• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.37-37
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• 2010

Silicate-silsesquioxane or siloxane-silsesquioxane hybrid thin films are strong candidates as matrix materials for ultra low dielectric constant (low-k) thin films. We synthesized the silicate-silsesquioxane hybrid resins from tetraethoxyorthosilicate (TEOS) and methyltrimethoxysilane (MTMS) through hydrolysis and condensation polymerization by changing their molar ratios ([TEOS]:[MTMS] = 7:3, 5:5, and 3:7), spin-coating on Si(100) wafers. In the case of [TEOS]:[MTMS] 7:3, the dielectric permittivity value of the resultant thin film was measured at 4.30, exceeding that of the thermal oxide (3.9). This high value was thought to be due to Si-OH groups inside the film and more extensive studies were performed in terms of electronic, ionic, and orientational polarizations using Debye equation. The relationship between the mechanical properties and the synthetic conditions of the silicate-silsesquioxane precursors was also investigated. The synthetic conditions of the low-k films have to be chosen to meet both the low orientational polarization and high mechanical properties requirements. In addition, we have investigated a new solution-based approach to the synthesis of semiconducting chalcogenide films for use in thin-film transistor (TFT) devices, in an attempt to develop a simple and robust solution process for the synthesis of inorganic semiconductors. Our material design strategy is to use a sol-gel reaction to carry out the deposition of a spin-coated CdS film, which can then be converted to a xerogel material. These devices were found to exhibit n-channel TFT characteristics with an excellent field-effect mobility (a saturation mobility of ${\sim}\;48\;cm^2V^{-1}s^{-1}$) and low voltage operation (< 5 V). These results show that these semiconducting thin film materials can be used in low-cost and high-performance printable electronics.

• 한국지형학회지
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• 제24권4호
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• pp.27-41
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• 2017

In this study, geomorphological and geological research has been carried out to estimate the possibility of ancient port location near Hwaseong Dangseong. Geomorphological characteristics around Eunsupo were analyzed through comparison of past and present topographic maps and field survey. Grain size, age dating, and geochemical analysis on surface sediments and borehole sediments were performed. Through the geomorphological characteristics analysis, it was interpreted that Eunsupo area was submerged in seawater especially at high tide in the past, and that ships could approach to the inside of the area through the tidal channel which were developed in the area. It is also assumed that ships were anchored at a low elevation point in the area. The paleo-environmental change in the area was analyzed based on the classification of sedimentary environment using grain size distribution of surface and borehole sediments and geochemical analysis. It was confirmed that the geomorphological interpretation for the possibility of ancient port location coincided well with the paleo-environmental change interpreted through sediment analysis. This study is a basic study for estimating ancient port location, and it is expected that more accurate paleo-environmental changes will be restored through detailed geomorphological survey and additional borehole analysis in the future research.

• 기술혁신학회지
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• 제22권1호
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• pp.1-27
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• 2019

이 연구는 '사회적 도전과제 대응과 지속가능한 발전을 지향하는 출연(연)으로의 전환'의 관점에서 출연(연)의 변화를 논의한다. 이를 위해 출연(연)에서 이루어지는 사회문제 해결형 연구개발을 전환실험으로 파악하여 그것의 진행과정을 살펴본다. 포커스 그룹 인터뷰 방식을 활용해서 시스템 전환의 틀에서 출연(연)의 사회문제 해결형 연구개발에 대한 인식, 연구개발의 진행과정, 그 문제점과 대응방향을 검토했다. 인터뷰 결과를 요약하면, 현재 전환의 필요성이 논의되고 전환실험이 소규모로 진행되고 있지만 아직 기존 틀에서 실험들이 진행되고 있다. 전환을 촉진하기 위해서는 출연(연) 내부로부터 진행되는 전환실험과 비전 형성작업이 필요하다.

