• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.551-558
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• 2005

The setting and hardening of concrete is accompanied with nonlinear temperature distribution caused by development of hydration heat of cement. Especially at early ages, this nonlinear distribution has a large influence on the crack evolution. As a result, in order to predict the exact temperature history in concrete structures it is required to examine thermal properties of concrete. In this study, the convection heat transfer coefficient which presents thermal transfer between surface of concrete and air, was experimentally investigated with variables such as velocity of wind, curing condition and ambient temperature. At initial stage, the convection heat transfer coefficient is overestimated by the evaporation quantity. So it is essential to modify the thermal equilibrium considered with the boiling effect. From experimental results, the convection heat transfer coefficient was calculated using equations of thermal equilibrium. Finally, the prediction model for equivalent convection heat transfer coefficient including effects of velocity of wind, curing condition, ambient temperature and boiling effects was theoretically proposed. The convection heat transfer coefficient in the proposed model increases with velocity of wind, and its dependance on wind velocity is varied with curing condition. This tendency is due to a combined heat transfer system of conduction through form and convection to air. From comparison with experimental results, the convection heat transfer coefficient by this model was well agreed with those by experimental results.

• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.65-72
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• 2016

ORC system was designed and constructed for utilizing the heat of the exhaust gas and coolant released from the gas engine which was modified to use natural gas as a fuel. In this paper the components of the ORC system were designed and manufactured based on measured data of the gas engine. The components are composed of two plate heat exchanger, the 5kW-class expander and multi stage centrifugal pump. The thermodynamic performance of the ORC system was analyzed by using the electric heater. Also, the developed ORC system was implemented to modified natural gas engine. Two gas engines were used to supply heat to the ORC system. As a result of test bench, when the heat source temperature is $110^{\circ}C$ expander shaft power, the pressure ratio and cycle efficiency is 5.22kW, 7.41, 9.09%. As a result of field test, when the heat source temperature is $86^{\circ}C$ expander shaft power, the pressure ratio and cycle efficiency is 2kW, 3.75, 6.45%.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.1
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• pp.67-77
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• 2018

This study investigated the recognition of Koreanesss, preference factors and the difference of recognition from adjacent Chinese and Japanese gardens for foreign visitors of Seoul gardens, a Korean traditional garden located within the Marzahn garden in Berlin, Germany. Overall, the Chinese garden and the Japanese garden were better known to most visitors than the Seoul garden due to their earlier construction. The awareness of the specialty to the Korean garden was at an average level indicating most visitors did not recognize the difference among the traditional gardens constructed from other countries. These less awareness on the Korean garden was because the traditional gardens of the three countries are located adjacent to the park in a continuous landscape with similar plant species created through natural planting techniques. This means the Korean garden is required for considering diversity and representativeness of planting species, uniqueness in space composition and recognition of Korean oriental garden culture in an initial design project stage. Visitors without prior information has better understanding on Korean garden and higher revisit intention resulting in increasing publicity and understanding of Korean traditional garden. Among the preference factors representing Koreaness of the Seoul gardens, the waterfall, stream, pavilion and natural stone within the water landscape were visitors favorite interests due to design concept with a representative Korean stream scenery of Dokrack-dang and Byeolseo garden resulting in differences from the landscape displaying technique for other oriental gardens. These stylistic differences in the dominant landscaping of garden architecture from surrounding the physical environments, the garden displaying technique derived from Korean natural landscape can be recognized as an unique garden element for foreign visitors.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.117-124
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• 2005

Recently the first stage of construction for Busan new port emerged over the sea surface at the north container terminal site. With this, there are lot of discussions and debates on increasing the water depth at the approaching channel and mooring basin from the existing 15m to 18m by dredging work in order to be able to serve 12,000TEU containership, and at the same time, correction to the reclamation plan of hinterland at the part of Undong Bay of the new port site. Since the attack of typhoon 'Maemi' in 2003, it is expected that the design wave parameters for coastal and harbor structures in this area would be somewhat changed and so the extreme wave condition at each terminal and tranquility of berthing area does, and therefore, it is necessary to analyze the tranquility at each berth. Hence in this study, we constructed a wave model for these conditions and performed simulation together with the circulation model simulation, compared with the field data collected. The result showed the increase of the harbor response throughout the basin but not severe condition. However, a certain location needs to be prepared for the rough sea condition when a severe typhoon hit the site.

