• 한국수자원학회논문집
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• 제36권1호
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• pp.23-32
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• 2003

본 연구는 지형학적 인자를 이용하여 유역 대표순간단위도의 유도를 목적으로 한다. 이를 위하여, Nash 모형을 지형학적 순간단위도 모형과 결합하여 대표순간단위도의 매개변수를 추정하고자 하였다. 금강수계의 지류인 보청천 유역의 산계지점을 대상유역으로 선정하여 총 18개 호우사상에 대한 분석을 수행하였다. 그 결과 n은 3.17, k는 7.01로 나타났으며, 모멘트법에 의해 유도된 순간단위도는 호우사상별로 상당한 차이를 보이고 있었다. 본 연구로부터 얻어진 대표순간단위도는 각 호우사상별로 얻어진 단위도들을 대표할 수 있는 중앙치로 나타났으며, 기왕의 방법들과 비교했을 때, 지형학적 요소를 고려한 본 연구방법의 우월성 및 물리적 의미가 크다고 판단된다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.199-212
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• 2020

A large percentage of maritime accidents in coastal seas are related to small fishing vessels. In order to investigate causes of maritime accidents, it is often necessary to carry out dynamic simulations for the estimation of trajectories and motions of vessels. Initial conditions of vessels such as main dimensions, loading conditions and hydrostatic properties are required for the accurate simulations. Small fishing vessels usually have few records of hydrostatic properties during their fishing operations. Therefore, in this study, estimation procedures for hydrostatic properties of small fishing vessels are proposed. At first, hull form characteristics of Korean small fishing vessels are investigated. Most of vessels have hard-chines and centerline skegs, they have similar hull forms. Bonjean curves of several small fishing vessels whose gross tonnages are below 10 tons are normalized with vessel breadths and depths. Representative bonjean curves are derived from normalized bonjean curves, and a representative hull plan is obtained as well. If the vessel loading conditions such as total weights and centers of gravity are given, fore and aft drafts can be calculated by using the representative bonjean curves with the constraint that weights and buoyancies are in equilibrium. Metacentric heights are also estimated by using the representative hull plan. Drafts and metacentric heights estimated by proposed iterative estimation procedures are compared with actual vessel data, estimated values are in good agreements with actual values. In addition, normalized fore and aft drafts, metacentric heights of vessels can be formulated as the linear functions of normalized total weights and centers of gravity. Empirical formulas of drafts and metacentric heights are proposed, and it is confirmed that the empirical formulas also provide reasonable results, which are similar to the results by iterative estimation procedures with representative bonjean curves and hull plan.

• Safety and Health at Work
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• 제15권1호
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• pp.42-52
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• 2024

Background: The lack of headforms that accurately reflect the head characteristics of Koreans and the demographic composition of the Korean population can lead to inadequate FFR testing and reduced effectiveness of FFRs. Method: Direct measurements of 5,110 individuals and 3D measurements of 2,044 individuals, aged between 9 and 69 years, were sampled from the data pool of Size Korea surveys based on the age and gender ratios of the Korean resident demographics. Seven head dimensions were selected based on the ISO 16976-2, availability of Size Korea measurements, and their relevance to the fit performance of FFRs. A principal component analysis (PCA) was performed using the direct measurements to extract the main factors explaining the head characteristics and then the main factors were standardized and remapped to 3D measurements, creating five size categories representing Korean head shapes. Lastly, representative 3D headforms were constructed by averaging five head shapes for each size category. Results: The study identified two main factors explaining Korean head characteristics by the PCA procedure specified in ISO 16976-2 and developed five representative headforms reflecting the anthropometric features of Korean heads: medium, small, large, short & wide, and long & narrow. Conclusion: This study developed representative headforms tailored to the Korean population for conducting total inward leakage (TIL) tests on filtering facepiece respirators (FFRs). The representative headforms can be used for TIL testing by employing robotic headforms to enhance the performance of FFRs for the Korean target population.

• 한국문헌정보학회지
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• 제58권2호
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• pp.177-198
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• 2024

2006년 12월에 전부 개정된 「도서관법」 제22조 제1항은 지역대표도서관을 법정기구로 규정하였고, 2021년 말에 재개정된 「도서관법」 제25조 제1항은 그 명칭을 광역대표도서관으로 개칭하고 수행해야 할 업무도 확장하였다. 시·도가 광역대표도서관을 지정 또는 설립 운영해야 하는 이유는 동법 제23조에 규정된 공중의 정보이용, 문화활동, 평생학습 등 공공도서관으로서의 역할에 더하여 제26조에 규정된 광역대표도서관의 법정업무를 주관하고 시·도 내 모든 공공도서관을 위한 정책도서관, 종합지식정보센터, 지원·협력 구심체, 조사연구, 공동보존서고 운영 등을 수행하여 도서관 및 지식문화 발전을 견인하는데 있다. 그렇다면 지난 15년간(2009-2023) 광역대표도서관은 법정 업무를 충실하게 수행하여 왔는가, 특히 디지털·모바일 시대에 부응하기 위해 법정업무의 계획 및 추진실적을 웹사이트에서 제대로 제공하고 있는지를 분석·진단할 필요가 있다. 이에 본 연구는 광역대표도서관의 현행 법정 업무를 기준으로 최근 2년간 수행실적을 조사·분석한 후 웹사이트를 통해 어느 정도로 제공하는지를 평가하여 웹서비스 강화를 위한 보완책을 제시하였다. 그 결과, 광역대표도서관이 수행해야 하는 법정업무에 대한 웹서비스는 상당히 부족하고 부실한 것으로 분석되어 홈페이지에서 법정업무를 위한 웹사이트 구축, 독립된 웹사이트 제공을 통한 접근 편의성 및 가시성 제고, 다양한 정책정보 및 웹서비스(포털검색, 상호대차와 원문제공, 공동DB 구축, 자료이관 및 보존 등) 방안, 지식정보 취약계층의 디지털 접근성 보장 등을 보완책으로 제시하였다.

