• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1993.10a
• /
• pp.118-118
• /
• 1993

We consider a discrete event dynamic system called periodic job shop, where an identical mixture of items called minimal part set(MPS) is repetitively produced in the same processing order and the primary performance measure is the cycle time. The precedence relationships among events(starts of operations) are represented by a directed graph with rocurront otructure. When each operation starts as soon as all its preceding operations complete(called earliest starting), the occurrences of events are modeled in a linear system using a special algebra called minimax algebra. By investigating the eigenvalues and the eigenvectors, we develop conditions on the directed graph for which a stable steady state or a finite eigenvector exists. We demonstrate that each finite eigenvector, characterized as a finite linear combination of a class of eigenvalue, is the minimum among all the feasible schedules and an identical schedule pattern repeats every MPS. We develop an efficient algorithm to find a schedule among such schedules that minimizes a secondary performance measure related to work-in-process inventory. As a by-product of the linear system approach, we also propose a way of characterizing stable steady states of a class of discrete event dynamic systems.

• Journal of information and communication convergence engineering
• /
• v.6 no.4
• /
• pp.430-433
• /
• 2008

A merged altimeter data products are used to estimate sea level variation in the East Sea between 1993 and 2006. The altimeter data show a high correlation coefficient (0.85) after applying gaussian low pass filter for 180days at Ulleung island. The both of Mukho coast and Ulleung island are minimal sea level in March to May and maximal in September to November. Sea level of Mukho coast is higher than that of Ulleung island during March to May, while Mukho coast is lower during September to November because the North Korea Cold Current flows along the coast line of Mukho. Generally sea level variation at Mukho coast and Ulleung island associated with seasonal variations.

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.538-543
• /
• 2007

A procedure is proposed to generate optimal grid with minimal user intervention while keeping a prescribed level of accuracy, using an adaptive X-FEM and applied to shape optimization. In spite of various advantages of X-FEM, however, there are several obstacles for practical applications. Because of using a uniform background mesh and additional degree of freedoms for enrichment, an X-FEM is usually computationally more expensive than traditional finite element method. Furthermore, there are often accuracy problems. For an automatic procedure of optimal mesh generation, an h-adaptive scheme and a posteriori error estimation obtained by a post-processing process are utilized. The procedure is shown by 2-D shape optimization examples.

• Proceedings of the KAIS Fall Conference
• /
• 2007.05a
• /
• pp.253-255
• /
• 2007

The increasing requirement for consistency and quality in the automotive industry started the development of a Machine Vision Inspection System (MVIS) for a car seat bottom cushion frame with the goal of providing a higher precision Inspection System with minimal components and less human intervention. The modifications made to an existing PC-based MVIS were shown to improve the accuracy and precision of the system. By using four monochrome cameras, the working distance was lowered and the image distortions were lessened without resorting to extensive image processing. The inspection scripts were evaluated if it could recognize good and bad products and were shown to be robust and able to reach an acceptable level of precision. It was also shown that the amount of human interaction was lessened.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07b
• /
• pp.1054-1056
• /
• 2002

High temperature Kermal diffusion from $POCl_3$ source usually used for conventional process through put of a cell manufacturing line and potentially reduce cell efficiency through bulk like time degradation. To fabricate high efficiency solar cells with minimal thermal processing, spin-on-doping(SOD) technique can be employed to emitter diffusion of a silicon solar cell. A technique is presented to emitter doping of a mono-crystalline solar cell using spin-on doping (SOD). Moreover it is shown that the sheet resistance variation with RTA temperature and time fer mono-crystalline and multi-crystalline silicon samples. This novel SOD technique was successfully used to produces 11.3% efficiency l04mm by 104mm size mono-crystalline silicon solar cells.

• Proceedings of the IEEK Conference
• /
• 2003.07b
• /
• pp.859-862
• /
• 2003

This paper proposes an emulation environment for SoC designs using small number of large gate-count FPGA's and a PC system. To overcome the pin limitation problem in partitioning the design when the design size overwhelms the FPGA gate count, we use bus splitter modules that replicate on-chip bus signals in one FPGA to arbitrary number of other FPGA's with minimal pin count. The proposed scheme is applied to the emulation of 2 million gate multimedia processing chip using two Xilinx Viretex-2 6000 FPGA devices in 6.6MHz operating frequency. An ARM core, memories, camera and LCD display are modeled in software using dual 2GHz Pentium-III processors. This scheme can be utilized for more than 2 FPGA's in the same ways as two FPGA case without losing emulation speed.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.9 no.2
• /
• pp.67-72
• /
• 1989

In nuclear power plants, nondestructive examinations(NDE) plays an important role in ensuring the integrity and reliability operation. As the number of plants and operational time increased, manual handling of voluminous data associated with PSI/ISI(preservice/inservice inspection) could result in many errors or mistakes in writing the examination plan or other reports. Several new approaches to process the data have been attempted and DBMS(Data Base Management System) has been well known concept with a faster and more accurate data processing. This paper proposes an application program, called NDTSYS designed with DBMS in micro computer. The program could be used for a tool to add new records to a data base, change existing records, delete records and request reports with the data base. It would be helpful to the user who manage the PSI/ISI data with minimal time and effort.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.20 no.1
• /
• pp.7-14
• /
• 1983

Linear feature such as lines and curves are one of important features in image processing. In this paper, new method of linear feature detection is suggested. Also, we have studied approximation technique which transforms detected linear feature into data structure for the practical. This method is based on graph theory and principle of this method is based on minimal spanning tree concept which is widely used in edge linking process. By postprocessing, Hairs and inconsistent line segments are removed. To approximate and describe traced linear feature, piecewise linear approximation is adapted. The algorithm is demonstrated through computer simulations.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.114-115
• /
• 2012

In this paper, we improve pre-processing method using markers and propose accurate lattice extraction of elemental image array using minimal markers to correct distortion. We propose a method that almost equal performance of existing method and be more simple calculation. For our method, we did computational experiments and compared with reconstructed images.

• Journal of Plant Biotechnology
• /
• v.36 no.4
• /
• pp.301-308
• /
• 2009

Higher agricultural commodity prices are a particular concern for food importing countries like Korea that has a very low self-sufficiency ratio. Korean people eat approximately 4.5 million metric tons of rice each year, which is met without a problem by domestic production. The domestic production of corn and soybean which are important raw materials for commercial food processing and livestock feed is only minimal. Demands of corn and soybean in Korea are approximately 7.2 million and 1.3 million metric tons per year, respectively. Since Korean consumers are reluctant to accept biotech (GM) foods, Korean food processors are fighting an up-hill battle in purchasing non-biotech (non- GM) crops which are becoming scarce.