• 한국운동역학회지
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• 제17권3호
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• pp.147-154
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• 2007

This study's purpose is to investigate the effects on leg muscle activity caused by perturbation, using a trapdoor system during the support phase of gait for healthy adults (n = 6, height $177.5{\pm}5.5cm$, weight $81.0{\pm}9.5kg$, age $30.0{\pm}3.3yrs$). The trapdoor had the functional ability of causing inversion or eversion. The release time for the trapdoor was specified for two times, 0.3 and 0.5 seconds after heel contact. While altering these variables, EMG was recorded for the leg muscles (rectus femoris, biceps femoris, vastus lateralis, tibialis anterior, gastrocnemius, soleus). The following conclusions were derived. The steptime was longer for the 0.5s eversion than 0.3s inversion condition. So in order to regain stability after the perturbation the unsupporting leg reached forward rapidly. This quick reflex can be observed through the center of pressure (COP) and its rapid change in direction. The gastrocnemius was activated throughout the total experiment. There was a low amount of activity recorded in the rectus femoris, vastus lateralis and tibialis anterior except for the condition of inversion 0.3s. For most of the conditions, the highest average EMG peak values were recorded during the condition of inversion 0.3s. The iEMG patterns were similar for the conditions of inversion 0.3s and eversion 0.3s. To cope with the rapid change in these conditions, the biceps femoris was activated. During the experiment except for the condition of normal gait, the activity of the soleus and gastrocnemius was relatively high. Therefore, to prevent injury from perturbation of the lower leg strengthening of the soleus and gastrocnemius is required. Likewise to prevent injury to the thigh strengthening for the biceps femoris.

• Archives of Plastic Surgery
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• 제34권4호
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• pp.448-454
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• 2007

Purpose: The objective of this study was to evaluate the outcomes of using the free flap in the reconstruction of maxillary defects. Methods: 27 consecutive cases of maxillary reconstruction with free flap were reviewed. All clinical data were analyzed, including ideal selection of flap, time of reconstruction, recurrence of cancer, postoperative complications, flap design, and follow-up results. The main operative functional items, including speech, oral diet, mastication, eye globe position and function, respiration, and aesthetic results were evaluated. Results: Among the 24 patients who underwent maxillary reconstruction with the free flap, 14 patients underwent immediate reconstruction after maxillary cancer ablation, and 10 patients underwent delayed reconstruction. There occurred 1 flap loss. Recurrences of the cancer after the reconstruction happened in 2 cases. Postoperative complications were 3 cases of gravitational ptosis of the flap, 2 cases of the nasal obstruction, and 1 case of fistula formation. Out of 27 free flaps, there were 15 latissimus dorsi myocutaneous flaps, 5 radial forearm, 4 rectus abdominis myocutaneous flaps, 1 scapular flap, 2 fibula osteocutaneous flap, respectively. Flaps were designed such as 1 lobe in 9 cases, 2 lobes in 9 cases, and 3 lobes in 5 cases. Among the 14 patients who had intraoral defect or who had palatal resection surgery, 2 patients complained the inaccuracy of the pronunciation due to the ptosis of the flap. It was corrected by the reconstruction of the maxillary buttress and hung the sling to the upper direction. All of the 14 patients were able to take unrestricted diets. In 6 patients who had reconstruction of inferior orbital wall with rib bone graft, they preserved normal vision. Aesthetically, most of the patients were satisfied with the result. Conclusion: LD free flap is suggested in uni-maxilla defect as the 1st choice, and fibular osteocutaneous flap and calvarial bone graft to cover the larger defect in bi-maxilla defect.

• Archives of Plastic Surgery
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• 제37권4호
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• pp.443-446
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• 2010

Purpose: Tragus is one of the key structure of the normal shape of auricle. We experienced several cases of hypoplastic tragus with preauricular appendage. This article describes the methods of reconstruction of atypical tragus using accessory tragus or macrotragus to make better aesthetic results rather than simple excision. Methods: From April, 2004 to March, 2009, 21 patients got operations by our method. Seven patients had bilateral deformity of tragus. Mean age was 12.7 years. For 17 cases of accessory tragus, simple excision, z-plasty and interpolation flap was performed. For 11 cases of macrotragus, debulking and z-plasty was performed. Mean follow-up period was 9.4 months. Results: Reconstructed tragus looked symmetric with the opposite side in contour, size, direction and partial coverage of auditory meatus. There was no enlargement of remnant appendage for the follow up period and there was no complication such as hematoma, infection and chondritis. Conclusion: In cases of small and deformed tragus, preauricular tissue such as accessory tragus and macrotragus could be a good source of tragal reconstruction.

