• Analytical Science and Technology
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• v.26 no.1
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• pp.73-79
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• 2013

The allyl isothiocyanate, capsaicin and dihydrocapsaicin as main components in self defense sprays were determined by gas chromatography-mass spectrometer (GC-MS). Although self defense spray was used to protect by myself, a social problem could be caused by the hazard of spray chemical due to use pungent liquid. To identify this, the pH of pungent liquid solutions, solubility to detergents, the existence of other materials and the types and amounts of pungent material in spray chemicals were investigated in this work. Finally, the amounts of allyl isothiocyanate, capsaicin and dihydrocapsaicin as pungent materials in them were determined by GC-MS. The pH of chemicals were about 5.7 as weak acid, the detergents can emulsify them with water well. And they did not contain fluorescent materials and hazard organic solvents. The pungent components in three real samples were only allyl isothiocyanate [47,600 mg/kg (47.6%)] in one sample, and mixtures with capsaicin [228 mg/kg~368 mg/kg (1.14%~1.84%)] and dihydrocapsaicin [224 mg/kg~414 mg/kg (1.12%~2.07%)] in the others, respectively.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.2
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• pp.60-66
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• 2014

As a evaluation method of combustion stability in a liquid rocket engine thrust chamber, external disturbance devices are used. In the paper, the study on pulse-gun ignition tests for a combustion stability rating test of a thrust chamber was performed. Charging volume of pulse-guns was determined by confirming the intensities of the pressure waves from the ignition tests in the cold-flow conditions. While using same injector head, combustion instabilities were not encountered during 14 hot-firing tests without pulse-guns but combustion instabilities were triggered by pulse-gun ignition during 2 hot-firing tests. The results showed that the pulse-gun ignition test could be the evaluation method and could reduce the hot-firing test number for the stability rating of a thrust chamber.

• Journal of Preventive Medicine and Public Health
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• v.9 no.1
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• pp.31-37
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• 1976

This study was conducted for the purpose of obtaining basic information on the patterns of medical care expenditures, and identifying some determinants of medical care expenditures in the rural Korea. Nine guns were chosen from the eight provinces, excluding Cheju island. One gun in each province and two villages were selected from the each myon or ub within the selected guns. The total number of households was 1,789 and the sample size was 9,826 non-institutionalized people. Followings are the major findings of the study : 1) Medical care expenditures increase proportionally with age in terms of cost per patient, per episode of illness, per treated case, and per person. Averagely, it cost 2,756 won per patient, 2,614 won per spell of illness, 4,361 won per treated case, and 413 won per person. 2) Medical care expenditures increase proportionally with educational level of patients. College graduates spent the most, 4,726 won per patient, 5,987 won per treated case, and 670 won per person. 3) The male spent a little more than the female in terms of per patient, per episode, and per person. For example, a male spent 23 won more than a female. 4) Those who were suffering from illnesses longer than 1 year spent three times more than that had illnesses of less than 1 year duration. 5) The simple correlation coefficient between activity restriction and medical care expenditures was the highest among others, 0.491. The next was 0.294 between duration of illness and medical care expenditures. 6) Attempts are made to identify the explanatory variables in medical care expenditures. Thirty one per cent of the variances in tile expenditures can be accounted for by the selected 15 predictors. Those predictors belonged to clinical renditions, such as activity restriction, duration of illness, and nature of conditions, are proved to be the most potent independent variabes. Level of education and monthly family income are also significant in terms of beta coefficient. Further studies are called for to unreveal the determinants of medical expenditures.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3062-3067
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• 2007

