• Korean Journal of Construction Engineering and Management
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• v.9 no.3
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• pp.185-193
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• 2008

In order to improve work efficiency in high-rise apartment building construction, it is required to establish the major criteria and practical method for selecting the construction lifts. It is necessary to analyze work efficiency and economic feasibility depending on speed, size and capacity of lifting equipment and characteristics of construction projects. The purpose of this research is to develop the fundamental process and information for selecting the lift in order to plan and manage the material lifting and laborers' vertical transporting in the high-rise apartment building projects more effectively. In order to satisfy the objective of the research, work performance of the lifting machines with different speed and carrying capacity is analyzed under the practical constraints. In addition, potential economic evaluation is conducted. One of the significant findings of the research is that the mid-speed lift shows 43% improvement in work efficiency compared with the low-speed lift. The results of the research will be used as the basis for developing the further optimal lifting management system.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.3
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• pp.235-242
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• 2019

The objective of this study is to modify the mixture proportions of concrete that were developed for section enlargement strengthening elements using a specially designed binder composed of 5% ultra-rapid hardening cement, 10% polymer, and 85% ordinary portland cement in order to assign the self-compaction property to such concrete. The self-compaction abilities of concrete were estimated by the performance criteria specified in JSCE and EFNARC provions. Test results showed that the increase in the unit binder content at the consistent water-to-bider ratio led to increase in viscosity of fresh concrete but did not exhibit the decrease in the fluidity due to a greater viscosity. The mixture proportioning of self-compaction section enlargement concrete could be considered at the following conditions: unit binder contents of $430kg/m^3{\sim}470kg/m^3$ and fine aggregate-to-total aggregate ratios of 40%~46% at the water-to-binder ratio of 38%.

• Journal of Korea Port Economic Association
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• v.23 no.2
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• pp.121-144
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• 2007

In general, the design of container yard and container handling system on container terminal are focused on operation of shipside than service about chassis from outside(C/O). It is not efficient for chassis from outside. The purpose of this paper is functional assessment of efficient container terminal and for higher performance of container terminal. first, the items which are concerned with container handling at the planning of container terminal are investigated and extracted through the practical data analysis of container terminal. Also, verified problems of planning and present condition through the functional assessment. Secondly, the improvements for container throughput in container yard are proposed and examined the effectiveness of improvements about queuing time of chassis from outside and service time of transfer crane by the evaluation decision model based upon multi criteria objectives.

• Journal of Korea Port Economic Association
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• v.30 no.1
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• pp.57-71
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• 2014

Information which port provide to users including shipping companies is essential information for their business performance. Thus, information service of several services which port provide to shipping company is also very important port-logistics service. However, despite of this importance, there have been little research related to port-logistics information service. The aim of this study is to analyze the satisfaction of information service for port logistics. To achieve this objective, evaluation criteria consisting of 16 items based on the previous research was established. And satisfaction index that can effectively show the current level of information service for port logistics was developed. The results of analysis showed that satisfaction index of information service provided by Busan port was 61.90. And from the data analysis, it was revealed that current level of information service in whole area was less than 63 points. It was implied that improvement for overall port-logistics information service was needed. Finally, from the follow-up research, it was found that information service provided by Busan port have weakness in the aspects of unification of information and celerity of information.

• Journal of Convergence for Information Technology
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• v.8 no.3
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• pp.107-114
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• 2018

Recently, as aviation industry has been activated, development of software related to composite materials has been demanded. Composite analysis requires specialized structural analysis and test evaluation. Therefore, it is necessary to use existing commercial software to analyze the composite structure, but existing commercial software only provides limited functions. Especially, since there is no specialized software for corner structure analysis of aerospace composites spa structure, much human resources and time are consumed in structural analysis. In order to solve this problem, we developed a GUI-based automation software based on user-friendly GUI that reflects the existing corner structure analysis procedure and provides multiple breakdown criteria. To verify the reliability of the structural analysis results of the developed software, it was confirmed that there is no problem in the structural analysis performance as a result of comparing with the existing analysis results.

