• Korean Journal of Construction Engineering and Management
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• v.24 no.3
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• pp.42-51
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• 2023

Freeze and burst water meter in winter causes many social costs, such as meter replacement cost, inability of water use, and secondary damage by freezing water. The government is making efforts to modernize local waterworks, and in particular, is promoting SWM(Smart Water Management) project nationwide. In this study suggests a new freeze risk notification information service based on the temperature by IoT sensor inside the water meter box rather than outside temperature. In addition, in order to overcome the quantitative and regional limitation of IoT temperature sensors installed nationwide, and AI based temperature prediction model was developed that predicts the temperature inside water meter boxes based on data acquired from IoT temperature sensors and other information. Through the prediction model optimization process, a nationwide water meter freezing risk information service was convinced.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.487-487
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• 2022

하천의 측방 이동은 충적 하도가 횡방향으로 이동하는 것으로 홍수에 의한 강턱 및 고수부지 침식 및 만곡사주 퇴적을 동반하는 지형형성작용이나 국내에서는 관련 연구가 적은 실정이다. 본 연구에서는 수 년간 인간의 교란이 없는 상태로 유지된 하천 구간인 내성천 고평 지점을 대상으로 항공사진, 드론 영상 및 DEM 자료를 이용하여 2015-2021년 사이에 발생한 하천의 측방 이동에 대한 계량적 분석을 실시하였다. 고평 지점의 내성천 하도는 시간에 따라 저수로 하폭이 증가하면서 공격사면이 횡방향 및 하류 방향으로 이동하였으며, 이 과정에서 사행도는 1.07에서 1.12로 소폭 증가하였다. 10개 단면에서 측방 이동은 2018년 5월과 11월 사이, 2020년 5월과 9월 사이에 발생하였으며, 공격사면 쪽으로 최대 60 m 이상 이동하였다. 동일한 두 시기에 측방 이동에 따른 홍수터의 침식 면적은 각각 5,572 m², 6,571 m²였으며, 2015-2021년 전체로는 16,000 m²에 달하였다. 이는 대상 구간의 2015년 기준 전체 저수로 면적의 약 20%에 해당한다. 단면에서의 변화는 측방 이동과 함께 저수시 하상의 저하가 함께 관찰되어 6년간 0.5-1.0m 저하되었다. 대상 구역 내에서의 침식량은 30,636 m³이며, 퇴적량은 14,904 m³으로 순침식량은 15,831 m³으로 나타났으며, 이는 2015년 기준 저수로 면적이 평균 51.7 cm 하강한 정도에 해당한다. 본 연구의 결과는 국내 충적 하천에서 홍수에 의해 하도의 측방 이동이 활발하게 발생하였음을 보여주며, 하천 관리 및 유사 분석에 있어서 측방 이동에 대한 고려가 필요함을 보여준다.

• The Journal of Society for e-Business Studies
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• v.25 no.3
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• pp.63-76
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• 2020

In the 21st century, informatization is playing a huge role in people's lives. Korea is experiencing the tremendous changes in social structure and lifestyle caused by informatization. This paper focuses on economic phenomena rather than discussion on social structure due to informatization. We check whether the Goodwin model, which can comprehensively express economic growth, economic cycle, and income distribution, is suitable for the Korean economy in the information age. This model is simulated by selecting a quantitative economic methodology that estimates coefficients from time series data of the Korean economy. The simulation results confirmed that the Goodwin model is suitable for analyzing functional income distribution in Korea.

• Journal of the Korean Society for information Management
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• v.31 no.3
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• pp.293-311
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• 2014

This study explored the research trends on Twitter in Korea by informetric methods. All 539 articles on Twitter published from 2009 to the April of 2014 were obtained from the KCI. Only article titles, abstracts, and keywords by authors were used in analysis. Academic journals in many different disciplines where Twitter articles were produced were analysed by profiling, and then, the subject areas of researches on Twitter were analysed by co-word analysis. The results of this study showed that Twitter-related papers were published in as many as 53 disciplines with journalism, business administration, and computer science to be core fields. It was also found that the core subject areas are political issues and business.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.181-181
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• 2011

