• Title/Summary/Keyword: Field wall

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Development of Simple Example of CFD Course in Mechanical Engineering Curriculum (I) (Laminar Pipe Flow) (기계공학교육과정에서의 전산유체동역학의 기초예제개발 (I) (수평 원관의 층류 유동))

  • Lee, Sung-Riong;Cho, Seok-Swoo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.7
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    • pp.72-80
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    • 2018
  • With the ever increasing advances in computers and their computing power, computational fluid dynamics(CFD) has become an essential engineering tool in the design and analysis of engineering applications. Accordingly, many universities have developed and implemented a course on CFD for undergraduate students. On the other hand, many professors have used industrial examples supplied by computational analysis software companies as CFD examples. This makes many students think of CFD as difficult and confusing. This paper presents a simple CFD example used in the department of mechanical design engineering of Kangwon National University and shows its effectiveness. Most students answered that a simple CFD example is more comprehensive than an industrial example. Therefore, it is necessary to develop simple computational analysis problems in the engineering education field.

Experimental Studies on the Second Intermediate Host of Clonorchis sinensis I. Survey on the metacercariae of some trematodes in fresh-water shrimps and experimental infection of Palaemon spp. with Clonorchis cercariae (간흡충(肝吸蟲)의 제이중간숙주(第二中間宿主)에 관(關)한 연구(硏究) I. 민물 새우의 metacercaria 조사(調査) 및 간흡충(肝吸蟲) cercaria의 Palaemon spp.에 대(對)한 감염시험(感染試驗))

  • Rhee, Jae Ku
    • Korean Journal of Veterinary Research
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    • v.9 no.1
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    • pp.71-78
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    • 1969
  • The present studies were undertaken to determine accurately whether Korean native fresh-water shrimps can serve as the second intermediate host of Clonorchis sinensis. The experimental results obtained were as follows; 1. Metacercaria of Clonorchis sinensis was not discovered in 36 Macrobranchium nipponensis (De Hann), 1992 Palaemon paucidens (De Hann) and Palaemon madestus Heller, and 860 Caridina leucastica Stimpson, collected in Kimhae district, which were digested in artificial gastric juice, using binocular dissecting microscope. 2. Cercariae of the Chinese liver fluke could not approach the body wall of young shrimps due to streaming caused by their motion. 3. Young Palaemon spp. of 247 were divided into two groups and placed in two different room aquariums, one is at high temperature, the other is normal. Then they were contacted with the cercariae. Only 11 degenerated metacercariae were found in 9 Palaemon spp. It was suggested that they had died immediately or within a few days after penetration. Furthermore the temperature did not affect the infective ratio. 4. At the field experimental aquarium, no metacercaria of Clonorchis sinensis was discovered tn 100 Palaemon spp. which had been brought into contact with 5000 Parafossarulus manchouricus two trials. 5. Specific changes in the cercariae mixed with the extract of shrimps meat were not observed through the dissecting microscope. 6. These results suggest that the Korean native shrimps cannot serve as the intermediate host of Clonorchis sinensis.

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Effect of Chamber Configuration on Combustion Characteristic Velocity of Full-scale Combustion Chamber (실물형 연소기의 형상에 따른 연소특성속도 비교)

  • Kim, Jong-Gyu;Han, Yeoung-Min;Ahn, Kyu-Bok;Kim, Mun-Ki;Seo, Seong-Hyeon;Choi, Hwan-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.05a
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    • pp.149-152
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    • 2008
  • Effects of chamber configuration on combustion characteristic velocity of full-scale combustion chamber for 30-tonf-class liquid rocket engine were studied. The configurations of combustion chamber are ablative and channel cooling chamber (${\varepsilon}$=3.2) which have detachable mixing head, and single body regenerative cooling chamber which has nozzle expansion ratio of 3.5 and 12, respectively. The combustion chambers have chamber pressure of 53${\sim}$60 bar and propellant mass flow rate of 89 kg/s, and the injectors of all combustion chamber have recess number 1.0 and double-swirl characteristics. The hot firing test results at design point show that the combustion characteristic velocity of the regenerative cooling chamber which has nozzle expansion ratio of 12 is higher than that of other combustion chambers. The reasons for the above result are the increases of combustion pressure and enthalpy of kerosene which is heated due to cooling of the chamber wall before injection into the combustion field.

