• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1723-1728
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• 2008

An efficient synthetic route for carbocyclic versions of stavudine analogues and their evaluation on antiviral activity are described. The construction of an ethynylated quaternary carbon at the 4'-position of carbocyclic nucleosides was accomplished using Claisen rearrangement of 11 and ring-closing metathesis (RCM) of dienyne 14 as key transformations. An antiviral evaluation of the synthesized compounds, 20, 21, 22, and 25 against HIV-1, HSV-1, HSV-2, and HCMV showed that only the guanine analogue 25 is moderately active against HIV-1 in the MT-4 cell line ($EC_{50}$ = 11.91 $\mu$mol).

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2180-2184
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• 2010

We synthesized and tested the anti-HIV activity of the SATE prodrug of a 2'-methyl 5'-norcarbocyclic adenine analogue. The introduction of a methyl group in the 2'-position was performed by the addition of a carbonyl using isopropenyl magnesium bromide. The adenine base was efficiently coupled using the Mitsunobu reaction. The chemical stability study of the bis(SATE) derivative 18 was measured at neutral (pH 7.2) and slightly acid (milli-Q water, pH 5.5) pH, and compounds 16 and 18 were evaluated as potential anti-HIV-1 agents.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.497-498
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• 2006

Powder Injection Molding (PIM) has recently been recognized as an advanced manufacturing technology for low-cost mass production of metal or ceramic parts of complicated geometry. With this regards, design technology of dental scaler tip PIM mold, which has complex shape, with the help of computer-aided analysis for powder injection molding process was developed. Compter aided analysis results, such as filling pattern, weldline formation, and air vent position prediction were investigated and eventually showed good agreements with experimental results.

• Special Issue of the Society of Naval Architects of Korea
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• 2007.09a
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• pp.94-98
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• 2007

The latest development of the submarine oil field and the deep-sea explorer, FPSO is commonly proposed and used for offshore oil production. And because the fundamental requirement of FPSOs to remain moored at their position, they are unable to avoid severe weather and environment. FPSO normally operates head to the weather, and sensitive equipment located the exposed area will be influenced by green water damages, the damages may occur to both onboard equipment and topside structures with resulting risk to personnel. In this paper, the main focus considers the physical structures of green water protector in order to preserve topside structures, equipment and personnel from green water.

• Journal of Mechanical Science and Technology
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• v.17 no.3
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• pp.336-342
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• 2003

Increasing demand on precision machining using computerized numerical control (CNC) machines have necessitated that the tool move not only with the smallest possible position error but also with smoothly varying feedrates in 3-dimensional (3D) space. This paper presents the simultaneous 3D machining process investigated using a retrofitted PC-NC milling machine. To achieve the simultaneous 3-axis motions, a new precision interpolation algorithm for 3D Non Uniform Rational B-Spline (NURBS) curve is proposed. With this accurate and efficient algorithm for the generation of complex 3D shapes, a real-time NURBS interpolator was developed using a PC and the simultaneous 3D machining was accomplished satisfactorily.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.208-213
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• 2016

In order to detect the exact position of high-speed train, it is necessary to obtain location information from the transponder tag installed along the track. When the transponder tag receives the energizing signal from the train, it sends a telegram to the reader, which includes location information. In high-speed railway environment, this telegram can be corrupted by electromagnetic interference caused by onboard electric train power equipments or wayside devices. In order to assess the performance of transponder system under this harsh environment, we carried out field test using HEMU-430X. Field test results are briefly introduced and discussed for the evaluation of the transponder system under development.

• Journal of Korean Society for Quality Management
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• v.49 no.1
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• pp.1-15
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• 2021

Purpose: The purpose of this study was to propose a sensor fusion algorithm that integrates vehicle motion sensor(VMS) into the hybrid navigation system. Methods: How to evaluate the navigation performance was comparison test with the hybrid navigation system and the sensor fusion method. Results: The results of this study are as follows. It was found that the effects of the sensor fusion method and α value estimation were significant. Applying these greatly improves the navigation performance. Conclusion: For improving the reliability of navigation system, the sensor fusion method shows that the proposed method improves the navigation performance in a combat vehicle.

• Journal of Information Display
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• v.9 no.1
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• pp.6-13
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• 2008

Mobile phones use the embedded memory in LDI (LCD Driver IC). In memory accessing mode, data overlapping phenomenon can occur. These days, various contents such as DMB, Camera, Game are merged to phone. Accordingly, with more data transmission, there would be more data overlapping phenomenon in memory accessing mode. Human eyes perceive this data overlapping phenomenon as simply horizontal line noise. The cause of the data overlapping phenomenon was analysed in this paper. The data overlapping phenomenon can be changed by the speed of data transmission between the host and LDI. The optimum memory accessing position can be defined. This paper proposes a new algorithm for avoiding data overlapping.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.106-110
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• 2002

4S-Van is being developed in order to provide the spatial data rapidly and accurately. 4S-Van technique is a system for spatial data construction that is heart of 4S technique. Architecture of 4S-Van system consists of hardware integration part and post-processing part. Hardware part has GPS, INS, color CCD, camera, B/W CCD camera, infrared rays camera, and laser. Software part has GPS/INS integration algorithm, coordinate conversion, lens correction, camera orientation correction, and three dimension position production. In this paper, we suggest that adequate 4S-Van design is needed according to application environment from various test results.

• Korean Management Science Review
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• v.34 no.2
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• pp.103-113
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• 2017

The artillery is a key element of the ground forces operation during wartime, and the military engineers support the artillery position development operation to support the smooth operation of the artillery. In establishing the artillery position development operation plan, the commander requires more than his intuition to find the best option reflecting a number of elements of the battlefield situation which changes every minute. Moreover, the number of available equipment is smaller than the number of required position developments, and the effective equipment operation becomes essential element of this issue. This study quantified the capability of the available engineering equipment, organized a number of teams enabling equipment to put out the maximum capacity based on the quantified figures, and formed the model which allocates the team to the developing points to minimize the developing time. The goal programming method was applied to resolve the problem. The developed model was applied to compare the total mission duration following the number of teams, the variable for commander's decision, and the result of this study can be used as the quantitative data for commander's decision making process in establishing the artillery position development support operation through effective equipment management.