• Journal of the Korean Solar Energy Society
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• v.30 no.5
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• pp.69-76
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• 2010

In this study, the solar thermal and geo-source heat pump(GSHP) hybrid system for heating and cooling of Zero Energy Solar House(ZESH) was analyzed by experiment. The GSHP in this hybrid system works like as aback-up device for solar thermal system. This hybrid system was designed and installed for Zero Energy Solar House (KIER ZeSH) in Korea Institute of Energy Research. The purpose of this study is to find out that this system is optimized and operated normally for the heating load of ZeSH. The analysis was conducted as followings ; - the thermal performance of facade integrated solar collector - the on/off characteristics of solar system and GSHP - the contribution of solar thermal system. - the performance of solar thermal and ground source heat pump system respectively. - the meet of thermal load (space and water heating load). This experimental study could be useful for the optimization of this system as well as its application in house. This hybrid system could be commercialized for the green home if it is developed to a package type.

• Steel and Composite Structures
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• v.34 no.6
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• pp.891-907
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• 2020

Many studies reveal that during destructive earthquakes, most of the structures enter the inelastic phase. The amount of hysteretic energy in a structure is considered as an important criterion in structure design and an important indicator for the degree of its damage or vulnerability. The hysteretic energy value wasted after the structure yields is the most important component of the energy equation that affects the structures system damage thereof. Controlling this value of energy leads to controlling the structure behavior. Here, for the first time, the hysteretic behavior and energy dissipation capacity are assessed at presence of elliptical braced resisting frames (ELBRFs), through an experimental study and numerical analysis of FEM. The ELBRFs are of lateral load systems, when located in the middle bay of the frame and connected properly to the beams and columns, in addition to improving the structural behavior, do not have the problem of architectural space in the bracing systems. The energy dissipation capacity is assessed in four frames of small single-story single-bay ELBRFs at ½ scale with different accessories, and compared with SMRF and X-bracing systems. The frames are analyzed through a nonlinear FEM and a quasi-static cyclic loading. The performance features here consist of hysteresis behavior, plasticity factor, energy dissipation, resistance and stiffness variation, shear strength and Von-Mises stress distribution. The test results indicate that the good behavior of the elliptical bracing resisting frame improves strength, stiffness, ductility and dissipated energy capacity in a significant manner.

• KIEAE Journal
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• v.10 no.5
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• pp.63-69
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• 2010

Recently, by the increase of demand on Super High-rise mixed-use housing and it's advanced quality, the interest on it has been raised socially. In accordance with it, the matter of resident's health and energy efficiency has been controversial in terms of living in super high-rise housing. This study started from the idea that it is necessary to have an objective data which that has many residents in narrow space with high density. The purpose of this study are as follows; Firstly, with the quantitative data analysis on energy, it will confirm the objective information on the unclear negative idea of super high-rise mixed-use housing. Secondly, it will establish the fundamental data on the energy of super high-rise mixed-use housing by examining the characteristic of energy consumption of the complex which was built more than 5 years ago. There are 4 methods of this study. Firstly, it follows the steps of theoretical view, and defines concept to study on the characteristic of super high-rise mixed-use housing. Secondly, referring to the previous study, it provides better understanding on th stream of this research and the limit as well to guide the direction in terms of energy consumption. Thirdly, it evaluates the characteristic of monthly consumption by researching the use of electricity energy and heating energy of super high-rise mixed-use housing. The major conclusions of this study are as follows; Firstly, the heating use of apartment complex is same, which is not influenced by the type of the building. Secondly, the electricity use of super high-rise mixed-use housing is from 1,2 to 1.5 as high as the normal apartment.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.911-917
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• 2023

In today's world, we find ourselves facing energy crises due to factors such as war and climate crises. To prepare for these energy crises, many researchers continue to study systems related to energy monitoring and conservation, such as energy management systems, energy monitoring, and energy conservation. In line with these efforts, nations are making it mandatory for energy-consuming facilities to implement these systems. However, these facilities, limited by space and energy constraints, are exploring ways to improve. This research explores the operation of a data collection system using low-performance embedded devices. In this context, it proves that an optimized version of RocksDB, a Key-Value store, outperforms traditional databases when it comes to time-series data. Furthermore, a comprehensive database evaluation tool was employed to assess various databases, including optimized RocksDB and regular RocksDB. In addition, heterogeneous databases and evaluations are conducted using a UD Benchmark tool to evaluate them. As a result, we were able to see that on devices with low performance, the time required was up to 11 times shorter than that of other databases.

• Korean Institute of Interior Design Journal
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• v.23 no.6
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• pp.78-86
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• 2014

Lighting in indoor space is being changed to system lighting converged with IT technology. Office space lighting with incandescent lamps and fluorescent lamps was completed through overall lighting plan by illumination in most cases, but convergence between LED lighting and IT technology enables the technology of responding to user requirements to be realized. Optical physical quantity suitable for humans and the lighting environment in accordance with user's sensibility, based on space function and user's behavior, would contribute to the improvement of service productivity, energy reduction, and enhancement of emotional satisfaction by providing user optimized lighting solution. Thus, user-customized system lighting guidelines to be applied with integration indicators of optics and sensibility are required. For the design elements required by users, environmental factors, product characteristics, optical characteristics, and sensibility factors are drawn from the design cases for office space and the survey, and the design check list and evaluation indicators are considered to reflect the requirements in the design and requirement indicators to give integrated satisfaction for optics and sensibility are developed. Purpose-centered design method from the user's viewpoint is applied to function-focused design through scenario, and it should be applied flexibly, as the new lightning design method solutions, to the concept design stage of space lighting design and device development. This paper, therefore, presents user-customized guidelines by pursuing the optics and sensibility evaluation and design method combining the requirement conditions and scenario, to be used for lighting content development and design.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.7
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• pp.622-627
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• 2014

A pico-class satellite has limitation to generate power from the solar cells due to its limited accommodation area to install the solar cells. The variation of incidence angle between solar panels and sunlight induced by the revolution and rotation of the satellite is one of the key parameters to determine the power generation. In this study, we proposed a concentrating photovoltaic system for pico-class satellite applications to enhance power generation when the ${\beta}$ angle between the sunlight and the solar panel is zero by effectively concentrating solar energy on solar panels. The feasibility of the conceptual idea has been demonstrated by power measurement test using solar simulator and commercial multi-array lens system.

