• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.32 no.5
• /
• pp.342-350
• /
• 2008

The effects of combustion instability on flow structure and flame dynamics with the inlet configurations in a model gas turbine combustor were investigated using large eddy simulation (LES). A G-equation flamelet model was employed to simulate the unsteady flame behaviors. As a result of mean flow field, the change of divergent half angle($\alpha$) at combustor inlet results in variations in the size and shape of the central toroidal recirculation (CTRZ) as well as the flame length by changing corner recirculation zone (CRZ). The case of ${\alpha}=45^{\circ}$ show smaller size and upstream location of CTRZ than those of $90^{\circ}$ and $30^{\circ}$ by the development of higher swirl velocity. The flame length in the case of ${\alpha}=45^{\circ}$ is shorter than other cases, while the case of ${\alpha}=30^{\circ}$ yields the longest flame length due to the decrease of effective reactive area with the absence of CRZ. Through the analysis of pressure fluctuation, it was identified that the case of ${\alpha}=45^{\circ}$ shows the largest damping effect of pressure oscillation in all configurations and brings in the noise reduction of 2.97dB, compared to that of ${\alpha}=30^{\circ}$ having the largest pressure oscillation. These reasons were discussed in detail through the analysis of unsteady phenomena related to recirculation zone and flame surface. Finally the effects of flame-acoustic interaction were evaluated using local Rayleigh parameter.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.2
• /
• pp.325-333
• /
• 2015

In this paper, we are aim to analysis the effects of optical cable fault on customer complaints. We considered several causes: the elapse time to allow repair from the optical cable fault, whether working day or not, seasonality and human error, external construction, optical cable cutting or core banding that is controllable causes and natural disasters, vehicle crash, fire that is uncontrollable causes. The results of analysis are as follows: First, customer complaints increase through indifferencial relationship when using the production function for the number of expected victims and elapsed time due to the optical cable fault. Second, not only the elapsed time but also controllable variables, human error, external construction, the core cut occurs, increased customer complaints due to optical cable faults.

• Journal of agriculture & life science
• /
• v.46 no.4
• /
• pp.31-39
• /
• 2012

In this study, biodiversity was classified as 4 sectors (genes, species, ecosystems, and cultures) and overall 14 indicators were subdivided by the classification criterion of 4 sectors. Among those 14 indicators, monetary evaluation was conducted for 11 indicators that can be quantified in economic perspectives. Results show that negative economy effects (forest degradation, forest fire, forest damage caused by diseases and insects, deforestation, and cost under the assumption with the adoption of the Nagoya Protocol to be compensated for traditional knowledge) by reducing forest biodiversity were evaluated as 254.5 billion won annually. Also, Bioindustry, indigenous species, forest production, protection area, and income associated with mountain village were considered as positive economy effects and their annual economic value was 6.72 trillion won. Net annual benefit by maintaining forest biodiversity was about 6.5 trillion won.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.21 no.3
• /
• pp.1-17
• /
• 2008

Purpose: Scutellaria baicalensis is a herb which has effect of eliminating heat, drying dampness, purging away fire, detoxicating. Clinically, has been used to remove fever and control of inflammation. We have studied in series to investigate the effective traditional oriental medicines of treatment for endometriosis. In this study, the effects of Scutellaria baicalensis administrated orally or rectally on surgically induced endometriosis in rat were investigated. Methods: The endometrial tissues of rats were autografted to their small intestine. Rats with surgically induced endometriosis were administered with Scutellaria baicalensis extracts for 40 days orally or rectally. We observed the tissue size of ectopic uterine implants at the mesenteric with the naked eye and examined the concentration of estradiol, progesterone, $TNF-{\alpha}$ and IL-2, IL-4, IL-6 and IL-10 in serum. Also, we inquired which was more effective between oral administration groups and rectal administration groups. Results: The size of ectopic uterine implants of orally or rectally treated groups was much smaller than those of control groups. The concentrations of estradiol, progesterone, $TNF-{\alpha}$, IL-2 and IL-6 were significantly decreased in oral administration experimental group compared with the control group. The concentrations of progesteron, $TNF-{\alpha}$, IL-2 and IL-6 were significantly decreased in rectal administration experimental group compared with the control group. The efficiency of oral administration group was better than that of rectal administration group at the serum concentration of estradiol and IL-4. Conclusion: Our data suggest that Scutellaria baicalensis inhibit the inflammation induced from ectopic uterine implants at the mesenteric wall and inhibit the growth of ectopic uterine implants. Judging from the above results, it can be suggested that Scutellaria. baicalensis should be a useful agent for inhibiting the inflammation induced from ectopic uterine implants and the proliferation of endometriosis. Maybe, oral administration of Scutellaria baicalensis is more effective than rectal administration.

