• Journal of Aerospace System Engineering
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• v.14 no.6
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• pp.1-9
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• 2020

Global e-commerce and delivery companies are actively pursuing last-mile delivery service using drones, and various delivery schedule planning studies have been conducted. In this study, separate individual route networks were constructed to reflect drone route constraints such as prohibited airspace and truck route constraints such as rivers, which previous studies did not incorporate. The A* algorithm was used to calculate the shortest path distance matrix between the starting point and destinations. In addition, we proposed an optimal delivery schedule plan using genetic algorithms and applied it to compare the efficiency with that of vehicle-only delivery.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.381-385
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• 2015

This research aims to investigate critical factors of the government's role in achieving success in Public Private Partnership (PPP) toll road projects in Indonesia according to government and private sectors' perceptions. A preliminary interview Subsequently a questionnaire survey was also conducted involving 143 respondents across the two sectors from eight operating toll were five critical factors of the government's roles in achieving success in PPP toll road projects, namely; "Active involvement in overall project stage activities", "Establishment of good bureaucracy", "Provision of conducive environment", "Appropriate project planning and competitive tendering" and "Provision of appropriate government support and supervision". This research finding is expected to assist the government in defining clear roles and underlying responsibilities in development of PPP toll roads in Indonesia.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.823-830
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• 2024

Effective project planning is essential in construction project management for timely delivery and economic benefit realization. Work packages are pivotal in this planning, providing clear organization and progress tracking. However, existing methods for creating work package schemes often overlook environmental sustainability, specifically carbon emissions-a growing concern in construction. This study introduces a tabu search-based optimization method for work package schemes, aiming to reduce both project costs and carbon emissions. A cost-carbon model is devised, and a tabu search algorithm is developed to identify the Pareto frontier for total project cost and carbon emissions. A case study shows the tabu search outperforms existing heuristics, reducing carbon emissions by 6.19% with a marginal cost increase of 0.9%. The algorithm's adaptability and generalizability suggest it could significantly enhance economic and sustainable outcomes in construction project planning.

• Smart Structures and Systems
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• v.13 no.6
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• pp.1065-1094
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• 2014

Civil engineers always face the challenge of uncertainty in planning, building, and maintaining infrastructure. These works rely heavily on a variety of surveying and monitoring techniques. Unmanned aerial vehicles (UAVs) are an effective approach to obtain information from an additional view, and potentially bring significant benefits to civil engineering. This paper gives an overview of the state of UAV developments and their possible applications in civil engineering. The paper begins with an introduction to UAV hardware, software, and control methodologies. It also reviews the latest developments in technologies related to UAVs, such as control theories, navigation methods, and image processing. Finally, the paper concludes with a summary of the potential applications of UAV to seismic risk assessment, transportation, disaster response, construction management, surveying and mapping, and flood monitoring and assessment.

• Korean Journal of Computational Design and Engineering
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• v.18 no.1
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• pp.58-70
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• 2013

This study for establishing specific standards of atrium design aims to discuss design of atrium to consider energy performance atrium in office buildings. In order to evaluate a type and a scale of atrium at the early design stage, modeling details of mass design were set as standards of conceptual design. In the experiment, Project Vasari was used to analyze modeling and energy consumption, based on the LOD 100-step suggested by AIA, because there is no guideline to specify a level of modeling details at each design process. From this analysis, the correlation among a simple-typed atrium and scale and energy load was considered. The result of this research is as follows: First, the single-sided atrium reduced energy the most, and it was followed by three-sided, two-sided, four-sided and continuous-typed ones. On the whole, they could decrease energy by up to about 15%. Also, the atrium with a wide facade facing in the south was more favorable to reduce energy. Second, planning the atrium within 10~30% of the whole building area was more energy efficient. Third, rather than the depth, adjusting the length in designing an atrium could reduce cooling and heating loads by 1.5% per 1m. As explained above, energy performance evaluation considering types and planning elements of atrium helps to assess alternatives in a reasonable way. In particular, considering the use of building needs to be preceded to select a type of atrium, although it is also important to consider its planning elements.

• Journal of Korea Water Resources Association
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• v.49 no.4
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• pp.315-325
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• 2016

Generally, a natural river discharge is highly regulated by the hydraulic structures, and the regulated flow is substantially different from natural inflow characteristics for the use of water resources planning. The natural inflow data are necessarily required for hydrologic analysis and water resources planning. This study aimed to develop an integrated model for more reliable simulation of daily dam inflow. First, a piecewise Kernel-Pareto distribution was used for rainfall simulation model, which can more effectively reproduce the low order moments (e.g. mean and median) as well as the extremes. Second, a Bayesian Markov Chain Monte Carlo scheme was applied for the SAC-SMA rainfall-runoff model that is able to quantitatively assess uncertainties associated with model parameters. It was confirmed that the proposed modeling scheme is capable of reproducing the underlying statistical properties of discharge, and can be further used to provide a set of plausible scenarios for water budget analysis in water resources planning.

