• 한국산학기술학회논문지
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• 제18권2호
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• pp.672-680
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• 2017

태양광 발전 시스템은 태양광 패널이 부착되어 있는 구조물, 이를 지지하는 부분과 발전된 전력을 계통 또는 부하측에 공급하는 장치로 구성된다. 태양광 패널의 발전효율은 태양빛의 입사량에 영향을 받기 때문에 패널이 태양빛을 가장 많이 받을 수 있는 방향으로 패널 구조물을 설치한다. 그러나 태양은 계속 이동하기 때문에 고정식 보다는 태양을 향하여 패널이 회전하는 방식이 더욱 효율이 좋다. 태양광 패널 구조물은 야외에 설치되므로 풍하중, 적설하중 지진하중 등이 작용한다. 본 논문에서는 태양광 패널 구조물에 가장 영향이 큰 풍하중을 유한요소법을 사용하여 구하고 이를 적용하여 태양 추적식 발전 장치의 구조물을 설계하였다. 특히 패널간의 간격에 따른 풍하중을 구하고, 패널 구조물이 지면과 이루는 각도에 따른 풍하중의 변화도 구하였다. 패널간의 간격은 간격이 없을 경우, 간격이 40 mm, 80 mm일 경우 등 3가지 경우에 대하여 해석을 하였으며, 지면과의 각도는 30도, 45도, 60도 등에 대하여 해석을 하였다. 해석결과 풍하중은 패널간의 간격이 없을 경우가 가장 적게 나타났고, 지면과의 경사각이 클수록 커지는 것을 알 수 있었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.873-878
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• 2000

Semiconductor packaging technology is changed rapidly according to the trends of the micro miniaturization of multimedia and information equipment. For I/O limitation and fine pitch limitation, DIP and SOP/QFP are replaced by BGA/CSP. This is one of the surface mount technology(SMT). Solder ball is bumped n the die pad and connected onto mounting board. In ball bump formation, vacuum suction type ball alignment process is widely used, However this type has some problems such as ionization, static electricity and difficulty of fifo(first-input first-out) of solder balls. Seesaw type is reducing these problems and has a structural simplicity and economic efficiency. Ball cartridge velocity and ball aligned plate angle are Important variables to improve the ball alignment Process. In this paper, seesaw-type CSP solder ball loader is developed and the optimal velocity and plate angle are proposed.

• 대한기계학회논문집A
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• 제36권6호
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• pp.645-651
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• 2012

본 논문은 부표로봇에 부착된 카메라 영상의 흔들림을 보정하기 위하여 새로운 방법을 제안한다. 본 연구에서는 부표로봇의 각도측정에 사용하는 자이로 센서의 누적오차 및 노이즈 등의 문제를 해결하기 위해 새로운 기구 메커니즘을 영상처리와 결합한 방법을 제안한다. 이 알고리즘은 특징 점을 추출하기 위한 타깃을 제안한 기구에 부착하여 타깃의 모형 특징을 기반으로 영상을 보정하는 방법이다.

• 한국항공우주학회지
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• 제33권4호
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• pp.17-26
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• 2005

새로운 개념의 위성발사 방식으로 연구되고 있는 초음속 공중발사로켓의 모선분리 현상을 파악하기 위하여 모선-로켓의 단순화된 형상에 대하여 발사속도, 장착각, 수평-수직방향의 장착위치 변화에 따른 발사체의 피칭모멘트의 변화를 고찰하였다. 정상상태의 유동해석을 위하여 삼차원 Euler 방정식을 수치적으로 해석했고, 이러한 연구를 통하여 모선날개에 장착된 초음속 공중발사로켓의 모선분리에 큰 영향을 주는 장착변수를 확인하였으며 각 변수의 변화에 따른 발사체의 거동의 변화를 반응면 모델을 구성하여 도식으로 나타내었다. 본 연구를 통하여 초음속 공중발사 메커니즘에 대한 공력특성과, 비정상 모선분리를 위한 최적 장착 위치에 대한 유용한 데이터를 제공하게 되었다.

• 제어로봇시스템학회논문지
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• 제4권3호
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• pp.384-391
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• 1998

When a device is mounted on the PCB, it is impossible to have zero defects due to many unpredictable problems. Among these problems, devices with bent corner leads due to mis-handling and which are not placed at a given point measured along the axis are principal problem in SMT(Surface Mounting Technology). It is obvious that given the complexity of the inspection task, the efficiency of a human inspection is questionable. Thus, new technologies for inspection of SMD(Surface Mounting Device) should be explored. An example of such technologies is the Automated Visual Inspection(AVI), wherein the vision system plays a key role to correct this problem. In implementing vision system, high-speed and high-precision are indispensable for practical purposes. In this paper, a new algorithm based on the Radon transform which uses a projection technique to inspect the FIC(Flat Integrated Circuit) device is proposed. The proposed algorithm is compared with other algorithms by measuring the position error(center and angle) and the processing time for the device image, characterized by line scan camera.

