• 대한기계학회논문집A
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• 제29권2호
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• pp.303-310
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• 2005

The systems with probe and SIL(Solid Immersion Lens) mechanisms have been researched as the technology to perform NFR(Near Field Recording). Most of them use the flying head mechanism to accomplish high recording density and fast data transfer rate. In this paper, ABS shape of flying head was optimized with the object of securing the maximum compliance ability of OFH. We suggest low different optimization processes to predict the static flying characteristics for the OFH. Two different approximation methods, regression analysis and back propagation neural network were used. And we compared the result of directly connected(between CAE and optimizer) method and two approximated optimization results. Design Optimization Tool(DOT) and ${\mu}GA$ were used as the optimizers.

• 천문학회보
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• 제40권2호
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• pp.44.1-44.1
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• 2015

We set up a project to make spectrometers for single dish observations of the Korean VLBI Network (KVN), a new future multi-beam receiver of the ASTE (Atacama Submillimeter Telescope Experiment), and the total power (TP) antennas of the Atacama Large Millimeter/submillimeter Array (ALMA). Traditionally, spectrometers based on ASIC (Application-Specific Integrated circuit) and FPGA (Field-Programmable Gate Array) have been used in radio astronomy. It is, however, that a Graphics Processing Unit (GPU) technology is now viable for spectrometers due to the rapid improvement of its performance. A high-resolution spectrometer should have the following functions: poly-phase filter, data-bit conversion, fast Fourier transform, and complex multiplication. We wrote a program based on CUDA (Compute Unified Device Architecture) for a GPU spectrometer. We measured its performance using two GPU cards, Titan X and K40m, from NVIDIA. A non-optimized GPU code can process a data stream of around 2 GHz bandwidth, which is enough for the KVN spectrometer and promising for the ASTE and ALMA TP spectrometers.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1998년도 유체기계 연구개발 발표회 논문집
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• pp.105-114
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• 1998

Flow field and near-field noise of a centrifugal fan has been studied with an efrcient compressible method and STAR-CD. The flow field of the centrifugal fan is assumed two-dimensional. Most of the compressible studies has been done by inviscid solver because viscous simulation shows little difference. The near field noise is estimated in term s of sound pressure level in frequency domain transformed from the computed pressure fluctuations using FFT. The simulation has been done on various design elements such as impeller blade shapes, the number of blades and cut-off clearance. The comparison shows that the number of blades has a significant effect on near-field noise without losing aerodynamic performance.

• 한국자기공명학회논문지
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• 제21권1호
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• pp.26-30
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• 2017

Dynamic properties of proteins can present key information on protein-ligand and protein-protein interaction. Despite their usefulness, the properties of protein dynamics have not been obtained easily due to protein stability and short-term measurement. Here, it is shown that combined method for analysis of dynamical properties. It utilizes predicted order parameter and NMR relaxation data such as $T_1$, $T_2$, and heteronuclear NOE. The suggested method could be used to know the flexibility of protein roughly without precise dynamical parameters such as order parameters through model-free analysis.

• Journal of Mechanical Science and Technology
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• 제14권11호
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• pp.1206-1215
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• 2000

This paper introduces the application of evolutionary fuzzy modeling (EFM) in constructing global function approximations to subsequent use in non-gradient based optimizations strategies. The fuzzy logic is employed for express the relationship between input training pattern in form of linguistic fuzzy rules. EFM is used to determine the optimal values of membership function parameters by adapting fuzzy rules available. In the study, genetic algorithms (GA's) treat a set of membership function parameters as design variables and evolve them until the mean square error between defuzzified outputs and actual target values are minimized. We also discuss the enhanced accuracy of function approximations, comparing with traditional response surface methods by using polynomial interpolation and back propagation neural networks in its ability to handle the typical benchmark problems.

