• Korean Institute of Interior Design Journal
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• v.13 no.6
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• pp.66-73
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• 2004

There has been preconceived assumption that, in good architecture, exterior and interior have to be harmoniously related to each other. However, in contemporary architecture, it is easy to witness that this harmonious relationship between exterior and intoner is severely challenged and various exterior surfaces have multi-faceted roles. Rem Koolhaas explained this sort of new situation in the light of 'lobotomy' that is a surgical method for mental disorders, based on the high-rise buildings in the early Manhattan. This study is started with the Rem Koolhaas' lobotomy concept and how this concept is applied to his projects. The multiple roles of exterior surface can be also found in many contemporary architects' projects. Among them, Jacques Herzog & Pierre do Neuron and Toyo Ito's recent projects are discussed to further analyze the new roles of surface and compared with Rem Koolhaas' case. Although the architects discussed present very limited scope of what is happening on the surface of comtemporary architecture, it is hoped to disclose some examples of new relationship between exterior and interior.

• Korean Journal of Materials Research
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• v.19 no.2
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• pp.111-114
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• 2009

For the fabrication of core-shell structure bimetallic lead-free solder balls, both the critical temperature ($T_{cr}$) for the phase separation of two immiscible liquid phases and the temperature coefficient of the interfacial tension between the two separated liquid phases are required. In order to obtain this information, the temperature dependence of the surface tension of 60%Bi-24%Cu-16%Sn(-REM) alloys was measured using the constrained drop method. The slope of the temperature dependence of the surface tension changed clearly at a critical temperature for the separation of two immiscible liquid phases. The critical temperature of the 60%Bi-24%Cu-16%Sn alloy was estimated to be 1097K. An addition of 0.05% Ce decreased the critical temperature to 1085K, whereas that of 0.05% La increased it to 1117K. It was found that the surface tension and its temperature coefficient of the 60%Bi-24%Cu-16%Sn alloy were slightly increased by the addition of 0.05% Ce and 0.05% La. In addition, additions of Ce and La increased the temperature coefficient of the interfacial tension.

• Journal of Periodontal and Implant Science
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• v.36 no.3
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• pp.705-716
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• 2006

The present study was performed to evaluate the effect of tetracycline-HCl on the change of implant surface microstructure according to application time. Implant with pure titanium machined surface, GBA surface and RBM surface were utilized. Implant surface was rubbed with 50mg/ml tetracycline-HCl solution for ${\frac{1}{2}}$min. 1min. $1{\frac{1}{2}}$min. 2min. and $2{\frac{1}{2}}$min. respectively in the test group. Then, specimens were processed for scanning electron microscopic observation. The results of this study were as follow. 1. Both test and control group showed a few shallow grooves and ridges in pure titanium machined surface implants. There were not significant differences between two group. 2. In GBA surfaces, control group exhibit many porous depression, and each depression were divided by strict border. Experimental group applied with tetracycline-HCl for 2min. were similar with control group. But when applied for $2{\frac{1}{2}}$min. surface alteration and border breakdown started, resulting enlargement of the porous depression. 3. In REM surface, control group exhibit rough, uneven surface with crater-like depression can be found. The surface alteration started when tetracycline-HCl was applied for 30sec. resulting breakdown of the crater-like depression. Depression became larger as applying time increased.

• Nuclear Engineering and Technology
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• v.2 no.2
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• pp.97-106
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• 1970

Radiation accidents which occured in the A.E.R.I. during last ten years are described (table 1). It seemed to the authors that some of these accidents were considered to be hazardous to man body and associated installations. This report deals with the following four major accidents involving body contamination incidents that our health physicists have been experienced. 1. Over-exposures (up to 130 rem) to the total body due to the mismanipulation in the Cobalt-60 gamma irradiation facility. 2. Floor surface contamination (up to 13 mrad/hr) and its spread out due to the mishandling of radioiodine contained in the bottle. 3. Body surface contamination and 0.36 uCi radioactivity accumulated in the thyroid gland of a worker due to the inhalation of gaseous iodine-131. 4. A void capsule due to the leakage out of the radium therapeutic source (3mg\ulcorner) These accidents were treated by definitely prompt action to protect the workers and associated installations from any radiation hazards and every possible efforts were made to confine the spread of radioactive contamination as small area as possible by means of elaborate decontamination work and monitoring.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.1
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• pp.69-79
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• 2004

