• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
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• pp.282-285
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• 2001

In general, the PSS/E program based on RMS mathematical models is used for analyzing the steady state and transient stability phenomena of full-scale large power system. Whereas, the EMTDC program unlike PSS/E, studies the specific reduced small-scale power systems as a basis of instantaneous value mathematical models and used to analyze the Electro-Magnetic transient characteristics. The PSS/E provides various control models such as exciter, governor, PSS models and TGOV5 model but there are few control models in EMTDC. In this paper, we developed EMTDC model for TGOV5 of a steam turbine and boiler which represents governor action, main, reheat and low-pressure effects, including boiler effects. The EMTDC model is developed by examining PSS/E control block and using User Define Model(UDM) in addition to default.lib provided by EMTDC. We verify the correctness of developed TGOV5 model with PSS/E and EMTDC simulation results using Governor Step(GSTEP) method.

• 태양에너지
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• 제20권2호
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• pp.85-96
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• 2000

When the liquid with the additive of ppm unit of a polymer flows, the pressure drop can be manifestly decreased compared to that of pure liquid: that's the drag reduction. This method is that a small amount of a polymer which doesn't make the transformation of the properties of the working fluid is dissolved into the working fluid, the links of chains of the polymer do a buffer action to the molecules of the working fluid which come out between near the wall of the pipe and the interface, so that the pressure drop is dramatically decreased. When we transport the fluid, therefore, we can save a lot of pumping power, or we can increase the transportation capacity with using the same transportation equipment. But when a polymer solution is also flowing in the fluid transportation system, the degradation which have a very close relation with the phenomena of the drag reduction occurs necessarily. When adding polymer to reduce the drag in two phase flow system, It is impossible to find some studies. This study is focussing on a searching examination for the experimental study considering the mechanical degradation in the closed tow phase system to find out the conditions which could improve the pump capacity.

• 대한화학회지
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• 제19권1호
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• pp.43-49
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• 1975

소량의 요오드 화합물이 윤활류에 함유될 때 금속표면사이의 마찰을 감소시키고 내마모성을 향상시키는데 이는 금속표면에 박층상구조의 이요오드화물이 형성되기 때문이라고 한다. 그러나 금속표면에서의 화학반응성, 마모와 극압실험 및 hot wire method에 의한 결과에 의하면 윤활기구는 이 요오드화물의 박층상 구조가 아니고 다른 기구에 의한 것임을 알았다. 유기 요오드화합물중에서 특히 N-iodopyridinium dichlorodate는 double charge transfer complex로써 다른 methyl iodide계의 화합물 보다 금속표면 사이의 마찰을 더욱 감소시키고 윤활기구는 interhalogen의 화학반응에 의한 것임을 알았다.

• 한국농공학회지
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• 제33권2호
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• pp.104-111
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• 1991

In Korea, small-scale reclaimed areas have been suffering from many problems because of the lack of comprehensive developing strategy although considerable investments have been inputed by the public sector since 1970's. For 3 reclaimed sites in Chonnam Province choser as case study areas, the analysis, the second attempt of widely-spanned studies on areal conditions, concentrated on their farming and economic conditions. Its results were as follows ; 1. Although farming pattern has been transferred to the full4ime rice cropping type by the creation of reclaimed paddy field, farming size in the areas has not been increased more than that in existing agricultural areas. This means that agricultural planning should be included in the initial stage of reclamation projects, especially with reference to the substantial enlargement of farming size. 2. Block parcelling of severely fragmented holdings in new and old lands should be carried out, which can make farming activities efficient and farming route shortened. In large-scale reclaimed areas, new village planning could be considered in its central zone for efficent farming. 3. Because soil in the areas contains much more salt and water than that in other areas, new design methodology should be introduced for the efficient use of agricultural machines in reclaimed areas. 4. There are deep-seated economic problems in reclaimed area, which have been caused by very poor level and agriculturally dominated structure of household income. These problems should motivate farmers to give up positive action for qualitative and quantitative improvement in farming.

• 설비공학논문집
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• 제29권3호
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• pp.127-133
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• 2017

Performance analysis has been carried out on a high side scroll compressor that had a fixed scroll equipped with a circular oil groove on its thrust surface. Oil was supplied to the oil groove through an intermittent opening from a high pressure oil reservoir formed inside the orbiting scroll hub. Oil in the groove was then delivered to both suction and back pressure chambers by pressure differentials and viscous pumping action of the orbiting scroll base plate. Mathematical modeling of this oil groove system was incorporated into a main compressor performance simulation program for an optimum oil groove design. The study findings were as follows. Pressure in the oil groove can be controlled by changing its configuration and the oil passage area. With an enlarged oil passage, the pressure in the oil groove heightens due to an increased flow rate, but the pressure elevation in the back pressure chamber is small, resulting in reduced friction loss at the thrust surface between the two scrolls. On the other hand, by increasing the oil passage area, the oil content in the refrigerant flow increases. Considering all these factors, the energy efficiency ratio could be improved by about 3.6% under the ARI condition by an optimal oil groove design.

