• Journal of the Korea Safety Management & Science
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• v.17 no.1
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• pp.179-192
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• 2015

In an automated industry PLC plays a central role to control the automation system. Therefore, fault free operation of PLC controlled automation system is essential in order to maximize a firm's productivity. A prior test of control system is a practical way to check fault operations, but it is a time consuming job and can not check all possible fault operation. A formal verification of PLC program could be a best way to check all possible fault situation. Tracing the history of the study on formal verification, we found three problems, the first is that a formal representation of PLC control system is incomplete, the second is a state explosion problem and the third is that the verification result is difficult to use for the correction of control program. In this paper, we propose a transformation method to reproduce the control system correctly in formal model and efficient procedure to verify and correct the control program using verification result. To demonstrate the proposed method, we provided a suitable case study of an automation system.

• The Journal of the Korea Contents Association
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• v.19 no.12
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• pp.151-163
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• 2019

The purpose of this study was to investigate the effects of safety culture on the safety consciousness and safety behaviors of manufacturing workers, and to suggest ways for manufacturing workers to understand the safety culture and improve safety consciousness and safety behavior. To achieve this research objective, out of 176 industrial complexes in Seoul and Gyeonggi Province registered with the Korea Industrial Complex Corporation, workers at 50 industrial complexes, including the Korea Export-Industrial Complex and Seoul's Onsuji, were subject to research. The implementation of this survey distributed 300 questionnaires through the mid-level managers of manufacturers and environment safety and health managers over a period of one month from August 1st to 31st, 2019, finally statisticalizing the data in 282 parts excluding 18 questionnaires deemed to have been unresponsive. First, the safety culture (safety climate, safety procedures) has a positive effect on the safety consciousness (recognition of importance, interest and participation inducement) of the manufacturing workers. Second, the safety culture (safety climate, safety procedures) has a positive effect on the safety behavior (safety planning, safety check) of manufacturing workers. Third, safety consciousness (recognition of importance, interest and inducement of participation) has a positive influence on the safety behavior (safety planning, safety check) of manufacturing workers. Fourth, the safety consciousness (recognition of importance, interest and inducement of participation) appears to have a partial mediating effect in relation to safety culture (safety climate, safety procedure) and safety behavior (safety planning, safety check) of manufacturing workers. The implication of this study is that although the industrial accidents have occurred in the manufacturing industry in recent years, the studies on the workers in the manufacturing industry are insufficient. However, this study is meaningful that it has suggested ways for manufacturing workers to understand the safety culture and improve the safety consciousness and safety behavior by analyzing the effects of safety culture on safety consciousness and safety behavior of manufacturing workers.

• Proceedings of the Safety Management and Science Conference
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• 1999.11a
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• pp.183-189
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• 1999

Nowadays advanced manufacturing companies are trying to find a way to check the performance of their production equipments and plants from remote sites. However, it is hard to monitor the status of machine or to check the performance of the processes because the regional limitation of distributed environment. This paper presents research results in the real time monitoring of machining processes and internet_based operation of machining centers via internet, which is implemented using VRML and JAVA.

• Journal of Korean Society of Disaster and Security
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• v.10 no.2
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• pp.43-47
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• 2017

There is no safety accident of the class 1 and 2 facilities that have been managed by the 'Special Act on Safety Management of Facilities' in the last 22 years. Safety accidents of the small sized facilities are increasing every year because of the lack of systematic management of the facilities. The government plans to enact a small portion of small sized buildings into the class 3 facilities, enabling them to enact a safety check. In this paper, we analyze the safety management status of the class 3 facilities of buildings and propose a plan for improving the safety of small sized buildings.

• Journal of the Korean Society of Safety
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• v.16 no.2
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• pp.80-84
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• 2001

Work stress and health are very important factors related to workers' condition and work safety, Author has conducted a couple of tests to check up three people's pulses before they work during their work for three types of safety guard in construction site. Work type, age, weight, sex experience year, ambient temperature n recorded as variables in this study. These are checked and asked by the author directly, before their pulse check Also, workers' Pulses were measured at height H-0 and H-9.0m to understand psychological the degree of psychological nervousness degree. POLAR protrainer NVTM HRM system(wrist recorder and sensor) was used for the site test. There are three(3) different types of construction safety guard which have been used for, this study. They are usually or frequently used and found in the site. Four different ranges of age groups(20's, 30's 40's, 50's) carpenters are assisted to the test sites with wearing pulse recorder and sensor respectively. All three types of safety guards have the same height 90㎝ even though they are different types. On top of five(5) stories tublar framed scaffolding is fabricated, similar to the one in site, where those safety guards are installed. The older(=more experienced) the workers are the more stable they are. it is shown. Also, It is verified the visually uncomfortable rail type can cause workers to psychologically be unstable.

