• 한국소음진동공학회논문집
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• 제11권8호
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• pp.322-330
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• 2001

The stability and the leakage performance of turbo pump unit seals supported by elastic-ring ball bearings are Investigated for the Improvement of onset speed of instability(OSI). The numerical analysis of floating ring seal in consistence with its geometry and operating conditions is executed with detailed comparison of various seal types. The results show that the floating ring seal has superior performance in terms of rotordynamic salability compared to the ocher type seals while it shows slightly inferior leakage performance. To Improve the leakage performance. floating ring seal could be combined with hole Pattern damper or labyrinth seal surface.

• 한국유체기계학회 논문집
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• 제16권1호
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• pp.32-39
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• 2013

The multi-stage control valve is one of the devices which controls cavitation and high pressure drop. To attain the high pressure drop, the conventional control valves adopted the multi-stage trim to avoid the occurrence of local cavitation in valves. This work studied the effect of divergence angle on the characteristics of multi-stage trim. Pressure drop and flow characteristics was calculated for the 1 passage of multi-staged trim by using the FLUENT 6.3.26. The result showed that the pressure drop is significantly influenced by the divergence angle of multi-stage trim. In addition, the pressure drop increased consistently as the Reynolds number and divergence angle increases.

• 대한수의학회지
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• 제34권3호
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• pp.421-433
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• 1994

This study was carried out to identify anatomical characteristics of the individual bones of the cranium of the Korean native goat. The pars lateralis and pans basilaris of the os occipitale were fused each other, whereas the squama occipitalis articulated with the pars lateralis, forming the sutrue. The sinus sphenoidale was formed in the corpus ossis presphenoidalis. The os prietale was observed as a single bone. In the os frontale, an fossa innominatum was found ventrolateral to the root of processus cornualis, and the orificium orbitale canalis supraorbitalis was also formed on the pars orbitalis. The meatus temporalis was formed in the medial side of the pars squama of the os temporalis. The lamina cribrosa of the os ethmoidale was membrane-like structure with many foramina. The labyrinth ethmoidalis was composed of four endoturbinalia and ten to twelve ectoturbinalia.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.1827-1831
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• 2009

본 연구에서는 래버린스 형태 중 비교적 연구가 거의 되어 있지 않은 직사각형 래버린스 위어의 유량특성을 분석하여 월류량 증대효과를 분석하고자 하며 직사각형 래버린스 위어의 복잡한 흐름현상을 구현하기위해 수리모형실험을 수행하였다. 수리모형실험은 직사각형 래버린스 위어의 다양한 형상을 고려하기 위해 유효길이와 위어 폭 비(L/W)의 범위를 2, 4, 6, 8, 10으로 적용하였다. 또한, 수리모형실험에서 수심 변화에 대한 범위는 전수두와 위어 높이의 비를 0.05에서 0.75범위로 수행하였다. 직사각형 래버린스에 대한 유량 특성을 유량비와 유량계수 곡선을 이용하여 월류량 증대효과를 분석하였다. 그 결과, 직사각형 래버린스 위어의 유량비는 L/W가 증가할수록 감소하는 경향을 나타냈으며, 전수두 비$(H_t/P)$가 증가할수록 작아지는 경향을 나타냈다. 즉, 일반 선형 위어보다 월류량 증대하는 효과가 낮은 전수두 비에서 발생하는 것으로 분석되었으며, 월류량 증대를 위한 수공구조물 설계의 기초자료로 활용이 가능할 것이다. 향후, 유량계수를 예측하는 관련 식이나 기법을 개발하여 효과적으로 래버린스 위어의 유량을 산정할 수 있을 것이다.

• The Korean Journal of Pain
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• 제12권2호
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• pp.235-237
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• 1999

Meniere's disease is a disorder of the membranous labyrinth that is characterized by vertigo, hearing loss, tinnitus and ear fullness. The etiology of Meniere's disease is yet to be described and the management is also very difficult. Fifty-one years old female patient had paroxysm of severe tinnitus and dizziness after medical therapy and surgical intervention during several years. Patient received stellate ganglion block (SGB) and her symptoms were completely relieved. Therefore, SGB could be considered another therapeutic modality for Meniere's disease.

