• 한국융합학회논문지
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• 제9권11호
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• pp.465-477
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• 2018

본 연구의 목적은 3주간의 고지대 스키 트레이닝이 크로스컨트리 스키 선수의 근기능에 미치는 영향을 분석하여 향후 크로스컨트리 스키 선수들의 근기능 향상 및 과학적 훈련프로그램 구성을 위한 기초 자료를 제공하는데 있다. 연구대상자는 크로스컨트리 스키 남자 대학 선수 6명을 대상으로 실시하였으며, 주기별과 고지대 트레이닝이 크로스컨트리 스키 선수들에 미치는 영향을 확인하기 위하여 일반선형모델 반복측정(General Linear Model ANOVA with repeated measure)과 대응표본 t 검정(Paired Samples t-test)을 적용하여 분석하였다. 고지대 스키 트레이닝을 3주간 실시한 결과 신체조성은 변화가 나타나지 않았지만, 어깨관절, 허리관절, 무릎관절, 발목관절의 등속성 근기능이 감소되는 것을 확인할 수 있었다. 따라서 SP기간과 같은 스키 트레이닝 기간 중에도 지속적인 근력훈련을 실시하여야 할 것으로 사료되면 이에 대한 추가 연구가 필요할 것으로 판단된다.

• 한국전자파학회논문지
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• 제30권2호
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• pp.169-172
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• 2019

FMCW 배열 안테나는 저비용 고해상도라는 장점 때문에 많은 분야에 널리 사용되고 있다. FMCW 배열을 이용하여 표적의 거리와 각도를 추정하기 위해서, 우선 deramped 수신신호로부터 거리-각도 행렬을 구성하고, 그 다음에 거리-각도 행렬에 2D-FFT와 같은 2차원 주파수 추정기법을 적용한다. 하지만, 이러한 주파수 추정기법은 bias 오차를 발생시키게 된다. 그 이유는 거리-각도 행렬의 두 개의 주파수가 서로 독립적이지 않기 때문이다. 따라서 FMCW 배열 안테나를 이용하여 표적의 거리-각도 동시추정을 위한 최대우도 기반 알고리즘을 제안하고, 거리와 각도 추정에 있어서 Cramer-Rao bound에 도달함을 보인다.

• Steel and Composite Structures
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• 제37권3호
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• pp.307-321
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• 2020

The slim-floor solution provides an efficient alternative to the classic slab-over-beam configuration due to architectural and structural benefits. Two deficiencies can be identified in the current state-of-art: (i) the technique is limited to nonseismic applications and (ii) the lack of information on moment-resisting slim-floor beam-to-column joints. In the seismic design of framed structures, continuous beam-to-column joints are required for plastic hinges to form at the ends of the beams. The present paper proposes a slim-floor technical solution capable of expanding the current application of slim-floor joints to seismic-resistant composite construction. The proposed solution relies on a moment-resisting connection with a thick end-plate and large-diameter bolts, which are used to fulfill the required strength and stiffness characteristics of continuous connections, while maintaining a reduced height of the configuration. Considering the proposed novel solution and the variety of parameters that could affect the behavior of the joint, experimental and numerical validations are compulsory. Consequently, the current paper presents the experimental and numerical investigation of two slim-floor beam-to-column joint assemblies. The results are discussed in terms of moment-rotation curves, available rotational capacity and failure modes. The study focuses on developing reliable slim-floor beam joints that are applicable to steel building frame structures located in seismic regions.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.833-841
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• 2008

Recently, the upheaval generation in the road which is under service had been reported. Due to the upheaval generation, total 4 lanes were forced to curtail to 3 lanes, and traffic was delayed. In normal situation of cut-slopes in korea, that condition is hard to detect since most cut-slopes contain discontinuous material, that is rock. Common collapses in rock-slopes is wedge failure, plane failure and toppling failure which is all individual mechanism of discontinuous rock mass. In contrast, such upheaval in the road in front of cut-slope can be generated only when circular movement is triggered within the cut-slope. In this sense, rock-slopes barely show any kind of movement in the road locates at the front of them. Numerical analysis is general method in simulation of slope displacement and evaluation of safety. However, numerical analysis programs which are related with rock-slopes are not able to simulate such upheaval movement because that programs are based on discontinuous modeling mechanism. In addition, although numerical analysis programs which are based on FEM/FDM and thus utilize continuous modeling mechanism are able to simulate circular movement and upheaval situation, they have weakness in reflecting discontinuities of rock-slope itself. In this study, detailed in-site investigation and numerical analysis based on in-site condition were performed in order to expect upheaval movement in the road. In this procedure, the FLAC program which uses continuous modeling method was utilized, and new approach reflecting discontinuity developed toward the road with a ubiquitous joint model was tried to derive reliable analysis result.

• Composites Research
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• 제16권6호
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• pp.16-22
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• 2003

음향방출 신호를 측정하면 운용 중에 구조물 내부의 파손 발생이나 진전 시점을 측정할 수 있는 장점이 있다. 본 연구에서는 보강된 복합적층 패널의 압축 시험에서 발생하는 음향방출 신호를 측정하여 누적 신호 분포와 주파수 특성을 분석하였다. 보강 패널의 좌굴 발생과 좌굴 모드의 변환시 음향방출 신호가 발생하였으며, 파손 발생 후 진전시 연속적인 신호가 나타났다. 복합재료 본딩 체결부의 강도 시험에서는 발생하는 음향방출 신호와 파손 형태와의 관계를 분석하였다. 본 연구의 음향방출 신호 분석에 사용된 특성은 시간에 따른 누적 히트(hit) 분포, 주파수 특성과 신호의 크기이다. 본 연구를 통하여 음향방출 신호의 연속적인 발생은 파손의 진전에 따라 나타나는 특성이며, 측정된 음향방출 신호의 주파수 특성을 분석함으로써 적층 복합재료에서 나타나는 파손 모드와의 관계를 유추할 수 있다. 내부 응력크기에 따라 모재균열, 층간분리 또는 디본딩, 섬유파손을 각각 100 근방, 220kHz 근방, 500kHz이상으로 분류할 수 있다.

