• Journal of the Korean Geographical Society
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• v.51 no.4
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• pp.491-508
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• 2016

This study has taken the Myeongjidong island, which has experienced spatial change due to various reasons ranging from the Japanese colonial era until today, as an instance in order to comprehend macroscopic spatial change of the Nakdonggang Delta and the adaptation process of the locals in a microscopic point of view. Spatial change of the Myeongjidong has been confirmed by collecting maps such as the atlas of late period of Chosun published in 1910, topographic map, regional geography, city records, and by applying coordinates with geographic reference function of GIS program, then checking for time sequential space change of individual regions. Space change driven by the Japanese government-general of Korea, Gimhae Irrigation Association, and by national policy or planning brought about environmental and humanistic changes unlike ever before, and land usage, housing and industry of the region and the locals experienced various adaptation processes. Such processes were compiled through collection and comparison of literature, and supplementation from interview of the locals during field study. As for the research region, it ranged from the construction of Nakdonggang bank and Myeongji seawall of 1935, agricultural rural landscape formed after the area expansion project by Gimhae Irrigation Association in 1940, to landscape that are becoming mercantile and urban due to the developmental plans of national and local governments.

• Applied Chemistry for Engineering
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• v.27 no.4
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• pp.397-401
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• 2016

A new solid oxidizer, pyridinium dinitramide (Py-DN) is a low toxic energetic material which can be utilized as a HPGP (high performance green propellant). In this work, Py-DN was synthesized using various starting materials including potassium sulfamate, pyridine hydrochloride, strong nitric acid and sulfuric acid. Physical and chemical properties of the Py-DN were characterized using UV-Vis, FT-IR and a thermal analyzer and their properties were compared to those of previously prepared salts including ammonium dinitramide[ADN, $NH_4N(NO_2)_2$] and guanidine dinitramide[GDN, $NH_2C(NH_2)NH_2N(NO_2)_2$] in our lab. Endothermic and exothermic decomposition temperatures of Py-DN were $77.4^{\circ}C$ and $144.7^{\circ}C$, respectively. The combustion caloric value was 1739 J/g, which is thermally more sensitive than that of conventional dinitramides. It may enable to lower the decomposition temperature, which can reduce preheating temperature required for satellite thruster applications.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.1
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• pp.12-25
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• 2009

The aim of this study is to analyze the periodical and spatial characteristics of urban crime and to find out the factors that affect the crime occurrence. For these, crime data of Masan City was examined and crime occurrence pattern is ploted on a map using crime density and criminal hotspot analysis. The spatial relationship of crime occurrence and factors affecting crime were also investigated using ESDA (Exploratory Spatial Data Analysis) and SAR (Spatial Auto-Regression) model. As a result, it was found that crimes had strong tendency of happening during a certain period of time and with spatial contiguity. Spatial contiguity of crimes was made clear through the spatial autocorrelation analysis on 5 major crimes. Especially, robbery revealed the highest spatial autocorrelation. However as a autocorrelation model, Spatial Error Model(SEM) had statistically the highest goodness of fit. Moreover, the model proved that old age population ratio, property tax, wholesale-retail shop number, and retail & wholesale number were statistically significant that affect crime occurrence of 5 most major crimes and theft crime. However population density affected negatively on assault crime. Lastly, the findings of this study are expected to provide meaningful ideas to make our cities safer with U-City strategies and services.

• Applied Chemistry for Engineering
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• v.19 no.1
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• pp.1-16
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• 2008

Titanium dioxide ($TiO_2$) is one of the most researched semiconductor oxides that has revolutionised technologies in the field of environmental purification and energy generation. It has found extensive applications in heterogenous photocatalysis for removing organic pollutants from air and water and also in hydrogen production from photocatalytic water-splitting. Its use is popular because of its low cost, low toxicity, high chemical and thermal stability. But one of the critical limitations of $TiO_2$ as photocatalyst is its poor response to visible light. Several attempts have been made to modify the surface and electronic structures of $TiO_2$ to enhance its activity in the visible light region such as noble metal deposition, metal ion loading, cationic and anionic doping and sensitisation. Most of the results improved photocatalytic performance under visible light irradiation. This paper attempts to review and update some of the information on the $TiO_2$ photocatalytic technology and its accomplishment towards visible light region.

• Journal of Conservation Science
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• v.26 no.3
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• pp.229-245
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• 2010

The pupose of this study was to identify the material characteristics, firing environments and making techniques for the jar coffins from the Oryangdong kiln site and the Ungokdong tomb site in Naju. All jar coffins had very similar physical, mineralogical and geochemical characteristics, although it was excavated from the different sites. The wall thickness of the jar coffins was about 2.3 to 5.3 cm. Under the microscopy, the jar coffins include a large quantity of various quartz with some microcrystalline and showed partly orthoclase and biotite. It is presumed that the mineral sherds added to maintain the thick wall and to control the percentage of contraction during drying and firing of jar coffins and it has contained about 11.4 to 19.8 %. Firing temperature of the jar coffins is estimated as 1,000 to $1,150^{\circ}C$. Also, all jar coffins and soils show similar geochemical behavior of elements and clay-mineralization degree within the site. This indicates making that the soil is probable to be a raw material of the jar coffins. But it shows different characteristics in major elements of soils which is collected at the kiln floor and the trench region of the Oryangdong kiln site because of the lack of quartz and feldspar in the soils. Therefore, it can use of the jar coffins making clay, if it goes through a simple special process such as mixing temper.

