• 한국기계가공학회지
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• 제14권4호
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• pp.126-133
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• 2015

To enhance the productivity and quality of the compound process of progressive dies and transfer dies, the semi-progressive method is applied in the material supply step to produce blanks, and then the transfer method is applied. Parts are transferred among processes by means of the finger and transfer bar in the transfer die, and the final seat cushion panel is produced. The main challenge in the current study is how to deform a seat cushion panel while meeting the design specifications without any defects. In order to obtain this technology, a sheet metal-forming simulation and die forming of the seat cushion panel were adopted; as a result, a compound die-forming technology for the automotive seat cushion panel, combining both semi-progressive die and transfer die for continuous production, was successfully developed.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.633-637
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• 2013

A wide range of applications for Foot Print Recognition System is discussed in this paper. The whole concept works under the principle that foot print is a parameter associated with biometrics that is very common as well as distinct. Its foremost application is at the government hospitals in the under developed and third world nations where there aren't the best of facilities. This system can be applied in the maternity ward of the hospitals for the identification or differentiation of the infants. Till date there has been no specialized system adopted for this purpose. The Foot Print Recognition System will overcome all the defects of any biometrics when applied here. Since the child will be very delicate for an iris scan and it will not be able to open its eyes wide or to correctly place its finger print on the sensor since the hands of a new born infant will be closed for a while. The Foot Print Recognition system can also be implemented in temples where there are cases of theft often reported. This can be used to grant access to the karpagraham of the deity by authorized users alone. These 2 applications of FPRS are discussed in this paper.

• Archives of Reconstructive Microsurgery
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• 제3권1호
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• pp.54-63
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• 1994

Pulp and palm of the hand and heel of the sole are anatomically unique. Satisfactory reconstruction of these areas presents the plastic surgeon with many challenges and requires durable and sensible skin coverage, minimal donor morbidity and reliable operative procedure. We presents 7 clinical cases of sensate instep free flap transfer in this paper during the last 2 years. Three cases were soft tissue defects due to crushing and avulsion injury on the pulp of finger. 1 case was unstable scar and redundant flap after reconstruction of soft tissue dect of palm and 1 case was contracture of first web of hand. One case was a soft tissue defect due to avulsion injury on heel. Lastly, one case was chronic osteomyelitis with open wound on lateral malleolar area. Follow-up period ranged from 3 months to 2 years. Through the whole follow-up period, all flaps were viable and durable to persistant stress or weight bearing and were sensible enough to porotect the recocstructed area from injuries and maintain functions. In conclusions, the instep free flap should be considered as a valuable tool in reconstruction of hand and extremity requiring durability and sensation.

• 한국재료학회지
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• 제34권4호
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• pp.215-222
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• 2024

Because collagen is inherently piezoelectric, research is being actively conducted to utilize it to harvest energy. In this study, a collagen solution was prepared using edible low-molecular-weight peptide collagen powder, and collagen films were fabricated using a dip coating method. The collagen films prepared by dip coating showed a smooth surface without defects such as pinholes or cracks. Dehydrothermal treatment of the collagen films was performed to induce a stable molecular structure through cross-linking. The collagen film subjected to dehydrothermal treatment at 110 ℃ for 24 h showed a thickness reduction rate of 19 %. Analysis of the collagen films showed that the crystallinity of the collagen film improved by about 7.9 % after dehydrothermal treatment. A collagen film-based piezoelectric nanogenerator showed output characteristics of approximately 13.7 V and 1.4 ㎂ in a pressure test of 120 N. The generator showed a maximum power density of about 2.91 mW/m² and an output voltage of about 8~19 V during various human body movements such as finger tapping. The collagen film-based piezoelectric generator showed improved output performance with improved crystallinity and piezoelectricity after dehydrothermal treatment.