• Resources Recycling
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• v.10 no.1
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• pp.56-65
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• 2001

Chemical decontamination techniques have been employed to reuse the high cost check valves contaminated with radioactivity and to reduce the radiation exposure during the inspection and maintenance work of safety injection system containing check valves. After chemical decontamination, an ultrasonic treatment was conducted to remove the fine solid particles retained in the crevices of check valves. The decontamination process conditions and the amount of chemical reagents were determined from the results of a pre-test, using the (list arm holder. The decontamination factors (DF), estimated from the activity in the solution, ranged from 14.5 to 18.5 corresponding to the activity removal of 93-95ft. The corrosion test data indicated that the general corrosion rate during a chemical decontamination-ultrasonic treatment process are low for type 304 S tainless steel, Inconel -600 and Stellite-6 materials $ (2.1\times10^{-2}$ $6.0\times10^{-2}$ and$ 1.7\times10^{-2}$ mil, respectively).

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2198-2202
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• 2005

In this paper we have presented a condition monitoring method of check valve using neural network. The acoustic emission sensor was used to acquire the condition signals of check valve in direct vessel injection (DVI) test loop. The acquired sensor signal pass through a signal conditioning which are consisted of steps; rejection of background noise, amplification, analogue to digital conversion, extract of feature points. The extracted feature points which represent the condition of check valve was utilized input values of fault diagnosis algorithms using pre-learned neural network. The fault diagnosis algorithm proceeds fault detection, fault isolation and fault identification within limited ranges. The developed algorithm enables timely diagnosis of failure of check valve’s degradation and service aging so that maintenance and replacement could be preformed prior to loss of the safety function. The overall process has been experimented and the results are given to show its effectiveness.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.128-134
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• 2018

With the increase in frequency of typhoons and heavy rains following the climate change, the scale of damage from the calamities in the mountainous areas has been growing larger and larger, which is different from the past. For the case of Korea where 64% of land is consisted of the mountainous areas, establishment of the check dams has been drastically increased after 2000 in order to reduce the damages from the debris flow. However, due to the lack of data on scale, location and kind of check dams established for reducing the damages in debris flow, the measures to prevent damages based on experience and subjective basis have to be relied on. Under this study, the high-precision DEM data was structured by using the terrestrial LiDAR in the Jecheon area where the debris flow damage occurred in July 2009. And, from the numerical models of the debris flow, Kanako-2D that is available to reflect the erosion and deposition action was applied to install the erosion control facilities (water channel, check dam) and analyzed the effect of reducing the debris flow shown in the downstream.After installing the erosion control facilities, most of debris flow moves along the water channel to reduce the area to expand the debris flow, and after installing the check dam, the flow depth and flux of the debris flow were reduced along with the erosion. However, as a result of analyzing the diffusion area, flow depth, erosion and deposition volume of the debris flow generated from the deposition part after modifying the location of the check dams with the damages occurring on private residences and agricultural land located on the upstream area, the highest reduction effect was shown when the check dam is installed in the maximal discharge points.

• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.363-370
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• 2012

Objective: The objective of this study is to analyze standards of ISO 9001, ISO 14001, KOSHA 18001, GAP and ISO 22000 to make an integrated system and check whether an integrated system can be used at small size companies. Background: There are many certification criteria for quality, safety and health such as ISO 9001, ISO 14001, KOSHA 18001, GAP and ISO 22000. However, these criteria are difficult and complicated to be used at a small size company. Thus. it is not easy for small size companies to obtain certifications using these criteria. But customers and workers of small size companies want the key points of these systems to be implemented. Method: ISO 9001, ISO 14001, KOSHA 18001, GAP and ISO 22000 were analyzed to find the commonality and duplications as well as the importance of the items in these standards. And a survey was conducted to check whether certain aspects of the anticipated integrated system can be implemented at small size companies. Results: Items were classified into categories based upon the importance to food safety, quality, safety, environment, and health. Items which are common among standards were also identified and thus give ideas to make the new standards simpler than the currently available standards. Items which were important but may not be easily implemented at the small size companies were also identified. Conclusion: By considering the fact that the currently used accreditation standards have many similar aspects, these systems can be integrated into one new system which small size companies can use relatively easily.

• The Journal of Sustainable Design and Educational Environment Research
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• v.18 no.1
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• pp.38-48
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• 2019

The purpose of this study is to present a more effective daily checklist than the formal routine check before the experiment to prevent accidents in the university laboratory. To do this, we reconstructed the current daily checklist and previous research data and conducted a second Delphi survey. As a result, there were four general safeties such as arranging the laboratory, three mechanical safeties such as abnormal condition of machine and tool tightening parts, three electric safeties such as prohibition of loading around the electric distribution panel, six chemical safeties such as handling and managing harmful factors, three items of fire safety such as fire extinguisher inspection, five cases of gas safety gas container inspection, one item of biological safety such as the state of hand sterilizer management and one other item, which were provided in the daily checklist as twenty six categories in total. According to the opinions of related experts, it is necessary to have an easy and simplified daily checklist for actual daily checkups.