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A Study on the Characteristics of the Folk Houses in the Upper Area of Seomjin River -focused on the generating housing floor plans- (섬진강 상류 지역의 민가건축에 관한 연구 -평명유형을 중심으로-)

  • 남해경;허성제
    • Journal of the Korean housing association
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    • v.11 no.3
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    • pp.43-51
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    • 2000
  • This study aims to find the characteristics of the folk houses in the upper area of Seomjin river in the view point of generating housing floor plans by their human and natural elements of environment. Because they are formed differently as them and have the characteristics as the houses in the upper area of Seomjin river. Seomjin river flows from mid-west area of the Korean peninsula to the southern sea. This is about 212.3km long and the fourth in the south of the Korean peninsula. It is surrounded high mountains in the upper area and makes open field in the mid and lower area of river. The study is surveyed and analyzed to the folk houses of the middle and lower class people in the area of Seomjin river. Because they have been formed by their natural and human elements of environment gradually. They are 35 houses - 13 in Jinan-kun, 4 in Imsil-kun, 10 in Namwon city, 10 in Sunchang-kun. They are analyzed by their floor plans and their spatial relations. The result of this study is that they are made by their natural and human elements of environment. There are some houses with semi-several wings and with storage that are appeared in the mountain village. It reflects that they are surrounded by high mountains. And there are some houses with wooden floor room that are appeared in the area of river little in the area of mountain. To prevent wind from the river the houses are layouted as a form . open ㄴ type, open ㄷ type, and their wall is made of stone and planted bamboo trees around their houses.

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A Study on the Cultural Heritage Administrative Approaching about the Ramparts Heritage of Baekje Historic Areas in World Cultural Heritage (세계문화유산 백제성곽의 보존관리와 활용사례에 관한 문화재행정적 접근방안 연구)

  • Jeon, Chil-Soo
    • Journal of the Korea Convergence Society
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    • v.8 no.11
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    • pp.321-329
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    • 2017
  • Baekje Historic Areas were inscribed on the UNESCO World Cultural Heritage List unanimously at the 2015 World Heritage Committee held in Bonn, Germany. There are three ramparts in Beakje Historic Areas; Gongsansung fortress in Gong-ju, Busosangsung fortress and the outer city wall in Buyeo. The purpose of this study is to research the use plan and the condition of the conservation and management for enhancing values of the World Cultural Heritage. This paper analyses basic survey, repair, documentation, conservation, management, and the cases of the utilizing these fortresses through literatures and a field studies. This study, based on the management and use of Baekje fortresses, could give implications for the conservation, management, and use of other fortresses.

Characteristics Analysis of the Design Factors Followed by Present Techniques of Waterscape Facilities in the Apartment Complex (공동주택단지 내 수경시설 연출기법에 따른 설계요소별 특성분석)

  • Lee, Gyeong-Jin;Choi, Ah-Young;Song, Byeong-Hwa
    • KIEAE Journal
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    • v.8 no.4
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    • pp.11-18
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    • 2008
  • This research case-study places are chosen Seoul Metropolitan City and Yong-In City where the distinction characteristics of outdoor spaces are introduced in Apartment Complex. In this study, the standard of waterscape facilities will be set through preliminary researches and detail design factors are prepared for each characteristics. Analyze and research the characteristics of design factors through the field research of places. The Group data from Cluster Analysis, which is about waterscape facilities, is analyzed and classified by types of waterscape facilities in common residence. and then each type of characteristics and representatives of waterscape facilities founded. Waterscape facilities are charactered in 4 main types. I Type is appeared to the natural artificially mountain stream, slope and a rest space type, and feelings type. This type has twenty sites. II Type is appeared to the fewest sites(11 sites). This type is appeared to the Eco-pond, Border planting next to the waterscape facilities. III Type is appeared to the largest sites(28 sites), that is, play style water facilities of no-plantation patterns. IV Type is appeared to the retaining wall type, the rest space of bench type. Research result led, detailed plan element 64 are selected with design elements Seoul Metropolitan City and the Yong-In City at the time of the fact that well is only reflected commonly from external spaces, the type by quality which leads a statistical analysis the type quality was well reflected relatively was judged.