• Journal of Korean Medical classics
• /
• v.34 no.2
• /
• pp.225-240
• /
• 2021

Objectives : The purpose of this paper is to examine Zhang Zihe's reinforcement method based on the theory of keeping balance(以平爲期). Methods : Based on his arguments in the Rumenshiqin and formula compositions, Zhang Zihe's reinforcement method was examined. Results & Conclusions : 1. Despite preconceptions that Zhang Zihe must have been critical of reinforcement methods due to his alliance to the offensive purgative group, in reality his criticism was not aimed at reinforcement methods entirely, but rather at warming and tonifying. 2. Zhang Zihe's criticism of warming and tonifying was based on his research of the Neijing, in which he realized the pathogenic effects of fire-heat and the side effects of warming and tonifying in clinical practice. This is a common conception among the Four Great Doctors of the Jin-Yuan period. 3. Zhang Zihe focused on eliminating pathogenic qi so that the body's qi would circulate smoothly to slowly restore the source qi. The theory of keeping balance was emphasized to achieve this goal. 4. Based on the theory of keeping balance, Zhang Zihe used various medicinals with different properties and flavors to allow for the medicinals in each of the sovereign, minister, assistant and courier positions to co-operate with each other, while using food reinforcement to restore the source qi.

• Journal of the Korea Convergence Society
• /
• v.9 no.12
• /
• pp.441-447
• /
• 2018

This study aimed to investigate the effect of firefighters' social capital on subjective happiness. This research was conducted from Jun 12 to Aug 25, 2017, and a descriptive analysis, t-test, hierarchical regression analysis was carried out based on the results of a survey with 351 firefighters in Gyeonggi-do to verify the research hypothesis. As a result, it was revealed that network(${\beta}=.315$, p<.001), trust(${\beta}=.293$, p<.01), cooperation(${\beta}=.225$, p<.01) and trust among other sub-variables of firefighters' social capital had significant effects on subjective happiness. Based on the results, this research suggested that various measures to strengthen social capital would be required in order to improve fire-fighters' happiness: efforts to increase trust within the organization, political support for vitalizing formal network as a communication channel among firefighters organizations, encouraging interest in the community and promoting informal network such as volunteer work, developing transparency in operating the organizational policy and system, etc.

