• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.5
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• pp.405-412
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• 2022

This paper studies the method of estimating power loss and classifying the factors for improving the power generation efficiency through O&M. It is installed under various climatic conditions worldwide, operational and maintenance technologies suitable for the characteristics of the installation location are required. Existing studies related to solar power generation efficiency have been actively quantifying the impact on short-term losses by environmental factors such as high temperature, dust accumulation, precipitation, humidity, and wind speed, but analysis of the overall impact from a long-term operation perspective is limited. In this study, the potential for efficiency improvement was analyzed by re-establishing a loss classification system according to the power flow of solar power to derive a comprehensive efficiency model for long-term operation and estimating power loss through a case study for each region where climate conditions are classified. As a result of the analysis, the average annual potential for improving soiling loss was 26.9%, Death Valley 7.2%, and Seoul 3.8%. Aging losses was 6.6% in the 20th year as a cumulative. The average annual potential due to temperature loss was 2.9 % for Doha, 1.9% for Death Valley, and 0.2% for Seoul.

• Journal of Appropriate Technology
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• v.6 no.2
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• pp.163-173
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• 2020

For the successful execution of an ODA project, it is necessary to know what areas are weak and necessary to the country of demand exactly. The health sector is also a top priority in most of developing countries. This study was carried out to introduce non-communicable disease (NCD) in Fiji for ODA projects planning. The major causes of death in Fiji in 2016 are diabetes, ischemic heart disease, cerebrovascular disease, chronic kidney disease, lower respiratory infect, asthma in ranking. The major causes of death in Korea in same year are cancer, ischemic heart diseases, cerebrovascular diseases, pneumonia, suicide, diabetes in the order of ranking. The chronic disease as non-communicable disease (NCD) has been increasing continuously due to changes in lifestyle and consumption patterns and population aging in prevalence rate. This global trend is also apparent in Fiji and Korea, reflected in increasing mortality and personal costs for the treatment and management of NCD. The need for a sustained comprehensive treatment tailored for individual patients has suggested from many studies and the development of a systematic program to manage NCD patients to provide such care have been recommended. The Fiji government developed Non-communicable Diseases Strategic Plan 2015-2019 and has tried to reduce the prevalence rate of non-communicable diseases by factors. The WHO global action plan guiding national-level NCD policies requires an NCD prevention and control model at the community level, presenting strategic goals and detailed options for the introduction and application of the approach to communities. It is necessary to develop an NCD prevention and control model, consisting of a strategy of community intervention, education for students and NCD patients, and the legal enactment of NCD that adequately meets the needs of community members.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.4
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• pp.433-447
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• 2023

There is a growing demand for the stability of existing dams due to abnormal climate and the aging of dams. Emergency Action Plans (EAPs) for reservoir or dam failure only consider a single rainfall event. Therefore, this study simulates dam failure caused by continuous rainfall events, and proposes the establishment of EAP by selecting the optimal shelters. We define a mega rainfall event scenario caused by continuous rainfall events with 500-year frequency in the Chungju Dam watershed and estimate the mega flood. The mega flood event scenario is divided into two cases: scenario A represents the flooding case caused by discharge release from a dam, while scenario B is the case of a dam break. As a result of flood inundation analysis, the flooded damage area by the scenario A is 50.06 km² and the area by the scenario B is 6.1 times of scenario A (307.45 km²). We select optimal shelters for each administrative region in the city of Chungju, which has the highest inundation rate in the urban area. Seven shelter evaluation indicators from domestic and foreign shelter selection criteria are chosen, and Analytical Hierarchy Process (AHP) method is used to evaluate the alternatives. As a result of the optimal shelter selection, the six shelters are selected and five are schools. This study considers continuous rainfall events for inundation analysis and selection of optimal shelters. Also, the results of this study could be used as a reference for establishment of the EAP.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6D
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• pp.859-869
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• 2008

These days, almost every industry's production line has become automatic and this phenomenon brought a lot of benefits such as increase in productivity and economical effect, assurance in industrial safety, better quality and compatibility. However, unlike industrial production line, in construction industry, automation has number of barriers like uncertainty incidents and intellectual judgment to make ability to make solution out of it. Therefore construction industry is still demanding use of construction machine through labor. Due to this matter operational labor in construction industry is aging and fading. To solve these problem, in developed nations like Europe, US or Japan are keep researching for the automation in construction and road pavement, strengthening and some other simple operations have been worked through automation but in civil engineering site, automation research is still low despite of its importance in constructional site. For automating civil engineering operation, effective operational plan have to be set by analyzing ground information acquainted. If skillful worker apply heuristics, trial & error can be reduced with increased safety and the effective work plan can be established. Hence, this research will introduce Intellectual Task Planning System for Intelligent Excavating System's effective work plan and heuristics applied in each steps.