• Progress in Superconductivity
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• 제5권1호
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• pp.80-83
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• 2003

Superconducting YBCO thin films are fabricated on single-crystalline substrates by Metallo-organic Depostion process employing Trifluoroacetic acid as a chelating agent (MOD-TFA). (100)-oriented single crystalline LaAlO$_3$ substrates were employed to grow superconducting film with high crystallinity. The fully processed YBCO thin films were characterized with XRD, SEM, EDS, etc. The microstructures of YBCO thin films show labyrinth-like patterns. The origin of this microstructure was delineated by compositional inhomogeneity during the MOD process and it was shown that the microstructure may be modified by additives. In this work, effects of additives on the microstructures and electrical properties of YBCO thin films have been investigated.

• 한국실내디자인학회논문집
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• 제14권1호
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• pp.20-27
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• 2005

This study is focused on the concept and spatial organization of bifurcation. After discussing the concept of bifurcation used in Borges' literature and Deleuze's Fold philosophy, case examples in contemporary architecture are analysed to comparatively investigate the relationship between the concept and space. In Deleuze's philosophy, bifurcation as well as pleats, inflection are used to form the world of fold that goes to infinity while, in Borges' literature, the structure of bifurcation is the key method to create the labyrinth of time. There are various projects in contemporary architecture based on the Deleuzian concept of bifurcation. Rem Koolhaas's Two Libraries for Jussieu University and UN Studio's Arnhem Central are selected and researched for further comparison study. In Jussieu project, the bifurcating spatial organization is 'intentionally' used to construct the indeterminant space whereas in Arnhem Central, bifurcation can be found in both the ever-bifurcating design process as well as the final spatial organization'unintentionally'generated from the process. This study is concluded with the comparative analysis between the representation and actualization of a concept that are crucially different.

• 한국공작기계학회논문집
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• 제17권6호
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• pp.132-145
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• 2008

We propose a new technique for autonomous navigation and travelling of mobile robot based on ultrasonic sensors through the narrow labyrinth that leave only distance of a few centimeters on each side between the guides and the robot. In our current implementation the ultrasonic sensor system fires at a rate of 100 ms, that is, each of the 8 sensors fires once during each 100 ms interval. This is a very good firing rate, implemented here for optimal performance. This paper presents an extensively tested and verified solution to the problem of obstacle avoidance. Our solution is based on the optimal placement of ultrasonic sensors at strategic locations around the robot. Both the sensor location and the associated navigation algorithm are defined in such a way that only the accurate radial sonar data is used for accurate travelling.

• Tribology and Lubricants
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• 제25권3호
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• pp.150-156
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• 2009

Precise leakage prediction for annular type seals of turbomachinery is necessary for enhancing their efficiency and various prediction methods have been developed. As the seal passage is designed intricately, the analysis based on Bulk-flow concept which has been mainly used in predicting seal leakage is limited. In order to improve the seal leakage prediction, full Navier-Stokes Equations with turbulent model derived in the seal flow passage have to be solved. In this study, 3D CFD (Computational Fluid Dynamics) analysis has been performed for predicting leakage of various non-contact type anular seals using FLUENT. Compared to the results by Bulk-flow model analysis, experiment, and 2D CFD analysis, the result of 3D CFD analysis shows improvement in predicting seal leakage, especially for the parallel grooved pump seal.

• 대한수의학회지
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• 제15권2호
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• pp.233-240
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• 1975

Glycogen and alkaline phosphatase were studied histochemically in the placenta of the golden hamster (Mesocricetus auratus). The results were summarized as followings: 1. The histochemical distribution of glycogen and alkaline phosphatase was described in the various cells of both the placenta and uterus from implantation (5 days past coitum) parturition. 2. Glycogen appeared in the extraembryonic ectorm of the implanting ovum and increased gradually in the ectoplacental cone with the development of the placenta. 3. Glycogen granules began to accumulate in the labylinthine trophoblast of chorioallantoic placenta at 10.5 days and in the endodermal cells the visceral yolk sac sac at 10 days, respectively, and in these both cells glycogen increased gradually until the 13 days post coitum and after this time decreased progressively. 4. Alkaline phosphatase activity was high in the labyrinth, junctional zone and decidua, but was not observed in the yolk sac and trophospongium.