• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.12
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• pp.1057-1064
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• 2014

Recently, there has been a growing interest in sustainable energy. One method that has been used is an organic Rankine cycle using conventional turbine technology with a low-temperature waste heat source. A 200-kW organic Rankine cycle (ORC) system was designed for a waste heat recovery application using R245fa as the working fluid. A radial turbine running at 15,000 rpm was employed to generate more than 200 kW with an expansion ratio of nine. Because an ORC turbine uses a refrigerant as the working fluid, the ideal gas law was not employed to design the turbine. In addition, the complexity of the molecular structure of R245fa made it difficult to design the turbine. Because R245fa has an Ma value of one at a low velocity for the working fluid (about 1/3 of the speed of sound in air) at about $100^{\circ}C$, it easily reaches a supersonic flow condition with a small pressure expansion. To increase the efficiency of the turbine, a dual stage radial-type turbine with a subsonic speed was suggested. This paper will describe the design procedure and performance evaluation of the ORC turbine using R245fa.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.133-140
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• 2016

The Ministry of Land, Infrastructure and Transport has introduced low-floor buses, which are convenient for passengers getting on and off the bus and for the handicapped. The standard bus model is 11 m long and uses compressed natural gas (CNG). However, this model has drawbacks in narrow rural road conditions such as those in farming and fishing villages and mountainous areas, as well as difficulty in refueling since CNG facilities are not readily available. In this study, running resistance values were obtained by coasting performance tests on actual roads using a Tata Daewoo LF-40 model with three different weight conditions: curb vehicle weight (CVW), half vehicle weight (HVW), and gross vehicle weight (GVW).The test methods include WHVC, NIER-06, and constant-speed driving at 60 km/h. These tests were used to measure the fuel economy of vehicles other than the target vehicles to obtain the combined fuel economy. The energy efficiency was highest in the case of CVW. In the WHVC mode, the fuel consumption rates of HVW and GVW were typically 3.5% and 12% higher than that of CVW, respectively. In constant-speed driving, the fuel efficiency of HVW was higher than that of CVW. Further research is required to analyze the exhaust gas data.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.3
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• pp.1-19
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• 2021

The domastic hard shoulder running(HSR) System has been gradually expanding since its initial implementation in September 2007 with the aim of increasing capacity and resolving congestion. Hard Shoulder is used as a space for driver's visual comfort and a place for vehicles to evacuate in case of emergency, but it is replaced by a space for driving when the HSR System is implemented. Therefore, it was intended to determine the improvement effect before and after implementation of the HSR system through safety analysis and mobility analysis. The safety analysis analyzed the impact of traffic accidents by comparing HSR sections and similar sections. The mobility analysis was to determine the improvement effect by quantifying the speed and traffic volume changes before and after HSR System implementation. According to safety yanalysis, there is no effect of reducing traffic accidents when implementing the HSR System. In mobility analysis, the implementation of the HSR System significantly improved the speed of traffic during peak hours and significantly reduces slow and delay hours.

• Journal of Fashion Business
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• v.1 no.1
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• pp.71-83
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• 1997

The purpose of this study is to analyze the present fashion phenomenon by considering the types of street fashion, the center of avant-grade modern fashion, that shows the origination background and special feature concretely. The times was defined through the 1980's from World War II that street style originated, so the range of study was the 1990's when the street style was influenced by that of the past and was revived. The ways of study were to analyze the records of ideology, art and music connected with the street style from World War II to the present when it has risen. The summary of result is as follows. (1) In the 1940's, Zooties was the jet of desire suppressed by African-Americans that couldn't receive favors socially and economically and Hipsters pursued reformative bebop that made up of soft Jazz. In the 1950's, Modernists were running after Cool Jazz to the minimum. In the 1970's, Funk appered in the sexual desire and erotic strength, and was surfaced from Negro Getto. In the 1980's B-boys & Flygirls showed the street style by the scribble art of slum in the New York. As mentioned above, In the 1990's, Acid Jazz influenced by the Jazz of Negro has been the fashion added to the tradition of musical form that come from eclecticism of Jazz tended Neo-Jazz. (2) In the 1940's, Western style dreamed the country life because of rapid urbanization. In the 1950's, Beat obtained the feeling of liberation from the dissolute life and activity. In the 1960's, Psychedelics showed the freedom affected by the Pop-art and Op-art, and Hippies pursued the true individuality as 'love & peace' life style and the return to nature. In the 1990's, Grunge look influenced by the above has been fashion that shows the practical use of second-hand clothing or patchwork contrary to elitism. (3) In the 1940's, Caribbean style appered in the typical textile color with the center of West Indies. In the 1960's, Rude boys showed the magnificence and difficulty of Jamaica, and Rastafarians had a tendency to come back to the ancient civilization of America. In the 1970's, Two-tone was the simple clothing for harmonizing among human races. In the 1990's, Jamaica look influenced by the above has been the Lege fashion introduced to a high fashion, appearing in the special bright color, applique, unique hair style, and so on. (4) In the 1950's, Sufers pursued natural rhythm, getting out of everything. In the 1970' s, Skaters enjoyed the speed on the paved road. In the 1980's, Casuals emphasized the spirit of cooperation of young-things. In the 1990's, Casual look Influenced by the above has been the fashion that forms the activity, function and strong spirit of cooperation by pursuing comfortable life and sports in the tension of life and variety of modern society. (5) It was hard for Bikers to adjust themselves in society after the war. In the 1950's, Coffee bar cowboys were the reckless running boys in the leather jacket. In the 1960's, Rockers created the group originality as disobedient outsiders and Greasers imitated Rolling Stones. In the 1980's, Punks resisted the viewpoint of the old generation in offensive fashion. In the 1990's, Cyberpunk influenced by the above has pursued the classless structure, electronic music and metallic clothing that forebodes gloomily as the computer generation of ultra-modern science times. Accordingly, in understanding a complex modern fashion phenomenon, it was analyzed that the street styles of the past, from World War II to the 1980's, were reflected in that of the 1990's dividing into the five types in a word, namely Acid Jazz, Grunge look, Jamaica look, Casual look and Cyberpunk.

