• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.1
• /
• pp.7-14
• /
• 2002

In this study, a stress analysis is made fur an ankle foot orthosis (AFO) in the view point of structural stability. The investigated AFO is a solid and standard type. To analyze the stress distribution on the neck of AFO, the maximum AFO angular translation data is obtained by gait analysis. The material test of polypropylene is made to obtain the mechanical properties of AFO. The maximum dorsiflexion appears at the midstance in the gait analysis. The experimental angular translation at the top of AFO is about 10.3$^{\circ}$ at mid stance. Three models of AFO with different width of neck are made and analyzed with ABAQUS 6.1. The stress levels and distributions of 3 different width(W$_1$, W$_2$=0.85W$_1$, W$_3$=0.60W$_1$) AFO are investigated. As a result, the standard type(W$_1$) appears to the maximum stresses at the medial edge of cutout area surrounding ankle joint. The maximum stresses of the narrower type(W$_2$) are occured on medial edge and center of ankle. The narrowest type(W$_3$) appears to the maximum stresses at center of ankle. The maximum stresses become smaller as ankle width of AFO is narrower.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.9
• /
• pp.1193-1199
• /
• 2010

Spot welding is the primary method of joining sheet metals in the automotive industry. As automobiles are subjected to fatigue loading, some spot welds may fracture before the whole system has failed. This local fracture of spot welds may lead to change in the dynamic response and consequently affect fatigue behavior of an automobile. Therefore, this change in dynamic response should be taken into consideration to assess the fatigue life of structures subjected to spectrum loading, such as automobiles. In this study, vibration fatigue analysis was performed by taking into consideration the change in the dynamic response due to accumulated damage at spot-welded parts. Fatigue tests were carried out on tensile-shear spot-welded specimens under constant amplitude loading condition. And the fatigue life of spot welds under spectrum loading was predicted using vibration fatigue analysis method based on finite element analysis.

• Archives of design research
• /
• v.9
• /
• pp.401-418
• /
• 1994

A fairy tale of information by word of mouth gets to this day with admitting the change of period. A fairy tale reflects the morality of the education of children. The late 17th century, the information by an author of classical literature collects and the literature genre of children begins to fix. In 1697, Perrault publicates and is a volume of eight volumes' tale. Perrault describes that female children guard against male by annexing a figurative allusion. Sara Moon of a photography artist in 20th century expresses this theme by symbolic expression of illustration. Her illustration brings about many questions and becomes conscious of the veiled significance of sentences by author's consideration. She deletes the Perrault's preccept in substitution of bed photography and she substitutes a wolf with a car or a dog and a shadow, etc .. The illustration of Sara Moon gets ready a foundation of early sex education as reflecting a period. Now, an illustrator gets to rebirth a fairy tail as a new dramatizer of today.

• Journal of Trauma and Injury
• /
• v.26 no.1
• /
• pp.14-17
• /
• 2013

Purpose: The open abdomen is now the standard of care in various clinical situations, especially it is used to treat abdominal compartment syndrome. Many techniques have been reported for closure after an open abdomen, but most take a long time for complete definitive closure and are associated with various problems. We describe a technique using biologic mesh that can achieve early definitive closure after an open abdomen. Methods: A 45-year-old man presented to the emergency room with a painful hip and painful lower extremities after a fall from 80 feet. Radiologic examination revealed multiple fractures of the pelvis and low extremities. Abdominal compartment syndrome caused by a retroperitoneal hematoma developed during the orthopedic surgery. We performed exploration immediately and closed abdomen temporarily. A peritoneal graft of porcine dermal collagen with anterior myofascial approximation of the rectus abdominis muscles and sliding skin flap was performed three days after the previous surgery. Results: There were no complications related to the wound. The patient was transferred to the Department of Orthopedic Surgery seven days after the initial surgery. Conclusion: Early definitive closure using porcine dermal collagen is a feasible method that can reduce the length of hospitalization and the number of operations for an open abdomen.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.571-571
• /
• 2009

지열은 날씨와 기온 등에 영향을 받지 않고 연중 가동할 수 있어 기저부하를 담담할 수 있는 유일한 신재생에너지 자원이므로 이에 대한 기술개발이 시급하다. 우리나라는 비화산지대이며 지중 온도가 가장 높은 지역의 5km에서 약 $170^{\circ}C$ 내외이므로 외국에 비해 지온경사도가 크지 않은 편이다. 그리고 3km 이상에서는 지하대수층이 거의 존재하지 않기 때문에 지열발전을 위해서는 EGS 기법을 도입할 수 밖에 없는 실정이다. 그리고 지열수를 확보할 수 있는 온도범위가 약 $100{\sim}150^{\circ}C$ 정도이므로 이에 적합한 지열발전 플랜트를 선정할 필요가 있다. 일반적으로 지열발전에 적용되는 플랜트는 건증기 지열발전, 플래쉬증기 지열발전, 바이너리 사이클 지열발전으로 분류할 수가 있으나 국내 여건에 맞는 방식으로서 바이너리 사이클 발전으로서 ORC 플랜트 또는 Kalina 사이클 플랜트가 적합하므로 이에 대한 기술 개발이 적극적으로 이루어져야 한다. 따라서 국내 지열발전의 기술개발에 있어서 핵심요소는 심부천공 및 EGS를 위한 인공파쇄기술과 지상 플랜트로서 저온지열 발전 플랜트의 기술확보가 필요한 실정이다. 이와 같은 기술개발이 완성되면 발전 뿐만아니라 집단지역난방, 온실 및 양어장 등에도 열공급이 가능한 열병합발전이 가능하게 될 것이다. 또한, EGS 기술로서 상업적 성공을 이룬 것은 세계적으로 2~3개 사례에 불과한 신기술로서, EGS 기술의 국내 조기 실현으로 기술 선점 및 해외 수출을 모색할 필요가 있다. 그리고 심부 지열자원은 국내 어디에나 부존하는 ubiquitous 자원이며 이산화탄소 배출이 전무한 청정 국산 에너지 자원이나, 이의 개발에는 높은 초기 투자비와 risk를 요하므로 민간 업체의 투자가 제약을 받는다. 따라서 정부의 적극적인 지원하에 산.학.연 중심으로 시범보급이 우선 이루어진 후 민간의 자발적 투자를 통한 지열 개발을 유도할 필요가 있다.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.17 no.2
• /
• pp.219-224
• /
• 2017

