• 한국운동역학회지
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• 제14권2호
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• pp.69-83
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• 2004

The purpose of this study is searching for technical merits and demerits of each weight lifting player through qualitative motion analysis system. Moreover, It is also analysis the repeating the establishment of exercise purpose and studying for the effect of the field adaptation. The subject of this study was five male weight lifting players who have been engaged in Korean Delegation Team. The institution of exercise target was made through two times qualitative analysis and the result of studying for the effect of the field adaptation was produced before offering feedback. Moreover, two time analysis added after offering feedback. All analysis was based on 2-D visual analysis. The results of this study are as follows: 1. Maximal barbell moving speed in starting phase was decreased after offering feedback. This result implies advancement of technical skills after offering feedback. 2. From starting posture to 앉아받기, forward and backward moving distance of hip joint was decreased after offering feedback in all subjects. This result represents advancement of technical skills after offering feedback. 3. In terms of pull phase, forward and backward moving distance of hip and shoulder joint was decreased after offering feedback in all subjects. This result represents advancement of technical skills after offering feedback. 4. In terms of pull phase, the difference of horizontal value of coordinates was decreased after offering feedback in all subjects. This result represents advancement of technical skills after offering feedback. 5. In terms of pull phase, the motion range of hip joint was decreased after offering feedback in three of five subjects and this represents advancement of technical skills after offering feedback. However, the rest of them were not variable or narrow decreasing. This result represents that feedback system could not brought tremendous effects. 6. From apex point of barbell to 앉아받기, the difference of barbell height was decreased after offering feedback in three of five subjects and this represents advancement of technical skills after offering feedback. However, the rest of them weren't variable or narrow increasing. This result represents that feedback system could not brought tremendous effects. 7. In terms of last-pull phase, the angular velocity of knee joint was increased after offering feedback in four of five subjects and this represents advancement of technical skills after offering feedback. However, the rest of them, only one subject, decreased. This result represents that feedback system could not brought tremendous effects. 8. In terms of last-pull, the conversional tendency of maximal extension to flextion came out all but simultaneously without offering feedback in four of five subjects. This is well-performed technique. Only one subject, however, could not use power effectively because the fact that his maximal extension came out in serial, from ankle to knee and waist means dispersion of power. In addition to, after offering feedback, only one subject made increasing the maximal extension of knee in last-pull and this result represents advancement of skills after offering feedback. However, the rest of them could not make meaningful development after offering feedback. 9. It might be assumed that searching for technical merits and demerits of each weight lifting player through qualitative motion analysis system could improve player's skill.

• 한국산업보건학회지
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• 제21권4호
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• pp.209-214
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• 2011

Objectives: To assess the risk of pushing or pulling the yarn-carrying cart, the survey was performed in some fiber manufacturing factories. Methods: We selected 6 fiber-twisting factories which agreed to in-site survey of their workplace. To measure both initial and sustained forces of the push-pull tasks, Chatillon CSD500 dynamometer(2004, Ametek, USA) was used. The mean of 3 tests for the same cart was adopted as the measured forces. Height and width of cart, weight of spooled yarns, and distance of movement were also measured. Inspection of cart wheel, moving path, and the actual hand position while moving was done. Results: More than one pushing or pulling task exceeded the push-pull force limits of design goal in 5 factories. Though the cart was not loaded the heaviest weight in the factory, the measured push or pull force exceeded the limits several times. A few cart wheels were worn out and tangled with pieces of yarn. It was also observed some holes in the moving path. Conclusions: While the push-pull task is not included in the 11 scopes of over-burdened work notified by Korean government, it should be recognized as risk factor of work-related musculoskeletal disorders. The maintenance work such as regular change and frequent cleaning of cart wheel, the use of fitting wheel, and flattening of bumpy floor through the moving path should be advised importantly in the worksite management of work-related musculoskeletal disorders.

• 한국지반신소재학회논문집
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• 제8권4호
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• pp.19-25
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• 2009

본 연구에서는 접이식 웨지가 장착된 경량 강관네일의 인발저항 증진효과를 평가하기 위하여 동일 지반조건에서 시험시공을 통한 접이식 웨지가 장착된 네일과 웨지가 장착되지 않은 네일의 현장 인발거동 특성을 평가하였다. 강관네일의 현장 인발거동 특성 평가는 극한인발저항력 ($T_L$), 단위주면 마찰저항($q_s$, $u_{max}$), 인발강성계수($K_{\beta}$) 및 네일의 인장력 분석을 통하여 수행되었으며, 그 결과 접이식 웨지를 장착할 경우 풍화토 지반에서 약 30% 정도의 인발저항 증진효과가 있는 것으로 나타났다.

