• Journal of the Korean Arthroscopy Society
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• v.14 no.2
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• pp.102-106
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• 2010

Purpose: The results of the repair for the superior labrum lesions attaching at the superior glenoid have not been satisfactory in every cases. We wanted to analyze the shoulder MRI and the anatomical morphology and pattern of the superior glenoid at which the superior labrum attaches to get anatomical information helpful in treating the superior labrum. Materials and Methods: We analyzed the coronal images of the shoulder MRI of 108 cases taken at our hospital. Average age was 52 years (range, 17~71 years), 55 males and 53 females. On two coronal images behind the attachment of the long head of biceps that the repair of the SLAP was performed at, the length of the attachment of superior labrum and the angle of the supero-lateral glenoid were measured. Results: The average length of the attachment of superior labrum was $9.78{\pm}1.64\;mm$. The average length was $10.1{\pm}1.61mm$ in male, $9.43{\pm}1.6\;mm$ in female. The angle of the supero-lateral glenoid was $89.6{\pm}7.6$ degrees. Conclusion: The attachment of the superior labrum in coronal plane was shorter in posterior spot than anterior. The angle of the supero-lateral glenoid was less in posterior spot.

• Journal of dental hygiene science
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• v.17 no.4
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• pp.315-322
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• 2017

The aim of this study was to explore the association between daily toothbrushing frequency and health risk behaviors of school-going adolescents in poor urban areas of Peru. A cross-sectional survey was conducted among 959 school-going adolescents 11~19 years of age in poor urban areas of Peru in 2014. Health risk behaviors we assessed in the study were smoking; drinking; consuming sugar-sweetened soft drinks (more than one cup); leisure time activities including watching television, playing games, and using the Internet; and never or rarely handwashing with soap. Daily toothbrushing frequency was divided into two groups (once and twice daily). For statistical analyses, the chi-square test and hierarchical logistic regression were used at 5% level of significance. Of the total respondents, 63 (14.3%) were boys and 53 (10.3%) were girls and 116 (12.1%) engaged in toothbrushing (${\leq}1$ times daily). According to the adjusted logistic regression analysis for socio-demographic characteristics, two behaviors (leisure time use activities, including watching television, playing games, and using the Internet (odds ratio [OR], 2.29; 95% confidence interval [CI], 1.20~4.35), and never or rarely hand washing with soap (OR, 4.09; CI, 2.48~6.75) were statistically associated with toothbrushing frequency (${\leq}1$ times daily). We found two health risk behaviors (leisure time activities, including watching television, playing games, and using the Internet, and never or rarely handwashing with soap) associated with toothbrushing frequency among adolescents in the study area. Thus, oral health promotion programs should consider these health risk behaviors associated with toothbrushing frequency.

• Journal of Korean Society of Steel Construction
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• v.27 no.5
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• pp.471-481
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• 2015

Modular building is a prefabricated construction system for building where factory-produced pre-engineered modular units are delivered to site and assembled as substantial elements of a building. There are two basic kinds of modular structures. One is a load-bearing wall structure designed to transfer the load through longitudinal walls. The other is a frame structure composed of columns and beams. For frame structure, square hollow section is often used as a column member and channel as a beam member in modular unit. Lower and upper modules are fasten with bolts via a pre-installed access hole in the SHS column. However, the access holes can weaken the panel zone that would affect the behavior of beam to column connection. The 5 specimens of beam to column connections with parameters of access hole, column thickness and diaphragm were made and this paper describes the test results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.126-136
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• 2018

A steel-plate concrete composite beam is composed of a steel plate, concrete and shear connector to combine inhomogeneous two materials. The steel plate is assembled by welding an existing composite beam. In this study, new steel-plate concrete composite beam, called a SPC Beam, was developed to reduce the shear connector and improve the workability. The SPC Beam was composed of folding steel plates and concrete, without a shear connector. The folding steel plate was assembled using high strength bolt instead of welding. To improve the workability in field construction, a hat-shaped Cap was attached to the junction with a slab. Monotonic load testing under two points was conducted under displacement control mode. The flexural strength of the specimen for positive moment and negative moment was calculated using the plastic stress distribution method. The test results showed that the flexural strength of the new SPC Beam had 80% of the strength of a complete composite beam. In addition, increasing the composite ratio was possible through clearance controls of the cap. In this study, the performance of the SPC Beam was verified through additional experiments and analyses with the cross-sectional shape and cap as variables, because the representative shape in the positive negative moment region is targeted.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.696-706
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• 2017

