• Journal of the Korean Geotechnical Society
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• v.25 no.10
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• pp.77-85
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• 2009

This paper describes the findings obtained from a research project aimed at investigating, via 1 g laboratory model tests, the ground movements caused by multiple side-by-side (sbs) tunnel construction in clay. The ground movements above a second tunnel showed different trends from those observed above a first tunnel. These trends include an increase in the overall volume loss, and a widening of the settlement troughs on the near limb of the trough accompanied by a shift of the maximum settlement towards existing tunnel. This would suggest that the use of simple predictive methods of adopting a Gaussian curve for analysing the ground settlements associated with twin (sbs) tunnel construction is not appropriate. Therefore the current paper adopts a method that modifies the Gaussian curve approach in order to improve the predictions. This paper comments on the parameter selection involved with adopting this new method to apply it to full-scale field situations, and also discusses its limitations.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.119-127
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• 2022

Most of the construction works are conducted outdoors, so the construction workers are affected by weather conditions such as temperature, humidity, and wind velocity which can be evaluated the thermal comfort as environmental factors. In our previous researches, it was found that construction accidents are usually occurred in the discomfort ranges. The safety management, therefore, should be planned in consideration of the thermal comfort and measured by a specialized simulation tool. However, it is very complex, time-consuming, and difficult to model. To address this issue, this study is aimed to develop a framework of a prediction model for improving the prediction accuracy about outdoor thermal comfort considering environmental factors using machine learning algorithms with hyperparameter tuning. This study is done in four steps: i) Establishment of database, ii) Selection of variables to develop prediction model, iii) Development of prediction model; iv) Conducting of hyperparameter tuning. The tree type algorithm is used to develop the prediction model. The results of this study are as follows. First, considering three variables related to environmental factor, the prediction accuracy was 85.74%. Second, the prediction accuracy was 86.55% when considering four environmental factors. Third, after conducting hyperparameter tuning, the prediction accuracy was increased up to 87.28%. This study has several contributions. First, using this prediction model, the thermal comfort can be calculated easily and quickly. Second, using this prediction model, the safety management can be utilized to manage the construction accident considering weather conditions.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.281-290
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• 2017

As various stakeholders are involved in construction projects, disputes between the parties are more likely to occur, which is a very important issue for the participants in the projects. Claims in construction projects, however, are very complex and thus difficult to manage. In particular, as the cause of a claim in the preceding stage that has not been resolved in a timely manner has an effect on the cause of a claim in the following stage, it is difficult to find a point of compromise regarding a claim caused by the relationship between the causes that occur in the preceding and following stages. In this regard, this study sought to examine the rules for the generation of change order claims, which occur most frequently among the construction claims, and thus to select the key management targets through the analysis of the relationship between the causes of claims arising in the preceding and following stages for the efficient management of claims. It is expected that the use of rules for the generation of change order claims as well as of representative and similar cases will help the construction practitioners in judging claims, considering the relationships among the causes of the claims. Meanwhile, in this study, association analysis was conducted regarding the causes of the occurrence of change order claims in a design-build delivery method, and therefore, it is necessary to verify the effectiveness of the method when applied to other delivery methods.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.63-74
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• 2020

The assembly of modular construction requires a series of thoroughly-considered decisions for crane lifting including the crane model selection, crane location planning, and lift path planning. Traditionally, this decision-making process is empirical and time-consuming, requiring significant human inputs. Recently, research efforts have been dedicated to improving lift planning practices by leveraging cutting-edge technologies such as automated data acquisition, Building Information Modelling (BIM) and computational algorithms. It has been demonstrated that these technologies have advanced lift planning to some degree. However, the advancements tend to be fragmented and isolated. There are two hurdles prevented a systematic improvement of lift planning practices. First, the lack of formalized lift planning workflow, outlining the procedure and necessary information. Secondly, there is also an absence of a shared information environment, enabling storages, updates and the distribution of information to stakeholders in a timely manner. Thus, this paper aims to overcome the hurdles. The study starts with a literature review in combination with document analysis, enabling the initial workflow and information flow. These were contextualised through a series of interviews with Australian practitioners in the crane-related industry, and systematically analysed and schematically validated through an expert panel. Findings included formalized workflow and corresponding information exchanges in a traditional lift planning practice via a Business Process Model and Notation (BPMN). The traditional practice is thus reviewed to identify opportunities for further enhancements. Finally, a BIM-based lift planning workflow is proposed, which integrates the scattered technologies (e.g. BIM and computational algorithms) with the aim of supporting lift planning automation. The resulting framework is setting out procedures that need to be developed and the potential obstacles towards automated lift planning are identified.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.133-140
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• 2013

