• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.590-592
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• 2003

The presence of congestion in transmission system can reduce the market size and split bulk system into smaller system. Consequently, this creates the problem concerining Local Market Power and can be main reason for the inclose of practical market price. In this paper, a range of indices have been derived to quantify the degree of local market power through statistical analysis in the uniform pricing market. Application of the indices has been illustrated using the electricity market in Korea. The indices proposed in this paper seem to be effectively applied in electricity market under uniform pricing scheme.

• Clinical Endoscopy
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• v.55 no.4
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• pp.480-488
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• 2022

Endoscopy is vital for diagnosis, assessing treatment response, monitoring and surveillance in patients with inflammatory bowel disease (IBD). With the growing importance of mucosal healing as a treatment target, the assessment of disease activity by endoscopy has been accepted as the standard of care for IBD. There are many endoscopic activity indices for facilitating standardized reporting of the gastrointestinal mucosal appearance in IBD, and each index has its strengths and weaknesses. Although most endoscopic indices do not have a clear-cut validated definition, endoscopic remission or mucosal healing is associated with favorable outcomes, such as a decreased risk of relapse. Therefore, experts suggest utilizing endoscopic indices for monitoring disease activity and optimizing treatment to achieve remission. However, the regular monitoring of endoscopic activity is limited in practice owing to several factors, such as the complexity of the procedure, time consumption, inter-observer variability, and lack of a clear-cut, validated definition of endoscopic response or remission. Although experts have recently suggested consensus-based definitions, further studies are needed to define the values that can predict long-term outcomes.

• Atmosphere
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• v.25 no.2
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• pp.323-337
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• 2015

This study explores the 6-month lead prediction skill of several climate indices that influence on East Asian climate in the GloSea5 hindcast experiment. Such indices include Nino3.4, Indian Ocean Diploe (IOD), Arctic Oscillation (AO), various summer and winter Asian monsoon indices. The model's prediction skill of these indices is evaluated by computing the anomaly correlation coefficient (ACC) and mean squared skill score (MSSS) for ensemble mean values over the period of 1996~2009. In general, climate indices that have low seasonal variability are predicted well. For example, in terms of ACC, Nino3.4 index is predicted well at least 6 months in advance. The IOD index is also well predicted in late summer and autumn. This contrasts with the prediction skill of AO index which shows essentially no skill beyond a few months except in February and August. Both summer and winter Asian monsoon indices are also poorly predicted. An exception is the Western North Pacific Monsoon (WNPM) index that exhibits a prediction skill up to 4- to 6-month lead time. However, when MSSS is considered, most climate indices, except Nino3.4 index, show a negligible prediction skill, indicating that conditional bias is significant in the model. These results are only weakly sensitive to the number of ensemble members.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.2
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• pp.69-79
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• 2008

Landscape indices are effective tools to explain the spatial structure and patterns of ecological landscape including area/density, shape, core area, isolation/proximity, contagion/interspersion, and connectivity. More than 100 indices have been developed and an increasing amount of research explains changes in urban spaces using the indices. However, landscape indices have a high level of sensitivity to the scale of analysis - grain size and extent. If the scale sensitivity of indices is not considered, the research may produce inaccurate results. This study examines the scale sensitivity of landscape indices to find relatively stable indices in the complex geographical features of Korea. The scale sensitivity was analyzed using 20 categories of grain size and 41 categories of extent change. Landsat TM and ETM+ images of five years - 1985, 1991, 1996, 2000 and 2003 - were used, and 54 class level indices mounted on the FRAGSTATS program were examined. The results are as follows: First, according to the analysis of the scale sensitivity, 19 out of 54 class level indices were found to be stable to scale change. Second, the scale sensitivity was closely related to the green area ratio, and the typical threshold of change was $40{\sim}50%$. Third, among the 16 indices which were frequently used in the research in Korea, only 6 indices were relatively stable to the scale change. These results can be an effective basis for the selection of indices in the landscape ecology research in Korea.