• International Journal of Highway Engineering
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• v.13 no.3
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• pp.177-184
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• 2011

There are several differences between freeways and general national roads in terms of structures, conditions and limited speeds. Likewise, the characteristics of $CO_2$ emission in these roads differ depending on the road types. For these reasons, it is necessary to compare the two types of roads in terms of $CO_2$ emissions. The study was performed targeting Gyeongbu Expressway and National Highway 1. Firstly, the amount of $CO_2$ emission each car was compared in the whole sections of the both. Secondly, top 10 sections were picked out, and then $CO_2$ emission each section were compared. Lastly, two sections which were with the highest and lowest amount of $CO_2$ emission per car, were compared. As results, it were found that there were less amount of $CO_2$ emission on freeways. because cars are running on uniform velocity at relatively high speed, and that there were more amount of $CO_2$ emission on the national highway. because of frequent intersections and associated congestion. It may be concluded that the amount of $CO_2$ emission at the national highway could be reduced if signal coordination and intersection intervals are improved there.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.1
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• pp.1-15
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• 2011

The RLC systems is one of the intelligent transportation systems that has gained a nation-wide support for last decades and being installed to discourage motorists from running the red lights at signalized intersections. It is taken for granted that the RLC will provide motorists with increased safety, so that their installments are always justifiable. However, in order to acquire more efficiency and wider supports from the general public in future RLC installments, an improved methodology for analyzing the effects of the RLC systems is required. In order to satisfy this requirement, this research performed the following tasks. First, the number of signal violations after the RLC systems were investigated in order to check its resulting effects. Second, the number of crashes after the RLC systems were collected and compared with the number of signal violations. Third, a statistical analysis was carried out to develop the relationships between the signal violations and the crashes based on negative binomial distribution. The analysis revealed that the number of crashes has a close relationship with the RLC placement, traffic volume, vehicle speed, the number of phases, and the number of lanes for major approaches. Finally, based on the results found in this analysis, this research presents a methodology for analyzing the safety effects of placing the RLC that should be of service when investigating the economic consequences of the RLC systems.

• Korean Journal of Applied Biomechanics
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• v.27 no.3
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• pp.197-203
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• 2017

Objective: The purpose of this study was to determine how exercise intensity affects muscle activity and kinematic variables during squat. Method: Fifteen trainers with >5 years of experience were recruited. For the electromyography (EMG) measurements, four surface electrodes were attached to both sides of the lower extremity to monitor the rectus femoris (RF) and biceps femoris. Three digital camcorders were used to obtain three-dimensional kinematics of the body. Each subject performed a squat in different conditions (40% one-repetition maximum [40%1RM], 60%1RM, and 80%1RM). For each trial being analyzed, three critical instants and two phases were identified from the video recording. For each dependent variable, one-way analysis of variance with repeated measures was used to determine whether there were significant differences among the three different conditions (p<.05). When a significant difference was found, post hoc analyses were performed using the contrast procedure. Results: The results showed that the average integrated EMG values of the RF were significantly greater in 80%1RM than in 40%1RM during the extension phase. The temporal parameter was significantly longer in 80%1RM than in 40%1RM and 60%1RM during the extension phase. The joint angle of the knee was significantly greater in 80%1RM than in 40%1RM at flexion. The range of motion of the knee was significantly less in 80%1RM than in 40%1RM and 60%1RM during the flexion phase and the extension phase. The angular velocity was significantly less in 80%1RM than in 40%1RM and 60%1RM during the extension phase. Conclusion: Generally, the increase of muscle strength decreases the pace of motion based on the relation between the strength and speed of muscle. In this study, we also found that the increase of exercise intensity may contribute to the increase of the muscle activity of the RF and the running time in the extension phase during squat motion. We observed that increased exercise intensity may hinder the regulation of the range of motion and joint angle. It is suitable to perform consistent movements while controlling the proper range of motion to maximize the benefit of resistance training.

