• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.4
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• pp.21-30
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• 2022

To mitigate the environmental impacts of the energy sector, the government of South Korea has made a continuous effort to facilitate the development and commercialization of renewable energy. As a result, the efficiency of renewable energy plants is not a consideration in the potential site selection process. To contribute to the overall sustainability of this increasingly important sector, this study utilizes the Black-Scholes model to evaluate the economic value of potential sites for off-site wind farms, while analyzing the environmental mitigation of these potential sites in terms of carbon emission reduction. In order to incorporate the importance of flexibility and uncertainty factors in the evaluation process, this study has developed a site evaluation model focused on system dynamics and real option approaches that compares the expected revenue and expected cost during the life cycle of off-site wind farm sites. Using sensitivity analysis, this study further investigates two uncertainty factors (namely, investment cost and wind energy production) on the economic value and carbon emission reduction of potential wind farm locations.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.335-341
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• 1999

To investigate the effect of sulfate deposition un forest tree nutrition, 15 forest stands of Pinus thunbergii were selected throughout Yochon industrial complex, in which is influenced by chronic air pollution. Concentrations of sulfate sulfur, nitrogen, phosphorus, potassium, calcium, and magnesium were analysed fur current and 1-year-old needles of Pinus thunbergii tree. The results obtained were as follows ; 1. Significant higher accumulation of sulfate S, computed with that of unpolluted needles, was observed at all sites, ranging front 0.11% to 0.35% in current needles, and from 0.13% to 0.32% in 1-year-old needles. 2. Ranging from 0.60% to 1.42% in current needles, and from 0.58% to 0.88% 1-year-old needles, respectively, nitrogen concentrations were significantly lower at 7 sites for current needles, and at all sites for 1-year-old needles than at unpolluted site. 3. Phosphorus and potassium levels were significantly lower at very few sites, compared with unpolluted site. 4. Calcium concentrations were significantly lower at 8 sites and 9 sites for current and 1-year old needles than at unpolluted site, ranging from 0.123% to 0.352% and from 0.201% to 0.371% in 1-year old needles, respectively. 5. Ranking from 0.077% to 0.152% in current needles, and from 0.056% to 0.105% in 1-year-old needles, magnesium concentrations were lower at only 2 sites for current needles tut at 12 sites for 1-year-old needles. 6. There were significant declines of concentrations of calcium and magnesium in current needles as sulfate accumulation increased. For 1-year-old needles, there were significant negative correlations-hips between sulfate and nitrogen, potassium, calcium, and magnesium concentration. It is concluded that deposition of sulfuric air pollutant deteriorated nutrients status, resulting in tree decline, in Pinus thunbergii forest in Yochon industrial complex.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.4
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• pp.281-292
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• 1998

Ambient concentrations of gaseous, particulate phase ionic species, and VOCs (volatile organic compounds) were measured at two monitoring sites in the City of Ulsan during August 1997: one in industrial area and the other in downtown area. At each site, a three- stage filter pack sampler was used to collect fine particles and gaseous species, and air for VOC analysis was collected in stainless steel canisters. Concentrations of the ionic species at both sites were similar to each other. The VOC concentrations at the industrial site were approximately twice higher than those at the downtown site. This might be mainly due to the release of VOCs from the petrochemical industries. Daily variations of VOC concentrations at the industrial site were higher than that at the downtown site. This might be explained by the fact that emissions from industries were more irregular than those in downtown. The VOC concentrations in downtown were affected by both the local emissions and the emission from the petrochemical industries. The concentrations of selected hazardous organic components (HAPs) at the industrial site were similar to those of Yocheon industrial area but slightly higher than other cites and industrial areas, while those at the downtown site were comparable to those in other urban areas.

