• Journal of Korea Technology Innovation Society
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• v.9 no.4
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• pp.842-864
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• 2006

This paper deals with an empirical study to statistically analyse various financial performances of the selected IPO firms using their investments on research and development(R&D) as an independent variables. The major results of statistical analyses have come up with the followings: 1) The regression analyses for change in average annual total market stock value/total assets over that of R&D expenditures showed the positive relationship, However, those of sales volume and net assets per share showed negative without statistical significances. 2) The statistical analyses in effect of the 3-year average total market stock value/total assets over the 3-year average R&D expenditures resulted in the positive coefficients what are statistically significant at 95% level. 3) Another statistical analysis showed that the financial performances of the IPO finns with deferred assets were better than those of the firms without them. In sum, the degree of investment on R&D by the IPO firms are expected to positively affect their financial performances except the Finns without having proper original technologies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3260-3269
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• 2014

The construction industry has strong ties with other industries, and so construction company insolvency also has a strong influence on other industries. Prediction models addressing the insolvency of construction company have been well studied. Although factors contributing to insolvency must precede those of predictions of insolvency, studies on these contributing factors are limited. The purpose of this study is to analyze the influence of changes in the housing market on construction company insolvency by using the Vector Error Correction Model. Construction companies were divided into two groups, and the expected default frequency(EDF), which indicates insolvency of each company was measured through the KMV model. The results verified that 10 largest construction companies were in a better financial condition compared to relatively smaller construction companies. As a result of conducting impulse response analysis, the EDF of large companies was found to be more sensitive to housing market change than that of small- and medium-sized construction companies.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.193-193
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• 2011

국제기구인 정부간 기후변화협의체(Intergovernmental Panel on Climate Change, 이하 IPCC)에서는 기후변화가 기온 상승에 따른 증발산량의 증가, 강수량 및 유출량의 시공간적 분포의 변동 등을 초래하여 수자원의 효율적 관리 및 안정적인 공급에 어려움을 증대시킬 것으로 전망하였다. 또한 IPCC 4차 보고서에 따르면 21세기말 지구의 평균기온은 현재보다 최대 $6.3^{\circ}C$정도 더 상승할 것으로 전망하였다. 전구평균기온이 $3.0^{\circ}C$ 증가할 경우 아시아에서만 연간 700만 명이상이 홍수피해 위기에 직면할 것으로 예상되고 있다. 국내의 경우 기온은 전구평균기온에 비해 2배 이상 높은 $1.5^{\circ}C$ 정도 상승하였으며, 최근 50년간의 강우일수는 감소한 반면 일강수량이 80mm 이상인 호우일수의 발생빈도는 증가되고 있다고 보고되었다. 또한 최근의 물수지 해석과 관련하여 거시적인 관점에서 기온 및 강수량 증가에 따른 물순환 과정을 모의하고, 농업용수, 댐건설, 도시화, 토지이용의 변화 등 인위적인 환경 변화 및 기후변화에 따른 유출량의 변화를 정량화하려는 연구들이 수행되고 있다(한국건설기술원, 2007). 이를 위하여 단기적이 아니라 장기적인 측면에서 유출분석을 할 필요가 있으나, 현재까지 보유하고 있는 실측 자료의 한계 및 이러한 조사를 위해 요구되는 시간 및 비용의 한계 때문에, 유출해석 모형을 주로 이용하고 있다. 본 연구에서는 장래 건설예정인 미계측 호소의 유량과 수질을 모의하기 위하여 하천, 하구, 호소 및 해역에 고루 적용할 수 있는 3차원 수리 동력학적인 모델인 EFDC 모형과 시간의 변화에 따른 수질을 모의하는데 가장 널리 이용하는 WASP 모형을 도입하였다. 향후, 내성천의 영주댐 건설과 같은 큰 변화가 발생하였을 기후 변화의 영향을 파악하기 위하여 EFDC와 WASP모형을 이용하여 대상유역에 대한 유출량과 수온의 변화를 통하여 A2, B1 기후변화 시나리오별로 2020년, 2050년, 2080년의 수질(BOD, TN, TP)변화를 분석하여 보았다. 연구의 결과는 다음과 같이 나타났다. EFDC 및 WASP 모형의 연계를 통한 기후 변화 시나리오에 따른 미래의 저수지 수질예측 모의를 수행한 결과, BOD, TN, TP 등 수질농도 변화는 2020년에서 2080년도로 갈수록 BOD, TN 다소 증가하는 경향을 나타내었고, TP농도는 감소하였다. 시나리오별 변화 특성은 TN, TP 농도는 A2 시나리오가 다소 높고, BOD 농도는 B1 시나리오가 A2보다 높은 것으로 나타났다. EFDC와 WASP을 이용하여 미계측 호소에 대한 기후변화 시나리오별로 적용하여 수질변화를 예측하여 보았는데, 향후 기후변화에 따른 기온, 유량변화와 수질 항목간의 상간관계 정립 및 수질 모의의 불확실성 등에 대한 추가 연구가 필요할 것으로 판단된다.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.3
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• pp.351-365
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• 2019