This Paper examines theoretical terrains and design strategies of landscape urbanism which is an emerging hybrid field at the intersection of architecture, landscape architecture, and urbanism. Landscape urbanism offers alternative approaches for theory, education, and practice in contemporary landscape architecture. It views the emergent urban complex sites-post-industrial sites, landfill, brownfield, urban void, etc., not as a weakness, but as a strength. Landscape urbanism poses an understanding of landscape as an element of urban infrastructure. In this sense, the landscape is seen in the context of contemporary urban development and public works. As a complex amalgam, landscape urbanism is more than a design style it is an ethos, an attitude, a way of thinking and acting. We can chart the main characteristics of landscape urbanism such as horizontality and surface, infrastructure, process, technique, and ecology. Multilayered examples of landscape urbanism can be seen in several experimental practices such as worts of Rem Koolhaas, MVRDV, Adriaan Geuze/West 8, James Comer, etc. It is possible to summarize the productive strategies for landscape urbanism as follows : thickening, folding, new materials, nonprogrammed use, impermanence, and movement.

• Journal of Periodontal and Implant Science
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• v.37 no.3
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• pp.585-597
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• 2007

The present study was performed to evaluate the effect of Tetracycline-HCI and Saline on the change of implant surface microstructure and surface roughness according to application time. Implants with resorbable blasting media surface were utilized. Before test all 13 implants were measured surface roughness. Among them, 6 implants were rubbed with 50mg/ml Tetracycline-HCl solution and other 6 implants with saline for $\frac{1}{2}$min., 1min., $1\frac{1}{2}$min., 2min., $2\frac{1}{2}$min and 3min. Then, specimens were processed for scanning electron microscopic observation and surface roughness after test. The results of this study were as follows. 1. Control group showed a few irregular, rough, uneven surface with crater-like depression. 2. The test group with Tetracycline-HCl conditioning showed an altered surface when Tetracycline-HCl was applied for 30secs, and showed a various surface alteration as application times go on. 3. The test group with Saline conditioning showed no significant surface differences and surface roughness. 4. The significant increase of Ra value was showed when Tetracycline-HCl was applied for 30secs. In conclusion, the 50mg/ml Tetracycline-HCl must not be applied for the RBM surface implant for surface treatment.

• Journal of architectural history
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• v.20 no.4
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• pp.115-134
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• 2011

International Competition for Parc de la Villette has evoked the old architectural question that is about the conflict between unchanging architecture and ever changing time. Tschumi and Koolhaas suggested well-known solutions for it, both of which had started from the criticism of general urban design approach that ignored changing factors in time. However, this study argues that the approaches of Tschumi and Koolhaas are even opposite to each other in spite of their common aims. Influenced by deconstructivists' theories, Tschumi tries to generate the 'text' on the surface of la Villette so that the different users of the park can read it differently. The text is built by 'superimposing' different systems such as points, lines, and surfaces. This study criticizes such formalistic approach since such 'forms' do not generate any dialogue with the real users but just stay as a backdrop for irrelevant events. Meanwhile, Koolhaas concentrates on the 'ground-ness' of la Villette. What he deals with is the real ground which embraces all the potentials on it already. His 'bands' express nothing but the metamorphosis of the ground, and the ground generates the 'differences' out of itself by repeating itself ceaselessly. This study tries to clarify all those happenings and meanings by intimate investigation of various drawing works for the la Villette project by Tschumi and Koolhaas.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.429-434
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• 1996

