• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.5
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• pp.543-547
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• 2015

The cooling process referred to as Tempcore has been applied to produce a high-strength rebar. Excellent rebar with strength and weldability can be manufactured from mild steel without the addition of alloying elements by using the Tempcore process. However, there are limitations to evaluating the effect of various chemical compositions and cooling conditions within a site facility. In this study, we developed an apparatus to simulate the Tempcore process and obtained microstructures with a hardened surface layer, an intermediate region and a soft inner core. The experimental apparatus has been equipped with a cooler set that is the same as the site facility and consists of a pump line that supplies pressure of 12-13 bar and flow rate of up to $50m^3/h$. In accordance with the simulation result of steel grade SD400 that requires more than 400 MPa of yield strength, both the hardened area ratio and the hardness with respect to each cooling depth were found to agree well with the product.

• The Journal of Korean Society for Radiation Therapy
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• v.8 no.1
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• pp.109-114
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• 1996

PURPOSE : To investigate the effect of asymmetric jaws for delivering a uniform accurate dose of radiation to the junctions. METHODS & MATERIALS : A linear accelerator with a set of asymmetric jaws(varian 600C, 2100C, 2100CD with 4mev, 10mev, 10mev). Dose disribution was measured at the junctions with films in phantom. Total $10{\times}20cm^2$ with each $10{\times}10cm^2$ in deviation of ${\pm}1mm$ jaws. RESULTS : Film dosimetry showed the accuracy of asymmetric jaws depending on the machine. CONCLUSION : Understanding the mechanical characteristics of the use of half-beam at the junctions, without hot or cold regions.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.431-441
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• 2011

As environment issues arise, environment-friendliness in convention industry has also been discussed. Guidelines are presented by government and convention organization to settle environment-friendly convention. However, these efforts focus on organizers and suppliers, lacking in understanding convention participants. This study tries to approach in perspective of convention participants to get useful information for environment-friendly convention. The research explores how they are aware of environment issues and accept environment-friendly convention attributes according to their cognition of environment. It also examines the relationship between those attributes and intention of participation according to their awareness of environment. The results shows that participants have high awareness about environmental issue and recognized high necessity for set up for specific action plan. They showed highest acceptance of venue followed by activity, transportation, food & beverage, and operation. High awareness group showed higher acceptance of environment-friendly convention attributes than low awareness group. 'Transportation', 'activity', and 'operation' among five attributes were examined to have significant effect on intention of participate environment-friendly convention in both groups.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.3
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• pp.309-321
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• 2007

Since the first diesel passenger car hit the local road in late 2005, the share of diesel cars is growing significantly; possibly up to the level as in the western Europe. In this study, the effects of introduction of diesel passenger cars on the ventilation rate and facility capacity are analyzed for the three individual cases with different basic exhaust rate based on the vehicle age, the vehicle class percentage and the smoke exhaust rate. The target tunnel for this comparative study is a typical 2 km-long 2-lane highway tunnel. Case 1 assuming the current local design standards and the diesel vehicles comprising 40% of the total passenger cars on the road required more ventilation rate and facility capacity than in the case only with the current standards. Case 2 which is the real tunnel currently in the designing stage taking into account the vehicle age but ignoring the diesel vehicle ratio, and Case 3 on the contrary considering the both factors show similar level of ventilation characteristics as EURO-3 emission regulation. Application of the emission standard set by the Ministry of Environment for newly manufactured vehicles in the current local tunnel design standard indicates higher requirements than for EURO-2 regulation, whereas the emission standard came into effect in 2006 results in the ventilation characteristics similar to EURO-4. This study aims at providing fundamental information for assessing the basic emission rate and determining the optimal ventilation rate and facility capacity considering the growing percentage of diesel cars and gradually decreasing level of smoke emission forced by the relevant laws.

• Environmental and Resource Economics Review
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• v.29 no.3
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• pp.313-333
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• 2020

This paper shows that when the exchange rate changes, there are conflicting effects on improving the quality and increasing market share of eco-friendly vehicles. In a vertically differentiated duopoly model consisting of high quality clean cars and low quality internal combustion engine cars, I set up a two-stage noncooperative game under perfect information that the quality levels and the prices of the cars are competitively determined. The vehicles are assumed to be produced in countries that use distinct currencies. When the exchange rate of the country that produces low quality cars rises, the producer prefers to intensify competition due to the relatively lowed cost, and the incentive for quality improvement arises from the intension of attempting to reduce the degree of differentiation of quality level. At this time, the clean car manufacturing firm tries to avoid competition due to weakened competitiveness, and increases the quality level to expand quality differentiation. However, in this case, the market share of eco-friendly vehicles shrinks. On the other hand, if the exchange rate changes in the opposite direction, the market share of eco-friendly vehicles is expected to increase, but the quality of both cars are deteriorated, causing a conflict effect.

