• 전력전자학회논문지
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• 제3권1호
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• pp.15-22
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• 1998

전동기의 전기적/기계적 파라미터 측정에 관한 연구는 브리시리스 전동기 적용에 까지, 비교적 오랜기간에 걸쳐 체계적인 연구가 진행되어져 왔다. 그러나 효율적인 전기 에너지 관리를 위해 전동기 구동시스템의 전력 파라미터의 분석 및 평가에 관한 체계적인 연구는 미진한 형편이다. 따라서 본 연구에서는 PC 화면상에 다양한 그래픽 화면과 수치로 디스플레이 가능한 사용자 위주의 전동기 구동장치의 전력 파라미터 분석 및 평가법을 제안하고 시스템을 개발하였다. 분석 및 평가시스템은 586-PC, DSP보드, 전력 파라미터의 분석 및 평가 소프트웨어 및 전동기 구동시스템으로 구성되어 있다. 전력 파라미터는 전압, 전류파형의 상호상관함수 알고리즘에 의해 분석되며, 이 분석 알고리즘을 DSP가 전담하여, 전력 파라미터를 실시간 분석하였다. 3차원 전류좌표계에 의하여 분석결과의 가시화를 행하였으며, 종래의 시간/주파수 영역에서의 2차원적인 평가법과 비교하였다. 적용대상 전동기로는 기동 토오크가 크며, 역률, 효율이 좋다는 장점 때문에 널리 이용되고 있는 단상 캐패시터 구동형 유동 전동기와 싸이리스터로 제어되는 구동 시스템을 선정하였다. 캐패시터 구동형 단상 유동전동기의 속도제어를 위하여 싸이리스터의 위상각을 변화시켰으며, 위상각 변화에 따른 전동기의 전력 파라미터를 분석 평가하여 본 연구의 유용성을 확인하였다.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2003년도 춘계학술발표회
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• pp.31-40
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• 2003

There are winds and waves in the sea, and they are changed frequently in accordance with the weather. By analyzing them which have the closest relation to the ship's safe voyage. evaluating the seakeeping performance and then taking a proper action, navigators should carry out safe navigation on the sea. A ship in seaways suffers continuous disturbances by irregular waves, and ship motions with irregular waves cannot be easily described as a system model which is adequate to a control system. But, in general, for seakeeping analysis, ship motions in irregular seas can be estimated by the superposition of the motion responses in regular wave components of the sea spectrum. After comparing and analyzing the winds and waves in major sea areas, this paper evaluates the navigational safety of ships on the Korean coast with potential dangerous seakeeping performance using the weather information provided by land. The conclusion is as follows : (1) It is possible that the safety of ships could be secured more accurately by evaluating the seakeeping performance of ships. (2) When the weather is bad, the departure of ships could be controlled by evaluating the navigational safety of ships. (3) When a ship is placed in commission in any area, this evaluation could be used to decide the type and size of ship in use.

• Ocean Systems Engineering
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• 제5권3호
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• pp.161-179
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• 2015

An emergency response system (ERS) for vessel oil spills is a complex and dynamic system comprising a number of subsystems and activities. Failures may occur during the emergency response operations, this has negative impacts on the effectiveness of the ERS. Of the classes of problems in analyzing failures, the lack of quantitative data is fundamental. In fact, most of the empirical data collected via questionnaire survey is subjective in nature and is inevitably associated with uncertainties caused by the human being's inability to provide complete judgement. In addition, incomplete information and/or vagueness of the meaning about the failures add difficulties in evaluating the effectiveness of the system. Therefore this paper proposes a framework to evaluate the ERS effectiveness by using the combination of fuzzy reasoning and evidential synthesis approaches. Based on analyzing the procedure of ERS for oil spills, the failures in the system could be identified, using Analytic Hierarchy Process(AHP)to determine the relative weight of identified failures. Fuzzy reasoning combined with evidential synthesis is applied to evaluate the effectiveness of ERS for oil spills under uncertainties last. The proposed method is capable of dealing with uncertainties in data including ignorance and vagueness which traditional methods cannot effectively handle. A case study is used to illustrate the application of the proposed method.

• 품질경영학회지
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• 제14권2호
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• pp.55-60
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• 1986

The efficient management for the research and development (R&D) manpower will absolutely be necessary for the successful accomplishment of R&D projects. In this respect, a methodology through analyzing and evaluating the degree of technology accumulation was presented, using the INGRES Data Base Management System (DBMS) in UNIX operating system.

