• 한국정밀공학회지
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• 제21권4호
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• pp.109-119
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• 2004

Rapid prototyping (RP) technologies have been widely used to reduce the lead-time and development cost of new products. $VLM-_{ST}$ process has been developed to overcome the currently developed RP technologies such as a large building time, a high building cost, an additional post-processing and a large apparatus cost. $VLM-_{ST}$ process requires an additional human interaction due to the manual stacking and bonding. Hence, building time, building cost and the part quality are dependent on the skill of labor. A novel RP process, fully automated $VLM-_{ST}$ process ($VLM-_{ST}$), has been developed to improve building efficiency of the process and the human dependency of the part. The objective of this work is to propose a $VLM-_{ST}$ process and to develop an apparatus for implementation of the process. $VLM-_{ST}$ process and its apparatus have various technical novelties such as two step cutting using a rotating table, an automatic stacking method using two pilot holes and two reference shapes, a concept of automatic unit shape layer (AUSL), and an automatic bonding using the bonding roller and building magazine. In order to examine the efficiency and the applicability of the proposed process, various three-dimensional shapes, such as a piston, a human head shape and a human bust shape, were fabricated on the apparatus.

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권3호
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• pp.10-17
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• 2017

In this study, the evolution and origin of major dissolved constituents of crystalline bedrock groundwater in a coastal area were evaluated using multivariate statistical and groundwater quality analyses. The groundwater types mostly belonged to the $Na(Ca)-HCO_3$ and $Ca-HCO_3$ types, indicating the effect of cation exchange. Stable isotopes of water showed two areas divided by first and secondary evaporative effects, indicating a pattern of rapid hydrological cycling. Saturation indices of minerals showed undersaturation states. Thus, the degree of evolution of groundwater is suggested as in the low to intermediate stage, based on field and laboratory analytical conditions. According to the principal component analysis (PCA) results, the chemical components of EC, $Ca^{2+}$, $Mg^{2+}$, $K^+$, $HCO_3{^-}$, $SO{_4}^{2-}$ (PCA 1), $F^-$ (PCA 3), $SiO_2$ (PCA 4), and $Fe^{2+}$ (PCA 5) are derived from various water-rock interactions. However, $NO_3{^-}$, $Na^+$, and $Cl^-$ (PCA 2) represented the chemical characteristics of both anthropogenic sources and natural sea spray.

• 한국토양비료학회지
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• 제45권4호
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• pp.582-592
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• 2012

Microorganisms present in the rhizosphere soil plays a vital role in improving the plant growth and soil fertility. Many kinds of fertilizers including chemical and organic has been approached to improve the productivity. Though some of them showed significant improvement in yield, they failed to maintain the soil properties. Rather they negatively affected soil eventually, the land became unsuitable for agricultural. To overcome these problems, microorganisms have been used as effective alternative. For past few decades, plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) have been used as effective inoculants to enhance the plant growth and productivity. PGPR improves the plant growth and helps the plant to withstand biotic and abiotic stresses. AM fungi are known to colonize roots of plants and they increase the plant nutrient uptake. Spore associated bacteria (SAB) are attached to spore wall or hyphae and known to increase the AMF germination and root colonization but their mechanism of interaction is poorly known. Better understanding the interactions among AMF, SAB and PGPR are necessary to enhance the quality of inoculants as a biofertilizers. In this paper, current knowledge about the interactions between fungi and bacteria are reviewed and discussed about AMF spore associated bacteria.

• Tribology and Lubricants
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• 제34권4호
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• pp.125-131
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• 2018

A precision tribometer consisting of a cantilever was designed to measure frictional forces in the micro-Newton range. As frictional forces are measured based on the bending of the cantilever, vibration of the cantilever is the most significant factor affecting the quality of the friction measurement. Therefore, improved design of the tribometer with double cantilevers and a connecting plate that united the two cantilevers mechanically was suggested. For the verification of the modified design of the tribometer, numerical analysis and experiments were conducted. Examination using the finite element method revealed that the tribometer with a double cantilever and a connecting plate exhibited faster damping characteristics than the tribometer with a single cantilever. In the experiment, effectiveness of the double cantilever and connecting plate for vibration reduction was also confirmed. Vibration of the tribometer with double cantilever decreased eight times faster than that of the tribometer with a single cantilever. The faster damping of the double cantilever design is attributed to the mechanical interaction at the contacting surfaces between the cantilever and the connecting plate. Tribotesting using the tribometer with a single cantilever resulted in random fluctuation of frictional forces due to the stick-slip behavior. However, using the tribometer with a double cantilever and connecting plate for the tribotest gave relatively uniform and steady measurement of frictional forces. Increased stiffness owing to using a double cantilever and mechanical damping of the connecting plate were responsible for the stable friction signal.

