• Journal of Korean Society of Steel Construction
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• v.21 no.1
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• pp.71-81
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• 2009

In this study, the seismic performance of the Buckling Restrained Knee Bracing (BRKB) system was evaluated through a pin-connected one-bay, one-story frame. The BRKB system developed in this study was composed of a steel plate as a load-resisting core member and two channel sections to restrain local and global buckling of the core plate. The main purpose of the BRKB system is to restrengthen/rehabilitate old low- and mid-rise RC buildings, which, it is assumed, were designed with non-seismic designs and details. The main variables for the test specimens were the size of the core plates and the stiffeners, and the condition of the end plates. The test results showed that the size of the core plate, which was the main element of the load-resisting member, was the most important parameter in achieving a ductile behavior under tension as well as compression until the maximum displacement exceeds twice the design drift limit.

• Journal of the Economic Geographical Society of Korea
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• v.20 no.4
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• pp.431-452
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• 2017

This paper examines the development process of China's venture capital industry and the characteristics of its capital spatial configuration. The results reveal that the development of China's venture capital industry has its unique modality, which varies greatly from existing studies, namely, the desynchronized paces of industry development as well as the regional real capital supply and demand trend. More detailed observation shows the Chinese venture capital's spatial configuration has three main characteristics: first, the separation of the registered location and the actual location of business operation; second, the division and spatial configuration of the venture fund's capital circulation. To find the relevant factors related to the above phenomena, a correlation analysis was conducted between both market factors and non-market factors with the above capital spatial configuration. The analysis confirmed that besides the market factors, local legislative condition also presents a high correlation with the phenomena.

• International Journal of High-Rise Buildings
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• v.7 no.1
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• pp.17-32
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• 2018

This paper explores the function of a structural skin with an embossed surface applicable to use for tall building structures. The major diagrid system with a secondary embossed surface structure provides an enhanced perimeter structural system by increasing tube section areas and reduces aerodynamic loads by disorienting major organized structure of winds. A parametric study used to investigate an optimized configuration of the embossed structure revealed that the embossed structure has a structural advantage in stiffening the structure, reducing lateral drift to 90% compared to a non-embossed diagrid baseline model, and results of wind load analysis using computational fluid dynamics, demonstrated the proposed embossed system can reduce. The resulting undulating embossed skin geometry presents both opportunities for incorporating versatile interior environments as well as unique challenges for daylighting and thermal control of the envelope. Solar and thermal control requires multiple daylighting solutions to address each local façade surface condition in order to reduce energy loads and meet occupant comfort standards. These findings illustrate that although more complex in geometry, architects and engineers can produce tall buildings that have less impact on our environment by utilizing structural forms that reduce structural steel needed for stiffening, thus reducing embodied $CO^2$, while positively affecting indoor quality and energy performance, all possible while creating a unique urban iconography derived from the performance of building skin.

• Journal of Pharmacopuncture
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• v.14 no.3
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• pp.19-45
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• 2011

Objectives: This study was performed to analyse the effects of Sweet Bee Venom(Sweet BV-pure melittin, the major component of honey bee venom) on the central nervous system in rats. Methods: All experiments were conducted at Biotoxtech Company, a non-clinical studies authorized institution, under the regulations of Good Laboratory Practice (GLP). Male rats of 5 weeks old were chosen for this study and after confirming condition of rats was stable, Sweet BV was administered in thigh muscle of rats. And checked the effects of Sweet BV on the central nervous system using the functional observational battery (FOB), which is a neuro-toxicity screening assay composed of 30 descriptive, scalar, binary, and continuous endpoints. And home cage observations, home cage removal and handling, open field activity, sensorimotor reflex test/physiological measurements were conducted. Results: 1. In the home cage observation, there was not observed any abnormal signs in rats. 2. In the observation of open field activity, the reduction of number of unit areas crossed and rearing count was observed caused by Sweet BV treatment. 3. In the observation of handling reactivity, there was not observed any abnormal signs in rats. 4. In the observation of sensorimotor reflex tests/physiological measurements, there was not observed any neurotoxic signs in rats. 5. In the measurement of rectal temperature, treatment of Sweet BV did not showed great influences in the body temperature of rats. Conclusions: Above findings suggest that Sweet BV is relatively safe treatment in the central nervous system. But in the using of over dose, Sweet BV may the cause of local pain and disturbance of movement. Further studies on the subject should be conducted to yield more concrete evidences.

