• 한국작물학회:학술대회논문집
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• 한국작물학회 2000년도 추계 학술대회지
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• pp.95-97
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• 2000

• 한국수산과학회지
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• 제39권spc1호
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• pp.132-141
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• 2006

Artificial structures have been designed as pilot structures to promote the creation and restoration of tidal flats. However, little information is available as to whether such artificial construction affects the macrobenthic community structure. We monitored the variation of the macrobenthic community structure and species composition near natural and artificial structures (seaweed and a timber fence) on the tidal flats near the Iwon Dike, Korea. In total, 137 macrobenthic species were recorded during this study, predominantly crustaceans (47%), polychaetes (18%), and molluscs (27%). Polychaetes comprised over 50% of the total density, followed by gastropods (38%) and crustaceans (11%). Macrobenthic species composition in the artificial and natural areas, was initially similar, but it differed after 7 months. The gastropod Umbonium thomasi, the most dominant species, was present at both sites in the first month after the start of the experiment, but disappeared at the artificial sites within 7 months, suggesting disturbance by the environmental factors. The number of species and diversity (H') varied significantly within sites at the beginning of the experiment, but no difference was observed after 7 months. Multivariate analysis (multidimensional scaling) revealed significant differences in community structure between the artificial and the natural areas from 7 months after the start of the experiment, except from 18 to 21 months. The community structures were mainly influenced by U. thomasi. Community structure at the artificial sites was affected by environmental variables, such as carbon, COD/IL sulfide, loss of ignition, kurtosis and silt, which changed over time. We observed no significant correlations between environmental variables and the dominant species, except in the case of Spio sp. and Macrophthalmus dilatatus, suggesting that the biological interactions and temporary disturbances such as typhoon, as well as the effects of artificial structures may also be important regulating factors in this system.

• 한국환경농학회지
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• 제18권1호
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• pp.6-7
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• 1999

The water quality at Mankyeong River was surveyed 13 sites of main stream for 6 months from April to September in 1995 and 1997. The monthly average value of $NH_4-N$, $SO_4^{2-}$ and $Cl^-$ showed the highest peak in April while that of $NO_3-N$ showed the highest peak in August. The monthly average value of COD showed the highest peak in September at high temperature season. Concentrations of $NH_4-N$ and $SO_4^{2-}$ in Mankyeong River stream exceeded the standard water quality criteria in many sites. The water quality of Mankyeong River stream was not suitable for the irrigation source excepted the sites such as Hari, Gosan stream and Soyang stream. The floodgate of Mokcheon, Yocheon, Jeonju and Samcheon stream were rapidly polluted by the sewage of city, otherwise the Iksan stream was rapidly polluted by the sewage of swine. The sum of ionic concentrations in Mankyeong River stream was the highest at floodgate of Yocheon by influence of the sewage from city and industry. The order of the major anions and cations concentration in Mankyeong River stream were $SO_4^{2-}$ > $Cl^-$ > $NO_3-N$ > $SO_4^{3-}$ and $Na^+$ > $Ca^{2+}$ > $NH_4^+$ > $Mg^{2+}$ > $K^+$, respectively.

• 디지털융복합연구
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• 제12권1호
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• pp.365-370
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• 2014

웹의 역할이 커져가고 있는 정보화 사회에서 장애인을 위한 웹 접근성의 중요도 또한 커져가고 있다. 본 논문에서는 장애인 관련 웹 사이트들의 접근성 실태를 알아보고자 학교 웹 사이트들과 비교 분석하여 보았다. 웹 접근성 평가 실험 결과 장애인 관련 웹 사이트들의 접근성이 일반 학교의 웹 접근성보다 낮게 평가 되었다. 본 연구 결과는 일반 웹 사이트들에 비하여 장애인 관련 웹 사이트들의 웹 접근성 향상 노력이 더욱 필요함을 보여준다.

• 대한치과교정학회지
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• 제14권2호
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• pp.203-215
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• 1984

This experiment was performed to explore the effect of electric currents and orthodontic forces on bone $PGE_2$ content and orthodontic tooth movement on cats. Stainless steel electrodes were connected a power pack consisting of five miniature batteries, a transistor, and a resistor. The current $(10{\pm}2{\mu}A)$ was provided by a constant source encased in a palatal acrylic plate. In first experiment, the cathode was placed mesial to the right maxillary canine tooth and the anode was positioned distal to the tooth, Sham electrodes were placed new the left cuspid, to serve as control. Nine cats were divided into three groups evenly. Groups of three animals were treated with electric currents only-for 1, 3 and 7 days, respectively. In second experiment, electric currents and the orthodontic forces of about 80 gm were applied to the right maxillary canine, and the orthodontic forces only were applied to the left maxillary canine. 3 groups of three cats each were treated in this experiment-for 1, 3 and 7 days, respectively. Alveolar bone samples were obtained from sites of tension and compression as well as from contralateral sites. Bone samples were extracted by homogenization in $40\%$ ethanal. The supernatant partitioned twice with 2 volumes of petroleum ether to remove neutral lipids and the aqueous supernatant partitioned in ethyl acetate. After drying the solvent, $PGE_2$ was measured by radioimmunoassay technique. The obtained results were as follows. 1. Teeth treated with combined force and electricity moved faster than those treated with force alone. 2. Alveolar bone $PGE_2$ content of electric stimulation was increased at both electrodes. 3. Alveolar bone $PGE_2$ content of mechanical stimulation at compression sites was gradually increased at all time period. At tension site, $PGE_2$ content increased after 1 day of mechanical stimulation remained elevated at all time period. 4. Alveolar bone $PGE_2$ content of compression sites was increased more than that of tension sites from mechanical stimulation as well as electrical stimulation.

