• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.88-90
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• 2003

We reported an AC PDP structure with grooved front panel dielectric layer. The structure exhibits low breakdown voltage, better luminance, and better endurance to crosstalk in high Xe contents. It also shows less luminous efficacy then conventional structure because of the thinner dielectric layer, but we can apply the higher Xe contents to the grooved dielectric structure, which results in the higher luminous efficacy. We made experiments with the Xe contents from 4 to16% and total gas pressure from 400 to 600Torr. The grooved dielectric structure shows the improvement of 20% luminous efficacy and 17% luminance. The firing voltages lower about 40V at 600Torr and Xe 12, 16%. The discharge characteristics of grooved dielectric structure are verified also with 2D simulation.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.528-535
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• 2011

According to railway safety regulations for securing the railway vehicle's quality and performance, it can be partly exempted that the performance tests and production inspections on the railway vehicles which are produced and assembled for the purpose of test and research. The reasons of this exemption are for ensuring maximum autonomy and for saving time considered the development period of railway vehicle. However, it was continuously demanded the necessity of supplementation on the confirmation about railway vehicle's quality & performance. Therefore, we added "The monitoring step" which is for securing the quality and performance in high speed railway vehicle's subsystem & compartment to supplement those tests & inspections in development. In this paper, based on a standard ABS(Activity Breakdown Structure) of railway vehicle and a WBS(Work Breakdown Structure) of the railway vehicle system, we investigate the necessity of monitoring in the High speed railway vehicle development. And by comparing and analyzing the essential requirements of international standard, IRIS(International Railway Industry Standard) & TSI(Technical Specification for Interoperability), we try to examine a standard monitoring procedure.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.11
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• pp.1571-1577
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• 2013

Electrical tree structure is one of the most important influencing factors for electrical treeing characteristics in polymers. In this paper, we focused on the structure characteristics of electrical treeing in epoxy resins (original) insulation under different high-frequency voltages (60, 500, 1000Hz). Effects of voltage frequency on the ac electrical treeing phenomena in an epoxy resins were carried out in needle-plate electrode arrangement. To measure the treeing initiation and propagation, and the breakdown rate, constant AC of 10 kV with three different voltage frequencies (60, 500 and 1,000 Hz) was applied to the specimen in needle-plate electrode specimen at $30^{\circ}C$ of insulating oil bath. At 60 Hz, the treeing initiation time was 360 min and the propagation rate was $6.85{\times}10^{-4}mm/min$, and the morphology was dense branch type. As the voltage frequency increased, the treeing initiation time decreased and the propagation rate increased. At 1,000 Hz, the treeing initiation time was 0 min and the propagation rate was $7.81{\times}10^{-2}mm/min$, and the morphology was dense bush type.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.241-246
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• 2008

Design of a high-speed railway line requires collaboration of heterogeneous application systems and of engineers with different background. Object-based 3D models with metadata can be a shared information model for the effective collaborative design. In this paper, railway infrastructure information model is proposed to enable integrated and inter-operable works throughout the life-cycle of the railway infrastructures, from planning to maintenance. In order to develop the model, object-based 3-D models were built for a 10km railway among Korea high-speed railway lines. The model has basically three information layers for designers, contractors and an owner, respectively. Prestressed concrete box-girders are the most common superstructure of bridges. The design information layer has metadata on requirements, design codes, geometry, analysis and so on. The construction layer has data on drawings, real data for material and products, schedules and so on. The maintenance layer for the owner has the final geometry, material data, products and their suppliers and so on. These information has its own data architecture which is derived from similar concept of product breakdown structure(PBS) and work breakdown structure(WBS). The constructed RIIM for the infrastructures of the high-speed railway was successfully applied to various areas such as design check, structural analysis, automated estimation, construction simulation, virtual viewing, and digital mock-up. The integrated information model can realize virtual construction system for railway lines and dramatically increase the productivity of the whole engineering process.

• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.1023-1029
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• 2007

우리는 국가 경쟁력의 한 분야인 사업관리에 있어 계획, 수행, 성과관리, 개선에 최적의 프로세스 보유가 요구된다. 그러나 Project관리체계의 현 실태는 일정관리, 범위관리, 비용관리에 초점을 맞춘 일정관리체계, WBS(Work Breakdown Structure) 및 OBS(Organizational Breakdown Structure)관리, 비용관리체계의 부분 통합 혹은 서로의 연계 정도이다. 본 연구는 최적의 사업관리를 위하여 계약관리에 체계공학을 연계하여 계약 전에 WBS, IMP/IMS(Integrated Master Plan)/(Integratcd Master Schedule), TPM(Technical Performance Measurement) 등의 SEP(Systems Engineering Plan)와 계약 후의 이행을 검증 할 수 있는 과정의 Guideline을 제시하고, IEEE 1220, ANSI/EIA 632 순기 의거 개념설계부터 통합시험에 이르는 체계공학 순기에 따른 비용예측이 가능한 USC(University of Southern CalIfornia) 대학의 COSYSMO (Constructive Systems Engineering Cost ModeI)를 소개하고 적용 가능성을 고찰하며, Project의 전순기에 걸쳐 TPM 혹은 Quality를 비용과 일정에 통합하여 관리하는 PBEV(Performance Based Earned Value)모델을 소개하고 적용 가능성을 제시한다. Project 관리에 있어 System 차원을 강조한 SE(Systems Engineering), 비용예측의 CM(Cost Management), 성과관리를 위한 EVM(Earned Value Management)의 통합은 사업 관리에 역량을 강화하며 경쟁력을 향상 시킬 수 있는 적절한 접근으로 사료된다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.207-213
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• 1999

