• 한국안전학회지
• /
• 제38권4호
• /
• pp.47-53
• /
• 2023

In the inspection of workplace hazards/risk factors by specialized institutions dedicated to safety management, inspection reports vary based on the inspectors, who lack the authority to enforce improvement of workplace hazards/risk factors. Thus, improvement and accident rates remain steady without decreasing. This study performed a regression analysis on the relationship between improvement and accident rates of categorized inspection items by classifying hazards/risk factors from inspection reports submitted by a specialized safety management institution in Chungbuk after inspecting 10 food and beverage manufacturers over the past three years. The hazards/risk factors were classified into five categories: mechanical, electrical, chemical, human, and environmental. The regression analysis revealed that the improvement rate of hazards/risk factors inspected by the specialized safety management institution influenced accident rates. To enhance improvement rates based on these findings, this study prioritized the correction of the five most frequently cited inspection items with the lowest improvement rates in each area. Based on these inspection items, this study suggested a checklist for use in workplace safety inspections of food manufacturers. This proposed checklist is expected to reduce accident rates in food manufacturing facilities. Currently, guidance and inspection of workplaces are mainly focused on accident rates rather than correcting hazards/risks. Thus, accident rates remain unchanged as workplace risks are inadequately improved according to the unique characteristics of each workplace. When conducting workplace guidance and inspection, policy measures and inspection methods are warranted to increase the improvement rate of hazards/risks.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 B
• /
• pp.668-670
• /
• 1999

We have developed a automatic surface inspection system for cold Rolled strips in steel making process for several years. We have experienced the various kinds of surface inspection systems, including linear CCD camera type and the laser type inspection system which was installed in cold rolled strips production lines. But, we did not satisfied with these inspection systems owing to insufficient detection and classification rate, real time processing performance and limited line speed of real production lines. In order to increase detection and computing power, we have used the Dark Field illumination with Infra_Red LED, Bright Field illumination with Xenon Lamp, Parallel Computing Processor with Area typed CCD camera and full software based image processing technique for the ease up_grading and maintenance. In this paper, we introduced the automatic inspection system and real time image processing technique using the Object Detection, Defect Detection, Classification algorithms. As a result of experiment, under the situation of the high speed processed line(max 1000 meter per minute) defect detection is above 90% for all occurred defects in real line, defect name classification rate is about 80% for most frequently occurred 8 defect, and defect grade classification rate is 84% for name classified defect.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2011년도 제42회 하계학술대회
• /
• pp.1780-1781
• /
• 2011

There have been numerous studies on application of robots to in-pipe inspection system. In this thesis, a mobile robot that can move through elbows and vertical pipes having diameter 100mm is developed. Defect detection technology for locating wall-thinnings, corrosions and foreign materials is developed for high temperature and pressure pipings in thermal power plants, utilizing laser sensors installed on the robot. Actual defect detection performance is evaluated with application of the developed robot system to a mock-up pipings.

• Smart Structures and Systems
• /
• 제22권2호
• /
• pp.193-200
• /
• 2018

From the viewpoint of engineering applications, the prediction of the failure of bogies plays an important role in preventing the occurrence of fatigue. Fatigue is a complex phenomenon affected by many uncertainties (such as load, environment, geometrical and material properties, and so on). The key to predict fatigue damage accurately is how to quantify these uncertainties. A Bayesian model is used to account for the uncertainty of various sources when predicting fatigue damage of structural components. In spite of improvements in the design of fatigue-sensitive structures, periodic non-destructive inspections are required for components. With the help of modern nondestructive inspection techniques, the fatigue flaws can be detected for bogie structures, and fatigue reliability can be updated by using Bayesian theorem with inspection data. A practical fatigue analysis of welded bogies is utilized to testify the effectiveness of the proposed methods.

