• International conference on construction engineering and project management
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• 2024.07a
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• pp.558-565
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• 2024

This paper presents the development of an optimization framework for road slope design. Recognizing the limitations of current manual stability analysis methods, which are time-consuming, are error-prone, and suffer from data mismatches, this study proposes a systematic approach to improve efficiency, reduce costs, and ensure the safety of infrastructure projects. The framework addresses the subjectivity inherent in engineers' decision-making process by formalizing decision variables, constraints, and objective functions to minimize costs while ensuring safety and environmental considerations. The necessity of this framework is embodied by the review of existing literature, which reveals a trend toward specialization within sub-disciplines of road design; however, a gap remains in addressing the complexities of road slope design through an integrated optimization approach. A genetic algorithm (GA) is employed as a fundamental optimization tool due to its well-established mechanisms of selection, crossover, and mutation, which are suitable for evolving road slope designs toward optimal solutions. An automated batch analysis process supports the GA, demonstrating the potential of the proposed framework. Although the framework focuses on the design optimization of single cross-section road slopes, the implications extend to broader applications in civil engineering practices. Future research directions include refining the GA, expanding the decision variables, and empirically validating the framework in real-world scenarios. Ultimately, this research lays the groundwork for more comprehensive optimization models that could consider multiple cross-sections and contribute to safer and more cost-effective road slope designs.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1325-1325
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• 2024

This research presents a joining system that changes an irregularly shaped material into a member that can be joined and disassembled as a single unit by attaching 3D printed joints. In extreme environments, including extraterrestrial environments, it takes much time and costs to supply materials from Earth. In addition, when living and working in such environments for long periods, a technology enabling the use of locally accessible materials or elements brought to the site for different purposes is essential to realize the construction based on the idea of In-Situ Resource Utilization (ISRU). This research proposes a joining system inspired by the traditional Japanese wooden joinery Kigumi. By integrating Kigumi's excellent features, such as high construction performance, disassemble performance, and mechanical performance, with 3D printing and 3D scanning technologies, the proposed joining system aims to enable irregular-shaped elements to be assembled and disassembled from one another without any fasteners (e.g., bolts, nails, and adhesive). Prototypes of the proposed joints, which apply the Japanese Koshikake-Ari-Tsugi technique, were printed by an additive manufacturing-type desktop 3D printer, then the investigation focused on determining the optimal clearance for the joint. Based on the results, a simple mockup was constructed. Its constructability and mechanical performance were examined. The findings revealed that the joints applying the traditional Japanese Kigumi were printable by the additive manufacturing-type desktop 3D-printer with proper clearance settings, and the proposed joining system shows high performance in construction, including disassembly. The findings provide insights into the feasibility of desktop 3D printing construction in extreme environments.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.27-30
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• 2008

Even though the frequency of constructing spatial structure is increasing currently, the problem is that no efficient medium to provide information of goof quality on spatial structure is existed. The information is available only for some limited number of major construction companies with experiences, not for the academic world, officials. It costs us much time and money gaining the information for spatial structure without integrated media. Thus the purpose of this study is to develop an integrated web database model for spatial structure.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.656-660
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• 2004

The Mobile Mapping System is an effective method to acquire the position and image data using vehicle equipped with the GPS (Global Positioning System), IMU (Inertial Measurement Unit), and CCD camera. It is used in various fields of road facility management, map update, and etc. In the general photogrammetry such as aerial photogrammetry, GCP (Ground Control Point)s are needed to compute the image exterior orientation elements (the position and attitude of camera). These points are measured by field survey at the time of data acquisition. But it costs much time and money. Moreover, it is not possible to make sufficient GCP as much as we want. However Mobile Mapping System is more efficient both in time and money because it can obtain the position and attitude of camera at the time of photographing. That is, Indirect Georeferencing must use GCP to compute the image exterior orientation elements, but on the other hand Direct Georeferencing can directly compute the image exterior orientation elements by GPS/INS. In this paper, we analyze about the positional accuracy comparison of ground point using the Direct Georeferencing and Indirect Georeferencing.

• Earthquakes and Structures
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• v.22 no.6
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• pp.561-570
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• 2022

It is of great importance to be able to evaluate different structural systems not only based on their seismic performance but also considering their lifetime service costs. Many structural systems exist that can meet the engineering requirements for different performance levels; therefore, these systems shall be selected based on their economic costs over time. In this paper, two structural systems, including special steel moment-resisting and the ordinary concentric braced frames, are considered, which are designed to meet the three performance levels: Immediate Occupancy (IO), Life Safety (LS), Collapse Prevention (CP). The seismic behavior of these two systems is studied under three strong ground motions (i.e., Tabas, Bam, Kajour earthquake records) using the Perform3D package, and the incurred damages to the studied systems are examined at two hazard levels. Economic analyses were performed to determine the most economical structural system to meet the specified performance level requirements, considering the initial cost and costs associated with damages of an earthquake that occurred during their lifetime. In essence, the economic lifetime study results show that the special moment-resisting frames at IO and LS performance levels are at least 20% more economical than braced frames. The result of the study for these building systems with different heights designed for different performance levels also shows it is more economical from the perspective of long-term ownership of the property to design for higher performance levels even though the initial construction cost is higher.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1293-1293
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• 2024

