• Asia pacific journal of information systems
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• 제30권3호
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• pp.590-613
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• 2020

As a part of advanced technology society, South Korean youth have been accessing the Internet at a very high pace. The Internet overuse could yield addiction where may be a serious psychological disorder of this century. The literature remarks that gender could make a significant difference on internet addiction. Therefore, this study aims to examine the effect of gender variable on internet addiction for a sample of South Korean university students (n = 815; 312 females and 503 males). The instrument had two sections; the demographics and twenty Internet Addiction survey items based on a five level scale; "Rarely, Occasionally, Frequently, Often and Always". The results showed that general tendency among the participants appeared between "Occasionally" and "Frequently" for internet addiction. In order to test five derived study hypotheses, the researchers conducted comparative statistical tests. The t-tests revealed that gender made statistically significant differences on nineteen items where males were higher than females showing that males significantly spend more time on the Internet than females. Additionally, t-tests results showed that seventeen of the survey items showed statistically significant differences with respect to types of technology dominant environment. The researchers created two dummy variables to combine gender and technology dominant environment variables and gender and school year variables, to have a better understanding the gender effect with one-way ANOVA. The gender difference still exists following its merge to technology dominant environment showing that the gender surpasses IT related environment. When school year combines to gender, males show higher scores for certain items, especially for freshman year.

• 한국환경복원기술학회지
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• 제15권1호
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• pp.15-25
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• 2012

Arundinaria munsuensis population were classified into Lespedeza maximowiczii dominant population and Spiraea prunifolia for. simpliciflora dominant population in the habitat of Jiri Mt. In the study sites, soil organic matter, total nitrogen, available phosphorous, exchangeable K, exchangeable Ca, exchangeable Mg contained, cation exchange capacity, and soil pH were ranged from 14.52~16.13%, 0.57~0.59%, 5.57~10.24 (mg/kg), 0.44~0.49 ($cmol^+/kg$), 0.62~0.92 ($cmol^+/kg$), 0.31~0.32 ($cmol^+/kg$), 28.26~32.44 ($cmol^+/kg$) and 4.33~4.48 respectively. DCCA ordination analysis showed that Lespedeza maximowiczii dominant population dwells where pH, exchangeable Ca and exchangeable Mg content are high and Spiraea prunifolia for. simpliciflora dominant population is placed where CEC, total nitrogen and organic matter content are high.

• 벤처창업연구
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• 제10권2호
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• pp.27-42
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• 2015

벤처기업에 관한 기존의 연구들은 자원을 획득하고 보유자원을 재조합하여 내부역량을 확보하기 위한 방법에 논의에 집중되었다. 하지만 자원과 역량이 부족한 벤처기업에게 중요한 것은 환경변화의 이해를 통해 기회를 포착하고, 생존할 수 있도록 안정적인 시장진입을 가능하게 하는 전략제시가 필요하다. 이를 위해, 본 연구는 벤처기업이 지배적 디자인 경쟁 환경의 산업에 진입하여 성공할 수 있었던 이유를 기회포착이라는 개념을 통해 알아보고자 한다. 기회포착은 벤처기업이 구현할 수 있는 역량을 고려하여 기회를 인식하는 것으로서 시장에 판매할 수 있는 재화 및 서비스를 공급하기 위해 필요한 기술을 선택하고, 기술획득에 필요한 협력방식을 선택하는 역량을 의미한다. 본 연구는 벤처기업의 기회인식과 전략적 대응방식에 주목하여 시장진입에 성공할 수 있었던 이유를 살펴보기 위해 지배적 디자인 경쟁이 진행되었던 산업에 진입하여 안정적으로 자리를 잡은 하드웨어 분야와 소프트웨어 분야 벤처기업 1곳 씩 선정하여 성공적인 진입이 가능했던 이유와 업종별 특성에 따른 차이점을 알아보았다. 연구결과 지배적 디자인 경쟁이 벌어지고 있는 환경에서 각 기술진영의 업체들은 자신의 기술이 확대되어 표준화가 되는 것이 목적이기 때문에 하드웨어 업체는 가격인하를 통한 시장 확대에 집중하였으며, 소프트웨어 업체는 보완기술의 보편화를 이루어 더 많은 사용자가 참여할 수 있게 유도하는데 노력한다. 지배적 디자인 경쟁환경은 벤처기업의 업종에 따라 기회포착 인식의 차이를 갖게 하는데 하드웨어 업체는 잠재수익률에 대한 기회인식의 차이로 인해 발생하는 틈새시장을 확보하도록 핵심기술을 확보하는 것이 중요하며, 소프트웨어 업체는 다수의 사용자가 참여하도록 유도하는 보완기술에 기회를 인식해야 함을 알 수 있었다.