• The Korean Journal of Franchise Management
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• v.2 no.1
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• pp.100-118
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• 2011

Since 1990, income has been grown rapidly in Korea. Thus, concerns of environmental pollution and health have been increased among Korea's consumers. As a result of this concern, demand for safe food and agricultural products has been growing in Korea. Recently, purchasing patterns of Korea's consumers have been changed as Korea's society has changed to an aging society, growth of unmarried person, and low birthrate. Korea's consumers prefer to buy only volume that they need. Thus, the volume of agricultural products that they purchase became small. Therefore, retailers should reflect such needs of consumers to their business. The purpose of this study is to build up new strategies in order to make a high profit through customer's satisfaction when selling agricultural products. Using literature review, this study has drawn results. The results of this study is that retailers should lay products with brand in their store and establish trust with customers in oder to make loyal customers. In addition, retailers should prepare individual package of agricultural products for sales of a small volume to keep pace with social changes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.235-242
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• 2008

Due to the lack of judgement in an information processing on road sign, older drivers usually are having a hard time driving than young group. Furthermore, according to increasing in aging population, older drivers in Korea have been growing much faster. That means research for older drivers' characteristics and the number of guide name for road sign should be needed. In accordance with suggestions, this study was carried out the number of guide names for road sign with a variety of ages from the twenties to the seventies. For the sake of this study, statistical verification was conducted to confirm a change of speed, a reading time and a misreading rate with Driving Simulator and Electrooculogram tool. As the results of study, change of speed in the age range has shown that the higher the proportion of age, the lower the rate of velocity. Also reading time in the age range with regression analysis found that the higher the proportion of age, the higher the rate of reading time by 0.106sec. Finally, a binary logistic model was used to find the main factors. As the results, 4 number of guide names for road sign have been the best of them for older driver. The result of this study verified the importance of ideal guide numbers on road sign for older driver and proved itself to be an effective method to determine the road safety for the road signs.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2D
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• pp.245-253
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• 2009

Road facility is the most fundamental infrastructure for traffic and various information for smooth traffic is included in road surfaces. Various information included in road surfaces should be often removed and reinstalled by partial damage and aging. In addition, the existing road surface information should be removed in order to mark new information as traffic information changes. The existing road surface removal method suing grinders and torches had problems such as dangerous working equipment and workers' direct exposure to cars. In addition, although water-jet system using super high-pressure water was used to remove road surface in order of improvement of traditional method, there are another problems such as limitations according to water-tanks and water frost on the road surfaces after work. Therefore, this study analyzes and suggests systems to develop prototype after analyzing dry ice blaster in order to improve the current road surface removal methods. In addition, the study analyzes the possibility of introduction of dry ice blaster through a test for proposing an automatized equipment for new road surface mark removal considering environment and work efficiency, and compare traditional method with introduced dry ice blaster for operating cost.

• Clean Technology
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• v.29 no.4
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• pp.305-312
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• 2023

Due to the strengthening of environmental requirements, aging denitrification facilities need to improve their performance. The present study aims to suggest the possibility of improving performance using computational analysis techniques. This involved modifying both the geometric design and the operating conditions, including the flow path shape of the equipment such as the inlet guide vane and the curved diffusing part, and the flow control of the ammonia injection nozzle. The conditions presented in this study were compared with existing operating conditions in terms of the flow uniformity, the NH₃/NO molar ratio of the mixed gas flowing into the catalyst layer, and the total pressure drop of the facility. The flow field applied in the computational analysis ranged from the outlet of the economizer in the combustion furnace to the inlet of the air preheater, the full domain of the denitrification facility. The performances were derived by solving the flow fields using ANSYS-Fluent and the injection amount of ammonia was adjusted for each nozzle using Design Xplorer. Compared to the denitrification performances of the equipment currently in operation, the conditions proposed in this study showed an improvement in the flow uniformity and NH₃/NO composition ratio by 45.1% and 8.7%, respectively, but the total pressure drop increased by 1.24%.

• Explosives and Blasting
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• v.41 no.3
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• pp.62-72
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• 2023

The aging of plant structures due to industrialization in the 1970s has increased the demand for blast demolition. While blasting can reduce exposure to environmental pollution by shortening the demolition period, improper blasting design and construction plans pose significant safety risks. Thus, it is vital to consider optimal blasting demolition conditions and other factors through collapse behavior simulation. This study utilizes a 3-D combined finite-discrete element method (FDEM) code-based 3-D DFPA to simulate the collapse of a chimney structure in a thermal power plant in Seocheon, South Korea. The collapse behavior from the numerical simulation is compared to the actual structure collapse, and the numerical simulation result presents good agreement with the actual building demolition. Additionally, various numerical simulations have been conducted on the chimney models to analyze the impact of the duct size in the pre-weakening area. The no-duct, duct, and double-area duct models were compared in terms of crack pattern and history of Z-axis displacement. The findings show that the elapse-time for demolition decreases as the area of the duct increases, causing collapse to occur quickly by increasing the load-bearing area.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.4
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• pp.173-191
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• 2022

The global economic crisis, the trend of an aging society, and the rapid digital transformation are huge burdens and crises for our society. Due to these environmental changes and the economic recession, entrepreneurship and re-employment issues after retirement have emerged as social issues. This study was conducted to empirically analyze what factors affect seniors when they may start a business. In particular, as the fourth industrial revolution progresses, the focus was on the capability to utilize information and communication technology (ICT) and digital media that cannot be avoided. For empirical analysis, an online survey of seniors was conducted and 287 valid samples were analyzed. SPSS 24.0 and Macro Process 4.0 were used for statistical analysis. As a result of the empirical analysis of this study, self-efficacy and personal innovation for information technology acceptance(ICT), and communication capability using digital media had a significantly positive (+) effect on senior's entrepreneurial intention. However, the perceived usefulness of information technology and the capability to utilize digital media devices were not tested for significance. Among the variables that had a significant effect, personal innovation was found to have the greatest effect. Opportunity recognition was found to play a mediating role between self-efficacy, personal innovation, communication capabilities, and senior's entrepreneurial intention. The results of this study are of academic and practical significance in that digital media utilization capability is also an influential factor among various factors influencing the entrepreneurial intention of seniors.