Virtual reality (VR) is increasingly utilized in the construction industry for diverse applications. Immersive virtual reality (IVR) offers practical experiences and educational opportunities for workers, enhancing productivity and safety. Efforts to optimize IVR involve analyzing biometric responses to monitor concentration, assess learning efficiency, and deliver personalized content. However, IVR faces challenges such as high production costs and prolonged production periods. Additionally, integrating biometric response recording into IVR experiences requires separate modules, further extending production timelines. To address these challenges, an integrated platform is necessary to streamline IVR production, user experience, and biometric response setup and recording. This study introduces such a platform designed to enhance the efficacy of IVR experiences through real-time biometric response analysis. The proposed platform comprises three main processes: (i) IVR content production using Unity; (ii) biometric response definition; and (iii) IVR content experience accompanied by generated logs for biometric responses. Firstly, IVR content production using Unity involves the development of IVR environments and scenarios. The platform incorporates diverse 3D models, including urban landscapes, building elements, and furniture, as the basis for IVR environments. Scenarios are constructed by integrating events into these environments, triggered by conditions such as reaching specific locations, the passage of time, or user interactions. Upon event activation, participants are presented with description UIs, quiz UIs, or route guidance, facilitating engagement and progression through interaction. Secondly, biometric responses encompass eye tracking and EEG. Eye tracking captures pupil diameter and fixation status on Areas of Interest (AOI), defined during IVR content production. EEG recording options include signals from each channel by default, as well as frequency-specific signals and EEG metrics such as attention, stress, fatigue, valence, and arousal. The platform supports the addition of new EEG metrics, enhancing customization and recording capabilities. Lastly, IVR content can be experienced alongside generated logs for biometric responses. The dataset enables monitoring and evaluation of participants' learning performance during IVR experiences, with the potential to enhance worker safety and productivity through immersive practical training and education.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.6
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• pp.887-892
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• 2019

Many researchers have developed a series of vision-based technologies to monitor construction sites automatically. To achieve high performance of vision-based technologies, it is essential to build a large amount and high quality of training image database (DB). To do that, researchers usually visit construction sites, install cameras at the jobsites, and collect images for training DB. However, such human and site-dependent approach requires a huge amount of time and costs, and it would be difficult to represent a range of characteristics of different construction sites and resources. To address these problems, this paper proposes a framework that automatically constructs a training image DB using web crawling techniques. For the validation, the authors conducted two different experiments with the automatically generated DB: construction work type classification and equipment classification. The results showed that the method could successfully build the training image DB for the two classification problems, and the findings of this study can be used to reduce the time and efforts for developing a vision-based technology on construction sites.

• Korean Journal of Construction Engineering and Management
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• v.19 no.6
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• pp.135-143
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• 2018

Normally there is a one-time relationship between stakeholders in the construction projects. Thus, project participants are easily exposed to opportunistic behavior. According to the theory of transaction costs, a contract effectively influence the behavior of counter-party. The important role of contracts in limiting opponent opportunistic behavior has been academically acknowledged and studied in inter-firm relationships. The purpose of this study is to reveal the mediating effect of the contract on the power of the contractor in the contractor's behavior. Power is divided into mediated and non-mediated power. We surveyed construction companies' employees who have conducted construction projects. Based on the questionnaire response, we examined the influence of the Employer's power on the behavior of the contractor. Both non-mediated power and mediated power were significant for in-role and out-role behaviors. Both non-mediated power and mediated power were found to have a significant effect on the control and coordination function of contracts. The results show that the control function of the contract is significant for the in-role behavior and the extra-role behavior. Finally, the mediating effect of the contract function was significant only in the control function.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.119-131
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• 2021

This study quantitatively derived the direct socio-economic effects of the Gyeongbu Expressway, which opened in 1970, and suggested a methodological approach for more reliable results. The scenario was set when the Gyeongbu Expressway was not constructed in 1970, the opening of the Gyeongbu Expressway was delayed by 10 years, and the toll road between Seoul and Daejeon, or between Seoul and Gangneung was opened instead of the Gyeongbu Expressway as suggested by the World Bank. In addition, direct benefits were estimated by calculating and comparing the current vehicle operating costs, travel time costs, traffic accident costs, and environmental pollution costs. As a result, it was estimated that about 351 trillion won in direct benefits occurred, and it can be seen that the promotion of the construction project of the Gyeongbu Expressway at that time had a huge impact on South Korea's social economy.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.10
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• pp.329-336
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• 2014

Pipe spool is the most important element of plant equipment in plant construction site. Currently, the plant construction site manage the pipe spool location and usage history by handwriting. Frequently, the pipe spool is moved to unpredictable places by field workers in many construction sites and in cases like this, the pipe stool is replaced with another similar pipe spool. Since it's hard to determine the exact location of some of the pipe spools, it takes unnecessary time and labour to find the missing pipe spools, which proves that stock management is not under control. The purpose of our system is to make the identification of real-time location of the field pipes possible by attaching UHF RFID tags to the pipe spool, which will be used to connect with UHF RFID reader and antenna on vehicles. A field test conducted by the proposed system resulted in the success rate of 98% and the missing 2% was recuperated by hands-on correction, which proved that stock management through the proposed method can be 100% effective. The proposed system is expected to reduce labour costs and make stock control of assets possible, as well as applicable to similar stock management environments.