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        검색결과 819

        281.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        바둑게임은 중국에서 적어도 2,500년 전에 창안되었으며, 게임을 이기기 위해 상대방보다 더 많은 영역을 둘러싸는 것을 목표로 한다. 간단한 규칙에도 불구하고 바둑은 인공지능(AI) 분야에서 아주 복잡한 전략적인 보드게임이다. 몬테카를로 트리탐색(MCTS)은 국면 평가의 어려움을 극복하고 게임트리 내의 엄청난 분기수를 줄여주는 최상우선탐색 알고리즘이다. 컴퓨터바둑 게임에서 MCTS는 수많은 플레이아웃을 수행한 후, 게임트리 내에 있는 현재노드로부터 단말노드까지의 임의의 수순을 표본 추출하여 다음 후보 착수에 대한 승률을 근사적으로 계산해낸다. AlphaGo를 포함한 모든 강력한 컴퓨터바둑 프로그램은 컴퓨터바둑 게임 진행에 있어 MCTS를 이용하여 가장 유망한 착수를 구해왔다. 본 연구는 소형바둑 컴퓨터게임에 있어 순수 MCTS를 이용하여 가장 유망한 일련의 수순을 찾고자 했다. 실험결과에 의하면 순수 MCTS는 소형바둑에서 19줄바둑게임에서 벌어지는 포석, 중반전, 끝내기라는 3단계가 아닌 중반전과 끝내기라는 단지 2단계를 진행하였으며, 아울러 순수 MCTS는 맥과 연단수와 같은 하위개념의 지식을 이해 못하는 것을 보였다.
        4,000원
        282.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, an experiment is performed to recover the Li in Li2CO3 phase from the cathode active material NMC (LiNiCoMnO2) in waste lithium ion batteries. Firstly, carbonation is performed to convert the LiNiO, LiCoO, and Li2MnO3 phases within the powder to Li2CO3 and NiO, CoO, and MnO. The carbonation for phase separation proceeds at a temperature range of 600oC~800oC in a CO2 gas (300 cc/min) atmosphere. At 600~700oC, Li2CO3 and NiO, CoO, and MnO are not completely separated, while Li and other metallic compounds remain. At 800 oC, we can confirm that LiNiO, LiCoO, and Li2MnO3 phases are separated into Li2CO3 and NiO, CoO, and MnO phases. After completing the phase separation, by using the solubility difference of Li2CO3 and NiO, CoO, and MnO, we set the ratio of solution (distilled water) to powder after carbonation as 30:1. Subsequently, water leaching is carried out. Then, the Li2CO3 within the solution melts and concentrates, while NiO, MnO, and CoO phases remain after filtering. Thus, Li2CO3 can be recovered.
        4,000원
        283.
        2018.07 구독 인증기관·개인회원 무료
        Many firms see organizational learning systems as critical to facilitating competitive advantage. However, until now, few tourism studies have empirically investigated and identified how the different characteristics of highly competitive organizations, such as travel agencies, influence competitive advantage in a dynamic environment. This study uses a mediation-moderation analysis for such an empirical examination. A total of 288 travel agencies from Taiwan were analysed. The authors found that travel agencies’ shared goals may influence competitive advantage through characteristics of dynamic capability development, differential strategy implication and social capital accumulation. Greater levels of organizational learning may positively strengthen the relationships between (a) shared goals and dynamic capability, (b) shared goals and social capital, and (c) social capital and competitive advantage. Implications of these findings for managerial and theoretical frameworks are also discussed.
        286.
        2018.05 구독 인증기관·개인회원 무료
        The corrugated steel plate culvert structure was developed and actively developed in the United States in the 1930s and was introduced into the domestic scene in the 1970s. Currently, about 1,000 corrugated steel structures were being used for expressway concrete passage culverts and waterway culverts. Compared to concrete materials that require a basic curing time, corrugated steel plates could be assembled and backfilled, so that the construction speed is fast and the economics were excellent. However, as the number of public years has elapsed, problems in maintenance have been found. Therefore, there is a growing interest in the stability of corrugated steel plate structures. Therefore, in this study, the improvement for the efficient maintenance of the corrugated steel structure constructed on the expressway was examined.
        287.