• The Journal of Industrial Distribution & Business
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• v.10 no.9
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• pp.37-43
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• 2019

Purpose - The self quality inspection which is mandatory in Republic of Korea can play an important role in promoting food safety, but the cost for self quality inspection is also a big burden especially for small businesses. In addition, excessive or duplicated inspection costs resulting from the standard gaps of various ministries and agencies ultimately effect negative social utility. Thus, this paper aims to suggest ways to improve the analysis of self quality inspection for the Ready-to-Eat Foods in terms of dried laver, in order to reduce costs caused by overinclusion. Research design, data, and methodology - The focus of interest is seaweed in Kimbab, which is to be exempted from the Vibrio parahaemolyticus test on the three grounds. First, existing literature provides little support for the necessity of performing a microbiological test. Second, laver products do not require the V.parahaemolyticus test by international standards such as the CODEX. Third, no case was found for seaweed products on the list of information on failed food items over the 2015~16 period. Results - Other types of seaweed such as exportable and seasoning seaweed are not subject to the test. Hence, exclusion of the V.pahaemolyticus test on seaweed is a valid point, bringing about large expected cost savings to many small businesses. Conclusions - Based on a complete survey of 75 food-testing agencies from March 20th to 30th, 2018, this paper finds that the proposed revision of the Kimbab test is likely to save an average of 130,000 won per business per year. Especially, in the case of the testing fee of Salmonella spp.(n,c,m,M), the cost difference by agencies was found to be up to five times. The regional gap in testing fees can be considered an unfair barrier. Accordingly, it is necessary to examine whether the testing fee is set at an appropriate level through the cost-extraction program proposed by the Ministry Food and Drug Safety. Hence, the survey results also point out that harmonization of testing fees charged by different food-testing agencies is appropriate with respect to transparency and efficiency.

• The Journal of the Korea Contents Association
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• v.7 no.9
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• pp.167-175
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• 2007

The purposes of this study were to examine the effect of interest and participation in ski, encouragement to participate in ski, and attitude to ski of significant others on the socialization. To attain the goal of the study described above paragraphs, the ski class participant of the university located in Seoul, 2005 year were set as a collected group. Then, using the cluster random sampling method, finally drew out and analyzed 200 people in total. The result of reliability check up was here below; over Chronbach's $\alpha$=.600. To analyze materials, confirmatory factor analysis, logistic regression analysis and multiple regression analysis were used as statistic analysis techniques. The conclusion based on above study method and the result of material analysis are below. Based upon the result of the study, the following conclusions appear warranted: First, significant others influence on the ski participation experience of the undergraduate. Second, significant others influence on the ski participation frequencies of the undergraduate. Third, significant others influence on the ski participation period of the undergraduate. Fourth, significant others influence on the ski participation skill of the undergraduate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.615-621
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• 2018

To enhance the energy saving and comfort of indoors, this study performed a stimulation of sound fluctuation, color temperature, and aroma. The experiment with EEG, HRV, and Vibra images was conducted in an environmental test room with a temperature of $25[^{\circ}C]$, relative humidity of 50[RH%], air current speed of 0.002[m/s], and illuminance of 1000[lux]. The stimulation experiment set up different sensory stimulation conditions, such as before exposure, single-sensory stimulation of fluctuation a=1.106 jazz music, single-sensory stimulation of RED color lighting, single-sensory stimulation of scent aroma, and multi-sensory stimulation of fluctuation a=1.106 jazz music, RED color lighting, and scent aroma. After the multi-sensory stimulation of fluctuation a=1.106 jazz music, RED color lighting and scent aroma, the capacity for work and attention were increased, and the stress index and fatigue degree were decreased. In addition, multi-sensory stimulation of fluctuation a=1.106 jazz music, RED color lighting, and scent aroma were effective in maintaining a stable heart and health. In addition, the Vibra image appeared to decrease tension/anxiety and stress. The multi-sensory stimulation of fluctuation a=1.106 jazz music, RED color lighting, and scent aroma help increase the Neuro-energy more than that by no exposure and single-sensory stimulation.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.1
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• pp.1-22
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• 2012

This paper tried to verify whether the fixed fire fighting system (FFFS) that is installed in road tunnel improves evacuation performance or not. Verification was performed according to the Disaster Prevention Facilities Installation and Management Guide at Road Tunnel. Twenty seven different fire scenarios were set up for the verification and the cases that FFFS was installed were compared with the cases that FFFS was not installed. The result of the comparison showed that the average equivalent death was reduced in 26 cases out of 27 cases when water spray extinguishing system was installed. It was confirmed that the risk when was not installed was unacceptable in Hong Kong and the Netherlands. On the other hand, it was confirmed that the risk was reduced to as low as reasonably practicable (ALARP) when was installed. The cumulative frequency of average death in case with FFFS was compared against the frequency of death without FFFS: death of one or more is about 50 times less; 10 or more is about 100 times less; and the death of more than 100 is four times less. It was verified that FFFS makes improved conditions to escape from the fires in road tunnel.

• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.605-613
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• 2016

This study was investigated to effect of tongue strength and accuracy training (TSAT) on tongue strength, swallowing function, quality of life in chronic stroke patients with dysphagia. Eighteen chronic stroke patients with dysphagia participated in this study, and were allocated randomly to experimental(n=9) and control group(n=9). both group conducted to traditional dysphagia therapy, and experimental group was carried out additionally TSAT. TSAT performed using Iowa Oral Performance Instrument(IOPI), and was set up to 50%, 75%, 100% of maximum isometric tongue strength. Two groups received the treatment for five per weeks, eight weeks. Outcome measurements performed that Maximum Isometric Strength(MIS) was assessed by using IOPI for measure the tongue strength, and Swallowing Function Test(SFT) was used to assess the swallowing function. Swallowing-Quality of Life(SWAL-QOL) was used to evaluate quality of life related to swallow. In results of study, experimental group in comparison of change score between two group significantly improve than control group in anterior and posterior MIS, and SFT. SWAL-QOL was not significantly difference in both group. Based on thin study results, TSAT may be a effective intervention to improve on tongue strength, and swallowing function in chronic stroke patients with dysphagia.