• Journal of the Ergonomics Society of Korea
• /
• v.36 no.5
• /
• pp.411-420
• /
• 2017

Objective: The purpose of this study is to analyze the accident characteristics according to the gender of the injured workers in building cleaning and to reflect them in the Industrial Accident Prevention Policy. Background: An analysis of industrial accidents is an essential process for establishing systematic industrial accident prevention measures. In order to establish industrial accident prevention measures for workers effectively, it is necessary to analyze accident characteristics by job type for workers who do the same work. Method: In this study, we analyzed the accident characteristics of 1,645 janitors who were approved of work-related injuries in 2015. We also analyzed the characteristics according to gender by dividing them into worker-related factors and accident-related factors. Results: The accidents caused to the janitors showed different characteristics according to gender, age, work experience, agency of accident, and distribution of original cause materials. In other words, 70.2% occurred to workers over 60 years old and 56.2% occurred to unskilled workers with less than a year of work experience. In the case of accident pattern, 79.1% occurred in tripping (slip) hazards, and 68.2% of accidents occurred on the floor (including the ground) and the stairs, indicating that the accident occurred most frequently during cleaning work on the floor or stairs. Conclusion and Application: The results of the study on the accident characteristics of the janitors can be used as basic data for systematic preventive measures against accidents occurring to the elderly female workers in the service industry.

• Laser Solutions
• /
• v.12 no.4
• /
• pp.17-25
• /
• 2009

The surface cleaning method based on the laser-induced breakdown (LIB) of gas and subsequent plasma and shock wave generation can remove small particles from solid surfaces. In the laser shock cleaning (LSC) process, a high-power laser pulse induces optical breakdown of the ambient gas above the solid surface covered with contaminant particles. The subsequently created shock wave followed by a high-speed flow stream detaches the particles. In this work, a novel surface cleaning process using laser-induced breakdown of liquid is introduced and demonstrated. LIB of a micro liquid jet increases the shock wave intensity and thus removes smaller particle than the conventional LSC method. Experiments demonstrate that the cleaning force and cleaning efficiency are also increased significantly by this method.

• Journal of Nutrition and Health
• /
• v.30 no.6
• /
• pp.690-703
• /
• 1997

The purpose of this study were to analyze work function and labor productivity in school foodservice systems through work sampling methodology. Conventional foodservice were classified into 5 group depending on the number of meals served. Commissary school foodservices were also classified into 5 group by cluster analysis using the number of meals served, the number of satellite schools, and the duration of time for delivery of food. Work measurement through work sampling methodology was conducted in at 5 conventional and 21 commissary food -services during 3 consecutive days from September to October in 1995. Results from work measurement through work sampling methodology were as followed : The most prevalent work functions was cleaning (26.5%) and then processing (25.1%) in conventional while it was processing (30.9%) and then cleaning(25.2%) in commissary school foodservice. Delay was 22.9% and 19.7% respectively. Mean labor minutes per meal of conventional and commissary foodservics were 4.57 and 4.09 minutes, respectively : no significant difference in labor minutes per meal existed between the two systems. but mean labor minutes per meal of commissary foodsevices(1.79min) was significantly lower than that of conventional foodservice(2.33min) during work time before service (p<0.05). Productivity was significantly lower in foodservices which served less than 400 servings ; n significant differences existed among 401-70, 701-1,100 and 1,101-1,500 meals. The highest productivity was in conventional school foodservices which served 1,501-1,900meals. Labor minutes per meal of commissary school foodservice which served less than 400meals per day was significantly lower than those of foodservice which served 401-1,900meals (p<0.05). Labor minutes per meal, preparation and cleaning were positively correlation in two school foodservice systems.

• Clean Technology
• /
• v.10 no.2
• /
• pp.61-72
• /
• 2004

In this study, aqueous/semi-aqueous cleaning agents which consist of organic solvent, surfactant, cosurfactant, and water were developed by changing formulation parameters such as organic solvent type and contents, surfactant type and contents, and cosurfactant/surfactant(A/S) ratio, etc.. And physical properties and flux removal of the formulated cleaning agents have been evaluated. Also, the performance of oil-water separation from the rinse water contaminated during the cleaning process was evaluated for its recycling. The formulated cleaning agents in this work expected to have good penetration because of their low viscosity and low surface tension values of 30.2~32.5 dyne/cm. The flux removal with the terpene type cleaning agent was higher than that with hydrocarbon type cleaning agent and two commercial products (CPA(commercial product A), CPB(commercial product B)). And the performance of oil-water separation by gravity settling from the rinse water contaminated with formulated cleaning agent and soils was shown to be very good. The cleaning agents developed in this work were applied to surface mounting technology(SMT) cleaning process for manufacturing electronic parts at L electronic company. As a result, the newly developed cleaning agents showed two times better cleaning speed for removal of solder cream than the conventional ond containing ethanol and IPA(isopropyl alcohol). In addition, malodor and VOC problems generated by the previous organic cleaning agents have been solved in the manufacturing field through introduction of the non-volatile and environmental-friendly cleaning agents to the field.

