• 한국지진공학회논문집
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• 제10권5호
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• pp.25-33
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• 2006

본 논문에서는 지진하중을 받는 내부 및 외부 철근콘크리트 보-기둥 접합부의 강도 및 연성능력을 평가하였다. 접합부에 인접한 보에 소성힌지가 발생한 이후 접합부가 파괴할 경우 접합부 내력은 보의 소성힌지의 영향을 받아 감소하게 된다. 보에 소성힌지가 발생하면 보의 부재축방향 변형률은 급격하게 증가하게 되며, 증가된 부재축방향 변형률은 접합부의 변형에 영향을 주어 접합부의 강도를 저감시킨다. 이 논문에서는 보에 소성힌지가 발생하기 이전에 파괴하는 접합부의 내력과 보에 소성힌지가 발생한 이후에 파괴하는 접합부의 연성능력을 접합부의 변형능력 및 스트럿의 강도저감을 이용하여 평가하였다. 제시한 평가법은 52개의 접합부 실험체를 이용하여 검증하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.127-130
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• 2004

For the quality control of the industrial products, an automatic hole measuring system has been developed. The measurement device allows X-Y movement due to contact forces between a hole and its own circular cone and the device is attached to an industrial robot. Its measurement accuracy is about 0.04mm. This movement of the plate is measured by two LVDT sensor system. But this system using the LVDT sensors is restricted by high cost and precision of measurement and correspondence of environment so particularly, a vision system with CCD-Camera is discussed in this paper for the above mentioned purpose. The device consists of two of two links jointed with hinge pins basically and, they guarantee free movement of the touch prove attached on the second link in the same plane. These links are returned to home position by the spring plungers automatically after each process for the next one. On the surface of the touch prove, it has a circular white mark for camera recognition. The system detect and notify the center coordinate of capture mark image through the image processing. Its measuring accuracy has been proved to be about $\pm$0.01mm through the repeated implementation over 200 times. This technique will shows the advantage of touch-indirect image capture idea using cone-shaped touch prove in various symmetrical shaped holes particulary, like tapped holes, chamfered holes, etc As a result, we attained our object in a view of the accuracy, economical efficiency, and functionality

• 한국양식학회지
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• 제17권3호
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• pp.197-208
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• 2004

백합과에 속하는 유용이매패류인 살조개, Protothaca jedoensis, 바지락, Rudirapes philippinam, 개조개, Saxidomus punuratus, 가무락조개, Cyciina sinensis, 백합, Meretrix lusoria 등 5종간의 패각 외부와 내부의 형태형질을 비교 조사하여 계통유연관계를 밝히고자 하였다. 계측형질중에서 주치의 길이만 패각의 크기와 일치할 뿐, 모든 계측형질의 크기가 패각의 크기순으로 나열되지 않는 점으로 보아, 계측형질은 고유의 종 형태적 특징을 나타낸다고 할 수 있겠다. 교판의 길이는 각장, 각고, 각폭 어느 것으로 비교하든지 종간 지수가 일정하게 나타났으나 다른 계측형질 지수는 일정하게 종간순으로 나타나지 않았다. 살조개와 바지락간의 형태적 유사도는 가장 높게 나타났으며, 살조개와 백합의 형태적 유사도는 낮은 값을 나타내었다. 이는 서식장의 환경적인 영향이 가장 크다고 생각되며, 형태형질의 비교에서 백합이 다소 유사도가 낮게 되는 것은 유전적인 형질에 의해서 영향을 받는다고 사료된다. 살조개를 자원증식을 위한 인공종묘생산을 시도하고자 한다면, 형태적 계통유연관계에서도 가장 근연종으로 보이는 바지락을 중심으로 활용방안을 모색해 보아야 할 것으로 사료된다

• International Journal of Precision Engineering and Manufacturing
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• 제8권2호
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• pp.70-74
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• 2007