Thirty-eight glutinous rice varieties were classified into nine groups on the scatter diagram by the upper two principal components (56% contribution to the total information) based on eleven physicochemical characteristics including the viscograms and physical properties of cooked rice. The first principal component was the factor mainly associated with the viscogram characteristics of rice flour emulsion and the second was the factor chiefly related to the physical properties of cooked rice and water absorbability of rice grain. Indica glutinous rices were clearly distinguished from japonica ones by the first principal component score. Javanica glutinous rices were widely distributed on the intermediate zone between indica and japonica or on several japonica rice groups. Significant positive or negative correlations were found among water absorption rates of rice grain, physical properties of cooked rice, and viscogram characteristics of rice flour. Especially in japonica glutinous rices, the breakdown and setback viscosities of rice flour were closely associated with the alkali digestion value of milled rice and the stickiness of cooked rice. The frequency ratio of short glucose chains (A-chain) to intermediate glucose chains (B-chain), the ratio of B- chains to long glucose chains (C-chain) and the relative frequency of A- or B-chain fractions representing the amylopection structure of rice starch was closely associated with the breakdown and setback viscosities of rice flour.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.43-44
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• 2009

3D bridge information models for a concrete box-girder bridge were built and a typical application example for the estimation linked with the 3D models was proposed. 3D geometry objects with PBS (product breakdown structure) were constructed using standard classification codes and 2D drawings. Information on the amount of materials according to the classification codes was utilized for the estimation system. A process for the estimation of concrete and rebars was developed and verified through the pilot test. Optimization of rebar fabrication was suggested as an additional function and was utilized for the cost reduction and standard fabrication.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.384-387
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• 2004

It is very important to manage the risk in building construction because construction process has too many internal risk compared with others. So construction managers need more developed risk management system than the Present. While the study for the solution and management of generated risk is comparatively enough, the effort to confirm the risk of construction phase on pre-construction phase haying an major effect on total duration, is insufficient. For supporting the schedule risk management of pre-construction, this study suggests the reclassified risk breakdown structure and the investigation form for advance preparations on pre-construction Phase, which help the Poorly experienced construction manager to make more correct decisions and efficiently to execute risk management.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.7
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• pp.546-550
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• 2001

A new Lateral Trench Insulated Gate Bipolar Transistor(LTIGBT) with p$^{+}$ diverter was proposed to improve the characteristics of the conventional LTIGBT. The forward blocking voltage of the proposed LTIGBT with p$^{+}$ diverter was about 140V. That of the conventional LTIGBT of the same size was 105V. Because the p$^{+}$ diverter region of the proposed device was enclosed trench oxide layer, he electric field moved toward trench-oxide layer, and punch through breakdown of LTIGBT with p$^{+}$ diverter was occurred, lately. Therefore, the p$^{+}$ diverter of the proposed LTIGBT didn't relate to breakdown voltage in a different way the conventional LTIGBT. The Latch-up current densities of the conventional LTIGBT and proposed LTIGBT were 540A/$\textrm{cm}^2$, and 1453A/$\textrm{cm}^2$, respectively. The enhanced latch-up capability of the proposed LTIGBT was obtained through holes in the current directly reaching the cathode via the p$^{+}$ divert region and p$^{+}$ cathode layer beneath n$^{+}$ cathode layer./ cathode layer.

• Korean Journal of Construction Engineering and Management
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• v.1 no.1 s.1
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• pp.53-62
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• 2000

This study proposes FREES(Fuzzy Risk Evaluation Expert System) for analyzing and evaluating risks occurring during the construction process. The feasibility of this system model was tested by virtual scenario. For the development of the model, at first, risk breakdown structure was established based on risks identified in the existing researches, that is quantitative and qualitative. FREES can reflect human cognition process in the risk analysis and evaluation by adopting artificial intelligence fuzzy theory, differentiating the existing quantitative analysis model. The FREES can be applied to all the project phases from planning to operation & maintenance stage.