Microstructures and Electrical Properties of $RuO_2$Bottom Electrode for Ferroelectric Thin Films

  • Shin, Woong-Chul;Yang, Cheol-Hoon;Jun-SiK Hwang;Yoon, Soon-Gil
    • The Korean Journal of Ceramics
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    • v.3 no.4
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    • pp.263-268
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    • 1997
  • RuO$_3$ thin films were deposited on Si(100) substrate at low temperatures by hot-wall metalorganic chemical vapor deposition. Bis(cyclopentadienyl) ruthenium, Ru$(C_5H_5)_2$, was used as the precursor RuO$_2$single phase was obtained at a low deposition temperature of 25$0^{\circ}C$ and the crystallinity of RuO$_2$thin films improved with increasing deposition temperature. RuO$_2$thin films grow perpendicularly to the substrate and show the columnar structure. The grain size of RuO$_2$films drastically increases with increasing the deposition temperature. The resistivity of the 180 nm-thick RuO$_2$thin films deposited at 27$0^{\circ}C$ was 136 $\mu$$\Omega$-cm and increased with decreasing film thickness. SrBi$_2Ta_2O_4$ thin films deposited by rf magnetron sputtering on the RuO$_2$bottom electrodes showed a fatigue-free characteristics up to ~10$^10$ cycles under 5 V bipolar square pulses and the remanent polarization, 2 P$_r$ and the coercive field, 2 E, were 5.2$\mu$C/$\textrm{cm}^2$ and 76.0 kV/cm, respectively, for an applied voltage of 5 V The leakage current density was about 7.0$\times$10$^{-6}$ A/$\textrm{cm}^2$ at 150 kV/cm.

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A Study on the Architectural Aspect of the Sutra Hall and the Promoters of the Rotating-sutra Case Cabinet of the Yeongguk Temple in the Koryo Dynasty (영국사(寧國寺) 대장전(大藏殿)과 전륜장(轉輪藏)의 조성주체와 건축특성)

  • Lee, Kyung-Mee
    • Journal of architectural history
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    • v.20 no.5
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    • pp.95-109
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    • 2011
  • The building for the Sutra appeared as the Sutra-belief became popular in the early years of the Koryo Dynasty. According to the written documents, there were two types of apparatus to keep sutras, one by fixing the cabinet to the wall and the other by rotating the cabinet at the center of the hall. There are no remains. Recently, at the excavation of the site of the Yeongguk Temple (寧國寺) in the Chungcheong Prevince (영동군), a building which was presumed as the Sutra Hall was recovered at the side of the Main Hall. At the center of the building, of 6meters width and 6meters depth, there was a large stone which had a round trace which was presumed to supporting the rotating sutra-case cabinet. By examining the concerned situations, this building was concluded as the Sutra Hall of the temple. The Yeongguk Temple had a close relationship with the royal household. Budddhist monk Gwangji, son of the 16th King Yejong was lived at the Temple. the tomb of King's advisory priest Wongak was also erected at the Temple. Two monks were well known as the defender of the Sutra. The Sutra Hall of the Yeongguk Temple regarded as a significant example which showed us how the archtectural aspect of the Sutra Hall was shaped in the Koryo Dynasty. It could be said that revealing the architectural aspect of the Stura Hall will help revealing the Buddhist architecture of the Koryo Dynsty which is veiled in many field.

