• KSCI Review
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• v.1 no.2
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• pp.47-72
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• 1995

지금까지 나타난 많은 리더십 이론이 주로 기독교 문화권인 서구에서 연구된 것을 문화권이 다른 우리나라에 적용하고자 하는 것이 기존의 연구 경향이었다. 오랫동안 전통이 되어 온 우리 특유의 조직 문화 중에서 특히 관료적이고 권위주의적인 조직 문화에 새로운 변화가 일어나고 있는 과도기적인 현시점에서 최근에 나타난 리더십 이론인 B.M.Bass의 변형적 리더십 이론을 모델로 하여 우리 기업에 적절한 리더십 유형을 찾는 것이 일차적 목적이며 여기서 찾아낸 리더십 유형 별로 조직원의 상사 만족도에 미치는 영향을 알아보는 것이 이 연구의 목적이었다. 따라서 이 논문에서 제시한 리더십 유형을 보면 변혁적 리더십 유형에 속하는 것으로 지원적 배려, 카리스마, 과업 동기 자극으로 3분류하였으며 거래적 리더십 유형에 속하는 것으로 상황적 보상, 예외 관리, 소극적 관리로 3분류하여 모두 6유형을제시하고 신뢰성과 타당성을 확인하였다. 실증 연구 결과를 보면 우리나라는 거래적 리더십유형인 상황적보상, 예외 관리, 소극적 관리가 모두 조직원의 상사 만족도에 영향을 미치는것으로 나타나 Bass의 주장과는 다소 상이하다. 그러나 변혁적 리더십 유형인 카리스마, 지원적 배려, 과업 동기 자극에서는 카리스마만이 조직원의 상사 만족도에 영향을 미치고 지원적 배려는 영향력의 정도가 미약하며 과업 동기 자극은 거의 영향을 미치지 못하는 것으로 나타났다. 따라서 리더의 부하 통솔 및 지도 방향에서 아직도 우리나라에서는 거래적 요소가 짙다는 것을 알 수 있었다. 비록 당분간은 리더가 거래적 리더십을 많이 사용하겠지만 기업의 역사가 길어지고 종업원의 교육 훈련의 기회가 많아지면 변혁적 리더십으로 전환되리라 생각된다.가 단층원주상피세포와 단층입방상피가 부위에 따라 다르게 분포하고 있으며, 상피세포 및 결합조직에는 두터운 근육층이 있어 음경의강한 운동성이 감지 되었다. 제주도 내의 서귀포 부근에서는 현재 천연기념물로 지정되어 있는 서귀포층내에서 많은 화석들이 산출되고 있다. 이 시대는 빙하기와 간빙기가 교호하던 시대로서, 분석 결과에 의하면 서귀포층이 쌓일 당시에 우리 나라는 빙하기의 영향을 받았던 것으로 생각된다.is)은 근섬유가 산재된 두꺼운 벽을 가졌으며 상음경보다 굵은 원통형이었다. 내강은 많은 돌출부에 의해 복잡하게 나뉘어 있으며 상피세포는 원주 세포로 이루어져 있었고 섬모는 관찰되지 않았다. 내강 내의 분비물과 세포의 형태로 보아 내강상피세포는 분비기능을 가진 것으로 사료된다.술적 문제가 적절히 해결되는 경우 비활성 가스 제너레이터는 민수용으로는 대형 빌딩, 산림, 유조선 등의 화재에 매우 적절히 사용되어 질 수 있을 뿐 아니라 군사적으로도 군사작전 중 및 공군 기지의 화재 그리고 지하벙커에 설치되어 있는 고급 첨단 군사 장비 등의 화재 뿐 아니라 대간첩작전 등에 효과적으로 활용될 수 있을 것으로 판단된다.가 작으며, 본 연소관에 충전된 RDX/AP계 추진제의 경우 추진제의 습기투과에 의한 추진제 물성 변화는 미미한 것으로 나타났다.의 향상으로, 음성개선에 효과적이라고 사료되었으며, 이 방법이 편측 성대마비 환자의 효과적인 음성개선의 치료방법의 하나로 응용될 수 있으리라 생각된다..7%), 혈액투석, 식도부분절제술 및 위루술·위회장문합술을 시행한 경우가 각 1례(2.9%)씩이었다. 13) 심각한 합병증은 9례(26.5%)에서 보였는데 그중 식도협착증이 6례(17.6%), 급성신부전증 1례(2.

