• 한국콘텐츠학회논문지
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• 제9권8호
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• pp.99-112
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• 2009

본 연구는 기술 거래 및 기술이전 활성화를 위해 기술 개발을 원하는 기술수요자가 기술을 개발해줄 수 있는 기술공급자를 역경매 형태로 선택하는 방안을 모색하고자 하였다. 기술수요자가 기술공급자를 직접 선택하는 역경매 방식의 기술이전으로, 개발 이전에 개발자를 선정하고 동시에 개발된 기술을 기술 이전하여 기술이 사장되는 것을 방지하고 기술이전을 활성화하는 U-IT Technology Transfer Re-auction System Model 설계를 목적으로 한다. 1단계로 기술수요자가 기술 개발을 원하는 기술과 이에 대한 조건을 입력 전송한다. 2단계로 기술을 제공할 수 있는 기술공급자 DB에 1단계 데이터가 전송된다. 3단계로 입찰에 참여를 원하는 기술공급자는 각자의 조건을 입력 후 시스템에 전송하여 입찰에 참여한다. 4단계로 조건 최적화 경매 방식으로 기술수요자가 낙찰 순위를 결정한다. 5단계로 기술수요자가 기술공급자에게 낙찰에 응하도록 한다. 6단계로 기간내에 낙찰을 하지 않을 시 유찰되는 것으로 한다. 2회 이상 유찰시 자동으로 거래가 소멸되는 것으로 하는 기술수요자 중심의 역경매 방식이다.

• 유기물자원화
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• 제20권2호
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• pp.89-95
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• 2012

내분비 교란물질로 알려진 Nonylphenol과 DEHP가 줄지렁이의 산란수, 부화율, 난포당 부화개체수에 미치는 영향을 조사하고, 포천시 소재 하수처리장에서 발생한 하수슬러지내에 포함된 두 물질의 농도를 조사하였다. Nonylphenol 농도 100 mg $kg^{-1}$이하인 먹이에서는 Nonylphenol이 줄지렁이의 산란수, 부화율, 난포당 부화개체수의 감소를 유발하지 않았다. DEHP 농도 1,500 mg $kg^{-1}$ 이상인 먹이에서는 DEHP가 줄지렁이의 산란수를 감소시켰으며, 농도 2,500 mg $kg^{-1}$ 이상에서는 DEHP가 난포의 부화율을 감소시켰다. 포천지역 하수처리장에서 발생되는 하수슬러지에서 Nonylphenol은 검출되지 않았으나, DEHP는 최대 1,640mg $kg^{-1}$ 이 검출되어 하수슬러지를 줄지렁이게 급이 할 경우 DEHP에 의한 줄지렁이 개체군 소멸 현상이 유발될 가능성을 시사하였다.

• 대한치과기공학회지
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• 제29권1호
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• pp.23-34
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• 2007

The quantity of MgO in the Zirconia of 20wt% Frit has been varied and the sintering temperature has been differentiated to monitor the changes in the mechanical features. The rise of sintering temperature from 1100$^{\circ}C$ to 1300$^{\circ}C$ was followed by higher sintering density. And, at a sintering temperature, the increase of the quantity of MgO was followed by lower sintering density. The bending strength has been lowered as the quantity of MgO increases in the Zirconia of 20wt% Frit, which seems to be because the MgO functions as impurities degrading the mechanical features. In terms of micro-structure analysis, the pore has been greatly enlarged, while the density varied very little, when the MgO of 3wt% was added. The size of pore became smaller as the added quantity of MgO increased larger in the sequence of 5wt% and 7wt%. But, the pore-generating rate became higher as the added quantity of MgO increased in the sequence of 3wt%, 5wt% and 7wt%. Thus, it is possible to summarize that the small quantity of MgO, say, of 3wt%, promotes the grain growth, and the large quantity of MgO, say, of 7wt%, hinders the grain growth. Also, if the quantity of MgO exceeds some level, the MgO hinders substances from moving, which, ultimately, keeps blowholes from becoming enlarged or extinct, and makes pores small and dispersed in broad area. In conclusion, the study on the change in the size of pore shows that the larger the quantity of MgO is, the more the micro pores are, thereby degrading the mechanical features.

