• Radiation Oncology Journal
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• v.37 no.1
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• pp.13-21
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• 2019

Purpose: Glioblastoma (GBM) carries a high propensity for in-field failure despite trimodality management. Past studies have failed to show outcome improvements with dose-escalation. Herein, we examined trends and outcomes associated with dose-escalation for GBM. Materials and Methods: The National Cancer Database was queried for GBM patients who underwent surgical resection and external-beam radiation with chemotherapy. Patients were excluded if doses were less than 59.4 Gy; dose-escalation referred to doses ≥66 Gy. Odds ratios identified predictors of dose-escalation. Univariable and multivariable Cox regressions determined potential predictors of overall survival (OS). Propensity-adjusted multivariable analysis better accounted for indication biases. Results: Of 33,991 patients, 1,223 patients received dose-escalation. Median dose in the escalation group was 70 Gy (range, 66 to 89.4 Gy). The use of dose-escalation decreased from 8% in 2004 to 2% in 2014. Predictors of escalated dose were African American race, lower comorbidity score, treatment at community centers, decreased income, and more remote treatment year. Median OS was 16.2 months and 15.8 months for the standard and dose-escalated cohorts, respectively (p = 0.35). On multivariable analysis, age >60 years, higher comorbidity score, treatment at community centers, decreased education, lower income, government insurance, Caucasian race, male gender, and more remote year of treatment predicted for worse OS. On propensity-adjusted multivariable analysis, age >60 years, distance from center >12 miles, decreased education, government insurance, and male gender predicted for worse outcome. Conclusion: Dose-escalated radiotherapy for GBM has decreased over time across the United States, in concordance with guidelines and the available evidence. Similarly, this large study did not discern survival improvements with dose-escalation.

• Journal of the Korean Society for Railway
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• v.16 no.2
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• pp.144-150
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• 2013

This paper presents an analysis of door design for the Ui LRT based on experiments to predict doorway flow-time and their analyses results. A similar railway vehicle (from Gimhae LRT) and operational conditions are utilized to assess the doorway flow-time through repetitive experiments. Design of the experiments consists of four scenarios, and the experiments are repeated 39 times in total. We use the results of the experiments to verify the design of doors of Ui LRT (e.g. the required number of doors and their width). Various statistical analyses are carried out for the flow-time with respect to the number of boarding/alighting passengers. We make three category levels of boarding/alighting passengers, and analyze the mean and variance for each category, and then carry out One-Way ANOVA to analyze how the number of boarding/alighting and onboard passengers impact flow-time. The results of this paper can be used for making decisions about doors of the LRT vehicle.

• Journal of National Security and Military Science
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• s.8
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• pp.271-309
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• 2010

The main theme of this study is about North Korea's contemporary military strategy which remained a blind spot in the 21st century. Indeed, Pyongyang's contemporary military strategy is evolved from the logic of War. On the basis of this logic, this study examined North Korea's contemporary military strategy with three analytical frameworks. The first is the discovery of Clausewitz's dictums and application of the Trinitarian analysis on the Korean cases. During the course of applying Clausewitzian main dictum--War as continuation of politics, the methodological analysis on war played a important role generalizing the pattern and matrix of North Korea's strategic thinking and military strategy. In particular, Clausewitz's Trinitarian framework on war -Government (reason), Army (chance), People (passion)- was a universal framework to scrutinize the North Korean missile and nuclear strategy. The second is about the matrix of North Korea's military strategy, The study suggested the genealogical feature of Pyongyang's military strategy. In principle, the dictum of 'Military-First Politics' 1S the combination of the political philosophy, Chuch'e (self-reliance) of Kim Il Sung and Kin Jong Il reflected in the military readiness. As a result this analysis was able to equate Clausewitz's dictums to explain Pyongyang's idea of the nature of war in that North Korea's military strategy is the central instrument of delivery to achieve political objectives. The third is about the theoretical encounter of 'Clausewitz's Wonderful Trinity' and 'Remarkable Trinity on North Korea's contemporary strategy'. On the basis, three elements are connected to one of three groups in society; the people, the military, and the government. In order to apply the Clausewitz's Trinitarian analysis into Kim Jong Il's 'Military-First' strategy, two case studies (Missile and Nuclear strategy) were examined. The finding of this study is that Clausewitzian dictum in the 19th century is still valid in the 21st century as it provided plausible theoretical framework to explain the North Korean contemporary military strategy with a reminder that the nature and logic of war are fixed in the socially constructed state.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1029-1036
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• 2006