• 한국자기공명학회논문지
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• 제21권3호
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• pp.85-89
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• 2017

Pyrazinamidase (PncA) from Mycobacterium tuberculosis is the hydrolytic enzyme (hydrolase) that can hydrolyze substrate PZA to active form pyrazoic acid (POA). To investigate hydrolytic reaction of M. tuberculosis PncA, 1D NMR spectra were monitored at various molar ratios of PncA and PZA. The line-width of PZA was changed as PncA was added into PZA with different molar ratios. These results suggested that determination of PncA enzymatic activity could potentially serve as an indirect measure of PZA susceptibility.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2013년도 제48차 하계학술발표논문집 21권2호
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• pp.409-413
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• 2013

21세기의 인터넷은 통신기술의 진보에 따라 정보의 전달과 상업적인 거래의 플랫폼부터 점점 사람들의 생활과 밀접하게 연관된 일상적인 공간이며, 공동체를 형성하고 자기정체성을 표현하는 사회활동 공간으로 발전하고 있다. 이와 함께, 사이버 공간에서 개인화, 상호작용, 참여, 사회성 등의 특징으로 대별되는 소셜 네트워크 서비스(Social Network Service, SNS)가 전 세계적으로 확산되고 있다. 본 연구에서는 기존문헌 연구를 바탕으로 바람직한 SNS가 갖추어야 하는 특성(시스템특성, 서비스특성, 정보특성, 감성특성)을 도출하고 이러한 특성과 서비스 채택의도간의 관련성이 있는가를 파악하고자 하였다. 또한, SNS 특성과 서비스 채택의도간의 관련성이 개인의 성향에 따라 차이가 있는가를 검토하고자 하였다. SNS 이용자를 대상으로 설문지를 의뢰하여 통계분석을 실시한 결과, SNS 특성이 서비스 채택의도에 통계적으로 유의한 수준에서 긍정적 영향을 미치고 있으며, SNS 특성과 서비스 채택의도간의 관련성이 개인적 성향에 따라 차이가 존재하고 있는 것으로 파악되었다.

• 천문학회보
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• 제39권2호
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• pp.116.1-116.1
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• 2014

Korea officially joined the ALMA (Atacama Large Millimeter/submillimeter Array) project on August 17, 2014. Korea was allowed to apply for the Cycle 2 call-for-proposal before joining the project. Korea submitted 17 proposals, and 4 of them were selected as high-priority. The fund of an 11-year Korean ALMA project in the KASI (Korea Astronomy and Space Science Institute) was approved. The project team formulated an ARC (ALMA Regional Center) node at the KASI and already started its supporting activities for the Korean Astronomical Society. The team also set up a future development plan for ASTE (Atacama Submillimeter Telescope Experiment) and ALMA. A couple of engineers are now doing concept design of a multi-beam receiver system for the ASTE, Because of the ALMA participation, Korea could also access open-use time of ASTE and Mopra telescopes organized by Japan. As of this writing, EACOA (East Asia Core Observatories Association) is now under discussion on making an organization called "East Asian Observatory" and the possible operation of JCMT (James Clerk Maxwell Telescope). I will briefly mention the future prospect of these activities.

• 천문학회보
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• 제39권2호
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• pp.116.2-116.2
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• 2014

As Korean engineering contribution to ALMA enhancement, development of focal plane arrays(FPAs) for the total power array in ALMA compact array has been projected mainly to increase mapping speed in interferometric multi-pointing observation(mosaicking). To tackle engineering issues expected in order to be compatible with the existing ALMA receivers, we plan to develop a prototype 300-500 GHz heterodyne FPA system including a software spectrometer using GPU clusters for ASTE(Atacama Submillimeter Telescope Experiment) telescope by 2017.

• 천문학회보
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• 제41권2호
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• pp.59.2-59.2
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• 2016

As an enhancement to increase mapping speed of the current ALMA TP array, development of a focal plane array system working at ultra wide frequency range of 275-500 GHz with GPU-based software spectrometers has been carried out since 2015. Major progresses on such component development as wideband DSB mixers, a profiled corrugated horn, receiver optics, LO system and GPU-based spectrometer are reviewed with brief introduction to implication of ALMA 2030 for technical implementation.