• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.8
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• pp.307-317
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• 2003

We analyze the performance of MC-CDMA and MC-DS/CDMA system on quasi-synchronized moble satellite return link. Quasi-synchronization is considered that chip offset between terminals is within a few chips. In 10-3 BER, performance of MC-DS/CDMA system with walsh code is 0.3dB better than that of MC-CDMA system when the number of user is 5 from -0.5 $T_{c}$ to 0.5 $T_{c}$ quasi-synchronization of MC-DS/CDMA system and from -5/64 $T_{c}$ $^{MC}$ to 5/64 $T_{c}$ $^{MC}$ quasi-synchronization of MC-CDMA system. MC-DS/CDMA system with walsh code is over 0.2dB better than that of MC-DS/CDMA system with extended m code and gold code. MC-CDMA system with walsh code is over 1.2dB better than that of MC-CDMA system with gold code when the number of user is 5 and lower than from -5/32 $T_{c}$ $^{MC}$ to 5/32 $T_{c}$ $^{MC}$ quasi-synchronization.

• Journal of Industrial Technology
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• v.34
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• pp.33-37
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• 2014

The current companion animal registration system is based on implanting microchip into animal body. Thus, the maintenance cost is high, and it may cause dangerous effect on the animal health. Moreover, it is very inconvenient in utilizing the information. This paper presents a pet registration and information providing system based on QR code for low cost and convenience in field application. The owner can simply register pet information on the web server, print the QR code and attach it to the pet. Any person can scan the QR code by smart phone, identify the information, and call the owner directly.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.501-504
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• 2000

In this paper, performance of a pseudonoise (PN) code tracking loop is analyzed and simulated for a direct-sequence/code-division multiple access ( DS/CDMA) system with imperfect power control in a multipath fading channel. A noncoherent first-order delay-locked loop (DLL) is considered as a PN code tracking loop. Power control error is modeled as a log-normally distributed random variable. From the simulation results, it is shown that for smaller discriminator offset, tracking jitter performance is improved while MTLL performance is degraded. It is shown that large power control error and heavy shadowing substantially degrade the PN tracking performance. The analysis in this paper can be applicable to design of PN code tracking loop for a DS/CDMA system.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4280-4295
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• 2022

In this paper, a new multi-group neutron-gamma transport calculation code system STRAUM-MATXST for complicated geometrical problems is introduced and its development status including numerical tests is presented. In this code system, the MATXST (MATXS-based Cross Section Processor for S_N Transport) code generates multi-group neutron and gamma cross sections by processing MATXS format libraries generated using NJOY and the STRAUM (S_N Transport for Radiation Analysis with Unstructured Meshes) code performs multi-group neutron-gamma coupled transport calculation using tetrahedral meshes. In particular, this work presents the recent implementation and its test results of the Krylov subspace methods (i.e., Bi-CGSTAB and GMRES(m)) with preconditioners using DSA (Diffusion Synthetic Acceleration) and TSA (Transport Synthetic Acceleration). In addition, the Krylov subspace methods for accelerating the energy-group coupling iteration through thermal up-scatterings are implemented with new multi-group block DSA and TSA preconditioners in STRAUM.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.335-338
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• 2005

In this paper, we propose a downlink power control scheme to apply in the unequal error protection multi-code CDMA mobile medicine system. The mobile medicine system contains (i) blood pressure and body temperature measurement value, (ii) ECG medical signals measured by the electrocardiogram device, (iii) mobile patient's history, (iv) G.729 audio signal, MPEG-4 CCD sensor video signal, and JPEG2000 medical image. By the help of the multi-code CDMA spread spectrum communication system with downlink power control scheme and unequal error protection strategy, it is possible to transmit mobile medicine media and meet the quality of service. Numerical analysis and simulation results show that the system is a well transmission platform in mobile medicine.

• Journal of the Korean Society of Safety
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• v.27 no.5
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• pp.55-63
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• 2012

The purpose of this study is to suggest new safety code to improve the safety of the flare safety system. Firstly, we analyzed the major accidents occurred at the flare system since 1996 and proposed 3 articles which is required to be added newly to the existing KOSHA code. Secondly, we also performed the HAZOP study for each study node and also suggested 5 articles. Finally, we analyzed the commented contents of PSM reports which have been submitted from the enterprise located in Honam province since 2005 and proposed 5 articles as well. We understand that all 13 articles proposed above, should be added to the KOSHA code in order to improve the safety in the flare system and to prevent the major fire and explosion accidents in the design stage.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.259-264
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• 2003

Failure code system must include data of maintenance history, classification of failure, affective range and situation when failure occur. But the present failure code system have used a simple code system for classification to include only merchandise and tools. Advantageously, expansional standard code system that will be developed, it make that users can take steps of standardized overhaul and inspection as proposal maintain contents when failure occur or something wrong in vehicle of urban transit. Standardized failure codes must be developed and used that manufacturing companies and urban transit operating companies in order to give effect to maintenance works.

• Proceedings of the Korea Society for Simulation Conference
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• 2004.05a
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• pp.101-108
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• 2004

KEPRI has developed an Nuclear Steam Supply System(NSSS) thermal-hydraulics simulation program (called ARTS-KORI), based on the best-estimate system code, RETRAN, as a part of the development project for the KORI unit 1 Nuclear Power Plant Simulator. A number of code modifications, such as simplifications and removing of discontinuities of the physical correlations, were made in order to change the RETRAN code as an nuclear Steam Supply System thermal-hydraulics engine in the simulator. Some simplified models and a backup system were also developed. This paper briefly presents the results of non-integrated standalone test of ARTS-KORI.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.6_2
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• pp.1091-1095
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• 2022

Dynamic stability of the main spindle system shall be ensured when operating the planer miller for remanufacturing the planer miller. This paper explains the analysis process that determines the stability of the planer miller spindle system in the design stage using ANSYS, an analysis program. First, the dynamic stability of the main spindle system is verified through risk speed analysis in the rated RPM range of the planer miller through ANSYS Modal Analysis, and second, the stability and durability of the main spindle system are verified through ANSYS nCode Analysis.

• Steel and Composite Structures
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• v.50 no.6
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• pp.643-658
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• 2024

The main aim of this study is to quantify the code seismic design coefficients of the RCS system, which consisted of reinforced concrete columns and steel beams, based on the FEMA P-695 methodology. The underlying intention is to evaluate the seismic performance of the RCS system at the system level rather than the connection level. A set of 24 archetype buildings with a various number of stories, beam span lengths, gravity load levels, and seismic load levels are selected and designed based on the prevailing code requirements. Nonlinear analytical models are developed and validated by experimental tests. The pushover and response history dynamic analyses are conducted to evaluate the required data in the performance quantification process. The results show that the design coefficients suggested by the code are acceptable. However, the level of conservatism is very high. Thus, it is possible to use a larger R-factor in the design process or make some relaxations in the design requirements related to this structural system.