• Title/Summary/Keyword: ENVIRONMENTAL ASSESSMENT

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Development of a Single Allocation Hub Network Design Model with Transportation Economies of Scale (수송 규모의 경제 효과를 고려한 단일 할당 허브 네트워크 설계 모형의 개발)

  • Kim, Dong Kyu;Park, Chang Ho;Lee, Jin Su
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.6D
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    • pp.917-926
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    • 2006
  • Transportation Economies of scale are the essential properties of hub networks. One critical property of the hub network design problem is to quantify cost savings which stem from economies of scale, the costs of operating hub facilities and opportunity costs associated with delays stemming from consolidation of traffic flows. Due to the NP-complete property of the hub location problem, however, most previous researchers have focused on the development of heuristic algorithms for approximate solutions. The purpose of this paper is to develop a hub network design model considering transportation economies of scale from the consolidation of traffic flows. The model is designed to consider the uniqueness of hub networks and to determine several cost components. The heuristic algorithms for the developed model are suggested and the results of the model are compared with recently published studies using real data. Results of the analysis show that the proposed model reflects transportation economies of scale due to consolidation of flows. This study can form not only the theoretical basis of an effective and rational hub network design but contribute to the assessment of existing and planned logistics systems.

Application of Multi-Dimensional Flood Damage Analysis for Urban Flood Damage (다차원 홍수피해산정방법을 이용한 도시지역의 홍수피해액 산정)

  • Lee, Keon Haeng;Choi, Seung An;Kim, Hung Soo;Shim, Myung Pil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.4B
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    • pp.363-369
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    • 2006
  • A simple and an improved methods for the economic analysis of the flood control project has been in previous studies in Korea. In 2004, the Multi-Dimensional Flood Damage Analysis (MD-FDA) was developed and now it is widely used for the economic analysis of flood control project. However, the MD-FDA was developed for general damage assessment and analysis without consideration of specific regional characteristics such as urban and rural areas. To compensate the MD-FDA for the application in urban area, a part of damage estimation components is modified and a component for the flood damage estimation is suggested. The component we suggest is for the consideration of the capability of stormwater pump stations in the study area. When flood is occurred in the urban area, the damage potential is larger than the rural area because of the concentration of human lives and properties. So, many stormwater pump stations are located in the urban area and the inundation depth is estimated by considering the capabilities of pump stations. We also compensate the damage components such as the damages of industrial area, and public facilities for the flood damage estimation of the urban area. The results by the compensated MD-FDA for the urban area application with those by original MD-FDA are compared. As a result the B/C ratio showed 6.75 and 5.51 respectively for the modified and original MD-FDA. This difference might be largely affected by the damage rate of the public facilities.

Tunnel Design/Construction Risk Assessment base on GIS-ANN (GIS-ANN 기반의 도심지 터널 설계/시공 위험도 평가)

  • Yoo, Chung Sik;Kim, Joo Mi;Kim, Sun Bin;Jung, Hye Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.1C
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    • pp.63-72
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    • 2006
  • Due to rapid development of many cities in Korea, many public facilities are required to be built as well as complementary civil structures. Consequently, a number of tunnel constructions are currently carried out throughout the country, and many more tunnels are planned to be constructed in the near future. Tunnel excavation in a city often causes serious damage to above-ground structures and sewer system because of unexpected settlement. In order to prevent the destruction, the tunnel, which bypasses the center of a city, must be specially evaluated for its influence to other structure. In addition, since a slight disturbance of above-ground structure causes numerous public complaints and civil appeals, it must be approached with different method than the mountain tunnels. In this paper, the evaluation method using the Artificial Neural Network (ANN) has been studied. The method begins with an analysis of the minimal sectional area. If its result can be used to approximate the general influence of the whole section, the actual evaluation using ANN will take off. In addition, it also studies the construction management method which reflects the real time soil behavior and environment influence during construction using Geographic Information System (GIS).

