• Journal of the Korean Society for Heat Treatment
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• v.9 no.2
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• pp.130-138
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• 1996

It has been investigated that the ion nitriding effects of a STD61 steel in various time conditions of 3 to 9 hours, and the microstructure of compound and diffusion layers of the ion nitrided specimen for 6 hours and subsequently reheated for 1 hour at various temperatures of $400{\sim}800^{\circ}C$ As the nitriding time increased, the thickness of compound and diffusion layers was increased, but the hardness of surface was not considerably increased (Max Hv=1045 at 9hrs). Some of the nitrogen was denitrided out of the surfac and diffused into the core, and also the oxides ($Fe_3O_4$, $Fe_2O_3$) were formed on the surface of the specimen during reheating. The compound layer was partially decomposed at about $600^{\circ}C$ but the diffusion layer was increased up to $800^{\circ}C$. With increasing reheated temperture, the hardness of the surface was decreased, whereas the hardness depth of diffusion layer (0.25mm) was increased up to $600^{\circ}C$ more than that of ion nitrided (0.18mm). The blend-heat treated STD61 steel by ion nitriding is therefore expected to hold on the characteristics of ion nitriding up to $600^{\circ}C$.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.5
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• pp.435-442
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• 2014

This paper describes an improved design model that can be used to configure a non-contact pneumatic device to turn a large sheet at the in-line system. For rotational moving in the conveyor system, the conventional method is to turn the system itself. The improved non-contact pick-up system mainly uses 8 pairs of L-shaped latches and 12 swirl type heads. It is positioned above the upward air flow table. This system performs the non-contact gripping and side-edge contact support in the vertical and rotational directions to hold the self-weight of a large flat sheet. A non-contact air head can exert a sufficient gripping ability at 4N lower than the standard working pressure. The side latches support 60% of the lifting force required. Through structural and flow analysis, the working conditions were simultaneously considered in accordance with the deflection and flatness of the glass.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.5
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• pp.527-536
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• 2010

Although the bubble-floc agglomerate floated and formed the float layer on the surface of the water in the DAF process, after inducing in the thickening tank a part of the bubble-floc agglomerate come up again to the surface and the other is settled at the bottom of the tank. The bubble-floc agglomerate divided into two group as the scum on the surface and the sludge of the bottom gives rise to operational troubles for the thickening process. In order to find out the cause of break-up and the effective thickening method for sludge from the DAF process, the composition of the bubble-floc agglomerate was investigated and a series of flotation experiments carried out. There was no difference of composition between the scum on the surface and the sludge of the bottom in the thickening tank. The coagulation was not effective to improve the trouble that the bubble-floc agglomerate divided into the scum and the sludge. It was estimated that for the bubble-floc agglomerate of thickening tank the trouble was caused by not the change or the difference of chemical composition but whether the bubble-floc agglomerate hold bubbles. Furthermore, for the effective thickening of sludge from the DAF process, it is required an additional flotation applied the AS ratio depending upon the solid concentration of sludge as the operation parameter.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.193-200
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• 2014

In this paper, the prototype of one-channel gamma-ray spectroscope for automatic radiopharmaceutical systhesis system was designed and characterized. The prototype employed CZT (CdZnTe) spear detector for gamma-ray detection and employed analog-type signal processing method. A radioactive sample Co-60 was used for measuring performance of the gamma-ray spectroscope and energy spectrum is gained with bandwidth of 1173keV. The analog board is made up of SF (shaping filter) and PHA (peak and hold amplifier) for shaping CZT output signal appropriately and ADC (analog to digital converter) and FPGA (field programmable gate array) for drawing gamma-ray spectrum by counting the digitalized gamma-ray signal data.

• The Journal of Fisheries Business Administration
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• v.36 no.1 s.67
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• pp.103-120
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• 2005

This study aims to examine the change of fish market(魚物市場) and inland brokers(客主, kaegju) on Gunsan(群山), (1899-1919). The increasement of productive capacity in the agriculture and the development of exchange economy in the late period of Chosun Dynasty activated the distribution of fishery products. As a result, the inland brokers who participated in the production and distribution of fishes grew largely. They made the basement of fishery modernization by providing the funds for the fisheries and making the national distribution network. But Japanese fishermen began to hold the domestic market as the Japan government supported legislatively and economically after the opening ports of Korea. On the contrary, the distribution of fishery products had the characteristics different from the production of some. The case of Gunsan which opened in 1899 showed these characteristics as Gunsan is a short distance from Kangkyung(江景), one of three biggest markets and was a base of fishery, That is to say, though the fishery merchants from Japan set up 'a fish market'(魚市場), they didn't hold the sales network on Gunsan, Because the inland brokers on Gunsan had a sales network and began the socio-economic movement. It goes without saying that the instability of price, the difficulties of charge and the racial taste difference in fish made the fish sales from Japan confronted with the difficulties. After Japanese Imperialism enforced the Company Law, the Market Regulation, the Chamber of Commerce Law before or after 1910, Korean inland brokers were disprited and Japanese 'fish market' began to grow largely. These phenomena appeared on Gunsan, too. Especially, the opening of a railway was the main factor which strengthened Japanese 'fish market'. After 1915, Japanese 'fish market' on Gunsan defeated the distribution network of inland brokers.