HVOF thermal spray guns are now being widely used to produce protective coatings, on the surfaces of engineering components. HVOF technology employs a combustion process to heat the gas flow and melt the coating materials which are particles of metals, alloys or cermets. Particle flow which is accelerated to high velocities and combustion gas stream are deposited on a substrate. In order to obtain good quality coatings, the analysis of torch design must be performed. The reason is that the design parameters of torch influence gas dynamic behaviors. In this study, numerical analysis is performed to predict the gas dynamic behaviors in a HVOF thermal spray gun with various torch shapes. The CFD model is used to deduce the effect of changes in nozzle geometry on gas dynamics. Using a commercial code, FLUENT which uses Finite Volume Method and SIMPLE algorithm, governing equations have been solved for the pressure, velocity and temperature distributions in the HVOF thermal spray torch.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.9
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• pp.22-29
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• 1997

This paper describes a three dimensional profile measurement method for sheet metal products which have flexible and porous sculptured surfaces. Shadow masks are used as measuring objects for practical implementation or this study. The shadow masks are located inside the fluorescent glasses of monitors for televisions or computers and used to prevent electron guns from interfering between pixels. Three dimen- sional surface profiles are measured by adopting a software autofocusing technique to capture focused images. The experimental results show that the method is very effecive and suitable for sheet meal prod- ucts with flexible and porous surfaces.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.4
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• pp.62-72
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• 2007

The Gun-Oreinted Anti-Air Warfare(GOAAW) which is still one of the important weapon systems of the vessel like the patrol killer to confront air threats comprises the components of the combat system - Command & Control(C2), Ballistic Calculation Unit, Sensors and Guns. In this paper, the GOAAW process of the patrol killer combat system is analyzed with probability and simulated to evaluate the effectiveness and capability of the GOAAW. As a result of the simulation, the performance measures of the GOAAW are discussed in the functional and operational aspects of the combat system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.11
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• pp.991-996
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• 2011

This study was carried out vibration attenuation of vibration absorber attached to the cantilever beam structure. Modern tank guns are stabilized to allow fire on the move while traversing uneven terrain. However, as the length of the barrel is extended, to meet required muzzle exit velocities, the terrain induced vibrations lead to increased muzzle pointing errors. Thus, reducing these vibrations should lead to increased accuracy. The vibration absorber includes a compliant energy storage device, such as a spring, and a mass secured to the energy storage device. In this study, it accomplished a research in about gun barrel vibration attenuation using tuned mass damper. The barrel was hung from a bungee cord for free-free condition. It accomplished a vibration experiment for verified attenuation efficiency.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.2
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• pp.159-169
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• 2017

This study aims to the increasing the reliability of gun firing system of patrol killer guided missile from failure mode analysis. In order to find out the breakdown parameter, the examination process of the sources of the problems and the quality improvement activities are analyzed with performance testing data. From this study, the rate of operation and the reliability of 76 mm naval guns will be increase. And the result of the study is expected to be used as a reference data in the naval gun firing system for another failure mode analysis.

• Journal of International Academy of Physical Therapy Research
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• v.7 no.1
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• pp.965-971
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• 2016

The purpose of this study was to investigate the effects of core strengthening training on baseball throwing. A total of 14 subjects were recruited from among middle school baseball players. The main outcome measures were as follows: speed guns were used to measure the velocity of baseballs thrown; scored targets were used to measure throwing accuracy; and 50m measuring tapes were used to measure throwing distances. It was found that core strengthening training improved the velocity of baseballs thrown and throwing accuracy and distance. Thus, core strengthening training is effective for improving the throwing ability of baseball players.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.627-632
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• 2011

This study was carried out vibration attenuation of vibration absorber attached to the cantilever beam structure. Modern tank guns are stabilized to allow fire on the move while traversing uneven terrain. However, as the length of the barrel is extended, to meet required muzzle exit velocities, the terrain induced vibrations lead to increased muzzle pointing errors. Thus, reducing these vibrations should lead to increased accuracy. The vibration absorber includes a compliant energy storage device, such as a spring, and a mass secured to the energy storage device. In this study, it accomplished a research in about gun barrel vibration attenuation using tuned mass damper. The barrel was hung from a bungee cord for free - free condition. It accomplished a vibration experiment for verified attenuation efficiency.