• Structural Engineering and Mechanics
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• v.70 no.6
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• pp.765-779
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• 2019

Most of the existing evaluation criteria of vibration serviceability rely on the peak acceleration of the structure rather than that of the people keeping their own body unmoved on the structure who is the real receiver of structural vibrations. In order to accurately assess the vibration serviceability, therefore, a full path assessment approach of vibration serviceability based on vibration source, path and receiver is not only tentatively proposed in this paper, taking the peak acceleration of receiver into account, but also introduce a probability procedure to provide more instructive information instead of a single value. In fact, semi-rigid supported on both sides of the structure is more consistent with the actual situation than simply supported or clamped due to the application of the prefabricated footbridge structures. So, the footbridge is regarded as a beam with semi-rigid supported on both sides in this paper. The differential quadrature-integral quadrature coupled method is not only to handle different type of boundary conditions, but also after being further modified via the introduction of an approximation procedure in this work, the time-varying system problem caused by human-structure interaction can be solved well. The analytical results of numerical simulations demonstrate that the modified differential quadrature-integral quadrature coupled method has higher reliability and accuracy compared with the mode superposition method. What's more, both of the two different passive control measures, the tuned mass damper and semi-rigid supported, have good performance for reducing vibrations. Most importantly, semi-rigid supported is easier to achieve the objective of reducing vibration compared with tuned mass damper in design stage of structure.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.5
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• pp.611-620
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• 2019

The shield tunnel was mostly applied to cable tunnel with a diameter of 3~4 m, recently 7.8 m diameter shield tunnel was constructed in the lower section of the Incheon International Airport runway and is planning or under construction to roads and railway tunnels in the lower section of the Han River. Segments are also becoming larger as the shield tunnel cross-section increases, which causes a number of problems in the design, construction, and performance evaluation of segments. In this study, segment lining structural safety, criteria for serviceability check considering axial forces and quality control method for approximately 8 m in diameter shield tunnel were reviewed by field measurements and full scale bending test.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.4
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• pp.151-160
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• 2019

EPC companies to continue operating overseas, it is increasingly becoming apparent that risk is no longer something to be avoided but a subject to be managed. During the bidding stage, the requirements, specifications and project line items within the bid package must be studied in details to analyze the various risk factors in order to avoid cost overruns. However, reviewing vast quantities of bidding documents is time consuming and labor intensive and is not an easy task and this is where automated information technology can help. For this study, I have constructed an ITB analysis model based on Watson AI that can analyze and apply vast amount of documents more effectively in a short time. Configuration of the Watson Explorer AI architecture for AI-based ITB risk management model research, the selection of learning procedures and analysis subjects, and the performance evaluation criteria were defined, and a test bed was constructed to conduct a pilot research. Consequently, I verified the effectiveness of the analytical time reduction and the quality of its results and VOC operations by professionals.

• Fashion & Textile Research Journal
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• v.23 no.6
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• pp.844-851
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• 2021

Due to the increase in consumers' interest about well-being, interest in eco-friendly products has been increasing due to the harmful effects of various harmful substances contained in textile products and environmental issues. As a result, natural dyes of less potential risk than synthetic dyes and digital textile printing(DTP) textile products with less environmental pollution are drawing attention. However, due to the lack of evaluation criteria for DTP textile products with natural ink and the nature of many colors are stacked layer by layer for dying, the need for simultaneous analysis is emerging. To evaluate whether the natural dye is derived from natural ingredients, the biocarbon content is analyzed. However, in the case of ink made using natural dyes and DTP textile products using natural ink, it is difficult to analyze the biocarbon content due to the limitation of the presence of a small amount of dye contained therein. In this study, we were shown the possibility of natural derived verification by cross-checking the analytes of natural dyes (Persicaria tinctoria, an indigo dye; Dactylopius coccus, a light red; and Curcum longa L., i.e., turmeric) and natural ink with HPLC-MS/MS. The coefficient of determination was 0.999 or higher, the limit of quantification was 0.647-3.664 ㎍/L and a %RSD of each indicator material was less than 10. Then, the extraction amount of natural dyes for five patterned fabrics was analyzed.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.5
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• pp.252-261
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• 2022

The present study concerns assessing the operability of a surface combatant, based on the Percent-Time-Operable (PTO). For validation of the seakeeping analysis in the regular waves, the model test is first conducted in a towing tank. The seakeeping analysis results in the regular waves are expanded to the irregular waves, considering the wave spectra around the Korean peninsula and in North Pacific. The seakeeping criteria of the surface combatant in transit, combat, replenishment operation, and survival condition are defined by the literature review. An annual operation scenario of the surface combatant in two operation areas, i.e., advance speed and wave direction, are combined with the seakeeping analysis results to assess PTO. The main constraints of operability of the surface combatant are identified as the pitch angle and vertical velocity at the helicopter deck.