• Proceedings of the KSME Conference
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• 2001.06a
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• pp.243-249
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• 2001

In this study, the progressive inelastic deformation, so called, thermal ratchet phenomenon which can occur in high temperature liquid metal reactor was simulated with thermal ratchet structural test facility and 316L stainless steel test cylinder. The inelastic deformation of the reactor baffle cylinder can occur due to the moving temperature distribution along the axial direction as the hot free surface moves up and down under the cyclic heat-up and cool-down of reactor operations. The ratchet deformations were measured with the laser displacement sensor and LVDTs after cooling the structural specimen which experiences thermal load up to $550^{\circ}$ and the temperature differences of about $500^{\circ}C$. During structural thermal ratchet test, the temperature distribution of the test cylinder along the axial direction was measured from 28 channels of thermocouples and the temperatures were used for the ratchet analysis. The thermal ratchet deformation analysis was performed with the NONSTA code whose constitutive model is nonlinear combined kinematic and isotropic hardening model and the test results were compared with those of the analysis. Thermal ratchet test was carried out with respect to 9 cycles of thermal loading and the maximum residual displacements were measured to be 1.8mm. It was shown that thermal ratchet load can cause a progressive deformation to the reactor structure. The analysis results with the combined hardening model were in reasonable agreement with those of the tests.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.8
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• pp.1613-1621
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• 2015

This paper analyzes the rate adaptation scheme and suggests applicable strategy of the MCS(Modulation and Coding Scheme) for improving DCF throughput in the IEEE 802.11ad and 802.11ad wireless LAN. IEEE 802.11ac and 802.11ad wireless LAN provide MCS technique that dynamically adjusts modulation level and code rate to the time-varying channel conditions in order to obtain considerably high data rates. But these standards did not provide rate adaptation algorithm, so this paper surveyes rate adaptation algorithm and suggests MCS scheme applied to IEEE 802.11ac and 802.11ad wireless LAN. Specially A MAC(Medium Access Control) layer throughput is evaluated over error-prone channel in the IEEE 802.11ac-based wireless LAN. In this evaluation, DCF (Distributed Coordination Function) protocol and A-MPDU (MAC Protocol Data Unit Aggregation) scheme are used. Using theoretical analysis method, the MAC saturation throughput is evaluated with the PER (Packet Error Rate) on the condition that the number of station, transmission probability, the number of parallel beams and the number of frames in each A-MPDU are variables.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.17
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• pp.7-35
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• 2002

In many international financing transactions Korean companies are required to issue a guarantee. Thus far, however, legal issues on international guarantees have not been fully discussed in Korea. This is partly because most of the international guarantees are governed by a foreign law such as English law or the laws of the State of New York. In this articles the author examines major concepts or terms and conditions of a typical international guarantee, e.g., language on consideration, primary obligor, joint and several guarantee, unconditional and irrevocable guarantee, continuing guarantee, right of subrogation, representations and warranties, covenant or undertaking, currency indemnity, assignment, participation, governing law and jurisdiction clause, etc. For reference, standard forms of a guarantee and a standby letter of credit are attached to the article. In examining the terms and conditions, the author compares them with similar or equivalent concepts under Korean law. The author further discusses some Korean law issues that may arise under international guarantees governed by a foreign law. These issues include the application of the ultra vires doctrine under Article 34 of the Civil Code of Korea, the validity of an international guarantee which a Korean company has issued in violation of the guarantee ceiling set under Article 10 of the Law on Monopoly Regulation and Fair Trade of Korea and the validity of an international guarantee which a Korean party has issued in violation of the Foreign Exchange Transaction Law. In addition, the author discusses some issues under a so-called independent guarantee and a standby letter of credit. In this regard, reference is made to the Uniform Rules for Demand Guarantee (URDG), International Standby Practices (ISP98) and the Convention on Independent Guarantees and Stand-by Letters of Credit adopted by the United Nations in 1995. Finally, the author examines major terms and conditions of typical comfort letters and discusses some legal issues, such as the binding force of the comfort letter. In dealing with the issues the author underscores that to the extent the issues are not properly dealt with by an international norm such as Uniform Customs and Practice for Documentary Credits or ISP 98, the issues must be analyzed by reference to the governing law of the relevant instrument.

