• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.487-489
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• 2016

본 논문에서는 쿼드콥터 편대비행 중 오류로 인해 높은 공중에서 추락할 경우 발생 가능한 문제들을 예방하는 방법을 제안한다. 기존 연구에서는 쿼드콥터 편대비행을 실내에서 구현하기 때문에 추락할 경우를 생각할 필요가 없었다. 본 연구는 비행 중 헤더노드의 Proportional-Integral-Derivative(PID) 값과 일치하지 않거나 쿼드콥터에 부착된 센서나 통신모듈 이상이 생길시 자가진단을 한 뒤 비행을 중지하여 2차 사고를 방지한다. 제안하는 방안은 쿼드콥터 편대비행 중 한 노드에 문제가 발생했을 시 추락을 방지하기 위해 헤드노드가 현재 상태를 서버로 전송하고 자가 진단하여 고도를 조절하는 시스템이다. 따라서 헤더노드와 비교한 PID 값의 차이가 지정된 값 이상이거나 센서나 통신모듈을 진단을 하여 결함을 발견했을 시 정지하여 안전한 곳으로 이동한다. 이 시스템은 가속도센서, 자이로센서, 다양한 센서들의 결함을 자가진단을 통해 발견하며 고도를 조절함으로 추가적인 피해를 최소화할 수 있다.

• Archives of Plastic Surgery
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• 제37권4호
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• pp.427-432
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• 2010

Purpose: The purpose of this study is to estimate muscle defect by ultrasonography in the patients with secondary deformities of the lip. We investigated the association between the muscle defect in the repaired cleft lip and the philtral appearance not only at resting state but also maximal puckering. Methods: From December 2006 to November 2007, 52 children were evaluated after primary or secondary cheiloplasty. Digital photographs were taken both from the front and both three quarter views in repose and at maximal pucker. Video clips were also taken in repose and at maximal pucker. A panel of four, scored the philtral ridge and dimple seen on these photographs and videos by using two visual analog scales. Eminence of the philtral ridge was scored by a 5 point grading scale, from "conspicuous groove" to "normal philtral ridge" and the philtral dimple was scored by 3 point grading scale, from "no dimple" to "prominent dimple". Ultrasound images of the upper lip were made using a linear array transducer at the resting position of the lip and evaluated by a single radiologist. Results: The philtral ridge eminence scored $2.79{\pm}0.54$ and $1.40{\pm}0.53$ at resting and maximal pucker, correlating with "flat" and "conspicous groove". The philtral dimpling scored $1.44{\pm}0.53$ and $2.27{\pm}0.66$ at resting and maximal pucker, correlating with "no dimple" and "slight dimple". Ultrasound imaging showed the average muscle dehiscence to be $3.78{\pm}2.14$ mm at resting position. Correlation between the muscle defect in ultrasound imaging and philtral ridge eminence at rest was statistically significant (p<0.050), but was not significant (p=0.756) at maximal pucker using Spearman's rank correlation. Correlation between the muscle defect in ultrasound imaging and philtral dimpling was not statistically significant both at rest (p=0.920) and at maximal pucker (p=0.815) using Spearman's rank correlation. Conclusion: Quantitative assessment of the muscle defect using ultrasonography correlates with the static philtral appearance, but does not correlate with the dynamic appearance. Also, the size of the muscle defect does not show any correlation with the philtral dimpling. Our findings reveal that ultrasound imaging partially reflect static appearance of philtrum but cannot reflect dynamic appearance and suggest the need for further research to evaluate dynamic appearance.

• 한국결정성장학회지
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• 제1권1호
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• pp.26-38
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• 1991

광기능소자로 응용성이 넓은 전기광학결정 $r－6Bi_2O_3{\cdot}SiO_2$(이하 BSO로 약칭)을 EFG(Edge-defined Film-fed Growth)법에 의하여 판상단결정으로 육성하는 기초적 조건을 조사하고 육성된 판단결정의 characterization 및 평가와 물성측정을 하였다. 본 연구에서 얻어진 최적성장조건은 온도구배가 $24^{\circ}C/cm$, 인상속도는 2.0mm/h이었다. 결정성장 최적조건에서 육성된 BSO결정은 제 2상의 석출이 없고 grain boundary가 존재하지 않으며 X선 분석으로도 단결정임이 확인되었다. 육성된 판상단결정의 판면은 (100)면이었고 결정성장 방위는 <100>이었다. 육성된 판상단결정은 편광현미경하에서는 pore, void, inclusion, striation 등의 성장결함이 없는 양질의 단결정이었으나 미세결함인 전위(dislocation)의 존재가 확인되었고 전위밀도는 $5.1{\times}10^5/\textrm{cm}^2$이었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권6호
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• pp.586-589
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• 2006