• 영재교육연구
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• 제26권3호
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• pp.473-491
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• 2016

본 연구에서는 유아교육기관에서의 유아영재 대상 차별화 교육 실태와 지원 요구를 조사하였다. 설문조사는 서울과 경기, 인천 지역의 유치원과 어린이집 및 기타(영어유치원 및 놀이학교) 유아교육기관에서 근무하는 교사 및 원장을 대상으로 실시하였으며, 최종 수집된 설문지는 총 309부였다. 연구 결과 첫째, 유치원, 어린이집, 기타기관 등의 유아교육기관에는 유아영재 대상의 차별화 교육을 위한 인프라가 충분히 구축되어 있지 않았다. 특히 유아영재를 위한 '차별화 교육 경험'이 세 기관 모두 보통보다 낮은 수준이었다. 둘째, 유아교육기관에서의 유아영재 대상 차별화 교육에 대한 교사의 요구도는 세 기관 모두 필요수준에 비해 현재 수준이 현저히 낮은 것으로 나타났다. 본 연구의 결과는 정규 유아교육기관에서 유아영재 대상으로 교육적 요구와 발달특성에 부합하는 차별화 교육 방향 모색에 필요한 기초자료를 제공한다는 측면에서 의의가 있다.

• 국제물리치료학회지
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• 제10권4호
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• pp.1914-1920
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• 2019

Background: Mobilization and cranio-cervical flexion exercise has been reported in reducing pain from cervical part and improving its motor function; also, has been represented that alleviate of neck pain and recover of neck muscles improve the normal gait performance. However, few studies have identified the effects of mobilization and exercise on pain and gait parameters with preceding issues. Objective: To examine the effects or changes of pressure pain threshold (PPT) and gait parameters in patients with chronic neck pain. Design: Cross-Sectional Clinical Trials Methods: Twenty patients with the history of neck pain (>3 months) performed the cervical mobilization and cranio-cervical flexion exercise. Gait parameters were assessed with wireless device and collected data were transmitted to the personal computer via Bluetooth. The PPT was measured posteroanterior direction at the prone position and the mean of subsequent three PPT measurements was used for the final analysis. Results: Both cervical central posteroanterior mobilization (CCPAM) (p<.000) and sling-based cranio-cervical flexion exercise (SBCCFE) (p<.000) group showed a significant increase in the PPT and the gait parameters, cadence (p<.023), was significantly increased in the CCPAM group, however slightly increased in the SBCCFE group. The comparison between the CCPAM and the SBCCFE groups after treatment did not show significant differences for the score on the PPT and gait parameters. Conclusions: This study suggests that CCPAM and SBCCFE increase PPT, cadence, and gait speed.

• Steel and Composite Structures
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• 제36권1호
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• pp.103-118
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• 2020

The static behavior of grouped large-headed studs (d = 30 mm) embedded in ultra-high performance concrete (UHPC) was investigated by conducting push-out tests and numerical analysis. In the push-out test, no splitting cracks were found in the UHPC slab, and the shank failure control the shear capacity, indicating the large-headed stud matches well with the mechanical properties of UHPC. Besides, it is found that the shear resistance of the stud embedded in UHPC is 11.4% higher than that embedded in normal strength concrete, indicating that the shear resistance was improved. Regarding the numerical analysis, the parametric study was conducted to investigate the influence of the concrete strength, aspect ratio of stud, stud diameter, and the spacing of stud in the direction of shear force on the shear performance of the large-headed stud. It is found that the stud diameter and stud spacing have an obvious influence on the shear resistance. Based on the test and numerical analysis results, a formula was established to predict the load-slip relationship. The comparison indicates that the predicted results agree well with the test results. To accurately predict the shear resistance of the stud embedded in UHPC, a design equation for shear strength is proposed. The ratio of the calculation results to the test results is 0.99.

