• 한국레이저가공학회지
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• 제3권3호
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• pp.31-37
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• 2000

In this paper, the possibilities of the laser overlap spot welding were studied to utilize the advantageous properties of amorphous metal foils. In order to estimate the usage of amorphous metals foils as structural members, the tensile shear strength and the fracture features were investigated. Although the crystalline zone on the surface was formed, it was not the direct cause of the fracture of the weld. The fracture of the weld resulted from the geometry discontinuity between the workpiece and the protrusion zone, which was formed during the weld process. The vein pattern - the typical feature of the fracture of the amorphous metal - was formed on the fracture surface. The tensile shear stress was reached to 1200 N/㎟ (2-foils overlap welding) and 900 N/㎟ (10-foils overlap welding), whereas the tensile strength of the workpiece was 1500-2000 N/㎟.

• 한국정보통신학회논문지
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• 제17권2호
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• pp.423-430
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• 2013

최근 손등이나 손바닥, 손가락의 정맥 혈관 패턴정보를 이용하여 개인을 인증하는 기술은 훼손, 복제 및 위조가 불가능하다는 장점으로 인해 연구가 활발하게 진행 중이다. 정맥영상은 피부층과 내부 골격등에 의한 빛의 산란 및 불균일한 내부 조직 때문에 정맥 영역이 뚜렷하게 나타나지 않아, 영상처리 방법을 통해 정맥 영역을 정확하게 분리하는 것이 어렵다. 특히 한 장의 영상에서도 밝기가 균일하지 않아서 지역 영역 단위로 다른 이진 임계치를 사용함으로 인해 처리시간이 오래 걸리고 혈관의 불연속면이 발생한다는 문제가 있다. 이를 해결하기 위해 본 논문에서는 조명 정규화 기반의 고속 정맥 영역 추출 방법을 제안한다. 본 연구는 기존의 방법에 비해 다음과 같은 장점을 가지고 있다. 첫째, 정맥영상의 불균일한 조명을 제거하기 위해 저역통과필터를 통해 조명 성분을 취득하고 이를 통해 조명성분이 균일한 영상을 얻었다. 둘째, 조명 정규화 영상으로부터 단일 임계치를 통해 얻어진 이진 영상의 처리를 통해 혈관 경로를 추출함으로써, 처리시간을 단축하였다. 실험을 통해 기존 방법들에 비해 혈관 영역 추출 정확도가 상승하고, 처리속도가 단축된 결과를 얻을 수 있었다.

• Archives of Reconstructive Microsurgery
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• 제6권1호
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• pp.29-38
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• 1997

A peripheral nerve when approximation of the ends imparts tension at the anastomosis and with a relatively long segment defect after excision of neuroma and neurofibroma cannnot be repaired by early primary suture. The one of the optimistic reconstruction method of severed peripheral nerves is to restore tension-free continuity at the repair site putting an autogenous nerve graft into the neural gap despite of ancipating motor or sensory deficit of the donor nerve area. To overcome the deficit of the autogenous nerve graft, several other conduits supplying a metabolically active environment which is able to support axon regeneration and progression, providing protection against scar invasion, and guiding the regrowing axons to the distal stump of the nerve have been studied. An author have used ipsilateral femoral vein, ipsilateral femoral vein filled with fresh thigh muscle, and autogenous sciatic nerve for the sciatic nerve defect of around 10 mm in length to observe the regeneration pattern in rat by light and electron microscopy. The results were as follows. 1. Light microscopically regeneration pattern of nerve fibers in the autogenous graft group was more abundant than vein graft and vein filled with muscle group. 2. On ultrastructural findings, the proxial end of the graft in various groups showed similar regenerating features of the axons, myelin sheaths, and Schwann cells. The fascicular arrangement of the myelinated and unmyelinated fibers was same regardless of the type of conduits. There were more or less increasing tendency in the number and the diameter of myelinated fibers correlated with the regeneration time. 3. In the middle of the graft, myelinated nerve fibers of vein filled with muscle group were more in number and myelin sheath was thinner than in the venous graft, but the number of regenerating axons in autogenous nerve graft was superior to that in both groups of the graft. The amount of collagen fibrils and amorphous materials in the endoneurial space was increased to elapsed time. 4. There was no difference in regenerating patterns of the nerve fibers of distal end of the graft. The size and shape of the myelinated nerve fbers were more different than that of proximal and middle portion of the graft. From the above results, the degree of myelination and regenerating activity in autogenous nerve is more effective and active in other types of the graft and there were no morphological differences in either ends of the graft regardless of regeneration time.

