• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.129-138
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• 1993

The shortage of agricultural labour due to industrial growth has greatly induced the mechanization in Korean agriculture. However small and scattered land holdings have been the main constraints in the process of mechanization. This paper describes the interrelationships of farm land structure, machinery selection and machinery operation areas. The sandy silt loam irrigated paddy land having single crop a year was selected as a target areas for this study. Machine operation cost is greatly influenced by operation period, plot geometry and operation area. On the improved geometry plots, optimal machine size increases slowly with increase in operation area. Operable area increases due to increased effective machine capacity on better geometry plot. The difference between the effects of operation period and plot geometry is that in the former case, the cost reduction is caused by delay in increase of machine size, whereas in the latter case timeliness cost is reduced by increase ffective capacity. The effect of farmland consolidation is greater on small plots than that on big plots. Increasing wage rates have induced the adoption of more labor saving machinery. Bigger labor saving machines require enlargement of operation area and larger plots through improvement in farm land structure. Machine cost on poor plot geometry increases more rapidly than that on the good plot geometry and as operation area increases machine cost reduces significantly. It is concluded that the development of agricultural mechanization ion Korea will depend on the improvement in farm land structure and enlargement of operation area.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.1602-1610
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• 2005

In this study was investigated and analyzed of damage characteristics for infrastructures by typhoon that have been many occur. The objective Structures were the road and hydraulic structure. The road structure was included the cut-slopes, retaining walls and bridges. The hydraulic structure is divided with the dike, small-scale dam, reservoir and floodgate. The analysis result of the bridge damage cause is river bottom height increase and passage ability decrease. The principal damage reasons of the cut-slope structure are weakening the ground due to the localized torrential downpour and drainage defective. Also, the principal damage reasons of the small-scale dam, reservoir, dike and the floodgate are continuous collapse of dike beside the floodgate.And we divided a typhoon damage occurrence cause with artificial and natural. As the result of analysis, the many damage occurrence cause will be removed by system improvement and technical development.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.383-386
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• 2006

In this study, we propose a new fast algorithm for calculating short range forces in molecular dynamics, This algorithm uses a new hierarchical tree data structure which has a high adaptiveness to the particle distribution. It can divide a parent cell into k daughter cells and the tree structure is independent of the coordinate system and particle distribution. We investigated the characteristics and the performance of the tree structure according to k. For parallel computation, we used orthogonal recursive bisection method for domain decomposition to distribute particles to each processor, and the numerical experiments were performed on a 32-node Linux cluster. We compared the performance of the oct-tree and developed new algorithm according to the particle distributions, problem sizes and the number of processors. The comparison was performed sing tree-independent method and the results are independent of computing platform, parallelization, or programming language. It was found that the new algorithm can reduce computing cost for a large problem which has a short search range compared to the computational domain. But there are only small differences in wall-clock time because the proposed algorithm requires much time to construct tree structure than the oct-tree and he performance gain is small compared to the time for single time step calculation.

• 한국전자파학회논문지
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• 제16권10호
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• pp.1003-1009
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• 2005

본 논문에서는 결함접지구조(Defected Ground Structure: DGS)의 전파 지연 특성을 이용하여 소형으로 구현한 휴대 인터넷용 고전력 Single Pole Double Throw(SPDT) 스위치의 특성이 제공되며 1/4 파장 전송선을 이용하여 제작된 일반적인 방식의 스위치와 그 특성이 비교된다. DGS를 활용하여 제작된 스위치는 높은 격리도를 확보하기 위해 병렬구조의 다이오드를 사용하여 구성되었으며 2.3 GHz에서 0.8 dB의 삽입 손실과 50 dB 이상의 격리도 특성을 보였고 50 W 이상의 전력을 다룰 수 있었다. DGS를 활용한 스위치는 기존의 전송선 방식의 스위치와 거의 동일한 스위칭 특성을 보이면서도 $50\%$ 가까운 회로의 크기 감소를 달성할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.656-659
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• 2005

Small peptides synthesized by nonribosomal peptide synthetases (NRPSs) genes are found in bacteria and fungi. While some microbial taxa have few, others make a large number and variety. However, biochemical characterization of the products synthesized by NPRS demands a great deal of efforts. Since the completion of genome projects of numerous microorganisms, the numbers of available NRPSs genes are being expanded. Prediction of the peptides encoded by NRPS could save time and efforts. We chose the NRPS gene from Bradyrhizobium japonicum as a model to predict the peptide structure encoded by NRPS genes. Using computational analyses, the domain structure of this gene was defined, and the structure of a peptide synthesized by this NRPS was deduced. It was found that it encoded a tripeptide consisting of proline-serine-phenylalanine. This method would be helpful to predict the structure of small peptides with various NPRS genes from the genome sequence.

• 한국전기전자재료학회논문지
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• 제18권11호
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• pp.1033-1037
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• 2005

We have studied on the effect of the operation voltage according to the reverse twist for the different fringe field switching (FFS) structure. The FFS structure with a vertically patterned edge of the pixel electrode (VPP) has lower operation voltage comparing to the one with a horizontally patterned edge of the pixel electrode (HPP). The reason is like that the number of the pattern of the pixel edge for the VPP structure is one third comparing with the HPP structure and thus, there is small reverse twist area for the VPP structure. Actually, the reverse twist disturbs the twist of LC near adjacent active area, result that LCs near there have the unstable dynamics. That is, the operation voltage increases as the reverse twist area increases. Therefore, it is very important to design pixel electrode with a small reverse twist region for the FFS mode.

