• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.586-589
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• 2009

Scramjet engine combustor was tested with "RAMSYS" blow down wind tunnel in Kakuda Space Center, JAXA. As a result, installation of a cavity showed larger combustion pressure than the case without a cavity. Zigzag cavity applied for the first time in this experiment, showed the largest combustion pressure and is expected to contribute to the stable and economic operation of scramjet.

• Journal of the Korean Mathematical Society
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• v.45 no.1
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• pp.29-40
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• 2008

In this paper, we introduce a modified three-step iteration scheme with errors for three classes of uniformly equi-continuous and asymptotically quasi-nonexpansive mappings in the framework of uniformly convex Banach spaces. We then use this scheme to approximate a common fixed point of these mappings. The results obtained in this paper extend and improve the recent ones announced by Khan, Fukhar-ud-di, Zhou, Cho, Noor and some others.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.309-310
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• 2006

Porous titanium implants can be produced by powder metallurgy in combination with suitable space holder materials. Various mechanical experiments were done to characterize this material regarding the influence of the processing parameters on microstructure and mechanical properties taking into account the properties of the human bone. In this paper, the anistropic behaviour of uniaxially compacted samples was analysed in compression tests and compared to the behaviour of isostatically pressed samples. The failure of the struts of the porous titanium and the crack- initiation and -growth was examined by in-situ SEM analysis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.377-379
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• 2018

In recent years, with the focus on the younger generation, a minimal life that pursues a simple and light life has attracted attention, and a product that occupies a small space and has high practicality attracts attention. Therefore, a lot of studies on small but realistic products are going on by combining plural products into one. In this study, we developed a smart stand that can save space on the desk. The stand is equipped with a smartphone holder, humidifier, negative ion generator, and speaker functions. Because of this study, it is expected that the efficiency of space and economy will be improved in a small house of one person.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.18 no.1
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• pp.203-212
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• 1988

This study was designed to observe mandibular condyle shape and position in an asymptomatic popular ion. Using Accurad-200 head holder(Denar Corp.) for transcranial radiography of the temporo-mandibular joint region, transcranial radiographs were taken at the centric occlusion and 1 inch mouth opening in 73 males and females who were asymptomatic for TMJ disturbances, had no severe carious or missing teeth, and no history of prosthodontic or orthodontic treatments. Mandibular condyles were classified morphologically at the centric occlusion and evaluated in positional relationship with mandibular fossa and articular eminence at the centric occlusion and 1 inch mouth opening. The results were as follows: 1. In the morphologic classification of mandibular condyle, the convex shape was more prevalent in an asymptomatic population(90.4%), the locally concave shape and wedge shape were 5.5%, 4.1%. 2. At the centric occlusion, the means of joint space were 3.43nm superiorly, 2.17㎜ anteriorly, and 2.61㎜ posteriorly. 3. At the centric occlusion, the mandibular condyles were placed slightly anterior to the center of their fossa. 4. At the 1 inch mouth opening, the mandibular condyles were placed anterior to the articular eminence more than posterior to or below the top of the articular eminence.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.3
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• pp.76-82
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• 2013

Survey on the hypergolic igniter and its rupture discs for liquid rocket engines was performed. The patents of the igniters for US MC-1 and Russia RD-170 engines and the discs for NASA's space vehicle were analyzed. The types of discs and holders, characteristics related to rupture pressures and working fluids, and ASME standards of the discs were examined. Also, survey on structural analyses of the disc were performed. Typical design features and experimental results of the currently developing igniter by the authors were presented.

• Journal of Biosystems Engineering
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• v.32 no.4
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• pp.237-246
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• 2007

In this study, the microwave free-space transmission technique was used to measure the dielectric property of powdered food at microwave frequencies. The sample holder was designed and fabricated to transmit the microwave signals ranging from 1 to 15GHz. From the microwave propagation theory the equation expressing the dielectric property of powdered food was derived and validated by standard dielectrics. The dielectric property of powdered food such as wheat flour, coffee powder and milk powder was measured and analyzed. In the uniform range of bulk density of material, the real parts of permittivity of the food samples increased with the increase of moisture content, bulk density and temperature of the samples. The propagation properties such as attenuation and phase shift increased linearly as the moisture density of the food samples increased. As a measuring frequency of the moisture content, the X-band was recommended.

• Tunnel and Underground Space
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• v.20 no.2
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• pp.125-130
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• 2010

Model blast experiments of mortar blocks were performed to investigate the effect of the guide hole on crack growth. The mortar block specimens have a blast charge hole and 8 guide holes. Two of circular guide hole, notched guide hole, diamond shaped guide hole and diamond shaped guide holder are installed around 110 mm, 165 mm and 220 mm apart from the charge hole for each specimen. From the blast experiments, it was revealed that all the guide hole used in this study were effective for controlling the crack growth at the fracture control.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.213-218
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• 2012

Survey on the hypergolic igniter and rupture disc for liquid rocket engines was performed. The patent of the igniter for US MC-1 and Russia RD-170 Engine and the disc for NASA's space vehicle were analyzed. The types, characteristics, performances, design parameters and ASME standards of the disc are examined. The performances have manufacturing tolerance, reverse pressure, flow disturbance, fragmentation, material, working fluid and operating ratio. Also, survey on structural analyses of the rupture disc were performed.

• Korean Institute of Interior Design Journal
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• v.21 no.1
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• pp.258-268
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• 2012

The bathroom is a space where humans fulfil certain daily needs, but for the disabled, it can be the most difficult space to use and may even be a cause of accidents and a source of danger. Previous studies on the bathroom have mostly proposed an ideal model of bathroom, but the majority of disabled people live in small homes of about $50m^2$ in size. As their bathrooms are usually very small, and existing houses have various structural limitations, more research should be conducted on the remodeling of residential bathrooms. This study analyzed a number of remodeling items in bathrooms, all of which were listed in previous studies. Based on 17 cases of residential bathroom remodeling in the homes of disabled people residing in Incheon in 2009, this study analyzed several remodeling items required according to the subject's characteristics, such as a lifestyle, gender, and family composition; and proposed the following remodeling requirements and improvement measures for ambulatory-disabled persons and sedentary-disabled people. First, as ambulatory-disabled people have lower-limb impairments, they required bathroom remodeling designed to improve their mobility in the bathroom. These subjects desired the installation of grab bars, as well as the elimination of floor level differences, the installation of non-slip flooring, a counter-top, a sink stand, and a shower holder whose height can be adjusted. Second, sedentary-disabled people move around in a sitting or crawling position, so many of them asked to eliminate floor level differences and vertically-installed bathroom furnishings. Basically, both people with ambulatory disabilities and people with non-ambulatory impairments requested the elimination of floor level differences and the installation of non-slip flooring and grab bars for the toilet and bathtub. They also asked for the heights of sinks, faucets, mirrors, shower holders, and cabinets to be adjusted to suit their needs.