• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.7
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• pp.813-819
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• 2011

In this research, we investigated the hydrogen-gas filling characteristics of ultra-light composite tanks that have a plastic or aluminum liner inside the composite shell. The study was performed for different gas and tank temperatures. The temperature changes at various positions in the Type-4 tank during hydrogen-gas filling were monitored in order to understand the effects of the filling conditions. The results were compared with those obtained for a Type-3 tank. As the filling speed was increased, a quicker temperature rise was observed, and the temperature distribution over the entire region showed significant discrepancies.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.4
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• pp.352-358
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• 2010

This paper presented compact CW sub-THz imaging system using the terahertz transmitter(Tx) that generating 0.34 THz electromagnetic wave on based electronic device. Using 0.34 THz electromagnetic wave generated by Tx, we transmitted to sample by point by point scan method and measured transmitting terahertz wave magnitude and phase information respectively with terahertz receiver(Rx) based on sub harmonic mixer. This paper measured and compared images of several samples to obtain better imaging results by changing time delay and step distance of scanning stage which affect image resolution. Also, through the imaging measurement of various samples, we were able to assure possibility of application of terahertz wave.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.181-186
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• 2010

Characteristics of household wastes production from fishing village in small island was investigated. Investigation was conducted in August and December to represent seasonal characteristics of summer and winter, respectively. Amount of household wastes production was 0.65 kg/capita·day and this is relatively low value compared with nationwide average. Food wastes, papers, vinyl and plastics are major part of combustible portion in household wastes. Composting is inappropriate method as a final disposal method in terms of C/N ratio calculated from elemental analysis. It is recommended that incineration can be appropriate way as a final disposal method of household wastes because low heating value of household wastes is equivalent to that of crude oil. The fraction of food wastes in household is considerably higher than the values obtained from other residential areas in nationwide. Thus, it is evaluated that household composting devices and vermicomposting facilities are necessary to reduce the amount of food wastes. It also can be evaluated that incineration is optimal method as disposal method of household wastes from fishing village except food wastes.

• The Journal of the Korea Contents Association
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• v.13 no.10
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• pp.19-26
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• 2013

In the Malaysian license plates, alphabets and numerals which are made by plastic, are adhered to a frame as embossing style and occasionally characters in horizontal, vertical directions are aligned with narrow space. So the extraction of character stroke information can be hard in the vehicle images of low illumination intensity. In this paper, Malaysian license plate recognition algorithm for low illumination intensity image is proposed. DoG filtering based character stroke generation method is introduced to derive exact connected components of strokes in the vehicle image of low illumination intensity. After localization of plate by connected component analysis, characters are segmented and recognized. Algorithm is experimented for the 6,046 vehicle images captured in Kuala Lumpur by IR camera without using any special light during day and night. The experimental results show that recognition accuracy of plates is 96.1%.

• Polymer(Korea)
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• v.35 no.2
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• pp.124-129
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• 2011

Wood plastic composites (WPCs) are attracting a lot of interest recently. In this study, wood flour/polyethylene (PE) composites panels comprised of a coupling agent and nanoclay were prepared by melt-blending followed by compression molding. Five maleic anhydride grafted polyethylene (MAPE) coupling agents were tested, and the best choice and its optimum content were determined. The mechanical properties of the WPCs were measured by UTM, and the thermal properties were measured by TGA, DMA, DSC, and TMA. Adding just a small amount (1 phr) of organoclay made the tensile and flexural strength and the crystallinity of the WPC somewhat increase and the storage modulus and dimensional stability of the WPC largely increase. SEM images showed that the coupling agent drastically improved wood flour/PE interfacial bonding. Selecting the best coupling agent optimized content and adding a small amount of organoclay resulted in a high performance wood flour/PE composite.

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.461-465
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• 2014

A 3-year-old colt Thoroughbred horse was referred with obvious lameness (3/5G) and mild heat and pain on left hoof of forelimb. He was diagnosed with quarter cracks that have a typical conformation of sheared heel, which are a different length and height between medial/lateral heels. Various materials and techniques were carried out to repair quarter cracks by using many different kinds of clips, bar shoes on fifth times for about 10 months. It worked on him without pain and heat on the cracked hoof, and then he could retrain for racing from the 36th weeks beginning of therapeutic shoeing. We suggested that especially fiberglass reinforced plastic (FRP) material and therapeutic shoeing were a great help to treat quarter cracks induced by sheared heel.

• The Korean Journal of Mycology
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• v.39 no.3
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• pp.231-234
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• 2011

This study was performed to develop new Hypsizygus marmoreus cultivars that have enhanced functional materials and improved physiological characteristics with mutagenesis by gamma ray irradiation. Protoplasts of H. marmoreus brown strain HYM-056 were irradiated by gamma ray for mutagenesis, and then 2,000 clones of mutants were randomly selected and the fruiting bodies were induced by bottle culture. Among them, 157 isolates with fast-growing, heavy and many fruiting body-producing were selected. The isolates were cultured in plastic bottle containing rice bran, barley hulls and fir sawdust to form the fruiting bodies. About 100 days after inoculation, characteristic of fruiting bodies were investigated. The isolates were divided into 6 groups based on color, shape and size of pileus, and length, diameter, number and weight of stipe. In addition, the genetic variation of the isolates was analyzed by URP-PCR fingerprinting.

• Elastomers and Composites
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• v.46 no.3
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• pp.223-230
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• 2011

Considering of utilizing renewable resources and recycled plastics, green composites consisted of recycled polyethylene (PE) as matrix and eco-friendly natural fibers as reinforcement were processed and characterized in the present study. First, the wood flour/recycled polyethylene pellets with different wood flour contents were prepared by twin-screw extrusion processing. Using the pellets, wood flour/recycled polyethylene green composites were fabricated and the effects of wood flour loading on their flexural, tensile, impact properties, heat deflection temperature and fracture behavior were investigated. It was concluded that the flexural strength, flexural modulus, tensile modulus and heat deflection temperature of wood flour/recycled polyethylene green composites were increased with wood flour, whereas the tensile strength and impact strength were decreased. The fracture behavior observed by means of scanning electron microscopy supported qualitatively the tendency of the impact strength with wood flour loading, compared with the ductile fracture pattern of recycled polyethylene.

• Journal of Digital Convergence
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• v.18 no.1
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• pp.265-270
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• 2020

The purpose of this study is to suggest ways to reduce plastic use, one of the main culprits of environmental pollution around the world. Recently, the use of disposable cups at a domestic cafe has not been effective due to growing the number of stores and cafe in various brands. Cafes recommend the use of tumblers as a solution to the problem, but actual there are not many users in cafe. I need to investigate the problems of tumbler use and individual opinions through the first phase is FGI (Focus Group Interview). In the second phase, I investigate similar services, which are currently implemented in domestic and overseas, as a case study. The results showed that although similar services are offered in domestic, the focus is on tumbler sharing, which is somewhat insufficient for convenience provided when using cafes. Through this study, I hope to provide convenience and voluntary environmental protection by proposing a plan to activate Tumbler sharing services for cafe and users.

• Composites Research
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• v.28 no.4
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• pp.143-147
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• 2015

This paper proposes laser ultrasonic technique for the impact damage inspection of hydrogen fuel tank and proves that the impact damage can be visualized using an ultrasonic wave propagation imager with an easy detachable sensor head as an impact damage inspection tool for hydrogen fuel tanks. Also the performances of the proposed ultrasonic propagation imager support it can be implemented in real-world technology when the hydrogen car becomes popular.