• Fire Science and Engineering
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• v.15 no.4
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• pp.78-85
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• 2001

This dissertation is research on the fireproof characteristic of molded transformer and the extinguishable characteristics of the NAF S-III. As the research method, a theoretical examination has been made for the combustion process of epoxy resin, which was the main material of molded transformer, and extinguishing process of NAF S-III, which has recently been used in the clean extinguishable chemicals. Furthermore, for its proof, the experiments on combustion and extin-guishment on molded transformer has been performed. By installing the actual molded transformer in and artificial the horizontal heating furnace which has similar conditions with the electrical substation, and after subsequently ignited, the extinguishing process has been observed by classifying it into the natural extinguishment of the ignited transformer, and extinguishable chemical in NAF S-III has been injected. The volume of injected extinguishable chemical was the economical amount which was equipped with the extinguishable capability on the molded transformer under combustion, and it was calculated with the Announcement of the Ministry of Government Administration and Home Affairs as the basis. With the injection of the calculated extinguishable chemicals, the ignited transformer has completely extinguished within one minute.

• Journal of the Korean Geographical Society
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• v.43 no.1
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• pp.117-133
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• 2008

Although development density control has received murk attention in urban planning, there has been little research on empirical methods that can examine local changes in development density. Recently, attempts have been made to develop cellular automata (CA) models that can be applied to urban landuse change. This paper aims to develop an extended landuse change model based on urban CA considering development density. The proposed model not only includes density control component in a model framework, but also directly estimates local density changes in land use. The developed model was applied to the study area, which was a part of central Seoul. The calibration of the model was carried out over the period $1900s\sim2000s$ using parcel-based land use data and related variables The results of the calibrated model have been tested by comparison with actual landuse data, and have demonstrated that the developed model can produce realistic simulations of urban landuse changes. But model output is dependent on the spacio-temporal resolution of input data. Further research is necessary to improve the calibration procedure and methods for evaluating model validity.

• Cartoon and Animation Studies
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• s.39
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• pp.321-348
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• 2015

The purpose of this study was to find a system and a progression principle in orchestral piece based on the outcome after comparatively analyzing the orchestral operation technique in "Battle for The Glory" out of the background music in the animation "Dragon Quest IV" by Koichi Sugiyama(1931~), who is a leading runner of Japan's animation music, based on functional parts daccord & Instrumentation Pattern, Rhythm Pattern, Voicing Pattern, and harmonic ratio by progression section devised by the writer. As a result, first, five themes in this music have specific instrumentation pattern, respectively. In a passage that is shown exposition, reprise, and representation in theme, the unity was emphasized by maintaining the same instrumentation pattern. On the contrary to this, a passage of being suggested new theme is being used the exchange method and addition & subtraction in musical instrument in order to strengthen diversity. Second, the voicing pattern is forming the vertical contrasting relationship of "thinness-thickness" on the whole. However, the diversity is being intensified that is changed into the structure of "thickness-thinness" in the third theme and of "thinness-thickness" that has two melodies in the fourth theme. Third, the rhythm pattern is forming the vertical contrasting relationship of "big-small" on the whole. However, the fifth theme is being given diversity with being changed into the structure of "small-big." Fourth, the harmony by progression section from the horizontal perspective is shown to be high in the proportion of unity in the section of being repeated and represented the theme and to be high in the proportion of diversity in the section of being suggested new theme. In this study, the balanced orchestral operation technique through the operation technique, which was used in this work, is what extracts the relationship of diverse proportions in the horizontal progression section based on the technique of vertical perspective. In this aspect, this analytical study is desired to be positioned as a new paradigm in establishing a theoretical system and an educational method in orchestration.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9B
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• pp.751-759
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• 2008

