• 소성∙가공
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• 제12권8호
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• pp.744-749
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• 2003

The effect of tempering temperatures on microstructures and mechanical properties was studied in a low carbon steel. The disappearance of continuous yielding and the formation of an extended region in engineering stress-strain curves at tempering temperatures ranging from 673 to 873K was caused by the reduction of mobile dislocations during tempering and dynamic recovery during tensile deformation. In addition, the occurrence of discontinuous yielding in the sample treated at the tempering temperatures above 923K was attributed to the formation of new strain-free polygonal ferrite grain.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.713-718
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• 1994

Voronoi diagrams for closed shapes have many practical applications, ranging from numerical control machining to mesh generation. Shape offset based on Voronoi diagram avoids the topological problems encountered in traditional offsetting algorithms. In this paper, we propose a procedure for generating a Voronoi diagram and an exact offset for planar curve. A planer curve can be defined by free-form curve segements. The procedure consists of three steps : 1) segmentation by minimum curvature, 2) construction of Voronoi diagram, and 2) generation of the exact offset.

• Nuclear Engineering and Technology
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• 제29권6호
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• pp.500-507
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• 1997

The development of detection techniques is needed, in order for regulating authorities to determine whether or not a particular food sample has been irradiated, and label it accordingly so that a consumer's free choice can be exercised. The chemical and physical changes brought about in foods by practical doses of irradiation are very small, and therefore very sensitive methods are required. A number of promising approaches have been developed and evaluated. These include chemical, physical and biological methods ranging from the very simple to highly sophisticated techniques.

• Archives of Reconstructive Microsurgery
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• 제22권1호
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• pp.29-32
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• 2013

Purpose: Reconstruction of scalp and calvarial defects should provide both aesthetic and functional aspects. The inelastic nature of the scalp and previous surgery or radiation preclude the use of primary closure or a local flap. With development of microsurgical technique, a free tissue transfer is a good option. We use the latissimus dorsi myocutaneous free flap for reconstruction. Materials and Methods: A review of all latissimus dorsi free flap reconstructions performed in nine patients from 2009 to 2012 was conducted. There were six males and three females, ranging in age from seven to 69 years, and nine different regions, including five temporal regions, two occipital regions, and two frontoparietal regions. The flaps ranged in size from $9.0{\times}10.0cm$ to $14.0{\times}15.0cm$. Recipient vessels available for microanastomosis were most often the superficial temporal vessels and two patients had anastomoses to the external carotid artery and internal jugular vein. Results: All flaps survived postoperatively. With a median follow-up period of 14 months, no major complications were noted. However, two patients developed minor wound dehiscence, and a hematoma was observed in one patient. Conclusion: We performed the latissimus dorsi myocutaneous free flap reconstruction, which is one of the most popular reconstructive methods. The latissimus dorsi myocutaneous free flap reconstruction has been proven successful in our patients with satisfactory results. During the long term follow-up period, even though depressions were observed on the defect area in some patients, they were treated successfully with cranioplasty. Therefore, we recommend the latissimus dorsi myocutaneous free flap for reconstruction of scalp and calvarial defects.

• 아동학회지
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• 제29권3호
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• pp.253-272
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• 2008

This study compared mother-toddler physical interaction by play type (traditional play, free play, block play), and child's sex and age. Subjects were 10 boys and 10 girls ranging in age from 25- to 36-months and their mothers. An observer videotaped the children and their mothers at play in their homes. Results showed that (1) mothers' physical interaction was not distinguished by play type or by child's sex or age. (2) Mothers expressed more positive emotion in traditional than in block play. (3) Younger children's play interactions were more nonverbal. (4) Children expressed more positive emotions in traditional play. This study provides groundwork for mother-toddler traditional play programs with potential for improving positive expression of emotion and attachment.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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• pp.207-212
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• 1993

When constructing highly precise production plants, for example, super LSI plants or semiconductor plants, it is important to take the necessary control countermeasures into consideration to obtain the working microvibration environment, which is directly related to product precision. Working environment of a clean room means vibration-free and there are only ultra-miro vibration which human cannot sense. In order to provide an place having a vibration-free working environment with only ultra-micro vibration it is necessary to posses a great number of vibration isolation technlogies, wide-ranging and abundant survey and teat data, and a high level of knowledge enabling comprehensive judgments to be made. In this study, experimental modal analysis is used to analyze the dynamic characteristics of double floor for vibration-proofing near apparatus which generate vibration. It is concluded that the double floor system with rubber pad inserted between floor panel and pedestal is good for vibration proof.

• 아동학회지
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• 제13권1호
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• pp.125-138
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• 1992

The purpose of the present study was to examine the development of embedding through relative clause formation in the first language acquisition of Korean. Results are reported from the study of the spantaneous natural speech of 36 young Korean children ranging from 16 months to 45 months in age acquiring Korean as their first language in Chinju, Korea. The results revealed a developmental order in the first language acquisition of Korean relative clause structures. Namely, a free or headless relative clause appears to be acquired first, before lexically headed restrictive relative construction. This order is consistent with one evidenced in English (and also Chinese) first language acquisition, 'free' relatives appear to provide a developmentally early stage in the acquisition of restrictive relative clauses. The Korean data provided additional evidence for an intermediary stage with an overt complementizer as well as an overt lexical head. Implications for the results are disscused with regard to a continuous theory of universal grammar in the first language acquisition.

• 한국안전학회지
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• 제25권6호
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• pp.14-21
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• 2010

A miniature single solder ball joint is designed to mimic the actual solder joints used in the micro-electric industries. Shear tests were conducted to evaluate the mechanical behavior of miniature single solder joints at intermediate strain rates from $0.019\;s^{-1}$ to $2.16\;s^{-1}$ at room temperature. The shear fracture strength of the present solder ball joints generally increased with increasing shear strain rate, ranging from 32 to 51MPa. This behavior is affected by the sensitivity of bulk solder strength to strain rate. Shear fracture mode changed from brittle to partial ductile (failure inside the bulk solder) with an increase of shear speed. The unloading shear fracture toughness is generally consistent with the measure of the amount of bulk solder on the fractured surface.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.172-174
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• 2003

Using MODIS data and several different compositing algorithms utilizing the average cloud free days in a compositing period, maximum ndvi, or dual maximum NDVI/minimum blue, multi resolution composites (250m, 500m, 1km) have been produced for Southeast Asia, with spectral bands ranging from the visible to short-wave infrared with a single band in the thermal (for land and sea surface temperature). A total of nine composites have been produced for the months of May and August in 2003, including blue, green, red, NIR, three in the SWIR, and several to specifically monitor vegetation health.

• Archives of Reconstructive Microsurgery
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• 제19권1호
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• pp.61-67
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• 2010

Emergency free flap has been advocated to cover the severely injured extremity for more than two decades, due to its numerous advantages such as low incidence of flap failure and infection rate and early recovery of function. But there are very few reports about these. The authors report their experience in using the emergency free flap for reconstruction of extremities. For last 10 years, 4 patients ranging from 3 to 27 years old with severely traumatized extremities were treated with emergency free flap transfers. Three were males and the other was a female. Flap size ranged from $2{\times}5\;cm^2$ to $7{\times}22\;cm^2$. The locations of the recipient site were the dorsum of the foot, the cubital fossa, the popliteal fossa and the upper arm. The number of the donor sites used was as follows: one scapular flap, two parascapular flaps, and one radial forearm flap with the radial bone. All of the flaps survived without need of re-exploration. There was no infection or flap loss. Involved joints have recovered a normal range of motion. Therefore, we consider that the emergency free flap is a very safe and reliable method to cover the severely injured extremities.