• 대한전자공학회논문지SP
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• 제46권1호
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• pp.23-31
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• 2009

최근 출입통제, 금융보안 및 전자여권 등 다양한 분야에서 얼굴인식, 지문인식, 홍채인식 등과 같은 생체인식기술의 적용이 활발히 이루어지고 있다. 또한 최근에는 손가락의 지정맥 패턴정보를 이용하여 개인을 인증하는 연구 역시 활발히 진행 중이다. 일반적으로 획득된 지정맥 영상은 손가락의 두께에 따른 적외선 빛의 투과도 및 카메라의 센서 잡음으로 인하여 정맥과 배경 분리에 많은 어려움이 있다. 이를 해결하기 위하여 본 논문에서는 고속으로 지정맥 영역을 추출하기 위한 새로운 방법을 제안한다. 본 연구는 기존의 방법에 비해 다음과 같은 2가지 장점을 가지고 있다. 첫째, 획득된 지정맥 영상에 적응적 지역 이진화 방법을 적용하여 지정맥 영역을 분리하였다. 둘째, 분리된 영상의 잡음을 열림 및 닫힘 연산을 이용하여 제거하고 최종적으로 골격화하여 지정맥 영역을 추출하였다. 실험결과, 기존의 방법들에서는 영상 잡음을 제거하기 위해 많은 필터를 사용하였으나 제안한 방법에서는 필터를 많이 사용하지 않으면서도 고속으로 정확하게 지정맥 영역을 추출할 수 있음을 보였다.

• 대한한의학원전학회지
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• 제34권2호
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• pp.85-94
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• 2021

Objectives : Pulse diagnosis is one of the main diagnostic methods of Korean Medicine that understands the patient's condition and illness by reading changes in the patient's pulse, which is described in terms of pulse condition While they are described in detail in medical texts, it is difficult to grasp their true nature, as the written descriptions fail to do justice to the experience of pulse taking it tries to convey. As a way to approach pulse condition the effect of the body's tension on the radial vein was measured using an ultrasonic device, after which the measured changes and how they could be reflected in pulse condition were studied. In other words, changes in the radial vein following induced tension were analyzed. Methods : 1) The thickness of the subject's radial vein was measured using a linear probe of an ultrasonic device[LOGIQ 5 Basic, GE, USA]. 2) Fatigue level was increased through artificial stimulation using the Gripmeter[ks-301, Lavisen, Korea]. 3) Thickness of the radial vein post tension induction was measured. 4) The results were analyzed with the Tukey test or paired t-test as post hoc tests. Results : Thickness of the radial vein of the subject pre- and post- Gripmeter stimulation decreased with significance. Conclusions : Constriction of the radial vein that happened after tension induction could be linked to the Tight Pulse[緊脈] that is related to patterns of contraction and pulling.

• Journal of Plant Biology
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• 제28권1호
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• pp.57-67
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• 1985

Leaf architectural studies have been made in 15 genera and 25 species belonging to 6 tribes of the Asteraceae. Major venation pattern conforms to pinnate craspedodromous (simple and semi), pinnate camptodromous with festooned brochidodromous secondaries, acrodromous and actinodromous. Qualitative leaf features and numerical data regarding the venation pattern are charted. Areoles of different sizes and shapes are observed. Tracheids occur either solitary or in groups. Grouped tracheids are either uniseriate, biseriate or multiseriate. Isolated free vein endings are observed in Centratherum phyllolaenum. Bundle sheath is prominent in Xanthium strumarium. Secretory cavities are observed in the lamina of Tricholepis amplexicaulis.