• 한국콘텐츠학회논문지
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• 제11권12호
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• pp.764-773
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• 2011

현대의 경찰 활동은 경찰공무원 개인에 의한 독자적인 수행보다는 조직구성원의 상호 작용을 통해서 이루어지고 있다. 국민의 생명과 신체 및 재산을 보호하고 사회 질서를 유지하기 위한 경찰 조직의 목표 달성에 있어서 적합한 경찰공무원의 선발 및 입직 후 경찰공무원의 자질 향상과 역량 강화는 중요한 요소이다. 하지만 경찰 조직은 팀별 활동에 기반을 두고 있는 특성을 갖고 있기에 조직 특성에 적합하게 활동하고 사회질서 유지를 위해서는 무엇보다 경찰공무원들의 상호 협력이 더욱 중시되고 있다. 따라서 본 연구는 초동적인 경찰 업무 활동을 하고 있는 외근 경찰공무원으로 국한하여 이들의 사회질서 유지를 위한 조직효과성에 대한 인식 차이를 살펴보았다. 실증 분석 결과, 외근 경찰공무원의 인구사회학적 특성에 대한 개인별 변수 중에서 성별, 연령, 근무지역, 경찰서 급지, 계급, 근무기간에 따라 조직효과성 인식은 통계적으로 유의미한 차이가 있는 것으로 조사되었다. 그러나 경찰공무원의 학력과 결혼여부에 따른 조직효과성의 인식은 차이가 없는 것으로 파악되었다. 이를 통해 경찰공무원의 조직효과성을 향상 시킬 수 있는 방안이 시급히 마련되어야 할 것이고 획일적인 운영과 관리에서 탈피하여 성별, 연령별, 지역별, 경찰서 급지별, 계급별, 근무기간에 따라 세분화하여 차별화된 교육 훈련이 필요하다고 본다. 내부 구성원의 조직효과성을 향상시키고 나아가 외부 고객인 국민의 만족을 유발하여 궁극적으로 사회질서 유지에 이바지할 수 있을 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권10호
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• pp.1473-1477
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• 2007

Four-and-a-half LIM-only protein 3 (FHL3) is a member of the LIM protein superfamily and can participate in mediating protein-protein interaction by binding one another through their LIM domains. In this study, the 5'- and 3'- cDNA ends were characterized by RACE (Rapid Amplification of the cDNA Ends) methodology in combination with in silico cloning based on the partial cDNA sequence obtained. Bioinformatics analysis showed FHL3 protein contained four LIM domains and four LIM zinc-binding domains. In silico mapping assigned this gene to the gene cluster MTF1-INPP5B-SF3A3-FHL3-CGI-94 on pig chromosome 6 where several QTL affecting intramuscular fat and eye muscle area had previously been identified. Transcription of the FHL3 gene was detected in spleen, liver, kidney, small intestine, skeletal muscle, fat and stomach, with the greatest expression in skeletal muscle. The A/G polymorphism in exon II was significantly associated with birth weight, average daily gain before weaning, drip loss rate, water holding capacity and intramuscular fat in a Landrace-derived pig population. Together, the present study provided the useful information for further studies to determine the roles of FHL3 gene in the regulation of skeletal muscle cell growth and differentiation in pigs.

• 한국콘텐츠학회논문지
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• 제17권2호
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• pp.288-297
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• 2017

정보통신의 발달과 함께 평등한 교육기회를 제공해야 한다는 인식은 원격교육의 발달을 가져오게 되었으며, 이는 미래의 새로운 교육시스템으로 자리 잡고 있다. 학위 취득을 원하는 현직 교사들에게 온라인 원격교육은 시간적, 공간적 제약, 비용과 같은 걸림돌 없이, 전문성을 함양할 수 있는 대안으로 제시되고 있으며, 미국에서는 이미 음악교육 분야에서 온라인 석사학위과정이 운영되고 있다. 이에 National Association of Schools of Music(NASM)이 승인한 총 8개의 대학을 선정하여, 입학요건, 프로그램의 특징, 교육과정을 비교분석하였다. 온라인 원격교육의 편리함을 담보로 한 양적 팽창과 함께 온라인 교육과정의 질에 대한 우려도 계속적으로 제기되고 있다. 온라인 교육을 위한 교수진의 재교육 뿐 아니라, 기술적 지원에 대한 문제, 지적재산권, 소유권과 같은 행정적인 문제, 시스템 구축을 위한 기술적 문제, 온라인 교육과정의 계획, 개발, 평가를 위한 기준 마련 등 생각해야 될 부분이 많이 있다. 하지만, 다양한 관점에서의 연구를 바탕으로 교육이론과 실제사이의 격차를 줄여 나간다면 궁극적으로, 지리적, 시간적으로 소외된 계층에게 학습의 기회를 제공함으로써 국가 경쟁력 강화에 이바지 할 것으로 기대된다.