South and North Koreas are putting forth efforts to overcome the distrust and animosity of the past 50 years to open an era of harmony and cooperation where the two halves can work together for mutual benefits. As part of those efforts, both parties are working now to reconnect the railways between the North and the South that remained broken for the past 60 years. In addition, the restoration of Trans-Korean railway paves the way for the "Silk Road Railway" which links European continent to Asian regions and Pacific Rim. The restoration project acts as a conduit for cooperation within in the Northeast Asian continent, hence, an important tool for facilitating peace and prosperity within the Northeast Asian region. Notably, the Railway project is regarded as the cardinal future-oriented peace building project for cultivating constructive, cooperative relations (Trans-Korean Railway and Trans-Asian Railway works) by stimulating human resources and commodity flows through railroad transportations. Northeast Asian region takes on a similar instance to the unification of European continent through its astounding development in railroad transportation, i.e., the international re-construction of Railroad lines will act as a catalyst to link Eurasian areas into one regional community for cooperation and peace. At present, the government is creating a momentum to bind trans-Eurasian railroad works and an initiative for "Northeast Asia Railroad networks and consultative organization". The South Korean administration paves the way to develop railroad network within South-North Korean, Russia and Eurasian region. It also fosters railroad cooperation with China for people and goods transports. To achieve such objectives, the project requires wide publicity and cross-border cooperation from concerned countries. The blueprint would have to be drafted up for Northeast Asian railroad train demonstration runs, Northeast Asian transportation agreements, with a bid to promote constitute Northeast Asian Railroad Consultation body. Moreover, the government would also have to prepare both, a draft of the linkage and the mandated standardized proposal.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.4
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• pp.405-415
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• 2011

The objective of this study was to compare greenhouse gas emissions from road transportation by calculation methods (Tier 1, Teir 2, and Tier 3). Tier 1 based on 2006 IPCC guidelines default emission factor and amount of fuel consumption. The Tier 2 approach is the same as Tier 1 except that country-specific carbon contents of the fuel sold in road transport are used. Tier 2 based on emission factor of guidelines for local government greenhouse gas inventories (Korea Environment Corporation), the fuel consumption per one vehicle, and the registered motor vehicles. The Tier 3 approach requires detailed, country-specific data to generate activity-based emission factors for vehicle subcategories (National Institute of Environmental Research) and may involve national models. Tier 3 calculates emissions by multiplying emission factors by vehicle activity levels (e.g., VKT) for each vehicle subcategory and possible road type. VKT was estimated by using GIS road map and traffic volume of the section. The GHG average emission rate by the Tier 1 was 728,857 $tonCO_2eq$/yr, while Tier 2 and Tier 3 were 864,757 $tonCO_2eq$/yr and 661,710 $tonCO_2eq$/yr, respectively. Tier 3 was underestimated by 10.1 and 20.7 percent for the GHG emission observed by Tier 1 and Tier 2, respectively. Based on this study, we conclude that Tier 2 is reasonable GHG emissions than Tier 1 or Tier 3. But, further study is still needed to accurate GHG emission from Tier 3 method by expanding the traffic survey area and developing the model of local road traffic.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.11a
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• pp.241-250
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• 2005

New product development (NPD) is defined as the transformation of a market opportunity and a set of assumptions about product technology into a product available for sale. Managers charged with project selection decisions in the NPD process, such as go/no-go choices and specific resource allocation decisions, are faced with a complicated problem. Therefore, the ability to develop new successful products has identifies as a major determinant in sustaining a firm's competitive advantage. The purpose of this study is to develop a new evaluation model for NPD project selection in the high -tech industry using support vector machines (SYM). The evaluation model is developed through two phases. In the first phase, binary (go/no-go) classification prediction model, i.e. SVM for high-tech NPD project selection is developed. In the second phase. using the predicted output value of SVM, feasibility grade is calculated for the final NPD project decision making. In this study, the feasibility grades are also divided as three level grades. We assume that the frequency of NPD project cases is symmetrically determined according to the feasibility grades and misclassification errors are partially minimized by the multiple grades. However, the horizon of grade level can be changed by firms' NPD strategy. Our proposed feasibility grade method is more reasonable in NPD decision problems by considering particularly risk factor of NPD in viewpoints of future NPD success probability. In our empirical study using Korean NPD cases, the SVM significantly outperformed ANN and logistic regression as benchmark models in hit ratio. And the feasibility grades generated from the predicted output value of SVM showed that they can offer a useful guideline for NPD project selection.

