• Applied Microscopy
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• v.7 no.1
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• pp.1-12
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• 1977

Ultrastructural changes of Entamoeba histolytica, a concomitant strain YS-9, which was treated in the immune serum was examined. The amoebae in the serum became immobilized state from about 30 minutes of the treatment and recovered at about 60-90 minutes. In the cells of control group, helix structures were scattered throughout the cytoplasm. The particles comprising the helix structure averaged 20 nm in diameter. At the beginning stage of the immobilization, helical aggregates(chromatoid body) which associated with vacuoles appeared abundantly in the cytoplasm, but gradually tended to aggregate along peripheral region of the cell, specially in intactly immobilized state. Each parallel array of aggregates measured about 45 nm in width. When the cells became remobilize, pseudopodia appeared again, but helical aggregates disappeared and numerous helix structures were observed in the cell periphery. Distribution of glycogen particles showed no change, and acid phosphatase activities were seen in both the immobilized and the control group. The reaction was markedly noticed in the vacuoles.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06c
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• pp.46-48
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• 2006

This paper addresses the problem of monitoring continuous k-nearest neighbor (k-NN) queries. Given a set of moving (or static) objects and a set of moving (or static) query points, monitoring continuous k-NN query retrieves and updates the closest k objects to a query point continually. In order to support location based services (LBSs) in highly dynamic environments, where objects and/or queries are frequently moving, monitoring continuous queries require real-time updated results when objects and/or queries change their locations. Thus, it is important to minimize time delay for maintaining up to date the results. In this paper, we present monitoring method to shorten time delay for updating continuous k-NN queries based on the notion of result region and the minimum bounding rectangle enclosing all objects in each cell, referred to as c-MBR, in the grid index structure. Simulations are conducted to show the efficiency of the proposed method.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.424-428
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• 2010

본 연구에서는 통계적 분석방법을 이용하여 수도권지역(서울특별시, 인천광역시, 경기도)의 화재발생 유형에 대한 분석을 통하여 체계적이고 효율적인 소방정책을 수립하기 위한 기초 자료를 확보하는데 주안점을 두었다. SPSS와 Clementine 프로그램을 이용하여 소방방재청 국가화재정보시스템의 2007년과 2008년 화재발생 자료를 대상으로 기초통계분석(교차분석, 빈도분석)을 비롯하여 의사결정트리 분석 등을 수행하였다. 분석결과로서, 수도권지역의 화재건수는 2007년 이후부터 감소하거나 유지하는 경향을 보이고 있으며, 화재유형은 50% 이상이 건축/구조물에 의한 것으로 나타났다. 또한, 인명피해를 보면 서울시는 다른 수도권지역과 달리 2007년 대비 2008년 부상자와 사망자 수가 감소하였으며, 재산피해의 경우, 서울을 비롯한 대부분의 수도권지역에서 감소한 것을 확인할 수 있었다.

• Plant Resources
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• v.5 no.1
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• pp.78-85
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• 2002

The material of Rhodiola sachatinensis collected from an alpine region of the west-northern China. For analysing the effect, 1 used Rhodiola sachatinensis's rhizome and cultivated callus. In EtOAc, BuOH, $H_2O$ separation the plant showed strong antioxidative activity, but not in Hexane. The radical scavenging effect of EtOAc(RC$_{50}$,35(g), BuOH(RC$_{50}$, 43(g), H$_2$0(RC$_{50}$, 50(g) fraction and MeOH extract(RC$_{50}$, 50(g) of the Rhodiola sachatinensis was comparable to that of synthetic antioxidant BHA(RC$_{50}$, 14(g) and $\alpha$-Tocopherol(RC$_{50}$, 12(g). Total amino acid concentration of plant of In nature condition were 18,009ppm, and major components were arginine, glutamic acid, aspartic acid and valine. The ratio of essential/total amino acid on plant of In nature condition was 46.93%. Total amino acid concentration of callus of In vitro condition were 32,435ppm, and major components were valine, histidine, lysine and leucine. The ratio of essential/total amino acid on callus of In vitro condition was 56.07%. was 56.07%.

• Journal of Power System Engineering
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• v.16 no.5
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• pp.26-31
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• 2012

A numerical study has been carried out to investigate the heat and mass transfer of an oil pumping system with a variable shape of the housing using the CFD method. Especially, the electric motor and the pump combined together, accomplishes a research about the oil supplying system. In this study, the temperature and velocity distribution of the oil pumping system by varying the flow rate of supplying oil have been investigated. The temperature changes with each five conditions(flow rate of supply oil : 2, 4, 8, 12, and 16 liter/min) have also been studied. The numerical results show that the exhaust temperature decreases as the flow rate of the supplying oil increases. It also reveals that the temperatures change differently with the housing shape.

