• 산업경영시스템학회지
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• 제10권16호
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• pp.133-141
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• 1987

Man-machine assignment problem with random service and processing times is considered in this paper. Assuming heterogeneous semi-automatic machines, the problem is dealt with as follow; 1. For the different type of machines that have probabilistics distribution of processing time and nan service time, man·machine assignment problem is solved by heuristic method using expected time value if machine. 2. Since each related time is a random variable, the performance of the optimal assignment obtained from the above method is verified through monte carlo simulation method. 3. The above procedures are programed by BASIC language to use easily and rapidly in the personal computer. The result of this study can contribute to productivity enhancement by increasing the efficiencies of both operators and machines.

• 품질경영학회지
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• 제29권3호
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• pp.66-78
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• 2001

This paper deals with problem of determining process target value under automated visual inspection(AVI) system. Three independent error sources - digitizing error, illumination error, and positional error - which have a close relationship with the performance of the AVI system, are considered. Assuming that digitizing error is uniformly or normally distributed and illumination and positional errors are normally distributed, respectively, the distribution function for the error of measured lengths is derived when the length of a product is measured by the AVI system. Then, Optimal target values under two error models of AVI system are obtained by minimizing the total expected cost function which consists of give away, rework and penalty cost. To validate two process setting models, AVI system for drinks filling process is made up and test results are discussed.

• Journal of information and communication convergence engineering
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• 제20권2호
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• pp.125-130
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• 2022

In modern society, as many data are used for research or commercial purposes, the value of data is gradually increasing. In related fields, research is being actively conducted to collect valuable data, but it is difficult to collect proper data because the value of collection is determined according to the performance of existing sensors. To solve this problem, a method to effectively reduce noise has been proposed, but there is a point in which performance is degraded due to damage caused by noise. In this paper, a device capable of collecting time series data was designed to correct such data noise, and a correction technique was performed by giving an error value based on the representatively collected ultrafine dust data, and then comparing before and after Compare performance. For the correction method, Kalman, LPF, Savitzky-Golay, and Moving Average filter were used. Savitzky-Golay filter and Moving Average Filter showed excellent correction rate as an experiment. Through this, the performance of the sensor can be supplemented and it is expected that data can be effectively collected.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2001년도 추계 기술심포지움
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• pp.61-66
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• 2001

In this research, the design parameters of embedded capacitors are extracted by modeling and fabrication. The traditional library of capactor has a few problems in applying the circuit. Its capacitance is discrete, so target values in any circuit often can't be obtained in library, To solve this problem, the characteristics of capacitors are detected in the variation with the shape and structure, and then the capacitors with the expected reactance value at target frequency are obtained, In this procedure, 3-dimensional structure simulation is performed to predict the characteiristics of capacitors.

• Journal of the Korean Statistical Society
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• 제12권1호
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• pp.36-45
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• 1983

After every decennial census in the U.S., national surveys such as the Consumer Expenditures surveys are redesigned. The redesigned samples will be multi-stage systematic samples. Many sampling schemes have been proposed for comparison which requires the estimation and variance estiamtion formula. This paper deals with the surveys redesign research which concerns the sample design within the Primary Sampling Unit (PSU). In constructing the estimators it deals with the problem of which first stage inflation factor to use. The expected value of the proposed estimators is also derived.

• 한국경영과학회지
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• 제20권1호
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• pp.179-193
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• 1995

A multi-objective, single-stage scheduling problem with stochastic processing times is considered where the objective is to simultaneously minimize the expected value and the variance of total flowtime, and the mean probability of tardiness. In cases where processing times follow normal distributions, a method using pairwise interchange of two jobs(PITJ) is proposed to generate a set of the approximate efficient schedules. The efficient schedules are not dominated by the criterion vectors of any other permutation schdules in the feasible region. Numerical experiments performed to ascertain the effectiveness of PITJ algorithm are also reported in the results.