The purpose of this study was to verify experimentally debris reduction facilities for culverts installed in small rivers. A culvert is defined as a structure laid under a road or a railroad that passes through an inner urban area or downtown area to make an artificial canal. Culverts are generally categorized into road culverts or waterway culverts, among which the latter are artificial structures designed to discharge running water into a river. At the time of floods, the structural safety of waterway culverts can be undermined by the accumulation of debris, such as soil, boughs and weeds, and they may be at risk of overflowing due to blockages. Debris reduction facilities are necessary to prevent such damage. In this study, the effects of the three existing types of debris reduction facilities were examined through hydraulic experiments. The results of the experiments showed that vertical separation to divert debris reduced the accumulation rate by 27.65 to 31.39 percent. The two types of screen designed to block and divert debris, respectively, were found to have excellent debris blocking abilities. However, when the effects of the rising water level are considered simultaneously, the screen to divert debris was found to show superior effects. The screen to block debris can be considered to have excellent debris blocking ability, but requires the continuous collection of the debris, due to the high risk of rising water levels caused by its accumulation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.1
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• pp.45-52
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• 2015

Fiber-reinforced polymer (FRP) has been generally accepted by civil engineers as an alternative for steel reinforcing bars (rebar) due to its advantageous specific tensile strength and non-corrosiveness. Even though some glass fiber reinforced polymer (GFRP) rebars are available on a market, GFRP is still somewhat uncompetitive over steel rebar due to their high cost and relatively low elastic modulus, and brittle failure characteristic. If the price of component materials of GFRP rebar is not reduced, it would be another solution to increase the performance of each material to the highest degree. The tensile strength generally decreases with increasing diameter of FRP rebar. One of the reasons is that only fibers except for fibers in center resist the external force due to the lack of force transfer and the deformation of only outer fibers by gripping system. Eliminating fibers in the center, which do not play an aimed role fully, are helpful to reduce the price and finally FRP rebar would be optimized over the price. In this study, the effect of the hollow section in a cross-section of a GFRP rebar was investigated. A GFRP rebar with 19 mm diameter was selected and an analysis was performed for the tensile test results. Parameter was the ratio of hollow section over solid cross-section. Four kinds of hollow sections were planned. A total of 27 specimens, six specimens for each hollow section and three specimens with a solid cross-section were manufactured and tested. The change by the ratio of hollow section over solid cross-section was analyzed and an optimized cross-section design was proposed.

• Journal of Korean Society of Steel Construction
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• v.9 no.4 s.33
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• pp.543-555
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• 1997

Generally, in a steel-concrete composite gilder, the shear connector which was constructed between concrete deck and steel girder should have enough stiffness to behave as one body, because the conformity between plate and concrete deck is influences by the stiffness and spacing of the shear connectors. If the stiffness of shear connectors are insufficient, slip would happen at the contact surface. Partial interaction is the case that takes account of slips. In this paper, an easy method is presented to evaluate the stiffness or spacing of the shear connector according to the degree of imperfection without difficult calculations for a composite gilder with partial interaction. Also, the horizontal shearing force applied to the shear connector and the longitudinal axial force, which is occurs at contact surface between concrete deck and steel girder, have been presented in a simple influence line that is various to the parameters of sectional properties, degree of imperfection and applied load points. Furthermore, through the case study, it determined the relationships between the degree of imperfection and the follows 1) spring constants 2) axial force and horizontal shearing force 3) stress and neutral axis by using the partial differential equation based on Newmark's Partial Interaction Theory.

• Korean Journal of Organic Agriculture
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• v.17 no.3
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• pp.393-403
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• 2009

This study was conducted to investigate the productivity of Hanwoo steers by feeding self-product organic rice straw and concentrates(conventional, T1 and organic T2). Sixteen Hanwoo steers(8 months on the average) were randomly assigned to two treatment groups. Feeding trail was carried out in 2 treatment(8 heads/ treatment) by Hanwoo steers for 600 days form 8 to 28 months in age. The range of average daily gains of T1 and T2 were 0.76 to 0.77kg in the growing stage, 0.93 to 0.90kg in the first fattening stage, 0.99 to 0.84kg in the middle fattening stage, and 0.59 to 0.64kg in the latter fattening, respectively, and the gains for overall period was higher in T1 than in T2. Concentrates and total digestive nutrients(TDN)(T1) intakes per unit of kg gains were higher than T2 without significant difference. In carcass characteristics, the carcass weight in T1 were higher about 5% than in T2. According to the above results, it may be concluded that dry matter(DM) intakes, crude protein(CP) and TDN contents of feedstuff between treatments was no significant difference. but marbling in T2 score was higher than in T1 about 20%. There were no significant differences rib-eye area, back fat thickness and fat color(p>0.05).

