• 대한기계학회논문집A
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• 제24권6호
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• pp.1379-1389
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• 2000

In this study, a design process of robotic cell is presented. This paper focuses only on the automation of workpiece handling with robot. The presented design process enables us to analyze effectiv ely the original production system and to redesign it as an optimum production system with robots. An original production system is analyzed with respect to its economical and technological requirements for automation. If automation of the given production system is feasible, the conceptual design for automation is firstly derived. Next, the detail design is derived for the optimum conceptual design. Finally, an optimum system solution is determined after the economical and technical evaluation of all the derived detail designs. The all specifications of each element of the redesigned production system and its layout are determined at the detail design phase. This paper shows a low cost supporting tool for layout design of robotic cell with SCARA type robots.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.49-54
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• 1992

A flexible robotic assembly cell is modeled using Petri net. A simulator is developed and used to predict the optimal status of the system. The assembly cell of flexible manufacturing system(FMS) pilot plant of Automation and Systems Research Institute(ASRI) in Seoul National University is modeled. The system consists of 3 robots, 4 conveyors, automatic guided vehicle(AGV) and auto-stacker. The simulator is programmed in Turbo C on IBM PC, supporting a simple graphic simulation with pull-down menu. The flexibility of the assembly cell in the FMS plant is guaranteed, since it is possible to predict the optimal status of the system using this simulator.

• Applied Microscopy
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• 제15권2호
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• pp.80-88
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• 1985

The tentacular epithelial cells of Cipangopaludina chinensis were studied with electron microscope. The tentacular epithelium consists of columnar supporting cells, numerous glandular cells and ciliated cells. Glandular cells are classified into three types; type I (mucous metachromasia cell), type II(mucous goblet cell) and type III. Ciliated cells are subdivided into two types; type I ciliated cell has cilia with typical axoneme(9+2), and type II ciliated cell has cilia with unusual axoneme.

• 한국수정란이식학회지
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• 제29권3호
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• pp.221-228
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• 2014

Despite that porcine spermatogonial stem cells (pSSCs) have been regarded as a practical tool for preserving eternally genetic backgrounds derived from pigs with high performance in the economic traits or phenotypes of specific human diseases, there were no reports about precise definition of niche conditions promoting proliferation and maintenance of pSSCs. Accordingly, we tried to determine niche conditions supporting proliferation and maintenance of undifferentiated pSSCs for short-term. For these, undifferentiated pSSCs were progressively cultured in different composition of culture medium, seeding density of pSSCs, type of feeder cells and concentration of growth factors, and then total number of and alkaline phosphatase (AP) activity of pSSCs were investigated at post-6 day culture. As the results, the culture of $4{\times}10^5$ pSSCs on mitotically in activated $2{\times}10^5$ STO cells in the mouse embryonic stem cell culture medium (mESCCM) supplemented with 30 ng/ml glial cell line-derived neurotrophic factor (GDNF) was identified as the best niche condition supporting effectively the short-term maintenance of undifferentiated pSSCs. Moreover, the optimized short-term culture system will be a basis for developing long-term culture system of pSSCs in the following researches.

• Journal of Microbiology and Biotechnology
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• 제18권3호
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• pp.490-496
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• 2008

Symbiobacterium toebii is a commensal symbiotic thermophile that cannot grow without support from a partner bacterium. We investigated the properties of Symbiobacterium growth-supporting factors (SGSFs) produced by the partner bacterium Geobacillus toebii. SGSFs occurred in both the cell-free extract (CFE) and culture supernatant of G. toebii and might comprise multifarious materials because of their different biological properties. The heavy SGSF contained in the cytosolic component exhibited heat- and proteinase-sensitive proteinaceous properties and had a molecular mass of >50 kDa. In contrast, the light SGSF contained in the extracellular component exhibited heat-stable, proteinase-resistant, nonprotein properties and had a molecular mass of <10 kDa. Under morphological examination using light microscopy, S. toebii cultured with the culture supernatant of G. toebii was filamentous, whereas S. toebii cultured with the CFE of G. toebii was rod-shaped. These results strongly suggest that the SGSFs produced by G. toebii comprise two or more types that differ in their growth-supporting mechanisms, although all support the growth of S. toebii. Upon the examination of the distribution of SGSFs in other bacteria, both cytosolic and extracellular components of Geobacillus kaustophilus, Escherichia coli, and Bacillus subtilis had detectable growth-supporting effects for S. toebii, indicating that common SGSF materials are widely present in various bacterial strains.