Carrier Ethernet backbone network integrates distributed layer-2 based metro networks. In this networks, Multiple Spanning Tree Protocol (MSTP) has been uscd as a main routing protocol that allows multiple spanning trees in a network. A better routing protocol called IEEE802.1aq - Shortest Path Bridging (SPB) is recently proposed, that generates the shortest spanning tree per a destination node. As SPB provides a routing path per a destination node, there is no way to adapt network traffic at normal condition. If we are free from the principle of "a spanning tree per a destination node", we can achieve adaptive routing. Based on this philosophy, we propose a new spanning tree based protocol - Edge Node Divided Spanning Tree (ENDIST). ENDIST divides an edge node into sub-nodes as many as connecting links from the node and each sub-node generates a single shortest path tree based on SPB. Depending on network or nodal status, ENDIST chooses a better routing path by flow-basis. This added traffic engineering ability contributes to enhanced throughput and reduced delay in backbone networks. The simulation informs us that ENDIST's throughput under heavy load performs about 3.4-5.8 and 1.5-2.0 times compared with STP's and SPB's one respectively. Also, we verified that ENDIST's throughput corresponds to the theoretical upper bound at half of cases we investigated. This means that the proposed ENDIST is a dramatically enhanced and the close-to-perfect spanning tree based routing schemes.

• Clean Technology
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• v.27 no.3
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• pp.269-274
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• 2021

Bioenergy is generally considered to be one of the options for pursuing carbon neutrality. However, for a period of time, combustion of harvested plant biomass inevitably causes more carbon dioxide in the atmosphere than combustion of fossil fuels. This paper proposes a method that predicts and minimizes the total amount and payback period of this carbon debt. As a case study, a carbon cycle impact assessment was performed for immediate switching of the currently used fossil fuels to biomass. This work points out a fundamental vulnerability in the concept of carbon neutrality. As an action plan for the sustainability of bioenergy, formulas for afforestation proportional to the decrease in the forest area and surplus harvest proportional to the increase in the forest mass are proposed. The results of optimization indicate that the carbon debt payback period is about 70 years, and the carbon dioxide in the atmosphere increases by more than 50% at a maximum and 3% at a steady state. These are theoretically predicted best results, which are expected to be worse in reality. Therefore, biomass is not truly carbon neutral, and it is inappropriate as an energy source alternative to fossil fuels. The method proposed in this work is expected to be able to contribute to the approach to carbon neutrality by minimizing present and future carbon debt of the bioenergy that is already in use.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.73-73
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• 2010

합금원소가 다량 첨가된 고합금강, 스테인리스강, Ni기 초내열합금 등은 용접시 혹은 후열처리 동안 열영향부 (HAZ: heat-affected-zone)에서 결정립계를 따라서 액화균열이 종종 발생한다. 이러한 액화균열은 급속한 가열시 HAZ의 결정립계가 국부적으로 용융되어 액상필름을 형성하고, 냉각시 수축으로 인한 인장구속응력에 의해 필름을 따라서 균열이 발생하여 생성된다. HAZ 결정립계 액화는 탄화물, 황화물, 인화물, 보론계 화합물 등이 급가열시 기지와의 반응에 의해 표피 액상을 형성하는 조성적 액화 (constitutional liquation)에 의한 액상의 결정립계 침투로 설명되거나, 결정립계 자체의 용융점을 상당량 낮추는 보론(B), 인(P), 황(S)등의 편석에 의한 국부적 입계 용융으로 주로 연관 지어 해석한다. HAZ 액화균열은 고온 입계균열 현상이므로, 결정립계의 특성에 따라 크게 영향을 받으며 결정립계 character 설계에 의해 액화균열 저항성을 개선시킬 수 있음을 유추할 수 있다. 한편, 본 연구자들은 최근 Ni기 초내열합금에 있어 입계 serration 현상을 새롭게 발견하였으며, 이론적 접근법을 통해 serration을 위한 특별한 열처리 방법을 개발하였다. 형성된 파형입계는 결정학적인 관점에서 조밀 {111} 입계면을 갖도록 분해 (dissociation)되어 낮은 계면에너지를 갖게 됨을 확인하였으며, 입계형상 변화뿐만 아니라 탄화물 특성변화까지 유도하여 크리프 수명을 기존대비 약 40% 정도 향상시킴을 확인하였다. 본 연구에서는 이러한 직선형 입계 대비 'special boundary'로 간주되는 파형입계가 도입될 경우, 보론 편석 및 HAZ 액화거동에 미치는 영향을 고찰하고자 하였다. SIMS (secondary ion mass spectrometry)를 이용하여 열처리 직후 결정립계 보론편석 정도를 비교하였다. 파형입계 시편의 경우, 일반직선형 시편에 비해 결정립계에 보론편석 저항성이 우수함을 확인할 수 있었다. 재현 HAZ 열사이클 시험을 통해 미세조직을 정량적으로 분석하였다. 파형입계 시편 및 일반직선형 시편 모두 최고온도 $1060^{\circ}C$이상부터 입계 탄화물이 기지내로 완전 용해되고 입계가 액화되기 시작하였다. 최고온도별로 입계액화비율을 정량적으로 비교한 결과, 파형입계가 직선입계 대비 훨씬 낮음을 확인할 수 있었으며, 때때로 액화된 필름이 입계를 따라 전파되지 않고 부분적으로 단락되어 있음이 관찰되었다. 액화시험 후 투과전자현미경을 이용한 EDS (energy dispersive spectrometry) 분석을 통해 결정립계 액화의 주요원인은 입계 $M_{23}C_6$의 조성적 액화반응 보다는 보론 편석 (원자 및 $M_{23}(CB)_6$)으로 인한 결정립계 국부용융이 더 유력함을 유추할 수 있었다. 따라서 상기 결과로부터 입계구조가 안정되어 계면에너지가 낮은 파형입계가 보론편석에 대한 저항성이 우수하였으며, 이러한 결과는 액화 저항성에 대응되어 영향을 미침을 알 수 있었다. 게다가 파형입계에 액상 필름이 생성되더라도 낮은 계면에너지에 의해 비롯된 상대적으로 낮은 적심성 (wettability)에 의해 필름이 쉽게 전파되지 않음을 'Smith 입계 wetting 이론'을 이용하여 해석할 수 있었다.