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.27-27
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• 2009

드라이브 샤프트는 일반적으로 엔진에서 발생된 회전력을 바퀴에 직접 전달하는 동시에 조향기능을 수행하는 자동차 부품이다. 최근에 경량화를 통한 에너지 절감을 위하여 기존 스틸소재를 알루미늄으로 대체하는 방안에 대한 연구가 집중되고 있다. 그러나 알루미늄 단일소재로 드라이브 샤프트를 제조하는 것은 비경제적이며 또한 기 개발된 자동차 부품들과의 연결을 고려하여 알루미늄 튜브와 스틸 요크의 이종금속 접합기술이 요구된다. 전자기 펄스용접은 전자기력을 이용하여 용접대상물을 고속으로 충돌시켜 용접하는 기술로서 열 발생이 적어 재료의 특성차로 인한 결함 및 변형이 발생하지 않아, 이종금속간 고품질 용접이 가능하며, 전자기 펄스 용접부의 품질과 밀접한 관계를 갖는 공정변수 경우 모재와 접합재의 재질 따라 적정 공정변수 범위가 변화되므로 공정에 따른 데이터의 축적은 대단히 중요하다. 전자기 펄스 용접을 이용한 이종금속 접합시 접합부 품질에 영향을 미치는 공정변수는 충전전압, 모재와 접합재 사이의 간격 및 접합재의 직경과 두께의 비(D/T비)로서 보고되었으며, Al/Steel 이종 금속 접합시 이들 공정변수가 접합부에 미치는 영향 및 최적의 공정변수 도출을 위한 연구는 시도되지 않았다. 따라서 본 연구는 전자기 펄스 용접기술을 이용한 Al/Steel 이종금속 접합 실험을 통하여 전자기 펄스용접의 적정성과 최적의 충전전압, 모재와 접합재 사이의 간격, D/T비를 도출하고자 한다. 전자기 펄스 용접 장치는 한국생산기술연구원과 웰메이트(주)에서 공동으로 개발한 $120{\mu}F$의 캐패시터 6개로 구성된 'W-MPW36'을 사용하였으며 이 장치의 최대충전전압과 최대접합용량은 각각 10kV, 36kJ이다. 접합재는 전기 전도율의 높은 Al 1070 파이프를 사용하였으며 모재는 기존 스틸 요크재인 SM45C 환봉을 사용하였다. 기보고된 연구를 통하여 코일과 접합재 사이의 간격이 좁을수록 높은 전자기력이 접합재에 작용하는 것을 확인하였으나 코일내 접합재와 모재 삽입 편의를 위하여 1mm로 설정하였다. 접합부의 품질 평가를 위하여 수압시험을 실시하였으며, 시험 후 접합부 단면을 주사전자현미경(SEM)을 이용하여 관찰하였다.

• Fire Science and Engineering
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• v.31 no.6
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• pp.40-46
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• 2017

As one of the solutions to deal with economic loss caused by traffic congestion in metropolitan area, a deep underground road has been planned and implemented at home and abroad. The part of them has been pushed ahead with a double-deck scheme which has an advantage in constructability and cost efficiency comparing to traditional road tunnel. However, the double-deck tunnel has a lower floor height than the general road tunnel due to the special structure used as the upper and lower lines by installing the middle slab on one excavation section. Therefore, it is relatively weak against fire accidents and ventilation problems occurring in tunnels. Thus study to develop the life safety system optimized to a double-deck tunnel has been systematically carried out in order to overcome their weak point. In this study, automatic monitoring fire extinguisher (AMFE) is developed to suppress a fire and prevent its spread at early stage of tunnel fire, conducting the performance test through vehicle fire tests as verification. The tests were conducted with AMFE being 30 m apart from the vehicle and 10 m apart from engine room. As a results, it was confirmed that AMFE enables to suppress a fire and prevent its spread in both cases.