• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.243-249
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• 2018

The study for curling control of plain concrete in underground parking lot was conducted in this study. The shrinkage reducing agent(SRA) was used to minimize the curling deformation of plain concrete in underground parking lot. For the quantitative curling control, the simplified prediction method applying the deflection theory of cantilever beam was proposed too, and the validity of prediction method was examined through the comparison between the experimental values and predictive values. In result, the curling of SRA 1.0% concrete was about 30% less than that of SRA 0.0% concrete, and the possibility of curling estimation by the simplified prediction method was confirmed through the comparison between the experimental values and predictive values.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.49-56
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• 2017

Curling sweeping is one of important motion to control the position of the curling stone, and sweeping speed and applied force to the broom pad are major research subjects. In this study, a device was developed to measure the force applied to the curling broom pad in curling sweeping motion, and two load cells were mounted between the broom pad and pad holder. Analog signals generated from the load cells were sampled about 300 times per second using a micro controller, and then converted to 10-bit digital signals. Calibration of the load cell and set up of regression equations to convert the measured electrical signals into mass (force) was done by three M1 class weights, and the developed system was designed as wearable device to minimize increasing of total weight of the broom. Same force was applied to the developed system and a force plate that was using as a reference force measurement system in field of sports, and the difference between the measured values were showed about $0.909{\pm}1.375N$(mean and standard deviation). The developed system could be applied other kinds of study which required force measurement function similar to sweeping motion.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.150-153
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• 2022

최근 XR은 LED스크린의 VR과 그 LED 스크린의 외부영역을 AR 그래픽으로 덮는 방법으로 LED에서 표현되는 VR영상과 확장된 AR의 효과로 LED VR의 확장의 개념으로 가상환경 제작으로서 많이 시도 되고 있다. 그러나, 여전히 LED 스크린의 VR에서 어떤 가상의 객체가 AR로 튀어 나올 때 타이밍을 맞추어 전환해야 할 경우 부자연스럽거나 동기가 맞지 않아 합성결과가 어긋나 품질이 떨어지며, 여러 객체를 동시에 수동으로 전환시켜야 할 때 객체의 제어에 어려움이 많을 수 있다. 본 논문에서는 그래픽 오브젝트가 VR과 AR의 경계를 오갈 때 자동으로 자연스럽게 전환/합성 가능하도록 하는 'Culling 박스'와 또, 여러 렌더링 머신에서 같은 오브젝트 제어를 동시에 제어 가능한 'TCP/IP 기반의 원격제어 UI'를 설명한다. 컬링박스는 전환해야 할 객체가 많은 복잡한 장면에서 모든 오브젝트가 일정 경계에서 자동으로 전환되며, 원격제어 UI의 타임라인 에디터와 이벤트 제어메뉴 UI를 통하여, 각각의 다른 머신의 시퀀스 및 오브젝트들을 제어 가능하여 효율적인 XR제작이 가능함을 확인 하였다.

• Journal of the Korea Institute of Building Construction
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• v.17 no.5
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• pp.445-451
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• 2017

Because of the supply-demand problem of aggregate, recently, the construction sites using 100% crushed sand are increasing and the use of low quality aggregate such as farmland sand is increasing too. When the low quality aggregate is used, the various quality defect of concrete such as the strength reduction, the increase of shrinkage and bleeding can be occurred. Therefore, in this study, the performance improvement PC admixture was developed to minimize the quality defect of plain concrete of basement parking area, when the low quality aggregate was used at the plain concrete of basement parking area. The slump loss to elapsed time test, the compressive strength test, the bleeding test and the drying shrinkage test were carried out.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.3
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• pp.64-74
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• 2007

The continuous chip in turning operation deteriorates precision of workpiece and causes a hazardous condition to operator. Thus the chip form control becomes a very important task for reliable machining process. So, grooved chip breaker is widely used to obtain reliable discontinuous chip. However, developing new cutting insert having chip breaker takes long time and needs lots of research expense due to a couple of processes such as forming, sintering, grinding and coating of product and many different evaluation tests. In this paper, performance of commercial chip breaker is evaluated with neural network which is learned with a back propagation algorithm. For the evaluation, several important elements(depth of cut, land, breadth, radius) which directly influence the chip formation were chosen among commercial chip breakers and were used as input values of neural network. With the results of these input values, the performance evaluation method was developed and applied that method to the commercial tools.