• Journal of Power Electronics
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• 제12권1호
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• pp.1-9
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• 2012

This study investigates an application of the Hamming network-dual extended Kalman filter (DEKF) based on pattern recognition for high accuracy state-of-charge (SOC)/capacity estimation and state-of-health (SOH) prediction at various temperatures. The averaged nine discharging/charging voltage-temperature (DCVT) patterns for ten fresh Li-Ion cells at experimental temperatures are measured as representative patterns, together with cell model parameters. Through statistical analysis, the Hamming network is applied to identify the representative pattern that matches most closely with the pattern of an arbitrary cell measured at any temperature. Based on temperature-checking process, model parameters for a representative DCVT pattern can then be applied to estimate SOC/capacity and to predict SOH of an arbitrary cell using the DEKF. This avoids the need for repeated parameter measuremet.

• 한국환경과학회지
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• 제29권1호
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• pp.25-32
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• 2020

The determination of soil parameters is important in predicting the simulated surface runoff using either a distributed or a lumped rainfall-runoff model. Soil characteristics can be collected using remote sensing techniques and represented as a digital map. There is no universal agreement with respect to the determination of a representative parameter from a gridded digital map. Two representative methods, i.e., arithmetic and predominant, are introduced and applied to both FLO-2D and HEC-HMS to improve the model's accuracy. Both methods are implemented in the Yongdam catchment, and the results show that the former seems to be more accurate than the latter in the test site. This is attributed to the high conductivity of the dominant soil class, which is A type.

• International Journal of Contents
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• 제4권2호
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• pp.24-28
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• 2008

In this paper, we propose a new approach for content-based video retrieval using non-parametric based motion classification in the shot-based video indexing structure. Our system proposed in this paper has supported the real-time video retrieval using spatio-temporal feature comparison by measuring the similarity between visual features and between motion features, respectively, after extracting representative frame and non-parametric motion information from shot-based video clips segmented by scene change detection method. The extraction of non-parametric based motion features, after the normalized motion vectors are created from an MPEG-compressed stream, is effectively fulfilled by discretizing each normalized motion vector into various angle bins, and by considering the mean, variance, and direction of motion vectors in these bins. To obtain visual feature in representative frame, we use the edge-based spatial descriptor. Experimental results show that our approach is superior to conventional methods with regard to the performance for video indexing and retrieval.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.41.3-41
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• 2002

Motion estimation using Full-Search(FS) and Block-Matching Algorithm(BMA) is often used in the case of moving object tracking by vision sensors. However these methods often miss the real-time vision data because these schemes suffer the heavy computational load. When the image size of moving object is changed in an image frame according to the distance between the camera of mobile robot and the moving object, the tracking performance of a moving object may decline with these methods because of the shortage of active handling. In this paper, the variable-representative block that can reduce a lot of data computations, is defined and optimized by changing the size of representative block accor...

• 한국분무공학회지
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• 제5권2호
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• pp.61-67
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• 2000

The interaction between chemistry and turbulence is treated by employing the Representative Interactive Flamelet (RIF) Model. The detailed chemistry of 114 elementary steps and 44 chemical species is adopted for the n-heptane/air reaction. In order to account for the spatial inhomogeneity of the scalar dissipation rate, the multi-RIF is used. The effect of the number of RIF on ignition delay is discussed in detail. Numerical results indicate that the present RIF approach successfully predicts the ignition delay time as well as the essential features of a spray auto-ignition process.

• 제어로봇시스템학회논문지
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• 제8권10호
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• pp.881-889
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• 2002

Mobility analysis for various mobile mechanisms including mechanisms with lack of geometric generality is performed. Joint screws are employed to find the sire of feasible joint motion space or each of independent loops of mobile mechanisms. Particularly, the concept of "representative screws" is introduced to represent the feasible motion spaces for subsets of joints belonging to either a loop or a sub-system consisting of several closed loops. Firstly. simplified joint model for each of low different typical wheels popularly employed in mobile robots is described. Then. mobility analysis fir various types of planar mobile robots and the Mars Rover mobile robot for navigation on the rocky road on Mars arc performed. It is confirmed that the obtained results in this study coincide with the previous ones which were obtained by suing imaginary Joints approach(1)pproach(1)