• 한국컴퓨터정보학회논문지
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• 제21권9호
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• pp.91-100
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• 2016

In this research, emergency vehicle dispatching problems faced with in the wake of massive natural disasters are considered. Here, the emergency vehicle dispatching problems can be regarded as a single machine stochastic scheduling problems, where the processing times are independently and identically distributed random variables, are considered. The objective of minimizing the expected number of tardy jobs, with distinct job due dates that are independently and arbitrarily distributed random variables, is dealt with. For these problems, optimal static-list policies can be found by solving corresponding assignment problems. However, for the special cases where due dates are exponentially distributed random variables, using a proposed dynamic programming approach is found to be relatively faster than solving the corresponding assignment problems. This so-called Pivot Dynamic Programming approach exploits necessary optimality conditions derived for ordering the jobs partially.

• 대한전기학회논문지
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• 제36권11호
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• pp.769-776
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• 1987

This paper deals with the topological observability analysis and the development of an observable island identification algorithm for state estimation in power systems, by using the incidence matrix and bus voltage grouping. An analogy of the DC power flow method to the DC circuit analysis is introduced, and all the relationships between power flows and phase angles are replaced by the corresponding current-voltage relation. As a result, a set of topological measurement equation expressed in the form of the incidince matrix is derived for the topological analysis, and the observability test is carried out by examining the rand of the measuremint matrix. The integer Gauss elimination method is introduced in the determination of matrix rand, so that the proposed observability test yields a precise observability criterion without any nearly-zero pivot problem encountered in the conventional algorithm. Also, an observable island identification algorithm reduced its computational time in comparision with the conventional algorithms. The proposed algorithms have been tested for sample systems, and their practicability has verified.

• 대한전기학회논문지:전력기술부문A
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• 제52권1호
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• pp.62-67
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• 2003

An important aspect of the study of power system markets involves the assessment of strategic behavior of participants for maximizing their profits. In models of imperfect competition of a deregulated electricity system, the key task is to find the Nash equilibrium. In this paper, the bimatrix approach for finding Nash equilibria in electricity markets is investigated. This approach determines pure and mixed equilibria using the complementarity pivot algorithim. The mixed equilibrium in the matrix approach has the equal number of non-zero property. This property makes it difficult to reproduce a smooth continuous distribution for the mixed equilibrium. This paper proposes an algorithm for adjusting the quantization value of discretization to reconstruct a continuous distribution from a discrete one.

• 대한가정학회지
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• 제34권5호
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• pp.249-264
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• 1996

The purpose of this study was to investigate automatic manipulating functions of dart of CAD system, and to classify the dart of women's front bodice. The results from this study: 1.3 CAD systems, were compared in automatic manipulating functions of dart. Gerber system & Investronica system were based on the pivot-method of dart manipulating, Yuka system was based on the slash-method. 2. It is classified and made a dart-design chart with using darts, which were as examples related to dart manipulating in text & reference of the pattern design. 3. In case of education of dart manipulation, the classified dart-design chart provides variations of a basic pattern through dart manipulation.

• 한국정보처리학회논문지
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• 제6권10호
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• pp.2630-2641
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• 1999

Most of the previous game development has proceeded in the approaches of the temporal-oriented synchronization because of producing game objects by using general authoring tools, and ad hoc or trial and error methods has been devised for representation of spatial concept. This paper is a study on the unification notation for spatio-temporal synchronization to conquest this fault. First of all, we classify game space as temporal object, spatial object, absolute/relative spatio-temporal space. The spatio-temporal relationships are divided into temporal extent, temporal location, spatial extent, and spatial location. In the paper the temporal and spatial relationships of game scene are defined to represent the synchronization, and we propose new unification notation by temporal and spatial concept to represent two concepts putting emphasis on space. Their relationships are presented on 3D by creating time axis related with time in scene unit of the two dimensional plane in the pivot on space. The usability of this representation method are shown by applying examples of game scenario.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2005년도 한국컴퓨터종합학술대회 논문집 Vol.32 No.1 (B)
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• pp.214-216
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• 2005

데이터 웨어하우스에서는 데이터를 다양한 관점으로 분석하기 위해 데이터를 다차원 형태로 유지한다. 이 다차원 데이터를 간단하고 편리한 형태로 사용자에게 표현하기 위해 피벗 테이블이 이용된다. 피벗 테이블은 데이터에 대한 요약된 정보를 제공하는데 널리 사용되는 편리한 표현 방법이지만, 실제 값이 열의 제목으로 나오기 때문에 많은 개수의 열을 가질 수 있다. 이러한 피벗 테이블을 그대로 저장할 경우 관계 DBMS의 테이블 컬럼 수에 제약을 받게 되며, 데이터 저장 및 질의 처리에 성능이 떨어질 수 있다. 이 논문은 관계 데이터베이스의 테이블을 이용하여 피벗 테이블을 효율적으로 저장하는 방법을 제안한다. 이때, 피벗 테이블에 대한 질의물 저장된 형태의 테이블에 적용 가능하도록 질의를 변환시켜야 한다. 따라서 이 연구에서는 피벗 테이블에 대한 관계 연산자들(실렉션, 프로젝션, 합집합, 차집합 카디션 곱)을 효율적으로 변환하는 질의 변환 방범을 제안한다.

• 대한의용생체공학회:의공학회지
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• 제15권2호
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• pp.209-216
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• 1994

The objective of the research reported in this paper is to design locomotion system of the motorized wheelchair, to develope the wall following algorithm. The indoor navigation of a motorized wheelchair can be based on the wall following techniques. In this paper, it is proposed to enhance stability and efficiency using the 3 ultrasonic sensors arranged at a same perpendicular pivot. Using this method, the angle between the motorized wheelchair and the wall is detected and the range of control commands has been increased. For the better stability, the calculated slope of a wall using LSLF algorithm was fed back to the control part. By adapting the suggested algorithm and method, the motorized wheelchair could follow a wall in 4 seconds, for a change of distance between the wheelchair and wall from 30 to 100cm.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1993년도 추계학술대회
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• pp.44-47
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• 1993

In this paper, the wall follwing method of a motorized wheelchair is discussed. The wall fellowing problem is characterized by maintaining a constant distance to the wall, which should be possible using a distance measuring sensor only. Ultrasonic sensors are cheap are fairly simple to use in this case. The main problem is the calculation of the distance and orientation of the wheelchair with respect the wall from the sensor data. This is solved by the method that sensor data is obtained from 3 ultrasonic sensors arranged at a same perpendicular pivot. The results show that a new method is very effiecient for a motorized wheelchair.

• 한국군사과학기술학회지
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• 제11권4호
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• pp.68-75
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• 2008

This paper proposes a new data hiding method for binary images using the weighting value of pixel-value differencing. The binary cover image is partitioned into non-overlapping sub-blocks and find the most suitable position to embed a secret bit for each sub-block. The proposed method calculates the weighted value for a sub-block to pivot a pixel to be changed. This improves the image quality of the stego-image. The experimental results show that the proposed method achieves a good visual quality and high capacity.

• Journal of Chest Surgery
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• 제54권5호
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• pp.389-392
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• 2021

Double outlet right ventricle (DORV) with pulmonary atresia (PA) is an uncommon congenital disease. Because of anatomical and physiological anomalies in the systemic and pulmonary circulation, corrective surgery may be challenging. We present the case of a patient with DORV and PA. This condition was successfully corrected using a modified Nikaidoh procedure, resulting in reduced obstruction of the left ventricular outflow tract.