• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1995년도 추계학술대회논문집
• /
• pp.57-68
• /
• 1995

A design methodology is applied for manufacturing the valve-spring retainer component. The design criterion is the forging load within the available press limit. Also, the final product should not have any geometrical defect. The rigid-plastic TEM has been applied to simulate the conventional five-stage manufacturing processes, which include mainly backward extrusion and heading process. Simulations of one step process from selected stocks to the final product shape are performed for a possibly better process than the conventional one.

• 한국안전학회지
• /
• 제20권2호
• /
• pp.140-145
• /
• 2005

The PL(Product Liability) Law has been going into effect in Korea since July 2002. Accordingly, a company's responsibility for customers who are damaged by the defect in the product safety has been gradually strict and imposed burden on management. Not only general consumers but also labors who work with machine in the field of production are included in the concept of victim of the PL Law. That is to say, when a worker is damaged by the defect of machine he can institute a PL lawsuit more aggressively, not just get the industrial accident compensation as usual, only if not his own fault but the defect of machine used in the course of production can be demonstrated. This paper intends to present suggestions to PL prevention of manufacturing companies of industrial machine through the case research of PL accidents in the area of industrial safety.

• International Journal of Precision Engineering and Manufacturing
• /
• 제4권6호
• /
• pp.12-19
• /
• 2003

This paper presents the effect of boundary conditions in various failure pressure models published for the estimation of failure pressure. Furthermore, this approach is extended to the failure prediction with the aid of a failure probability model. The first order Taylor series expansion of the limit state function is used in order to estimate the probability of failure associated with each corrosion defect in buried pipelines for long exposure period with unit of years. A failure probability model based on the von-Mises failure criterion is adapted. The log-normal and standard normal probability functions for varying random variables are adapted. The effects of random variables such as defect depth, pipe diameter, defect length, fluid pressure, corrosion rate, material yield stress, material ultimate tensile strength and pipe thickness on the failure probability of the buried pipelines are systematically investigated for the corrosion pipeline by using an adapted failure probability model and varying failure pressure model.

• 제어로봇시스템학회논문지
• /
• 제22권8호
• /
• pp.627-632
• /
• 2016

In this paper, we propose a new vision-based defect inspection system for the surface of hot slabs. To minimize the influence of self-emission from slab surfaces with high temperature, an optic method based on blue LED light and a blue pass filter is proposed. Because the slab surface is partially covered with scales, which are unavoidable oxidized substances caused during manufacturing, it is difficult to distinguish between vertical cracks and scale. In order to resolve this problem and to improve the detection performance, the use of a Gabor filter and dynamic programming are proposed. Finally, the effectiveness of the proposed method is shown by means of experiments conducted on images of hot slabs that were obtained from an actual slab production line.

• 산업경영시스템학회지
• /
• 제35권4호
• /
• pp.1-9
• /
• 2012

Decisions on reliability screening rules and burn-in policies are determined based on the estimated reliability. The variability in a semiconductor manufacturing process does not only causes quality problems but it also makes reliability estimation more complicated. This study investigates the nonuniformity characteristics of integrated circuit reliability according to defect density distribution within a wafer and between wafers then develops optimal burn-in policy based on the estimated reliability. New reliability estimation model based on yield information is developed using a spatial stochastic process. Spatial defect density variation is reflected in the reliability estimation, and the defect densities of each die location are considered as input variables of the burn-in optimization. Reliability screening and optimal burn-in policy subject to the burn-in cost minimization is examined, and numerical experiments are conducted.

• 한국항공운항학회지
• /
• 제13권1호
• /
• pp.43-49
• /
• 2005

There are several ways to mold the complex material, and it is divided to vacuum pack mold, compression mold, and hand lay up for a high molecular substance as a basic material. Moreover, it can be divided to general manufacturing (Single form) and mold manufacturing(Mold form) under normal temperature for Firefly. Firefly was manufactured with hand lay up and general manufacturing that using the foam core, glass fabric, and template without mold. However, mold manufacturing that is producing the surface by semi-sandwich using thin foam core and glass fabric then reinforce the inside with spar and rib is on developing. Mold manufacturing can make easy to production, standardize the quality, and possible to mass producing. In this paper, we present the mold producing process for canard aircraft "Firefly", and the problems and solutions during producing Firefly. Moreover, it complements the defect that the problems caused by master manufacturing error when produce several masters of a large part, and make the manufacturing process to be shortened by the replacement from the supplementary plate to the foam that is installed when producing lay up mold.

• 한국기계가공학회지
• /
• 제18권5호
• /
• pp.37-47
• /
• 2019

Recently, as demand for various paper containers has rapidly grown, it is inevitable that paper cup-forming machines have increased their manufacturing speed. However, the faster manufacturing speed naturally brings more frequent manufacturing failures, which decreases manufacturing efficiency. As such, it is necessary to develop a system that monitors the failures in real time and diagnoses the failure progress in advance. In this research, a paper cup-forming machine diagnosis system was developed. Three major failure targets, paper deviation, temperature failure, and abnormal vibration, which dominantly affect the manufacturing process when they occur, were monitored and diagnosed. To evaluate the developed diagnosis system, extensive experiments were performed with the actual data gathered from the paper cup-forming machine. Furthermore, the desired system validation was obtained. The proposed system is expected to anticipate and prevent serious promising failures in advance and lower the final defect rate considerably.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2006년도 춘계학술대회 논문집
• /
• pp.637-638
• /
• 2006

V-belt pulleys play a key role in driving cooling pump, oil pump, air-conditioner and so on by using an engine power. Precision deep drawing is one of the main processes for manufacturing the pulleys. Operation variables of the deep drawing equipment, called the setup parameter, must be re-determined whenever the specifications of pulley to be produced are changed. The defect rates during a setup of equipment and the working hours needed for the setup are almost dependent on workers' know-how. This study designs the program for easily determining setup conditions in pulley manufacturing process.

• 품질경영학회지
• /
• 제34권4호
• /
• pp.51-64
• /
• 2006

The PL (Product Liability) Law has been going into effect in Korea since July 2002. Accordingly, a company's responsibility for customers who are damaged by the defect in the product safety has been gradually strict and imposed burden on management. This paper presents suggestions as to PL prevention of diary manufacturing companies through the case research of PL prevention strategies and the prevention systems of the domestic diary manufacturing company.

• 한국정밀공학회지
• /
• 제21권12호
• /
• pp.92-99
• /
• 2004

The formation degree of sustain (ITO pattern) decides quality of PDP (Plasma Display Panel). For this reason, it makes efforts in searching defects more than 30 un as 100%. Now, the existing inspection is dependent upon naked eye or microscope in off-line PDP manufacturing process. In this study developed prototype inspection system of PDP 170 glass is based on line-scan mechanism. Developed system creates information that detects and sorts kinds of defect automatically. Designed inspection technology adopts multi-vision method by slip-beam formation for the minimum of inspection time and detection algorithm is embodied in detection ability of developed system. Designed algorithm had to make good use of kernel matrix that draws up an approach to geometry. A characteristic of defects, as pin hole, substance, protrusion, are extracted from blob analysis method. Defects, as open, short, spots and et al, are distinguished by line type inspection algorithm. In experiment, we could have ensured ability of inspection that can be detected with reliability of up to 95% in about 60 seconds.