• 전기전자학회논문지
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• 제18권4호
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• pp.572-580
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• 2014

본 연구에서는 교육 및 놀이를 통해 창의력 증진이 가능한 재구성 모듈러 로봇에 대하여 다루고 있다. 보통 모듈러 로봇은 각각 셀들의 조합으로 변형 재구성하고 다양한 형태의 구조를 만드는데 적합한 로봇으로 설계되어 있지만 이를 이용하여 교육과 놀이를 주제로 한 연구는 국외에 소수 있으며 국내에는 전무하다. 제안하는 형태는 기존 모듈러 로봇과 같이 같은 동작만 반복하는 모듈이 아니라 소리를 내는 소리모듈, 바퀴가 달린 바퀴모듈, 시각적 표현을 위한 LED모듈, 전원공급을 위한 전원모듈, 통신을 위한 블루투스모듈, 움직이는 동작을 구현 가능하도록 하는 관절모듈이 있는 구조로 설계되어 있다. 이와 같은 다른 능력이 부여된 각 모듈의 다양한 결합을 이용하여 창의적 활동이 가능하도록 하고, 아이들이 쉽게 사용 할 수 있도록 한다. 본 연구에서는 모듈별 각기 다른 능력을 부여하여 교육과 놀이가 가능하도록 하는 방식의 모듈러 로봇의 설계 및 동작을 다루고 있다. 그리고 연구된 동작은 실제 제작 및 실험을 통해 동작의 유용성을 보였다.

• 대한관절경학회지
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• 제1권1호
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• pp.132-138
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• 1997

The purpose of this study is to compare the results between conventional and accelerated rehabilitation program following ACL reconstruction using bone-patellar tendon-bone. Conventional rehabilitation focused on protecting the new ligament by blocking terminal extension and avoiding active quadriceps function in the terminal degrees of extension. But there is current trend toward early postoperative mobilization and intensive. so called 'accelerated', rehabilitation stressing hyperextension of the knee. The results of intraarticular ACL reconstruction with conventional and accelerated rehabilitation were prospectively compared for one year postoperatively in a series of 27 patients. Range of motion and thigh circumference were checked preoperatively, and weekly up to 8 weeks, 3 months. 6 months, and 1 year postoperatively. Stress radiologic test, KT-1000 arthrometer. Cybex II dynamometer were checked in preoperatively, and 3 months, 6 months, and 1 year postoperatively. There were no differences of objective stability and restoration of muscle power. But the accelerated group had a low incidence of extension loss. excellent range of motion, and less difference of thigh circumference. We concluded that accelerated rehabilitation program is recommendable due to superiority in terms of range of motion, especially less extension loss without increasing laxity of knee joint.

• 한국산학기술학회논문지
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• 제15권3호
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• pp.1390-1395
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• 2014

본 연구는 대학에서 새로이 개발한 멀티크림의 속성별 가치를 추정하여 신제품의 가격을 책정하고 제품 개발 방향을 설정하는 등 마케팅 전략 수립을 위한 기초자료를 제공하는데 그 목적이 있다. 분석 방법으로는 선택형 실험을 이용하였으며, 조건부 로짓 모형을 추정하여 브랜드, 용기 형태, 기능성, 가격 등 각 속성별 한계지불의사금액을 도출하였다. 연구 결과 소비자의 한계지불의사금액은 브랜드에 있어서는 대기업이 개당 21,754원, 중소기업이 11,033원, 대학은 16,178원으로 나타났으며, 기능성에 있어서 보습효과 강화는 7,476원, 주름개선효과 강화는 12,107원으로 추정되었다. 대학 브랜드가 중소기업 브랜드보다 선호도가 더 높은 것으로 나타났으므로, 대학과 중소기업이 협력하여 공동으로 사업을 추진할 경우 저가 브랜드 시장에서 경쟁력을 높일 수 있을 것이다. 또한 보습효과나 주름개선효과 등 기능성을 강화한 제품을 개발할 필요도 있다.