• Journal of Korean Society of Forest Science
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• v.56 no.1
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• pp.51-65
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• 1982

The growth characteristics and appropriate fertilizer-managements in the rejuvenating bamboo grove were studied with Phyllostachys reticulata. The bamboo soil was the sandy loam with rich humus. In the fertilized plots, the N-fertilizer was significantly absorbed, and it was necessary to fertilize the K-fertilizer continuously. According to the development of rejuvenating after flowering, the temperature and relative illumination became lower. while the moisture became higher. The relationship between the diameter at eye height (D) and the culm length (H) of each bamboo can be expressed as follow; $H=2.5538D^{0.5031}$ The leaf area is the major factor for the production of the bamboo grove. Therefore in the rejuvenating grove, we should refrain form pruning or felling of not -flowering bamboo. The theoretical distribution of the internodal length was obtained by the distribution curve line of the internodal length derived from the regular distribution curve line. Relatively long and even internodal length was found in the fertilized plots 2 and 4. The relation between $D^2H$ and dry weight of culm or dry weight of the above ground part were given by linear regression in both relations respectively on the logarithmic coordinates, but the propertional relation was not established in these relations. The biomass of the above ground part obtained by the allometry method showed high values in the fertilized plots 2.5 and 6. The appropriate amounts of the three elements, N, P and K for the maximum dry matter were 24.19, 15.51, 8.63 kg/10a, respectively.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.43-43
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• 2009

