• 전자공학회논문지
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• 제51권8호
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• pp.3-10
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• 2014

최근 폭증하는 모바일 데이터 트래픽을 수용하기 위하여 밀리미터파 (mmWave)가 큰 관심을 받고 있으며, 4 세대 LTE-A(Long Term Evolution-Advanced) 표준을 기반으로 MMB (Millimeter Mobile Broadband) 시스템의 필요성이 대두되고 있다. 현재 mmWave 통신 채널에 대한 많은 연구가 이루어지고 있으며, MMB 채널 환경에 대한 성능 분석 또한 관심의 대상이다. 본 논문에서는 5세대 이동통신을 위한 MMB 시스템을 설계하고 mmWave의 전파 특성 분석을 통한 채널 모델을 제안한다. 또한 MMB 시스템의 28 GHz 대역에서 MMB 채널 환경에 대한 성능을 비교 분석한다.

• 한국전자거래학회지
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• 제21권2호
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• pp.121-133
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• 2016

모든 산업은 ICT 기술의 적용 및 산업기술의 급속한 발전에 따라 신기술 개발 및 확보를 위한 연구 투자가 확대되고 있으며, 이러한 신기술을 보호하려는 노력도 동시에 강화되고 있다. 하지만 이러한 기술보호에 대한 노력은 단순히 기업에서 이루어져야 하는 것이 아니라 국가 경쟁력 차원에서 여러 정부기관이 관심을 가지고 다양한 산업보안 활동을 수행해야 한다. 본 논문에서는 산업자산 보호 및 기술유출 방지를 위해 산업보안 활동을 수행하고 있는 산업보안 유관기관에 대해 조사해보고 각 기관의 산업보안 업무에 대해서 알아보고자 한다. 또한 본 논문에서는 산업보안 유관기관 조사 및 비교를 통해 현재 정부기관의 산업보안 운영에 대한 문제점을 논의해보고 산업보안 발전 및 효율적 업무를 위한 정부 내 산업보안 담당부서의 필요성에 대해 제고해보려고 한다.

• BMB Reports
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• 제53권5호
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• pp.278-283
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• 2020

Muscle fibers are generally formed as multinucleated fibers that are differentiated from myoblasts. Several reports have identified transcription factors and proteins involved in the process of muscle differentiation, but the roles of microRNAs (miRNAs) in myogenesis remain unclear. Here, comparative analysis of the miRNA expression profiles in mouse myoblasts and gastrocnemius (GA) muscle uncovered miR-3074-3p as a novel miRNA showing markedly reduced expression in fully differentiated adult skeletal muscle. Interestingly, elevating miR-3074-3p promoted myogenesis in C2C12 cells, primary myoblasts, and HSMMs, resulting in increased mRNA expression of myogenic makers such as Myog and MyHC. Using a target prediction program, we identified Caveolin-1 (Cav1) as a target mRNA of miR-3074-3p and verified that miR-3074-3p directly interacts with the 3' untranslated region (UTR) of Cav1 mRNA. Consistent with the findings in miR-3074-3p-overexpressing myoblasts, knockdown of Cav1 promoted myogenesis in C2C12 cells and HSMMs. Taken together, our results suggest that miR-3074-3p acts a positive regulator of myogenic differentiation by targeting Cav1.

• Journal of Korean Neurosurgical Society
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• 제61권2호
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• pp.180-185
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• 2018

Objective : Many lumbosacral fixation techniques have been described to offer a more screw-bone purchase. The forward anatomical fixation parallel to the endplate is still the most preferred method. Literature revealed little knowledge regarding the mechanical stability of lumbosacral trans-endplate fixation compared to the traditional trans-pedicular screw fixation method. The aim of this study is to assess the pull-out strength of lumbosacral screws penetrating the end plate and comparing it to the conventional trans-pedicular screw insertion method. Methods : Eight lumbar and eight sacral vertebrae, with average age 69.4 years, Left pedicles of the 5th lumbar vertebrae were used for trans-endplate screw fixation, group 1A, right pedicles were used for anatomical trans-pedicular screw fixation, group 1B. In the sacral vertebrae, the right side S1 pedicles were used for trans-endplate fixation, group 2A, left side pedicles were used for anatomical trans-pedicular screw fixation, group 2B. The biomechanical tests were performed using the axial compression testing machine. All tests were applied using 2 mm/min traction speed. Results : The average pull-out strength values of groups 1A and 1B were $403.78{\pm}11.71N$ and $306.26{\pm}17.55N$, respectively. A statistical significance was detected with p=0.012. The average pull-out strength values of groups 2A and 2B were $388.73{\pm}17.03N$ and $299.84{\pm}17.52N$, respectively. A statistical significance was detected with p=0.012. Conclusion : The trans-endplate lumbosacral fixation method is a trustable fixation method with a stronger screw-bone purchase and offer a good alternative for surgeons specially in patients with osteoporosis.

