• Archives of Plastic Surgery
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• 제47권6호
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• pp.590-596
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• 2020

Background The introduction of the partial second toe pulp free flap has enabled superior aesthetic and functional results for fingertip reconstruction in adults. Children undergoing fingertip amputation for various reasons have limited options for reconstruction. Conventional treatment could shorten the finger, leading to poor cosmesis and function. We report 18 years of our experiences with fingertip reconstruction using partial second toe pulp free flaps in patients in early childhood. Methods Medical charts of children who had undergone fingertip reconstruction using partial second toe pulp free flaps from 2001 to 2018 were retrospectively reviewed. The surgical procedures were identical to those for adults, except for the usage of 11-0 nylon sutures. Patients' demographic data, vessel size, flap dimensions, length of the distal phalanx, and functional outcomes over the course of long-term follow-up were documented. The statistical analysis was performed with the Student t-test, the Mann-Whitney U test, and Pearson correlation analysis. Results Eighteen toe pulp flaps in 17 patients (mean age, 3.0 years) were identified. All the flaps survived without any major complications. In long-term follow-up, the flap-covered distal phalanges showed growth in line with regular development. There was no donor-site morbidity, and all children adapted to daily life without any problems. In two-point discrimination tests, the fingertip sensation recovered to almost the same level as that in the contralateral finger. Conclusions Partial second toe pulp free flaps are an excellent option for fingertip reconstruction in young children, as well as in adults.

• Archives of Reconstructive Microsurgery
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• 제23권1호
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• pp.29-32
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• 2014

Few articles have been written about the flexor tendon sheath ganglion in the finger, especially, between A1 pulley and A2 pulley. We report on rare cases of flexor tendon sheath ganglion with one symptomatic and two asymptomatic. All masses were evaluated using real-time ultrasonography and well-defined anechoic cystic lesions with posterior enhancement were observed. A 17-year-old female had a small mass at the 4th metacarpophalageal joint of her right hand, with pain and triggering. The patient underwent simple excision and a ganglion measuring $1.0{\times}0.8$ cm in size was derived from Camper's chiasm, between A1 pulley and A2 pulley. In two asymptomatic cases, ganglia measuring less than 0.5 cm in size observed. Based on our experience, real-time ultrasonography would be an excellent diagnostic modality in determining the treatment method in flexor tendon sheath ganglia, and surgical excision is recommended in symptomatic, especially triggering patients.

• Archives of Reconstructive Microsurgery
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• 제21권2호
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• pp.131-136
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• 2012

Purpose: Arterialized venous flap is useful for reconstruction of the traumatic soft tissue defect in fingers, but insufficient circulation of the traumatic fingers makes surgeons annoying to use the flap. We have grafted flaps in 7 fingers with insufficient vascular bed hoping to expanded the category of the flap. Materials and Methods: Arterialized venous flap have transplanted in 7 fingers from March 2008 through February 2010 and followed up for 4 to 16 months(average 7.2 months). They were all male with a mean age at the time of surgery was 33. The main injury was crushing in 4 degloving, contact burn and saw injury was I respectively. Time interval from injury to flap transplantation was average 3.1. weeks(3 days to 6 weeks). Designed flap size ranges from $8cm{\times}3.5cm$to $4cm{\times}3cm$. Vessel type of flap was one artery with two veins were 5 cases and one artey with one vein 2. Flap type was cutaneous in 3, tendocutaneous 2, neurotendocutaneous 1 and neurocutaneous 1. The circulation state of recipient site was avascular in 2 cases, insufficiency 3 and tip avascular 2. Results: Arterialized venous flap was complete survived in 2 cases, partial necrosis(less than 10%) 3 and failed in 2. Conclusion: An arterialized venous free flap could be a useful procedure for reconstruction in soft tissue or combined defect of the finger despite an avascular or insufficient vascular beds if the recipient beds were free from infection.

• 한국물환경학회지
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• 제24권6호
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• pp.793-800
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• 2008

Recently domestic drinking water industry has recognized membrane-based technology as a promising alternative for water treatment. To ensure successful application of membrane processes, the integrity of membrane systems should be maintained. According to US EPA guidance, the pressure decay test based on the bubble point theory is recommended to detect any membrane defection of which size is close to the smallest diameter of Cryptosporidium oocysts, $3{\mu}m$. Proper implementation of the pressure decay test is greatly affected by initial test pressure, and the interpretation of the test results is associated with upper control limit. This study is conducted to investigate various factors affecting determination of initial test prtessure and upper control limit, including membrane-based parameters such as pore shape correction factor, surface tension and contact angle, and system-based parameters, such as volumetric concentration factor and total volume of system. In this paper, three different hollow fibers were used to perform the pressure decay test. With identical initial test pressure applied, their pressure decay tendency were different from each other. This finding can be explained by the micro-structure disparity of those membranes which is verified by FESEM images of those membranes. More specifically, FESEM images revealed that three hollow fibers have asymmetry, deep finger, shallow finger pore shape, respectively. In addition, sensitivity analysis was conducted on five parameters mentioned above to elucidate their relation to determination of initial test pressure and upper control limit. In case of initial pressure calculation, the pore shape correction factor has the highest value of sensitivity. For upper control limit determination, system factors have greater impact compared to membrane-based parameters.