This paper describes the development of a nano-positioning system for nanoscale science and engineering. Conventional positioning systems, which can be expensive and complicated, require the use of laser interferometers or capacitive transducers to measure nanoscale displacements of the stage. In this study, a new self-displacement sensing (SDS) nano-stage was developed using mechanical magnification of its displacement signal. The SDS nano-stage measured the displacement of its movement using a position-sensitive photodiode (PSPD), a laser source, and a hinge-connected rotating mirror plate. A beam from a laser diode was focused onto the middle of the plate with the rotating mirror. The position variation of the reflected beam from the mirror rotation was then monitored by the PSPD. Finally, the PSPD measured the amplified displacement as opposed to the actual movement of the stage via an optical lever mechanism, providing the ability to more precisely control the nanoscale stage. The displacement amplification process was modeled by structural analysis. The simulation results of the amplification ratio showed that the distance variation between the PSPD and the mirror plate as well as the length L of the mirror plate could be used as the basic design parameters for a SDS nano-stage. The PSPD was originally designed for a total travel range of 30 to 60 mm, and the SDS nano-stage amplified that range by a factor of 15 to 25. Based on these results, a SDS nano-stage was fabricated using principle of displacement amplification.

• 대한조선학회논문집
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• 제57권1호
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• pp.8-14
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• 2020

The implosion phenomena of pressure vessels operating in deep water under extremely high external pressure have been well known. The drastic energy release to ambient field in the form of pressure pulse is accompanied with catastrophic collapse of shell structure. Such a proximity shock wave could be a serious threat to the structural integrity of adjacent submerged body and several suspected accidents have been reported. In this study, basic research for the occurrence and development of shock wave due to implosion was carried out. The mechanism of pressure pulse generation and energy dissipation were investigated, and a simplified kinematic model to approximate the collapse modes of circular tubes which can be generated by external pressure and implosion was examined. Using the simplified kinematic model, the process of energy dissipation was formulated, and the magnitude of released pressure shock wave was estimated quantitatively. To investigate the validity of developed kinematic model and shock wave estimation process, the results from a nonlinear FE analysis code and collapse test carried out using pressure chamber were compared with the results from the developed kinematic model.

• Journal of Biosystems Engineering
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• 제42권2호
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• pp.86-97
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• 2017

Purpose: This study aims to evaluate the applicability of a tractor-baler system equipped with a newly developed round baler by conducting stability analyses via static-state mathematical simulations and verification experiments for the tractor equipped with a loader. Methods: The centers of gravity of the tractor and baler were calculated to analyze the transverse overturning of the system. This overturning of the system was analyzed by applying mathematical equations presented in previous research and comparing the results with those obtained by the newly developed mathematical simulation. For the case of the tractor equipped with a loader, mathematical simulation results and experimental values from verification experiments were compared and verified. Results: The center of gravity of the system became lower after the baler was attached to the tractor and the angle of transverse overturning of the system steadily increased or decreased as the deflection angle increased or decreased between $0^{\circ}$ and $180^{\circ}$ on the same gradient. In the results of the simulations performed by applying mathematical equations from previous research, right transverse overturning occurred when the tilt angle was at least $19.5^{\circ}$ and the range of deflection angles was from $82^{\circ}$ to $262^{\circ}$ in counter clockwise. Additionally, left transverse overturning also occurred at tilt angles of at least $19.5^{\circ}$ and the range of deflection angles was from $259^{\circ}$ to $79^{\circ}$ in counter clockwise. Under the $0^{\circ}$ deflection angle condition, in simulations of the tractor equipped with a loader, transverse overturning occurred at $17.9^{\circ}$, which is a 2.3% change from the results of the verification experiment ($17.5^{\circ}$). The simulations applied the center of gravity and the correlations between the tilt angles, formed by individual wheel ground contact points excluding wheel radius and hinge point height, which cannot be easily measured, for the convenient use of mathematical equations. The results indicated that both left and right transverse overturning occurred at $19.5^{\circ}$. Conclusions: The transverse overturning stability evaluation of the system, conducted via mathematical equation modeling, was stable enough to replace the mathematical equations proposed by previous researchers. The verification experiments and their results indicated that the system is workable at $12^{\circ}$, which is the tolerance limit for agricultural machines on the sloped lands in South Korea, and $15^{\circ}$, which is the tolerance limit for agricultural machines on the sloped grasslands of hay in Japan.