• Journal of the Korean Institute of Gas
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• v.19 no.2
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• pp.29-36
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• 2015

This study is an 1-D numerical study prior to modification of diesel engine for power plants to natural gas/diesel dual fuel engine using GT-Power with 1.5MW diesel engine for power generation. Natural gas injector was installed to intake manifold for dual fuel engine model. Effects on engine performance and characteristics were investigated when dual fuel is used in unmodified diesel engine. The analysis was done under 5 conditions from 0% to 40% of mixing rate on 720RPM engine speed. As a result of research, the engine performance was decreased as increasing ratio of natural gas. Engine brake power was decreased by 18.4% under 40% mixing rate condition. To clarify the reason, effects of injection timing and period were evaluated with DOE method. Considering this result, optimization was done for these parameters. Also, comparison between performances of dual fueled engine and diesel engine was made after optimizing the timing of injection by DOE method. As a result, engine brake power was decreased by 8.55% under mixing rate 40% condition showing 12.5% improvement.

• Korean Chemical Engineering Research
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• v.56 no.6
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• pp.856-863
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• 2018

In order to investigate the re-carbonation behaviors of limestones in an oxy-circulating fluidized bed combustor (Oxy-CFBC), the re-carbonation characteristics of domestic 4 different limestone samples were analyzed in a thermogravimetric analyzer (TGA-N1000) with the higher concentration of $CO_2$. Effect of reaction temperature ($600{\sim}900^{\circ}C$) and $CaCO_3$ content (77~95%) of limestones were determined and the mass change of the CaO was observed. Under the temperature of $800^{\circ}C$, the conversion rate increased with increasing reaction temperature. However, the conversion rate decreased with increasing reaction temperature over $800^{\circ}C$. In the case of $CaCO_3$ content, the conversion was remarkably different at $870^{\circ}C$. In addition, reaction rate equations for simulating the re-carbonation of limestone by using gas solid reaction models were proposed in this study.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.4
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• pp.468-475
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• 2019

An end-line flame arrester allows free venting in combination with flame protection for vertical vent applications. End-line flame arresters are employed in various fields, especially in shipping. In flame arresters, springs are essential parts because the spring load and the spring's elasticity determine the hood opening moment. In addition, the spring has to work under a high-temperature condition because of the burning gas flame. Therefore, it is necessary to analyze the mechanical load and elasticity of the spring when the flame starts to appear. Based on simulations of the working process of a specific end-line flame arrester, a thermal and structural analysis of the spring is performed. A three-dimensional model of a burned spring is built using computational fluid dynamics (CFD) simulation. Results of the CFD analysis are input into a finite element method simulation to analyze the spring structure. The research team focused on three cases of spring loads: 43, 93, and 56 kg, correspondingly, at 150 mm of spring deflection. Consequently, the spring load was reduced by 10 kg after 5 min under a $1,000^{\circ}C$ heat condition. The simulation results can be used to predict and estimate the spring's load and elasticity at the burning time variation. Moreover, the obtained outcome can provide the industry with references to optimize the design of the spring as well as that of the flame arrester.

• Clean Technology
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• v.16 no.3
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• pp.213-219
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• 2010

Vortex tube is the device that can separate small particles from the compressed gas, as well as compressed gas into hot and cold gas. Due to energy and particle separation ability, a vortex tube can be used as the main component of the $CO_2$ absorption device. In this study, experimental approach has been performed to analyze the energy separation characteristics of the vortex tube. To obtain the preliminary design data, energy separation characteristics of the vortex tube has been tested for orifice diameter, nozzle area ratio, and tube length. As a result, the orifice diameter is the major factor of the vortex tube design. The nozzle area ratio and tube length have a minor effect on the energy separation performance. For Dc=0.6D, AR=0.14~0.16, and L=16D, maximum energy separation has been occurred. The result from this study can be used as the basic design data of the $100Nm^3$/hr class vortex tube applied to the $CO_2$ absorption device. Compared with the $CO_2$ absorption process containing an absorption tower, the process with a vortex tube is expected to have a huge advantage of saving the installation space and the operating cost.

