• Korean Journal of Construction Engineering and Management
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• v.11 no.1
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• pp.160-169
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• 2010

In domestic public works, there are several problems in the measurement of payments based on the bill of quantity, which doesn't match with the activity progress rate, heavy paper works and complicated procedures. It can be classified formal and simplified method. By using the simplified method, it can be solved many problems by summarizing the procedure, but is not generally used. This paper proposes a payment method by progress measurement for specified activity based on WBS(Work Breakdown Structure) verifying efficiency which reduced cost account and advanced work on payment compare to method of domestic public works using the data about construction of eco-river. This method will be an important contribution on being a base for cost-schedule integrated management which were verified and also improving efficiency on measuring payment.

• Journal of Radiation Protection and Research
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• v.34 no.4
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• pp.170-175
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• 2009

For the emergency radiation monitoring using gamma spectrometry, we should sufficiently survey the background spectra as environmental samples with systematic nuclide identification method. In this study, we obtained the gamma ray energy spectrum using a HPGe gamma spectrometry system from an air sample. And we identified nuclide of the gamma ray energy peaks in the spectrum using two methods -1) Half life calculation and 2) survey for cascade coincidence summing peaks using nuclear data. As the results, we produced the nuclide identification results for the air sample.

• Korean Journal of Remote Sensing
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• v.33 no.5_1
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• pp.587-598
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• 2017

Volcanic ash is a fine particle smaller than 2 mm in diameters. It falls after the volcanic eruption and causes various damages to transportation, manufacturing industry and respiration of living things. Therefore diffusion information of volcanic ash is highly significant for preventing the damages from it. It is advantageous to utilize satellites for observing the widely diffusing volcanic ash. In this study volcanic ash diffusion information about two eruptions of Mt. Sakurajima were calculated using the geostationary satellite, Communication, Ocean and Meteorological Satellite (COMS) Meteorological Imager (MI) and polar-orbiting satellite, Landsat-8 Operational Land Imager (OLI) and the Thermal InfraRed Sensor (TIRS). The direction and velocity of volcanic ash diffusion were analyzed by extracting the volcanic ash pixels from COMS-MI images and the height was retrieved by adjusting the shadow method to Landsat-8 images. In comparison between the results of this study and those of Volcanic Ash Advisories center (VAAC), the volcanic ash tend to diffuse the same direction in both case. However, the diffusion velocity was about four times slower than VAAC information. Moreover, VAAC only provide an ash height while our study produced a variety of height information with respect to ash diffusion. The reason for different results is measured location. In case of VAAC, they produced approximate ash information around volcano crater to rapid response, while we conducted an analysis of the ash diffusion whole area using ash observed images. It is important to measure ash diffusion when large-scale eruption occurs around the Korean peninsula. In this study, it can be used to produce various ash information about the ash diffusion area using different characteristics satellite images.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.3
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• pp.3-10
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• 2010

The development of various spatial information and GIS has led to the research on interpretation of natural phenomena and correlational studies. This study is aimed to analyze the correlation between RUSLE(Revised Universal Soil Loss Equation) around Nakdong River area during the period of 1955 to 2005 and the amount of area change in the islets at the estuary terrain calculated in the study "Change Detection at the Nakdong Estuary Delta using Satellite Image and GIS". For the calculation of RUSLE, The 'Revised-USLE' model, a modified USLE model commonly used in Korea was used. For the rainfall erosion factor to calculate and compare the area of islets, the actual observation data for one year before the observation of satellite image from all observatories across Korea was used. The correlation coefficient between RUSLE and area change of islets was 0.57 for Jinwoo Islet; 0.7 for Sinja Islet; 0.87 for Doyodeung. This results showed that there was a great influence from Doyodeung where the main water way of Nakdong River runs. This study showed that the study using USLE for various fields and through identifying the characteristics of each factor is useful to understand natural phenomenon in practice.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.1
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• pp.37-44
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• 2015

In traditional social network analysis, the betweenness centrality measure has been heavily used to identify the relative importance of nodes. Since the time complexity to calculate the betweenness centrality is very high, however, it is difficult to get it of each node in large-scale social network where there are so many nodes and edges. In our past study, we defined a new type of network, called the expanded ego network, which is built only with each node's local information, i.e., neighbor information of the node's neighbor nodes, and also defined a new measure, called the expanded ego betweenness centrality. In this paper, We propose algorithm that quickly computes expanded ego betweenness centrality by exploiting structural properties of expanded ego network. Through the experiment with virtual network used Barab$\acute{a}$si-Albert network model to represent the generic social network and facebook network to represent actual social network, We show that the node's importance rank based on the expanded ego betweenness centrality has high similarity with that the node's importance rank based on the existing betweenness centrality. We also show that the proposed algorithm computes the expanded ego betweenness centrality quickly than existing algorithm.

