• Archives of Plastic Surgery
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• 제35권2호
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• pp.208-213
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• 2008

Purpose: Distally based superficial sural artery island flap has some disadvantages such as postoperative flap edema, congestion, and partial necrosis of the flap margin. Venous congestion is an area of considerable concern in distally based superficial sural artery fasciocutaneous flap and is one of the main reasons for failure, particularly when a large flap is needed. However, we could decrease these disadvantages by means of venous superdrainage. Methods: From June of 2006 to June of 2007, a total of two patients with soft tissue defects of lower one third of the leg underwent venous supercharging distally based superficial sural artery island flap transfer. The distal pivot point of this flap was designed at septocutaneous perforator from the peroneal artery of the posterolateral septum, which was 5 cm above the tip of the lateral malleolus. Briefly, this technique is performed by anastomosing the proximal end of the lesser saphenous vein and collateral vein to any vein in the area of the recipient defect site. Results: No venous congestion was noted in any of the two cases. No other recipient or donor-site complications were observed, except for minor wound dehiscence in one case. In 3 to 6 months follow-up, patients had minor complaints about lack of sensation in the lateral dorsal foot. Conclusion: The peroneal artery perforator is predictable and reliable for the design of a distally based superficial sural artery island flap. Elevation of the venous supercharging flap is safe, easy, and less time consuming. In conclusion, the venous supercharging distally based superficial sural artery island flap offers an alterative to free tissue transfer for reconstruction of the lower extremity.

• 화약ㆍ발파
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• 제22권3호
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• pp.103-111
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• 2004

기존 절리측정 방법은 크게 시추공을 이용한 측정방법과 수치사진측량을 이용한 측정 방법으로 나눌 수 있다. 그러나 이러한 측정방법은 공간적 제약과 국한된 구간에서의 자료의 획득, 측정시의 오차로 전반적 인 절리 자료의 획득에는 한계를 가질 수밖에 없었으며, 객관적이고 정확한 결과를 얻기엔 무리가 있었다. 이러한 기존 절리측정 방법의 난점을 극복하고 정확도 및 효율성을 극대화 할 수 있는 방안으로 3차원 레이저 스캐너를 이용한 측정방법을 제시하고자 한다. 본 연구에서는 암반사면을 대상으로 3차원 레이저 스캐너를 이용한 절리측정의 정확성 및 활용 가능성을 연구하였다. 이를 위하여 레이저 스캐너와 클리노미터를 이용하여 대상사면의 절리를 측정하였으며, 이를 비교 분석하였다. 레이저 스캐너와 클리노미터로 측정한 절리 분포 및 절리군의 방향성을 비교한 결과, 절리의 분포는 거의 동일하게 투영되었으며, 3차원 스캐너를 이용한 결과에서는 다수 절리의 획득으로 클리노미터로 측정한 부분보다 더 많은 절리 데이터를 얻을 수 있었다. 따라서 암반사면조사 자료의 객관화, 조사기간의 단축, 조사 경비 절감 등의 효과가 있으며, 암반사면의 근접조사가 어려운 경우에도 조사가 가능하고 조사자의 안정성도 확보할 수 있어 절리측정에 매우 효과적인 방법임을 알 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제16권4호
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• pp.40-47
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• 1988

Our plywood manufacturing industries which entertained prosperous stage in late 1970's have come to be in face of the problems of conceedingly obtaining good quality logs and yield up-grading, which is considered by future-replaceable forest resources. In view of this point, manufacturing characteristic on softwood plywood using Japanese larch, pitch pine as domestic plantation species, and western hemlock as foreign species was studied. In this study, veneer- and plywood manufacturing yields were discussed in relation to log properties and veneer defects (knots). The summarized conclusions were as follows: 1. The majority of sample logs belonged to second grade on the standard. And, eccentricity of larch was the highest 11%, about 2 times those of pitch pine, hemlock. 2. Knot frequency of occurrence of larch reached 19% within log height 8m, and pitch pine 13% within 4m. Correspondingly, the log height of larch available for plywood manufacture was higher by about 2 times that of pitch pine. 3. In the knot types, most of knots of larch appeared dead, whereas those of pitch pine and hemlock appeared live. In size of knots, larch and hemlock showed relatively small 1-2cm dia. by 70% or more and pitch pine did the larger 24cm by 65%. Generally the more knot emerged in the inner side of veneer than the outer. 4. Plywood manufacturing yields by peeling with spindle revolution lathe were 37% in larch > 32% in hemlock> 26% in pitch pine. S. Jointed core veneer yields by peeling with outer perimeter back-up lathe were 55% in hemlock> 53% in larch> and 48% in pitch pine.

