• 산업기술연구
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• 제28권A호
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• pp.81-88
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• 2008

Generally, Hertz theory is used to analyze the contact problem of two bodies. It is simple derivation of solution in the contact part. And calculation time is short Moreover, it can mean well that many wear occurs relatively. However, material property becomes plastic deformation when large perpendicular pressure acts on a small contact surface product. In this case, Hertz theory is inapplicable. Therefore this thesis carried the finite element analysis in consideration of material elasticitystrain and the shape of the geometric from contact point. And it compared with Hertz theory that change of the contact surface and contact pressure.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1994년도 춘계공동학술대회논문집; 창원대학교; 08월 09일 Apr. 1994
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• pp.437-450
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• 1994

The problem of testing for a change in the parameter of a stochastic process is particularly important in simulation studies. In studies of the steady state characteristics of a simulation model, it is important to identify initialization bias and to evaluate efforts to control this problem. A simulation output have the characteristics of chaotic behavior because of sensitive dependence on initial conditions. For that reason, we will apply Lyapunov exponent for diagnosis of chaotic motion to simulation output analysis. This paper proposes two methods for diagnosis of steady state in simulation output. In order to evaluate the performance and effectiveness of these methods using chaos theory, M/M/I(.inf.) queueing model is used for testing point estimator, average bias.

• 산업경영시스템학회지
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• 제22권51호
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• pp.29-40
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• 1999

The distribution center location and routing problem involves interdependent decisions among facility, transportation, and inventory decisions. The design of distribution system affects the customers' purchase decision by sets the level of customer service to be offered. Thus the lower product availability may cause a loss of demand as falls off the customers' purchase intention, and this is related to the firm's profit reduction. This study considers the product availability of the distribution centers as the measure of the demand level change of the demand points, and represents relation between customer service and demand level with linear demand function. And this study represents the distribution center location and routing to demand point in order to maximize the total profit that considers the products' sales revenue by customer service, the production cost and the distribution system related costs.

• 융합신호처리학회논문지
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• 제12권1호
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• pp.26-32
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• 2011

This paper proposes a new method to process panoramic image stitching using SURF(Speeded Up Robust Features). Panoramic image stitching is considered a problem of the correspondence matching. In computer vision, it is difficult to find corresponding points in variable environment where a scale, rotation, view point and illumination are changed. However, SURF algorithm have been widely used to solve the problem of the correspondence matching because it is faster than SIFT(Scale Invariant Feature Transform). In this work, we also describe an efficient approach to decreasing computation time through the homography estimation using RANSAC(random sample consensus). RANSAC is a robust estimation procedure that uses a minimal set of randomly sampled correspondences to estimate image transformation parameters. Experimental results show that our method is robust to rotation, zoom, Gaussian noise and illumination change of the input images and computation time is greatly reduced.

• Journal of Platform Technology
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• 제11권6호
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• pp.3-12
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• 2023

In today's system operation, it is difficult to detect failures and take immediate action in the case of a shortage of manpower compared to the number of equipment or failures in vulnerable time zones, which can lead to delays in failure recovery. In addition, various algorithms exist to detect abnormal symptom data, and it is important to select an appropriate algorithm for each problem. In this paper, an ensemble-based isolation forest model was used to efficiently detect multivariate point anomalies that deviated from the mean distribution in the data set generated to predict system failure and minimize service interruption. And since significant changes in memory space usage are observed together with changes in CPU usage, the problem is solved by using LSTM-Auto Encoder for a collective anomaly in which another feature exhibits an abnormal pattern according to a change in one by comparing two or more features. did In addition, evaluation indicators are set for the performance evaluation of the model presented in this study, and then AI model evaluation is performed.

• 통상정보연구
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• 제8권2호
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• pp.229-247
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• 2006

The company culture is becoming usual term in business management field. That organization culture of these phenomenon becomes resource of company competitive power indeed, it is basing to logic for important leading person for elevation with systemicity. also, great many scholars do research to subject that is change management of company administration and there are not much example that companies succeed in change actually despite had announced treatise etc. This research tries to synthesize several research subjects by single model regarding confrontation(culture collision) phenomenon between culture that can happen in company through literature research and example analysis basically. Specially, try to classify and divide this by specific developing and arrange in each type with using much this culture analysis in negotiation analytics. Through this problem and suggestion point by this confrontation way in this culture negotiation side and culture risk management side of administration make try to.