• The Korea Journal of Herbology
• /
• v.24 no.4
• /
• pp.39-47
• /
• 2009

Objectives : Hwangnyeonhaedok-tang (Huanglian Jiedu Tang; HHT) has been widely used for purging' 'fire' and lessening virulence of any pathogenic organism. However it has been rarely conducted to evaluate the immuno-biological activity. In this study, we evaluated anti-inflammatory effects of HHT in LPS-activated Raw264.7 cells. Methods : Cells were treated with $1\;{\mu}g/ml$ of LPS 1 h prior to the addition of HHT. Cell viability was measured by MTT assay. The production of NO was determined by reacting cultured medium with Griess reagent. PGE2 and proinflammatory cytokines were detected by ELISA. Expression of iNOS, COX-2, $I{\kappa}B{\alpha}$ and NF-${\kappa}B$ were analyzed by immunoblot analysis. Results : All three doses of HHT (0.03, 0.10 and 0.30 mg/ml) had no significant cytotoxicity during the entire experimental period. The levels of NO and PGE2 were dramatically augmented by LPS compared to control. However, HHT extract dose-dependently reduced these increases. Expression of iNOS and COX-2 protein were also decreased by treatment with HHT extract. Furthermore, HHT extract significantly reduced the nuclear translocation of NF-${\kappa}B$ which is critical in regulating inflammation through transcription of iNOS and COX-2. In addition, HHT extract reduced the elevated production of inflammatory cytokines including TNF-$\alpha$, IL-$1{\beta}$ and IL-6. Conclusions : The results in this study demonstrate that HHT extract exerts anti-inflammatory activities through the inhibition of NO, PGE2 and proinflammatory cytokines production via the suppression of NF-${\kappa}B$.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.22 no.3
• /
• pp.117-134
• /
• 2009

Purpose: In the theory of traditional medicine, Scutellariae Radix (SR) can clear away heat and remove dampness, purge the sthenic fire and remove toxic materials, cool blood and stop bleeding to prevent miscarriage. Recently, SR is known to have anti-cancer activity. For this reason, the present author designed to investigate the effect of SR on proliferation rates of cervical cancer cell line, then effects on genetic profile by SR. Methods: The genetic profile for the effect of SR on human derived cervical cancer cell line, SNU-703, was measured using microarray technique, and the functional analysis on these genes was conducted. Results: Total 519 genes were up-regulated and 606 genes down-regulated in cells treated with SR. Genes induced or suppressed by SR were all mainly concerned with metabolic process, regulation of biological process and protein binding. The network of total protein interactions was measured using cytoscape program, and some key molecules, such as TNFRSF1A, AKT1, MAPK3, and STAT3 that can be used for elucidation of therapeutical mechanism of medicine in future were identified. Conclusion: These results suggest possibility of SR as anti-cancer drug and also suggest that related mechanisms are involved in TNFRSF1A, AKT1, MAPK3, and STAT3 related signalling pathways.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.6
• /
• pp.471-478
• /
• 2023

The purpose of this study is to examine the effects of parental abuse and neglect on adolescents' internet addiction, and to verify the mediating effect of subjective happiness in the relationship between parental abuse and neglects and adolescent internet addiction. To this end, dat from the 16th year of the 2021 Korea Welfare Panel(KWPS) conducted by the Korea Institute for Health and Social Affairs were used. In this study, 1st, 2nd and 3rd graders of high school were analyzed, and data from a total of 325 students were analyzed. The analysis utilized SPSS 27.0 and Hayes(2013)'s Macro Process(model 4) to verity correlation analysis and mediating effects between related variables. The results of the analysis are as follows: First, abuse and neglect from parents directly affect adolescents' Internet addiction. Second, it was analyzed that subjective happiness mediated the effect of parental abuse and neglect on adolescents' Internet addiction.

• Journal of the Korean Institute of Gas
• /
• v.28 no.1
• /
• pp.85-99
• /
• 2024

As the proliferation of hydrogen electric vehicles accelerates, there is observed diversification in hydrogen refueling station models. This diversification raises safety concerns for different types of stations. This study conducted a quantitative risk assessment of a multi-vehicle hydrogen station, capable of simultaneously refueling cars, buses, and trucks. Utilizing Gexcon's Effects&Riskcurves Software, scenarios of fire and explosion due to hydrogen leaks were assessed. The study calculated the impact distances from radiative heat and explosion overpressure, and measured risks to nearby buildings and populations. The largest impact distance was from fires and explosions at dispensers and high-pressure storage units. High-pressure storage contributes most significantly to personal and societal risk. The study suggests that conservative safety distances and proper protective measures for these facilities can minimize human and material damage in the event of a hydrogen leak.