This study aims to predict the changes in population distribution in Korea by considering spatio-temporal characteristics of major migration reasons. For the purpose, we analyze the spatio-temporal characteristics of each major migration reason(such as job, family, housing, and education) and estimate the transition probability, respectively. By appling Markov chain model processes with the ChapmanKolmogorov equation based on the transition probability, we predict the changes in the population distribution for the next six years. As the results, we found that there were differences of population changes by regions, while there were geographic movements into metropolitan areas and cities in general. The methodologies and the results presented in this study can be utilized for the provision of customized planning policies. In the long run, it can be used as a basis for planning and enforcing regionally tailored policies that strengthen inflow factors and improve outflow factors based on the trends of population inflow and outflow by region by movement factors as well as identify the patterns of population inflow and outflow in each region and predict future population volatility.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.492-497
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• 2011

Soil management for orchard depends on the effects of soil microbial activities. The present study evaluated the soil microbial community of 25 orchard in Gyeongnam Province by fatty acid methyl ester (FAME) method. The average concentrations in the orchard soils were $332nmol\;g^{-1}$ of total FAMEs, $94nmol\;g^{-1}$ of bacteria, $46nmol\;g^{-1}$ of Gram-negative bacteria, $42nmol\;g^{-1}$ of Gram-positive bacteria, $4.8nmol\;g^{-1}$ of actinomycetes, $54nmol\;g^{-1}$ of fungi, and $9.1nmol\;g^{-1}$ of arbuscular mycorrhizal fungi. In addition, sandy loam soils had significantly low ratio of cy19:0 to 18:$1{\omega}7c$ compared with that of loam soils (p<0.05), indicating that microbial stress decreased. The average soil microbial communities in the orchard soils were 28.1% of bacteria, 15.9% of fungi, 13.6% of Gram-negative bacteria, 12.5% of Gram-positive bacteria, 2.8% of arbuscular mycorrhizal fungi, and 1.4% of actinomycetes. The soil microbial community of Gram-negative bacteria in peach cultivating soils was significantly higher than that of pear cultivating soils (p<0.05).

• Journal of Korea Port Economic Association
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• v.37 no.1
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• pp.71-85
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• 2021

A variety of methods have been proposed through a number of studies on sophisticated demand forecasting models that can reduce logistics costs. These studies mainly determine the applicable demand forecasting model based on the pattern of demand quantity and try to judge the accuracy of the model through statistical verification. Demand patterns can be broadly divided into regularity and irregularity. A regular pattern means that the order is regular and the order quantity is constant. In this case, predicting demand mainly through regression model or time series model was used. However, this demand is called "intermittent demand" when irregular and fluctuating amount of order quantity is large, and there is a high possibility of error in demand prediction with existing regression model or time series model. For items that show intermittent demand, predicting demand is mainly done using Croston or HOLTS. In this study, we analyze the demand patterns of various items of air cargo with intermittent patterns and apply the most appropriate model to predict and verify the demand. In this process, intermittent optimal demand forecasting model of air cargo is proposed by analyzing the fit of various models of air cargo by item and region.

• Ecology and Resilient Infrastructure
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• v.6 no.1
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• pp.23-33
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• 2019

Naeseong Stream is a sand-bed river that flows through the northern area of Gyeongbuk province. It is characterized by dynamic sandy bedforms developed in response to the seasonal hydrological fluctuation and by its unique riverine landscape called "white river." However, changes including construction of Yeongju Dam from 2010 and the extensive vegetation establishment around 2015 occurred along the Naeseong Stream. This paper aims to analyze climate, hydrology, and water quality as factors and to examine the possibility of channel changes accordingly. The second least precipitation during the last 60 years happened in 2015, which led to the lowest peak discharge in 50 years. The sediment characteristics of Naeseong Stream were not significantly different along the upstream and downstream reaches, but it was confirmed that annual minimum water level of the stream decreased continuously regardless of the dam construction. This suggests that intermittent drought and change in water quality are likely to provide favorable conditions for riparian vegetation establishment and the resulting physical changes have affected riverbed degradation. Therefore, it is necessary to conduct diversified monitoring in connection with river vegetation change in order to analyze the causes of river changes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4D
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• pp.361-368
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• 2010