The purpose of this study is identifying the relationship among the business strategy, order receiving capability and leverage variables of a construction company using industry characteristic variables, in addition to the explanation variables used in the previous studies. The samples of this study were limited to the construction companies listed in Korean stock market. This study built multiple regression analysis models, which have been frequently used in traditional previous studies, in the explanation of company capital structure. Empirical analysis on Static Trade-off Theory and Pecking Order Theory was done by the built model. The study results suggested that the capital structure determination behavior of a construction company generally follows Static Trade-off Theory; however, profitability was found to follow Pecking Order Theory. The explanation variables used in the previous capital structure studies mostly produced significant results; however, the variables, which this study experimentally used, did not produce significant results. It is believed that it implies that additional studies are required in the selection of variables and study methodology. Consequently, a case that unconditionally supports a particular theory is scarce. It has been also found that a case can support both theories at the same time. Therefore, it is believed that development study methodology or introduction of new study methodology that can identify the dynamic characteristic of construction company capital structure formation is required.

• Journal of the Korean Geosynthetics Society
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• v.22 no.4
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• pp.63-71
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• 2023

The extreme cold regions, including the South and North Poles, are rich in resources, but there are many constraints on resource development projects due to difficult access and a construction environment that is completely different from that of Korea. In recent years, global warming has increased the demand for the construction of resource exploitation plants. For resource development construction activities, a preliminary site analysis is required to minimize the risk of project implementation. In this study, the factors were analyzed to be considered in construction activities in extreme cold and optimal location selection system based on Geographic information system(GIS) has been developed. As a result of applying the development system to Alberta, Canada, where oil sand development is actively underway, it was confirmed that the results were consistent with the currently operating oil sand mining area.

• The Journal of the Convergence on Culture Technology
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• v.10 no.5
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• pp.201-208
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• 2024

This study aims to analyze the causes and characteristics of conflicts arising from the relocation of national defense facilities, focusing on the Jeonju Aviation School relocation project, and to explore effective conflict management strategies. As urbanization progresses, military facilities initially located on the outskirts of cities have been integrated into urban areas, increasing the need for relocation. This process frequently results in conflicts among the government, the military, and local residents due to differing interests. This study employs a combination of literature review and surveys to examine perceptions of conflict causes and resolution strategies. The findings reveal that the primary conflict factors include inadequate information provision and consultation, noise and property value decline, and unilateral decision-making processes. Participatory decision-making was found to be effective in resolving conflicts. Based on these findings, the study proposes policy recommendations such as institutional improvements, enhanced information disclosure and communication, comprehensive compensation systems, and strengthened expertise in conflict management. This research is significant in empirically confirming the importance of participatory decision-making in national defense facility relocation projects and providing specific policy suggestions for conflict management.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.6
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• pp.53-66
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• 2019