A study on Actual Conditions Analysis for Regeneration of High-rise and High-density Apartment in the 1st period New Town (1기 신도시 고층고밀 아파트단지의 재생을 위한 개발현황 분석에 관한 연구 - 분당신도시를 중심으로 -)

  • Cho, Sung Heui;Lee, Tae Kyung;Oh, Deog Seong
    • KIEAE Journal
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    • v.9 no.2
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    • pp.17-26
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    • 2009
  • High-rise and high-density apartment complexes have been built and supplied on a large scale in the 1st period New Town of metropolitan areas since the late 1980s. Recently it has become necessary to improve those apartment complexes which have blight problems for aging more than about 20 years accompanying simultaneity and a large scale. The purpose of this study is to analyze actual conditions of high-rise and high-density apartments in a view of sustainable regeneration. The contents and methods of this study are as follows. First, the concept of high-rise and high-density in domestic apartment developments were identified through review of literature and the law. Second, development conditions of Bundang new town and 1st period new town were studied. Third, the evelopment conditions of high-rise and high-density apartments in cases of 6 apartment complexes were analyzed from points of view of sustainable development by literature review and a field study. The results of this study are as follows. First, high-density range in domestic apartments can be conceptualized as 600 persons/ha. High-rise range in domestic apartments can be onceptualized as more than 11 stories under 30 stories. Second, characteristics and subjects based on actual conditions analysis could suggest on physio-environmental aspect and socio-economic aspect. Major characteristics and subjects of the physio-environmental aspect were 1.satisfaction of convenient facilities and public transportation service, 2.shortage of parking space, 3.uniform & blight of community facilities, 4.uniformed building layout, and 5.uniform pattern of unit plan and low flexibility by the bearing wall structure. And those of the socio-economical aspect were 1.satisfaction of current community, 2.increase and diversity of needs of the elderly by socio-demography change, 3.improvement of size and method of apartment complex development and 4.raising of economic-sufficiency.

Growth and Optoelectrical Properties for $CuInS_2$ Single Crystal Thin Film ($CuInS_2$ 단결정 박막 성장과 광전기적 특성)

  • Hong, Kwang-Joon;Lee, Sang-Youl
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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    • pp.230-233
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    • 2004
  • The stochiometric mix of evaporating materials for the $CuInS_2$ single crystal thin films was prepared from horizontal furnance. Using extrapolation method of X-ray diffraction patterns for the $CuInS_2$ polycrystal, it was found tetragonal structure whose lattice constant $a_0$ and $c_0$ were $5.524\;{\AA}$ and $11.142\;{\AA}$, respectively. To obtain the single crystal thin films, $CuInS_2$ mixed crystal was deposited on throughly etched semi-insulator GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperature were 640 t and 430 t, respectively and the thickness of the single crystal thin films was $2{\mu}m$. Hall effect on this sample was measured by the method of van dot Pauw and studied on carrier density and temperature dependence of mobility. The carrier density and mobility deduced from Hall data are $9.64{\times}10^{22}/m^3,\;2.95{\times}10^{-2}\;m^2/V{\cdot}s$ at 293 K, respectively The optical energy gaps were found to be 1.53 eV at room temperature. From the photocurrent spectrum by illumination of perpendicular light on the c - axis of the thin film, we have found that the values of spin orbit coupling splitting ${\Delta}So$ and the crystal field splitting ${\Delta}Cr$ were 0.0211 eV and 0.0045 eV at 10 K, respectively. From PL peaks measured at 10K, 807.7nm (1.5350ev) mean Ex peak of the free exciton emission, also 810.3nm (1.5301eV) expresses $I_2$ peak of donor-bound exciton emission and 815.6nm (1.5201eV) emerges $I_1$ peak of acceptor-bound exciton emission. In addition, the peak observed at 862.0nm (1.4383eV) was analyzed to be PL peak due to donor-acceptor pair(DAP).

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