• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.5
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• pp.95-105
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• 1996

This study was performed to evaluate the mechanical properties of permeable polymer concrete using fillers and unsaturated polyester resin. The following conclusions were drawn; 1. The unit weight was in the range of 1, 663~ l, 892kg/$cm^3$, the weights of those concrete were decreased 18~28% than that of the normal cement concrete. 2. The highest strength was achieved by fly ash filled permeable polymer concrete, it was increased 22% by compressive strength, 190% by tensile strength and 192% by bending strength than that of the normal cement concrete, respectively. 3. The external strength of permeable pipe was in the range of 3, 083~3, 793kg/m, the external strengths of those concrete were increased 2~26% than that of the normal cement concrete. Accordingly, these permeable polymer concrete pipe can be used to the members and structures which need external strength. 4. The static modulus of elasticity was in the range of $5.7{\times} 10^4 ~ 15.4{\times} 10{^4}kg/cm^2 $, which was approximately 35~64% of that of the normal cement concrete. Fly ash filled permeable polymer concrete was showed relatively higher elastic modulus. The poisson's number of permeable polymer concrete was less than that of the normal cement concrete. 5. The dynamic modulus of elasticity was in the range of $83{\times} 10^3 ~ 211{\times} 10{^3}kg/cm^2 $, which was approximately Ins compared to that of the normal cement concrete. Fly ash filled permeable polymer concrete was showed higher dynamic modulus. The dynamic modulus of elasticity were increased approximately 22~45% than that of the static modulus. 6. The ultrasonic pulse velocity was in the range of 2, 584 ~ 3, 587m/sec, . which was showed about the same compared to that of the normal cement concrete. Fly ash filled permeable polymer concrete was in the range of$0.58~8.88 {\ell}/cm^2/hr$, , and it was larglely dependent upon the mixing ratio. These concrete can be used to the structures which need water permeability.

• Journal of Korean Association for Spatial Structures
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• v.6 no.1 s.19
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• pp.91-99
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• 2006

This paper presents wind pressure distribution on high-rise apartment buildings through wind-tunnel tests. In order to investigate wind-induced interference efforts on building claddings an apartment complex, which was damaged on the claddings during typhoon attack, was exampled and constructed as a scaled model. A series of wind tunnel tests using pressure models were performed in a boundary layer wind tunnel. The test results with and without interfering buildings were compared and discussed. It is observed that the wind pressure on buildings 105 and 106 with surrounding buildings shows highly negative, while the pressure without surrounding buildings were positive. Therefore the wind-induced interference effects should be taken into account in the design of claddings through wind-tunnel tests.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3_1spc
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• pp.573-579
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• 2013

Once-through helically coiled steam generator tubes subjected to external pressure are of interest because of their application to advanced small- and medium-sized integral reactors, in which a primary coolant with a relatively higher pressure flows outside the tubes, while secondary water with a relatively lower pressure flows inside the tubes. Another notable point is that the values of the mean radius to thickness ratio of these steam generator tubes are very small, which means that a thick-walled cylinder is employed for these steam generator tubes. In the present paper, the maximum allowable pressure of helically coiled and thick-walled steam generator tubes with through-wall cracks under external pressure is investigated based on a detailed nonlinear three-dimensional finite element analysis. In terms of the crack orientation, either circumferential or axial through-wall cracks are considered. In particular, in order to quantify the effect of the crack location on the maximum external pressure, these cracks are assumed to be located in the intrados, extrados, and flank of helically coiled cylinders. Moreover, an evaluation is also made of how the maximum external pressure is affected by the ovality, which might be inherently induced during the tube coiling process used to fabricate the helically coiled steam generator tubes.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.410-413
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• 2005

The results of an experimental and analytical study of composite pressure hull on buckling pressure are presented for LRN 300. Composite tensile test was done to know the composite material properties applied FE analysis for URN composite. We predicted the buckling and post buckling analysis of composite laminated cylindrical panels under external compression by using ABAQUS /Standard[Ver 6.4]. To obtain nonlinear static equilibrium solutions for unstable problems, where the load-displacement response can exhibit the type of nonlinear buckling behavior, during periods of the response, the load and/or the displacement may decrease as the solution evolves, used the modified Riks method. The modified Riks method is an algorithm that allows effective solution of such cases [7]. Experiments were conducted to verify the validation of present analysis for cross-ply laminated shells. The shells considered in the study have two different lamination patterns, $[{\pm}45/0/90]_{18s\;and}\;[/0/90]_{18s}$. Cylindrical panel of experiment and analysis have the radius of 200mm, length of 210mm and 60 degree of cutting angle. The critical load from experiment is $69\%$ of that of numerical analysis, because the fracture of matrix was generated before buckling. So URN 300 is not proper to use at the condition under high external pressue.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.187-195
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• 2015

This paper purposes to identify who is/are in charge of KBS broadcasting programming in view of freedom of broadcasting and interest of audience under the circumstance that Blue House put pressure on KBS to refrain from reporting Sewol Ferry disaster. For this purpose this study has reviewed prior theses, books, journals, laws, and cases, etc. It is analyzed that principal agents in charge of freedom of broadcasting journalism and programming are KBS employees in charge of producing broadcasting programs and KBS chief programming officer, who is appointed by KBS CEO. KBS CEO, who can easily be influenced by governmental pressure in terms of KBS structure, should avoid interfering with programming and producing directly or indirectly for freedom of the press and public interests.

