• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.70.1-70.1
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• 2013

We present long-term optical to NIR data of the tidal disruption object, Swift J1644+57. The data were obtained with CQUEAN, UKIRT WFCAM observations. We analyze the morphology of the host galaxy of this object and decompose the bulge component using high resolution HST WFC3 images. We conclude that the host galaxy is bulge dominant. We also estimate the multi-band fluxes of the host galaxy through the light curves based on the long-term observational data. We fit the SED models to the multi-band fluxes of the host galaxy and determine its stellar mass. Finally, we estimate the mass of the central super massive black hole which is thought to be the main role of the tidal disruption event. The estimated stellar mass and black hole mass are $10^{9.1}M_{\odot}$, $10^{6.8}M_{\odot}$ respectively. We compare our results to other results that have studied before.

• Transactions of the Korean Society of Mechanical Engineers
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• v.7 no.3
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• pp.286-293
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• 1983

This study measures polar compressive thickness strain and radius of curvature of the bulge through Moire' method in bulge test. Hill's and Alexander's bulge theories, instability conditions derived by Swift's, Hill's, Alexander's and wang's theories, are also investigated, compared with Moire' experimental results. In order to review and compare with Hill's and Alexander's bulge theories, the relationships between radius of curvature of the bulge and polar height, between polar compressive thickness strain and polar height, are used. Mild steel, soft copper and commercial pure aluminum are used in Moire' experiment. According to this study, Hill's and Alexander's bulge theories, instability conditions derived by Swift's, Hill's, Alexander's and Wang's theories are agreement to Moire' experiment results.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.11
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• pp.1096-1103
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• 2010

This paper proposes CDC (Continuous Damping Control) algorithm and verifies in multi-body dynamic vehicle. In order to distinguish a road profile on driving, waviness calculated by the filtered vertical-accelerations of sprung and unsprung masses is introduced. Sky-hook control is used at a low waviness road and constant damping level control is used at a high waviness road, where the hard damping level is determined by waviness, roll rate, acceleration, and deceleration. The damping levels of ride, anti-roll, anti-squat, and anti-dive modules are calculated by tuning parameters which is dependent upon vehicle velocity. Therefore this high tunable algorithm is useful to improve the ride and handling performance under various driving conditions. In the simulations, tire and dampers are modelled by SWIFT (Short Wavelength Intermediate Frequency Tire) model and 1st order delay model, and results are compared with conventional damper's.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.48.2-48.2
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• 2014

We present long-term optical to NIR data of the tidal disruption object, Swift J1644+57. The data were obtained with CQUEAN, UKIRT WFCAM observations. We analyze the morphology of the host galaxy of this object and decompose the bulge component using high resolution HST WFC3 images. We conclude that the host galaxy is bulge dominant. We also estimate the multi-band fluxes of the host galaxy through the light curves based on the long-term observational data. We fit the SED models to the multi-band fluxes of the host galaxy and determine its stellar mass. Finally, we estimate the mass of the central super massive black hole which is responsible for the tidal disruption event. The estimated stellar mass and black hole mass are ${\sim}10^{9.1}M_{\odot}$, ${\sim}10^{6.8}M_{\odot}$, respectively. We compare our results to other previous estimates.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.213-216
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• 2014

본 논문에서는 웹 개발에 있어 확장성 높은 스프링 프레임워크 기반의 오픈소스 커머스 스위프트인 브로드리프 커머스(broadleaf commerce)를 기반으로 한 전자 상거래 웹 사이트 구축의 국내 동향과 이 프레임워크를 통해 만들어진 웹 사이트를 벤치마킹 하고 브로드리프 커머스의 특징과 장점들을 분석하여 어떤 전자상거래 웹을 만들어야 할지 그 방향을 제시한다.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.475-476
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• 2015

We analyze the host galaxy of the tidal disruption object, Swift J1644+57, based on long-term optical to NIR data obtained with CQUEAN and UKIRT WFCAM observations. We decompose the bulge component using high resolution HST WFC3 images. We conclude that the host galaxy is bulge dominant. We investigate optical to NIR light curves and estimate the multi-band fluxes of the host galaxy. We fit spectral energy distribution (SED) models in order to determine the stellar mass. Finally, we estimate the mass of the black hole in the center of the host galaxy based on several scale relations.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.234-237
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• 2015