It is general that mostly congested sections of national backbone networks have been improved based on the national network expansion plan. However, in case of intermodal terminals which are origins of logistics, it is still so congested that travel time between origin and destination is long. Therefore, intermodal transportation systems plan of major intermodal terminals for the intermodal connector networks between intermodal terminal and national backbone network or intermodal terminal was established. With the limitation of priority methodology applying to intermodal connector facility under existing methodology, this study suggests an improved priority methodology. This study includes characteristics of terminal on the hierarchical structure and assessment list, but it does not concentrate on the specific terminal type through survey. To avoid a certain concentration, budget constraint for each terminal type was considered ahead of priority. Finally priority methodology was developed with two-step assessment under consideration that specific terminal is not involved in intermodal connector facility project. As a result of calculating weights by survey, effects such as d/c and accessibility fluctuations index through project implementation gain high weight, and degree of region underdevelopment gets next. Although the methodology in this study could not yields the priority by assessment list, it will be useful for setting the direction on policy related to intermodal connector facility projects.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.4
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• pp.213-223
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• 2011

The status and changes of water quality of national fishing harbors and designated ports in East Coast of Korea were analyzed to support establishment effective water environmental management. COD (Chemical Oxygen Demand) concentration was satisfied to designated water quality criteria in most areas, but TN (Total Nitrogen) and TP (Total Phosphorus) exceeded the criteria frequently. Also, peak concentration was summer in COD and SS (Suspended Solid), but winter in TP. Eutrophication index of Ganggu and Pohang (old) area were the highest. Pollution index by function of COD, TN, and TP of Ganggu, Pohang, Jumunjin, and Guryongpo was high with gradual increasing recently, on the contrary, that of Samcheok, Imwon, and Chuksan was decreased. Pollution index involving multi-indictors relation to organics and inorganics was necessary for water quality assessment. Designated water quality criteria needed to be improved because the criteria of Jukbyun and Chuksan was applied more strictly compared to the other regions although without difference of environmental characteristics. Furthermore, the criteria notified lately needed to be related to management pollutants from land-based sources. The continuous diagnosis and monitoring on sediment quality within the study area were necessary for prevention of water pollution and eco-friendly disposal of dredged sediment. Especially, monitoring of Designated Ports was implemented partially, however monitoring ratio of National Fishing Har-bors was 7% to whole part. Therefore, systematic and integrated environmental monitoring for ports and harbors with charge of national management was reestablished by strengthening and securing a legal basis.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.3
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• pp.229-234
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• 2008

Hepatobiliary scintigraphy is very sensitivity of hepatic cell and gallbladder, biliary track atresia and biliary leakage. however, Hepatobiliary scan of biliary leakage diagnosis was separated determine biliary leakage and bowl drainage bile-juice. The object of this study will determine biliary leakage and bowl drainage bile-juice to hepatobiliary scintigraphy both decubitus position in bile leakage patients. Material & Methode: 31 patients (meal 14, Femeal 17), $51.1{\pm}14.4$ years. dynamic scan acquisition 60 farme for 60 minute on supine position. and delay scan was 2 hrs, 4 hrs, 24 hrs for 5 minute on supine, both decubitus position. Both decubitus position scan was kept for 5 minutes. Efficient of Hepatobiliary Scintigraphy both decubitus position in bile leakage patients was compared leakage size, density, image of supine position and both decubitus position. Results: 23 patients for 31 bile leakage patients was checked up function image or delay image, and 8 patients was checked up bile leakage on both decubitus. anatomical leakage location was supine position very well, but both decubitus position was separated bile leakage and moving bile-juice in bowl. also, uptake (counts/pixel) average of roi and bkg was supine 5.02, left decubitus 2.08, right decubitus 2.68. No. pixels of supine ROI counted 1.91 times than left decubitus, 1.05 times than right decubitus. Conclusion: 31 patient both decubitus position, but decubitus position was separated bile juice movement in bowl leakage location. also, It was compared ROI/BKG ratio and ROI No. pixels of supine, both decubitus in 38.5% patients. And No. pixels of supine position was large 19%, 5% than left decubitus, right decubitus, And density was in low 60%, 50% than left decubitus, right decubitus. It was mean bile leakage of ROI. so, If Hepatobiliary Scintigraphy was additional both decubitus position scan in bile leakage patients, this study will be more valuable in diagnosis of bile leakage.