• 태양에너지
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• 제17권4호
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• pp.3-11
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• 1997

다결정 실리콘에서 결정입계는 광생성된 반송자들의 재결합 중심으로 작용할 뿐 아니라 전위장벽으로 작용하여 태양전지의 변환효율을 감소시킨다. 결정입계의 영향을 줄이기 위해 열처리, 결정입계에 대한 선택적 식각, 결정입계로 함몰전극을 형성하는 방법, 다양한 전극 구조, 초박막 금속 형성 후 전극형성 등 여러가지 요소들을 조사하였다. 질소 분위기에서 $900^{\circ}C$ 전열처리, $POCl_3$ 확산을 통한 게터링, 후면전계 형성을 위한 Al 처리로 다결정 실리콘의 결함밀도를 감소시켰다. 결정입계에서의 반송자 손실을 감소시키기 위한 기판 처리로 Schimmel 식각액을 사용하였다. 이는 texturing 효과와 함께 결정입계를 선택적으로 $10{\mu}m$ 깊이로 식각하였다. 결점입계를 우선적으로 식각한 후면으로 Al을 확산하여 후면에서의 재결합 손실을 감소시켰다. 전극 핑거(grid finger) 간격이 0.4mm인 세밀한 전극 구조에 결정입계로 $0.4{\mu}m$ 깊이로 함몰전극을 추가로 형성하여 태양전지의 단락 전류 밀도가 개선되었다. 80% 이상의 광투과율을 보인 20nm 두께의 크롬 박막 형성으로 직렬 저항을 감소시켰다. 본 논문은 저가의 고효율, 지상 전력용 태양진지를 위해 결정입계에 대한 연구를 하였다.

• Archives of Plastic Surgery
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• 제46권6호
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• pp.580-588
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• 2019

Background There are various reconstructive options for nail bed defects. However, it is challenging not to leave a deformity. In this study, we investigated differences in outcomes depending on the reconstruction method, attempted to determine which method was better, and analyzed other factors that may affect outcomes. Methods The long-term outcomes of nail bed reconstruction were reviewed retrospectively. We performed three types of reconstruction depending on the defect type: composite grafts of severed segments, nail bed grafts from the big toe, and two-stage surgery (flap coverage first, followed by a nail bed graft). Subsequent nail growth was evaluated during follow-up, and each outcome was graded based on Zook's criteria. The reconstruction methods were statistically analyzed. Other factors that could contribute to the outcomes, including age, the timing of surgery, germinal matrix involvement, defect size, and the presence of bone injuries, were also compared. Results Twenty-one patients (22 digits) who underwent nail bed reconstruction were evaluated. The type of reconstruction method did not show a significant relationship with the outcomes. However, patients who sustained injuries in the germinal matrix and patients with a defect larger than half the size of the nail bed had significantly worse outcomes than the comparison groups. Conclusions The results suggest that no operative method was superior to another in terms of the outcomes of nail bed reconstruction. Nevertheless, involvement of the germinal matrix and defect size affected the outcomes.

• Archives of Plastic Surgery
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• 제39권2호
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• pp.138-142
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• 2012

Background : Electrical burns are one of the most devastating types of injuries, and can be characterized by the conduction of electric current through the deeper soft tissue such as vessels, nerves, muscles, and bones. For that reason, the extent of an electric burn is very frequently underestimated on initial impression. Methods : From July 1999 to June 2006, we performed 15 cases of toe tissue transfer for the reconstruction of finger defects caused by electrical burns. We performed preoperative range of motion exercise, early excision, and coverage of the digital defect with toe tissue transfer. Results : We obtained satisfactory results in both functional and aesthetic aspects in all 15 cases without specific complications. Static two-point discrimination results in the transferred toe cases ranged from 8 to 11 mm, with an average of 9.5 mm. The mean range of motion of the transferred toe was $20^{\circ}$ to $36^{\circ}$ in the distal interphalangeal joint, $16^{\circ}$ to $45^{\circ}$ in the proximal interphalangeal joint, and $15^{\circ}$ to $35^{\circ}$ in the metacarpophalangeal joint. All of the patients were relatively satisfied with the function and appearance of their new digits. Conclusions : The strategic management of electrical injury to the hands can be both challenging and complex. Because the optimal surgical method is free tissue transfer, maintenance of vascular integrity among various physiological changes works as a determining factor for the postoperative outcome following the reconstruction.