Deep circumflex iliac artery (DCIA) flap can be harvested as a composite free flap and is often used to adequately reconstruct wide mandibular defects. However, the harvesting of this DCIA flap can result in severe osseous defect of the donor site causing a morphologic defect in the iliac crest. To reconstruct this defect of the iliac donor site, several innovative techniques using bioactive ceramic spacers, autogenous rib bone, polylactic acid mesh, or titanium plates have been introduced. Nonetheless, these methods have not been widely used due to high cost, secondary donor site morbidity, difficulty of use, and postoperative dissatisfaction. We used two titanium plates to reconstruct the donor iliac site defect at the harvesting time of primary DCIA flap surgery in the 30-year old female with an ameloblastoma in the left mandible. Postoperatively, both iliac sites were relatively balanced and there were few complications. At the 2 years follow-up, there were no specific abnormal radiographic findings and the patient was very satisfied with her esthetic iliac contouring. In our report, we evaluate the effect of two titanium plates on the reconstruction of the iliac donor site in the aspects of esthetics and usefulness. This technique has many advantages, such as reduced cost, simplicity, decreased postoperative pain or discomfort, and improved bilateral balance of both anterior iliac crest contours, especially in young female patients.

• Archives of Plastic Surgery
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• 제33권5호
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• pp.531-535
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• 2006

Purpose: To report our experience of retro-angular flap for reconstruction of the midface defect. The midface, including nose, lower eyelid, and intercanthal area, is the very prominent area of face. Also midface is more vulnerable to trauma and skin cancer and defect of mid face of highly perceptible. Reconstruction of mid face is difficult because of complexity of anatomy and functions. Following factors should be considered in reconstructive prcedure of midface. First, multiple procedure may need for complete the reconstruction of mid face defect. Second, secondary reconstructive surgeries such as flap rotation or skin graft may need for donor site morbidity. Third, the color, texture and thickness of the skin used are not always complacency. Methods: 8 cases of the midface defects (3 cases of lower eyelid, 1 case of intercanthal area, and 4 cases of nose) from skin cancer were reconstructed with retroangular flap from March 2004 to August 2005. Results: Satisfactory result were obtained in color, texture and donor site scar. There was no major complication such as wound disruption, hematoma, and atrophy of flap. But partial necrosis of flap and bulkiness were observed one case in each. Retroangular flap is simple procedure that can be preceded in one stage under local anesthesia closing primary wound closure. It will leave less visible donor scar, acceptable color, texture and thickness of the skin. Conclusions: The retro-angular flap could be suggested as a safe and effective method for midface reconstruction.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.118-119
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• 2013

High power, short wavelength red laser diodes (LDs) have attracted significant interests in a variety of fields due to their advantages in terms of reliability, compactness and cost. The higher brightness for human eyes is required, the shorter wavelength like 630 nm is necessary with higher output power. In this respect, LDs are promising as alternative candidates of gas or dye lasers for such applications due to their small size, high optical/electrical power conversion efficiency, robustness and so on. The crystalline quality of GaInP-AlGaInP multiple quantum wells (MQWs) and AlInP cladding layers is a crucial part in the device performance of GaInP red LDs. Here, we first investigated the effect of Si diffusion on the optical properties of GaInP-AlGaInP MQWs grown with different growth temperatures. Secondary ion mass spectroscopy (SIMS) measurements revealed that both the Mg and Si diffusion into MQW active region was significant. To reduce such diffusion, we employed undoped Mg and Si diffusion barrier and could improve the properties.Without both Mg and Si diffusion barriers, no lasing emission was observed. However, lasing emission was observed clearly for the red LDs with both Mg and Si diffusion barriers. We then investigated the temperature dependent optical properties of MQW layers grown with different well thicknesses (6, 8 and 10 nm). When the well thickness was 10 nm, the better crystalline quality was obtained. However, the observed LD performances were similar, probably due to the defects and impurities in the AlGaInP layer. Further investigation with the detailed analyses will be presented later.

