Double Fascicular Nerve Transfer to Restore Elbow Flexion Following Neuralgic Amyotrophy: A Case Report

Chung Kyungmin,양진서,Cho Yongjun,Kang Sukhyung,최혁재,전진수 대한말초신경학회 2022 The Nerve Vol.8 No.2

Double fascicular nerve transfer (DFNT) involves transferring fascicles from the median and ulnar nerves to the musculocutaneous nerve to restore elbow flexion. We performed this procedure on a patient who was diagnosed with neuralgic amyotrophy (NA) 2 years previously. We aimed to investigate the short-term outcomes and feasibility of DFNT applied to non-traumatic neuropathy. A 63-year-old, right-handed man presented to us with persistent right elbow flexion weakness 24 months after receiving the diagnosis of NA. On examination, biceps strength was 0/5, and shoulder abduction strength was 3/5. Magnetic resonance neurography demonstrated muscle atrophy in the upper trunk. DFNT was considered to restore elbow flexion. The donor and recipient fascicles were then coapted (flexor digitorum superficialis to biceps brachii, flexor carpi ulnaris to brachialis). Postoperatively, paresthesia was reported in the area of ulnar innervation, and the patient complained of hand clumsiness. From postoperative day 10 onward, biceps muscle contracture was identified and on the 14th day, grade 3 elbow flexion strength was observed. We suggest that DFNT may be a safe and effective method to restore elbow flexion in patients with NA.

황 이중라디칼이 Polycarbonate, Poly(styrene-co-acrylonitrile), Polystyrene의 유변물성에 미치는 영향

정경민(Kyungmin Chung),김형수(Hyungsu Kim) 한국고분자학회 2019 폴리머 Vol.43 No.1

Polycarbonate(PC), poly(styrene-co-acrylonitrile)(SAN), 그리고 polystyrene(PS) 용액을 고강도 초음파로 가진하는 과정에 황을 도입하여 각 고분자의 유변 물성 변화를 조사하였다. 고리구조를 가지는 황 분자들은 초음파의 동공현상으로 인하여 고리가 열려 이중 라디칼로 변환되었고, 고분자 라디칼들과의 결합 반응을 통하여 고분자의 유변물성을 변화시켰다. 가진 시간에 따른 PC, SAN, PS의 용융 점도는 순수한 상태에 비하여 증가되거나 감소되는 특징을 나타내었으나, 각 수지의 전단 담화 경향이 증가되었고 Cole-Cole plot에서는 순수한 고분자의 동일한 점성대비 높은 탄성을 나타내었다. 응력 완화의 거동에서도 개질된 고분자 완화 시간이 증가된 것으로 확인되었다. 황과 초음파에 의하여 나타난 유변 물성의 변화를 고분자의 사슬 구조 변환과 연관지어 해석하였고, FTIR 분석과 함께 달성 가능한 가지구조의 메커니즘을 제시하였다. The rheological properties of polycarbonate (PC), poly(styrene-co-acrylonitrile) (SAN), and polystyrene (PS) were investigated by introducing sulfur during the sonication of polymer solutions. It was found that the ring of sulfur was opened by the cavitation of ultrasound, producing the sulfur diradicals. These radicals were coupled with the macroradicals, which led to the remarkable changes in the rheological properties of the polymer. Although the melt viscosities of each polymer were increased or decreased depending on the sonication times, the shear sensitivities of PC, SAN, and PS were consistently increased and the Cole-Cole plot of the modified polymer showed higher elastic moduli at the same loss moduli of the pure resin. In the stress relaxation behavior, the relaxation time of each polymer was increased after the modification. The observed rheological properties were explained in relation to the structural variation of polymer chain and a plausible mechanism for the branched structure was proposed along with the FTIR analysis.

Novel pandemic influenza A (H1N1) and community-associated methicillin-resistant <i>Staphylococcus aureus</i> pneumonia

Chung, Doo Ryeon,Huh, Kyungmin Informa UK, Ltd 2015 Expert review of anti-infective therapy Vol.13 No.2

<P>Postinfluenza bacterial pneumonia is a leading cause of influenza-associated death, and <I>Staphylococcus aureus</I> and <I>Streptococcus pneumoniae</I> have been important pathogens that have caused pneumonia since the influenza pandemic in 1919. Emergence of novel influenza A (H1N1) pdm09 and the concomitant global spread of community-associated methicillin-resistant <I>S. aureus</I> (CA-MRSA) have led to increasing prevalence of CA-MRSA pneumonia following influenza infection. Such an epidemiologic change poses a therapeutic challenge due to a high risk of inappropriate empiric antimicrobial therapy and poor clinical outcomes. Early diagnosis and initiation of appropriate antimicrobial therapy for post-influenza bacterial pneumonia have become even more important in the era of CA-MRSA. Therefore, novel molecular diagnostic techniques should be applied to more readily diagnose MRSA pneumonia.</P>

