• Wind and Structures
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• v.15 no.6
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• pp.531-553
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• 2012

Many tall buildings possess through-building gaps at middle levels of the building elevation. Some of these floors are used as sky gardens, or refuge floors, through which wind can flow with limited blockage. It has been reported in the literature that through-building gaps can be effective in reducing across-wind excitation of tall buildings. This paper systematically examines the effectiveness of two configurations of a through-building gap, at the mid-height of a tall building, in reducing the wind-induced dynamic responses of the building. The two configurations differ in the pattern of through-building opening on the gap floor, one with opening through the central portion of the floor and the other with opening on the perimeter of the floor around a central core. Wind forces and moments on the building models were measured with a high-frequency force balance from which dynamic building responses were computed. The results show that both configurations of a through-building gap are effective in reducing the across-wind excitation with the one with opening around the perimeter of the floor being significantly more effective. Wind pressures were measured on the building faces with electronic pressure scanners to help understand the generation of wind excitation loading. The data suggest that the through-building gap reduces the fluctuating across-wind forces through a disturbance of the coherence and phase-alignment of vortex excitation.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.1
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• pp.9-17
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• 2015

The basic flow configuration is composed of a plane, double shear layer where relatively thin mid gas layer is sandwiched between air and fuel stream. The present study describes numerical investigations concerning the combustion enhancement according to a variation of mid layer thickness. In this case, the effect of heat release in turbulent mixing layers is important. For the numerical solution, a fully conservative unsteady $2^{nd}$ order time accurate sub-iteration method and $2^{nd}$ order TVD scheme are used with the finite volume method including k-${\omega}$ SST model. The results consists of three categories; single shear layer consists of fuel and air, inert gas sandwiched between fuel and air, cold fuel gas sandwiched between fuel and air. The numerical calculations has been carried out in case of 1, 2, 4 mm of mid layer thickness. The height of total gas stream is 4 cm. The combustion region is broadened in case of inert gas layer of 2, 4 mm thickness and cold fuel layer of 4 mm thickness compared with single shear layer.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.6
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• pp.1177-1183
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• 2002

We investigated the effects of Sabaek-san (SBS) water extract on the cell proliferation of human lung carcinoma A549 cells. SBS treatment resulted in the inhibition of cell proliferation in a concentration-dependent manner. This anti-proliferative effect of A549 cells by SBS treatment was associated with morphological changes such as membrane shrinking and cell rounding up. DNA flow cytometric histograms showed that population of G1 phase of the cell cycle was increased by SBS treatment in a concentration-dependent manner. SBS treatment induced a marked accumulation of tumor suppressor p53 and a concomitant induction of cyclin-dependent kinase (Cdk) inhibitor p21WAF1/CIP, which appears to be transcriptionally upregulated and is p53 dependent. In addition, SBS treatment resulted in down-regulation of cyclooxygenase-2 (COX-2) as determined by RT-PCR analysis. The present results indicated that SBS-induced inhibition of lung cancer cell proliferation is associated with the blockage of G1/S progression the induction of apoptosis.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.3
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• pp.677-683
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• 2003

We investigated the effects of Insamsapye-tang (ISSPT) water extract on the growth of human lung carcinoma A549 cells. Upon treatment with ISSPT extract, a concentration-dependent inhibition of cell viability was observed and cells developed many of the hallmark features of apoptosis, including condensation of chromatin. Flow cytometry analysis confirmed that ISSPT treatment increased populations of apoptotic-sub G1 phase. In addition, proteolytic degradation of poly(ADP-ribose) polymerase (PARP) and β-catenin protein were observed after treatment of ISSPT extract. These apoptotic effects of ISSPT in A549 cells were associated with marked inhibition of Bel-xL expression in a dose-dependent manner, however the levels of Bcl-2 and Bax expression were not affected. ISSPT treatment also induced the expression of tumor suppressor p53 mRNA and inhibited the expression of caspase-3 mRNA. The previous and present results indicated that ISSPT-induced inhibition of lung cancer cell proliferation is associated with the blockage of G1/S progression and the induction of apoptosis.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.5
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• pp.1309-1314
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• 2003

We examined the effects of Oak Smoke Flavoring (OSF, Holyessing) on the cell proliferation of DU145 and PC3 human prostate carcinoma cell line. OSF treatment resulted in a concentration-dependent inhibition of the cell viability in both DU145 and PC3 cell lines. The anti-proliferative effects by OSF treatment in DU145 and PC3 cells were associated with morphological changes such as membrane shrinking and cell rounding up. DNA flow cytometric histograms showed that population of S phase of the cell cycle was increased by OSF treatment in a dose-dependent manner. Western blot analysis revealed that cyclin B1 and cdc2 proteins were reduced by OSF treatment in DU145 cells, whereas cyclin A was markedly inhibited in PC3 cells. Furthermore, we observed an increase of Cdk inhibitor p16 and p27 protein, and an inhibition of phosphorylation of pRB by OSF treatment in a dose-dependent manner. The present results indicated that OSF-induced inhibition of human prostate carcinoma cell proliferation is associated with the blockage of S phase progression.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.451-456
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• 2003