• Industrial Engineering and Management Systems
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• v.9 no.3
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• pp.227-241
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• 2010

A memory module industry's supply chain usually consists of multiple manufacturing sites and multiple distribution centers. In order to fulfill the variety of demands from downstream customers, production planners need not only to decide the order allocation among multiple manufacturing sites but also to consider memory module industrial characteristics and supply chain constraints, such as multiple material substitution relationships, capacity, and transportation lead time, fluctuation of component purchasing prices and available supply quantities of critical materials (e.g., DRAM, chip), based on human experience. In this research, a directed graph-based supply network planning (DGSNP) model is developed for memory module industry. In addition to multi-site order allocation, the DGSNP model explicitly considers production planning for each manufacturing site, and purchasing planning from each supplier. First, the research formulates the supply network's structure and constraints in a directed-graph form. Then, a proposed genetic algorithm (GA) solves the matrix form which is transformed from the directed-graph model. Finally, the final matrix, with a calculated maximum profit, can be transformed back to a directed-graph based supply network plan as a reference for planners. The results of the illustrative experiments show that the DGSNP model, compared to current memory module industry practices, determines a convincing supply network planning solution, as measured by total profit.

• Journal of the Korean Institute of Gas
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• v.28 no.2
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• pp.93-104
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• 2024

Facility diagnosis is essential for the smooth operation and life extension of rotating equipment used in industrial sites. Compared to other diagnostic methods, vibration diagnosis can find most of the initial defects, such as unbalance, alignment failure, bearing defects and resonance, compared to other diagnostic methods. Therefore, vibration analysis is the most commonly used facility diagnosis method in industrial sites, and is usefully used as a predictive preservation (PdM) technology to manage the condition of the facility. However, since the vibration diagnosis method is performed based on experience based on the standard, it is carried out by experts. Therefore, it is intended to contribute to the reliability of the facility by establishing a system that anyone can easily judge defects by establishing a vibration diagnosis method performed based on experience as a knowledgeable code system. An algorithm was developed based on the ISO-20816 standard for vibration measurement, and the reliability was verified by comparing the results of vibration measurement at various demonstration sites such as petrochemical plant compressors, hydrogen charging stations, and industrial machinery with the results of analysis using a development system. The developed algorithm can contribute to predictive maintenance (PdM) technology that anyone can diagnose the condition of the rotating machine at industrial sites and identify defects early to replace parts at the exact time of replacement. Furthermore, it is expected that it will contribute to reducing maintenance costs and downtime due to the failure of rotating machines when applied to various industrial sites such as oil refining facilities, transportation, production facilities, and aviation facilities.

• Journal of the Korean Society of Safety
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• v.35 no.2
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• pp.47-54
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• 2020

The purpose of this study is to determine whether the variables of the agency factors affected the number of occupational fatalities in the construction industry in order to determine whether there is a relationship between the number of occupational fatalities occurring at the construction sites and the agency. The considered agencies are KOSHA (Korea Occupational Safety and Health Agency) and MOEL (Ministry of Employment and Labor). The variables of two agency factors are classified as follows: the variables of two agency factors are the number of employees, budget amounts, technical support and guidance for construction sites of KOSHA, and the number of labor inspectors, the number of inspection and oversight workplace, the number of criminally punished construction sites and fines levied on them in the industrial accident prevention departments of Regional Employment and Labor Office. The multiple regression analysis was conducted to determine the effect of two agency factors on the total number of occupational fatalities in the construction industry. The policy implications derived from this study are that, in order to reduce the fatalities of construction sites by KOSHA, the appropriate level of increased budget for KOSHA must be secured every year. In addition, the amount of fines levied on construction sites by the labor inspector in the industrial accident prevention departments of Regional Employment and Labor Office reduces the occupational fatalities at the construction sites.

• Journal of the Korean Society of Safety
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• v.30 no.6
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• pp.85-93
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• 2015

Construction sites have various risks, and safety managements are enforced based on the law such as Industrial Safety and Health Act, etc. Safety management by the law saves lives and preserves health of workers by removing and understanding risks in advance. When the emergency situation has come, poor response causes loss of lives and physical damages. This study suggests basic strategy that can mitigate the industrial disaster in all construction sites. A survey was conducted to identify the current safety consciousness and to evaluate first aid ability of coworkers. Finally, four measures were suggested: (1) designating muster points; (2) hiring occupational health managers; (3) increasing the first aid ability of coworkers; and (4) carrying safety brochure. The proposed suggestions can be helpful in mitigating the construction disaster, and in responding the major accident efficiently within a short time.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.2
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• pp.109-119
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• 2016