• Korean Journal of Construction Engineering and Management
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• v.21 no.1
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• pp.21-31
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• 2020

Recently, interest and financial investment in community infrastructure have been growing. Accordingly, Korean Ministry of Land, Infrastructure and Transport suggested a standard for community infrastructure planning. The standard was based on time distance which represents citizens' accessibility to infrastructure facilities. This paper presents a method to use the navigation application programming interface (API) to calculate travel time. Buffer analysis using Euclidean distance has been widely used so far to evaluate accessibility. However, this method has limitation in that it does not reflect situations in the real world such as crosswalks and slope ways. The infrastructure accessibility indices of local towns in Yeonsu-gu, Incheon were computed based on the time obtained by navigation API. Also, Yeonsu-gu was spatially analyzed to reveal the resident units that are marginalized from community infrastructure facilities. Using navigation API enables to compute realistic accessibility indices and to find unbenefitted residential areas. The method presented in this paper can help community infrastructure planners for their facility spatial plan and budget distribution.

• Journal of Korea Water Resources Association
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• v.39 no.11 s.172
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• pp.947-960
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• 2006

This study shows the application of sustainable water resource planning procedure developed in the previous paper. Its goal is to prevent the streamflow depletion in upstream watershed of the Anyangcheon which is a typical urban stream. The pressure-state-response model which is the framework to reflect the sustainability was applied. The composite programming which is the multilevel multicriteria decision making technique is also used in the calculation of state and evaluation index. The feasible alternatives were proposed and hydrologically analyzed by SWAT(Soil and Water Assessment Tool) and the priority ranking of alternatives were proposed based on the results of SWAT.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1183-1188
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• 2009

Estimating project costs during the early stage of conceptual planning is very important when deciding whether to approve the project and allocate an appropriate budget. However, due to greater uncertainties involved in a project, it is challenging to estimate costs during this initial stage within a reasonable tolerance. This paper attempts to develop a cost-estimate model for public road projects under these circumstances and limitations. In the conceptual planning stage of a road project, there is only limited information for cost estimation, for example, such input data as total length of the route, origin and destination, number of lanes, general geographic characteristics of the route, and other basic attributes. This implies that the model should individuate suitable but restricted information without considering detailed features such as quantity of earthwork and a detailed route of a given condition. With these limited facts, this paper applies a case-based reasoning (CBR) method to solve a new problem by deriving similar past problems, which in turn is used to estimate the cost of a given project based on best-fitted previous cases. To develop a CBR cost-estimate model, the authors classified 8 representative variables, including project type, the number of lanes, total length, road design grades, etc. Then, we developed the CBR model, primarily by using 180 actual cases of public road projects, procured over the last decade. With the CBR model, it was found that the degree of error in estimation can be reasonably reduced, to below approximately 30% compared to the final costs estimated upon the completion of detailed design.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.923-928
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• 2022

Wildfire disasters in the United States impact lives and livelihoods by destroying private homes, businesses, community facilities, and infrastructure. Disaster victims suffer from damaged houses, inadequate shelters, inoperable civil infrastructure, and homelessness coupled with long-term recovery and reconstruction processes. Cities and their neighboring communities require an enormous commitment for a full recovery for as long as disaster recovery processes last. State, county, and municipal governments inherently have the responsibility to establish and provide governance and public services for the benefit and well being of community members. Municipal governments' comprehensive and emergency response plans are the artifacts of planning efforts that guide accomplishing those duties. Typically these plans include preparation and response to natural disasters, including wildfires. The standard wildfire planning includes and outlines (1) a wildfire hazard assessment, (2) response approaches to prevent human injury and minimize damage to physical property, and (3) near- and long-term recovery and reconstruction efforts. There is often a high level of detail in the assessment section, but the level of detail and specificity significantly lessons to general approaches in the long-term recovery subsection. This paper aims to document the extent of wildfire preparedness at the county level in general, focusing on the long-term recovery subsections of municipal plans. Based on the identified challenges, the researchers provide recommendations for better longer-term recovery and reconstruction opportunities: 1) building permit requirements, 2) exploration of the use of modular construction, 3) address through relief from legislative requirements, and 4) early, simple, funding, and the aid application process.