• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.957-967
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• 2013

While a vast number of cad drawings are produced in the life cycle of construction projects from the planning, design, and construction phases to the maintenance and control phases, the creation and distribution of non-standard drawings make it difficult for the construction parties to communicate with one another and to recycle, maintain, and control drawings by project phase. The Korea standard of CAD drawing in construction CALS/EC, which stipulates the standard for construction CAD drawings, is based on roads, rivers, and railways in line- and unit-based structures, allowing the creation of standardized CAD drawings. Such standard, however, cannot be easily applied to construction projects with multiple facilities like harbors, housing sites, or lands consisting of surface forms. In particular, port field consist of complex docks and amenities located in a certain coastal area based on multiple objectives. They also contain the concept of housing sites, like background land, and are composed of various civil engineering facilities, construction facilities, and port field, so that the existing CAD drawing standard cannot be easily implemented. Therefore, the purpose of this study is to maximize the efficiency of the information related to drawing information and to ultimately support smooth information exchanges in construction design by conducting a development research on the expansion of the CAD drawing standard that meets the needs of port field.

• Journal of the Korea Concrete Institute
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• v.23 no.5
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• pp.667-674
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• 2011

This paper discusses the analysis method of prestressed concrete girder integral abutment bridges for a 75-year bridge life and the development of prediction models for abutment displacements under thermal loading due to annual temperature fluctuation and time-dependent loading. The developed nonlinear numerical modeling methodologies considered soil-structure interaction between supporting piles and surrounding soils and between abutment and backfills. Material nonlinearity was also considered to simulate differential rotation in construction joints between abutment and backwall. Based on the numerical modeling methodologies, a parametric study of 243 analysis cases, considering five parameters: (1) thermal expansion coefficient, (2) bridge length, (3) backfill height, (4) backfill stiffness, and (5) pile soil stiffness, was performed to established prediction models for abutment displacements over a bridge life. The parametric study results revealed that thermal expansion coefficient, bridge length, and pile-soil stiffness significantly influenced the abutment displacement. Bridge length parameter significantly influenced the abutment top displacement at the centroid of the superstructure, which is similar to the free expansion analysis results. Developed prediction model can be used for a preliminary design of integral abutment bridges.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.3
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• pp.199-205
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• 2012

In this study, wave transformation by damping due to the permeable bed of finite depth is investigated. The relationship between wave damping rate and relative water depth are presented. The damping rate is used in the eigenfunction expansion method to calculate the wave dissipation over the permeable bed. For a permeable shoal, the eigenfunction expansion model result is compared with that of the integral equation method to show good agreement. The model is also used to examine the wave reflection over the permeable planar slope of various frequency. It has been found that in general relatively short waves are more influenced by the permeability of the permeable seabed than relatively long waves unless the water depth is so large that the influence of permeable bed on surface water waves disappears.

• Journal of Korean Library and Information Science Society
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• v.51 no.1
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• pp.305-327
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• 2020

This study aims to suggest the ways to reinforce academic library's research support services for professors and researchers in Korea. For this purpose, this study collected the development plans of academic libraries in Korea, and analysed the plans for supporting research activities, and also analysed each library's homepage. And this research classified the research support services of academic libraries into eight types for further analysis. The types are 'subject guide', 'academic information literacy', 'research analysis service', 'research consulting', 'research ethics education', 'thesis writing guide', 'bibliography management program', 'interlibrary loan·original text copy'. As a result, it is shown that the most libraries emphasized 'custom-tailored user education' and marked it on development plan. As subsequent plans, libraries provided the action plans of 'expansion of scholarly DB instruction on each subject', 'expansion of custom-tailored research support services', 'construction of research support service system' one after another. This study suggests 'activation of subject guide service', 'expansion of academic information literacy programs for supporting research', 'introduction of research performance analysis services', and 'support for establishment of research ethics' as ways to strengthen academic libraries' research support services.

• Journal of the Korean Geotechnical Society
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• v.23 no.8
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• pp.77-85
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• 2007

In order to estimate undrained shear strength and evaluate cone factors, various in-situ and laboratory test results at new harbor construction area near Pusan were analyzed. To evaluate Nk values and equation applicable in Korea, measured and theoretical cone factors were compared based on the test results. For comparison, various analytical solutions were adopted and used. Adopted methods include cavity expansion solutions of Baligh (1975) and Yu (1993) and steady state solutions of Teh and Houlsby (1991) and Yu et al. (2000). According to the result of comparison, cavity expansion solutions were found to be reasonable for the CPTu-based undrained shear strength evaluation.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1382-1399
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• 2023