• 한국안전학회지
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• 제17권2호
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• pp.69-75
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• 2002

Current fire safety in the construction sites has developed piecemeal over a considerable period of time. However, the law and regulation of fire safety is insufficient to protect fro in the construction sites. The frequency of fire in the construction sites is very rare but it brings longterm deterioration durability of building structure and large scale industrial calamity. There are many process of works and each work deals with many kind of flammable material, so it is very difficult to find a proper safety fire prevention. This study executed the questionnaire and fire experiment of the welding work to provide effective fire prevention counterplan.

• 한국작물학회지
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• 제27권2호
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• pp.99-106
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• 1982

본 연구는 1978년 국제연락수도내랭성검정시험(IRCTN) 계획에 따라 237품종을 10개지역에 공시하여 한국의 춘천 내랭성검정포에서의 수도생육기간과 타지역에서의 생육기간과의 비교분석하여 수도품종의 출수성에 대한 지역감의 관계를 알기 위하여 실시하였다. 1. 춘천과 타지역간의 수도생육기간은 모두 높은 정의 상관관계를 보였는데 일장반응이 예민한 품종들은 예외적인 반응을 보였다. 2. 타지역에서 생육기간이 짧았던 품종이 춘천에서도 동일한 경향을 보일 수 있는 확율은 63-72%였는데 이는 춘천이 타지역보다 생육기간중의 일장이 길기 때문이었다. 3. 춘천에서 생육기간이 짧은 품종을 병발하여 위도가 낮은 지역에 보내면 일장반응에 의하여 생육기간이 짧았던 품종들이 제외되는 결과를 가져오며 내랭성을 동시에 검정할 수 있기 때문에 육종효과를 증대시킬 수 있을 것이다.

• 한국농공학회논문집
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• 제64권2호
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• pp.37-45
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• 2022

In-situ pilot experiment was carried out to establish a countermeasure on the soil loss from the hill side uplands that was rehabilitated by soil remediation method nearby abandoned mine sites for 2 years. It was considered that the affect of an inclination of cover surface, a stabilization treatment of cover layer by lime and steel refining slag (SRS) and a vegetation of soil surface as an effect factors in the experiment. It was constructed 4 lysimeters (plots, 22 m long, 4 m width) on the hilly side (37% inclination). One plot was control and two plots was treated by 1% lime and SRS. A remind one plot was modified a inclination to 27% to compare the affect of inclination on the amount of cover soil loss. It was attached a reservior tank and water level gauge in the end of lysimeters to measure the amount of the surface water flow and soil loss. It was also installed the automated sensors that could be collect the precipitation, soil moisture content, tension of cover layer in each plots. It was observed that the event of precipitation were caused the soil loss and it were related the physical and chemical properties of cover soil and inclination of surface layer of plots. During the experiment, it was exceeded the national regulation (50 t/ha/yr) in 37% inclination plots even though it was vegetated on the cover soil surface. However, in 27% inclination plot, it was shown that the amount of soil loss was maintained below the national regulation and, more ever, vegetation could reduce the the amount of soil loss. Therefore it was expected that such results could be applied to the future design of rehabilitation projects on the polluted farmland nearby abandoned mine sites.

• 한국약용작물학회지
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• 제14권3호
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• pp.178-182
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• 2006

둥굴레 유전자원의 유연관계를 위한 기초 자료를 얻고자 둥굴레속 식물 수집종 10종에서 18S ribosomal RNA를 암호화하는 18S rDNA 영역의 염기서열을 결정하고 그 특성을 분석한 결과를 요약하면 다음과 같다. 둥굴레속 10종의 18S rDNA 영역 전체의 길이는 $913{\sim}914bp$로 비슷하였으나, 총 8개 지점에서 염기의 치환 및 결실에 의한 변이가 발생하였다. 전위는 $T{\rightarrow}C$전위가 4개 지점에서 발생하였고, $A{\rightarrow}G$ 전위가 1개 지점에서 발생하였으며, 전좌는 $C{\rightarrow}A$ 전좌가 1개 지점에서 발생하여 전위가 전좌보다 5배 만큼 발생하였다. 결실은 2개 지점에서 발생하였다. 18S rDNA의 염기의 조성은 adenine $23.09{\sim}23.33%$, guanine $23.33{\sim}23.52%$, thymine $25.60{\sim}25.85%$, cytosine $27.38{\sim}27.79%$로 pyrimidine계가 purine계보다 많았다. 18S rDNA의 A + T 함량은 $48.80{\sim}49.18%$로 평균 48.99%였고, G+C 함량은 $50.82{\sim}51.20%$로 평균51.01%였다. 다중 정렬에 의해 염기서열을 비교한 결과 $99.7{\sim}100%$ 일치하여 종간에 차이가 적었다.

• 산업공학
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• 제19권3호
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• pp.225-235
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• 2006

In this paper, we propose an intelligent e-commerce meta-search engine which integrates distributed e-commerce sites and provides a unified search to the sites. The meta-search engine performs the following functions: (1) the user is able to create a category-based user query, (2) by using the WordNet, the query is semantically refined for increasing search accuracy, and (3) the meta-search engine recommends an e-commerce site which has the closest product information to the user’s search intention by matching the user query with the product catalogs in the e-commerce sites linked to the meta-search engine. An experiment shows that the performance of our model is better than that of general keyword-based search.