• Journal of Society of Preventive Korean Medicine
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• v.22 no.2
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• pp.25-32
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• 2018

Objectives : This study was conducted to investigate the frequent diseases among the people who had been treated by collaborative treatment of Korean medicine and Western medicine, and to compare their medical use behaviors before and after the collaborative first-stage pilot project between Korean medicine and Western medicine. Methods : 4,467 patients were identified as the patients who are participated in the collaborative first-stage pilot project between Korean medicine and Western medicine during the period between July 15, 2016 and March 31 2017. We used 28,480 records of Korean national health insurance claim data from January 1 2016 to March 31 2017 to analyzed present condition of cooperative medical usage. Also we conducted a paired t test to compare the percentage of collaborative treatment days before and after the pilot project period. Results : We found that the most frequent diseases treated in the pilot project were the diseases of musculoskeletal and nervous system and then 10 major diseases such as H, K, J, C (D), N, L, E, A, H and F disease codes in order. Also it was confirmed that 14 major and 53 medium diseases are included from more than 90% of total patients. As a result of high frequency of medical treatment in Western medicine or Korean medicine is "administration of Korean medicine", which is same as before and within the pilot project. The ratio of utilizing both Western and Korean medical care for the same disease on the same day by both general patients and patients in KCD-7 disease code group C, G, I, M and S had been increased significantly. Conclusions : The pilot project might change the behavior of utilizing the medical care service by increasing the ratio of collaborative treatment of Western medicine and Korean medicine for the same disease on the same day.

• Molecular & Cellular Toxicology
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• v.4 no.4
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• pp.307-310
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• 2008

AAD16034 is an alginate lyase from Pseudoalteromonas sp. IAM14594. A very close homologue with known 3D structure exists (marine bacterium Pseudoalteromonas sp. strain no. 272). A three-dimensional structure of AAD16034 was generated based on this template (PDB code: 1J1T) by comparative modeling. The modeled enzyme exhibited a jelly-roll like structure very similar to its template structure. Both enzymes possess the characteristic alginate sequence YFKhG+Y-Q. Since AAD16034 displays enzymatic activity for poly-M alginate, docking of a tri-mannuronate into the modeled structure was performed. Two separate and adjacent binding sites were found. The ligand was accommodated inside each binding site. By considering both binding sites, a plausible binding pose for the poly-M alginate polymer could be deduced. From the modeled docking pose (i.e., the most important factor that attracts alginate polymer into this lyase) the most likely interaction was electrostatic. In accordance with a previous report, the hydroxyl group of Y345 was positioned close to the ${\alpha}$-hydrogen of ${\beta}$-mannuronate, which was suitable to initiate a ${\beta}$-elimination reaction. K347 was also very near to the carboxylatemoiety of the ligand, which might stabilize the dianion intermediate during the ${\beta}$-elimination reaction. This implies that the characteristic alginate sequence is absolutely crucial for the catalysis. These results may be exploited in the design of novel enzymes with desired properties.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.168-172
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• 2012

This article presents an evaluation of the effects of coating conditions on the enteric coating quality of soft gelatin capsules containing Omega-3 fatty acids. Three conditions were controlled: concentration of hydroxypropyl methylcellulose phthalate (6, 8, and 10 wt% in solution), temperature of the inlet air (32, 35, and $38^{\circ}C$), and the coating solution feed rate (7.5, 11.25, and 15.0 g/min). The transparency of the enteric coated soft gelatin capsules was evaluated by measuring the degree of whiteness of the surface using a spectrophotometer. Results showed that the most important parameter in the enteric coating process was the coating solution feed rate. As the coating solution feed rate decreased and inlet air temperature increased, the degree of whiteness of coating surfaces decreased. We also evaluated the disintegration properties of the enteric coated capsules in accordance with the Korea Health Functional Food Code.

