• 한국포장학회지
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• 제11권1호
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• pp.1-10
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• 2005

Paper angle, environment friendly packaging material, has been mainly used as an edge protector. But, we have perceived its application to package design of heavy product such as strength reinforcement or unit load system (ULS) in the future. Above all, understanding of buckling behavior for angle itself and compression strength and quality standard have to be accomplished for the paper angle to be used for this purpose. The purpose of this study was to elucidate the buckling behavior through theoretical and finite element analysis, and to develop compression strength model by compression test for symetric and asymetric paper angle. Based on the result of theoretical and finite element analysis, increasing rate of buckling of asymmetric paper angle was higher as applied load level was bigger and/or the length of angle was longer than that of symmetric paper angle. Decreasing rate of minimum principal moment of inertia was remarkably increased as the extent of asymmetric angle is bigger, and buckling orientation of angle was open direction near the small web. Increasing rate of maximum compression strength (MCS) for thickness of angle was smaller as the web size was bigger in symmetric angle. MCS of asymmetric angle of $43{\times}57$ and $33{\times}67$ was decreased $15{\sim}18%$ and $65{\sim}78%$, and change of buckling was increased $12{\sim}13%$ and $62{\sim}66%$, respectively.

• 한국소음진동공학회논문집
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• 제20권1호
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• pp.10-21
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• 2010

Equations of chordwise and flapwise bending motions for the vibration analysis of rotating pre-twisted blades having tapered cross section and setting angle are derived by using hybrid deformation variable modeling. The two motions are couples to each other due to the pre-twisted angle of the beam cross section. The derived equations are transformed into dimensionless forms in which dimensionless parameters are identified. The effects of the dimensionless parameters on the modal characteristics of rotating pre-twisted blades having tapered cross section and orientation angle are investigated. The eigenvalue loci veering phenomena are also investigated and discussed in this work.

• 한국자동차공학회논문집
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• 제18권2호
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• pp.67-73
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• 2010

In this study, a camber angle generating mechanism for rear suspension is suggested. An experimental device is implemented and tested. A full vehicle model with camber angle generating device by using ADAMS/Car is modeled. Rear left wheel and rear right wheel have 5 different camber angles in the simulations, respectively. Step steer and pulse steer simulations are carried out for investigating the effects of vehicle handling performance due to camber angle control of rear suspension. According to the results, the camber angle of rear suspension affects the vehicle handling performance during both simulations. Therefore, when the vehicle makes the right turn or left turn, left and right wheel should have the proper orientation for improving the handling performance, respectively.

• 한국자동차공학회논문집
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• 제19권6호
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• pp.23-29
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• 2011

In this study, a camber angle generating mechanism for front and rear suspension is suggested. An experimental device is implemented and tested. A full vehicle model with camber angle generating device by using ADAMS/Car is modeled. Step steer simulations are carried out for investigating the effects of vehicle handling performance due to camber angle change of front and rear wheel. According to results, the camber angle of rear suspension affects the vehicle handling performance during both simulations. Therefore, when the vehicle makes the right turn or left turn, left and right wheel of front and rear suspension should have the proper orientation for improving the handling performance, respectively.

• 한국지리정보학회지
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• 제8권4호
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• pp.123-133
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• 2005

본 연구는 측량용 디지털 카메라인 d7 $metric^5$를 이용하여 수렴각을 변화시켜가면서 촬영을 실시하였으며, 표정 시 발생하는 오차를 최소화하기 위해 프로그램 상에서 자동적으로 상호표정 되는 원형표지를 이용하였다. 그리고 사진의조정기법은 해석적 방법 중에서 현재 가장 좋은 정도를 얻을 수 있는 광속조정법(bundle adjustment)를 이용하였다. 또한 대상물과 수렴각간의 기하학적 형태변하에 따른 함수모형화를 통해 최적촬영식을 제시한다. 이러한 연구는 향후 근거리수치사진측량에서 요구하는 정도의 사진촬영과 예상되는 정도를 판단하는데 중요한 자료로 이용될 것으로 판단된다.

• 소성∙가공
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• 제15권6호
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• pp.421-427
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• 2006

Drawing process of Al-1%Si bonding wire considering fine Si particle is analyzed in this study using FE-simulation. Al-1%Si boding wire requires electric conductivity because Al-1%Si bonding wire is used for interconnection in semiconductor device. About 1% of Si is added to Al wire for dispersion-strengthening. Distribution and shape of fine Si particle have strongly influence on the wire drawing process. In this study, therefore, the finite-element model based on the observation of wire by continuous casting is used to analyze the effect of various parameters, such as the reduction in area, the semi-die angle, the aspect ratio, the inter-particle spacing and orientation angle of the fine Si particle on wire drawing processes. The effect of each parameter on the wire drawing process is investigated from the aspect of ductility and defects of wire. From the results of the analysis, it is possible to obtain the important basic data which can be guaranteed in the fracture prevention of Al-1 %Si wire.