In South Korea the need of sustainably managing development on forest lands has required to develop a new approach to estimating environmental impacts on forest surrounding development sites in a scientific manner. As for forest-related development, two types of development were selected: golf courses and industrial complexes. Using Fragstats 4.2, the fragmentation effects and patterns of each type by forest area within project sites and buffer zones ranging from the outside of project sites up to 2,000 meters were analyzed. As a result, golf courses were strongly related to a group of fragmentation indexes: CA, NP, PD, TE, LSI, TCA, NDCA and CONNECT, whereas industrial complexes were associated with CA, NP, PD, TE, LSI and CONNECT. Among them, NP, LSI, TCA and NDCA of golf courses were considered as representative indexes reflecting the average impact ranges of each sub-group by forest area, and focussing on the size of core areas. In the case of industrial complexes, PD, TE and LSI were the representatives, vulnerable to the composition of given landscape. For two case studies, one for golf courses and the other for industrial complexes, they showed there existed a difference between the average of a group and the individual results. Therefore, to minimize the variations in impact range within a group, it is needed to analyze more individual cases. This study proved there was a distinction between project types in terms of the range of environmental impact. To effectively and comprehensively manage forest development, further research on analyzing other development types related to forests with more cases is needed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.72-80
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• 2016

The market size of plant projects in overseas is so large that domestic EPC project contractors are actively seeking the overseas projects and then trying to meet completion plans since successful fulfillment of these projects can provide great opportunities for them to expand into new foreign markets. International EPC projects involve all of the uncertainties common to domestic projects as well as uncertainties specific to foreign projects including marine transportation, customs, regulations, nationality, culture and so on. When overseas project gets off-schedule, the resulting uncertainty may trigger unexpected exceptions and then critical effects to the project performance. It usually require much more time and costs to encounter these exceptions in foreign sites compared to domestic project sites. Therefore, an exception handling approach is required to manage exceptions effectively for successful project progress in foreign project sites. In this research, we proposed a methodology for prediction and evaluation of exceptions caused by risks in international EPC projects based on sensitivity analysis and Bayesian Networks. First, we identified project schedule risks and related exceptions, which may meet during the fulfillment of foreign EPC projects that is performed in a sequence of engineering, procurement, preparatory manufacture, foreign shipping, construction, inspection and modification activities, and affect project performance, using literature review and expert interviews. The impact of exceptions to the schedule delay were also identified. Second, we proposed a methodology to predict the occurrence of exceptions caused by project risks and evaluate them. Using sensitivity analysis, we can identify activities that critically affect schedule delay and need to focus by priority. Then, we use Bayesian Networks to predict and evaluate exceptions. Third, we applied the proposed methodology to an international EPC project example to validate the proposed approach. Finally, we concluded the research with the further research topics. We expect that the proposed approach can be extended to apply in exception management in project management.

• Journal of the Korean Society of Safety
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• v.35 no.2
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• pp.67-75
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• 2020

Due to various industrial accident that occur to the staff in the broadcasting production sites, the issue of safety at the broadcast production site is becoming a social issue. Nevertheless, not many researches have been carried out on the actual conditions of the staff's production environment and its safety issues. Therefore, the purpose of this study was to prepare a countermeasure based on engineering knowledge by analyzing working environment to improve the poor working environment of staff. First, this study analyzed statistical data of industrial accidents over the past five years to find out the current status of disasters at broadcasting production sites. As a result, the intensity of the accident was not weak in that the loss days was more than one month in 85% of accident. In addition, the type of accident was high in the fall/trip accidents. Second, this study visited 10 broadcasting production sites for risk assessment. By analyzing the characteristics of the working environment and 104 questionnaires, we predicted the types of accidents that can occur in the broadcasting production site. As a result, accident types such as fall, collision, and trip were relatively high, similar to the characteristics of construction site. Third, it was possible to quantify the scale of the risk in the broadcasting production, and as a result, the quantity of temporary structure and accident risk were proportional. In other words, this study analyzes broadcasting work environment and defines risk factors based on safety engineering knowledge. Finally, this study suggested a guideline to improve the safety of the broadcasting production site.