The purpose of this study was to suggest indicator-based selection and improvement plans for evaluating urban regeneration projects. First, we selected the indicators by conducting expert surveys and analysis of the responses received. Additionally, using the selected indicators, we analyzed the residents' opinions in Wongogae Village, where urban regeneration projects were in progress. Based on these, we suggested a plan to improve Wongogae Village. According to the study, we classified the urban regeneration evaluation indicators into 'Physical environment', 'Social environment' and 'Economic environment' according to their characteristics. We selected urban regeneration evaluation factors through the first expert survey and MCB analysis. As a result, we selected six factors for the 'Physical environment' category: 'Traffic and pedestrian environment', 'Residential (housing) environment', 'Safety and security environment', 'Greenspace', 'Landscape improvement' and 'Public space', In the 'Social environment' category, four factors were chosen: 'Resident participation', 'Community activation', 'Role of the local government and support centers' and 'Resident education' while for the 'Economic environment' category three factors were selected: 'Local economic revitalization', 'Creating an economy-based environment', 'Job creation'. Next, we conducted a second expert survey and carried out an AHP analysis using the selected evaluation factors to derive the overall weight for each. Among the evaluation factors for urban regeneration, the 'Residential (housing) environment' has the highest weighted value of 0.108, followed by 'Local economic revitalization' and 'Resident participation'. Lastly, the analysis of the residents' opinions of Wongogae Village using the urban regeneration evaluation factors, Parking environment', 'Maintenance of old houses and living environment', 'Environment for founding town and social enterprises', 'Improve commercial and business environment', 'Maintain and activate existing business' and 'Vitalizing small regional economies such as domestic handicrafts and side-job' had high overall importance, but low satisfaction, which means that it is necessary to improve the focus. Therefore, in order to improve the urban regeneration project in villages, it is necessary to improve the parking environment by expanding public parking lots, eliminate close houses, and idle lands, or open a school playground in the village for the residents. In addition, it is essential to encourage economic activities, such as fostering village enterprises and social enterprises in connection with cooperatives and allow for the selling of the products through resident activities, such as neighboring markets.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.1 no.1
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• pp.73-82
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• 2000

Conventional funding system for the university research projects is limited to a grant or subsidy type funding method which does not require an obligation of refund. Such a funding system is known as ideal one for the university research activities which in general is not a profit oriented activities. It is considered ideal in a sense that nonprofit oriented research activities gives more emphasis on creativity than on efficiency or practical value. A venture- business-start-up research activity can not be considered as a pure nonprofit oriented activities. It clearly gives more emphasis on efficiency and practical value than on creativity Recently a large portion of the venture-business-start-up research activities are carried out in the universities. When a conventional research funding system is applied to such a new type of research activities, it turned out that the success rate is much lower than expectancy. This is why a new and differentiated funding system is sought for such a new type of research activities. A funding system of loan type for a venture-business-start-up research activities is proposed herewith. A loan system naturally requires a pay back after the successful start up of the venture business. This loan system nay be considered that a business concept is grafted on a conventional funding system for the university research activities. This means that a rather loose or generous terms and conditions of the money loan case is introduced into this funding system to remedy the short comings of the intrinsic nonprofit nature of the university research activities. The point is how to improve the success rate and how to reduce the undesirable aspect of the conventional university research activities when it is practiced with the new type of research activities. After one and half year of practicing with the new funding system. it can not be asserted that a definitely positive results could be obtained. but a trend of desirable aspects could be observed such as low drop out rate. project selection efficiency, higher sense of responsibility. etc.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.6
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• pp.70-83
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• 2022

This study aims to select evaluation items that can be used in planning park creation to evaluate the proposal to solve the environmental and social problems in promoting private-initiated park development projects. To this end, evaluation items that can consider various aspects of the development project were selected, and the indicators' validity and appropriateness were carried out through an expert Focus Group Interview (FGI). Firstly, an expert FGI was performed for six major categories and 50 evaluation items derived from literature reviews and brainstorming. As a result, five major and 27 middle category items were selected. Based on the derived major and middle classification items, 95 detailed items were selected. Secondly, 55 sub-items were derived through a suitability questionnaire. As a result of the suitability survey, the average scores of the subcategories for the major categories of natural environment, function of parks, and use of land were relatively high. The average scores for environmental index items such as ecology/vegetation, topography and slope, landscape, park service, wildlife, wide-area ecosystem, and park items were high in the middle classification. The average score of indicators in the natural environment was relatively high, and the average score in the function of parks also soared. In the environmental impact assessment, the occurrence of plan change issues, including the reappraisal of the location, led to unclear detailed evaluation factors for the faithfulness of the plan and the appropriateness of the plan direction. This study is significant in that it is a study on the selection of evaluation items that can minimize the problem of plan alteration and achieve objective evaluation when promoting development projects. This study could be used to forward development projects in the future and evaluate long-term unexecuted urban parks.