Assessment of Public Engagement Approach in Various Project Stages: The Case Study of Central Market, Hong Kong

  • Wong, Crystal;Chan, Icy;Lam, Lily;Zayed, Tarek;Sun, Yi
    • International conference on construction engineering and project management
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    • 2020.12a
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    • pp.267-277
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    • 2020
  • The present research evaluates the public engagement approach in various project stages. Hong Kong had long been criticized as top-down and executive-led jurisdiction by overlooking the importance of cultural heritage and public concerns on public projects. It was suggested to the government to engage public and provide sufficient public consultation. Thereby, the government announced a series of revitalization and conversion measures in Policy Address in 2008. To carry out the measures, there were voices, because of diverse and sometimes conflicting interests, over the effect of revitalization project. On the other hand, studies reveal that there are benefits of revitalization and enhancement of public engagement approach. In pursuit of the subject, the present research aims at studying the Central Market as a case study pilot project. In October 2009, the Policy Address announced that the Central Market be revitalized. Tasked to implement the project, Urban Renewal Authority (URA) continued to adopt the people-oriented approach as the guiding principle in its core business and in heritage preservation and revitalization so as to create a sustainable development. Between government and the public, URA acts as a bridge for communication. As between URA and the public, URA conducted public consultation, set up an ad-hoc committee in January 2016 to be in charge of the project and will continuously inform the government and public with the updates and project progress. The main objectives of the present research are to assess the advantages and challenges in different stages of public engagement approach, to evaluate the engagement system, to give a comprehensive view for participation of stakeholders, and to find out effective strategies to enhance civil engagement. Research was achieved through interviews to key persons in the project, questionnaire that was distributed to community and experts in the field. Case Study of the Central Market was studied and investigated using different sources, such as newspapers, journals, etc, to evaluate the degree of public engagement in the project. Both detailed qualitative methodological approaches of interview, questionnaire, and case study, act as a synergy to demonstrate the research objectives and provide the comprehensive perceptions on the revitalization project. The results show that public participants in revitalized project have generated considerable value enhancements to social-cultural, environmental, political and economic aspect. This study provides valuable insights that the public participation can make positive contribution to sustainability in the city. The findings indicate that no any single system is flawless therefore seeking both public opinions and professional advices are also important as a comprehensive approach to achieve higher sustainability of the building.

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Unmanned AerialVehicles Images Based Tidal Flat Surface Sedimentary Facies Mapping Using Regression Kriging (회귀 크리깅을 이용한 무인기 영상 기반의 갯벌 표층 퇴적상 분포도 작성)

  • Geun-Ho Kwak;Keunyong Kim;Jingyo Lee;Joo-Hyung Ryu
    • Korean Journal of Remote Sensing
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    • v.39 no.5_1
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    • pp.537-549
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    • 2023
  • The distribution characteristics of tidal flat sediment components are used as an essential data for coastal environment analysis and environmental impact assessment. Therefore, a reliable classification map of surface sedimentary facies is essential. This study evaluated the applicability of regression kriging to generate a classification map of the sedimentary facies of tidal flats. For this aim, various factors such as the number of field survey data and remote sensing-based auxiliary data, the effect of regression models on regression kriging, and the comparison with other prediction methods (univariate kriging and regression analysis) on surface sedimentary facies classification were investigated. To evaluate the applicability of regression kriging, a case study using unmanned aerial vehicle (UAV) data was conducted on the Hwang-do tidal flat located at Anmyeon-do, Taean-gun, Korea. As a result of the case study, it was most important to secure an appropriate amount of field survey data and to use topographic elevation and channel density as auxiliary data to produce a reliable tidal flat surface sediment facies classification map. In addition, regression kriging, which can consider detailed characteristics of the sediment distributions using ultra-high resolution UAV data, had the best prediction performance compared to other prediction methods. It is expected that this result can be used as a guideline to produce the tidal flat surface sedimentary facies classification map.

Efficiency Assessment of China's Yangtze River Ports- Based on the 3-Stage DEA (중국 양쯔강(장강) 내륙항만의 효율성 평가 - 3단계 DEA 모델을 토대로)

  • Xi-Na Ji;Kyoung-Suk Choi
    • Korea Trade Review
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    • v.48 no.1
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    • pp.215-241
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    • 2023
  • As competition between ports intensifies, port efficiency has always been a hot topic in the port and shipping economy. Boosting regional and national economies by improving port efficiency and promoting sustainable development of ports is also a concern for port operators and local and national governments. In this situation, this study has the following objectives. First, using panel data from 2010 to 2017, the efficiency of 14 major inland ports along the Yangtze River was analyzed, and changes in port efficiency over time were examined. Second, 14 inland ports are divided into the middle, upper, and lower Yangtze River port groups to compare and review differences in efficiency levels of ports by basin. For the study, we applied a three-step DEA analysis method, which evaluated the pure relative efficiency of the port itself by removing the effects of environmental factors and statistical noise that could affect the efficiency evaluation and presented the results. As a result, it was confirmed that there was a clear difference in the efficiency value of the port between the first-stage and the third-stage efficiency evaluation result. In addition, the downstream ports showed relatively high efficiency compared to the middle and upstream ports.

