• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.215-222
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• 2007

Coating of Hot-dip galvannealed steel consists of various Fe-Zn intermetallic compounds. Since the coating is hard and there for is very brittle, the surface of steel sheet is easy to be ruptured during second manufacturing processing. This is called as powdering. In addition, forming equipment might be polluted with debris by powdering. Therefore, various research have been carried out to prohibit powdering fur improving the quality of GA steel. This paper carried out finite element analysis combined with damage model which simulate the failure of local layer of hot-dip galvannealed steel surface during v-bending test. Since the mechanical property of intermetallic compound was unknown exactly, we used the properties calculated from measurements. The specimen was divided into substrate, coating layer and interface layer. Local failure at coating layer or interface layer was simulated when elemental strain reached a prescribed strain.

• Journal of the Korean Society of Manufacturing Process Engineers
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• 제12권2호
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• pp.68-74
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• 2013

In this paper, an average surface roughness, $R_a$, was measured by optical measurement and its mathematical model according to spindle speed and feedrate was obtained by least square method. Also, its result is compared and investigated with real measured average surface roughness. The optical measurement of surface roughness is performed by CLSM(confocal laser scanning microscope) and the captured HEI(height encoded image) data is used as an original data for the generation of average surface roughness and its mathematical plane or contour surface of surface roughness. Using this polynomial model with two independent variables, the behavior of an average surface roughness is investigated and analyzed with an experimental modeling of least square algorithm. And it can be used for the prediction of $R_a$ in different condition of machining.

• Journal of the Korean Society for Precision Engineering
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• 제14권7호
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• pp.99-107
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• 1997

An algorithm is developed to find optimal machining parameters for multiple machining environments. The cutting rate-tool life (R-T) characteristic curve presents the general loci of optima and is useful for the flexible machining operations planning. The R-T characteristic curve for the machining economics prob- lems with linear-logarithmic tool lofe model may be determined by applying sensitivity analysis to log-dual problems. Three cases of the change of machining environments are considered. An end milling example is constructed to illustrate the algorithm.

• Transactions of the Korean Society of Machine Tool Engineers
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• 제10권1호
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• pp.59-64
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• 2001

This paper is on a new cutting force model which includes the force caused by unbalance. The cutting under the different additional masses are measured with the spindle speed changed. The model is justified through correlation between simulation and experimental result.

• Digital Contents
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• 8호통권135호
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• pp.80-81
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• 2004

공공정보는 더이상 단순한 공개대상이 아니다. 적절한 가공을 통해 부가가치를 만들어 낼 수 있는 무한한 콘텐츠다. 일반 국민을위해 제공되는 보편적 서비스와는 별개로 공공정보를 상용화하려는 움직임은 선진국을 중심으로 상당히 진전돼 있다. 우리나라도 공공정보로 돈을 버는 업체들이 속속 등장하고 있다. 지난달 15일 한국데이터베이스진흥센터가 한국관광공사 상영관에서 개최한 세미나는‘공공정보 상용화’에 대한 국내외 현황과 전략, 모델을 살펴볼 수 있는 좋은 자리였다.

• Journal of the Korean Society of Propulsion Engineers
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• 제14권4호
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• pp.39-45
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• 2010

Thick-walled cylinders, such as a cannon or nuclear reactor, are autofrettaged to induce advantageous residual stresses into pressure vessels and to increase operating pressure and the fatigue lifetimes. As the autofrettage level increases, the magnitude of compressive residual stress at the bore also increases. The purpose of the present paper is to predict the accurate residual stress of SCM440 high strength steel using the Kendall model which was adopted by ASME Code. Hydraulic pressure process was applied in the inner part and thick-walled cylinders were autofrettaged up to 30% overstrain levels. Electro polishing on the surface of autofrettage specimen was performed to get more accurate residual stress. Residual stresses were measured by X-ray diffraction method. The autofrettage surface which was plastically deformed analyzed using a scanning electron microscope(SEM). Although there were some differences in measured residual stress and numerical results, it has a tendency to agree comparatively with each other.

• Journal of the Korean Society of Manufacturing Process Engineers
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• 제14권5호
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• pp.107-112
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• 2015

Increased productivity and cost reduction have emerged as the main goals of the industry due to the development of the machinery industry, and mechanical materials with excellent properties with the development of the machine tool industry are widely used in machine parts or structures. In addition, the cutting process of production plays a pivotal role in the production technology. Studies on cutting have involved a lot of research on the material, the cutting tool, the processing conditions, and numerical analysis. Due to the development of the computer through numerical analysis, cutting conditions, the assessment of cutting performance, and cutting quality could be predicted. This research uses the creation of the material model and AdvantEdge Production module for the NC code analysis. To improve the productivity, this research employs the optimization method to reduce cutting time.

• The Journal of the Convergence on Culture Technology
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• 제9권5호
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• pp.737-745
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• 2023

This paper discusses a study on developing an artificial intelligence model to detect incidents of fires in distribution switchboard using thermal images. The objective of the research is to preprocess collected thermal images into suitable data for object detection models and design a model capable of determining the occurrence of fires within distribution panels. The study utilizes thermal image data from AI-HUB's industrial complex for training. Two CNN-based deep learning object detection algorithms, namely Faster R-CNN and RetinaNet, are employed to construct models. The paper compares and analyzes these two models, ultimately proposing the optimal model for the task.

• Transactions of the Korean Society of Mechanical Engineers A
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• 제35권10호
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• pp.1307-1313
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• 2011

The mechanical limited slip differential (LSD) in vehicles is being replaced by the electromagnetic LSD because of its fast response and better active control characteristics. The coil housing made of STS 304 is one of the most important parts in the solenoid assembly of the electromagnetic LSD. High geometrical accuracy is a prerequisite for the manufacture of such coil housings, but precision machining is difficult because of the use of STS 304 thin plate and the variance in machining variables. The aim of this study is to optimize the mean and variance of the shape accuracy in the coil housing by finding a robust solution for the machining process conditions. The mean and standard deviation of the jaw contact pressure, cutting speed, and feed rate are considered to be the major parameters for minimizing the geometrical mean and variance. The response surface model based on the second-order Taylor series is combined together to minimize the mean and variance of the shape accuracy of the coil housing.

• Journal of Internet of Things and Convergence
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• 제9권3호
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• pp.93-98
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• 2023

In this paper, an artificial neural network based on simulated annealing was constructed. The mapping relationship between the parameters of micro-scaled flow channels electrochemical machining and the channel shape was established by training the samples. The depth and width of micro-scaled flow channels electrochemical machining on stainless steel surface were predicted, and the flow channels experiment was carried out with pulse power supply in NaNO3 solution to verify the established network model. The results show that the depth and width of the channel predicted by the simulated annealing artificial neural network with "4-7-2" structure are very close to the experimental values, and the error is less than 5.3%. The predicted and experimental data show that the etching degree in the process of channels electrochemical machining is closely related to voltage and current density. When the voltage is less than 5V, a "small island" is formed in the channel; When the voltage is greater than 40V, the lateral etching of the channel is relatively large, and the "dam" between the channels disappears. When the voltage is 25V, the machining morphology of the channel is the best.