• 한국해양학회지
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• v.30 no.5
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• pp.403-412
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• 1995

The present study was performed to determine th growth and production of Mactra veneriformis on the Songdo tidal flat off Inchon. west coast of Korea. Monthly samples were collected from Marc 1989 to September 1990. The size distributions of shell length showed unimodal patterns from March to August 1989. The binodal pattern after September 1989 indicated a recruitment of young clams during this period. The density fluctuated irregularly, but showed a decreasing pattern over time on the whole. The density of the year class 1989 increased markedly after February 1990. The growth in shell length showed three phases during a year, a fast growth phase in spring, a slow growth phase in summer and autumn, and a lag phase in winter. The annual increment in shell length reduced with age. The flesh dry weight showed a peak in late spring just before the spawning period, and another peak in autumn. The length of annuli and the back-calculated flesh dry weight were used to describe the annual growth. The growth in shell length fitted to the von Bertalanffy model and the flesh dry weight to the Gompertz model. The absolute growth rate of the shell length reduced gradually with age. The year class 1985 had the highest L, and the yeat class 1986 the lowest L. The annual growth in weight showed a typical sigmoid curve. The growth rate was maximum at the age of 2 to 3. Year classes of 1984 and 1985 had higher values of W and higher absolute growth rates than those of 1986 and 1987. Maximum absolute growth rates of 1986 and 1987 year classes were recorded at younger ages than 1984 and 1985 year classes. The annual relative growth rates of length and weight decreased exponentially with age. Biomass in flesh dry weight increased till spring and thereafter decreased progressively. Maximum biomass was 134.6g m/SUP -2/ in August 1990. The biomass of 1989 yeat class occupied highest proportion in total biomass. Annual production in flesh dry weight from March 1989 to March 1990 was 67.9 g m/SUP -2/ year/SUP -1/. Cumulative production of 1989 year class was highest among all year classes, and that of year class 1984 was lowest. The production is high in spring and autumn, and very low in summer and winter.

• Journal of Food Hygiene and Safety
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• v.19 no.4
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• pp.176-184
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• 2004

This study was conducted to compare and estimate the daily PAHs dietary intake from both home-cooking and dining-out, through approach of model diet used in exposure assessment of food contaminants. Food commodities reflecting in model diet were selected from the KHIDI report and were analysed in cooked or uncooked edible forms using HPLC-Fluorscence Detector. The PAHs dietary intake comparison between home-cooking and dining-out was based on one meal intake suggested in model diet and PAHs dietary intake was estimated by using food consumption rate and body weight of the Korean adult group. The daily PAHs dietary intake was calculated by permutation and combination method with assumption that a person consumed 2 meals from home-cooking menu and 1 meal from dining-out menu. The total PAHs levels in 36 food commodities with 200 samples were ranged from 2.00 ug/kg to 141.28 ug/kg and a food showing the highest PAHs level was the stir-fried anchovy. The $TEQ_{BaP}$ levels of PAHs were calculated using benzo(a)pyrene equivalents individual congener level and corresponding TEF value and the $TEQ_{BaP}$ level were ranged from $0.03\;ugTEQ{BaP}$ to $1.31\;ugTEQ_{BaP}$ and a food showing the highest $TEQ_{BaP}$ level was the hamburger. The PAHs dietary intakes per one meal from home-cooking and dining-out were $2.4\times10^{-3}\;ugTEQ_{BaP}/kg/meal\;and\;4.0\times10^{-3}\;ugTEQ_{BaP}/kg/meal$, respectively. This data showed the PAHs dietary intake from dining-out was about 1.7 times higher than from the home-cooking. The daily PAHs dietary intakes of general Korean adult having two meals from home-cooking and one meal from dining-out per a day were ranged between $8.0\times10^{-3}\~9.7\times10^{-3}\;ugTEQ_{BaP}/gg/day$ and mean value as $8.9\times10^{-3}\~9.7\times10^{-3}\;ugTEQ_{BaP}/gg/day$.

• Journal of the Society of Disaster Information
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• v.11 no.1
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• pp.135-147
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• 2015