• 한국융합학회논문지
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• 제9권7호
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• pp.69-75
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• 2018

스마트 팩토리 내의 디바이스를 비롯한 다양한 엔터티 들은 보다 활동적이고 능동적으로 발전하고 있어서, 엔터티의 특성에 맞는 세분화된 접근제어가 필요하지만 기존의 디바이스에 대한 접근제어는 세분화된 접근제어가 부족하고, 사용자에 대한 접근제어는 절차가 복잡하고 가변적인 내용을 빠르게 적용하기에 어려움이 많다. 이 논문에서는 스마트 팩토리 엔터티에 최적화되어 효율성과 보안성을 유지할 수 있는 접근제어 방법을 제안한다. 기존에 PKC(Public Key Certificate)의 속성부여를 위해 정의되었던 AC(Attribute Certificate)를 PAC(Permission AC)로 확장하여 각 역할에 부여하여 통합관리가 용이한 RBAC(Role-basedAccessControl)를 제안한다. 또한 ACI(AC Issuer)의 디지털 서명된 PAC를 블록체인 기반의 모델에 적용하여 배포함으로써 수시로 바뀌는 엔터티의 역할에 대한 접근 및 권한 부여를 빠르고 정확하게 확인 및 반영할 수 있는 블록체인 기반의 RBAC-PAC 모델을 제안 한다. 기존연구와 효율성 측면에서 비교 분석하였고, 특히 엔터티 수가 많고 권한 갱신이 빈번할수록 효율성이 높아진 것을 확인하였다.

• 한국어류학회지
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• 제21권sup1호
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• pp.29-37
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• 2009

The tiny fragment of freshwater body is providing home for huge biodiversity and resources for the existence of human. The competing demand for freshwater have been increased rapidly and it caused the declination of biodiversity in recent decades. Unlike the natural process of extinction in gradual progress, the current species extinction is accelerated by human activity. As a result many fish species are already extinct or alive only in captivity in the world and about fifty eight animal species are in endangered in Korea including eighteen freshwater species. Conservation of biodiversity is the process by which the prevention of loss or damage is attained, and is often associated with management of the natural environment. The practical action is classified into in-situ, or ex-situ depending on the location of the conservation effort. Recovery means the process by which the status of endangerment is improved to persist in the wild by re-introduction of species from ex-situ conservation population into nature or translocation of some population. However there are a lot of restrictions to complete it and successful results are known very rare in case. In this article the authors explore some strategies for conservation and restoration of freshwater fish species conducted in Korea for few years. The major causes are discussed in relation with the decline of freshwater fish diversity during few decades and some strategies are evaluated to advance the process of conservation. A study on the Korean bullhead, Pseudobagrus brevicorpus, is introduced as a case for ex-situ conservation and restoration in freshwater ecosystem.

• 천문학회보
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• 제42권2호
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• pp.39.1-39.1
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• 2017

The standard hierarchical galaxy formation scenario in the popular LCDM cosmogony has been very successful in explaining the large-scale distribution of galaxies. However, one of the failures of the theory is that it predicts too many satellite galaxies associated with massive galaxies compared to observations, which is called the missing satellite galaxy problem. Isolated groups of galaxies hosted by passively evolving massive early-type galaxies are ideal laboratories for finding the missing physics in the current theory. We discover through a deep spectroscopic survey of galactic satellite systems that bright isolated early-type galaxies have almost no satellite galaxies fainter than the r-band absolute magnitude of about Mr=-14. The cutoff is at somewhat brighter magnitude of about Mr=-15 when only early-type satellites are used. Such a cutoff is not observed in the luminosity function of galaxies in the field. Physical properties of the observed satellites depend sensitively on the host-centric distance. All these are strong evidence that galactic satellites can become invisible due to astrophysics of satellite-host galaxy interaction. A recent state-of-the-art hydrodynamic simulation of galaxy formation does not reproduce such a cutoff in the satellite galaxy luminosity function. But the past history of the simulated satellites shows that many satellite galaxies near or somewhat fainter than the cutoff magnitude have recently become extinct through fatal encounters with the host or other satellite galaxies. Our observation indicates that the missing satellite galaxy problem could be mitigated if the astrophysics of galaxy interaction is more elaborated in the theory.

• 복식
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• 제36권
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• pp.53-75
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• 1998

The kind, the structure, and the motif of the Chosun dynasty's fabrics found mainfy within the Buddhist statues were studied. The total of 62 pieces of fabrice can be classified chronologically as follows ; 27 pieces in the year of 1431, 20 pieces of 1550, 9 pieces of 1664, and 6 pieces of 1735. These 62 fabrics also categorized by the weaving method as follows; 27 plain weaved, 17 twill weaved, 10 pieces of satine weaved, 7 pieces of Leno weaved, and 1 piece of double weaved fabrics. Most of the studied fabrics were silk, the rest were 2 pieces of yam and 1 piece of cotton, Kyun, Chu, and Cho were the plain weaved silk as Nung and Ki were the twill weaved silk, Satine weaved silk was called as Dan and double weaved silk was called Chikum in the Chosun dynasty. 1. The antique fabrics were composed of mainly silk. This is believed due to the utmost devotion to the buddhist statue as an object of worship. 2. In the fabric's structural point of view, th ecrossed 4-ply threads of warp yarn which is one of Leno weaved can be observed fre-quently in the period of Korea dynasty's fabrics. But it started to disappear in the beginning of Chosun dynasty, since only one piece of Ra could be found in the 1431's fabrics. Keum, one of the double weaved structure is assumed to be extinct from the Korea dynasty. Satin weaved fabrics started to be woven from the latter period of Korea dynasty and was very popular in Chosun dynasty. 3. The widths of fabrics in the Chosun dynasty gradually decreased compared with those of Korea dynasty.

