• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.613-616
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• 1999

An active-matrix LCD using thin film transistors (TFTs)has been widely recognized as having potential for high-quality color flat-panel displays. Pixel-Design Array Simulation Tool (PDAST) was used to profoundly understand the gate signal distortion and pixel charging capability, which are the most critical limiting factors for high-quality TFT-LCDs. Since PDAST can simulate the gate data and pixel voltages of a certain pixel on TFT array at any time and at any location on an array, the effect of the new set of capacitance models on the pixel operations can be effectively analyzed, The set of models which is adopted from VLSI interconnections calculate more precise capacitance. The information obtained from this study could be utilized to design the larger area and finer image quality panel.

• 한국항만경제학회지
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• 제27권3호
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• pp.135-146
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• 2011

오늘날 물류산업은 인수 합병을 통해 거대기업으로 전환되고 있으며, 세계물류시장에서의 경쟁은 점차 치열해지고 있다. 이에 우리나라 정부는 글로벌 경쟁력을 갖춘 물류기업으로 육성하기 위하여 관련기업들의 수직적 또는 수평적 통합을 추진하고 있다. 이의 일환으로 종합물류기업 인증제도를 시행하여 동북아 물류시장의 중심지화 전략을 추구하고 있다. 그런데 종합물류기업의 경쟁력에 있어서 효율성은 대단히 중요한 비중을 차지한다. 이에 본 고는 대형물류기업에 초점을 두고 효율성을 도출한 후 효율성에 영향을 미치는 요인을 식별한다. 토빗분석을 통해 자산, 자본금, 종업원 수의 증가가 효율성을 증가시킨다는 것과 자산의 영향력이 가장 크다는 것을 보인다. 또한 패널분석을 통해 자산, 자본금, 종업원이 매출액 증가에 긍정적 영향을 미친다는 것도 보인다. 이러한 패널분석결과가 장기분석과 부합하는가를 조사하기 위하여 패널공적분벡터를 이용하여 그룹공적분벡터가 양의 부호로 유의하다는 것과 자산과 종업원의 영향력이 별다른 차이를 보이지 않은 패널분석에 비해 장기에서는 상당한 차이를 보인다는 것을 밝힌다.

• 한국농공학회논문집
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• 제47권3호
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• pp.29-37
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• 2005

This study was carried out to file up structural design data for optimizing Pleurotus eryngii growing houses. Design data are including current farm status of Pleurotus eryngii growing houses in the aspect of structural configuration as well as environmental conditions to be controlled and maintained inside. A structural analysis was performed for the on-farm structures as well as some structures modified and suggested through field survey and analysis. The results are summarized as follows. According to the results of status analysis, Pleurotus eryngii growing houses were categorized as arch-roofed simple type and sandwich panel type. Though the size of Pleurotus eryngii cultivation facilities were considerably diverse, the basic dimensions of Pleurotus eryngii cultivation facilities showed relatively similar pattern: more or less of 20m of length, $6.6\~7.0m$ of width, $4.6\~5.0m$ of peak height, $1.2\~1.6m$ of bed width, and 4 layers of bed. In the aspect of spatial use of cultivation facilities, suggested models were shown to be mostly reasonable in the aspect of heating and cooling, micro-meteorological stability, land use efficiency per unit floor area, etc.. Especially, the standard models suggested so far were thought to be not efficient in its surface area and spatial volume per unit floor area as well as its uneffective structural design in the area around ceiling. In the results of structural analysis for the models suggested through this study by using those section frames to be found on farms, the panel type structures of both single span and double span were estimated to be over designed, whereas arch-roofed pipe houses were mostly found to be under-designed.

• 대한조선학회논문집
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• 제50권5호
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• pp.314-323
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• 2013

Production simulation technology is beneficial to solve the complicated and fluctuated problems in a shipyard. It takes too much time and effort to build simulation models in the field, though. This research proposes a feasible method to reduce the difficulties related to simulation modeling for the factory or shop capacity analysis. In addition, a proposed neutral data format for production information is efficient to manage information acquisition for simulation modeling automation. A panel block shop model is contributed to comparison between the conventional technique and the automated one. The automation technique is highly recommended to run a rapid simulation in the shipyard problem.

• Earthquakes and Structures
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• 제23권6호
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• pp.549-580
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• 2022

This paper assesses the influences of modeling assumptions and uncertainties on the performance of the non-linear finite element (FE) model updating procedure and model clustering method. The results of a shaking table test on a four-story steel moment-resisting frame are employed for both calibrations and clustering of the FE models. In the first part, simple to detailed non-linear FE models of the test frame is calibrated to minimize the difference between the various data features of the models and the structure. To investigate the effect of the specified data feature, four of which include the acceleration, displacement, hysteretic energy, and instantaneous features of responses, have been considered. In the last part of the work, a model-based clustering approach to group models of a four-story frame with similar behavior is introduced to detect abnormal ones. The approach is a composition of property derivation, outlier removal based on k-Nearest neighbors, and a K-means clustering approach using specified data features. The clustering results showed correlations among similar models. Moreover, it also helped to detect the best strategy for modeling different structural components.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.733-738
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• 2006

As the film transistor-liquid crystal display (TFTLCD) panels become larger and provide higher resolution, the propagation delay of row and column lines, the voltage modulation of Vcom, and the response time of liquid crystal affect the display images now more than in the past. It is more important to understand the electrical characteristic of TFT-LCD panels these days. This paper describes the electrical model of a 15-inch XGA ($1024{\times}768$) TFT-LCD panel. The parasitic resistance and capacitance of its panel are obtained by 3D simulation of a sub pixel. The accuracy of these data is verified by the measured values in an actual panel [1]. The developed panel simulation platform, the equivalent circuit of a 15-inch XGA panel, is simulated by HSPICE. The results of simulation are compared with those of experiment, according to changing the width of signal. Especially, the proposed simulation platform for modeling TFTLCD panels can be applied to large size LCD TVs. It can help panel and circuit designers to verify their ideas without making actual panels and circuits.

