• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.517-526
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• 2023

To avoid arbitrary design and excessive braces of system supports with high reusability in the field, this study aimed to propose connection conditions for the vertical and horizontal joints of the system supports based on performance evaluation. Disk-type and pocket-type connection materials, widely used in domestic construction sites, were selected for evaluation of rotational stiffness based on load directions(vertical and horizontal) and loading methods (monotonic and cyclic). Contrary to the current design standards specifying a rotational stiffness of "0" for connection materials, the experimental results revealed that, contrary to the current design standards specifying a rotational stiffness of "0" for connection materials, all specimens exhibited rotational stiffness values. The maximum rotational stiffness was observed to be 19.624 kNm/rad in specimens subjected to repeated loading in the vertical direction using disk-type connection materials.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.159-161
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• 2004

FSW공전은 특수하게 설계된 용접툴(tool)을 특정한 회전수로 회전시키면서 용접하고자하는 재료의 용접라인에 삽입하여 용접에 필요한 마찰열과 소성변형을 발생시키고, 그 후 용접라인을 따라 툴을 이동시킴으로써 용접이 이루어지는 매우 간단한 공정이다. (중략)

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.04b
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• pp.68-72
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• 1996

본 연구에서는 에어오일 윤활하의 고속용 앵귤러 콘택트 볼베어링에 있어서, 여러 축방향의 하중과 윤활량의 변화에 대하여 회전속도에 따른 베어링의 마찰 토오크를 변화를 측정하고, 또한 회전속도, 하중 및 윤활량의 변화가 베어링 접촉부에서의 유막형성에 어떠한 영향을 미치는가를 알아보고자 한다.

• Journal of Korean Society of Steel Construction
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• v.13 no.6
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• pp.715-723
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• 2001

This paper represents the behavior of CFT column to H-beam full-scale connection with external T-stiffener. 6 specimens whose T-stiffeners which are compounded of vertical element and horizontal element were made under the parameter of the strength ratio of each elements(vertical element and horizontal element in T-stiffener) to the beam full plastic moment. The analysis-parameters demonstrated in the base of the data that we get in experiment are strength stiffness, and plastic rotational capacity. All of specimen showed stable hysteretic behavior, and the horizontal element is more critical than vertical element in strength and stiffness. The mean beam plastic rotation of all specimen except the TS-2 specimen is 2.97% rad.

• Aerospace Engineering and Technology
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• v.3 no.2
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• pp.72-80
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• 2004

LOX pump is one of the sub-assemblies constructing turbopump unit. In the current study, static structural analysis on such rotating parts as impeller and inducer has been carried out. Three major factors which can affect the structural stability of the rotating parts of LOX pump, are temperature, pressure, and centrifugal force. The effect of each factor was preliminarily investigated, then the analysis under the consideration of the combined loading conditions has been carried out. The major factor that affects the structural stability was proved to be temperature. The analyses of the combined cases showed that the designed impeller and inducer had reasonable safety margins, which means that the impeller and the inducer will be stable in static structural strength. Although there was no problem in the structural strength of the impeller and the inducer, a model analysis should be followed in order to verify the interference between the rotating part and the inner surface of casing.

• Physical Therapy Korea
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• v.7 no.4
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• pp.8-15
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• 2000

이 연구의 목적은 노인들 중, 넘어지는 사람들(fallers)과 안 넘어지는 사람들(nonfallers)의 경부, 체간, 하지의 관절가동범위를 측정하여 비교하는 것이다. 본 연구대상은 남자 6명, 여자 22명, 나이 65세에서 88세의 노인으로 독립적으로 활동할 수 있는 사람들을 두 개의 집단으로 한 사람씩 면접을 통해 분류하였다. 대상자 선정 이전 일년 동안 한번 이상 넘어진 경험이 있는 사람들을 넘어진 사람들로 규정, 그리고 넘어진 경험이 없는 사람들을 안 넘어진 사람들로 정의하였다. 관절가동범위는 각도기로 측정하였고 미국 정형외과 학회(American Academy of Orthopaedic Surgeons)의 표준화된 가동 범위 측정방법을 사용하였다. 넘어진 사람들과 안 넘어진 사람들의 연구 결과의 차이를 알아보기 위하여 양측 독립성 t-검정을 사용했다. 연구결과, 넘어진 사람들과 안 넘어진 사람들간의 관절가동범위 중 흉요부의 굴곡, 신전, 우측굴곡, 좌측굴곡, 그리고 우측회전과 좌측회전, 고관절부의 신전, 내전, 외측회전과 내측회전, 그리고 족관절의 배굴에서 유의한 차이가 있었다. 이와 같은 결과는 체간, 고관절부 그리고 발목의 유연성이 노인들의 균형을 유지하는데 영향을 준다고 말할 수 있다.