• Geomechanics and Engineering
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• 제31권6호
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• pp.573-582
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• 2022

The geometry of the gravity-type anchorage changes depends on various factors such as the installation location, ground type, and relationship with the upper structure. In particular, the anchorage geometry embedded in the ground is an important design factor because it affects the pull-out resistance of the anchorage. This study examined the effect of four parameters, related to anchorage geometry and embedded ground conditions, on the pull-out resistance in the gravity-type anchorage through two-dimensional finite element analysis, and presented a guide for major design variables. The four parameters include the 1) flight length of the stepped anchorage (m), 2) flight height of the stepped anchorage (n), 3) the anchorage heel height (b), and 4) the thickness of the soil (e). It was found that as the values of m increased and the values of n decreased, the pull-out resistance of the gravity-type anchorage increased. This trend is related to the size of the contact surface between the anchorage and the rock, and it was confirmed that the value of n, which has the largest change rate of the contact surface between the anchorage and the rock, has the greatest effect on the pull-out resistance of the anchorage. Additionally, the most effective design was achieved when the ratio of the step to the bottom of the anchorage (m) was greater than 0.7, and m was found to be an important factor in the pull-out resistance behavior of the anchorage.

• 한국지반환경공학회 논문집
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• 제24권4호
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• pp.13-22
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• 2023

본 논문에서는 시험적 연구를 통해 록볼트가 지보효과를 발휘하는 시기를 그라우트 강도로 제시하고, 수치해석적 연구를 통해 지반조건과 경계면 강도감소계수에 따른 록볼트 인발 거동을 분석한 연구를 다루었다. 그 결과 록볼트는 그라우트 강도 5 MPa(재령 18시간)에서 지보효과를 발휘하였으며, 경계면 강도감소계수의 영향은 록볼트 변위의 경우 연약한 지반일수록, 그라우트- 지반의 전단응력의 경우 지반의 탄성계수가 높을수록, 그라우트 응력의 경우 모든 지반조건에서 영향이 큰 것으로 분석되었다. 이러한 연구결과는 록볼트 인발시험의 구체적인 기준 재정립과 록볼트 수치해석에 도움이 될 것으로 판단된다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제11권2호
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• pp.88-94
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• 2011

In this paper, we design a 1-kb OTP (Onetime programmable) memory IP in consideration of BCD process based EM (Electro-migration) and resistance variations of eFuse. We propose a method of precharging BL to VSS before activation of RWL (Read word-line) and an optimized design of read NMOS transistor to reduce read current through a non-programmed cell. Also, we propose a sensing margin test circuit with a variable pull-up load out of consideration for resistance variations of programmed eFuse. Peak current through the non-programmed eFuse is reduced from 728 ${\mu}A$ to 61 ${\mu}A$ when a simulation is done in the read mode. Furthermore, BL (Bit-line) sensing is possible even if sensed resistance of eFuse has fallen by about 9 $k{\Omega}$ in a wafer read test through a variable pull-up load resistance of BL S/A (Sense amplifier).

• 한국의류산업학회지
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• 제25권1호
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• pp.119-126
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• 2023

This study aimed to determine the effects of relative humidity and fiber properties on the moisture permeability of multilayer systems by measuring water vapor transmission in the overlapping condition of various fabrics. The results confirmed that the property of the fabric in contact with the humid environment affects the moisture permeability. If the layer facing the humid environment is hydrophobic and the layer facing the dry environment is superhydrophobic, water vapor transmission increases by up to 17.8% compared to the opposite conditions. Comparing the correction values of the water vapor transmission reflecting the thickness of the specimen under the multilayer condition showed that permeability was higher when the hydrophilic or hydrophobic layer was facing the humid environment. The opposite was true from the "push-pull" effect of absorption mechanism. In the case of moisture permeability, the more hydrophilic the surface facing the humid environment, the more permeable that water vapor diffuses and passes through. It was concluded that the "pull-push" effect, in which water vapor diffuses widely through the hydrophilic facing a humid environment and then passes through the hydrophobic layer, contributes to the improvement of permeability. Permeability differed according to the multilayer overlapping condition. When the relative humidity was high, the "pull-push" effect was insignificant. This is caused by water droplets absorption after the partial migration of water due to condensation. These results suggest that the overlapping conditions and properties of fabrics should vary depending on heavy sweating or not.