• 수산해양기술연구
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• 제55권3호
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• pp.243-251
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• 2019

The ichthyoplanktons were sampled by Bongo net to study the distribution of the eggs and larvae in the West coastal waters of Korea during the study period (February, May, August and October of 2017). Collected fish eggs were divided into Engraulis japonicus and unidentified species. The most dominant species, Engraulis japonicus accounted for 79.52% of the total fish egg, which was followed by unidentified species (20.48%). The total of 36 taxa in fish larvae were identified based on morphological and molecular characteristics. Fish larvae were dominant by Gobiidae species. 48.30% of the total catch in abundance, which was followed by Engraulis japonicus (31.86%). These two taxa composed 80.16% of the total collected fish larvae. The seasonal diversity index of species from the collected fish larvae in the West coastal waters in 2017 was 0.625-1.883 and the evenness index was 0.380-0.865. In addition, dominance index was 0.618-0.920 and richness was 0.573-3.189.

• Nuclear Engineering and Technology
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• 제33권4호
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• pp.355-364
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• 2001

In order to evaluate and finally optimize the vitrification condition for combustible dry active waste (DAW), dust and gas generation characteristics were investigated for PE, cellulose, and mixed waste Tests were conducted by varying the operation variables such as melter configuration, excess oxygen amount, and waste feeding rate. Results showed that dust generation characteristics were affected by the operation parameters and the melter＇s configuration is the dominant one. For all tested DAWs, dust generation was reduced by increasing the waste feeding rate and the excessive oxygen amount in the melter. Among waste types, dust amount was decreased by the order of mixed wastes, PE, and cellulose. Other parameters such as temperature variation and operation time have also affected the dust generation. The optimum condition for the DAW vitrification was determined as the melter＇s configuration equipped for minimizing the waste dispersion with 20 kg/h of waste feeding rate and 100% of excessive oxygen supply. CO gas concentration in the off-gas was immediately influenced by the combustion state in the melter, but showed similar trend as the dust generation. For the NOx production during the vitrification process, thermal NOx, which is generated from the Post Combustion Chamber (PCC), rather than fuel NOx was assumed to be dominant. The gas cleaning of efficiencies of the PCC, wet scrubber, and Selective Catalytic Reduction system (SCR) were found to be high enough to keep the concentration of pollutants (CO, NOx, SOx, HCI) in the stack below their relevant emission limits.

• Journal of Microbiology and Biotechnology
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• 제17권11호
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• pp.1772-1781
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• 2007

Activated sludge was sequentially adapted to benzene, toluene, and o-xylene (BTX) to study the effects on the change of microbial community. Sludge adapted to BTX separately degraded each by various rates in the following order; toluene>o-xylene>benzene. Degradation rates were increased after exposure to repeated spikes of substrates. Eleven different kinds of sludge were prepared by the combination of BTX sequential adaptations. Clustering analyses (Jaccard, Dice, Pearson, and cosine product coefficient and dimensional analysis of MDS and PCA for DGGE patterns) revealed that acclimated sludge had different features from nonacclimated sludge and could be grouped together according to their prior treatment. Benzene- and xylene-adapted sludge communities showed similar profiles. The sludge profile was affected from the point of the final adaptation substrate regardless of the adaptation sequence followed. In the sludge adapted to 50 ppm toluene, Nitrosomonas sp. and bacterium were dominant, but these bands were not dominant in benzene and benzene after toluene adaptations. Instead, Flexibacter sp. was dominant in these cultures. Dechloromonas sp. was dominant in the culture adapted to 50 ppm benzene. Thauera sp. was the main band in the sludge adapted to 50 ppm xylene, but became vaguer as the xylene concentration was increased. Rather, Flexibacter sp. dominated in the sludge adapted to 100 ppm xylene, although not in the culture adapted to 250 ppm xylene. Two bacterial species dominated in the sludge adapted to 250 ppm xylene, and they also existed in the sludge adapted to 250 ppm xylene after toluene and benzene.