• 항공우주시스템공학회지
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• 제18권3호
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• pp.17-26
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• 2024

항공기 엔진은 비행 중 고온, 고압과 터빈 축의 회전으로 인한 응력이 발생한다. 이러한 하중으로 인해 구조 내/외부에 미세한 균열이 발생할 수 있다. 이는 구조적 결함으로 이어져 부품의 수명에 악영향을 줄 수 있다. 이러한 현상을 사전에 방지하고자 균열에 대한 유한요소해석이 진행된다. 하지만 이 과정은 반복적인 균열 모델링이 이루어져 많은 시간과 노력을 수반한다. 그러므로 본 논문에서는 유한요소모델 기반의 균열 모델링 기법을 개발하였다. 균열 모델링에는 점 간의 연결에 제한을 가지고 공간을 삼각 분할하는 Constrained Delaunay Triangulation(CDT)을 사용하였다. 반타원 균열을 가지는 평판과 원통형 용기에 대한 응력확대계수 비교를 통해 기법을 검증하였으며, 균열 해석에 유용함을 보였다.

• International Journal of Advanced Culture Technology
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• 제5권1호
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• pp.58-63
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• 2017

Emergencies and disasters can happen any time without any warning, and things can change and escalate very quickly, and often it is swift and decisive actions that make all the difference. It is a responsibility of the building facility management to ensure that a proven evacuation plan in place to cover various worst scenario to handled automatically inside the facility. To mapping out optimal safe escape routes is a straightforward undertaking, but does not necessarily guarantee residents the highest level of protection. The emergency evacuation navigation approach is a state-of-the-art that designed to evacuate human livings during an emergencies based on real-time decisions using live sensory data with pre-defined optimum path finding algorithm. The poor decision on causalities and guidance may apparently end the evacuation process and cannot then be remedied. This paper propose a cloud connected emergency evacuation system model to react dynamically to changes in the environment in emergency for safest emergency evacuation using IoT based emergency exit sign system. In the previous researches shows that the performance of optimal routing algorithms for evacuation purposes are more sensitive to the initial distribution of evacuees, the occupancy levels, and the type and level of emergency situations. The heuristic-based evacuees routing algorithms have a problem with the choice of certain parameters which causes evacuation process in real-time. Therefore, this paper proposes an evacuee routing algorithm that optimizes evacuation by making using high computational power of cloud servers. The proposed algorithm is evaluated via a cloud-based simulator with different "simulated casualties" are then re-routed using a Dijkstra's algorithm to obtain new safe emergency evacuation paths against guiding evacuees with a predetermined routing algorithm for them to emergency exits. The performance of proposed approach can be iterated as long as corrective action is still possible and give safe evacuation paths and dynamically configure the emergency exit signs to react for real-time instantaneous safe evacuation guidance.

• Journal of Forest and Environmental Science
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• 제32권2호
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• pp.219-235
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• 2016

Forest tree diversity inventory and its periodical monitoring are important to understand changes in tree population structure and to provide information useful for biodiversity conservation and reserve management. In a long-term forest dynamics program in Indian tropical dry evergreen forest, this communication deals with tree diversity changes at decadal interval. The initial inventory of tree diversity was carried out in 2003, in four tropical dry evergreen forest sites - (much disturbed sites Shanmuganathapuram - SP and Araiyapatti - AP and moderately disturbed sites - Karisakkadu - KR and Maramadakki - MM) on the Coromandel Coast of peninsular India, by establishing four 1ha permanent plots, one in each site. In 2013, the four plots were re-inventoried for tree diversity (${\geq}10cm\;gbh$) changes which yielded 56 species from 46 genera and 26 families. The studied forest sites are threatened by disturbance due to multiple reasons; cutting of trees inside of the forest, grazing by goats, construction of temple approach road, and some aspects cultural attachment of local people like constructing new, additional strctures of temple by denuding a portion of forest etc.. Tree species richness over a decade increased by four species in site SP, two species in site AP, and one species in site KR, but decreased by one species in site MM. Tree density decreased drastically by 480 (28.92%) and 102 (12.63%) stems $ha^{-1}$ respectively in sites SP and AP, but moderately increased by 82 (12.09%) stems $ha^{-1}$ in site KR and 26 (3.46%) stems $ha^{-1}$ in site MM. Tree basal area declined in site KR from $21.6m^2$ to $20.26m^2ha^{-1}$ and in site SP from 21.1 to $20.38m^2ha^{-1}$, but increased from $19.1m^2$ to $19.43m^2$ and from 15.5 to $18.63m^2ha^{-1}$ in sites AP and MM respectively. Three tree species (Allophylus serratus, Maytenus emarginata and Ehretia pubescens) were lost out of the 57 species recorded in 2003, and two species (Jatropha gossypiifolia and Streblus asper) were new additions in ten years. The long-term forest monitoring data will be valuable to understand forest dynamics and for conservation and management of this and similar tropical forests.