• 근관절건강학회지
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• 제23권2호
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• pp.84-94
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• 2016

Purpose: This research aimed to identify levels of nurses' perception and practice of fluid intake and output (I & O) measurement and to explore the relationship between perception and practice of it. Methods: Using a cross-sectional survey design, 195 nurses who practiced fluid I & O measurement were recruited from a general hospital. Nurses who agreed to participate in this study completed a structured study questionnaire to assess their levels of perception and practice of fluid I & O measurement. Results: A level of perception of I & O measurement was high (3.46 points out of 5), and scores for 3 subdomains of I & O (importance, accuracy, and efficacy) were evenly high. The level of practice of I & O was fairly high (3.76 points out of 5). Perception and practice of I & O were highly correlated (r=.73, p<.001). Conclusion: Nurses seem to have higher levels of perception and do practice fluid I & O measurement correctly. In order to have reliable and valid I & O measures, nurses need to have continuous education on I & O measurement based on clinical guideline to utilize it as an invaluable clinical instrument.

• 대한족부족관절학회지
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• 제1권1호
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• pp.23-29
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• 1997

Freiberg's disease is a pathologic condition of the second or third metatarsal head, rarely the forth or fifth metatarsal head, and it becomes abnormally enlarge due to avascular necrosis of subchondral cancellous bone. From Nov. 1982 to Sep. 1994, we treated surgically 10 cases of the disease who complained the continuous symptoms inspite of proper conservative management. Metatarsal head excision was done in 8 cases and resurfacing of the cartilagenous portion of the metatarsal head in 2 cases. During the average follow up of 55 months, the pain was relieved in all patients who were underwent surgical intervention but the stiffness of the metatarsophalangeal joint was remained in most of cases. It seems to be a logical treatment of choice in younger and active patients that conservative management is the initial treatment but more ablative procedure is needed for the continued symptoms. We can propose the metatarsal head excision or resurfacing of the involved joint is effective treatment method with simple procedure and minimize morbid period than other procedures such as corrective osteotomy.

• 대한골관절종양학회지
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• 제1권1호
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• pp.60-67
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• 1995

It is difficult to manage the growing deformity of forearm bone caused by hereditary osteochondromatosis in children, because deformity and discrepancy of limb length is progressive. The are many treatment methods of these problems including excisio of osteochondroma, lengthening of ulna, shortening of radius, corrective osteotomy with or without lengthening apparatus. Among many treatment methods, we tried free vascularized epiphyseal transplantation with the proximal fibular epiphysis in 3 patients of hereditary osteochondromatosis for inducement of continuous bone growth and deformity correction. The average duration of follow up was 7 years and 1 month, the shortest duration being to 4 years and 5 months and the longest 10 years and 8 months. Serial radiologic and clinical evaluation were carried out during follow up and there were satisfactory length gain, deformity correction and improvement of adjacent joint motion in 2 cases. According to our follow up evaluation, free vascularized epiphyseal transplantation is valuable procedure in forearm deformity of hereditary osteochondromatosis although it needs skillful and experienced operative technique.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제39권1호
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• pp.35-40
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• 2013

Osteochondroma is a common benign tumor of the axial skeleton, especially in the distal metaphysis of the femur and the proximal metaphysis of the tibia, that can occur on the facial skeleton (albeit rarely). Osteochondroma is differentiated from chondroma, osteochondromatosis and osteoma. Osteochondroma shows an irregular radiopaque lesion and chondromatic area surrounded by the osteoma. When it develops in the long bone, it has a marked tendency to occur at 10 to 20 years of age and ceases with the end of pubertal growth. However, when it develops in the mandibular condyle, it is prevalent in the third decade and continuous to develop. Tumors that develop in the long bone have a predilection for men, but tumors in the mandible have a predilection for women. In osteochondroma of the mandibular condyle, clinical features presented include occlusal changes, facial asymmetry, headaches, pain and joint noise on the temporomandibular joint, mouth opening limitations, and jaw deviation at the involved site. The first choice of treatment for the massive osteochondroma is surgical removal. A 70-year-old female patient with an osteochondroma on her right mandibular condyle visited our clinic. We surgically removed the mass with favorable results. It is presented here along with a review of literature on osteochondroma.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권3호
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• pp.1425-1440
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• 2017

In wireless communications, antenna selection (AS) is a widely used method for reducing comparable cost of multiple RF chains in MIMO systems. As is well known, most of literatures on combining AS with MIMO techniques concern linear modulations such as phase shift keying (PSK) and quadrature amplitude modulation (QAM). The combination of CPM and MIMO has been considered an optimal choice that can improve its capacity without loss of power and spectrum efficiency. The aim of this paper is to investigate joint transmit and receive antenna selection (JTRAS) in CPM MIMO systems. Specifically, modified incremental and decremental JTRAS algorithms are proposed to adapt to arbitrary number of selected transmit or receive antennas. The computational complexity of several JTRAS algorithms is analyzed from the perspective of channel capacity. As a comparison, the performances of bit error rate (BER) and spectral efficiency are evaluated via simulations. Moreover, computational complexity of the JTRAS algorithms is simulated in the end. It is inferred from discussions that both incremental JTRAS and decremental JTRAS perform close to optimal JTRAS in BER and spectral efficiency. In the sense of practical scenarios, adaptive JTRAS can be employed to well tradeoff performance and computational complexity.