• Journal of Preventive Medicine and Public Health
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• v.26 no.2 s.42
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• pp.192-201
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• 1993

Epidemiologic investigation was conducted on January, 1993 in Seoul to identify the cause of an infant methemoglobinemia. Field investigation of the area of outbreak, survey of household and family members, analysis of ground water, and blood tests of involved family members were performed. Following results were obtained On analyzing the quality of the ground water on patient's household high levels of nitrate was found indicating contamination of water as the cause of a methemoglobinemia outbreak. On analysing the quality of the ground waters on seven other places within the neighborhood five were contaminated by nitrate in concentration that exceeded the permissible limit implying presence nearby source of contamination. Sources of contamination were thought to be originating from human waste in conventional bathroom facilities, chicken manure used in nearby orchards and plant fields or fertilizers. But the results of water analysis with presence of bacteria or E.coli, concentration of potassium, phosphate and the past history of diarrhea among family members, chicken manure suggested the most possible source of contamination. To evaluate the health status of members in the neighborhood past history was reviewed revealing no prior existence of patient with cyanosis and 65 people in the neighborhood had normal levels of methemoglobin concentration in their blood. Conclusively, the ground water on patient's household was contaminated with nitrate and despite provision of adequate water supply, family members of the patient along with their distrust in the water supply system had used ground water as their source of drinking water resulting of methemoglobinemia. Many suburban area of Seoul and country side thought to be having similar problems concerning contaminated ground water supply and dormant outbreak of patients as a result of the drinking of the contaminated water. Epidemiologic investigation and water analysis of ground waters are advised.

• Journal of Korean Medical Science
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• v.33 no.46
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• pp.304.1-304.7
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• 2018

Background: The Republic of Korea has a very low prevalence of human immunodeficiency virus (HIV) infection, but the number of new HIV diagnoses has steadily risen, strongly indicating a large number of undetected HIV infections. Thus, it is important for Korean public health authorities to adopt and encourage cost-effective HIV detection tools, such as rapid HIV screening tests. In this study, we aimed to evaluate the cost-effectiveness of enzyme-linked immunosorbent assays (ELISA) and rapid tests in a public health center (PHC) setting. Methods: We developed a decision analytic model to assess the per-examinee cost and the cost-effectiveness of identifying HIV patients in a PHC setting using two HIV testing strategies: conventional HIV screening by ELISA versus rapid HIV testing. Analysis was performed in two scenarios: HIV testing in an average-risk population and in a high-risk population. Results: Compared to the ELISA, the rapid test was cost-saving and cost-effective. The per-examinee cost was USD 1.61 with rapid testing versus USD 3.38 with ELISA in an average-risk population, and USD 4.77 with rapid testing versus USD 7.62 with ELISA in a high-risk population. The cost of identifying a previously undiagnosed HIV case was USD 26,974 with rapid testing versus USD 42,237 with ELISA in an average-risk population, and USD 153 with rapid testing versus USD 183 with ELISA in a high-risk population. Conclusion: Rapid testing would be more cost-effective than using conventional ELISA testing for identifying previously undiagnosed HIV-infected cases in Korea, a country with extremely low HIV prevalence.

• Journal of Climate Change Research
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• v.4 no.3
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• pp.245-254
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• 2013

Korea government promote renewable energy as the core of their energy matrix to break the dependence and reduce greenhouse effects. This study analyzes the economic assessment of Solid Refuse Fuel project in urban area, considering the marginal external costs of air pollution in this area. Assessment index defined as costs (i.e., construction cost, operation cost) and benefit (margin, external cost) data which is located in Sudokwon landfill site. The result indicates that cost-benefit analysis of SRF is calculated as 1.0. In addition, SRF project is very sensitive about electric power selling price, operating cost and labor cost according to inflation rates. This study shows that the sustainability of SRF project is required the government financial support like investment funds as well as policy support. Variability analysis of SRF economic assessment due to renewable energy can be used for making policies in various fields such as waste and public energy field.

• Asian Journal for Public Opinion Research
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• v.9 no.4
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• pp.331-351
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• 2021

The unprecedented situation of COVID-19 caused the government of India to instruct educational institutions to switch to an online mode to mitigate the losses for students due to the pandemic. The present study attempts to explore the impact of online learning introduced as a stop-gap arrangement during the pandemic in India. A survey was conducted (N=289), via Facebook and WhatsApp, June 1-15, 2020 to understand the accessibility and effectiveness of online learning and constraints that students of higher education across the country faced during the peak times of the pandemic. The analysis and interpretation of the data revealed that the students acclimatized in a short span of time to online learning, with only 33.21% saying they were not satisfied with the online learning mode. However, the sudden shift to online education has presented more challenges for the socially and economically marginalized groups, including Scheduled Caste (SC), Scheduled Tribes (ST), Other Backward Class (OBC), females, and students in rural areas, due to factors like the price of high-speed Internet (78.20% identified it as a barrier to online learning), insufficient infrastructure (23.52% needed to share their device frequently or very frequently), poor Internet connectivity, etc. According to 76.47% of respondents, the future of learning will be in "blended mode." A total of 88.92% of the respondents suggested that the government should provide high-quality video conferencing facilities free to students to mitigate the division created by online education in an already divided society.