• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.78.3-78.3
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• 2015

About 70 high redshift quasars with $z{\geq}5$ have been discovered through combinations of standard broad-band filters to distinguish them from contaminating sources. However, among the discovered quasars so far, there is a redshift gap at $5{\leq}z{\leq}6$ due to the limitation of traditional filter sets and selection techniques. To understand the early mass growth of supermassive black holes and the final stage of the cosmic reionization, it is important to find a statistically meaningful sample of quasars with various physical properties. Here we suggest a new selection technique of high redshift quasars using medium-band filters: nine filters with bandwidths of 50nm and central wavelengths from 625 to 1025nm. Photometry with these medium-bands traces the spectral energy distribution (SED) of a source, similar to spectroscopy with R~15. We installed these filters to SED camera for QUasars in EArly uNiverse (SQUEAN) on the 2.1m telescope at McDonald Observatory, and conducted test observations of known high redshift quasars at $4.7{\leq}z{\leq}6.1$ and also dwarf stars for comparison. We found differences in SED shapes between high redshift quasars and dwarf stars, determined their locations on color-color diagrams, and demonstrated that the medium-band filters can enhance the efficiency of selecting robust quasar candidates in this redshift range. In this poster, we propose an effective selection method of high redshift quasars using these medium-band filters and discuss its effect on our high redshift quasar survey.

• Journal of Environmental Impact Assessment
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• v.6 no.2
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• pp.35-59
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• 1997

In this study, for the effective environmental investigation at the level of planning, environmental assessment model to be integrated with urban comprehensive plans was developed. This model was applied to the Suwon City urban comprehensive plan and was tested to derive the future application program and the adaptability to the current research issues. The results of this study can be summarized as follows: First, we defined basic items for environmental assessment as to be used in the developed SEA model. We also defined three ranges and twelve items for the environmental assessments, which can be used in the assessment of the urban comprehensive plan through the expert advices. Second, we performed the case study by applying the developed SEA model to the Suwon City urban comprehensive assessment, and investigated the environmental impacts through an expert inquiry at the "phase 5" of the model. The results of the case study showed that Suwon City urban comprehensive plan contained partially discrepancies at the goal of the planning. The spatial strategy for leisure, park and open space, and green belt was analysed not to be effective in energy use. The case study also indicated that the environments of Suwon City are expected to be much worse in each sectional plan, if the City was to implement the present five sectional plans for life boundary and distribution of population, land use plan, transportation plan, industrial development plan, and life environmental plan. Third, according to the result of the case study, an mitigation plan for urban comprehensive plan of Suwon City was proposed as the following four stages; modification of planning goal, modification of site alternatives, modification of planning contents, and proposal of mitigation measures.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2323-2329
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• 2013

Web-services employ an XML to represent data and an XML parser is needed to use data. The DOM(Document Object Model) is widely used to parse an XML, but it is not suitable for any systems with limited resources because it requires a preprocessing to create the DOM and additional memory space. In this paper, we propose the StreXTree(Streaming XML Tree) with failure transitions and without any preprocessing tasks in order to improve the system performance. Compared to other works, our StreXTree parser achieves 2.39x and 3.02x improvement in system performance in Search and RBStreX, respectively. In addition, our StreXTree parser supports Well-Formed checking to verify the syntax and structure of XML.

• Tunnel and Underground Space
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• v.22 no.2
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• pp.93-105
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• 2012

This paper compares the two- and three-dimensional (2D and 3D) approaches for the numerical determination of the equivalent mechanical properties of fractured rock masses. Both orthogonally-fractured model and discrete fracture networks (DFN) were used for the geometry and 2D models were cut in various directions from 3D model to compare their mechanical properties. Geological data were loosely based on the data available from Sellafield, UK. Analytical method based on compliance tensor transformation was used for investigation in orthogonally fractured rock and numerical experiments were conducted on fractured rock mass with DFN geometry. It is shown that 2D approach always overestimates the elastic modulus of fractured rock masses by a factor of up to around two because fractures are assumed to be perpendicular to the model plane in 2D problems. Poisson ratios tend to have larger values in 2D analysis while there is opposite trend in some sections. The study quantitatively demonstrates the limitation of the 2D approach that uses the simplified model from true 3D geometry.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.243-248
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• 2012