• Journal of Mechanical Science and Technology
• /
• 제14권10호
• /
• pp.1072-1080
• /
• 2000

Leakage magnetic flux (LMF) is widely used for non-contact detection of cracks. The combination of optics and LMF offers advantages such as real time inspection, elimination of electrical noise, high spatial resolution, etc. This paper describes a new nondestructive evaluation method based on an original magneto-optical inspection system, which uses a magneto-optical sensor, LMF, and an improved magnetization method. The improved magnetization method has the following characteristics: high observation sensitivity, independence of the crack orientation, and precise transcription of the geometry of a complex crack. The use of vertical magnetization enables the visualization of the length and width of a crack. The inspection system provides the images of the crack, and shows a possibility for the computation of its depth.

• 반도체디스플레이기술학회지
• /
• 제19권3호
• /
• pp.12-18
• /
• 2020

In semiconductor manufacturing, defect detection is critical to maintain high yield. Currently, computer vision systems used in semiconductor photo lithography still have adopt to digital image processing algorithm, which often occur inspection faults due to sensitivity to external environment. Thus, we intend to handle this problem by means of using Mask R-CNN instead of digital image processing algorithm. Additionally, Mask R-CNN can be trained with image dataset pre-processed by means of the specific designed digital image filter to extract the enhanced feature map of Convolutional Neural Network (CNN). Our approach converged advantage of digital image processing and instance segmentation with deep learning yields more efficient semiconductor photo lithography inspection system than conventional system.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 제38회 하계학술대회
• /
• pp.1720-1721
• /
• 2007

This paper presents a Fuzzy+PID control method for a Bridge Inspection Robot(BIR) system. The BIR has been developed with the aim of checking the safety status of a real bridge, gathering accurate data and performing maintenance. The developed robot system is composed of the specially designed car for bridge inspection, the guide rail and the inspection robot. The proposed Fuzzy+PID controllers are used to track speed reference signal of X axis and position reference signal of Z axis. Experimental results verify that the proposed Fuzz+PID control design method can achieve favorable control performance with regard to external disturbance.

• 전기학회논문지P
• /
• 제58권2호
• /
• pp.231-234
• /
• 2009

Recently, to the development of a highly information-oriented society to a large increase in dependence on power, Accordingly, it is need that active development and spread of preservation technology on accident prevention in operation electrical equipment. However, to lack of the use on maintenance technology of power equipment and to increase of power usage is growing deterioration of power equipment, this is a cause on casualties, property damage and the occurrence of disasters is a growing. GIS equipments which are operated from domestic except the equipment which manages from the big business are depend on a most visual inspection, and do inspection method or measuring instrument etc. a condition which is not supplied widely. Currently, many to measure instrument used in domestic is very expensive or foreign, it will be able to substitute this, the development necessity of the diagnosis technique and the measuring instrument is demanded.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2011년도 제42회 하계학술대회
• /
• pp.2202-2203
• /
• 2011

AC substation of urban transit supplies a suitable AC power on electricity vehicles. AC substation is verified electrical safety of system through pre-operation inspection on electrical installations to be supplied power from KEPCO. However, because test items and method for AC traction system are unprepared on pre-operation inspection, the general safety and performance verification of AC traction system are very insufficient. Therefore this paper analyze the test examples such as factory equipment tests, factory combined tests and railway tests for the safety and performance verification of AC traction system and present a suitable test items and test standard in domestic.

• Journal of Electrical Engineering and Technology
• /
• 제13권6호
• /
• pp.2344-2353
• /
• 2018

A coupled recursive total least squares (CRTLS) algorithm is proposed for parameter estimation of permanent magnet synchronous machines (PMSMs). TLS considers the errors of both input variables and output ones, and thus achieves more accurate estimates than standard least squares method does. The proposed algorithm consists of two recursive total least squares (RTLS) algorithms for the d-axis subsystem and q-axis subsystem respectively. The incremental singular value decomposition (SVD) for the RTLS obtained by an approximate calculation with less computation. The performance of the CRTLS is demonstrated by simulation and experimental results.