• Archives of Plastic Surgery
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• 제35권4호
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• pp.483-486
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• 2008

Purpose: Fingertip injuries are the most common hand injuries and may lead to significant disability. Knowledge of fingertip anatomy is mandatory to treat these injuries effectively. All surgical techniques used for coverage of fingertip injuries must be based on the nature of the injury and the patient's age. Many authors have studied the method of fingertip reconstruction because goals of these treatments should include maintaining length, sensibility, motions, and appearance. The purpose of this study is to evaluate the effect of digital artery perforator flap for fingertip reconstruction without aesthetic and functional problems. Methods: From November 2006 to March 2007, the authors performed fingertip reconstruction on 3 fingers of 3 patients, aged between 41 to 54 years (average age, 47 years) using digital artery perforator flap. Results: All fingers recovered successfully and there were no necrosis of the flap. We followed up 3 cases more than 5 months. Light touch and temperature sensation could be detected in all flaps and the static two-point discrimination test was 8 mm. Conclusion: This flap is an alternative choice for coverage of fingertip defects. This method also takes short time to procedure and to recovery. The digital artery perforator flap has never been reported in Korea, however it is considered as a useful method for treatment of fingertip injury.

• 비파괴검사학회지
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• 제5권1호
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• pp.34-47
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• 1985

The developing country, KOREA where does not possess the natural resources for traditional energy such as oil and gas, so. The nuclear energy is the most single reliable source available for closing the energy gap. For these reason, It is inavoidable to construct the nuclear power plant and to develop technology related nuclear energy. The rate of operation in large nuclear power facilities depends upon the performance of work system through design and construction, and also the applied technology. Especially, it is the most important element that safety and reliability in operation of nuclear power plant. In view of this aspects, Nuclear power plant is performed severe examinations during preservice and inservice inspection. This study provide an automation of analysis for volumetric examination which is required to nuclear power plant components. It is composed as follows: I. Introduction II. Inservice Inspection of Nuclear Power Plant ${\ast}$ General Requirement. ${\ast}$ Principle and Methods of Ultrasonic Test. ${\ast}$ Study of Flaw Evaluation and Design of Classifying Formula for Flaws. III. Design of Automation for Flaw Evaluation. IV. An Example V. Conclusion In this theory, It is classifying the flaws, the formula of classifying flaws and the design of automation that is the main important point. As motioned the above, Owing to such as automatic design, more time could be allocated to practical test than that of evaluation of defects, Protecting against subjective bias tester by himself and miscalculation by dint of various process of computation. For the more, adopting this method would be used to more retaining for many test data and comparative evaluating during successive inspection intervals. Inspite of limitation for testing method and required application to test components, it provide useful application to flow evaluation for volumetric examination. Owing to the characteristics of nuclear power plant that is highly skill intensive industry and has huze system, the more notice should be concentrated as follows. Establishing rational operation plan, developing various technology, and making the newly designed system for undeveloped sector.

• 한국수자원학회논문집
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• 제37권3호
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• pp.233-240
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• 2004

수자원 분야에서 대부분의 수문해석은 강우자료의 수집 및 분석으로부터 시작되며, 지점 강우량으로부터의 면적 평균강우량 추정 및 결측치에 대한 자료보완 기법은 여러 가지가 있다. 이러한 강우분석 기법으로 기존에 사용되어온 티센법 및 RDS법은 전통적인 자료보완 기법으로 매개변수의 특성이 관측소간 거리에만 의존하며, 공간적인 연속성을 가질 수 없다는 단점이 있다. 본 연구에서는 이러한 전통 기법들의 단점을 보완하고 강우의 공간적인 통계특성을 반영하기 위하여 크리깅 기법을 낙동강 유역의 강우해석에 적용하였다. 공간상관 및 반분산 분석으로 낙동강 유역 강우의 지역적인 통계특성을 파악하였으며, 낙동강 유역 격자시스템에 대한 크리깅 분석을 통하여 공간격자 강우량 및 소유역별 평균강우량을 산정하였다. 또한, 크리깅 기법의 공간추정 오차 분석으로 시강우량에 대한 격자별 내삽오차 및 소유역별 평균오차를 제시하여 낙동강 유역의 강우관측 취약지역을 파악할 수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.128-128
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• 2012