Recent underground common utility tunnels are underground facilities for jointly accommodating more than 2 kinds of air-conditioning and heating facilities, vacuum dust collector, information processing cables as well as electricity, telecommunications, waterworks, city gas, sewerage system required when citizens live their daily lives and facilities responsible for the central function of the country but it is difficult to cope with fire accidents quickly and hard to enter into common utility tunnels to extinguish a fire due to toxic gases and smoke generated when various cables are burnt. Thus, in the event of a fire, not only the nerve center of the country is paralyzed such as significant property damage and loss of communication etc. but citizen inconveniences are caused. Therefore, noticing that most fires break out by a short circuit due to electrical works and degradation contact due to combustible cables as the main causes of fires in domestic and foreign common utility tunnels fire cases that have occurred so far, the purpose of this paper is to scientifically analyze the behavior of a fire by producing the model of actual common utility tunnels and reproducing the fire. A fire experiment was conducted in a state that line type fixed temperature detector, fire door, connection deluge set and ventilation equipment are installed in underground common utility tunnels and transmission power distribution cables are coated with fire proof paints in a certain section and heating pipes are fire proof covered. As a result, in the case of Type II, the maximum temperature was measured as $932^{\circ}C$ and line type fixed temperature detector displayed the fire location exactly in the receiver at a constant temperature. And transmission power distribution cables painted with fire proof paints in a certain section, the case of Type III, were found not to be fire resistant and fire proof covered heating pipes to be fire resistant for about 30 minutes. Also, fire simulation was carried out by entering fire load during a real fire test and as a result, the maximum temperature is $943^{\circ}C$, almost identical with $932^{\circ}C$ during a real fire test. Therefore, it is considered that fire behaviour can be predicted by conducting fire simulation only with common utility tunnels fire load and result values of heat release rate, height of the smoke layer, concentration of O2, CO, CO2 etc. obtained by simulation are determined to be applied as the values during a real fire experiment. In the future, it is expected that more reliable information on domestic underground common utility tunnels fire accidents can be provided and it will contribute to construction and maintenance repair effectively and systematically by analyzing and accumulating experimental data on domestic underground common utility tunnels fire accidents built in this study and fire cases continuously every year and complementing laws and regulations and administration manuals etc.

• Journal of the Korean earth science society
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• v.41 no.6
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• pp.557-574
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• 2020

The purpose of this study is to analyze the cause of high PM2.5 mass concentrations in Cheongju for the period of non-Asian dust days using the weather chart, the stream lines at 850 hPa, the backward trajectory, and the weather and air quality model. As a result of analyzing the time series of PM2.5 concentrations and weather charts for the episodic days in Cheongju, the weather patterns were shown in related to long-range transport of PM2.5 from China or surrounding areas. In fact, in the PM2.5 time series, 60-80 ㎍ m-3, which is more than 2-3 times higher than the concentration attributed to Cheongju activities, was observed as a background concentration related to long-range transport. The distribution of high PM2.5 concentration was typically dependent on the locations of the high and low pressures above the ground while the upper jet stream passed through the Korean Peninsula. Consequently, the high PM2.5 concentration in Cheongju is due to massive air pollutants in the form of smog originated from industrial, household and energy combustion sources of Beijing and other nearby regions of China. These air pollutants move along a fast zonal wind caused by the atmospheric pressure arrangement. high concentration of PM2.5 in Cheongju City is because the mass of air pollutants in the form of smog generated from industrial, household and energy combustion origins in Beijing or other nearby regions of China move along a fast wind speed zone according to the atmospheric pressure arrangement of long-distance transportation. Air pollutants including PM2.5 show an M-shaped pattern that passes through the topography of the Cheongju basin from north to south as a belt or band-shaped pollutant. The ground high pressure according to the above-ground high pressure expansion area and cut-off low or low pressure arrangement, or the bands in the form of river stems appear in a gradual incremental pattern that changes into a U-shape under the influence of the wind.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.260-267
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• 1995

In temperate zone planting rice at different date subjects the Crop to different climatic condition. The present study aimed at comparison of the change in source-sink relationship of the Japonica(J) and that of IndicaxJaponica(I$\times$J) type rice cultivars caused by shift of heading date. Two J- and two I$\times$J-type cultivars were made to head on August 16, August 26, and September 5. Sink capacity was changed by shift of heading date in different mode between the types of cultivars. In both types major determinant of sink capacity was number of effective tillers, and the number of spikelets per panicle was the minor. In J-type earlier planting/heading was beneficial to increased panicle numbers and this was due mainly to a larger diurnal difference in temperature. I$\times$J-type cultivars favored a higher daily mean temperature to increase the sink capacity. The ability of source at heading, in terms of leaf area per panicle, chlorophyll content per spiklet, photosynthetic ability of leaves per unit area at 25$\^{\circ}C$, carbohydrate and N contents of leaves, was not so different among different heading dates in both types. However, the source activity was governed principally by temperature during grain filling. The J-type cultivars headed on Sept. 5 and I$\times$J-type cultivars headed later than August 16 could not have had sufficient source activity in grain filling due to lower temperature.