• 대한한방내과학회지
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• 제11권1호
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• pp.93-107
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• 1990

Studies on diagnosis and treatment of tumor . abscess . ulcer in intestinal carbuncle were carried out. The result of studies were summerized as follows: 1. By Nai-Gyung carbuncle-tumor arose from disharmony between nutrient and defensive because of cold, abscess arose from fever victory between cold and fever, ulcer arose from decreasing function of Bi-Kam year. By latter literature Bi-Kam year could be interpreted that spleen stomach was invaded evil influence from unattainable vital force of the earth. 2. Sites of intestinal carbuncle were large intestine, small intestine, intestinal inside or outside between large and small intestine, Intestinal carbuncle was common name of a disease about large intestinal carbuncle, small intestinal carbuncle, pelvic intestinal carbuncle, shrink leg intestinal carbuncle etc.. Pain appeared Chunchu-Hyul in large intestinal carbuncle, and Gwanweon-Hyul in small intestinal carbuncle. 3. On abdominal diagnosis tumor had indistinct pain of Gwanweon Chunchu, edema and heary feeling in low abdomen, no excessive pain by hand press and intestinal boiling sound. In abscess pain descended from right side of low abdomen to huckle, and there was rejection against press, feeling about fever,water sound with flank movement. In ulcer hand approach was difficult since excessive pain diffuse to whole abdomen, and perforating ulcer sometimes caused a serious symptom of umbilical pus. 4. On fecal and urinary diagnosis in tumor urine was yellowish red pollakiuria like gonorrhoea and occasional constipation. In abscess uncomfortable rough pain short red early urine like gonorrhoea appeared during urination, and constipation with stinging pain appeared during defecation. In ulcer red rough pyuria appeared, and stinging and pain with puruloid blood appeared during defecation. 5. On treatment in tumor Daiwhang-Tang Daisenggi-Tang Dangui-Jun by dissipation method, calming down method, interior reliance maturation method, in abscess Mokdan-San Euiiin-Tang Jeokduiin-Tang by the method of water repelling pus discharge, acute breaking, in ulcer Takridanggui-Tang Paljin-Tang Bojungikki-Tang were each used by the method of interior reliance, virulence astriction, supplement vital force and blood, supplement spleen stomach. 6. On treatment patient may have to be careful of excessive moving and suprising anxiety. Abuse of acupuncture and moxibustion made patient worse, misuse of analgesics purgative intestinal irrigation etc. could provoke difficult diagnosis and perforation. So you must treat after exact diagnosis. 7. Prognosis of ease tumor ease abscess ease ulcer and ease astriction was good. If the intestinal carbuncle were not to promote to abscess and ulcer for a long time, its prognosis was bad and it could metastasize to cancer because of dark purple with hardness. So tumor abscess ulcer in intestinal carbuncle may be significant of precancerous lesion.

