• 전기학회논문지
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• 제68권1호
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• pp.83-89
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• 2019

In this paper, beam forming using moving least squares method (MLSM) is studied. In the previous research, the least squares method (LSM), one of the data interpolation methods, was used to determine the desired beam pattern and obtain a beam pattern that minimizes the square of the error with the desired beam pattern. However, LSM has a disadvantage in that the beam pattern can not be formed to satisfy the exact steering angle of the desired beam pattern and the peak sidelobe level (PSLL) condition. To overcome this drawback, MLSM is used for beam forming. In order to verify, the proposed method is applied in beam forming of Bezier platform array antenna which is one of conformal array antenna platform.

• Design & Manufacturing
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• 제2권4호
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• pp.32-36
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• 2008

Roll forming process for the bumper beam of high strength steel is developed by an experimental method. The size of the bumper beam is reduced to 1/1.8 to save development time and cost. The developed forming rolls are installed in the small three-stage roll forming machine and roll forming experiments are carried out. It is found that the experimental method using small forming machine is effective in developing roll forming process for the bumper beam of high strength steel.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.826-828
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• 2015

본 논문에서는 고정국에서 효율적으로 운용할 수 있는 Beam-Steering 기법을 제시한다. 일반적인 Beam-forming 기법은 각 배열안테나에 도달하는 신호 간의 지연시간을 이용하여 수행한다. 이러한 빔포밍 방식은 많은 복잡도와 비용을 요구한다. 본 논문에서는 신호대 잡음비와 수신신호세기를 사용한 빔스티어링 기법을 제시한다. 또한 제시한 기법에 대한 알고리즘을 분석한다.

• 한국기계가공학회지
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• 제11권6호
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• pp.82-87
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• 2012

The purpose of this study is to produce a side impact beam with high tensile steel using a roll forming process. The door side impact beam plays an important roll in a car because it protects passengers from external crash. The roll forming process is a continuous bending process wherein a long metal sheet is bended as it continuously passes several rolls. The characteristic of this study is that an impact beam is produced by a continuous process using a ultra high strength steel without a hardening heat treatment. A model was determined by analysing plasticity of a cross section shape considering high strength. Design parameters of the impact beam was determined by crash-analysing the model. Workpiece products were manufactured by designing dies for roll forming and setting them up in a following process line. Results of a bending test and a FEM analysis was considered and reviewed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1376-1380
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• 2005

In recent automotive industry, vehicle weight can be reduced by one-step forming of tailored blanks welded with two or more sheets of metal blanks. Tailored blank(TB) welding is a production method for blanks involving welding together materials of different quality, thickness, and coating, and has proved popular in fabrication automotive parts. This paper deals with the forming characteristics of mash seam welded tailored blanks. Using these forming characteristics, the bumper beam was developed using the mash seam welded tailored blank with the different thickness. We performed the forming simulation with respect to strain distribution on blank during the stamping of the bumper rail part. Based on these results, we made some stamping tryouts with selected types of blank designs to investigate the formability of tailored blank with different thickness. During the tryouts, we knew that it was important the BHF(Blank Holding Force). We obtained to reducing 10.5% weight and cost with adapting the bumper beam of automotive component using the tailored blank of mash seam welding.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.199-202
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• 2009

In roll forming process, a sheet metal is continuously progressively formed into a product with required cross-section and longitudinal shape, such as a circular tube with required diameter, wall-thickness and straightness, by passing through a series of forming rolls in arranged in tandem. Tn this process, each pair of forming rolls installed in a forming machine play a particular role in making up the required cross-section and longitudinal shape of the product. In recent years, that process is often applied to the bumper rail in the automotive industries. In this study, a optimal Front Bumper Beam manufacturing technology, model deign and proper roll-pass sequences can be suggested by forming number of roll-pass and bending angle. And also effects of the process parameters on the final shape formed by roll forming defects were evaluated.

• 소성∙가공
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• 제31권1호
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• pp.29-38
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• 2022

Recently, the composite material market is gradually growing. Various composite forming processes have been developed in order to reduce the production cost of the composite material. Unlike the conventional forming process, the microwave composite forming process has the advantage of reducing the processing time because the composite material is heated directly or indirectly at the same time. Due to this advantage, in this study, a double cantilever beam test was conducted with specimens manufactured by the microwave composite forming process. The purpose of this study was to compare mode-I energy release rate for specimens manufactured by prepreg compression forming and microwave composite forming processes. First, a microwave oven was proposed to conduct the microwave composite forming process. Double cantilever beam specimens were manufactured. After that, the double cantilever beam test was conducted to obtain the mode-I energy release rate. Mode-I energy release rates of specimens manufactured by the microwave composite forming and prepreg compression forming processes were then compared. As a result, mode-I energy release rates of specimens fabricated by the microwave composite forming process were similar to those fabricated with the prepreg compression forming process with a relatively reduced process time.

• 국제강구조저널
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• 제18권5호
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• pp.1772-1783
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• 2018

Nowadays, the researches about composite structure system are being implemented in various fields, and many steel structures are designed based on that. In this study, the bending and seismic performance of the newly developed high-performance cold forming composite beam are evaluated by several experiments. As a result of the bending performance test, the bending moment of beam was increased stably depending on the depth and plate thickness of beam, and it is considered that the bending moment can be evaluated by the equation of a composite beam design. As a result of the seismic performance test, it was verified that sufficient seismic performance was obtained despite the increase of a negative moment rebar and depth of beam. In addition, the nominal bending moment has obtained the strength above the plastic bending moment, and also the plastic rotation angle has satisfied the requirement of composite intermediate moment frame.

• 한국전자파학회논문지
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• 제25권10호
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• pp.1069-1076
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• 2014

본 논문은 능동위상배열 레이더가 여러 개의 표적을 탐지/추적하기에 효과적인 수신빔 구조에 대해 기술하고 있다. 위상배열 레이더가 갖는 특성 중 하나는 원하는 방향으로 빔을 조향하고, 디지털적으로 여러 개의 빔을 동시에 형성하는 것이다. 이와 같은 디지털 빔 형성 수신빔 구조를 통해서 동시 다발적으로 발생하여 접근하는 위협 표적을 빠르고 정확하게 탐지하는 방식을 제안한다. 본 논문에서 제안된 기법들은 시뮬레이션을 통해서 표적의 탐지 정확도 성능을 제시한다.

• 한국위성정보통신학회논문지
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• 제7권2호
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• pp.25-29
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• 2012

본 논문에서는 스텝핑 모터와 연동하여 방향 제어되는 LED 빔 포밍 통신 시스템을 HW로 구현하였다. ATMega1284 MCU를 이용하여 제어 보드를 구성하였으며, PC와 연결되는 RS232 IO와 스텝핑 모터 구동 보드 제어용 포트(Port)를 이용하여 외부 인터페이스를 구성하였다. 스텝핑 모터는 200 PWM으로 360도 회전하고 동시에 반경이 커지는 아르키메디스의 소용돌이(Archimedian Spiral) 방식을 적용하여 목표하는 지점을 선택적으로 조명할 수 있도록 하였다. 이 빔 포밍은 RS232와 연결된 PC 툴(tool)에 의해서 제어되며, ATMega1284 MCU 보드가 호스트(host) 역할을 하였다. 빔 포밍의 동작은 실제 구현된 HW/SW 기반으로 그 유용성을 검증하였다.