• 중소기업연구
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• 제42권3호
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• pp.221-243
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• 2020

본 연구는 재직중인 중장년층의 자립욕구와 창업성공가능성 및 고용안정성이 Push-창업의지를 매개로 Pull-창업의지에 미치는 영향을 알아보고자 한다. 경제 활성화와 고용확대를 위해 생계형 창업보다는 기회형 창업으로 질적 확대를 권장하고 있지만, 경험과 기술, 기회를 갖고 있는 중장년층이 기회형 창업보다는 생계형 창업으로 양적 창업 확대가 나타나는 것이 현상이다. 본 연구는 이런 현상에 대해 창업의지를 기존의 결과변수로 보기보다는 창업자 개인이 인식하는 창업성공가능성 및 고용안정성에 따라 창업의지를 자립욕구, Push-창업의지, Pull-창업의지로 구분하고 변수로 반영하여 그에 따른 영향을 연구하였다. 그 결과는 다음과 같다. 본 연구결과 첫째, 자립욕구는 Pull-창업의지와 Push-창업의지에 정(+)의 영향을 주는 것으로 나타났다. 둘째, 창업성공가능성은 Pull-창업의지에 정(+)의 영향을 Push-창업의지에는 유의적 영향을 주지 않는 것으로 나타났다. 셋째, 고용안정성은 Pull-창업의지에 정(+)의 영향을 Push-창업의지에는 유의적 영향을 주지 않는 것으로 나타났다. 넷째, 자립욕구는 Pull-창업의지에 정(+)의 영향을 Push-창업의지는 부(-)의 영향으로 매개효과가 있는 것으로 나타났다. 본 연구의 시사점으로는 실업에 밀려서 창업되는 생계형 창업보다는 자립욕구를 갖는 잠재창업자가 Push-창업의지의 상황이 개선되면 Pull-창업의지로 전개될 수 있음 인식하였다. 또한, 자립욕구를 갖는 재직자를 대상으로 창업교육과 창업프로그램의 활성화가 기회형 창업을 확대할 수 있는 방안으로 본다.

• 한국ITS학회 논문지
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• 제10권1호
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• pp.42-48
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• 2011

본 논문에서는 GaN HEMT (Gallium Nitride High Electron Mobility Transistor) bare-chip을 이용하여 X-대역에서 수동로드 풀(Passive load-pull)을 수행하였다. 열로 인한 특성 변화가 최소화 된 동작 조건을 얻기 위해 드레인 바이어스 전압과 입력 RF 신호를 펄스로 인가하였다. 전자기장 시뮬레이션과 회로 시뮬레이션을 병행하여, 와이어 본딩 효과를 고려하여 드레인 경계면에서의 정확한 임피던스 정합 회로를 구현하였다. 임피던스를 변화시키기 위해 마이크로스트립 라인 스터브의 길이가 조절 가능한 회로를 설계하였다. 펄스 로드 풀 실험 결과 8.5 GHz에서 9.2 GHz 대역에서 최대 42.46 dBm의 출력 전력을 얻었으며, 58.7%의 드레인 효율 특성을 얻었다.

• 한국구조물진단유지관리공학회 논문집
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• 제12권2호
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• pp.103-112
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• 2008

FRP와 콘크리트의 접착강도를 평가하기 위해 현장에서 일반적으로 사용되는 Pull-off 실험방법은 FRP 복합체의 손상을 초래하며 더욱이 FRP의 최대 pull-off 강도가 콘크리트의 인장강도에 의해 제한되는 단점을 지니고 있다. 이에 따라 구조보강용 접착제의 역학적 특성을 1차적으로 평가할 수 있는 간접적인 실험방법의 개발이 요구된다. 본 연구에서는 여러나라에서 각기 제안되고 있는 실험규격에 대한 비교실험을 통하여 구조보강용 접착제의 역학적 특성을 개략적으로 예측할 수 있는 표준화된 실험방법 및 평가기준을 제안하고자 하였다. 본 연구결과를 바탕으로 인장전단접착강도 시험의 접착제 두께, 압축/휨강도 시험체의 제원 등이 통일되어 표준시험체 제원을 도출할 수 있었다.