• 대한의용생체공학회:의공학회지
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• 제43권6호
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• pp.417-423
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• 2022

The present study proposed a new interface system for capsule endoscopy by using head mounted display (HMD) device, which can control the orientation of the capsule endoscope with electromagnetic actuator (EMA) system. The orientation information of the HMD user was detected by the gyroscope sensor built into the device and then calculated to as an angle increment using Unity Engine compiler. The measured angle changes from the HMD were converted to the current values of the corresponding coils to be changed in the EMA system. Two experiments were designed to measure the accuracy and the intuitiveness of the HMD interface system. In the angle accuracy measurement, the capsule endoscope driven by HMD interface system showed the averaged errors of 0.68 degrees horizontally and 1.001 degrees vertically for given test angles. In the intuitiveness measurement, HMD interface system showed 1.33 times faster manipulation speed rather than the joystick interface system. In this respect, the HMD interface system for capsule endoscopy was expected to improve the overall diagnostic environment while maintaining comfort of patients and clinicians.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1434-1439
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• 2004

CFRP composite materials have wide application in structure materials of airplane, ships, and aero space vehicles because of their high strength and stiffness. This paper is to study the effects of curvature and orientation angle on the penetration characteristics of CFRP laminate shell. They are staked with 8 Ply specimens [0$_2$/90$_2$]$_{s}$, [0/90$_2$/0]$_{s}$ and the stacked of outer plates degree with 12 Ply specimens [0$_3$/90$_3$]$_{s}$, [0$_2$/90$_2$/0]$_{s}$ and [90$_3$/0$_3$], [90$_2$/0$_2$/90]S. They are manufactured to varied curvature radius (R=100,150,200mm and $\infty$). They are cured by heating to the appropriate harding temperature(13$0^{\circ}C$) by mean of a heater at the vaccum bag of the autoclave. Test specimens were prepared with dimensions 100mm$\times$140mm. When the specimen is subjected to transverse impact by a steel ball, the velocity of the steel ball was measured both before and after impact by determining the time for it to pass two ballistic-screen sensor located a known distance apart. In general, kinetic energy after impact-kinetic energy before impact rised in all specimens. This study observed a fracture mode inside the specimen after a penetration test using a digital camera and it examined a fracture mode and a penetration mode to stack of outer orientation angle and curvature.rvature.

• Steel and Composite Structures
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• 제16권4호
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• pp.375-387
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• 2014

The purpose of this paper is to propose a method for evaluation of varying stiffness coefficients of tailored conical shells (TCS). Furthermore, a comparison between buckling loads of these shells under axial load with the different fiber path is performed. A circular truncated conical shell subjected to axial compression is taken into account. Three different theoretical path containing geodesic path, constant curvature path and constant angle path has been considered to describe the angle variation along the cone length, along cone generator of a conical shell are offered. In the TCS with the arbitrary fiber path, the thickness and the ply orientation are assumed to be functions of the shell coordinates and influencing stiffness coefficients of the structure. The stiffness coefficients and the buckling loads of shells are calculated basing on classical shells theory (CST) and using finite-element analysis (FEA) software. The obtained results for TCS with arbitrary fiber path, thickness and ply orientation are derived as functions of shell longitudinal coordinate and influencing stiffness coefficients of structures. Furthermore, the buckling loads based on fiber path and ply orientation at the start of tailored fiber get to be different. The extent of difference for tailored fiber with start angle lower than 20 degrees is not significant. The results in this paper show that using tailored fiber placement could be applied for producing conical shells in order to have greater buckling strengths and lower weight. This work demonstrates the use of fiber path definitions for calculated stiffness coefficients and buckling loads of conical shells.

• 터널과지하공간
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• 제23권5호
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• pp.392-400
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• 2013

채굴적에 의한 지표에서의 지반침하발생 위치를 추정함에 있어, 절리군은 필수적으로 고려되어야하는 요소 중의 하나인 바, 각 절리군의 역학적 특성과 이들이 채굴적 상부 암반에 분포하는 양상은 지반침하발생을 가속시킬 수 있다. 따라서 본 연구에서는 침하발생 범위의 추정에 관한 선행연구의 근거자료로 이용된 자료 중 절리군의 방향성에 대한 조사정보의 신뢰성이 비교적 양호한 자료들을 선별하여 절리군의 방향성을 중심으로 지반침하 발생위치와의 상관관계를 재검토하였으며, 추정각과 침하 지역에 분포하는 주절리군 $J_1$의 경사각을 비교하여 주절리군 $J_1$이 침하에 미치는 영향을 분석하였다.