• 한국환경복원기술학회지
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• 제18권1호
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• pp.103-113
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• 2015

Korean pines(Pinus koraiensis) are one of the major plantation species in the Republic of Korea and their natural habitats range from Japan and China to Siberia. The seed of Korean pines, pine nuts, are well know for good food reserves. Due to the global changes which drive the Korean peninsula into the semi-tropical climate, current plantations and natural habitats of Korean pines are faced with the change in the environmental conditions to some extent. To anticipate suitable sites for Korean pines in the future, the location of Korean pines were extracted from the 'Map of suitable trees on a site' that provides the map of suitable trees on a site considering tree species for timber and special uses, and then MaxEnt modelling was used for generating a prediction map on the basis of statistical analysis. As a result, the order of predicted suitable sites were Kangwon-do, Kyungsangbuk-do and Chungcheongbuk-do provinces and sites with high elevation within those provinces were considered most suitable in common. The prediction map of suitable sites for Korean pines presented that suitable sites in the future decreased by 72.2% by 2050's and almost disappeared with a decrease of 92.1% by 2070's on a nationwide scale. In relation to the major production regions of pine nuts in South Korea - Gapyung gun and Yangpyung gun, Kyunggi province and Hongcheon gun, Kangwon province, suitable sites within their areas were predicted to increase by 2050's but become extinct in South Korea by 2070's. To establish a long-term countermeasures against the improvement on forest productivity quality in terms of managing national food security, the result from this study can be considered as a firm basis of predicting plantation suitability. Also, it can be used to predict the changes in supply of forest products and thereby market values in accordance with climate change scenarios.

• 한국환경복원기술학회지
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• 제18권1호
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• pp.25-35
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• 2015

Pennisetum aloperculoides is a key revegetation species mixed with other plants species and used for revegetating cut-slopes. The purpose of this research is to identify the effects of mixed seeding of revegetation plants on cut-slope revegetation with respect to the quantity of Pennisetum aloperculoides seeds. The coverage ratio and appearance frequency of Pennisetum aloperculoides, and other revegetation species were measured to assess the cut-slope revegetation. We divided Pennisetum treatments into four groups with different Pennisetum seed quantities of $0g/m^2$, $5g/m^2$, $10g/m^2$, and $15g/m^2$. For each treatment group, we mixed identical quantities of seeds from herbaceous flowers (bird's-boot trefoil, aster, chrysanthemums, golden coreopsis and china pink), cool-season turfgrasses, and woody plants (korean lespedeza, indigo and silk tree). The increase in the quantity of the Pennisetum seeds resulted in the higher coverage ratio for Pennisetum, but in the lower coverage ratio for herbaceous flowers, cool-season turfgrasses, and woody plants. We observed a short-term succession process in which the dominant species shifted in the following order: the initial species Pennisetum, herbaceous flowers, and then lastly woody plants. In case of the appearance frequency, we also observed the higher appearance frequency for Pennisetum and the lower appearance frequency for the other plants due to the increase in the quantity of Pennisetum seeds. Pennisetum, bird's-foot trefoil and china pink showed the tendency to decrease the appearance frequency from one month after seeding while cool-season turfgrasses became extinct due to summer drought. In the woody plants, the appearance frequencies of korean lespedeza and indigo were high due to the decrease in quantity of Pennisetum seeds. The silk trees were damaged from winter frost and none emerged at all in 2013 (the following year after the seeding). Korean lespedeza and indigo appeared to have the short-term rapid dominance over other treated revegetation plants.

• 자원ㆍ환경경제연구
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• 제17권2호
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• pp.349-379
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• 2008

수달은 준멸종위기 야생동물이자, 생태적으로 건강한 하천의 지표종이다. 본 연구의 목적은 청주시와 청원군의 수달 서식지 보호의 비시장적 가치를 측정하는 것이다. 응답자의 지불의사를 추정하기 위하여 일점오양분선택형 조건부가치측정법을 적용하였다. 청주 청원 지역 거주민 311명의 표본을 대상으로 수달 서식지 보호를 위한 지불의사를 물었다. 청주 청원 지역 거주민들이 부여한 수달 서식지 보호치 지불의사는 일점오양분선택형 선형로짓모형의 중앙값을 대표값으로 선정하면, 가구당 매월 5,904원으로 산출되었다. 2005년 현재 청주 청원 지역내의 총 가구수가 255,750가구임을 감안하면 총 가치는 매월 12억~17억 원으로 추정된다. 본 연구의 결과는 공익적 편익을 제공하는 수달 서식지 보호정책의 필요성을 시사한다.