• Title/Summary/Keyword: environmental approach

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Spatio-Temporal Variability Analysis of Precipitation Data Through Circular Statistics (순환통계 분석을 통한 강수량 시계열의 시공간적 변동성 분석)

  • Kwon, Hyun-Han;Lee, Jeong-Ju
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.2B
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    • pp.191-198
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    • 2010
  • Assessing seasonality of precipitation is necessarily required to establish future plans and policies for water resources management. In this regard, a main objective of the study is to introduce an effective approach for assessing the seasonality of the precipitation and evaluate the seasonality through the proposed one. We have used circular statistics to characterize the seasonality on the precipitation in Korea. The circular statistics allow us to effectively assess changes in timing of the seasonality in detail. It was found that peak time on monthly rainfall occurred between end of June and early July in southern coastal area while the timing was delayed in northern part of Korea because of monsoon moving in from south to north. In case of annual daily peak precipitation, spatio-temporal variation of the peak time was increased. It is mainly because of geophysical effects, frequency and paths of typhoons. Finally, temporal variations on the timing of the peak seasons were evaluated through circular statistics by 30-year moving average data. The peak season in the Northen part of Korea (e.g. Seoul and Gangrung) has been moved back from early July to end of July while the peak season has been moved up from middle of July to early July in the Southern part of Korea (e.g. Busan and Mokpo). It seems that changes in seasonality are mostly modulated by variability in the east-asia monsoon system.

Nonlinear Analysis of Steel-concrete Composite Girder Using Interface Element (경계면 요소를 사용한 강·콘크리트 혼합 거더의 비선형 거동 해석)

  • Kwon, Hee-Jung;Kim, Moon Kyum;Cho, Kyung Hwan;Won, Jong Hwa
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.4A
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    • pp.281-290
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    • 2009
  • In this study, an analysis technique of hybrid girder considering nonlinearity of steel-concrete contact surface is presented. Steel-concrete hybrid girder shows partial-interaction behavior due to the deformation of shear connectors, slip and detachment at the interface, and cracks under the applied loads. Therefore, the partial-interaction approach becomes more reasonable. Contact surface is modeled by interface element and analyzed nonlinearly because of cost of time and effort to detailed model and analysis. Steel and Concrete are modeled considering non-linearity of materials. Material property of contact surface is obtained from push-out test and input to interface element. For the constitutive models, Drucker-Prager and smeared cracking model are used for concrete in compression and tension, respectively, and a von-Mises model is used for steel. This analysis technique is verified by comparing it with test results. Using verified analysis technique, various analyses are performed with different parameters such as nonlinear material property of interface element and prestress. The results are compared with linear analysis result and analysis result with the assumption of full-interaction.

A Study on Factors Influencing Perceived Overall Quality and Performance in Financial Services (금융 서비스의 지각된 전반적 품질에 미치는 영향 요인 및 성과에 관한 연구)

  • Hong, Seong Tae;Lee, Won-Jun;Kim, Chong-Dae;Kim, Byoung-Jai
    • Asia Marketing Journal
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    • v.13 no.4
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    • pp.191-212
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    • 2012
  • With the introduction of the Capital Market Integration Act in 2009, the new competitive scope and paradigm is opened in Korean financial services market. The change of financial industry and institutions will lead to the behavioral change of customers who consume and choose financial services. While researches from the financial perspective have been conducted, works from the marketing or customer oriented approach has long been relatively ignored. The purpose of this study is to investigate influencing factors and process of financial services customers' choice behavior. More specifically, the main theme is how to enhance customer brand loyalty and purchase intention through the perception of overall quality of the service product. An integrated conceptual model including antecedents, mediating variables and consequences is established through comprehensive literature reviews of extant works on environmental change, customer behavioral change and choice behaviors. Hypothesis testing is done with SEM analysis. According to the results, the attractiveness of financial product, the reputation of financial firm, and self-brand image congruence among exogenous variables make a positive effect on perceived overall quality. And perceived overall quality has a significant effect on brand loyalty.

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Analysis of Individualized Education Support Team Intervention Objectives Using International Classification of Functioning, Disability and Health-Children and Youth Version and the Necessity of Occupational Therapists as IEP Members: A Systematic Review (국제기능장애 건강분류: 아동 청소년 버전을 이용한 개별화교육지원팀 중재목표 분석 및 개별화교육계획 구성원으로서 작업치료사의 필요성: 체계적 고찰)

  • Yun, Sohyeon;An, Hyunseo;Kim, Inhye;Park, Hae Yean
    • Therapeutic Science for Rehabilitation
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    • v.12 no.4
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    • pp.23-37
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    • 2023
  • Objective : This study systematically reviewed the collaborative team interventions of the Individualized Education Plan (IEP) using the International Classification of Functioning, Disability, and Health-Children and Youth (ICF-CY) framework to establish the professional domain of occupational therapists in Korea and their role as experts in IEP cooperative team interventions in special education. Methods : Articles were collected from the EBSCOhost, ProQuest, and PubMed databases. International search terms included "Special education," "Individualized education plan (IEP)," "IEP process," "IEP implementation," and "Occupational therapy." The study period was limited from January 2013 to February 2023, and the final 10 studies were analyzed using secondary classification. Results : Most studies were randomized experiments targeting individuals with autism, and often employed environmental improvements. The IEP collaborative team interventions using the ICF-CY framework emphasized goals related to activity (five studies), participation (four studies), and body structure/function (one study). Conclusion : Occupational therapists play a crucial role in collaborative IEP team interventions. This study established expertise in the context of special education in South Korea.

