• East Asian mathematical journal
• /
• v.25 no.1
• /
• pp.11-26
• /
• 2009

In this paper, the concepts of compatible mappings of types (A) and (P) are introduced in an induced metric space, two common xed point theorems for two pairs of compatible mappings of types (A) and (P) in an induced complete metric space are established. As their applications, the existence and uniqueness results of common solution for a system of functional equations arising in dynamic programming are discussed.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2021.06a
• /
• pp.131-134
• /
• 2021

지상파 방송에서는 청각장애인을 위해 폐쇄자막(closed caption) 서비스가 제공되고 있지만, 이를 저장하여 VOD 서비스 등에 제공하고자 할 때는 영상과의 비동기화(desynchronization) 문제로 인해 활용할 수 없는 문제가 있다. 본 논문에서는 이를 해결하기 위해 자동 음성인식(automatic speech recognition)과, 자막 동기화 문제에 맞게 변경된 동적계획법(modified dynamic programming)을 이용하는 방법을 제안한다. 문자열 정렬에서 삽입과 삭제 등 간격(gap)의 발생을 제어하는 제약조건과 그에 따른 점수 구조를 적용함으로써 문자열 정렬 성능을 개선한다. 또한 정렬된 폐쇄자막과 음성인식 문자열로부터 시간 동기정보를 복원하고 동기화된 자막을 생성하는 방법을 제안한다. 실제 TV 프로그램과 자막에 적용하여 기존 방법에 비해 성능의 향상이 있음을 확인하였다.

• Proceedings of the Korean Society for Language and Information Conference
• /
• 1998.02a
• /
• pp.283-294
• /
• 1998

• Proceedings of the Korea Water Resources Association Conference
• /
• 1992.07a
• /
• pp.448-456
• /
• 1992

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1999.04a
• /
• pp.583-583
• /
• 1999

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1999.04a
• /
• pp.311-312
• /
• 1999

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.21 no.1
• /
• pp.62-72
• /
• 1997

High flexibility and productivity using industrial robots are being achieved in manufacturing lines with off-line robot programmings. A good off-line programming system should have functions of robot modelling, trajectory planning, graphical teach-in, kinematic and dynamic simulations. Simulated results, however, can hardly be applied to on-line tasks until any calibration procedure is accompained. This paper proposes a visual calibration scheme in order to provide a calibration tool for our own off-line programming system of SCARA robots. The suggested scheme is based on the position-based visual servoings, and the perspective projection. The scheme requires only one camera as it uses saved kinematic data for three-dimensional visual calibration. Predicted images are generated and then compared with camera images for updating positions and orientations of objects. The scheme is simple and effective enough to be used in real time robot programming.

• Journal of Korea Society of Industrial Information Systems
• /
• v.9 no.3
• /
• pp.19-31
• /
• 2004

The purpose of this study is to show a case integration of web programming with database using Visual InterDev as a conceptual client and Web Server as server, Through this case study, we can see how easily dynamic web database programming used in Internet and Interanet can be developed in one integrated design environment such as Visual InterDev eliminating the inconvenience of developing database file and web page separately. Some literature survey and experimental practices were done to provide future developers with the principles and methodologies of developing web database programing using Visual InterDev with much less coding efforts and more convenient and easy way compared to other web developing tools.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2002.05a
• /
• pp.179-184
• /
• 2002

We consider the heterogeneous fleet vehicle routing problem (HVRP), a variant of the classical vehicle routing problem (VRP). The HVRP differs from the classical VRP in that it deals with a heterogeneous fleet of vehicles having various capacities, fixed costs, and variables costs. Therefore the HVRP is to find the fleet composition and a set of routes with minimum total cost. We give an integer programming formulation of the problem and propose an algorithm to solve it. Although the formulation has exponentially many variables, we can efficiently solve the linear programming relaxation of it by using the column generation technique. To generate profitable columns we solve a shortest path problem with capacity constraints using dynamic programming. After solving the linear programming relaxation, we apply a branch-and-bound procedure. We test the proposed algorithm on a set of benchmark instances. Test results show that the algorithm gives best-known solutions to almost all instances.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.5
• /
• pp.46-55
• /
• 2006

In general, 3-dimensional point-mass equation has been widely used for the trajectory optimization of the fixed-wing aircraft and reentry vehicle. But it should be modified and represent target vehicle's own characteristics. For a lighter-than-air vehicle such as an airship, there exists different and peculiar flight characteristics compared with the aircraft. The first part of this paper is to derive the dynamic equation of motion for the mid-altitude unmanned airship and the second part is to obtain the optimal trajectories under the minimal time flight given constraints. The trajectory optimization problem is converted into the nonlinear programming problem using Sequential Quadratic Programming approach. Finally numerical solutions are presented in the last part of the paper.