• 대한후두음성언어의학회지
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• 제10권1호
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• pp.12-16
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• 1999

Background and Objectives : The common cause of voice disorders may be bad habits of phonation. faulty vocal habits might aggravate the voice disorder or make the dysphonia. Authors thought the analysis of faulty vocal habits might help to evaluate the causes and to choose the treatment methods in patients with dysphonia. Authors studied to evaluate which vocal habits were used in patients with dysphonia. Materials and Methods : Patients with dysphonia(N= 32) and person without dysphonia(N=20) were evaluated through pre-evaluation test by otolaryngologist and SLP. All subjects were evaluated accordingly Posture of body, expansion of cervical vein, excessive movements of thyroide prominence, position of tongue, tension of lower lip, tension of jaw, breathing pattern related with phonation. Results : In dysphonia group, we found 23 cases with tension of jaw, 15 cases with expansion of cervical vein, 7 cases with bad position of tongue, 3 cases with excessive movement of thyroid prominence and a lot of cases with bad breathing Pattern on Phonation. In control group, only 3 cases with bad position of tongue, 2 cases with tension of lower lip, 1 case with tension of jaw were found. Conclusions : More faulty vocal habits were found in dysphonia group. Authors thought faulty vocal habits could be the cause of dysphonia and aggravate the dysphonia and the control of vocal habits would be very important in patients with dysphonia.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1246-1251
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• 2003

The fracture behaviors of Zr-based bulk amorphous metals(BAMs) having compositions of $Zr_{55}Al_{10}Ni_{5}Cu_{30}$, were investigated under impact loading and quasi-static conditions. For experiments, a newly devised instrumented impact testing apparatus and the subsize Charpy specimens were used. The influences of loading rate and the notch shape on the fracture behavior of the Zr-based BAM were examined. The Zr-based BAMs showed an elastic deformation behavior without any plastic deformation on it before fracture. Most fracture energies were absorbed in the process of the crack initiation. The maximum load and fracture absorbed energy under quasi-static condition were larger than those under impact condition. However, there existed relatively insignificant notch shape effect. Fracture surfaces under impact loading were smoother than those under quasi-static loading. The absorbed fracture energy appeared differently depending on the extent of the vein-like pattern region due to the shear bands developed at the notch tip. It can be found that the fracture energy of the Zr-Al-Ni-Cu alloy is closely related with the development of shear bands during fracture.

• 자원환경지질
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• 제37권4호
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• pp.383-389
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• 2004

지표 및 심토환경에서 물과 용액의 유동특성을 파악하는 것은 토양 및 지하수의 오염을 저감하고 방지하거나 기 오염 지역을 조사하고 정화하는데 있어서 필수적인 요소이다. 본 연구에서는 이 비형광, 비독성의 식용색소인 청색1호(Brilliant Blue FCF, $C_{37}H_{34}N_{2}Na_{2}O_{9}S_{3}$)를 염료 추적자로 이용하여 화강암에서 발달된 잔적토양에서의 침투 유형 및 그 특성을 조사하였다. 디지털 촬영된 수직 및 수평 착색영상은 지형정보 영상처리 프로그램인 ER Mapper, Version6.2를 이용하여 염료착색범위(dye coverage)로 전환되었다. 균질기반유동(homogeneous matrix flow)은 미약 입상 구조를 보이는 A 층위에서 발생하였으며, 상대적으로 세립조직인 A층위와 조립조직인 C층위의 경계에서는 선침투류(先浸透流, fingering)의 특징을 보여주었다. 모암인 화강암 조직의 기원인 거정질 광맥(pegmatitic vein)과 식물 뿌리는 C 층위에서 선택적 유동(preferential flow)을 유도하였음을 확인하였다.

• Anatomy and Cell Biology
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• 제56권4호
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• pp.428-434
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• 2023

Pulmonary veins (PVs) and their myocardial sleeves play an important role in the development of atrial fibrillation. Hence, detailed knowledge of PV anatomy is required to improve the procedural success rate and prevent complications during cardiac procedures. The aim of this study was to evaluate the PV anatomy along with anatomical variations in the Indian population. Total 100 formalin fixed cadaveric hearts were examined. The number and pattern of the PVs were observed along with the measurement of their horizontal and vertical diameters. The ovality index for each PV was calculated. Classical PV pattern was observed in 62% cases. Variant pattern like additional right middle PV pattern and left common PV pattern were found in 20% and 10% cases respectively. A separate pattern with presence of both right middle PV and left common PV was observed in 6% cases. In the classical pattern right superior PV was the largest followed by right inferior, left superior and left inferior PV. The additional right middle PV had the smallest diameter whereas the left common PV had the largest diameter. Almost all the veins had greater vertical diameters in comparison to horizontal diameters. The variant PVs were oval and had greater ovality index compared to the normal PVs. In classical pattern 54.8% hearts whereas in variant pattern 79% hearts had one or more oval PV. The given data can help clinicians for planning and execution of various interventional and electrophysiological procedures involving PVs.