• Smart Structures and Systems
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• 제24권1호
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• pp.95-110
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• 2019

The semi-active impact damper (SAID) is proposed to improve the damping efficiency of traditional passive impact dampers. In order to investigate its damping mechanism and vibration control effects on realistic engineering structures, a 20-story nonlinear benchmark building is used as the main structure. The studies on system parameters, including the mass ratio, damping ratio, rigid coefficient, and the intensity of excitation are carried out, and their effects both on linear and nonlinear indexes are evaluated. The damping mechanism is herein further investigated and some suggestions for the design in high-rise buildings are also proposed. To validate the superiority of SAID, an optimal passive particle impact damper ($PID_{opt}$) is also investigated as a control group, in which the parameters of the SAID remain the same, and the optimal parameters of the $PID_{opt}$ are designed by differential evolution algorithm based on a reduced-order model. The numerical simulation shows that the SAID has better control effects than that of the optimized passive particle impact damper, not only for linear indexes (e.g., root mean square response), but also for nonlinear indexes (e.g., component energy consumption and hinge joint curvature).

• 도시과학
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• 제8권1호
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• pp.15-23
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• 2019

The goal of this study is to examine municipality comprehensive plans by recognizing the problem that adverse impacts of urban regeneration impede the sustainability of specific renewal project. 10 major cities in Korea that are experiencing urban decline were chosen for the study area and plan evaluation indexes were adopted based on the sustainable urban regeneration principles in terms of environmental, social, and economic aspects. Plan evaluation was conducted by employing the content analysis method and developed assessment indexes for three sectors (factual basis, goal/objective, and policy/action) of plan. The findings show that policies, such as 'expansion of parks in urban area,' 'pedestrian-oriented street improvement project,' and 'countermeasures for local industry revitalization,' should be fundamentally included in adopting sustainable urban regeneration plans. Plan scores regarding sustainable urban regeneration had an insignificant relationship with the status of administrative district and plan adopted year. This is because metropolitan municipalities, including Ulsan, Daejeon, and Daegu, received relatively low plan score compared to local governments like Goyang and Suwon. Also, Daegu and Suwon, which established their comprehensive plan in 2018 obtained lower score than Seoul and Incheon, where its plans were created before 2015. Evaluation protocol and indexes that were suggested in this study can be used while reorganizing each locality's comprehensive plan, and thus, play as one of major bases in preparing future sustainable urban regeneration projects.

• 자원환경지질
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• 제41권5호
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• pp.485-496
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• 2008

본 연구에서는 국가별 석탄의 수요와 공급과 전력산업에 대한 통계자료를 분석하여 향 후 석탄과 전력산업의 패키지형 진출을 위해 적합한 대상 국가를 제시하고자 하였다. 패키지형 자원 개발의 대상 국가를 선정하는데 있어 중요한 기준이 될 수 있는 사항들은 해당 국가의 석탄 매장량, 매장된 석탄의 종류, 1인당 전력 소비 규모, 1인당 국민생산량 등이다. 이러한 기준을 만족시키는 국가들은 대부분 방글라데시, 몽고, 나이지리아 등 아시아나 아프리카에 분포하는 저개발 국가들이다.

• 한국환경보건학회지
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• 제40권5호
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• pp.355-366
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• 2014

Objectives: This study seeks to evaluate the vulnerability assessment of the human health sector for $PM_{10}$, which is reflected in the regional characteristics and related disease mortality rates for $PM_{10}$ in Busan over the period of 2006-2010. Methods: According to the vulnerability concept suggested by the Intergovernmental Panel on Climate Change (IPCC), vulnerability to $PM_{10}$ is comprised of the categories of exposure, sensitivity, and adaptive capacity. The indexes of the exposure and sensitivity categories indicate positive effects, while the adaptive capacity index indicates a negative effect on vulnerability to $PM_{10}$. Variables of each category were standardized by the rescaling method, and each regional relative vulnerability was computed through the vulnerability index calculation formula. Results: The regions with a high exposure index are Jung-Gu (transportation region) and Saha-Gu (industrial region). Major factors determining the exposure index are the $PM_{10}$ concentration, days of $PM_{10}{\geq}50$, ${\mu}g/m^3$, and $PM_{10}$ emissions. The regions that show a high sensitivity index are urban and rural regions; these commonly have a high mortality rate for related disease and vulnerable populations. The regions that have a high adaptive capacity index are Jung-Gu, Gangseo-Gu, and Busanjin-Gu, all of which have a high level of economic/welfare/health care factors. The high-vulnerability synthesis of the exposure, sensitivity, and adaptive capacity indexes show that Dong-Gu and Seo-Gu have a risk for $PM_{10}$ potential effects and a low adaptive capacity. Conclusions: This study presents the vulnerability index to $PM_{10}$ through a relative comparison using quantitative evaluation to draw regional priorities. Therefore, it provides basic data to reflect environmental health influences in favor of an adaptive policy limiting damage to human health caused by vulnerability to $PM_{10}$.

