• Design & Manufacturing
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• v.2 no.1
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• pp.15-19
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• 2008

While recent industrial structure is various, it is small quantity batch production structure, and products requiring of various functions are increasing. In order to improve the quality of the sheared surface in cutting of inner structure bonded sheet metal the cut-off operation is mainly investigated, which is the typical shearing process in sheet metal forming technology. The sandwich sheet metals considered have inner structure which is constructed in the form of crimped expanded metal and woven metal. The inner structure is bonded between solid sheet by resistance welding or adhesive bonding. The shearing process is visualized by the computer vision system installed in front of the cut-off die and the sheared surface is measured and quantitatively compared with the help of the optical microscope after cut-off operation. From test results we found that the influence of sheared position can be observed and explained clearly and this result can be utilized to get the better sheared surface.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.345-348
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• 2002

This paper presents new fast scalar multiplier of elliptic curve cryptosystem that is regarded as next generation public-key crypto processor. For fast operation of scalar multiplication a finite field multiplier is designed with LFSR type of bit serial structure and a finite field inversion operator uses extended binary euclidean algorithm for reducing one multiplying operation on point operation. Also the use of the window non-adjacent form (WNAF) method can reduce addition operation of each other different points.

• The Journal of Korean Association of Computer Education
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• v.7 no.1
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• pp.27-35
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• 2004

Software documents consist of a number of objects and relationships between them, and structure of documents can be changed frequently. In the existing software version management models, changes in one object may be propagated to other objects unnecessarily. In this paper, we propose an efficient version management model for software objects based on history of operations applied to software objects. Operations applied to objects are recorded in the operation history, and those are used to retrieve versions of a document. Because versions of objects are stored and retrieved using the operation delta, it is not required to compare versions of a document to extract delta during check-in process. In addition, it can manage changes of structure of objects efficiently because it supports not only object creation, deletion, and update operation but also object move operation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.7
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• pp.633-640
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• 2002

In this paper, the small chip meander antenna for dual-frequency operation is presented. The proposed chip meander antennas was fabricated by the ceramic chip using LTCC-MLC process. It is a novel compact dual-frequency design using a meandered patch that achieves more degrees of freedom for adjusting dual-frequency operation and the size reduction with narrow frequency ratio. And it is proposed that the 3D structure for additional size reduction of the meander antenna. The size reduction of the 3D meander antenna is as large as 50 % as compared to the design for dual-frequency operation not using 3D structure. It is observed that the principle of dual-frequency operation through current distribution, return loss and radiation pattern.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.239-249
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• 2002

The Turbine Building of nuclear power plant is classified as non safety-related structure. During the operation, there may be possibility the original licensing basis would be changed, which makes non safety-related structure safety-related. Such a change in regulation requires utility to perform seismic qualification for the existing structure and their facilities. Thus it is meaningful to evaluate seismic margin of the existing non-qualified building structure. In addition, in this paper it is shown that a modification to the structure can enhance their seismic capacity.

• Journal of the Korea Safety Management & Science
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• v.5 no.1
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• pp.143-162
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• 2003

The governance structure of corporate is very important to raise the nation's economic efficiency and the operation result of firm. However, the innovation of corporate governance structure is a important problem to improve international confidence in our country, since most large corporate in our country has a promodern governance structure to be influenced in decision making of corporate group by minority governance-shareholder. Therefore, in our country the improvement of corporate governance structure is very urgent. This study examine the improvement device of corporate governance structure to be introduced in our country, and present the improvement direction to be suitable to our country's economic circumstance.

• Journal of Navigation and Port Research
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• v.30 no.6 s.112
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• pp.509-515
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• 2006

As international trade has been increased, the competition of major ports is getting hard. The objective of this competition is that to get more cargoes, so port managements and operators are struggling to obtain cargoes. In addition the competition structure has classified several forms bemuse of specialization, integration and subdivision of port players. In this paper, therefore, we analyze the change of competition structure by port players' development characteristics. In the result of this study, competition structure is divided into five groups as among nations, among ports, among container terminal operation companies, among global container terminal operation companies and among container terminal operation companies operated by shipping companies. And they have showed not only competition but also co-operation partly in order to get strategic position.

• Journal of the Korea Safety Management & Science
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• v.14 no.2
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• pp.49-54
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• 2012

As all kind of industry has developed, metal structure and machine instrument use bolt, pin, rivet and welding for assembly and combination. For pin and hinge, dimension accuracy is crucial to keep the operation and safety of the structure and machine instrument. In case of complex machine, the hinge for cover open-loop system is one of the significant design elements. Most of the hinges are being imported and assembled sine they give high technology development cost for its unit cost position. The reason is that the localization of hinge is inadequate. As the demand increase and the necessity of localization grow, it is now more important than ever to develop low cost structure. By the low cost structure, a new technology could be obtained for electronic product and structural hinge since it would enable for complex machine hinge to be guaranteed, technologically. Open-loop hinge is the link type and designed for the structure to keep constant open-loop. And, the hinge is examined in design stability by finite element analysis method. In this paper, the operation result is presented when the hinge for complex machine open-loop is designed for link type structure.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.10C
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• pp.1451-1459
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• 2004

In this paper, a low-power 32-point IMDCT structure is proposed for MP3. Through re-odering of IMDCT matrices, we propose the systolic structure operating with 16, 8, 4, 2, and 1 cycle, respectively. To reduce power consumption, multiplication of each sub blocks are implemented by add and shift operation with CSD(Canrmic sigled digit) form coefficients. To reduce, furthermore, the number of adders, we utilize the common sub-expression sharing techniques. With these techniques, the relative power consumption of the proposed structure is reduced by 58.4% comparison to the conventional structure using only 2's complement form coefficient. Validity of the proposed structure is proved through Verilog-HDL coding.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.2
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• pp.142-149
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• 2004

PMLSM(Permanent Magnet linear Synchronous Motor) has widely applied to industrial automations, machine tools and semiconductor equipments due to the merit on the reduction of noise, vibration and the superior dynamic characteristics in comparison to the conventional method, which uses mechanical transfer equipments. Especially, in the case of applying to Z-axis operation structure, control system needs the method of an initial angle setting and the improvement of up/down operation characteristics. This paper proposes an initial angle setting algorithm and a variable gain schedule using real speed and moving direction to improve up/down operation characteristics. The effectiveness of proposed algorithms Is demonstrated by comparing to a conventional gain system via 4-point absolute positions profile with each velocity, acceleration and deceleration.