• 한국철학논집
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• 제30호
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• pp.191-225
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• 2010

이 논문은 한자(漢字)의 다의성(多義性)과 품사(品詞)의 비결정성(非決定性)에 초점을 맞추어 "논어(論語)" 해독을 시도하였다. 먼저, 이 글은 한자가 인간과 세계에 대한 문제를 표현하는 사유의 언어(다른 말로 철학언어)로서 제 기능을 할 수 있는가? 는 물음에 대한 본격적인 논의를 전개하였다. 16세기 마테오 리치는 보편적인 '표의문자체(ideographic script)'의 가능성을 한자에서 발견하려고 노력함으로써 이 물음에 긍정적인 답변을 제시하였다. 반면, 헤겔과 하이데거 등은 한자는 첫째, 전치사와 관사가 없는 언어체계이며, 둘째, 이중의미, 반대의미를 표시하는 단어가 없으며, 셋째, 어형변화 없이 어순에 의해서만 의미를 표현, 전달하기 때문에 복잡한 인간의 사유와 엄밀한 논리를 표현하는 철학 언어로서 부적합하다고 주장한다. 그러나 카시러와 울만, 소쉬르, 그리고 데리다 등의 언어관을 경유하면서, 우리는 헤겔과는 다른 입장에서 한자의 사유언어로서의 기능을 발견할 가능성을 확인한다. 서양의 언어체계와 달리 한자는 언제나 개별적으로 존재하는 단어들의 의미 보다 문맥에서의 언어 기능이 보다 중요하다. 한자는 고유의 품사를 감추고, 다른 문자들과의 관계망 속에서 어떤 사건과 사물의 의미를 표현하면서 자신의 본색을 드러낸다. 한자는 이른바 '불가결정성(indecidability)'의 언어인 것이다. 이러한 한자의 다의성과 품사의 부재는 바로 '불가결정성'에 기인한다. 이렇게 본다면, 비록 전치사, 관사, 어형변화, 품사 등을 결여하는 있는 문자체계일지라도 '다의(多義)'의 특성을 지닌 한자는 인간의 복잡한 사유를 나름의 방식으로 표현하는 철학언어로서 충분한 기능을 할 수 있는 것이다. 이를 토대로 "논어(論語)"읽기의 다양성을 담보할 수 있을 것이다.

• 동양고전연구
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• 제48호
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• pp.91-116
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• 2012

글쓰기란 틀에 박힌 형식이 아닌 자신의 느낌과 생각을 있는 그대로 표현하는 일인데도 불구하고 조선후기의 문풍은 그렇지 못했다. '문필진한(文必秦漢), 시필성당(詩必盛唐)'이라는 복고주의 문장론이 지배적이었기 때문에 문장의 법도를 무시한 채 자신의 감정을 있는 그대로 표현한다는 것은 사실상 금기시되었다. 하지만 도그마에 빠져 변화하는 세상을 바라보지 못하는 성리학과 내용은 없이 껍데기만을 모의하는 의고적 글쓰기에 지친 문장가들은 익숙함과 전범에서 벗어나고자 새로운 글쓰기를 시도했다. 이러한 변화의 가운데에 있던 이용휴는 당시 수입된 최신의 중국 서적들을 통해 명말청초의 사조들을 익히며 자신만의 개성적인 글쓰기를 만들었다. 그는 당시 지배 이데올로기인 성리학적 사유체계를 거부하고 인간성 본래의 측면에 관심을 가지며 주체 회복을 강조하였으며, 반의고적 글쓰기를 통해 허위에 찬 당시의 풍토를 비판했다. 그리고 진정한 나를 찾기 위해서는 어린 시절 순수한 마음[천리(天理)]를 회복하고, 이를 위해서는 마음[심(心)]을 바르게 해야 한다고 주장하였다. 그런데 이러한 그의 주장은 '심즉리(心卽理)'를 내세우는 양명학과 비슷했다. 양명학은 마음[심(心)]을 윤리의 준칙[이(理)]으로 삼고 있어서, '이(理)는 외재적이고 초월적이며, 이것은 성인에 의해 언어화되고, 경전으로 문자화 되어 있다.'는 성리학과는 확연히 갈라졌다. 그는 이들처럼 이(理)의 외재성을 부정하고 내재성을 강조하면서 성리학의 경전 중심주의를 해체했다. 그가 내세운 전범의 부정과 주체 회복의 글쓰기는 이러한 사상에 영향을 받았다. 그러나 이러한 영향 때문에 그를 양명학자로 단정 짓거나, 그를 비롯한 반의고적 태도를 갖는 문인들의 사상적 근거를 양명학이라 확정해서는 안 된다. 왜냐하면 그의 문학을 주자학이든 양명학이든 단정 짓는 순간 그것이 또 전범이 되어 주체는 사라지게 될 것이기 때문이다. 그는 일체의 전범을 부정하고 주체적으로 살아가기를 바랐고, 그것을 글로 남겼다. 우리가 200여년이 지난 지금에도 그의 글을 읽는 것은 바로 이러한 이유에서 일 것이다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제20회 춘계학술대회 논문집
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• pp.91-93
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• 2003