• The Korean Journal of Food And Nutrition
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• v.31 no.2
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• pp.272-277
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• 2018

This research was conducted to elucidate the optimum conditions for the antibacterial activity of konjak jelly using the evolutionary operation-factorial design technique. In the first set of experiments, concentration of a coagulation agent, soaking liquid, and temperature of water were set to 0.4%, $0.6{\times}10^{-2}N$, and $65^{\circ}C$ as a central point, respectively. The highest antibacterial activity was acquired at E21, in which the number of bacteria was 1.25 log cfu/g. Because the code of changes in the main effect was (-), it could be decided that the central point of the first set was not the optimum point. Although antibacterial activity in the second set was improved, the values of the main effect were higher than that of changes in the mean effect. The central point of third set was concentration of coagulation agent 0.8%, concentration of soaking liquid $1.0{\times}10^{-2}N$, and temperature of water $65^{\circ}C$. It was found that the antibacterial activity of central point in the third set was highest among all the tested set. Further, all the necessary conditions were appropriate to reach the optimum condition. The antibacterial activity of the central point in third set was more than 1,000 times higher than that of E11, in first set.

• Journal of Radiation Protection and Research
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• v.14 no.1
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• pp.56-65
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• 1989

The nuclear criticality of the KSC-4 shipping cask which can load four assemblies of PWR spent fuel was analyzed using KENO-IV computer code and 19-group nuclear cross section set generated from 218-group neutron cross section library(DLC-43/CSRL) using AMPX system. In accordance with 10CFR71, the analysis was performed for fresh fuel assemblies, instead of the spent fuels, under both norml transportation and hypothetical accident conditions. The calculated maximum multiplication factors(Keff) of the KSC-4 cask were 0.85289 and 0.94185 for the normal transportation and hypothetical accident conditions, respectively. The highest Keff of the KSC-4 cask is within the subcritical limit prescribed in l0CFR71 and accordingly the KSC-4 cask is safely designed in terms of nulear criticality.

• Journal of Radiation Protection and Research
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• v.38 no.4
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• pp.189-193
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• 2013

Annual dose on the containment building wall of the interim storage facility at normal condition was calculated to estimate the dose rate transition of the facility of PWR spent nuclear fuel. In this study, source term was generated by ORIGEN-ARP with 4.5 wt% initial enrichment, 45,000 MWd/MTU burnup and 10 years cooling time. Modeling of the storage facility and the containment building and radiation shielding evaluations were conducted by MCNP code depending on the distance between the wall and the facility in the building. In the case of the centralized storage system, the distance required for the annual dose rate limit from 10CFR72 was estimated to be 50 m.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.396-401
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• 2004

In this paper, a 1MW HAWT(FIL-1000) rotor blade has been designed by BEMT(Blade Element Momentum Theory) with Prandtl's tip loss. Also, a 3-D flow and performance analysis on the FIL-1000 rotor blade has been carried out by using the 3-D Navier-Stokes commercial solver (CFX-5.7) to provide more efficient design techniques to the large-scale HAWT engineers. The rated power and itsapproaching wind velocity at design point (TSR=7.5) are 1MW and 9.99m/s respectively. The rotor diameter is 54.5m and the rotating speed is 26.28rpm. Airfoils such as FFA W-301, DU91-W-250, DU93-W-210, NACA 63418, NACA 63415 consist of the rotor blade from hub to tip. Recent CFX version, 5.7 was adopted to simulate 3-D flow field and to analyze the performance characteristics of the rotor blade. Entire mesh node number is about 730,000 and it is generated by ICEM-CFD to achieve better mesh quality The predicted maximum power occurringat the design tip speed ratio is 931.45kW. Approaching to the root, the inflow angle becomes large, which causesthe blade to be stalled in the region. Therefore, k-$\omega$ SST turbulence model was used to predict the quantitative flow information more accurately. Application of commercial CFD code to optimum blade design and performance analysis was proved to be more effective environment to HAWT blade designers.