• 전기학회논문지
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• 제68권3호
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• pp.405-415
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• 2019

The considerations of the electrical device' characteristics and the customers' satisfaction have been important criteria for efficient smart grid systems. In general, an electrical device is classified into a non-interruptible device or an interruptible device. The consideration of the type is an essential information for the efficient smart grid scheduling. In addition, customers' scheduling preferences or satisfactions have to be considered simultaneously. However, the existing research studies failed to consider both criteria. This paper proposes a new and efficient smart grid scheduling framework considering both criteria. The framework consists of two modules - 1) A day-head smart grid scheduling algorithm and 2) Real-time sudden demand negotiation framework. The first method generates the smart grid schedule efficiently using an embedded genetic algorithm with the consideration of the device's characteristics. Then, in case of sudden electrical demands, the second method generates the more efficient real-time smart grid schedules considering both criteria. In order to show the effectiveness of the proposed framework, comparisons with the existing relevant research studies are provided under various electricity demand scenarios.

• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1741-1744
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• 2013

A new polymeric catalyst was prepared by supporting $GaCl_3$ on cross-linked polyvinylpyrrolidone ($GaCl_3$/PVP). This catalyst was employed for efficient and regioselective ring-opening reaction of epoxides by various alcohols under solvent-free conditions at room temperature. In our procedure, this heterogeneous catalyst was used at neutral and mild reaction conditions to afford high yields of ${\beta}$-alkoxy alcohols. Also, regioselective conversion of epoxides to ${\beta}$-azidohydrines was accomplished by sodium azide in MeOH in the presence of $GaCl_3$/PVP at room temperature. $GaCl_3$/PVP is a non-hygroscopic and recoverable catalyst and is easily separated from reaction mixture by a simple filtration and re-used repeatedly. Also, this catalyst has good handling and can be stored for long time without any reducing of its reactivity.

• 한국CDE학회논문집
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• 제9권4호
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• pp.294-305
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• 2004

Highly detailed geometric models are rapidly becoming commonplace in computer graphics and other applications. These complex models, which is often represented as complex1 triangle meshes, mainly suffer from the vast memory requirement for real-time manipulation of arbitrary geometric shapes without loss of data. Various techniques have been devised to challenge these problems in views of geometric processing, not a representation scheme. This paper proposes the new mesh structure for the compact representation and the efficient handling of the highly complex models. To verify the compactness and the efficiency, the memory requirement of our representation is first investigated and compared with other existing representations. And then we analyze the time complexity of our data structure by the most critical operation, that is, the enumeration of the so-called one-ring neighborhood of a vertex. Finally, we evaluate some elementary modeling functions such as mesh smoothing, simplification, and subdivision, which is to demonstrate the effectiveness and robustness of our mesh structure in the context of the geometric modeling and processing.

• 대한산업공학회지
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• 제23권3호
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• pp.559-580
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• 1997

It is essential to construct on efficient material flow system for the successful introduction of automated manufacturing systems. Automated Guided Vehicle System(AGVS) ploys a significant role more and more in modern manufacturing environments, because of the flexibility and the precision they offer. However, as the size and the complexity of systems increase, the problems of dispatching, routing and scheduling of AGVs became complicated due to their independent and asynchronous demands. In this paper, we review relevant papers, and provide a new and more efficient method for partitioning the AGV system by introducing the concept of Central Path. This method named Central Path design has advantages, since each partitioned workstation group is served by one AGV and the material handling between groups is performed by special AGV that is used for the Central Path. Therefore the congestion problems never occur. Furthermore Central Path Design has a high flexibility for alteration and extension of system. Finally, we demonstrate its efficiency using simulation.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1998년도 추계학술대회 논문집
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• pp.67-70
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• 1998

The computational speed of interior point method of linear programming depends on the speed of Cholesky factorization to solve AΘA$^{T}$ $\Delta$y=b. If the coefficient matrix A has dense columns then the matrix AΘA$^{T}$ becomes a dense matrix. This causes Cholesky factorization to be slow. The Schur complement method is applied to treat dense columns in many implementations but suffers from its numerical unstability. We study efficient implementation of Schur complement method. We achieve improvements in computational speed and numerical stability.rical stability.