• Journal of Pharmacopuncture
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• v.18 no.2
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• pp.76-85
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• 2015

Objectives: Radix Ginseng has been traditionally used as an adaptogen that acts on the adrenal cortex and stimulates or relaxes the nervous system to restore emotional and physical balance and to improve well-being in cases of degenerative disease and/or old age. Radix Ginseng has been used for a long time, but the safety of ginseng pharmacopuncture needs testing. This study was done to analyze the single-dose toxicity of water- soluble ginseng pharmacopuncture (GP) intramuscular injections in rats. Methods: All experiments were performed at Biotoxtech, an institution authorized to perform non clinical studies under the regulations of Good Laboratory Practice (GLP). Each group contained 10 Sprague-Dawley rats, 5 males and 5 females. GP was prepared in a sterile room at the Korean Pharmacopuncture Institute under regulations of Good Manufacturing Practice (GMP). GP dosages were 0.1, 0.5 and 1.0 mL for the experimental groups; normal saline was administered to the control group. The animals general condition was examined daily for 14 days, and the rats were weighed on the starting day and at 3, 7 and 14 days after administration of the pharmacopuncture. Hematological and biochemistry tests and autopsies were done to test the toxicological effect of GP after 14 days. This study was performed with approval from the Institutional Animal Ethics Committee of Biotextech. Results: No deaths were found in this single-dose toxicity test of intramuscular injections of GP, and no significant changes in the general conditions, body weights, hematological and biochemistry tests, and autopsies were observed. The local injection site showed no changes. Based on these results, the lethal dose was assumed to be over 1.0 mL/animal in both sexes. Conclusion: These results suggest that GP is relatively safe. Further studies, including a repeated toxicity test, are needed to provide more concrete evidence for the safety of GP.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.1
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• pp.83-88
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• 2013

Progressive collapse is a chain reaction of failures propagating throughout a portion of a structure that is disproportionate to the original local failure. When column members are subjected to unexpected load (compression load), they will buckle if the applied load is greater than the critical load that induces buckling. The post-buckling strength of the columns will decrease rapidly, but if there is enough residual strength, the members will absorb the potential energy generated by the impact load to prevent progressive collapse. Thus, it is necessary to identify the relationship of the load-deformation of a column member in the progressive collapse of a structure up to final collapse. In this study, we carried out nonlinear FEM analysis and based on deflection theory, we investigated the load-deformation relationship of H-section steel columns when both ends were fixed.

• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.589-600
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• 2022

Investigations on the molten-pool sloshing behavior are of essential value for improving nuclear safety evaluation of Core Disruptive Accidents (CDA) that would be possibly encountered for Sodium-cooled Fast Reactors (SFR). This paper is aimed at synthesizing the knowledge from our recent studies on molten-pool sloshing behavior with solid particles conducted at the Sun Yat-sen University. To better visualize and clarify the mechanism and characteristics of sloshing induced by local Fuel-Coolant Interaction (FCI), experiments were performed with various parameters by injecting nitrogen gas into a 2-dimensional liquid pool with accumulated solid particles. It was confirmed that under different particle-bed conditions, three representative flow regimes (i.e. the bubble-impulsion dominant, transitional and bed-inertia dominant regimes) are identifiable. Aimed at predicting the regime transitions during sloshing process, a predictive empirical model along with a regime map was proposed on the basis of experiments using single-sized spherical solid particles, and then was extended for covering more complex particle conditions (e.g. non-spherical, mixed-sized and mixed-density spherical particle conditions). To obtain more comprehensive understandings and verify the applicability and reliability of the predictive model under more realistic conditions (e.g. large-scale 3-dimensional condition), further experimental and modeling studies are also being prepared under other more complicated actual conditions.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• v.62 no.2
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• pp.75-81
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• 2019