• 수산해양교육연구
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• 제29권3호
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• pp.627-635
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• 2017

Sea level rise caused by climate change has become a global issue. Sea level rise seems to be an important factor of the research for coastal areas as it affects topography and vegetation of coasts and especially for the plan of coastal wetlands restoration which needs to be carried out for a long term, it has to be considered sufficiently. The coastal wetlands in Korea was damaged by the land reclamation project but recent concerns on the restoration have increased as its value is evaluated highly. Suncheon Bay had also reclaimed from wetlands to rice field once however this site is very active for restoration nowadays. This study estimated an effect according to sea level rise by 2100, reappearing the none dike condition of Suncheon Bay so that it can be taken account of a future plan of wetland restoration. The Sea Level Affecting Marshes Model(SLAMM) was selected as predicting model. The input data such as DEM(Digital Elevation Model), slope, wetlands category, sea level rise senario, tidal range and accretion rate was applied for the simulation. The results showed a decrease in tidal flat, an increase in sea area and a change of the rice field to transitional salt marsh consistently by 2100. These results of this study could be used as baseline data in the future plan of ecological restoration in Suncheon Bay.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.102-102
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• 2016

Water, which is most abundant in Earth surface and very closely related to all forms of living organisms, has a simple molecular structure but exhibits very unique physical and chemical properties. Even though tremendous effort has been paid to understand this nature's core substance, there amazingly still lefts much room for scientist to explore its novel behaviors. Especially, as the scale goes down to nano-regime, water shows extraordinary properties that are not observable in bulk state. One of such interesting features is the formation of nanoscale bubbles showing unusual long-term stability. Nanobubbles can be spontaneously formed in water on hydrophobic surface or by decompression of gas-saturated liquid. In addition, the nanobubbles can be generated during electrochemical reaction at normal hydrogen electrode (NHE), which possibly distorts the standard reduction potential at NHE as the surface nanobubble screens the reaction with electrolyte solution. However, the real-time evolution of these nanobubbles has been hardly studied owing to the lack of proper imaging tools in liquid phase at nanoscale. Here we demonstrate, for the first time, that the behaviors of nanobubbles can be visualized by in situ transmission electron microscope (TEM), utilizing graphene as liquid cell membrane. The results indicate that there is a critical radius that determines the long-term stability of nanobubbles. In addition, we find two different pathways of nanobubble growth: i) Ostwald ripening of large and small nanobubbles and ii) coalescence of similar-sized nanobubbles. We also observe that the nucleation and growth of nanoparticles and the self-assembly of biomolecules are catalyzed at the nanobubble interface. Our finding is expected to provide a deeper insight to understand unusual chemical, biological and environmental phenomena where nanoscale gas-state is involved.

• 한국의상디자인학회지
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• 제19권4호
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• pp.29-41
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• 2017

Because infants lack full communication skills and are not active main agents, nurturing and protection are essential. The value of smart devices that can help prevent potential threats and manage infant care is evaluated highly. This study offers basic research data that contributes to the development of devices for infant and parents as well as to future planning. This study compared and analyzed literature materials and visual materials based on news articles, advanced research, and official websites of brands. The research ranges and subjects are wearable devices for infants that were released or will be released between 2014 and 2017. Wearable devices that help protect and manage infant care are roughly separated into clothing, accessory, and the like. In this study, four kinds of clothing products, six kinds of accessories products, and fifteen kinds of other products were researched and a total of 25 kinds of products were analyzed. Categories was made in accordance with morphological characteristics, main features, materials and the design of wearable devices for infants depending on the device features. Wearable devices for infants that will be developed in the future must be based on a variety of suggestions in order to know best how to attach a sensor to an infant. From this study, the deduced trend analysis of wearable devices for infants can suggest new ways for follow-up studies as well as product development.