• 한국농공학회논문집
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• 제59권4호
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• pp.1-15
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• 2017

Eutrophication of surface waters is of concern worldwide, because it can result in many undesirable water-quality and ecological problems, such as hypoxic 'dead' zones and harmful algal blooms, both associated with considerable economic costs. In this study, we used LSM (Land Surface Model) to simulate nitrogen in five major rivers in the Southern Korean Peninsula. The main objective of this research was to enhance nitrogen data for input of LM3V model in South Korea. Input data for nitrogen fluxes were categorized into three sections including agriculture fertilizer, livestock manure, atmosphere deposition, biological fixation, and sewage pollutants were used as the nitrogen input. For using LM3V model, the nitrogen input data were regenerated by considering states of agriculture and industry in South Korea at a $1/8^{\circ}$ resolution. Then, we simulated stream/river flows and N loads throughout the entire drainage networks in South Korea at a $1/8^{\circ}$ resolution. By using the same parameters for the entire country ($100,210km^2$), composed of 5 river basins with varying climate and land use, the model simulates spatial (11 sites) and temporal (1999~2010) patterns of flows and nitrate-N loads are resonable by comparing observed flow and nitrate-N loads. The r (Pearson's linear correlation) for water temperature, flow and nitrate-N at river were 080~0.93, 0.62~0.92 and 0.5~0.9 respectively. Based on enhanced N input data and model results, we find that LM3V model as land surface model can be applied in South Korea with interaction of atmosphere and land conditions.

• 산경연구논집
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• 제10권1호
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• pp.69-76
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• 2019

Purpose - The purpose of this paper is to empirically investigate the effectiveness of Offcial Development Assistance (ODA) in recipient countries' economy. ODA is designed to mitigate poverty and stimulate economic growth in the developing countries. We classify total ODA into bilateral ODA and multilateral ODA depending on the number of donor countries. If the ODA flows from one donor country to one recipient country, it is classified as bilateral ODA. If the multiple countries simultaneously become donor countries through the international organizations such as United Nations and World Bank, it is classified as multilateral ODA. This paper compares the effect of bilateral ODA and multilateral ODA in determining recipient countries' economic development, and tries to provide policy implications to Korean ODA. Research design, data, and methodology - Our primary explanatory variables are bilateral and multilateral ODA. Private credit in recipient countries is adopted as additional explanatory variables to capture the level of financial development in recipient countries. We measure the ODA effectiveness using economic growth and quality of life of the recipient countries as the dependent variable. We collect 142 recipient countries' data from OECD statistics, during the period from 1970-2014. Panel least squares estimation with country fixed effect is employed as the empirical model. Results - Our results support that ODA variable has a negatively significant impact on recipient countries' economic growth, while it is positively correlated with human development index. Recipient countries' private credit is positively correlated with economic growth and human development index. The interaction variable of ODA and financial development turns out to be significant in general. We find that the positive effect of ODA depends on recipient countries' financial market development and this effect is stronger in multilateral aid than bilateral one. Conclusions - From the analysis, we have confirmed that the recipient countries financial development is the necessity condition to achieve positive effect of ODA. Based on these results, we suggest that Korean government should increase the share of multilateral funding and pay attention to recipient countries' financial market development to maximize the effectiveness of ODA.

• 한국콘텐츠학회논문지
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• 제7권9호
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• pp.108-116
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• 2007

3D 콘텐츠의 등장인물과 실내 환경 구현에 집중하던 개발자들은 하드웨어 성능의 빠른 향상과 야외환경을 배경으로 제작되는 콘텐츠의 수요가 증가됨에 따라 사실적인 3D 야외환경을 표현하기 위한 자연현상 표현 기술 개발에 관심을 두고 있다. 특히, 야외를 배경으로 제작되는 e-sports 콘텐츠와 시뮬레이션 콘텐츠는 더욱 사실적인 자연환경 표현이 중요하다. 본 논문에서는 실외를 배경으로 하는 e-sports 콘텐츠 및 3D 시뮬레이션 콘텐츠에 적용할 수 있는 사실적인 3D 자연환경을 보다 쉽고 편리하게 제작하기 위한 소프트웨어 "EMtool(Environment Making Tool)"을 제안한다. EMtool은 자연현상들의 유대관계 및 상호작용을 사실적으로 표현하기 위한 기술에 중점을 두고 개발되었으며, 3D가상공간 내에서 자연환경을 표현하기 위한 기술들과 자연물을 표현하기 위한 기술들을 포함한다. 제안된 방법은 쉽고 빠르게 3D 야외 환경 구성이 가능함에 따라 사실적인 자연환경을 배경으로 제작되는 게임이나 가상 시뮬레이션 등 실시간 3D 콘텐츠에 활용이 가능할 것이다. 또한 사실적인 3D 자연환경 제작 기술을 제공함으로서 콘텐츠의 품질 향상은 물론 콘텐츠 맞춤형 3D 자연환경을 실시간에 제작할 수 있음으로 생산성을 증대시킬 수 있을 것이다.