• Safety and Health at Work
• /
• v.6 no.4
• /
• pp.345-352
• /
• 2015

Background: Goal-oriented communication of risk of hazards is necessary in order to reduce risk of workers' exposure to chemicals. Adequate training of workers and enterprise priority setting are essential elements. Cleaning enterprises have many challenges and the existing paradigms influence the risk levels of these enterprises. Methods: Information on organization and enterprises' prioritization in training programs was gathered from cleaning enterprises. A measure of enterprises' conceptual level of importance of chemical health hazards and a model for working out the risk index (RI) indicating enterprises' conceptual risk level was established and used to categorize the enterprises. Results: In 72.3% of cases, training takes place concurrently with task performances and in 67.4% experienced workers conduct the trainings. There is disparity between employers' opinion on competence level of the workers and reality. Lower conceptual level of importance was observed for cleaning enterprises of different sizes compared with regional safety delegates and occupational hygienists. Risk index values show no difference in risk level between small and large enterprises. Conclusion: Training of cleaning workers lacks the prerequisite for suitability and effectiveness to counter risks of chemical health hazards. There is dereliction of duty by management in the sector resulting in a lack of competence among the cleaning workers. Instituting acceptable easily attainable safety competence level for cleaners will conduce to risk reduction, and enforcement of attainment of the competence level would be a positive step.

• Safety and Health at Work
• /
• v.7 no.4
• /
• pp.389-393
• /
• 2016

Job hazard analyses were conducted to assess exposure to musculoskeletal disorder (MSD) risk factors in seven workers of three dry-cleaning establishments. In accordance with the Washington State Ergonomics Rule, the analyses were performed in two separate steps: (1) observation and checklist approaches were made to identify a "caution zone job" in the seven workers' pressing operations across the three shops; and (2) detailed posture and motion analyses were undertaken to determine a "MSD hazard" in one worker's operation using a video technique. One "caution zone job" was identified and it was the pressing operation job in which five physical risk factors were found in the pressing operations. The detailed analyses confirmed that one "MSD hazard", i.e., awkward posture in shoulders, was prevalent in the pressing operations of the three dry-cleaning facilities. It would be desirable to reduce MSD risk factors including awkward shoulder posture in the dry-cleaning industry.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.11a
• /
• pp.195-196
• /
• 2011

Recently, the number of high-rise buildings has been on the rise, which has meant that maintenance cost has increased by two and three times, along with the increase in the construction cost. It is suggested that the use of an auto-cleaning robot could increase the productivity and safety of cleaning work, which is mostly done outside of a building. In particular, the guide rail on a high-rise building could be useful in this capacity, as it has the advantage of not being significantly influenced by factors of the external environment, including wind pressure. For this reason, this research is preliminary research into a cleaning automation for a high-rise building, and aims to draw up a scenario for the vertically moving robot.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.157-159
• /
• 2012

In recent years, the number of high-rise buildings has been on the rise. As buildings have become larger in scale, significantly different issues related to their construction and maintenance have emerged. In addition, the automation and mechanization of the cleaning work for the curtain wall, one of the most frequently-performed tasks in building maintenance, is required as a fundamental measure. For this reason, a guide-rail type cleaning robot system is emerging as one of the measures in response to external factors, including gust. The major objective of this study is to propose an economic feasibility forecasting model and to apply the a building facade cleaning robot which is now under development.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.3 no.2
• /
• pp.74-79
• /
• 2002

In the a rapid changes of the semiconductor manufacturing technologies for early 21st century, it may be safely said that a kernel of terms is the size increase of Si wafer and the size decrease of semiconductor devices. As the size of Si wafers increases and semiconductor device is miniaturized, the units of cleaning processes increases. A present cleaning technology is based upon RCA cleaning which consumes vast chemicals and ultra pure water (UPW) and is the high temperature process. Therefore, this technology gives rise to the environmental issue. To resolve this matter, candidates of advanced cleaning processes has been studied. One of them is to apply the electrolyzed water. In this work, Compared with surface on Si wafer with electrolyzed water cleaning and various chemicals cleaning, and analyzed Si wafer surface condition treated with elecoolyzed water by cleaning temperature and cleaning time. Especially. concentrate upon the contact angle. finally, contact angle on surface treated with cathode water cleaning is 17.28, and anode water cleaning is 34.1.

• Korean journal of food and cookery science
• /
• v.8 no.3
• /
• pp.323-332
• /
• 1992

This study was carried out to investigate work analysis by use of work sampling and productivity of school feeding at three elementary schools in Seoul. The results were as knows: 1. In the mean work percent of dietitians The direct work functions showed the highest, as the mean work percent was 40.4% for me direct work functions, 29.9% for me indirect work functions and 29.8% for me delays. Among the direct work functions, routine clerical was 30.9%, and receiving was 9.5%. 2. In the mean work percent of bakers The direct work functions (73.5%) marked the highest. Among those, cooking was 41.8%, transportation was 15.9%, and cleaning was 8.5%. 3. In the mean work percent of workers The direct work functions (781%) were me highest. Among those, the decreasing order was cooking (32.3%), cleaning (27.8%), and transportation (13.8%). 4. Work percent per labor hour The work percent per labor hour of dietitians was higher in the morning than in me afternoon, while they continued to work even during the lunch time. Bakers usually worked in me morning, but rarely worked in me afternoon. Workers had lunch and break time after their food service. In me school aided by parents volunteers, the total work time of workers was reduced by an hour and their work percent in me afternoon was high. 5. The number of mea1s served per labor hour was 32.6 meals, and me labor time spent per served mea1 was 1.8 minutes.