• 콘크리트학회논문집
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• 제24권6호
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• pp.705-714
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• 2012

프리캐스트 중공 사각형 철근콘크리트 교각에 대하여 준정적 실험을 수행하여 내진성능을 검증하였다. 기둥 실험체는 프리캐스트 세그먼트를 접합하고 나서, 미리 배치된 쉬스관에 축방향 철근을 연결 없이 연속으로 배치한 후 모르타르로 그라우팅하는 방법으로 제작하였다. 실험의 주요변수는 형상비, 축방향 철근비, 횡방향 철근량, 프리캐스트 세그먼트의 접합위치이다. 기둥 실험체의 형상비는 4.5와 2.5, 축방향 철근비는 1.15%와 3.07%로 각각 두 가지의 값을 가진다. 횡방향 철근량은 도로교설계기준에서 규정하고 있는 완전연성 설계에 요구되는 양의 99%, 55%, 50%, 27%로 배근되었다. 소성힌지 구역에서의 프리캐스트 세그먼트 접합위치는 기둥 하단에서 기둥단면 두께의 0.5배와 1.0배인 위치로 하였다. 실험 결과로서 균열 및 파괴모드, 축력-휨 강도, 하중-변위 포락선, 변위연성도를 분석하였으며, 도로교설계기준의 연성도 내진설계법을 적용하였을 때의 안전율을 분석하였다. 기둥 실험체는 축방향 철근이 모르타르와 쉬스관에 의하여 구속되고, 쉬스관이 횡방향 철근으로 구속되는 구조로 인하여 큰 변위까지 축방향 철근의 좌굴이 지연되어 연성도가 크게 나타났다.

• 대한기계학회논문집B
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• 제36권3호
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• pp.351-361
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• 2012

슬관절 내반슬과 외반슬의 부정정렬을 교정하는 방법 중 대표적인 수술법이 근위경골절골술이다. 개방형 쐐기 근위경골절골술(OWHTO)의 경우 근위비골 인접부의 경골외측 비골신경을 손상시킬 우려가 없고, 수술도중 교정각의 개방 정도를 임의대로 조절 변경 가능한 장점으로 최근 선호되고 있다. 그러나 술후 관상면에서의 외반 및 내반 교정은 바르게 이루어지는 반면, 시상면에서는 수술자가 의도하지 않은 경골내측고평부의 후방경사각(PSA) 변화가 발생한다는 문제점이 있다. 저자들은 이와 같은 문제의 극복을 위해 Computer Assisted Surgery를 이용한 근위경골절골술 기법을 자체적으로 개발하였고, 근위경골부의 CT 이미지 3차원 재건과 컴퓨터를 이용한 가상절골술을 수행하였다. 또한 술후에도 후방경사각(PSA)이 변화하지 않는 수술기법에 대해 제시하였다. 본 연구결과는 환자고유의 전내측피질골 경사각(ACOA)과 후방경사각(PSA)의 명확한 관계성에 대해 제시해줄 것이며 환자마다 다른 최적의 후방경사각 결정법에 대해 제시해 줄 것으로 판단된다.