The objective of this study was to perform a systematic review of the literature for application of intranasal sodium citrate in the patients with olfactory dysfunction to help determine the sodium citrate treatments for this condition. Two authors independently searched the data base (Medline, Scopus, and the Cochrane database) for relevant studies from inception to January 2018. Included studies were randomized controlled studies published in English comparing topical sodium citrate application (treatment group) with saline (control group) in patients who had olfactory dysfunction. Outcomes of interest included the change of olfactory identification and threshold during 2 hours post-treatment. Three studies were enrolled in the meta-analysis. Compared with control group, treatment group did not increase posttreatment score of olfactory identification [standardized mean difference (SMD)=-0.03; 95% confidence interval (CI)=-0.29-0.24; I²=0%] and olfactory threshold (SMD=0.18; 95% CI=-0.09-0.45; I²=0%) significantly. In the degree of pre-post improvement of two outcomes, although treatment group statistically showed the significant improvement in olfactory threshold (SMD=0.30; 95% CI=0.05-0.55; I²=17%), the clinical significance of this outcome was meaningless. Similarly, there was no significant difference in olfactory identification between two groups (SMD=0.17; 95% CI=-0.11-0.45; I²=22%). Unlike the recent favorable results, our summated results presented the uselessness for the local application of sodium citrate in improving patient's olfactory function. However, we also had some limitation such as small sample size and inconsistent application methods. Therefore, larger trials and standardized methodology are needed to reach more stronger and exact results.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.5
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• pp.483-490
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• 2006

In order to breed hemp variety with nondrug type adapted to Korea, a total of 44 accessions were introduced from Center for plant breeding and reproduction research (CPRO) In Netherland and evaluated for plant growth characteristics and contents of cannabinoids such as tetrahydrocannbinol (THC), cannabidiol (CBD), Cannabinol (CBN) in Korean climatical and geographical condition. 1. In Korean geographical position which latitude is $34^{\circ}N$, days to flowering and stem length were shorter than in Netherlands which latitude is $52^{\circ}N$. But THC content was not shown significant difference between two areas. 2. Corrected accessions of hemp were classified into 3 variety groups by cluster analysis and 4 accessions including Korean local variety were not classified into any variety group. 3. Most hemp accessions have low THC contents but were not suitable for fiber production in Korea due to short days to flowering and stem length. 4. Among the introduced accessions, IH3 was suitable for breeding material of fiber hemp with non-drug type because of low THC content and similar days to flowering with Korean local variety.

• Journal of the Korean Solar Energy Society
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• v.28 no.2
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• pp.64-69
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• 2008

As the grid-connected photovoltaic power conditioning systems (PVPCS) are installed in many residential areas, these have raised potential problems of network protection on electrical power system. One of the numerous problems is an Islanding phenomenon. There has been an argument that it may be a non-issue in practice because the probability of islanding is extremely low. However, there are three counter-arguments: First, the low probability of islanding is based on the assumption of 100% power matching between the PVPCS and the islanded local loads. In fact, an islanding can be easily formed even without 100% power matching (the power mismatch could be up to 30% if only traditional protections are used, e.g. under/over voltage/frequency). The 30% power-mismatch condition will drastically increase the islanding probability. Second, even with a larger power mismatch, the time for voltage or frequency to deviate sufficiently to cause a trip, plus the time required to execute a trip (particularly if conventional switchgear is required to operate), can easily be greater than the typical re-close time on the distribution circuit. Third, the low-probability argument is based on the study of PVPCS. Especially, if the output power of PVPCS equals to power consumption of local loads, it is very difficult for the PVPCS to sustain the voltage and frequency in an islanding. Unintentional islanding of PVPCS may result in power-quality issues, interference to grid-protection devices, equipment damage, and even personnel safety hazards. Therefore the verification of anti-islanding performance is strongly needed. In this paper, improved RPV method is proposed through considering power quality and anti-islanding capacity of grid-connected single-phase PVPCS in IEEE Std 1547 ("Standard for Interconnecting Distributed Resources to Electric Power Systems"). And the simulation results are verified.