Nearby spiral galaxies M101 and M81 are considered to have undergone a galaxy-galaxy interaction. M101 has experienced HI gas infall due to the interaction. With AKARI far-infrared (IR) photometric observations, we found regions with enhanced star forming activity, which are spatially close to regions affected by the interaction. In addition, the relation between the star formation rate (SFR) and the gas content for such regions shows a significant difference from typical spiral arm regions. We discuss possible explanations for star formation processes on a kiloparsec scale and the association with interaction-triggered star formation. We also observed the compact group of galaxies Stephan's Quintet (SQ) with the AKARI Far-infrared Surveyor (FIS). The SQ shows diffuse intergalactic medium (IGM) due to multiple collisions between the member galaxies and the IGM. The intruder galaxy NGC 7318b is currently colliding with the IGM and causes a large-scale shock. The 160 micron image clearly shows the structure along the shock ridge as seen in warm molecular hydrogen line emission and X-ray emission. The far-IR emission from the shocked region comes from the luminous [CII]$158{\mu}m$ line and cold dust (~ 20 K) that coexist with molecular hydrogen gas. Survival of dust grains is indispensable to form molecular hydrogen gas within the collision age (~ 5 Myr). At the stage of the dusty IGM environment, [CII] and $H_2$ lines rather than X-ray emission are powerful cooling channels to release the collision energy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5465-5470
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• 2012

FPGA(Field Programmable Gate Array) devices are widely used due to their merits in circuit development time, and development cost. Among various FPGA technologies, SRAM-based FPGAs have large cell capacity so that they are attractive for complex circuit design and their reconfigurability. However, they are weak in space environment where radiation energy particles cause Single Event Upset(SEU). In this paper, we designed a controller supervising SRAM-based FPGA to protect configuration memory inside. The controller is implemented on an Anti-Fusing FPGA. Radiation test was performed on the implemented computer board and the result show that our controller provides better SEU-resilience than TMR-only system.

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.42-48
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• 2020

This research illustrates how the hybrid engine system comprising of a two-cycle reciprocal engine with an integrated generator and a battery is prepared for the design process. The purpose of this research is to increase flight endurance taking advantage of the high energy density of hybrid propulsion systems as well as to cope with current environmental issues by reducing fossil fuel. The hybrid system is designed to offer 6 kW power, and the power can be adjusted by controlling the engine's RPM in accordance with load variations. In addition, the battery is adopted to offer extra electric power that this hybrid system cannot cover, and can function as the main power source in limited time in the case of an emergency situation. Besides that, the generator is directly mounted on an engine crank-shaft, and in turn, they can share the same RPM. Thus, it is hypothesized that this integration method can make a compact design possible by reducing space for the installation in the fuselage of UAVs.

• Proceedings of the ESK Conference
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• 1992.10a
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• pp.63-67
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• 1992