• 대한기계학회논문집B
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• 제39권6호
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• pp.535-540
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• 2015

등판이 기울어지는 사무용 의자에서 등판 회전축 위치를 인체의 엉덩관절에 일치시키면 인체와 등판이 일체화되어 기울어짐으로써 사용성을 향상시킬 수 있다. 그러나 등판 힌지가 외부로 돌출되지 않도록 하기 위해 적용되는 핀인슬롯 조인트에서 기구적인 마찰이 발생해 등을 기울이고 세우는 동안 사용자에 영향을 줄 것으로 예상된다. 본 연구에서는 마찰 정도가 다른 조인트 부품으로서 슬라이더, 롤러 그리고 베어링 세 가지 유형을 적용하고, 등판 기울임 시 대비 복귀 시의 반발력 비율을 측정하였다. 실험 결과 베어링, 롤러, 슬라이더를 적용한 경우 등판 반발력 비율은$[{\pm}SD]$은 각각 $59.7[{\pm}10.3]%$, $47.2[{\pm}13.6]%$, $30.3[{\pm}18.1]%$로 나타나 베어링을 적용할 경우 마찰이 가장 작았다. 그러나 각 부품들은 생산단가 측면에서 차이를 보이기 때문에 부품 선정 시 마찰감소 성능뿐만 아니라 사용자의 주관적인 만족도를 함께 고려할 수 있음을 제시하였다.

• 대한한의학원전학회지
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• 제4권
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• pp.75-100
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• 1990

As a result, the investigation into Gyung-Ak (景岳)'s theory of Myungmun (命門) was led to the next conclusions. First, Gyung-Ak (景岳) defmed Myungmun as the gate of Suncheon (先天) and Whoocheon (後天), by which the life of Suncheon is obtained and the life of Whoocheon is maintained. He maintained that Myungmun is located between two kindneys, not sided to the right as in the Nankyeong (難經), and considered the substance of Myungmun as Jagung (子宮 ${\fallingdotseq}$ uterus) or the other names as such Jaho (子戶), Jajang (子腸) Danjeon (丹田), Hyeolsil (血室), etc. On the essence or function of Myungmun it was considered as Taegeuk (太極) of the body which shapes the North Pole in the center of the body, and as the hinge of rise and fall, as controller of Soowha-action (水火作用) and Eumyang-changing (陰陽變化), and as storage of Suncheon Jinil-ki (先天 眞一之氣), the source of life and vitality and as the spring of Twelve-Jang (十二藏). Thus, the function of Five-Jang (五臟 ${\fallingdotseq}$ Five-Viscera) and Six-Boo (六腑 ${\fallingdotseq}$ Six-Bowels) and actions of life is obtainded by Myungmun, and the life and death of man and the change of life is related to that. Bi-Wi (脾胃 ${\fallingdotseq}$ Spleen & Stomach) as well as Myungmun is the root of Five-Jang and Six-Boo, but since Bi-Wi is the base of postnatal nutrition to belong to the son of Wonyang (元陽), Myungmun is treated more important as the mother of Bi-Wi. Sin (賢 ${fallingdotseq}$ Kidney) was perceived as inseparably related with Myungmun, but in the course of theoretical development the function of Sin was considered to be ultimately operated by the action of Myungmun. In the Theory of Jineum (眞陰論), Gyung-Ak full accounted the diverse nature of disease and patholog from Soowha-shortage of Myungmun, and presented the laws and methods of medical treatment to those. Finally, in his theory related to Myungmun, some logical contradiction and confusion in conceptions was discovered and the anatomy of Present age proved that the location of Jagung and DanJeon, which he recognized as the substance of Myungmun is not coincided. Summerizingly, the Gyung-Ak's theory of Myungmun closely related the theory of Myungmun to the theory of Eumyang-Jungki (陰陽精氣論), by whole discourse of the characteristics of physiology possessing Soowha of Myungmun on the foundation of Eumyang-hogeun (陰陽互根) and Jungki-hosaeng (精氣互生). Gyung-Ak regarded the function of Myungmun as more important than any other Jang, discoursed more systematically and more specifically about the Myungmun than any others, and presented the theory of Sin-Myung (賢命理論) and prescription which is important to Care of Health and Medical Treatment (養生治病), thus influenced very greatly on the development of Oriental Medicine.