현재 RDBMS는 대부분 블록기반의 스토리지를 사용하는데 오늘날 정형화 되지 않은 데이터 타입에 대한 요청이 많아지고 있어서 오브젝트 스토리지를 사용하려는 연구가 활발히 진행 되고 있다. 그래서 본 논문을 통해 오브젝트 스토리지를 사용하는 RDBMS 환경을 제안한다. 오브젝트 스토리지 중 오픈 소스로 많이 사용되고 있는 Swift와 Ceph를 사용하여 시스템을 구축, 두 시스템간의 파일 및 RDBMS 성능비교를 진행하였다. Swift와 Ceph는 동일한 인터페이스가 아니기에 중간에 새로운 레이어를 추가하여 POSIX 환경에서 테스트가 가능하도록 하였다. 데이터베이스는 Postgresql을 사용하였고 두 시스템 간의 성능측정은 파일벤치마크인 IOzone 그리고 Posgresql에서 지원하는 TPC-B 기반 pgbench를 사용, 노드 확장성과 가상 클라이언트 수를 비교표로 활용하여 실험을 진행하였다.

• International Commerce and Information Review
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• v.17 no.2
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• pp.3-18
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• 2015

This thesis examines the performance and improvement strategy of SWIFTNet TSU's BPO for computerization and suggests the following results: First, the URBPO should be legally complemented, and the SWIFT and banks need to keep improving the systems to meet trade parties' diverse needs. Second, the SWIFTNet TSU's BPO should have an institutionally unified sharing platform with security, stability and convenience. In other words, it is needed to develop services which meet e-payment paradigm and international and regional environments through continued analysis on market changes and flow. Third, in order for the SWIFTNet TSU BPO to evolve into a perfect global system, there should be an innovative payment solution which can meet all trade parties all over the world. For this, technology standardization for a worldwide e-trade payment system is essential. Lastly, based on the results derived from this study, an analysis framework with which more diverse and practical environmental variables can be analyzed should be developed.

• Journal of the Korea Convergence Society
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• v.8 no.7
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• pp.29-37
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• 2017

Compared to the commercial networks, R&E networks have the strength such as flexible network engineering and design. Based on those features of R&E networks, we propose our storage cloud service model which supports general-purpose network users in a central region and experimental network users in distributed regions simultaneously. We prototype our service model utilizing multiple proxy controllers of OpenStack Swift service in order to deploy several regions via experimental backbone networks. Our experiments on the influence of the network latency and the size of data to be transmitted show that the bigger size of data is preferable to the smaller size of data in an experimental backbone network where the network latency increases within 10ms because the rate of throughput decline in the bigger object is comparatively small. It means that our service model is appropriate for experimental network users who directly access the service in order to move intermittently high volume of data as well as normal users in the central region who access the service frequently.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.8
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• pp.889-897
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• 2011

In this work, we investigated the theoretical forming limit models for Zircaloy-4 and Zirlo used for spacer grid of nuclear fuel rods. Tensile and anisotropy tests were performed to obtain stress-strain curves and anisotropic coefficients. The experimental forming limit diagrams (FLD) for two materials were obtained by dome stretching tests following NUMISHEET 96. Theoretical FLD depends on FL models and yield criteria. To obtain the right hand side (RHS) of FLD, we applied the FL models (Swift's diffuse necking, M-K theory, S-R vertex theory) to Zircaloy-4 and Zirlo sheets. Hill's local necking theory was adopted for the left hand side (LHS) of FLD. To consider the anisotropy of sheets, the yield criteria of Hill and Hosford were applied. Comparing the predicted curves with the experimental data, we found that the RHS of FLD for Zircaloy-4 can be described by the Swift model (with the Hill's criterion), while the LHS of the FLD can be explained by Hill model. The FLD for Zirlo can be explained by the S-R model and the Hosford's criterion (a = 8).