• 정보보호학회논문지
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• 제26권5호
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• pp.1161-1170
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• 2016

본 논문에서는 스마트폰에서 손가락으로 서명하는 동적서명에서 위조서명에 강건한 검증 방법을 제안한다. 본 논문에서는 위조서명을 효과적으로 구분할 수 있도록 재생산 신경망의 일종인 1 class Auto-Encoder 모델을 사용한다. 핑거서명에서는 지원되지 않는 펜 압력 등 기존의 특징 정보 대신 대부분의 스마트폰에서 지원하는 가속도센서를 추가로 활용하여 서명이 이루어지고 있는 동안 스마트폰의 동적인 움직임의 특징정보를 추출한다. 서명 데이터는 리샘플링을 통해 길이를 맞추고, 일정한 크기로 정규화하여 사용한다. 제안 방법의 성능을 평가하기 위해 테스트셋을 구축하여 단일세션검증, 시간차 검증, 위조서명 검증의 3가지 실험을 실시하였다. 실험결과 위조서명 구분에 있어서 제안방법은 기존 방법보다 EER이 최대 6.9% 더 낮았다. 또한, 서명의 모양과 속도만 사용한 기존의 방식보다 가속도센서를 추가한 방식이 1.5% 나은 성능을 보였고, 최고 3.5%의 에러율을 얻었다.

• 한국기계가공학회지
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• 제10권5호
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• pp.51-57
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• 2011

The lightweight and compact actuator with high power is required to perform motion with multiple degrees of freedom. To reduce the size and inertia of a robot manipulator, the mechanical transmission system is used. The shape memory alloy(SMA) is similar to the muscle-tendon-bone network of a human hand. However, there are some drawback and nonlinearity, such as the hysteresis and the stress dependence. In this paper, the design of the underactuated robot hand is studied. The 3-finger dexterous hand is driven by the SMA actuator using segmental mechanism. This digital approach enables to overcome the nonlinearity of SMA wire. The translational displacement of SMA actuator required to bend a phalanx of the underactuated robot hand is estimated and the bending angle of the underactuated robot hand according to input displacement of SMA actuator is predicted by the multi-body dynamic analysis.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.985-989
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• 1990

This paper presents a fundamental study of a millimeter-sized master-slave robot driven by conduit-guided wires, which is expected to be applied to the delicate surgical operations, the assembling precise and small parts and so on. This system consists of a millimeter-sized slave robot and a master manipulator of which the size is adapted to a human finger. Displacement and torque of the master side can be reduced and transferred to the slave robot by controlling the motor torque against the master torque by feeding back tension signals. The master can feel the tensions by the motor torque. In this paper, the design method and making process of the master-slave system and the dynamical characteristic of displacement and torque control are proposed.

• International journal of advanced smart convergence
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• 제6권2호
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• pp.16-23
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• 2017

In contemporary modern society, people are constantly exposed to many kinds of noise, such as that from machinery, aircraft, construction sites, or road traffic. Noise is considered one of the most indispensable and influential parts of human life. This study investigates the acoustic characteristics of noise transfer from external sources to the human ear. For this study, we measured and analyzed various types of noise environments, installed monitoring speakers in a semi-anechoic room, and conducted intentional noise-filled experiments. In this environment, the size of the sounds generated by use of a portable device was also measured and the SNR (signal to noise ratio) calculated to study the influence of the noise. As sound is transmitted to the ear and the human body, it affects not only auditory damage but also other parts of the body. In this paper, we propose a proper SNR for noise emitted by portable IT equipment to prevent hearing loss when IT equipment is used.

• 대한안전경영과학회지
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• 제14권1호
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• pp.75-85
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• 2012

In this study, the representative hand shapes for the adult Koreans were analyzed by factor analysis and cluster analyses. The analyses were conducted on the anthropometric data of 58 hand dimensions from 325 subjects having nonhomogeneous demographics. Maximum hand circumference, first phalanx length of index finger, and ratio between the two measures were the independent variables for the cluster analyses. The results of the study showed that Korean hand shapes can be divided into 2 clusters irrespective of their size for each of the male and female group. There were slight differences in component ratio of hand shapes with respect to the occupation and the age, but their differences were not statistically significant. The representative Korean hand shapes and their anthrpometric dimensions could be used to design and establish proper sizing system for various hand operating devices.

• 대한소아치과학회지
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• 제24권3호
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• pp.603-609
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• 1997

Sialolithiasis is the formation of calcific concretions within the ductal system of major or minor salivary glands. The exact nature of sialolith evolution is not known. It may occur at any age but, it is most common in middle-aged adult and rare in childhood. In this paper, a case of sialolithiasis just beneath the mucosa in the anterior portion of the Wharton's duct observed in a 5-year old boy. It was approximately $2.5{\times}5$ mm in size and has no clinical symptoms. Under local anesthesia, it was removed by dilatation of orifice of the duct and pressure on the floor of oral cavity by finger.