• Journal of Communications and Networks
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• 제18권6호
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• pp.913-925
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• 2016

In-band wireless full-duplex is a promising technology that enables a wireless node to transmit and receive at the same time on the same frequency band. Due to the complexity of self-interference cancellation techniques, only base stations (BSs) are expected to be full-duplex capable while user terminals remain as legacy half-duplex nodes in the near future. In this case, two different nodes share a single subchannel, one for uplink and the other for downlink, which causes inter-node interference between them. In this paper, we investigate the joint problem of subchannel assignment and power allocation in a single-cell full-duplex orthogonal frequency division multiple access (OFDMA) network considering the inter-node interference. Specifically, we consider two different scenarios: i) The BS knows full channel state information (CSI), and ii) the BS obtains limited CSI through channel feedbacks from nodes. In the full CSI scenario, we design sequential resource allocation algorithms which assign subchannels first to uplink nodes and then to downlink nodes or vice versa. In the limited CSI scenario, we identify the overhead for channel measurement and feedback in full-duplex networks. Then we propose a novel resource allocation scheme where downlink nodes estimate inter-node interference with low complexity. Through simulation, we evaluate our approaches for full and limited CSIs under various scenarios and identify full-duplex gains in various practical scenarios.

• 대한물리치료과학회지
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• 제13권2호
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• pp.7-16
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• 2006

The purpose of this study was to investigerate the changes of isokinetic muscular function in elderly people who have been to take from osteoarthritis in both knee joints after 36 weeks' rehabilitative therapy programs. In this study the subjects were 20 women residing in S-Tower(n=10) and H-welfare Town(n=10) respectively. The rehabilitative group(equal to experimental group) had taken part in exercise program 5 days per week. And then was performed by warm up, workout(involving aerobic exercise and weight training), cool down, physical therapy(cryotherapy, TENS, ultrasound). Also its programs were classified in conditioning phase($0{\sim}12$ weeks), improvement phase($13{\sim}24$ weeks), and maintenance phase($25{\sim}36$ weeks) respectively. The results of inspections were as followed: In the isokinetic muscular function, there were significant differences in right leg's flexor and extensor in $60^{\circ}$/sec. And there were significant differences in right leg's flexor and left leg's extensor in $180^{\circ}$/sec. At last, there were significant differences in right leg's flexor and left leg's extensor in $240^{\circ}$/sec. In other words, the rehabilitative programs for 36 weeks could increase the muscular function in elderly with OA. In conclusion, the rehabilitative programs of this paper has shown the positive results, which involved in the muscular function variables in elderly people with OA in both knee.

• 한국운동역학회지
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• 제22권1호
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• pp.105-111
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• 2012

The purpose of this study was to investigate the effect that difference in forefoot of shoe flexibility during the quick lunge from a jump smashing on the lower limbs and the plantar pressure distribution. For this 10 elite badminton players with over 10 years experience and right handed participated. Two kinds of badminton shoes were selected and tested mechanical testing for the forefoot flexibility. Motion analysis, ground reaction forces and plantar pressure distribution were recorded. It was required to conduct lunge movement after jumping smashing as possible as high. Photo sensor was located in 3 meter away from standing position and its height was 40 cm. Subjects were conducted to return original position after touching the sensor as under clear movement as possible as fast. Forefoot stiffness had an effect on shoe peak bending degree and peak bending angular velocity in propulsion phase. Forefoot flexibility had an effect on ankle plantar flexion and knee flexion moment. It appears that joint power on lower limb and peak plantar pressure were not influenced by the flexibility of shoes.

• 한국운동역학회지
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• 제17권4호
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• pp.181-190
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• 2007

The purpose of this study was to analyze the muscle fatigue for lower limbs during the level and downhill running. The subjects were 6 males of twenties who have no experience to get the injury in the lower limbs and required to run on the level and downhill which was -7% grade treadmill at 8.3km/h. EMG signal was gained by ME3000P8 Measurement Unit and computed the Median Frequency(MF) with the power spectrum analysis in the Megawin software. Rectus femoris(RF), Vastus lateralis(VL), Gluteus medius(GLU), Biceps Femoris(BF), gastrocnemius medial head(GM), gastrocnemius lateral head(GL), Tibialis anterior(TA) were selected. The result of this study were as follows: The MF of RF decreased in the downhill running than level running in length of time but, the MF of VL was opposite. The MF of BF decreased in the level and downhill running, but, the MF of BF decreased much in the level than downhill running. The MF of GLU decreased much in the downhill running but, almost no change in the level running. The MF of TA decreased in the level running than downhill running. The MF of GL decreased in the level running but, the MF of GM decreased in the downhill running in length of time. This study analyzed the muscle fatigue of the lower limbs with the median frequency on the basis of an assumption that the impact force for the flexion and extension of the joint and the body mass may be much in the eccentric contraction such as the downhill running than level running. RF and GM showed the muscle fatigue in the downhill running than level running. BF and GL showed the muscle fatigue in the level running than downhill running.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권4호
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• pp.1481-1500
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• 2016