• KIEE International Transactions on Power Engineering
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• v.3A no.3
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• pp.155-160
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• 2003

Reliability assessment of power systems has been an important topic for the past several decades. It is becoming even more important nowadays as the power market moves toward a new competitive environment. This paper deals with two topics on reliability assessment. The first is how to select probability distributions and determine their parameters to model the probabilistic events in a power system. The second is how to consider restorative actions in the assessment, which directly influence reliability indices. This paper proposes simple but convincing alternative solutions on the two topics. In the case study, this paper shows the influences of the probability distributions that are used in power system modeling.

• Fire Science and Engineering
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• v.15 no.4
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• pp.64-70
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• 2001

This study suggests fire, explosion safety assessment items and risk assessment technique for underground shopping malls by extracting dangerous elements in the management stage through examination of related accidents, documents and present conditions. This will also suggest importance of seven items to be key indices for a counterplan by classifying characteristics and trends of the large scale, depth and complexity of underground shopping malls.

• Journal of Korean Society of Rural Planning
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• v.10 no.2 s.23
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• pp.43-49
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• 2004

According to the growing concerns of the public with efficiency and effects of regional policies, their assessment works have become an important issue. Up to now, several studies have been carried out on economic effects of policies using conventional cost/benefit analysis, while there have been few studies on assessment of amenity oriented policies. From the above consideration, this study tried to develop An Annual Expenditure Assessment Model (AEAM) for amenity-oriented policy-making in rural area. As a pre-work for model development, the hierarchical indices system for rural development and the classification system of expenditure were designed. Being based on high significant relationship between rural amenities and local government expenditure, a linear optimization model for maximization of regional amenity was constructed. Through a case study of Sunchang-gun, Chonbuk-province, the model applicability was ascertained.

• Journal of Korean Institute of Industrial Engineers
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• v.40 no.2
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• pp.240-249
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• 2014

This study aims to identify an assessment system based on multiple patent indices that can predict the likelihood of success in the commercialization of a patented technology in advance. In addition, we examine the effectiveness of our predictive model in identifying valuable technologies early on. We analyzed 3,063 secondary battery technologies patented in the US over the past 10 years. Our analysis identified 22 of the 25 most promising patented technologies, corresponding with the top 50% of industry-patented technologies that directly and indirectly succeeded in commercialization. These results support our claim that it is possible to identify attributes for the assessment of patent commercial potential to a significant degree. Our system presents a useful assessment index in the forecasting and determination of potential commercial success of patented technologies.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.1
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• pp.41-53
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• 2015

This study was performed to assess the level of ozone risk for wheat in the central region of the Korean Peninsula by using two ozone indices, the ozone-concentration based index (AOT40) and the ozone-flux based index ($AF_{st}Y$), and to analyze the relationship between the two indices. In the present study for $AF_{st}Y$ calculation, the Monin-Obukhov length was estimated using the Pasquill stability class which was determined from routine meteorological data such as wind speed, solar radiation and cloudiness. The AOT40 and $AF_{st}6$ indices were calculated for wheat at 3 sites in the central region of the Korean Peninsula during a period of 3 months from April 1 to June 30, 2006. It should be noted that the estimation of ozone index $AF_{st}6$ in this study was performed under several assumptions. The results for both indices, AOT40 and $AF_{st}6$, showed that agricultural crops could be seriously damaged by ozone in the local region of the Korean Peninsula.

• Steel and Composite Structures
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• v.19 no.4
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• pp.811-827
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• 2015

This paper presents a probabilistic investigation of American and European specifications (i.e., AISC and Eurocode 4) for square concrete-filled steel tubular (CFT) stub columns. The study is based on experimental results of 100 axially loaded square CFT stub columns from the literature. By comparing experimental results for ultimate loads with code-predicted column resistances, the uncertainty of resistance models is analyzed and it is found that the modeling uncertainty parameter can be described using random variables of lognormal distribution. Reliability analyses were then performed with/without considering the modeling uncertainty parameter and the safety level of the specifications is evaluated in terms of sufficient and uniform reliability criteria. Results show that: (1) The AISC design code provided slightly conservative results of square CFT stub columns with reliability indices larger than 3.25 and the uniformness of reliability indices is no better because of the quality of the resistance model; (2) The uniformness of reliability indices for the Eurocode 4 was better than that of AISC, but the reliability indices of columns designed following the Eurocode 4 were found to be quite below the target reliability level of Eurocode 4.