• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1686-1690
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• 2005

Although metal ball can be used as parts of bearing or metal filter, that is used by single product with solder ball or shot ball. Also, according as demand of metal ball of various diameter increase, processing property 솜 extension of coverage are important. Especially an optimal design of cutting roller was investigated for determining appropriate dimensions of components of manufacturing system. In this study, the effects of the diameter and the round radius of cutting roller were calculated and analyzed. We applied data of rigid-plastic FEM Simulation in basis design of equipment to solve these issues, and confirmed processing factor about metal ball manufacturing process that use cutting process of metal wire in this research

• International Journal of Highway Engineering
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• v.2 no.1
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• pp.147-156
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• 2000

Compaction is known to critically affect pavement performance. Due to its importance, a theoretical modelling of compacted density in the term of number of roller coverages is attempted by assuming compaction process essentially identical to pavement rutting. Excellent data fittings by the developed equation may prove the validation of assumptions made as well as justification of its use. According to the derived equation, a plot of density difference with respect to number of roller coverages in the logarithmic scale Produces a linear relationship. However, this linearity is turned out to be deviated by cooling effect, change of amplitude and frequency. Investigation of these three factors proposes a new generalized compaction density equation, which shows a promising future. By applying this general formula, the equations for the number of roller coverages required and the final compaction density obtained for a particular compaction project is derived first time in compaction research.

• Journal of Chest Surgery
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• v.27 no.10
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• pp.888-892
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• 1994

Acquired, traumatic tracheoesophageal fistula [TEF] is rare and difficult problem to manage. This 55 years old man met with a roller accident of a tractor. During accident, he received a penetrating injury on the left upper sternal border. At local clinic, he received closed thoracotomy drainage [CTD]for relief of pneumothorax[left]. Three days after CTD, he complained abdominal pain and hematemesis. The endoscopy revealed large ulcer at the stomach, so he received subtotal gastrectomy. On 10th day post subtotal gastrectomy, he developed aspiration and coughing from a TEF. The esophagogram showed large TEF at the mid-trachea level. So he transfered to our hospital for operation. This patient was operated on for late TEF three weeks after injury. We have used absorble 4-0 Vicryl sutures to repair trachea. We repair all esophageal injuries with two layers of nonabsorbable silk suture. Where suture line on the esophagus, the strap muscle was interposed for reinforcement. And for feeding, the feeding jejunostomy was performed. Postoperatively the osteomyelitis of the manubrium site was developed, so on the 30th postoperative day, an ostectomy of manubrium, both clavicle and fight 1st, 2nd ribs, and the pectoralis major musculo-cutaneous flap coverage were performed.

• Horticultural Science & Technology
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• v.33 no.3
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• pp.340-348
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• 2015

Mowing turfgrasses, especially fast growing species like perennial ryegrass, is one of the most time and money consuming tasks of their management. Trinexapac-ethyl (TE) is a popular plant growth regulator used to reduce mowing requirements, improve stress tolerance, and enhance turf quality. This study was conducted to investigate the effect of TE rate and frequency of applications on growth response and traffic tolerance of perennial ryegrass. The experiment was a split-plot laid out in a randomized complete block (RCB) design with three replications. TE was applied to main plots at 0.00, 0.25, and $0.50kg\;a.i.\;ha^{-1}$. Application pattern included an initial application, followed by two sequential applications at 6-wk intervals. Traffic treatment was applied to subplots with a cleated roller. Results demonstrated that TE consistently reduced vertical shoot growth, clippings dry weight, with maximum growth reduction of 59% and 65%, for 0.25 and $0.50kg\;a.i.\;ha^{-1}$, respectively, occurring at 2 weeks after initial TE treatment (WAT). Traffic also dramatically reduced vertical shoot growth and clippings dry weight. Overall, quality of perennial ryegrass was enhanced by sequential TE applications, however, turf quality and surface coverage reduced greatly under traffic, regardless of TE treatment. Total chlorophyll, chlorophyll a and chlorophyll b and total carbohydrates (TC) contents were also positively influenced following sequential TE application. Our results indicated that TE reduces mowing frequency and enhances turf quality rather than influencing traffic resistance.