• Journal of Korean Society of Transportation
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• v.26 no.2
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• pp.47-56
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• 2008

Two-Lane Highway of Korea is important, Because it has the largeest portion of all roads of Korea. But it has only one lane for one direction. So, If Delays are happened by low-speed vehicles, high-speed vehicles should over-take through the other side of the road. This over-takings can generate the high possibility of traffic accidents and the severity of traffic accidents by over-takings is very high. Because it generates a head-on collision. But the level of Service that indicates the operation states of Two-Lane Highway is defined as a conception that explains the operation conditions of traffic safety etc. Whencalculating the Level of service. It is considered by only delays. So, in this paper, first, this author wants to present the calculation of delay-time by Total-Delay Rate. Second, by multiplying this delay-time by the costs of delays wants to present the method of calulates the total delay costs. Third, to consider the traffic accidents, After predicting the number of traffic accidents, As multipling this by the average of costs of traffic accidents. want to present the method to calculate Total traffic accidents costs. Forth, present the operation costs.

• Journal of the Mineralogical Society of Korea
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• v.17 no.4
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• pp.339-355
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• 2004

Locality of domestic high-Ca limestones can be divided into three districts, i.e., (1) the Jecheon-Danyang area, (2) the Samcheok-Taebaek-Jungsun area, and (3) the Uljin-Andong area, in accordance with their geologic background and type of the deposits. Except for some crystalline limestones from the Jecheon-Danyang area, domestic high-Ca limestones were mostly recrystallized and Ca-enriched by the effects of hydrothermal alteration and/or thermal metamorphism. The lime-stones can be also divided into crystalline limestone type, marble type, micro- and mega-crystalline calcite types on the basis of their composition, crystallinity, and mineral facies. An applied-mineralogical characterization of the high-Ca limestones was done through the systematic analyses and tests for the limestones. The high-Ca limestones from the area (1), which are megascopic ally close to the original limestone in lithology, display lower whiteness, higher contents of CaO (51 ～ 54 wt.%), low crystallinity, and fine-grained texture. Two typical hydrothermal types of the high-Ca limestones from the area (2), i.e., micro- (mostly 0.2～0.3 mm) and mega-crystalline (2～15 em) calcite types, have comparatively higher whiteness and rather variable CaO contents (50～55 wt.%) with exhibiting quite different crystallinity each other. The micro-crystalline calcite type is especially dominant in this area, and has comparatively uniform crystallinity and homogeneous composition. Compared to these limestones, the high-Ca limestones from the area (3) show remarkable differences in grade and quality according to their types of deposit and occurrence. Based on these mineral characters and chemical composition, a possible scheme for industrial uses of the domestic high-Ca limestones was suggested.

• Journal of the Korean Society for information Management
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• v.4 no.1
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• pp.47-86
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• 1987

The purpose of this study is to present an effective automatic indexing method of Korean texts based on statistical criteria. Titles and abstracts of the 299 documents randomly selected from ETRI's DOCUMENT data base are used as the experimental data in this study the experimental data is divided into 4 word groups and these 4 word groups are respectively analyzed and evaluated by applying 3 automatic indexing methods including Transition Phenomena of Word Occurrence, Inverse Document Frequency Weighting Technique, and Term Discrimination Weighting Technique.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.209.1-209.1
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• 2010

본 연구에서는 울산산업단지 및 인근 지자체에서 발생하는 가연성폐기물 중 화학산업의 원료로 공급하기 위하여 활용가능한 폐기물들을 선정하고, 선정된 폐기물들의 안정적인 수급을 위하여 자원순환네트워크를 구축하는 연구를 수행하였다. 활용가능한 폐기물을 선정하기 위하여 먼저 선정기준을 설정하고, 울산지역에서 발생하는 가연성폐기물의 발생 및 처리현황, 폐기물의 특성 등을 고려하여 활용가능량을 산출하였다. 또한 이들 폐기물을 지속적으로 수급하기 위하여 울산산업단지 기업과 지자체, 합성가스 이용 업체 등으로 구성된 컨소시움을 구축하는 방안을 제안하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.177-179
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• 2010

해상 교통 안전을 향상하고 선박 사고를 사전에 방지하기 위해서 선박 사고에 대한 위험도 평가가 선행되어야한다. 선박의 위험도에 대한 개념은 여러 가지로 정의되고 있는데, 본 연구에서는 데이터베이스를 기반으로 사고 발생 가능성과 피해를 예측하여 위험지수를 산출하는 위험도 평가 방법에 대해 고찰해보았다. 사고 발생에 따른 인명 손실과 오염 규모 등의 피해 결과에 따라 고위험 선박이 선별될 수 있으며, 선박의 위험도의 정량적 기준은 사고 발생 확률과 사고 결과의 심각성으로 결정된다. 대량의 데이터베이스를 통계적으로 분석하여 위험도를 도출하기 위해서는 데이터베이스의 확보 뿐 아니라 데이터베이스의 구조화가 기반이 되어야 한다. 또한 과거 자료에 입각한 데이터베이스만으로 위험도를 평가할 경우 미래 사고 발생을 예측하는데 한계가 있을 수 있으므로 데이터베이스의 보강 및 보정이 필요하다.