• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.4
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• pp.795-802
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• 2007

The fire not to back to its origin(火不歸原) is said that source yang(元陽) of sea of qi(氣海) rises because fire(火) of lower energizer(下焦) can't return to its origin. Successive medical men regarded the cause of it as yang deficiency(陽虛) or yin deficiency(陰虛) generally, but Jangseoksun(張錫純) presented eight kinds of cause, they are syndrome of upcast yang(戴陽證), deficiency of qi(氣虛), yin deficiency, yin and yang deficiency(陰陽虛), thoroughfare qi ascending counterflow(衝氣上衝), heart fire(心火), yang deficiency with cold fluid retention(寒飮) in middle energizer(中焦寒飮), yang deficiency with sunken cold locked in(沈寒錮冷). The method of conducting fire back to its origin may be the treatment of fire not to back to its origin as an interpretation of the phrase in a broad sense, but it is limited to yang deficiency with sunken cold locked in besides syndrome of upcast yang as the treatment based on pathological conditions. By this standpoint Eunsuryong(殷壽龍) used conducting fire back to its origin to remove hidden cold(伏寒) and make rising false fire(假火) settle. The meaning of conducting fire back to its origin is not just raise yang qi(陽氣) but break sunken cold locked in by using the drugs like Buja(附子), Yukgye(肉桂). Jakyak(芍藥) can concentrate yang qi on the life gate(命門) by converging it, Sukjihwang(熟地黃) can supply yin essence(陰精) and check the intense nature of tonifing yang(補陽) drugs. So if we want to use the method of conducting fire back to its origin, we should confirm the symptoms of sunken cold locked in and yang deficiency not to misdiagnose yin deficiency.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.4
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• pp.374-381
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• 2007

In order to verify the feasibility of expansion of back-fire limit equivalence ratio in the hydrogen-fueled engine with external mixture, the characteristics of performance and combustion are experimentally analyzed with change of intake/exhaust valve timings under the fixed valve overlap period of $0^{\circ}$ CA(non-valve overlap period). These characteristics are also tested for the change of exhaust valve closing timing while intake valve opening timing is fixed to clear the main cause of back-fire occurrence. As the results, the less valve overlap period center is retarded, the more back-fire limit equivalence ratio increases and back-fire does not occurred after TDC. In addition, it was shown that the control of back-fire is dependent on intake valve opening timing than valve overlap period.

• Journal of the Korean Society of Safety
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• v.25 no.1
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• pp.32-37
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• 2010

When back-out & firing Process applies heat, hume is piled up in exhaust duct by organic compound and it have high dangerousness. There by, the process is happening a lot of damage that is exhaust duct fire. However we do not have certain fire dangerousness estimation and digestion countermeasure. So we need preventive measure. Back-out & firing is a process which has fine structure, electrical and mechanical characteristics, such as firing kiln and back-out kiln which has pipe line and box type. The box oven is made of heating coil, fan motor and control panel. Back-out & firing process has air circulation institution of quick ventilation type. When we operate this process for long time, fire can break out easily. Duct is made by zinc shredder. If fire breaks out in duct inside, fire by deposit fume can be dispersed easily. Accordinglym, This project estimate danger for back-out & firing process exhaust duct through real fire test. And there is purpose of study to establish preventive measure.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.3
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• pp.348-355
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• 2007

To grasp a feasibility of back fire control by valve overlap period, back fire limit equivalence ratio was estimated with valve overlap period which has the same supply energy and positive intake pressure as valve overlap period $300^{\circ}\;CA$. As the result, it was shown that the smaller valve overlap period has the higher back fire limit equivalence ratio under valve overlap period $300^{\circ}\;CA$ as well as VOP $0^{\circ}\;CA$. This result means that expansion of back fire equivalence ratio by decreasing valve overlap period was caused by decrease of back flow duration of flame from in-cylinder to intake port than decrease of lower supply energy.

• Health Policy and Management
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• v.17 no.4
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• pp.99-112
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• 2007

The purpose of this study was to analyze the effect of fire fighters' duty type on occurrence and severity of low back pain. Data were collected with questionnaire to 450 fire fighters working at 119 safety center and rescue unit of 30 fire stations in Gyeonggi-do. Finally the study was analyzed for 360 persons among them. The risk of experiencing of lower back pain occurred in the order of Rescue[odds ratio(OR) 3.36, 95% confidence interval(95% CI) 1.18-9.52], Vehicle operation(OR 2.63, 95% CI 1.26-5.50), First aid(OR 2.18, 95% CI 1.03-4.59), and Putting out a fire. The risk on severity of lower back pain occurred in the order of Vehicle operation(OR 4.00, 95% CI 1.57-9.80), First aid(OR 1.88, 95% CI 1.00-4.81), Putting out a fire, and Rescue. These result suggest that duty type of fire fighters may be a prognostic factor for occurrence and severity of low back pain. The potential implications of these findings are discussed about different approach for primary and secondary prevention by duty type of fire fighters.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.3
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• pp.156-163
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• 2009

In this study, comparative analysis on the back-layer phenomena in the tunnel-fire driven flow is performed using numerical simulation with LES and RANS. FDS(Fire Dynamics Simulator) code is employed to calculate the fire-driven turbulent flow for LES and Smartfire code is used for RANS. Hwang and Wargo's data of scaling tunnel fire experiment are employed to compare with the present numerical simulation. The modeled tunnel is 5.4m(L) ${\times}$ 0.4m(W) ${\times}$ 0.3m(H). Heat Release Rate (HRR) of fire is 3.3kW and ventilation-velocity is 0.33m/s in the main stream. The various grid-distributions are systematically tested with FDS code to analyze the effects of grid size. The LES method with FDS provides an improved back-layer flow behavior in comparison with the RANS (${\kappa}-{\epsilon}$) method by Smartfire. The FDS solvers, however, overpredict the velocity in the center region of flow which is caused by the defects in the tunnel-entrance turbulence strength and in the near-wall turbulent flow in FDS code.

• Fire Science and Engineering
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• v.16 no.2
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• pp.38-42
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• 2002

This experiment is to understand a characteristics of smoke layer formation affected periodicity of fire plumes. The ON-OFF jet was used to constitute the oscillating flow, which was formed by a mixture of nitrogen gas with kerosene particles. The instantaneous images was obtained by digital video camera using laser sheet technique. The results were confirmed that the smoke layer in the near fire source comprise vortices which are formed by impingement from the periodicity of fire plume. The periodic impinging of plumes were thickened the smoke layer and produced the back-flow.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2007.04a
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• pp.101-106
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• 2007

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.277-280
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• 2008

This research examined for the fire safety performance improvement though which the construction of skyscrapers, disaster occurring and fire type in the skyscrapers.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.281-285
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• 2008

This research suggest the survey result of 26 fire stations for understanding the problem of fire fighting equipment in our country, knowing the improvement plan.