• Journal of the Korean Data and Information Science Society
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• 제6권1호
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• pp.31-37
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• 1995

We consider density estimates of the usual type generated by a kernel function. By using the limit theorems for the maximum of normalized deviation of the estimate from its expected value, we propose to use data dependent bandwidth in the tests of goodness of fit based on these statistics. Also a small sample Monte Carlo simulation is conducted and proposed method is compared with Kolmogorov-Smirnov test.

• 한국융합학회논문지
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• 제12권11호
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• pp.91-97
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• 2021

본 논문은 불완전한 데이터를 처리하기 위해 본래 규칙개선 문제를 위해 고안되었던 데이터 확장 기법을 사용한다. 이 기법은 사건마다 중요도를 의미하는 가중치를 가질 수 있으며 각 변수를 확률값으로 나타낼 수 있는 특징이 있다. 본 논문에서의 핵심 문제가 손실값과 가장 근사한 확률을 구하여 손실값을 확률로 대치하는 것이므로, 3가지 다른 알고리즘으로 손실값에 대한 확률을 구한 후 이 데이터 구조의 형식으로 저장한다. 그리고 각각의 확률 구조에 대한 평가를 위해 SVM 분류 알고리즘으로 각각의 정보 영역을 분류하는 학습을 한 후, 본래의 정보와 비교하여 얼마나 서로 일치하느냐를 측정한다. 손실값의 대치 확률을 위한 3가지 알고리즘들은 같은 데이터 구조를 사용하고 있으나 접근 방법에서는 서로 다른 특징을 가지고 있어 적용 분야에 따라 다양한 용도로 이용될 수 있기를 기대한다.

• 한국콘텐츠학회논문지
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• 제20권12호
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• pp.136-144
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• 2020

선행연구에서는 노동투자비효율성이 정보비대칭이 심하고, 경영자와 외부 투자자들간의 대리인 문제가 클수록 발생한다고 보고하였다. 따라서 노동투자의 비효율성이 높은 기업의 경우 경영자가 기업가치를 훼손시킬 수 있는 기회주의적 의사결정을 내릴 가능성이 높아진다. 이에 본 연구는 시장에서 투자자들이 비효율적으로 노동투자 의사결정이 이루어지는 기업들의 회계정보를 투자의사결정에 유용하게 사용할 가능성이 낮아짐에 따라 노동투자 비효율성이 높아질수록 회계정보의 가치관련성이 감소하는지 살펴보고자 한다. 노동투자효율성은 기업의 실제 노동투자수준과 예상되는 적정노동투자수준의 차이로 측정하여 이 차이가 커질수록 노동투자가 비효율적으로 이루어지는 것으로 판단하였다. 2002년부터 2018년까지 한국거래소에 상장된 기업의 데이터를 사용하여 분석한 결과, 노동투자에 대한 비효율성이 증가할수록 회계이익의 가치관련성이 감소하는 것으로 나타났다. 본 연구는 기업의 경쟁력에 중요한 요인으로 작용하는 인력에 대한 투자가 비효율적으로 이루어지는 기업일수록 회계이익에 대한 정보 유용성이 감소한다는 실증적인 근거를 제시하였다는 측면에서 공헌점을 찾을 수 있다.

• International Journal of Aeronautical and Space Sciences
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• 제14권3호
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• pp.256-263
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• 2013

The saturation of the actuator impairs the response performance of the near space interceptor control system. A control system based on the properties of linear tracking system is designed for this problem. The properties are that the maximum value of the pseudo-Lyapunov function of the linear tracking control system do not present at the initial state but at the steady state, based on which the bounded stability problem is converted into linear tracking problem. The pseudo-Lyapunov function of the linear tracking system contain the input variables; the amplitude and frequency of the input variables affect the stability of the nonlinear control system. Designate expected closed-loop poles area for different input commands and obtain a controller which is function of input variables. The coupling between variables and linear matrices make the control system design problem non-convex. The non-convex problem is converted into a convex LMI according to the Shur complement lemma and iterative algorithm. Finally the simulation shows that the designed optimal control system is quick and accurate; the rationality of the presented design techniques is validated.