• International Commerce and Information Review
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• v.17 no.3
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• pp.225-250
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• 2015

While strategic alliance of multinational corporation has boost, opportunistic behavior is also increased recently. This study examines the cause of opportunism in strategic alliance by focusing on the development of opportunistic behavior, a process in which resource complementarity and risk perception decides attitudinal direction, ultimately leading to opportunism. Empirical test based on 257 alliance participants shows that risk perception had a greater influence on firms' attitudinal and behavioral directions compared to benefit perception. Notably, relational risk heavily influenced firms' competitive attitude and opportunistic behavior. Finally, the study concludes that firms' competitive and independent attitude caused by risk perception negatively influence alliance outcome. Based on the results, it is drawn that alongside the external tools such as surveillance, control, monitoring or legalistic pleas, management of risk perception during the alliance process has significance influence on the achievement of alliance goals.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.4
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• pp.651-668
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• 2017

For initial stability of the tunnel, the primary support, Shotcrete and rockbolt shall be placed in the most appropriate time. This is because the role of such support plays a vital role in long-term and short-term tunnel stability. In this study, the rock bolt is an important supporting system that receives the external pressure generated by the stress relaxation during tunnel excavation as axial force and transmits it to the shotcrete on the tunnel excavation surface. Until now, most of the materials of rock bolts have been used in the field, but there have been many problems such as uncertain quality of Chinese materials entering the market, poor packing due to falling down of rock bolts when filled with mortar, and corrosion due to water. Therefore, in this study, we have developed a high strength steel pipe rock bolt using Autobeam material to solve and improve various problems of existing rock bolts. In order to evaluate the performance of the developed bolt, field tests were carried out and the existing mortar filler in order to improve the performance of the rock bolt, the design and construction criteria were studied and the results were included in this paper.

• Journal of Radiation Protection and Research
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• v.31 no.1
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• pp.37-46
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• 2006

For the first step to develop a reference disposal container of spent fuel to be used in a deep geological repository, this paper examined safe dimensions of the disposal container on the points of nuclear criticality and radiation safety and mechanical structural safety and provided basic information for dimensioning the container and configuration of the container components, and establishing the favorable and safe disposal conditions. When the safety factor for stress due to the external loads (hydrostatic and swelling pressure) is taken as 2.0, the safe diameter of the filler material to provide enough container strength under the assumed external loads is found to be 112cm with 13cm spacing between inner baskets in PWR container. Also the thickness of the thinner section between the fuel basket and the surface of the cast insert is determined to be 150 mm. Regarding these dimensions of the container, the PWR fuel container is sketched to accommodate 4 square assemblies or 297 CANDU fuel 297 bundles (33 circle tubes x 9 stacks). However the top and bottom parts need to be checked again through the detail radiation shielding analysis with respects to the emplacement position and handling processes of the disposal container.

• Convergence Security Journal
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• v.14 no.1
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• pp.23-32
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• 2014

Quantitative rise and This study carried out qualitative research by utilizing NVivo 10 focusing on the contents of mass media such as newspaper or internet on the presidential security service up to the Park Geun-hye government from the 3rd Republic of Korea, which was established the presidential security service. The aim is to present opinion so that the presidential security organization can strengthen capability and function within the governmental organization down the road based on the contents of categories, which were elicited through this. First, there is a need of solidifying the internal stability with the expansion in the activity sphere of organization and of externally approaching the public with removing sense of difference caused by offering personal protection only to some of the privileged class in the meantime. Second, it is the foundation of a reason related to crime in a cause for Discharge by Authority pertinent to "law on security for president and others" in Article 10 in order to prevent a criminal act of having abused the task characteristic and the position superiority or an external pressure act related to intervention in rights. Third, there is a need of making it recognized as very important organization with putting differentiation from other organizations of the government by providing the disciplinary level more strictly than "disciplinary order on public officials" based on particularity and importance dubbed presidential security service along with correspondingly applying "disciplinary order on public officials" in Article 31 in accordance with "enforcement ordinance of law on security for president and others" in terms of service negligence and false-information report in relation to task performance.

• (The)Study of the Eastern Classic
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• no.57
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• pp.407-435
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• 2014

Gusadang Kim, Nak-Haeng is a scholar of 18th century in Yeongnam region who wrote about 130 Chinese poems. In this study, I searched Gusadang's inner world by interpreting his Chinese poems. His life is closely related to his father Jesan Kim, Seong-Tak who was exiled. The fact that he devoted himself to his father for 10 years shows he had strong standards in making decisions in life. In short, Gusadang was a person who looked gentle but was tough inside and he remained firm in his faith even with outside pressure. He could not achieve glory because he spent time serving his father in his thirties. Although he heard compliments from others that he was talented enough to succeed as a scholar, he lacked time and mental energy to study. Also, he was a moralist and wrote some poems about impressive events in his life even though he did not fully devote himself to writing poems. In this study, I searched his inner world focusing on how he felt and thought about outside world by analyzing his poems. In conclusion, I found three characteristics from his poems. Firstly, depressed feelings are shown based on excessive self-consciousness in the poems related to his father. Secondly, his will to keep balance in life is shown because he wanted a harmonious life as a seeker after truth. Thirdly, a sense of isolation is shown because he had to keep a distance from outside world.