• 디지털콘텐츠학회 논문지
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• 제3권2호
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• pp.177-185
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• 2002

E-Business분야는 다양한 소비자의 욕구를 지원하기 위한 컨텐츠를 기반으로 활성화되고있다. 즉, 효율적인 비즈니스 트랜잭션 처리를 위한 기법들이 연구되고 있으며 EJB와 같은 웹 기반 컴포넌트 기술이 응용되고 있다. 따라서, 본 연구는 웹 기반 EJB 컴포넌트 기술을 응용한 효율적인 E-Business 컨텐츠 관리 및 처리를 위한 워크플로우를 설계하였다. 이에 따라, 다양한 컨텐츠의 핸들링을 위하여 웹 서버 컴포넌트 모델인 EJB를 사용하였으며, 기능단위의 컴포넌트들이 다양한 컨텐츠를 처리함으로써 재사용, 유지보수등의 시스템 개발 효율성을 높일 수 있다.

• 대한기계학회논문집A
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• 제25권3호
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• pp.443-451
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• 2001

This paper addresses an on-line scheduling method for track systems in semiconductor fabrication. A track system is a clustered equipment performing photolithography process in semiconductor fabrication. Trends toward high automation and flexibility in the track systems accelerate the necessity of the intelligent controller that can guarantee reliability and optimize productivity of the track systems. This paper proposes an-efficient on-line scheduling method that can avoid deadlock inherent to track systems and optimize the productivity. We employ two procedures for the on-line scheduling. First, we define potential deadlock set to apply deadlock avoidance policy efficiently. After introducing the potential deadlock set, we propose a deadlock avoidance policy using an on-line Gantt chart, which can generate optimal near-optimal schedule without deadlock. The proposed on-line scheduling method is shown to be efficient in handling deadlock inherent to the track systems through simulation.

• 한국정밀공학회지
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• 제25권3호
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• pp.147-156
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• 2008

A new approach based on cone prism intersection method combined with sorting algorithm is proposed for the fast and robust signed distance field computation. In the method, the space bounding the geometric model composed of triangular net is divided into multiple smaller cells. For the efficient calculation of distance fields, valid points among the triangular net which will generate minimum distances with current cell are selected by checking the intersection between current cell and cone prism generated at each point. The method is simple to implement and able to achieve an order of magnitude improvement in the computation time as compared to earlier approaches. Further the method is robust in handling the traditional sign problems. The validity of the suggested method was demonstrated by providing numerous examples including Boolean operation, shape deformation and morphing of complex geometric models.

• 한국시뮬레이션학회논문지
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• 제14권4호
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• pp.31-41
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• 2005

This paper proposes a novel Web Services enhancement method, which enhances XML based e-commerce and Web Services securely and efficiently. Recently, the ratio of XML Denial of Services (XDOS) is increased significantly However, XML data is visible only at the target application site or the application layer. Thus, an efficient and secure mechanism handling XML data on the network layer to provide fast performance on the server and protect XDOS at network level is strongly required basic component. This paper presents many issues and gives useful results from the various experiments to support an implemented XAN platform.

• 산업공학
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• 제11권1호
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• pp.97-103
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• 1998

In these days many people have studied on the berthing problem. The operation rules differ from port so port and the problem is highly dependent on the environment of port. The purpose of this study is to develop a decision support system decision makers of the berthing problem for Inchon Port. The system is developed with graphic user interface(GUI) using user-interactive approach and some general and specific rules for Inchon Prot are considered. The system is composed of the following four parts ; the input/output part, the automatic berthing part by the system using rules, the manual berthing part by user, and the part for modifying results or handling exceptional events. The system is designed to assign ship to berths by matching the characteristics with environmental and operational constraints of Inchon Port. We expect that this system can provide decision makers with an efficient and fast way to berthing and can reduce wastes of time, space, and manpower in port operations.