• 대한의용생체공학회:의공학회지
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• 제31권5호
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• pp.401-406
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• 2010

Recently, many implantable medical devices have been developed and manufactured in many countries. In these devices, generally, energy is supplied by a transcutaneous method to avoid the skin penetration due to the power wires. As the most transcutaneous power transmission methods, the electromagnetic coupling between two coils and resonance at a specific frequency has been used widely. However, in case of a transcutaneous power transmitter with a fixed switching frequency to drive an electromagnetic coil, inefficient power transmission and thermal damage by the undesirable current variation may occur, because the electromagnetic coupling state between a primary coil and a secondary coil is very sensitive to skin thickness of each applied position and by person. In order to overcome these defects, a transcutaneous power transmitter of which operating frequency can be automatically tracked into the resonance frequency at each environment has been designed and implemented. Through the results of experiments for different coil surroundings, we have been demonstrated that the implemented transcutaneous power transmitter can track automatically into a varied resonance frequency according to arbitrary skin thickness change.

• Clinical and Experimental Pediatrics
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• 제53권8호
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• pp.809-813
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• 2010

Bartter syndrome (BS) is an autosomal recessively inherited rare renal tubular disorder characterized by hypokalemic metabolic alkalosis and hyperreninemic hyperaldosteronism with normal to low blood pressure due to a renal loss of sodium. Genetically, BS is classified into 5 subtypes according to the underlying genetic defects, and BS is clinically categorized into antenatal BS and classical BS according to onset age. BS type I is caused by loss-of-function mutations in the $SLC12A1$ gene and usually manifests as antenatal BS. This report concerns a male patient with compound heterozygous missense mutations on $SLC12A1$ (p.C436Y and p.L560P) and atypical clinical and laboratory features. The patient had low urinary sodium and chloride levels without definite metabolic alkalosis until the age of 32 months, which led to confusion between BS and nephrogenic diabetes insipidus (NDI). In addition, the clinical onset of the patient was far beyond the neonatal period. Genetic study eventually led to the diagnosis of BS type I. The low urinary sodium and chloride concentrations may be caused by secondary NDI, and the later onset may suggest the existence of a genotype-phenotype correlation. In summary, BS type I may have phenotype variability including low urine sodium and chloride levels and later onset. A definitive diagnosis can be confirmed by genetic testing.

• 소성∙가공
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• 제29권3호
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• pp.135-143
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• 2020

Low-cost alloying elements were added to a modified Al-6.5Si alloy and its microstructure, tensile and impact toughness properties were investigated. The alloying elements added were Mg, Zn, and Cu, and two kinds of alloy A (Mg:0.5, Zn:1, Cu:1.5 wt.%) and alloy B (Mg:2, Zn:1.5, Cu:2 wt.%) were prepared. In the as-cast Al-6.5Si alloys, Si phases were distributed at the dendrite interfaces, and Al₂Cu, Mg₂Si, Al₆ (Fe,Mn) and Al₅ (Fe,Mn)Si precipitates were also observed. The size and fraction of casting defects were measured to be higher for alloy A than for alloy B. The secondary dendrite arm spacing of alloy B was finer than that of alloy A. It was confirmed by the JMatPro S/W that the cooling rate of alloy B could be more rapid than alloy A. The alloy B had higher hardness and strength compared to the values of alloy A. However, the alloy A showed better impact toughness than alloy B. Based on the above results, the deformation mechanism of Al-6.5Si alloy and the improving method for mechanical properties were also discussed.

• Archives of Plastic Surgery
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• 제40권2호
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• pp.91-96
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• 2013

Background A thinned anterolateral thigh (ALT) flap is often harvested to achieve optimal skin resurfacing. Several techniques have been described to thin an ALT flap including an adipocutaneous flap, an adipofascial flap and delayed debulking. Methods By systematically reviewing all of the available literature in English and French, the present manuscript attempts to identify the common surgical indications, complications and donor site morbidity of the adipofascial variant of the ALT flap. The studies were identified by performing a systematic search on Medline, Ovid, EMBASE, the Cochrane Database of Systematic Reviews, Current Contents, PubMed, Google, and Google Scholar. Results The study selection process was adapted from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, and 15 articles were identified using the study inclusion criteria. These articles were then reviewed for author name(s), year of publication, flap dimensions and thickness following defatting, perforator type, type of transfer, complications, thinning technique, number of cases with a particular area of application and donor site morbidity. Conclusions The adipofascial variant of the ALT flap provides tissue to fill large defects and improve pliability. Its strong and safe blood supply permits adequate immediate or delayed debulking without vascular complications. The presence of the deep fascia makes it possible to prevent sagging by suspending and fixing the flap for functional reconstructive purposes (e.g., the intraoral cavity). Donor site morbidity is minimal, and thigh deformities can be reduced through immediate direct closure or liposuction and direct closure. A safe blood supply was confirmed by the rate of secondary flap debulking.