We investigated the atomic and electronic properties of graphene grown by Pd silicidation and intercalation using LEED, STM, and ARPES. Pd was deposited on the 6H-SiC(0001) surface at RT. The formation of Pd silicide gives rise to breaking of Si-C bonds of the SiC crystal, which enables to release C atoms at low temperature. The C atoms are transformed into graphene from $860^{\circ}C$ according to the LEED patterns as a function of annealing temperature. Even though the graphene spots were observed in the LEED pattern and the Fourier transformed STM images after annealing at $870^{\circ}C$, the topography images showed various superstructures so that graphene is covered with Pd silicide residue. After annealing at $950^{\circ}C$, monolayer graphene was revealed at the surface. The growth of graphene is not limited by surface obstacles such as steps and defects. In addition, we observed that six protrusions consisting of the honeycomb network of graphene has same intensity meaning non-broken AB-symmetry of graphene. The ARPES results in the vicinity of K point showed the non-doped linear ${\pi}$ band structure indicating monolayer graphene decoupled from the SiC substrate electronically. Note that the charge neutrality of graphene grown by Pd silicidation and intercalation was sustained regardless of annealing temperature in contrast with quasi-free- standing graphene induced by H and Au intercalation. Further annealing above $1,000^{\circ}C$ accelerates sublimation of the Pd silicide layer underneath graphene. This results in appearance of the $(6r3x6r3)R30^{\circ}$ structure and dissolution of the ${\pi}$ bands for quasi-free-standing graphene.

• Archives of Plastic Surgery
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• 제47권2호
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• pp.187-193
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• 2020

Upper limb nerve damage is a common condition, and evidence suggests that functional recovery may be limited following peripheral nerve repair in cases of delayed reconstruction or reconstruction of long nerve defects. A 26-year-old man presented with traumatic injury from a wide, blunt wound of the right forearm caused by broken glass, with soft tissue loss, complete transection of the radial and ulnar arteries, and a large median nerve gap. The patient underwent debridement and subsequent surgery with a microsurgical free radial fasciocutaneous flap to provide a direct blood supply to the hand; the cephalic vein within the flap was employed as a venous vascularized chamber to wrap the sural nerve graft and to repair the wide gap (14 cm) in the median nerve. During the postoperative period, the patient followed an intensive rehabilitation program and was monitored for functional performance over 5 years of follow-up. Our assessment demonstrated skin tropism and sufficient muscle power to act against strong resistance (M5) in the muscles previously affected by paralysis, as well as a good localization of stimuli in the median nerve region and an imperfect recovery of two-point discrimination (S3+). We propose a novel and efficient procedure to repair >10-cm peripheral nerve gap injuries related to upper limb trauma.

• 한국재료학회지
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• 제30권2호
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• pp.68-73
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• 2020

Due to its favorable optical properties, Cu₂SnS₃ (CTS) is a promising material for thin film solar cells. Doping, which modifies the absorber properties, is one way to improve the conversion efficiency of CTS solar cells. In this work, CTS solar cells with selenium doping were fabricated on a flexible substrate using sputtering method and the effect of doping on the properties of CTS solar cells was investigated. In XRD analysis, a shift in the CTS peaks can be observed due to the doped selenium. XRF analysis confirmed the different ratios of Cu/Sn and (S+Se)/(Cu+Sn) depending on the amount of selenium doping. Selenium doping can help to lower the chemical potential of sulfur. This effectively reduces the point defects of CTS thin films. Overall improved electrical properties were observed in the CTS solar cell with a small amount of selenium doping, and a notable conversion efficiency of 1.02 % was achieved in the CTS solar cell doped with 1 at% of selenium.

• 한국재료학회지
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• 제17권9호
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• pp.453-457
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• 2007

Interest in use of ink-jet printing for pattern-on-demand fabrication of metal interconnects without complicated and wasteful etching process has been on rapid increase. However, ink-jet printing is a wet process and needs an additional thermal treatment such as an annealing process. Since a metal ink is a suspension containing metal nanoparticles and organic capping molecules to prevent aggregation of them, the microstructure of an ink-jet printed metal interconnect 'as dried' can be characterized as a stack of loosely packed nanoparticles. Therefore, during being treated thermally, an inkjet-printed interconnect is likely to evolve a characteristic microstructure, different from that of the conventionally vacuum-deposited metal films. Microstructure characteristics can significantly affect the corresponding electrical and mechanical properties. The characteristics of change in microstructure and electrical resistivity of inkjet-printed silver (Ag) films when annealed isothermally at a temperature between 170 and $240^{\circ}C$ were analyzed. The change in electrical resistivity was described using the first-order exponential decay kinetics. The corresponding activation energy of 0.44 eV was explained in terms of a thermally-activated mechanism, i.e., migration of point defects such as vacancy-oxygen pairs, rather than microstructure evolution such as grain growth or change in porosity.