• Journal of Korean Elementary Science Education
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• v.18 no.2
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• pp.145-151
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• 1999

There is an experiment in the elementary science textbook which a burning candle hold upright in a water tank and a beaker is converted over the burning candle, the candle flame goes out and the water rises into the beaker. Some reference books including teachers' guide for the elementary school teachers explain the reason why water rises that oxygen is "used up", so water rises the same volume of consumed oxygen into the beaker. But this explanation is only partially correct. In this study, discrepancies of the explanation that oxygen is "used up" are analyzed. Water rises by two major reasons. One is that water can rise to the level about l/3 of the volume of consumed oxygen. The other is that the beaker is converted over the burning candle which produces hot CO2 and water vapor, and the candle's flame heats the air around it to expand, after the candle flame goes out, the air in the beaker cools and water vapor changes to liquid water, so, air pressure in the beaker is reduced, and the water is pushed into the beaker by great air pressure outside. 1 demonstrate a inquiry teaching method of the candle experiment.

• Korean Journal of Psychosomatic Medicine
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• v.5 no.1
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• pp.82-88
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• 1997

Background : Patients with command hallucinations are commonly assumed to be at high risk for dangerous behavior. However the issue of whether command hallucinations hold any clinical relevance in schizophrenic patients has not been established. Method : The author analyzed the clinical and research records of schizophrenic patients with auditory hallucinations who participated in outpatient research follow-up for 9 months after discharge. Patients with auditory hallucinations were classified as experiencing or not experiencing command hallucinations based on clinical psychiatric assessment. Results : Of 63 patients with auditory hallucinations, 29(46%) reported the command hallucinations and these hallucinations often were violent in content(44.8%). Patients with command hallucinations were not significantly different from patients without command hallucinations on sociodemographic and clinical characteristics, and clinical or prognostic course variables, but patients with command hallucinations had significantly more short hospitalizations(less than one month) than patients without command hallucinations. 3 of the patients with command hallucinations who committed suicide during the follow up periods were died. Conclusion : Command hallucinations may be frequent, and in most cases they have minimal influence on the outcome of schizophrenia, but if the patients with command hallucinations have a history of suicide attempts before admission, the possibility of suicide attempts by command hallucinations should be considered.

• Journal of the military operations research society of Korea
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• v.33 no.1
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• pp.75-92
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• 2007

Most of countries in the world are stepping up military conversion to achieve military modernization. The issues of military conversion hold reallocation of financial resources, reorientation of R&D, restructuring of military industry, demobilization, base closure and relocation, scrapping of surplus weapons and so on. Also ROK is stepping up military modernization through defense reform. In particular, ROK has the plan to convert bases; transfering U.S. Forces in Korea and conducting the merger and abolition of bases. In this respect, we expect increase of base conversion easily in the future. Therefore, we tried to find the strategy of base conversion that ROK can conduct base conversion with success in this study. So that we analyze cases of base conversion which were conducted in ROK and U.S. Moreover, we extract problems of the process of base conversion in ROK and finally find out substitutes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3114-3120
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• 2014

Wireless emergency call switch used in industry, the most important thing is the sustainable power supply. This paper describes the development and performance test results of a compact electromagnetic energy harvesting mechanism for batteryless wireless switch. This paper summarizes proposed structure design and magnetic field analysis results of the mechanism to generate an induced electromotive force using 2mm stroke of a single push action. This analysis results show the power output of the proposed mechanism up to VDC $4.5V{\pm}25%$ and it can hold up to 65ms of the power generation with greater than 2.5V.

• PNF and Movement
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• v.16 no.3
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• pp.397-404
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• 2018

Purpose: The purpose of this study was to investigate the effect of climbing training combined with coordinative locomotor training on muscle thickness in normal adults and to provide basic data regarding its applicability to clinical practice. Methods: Coordinative locomotor and climbing training was conducted three times per week for six weeks. Each exercise session consisted of ten minutes of warm-up and 40 minutes of the main exercise. A post-test was conducted six weeks after the training began, and a follow-up test was done two weeks after the training ended. Results: There were significant differences in the participants' external and internal oblique abdominis muscles over time (p<0.05). There were also significant interactions in the external and internal oblique abdominis muscles over time and according to group (p<0.05). Conclusion: The findings indicate that coordinative locomotor training with climbing had positive effects in normal adults, including increased thickness of the external and internal oblique abdominis muscles. The findings hold value for patient rehabilitation and clinical applications and interventions using coordinative locomotor training in combination with climbing.