• Journal of Yeungnam Medical Science
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• v.14 no.2
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• pp.393-398
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• 1997

An accurate early diagnosis of congenital midgut malrotation is essential to prevention of catastrophic effects of volvulus. To evaluate the usefulness of radiologic examinations in diagnosing intestinal malrotation, we retrospectively analyzed radiologic findings and operation records of 17 intestinal malrotation patients, who were radiologically diagnosed. The age range of the patients studied were from 1day to 12years. The presenting symptoms were vomiting, vomiting with abdominal pain, abdominal distention, diarrhea and failure to thrive. The viewpoints of this analysis were the location of duodeno-jejunal flexure on barium meal and cecal location on barium enema. Sixteen of 17 patients, who were radiologically diagnosed, were surgically proven, but one patient with annular pancreas was false positive. In the case of 3 surgically proved patients, malrotation was suspected on barium meal prior to the barium enema, but final diagnosis was determined on barium enema examination. We concluded that a barium enema should be performed on all children with suspected malrotation where the initial upper gastro-intestinal study was normal or suspicious on account of the small incidence of false positive and false negative barium meals.

• Journal of Korean Orthopaedic Sports Medicine
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• v.10 no.2
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• pp.61-68
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• 2011

Purpose: We evaluated the clinical outcome after arthroscopic repair in full thickness rotator cuff tears with and without delamination. Materials and Methods: From March 2006 to October 2008, we included 48 consecutive shoulders (31 males, 17 females; mean age 57.6 years; 45~68) who had arthroscopic double row repair for fullthickness tears of the rotator cuff. Mean rotator cuff tear size was 2.8 cm (range: 1.2~3.6) and the techniques of tendon-to-bone fixation varied according to the presence of delamination; separate row fixations of bursal and articular layer were used in delaminated tear. The mean follow-up was 26 months (range: 18~33) and functional and structural results were evaluated by American Shoulder and Elbow Surgeons (ASES), University of California at Los Angeles (UCLA) scale, isokinetic strength testing and magnetic resonance imaging (MRI) obtained mean 8 months (range:6~13) postoperatively. The patterns of delamination, age, sex, symptom duration, size of tear, satisfaction rate, retear rate ware compared and significance was set at p values < 0.05. Results: Postoperative functional shoulder score improved significantly in 44 shoulders (91.7%). Delamination was observed in 15 shoulders (31%) and it extended proximally and posteriorly in the majority of shoulders, and the articular layer was thicker (8/15, 53%) and more retracted (9/15, 60%) compared with the superficial bursal layer. Final follow up functional shoulder scores showed no differences between non-delaminated and delaminated tears and the presence of delamination had no correlations with sex, symptom duration, tear size and satisfaction rate, however, older age had more delaminated tears (p=0.041). Follow up MRI in 29 shoulders revealed that fourteen (48%) shoulders had complete healing; nine (31%), partial healing; six (21%), complete retear but the half of the retear group showed favorable clinical results. 79% (15/19) in non-delaminated tear and 80% (8/10) in delaminated tear were judged as healed tendon on MRI and double-layer double row repairs in delaminated tears resulted in nearly same rate of structural integrity of single-layer double row repairs (p=0.165). Conclusion: The incidence of delamination in our series was 31% and older age had more delaminated tears. Sex, symptom duration, preoperative size of the tear, functional results and satisfaction rate had no significant correlations with the presence of delamination. Nearly the same postoperative structural integrity was noted in both delaminated and non-delaminated tears.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2073_2074
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• 2009

본 연구에서는 경 부하 구간에서 유도전동기의 회전자 바 고장 진단을 개선하는 방법을 제안하였다. 유도전동기의 회전자 바 고장 진단에 있어 25% 이하의 경 부하에서 정확한 진단이 어렵다. 경 부하에서는 종래의 방법에서 적용했던 회전자 바 고장 특징주파수 대역과 다른 특징 주파수 대역을 적용하여 진단하는 방법을 제안하였다. 기존에 진단이 어려웠던 경 부하에서 유도전동기 회전자 바 고장 진단을 개선하는 방법을 제안하고 실험을 통해 그 타당성을 입증하였다.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2031-2033
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• 2003

본 논문에서는 25%, 50%, 75%, 100% 정격 부하 아래에서 b유도전동기의 회전자 고장을 검출하기 위한 효과적인 FFT 기반 알고리즘을 제안하였다. 제안한 방법은 고정자 전류 스펙트럼 성분 중에서 회전자 고장에 큰 영향을 주는 주파수 성분에서 미리 결정한 기준벡터와 특정벡터 사이의 평균 절대치 차이(Mean Absolute Difference)를 이용하였다. 기준벡터는 정상 상태의 고정자 전류 스펙트럼 성분 중에서 기본 주파수 상, 하의 두개의 측파대 주변의 좁은 영역에서 추출하였고 특징벡터는 정상상태와 회전자 바 고장상태의 고정자 전류 스펙트럼 성분 중에서 또한 기준벡터와 동일한 영역에서 추출하였다. 부하실험을 통하여 제안한 알고리즘의 적용 결과는 각각의 정격 부하에서 유도전동기의 회전자 바 고장을 효과적으로 검출할 수 있음을 입증하였다.