(AHP) method for deciding the best smart TVs regarding many selection criteria. The method provides a decision support for consumers who like to purchase a smart TV. We describe criteria affecting the smart TV selection through a literature review and suggest a user testing method in order to derive accurate judgments from consumers. Using the Expert Choice software package, we show a an numerical example how the priority of smart TVs are computed.

• 한국벤처창업학회:학술대회논문집
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• 2010.08a
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• pp.263-288
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• 2010

본 연구에서는 현재 사업을 운영하고 있는 사업자와 사업을 운영하지 않고 있는 잠재창업자인 20세 이상 남녀를 조사대상으로 사업에 대한 태도 및 위험인지가 여러 특성에 따라 어떤 차이가 있는지 그리고 어떤 변수들에 의해 영향 받는지를 조사하였다. 또한, 태도 행동 모델과 소비자의사결정 모델을 응용하여 사업태도와 위험인지 변수가 창업 및 사업유지의사에 미치는 영향력을 조사하였다. 본 연구결과를 정리 요약하면 다음과 같다. 첫째, 분산분석결과 남성, 비전문직 종사자, 부모가 창업경험을 가진 경우 사업에 대한 태도가 긍정적인 것으로 나타났다. 한편, 취업하지 않은 경우, 연령이 40대 이상인 경우, 과거 사업경험이 있는 경우 사업에 대한 위험인지 수준이 높은 것으로 드러났다. 둘째, 남성, 부모가 창업한 경험이 있는 경우, 자아실현의 창업동기를 갖는 경우 창업의사가 강한 것으로 드러났다. 한편, 사업실패경험이 없는 경우, 101억부터 1천억 사이의 매출액을 갖고 있는 사업체 운영자, 긍정적인 사업태도를 가진 경우 사업유지의사가 높은 것으로 나타났다. 셋째, 남성, 비전문직에 취업한 경우, 사업경험이 있는 경우 사업에 대한 태도가 긍정적인 것으로 드러났다. 한편, 연령이 높은 경우, 취업하지 않은 경우, 사업경험이 있는 경우 사업에 대한 위험인지 수준이 높은 것으로 드러났다. 끝으로, 남성, 취업하지 않은 경우, 사업에 대한 태도가 긍정적인 경우, 부모가 창업을 한 경험이 있는 경우 창업에 대한 의사가 강한 것으로 드러났다. 한편, 긍정적인 사업태도, 사업실패경험이 없는 경우 사업유지의사가 강한 것으로 드러났다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.8
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• pp.2508-2515
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• 1996

Determination of an optimal feed rate is valuable in the sense of the precision and efficient machining. In this regard, a new surface roughness model for the face milling operation that considered the radial and axal runouts of the inserts in the cutter body was developed. The validity of the model was proved through the cutting experiments, and the model is able to predict the real machined surface roughness exactly with the information of the insert runouts and the cutting conditions. From the estimated surface roughness value, the maximum feed rate that obtains a maximum naterial removal rate under the given surface roughness constraint can be selected by using a bisection method. Therefore, this mehod for optimizing the feed rate can be well applied to the using a bisection method. Therefore, this method for optimizing the feed rate can be well applied to the using selsction of the cutting condition during the NC data generation in CAM.

• Korean Journal of Computational Design and Engineering
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• v.11 no.5
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• pp.335-343
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• 2006

Design changes for an original surface model are frequently required in a manufacturing area: for example, when the physical parts are modified or when the parts are partially manufactured from analogous shapes. In this case, an efficient 3D model updating method by locally adding scan data for the modified area is highly desirable. For this purpose, this paper presents a new procedure to update an initial model that is composed of combinatorial triangular facets based on a set of locally added point data. The initial surface model is first created from the initial point set by Tight Cocone, which is a water-tight surface reconstructor; and then the point cloud data for the updates is locally added onto the initial model maintaining the same coordinate system. In order to update the initial model, the special region on the initial surface that needs to be updated is recognized through the detection of the overlapping area between the initial model and the boundary of the newly added point cloud. After that, the initial surface model is eventually updated to the final output by replacing the recognized region with the newly added point cloud. The proposed method has been implemented and tested with several examples. This algorithm will be practically useful to modify the surface model with physical part changes and free-form surface design.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.423-425
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• 2017

When many space launchers and rockets need to be separated, the pyrotechnic separators have been widely used because of their high reliability and high energy generation. However, intensive pyroshock and debris from the high-explosive type separator may cause fatal damage to the equipment inside of the space launchers or rockets. To solve this problem, a pressure-cartridge type low-impact separator has been developed. In this study, one of the low-impact separators, the split-type pyrolock, was used. We established a mathematical model for the split-type pyrolock that simulates the state of combustion gas and the separation behavior of four independent internal components and verified the mathematical model through comparing with experiment results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.315-320
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• 2006

This paper describes access control, user authentication, and User Security and Encryption technology for the construction of database security system from network users. We propose model of network encrypted database security system for combining these elements through the analysis of operational and technological elements. Systematic combination of operational and technological elements with proposed model can construct encrypted database security system secured from unauthorized users in distributed computing environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1343-1354
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• 2007

Secondary batteries become more important in our lives as the use of portable electric devices, such as camera, cellular phone, laptop, etc. Especially, because of their high energy densities and high voltage, lithium-ion batteries are being used in many systems. For the optimum design of such systems which include lithium-ion batteries, virtual prototype is required generally. However, since the complex chemical and physical processes are involved, the behavior of battery becomes harder to be predicted compared with that of electric and mechanic devices. This paper, proposes a new static model of lithium secondary battery, which accounts for nonlinear equilibrium potentials, rate and temperature dependencies, thermal effects, lifetime characteristic. The results of the simulation of the model are analysed and compared with experimental data to inspect their validity.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.5
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• pp.541-545
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• 2010

AUTOSAR, a standard software platform for automotive, has been developed to manage software complexity and improve software reuseability. However reuse of test system is difficult because it is dependant on implementation language and test phase. In this paper, we suggest a test system generation method for AUTOSAR software component using TTCN-3, a standardized testing language. TTCN-3 test system is generated automatically from AUTOSAR XML containing software design information. The test system consists of TTCN-3 tester and target system and tests functionality and worst case response time of software under simulation environment. With the proposed testing techniques we can reduce time and effort to build the testing system and reuse testing environment.

• Nuclear Engineering and Technology
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• v.19 no.3
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• pp.198-204
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• 1987

A plant simulation code, MCSIM (Micro-Computer SIMulator), has been developed to simulate plant transient accidents for pressurized water reactors. Reactor coolant system is modeled using decoupled energy and momentum equations, drift flux two-phase flow model and integral momentum equation. A two-fluid pressurizer model is used to simulate the pressurizer dynamics. Pot Boiler model is used for steam generator, steady-state decoupled energy and momentum equations for secondary side system, and point kinetics equations for nuclear power calculation. For test of the present version of MCSIM, complete loss of flow and RCCA withdrawal accidents are calculated with MCSIM. The results are compared with those in FSAR of KNU 5 & 6.