• 응용통계연구
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• 제19권2호
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• pp.369-377
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• 2006

현재 발생중인 시계열 데이터에 분산변화가 일어날 경우 이동 분산비를 사용하여 분산 변화점을 빠른 시간 내에 탐지하는 문제를 다룬다. 이동 분산비의 분포로서 F분포와 데이터에 의존하여 추정되는 실증적 분포를 제안한 후 상호비교를 통하여, 어느 방법이 시계열 데이터에서 분산의 변화점을 잘 탐지하는지 연구하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.288-292
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• 2006

Usually, equations that calculate ground resistance of earth electrode was already informed well by form of earth electrode. But, when apply on the spot because general expressions are very insufficient at point that calculate exact ground resistance value by variation of earth electrode, and constant value that corrective coefficient for ground resistance calculation is fixed regardless of change of the earth resistivity specially is presented, it is actuality that difficulty is. Therefore, in this study, about these problem, proposed corrective coefficient for calculation of ground resistance according to change of the earth resistivity.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.593-598
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• 2000

In this paper the critical speed analysis and design sensitivity investigation are carried out with an APU(auxiliary power unit) gas turbine having a spline shaft connection. The DDM(direct differential method) is directly applied to formulate the critical speed design sensitivity problem of a general nonsymmetric-matrix rotor-bearing system. The design sensitivity analysis have shown that the critical speed change rate to the support modeling of the spline shaft connection point is extremely negligible, and thereby its design uncertainty is lifted. It has also been confirmed that the critical speeds up to the 4th are not sensitive to the design stiffness coefficients of 4-main bearings or supports, including two air foil bearings. Further, the critical speed change rate to the shaft-element length have shown quantitatively that the spline shaft has some limited influence on the 4th critical speed.

• 한국초등수학교육학회지
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• 제13권2호
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• pp.211-229
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• 2009

본 연구에서는 7차 교육과정에서 6학년 때 도입되는 교과서의 비례 문제들이 학생들의 비례 추론 능력과 어떠한 관련이 있는지를 알아보기 위해 교과서의 비례 문제 해결 실태를 파악하고, 수준별 비례 추론 능력을 하위영역으로 나누어 교과서 비례 문제 해결 능력에 따라 하위영역별로 비례추론 능력이 어떠한지 분석하였다. 연구결과 교과서의 비례 문제에서 정답률이 높은 문제들은 설명에서 비례식을 이용해서 풀 수 있도록 제시되어 있었으며, 비례식을 세웠을 때 두 비 사이의 관계가 정수비로 계산이 간단하였다. 비례 추론 하위 영역 중 비감각 영역의 문제 해결을 잘하였고, 양과 변화 영역에 대한 부분의 능력은 가장 뒤떨어졌다. 교과서의 비례 문제 해결 능력과 비례 추론의 관계에 대해서는 교과서의 비례 문제 해결이 우수한 학생일수록 비례 추론 능력이 우수였다. 교과서 비례문제의 해결 결과가 비례추론 능력을 예언할 수 있다고 볼 수 있다. 교과서 비례문제 수준에 따라서 비례 추론 문제 해결의 수준차를 알아본 결과, 차이가 많이 나지 않는 문제는 꼭 비와 비율 관련 단원이 아니라도 수학 교과서에서 다양하게 접할 수 있는 문제였고, 수준별 차이가 많이 나는 문제는 그동안 교과서에서 쉽게 접해보지 못한 유형으로 단순히 비례식을 이용해서는 해결할 수 없는 문제들이었다. 따라서, 비례추론 하위 영역별로 모든 영역에 대하여 능력을 향상시키기 위해서는 교과서에 비례식 외에 다양한 상황과 내용의 비례문제를 포함하여 지도하여야 할 것이다.