• 한국중재학회지:중재연구
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• 제28권2호
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• pp.91-110
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• 2018

Consumers repeatedly make small sum purchases through business-to-consumer contracts, usually without incident. Consumer areas have been increasing; therefore, consumer disputes have been occurring frequently as well. In international consumer transactions, it is not easy to solve consumer disputes by applying the laws of different countries. Resolving disputes by using the consumer arbitration system can be a measure to protect consumers. In the U.S., a class arbitration is being operated as a mixed dispute resolution system of class action and arbitration. Consumer Arbitration has long been a controversial issue in the U.S. It is therefore a lesson for us to examine related cases. A recent U.S. Supreme Court decision, DIRECTV v. Imburgia, was looked into and after a summary of the facts, issues, and opinions and opposing opinions that had a tight controversy, a close analysis was done. The analysis through this judgment is as follows: first, the contraction of consumer protection; second, the expansion of the Federal Arbitration Act scope; third, the class arbitration's restriction; and fourth, the submission of the arbitration fairness act.

• 대한간호학회지
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• 제46권6호
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• pp.858-870
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• 2016

Purpose: The purpose of the study was to explore and describe the adaptation process of older people to group homes. Methods: Participants were twenty older adults aged 65 or older who were living in group homes. Data were collected from January to April, 2015. In-depth unstructured interviews were conducted with individual participants. Data were analyzed using Strauss and Corbin's grounded theory method. Results: From open coding, 100 concepts, 38 sub-categories, and 14 categories were identified. Analysis showed that the central phenomenon of the adaptation process of older people to group homes was 'gradually giving up'. Causal conditions were 'good-for-nothing body', contextual conditions were 'pushed', 'beleaguered'. Intervening conditions were 'reliable pillar: children', 'having affection (情) more than having it from family: facility workers', 'comfort - like feeling at home', 'relieved: system'. Action/interaction strategies were 'facing the unfamiliar reality', 'building relationships with other people', 'accepting reality'. Consequences were 'a good place, more than expected', 'hope for the remaining days', 'waiting for a peaceful death'. Conclusion: The results of this study provide an in-depth understanding of the experience of the adaptation process of older people to group homes. The findings from this study can be used as basic data to establish policies to increase the number of small scale facilities which can help older adults adapt easily to the facilities.

• 한국해양공학회지
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• 제20권4호
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• pp.43-49
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• 2006

Detailed investigations were carried out on the stability of the dredged soil bed against wave actions, aimedat establishing the design method of artificial tidal flats using dredged soil. The soil was dredged at Nagoya port, Japan, and has a mean grain size of 0.013mm. Basic features of artificial dredged soil bed against wave actions were explained from a series of model experiments in a wave flume. The two types of section shapes were employed; one is a horizontal bed and the other is a sloped one. Changes of the bed profile, shear strength, grain size distribution and water content, according to the wave actions, were measured in detail. The cumulative effect of the wave actions, over about one week, was investigated. A dredged soil bed moves withthe wave actions with relatively small wave height. It should be especially. noted that the clay component is dissolved and flown out, away from the surface layer, and consequently the surface layer hardens, as if it is covered with sand. Wren the wave height is gradually increased, the bed is not liquefied and the shear strength of the dredged bed is increased by a wave-induced dissipation of pore pressures in the bed and a decrease of clay component by the wave-induced leakage.

• Genomics & Informatics
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• 제12권4호
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• pp.225-230
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• 2014

Platelets are derived from the fragments that are formed from the cytoplasm of bone marrow megakaryocytes-small irregularly shaped anuclear cells. Platelets respond to vascular damage, contracts blood vessels, and attaches to the damaged region, thereby stopping bleeding, together with the action of blood coagulation factors. Platelet activation is known to affect genes associated with vascular risk factors, as well as with arteriosclerosis and myocardial infarction. Here, we performed a genome-wide association study with 352,228 single-nucleotide polymorphisms typed in 8,842 subjects of the Korea Association Resource (KARE) project and replicated the results in 7,861 subjects from an independent population. We identified genetic associations between platelet count and common variants nearby chromosome 4p16.1 ($p=1.46{\times}10^{10}$, in the KIAA0232 gene), 6p21 ($p=1.36{\times}10^{-7}$, in the BAK1 gene), and 12q24.12 ($p=1.11{\times}10^{-15}$, in the SH2B3 gene). Our results illustrate the value of large-scale discovery and a focus for several novel research avenues.

• BMB Reports
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• 제50권5호
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• pp.247-256
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• 2017

CRISPR/Cas9 is the latest tool introduced in the field of genome engineering and is so far the best genome-editing tool as compared to its precedents such as, meganucleases, zinc finger nucleases (ZFNs) and transcription activator-like effectors (TALENs). The simple design and assembly of the CRISPR/Cas9 system makes genome editing easy to perform as it uses small guide RNAs that correspond to their DNA targets for high efficiency editing. This has helped open the doors for multiplexible genome targeting in many species that were intractable using old genetic perturbation techniques. Currently, The CRISPR system is revolutionizing the way biological researches are conducted and paves a bright future not only in research but also in medicine and biotechnology. In this review, we evaluated the history, types and structure, the mechanism of action of CRISPR/Cas System. In particular, we focused on the application of this powerful tool in autophagy research.