• 정보처리학회논문지A
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• 제17A권6호
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• pp.275-280
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• 2010

본 논문에서는 Cell BE 프로세서를 사용한 효율적인 병렬 블록 암호화 알고리즘을 제시한다. 제안하는 알고리즘은, 이종 프로세서인 Cell BE의 특성을 효율적으로 활용하기 위하여 PPE와 SPE에 서로 다른 부호화/복호화 방식을 적용하여 그 성능을 개선하였다. 본 논문에 제시된 구현 방식을 바탕으로 검증된 결과에 따르면, 제안하는 알고리즘은 고성능 네트워크 시스템을 지원할 수 있는 2.59Gbps의 성능을 보여준다. 이는, 다른 다중 코어 프로세서의 병렬 구현 방식과 비교할 때, 1.34배 증가된 성능의 부호화/복호화 속도를 제공한다.

• Asia pacific journal of information systems
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• 제6권2호
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• pp.107-124
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• 1996

본 연구에서는 인터넷 환경에서 그룹의사결정시스템(GDSS)을 활용하기 위해 현재의 인터넷 기능개선 방향에 대해 분석하였다. 이를 위해 먼저 그룹의사결정지시스템의 요구사항을 기존의 문헌을 통해 정보전달, 의사결정 지원 정보제공 및 정보전달 흐름제어로 분류하였다. 다음에는 각 분야별로 현재의 인터넷이 가지고 있는 한계를 분석하고 이러한 한계를 극복할 수 있는 기술적인 대안들을 OSI 계층별로 분석하였다. 분석결과 현재의 인터넷에서 응용 프로그램과 TCP/IP계층 사이에 전달정보흐름 추적기능(Tracing), 응용 프로그램 코딩기능(Application Dependent Coding), 정보전달모드 제어기능(communication Mode Selection) 및 정보보안기능(Encoding/Decoding)이 추가되는 것으로 분석되었다. 또한 링크계층에는 셀교환 방식이 적합한 것으로 분석되었다. 본 연구의 결과는 그룹의사결정지원시스템 디자인 및 향후 인터넷 화상회의를 위한 시스템 디자인에서도 유용하게 적용될 수 있을 것으로 판단된다.

• Clinical and Experimental Reproductive Medicine
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• 제41권3호
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• pp.97-107
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• 2014

The placenta is a temporary fetomaternal organ capable of supporting fetal growth and development during pregnancy. In particular, abnormal development and dysfunction of the placenta due to cha nges in the proliferation, differentiation, cell death, and invasion of trophoblasts induce several gynecological diseases as well as abnormal fetal development. Autophagy is a catalytic process that maintains cellular structures by recycling building blocks derived from damaged microorganelles or proteins resulting from digestion in lysosomes. Additionally, autophagy is necessary to maintain homeostasis during cellular growth, development, and differentiation, and to protect cells from nutritional deficiencies or factors related to metabolism inhibition. Induced autophagy by various environmental factors has a dual role: it facilitates cellular survival in normal conditions, but the cascade of cellular death is accelerated by over-activated autophagy. Therefore, cellular death by autophagy has been known as programmed cell death type II. Autophagy causes or inhibits cellular death via the other mechanism, apoptosis, which is programmed cell death type I. Recently, it has been reported that autophagy increases in placenta-related obstetrical diseases such as preeclampsia and intrauterine growth retardation, although the mechanisms are still unclear. In particular, abnormal autophagic mechanisms prevent trophoblast invasion and inhibit trophoblast functions. Therefore, the objectives of this review are to examine the characteristics and functions of autophagy and to investigate the role of autophagy in the placenta and the trophoblast as a regulator of cell death.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2002년도 연료전지심포지움 2002논문집
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• pp.197-200
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• 2002

The electrooxidation of methanol was studied using carbon-supported PtRu(1:1) alloy nanoparticles In sulfuric acid solution for application to a direct methanol fuel cell. The GNF-supported catalyst showed excellent catalytic activities compared to those of Vulcan XC-72. The structure and electrocatalytic activity of carbon-supported electrocatalyst were investigated using X-ray diffraction (XRD), Transmission electron microscopy (TEM), cyclic voltammetry (CV), chronoamperometry (CA), X-ray photoelectron spectroscopy (XPS). The CV and CA confirmed the advantage of GNF as the supporting material. This can be explained by assuming that the enhanced activities of GNF-supported catalyst for methanol electrooxidation were caused by the unique properties of GNF.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1847-1850
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• 2002

In this paper, MPLS Router module supporting Differentiated Service(Diffserv) for quality of Service (QoS) and High-speed switching is proposed and implemented. And we compare and analyze the proposed architecture with the conventional one in terms of CLR (Cell Loss Rate) and average delay. Switch is an extended system of Queue of each VOQ and PHB in the manner of Input Queuing for QoS. Algorithm, Priority-iSLIP is used for its scheduling algorithm. The proposed architecture is modeled in C++ and verified.