These days, it is developed renewable energy-based wind power technology. Wind power generation is relatively quiet, and environmental damage is relatively low. In developed countries, a lot of wind power generation is being built. In Korea, the generation efficiency is low because there are few areas where the wind speed is maintained for four seasons. In recent years, forest damage, low noise, and environmental degradation complaints are frequent. In this paper, we performed an experiment to manage pitch control effectively by analyzing wind, direction, and temperature in real time based on FUZZY rule and cluster analysis.Using the new algorithm proposed by the simulation results, we could verify the efficiency of wind power generation pitch control for wind condition and direction condition by using the pitch control analysis technique.Furthermore, visualization representations have proven to automatically analyze early warning and efficiency of generator performance.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.1065-1068
• /
• 2008

Marine bridges are readily deteriorated due to the exposure to marine environment. The concrete deterioration occurred by corrosion of steel in concrete is mainly relevant to chloride in seawater. Chloride ions penetrate through porous concrete, and then reach to the reinforcing steel, and finally corroded them. The corrosion by-products(rusts) increase the volume as much as 6 to 10 times of origin steel. this creates expanding pressure and tensile stress, which cause the structures cracking and spalling. Sometimes the rebar corrosion is accelerated, and then collapsed catastrophically. In order to prevent corrosion damage, it is important to understand well regarding the reason of concrete corrosion, the quantification of its damage, and protection method/system to stop or to mitigate the corrosion. In this study, slab specimens were fabricated to evaluate the effect of cathodic protection which was simulated to marine bridges, and/or port structures. Zn-mesh sacrificial anode has been applied as a chathodic protection system and accelerated test conditions, i.e. temperature and salt concentration have been used in this study.

• Journal of Korea Port Economic Association
• /
• v.30 no.4
• /
• pp.91-110
• /
• 2014

The Korean Government is planning to build commercial districts and amenities for the major port such as Busan, Gwangyang, and Incheon in order to activate the hinterland in each port. The foreign ports in Germany, Japan and China is competing with Korean ports are developing the commercial districts and amenities of seaport hinterland in order to support urban functions. The purpose of this study is to predict the demand for the facility of commercial districts and amenities planned in the Gwangyang seaport hinterland, then to propose its utilization plans. By the demand forecasting, the districts and amenities need to be full of office, accommodation and commercial facilities, etc. In addition, the districts need to be developed gradually for the target of 2035, considering the demand growth. Leasing out the property to secular tenants, it needs to charge rent for profits of port authority. Therefore, it is required to revise the National Ports Act for the private agency to take part in building the facilities of the commercial districts and amenities.

• Tribology and Lubricants
• /
• v.31 no.6
• /
• pp.281-286
• /
• 2015

Automotive transmission systems are assembled with a large number of gears and shafts, and rolling bearings are used to ensure their smooth operation. Gear oil in the gear box contains solid particles such as wear debris from contacting gears and metallic chips. This particle-enriched lubricating oil can cause premature failure of the rolling bearings. Research aimed at improving the service life of these rolling bearings has been confined mainly to design and lubrication of the inner/outer rings and the rolling elements. In this paper, we redesigned the shape of the cage pocket of a deep groove ball bearing to reduce the premature failure due to particle contamination. Test bearings are assembled with this new cage design containing a hole punched in the cage pocket. Endurance tests are carried out using the contaminated lubricating oil with miracle grid as hard particle. The duration and damaged bearing component shapes are compared for two different cages. The B₁₀ life of bearing with new cage is increased by about 66% compared to the conventional cage. This is because the hard particles can be easily discharged through the pocket hole without staying for a long time in the lubrication regions. This greatly decreases abrasive wear and dents on the highly stressed ball bearing surfaces. Therefore, the cage design of this study, containing a pocket hole, can significantly delay the premature failure of rolling bearings and improve the endurance life.

• FLOWER RESEARCH JOURNAL
• /
• v.17 no.4
• /
• pp.324-327
• /
• 2009

The white flowered 'Eorayeon 1ho' is the first Kangwon National University cultivar of L. ${\times}$ formolonga, commonly known as seed propagating lily. Crosses were conducted from 1999 to 2003 among the selected selfing lines($S_3$) of L. longiflorum 'Lorina', L. ${\times}$ formolonga 'Augusta' and 'Raizan Herald'. A new cultivar was preliminarily selected as 'E-No.1' in 2003 for its stable upward flowering habit. The evaluation of characteristics was investigated from 2003 to 2004 in Chuncheon and Yungweol, Kangwon province. 'Eorayeon 1ho' blooms in early July at outside, with high resistance to Botrytis and having upward flowering habit. The plant height is 112.4 cm and the percentage of seed germination is 96.4%. This seed propagating cultivar shows good quality as a cut flower and low blasting rate.