Field Validation of Earthwork Compaction Quality Control Based on Intelligent Compaction Technology (지능형 다짐 기술 기반 토공사 다짐 품질관리 실증 연구)

  • Baek, Sung-Ha;Kim, Jin-Young;Kim, Jisun;Cho, Jin-Woo
    • Journal of the Korean Geotechnical Society
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    • v.39 no.11
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    • pp.85-95
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    • 2023
  • This study implemented intelligent compaction technology at the construction site of the AY Highway in Gyeonggi Province, with a focus on obtaining the representative intelligent compaction value, CMV. The target CMV for quality control was established through trial construction, and the validation of the compaction quality control process based on intelligent compaction was conducted. The optimal approach for determining the target CMV was confirmed to be through linear regression of the average CMV measured within a 5-m radius from the plate load testing location. Upon assessing compaction quality against the target CMV, it was observed that the quality criteria outlined in the domestic intelligent compaction standard were met. However, the criteria outlined in Austria and the United States were not satisfied. Notably, indicators related to the variability of compaction quality did not meet the specified criteria, suggesting a stringent standard compared to the observed variability of CMV, ranging from 17% to 55%. Consequently, it is recommended to conduct additional field tests to further validate the compaction quality control process based on intelligent compaction. This will aid in confirming and enhancing the appropriateness of the regulations stipulated in each standard.

Climatic Yield Potential Changes Under Climate Change over Korean Peninsula Using 1-km High Resolution SSP-RCP Scenarios (고해상도(1km) SSP-RCP시나리오 기반 한반도의 벼 기후생산력지수 변화 전망)

  • Sera Jo;Yong-Seok Kim;Jina Hur;Joonlee Lee;Eung-Sup Kim;Kyo-Moon Shim;Mingu Kang
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.25 no.4
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    • pp.284-301
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    • 2023
  • The changes in rice climatic yield potential (CYP) across the Korean Peninsula are evaluated based on the new climate change scenario produced by the National Institute of Agricultural Sciences with 18 ensemble members at 1 km resolution under a Shared Socioeconomic Pathway (SSP) and Representative Concentration Pathways (RCP) emission scenarios. To overcome the data availability, we utilize solar radiation f or CYP instead of sunshine duration which is relatively uncommon in the climate prediction f ield. The result show that maximum CYP(CYPmax) decreased, and the optimal heading date is progressively delayed under warmer temperature conditions compared to the current climate. This trend is particularly pronounced in the SSP5-85 scenario, indicating faster warming, except for the northeastern mountainous regions of North Korea. This shows the benef its of lower emission scenarios and pursuing more efforts to limit greenhouse gas emissions. On the other hand, the CYPmax shows a wide range of feasible futures, which shows inherent uncertainties in f uture climate projections and the risks when analyzing a single model or a small number of model results, highlighting the importance of the ensemble approach. The f indings of this study on changes in rice productivity and uncertainties in temperature and solar radiation during the 21st century, based on climate change scenarios, hold value as f undamental information for climate change adaptation efforts.

Analysis of Changes in Restaurant Attributes According to the Spread of Infectious Diseases: Application of Text Mining Techniques (감염병 확산에 따른 레스토랑 선택속성 변화 분석: 텍스트마이닝 기법 적용)

  • Joonil Yoo;Eunji Lee;Chulmo Koo
    • Information Systems Review
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    • v.25 no.4
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    • pp.89-112
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    • 2023
  • In March 2020, as it was declared a COVID-19 pandemic, various quarantine measures were taken. Accordingly, many changes have occurred in the tourism and hospitality industries. In particular, quarantine guidelines, such as the introduction of non-face-to-face services and social distancing, were implemented in the restaurant industry. For decades, research on restaurant attributes has emphasized the importance of three attributes: atmosphere, service quality, and food quality. Nevertheless, to the best of our knowledge, research on restaurant attributes considering the COVID-19 situation is insufficient. To respond to this call, this study attempted an exploratory approach to classify new restaurant attributes based on understanding environmental changes. This study considered 31,115 online reviews registered in Naverplace as an analysis unit, with 475 general restaurants located in Euljiro, Seoul. Further, we attempted to classify restaurant attributes by clustering words within online reviews through TF-IDF and LDA topic modeling techniques. As a result of the analysis, the factors of "prevention of infectious diseases" were derived as new attributes of restaurants in the context of COVID-19 situations, along with the atmosphere, service quality, and food quality. This study is of academic significance by expanding the literature of existing restaurant attributes in that it categorized the three attributes presented by existing restaurant attributes and further presented new attributes. Moreover, the analysis results have led to the formulation of practical recommendations, considering both the operational aspects of restaurants and policy implications.