• 대한기계학회논문집
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• 제18권8호
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• pp.2158-2166
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• 1994

In order to understand the package crack emanating from the edge of leadframe after the delamination between leadframe and epoxy molding compound in an electronic packaging of surface mounting type, the M-integral and J-integral in fracture mechanics are obtained. The effects of geometry, material properties and molding process temperature on the package crack are investigated taking into account the temperature dependence of the material properties, which simulates a more realistic condition. If the temperature dependence of the material properties is considered the result of analysis conforms with observations that the crack is kinked at between 50 and 65 degree. However, in case of constant material properties at the room temperature it is found that the J-integral is underestimated and the kink crack angle is different form the observation. The effects of the material properties and molding process temperature on J-integral and crack angle are less significant that the chip size for the cases considered here. It is suggested that the geometric factors such as ship size, leadframe size are to be well designed in order to prevent(or control) the occurrence and propagation of the package crack.

• 항공우주시스템공학회지
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• 제3권4호
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• pp.11-18
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• 2009

This paper is about EO sensor module control based on the image processing. The main purpose of this research is acquiring a latitude and longitude of the target located on the ground by using image processing. For image processing, OpenCV is employed which is a computer vision library originally developed by Intel, and ATmega128 is used for the EO sensor module control. This task also involves realization of control programs and acquisition of sensor view angle for the position of the target.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1996년도 춘계 학술대회논문집
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• pp.52-57
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• 1996

Mixing is most important for developing an electric washer which transforms angular momentum from rotating solid wall to laundry clothes inside it. For magnification of this mixing effect, some inventions are introduced to washing machine system, i. e., washing plate, washing rod, and even for washing cap in a model of a Korean manufacture. However, the previous efforts show dissatisfaction up till now. In this paper, a triumph to enhance mixing effects to increase washing performance is presented and verified by numerical investigation. The present model to simulate a washing tub is the simple circular cylinder with two endwall disks which is completely filled with a viscous liquid. The present improvement is to change mounting position of a bottom disk of the model cylinder. Therefore, the aim of this work just proposes a new idea, which is numerically inspected, to a producer of washing machine, In detail, this invention is alternating the mounting position of a rotating bottom disk. Actually skewed pulsator is placed in steady of a flat disk, so the two endwall disks at top and bottom are not in parallel. The angle between an inclined bottom disk and the horizontal plane is fixed as 5 degree and physical domain to consider poses a sliced cylinder. Flow fields in both a right circular cylinder and the present improved model are fully depicted by numerical integration on a body fitted nonorthogonal regular uniform grid system. Numerical data to explain flow structure are plotted for understanding of the effects of the inclined disk. Also enhanced mixing effects by the inclined rotating disk are gauged by accurate numerical data used in this work.

• 한국안전학회지
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• 제24권4호
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• pp.28-33
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• 2009

This study examined the mounting status of cigar lighter receptacles for vehicles and analyzed the tracking phenomenon that occurs when foreign material entered a cigar lighter receptacle to obtain data for the analysis of accident investigation. Regardless of the vehicle's output, cigar lighter receptacles are mounted in a vehicle horizontally, vertically, or at tilting or inclined angle. The tilting type cigar lighter receptacle is much easier to use but current leakage resulting from foreign materials (coffee, beverages, water, etc.) falling into the cigar lighter receptacle may cause a fire to start. This study used a vehicle battery (DC 12V) as a power supply for the tracking test and configured its circuit in the same way as that of an electrical device in a vehicle. The tracking phenomenon that occurred in the standby mode of the vehicle exhibited a fine flame and an irregular occurrence of smoke. While this tracking phenomenon was occurring, the leakage current and the reaching distance of the flame were measured to be approximately 930mA and $20{\sim}50cm$, respectively. It is thought that the resultant flame may ignite toluene, dust, cigarettes, etc. It was observed that as the tracking progressed, the internal metal socket melted and a hole was created, the surface of which was also severely carbonized. In addition, the electrical resistance of the carbonized conductive path was measured to be approximately $30{\Omega}$. It is thought that this much resistance may cause local heating when leakage current flows and could ignite any nearby flammable material.

• 센서학회지
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• 제32권5호
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• pp.320-327
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• 2023

In this study, an FPGA-based sealer inspection system was developed to inspect the sealer applied to install vehicle glass on a car body. The sealer is a liquid or paste-like material that promotes adhesion such as sealing and waterproofing for mounting and assembling vehicle parts to a car body. The system installed in the existing vehicle design parts line does not detect the sealer in the glass rotation section and takes a long time to process. This study developed a line laser camera sensor and an FPGA vision signal processing module to solve this problem. The line laser camera sensor was developed such that the resolution and speed of the camera for data acquisition could be modified according to the irradiation angle of the laser. Furthermore, it was developed considering the mountability of the entire system to prevent interference with the sealer ejection machine. In addition, a vision signal processing module was developed using the Zynq-7020 FPGA chip to improve the processing speed of the algorithm that converted the profile to the sealer shape image acquired from a 2D camera and calculated the width and height of the sealer using the converted profile. The performance of the developed sealer application inspection system was verified by establishing an experimental environment identical to that of an actual automobile production line. The experimental results confirmed the performance of the sealer application inspection at a level that satisfied the requirements of automotive field standards.