• Journal of information and communication convergence engineering
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• 제8권2호
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• pp.140-144
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• 2010

This paper is a research on an evaluating method for the dynamic signature verification system. It is described about various factors such as error rate, the size of signature verification engine, the size of the characteristic vectors of a signature, the ability to distinguish similar signatures, the processing speed of signature verification and so on. This study identifies factors to consider in evaluating signature verification systems comprehensively and objectively without an officially approved signature database, examines the meaning of each of the factors, and proposes criteria for evaluating and analyzing the factors.

• 대한인간공학회지
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• 제32권1호
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• pp.153-158
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• 2013

Objective: This study aims to suggest different approaches in analyzing risks associated with musculoskeletal disorders (MSDS) for risk assessment. Background: Upon concluding that the changes in the industrial environments have made it hard to regulate diverse risk factors, the government has implemented a policy for risk assessment. Method: This study has proposed a method, creating programs using Excel that perform qualitative or quantitative analysis, for evaluating risk factors in risk assessments and has applied this in manufacture and service industries. Results: To verify the validity of the developed program, risk assessment has been performed on restaurant chefs as an example. For quantitative evaluation, the study has suggested approaches using the results for REBA evaluation and the analysis report on the work scenes of a fitting-shop in a shipbuilding industry. Application: Constructing and adapting a system using Excel in evaluating risk factors for risk assessments as this study suggests, is expected to contribute to revitalizing risk assessments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.479-483
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• 1997

In general, motor parameters can be divided into mechanical/electrical parameters and harmonic parameters. Mechanical/electrical parameters identification of motor have been studying systematically for a long time. But, systematical study on harmonic parameters analysis for efficient motor drive system are very poor. The goal of this paper is to propose analyzing method of harmonic parameters for motor drive system with various experimental graphic screens and numerical results and to develope harmonic parameters analyzer. A developed analyzer is made up 586-PC and DSP (digital signal processor) board, motor drive system, power and harmonic parameters analyzing software for windows. Harmonic parameters are analyzed using correlation signal processing techniques based on the correlation between voltage and current waveforms. Analysis results are visualized by 3-D current coordinates, and it is compared and evaluated with conventional time/frequency domain. To verify the validity of the proposed system, 1/4HP capacitor run type single phase induction motor and thyristor speed controller is used for analyzing. Harmonic parameters of motor drive system is analyzed and verified, with varying fire angle of thyristor speed controller, and the proposed approach is to confirm validity.

• 조명전기설비학회논문지
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• 제25권6호
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• pp.108-114
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• 2011

In order to mitigate the possible hazards from electric shock due to the touch and step voltages, the high resistivity material such as gravel is often spread on the earth's surface in substations. When the grounding electrode is installed in two-layer soil structures, the surface layer soil resistivity is different with the resistivity of the soil contacted with the grounding electrodes. The design of large-sized grounding systems is fundamentally based on assuring safety from dangerous voltages within a grounding grid area. The performance of the grounding system is evaluated by tolerable touch and step voltages. Since the floor surface conditions near equipment to be grounded are changed after a grounding system has been constructed, it may be difficult to determine the tolerable touch and step voltage criteria. In this paper, to propose an accurate and convenient method for evaluating the protective performance of grounding systems, the propriety of the method for evaluating the current flowing through the human body around on a counterpoise buried in two-layer soils is presented. As a result, it is reasonable that the grounding system performance would be evaluated by measuring and analyzing the current flowing through the human body based on dangerous voltages such as the touch or step voltages and the contact resistance between the ground surface and feet.

• 센서학회지
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• 제16권5호
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• pp.369-376
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• 2007

Recently, obesity that is increasingly becoming a major cause of various diseases is emerging as a serious social problem. In order to solve this problem, the necessity of measurement systems for overweight management has increased. This paper is a study on the measurement system for obesity management that can offer right medical services everywhere and allways by analyzing EMG (electromyograph) of the abdomen and then checking one's health state. For analyzing EMG signals of the abdomen, algorithms for energy detection, signal feature extraction, classification and recognition are presented. This paper proposes a system that provides an appropriate an estimation on the health status by evaluating the obesity degree and muscular strength of the abdomen through the system applying these algorithms.

• 해양환경안전학회지
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• 제9권1호
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• pp.41-50
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• 2003

한국 연안의 각 항로에 취항하고 있는 대표적인 선형의 여객선들을 대상으로, 각 선형별로 선체운동 계산, 내항성능을 분석하여 선박의 안전성을 평가하였다. 이를 위하여 선박의 안전운항과 가장 밀접한 관련을 갖는 바람과 파랑을 주요 해역별로 비교 분석하였다. 이러한 기강정보를 입력요소로 하여 주요해역을 항행하는 대표적인 선형의 여객선들에 대하여 수치 시뮬레이션을 실시하여 여객선의 항해안정성을 평가하였다.