• Journal of Applied Biological Chemistry
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• 제57권4호
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• pp.337-340
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• 2014

본 연구에서는 지리산오가피와 흰털오가피의 항산화 및 항염증 활성의 차이를 알아보기 위해 총 폴리페놀 및 플라보노이드 함량, ABTS 및 DPPH 라디칼 소거능, FRAP assay를 이용한 환원력을 비교 조사하였고, mouse의 대식세포인 Raw 264.7 cell에 LPS를 이용하여 자극시킨 후 생성되는 NO의 함량을 비교하였다. 총 폴리페놀 및 플라보노이드 함량은 흰털오가피가 유의하게 높은 것으로 나타났으나 그 차이가 크지 않으며 ABTS 및 DPPH 라디칼 소거능과 FRAP 방법을 이용한 환원력에서는 두 오가피 종에서 차이가 없는 것으로 나타났다. 항염증 활성을 비교하기 위해 확인한 NO 생성양은 지리산오가피가 고농도 처리시 유의하게 항염증 활성이 높은 것으로 나타났다.

• 대한토목학회논문집
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• 제33권5호
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• pp.1989-1998
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• 2013

최근 '자전거이용 활성화'가 서서히 사회적으로 중요성이 부각되면서 자전거 중심의 교통체계로의 전환을 위한 다양한 노력이 있어 왔으나 그 효과는 부진한 면이 있다. 본 연구에서는 자전거 주차장 등의 시설을 구축하는 데 있어서 필요한 주차장입지선정을 공학적 분석을 통해서 구현하여 보자는데 있다. 즉, 자전거 주차장의 최적 개수 및 위치를 찾는 방법을 제안하는 것이 목적인 바, 구축 모형은 Heuristic P-Median 알고리즘을 이용하였으며, 예산제약의 유무에 따라 모형을 각각 제시하였다. 모형의 적용을 위하여 시험 네트워크를 구축하고 30개의 예비 주차장 (센트로이드-수요지)을 구성하였다. 분석 결과 자전거 주차장의 입지점은 예산제약이 있는 경우 9개, 예산제약이 없는 경우 20개로 선정되었으며, 선정된 입지점들은 실제 자전거 주차장의 이용률이 높은 곳과 일치하는 것으로 나타났다. 이러한 알고리즘은 실제 공용자전거 등의 대상지, 또는 신규 예상입지선정에 활용되어 질 수 있을 것으로 판단된다. 약간의 한계와 향후연구과제에 대해서도 논하였다.

• Annals of Clinical Neurophysiology
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• 제15권1호
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• pp.7-12
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• 2013

Background: Local steroid injection is used to treat carpal tunnel syndrome (CTS). The aim of this study was to evaluate the clinical and electrophysiological effects of local steroid injection in patients with CTS over a 3-months period. Methods: Twenty-one patients (35 hands) with clinical and electrophysiological evidence of CTS were treated by injection of triamcinolone 40 mg to the carpal tunnel. Visual analog scale (VAS), Boston Carpal Tunnel Questionnaire (BCTQ), rates of paresthesia, night awakening, and electrophysiological studies were used as outcomes. Clinical and electrophysiological assessments were performed before, 1 and 3 months after treatment. Results: Prior to treatment, 86% of patients complained of night awakening. At 1 and 3 months after injection, only 17% and 29% of the patients, respectively, had night awakening (p<0.001). All patients complained of paresthesia before the treatment. This symptom disappeared in 60% and 31% of the patients after 1 and 3 months, respectively (p<0.001). Compared to baseline, both BCTQ and VAS show significant improvement during the 3 months of the study (p<0.005). Although significant improvements in clinical parameters were shown, electrophysiological parameters were not significantly improved at 1 and 3 months. Conclusions: Local corticosteroid injection for the treatment of CTS provides significant improvement in symptoms for 3 months. On the other hand, no significant improvement was observed in electrophysiological parameters.