• Nuclear Engineering and Technology
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• v.48 no.4
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• pp.1002-1008
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• 2016

An understanding of the coarsening process of the large fission gas pores in the high burn-up structure (HBS) of irradiated $UO_2$ fuel is very necessary for analyzing the safety and reliability of fuel rods in a reactor. A numerical model for the description of pore coarsening in the HBS based on the Ostwald ripening mechanism, which has successfully explained the coarsening process of precipitates in solids is developed. In this model, the fission gas atoms are treated as the special precipitates in the irradiated $UO_2$ fuel matrix. The calculated results indicate that the significant pore coarsening and mean pore density decrease in the HBS occur upon surpassing a local burn-up of 100 GWd/tM. The capability of this model is successfully validated against irradiation experiments of $UO_2$ fuel, in which the average pore radius, pore density, and porosity are directly measured as functions of local burn-up. Comparisons with experimental data show that, when the local burn-up exceeds 100 GWd/tM, the calculated results agree well with the measured data.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.7 s.361
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• pp.81-87
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• 2007

While conventional frequency reuse techniques for cellular communication systems divide frequency resources into multiple regions and each mobile is statically assigned to a certain frequency region, frequency reuse techniques for cellular OFDMA communication systems can be regarded as dynamic scheduling problems of finding best-fitted subcarriers for each packet transmission. Unlike conventional frequency reuse techniques allocating mutually exclusive frequency resources to adjacent cells, this paper proposes the use of a frequency reuse technique with irregular frequency allocation patterns assigned statically based on the cell numbers. This paper shows that the use of irregular frequency patterns can allow efficient interference avoidance and high data throughputs comparable to those with carefully planned frequency patterns.

• Journal of the Korean Institute of Rural Architecture
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• v.22 no.2
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• pp.35-42
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• 2020

The new urbanization is one of prestige growth engines to lead the next generation of China economy, it promotes new sustainable urban development models guided by various planning polices to improve urban livability and sustainability in accommodation with economy, social, and environmental consideration. The expanding urban periphery to rural area should leverages existing assets, infrastructure, local context and plans as a showcase of environmental and economic balance in a responsibly high-density, green community designed to human development and ecological settlement. The Beijing Chaoyang District and Tianjin Binhai area are a strategic advancement in the policy of building one of the most powerful economic regions, the Bohai Rim. Recently released 'Jingjinji development plan' supports various urbanization policies and encourages sustainable developments including 2 significant city center projects which are under way in global attention. The study compared on the characters of development policies and the cutting-edge smart design strategies by which they are applied, the master plan of the Beijing Chaoyang District expansion plan and Tianjin Yujiapu CBD project embrace innovative sustainable technologies.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.6
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• pp.15-20
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• 2017

This study analyzed the load change of the gear generated by the operation of the vehicle recliner through Finite Element Analysis. The basic model of the recliner used was a commercial product, and the effect of the seat frame was excluded. The load conditions applied to the recliner were set considering gravity, the mass of the seat's back frame, and the weight of a person. The operating mode was set to move the seat back from the vertical to the reclined position. As a result, it was found that the tooth bending amount of the gear rim and wheel increased from the cam rotation angle of 450 degrees, and a change in the contact ratio occurred. Furthermore, excessive torque fluctuations occurred in the ranges of 390 to 450 and 750 to 710 degrees. It was found that this occurred in the region of about 30 degrees before and after the point where the x-axis direction load is larger than the y-direction load. From this torque fluctuation it was determined to likely to cause chattering noise.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.494-498
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• 2007

Purpose: This study was done to know the usefulness of fractal analysis when evaluating the radiologic changes after decompression on jaw bone cystic lesions using fractal analysis. Materials and methods: 30cases of cystic lesions were followed up after decompression. Panoramic image was used to observe radiologic changes around the cystic lesion. The part of the panoramic image which showed radiologic change was defined as region of interest(ROI); The fractal dimension of the ROI was calculated using box-counting method. Results: Using sign-rank test, there was a statistically significant difference in fractal dimensions after decompression therapy(P<0.0001). The fractal dimensions statistically increased after decompression(the median of D:0.12). Conclusions: The ROI after decompression showed higher fractal dimensions which offer the objective proof of the bone healing around cystic lesions after decompression treatment.