인간이 역사를 이루며 살아오면서 피복은 인간의 생활 수단으로서 빠뜨릴 수 없는 존재가 되었다. 사외 생활을 하면서 인간은 자신을 보호하고 남에게 자신의 이미지를 전달하고 자신의 욕구를 표출하면서 만족시키는데 있어 의복은 가장 중요한 역활을 하고 있고 인간 역시 그러한 것들을 의복에 의존하고 있는 것이다. 그러나 정상인을 위한 의복만 취급되어지는 시장에서 신체장애자들은 정상인보다도 더 세심하게 기능들이 고려된 의복이 필요함에도 불구하고 의복의 기능들을 생각하면서 의복을 선택할 수가 없다. 이러한 사앙들이 대두되면서 현대에 들어 신체 장애자 의복에 있어서 불편함을 없애고 보다 적합한 의복을 만들기 위한 연구가 진행되었다. 신체 장애자의 의복 연구는 Ward가 이 부분에 관심을 표명한 이후 임상 의사들에 의해 연구가 이루어지기 시작했다. 우리나라에서도 1976년 심성식의 한국 신체 장애자의 의복에 관한 연구를 기점으로 이 분야의 관심도가 높아지고 있으나 아직까지는 전반적으로 부족한 실정이다. 특히 위생적인 분야에서는 자료가 매우 부족하다. 이에 본 연구에서는 휠체어를 사용하는 하지 마비자의 체표 면을 떠서 기성복 패턴과 비교를 통해 보다 편안한 바지 패턴을 제시하고, 여름철에 많이 사용하는 직물로 바지를 제작하고 착용시킨후 인체 생리 반응을 분석하여 여름철에 쾌적한 바지를 알아 보았다. 이 연구를 통해 일반인과는 생활 자세가 다른 휠체어를 사용하는 하지 마비자와 일반인이 입는 기성복 바지를 착용 했을 때 생기는 불합리한 요소들을 고려하여 미적이고 기능적 및 위생적인 측면에서 신체 장애자에게 보다 적합한 바지를 제작하기 위한 기초 자료를 제공하고자 한다.값은 $f^{m}$ (p-1)-1 이다. (n=2m)이 많고 흡연 등의 만성 자극 요인이 있으며 술후 음성 호전에 걸리는 기간이 길어 보다 복합적인 측면에서 치료에 임하여야 할 것으로 사료된다. with such configuration.trap with 2.88[eV] deep of injected space charge from the chathode in the crystaline regions. The origin of ${\alpha}$$_2$ peak was regarded as the detrapping process of ions trapped with 0.9[eV] deep originated from impurity-ion remained in the specimen during production process of the material, in the crystalline regions. The origin of ${\beta}$ peak was concluded to be due to the depolarization process of "C=0"dipole with the activation energy of 0.75[eV] in the amorphous regions. The origin of ${\gamma}$ peak was responsible to the process combined with the depolarization of "CH$_3$", chain segment, with the activation

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.4
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• pp.106-117
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• 2016

Recently, solar power plants have spread widely as part of the transition to greater environmental protection and renewable energy. Therefore, regular solar plant inspection is necessary to efficiently manage solar-light modules. This study implemented a test that can detect solar-light module faults using an UAV based thermal infrared camera and GIS spatial analysis. First, images were taken using fixed UAV and an RGB camera, then orthomosaic images were created using Pix4D SW. We constructed solar-light module layers from the orthomosaic images and inputted the module layer code. Rubber covers were installed in the solar-light module to detect solar-light module faults. The mean temperature of each solar-light module can be calculated using the Zonalmean function based on temperature information from the UAV thermal camera and solar-light module layer. Finally, locations of solar-light modules of more than $37^{\circ}C$ and those with rubber covers can be extracted automatically using GIS spatial analysis and analyzed specifically using the solar-light module's identifying code.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1625-1629
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• 2011

Kinetic studies of the reactions of O,O-diphenyl Z-S-aryl phosphorothioates with X-benzylamines have been carried out in dimethyl sulfoxide at 55.0 $^{\circ}C$. The Hammett (log $k_2$ vs ${\sigma}_X$) and Bronsted [log $k_2$ vs $pK_a(X)$] plots for substituent X variations in the nucleophiles are biphasic concave downwards with a maximum point at X = H, and the unusual positive ${\rho}_X$ and negative ${\beta}_X$ values are obtained for the strongly basic benzylamines. The sign of the cross-interaction constant (${\rho}_{XZ}$) is negative for both the strongly and weakly basic nucleophiles. Greater magnitude of ${\rho}_{XZ}$ value is observed with the weakly basic nucleophiles (${\rho}_{XZ}$ = -2.35) compared to with the strongly basic nucleophiles (${\rho}_{XZ}$ = -0.03). The deuterium kinetic isotope effects ($k_H/k_D$) involving deuterated benzylamines [$XC_6H_4CH_2ND_2$] are primary normal ($k_H/k_D$ > 1). The proposed mechanism is a concerted $S_N2$ involving a frontside nucleophilic attack with a hydrogen bonded, four-center-type transition state for both the strongly and weakly basic nucleophiles. The unusual positive ${\rho}_X$ and negative ${\beta}_X$ values with the strongly basic benzylamines are rationalized by through-space interaction between the ${\pi}$-clouds of the electron-rich phenyl ring of benzylamine and the phenyl ring of the leaving group thiophenoxide.