단련용 다결정 Ni기 초내열합금은 우수한 가공성, 내산화성, 고온특성 등으로 가스터빈 연소기, 디스크, 증기발생기 전열관 등 발전용 고온부품 소재에 널리 적용되고 있다. 최근 발전설비의 고효율화를 꾀하기 위해 작동 온도를 현격히 증가시키는 기술방향으로 발전하고 있고, 소재측면에서는 기존의 초내열합금 대비 고기능성을 확보할 수 있는 차세대 Ni기 초내열합금 개발이 유럽, 미국, 일본, 중국 등을 중심으로 활발히 이루어지고 있다. 이러한 소재의 고온강도 (온도수용성)를 향상시키기 위해서는 통상 규칙격자 금속간화합물인 $Ni_3(Al,Ti)-{\gamma}'$상의 분율을 증가시킬 수 있지만, ${\gamma}'$상분율이 증가할 경우 용접 및 후열처리 동안 용접열영향부 (HAZ)에서 액화균열이 발생할 가능성이 높아진다. 결정립계를 따라 발생하는 HAZ 액화균열은 입계특성에 의해 크게 영향을 받을 것으로 판단된다. 한편, 본 연구자들은 최근 입계 serration 현상을 단련용 합금에 도입시키는 특별한 열처리를 이론적 접근법을 통해 개발하였다. 형성된 파형입계는 결정학적인 관점에서 조밀 {111} 입계면을 갖도록 분해 (dissociation)되어 낮은 계면에너지를 갖게 됨을 확인하였으며, 입계형상 변화뿐만 아니라 탄화물 특성변화까지 유도하여 크리프 수명을 기존대비 약 40% 정도 향상시킴을 확인하였다. 이러한 직선형 입계 대비 'special boundary'로 간주되는 파형입계가 도입될 경우, HAZ 결정립크기 변화 및 액화거동에 미치는 영향을 고찰하고, 아울러 입계특성 제어가 용접성/용접부 품질 향상에 기여할 수 있는 가능성도 토의하고자 하였다. 본 연구에서는 재현 HAZ 열사이클 시험을 통해 미세구조를 정량적으로 비교하였다. 상대적으로 입계구조가 안정된 파형입계의 이동속도가 高계면 에너지를 갖는 직선형 입계보다 느려 HAZ 결정립 성장이 효과적으로 억제됨을 확인할 수 있었다. 입계 액화거동을 살펴보면, 두 시편 모두 $M_{23}C_6$, MC 등 입계탄화물 계면이 빠른 승온중 액화반응 (constitutional liquation)에 의해 입계가 액화되었으며, 이후 급냉에 의해 입계에 액상막이 존재한 흔적이 발견되었다. 최고온도별로 입계액화 폭/비율을 정량적으로 비교한 결과, 파형입계가 직선입계 대비 대체로 낮음을 확인할 수 있었으며, 때때로 액화되지 않고 잔존하는 입계 탄화물이 관찰되었다. 재현 HAZ 미세조직을 통해 Hot ductility 시험 결과를 유추하자면, 파형입계가 직선입계 보다 좁은 취성온도영역 (Brittle Temperature Range)을 나타낼 것으로 예상되어, 입계특성제어에 의해 Ni기 초내열합금의 용접성을 향상 가능성을 확인하였다.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.681-689
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• 2013

The purpose of this study was to investigate the effect of alcoholic drinking on the dietary habits among university students. The data was collected from 355 students (male : 188, female : 167) living in Busan. The questionnaire composed of general information, person with the lunch meal time, skipping meal, meal type place overeating, snacking eating out, food intake pattern. For statistics analysis, SPSSWIN 12.0 was used. The results were summarized as follows. First, the rates of alcohol drinking in male and female students were 94.1% and 93.4% respectively and the rate of under 19 years old's drinking were 94.4%. Second, in the appearance of drinking, the difference in dietary habits wasn't shown to be significant. However in term of dinner, few female students sometimes haven't dinner (p<0.01). And female group showed frequently eating out (p<0.05) and overeating more than male group(p<0.001). Third, the alcohol drinking group and non-alcohol drinking group showed significantly similar consumption frequency of cereal, meat products, fruits vegetable, oil sugars. But the intakes of milk and dairy products in male students were significantly higher than in female students (p<0.001). These results indicated that more attention should be taken to university students, having habits of skipping meal, alcohol drinking and low intake for nutrition knowledge or attitude so as to improve their health.

• The Journal of the Korea Contents Association
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• v.14 no.4
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• pp.189-210
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• 2014

The purpose of this study was to investigate the casual relationship among social activity, leisure activity and subjective quality of life of the rural elderly. For this end, this study analyzed the differences of the factors by the demographic characteristics and the effects of the social activity and leisure activity on subjective quality of life of the rural elderly. The data was collected using structured questionnaires, and total 324 responses were used in the data analysis. According to the results of this study, the social activity, leisure activity and subjective quality of life was shown to the partially differences by the demographic characteristics. The social activity and leisure activity of the rural elderly had a positive effect on the satisfaction and expectation of life as the subjective quality of life. The religious activities and leisure activity had a positive effect on the satisfaction of life, and the leisure activity through hobbies had a positive effect on the expectation of life. The economic activity had a positive effect on the subjective economic satisfaction, expectation of living standard and municipal government. Also, the volunteer activity and pastime had a positive effect on the subjective health satisfaction. Finally, this study was discussed the theoretical and practical implications as well as the solution to the subjective quality of life of the rural elderly.