A comprehensive numerical study is carried out to investigate for the understanding of the flow evolution and flame development in a supersonic combustor with normal injection of ncumally injecting hydrogen in airsupersonic flows. The formulation treats the complete conservation equations of mass, momentum, energy, and species concentration for a multi-component chemically reacting system. For the numerical simulation of supersonic combustion, multi-species Navier-Stokes equations and detailed chemistry of H2-Air is considered. It also accommodates a finite-rate chemical kinetics mechanism of hydrogen-air combustion GRI-Mech. 2.11[1], which consists of nine species and twenty-five reaction steps. Turbulence closure is achieved by means of a k-two-equation model (2). The governing equations are spatially discretized using a finite-volume approach, and temporally integrated by means of a second-order accurate implicit scheme (3-5).The supersonic combustor consists of a flat channel of 10 cm height and a fuel-injection slit of 0.1 cm width located at 10 cm downstream of the inlet. A cavity of 5 cm height and 20 cm width is installed at 15 cm downstream of the injection slit. A total of 936160 grids are used for the main-combustor flow passage, and 159161 grids for the cavity. The grids are clustered in the flow direction near the fuel injector and cavity, as well as in the vertical direction near the bottom wall. The no-slip and adiabatic conditions are assumed throughout the entire wall boundary. As a specific example, the inflow Mach number is assumed to be 3, and the temperature and pressure are 600 K and 0.1 MPa, respectively. Gaseous hydrogen at a temperature of 151.5 K is injected normal to the wall from a choked injector.A series of calculations were carried out by varying the fuel injection pressure from 0.5 to 1.5MPa. This amounts to changing the fuel mass flow rate or the overall equivalence ratio for different operating regimes. Figure 1 shows the instantaneous temperature fields in the supersonic combustor at four different conditions. The dark blue region represents the hot burned gases. At the fuel injection pressure of 0.5 MPa, the flame is stably anchored, but the flow field exhibits a high-amplitude oscillation. At the fuel injection pressure of 1.0 MPa, the Mach reflection occurs ahead of the injector. The interaction between the incoming air and the injection flow becomes much more complex, and the fuel/air mixing is strongly enhanced. The Mach reflection oscillates and results in a strong fluctuation in the combustor wall pressure. At the fuel injection pressure of 1.5MPa, the flow inside the combustor becomes nearly choked and the Mach reflection is displaced forward. The leading shock wave moves slowly toward the inlet, and eventually causes the combustor-upstart due to the thermal choking. The cavity appears to play a secondary role in driving the flow unsteadiness, in spite of its influence on the fuel/air mixing and flame evolution. Further investigation is necessary on this issue. The present study features detailed resolution of the flow and flame dynamics in the combustor, which was not typically available in most of the previous works. In particular, the oscillatory flow characteristics are captured at a scale sufficient to identify the underlying physical mechanisms. Much of the flow unsteadiness is not related to the cavity, but rather to the intrinsic unsteadiness in the flowfield, as also shown experimentally by Ben-Yakar et al. [6], The interactions between the unsteady flow and flame evolution may cause a large excursion of flow oscillation. The work appears to be the first of its kind in the numerical study of combustion oscillations in a supersonic combustor, although a similar phenomenon was previously reported experimentally. A more comprehensive discussion will be given in the final paper presented at the colloquium.