• 한국환경복원기술학회지
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• 제12권6호
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• pp.36-50
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• 2009

To suggest the native plants combination for restoration of the dissected sloping area, the plant communities of thirty seven quadrats from five localities of mid-southern part of Korean peninsula were surveyed from 2007 to 2008. Their flora, vegetation structure, and dominant species based on the importance value were investigated. And the soil characters (pH, moisture content, water holding capacity, and organic matter) of each dominant species were analyzed. Also, germination tests were performed to check the stability of restored native plants using seed chips. As a result, 79 native plants were suggested for the dissected sloping area : 20 trees and subtrees for the upper layer, 18 shrubs and vines for the middle layer, and 41 herbs for the lower layer, taken together their flora, dominant species, vegetation structure, soil condition, germination test, flowering period.

• 한국환경생태학회지
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• 제29권2호
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• pp.221-227
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• 2015

This study was carried out to measure seasonal changes in the community structure and species composition of marobenthos in the intertidal area of Dokdo. The macrobenthos identified during this study was comprised of 36 species: predominately 25 species of mollusks(69.4 %), 6 species of arthropods(16.7 %), 3 species of echinodermata(8.3 %) and 1 species of cnidaria (5.6 %). The number of marobenthos species ranged from 27 in Spring to 33 in Autumn. In terms of the top 10 dominant species, there were 7 species of mollusks and 3 species of arthropods in the this study. After analyzing the bray-curtis similarity, it was divided into two large groups(A, B). Such group classification matched the SIMPROF(Similarity Profile Analysis) and the one-way ANOSIM(Analysis of similarities) analysis.

• 수산해양기술연구
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• 제49권3호
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• pp.238-249
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• 2013

Species composition and seasonal variation of aquatic organism in the marine ranchig ground of Taean, Korea were investigated using shrimp beam trawl from January to December 2010. A total of 99 species, $5,355,816ind./km^2$ and $84,697kg/km^2$ of aquatic organism were collected. Among them, fish include 9 orders 33 families 54 species, crustaceans include 2 orders 15 families 30 species, cephalopods consist of 3 orders 4 families 5 species, gastropods include 2 orders 3 families 4 species, echinoidea sp. include 1 order 2 families 2 species, bivalves were composed of 2 orders 2 families 2 species, and holothuroids include 1 family 1 order. According to the dominants by month, Palaemon gravieri was dominant in January, Cynoglossus joyneri was dominant in February, March, and June, and Hexagrammos otakii was dominant, in July. And Oratosquilla oratoria was dominant echinoidea sp. was dominant in April, May, and August and in September, October, November, and December. Cluster analysis based on species composition of the 38 most common species showed that the species were separated into 5 different groups. Group A was composed of species which were abundant in spring and summer, group B was composed of year-round residents, and group C was composed of species which were abundant in autumn.

• 한국환경복원기술학회지
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• 제12권1호
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• pp.92-100
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• 2009

This study was carried out to investigate vegetation structure and soil properties of Angelica gigas population distributed in Jeombongsan, Bangtaesan, Odaesan, Gyebangsan and Jirisan. From August 2007 until September 2008, 5m${\times}$5m quadrat was established in native area of Angelica gigas in order to record a dominants and coverage, and soil factors at 20 sites. It was found that the altitude in the distributed areas for Angelica gigas population was 710m or more. Angelica gigas population was classified into Parasencio auriculata var. kamtschatical dominant population, Pseudostellaria palibiniana dominant population, Isodon excisus dominant population and typical dominant population. In the site of study, soil pH, electrical conductivity, soil organic matter, available phosphorous, and exchangeable potassium, exchangeable calcium, exchangeable magnesium, exchangeable natrium concentration and total nitrogen were ranged from 5.1~6.2, 0.1~0.79dS/m, 2.21~22.11%, 9.56~37.97mg/kg, 1.85~23.88cmol+/kg, 0.21~1.18cmol+/kg, 1.07~5.09cmol+/kg, 0.04~0.14cmol+/kg and 0.09~1.04% respectively. The Parasencio auriculata var. kamtschatical dominant population was found in area of high altitude and had high slope degree. But Pseudostellaria palibiniana dominant population was found in area of low altitude and low slope degree. Isodon excisus dominant population was found to have higher soil pH and exchangeable potassium concentration than the other dominant population.