• 대한원격탐사학회지
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• 제23권6호
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• pp.501-506
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• 2007

본 연구에서는 합성개구레이더(synthetic aperture radar, SAR) 영상의 보정에 사용되고 있는 반사기(corner reflector, CR)를 이용하여 목표물의 식별과 인식을 위한 기초적인 연구를 실시하였다. 사각형 삼면 전파반사기를 기반으로 전방향(omni-directional) 반사기를 제작하였다. 여기서는 한 변의 길이가 15cm인 4-배열 사각형 삼면 전파반사기를 사용하여 C-밴드(주파수: 5.3 GHz) 의 편파별(VV, HH, VH, HV) RCS(radar cross section)특성을 해석하였다. 전파반사기는 대칭형이므로 방위각 180도 범위에 대해서 레이더 산란단면적 패턴을 측정하였다. VV편파의 경우, 방위각에 따른 RCS값의 차이가 8dB정도로 다른 편파보다 전방향 특성이 더 좋은 것으로 확인되었고, 방위각이 $0^{\circ}$ (단면과 동일 방향)와 $45^{\circ}$ (이웃하는 단면들의 중앙) 일 때, 가장 높은 RCS값을 보였다. 또한, 실험에서 얻어진 RCS값을 수치 해석 시뮬레이션과 이론적 계산과 비교를 실시한 결과, 서로 잘 일치하는 것으로 나왔다.

• Wind and Structures
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• 제17권3호
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• pp.317-343
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• 2013

When evaluating flutter instability, it is often assumed that incident wind is normal to the longitudinal axis of a bridge and the flutter critical wind speed estimated from this direction is most unfavorable. However, the results obtained in this study via oblique sectional model tests of four typical types of bridge decks show that the lowest flutter critical wind speeds often occur in the yaw wind cases. The four types of bridge decks tested include a flat single-box deck, a flat ${\Pi}$-shaped thin-wall deck, a flat twin side-girder deck, and a truss-stiffened deck with and without a narrow central gap. The yaw wind effect could reduce the critical wind speed by about 6%, 2%, 8%, 7%, respectively, for the above four types of decks within a wind inclination angle range between $-3^{\circ}$ and $3^{\circ}$, and the yaw wind angles corresponding to the minimal critical wind speeds are between $4^{\circ}$ and $15^{\circ}$. It was also found that the flutter critical wind speed varies in an undulate manner with the increase of yaw angle, and the variation pattern is largely dependent on both deck shape and wind inclination angle. Therefore, the cosine rule based on the mean wind decomposition is generally inapplicable to the estimation of flutter critical wind speed of long-span bridges under skew winds. The unfavorable effect of yaw wind on the flutter instability of long-span bridges should be taken into consideration seriously in the future practice, especially for supper-long span bridges in strong wind regions.

• 융합정보논문지
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• 제8권4호
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• pp.15-25
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• 2018

연구는 환경미화원의 구강건강행태를 파악하여 산업구강건강 증진을 위한 정책 방향의 기초를 마련하고자 한다. 광주광역시 일부 지역 환경미화원을 대상으로 자기기입식 설문 79부를 분석하였다. 연구결과 스케일링 경험 80%에 비해 구강보건교육 경험은 약 25%로 나타났다. 구강위생관리는 학력, 고용형태, 근무년수와 관계가 있었다. 치주상태는 고졸이상에서 '시린이'와 '잇몸부음' 증상이 높게 나타났고, 소득과 학력이 높을수록 치주상태가 '보통'이거나 '나쁨'으로 인식하였다. 따라서 다양한 노동자 중 환경미화원을 대상으로 분석한 것에 대하여 의의가 있으며, 환경미화원의 환경을 잘 고려하여 구강보건교육의 기회를 넓히고 적극적이고 융복합적인 프로그램을 개발하여 산업구강건강증진을 위한 다양한 노력과 대책이 필요하다.

• 대한조선학회논문집
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• 제31권4호
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• pp.66-72
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• 1994

선박의 조종성능을 정확히 평가하기 위해서 지난 약 10년간 각종모형시험이 수행되었다. 그러나 수학모델에 나타나는 변수들은 너무 다양하고, 복잡한 특성을 나타내기 때문에 아직까지 설계분야에 직접 사용할 수 있는 유용한 형태가 구축되지 않았다. 본 연구에서는, 이 수학모델에서 가장 중요한 변수인 프로펠러에서의 유효반류계수($1-{\omega}_P$)와, 유효타각 $\delta_R(\beta_R)$)을 회류수조에서 조사하였다. 모델은 설계속도와 저속에서 각각 실험이 이루어졌고, 흘수 또한 만재상태와 밸러스트상태에서 실시되었다. 프로펠러 추력과 타직압력은 주어진 사항각과 프로펠러 회전수에서 측정되었다. 이 추력은 유효유입속도나 유입방향의 해석에 사용된다.