Creation of Crack BIM in Bridge Deck and Development of BIM-FEM Interoperability Algorithm (교량 바닥판의 균열 BIM 생성 및 BIM-FEM 상호 연계 알고리즘 개발)

  • Yang, Dahyeon;Lee, Min-Jin;An, Hyojoon;Jung, Hyun-Jin;Lee, Jong-Han
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.6
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    • pp.689-693
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    • 2023
  • Domestic bridges with a service life of more than 30 years are expected to account for approximately 54% of all bridges within the next 10 years. As bridges rapidly deteriorate, it is necessary to establish an appropriate maintenance plan. Recent domestic and international research have focused on the integration of BIM to digitize bridge maintenance information and then enhance accessibility and usability of the information. Accordingly, this study developed a BIM-FEM interoperability algorithm for bridge decks to convert maintenance information into data and efficiently manage the history of maintenance. After creating an initial crack BIM based on an exterior damage map, bridge specification and damage information were linked to a numerical analysis that performs damage analysis considering damage scenarios and design loads. The spread of cracks obtained from the analysis results were updated into the BIM. Based on the damage spread information on the BIM, an automated technology was also developed to assess both the current and future condition ratings of the bridge deck. This approach can enable an efficient maintenance of the deck using the history data from bridge inspection and diagnosis as well as future information on cracks and defects. The expected early detection and prevention would ultimately improve the lifespan and safety of bridges.

Structural Performance Evaluation of Anchors for Power Equipment Electrical Cabinets Considering On-Site Installation Conditions (현장 설치 조건을 고려한 발전설비 전기 캐비닛 정착부 앵커의 구조성능 평가)

  • Lee, Sang-Moon;Jung, Woo-Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.6
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    • pp.709-719
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    • 2023
  • In general, most of the electrical equipment responsible for control within power plants is housed in self-standing cabinets. These cabinets are typically fixed to a slab using post-installed anchors. Although the fixation method of using post-installed anchors provides stability, there is a risk of conductor failure due to external forces, including moments. However, the performance assessment of current anchors is only evaluated through uniaxial material tests. Therefore, the primary purpose of this study is to compare the static performance of post-installed anchors, considering on-site installation conditions, with their performance in material tests and to analyze the behavioral characteristics of the anchors. While conducting experiments using actual cabinets would be ideal, practical and spatial constraints make this approach difficult. As an alternative, experiments were conducted using a test specimen consisting of a steel column and a support. As a result, the pull-out performance of anchors reflecting on-site installation conditions was measured to be about 10% higher than that observed in material tests. The trends in load reduction and the point of maximum performance for the anchors also differed. To verify the reliability of the experimental study, a 3D FEM analysis was performed, which will provide predictive information on the loads transferred to the post-installed anchors for structural performance evaluations of electrical cabinets using shaking table test in the future.

Analysis of Flood Level Changes by Creating Nature-based Flood Buffering Section (자연성기반 홍수완충공간 조성에 따른 홍수위 변화 분석)

  • Ryu, Jiwon;Ji, Un;Kim, Sanghyeok;Jang, Eun-kyung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.6
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    • pp.735-747
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    • 2023
  • In recent times, the sharp increase in extreme flood damages due to climate change has posed a challenge to effectively address flood-related issues solely relying on conventional flood management infrastructure. In response to this problem, this study aims to consider the effectiveness of nature-based flood management approaches, specifically levee retreat and relocation. To achieve this, we utilized a 1D numerical model, HEC-RAS, to analyze the flood reduction effects concerning floodwater levels, flow velocities, and time-dependent responses to a 100-year frequency flood event. The analysis results revealed that the effect of creating a flood buffer zone of the nature-based solution extends from upstream to downstream, reducing flood water levels by up to 30 cm. The selection of the flow roughness coefficient in consideration of the nature-based flood buffer space creation characteristics should be based on precise criteria and scientific evidence because it is sensitive to the flood control effect analysis results. Notably, floodwater levels increased in some expanded floodplain sections, and the reduction in flow velocities varied depending on the ratio of the expanded cross-sectional area. In conclusion, levee retreat and floodplain expansion are viable nature-based alternatives for effective flood management. However, a comprehensive design approach is essential considering flood control effects, flow velocity reduction, and the timing of peak water levels. This study offers insights into addressing the challenges of climate-induced extreme flooding and advancing flood management strategies.