• Communications for Statistical Applications and Methods
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• 제22권6호
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• pp.543-556
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• 2015

We present a survey of contributions that defined the nature and extent of robust statistics for the last 50 years. From the pioneering work of Tukey, Huber, and Hampel that focused on robust location parameter estimation, we presented various generalizations of these estimation procedures that cover a wide variety of models and data analysis methods. Among these extensions, we present linear models, clustered and dependent observations, times series data, binary and discrete data, models for spatial data, nonparametric methods, and forward search methods for outliers. We also present the current interest in robust statistics and conclude with suggestions on the possible future direction of this area for statistical science.

• 전자공학회논문지D
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• 제36D2호
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• pp.1-10
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• 1999

FET 소신호 모델의 직접추출법은 기생소자값을 구하기 위해 주로 순방향 소동(cold) FET 조건을 이용하고 있다. 본 논문은 수동 FET 조건에서 해석적 채널모델을 유도하고, 정상수동 소자 조건에서도 순방향 수동 FET 조건과 동일 한 정보를 얻을 수 이Tdmadmff 보인다. 이와 함께 수동 FET 조건에 의해 제한되는 능동 FET 소신호 모델의 오차를 추적하여 수동 FET 방법을 이용한 직접 추출 모델의 오차 한계를 살피고, 오차 최소점의 유무를 통해 수동 FET 기생저항값의 유효성을 검토한다.

• Ocean Systems Engineering
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• 제1권4호
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• pp.297-315
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• 2011

New applications of streamlined Autonomous Underwater Vehicles require an AUV capable of completing missions with both high-speed straight-line runs and slow maneuvers or station keeping tasks. At low, or zero, forward speeds, the AUV's control surfaces become ineffective. To improve an AUV's low speed maneuverability, while maintaining a low drag profile, through-body tunnel thrusters have become a popular addition to modern AUV systems. The effect of forward vehicle motion and sideslip on these types of thrusters is not well understood. In order to characterize these effects and to adapt existing tunnel thruster models to include them, an experimental system was constructed. This system includes a transverse tunnel thruster mounted in a streamlined AUV. A 6-axis load cell mounted internally was used to measure the thrust directly. The AUV was mounted in Memorial University of Newfoundland's tow tank, and several tests were run to characterize the effect of vehicle motion on the transient and steady state thruster performance. Finally, a thruster model was modified to include these effects.

• Tribology and Lubricants
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• 제29권1호
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• pp.1-6
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• 2013

Hydraulic transmission is the main component delivering power to the drive wheels of an excavator during forward and backward movement, and it has low speed, high torque and high speed, low torque gear change ratios as a forward/backward two-speed main function. It also has additional function of ensuring that the excavator is stably fixed on the ground with the built-in parking brake during excavation operations. In this study, optimal design specifications are determined by modeling and simulating about the multi-disc-type friction clutch, which is the main component improving the reliability of the hydraulic transmission for a 14-ton wheel excavator, and the friction properties of the transmission clutch are analyzed by performing sample tests.

• 한국실내디자인학회논문집
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• 제25권6호
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• pp.70-78
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• 2016

This paper aims to describe a case study of parametric interior design based on BIM (Building Information Modeling). As the practical use of BIM-based design grows, its influence expands into the field of interior architecture design. BIM makes possible to check various design plan, reach decision making in an effective way, and change design plan in an efficient method. Therefore, BIM is also promising field in interior architecture design. However, compared to other fields in architecture, engineering, and construction (AEC) industry, there have been less research and projects on BIM in the field of interior architecture. For increasing the feasibility of adapting BIM in interior architecture design, this paper describes a case study-projecting images for designing interior panels using parametric modeling. This process needs elaborate, delicate, and precise steps for harmonious output. For continuous use of building, users look forward to the design which variable and changeable according to user's preference and environment. Therefore, demand for parametric design in the interior design part such as panel pattern design for various decoration is growing. Treated process in this paper deals with an advanced phase which much effective in decreasing time consumption and useless part of process. Finally, this paper suggests the possibility of using BIM in the interior design process and field where BIM can be applied.

• 대한음성학회지:말소리
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• 제59호
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• pp.53-68
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• 2006

We report the evaluation results of the Korean speech recognition platform called ECHOS. The platform has an object-oriented and reusable architecture so that researchers can easily evaluate their own algorithms. The platform has all intrinsic modules to build a large vocabulary speech recognizer: Noise reduction, end-point detection, feature extraction, hidden Markov model (HMM)-based acoustic modeling, cross-word modeling, n-gram language modeling, n-best search, word graph generation, and Korean-specific language processing. The platform supports both lexical search trees and finite-state networks. It performs word-dependent n-best search with bigram in the forward search stage, and rescores the lattice with trigram in the backward stage. In an 8000-word continuous speech recognition task, the platform with a lexical tree increases 40% of word errors but decreases 50% of recognition time compared to the HTK platform with flat lexicon. ECHOS reduces 40% of recognition errors through incorporation of cross-word modeling. With the number of Gaussian mixtures increasing to 16, it yields word accuracy comparable to the previous lexical tree-based platform, Julius.