Wet-AMD on a Chip: Modeling Outer Blood-Retinal Barrier In Vitro

Chung, Minhwan,Lee, Somin,Lee, Byung Joo,Son, Kyungmin,Jeon, Noo Li,Kim, Jeong Hun Wiley (John WileySons) 2018 Advanced Healthcare Materials Vol.7 No.2

Underwater 3-D Spatial Attenuation Characteristics of Electromagnetic Waves With Omnidirectional Antenna

Kyungmin Kwak,Daegil Park,Wan Kyun Chung,Jinhyun Kim IEEE 2016 IEEE/ASME transactions on mechatronics Vol.21 No.3

<P>In this paper, an underwater 3-D spatial attenuation model of electromagnetic waves is proposed to establish a position recognition system in underwater 3-D space using distance estimation. The distance estimation is based on signal attenuation characteristics of electromagnetic waves radiated through several omnidirectional antennas. Positions in underwater environments have been predominantly estimated by an ultrasonic position recognition system using travel time and phase difference. However, such a system provides inaccurate estimation on account of the multipath effect in a structured environment or complex environment with many obstacles. A position estimation method that uses signal attenuation of electromagnetic waves has been proposed to overcome this limitation. That method can precisely estimate position on a structured 2-D plane. In this paper, an existing underwater position estimation system based on electromagnetic waves is expanded into 3-D space using the Friis formula and plane wave equation, thereby classifying attenuation characteristics of electromagnetic waves into the effects of medium, radiation, and antenna. These effects are summarized to deduce the signal attenuation characteristics of electromagnetic waves in 3-D space. In addition, the relative position (R, Theta, Phi) and attitude (phi, theta, psi) of transceiver antennas are used to define a coordinate system for 3-D estimation; moreover, an attenuation model is defined for individual factors in the coordinate system. A generalized attenuation model of an omnidirectional antenna in 3-D space is presented, and the validity of the proposed model is demonstrated through experiments. Based on the results, the proposed model demonstrates the potential application to an omnidirectional antenna and expansion into an attenuation model based on the 3-D position between random antennas.</P>

Biomimetic Model of Tumor Microenvironment on Microfluidic Platform

Chung, Minhwan,Ahn, Jungho,Son, Kyungmin,Kim, Sudong,Jeon, Noo Li Wiley (John WileySons) 2017 Advanced healthcare materials Vol.6 No.15

Prediction of Nucleate Pool Boiling Heat Transfer Coefficients of Ternary Refrigerant R407C

Kyungmin Kwak,Cheolho Bai,Mo Chung 대한설비공학회 1998 International Journal of Air-Conditioning and Refr Vol.6 No.-

The nucleate boiling heat transfer experiments are performed using a ternary refrigerant R407C which is a candidate of alternatives of HCFC 22. The boiling phenomena of R-32, R-l25 and R-l34a which are the constituent refrigerants of R407C are also investigated. The nucleate boiling heat transfer coefficients of R407C are less than those of HCFC 22 which have the similar physical and transport properties. In our experimental pressure range, which is similar to the operational pressure of air conditioning system, the deterioration of boiling heat transfer coefficients of mixture refrigerant R407C does not appear for moderate wall superheat region. Since nucleate boiling heat transfer coefficients cannot be obtained from ideal mixing law of mixture, Thome's method was used to predict. To account for the heat flux effect and system pressure in Thome's method, the correcting factor, α(P, ΔT), was introduced and obtained from experiments for ternary refrigerant R407C.

가족 단위 철도 여행객의 추진(Push)동기 요인과 유인(Pull)동기 요인의 영향력 연구

이경민(Kyungmin Lee),구철모(Chulmo Koo),한희정(Heejeong Han),정남호(Namho Chung) 한국경영학회 2017 Korea Business Review Vol.21 No.2