Prediction of Water Storage Rate for Agricultural Reservoirs Using Univariate and Multivariate LSTM Models (단변량 및 다변량 LSTM을 이용한 농업용 저수지의 저수율 예측)

  • Sunguk Joh;Yangwon Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.5_4
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    • pp.1125-1134
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    • 2023
  • Out of the total 17,000 reservoirs in Korea, 13,600 small agricultural reservoirs do not have hydrological measurement facilities, making it difficult to predict water storage volume and appropriate operation. This paper examined univariate and multivariate long short-term memory (LSTM) modeling to predict the storage rate of agricultural reservoirs using remote sensing and artificial intelligence. The univariate LSTM model used only water storage rate as an explanatory variable, and the multivariate LSTM model added n-day accumulative precipitation and date of year (DOY) as explanatory variables. They were trained using eight years data (2013 to 2020) for Idong Reservoir, and the predictions of the daily water storage in 2021 were validated for accuracy assessment. The univariate showed the root-mean square error (RMSE) of 1.04%, 2.52%, and 4.18% for the one, three, and five-day predictions. The multivariate model showed the RMSE 0.98%, 1.95%, and 2.76% for the one, three, and five-day predictions. In addition to the time-series storage rate, DOY and daily and 5-day cumulative precipitation variables were more significant than others for the daily model, which means that the temporal range of the impacts of precipitation on the everyday water storage rate was approximately five days.

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.

Automation of Sampling for Public Survey Performance Assessment (공공측량 성과심사 표본추출 자동화 가능성 분석)

  • Choi, Hyun;Jin, Cheol;Lee, Jung Il;Kim, Gi Hong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.44 no.1
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    • pp.95-100
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    • 2024
  • The public survey performance review conducted by the Spatial Information Quality Management Institute is conducted at the screening rate in accordance with the regulations, and the examiner directly judges the overall trend of the submitted performance based on the extracted sample. However, the evaluation of the Ministry of Land, Infrastructure and Transport, the evaluation trustee shall be specified by random extraction (Random Collection) is specified by the sample. In this study, it analyzed the details of the actual site and analyzed through securing actual performance review data. In addition, we analyzed considerations according to various field conditions and studied ways to apply the public survey performance review sampling algorithm. Therefore, detailed sampling criteria analysis by performance reviewers is necessary. A relative comparison was made feasible by comparing the data for which the real performance evaluation was performed with the outcomes of the Python automation program. This automation program is expected to be employed as a foundation program for the automated application of public survey performance evaluation sampling in the future.

Physical habitat characteristics of freshwater crayfish Cambaroides similis (Koelbel, 1892) (Arthropoda, Decapoda) in South Korea

  • Jin-Young Kim;Yong Ju Kwon;Ye Ji Kim;Yeong-Deok Han;Jung Soo Han;Chae Hui An;Yong Su Park;Dongsoo Kong
    • Journal of Ecology and Environment
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    • v.47 no.4
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    • pp.200-210
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    • 2023
  • Background: Cambaroides similis is an endangered candidate species living in the stream of South Korea. Freshwater crayfish is known to decline rapidly not only domestically, but also internationally. Its decline is projected to be further exacerbated due to climate change. Understanding physical characteristics of the habitat is crucial for the conservation of an organism. However, comprehensive data regarding the distribution and physical habitat characteristics of C. similis are currently unavailable in South Korea. Thus, the objective of this study was to ascertain preferred ranges for water depth, current velocity, and streambed substrate of C. similis using Weibull model. Results: In this study, C. similis was found at 59 sites across 12 regions in South Korea. Its optimal water depth preferences ranged from 11.9 cm to 30.1 cm. Its current velocity preferences ranged from 9.8 cm s-1 to 29.1 cm s-1. Its substrate preferences ranged from -5.1 𝜱m to -2.5 𝜱m. Median values of central tendency were determined as follows: water depth of 21.4 cm, current velocity of 21.2 cm s-1, and substrate of -4.1 𝜱m. Mean values of central tendency were determined as follows: water depth of 21.8 cm, current velocity of 22.0 cm s-1, and substrate of -4.4 𝜱m. Mode values of central tendency were determined as follows: water depth of 21.7 cm, current velocity of 20.1 cm s-1, and substrate of -3.7 𝜱m. Conclusions: Based on habitat suitability analysis, physical microhabitat characteristics of C. similis within a stream were identified as Run section with coarse particle substrate, low water depth, and slow current velocity. Due to high sensitivity of these habitats to environmental changes, prioritized selection and assessment of threats should be carried out as a primary step.