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.207-211
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• 2015

Many pronuclear stage eggs were used to generate transgenic mice (Tg) by microinjection. In this study, we used in vitro fertilized mouse eggs, followed by ultrarapid freezing to establish a simple procedure for production of Tg mice. We produced in vitro fertilized mouse eggs and cryopreserved them by ultrarapid freezing method. A total of 139 cryopreserved-thawed pronuclear eggs, of which 101 (72.6%) were survived following microinjection of chicken ${\beta}-actin$ promoter-driven firefly improved luciferase cDNA (${\beta}-act/luc^+$) and were transferred into 5 recipients. All recipients became pregnant and gave birth to a total of 15 (14.8%) pups. As a control, same DNA construction (${\beta}-act/luc^+$) was also injected into 450 in vitro fertilized eggs, of which 338 (75.1%) were survived and then were transferred into 14 recipients. Eleven (78%) mice became pregnant and littered a total of 54 (19.1%) pups. Southern blotting analysis of Tg mice indicated that one (1/15, 6.6%) and three (3/54, 5.5%) transgenic mice were production from cryopreserved and in vitro fertilized eggs, respectively. All Tg mice produced from both eggs showed the expression of improved luciferase gene. These results indicated that efficiency of produced of Tg mice from cryopreserved eggs was comparable to that from in vitro fertilized eggs. Furthermore, it is suggested that microinjection of transgene into in vitro fertilized eggs cryopreserved by ultrarapid freezing is an easy and conveniently method for production of Tg mice.

• Journal of Navigation and Port Research
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• v.44 no.3
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• pp.195-202
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• 2020

The production of larger of ships is a survival strategy for global shipping companies to pursue the economics of scale. According to this strategy, to respond to this situation, many containers are loading/unloading simultaneously in the hub port. Additionally, the container terminals are promoting the introduction of automation to expand the terminal facilities and increase efficiency/productivity of the container yards. European ports have introduced automation to address rising labor costs and shortages of labor. Recently, the construction of fully automated container terminals is increasing in the United States and China to resolve problems such as the slow growth of the global economy, the emergence of large ships, air pollution, and safety accidents. Domestic ports are at an early stage compared to the world's advanced container terminals, and countermeasures are being prepared to respond to the changing ports. However, research on the recognition difference analysis that examines the opinions of stakeholders is insufficient. As a result of analyzing the recognition among the groups, it was found that container terminal operators reduced labor costs, improved shipping services for shipping companies, prevented safety accidents for port union labor, and increased service for port authority and government agencies. Thus, to closely examine the perception among the groups, one-way ANOVA was performed, and then the implications were deduced as the basic data for the smooth introduction of automation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6336-6343
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• 2014

The aim of this study was to consider new 3D printing techniques and how to use them in architecture, compare the 3D printing and current techniques, and analyze them economically. 3D printing technology is expected to result in considerable changes to the entire system, such as production and distribution using this new technology in the near future. In addition, architecture is expected to follow this trend. This study examined how to take advantage of 3D printing technology in construction to prepare for a new architectural trend of 3D printing technology in the future. This study examined the 3D printing technology that is used in buildings and the current state of 3D printing technology. In addition, the 3D printing technology and current technology was also compared, and analyzed economically. 3D printing technology is the step before the stage of practical use. On the other hand, the commercialization of 3D printing technology makes it possible to reduce the cost compared to the current method. Furthermore, as the technology is developed in the future, the cost is expected to be reduced further. Therefore, the use of 3D printing technology in architecture is expected increase continually.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.5
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• pp.187-194
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• 2010