Device-to-Device (D2D) communication underlaying macro-small cell networks, as one of the promising technologies in the era of 5G, is able to improve spectral efficiency and increase system capacity. In this paper, we model the cross- and co-tier D2D communications in two-tier macro-small cell networks. To avoid the complicated interference for cross-tier D2D, we propose a mode selection scheme with a dedicated resource sharing strategy. For co-tier D2D, we formulate a joint optimization problem of power control and resource reuse with the aim of maximizing the overall outage capacity. To solve this non-convex optimization problem, we devise a heuristic algorithm to obtain a suboptimal solution and reduce the computational complexity. System-level simulations demonstrate the effectiveness of the proposed method, which can provide enhanced system performance and guarantee the quality-of-service (QoS) of all devices in two-tier macro-small cell networks. In addition, our study reveals the high potential of introducing cross- and co-tier D2D in small cell networks: i) cross-tier D2D obtains better performance at low and medium small cell densities than co-tier D2D, and ii) co-tier D2D achieves a steady performance improvement with the increase of small cell density.

• 디지털융복합연구
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• 제11권3호
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• pp.189-197
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• 2013

최근 경쟁력이 약한 중소기업들은 브랜드 파워와 마케팅 능력을 강화시킬 수 있는 공동브랜드에 대한 관심이 높아지고 있다. 이러한 상황에서 본 연구에서는 국내 공동브랜드의 운영현황을 고찰하고 활성화 전략을 제시하고자 하는 목적에서 이루어졌다. 먼저, 공동브랜드 개념을 다양한 측면에서 알아보고, 공동브랜드의 장, 단점을 살펴보았다. 둘째, 공동브랜드의 유형별을 협동조합형, 기업간 연합형, 선도기업 주도형 및 민 관 합작형 공동브랜드로 구분하여 각각의 장단점을 살펴보았다. 셋째, 국내 주요 공동브랜드의 현황을 제시하였다. 넷째, 중소기업청 지원 공동브랜드의 현황을 살펴보았다. 이를 위해 연도별 지원현황을 살펴보고, 공동상표 업종별 분포 현황 및 공동브랜드 중단유형에 대해 세부적으로 살펴보았다. 끝으로 이러한 자료를 근거로 국내 공동브랜드 활성화 전략을 단기적 측면과 중장기적 측면에서 제시하였다. 본 연구결과는 향후 국내 공동브랜드 사업의 개선방안을 모색하는데 토대가 될 것으로 정부의 지원제도를 마련하는데 도움이 될 것으로 기대한다.

• Nuclear Engineering and Technology
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• 제50권1호
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• pp.116-125
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• 2018

Modified 9Cr-1Mo ferritic steel is a preferred material for steam generators in nuclear power plants for their creep strength and good corrosion resistance. Austenitic stainless steels, such as type 316LN, are used in the high temperature segments such as reactor pressure vessels and primary piping systems. So, the dissimilar joints between these materials are inevitable. In this investigation, dissimilar joints were fabricated by the Shielded Metal Arc Welding (SMAW) process with Inconel 82/182 filler metals. The notch tensile properties and Charpy V-notch impact toughness properties of various regions of dissimilar metal weld joints (DMWJs) were evaluated as per the standards. The microhardness distribution across the DMWJs was recorded. Microstructural features of different regions were characterized by optical and scanning electron microscopy. Inhomogeneous notch tensile properties were observed across the DMWJs. Impact toughness values of various regions of the DMWJs were slightly higher than the prescribed value. Formation of a carbon-enriched hard zone at the interface between the ferritic steel and the buttering material enhanced the notch tensile properties of the heat-affected-zone (HAZ) of P91. The complex microstructure developed at the interfaces of the DMWJs was the reason for inhomogeneous mechanical properties.