        2018.05 구독 인증기관·개인회원 무료
        Some of the deicer ingredients are the same as fertilizer ingredients from agricultural activities. The goal of this study is to distinguish the components of highway deicer from the components used for agriculture. Among the deicer ingredients, Ca and Cl are substances which can be supplied by fertilizer or livestock manure. However, fertilizer and livestock manure contain plenty of nitrogen, organic matter, phosphoric acid and magnesium, including deicer ingredients. The soil physico-chemical characteristics were analyzed according to the distance from the highway. The physico-chemical analysis items of the soil include electrical conductivity, total nitrogen (TN), available phosphate (Av.P), organic matter (OM), ammonia nitrogen (NH4-N), Cation Exchange Capacity (CEC). In the case of effective phosphoric acid, leaching into the subsoil is very low due to various binding mechanisms in the soil. However, it is considered that the compost (fertilizer) applied to the topsoil is mixed with the soil by the tillage or flattening operation. In addition to the organic matter content of the subsoil appear to 10% or more is that in some cases exhibit a similar level as the topsoil. The average soil organic matter content of about 2.6%. This results shows that an excess of organic compost in the study area flows into subsoil and was mixed with the subsoil. The high EC value at the points outside the snow removal effect range level is not considered to be affected by the deicer. The results of the survey showed that the values were differently detected by agricultural activities, and that they should be approached in a complex way in their interpretation.
        288.
        2018.05 구독 인증기관·개인회원 무료
        On the expressway, culvert structures serve as a channel or channel connecting villages and towns blocked by clay. The culvert structures are mainly constructed of reinforced concrete or corrugated steel sheets in various ground conditions. Most culverts are divided into aging and damage trends according to the number of public years. However, most of the damage to the culvert structures applied on the soft ground is likely to be caused by the subsidence of the ground. In addition, even if the settlement of the paper sheet is stabilized, if the road is constructed at the upper part, the culvert structure is also expanded at the time of the expansion work, and damage due to a behavior different from that before the expansion work may be found. Therefore, in this study, the behavior of the culvert structures according to the ground supporting force was analyzed. For this purpose, the causes of damage are derived through design review and field investigation.
        289.
        2018.05 구독 인증기관·개인회원 무료
        Recently, maintenance science has been promoted and many advanced equipments have been developed such as GPR surveying, automatic gauging robot, bridge deck inspection robot. And the government - led policy on the fourth industrial revolution affects the R & D field of science and technology, and science for all fields remains a challenge. However, the equipment that has been developed so far is applied separately to each field, so that it is not possible to grasp the state of the entire structure. Therefore, in this study, the applicability of BIM and image information mapping technology in expressway maintenance was analyzed. To accomplish this, a basic analysis was conducted to identify the characteristics of the equipment developed for the current structure inspection and to build a platform to manage the collected data collectively.
        292.
        2018.04 구독 인증기관·개인회원 무료
        Climatic factors are known to be the most critical on estimating potential distribution of species, suggesting that an area having similar climate to origin of a pest may be vulnerable to its invasion. In this study, we selected Leptoglossus occidentalis, a pest causing significant forest damage in South Korea, and compared current climate of its 3 known origins with that of 74 cities in South Korea by using ‘Match Climate’ function in CLIMEX software. Result showed that overall climatic similarity between them was moderately high, indicating consistency of climatic similarity with the current distribution of Leptoglossus occidentalis in South Korea.
        293.
        2018.04 구독 인증기관·개인회원 무료
        Phthorimaea operculella is a pest causing serious damages in worldwide potato cultivation. As climatic factors are considered to be the most crucial on species’ distribution, we tried to compare climatic conditions between a native area of Phthorimaea operculella with cities in South Korea and other areas in Asia based on climatic similarity provided by 'Match Climates' function of CLIMEX software. Even though there is arguing regarding origin of Phthorimaea operculella, we selected Peru and Bolivia as home climate, and compared its climatic similarity to other areas in Asia with application of SRES A1B 2030 climate change scenario. Result showed that South Korea has favorable climatic condition for Phthorimaea operculella. Also, most of Asia except north China and south Russia showed the similar climate suitable for Phthorimaea operculella.
        294.