• Journal of Oral Medicine and Pain
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• v.24 no.4
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• pp.397-410
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• 1999

In order to obtain the basic data concerning the optimal parameters in using Nd:YAG laser as a therapeutic modality to dentinal hypersensitivity, the author prepared 3 sections of sound dentin and 10 sections of sclerotic dentin with thickness of $0.5mm{\pm}0.1mm$ from human extracted teeth of anteriors and premolars, and applied the laser energy from a fiberoptic delivered, free running, pulsed Nd:YAG laser (wavelength 1064nm, pulse duration $120{\mu}sec$, fiber diameter $320{\mu}m$) to surfaces of sound and sclerotic dentin sections for 1 second with contact/unidirectional moving mode of the fiber under speed of 3mm~4mm/sec and parameters of 0.5W/10Hz, 1.0W/10Hz, 1.5W/10Hz, 2.0W/10Hz: $62J/cm^2$, $124J/cm^2$, $187J/cm^2$, $249J/cm^2$. The author comparatively evaluated the characteristics of ultrastructural changes on surfaces of sound and sclerotic dentin sections irradiated by the pulsed Nd:YAG laser using the scanning electron microscopy. A fairly ill-defined bordered surface of partially closed and melted dentinal tubules can be seen on the scanning electron microscopic feature of the sound dentin surface irradiated by the pulsed Nd:YAG laser with energy density of $62J/cm^2$. The physical modification of sound dentin surface extensively occurred depended on the increase of energy density from $62J/cm^2$ to $124J/cm^2$, $187J/cm^2$, $249J/cm^2$. While, a fairly well-defined bordered surface of partially closed and melted dentinal tubules with thickened peritubular dentin can be seen on the scanning electron microscopic feature of the sclerotic dentin surface irradiated by the pulsed Nd:YAG laser with energy density of $62J/cm^2$. The physical modification of sclerotic dentin surface of a fairly rough, shallow depression with many cracks, thickened peritubular dentin and structureless dentinal tubules extensively occurred depended on the increase of energy density from $62J/cm^2$ to $124J/cm^2$, $187J/cm^2$, $249J/cm^2$ compared to those of sound dentin surface irradiated by the pulsed Nd:YAG laser under the same parameters. Therefore, it is recommended that the pulsed Nd:YAG laser as a therapeutic modality to dentinal hypersensitivity should be applied with the less energy density than $62J/cm^2$ on the sound dentin surface, and its energy density on the partially sclerotic dentin surface should be lower than that on the sound dentin surface to preserve tooth from unnecessary excessive structural destruction.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.145-155
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• 2013

In this paper, we proposed a $4{\times}4$ block parallel architecture of interpolation for high-performance H.264/AVC Fractional Motion Estimation in 8K UHD($7680{\times}4320$) video real time processing. To improve throughput, we design $4{\times}4$ block parallel interpolation. For supplying the $10{\times}10$ reference data for interpolation, we design 2D cache buffer which consists of the $10{\times}10$ memory arrays. We minimize redundant storage of the reference pixel by applying the Search Area Stripe Reuse scheme(SASR), and implement high-speed plane interpolator with 3-stage pipeline(Horizontal Vertical 1/2 interpolation, Diagonal 1/2 interpolation, 1/4 interpolation). The proposed architecture was simulated in 0.13um standard cell library. The gate count is 436.5Kgates. The proposed H.264/AVC Fractional Motion Estimation can support 8K UHD at 30 frames per second by running at 187MHz.

• Journal of Life Science
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• v.22 no.6
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• pp.772-777
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• 2012

The purpose of this study was to investigate the effects of black garlic supplementation and exercise on TBARS, HSP 70, and COX-2 expression after high-intensity exercise in rats. Twenty-four male Sprague-Dawley rats (4 weeks) were used in this study. Experimental groups were a control group (A, n=6), black garlic supplementation group (B, n=6), exercise group (C, n=6), and black garlic supplementation with exercise group (D, n=6). High-intensity exercise was performed by treadmill running (every 10 min speed increased gradually; 15~24 m/min, $0^{\circ}$ grade) and 2.86 g/kg black garlic for 4 weeks. The findings of this study were as follows: TBARS levels were significantly lower in the D group compared to the other group and B and C groups were significantly lower in TBARS levels than in the A group. HSP 70 expression was lower in the B group compared to the other groups. COX-2 expression has showed a similar expression in all groups. Therefore, it is considered that black garlic intake and exercise may reduce oxidative stress.