최근 정부에서는 자연형 하천정비사업을 추진하고 있으나 정비방안이나 정비공법을 선정하기 위한 하천의 환경특성분석은 기술적 관점에서 주관적으로 이루어지고 있는 실정이다. 경제적이고 효율적인 하천정비를 위해서는 객관적이고 계량적인 지표를 이용한 구간별 하천환경 특성분석이 필요하다. 그러나, 적절한 구간구분기준과 하천환경특성을 분석하기 위한 합리적 판단방법이 마련돼 있지 않다. 따라서 본 연구에서는 하천환경지수라는 계량적 지표를 개발하여 국가하천을 대상으로 구간별 하천환경특성을 분석하였다. 하천환경지수는 하천의 형태적 특성, 생태 환경적 특성, 이 치수적 특성, 사회 문화적 특성과 관련된 여러 인자들 중에서 인자선정원칙과 자료의 구득성을 고려하여 선정된 16개 인자로 구성하였고, 하천환경지수의 적용가능성을 검토하기 위하여 합리적인 하천구간 구분기준도 제시하였다. 아울러 국가하천에 대한 GIS 정보와 선정된 하천환경지수 및 구간구분기준을 적용하여 국가하천에 대한 하천환경특성을 분석하였다. 본 연구의 결과는 구간별 하천환경 정비사업 우선순위 및 정비방안을 설정하고자 할 때 적용될 수 있을 것이다.

• Journal of the Korean Society for information Management
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• v.40 no.4
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• pp.279-306
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• 2023

This study analyzed bibliographic attributes related to the selection and use of reading materials based on data on books borrowed or purchased together in order to understand the properties of reading materials that have complex user needs from various perspectives. As a result of creating co-occurrence matrices of bibliographic attribute terms by dividing them into 26 sub-attribute units related to KDC main class, target reader, and user age, and performing network analyses, the details and prominent mediating role of bibliographic attributes of reading materials were identified. The results of this study will be helpful in designing facets of reading information systems, including library OPAC, in the future.

• Journal of Korea Port Economic Association
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• v.24 no.3
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• pp.57-77
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• 2008

The aim of this paper is to make projection of the demand for export loaded container throughput originating at Incheon port in Korea over the period in question. Systematic analysis is used as a forecasting method instead of quantitative analysis. First of all, the method explores coincident indicators which may reflect the square measure of neighboring industrial complexes which originate/destinate general cargo in export traffic trends. It is noted that in terms of the export loaded container throughput, per unit production scale is intermediated transforming from square measure of production facilities to freight weight in Korea. Consequently, the future progress of the volume can be anticipated relying on the development schemes for developing square measure out of the total square of the industrial complexes. Thus, moving-into percentage of the industrial complexes, percentage of business categories, percentage of capacity and percentage of passing through via Incheon port are adopted and the future traffic demand is projected taking advantage of them.

• International Journal of Highway Engineering
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• v.9 no.3
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• pp.63-74
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• 2007

Traffic information provision plays an important role in increasing the efficiency of network operation and in providing convenience for roadway users. As a typical device for disseminating real-time traffic information for collective general public, VMS is a prevalent device nowadays and it is being expanded. However, the actual monetary value of traffic information is not quantified up to now. The previous studies regarding VMS traffic information are mainly focused on the behavioral aspects of road users such as departure time and route choices under traffic information provision conditions. This paper tried to estimate the monetary value of VMS traffic information using discrete choice theory and logit model through the stated preference study(SP). The methodological framework adopted in this paper can also be used in evaluating the monetary value of other traffic information providers including PDA, CNS, and mobile phone.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.815-824
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• 2013

Traditional Pearson chi-squared test is not appropriate for the data collected by the complex sample design. When one uses the traditional Pearson chi-squared test to the complex sample categorical data, it may give wrong test results, and the error may occur not only due to the biased variance estimators but also due to the biased point estimators of cell proportions. In this study, the design based consistent Wald test statistics was derived for k-population homogeneity test, and the traditional Pearson chi-squared test statistics was partitioned into three parts according to the causes of error; the error due to the bias of variance estimator, the error due to the bias of cell proportion estimator, and the unseparated error due to the both bias of variance estimator and bias of cell proportion estimator. An analysis was conducted for empirical results of the relative size of each error component to the Pearson chi-squared test statistics. The second year data from the fourth Korean national health and nutrition examination survey (KNHANES, IV-2) was used for the analysis. The empirical results show that the relative size of error from the bias of variance estimator was relatively larger than the size of error from the bias of cell proportion estimator, but its degrees were different variable by variable.

• The Korean Journal of Applied Statistics
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• v.10 no.1
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• pp.105-119
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• 1997

Barnwal and Paul(1988) derived the likelihood ratio statistic and $C(\alpha)$ statistic for testing the equality of the means of several groups of count data in the presence of a common dispersion parameter. These tests are generalized to be applicable without the restriction of a common dispersion parameter. And the assumed model of data is also extended from negative binomial to double exponential Poisson model. Monte Carlo simulations show the superiority of $C(\alpha)$ statistic based on the double exponential Poisson family which has a very simple form and requires estimates of the parameters only under the null hypothesis.