K-REM［1］, which is under development as a realistic evaluation model of large break LOCA, is applied to the analysis of cold leg guillotine break of Ulchin 3&4. Fuel parameters on which statistical analysis of their effects on the peak cladding temperature (PCT) are made and system parameters on which the concept of limiting value approach (LVA) are applied, are determined from the single parameter sensitivity study. 3 parameters of fuel gap conductance, fuel thermal conductivity and power peaking factor are selected as fuel related ones and 4 parameters of axial power shape, reactor power, decay heat and the gas pressure of safety injection tank (SIT) are selected as plant system related ones. Response surface of PCT is generated from the plant calculation results and on which Monte Carlo sampling is made to get plant application uncertainty which is statistically combined with code uncertainty to produce the 95th percentile PCT. From the break spectrum analysis, blowdown PCT of 1350.23 K and reflood PCT of 1195.56 K are obtained for break discharge coefficients of 0.8 and 0.5, respectively.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.278-286
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• 2023

The present work evaluated the production of biohydrogen under mesophilic and thermophilic conditions through dark fermentation of palm oil mill effluent (POME) in batch mode using the design of experiment methodology. Response surface methodology (RSM) was applied to investigate the influence of the two significant parameters, POME concentration as substrate (5, 12.5, and 20 g/l), and volumetric substrate to inoculum ratio (1:1, 1:1.5, and 1:2, v/v.%), with inoculum concentration of 14.3 g VSS/l. All the experiments were analyzed at 37 ℃ and 55 ℃ at an incubation time of 24 h. The highest chemical oxygen demand (COD) removal, hydrogen content (H₂%), and hydrogen yield (HY) at a substrate concentration of 12.5 g COD/l and S:I ratio of 1:1.5 in mesophilic and thermophilic conditions were obtained (27.3, 24.2%), (57.92, 66.24%), and (6.43, 12.27 ml H₂/g COD_rem), respectively. The results show that thermophilic temperature in terms of COD removal was more effective for higher COD concentrations than for lower concentrations. Optimum parameters projected by RSM with S:I ratio of 1:1.6 and POME concentration of 14.3 g COD/l showed higher results in both temperatures. It is recognized how RSM and optimization processes can predict and affect the process performance under different operational conditions.

• Journal of Periodontal and Implant Science
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• v.37 no.2
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• pp.223-236
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• 2007

This study was attempted to evaluate home-manufactured implants by placing $Stage-1^{(R)}$ Implant (Lifecore, Co., USA) whose surface is treated with REM that has already been varified clinically,$Chaorum^{(R)}$ Implant(Chaorum Co., Korea) whose surface treatment is same as that of Stage-1 Implant and $Atlas^{(R)}$ Implant(Cewellmedi Co., Korea) whose surface is treated with anodic oxidation immediately after the teeth of experimental animals were extracted to compare histological findings among them. Stage-l Implant(diameter: 3.5mm, length: IOmm), Chaorum Implant(diameter: 3.3mm, length: 8.5mm) and Cowell medi Implant(diameter: 4.0mm, length: 8.0mm) were placed into the mandible premolars of 2 adult beagle dogs immediately after their teeth were extracted, and then histological findings were analyzed at 6 weeks. After those implants were inserted directly after their teeth were extracted, the results of periotest were recorded, radiography was done, the subjects went through thorough control for 6 weeks, and then comparison among periotest, radiography and histological finding was made. After comparison of those findings, the values of periotest were satisfactory and bone healing was relatively satisfactory on radiography at 6 weeks. For osseointegration with the bone tissue, Stage-1 was 45.3%, Chaorum 55.3%, and Cowellmedi 52.5%, which was a satisfactory result. Although implant surgery immediately after teeth were extracted involves difficulties among recent implant surgeries, it is being frequently used in that it may reduce surgery hours, the frequency of surgery, and bone loss for patients. This experiment was conducted to evaluate the technological levels of home-manufactured implants that have been remarkably developed in recent years and in conclusion, those implants showed nearly similar result.