        2018.04 구독 인증기관·개인회원 무료
        국립생태원에서는 2016~17년에 걸쳐 한반도의 남부지역에 해당되는 충청ꞏ전라, 경상 지역에서 외래생물 전국 서식실태조사를 수행하였으며, 그 중 외래곤충 현황에 대한 결과이다. 2016년 충청ꞏ전라권역 65개 시ꞏ군에서 총 8목 20과 28종의 외래곤충이 조사되었으며, 그 중 2종의 미기록종(Hindoloides bipunctatus, Salurnis marginella)이 확인되었다. 해당 권역에 분포하는 외래곤충 중 갈색날개매미충은 48개 시ꞏ군으로 가장 많은 지역에서 서식이 확인되었고, 다음으로 꽃매미(41), 등검은말벌(35), 버즘나무방패벌레, 해바라기방패벌레(30), 미국선녀벌레(27) 순이 었다. 2017년 경상권역 43개 시ꞏ군에서 총 6목 24과 32종의 외래곤충이 조사되었으며, 그 중 1종의 미기록종(Dentatissus damnosus)과 2종의 미접종(뾰족부전나비, 무늬박이제비나비)이 확인되었다. 해당 권역에 분포하는 외래곤충 중 남방노랑나비가 37개 시ꞏ군으로 가장 많은 지역에서 서식이 확인되었고, 다음으로 꽃매미(36), 해바라기방패벌레(35), 등검은말벌(31), 돼지풀잎벌레(30) 순이었다. 남부지역 총 133개 시ꞏ군에서 꽃매미가 가장 많은 지역(77)에서 서식이 확인되었으며, 다음으로 갈색날개매미충(70), 등검은말벌(66), 해바라기방패벌레(65) 순이었다.
        295.
        2018.04 구독 인증기관·개인회원 무료
        Heterodera trifolii, mostly known as clover cyst nematode, is currently a serious problem for Chinese cabbage growers of the highland area in Korea. Due to lack of readily information about the nematode on Chinese cabbage in Korea, the pest steadily spread within the highland areas and has become a serious setback. Occurrence, spatial aggregation, egg hatching and the pathogenicity of this nematode are depicted in this study from ecological point of view. The study results suggest site-specific control and a potential planting time for the cabbage to avoid severe damage caused by this nematode.
        296.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the effects of freeze dried placenta supplementation on reproductive performance, colostrum and plasma biochemical composition in pregnant sows. Eleven Landrace × Large white sows were fed with corn-soybean meal diets supplemented with or without 1% freeze dried placenta powder from 10 days before their expected farrowing dates until 10 days postpartum. The colostrum protein content was significantly higher(P=0.043) in the treatment group than in the control group. Compared to the control group, the immunoglobulin G(IgG) concentration in the colostrum was significantly higher(P=0.004) in the treatment. In day 25 piglets plasma, the IgG concentration was higher(P=0.184) in the treatment than the control. The mortality rate was lower(P=0.102), and the piglet weight gain was higher(P=0.35) in the treated group. Overall, the treatment group showed greater levels of protein and IgG concentration in the colostrum, when compared to control group. Therefore, the freeze dried placenta supplementation on pregnant sows can enhance its colostrum composition, hence decrease the mortality and increase the growth rate of piglets.
        4,000원
        297.
        2018.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 공기주입 이중피복온실과 관행 이중피복온실의 생육환경과 단열성능을 비교하기 위하여 수 행하였다. 두 온실의 온도, 상대습도, 포차, 이산화탄소농도, 일사량, 딸기 생산량 및 난방연료소비량을 비교하 였다. 공기주입온실이 관행온실보다 야간에 상대습도가 더 높고 포차는 더 낮게 나타나 딸기의 생육에 좋지 않은 환경을 보여주었다. 이산화탄소농도는 공기주입온실이 관행온실보다 더 높게 나타났으며, 이는 공기주입 온실이 더 밀폐되어 있어 환기량이 적기 때문인 것으로 판단된다. 관행온실의 광투과율이 77%로 공기주입온실 의 72%보다 더 높아 관행온실의 광환경이 더 우수한 것으로 나타났다. 관행온실의 딸기 생산량이 더 높게 나 타났으며, 이는 관행온실의 생육환경이 공기주입온실보다 더 우수한 결과로 판단된다. 난방연료는 공기주입온 실에서 더 적게 소모되어 공기주입온실의 단열성능이 더 우수한 것으로 나타났다.
        4,000원
        298.
        2017.11 구독 인증기관·개인회원 무료
        Transcellular transport in epithelial cell is a method for absorbing calcium from intestine to blood, providing effective mechanism of utilizing calcium at low calcium intake. In this study, we aimed at theoretically developing a simple mechanistic model explaining transcellular transport in calcium absorption process. Transcellular calcium transport was schematized into 3 steps which were entry, diffusion, and extrusion. Each step was separately modeled to include the specific feature of them. In detail, electro-diffusion, facilitated diffusion, and Michaelis-Menten kinetics were employed to model calcium entry, diffusion, and extrusion, respectively. Then, the developed models were numerically solved to find a solution which simultaneously satisfied 3 models under steady-state assumption. Result of model simulation was consistent with the known behavior of transcellular calcium absorption, showing that transcellular calcium transport became saturated with increase of luminal calcium concentration. Because transcellular calcium transport depends on calcium binding protein mediated by vitamin D we expect that this model can be used to find optimal regulatory point for increasing calcium absorption.