• Journal of the Korean GEO-environmental Society
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• v.17 no.11
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• pp.55-64
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• 2016

Recently, it has been made many adjacent construction of inter-facility by the expansion of urban infrastructure facilities using the underground space. The complaints relating to the stability of the facility by adjacent construction is common. In this study, it was conducted for the subway line 5 Gimpo airport station structure in the upper Gimpo urban railway to determine the behavior characteristics of station structure according to adjacent construction. It was performed evaluation of the safety zone and excavation method for station structure. And after a review of damage evaluation, track irregularities and structural calculation by using a numerical analysis, stability of the station structure according to adjacent construction was evaluated to be secured. This study is expected to be used as basic data in advance if you need to review the effects of nearby structure according to adjacent construction.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.5 no.1
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• pp.1-6
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• 2009

In this study, an ORC (Organic Rankine Cycle) is investigated for a low-temperature geothermal power generation by a simulation method. A steady-state simulation model is developed to analyze cycle's performance. The model contains a turbine, a pump, an expansion valve and heat exchangers. The turbine and pump are modelled by an isentropic efficiency. Simulations were carried out for the given heat source and sink inlet temperatures, and given flow rate that is based on the typical power plant thermal-capacitance-rate ratio. HFC-245fa is considered as a working fluid of the cycle. Simulation results, at the given secondary working fluids conditions, show that even though the power can be presented by both the evaporating temperature and the turbine inlet superheat, it depends on the evaporating temperature primarily.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.3
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• pp.110-117
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• 2011

This study investigated possibilities for a new reducing shrinkage method of soybean oil(SO) and waste oil(WO) to compare with shrinkage reducing agent(RS) and expansion additive(EA). There was no big difference to flow, air contents, and compressive strength of plain to use SO and WO. For the reducing shrinkage performance, SO and WO was more effective than RS and EA, because their fatty acid reacted with calcium hydroxide of concrete to turn soap. For the pore distribution by porosimter, $0.01{\sim}0.1{\mu}m$ pores of SO and WO were 0 ml/g, and $10{\sim}100{\mu}m$ also remarkably lower than any others. In these results, it inferred that they filled up capillary pore and mitigated autogenous shrinkage by their saponification of their fatty acid and calcium hydroxide.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.45.1-45.1
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• 2013

Type Ia supernovae (SNe Ia) are a powerful tool to investigate the expansion history of the universe, because their peak luminosity is as bright as a galaxy and is known as an excellent standard candle. Since the discovery of the acceleration of the universe based on the observations of SNe Ia, higher than ever accuracy of their peak luminosity is needed to investigate various problems in cosmology. We started a project to improve the accuracy of the calibration of the peak luminosity of SNe Ia by measuring accurate distances to nearby resolved galaxies that host SNe Ia. We derive accurate distances to the SN Ia host galaxies using the method to measure the luminosity of the tip of the red giant branch (TRGB). In this study we present the results for M66 and M96 in the Leo I Group which are nearby spiral galaxies hosting SN 1989B and SN 1998bu, respectively. We obtain VI photometry of resolved stars in these galaxies from F555W and F814W images in the Hubble Space Telescope archive. We derive the distances to these galaxies from the luminosity of the TRGB. With these results we derive absolute maximum magnitudes of two SNe (SN 1989B in M66 and SN 1998bu in M96). We derive a value of the Hubble constant from the optical magnitudes of these SNe Ia and SN 2011fe in M101 based on our TRGB analysis. This value is similar to the values derived from recent estimates from WMAP9 and Planck results, but smaller than other recent determinations based on Cepheid calibration for SNe Ia luminosity.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.6 s.109
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• pp.574-586
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• 2006

Recently radio communication environment have being standarded by the leading nations against the various technology of communication. Therefore to manage the changing communication environment, research about technology standard and standardization has gone variously in our country. In this dissertation, we discuss the trends of policy and analyze the technical regulation for the extremely low power devices in other countries. In addition, this paper proposes a draft revision of technical regulation for new efficient electric field strength of extremely low power devices in accordance with the technical requirement of Electromagnetic Compatibility. Based on these researches, the contents of this study will be useful to contribute a domestic efficient expansion and development of extremely low power devices and strengthen a competitiveness on international communication markets.