• 수산경영론집
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• 제46권3호
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• pp.103-118
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• 2015

The purpose of this paper is to discuss possibilities of applying growth curve models, such as Logistic, Log-Logistic, Log-Normal, Gompertz and Weibull, to three specific technology areas of Fishery Science and Technology in the process of measuring their technology level between Korea and countries with the state-of-the art level. Technology areas of hazard control of organism, environment restoration, and fish cluster detect were selected for this study. Expert panel survey was conducted to construct relevant panel data for years of 2013, 2016, and a future time of approaching the theoretical maximum technology level. The size of data was 70, 70 and 40 respectively. First finding is that estimation of shape and location parameters of each model was statistically significant, and lack-of-fit test using estimated parameters was statistically rejected for each model, meaning all models were good enough to apply for measuring technology levels. Second, three models other than Pearl and Gompertz seemed very appropriate to apply despite the fact that previous case studies have used only Gompertz and Pearl. This study suggests that Weibull model would be a very valid candidate for the purpose. Third, fish cluster detect technology level is relatively higher for both Korea and a country with the state-of-the-art among three areas as of 2013. However, all three areas seem to be approaching their limits(highest technology level point) until 2020 for countries with the state-of-the-art. This implies that Korea might have to speed up her research activities in order to catch up them prior to 2020. Final suggestion is that future study may better apply various and more appropriate models respectively considering each technology characteristics and other factors.

• Steel and Composite Structures
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• 제43권3호
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• pp.327-340
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• 2022

A vast amount of experimental and analytical research has been conducted related to the seismic behavior and performance of concrete filled steel tubular (CFT) columns. This research has resulted in a wealth of information on the component behavior. However, analytical and experimental data for structural systems with CFT columns is limited, and the well-known behavior of steel or concrete structures is assumed valid for designing these systems. This paper presents the development of an analytical model for nonlinear analysis of composite moment resisting frame (CFT-MRF) systems with CFT columns and steel wide-flange (WF) beams under seismic loading. The model integrates component models for steel WF beams, CFT columns, connections between CFT columns and WF beams, and CFT panel zones. These component models account for nonlinear behavior due to steel yielding and local buckling in the beams and columns, concrete cracking and crushing in the columns, and yielding of panel zones and connections. Component tests were used to validate the component models. The model for a CFT-MRF considers second order geometric effects from the gravity load bearing system using a lean-on column. The experimental results from the testing of a four-story CFT-MRF test structure are used as a benchmark to validate the modeling procedure. An analytical model of the test structure was created using the modeling procedure and imposed-displacement analyses were used to reproduce the tests with the analytical model of the test structure. Good agreement was found at the global and local level. The model reproduced reasonably well the story shear-story drift response as well as the column, beam and connection moment-rotation response, but overpredicted the inelastic deformation of the panel zone.

• Communications for Statistical Applications and Methods
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• 제2권2호
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• pp.129-134
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• 1995

The ordinary least square estimator of the disturbance variance in the pooled cross-sectional and time series regression model is shown to be asymptotically unbiased without any restrictions on the regressor matrix when the disturbances follow an equicorrelated error component models.

• 대한교통학회지
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• 제20권6호
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• pp.129-140
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• 2002

본 연구에서는 개인의 사회, 경제적 특성과 활동참여, 통행행동의 관계를 규명하기 위하여 개인의 사회 경제적 특성을 시간 변동 외생변수와, 시간 불변동 외생변수로 설정하고 개인의 활동참여와 통행행동에 관한 변수를 내생변수로 설정하여 모형을 구축하였다. 모형의 실효성을 검증하기 위하여 분석에 사용된 자료는 1991년, 1992년 미국 Puget Sound 지역의 Transportation Survey 자료를 이용하였으며, Panel 자료의 변수 간 복잡한 상호관계를 규명해 내기 위하여 Dynamic Structural Equation Model을 구축하였다. 활동참여와 통행행 동에 관한 10개의 내생변수와 개인의 사회, 경제적 특성인 10개의 외생변수를 사용하여 모형추정을 한 결과, 개인의 생계활동에 의해 유지활동과 여가활동은 시간적 제약을 받고, 여가활동은 유지활동에 제약을 받게 된다는 것을 알게 되었으며, 개인의 사회경제지표에 의해 영향을 받는 것으로 나타났다. 또한, 개인의 활동 패턴은 과거 연도의 각 활동 지속시간과 통행패턴에 영향을 받는 것으로 나타나 Panel 자료 분석의 필요성이 부각되었다. 본 연구의 결과로부터 보다 충실한 활동기반모형의 구축을 위해서는 Panel 자료의 구축의 필요성이 더욱 요구된다.