• The Korean Journal of Zoology
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• v.29 no.2
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• pp.107-120
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• 1986

The activities of serum of serum lactate dehydrogenase (SLDH), serum alkaline phosphatase (SALP), serum creatine phosphokinase (SCPK), and their isozymes were determined in adult male Sprague-Dawley rats acclimated to cold environment $(4\\pm1^\\circC)$ for 36 days. The SLDH activity was significantly higher in the early stage of acclimated period. The steady state of SLDH activity seemed to be reached by the end of acclimated period. Electrophoretic separation of serum of control rat showed three SLDH isozymes. Isozymes SLDH4 and SLDH5 appeared most prominently, whereas only trace of SLDH1 or SLDH2 was found. The increase in SLDH level during acclimation to cold environment is a reflection of an immediate increase in the SLDH1, SLDH2, and SLDH3 type of SLDH isozyme. The acclimation to cold environment increased significantly level of SALP in the early state of acclimated period. SALP activity showed a attaining steady state with the resting level after transient rise. Electrophoretic separation of SALP of control rats showed the SALP1 and SALP2 fractions. The transient rise in SALP activity of rats acclimated to cold environment coincided with a transient rise in SALP1 fraction. Immediately after exposure to cold environment, there was significant elevation in SCPK activity. Value returned to normal after transient rise. A new steady state of SCPK activity seemed to be reached by 36 days. It may be inferred from the above data that thermal compensation appears to result from a change in the activity of an enzyme and that the SLDH, SLDH-isozyme, SALP-isozyme, and SCPK may be involved directly or indirectly in thermoregulation during acclimation to cold environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.592-597
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• 2013

The heat generated at the motor and inverter inside the electric compressor of inverter built-in type is mainly cooled by refrigerant and generally, there is not a thermal problem. However, the close relation of heat transfer from the motor and inverter parts to the compression part affects on compressor efficiency. Also, according to the surrounding environment and system operation condition, the increased temperature of the motor and inverter can affect the power density of the motor system, and especially, the inverter may be prevented to operate by the temperature limits. In this study, we performed thermo-flow analysis of electric compressor motor system, and investigated the heat dissipation enhancement of the motor and inverter. The motor part in the operation region of the electric compressor was generally maintained at low temperature and the inverter part at high compressor speed was lower temperature than the temperature limit of $85^{\circ}C$. However, the case of the inverter at low speed harsh condition was in excess of $10^{\circ}C$. Therefore, in order to solve the thermal problem, the heat reduction technology of the motor and inverter is essential as well as the improvement of flow path in the compressor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.386-393
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• 2019

In this study, we investigated the cause of a voltage controller failure that occurred in the operation of a combat vehicle and attempted to establish a solution for the failure. The failure in the voltage controller was found to be related to thermal resistance, which could be identified by disassembly analysis and a high temperature operation test. Especially, in the disassembly analysis, there was damage caused by high temperature such as soot on the molding material and cracking of the resisters. In addition, in the high temperature operation test, the test results show that the internal temperature of the voltage controller was relatively higher than the external temperature. This means that the voltage controller failure could be attributed to the excessive heat and insufficient thermal resistance. In order to improve the thermal resistance of the voltage controller, several designs with changing circuits and structures were devised. Improvement of thermal resistance was verified by measuring reduction of internal temperatures in the high temperature comparison test.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.4
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• pp.295-304
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• 2000

Vertical measurement of CTDT at about 30 min intervals and spatial surface temperature, salinity, and concentration of suspended particulate matters were conducted to elucidate the character of water column and the dispersal pattern in a floating ice-dominated fjord, Marian Cove, West Antarctica. Marian Cove showed two distinct water layers in terms of turbidity; 1) cold, fresh, and turbid surface plume in the upper 2 m,2) warm, saline, and relatively clean Maxwell Bay inflow between 15-45 m in water depth. Thermal melting of Maxwell Bay inflow and tidewater glacier/floating ices developed the surface mixed layer and the activity of floating ices cause Maxwell Bay inflow to be unstable. Due to the unstable water column, the development of Maxwell Bay inflow and subsequent surface plume are not influenced by tidal frequency. Coastal current generated by strong northwesterly wind may extend warm, saline, and turbid surface plume into the central part of the cove along the northern coast via the western coast of Weaver Peninsula. Terrigenous sediments of meltwaters from the glaciated ice cliffs near the corner of tidewater glacier and some coasts enter into the cove and their dispersion depends upon the hydrographic regimes (tide, wind, wave etc.). At the period of spring tide, the strong wind stress with the northwesterly wind direction reserve suspended sediment-fed surface plume and so allow the possibility of deposition of terrigenous sediments within the basin of cove.

• Journal of the Korean Society for information Management
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• v.30 no.4
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• pp.215-239
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• 2013

Even though the overall scholarly community has recognized a dramatic growth and changes in the Information Science research in Korea over the last few decades, there are still only few studies that have identified the changes in terms of long-term and dynamic point of view. We have analyzed 1,007 IS-research articles from leading Korean journals in KCI (Korea Citation Index), published between 2000 and 2011. To discern the trendline of changes in research interests over time, we conducted a time-series analysis by developing grounded subject scheme from the article set and checking the growth rate of the number of published articles and title keywords. A comparative analysis was also conducted by constructing and comparing co-word maps over time to discover visible changes in research topics over this 12-year period of the IS-research in Korea. As a result, we identified some developments and transformations in major subject areas and knowledge structure of the IS-research in Korea over time. The major trend we discovered is that IS-studies over the 12-year period evolved from system-oriented research to library-application research. The changes are especially observed in knowledge management, Web-based system evaluation, and information retrieval areas. When compared to the results of other studies, the result of our study may serve as an evidence of the localization of Korean IS-studies in the first decade of the $21^{st}$ century.