• Journal of Hydrogen and New Energy
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• v.17 no.4
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• pp.461-469
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• 2006

This paper deals with the national competitiveness of hydrogen energy. The effectiveness of investments for hydrogen energy R&D and constructions of hydrogen energy infrastructures can be evaluated by the national competitiveness of hydrogen energy, and it is evaluated by an AHP(analytic hierarchy process) method. The evaluation indices of the national competitiveness are selected as the technical level, the number of researchers, the investments for R&D, and the infrastructure of hydrogen energy. Similarly, the technical level is divided into the number of published papers, the number of foreign patents, and the number of published proceeding papers. The evaluation indices of the technical level and the number of researchers were investigated by database searches. It appears that South Korea locates the sixth position in the world. The results of our study suggest that South Korea is relatively competitive in the technical level and the number of researchers. However, our country needs the long-term and well-focused R&D, and the expansion of infrastructures to enhance the national competitiveness of hydrogen energy in the future.

• Progress in Superconductivity and Cryogenics
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• v.5 no.1
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• pp.111-117
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• 2003

In the design of the split type free displacer Stilting cryocooler the motion of the displacer is very important to decide the cooling capacity, which depends upon the working gas pressure, the swept volume in the compression space and the expansion space, operating frequency, the phase shift between piston and displacer, etc. In this study, Stirling cryocooler actuated by the electric farce of the dual linear motor is designed and manufactured. Cool down characteristics of the cold end with laser displacement sensor in the expander of the Stilting cryocooler is evaluated. The charging pressure was 15kg$_{f}$/$\textrm{cm}^2$ and operating frequency was 50Hz. Input power and the lowest temperature were about 32W and 67K, respectively. And, displacement of the piston is measured by LVDTs (Linear Variable Differential Transformers), displacement of thedisplacer is measured by laser optic method, and phase shift between piston and displacer is discussed. As the peak-to-peak pressure of the compressor was increased, peak-to-peak displacement of the displacer was increased. The peak-to-peak displacement of the displacer increases in the range of 0 - 64.5Hz(resonant frequency of the displacer), but decreases steeply when the operating frequency is bigger than the resonant frequency. Finally when the phase shift between displacements of the Piston and displacer is 45。, operating frequency is optimum and is decided by resonant frequency of the expander, mass and cross section area of the displacer and constant by friction and flow resistance.e.

• Convergence Security Journal
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• v.13 no.5
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• pp.129-135
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• 2013

The revised security industry law revised 17 provisions among 31 provisions in order to root out the violent event. The main contents of the revised security industry law is the intensitfication of the required condition of permission, intensitfication of the obligation, management strengthening of the public resentment of group field, official, reason of expansion of the expenses instructor and guard, dress and equipment, vehicle, intensitfication of the managing director, intensitfication of the punishment, and etc. However, there is the problem including the putting under an obligation of the arrangement new appointment education, cause provider punishment of the service company violence, awareness of the police to the security company, excessive regulation, intensification of punishment problem, supervision power intensitfication of the revised security industry law is excessive the police, and etc. The individual responsibility education completion method and public resentment of group field in addition to is thought in order to solve this that exclusion of the prior education obligation, revision of the security industry law, burden on tax payers of the extra charge, punishment of the violence request contract trader, introduction of the guard qualification certificate system, and etc. are needed.

• Journal of the Korean Society of Costume
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• v.56 no.7 s.107
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• pp.33-45
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• 2006

This study was to provide the fundamental data for a scientific and rational clothing construction by investigating the length variation of the upper arm surface, using the method of surgical tape, and to understand the expansion and contraction of parts of body for the making of clothing adaptable to movement. The subjects were li early elementary schoolgirls in Busan area classified with three somatotypes, and arm-movements consisted of 6 types. The statistical analyses used in this study were mean, standard deviation and the ANOVA and LSD procedure. The results of the analysis of the length of the upper arm surface are as follows: By arm-movements, in the items of horizontal, upper arm length changed more in the front than in the back, and in the items of vertical, represented the opposite of horizontal items. In the items of upper arm, the anterior-posterior axilla length and under arm length were influenced by arm-movements, and the under length of the upper arm represented the maximum rate increase of 74.59%(3.20cm)$\sim$138.72%(4.28cm). In the somatotypes of early elementary schoolgirls, type II was more influenced by arm-movements, and for the making of clothing adaptable to movement, type III needed to reflect more surplus length(2cm) than the other types.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.9 no.4
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• pp.182-193
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• 1997

The interaction of monochromatic incident waves with a horizontal flexible membrane is investigated in the context of two-dimensional linear hydro-elastic theory. First, analytic diffraction and radiation solutions for a submerged impermeable horizontal membrane are obtained. Second, the theoretical prediction was compared with a series of experiments conducted in a two-dimensional wave tank at Texas A & M University. The measured reflection and transmission coefficients reasonably follow the trend of predicted values. Using the developed computer program, the performance of surface-mounted or submerged horizontal membrane wave barriers is tested with various system parameters and wave characteristics. It is found that the properly designed horizontal flexible membrane can be an effective wave barrier.