• Bulletin of the Korean Space Science Society
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• 1992.10a
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• pp.21-21
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• 1992

The X-ray binary pulsar Her X-1 was observed with Ginga on 1988 August 28 during the orbital phase of 0.76 to 0.85 at the main-on phase of the 35 day cycle. During the observations the X-ray intensity varied by a factor of five or more on a time scale as short as 30 sec, due mostly to the soft X-ray absorption in the pre-eclipse phase. From the studies of pulse profiles and energy spectra, we revealed that there exists in the dipphase an unpulsed component which is "3% of the intensity at the non-absorbed high-level. We suggest that scattering of the source continuum by the optically thin hot corona is responsible for the unpoised component. In the spectral analysis, we find that the high-state non-absorbed spectra can be fitted by a power-law without absorption, and the spectra observed in the different abgorption states by two components of a power-law with the same photon index. An iron-K emission line is required in to the cases of fitting. The estimated equivalent width of the iron line varies from 0.18 to 0.51 key according to the change in the absorption column density along the line of sight. We suggest that the fluorescent iron line arises in a cool and relatively small region, like the Alfvensur face, and may be partially intercepted by the optically thick gas cloud passing across the line of sight.1 Korea Astronomy Observatorya The Institute of Space and Astronautical Science in Japan3 Korea Advanced Institute of Science and Technology

• Journal of Astronomy and Space Sciences
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• v.18 no.2
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• pp.163-173
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• 2001

In this paper, space radiation environment and single event effect(SEE) have been analyzed for the KOMPSAT-2 operational orbit. As spacecraft external and internal space environment, trapped proton, SEP(solar energetic particle) and GCR(galactic cosmic ray) high energy Protons and heavy ions spectrums are analyzed. Finally, SEU and SEL rate prediction has been performed for the Intel 80386 microprocessor CPU that is planned to be used in the KOMPSAT-2. As the estimation results, under nominal operational condition, it is predicted that trapped proton and high energetic proton induced SBU effect will not occur. But, it is predicted that heavy ion induced SEU can occur several times during KOMPSAT-2 3-year mission operation. KOMPSAT-2 has been implementing system level design to mitigate SEU occurrence using processor CPU error detection function of the on-board flight software.

• KIEAE Journal
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• v.10 no.4
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• pp.137-145
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• 2010

Active sunlighting systems have been applied to deliver sunlight into the indoor space where natural light is insufficient, mainly because of the congested high-rise buildings in urban areas. Among various active sunlighting systems, a mirror sunlighting system which is simple structure and economically reasonable has been widely used in different types of spaces such as underground, north facing place and atrium. This study was to evaluate the mirror sunlighting systems, which were consisted of the first mirror of $3.5m{\times}2.5m$, the eight sets of the second mirrors of $1.0m{\times}1.25m$ and a sun tracker. Ten sets of the systems were installed for 40 apartment living rooms, the configuration of $3.5m(W){\times}4.0m(D){\times}2.5m(H)$ where sunlighting were not possible due to high retaining walls located in the front of the living rooms. The 45 HOBO data logger sensors for the indoor illuminance were equipped and 2 Li-cor photometers for outdoor illuminance. Both indoor and outdoor horizontal illuminances were monitored every second from 9am to 3pm on 17 January 2010 under clear sky condition. The results showed that the indoor illuminance of installed mirror sunlighting system was significant relationship with outdoor illuminance and increased the indoor illuminance level by 4.2 times on the whole floor space, by 8 times on the sun patch space of 6m2 and even by 2 times on the no sun patch space. In addition, the luminous conditions of the living room under real sky conditions met the KS recommendation for difficult task (600-1000-1500 lux) such as sewing and reading on whole floor space and sun patch space. It was proved that the benefits of mirror sunlighting systems included an effective technology for penetrating daylight into indoors where sunlighting was not possible and improving occupants' satisfaction and health, and contributing to energy saving in apartments during daytime.

• Journal of The Korean Astronomical Society
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• v.46 no.6
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• pp.253-259
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• 2013

We present near-infrared light curves of HBC 722 after its the September 2010 outburst. We have been monitoring its near-infrared light curves since November 2010 with Korean Astronomy and Space Science Institute Infrared Camera System (KASINICS). HBC 722 exhibits large changes in optical and near-infrared brightness since its outburst. The J, H, and $K_s$ light curves over about 2.5 years show that in all observed bands HBC 722 progressively became fainter until around April 2011, down to J ~10.7, H ~9.9, $K_s$ ~9.3, but it is getting brighter again. Large scatter in the obtained light curve prevents us from finding whether there is any short timescale variation as reported in other optical observations. The near-infrared color of HBC 722 is becoming bluer since its outburst. The pre-outburst Spectral Energy Distribution (SED) of HBC 722 is consistent with that of a slightly reddened Class II YSO with the exception of the extraordinary IR-excess in the far-infrared region.