• 한국산학기술학회논문지
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• 제13권3호
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• pp.1310-1318
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• 2012

본 연구는 기존의 생체인식 시스템 중 가장 활발하게 활용되고 있는 지문인식 시스템이 가지고 있는 환경적인 요소나 물리적 요소에 의한 인식률 저하를 보완할 수 있는 시스템을 새롭게 제안한다. 지문인식은 사용의 편리함과 저가의 초기 투자비용, 그리고 소형화의 가능으로 생체인식 중에서 실생활에 사용되기 가장 적합한 기법으로 여겨져 다양한 응용 분야에 널리 사용되고 있다. 그러나, 지문인식 시스템은 다른 생체인식 시스템에 비해 환경적인 요인, 물리적 피부 손상, 가변적 센서 접촉등 인식률 저하 요인이 많은 단점을 가지고 있다. 따라서, 본 연구에서는 기존의 지문인식 시스템을 기반으로 하여 간단하고 저렴한 추가 장비로 손가락에서 추가적인 생체정보와 3차원의 손가락 형태 정보를 획득하여 인식률 향상시키고 다양한 분야에서 활용이 가능한 보다 효율적인 시스템을 제안한다.

• 기술사
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• 제17권3호
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• pp.22-31
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• 1984

Sardine ant mackerel so called dark muscled fish have been underutilized due to the disadvantages in bloody meat color, high content of fat, and postmortem instability of protein. Recent efforts were made to overcome these defects and develope new types of product such as texturized protein concentrates and dark muscle eliminated minced fish. Approach of this study is based on the rapicl dehydration of foamed fish-starch paste by dielectric heating. In process comminuted sardine meat was washed more than three times by soaking and decanting in chilled water and finally centrifuged. The meat was ground in a stone mortar added with adequate amounts of salt, foaming agent, and other ingredients for aid to elasticity and foam stability. The ground meat paste was extruded in finger shape and heated in a microwave oven to give foamed, expanded, and porous solid structure by dehydration. Dielectric constant ($\varepsilon$′) and dielectric loss ($\varepsilon$") vcalues of sardine meat paste were influenced by wavelength and moisture level. Those values at 100KHz and 15MHz were ranged 2.25∼9.86 ; 2.22∼4.18 for $\varepsilon$′ and 0.24∼19.24 ; 0.16∼1.25 for $\varepsilon$", respectively, at the moisture levels of 4.2∼13.8％. For a formula for fish-starch paste preparation, addition of 20∼30% starch (potato starch) to the weight of fish meat, 2∼4% salt, and 5∼10% soybean protein was adequate to yield 4∼5 folds of expansion in volume when heated. Addition of egg yolk was of benefit to micronize foam size and better crispness. In order to provide better foaming and dehydration, addition of 0.2∼0.5% sodium bicarbonate foaming agent, was proper to result in foam size of 0.5∼0.7mm and foam density of 200∼400/$\textrm{cm}^2$ which gave a good crispness.

• 경영과정보연구
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• 제6권
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• pp.227-266
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• 2001

These days the use of personal computer has become generalized at factory, office, house, etc and this fact indicates that visual display terminal work became popular in every field of our society. The use of computer improves work efficiency, productivity & qualify but in addition, it also generated the physical and mental diseases or defects so called VDT syndrome to workers. The purpose of this paper is to analyse the computer-work-related anti-physical, anti-psychogenic symptoms & side effects through the data drawn from workers who use computers on their works, and to find out methods of improvement & humanization of computer works. The follows are the results of questions about personal sensibility of VDT syndrome. 1. Female workers are more sensitive to the side effects of computer labor than males. 2. Workers aged twenties feel more severe symptoms of VDT syndrome than thirties or fourties, but there are no level of significance. 3. Middle managements workers are the most sensitive group to VDT syndrome, on the other hand tow managements are less sensitive than operators. 4. The result of questions indicates that a phone conductress show more severe VDT syndrome symptoms than business affairs or an engineer workers, with level of significance. 5. The longer computer work engagement period, the more evident VDT syndrome symptoms appear. For instance, workers who have more than 2 year engagement period complain more severe symptoms, compared workers who have less than 2 year engagement period. 6. Long computer working time per day also increases VDT syndrome severity specially people who have more than 2 hours in working time in a day have much less severe symptoms, compared people whose daily working time exceeds 2 hours. 7. Specific body part which shows VDT syndrome symptoms is shoulder, wrist, neck, finger, eye, waist, arm in the order of severity. 8. Sensibility of VDT syndrome symptoms have effect on degree of vocational satisfaction.