철도를 단순한 교통 이동 수단으로 활용하는 것뿐만 아니라 관광 경험의 대상으로 하는 여러 가지 관광 상품과 서비스들의 등장과 함께 철도를 이용하는 여행객이 꾸준히 증가하고 있다. 이에 본 연구에서는 여행의 수단이자 경험의 대상이 되는 철도 여행과 개별 관광의 한 축을 담당하는 가족관광의 속성에 대해 동시에 검증하여, 철도라는 여행 경험의 대상과 가족이라는 관광의 유형에 따른 여행객의 동기를 세분화하여 연구하고자 한다. 즉, 철도여행과 가족관광의 독특한 속성에 대한 세분화된 관광동기들이 여행 만족도나 행동의도에 미치는 영향에 대한 실증 연구를 목적으로 하였다. 본 연구는 관광동기 관련 동기이론들 중 추진(Push)요인과 유인(Pull)요인으로 구분한 동기이론을 토대 이론으로 연구를 설계하였다. 또한, 기존의 철도여행 연구와 가족관광 연구들의 결과, 철도여행의 중요 속성인 철도 여행의 매력성과 가족 관광의 속성인 가족 관광의 친화성을 추진(Push)동기 요인으로, 철도 여행의 단점으로 인식되는 관광접근성을 유인(Pull)동기 요인으로 선정하여, 철도 여행과 가족 관광의 특징을 반영하는 각각의 동기들이 관광만족도와 행동의도에 미치는 영향력을 분석하였다. 연구 결과, 추진(Push)동기 요인인 철도여행 매력성과 가족관광 친화성, 유인(Push)동기 요인인 공간접근성이 만족도를 통해 행동의도에 영향을 미친다는 것을 확인하였다. 또한 만족도의 매개효과 검증에서 철도여행 매력성과 가족관광 친화성은 그 자체로써, 혹은 만족도를 통해서 행동 의도에 긍정적인 영향을 미쳤으며, 공간접근성은 만족을 할 경우에만 행동의도에 영향을 미친다는 결과를 도출하였다. Railway construction endeavors to develop several customized products and services for tourists, because railroad has both of roles as means to move and as a object to experience for travel. Additionally, family tour has been raised to make bonding between family members. To understand these phenomenon, this research focuses on motivations of railroad travelers and family tourists with push and pull factors. We attempt to combine attributes of railroad and family for elaborating travelers‘ motivations and for investigating the effect of these different motivations on satisfaction and behavioral intentions. The effort of this study contributes to the contemporary research theme by suggestion, such as how to array between which objects of travel experience and what kinds of tour, to examine the influences each constructs and to enhance comprehension about complicated tourism industry. Research findings from railroad travelers with their family indicate that attractiveness of train track, togetherness of family tour as Push motivation factors, and spatial accessibility as a pull motivation factor are significantly leads to satisfaction and behavioral intentions. Regarding to satisfaction as a mediating variable, we found partial mediating effect between push motivation factors on behavioral intentions. However, there is only full mediating effect of satisfaction with spatial accessibility.

전시회의 지능형 IT 현장사용과 통합성과가 참관객 만족에 미치는 영향에 대한 연구

이경민(Kyungmin Lee),이선영(SunYoung Hlee),정남호(Namho Chung),구철모(Chulmo Koo) 한국인터넷전자상거래학회 2016 인터넷전자상거래연구 Vol.16 No.6

As a result of the phenomenal growth of IT, several technologies have been used in trade show to provide a enhanced service. The goal of this study is to find out whether the IT onsite usage leads to attendee’s satisfaction of trade show with product intelligence theory. We investigate the applicability of attributes’ product intelligence to measure onsite usage in trade show, and manifest its effect though relative advantage to satisfaction of participation in exhibition. Besides onsite usage’s effect, the role of overall effectiveness about the exhibition has been investigated in this study. We try to find out the mechanism that influences on attendee’s satisfaction with overall effectiveness as well as IT usage of exhibition onsite.

UUV의 수중 도킹을 위한 전자기파 신호 기반의 위치인식 센서 개발

곽경민 ( Kyungmin Kwak ),박대길 ( Daegil Park ),정완균 ( Wan Kyun Chung ),김진현 ( Jinhyun Kim ) 한국센서학회 2017 센서학회지 Vol.26 No.3

In this paper, we developed an underwater localization system for underwater robot docking using the electromagnetic wave attenuation model. Electromagnetic waves are generally known to be impossible to use in water environment. However, according to the conclusions of the previous studies on the attenuation characteristics in underwater, the attenuation pattern is uniform and its model was accurately proposed and verified in 3-dimensional space via the omnidirectional antenna. In this paper, a docking structure and localization sensor system are developed for a widely used cone type docking mechanism. First, we fabricated electromagnetic wave range sensor transmit modules. And a mobile sensor node is equipped with unmanned underwater vehicle(UUV)s. The mobile node senses the four different signal strength (RSS: Received Signal Strength) from fixed nodes, and the obtained RSS data are transformed to each distance information using the 3-Dimensional EM wave attenuation model. Then, the relative localization between the docking area and underwater robot can be achieved according to optimization algorithm. Finally, experimental results show the feasibility of the proposed localization system for the docking induction by comparing the errors in the actual position of the mobile node and the theoretical position through the model.