• Journal of Electrical Engineering and Technology
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• 제11권3호
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• pp.592-601
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• 2016

This paper presents the modeling of insulated-gate bipolar transistor (IGBT) in electromagnetic transients program (EMTP) simulation for the reliable calculation of switching and conduction losses. The conventional approach considering the physical property of switching devices requires many attribute parameters and large computation efforts. In contrast, the proposed method uses the curve fitting and interpolation techniques based on typical switching waveforms and a user-defined component with variable resistances to capture the dynamic characteristics of IGBTs. Therefore, the simulation time can be efficiently reduced without losing the accuracy while avoiding the extremely small time step, which is required in simulation by the conventional method. The EMTP based simulation includes turn-on and turn-off transients of IGBT, saturation state, forward voltage of free-wheeling diode, and reverse recovery characteristics, etc. The effectiveness of proposed modeling for the EMTP simulation is verified by the comparison with experimental results obtained from practical implementation in hardware.

• 한국BIM학회 논문집
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• 제12권3호
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• pp.18-29
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• 2022

Recently, research on the application of BIM has continuously been active not only in architecture but also in civil engineering in order to improve work efficiency across the project's planning, design, construction and maintenance phases. However, the empirical applications of BIM targeting to civil engineering scope of construction sites still lags compared to architectural sized projects. This is because BIM tools are mainly based upon vertical structures of architecture, thereby most of them have difficulties and limitations to get utilized on horizontal structures of civil engineering. Therefore, this study intends to propose automation technology of design using BIM library and to indicate its field availability through case application on a railway project representing linear infrastructure. In addition, it put forward the utilization plan of the automation technology upto 4D and 5D by continue making use of the BIM model created in the project's design stage up through the maintenance stage. The novel method of the technology proposed in this paper incorporates the automatic creation of the BIM library based on two-dimensional tunnel cross-sections and sweeping of it over three-dimensional alignment to create a BIM model of linear infrastructure. The proposed technology is anticipated to improve the efficiecny of modeling process of railway projects based on linear structures.

• 지구물리와물리탐사
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• 제18권4호
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• pp.216-222
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• 2015

항공 전자 탐사법은 지하 천부의 전도성 광체 탐사를 위하여 이미 수십년 전에 도입되었다. 그러나 통상적인 시간 영역 항공 전자 탐사(ATEM) 시스템은 신호가 미약하여 가탐 심도에 한계가 있다. 최근 이러한 문제점을 극복하기 위하여 지상 송신원 시간 영역 항공 전자 탐사법(GREATEM)이 개발되었다. GREATEM은 지상에 설치된 긴 전선을 송신원으로 사용하는 준 항공 전자 탐사법이다. 항공 전자 탐사에서는 방대한 자료가 획득되므로, 계산 시간의 절감을 위하여 대개 1차원 해석 방법이 사용되고 있다. 그러나 GREATEM은 1차원 모델링의 경우에도 긴 전선을 따라 수치 적분이 필요하므로 루프 송신원을 사용하는 ATEM의 1차원 모델링에 비하여 계산 시간이 많이 걸린다는 문제점이 있다. 이 논문에서는 일반적인 1차원 모델링보다 비교할 수 없을 정도로 계산 속도가 빠른 ABFM법을 도입하여 ATEM 1차원 모델링을 수행하였다. 통상적인 모델링과 ABFM 결과를 비교한 결과, ABFM법은 GREATEM 1차원 모델링에도 적용 가능할 것으로 확인되었다.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.103-110
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• 2021

In the development of a Risk Monitor probabilistic safety assessment (PSA) model from the basic PSA model of a nuclear power plant, the modeling of common-cause failure (CCF) is very important. At present, some approximate modeling methods are widely used, but there lacks criterion of modeling accuracy and error analysis. In this paper, aiming at ensuring the accuracy of risk assessment and minimizing the Risk Monitor PSA models size, we present three basic issues of CCF model resulted from the changes of a nuclear power plant configuration, put forward corresponding modeling methods, and derive accuracy criteria of CCF modeling based on minimum cut sets and risk indicators according to the requirements of risk monitoring. Finally, a nuclear power plant Risk Monitor PSA model is taken as an example to demonstrate the effectiveness of the proposed modeling method and accuracy criteria, and the application scope of the idea of this paper is also discussed.