• Genomics & Informatics
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• 제9권2호
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• pp.74-78
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• 2011

Numerous restraints and simplifications have been developed for methods that anticipate protein structure to reduce the colossal magnitude of possible conformational states. In this study, we investigated if globularity is a general characteristic of proteins and whether they can be applied as a valid constraint in protein structure simulations with approximated measurements (Gb-index). Unexpectedly, most of the proteins showed strong structural globularity (i.e., mode of approximately 76% similarity to the perfect globe) with only a few percent of proteins being outliers. Small proteins tended to be significantly non-globular ($R^2$=0.79) and the minimum Gb-index showed a logarithmic increase with the increase in protein size ($R^2$=0.62), strongly implying that the non-globular characteristics might be more acceptable for smaller proteins than larger ones. The strong perfect globe-like character and the relationship between small size and the loss of globular structure of a protein may imply that living organisms have mechanisms to aid folding into the globular structure to reduce irreversible aggregation. This also implies the possible mechanisms of diseases caused by protein aggregation, including some forms of trinucleotide repeat expansion-mediated diseases.

• Design & Manufacturing
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• 제11권1호
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• pp.39-44
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• 2017

The domestic mold industry is composed of 6,560 small and medium sized mold companies as of 2015. The structure of mold industry centered on less than 10 people in the past has been improved in the direction of increasing number of medium and large scale companies with more than 20 competitors with global competitiveness and has maintained its position as the world's second largest mold exporter with global competitiveness. Nevertheless, the manpower structure and corporate competitiveness structure of the mold industry is very high, with the proportion of production manpower reaching 70% and shortage rate of 10% or more in order to respond to the orders of customers. However, the development base for new employees with technological skills required by the industrial field is poor, and the inflow of young people is very limited due to factors such as the avoidance of small and medium enterprises and production jobs. It is expected that the labor shortage of mold enterprises will be further increased in the future. In the mold industry, due to the characteristics of small quantity multi-product production corresponding to the demand of the consumer, many production processes are individually and independently carried out, resulting in low labor productivity, and the structural time required for the worker to increase the working time Due to limitations, the working hours per week of the employees are about 50 hours. The implementation of the working time reduction bill, which is recently promoted by the government, is a crisis factor. In order to cultivate the mold industry, it is necessary to expand the base of molds to meet the intensification of global competition, the convergence of technologies to actively respond to the restructuring of the industrial structure, and the response to the new industry, It is necessary to improve labor productivity through policies such as development and dissemination of system, and to secure price, delivery and quality competitiveness in global market.

• 건축역사연구
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• 제11권3호
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• pp.21-34
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• 2002

This study is to analyse the transformation process of spatial structure of traditional small city structure in Jeollabuk-Do in the process of modern urbanization between 19th century and the year 2000. The small cities, IM-PI, YONG-AN, YEO-SAN, OK-GOO, GO-SAN, MU-JANG, GUM-MA, GO-BU, which have been local administrative center in CHO-SUN dynasty, have role of local administrative center of subdivision of country-myon, except OK-GOO. The method of this study is to investigate the transformation process of spatial structural elements of with the actual field surveys, the analysis of Gunhyun map made in 1872, land registration maps in 1910s and 2000, and various topological maps. The elements of analysis are the topological site and geographical situation conditions, the urbanized areas, the street systems, the function of streets, the focal points of urban land use, the land use systems, and the location of major facilities such as administration facilities, markets, bus terminals. The analytical point of view and the results are as follows. There is strong relationship between the transformation of internal matrix route system and the growth pattern of urbanized areas, Especially on the contrary to the matrix route with East-West direction which has the role of checking the growth of urbanized area, the South-North direction route acts as the leading line of the growth. The focal points structure of urban land use shows transformation process from the point of central space of administrative district in front of Nae-A, to the access point to administrative district or to the access point to housing and neighborhood commercial area. From the point of functional area structure and major facilities location, line-type commercial area is developed along the line of central axis route and access route to administrative district. Especially direction of the growth of commercial area is strongly connected with the interrelationship between the study area and its neighboring cities. Pattern of commercial district development is varied with the direction of matrix route. That is, commercial district, which shows one side development pattern along the East-West direction route, is developed on both sides of street along the South-North direction route.

• 한국환경과학회지
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• 제18권1호
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• pp.99-111
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• 2009

In this study vegetation structure was monitored focusing on slanting surface of stream for the purpose of developing a management plan and ecological restoration of small stream in Paju. The study was conducted by types of geographical structure, yearly flora, naturalization rate changes, actual vegetation changes, plant community changes. Slope area of small stream in Paju was varied in the slope range of $10{\sim}35^{\circ}$. The survey results of yearly flora showed that 37 species appeared in 2000, 55 species in 2001, 95 species in 2002, and 125 species in 2003. Therefore, the trend of continuous increase of flora each year was observed. In the case of yearly changes of actual vegetation, indigenous wetland herb community including Phragmites communis$(19.99%{\rightarrow}18.42%{\rightarrow}19.60%)$ did not show substantial changes in the area, while the influence of controlled flora such as Humulus scandens$(8.86%{\rightarrow}5.26%{\rightarrow}9.73%)$, and Ambrosia artemisiifolia$(1.06%{\rightarrow}1.43%{\rightarrow}6.93%)$ were increased. The vegetation structure investigated by 18 preset belt-transects also indicated that Phragmites communis and Miscanthus sacchariflorus were maintaining the status or decreasing the population, while the population of Humulus scandens, Ambrosia artemisiifolia, Setaria viridis, and Erigeron canadensis were greatly increased. Our proposal management to restore ecology is as follows: first, preservation and restoration of Phragmites communis landscape; second, restoration of potential stream vegetation community; third, selection and removal of controlled plants.