Pressure relief valve (PRV) is one of the important control valves used in nuclear power plants, and its sealing performance is crucial to ensure the safety and function of the entire pressure system. For the sealing performance improving purpose, an explicit function that accounts for all design parameters and can accurately describe the relationship between the multi-design parameters and the seal performance is essential, which is also the challenge of the valve seal design and/or optimization work. On this basis, a surrogate model-based design optimization is carried out in this paper. To obtain the basic data required by the surrogate model, both the Finite Element Model (FEM) and the Computational Fluid Dynamics (CFD) based numerical models were successively established, and thereby both the contact stresses of valve static sealing and dynamic impact (between valve disk and nozzle) could be predicted. With these basic data, the polynomial chaos expansion (PCE) surrogate model which can not only be used for inputs-outputs relationship construction, but also produce the sensitivity of different design parameters were developed. Based on the PCE surrogate model, a new design scheme was obtained after optimization, in which the valve sealing stress is increased by 24.42% while keeping the maximum impact stress lower than 90% of the material allowable stress. The result confirms the ability and feasibility of the method proposed in this paper, and should also be suitable for performance design optimizations of control valves with similar structures.

• Journal of the Korea Institute of Building Construction
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• v.2 no.2
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• pp.165-172
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• 2002

A reinforced concrete building neighboring in Pusan or Ulsan where is directly exposed to salt water contrasting with other in land areas contains much salt content percolated from the outside that the high salt content percolates and diffuses through the inside of reinforced concrete; therefore, an immovable tunic surrounding it begins to be destroyed and eroded with high speed. At the time, the cross-sectional area and volume expansion of re-bar reinforcing result in being cracks make a rapid progress gradually until they appear in the surface of the one, the phenomenon such as being a thin layer or falling off the part of it causes a lowering of its durability and might collapse the concrete construction. So far, we've investigated into salt content of reinforced concrete constructions neighboring in a seaside district and damage by carbonation, and we came to a conclusion as follows: $\circled1$ Under the oceanic circumstance a concrete construction is influenced by sea water directly that contains much amount of salt content contrasting with other constructions on inland areas. $\circled2$ Because of chloride penetration the carbonation of reinforced concrete made a rapid progress until more than the covering thickness of re-bar. $\circled3$ An old reinforced concrete building which has been piled up salt injury and proceeding the carbonation of its cross-sectional area. $\circled4$ According to rapidly cracking from the inside to surface of reiforced concrete, the phenomenon of being a thin layer or falling off the part of reinforced concrete results in a lowering of durability and shortening the life-time of concrete construction itself.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.283-286
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• 2002

Defect problems happening in the course of stressing quantity expansion of residence supply due to lark in maintenance are intensifying insincerity of construction business resulting from the psychological and economic damage, and there are many quarrel between residence suppliers and consumers. Because an apartment house's qualify is decided by various elements from design, to lotting-out, construction, and after-management, it is limited to express house capacity and standard to appraise defect objectively and quantifiably. The bound of defect and the period of guarantee expressed cleary in regulation of apartment house lack in quantifiable concept, and guarantee of defect is composed of a general concept. Therefore the big difference in opinion about defect and the bound of repair makes repair process slow and only to increase social costs. This research will give residence suppliers and consumers a resonable way to solve repair process during tile obliged period of guarantee since moving into from a process which are design, planing, construction, and after management. Furthermore it will present each business and role to conclude defect repair easily, so I planed to promote maintenance after conclusion of defect repair.

• Journal of Korea Multimedia Society
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• v.14 no.11
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• pp.1450-1457
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• 2011

Currently most of leak detection monitoring systems use digital maps with paying royalties, and this increases the cost of system construction and financial burdens on local self-governing bodies that manage such systems. Moreover, they have inefficiencies in repair and maintenance, functional expansion, and compatibility with other systems. Thus, this study developed a waterworks pipe network monitoring system that pursues low cost and high efficiency using general-purpose maps on the Internet such as google maps. As this system uses highly compatible free maps, it costs less in construction and its hardware requirements are lower than existing systems, and consequently, overall monitoring performance is enhanced and the cost of construction goes down sharply. This study also proposed a method for pipeline DB construction, which can be started together with the construction of the monitoring system, in order to improve the field applicability of the system.

• Korean Journal of Construction Engineering and Management
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• v.13 no.2
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• pp.25-36
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• 2012

As the international construction market is rapidly expanding, Korean contractors have the need for having new leading businesses for their sustainable growth and high performance. Thus, this research tried to explore new leading businesses with two questions: 'What can be the new leading businesses?' and 'How can Korean contractors implement new leading businesses?' To this end, based on Porter's five forces framework and the resource-based view (RBV), we first derive three evaluation criteria (possibility of market entry, possibility of profit earning, and possibility of value-added earning). Next, we developed a framework for business evaluation which considers external market condition, internal competitiveness, and spin-off effects toward domestic market. Based on the framework, we defined green-energy plant, environmental plant, desalination plant, nuclear power plant, new urban development, and high-rise building as new leading business. Then, we selected green energy plant, environmental plant, and new urban development for the purpose of prior occupation of the market, consolidation of the competitiveness, and expansion of the ripple effect, respectively. Finally, we deduced market entry strategies for each business by investigating experts' opinions.