• 신재생에너지
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• 제10권3호
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• pp.47-54
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• 2014

Recently, BESS is considered as one of essential countermeasure for demand side management. However, an economic evaluation is critical issue for the introduction of power system because the cost of BESS is very high in present stage. Therefor, this paper presents economic evaluation method for customer use case by considering peak shaving function based on the real time price. From the case study on the model power system and educational customer, it is confirmed that the proposed method is a practical tool for the economic analysis of BESS. and analytical approach for the reliability assessment in radially operated distribution systems. The approach can estimate the expected reliability performance of distribution systems by a direct assessment of the configuration of the systems using the reliability indexes such as NDP (Non-Delivery Power) and NDE (Non-Delivery Energy). The indexes can only consider the number and configuration of the load, but can not consider the characteristics of the load which is the one of the most important factor in the investment cost for the distribution systems. Therefore, this paper presents the new performance indexes for the investment of the distribution facilities considering both the expected interruption cost for the load section and the operation characteristics of Energy Storage System. The results from a case study show that the proposed methods can be a practical tool for the reliability management in distribution systems including Energy Storage System.

• 한국환경과학회지
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• 제11권8호
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• pp.793-800
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• 2002

Butyltin (BT) compounds were measured in seawater, sediment, sediment core, settling solids, and plankton from Gwangyang Bay in 2001, Tributyltin (TBT) was detected in seawater from 1 out of the 7 seawater sampling sites and in sediment from 18 out of the 35 sediment sampling sites. The highest concentration of TBT was found in the sediment from the site near Yeosu Harbor (53 ng Sn/g dry wt), acting as the point source for TBT The mean concentrations of TBT were in the order of plankton> settling solids> sediment. The degradation indexes ([DBT]+[MBT]/[TBT]) for the plankton were less than 1, indicating the possibility of recent inputs of TBT. The indexes for the sediment and settling solids ranged from 1.14 to 8.73. The composition of the BT compounds found in the settling solids was similar to that found in the sediment. The vertical profile of the total BT compounds in the sediment was characterized by an abrupt decline from the surface. However, no butyltin compounds appeared below a depth of 10 cm, corresponding to the 1980s. Accordingly, the current results demonstrated that the levels of all butyltin species in the environment of Gwangyang Bay were relatively lower than those in other polluted coastal areas. The vertical profile also suggested a fairly recent history for the down-core.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2009년도 추계학술대회 논문집
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• pp.663-664
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• 2009

• 보건교육건강증진학회지
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• 제31권3호
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• pp.109-117
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• 2014

Objectives: Although many cities have adopted Healthy Cities approach in Republic of Korea, few studies have been reported about city health profile. So we report a case of city health profile made of subjective indexes and objective indicators using available recent evidence. Methods: To assess subjective city health indexes, questionnaire survey was implemented to public officers and citizen adapting the 'Signs of progress, signs of caution of 12 stage tool from Ontario Healthy Community Coalition. Based on recent literature objective city health indicators were collected for time-series comparison and for the comparison with those of larger province mainly using Korean Statistical Information Service. Results: Subjective city health indexes were successfully constructed in four areas including human health, environment, social and economic area. The score was especially low in environmental area. Specific items in each area for improvement were identified. Objective city health indicators were collected for three year time-series comparison and for the compared with those of larger province. Conclusions: City health profile comprised of subjective city health indexes and objective city health indicators could successfully be made from primary survey and secondary data in a medium-sized Korean city. That City health profile was useful in subsequent city health planning through participatory process.

• 대한토목학회논문집
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• 제31권4D호
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• pp.547-553
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• 2011

본 연구는 대중교통취약지역 평가척도인 이동성 지표와 잠재수요에 대한 개념을 새로 정립하고 이들 지표를 적용하여 대중교통이동성 취약지역 선정과 이들 지역 간을 연결하는 대중교통 직결노선 선정방법을 제시하였다. 이동성 지표와 잠재수요평가지표를 적용하여 4개 대도시권의 대중교통 취약지역을 선정하고 이들 지역 간을 운행하는 직결 버스 노선을 사례연구를 통해 분석하였다. 분석결과 대중교통 이동성 사각지대는 대중교통통행시간이 승용차에 비해 현저히 높게 소요되거나 대중교통노선의 서비스가 제공되지 않은 지역으로 분석되었다. 또한, 이러한 대중교통취약지역을 해소하기 위한 직결버스노선은 대중교통통행시간을 승용차 통행시간과 동등한 수준을 유지할 수 있도록 자동차 전용도로로 운행하고 승 하차로 인한 통행시간 손실을 최소화 시키고 연계를 극대화 할 수 있는 노선체계가 구축되어야 할 것으로 분석되었다.

• Journal of Microbiology and Biotechnology
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• 제30권9호
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• pp.1310-1320
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• 2020

Low-quality soil for land reuse is a crucial problem in vegetation quality and especially to waste disposal sites in mining areas. It is necessary to find suitable materials to improve the soil quality and especially to increase soil microbial diversity and activity. In this study, pot experiments were conducted to investigate the effect of a mixed material of humic acid, super absorbent polymer and biochar on low-quality soil indexes and the microbial community response. The indexes included soil physicochemical properties and the corresponding plant growth. The results showed that the mixed material could improve chemical properties and physical structure of soil by increasing the bulk density, porosity, macro aggregate, and promote the mineralization of nutrient elements in soil. The best performance was achieved by adding 3 g·kg^-1 super absorbent polymer, 3 g·kg^-1 humic acid, and 10 g·kg^-1 biochar to soil with plant total nitrogen, dry weight and height increased by 85.18%, 266.41% and 74.06%, respectively. Physicochemical properties caused changes in soil microbial diversity. Acidobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Firmicutes, Nitrospirae, Planctomycetes, and Proteobacteria were significantly positively correlated with most of the physical, chemical and plant indicators. Actinobacteria and Armatimonadetes were significantly negatively correlated with most measurement factors. Therefore, this study can contribute to improving the understanding of low-quality soil and how it affects soil microbial functions and sustainability.