As the design of the pillar width (PW) of the parallel tunnels in downtown area, in which are located in plains zone with deep alluvium compared with mountain tunnels, is directly related with pre-compensation payment and costs of the underground area, it has to be planned as to keep minimum distance while securing the stability of the parallel tunnels. Although PW of downtown road tunnel in Korea is standardized as 1.5D(D: diameter of the tunnels), PW sometimes has to be reduced within 1.5D to adjust the tunnel lines to the city plan in the cases of the inlet and outlet of the tunnels. In this paper, the design and the analyses of optimum PW of the NATM type road tunnel in the downtown area are introduced. The relationship among the tunnel line planning and underground compensation fee, and ground characteristics are evaluated. In the determination of PW distance, the numerical analyses of underground road tunnels were performed, including the use of the strength decrease method and strength/stress ratio method. In the cases of inlet and outlet part of the tunnels where the stability of the pillars is poor due to contiguous construction of the parallel tunnels, the reinforcement methods are recommended for securing the stability. Numerical verification was performed for the reinforcement proposed.

• Journal of Wetlands Research
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• v.17 no.2
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• pp.163-175
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• 2015

In this paper, soil erosion and soil loss management system (SMS) of the City of Calgary in Albert, Canada was reviewed. Regulatory basis supporting this soil management system, permit process and conditions, guidelines and principles for the SMS, and monitoring and repair duties, inspection were discussed. Permit process in the City of Calgary is handled mainly by Urban Development Division, in which special task force called CPAG (Coorporative Planning Application Group) (if necessary circulated through related subdivisions). Inspects all the permit conditions and decides permit or refusal, and LUM (Land Use and Mobility) advertises the approval, if there is no appeals, permit is released to developers. If permit is rejected, applicant can appeals Development Appeal Board, it can approve or reject. In addition to permit, the city has manual for soil management plan, which includes BMP selection, design, monitoring, maintenance, and inspection activities. Perfect SMS policy does not necessarily guarantee relieving the soil-particle related pollution problem, but in Korea, we have to recognize that construction works during development is potentially the most destructive stage of environmental pollution. The central and local governments must make preparations for the effective and tight regulations and ordinance which is appropriate for regional social-economic conditions.

• Journal of Photoscience
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• v.11 no.3
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• pp.115-120
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• 2004

For the expression study of antioxidant isoenzyme genes in rice (Oryza sativa L.) plants, extensive searches for genes of superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT) isoforms were performed through the GenBank database. The genes for two cytosolic and one plastidic CuZn-SOD, one Fe-SOD, two Mn-SOD, two cytosolic and two chloroplastic (stromal and thylakoid) APX, and three CAT isoforms were available in japonica-type rice. These isoforms were named as cCuZn-SOD1, cCuZn-SOD2, pCuZn-SOD, Fe-SOD, Mn-SOD1, Mn-SOD2, cAPXa, cAPXb, Chl_sAPX, Chl_tAPX, CATa, CATb, and CATc, respectively. Since they shared a high degree of homology in the nucleotide and amino acid sequences, the gene-specific primers for the genes were designed directly from their full-length cDNAs found in the database except for the CATa gene. These primers were used in the RT-PCR analysis to investigate the differential expression of antioxidant isoenzyme genes in rice plants from the seeds irradiated with low doses (2, 4, 8, and 16 Gy) of gamma-radiation. The gammairradiation slightly increased the transcripts of pCuZn-SOD, while those of Fe-SOD, cAPXb, and CATb decreased. However, no substantial differences were observed in the expression of all the isoenzyme genes between the control and irradiated groups. In this study, gene specific primers for thirteen SOD, APX and CAT isoenzymes were constructed from the full-length cDNAs. The results of RT-PCR analysis obtained by using these primers suggests that the expression levels of SOD, APX, and CAT isoenzyme genes in rice seedlings were hardly affected by gamma-irradiation at the seed stage.