We investigated the effects of Sabaek-san (SBS) water extract on the growth of human lung carcinoma A549 cells. Upon treatment with SBS extract, a concentration-dependent inhibition of cell viability was observed and cells developed many of the hallmark features of apoptosis. including condensation of chromatin. Flow cytometry analysis confirmed that SBS treatment increased populations of apoptotic-sub G1 phase. In addition. proteolytic cleavages of poly(ADP-ribose) polymerase and β-catenin protein were observed after treatment of SBS extract. These apoptotic effects of SBS in A549 cells were associated with marked inhibition of Bcl-2 and Bel-xL mRNA in a dose-dependent manner. however the levels of Bax expression were not affected, SBS treatment also induced a proteolytic activation of caspase-3. which is believed to play a central role In the apoptotic signaling pathway. The previous and present results indicated that SBS-induced inhibition of lung cancer cell proliferation is associated with the blockage of G1/S progression and the induction of apoptosis.

• Wind and Structures
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• v.25 no.3
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• pp.233-259
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• 2017

Investigations on simulated near-surface atmospheric boundary layer (ABL) in an open-jet facility are carried out by conducting experimental tests on small-scale models of low-rise buildings. The objectives of the current study are: (1) to determine the optimal location of test buildings from the exit of the open-jet facility, and (2) to investigate the scale effect on the aerodynamic pressure characteristics. Based on the results, the newly built open-jet facility is well capable of producing mean wind speed and turbulence profiles representing open-terrain conditions. The results show that the proximity of the test model to the open-jet governs the length of the separation bubble as well as the peak roof pressures. However, test models placed at a horizontal distance of 2.5H (H is height of the wind field) from the exit of the open-jet, with a width that is half the width of the wind field and a length of 1H, have consistent mean and peak pressure coefficients when compared with available results from wind tunnel testing. In addition, testing models with as large as 16% blockage ratio is feasible within the open-jet facility. This reveals the importance of open-jet facilities as a robust tool to alleviate the scale restrictions involved in physical investigations of flow pattern around civil engineering structures. The results and findings of this study are useful for putting forward recommendations and guidelines for testing protocols at open-jet facilities, eventually helping the progress of enhanced standard provisions on the design of low-rise buildings for wind.

• Journal of Korean Society of Transportation
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• v.21 no.4
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• pp.79-90
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• 2003

Internal metering policy(IMP) is a control strategy to improve the quality of traffic flow within a network by avoiding queue spillback or intersection blockage. It is a more aggressive control strategy than the current control strategy employed in COSMOS. A preliminary study was made to incorporate the IMP logic within the COSMOS system to improve its' functionality at oversaturated conditions. From the study results, a set of guideline for real implementation was recommended : traffic conditions, detector configurations, and control procedures, etc. A simulation study was performed to evaluate the effectiveness of the proposed guidelines. It was shown that the occurrence of queue spillback was minimized. and overall network performance was also improved by applying IMP logic as compared to COSMOS control onl.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.545-550
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• 2012

Steam generator is one of the major components of nuclear power plant and steam generator tubes are the pressure boundary between primary and secondary side, which makes them critical for nuclear safety. As the operating time of nuclear power plant increases, not only damage mechanisms but also scaled deposits on steam generator tubes are known to be problematic causing tube support flow hole blockage and heat fouling. The ability to assess the extent and location of scaled deposits on tubes became essential for management and maintenance of steam generator and eddy current bobbin data can be utilized to measure thickness of scale on tubes. In this paper, tube reference standards with various thickness of scaled deposit has been set up to provide information about the overall deposit condition of steam generator tubes, providing essential tool for steam generator management and maintenance to predict and prevent future damages. Also, methodology to automatically measure scale thickness on tubes has been developed and applied to field data to estimate overall scale amount.

• Journal of the Society of Disaster Information
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• v.15 no.3
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• pp.450-458
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• 2019

Purpose: The purpose of this study is to develop a new sewage bay that has removed its previous problems and verify the excellence of the maintainability of the new sewage bay. Method: The fluid characteristics in the developed sewage bay was analysed with computer simulation tool(COMSOL MultiphysicsTM ver. 3.2 ; COMSOL) and clarified the problems of the existing sewage bay. In addition, the durability of the newly developed sewage bay was verified by the long-term usability testing. Results: As a result of the simulation of a blocked drainage trap, an whirlpool and blockage did not occurred at the flow rate of 0.6m/sec, and we verified that switch device of drain trap was in good condition durably with 6 months long-term usability test. Conclusion: In this study, a newly advanced sewage bay was developed that solved the problems of the existing sewage bay structure. With the fluid simulation and the long-term usability tests, the excellence of the maintenance ability of the newly developed sewage bay was proved.