• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.1
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• pp.1-8
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• 2012

Objectives: The aim of this study is to review occupational hygiene activities, including work environment measurement as required by the industrial safety and health laws of Korea, and suggest improvements required to establish an effective exposure surveillance system. Methods: The controversial limitations of exposure surveillance examining the work-association of several types of cancers in semiconductor workers were reviewed. Results: The bulk of the exposure surveillance system was found to focus purely on work environment measurements without providing other important exposure surrogates, such as job title, operation, exposure duration, etc. The current work environment measurement system is limited in terms of the efficient assessment of the exposure status of workers due to a lack of exposure information. Conclusion: The introduction of a national standard classification of occupations and job titles into the exposure and health effect surveillance system should be discussed in order to retrospectively assess exposure characteristics.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.4
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• pp.525-533
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• 2015

Objectives: Alongside smoking, occupational exposure is an important risk factor for chronic obstructive pulmonary disease. The purpose of this study was to evaluate factors associated with occupational pulmonary function decline that can be used to create guidelines for the health management of shipyard workers Materials: This study analyzed spirometry from 10,597 male shipbuilding workers. Functional decline in spirometry was defined as FEV1/FVC <70% and logistic regression for work duration and occupational hazard exposure was performed Results: Among the subjects, 4.2% showed an obstructive pattern in pulmonary function. The odds ratios for hazard exposure were 1.67(indirect) and 3.54(direct), and for work duration 1.97(10-18 years), 2.29(19-27), and 5.02(28+). After adjusting for smoking and work-related factors, the odds ratios for work durations of over 10 years were 1.73(10-18 years), 1.99(19-27), and 4.09(28+), but for hazards exposure was 1.71(direct) alone after adjustment. Conclusions: Occupational COPD is insidious and chronic, and thus long-term hazard exposed(especially over 10 years) shipyard workers with functional decline in spirometry need to prevent and manage COPD. This study is important for establishing guidelines to manage hazard exposure among shipyard workers and prevent COPD.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.1
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• pp.18-26
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• 2009

Recently, from an environmental conservative point of view, the need of high-efficiency lighting system, using LED(Light Emitting Diode) light sources have been increased. However, applied LED light sources without regard to its color and pattern provide visual discomfort to occupant. The objective of this study is not only to evaluate the performance of task work under different correlated color temperature condition, but also furnish the preliminary data as concerning its purpose and user of inner space. For the purpose of this study, two types of LED light sources and a fluorescent light source were selected. Thirty undergraduate students served as the participants. Two different task work sheets were conducted to evaluate the accuracy and duration of time. Results from subjective performance, task work of error modification showed that LED light sources were 2.5[%] higher in accuracy with 17.1[%] lower duration than a fluorescent light source. In the case of reading task work, It is presented 20.6[%] decrease with the LED light sources comparison with a fluorescent light source.

• Korean Journal of Construction Engineering and Management
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• v.7 no.1 s.29
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• pp.148-158
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• 2006

Public construction companies have strictly followed a rule that they should not do the works using water such as concrete pouring for the structural frame for a certain period during the winter season. It is usually known that the designated non-working period during the winter causes increase of the project duration and the project cost escalation. The halted work also makes negative effects on national economy because it reduces worker's income. However, the situation would be a lot better if the work for the structural frame is allowed under some conditions. The structural framework done alone without being followed by finish works gives a lot of stresses on the finish works. In this sense, this study examines how the structural framework performed during the winter season affect on the critical path of the finish works. To accomplish the objective of this research, the subnet for the finish works as well as a master network are prepared along with critical paths for a virtual construction site. Using the prepared networks, simulations are carried out to see the effects described above. This study is expected to be used in estimating the construction duration of high-rise apartment housing when the site work for the structural frame should be performed during this period.

• The Korean Journal of Pain
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• v.32 no.1
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• pp.47-50
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• 2019

Background: It is uncommon for patients who have received a permanent implant to remove the spinal cord stimulator (SCS) after discontinuation of medication in complex regional pain syndrome (CRPS) due to their completely painless state. This study evaluated CRPS patients who successfully removed their SCSs. Methods: This 10-year retrospective study was performed on patients who had received the permanent implantation of an SCS and had removed it 6 months after discontinuation of stimulation, while halting all medications for neuropathic pain. Age, sex, duration of implantation, site and type of CRPS, and their return to work were compared between the removal and non-removal groups. Results: Five (12.5%, M/F = 4/1) of 40 patients (M/F = 33/7) successfully removed the permanent implant. The mean age was younger in the removal group ($27.2{\pm}6.4$ vs. $43.5{\pm}10.7$ years, P < 0.01). The mean duration of implantation in the removal group was $34.4{\pm}18.2$ months. Two of 15 patients (13.3%) and 3 of 25 patients (12%) who had upper and lower extremity pain, respectively, had removed the implant. The implants could be removed in 5 of 27 patients (18.5%) with CRPS type 1 (P < 0.01). All 5 patients (100%) who removed their SCS returned to work, while only 5 of 35 (14.3%) in the non-removal group did (P < 0.01). Conclusions: Even though this study had limited data, younger patients with CRPS type 1 could remove their SCSs within a 5-year period and return to work with complete pain relief.

• Journal of Preventive Medicine and Public Health
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• v.39 no.1
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• pp.74-80
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• 2006

Objectives: The purpose of this study is to examine the factors affecting the rate and duration of breastfeeding. Methods: We analyzed the data from the year 2000 Korea National Fertility Survey that was collected through direct interviews. In particular, the mothers who delivered their last child and the child was under 1 year of age from January 1998 to June 2000 (N=1,066) were analyzed via a logistic model to assess the factors affecting the breastfeeding rate. Among the study subjects, those who had initiated breastfeeding (N=740) were analyzed through Cox's proportional hazard model to evaluate the factors affecting the duration of breastfeeding. Results: The multivariate logistic model showed that the delivery type and the baby's birth-weight have a statistically significant influence on the breastfeeding rate. Women who delivered their babies through Cesarean section were less likely than others to breastfeed. In contrast, the women whose babies weighed 2.5Kg or more were more likely than others to breastfeed. The results obtained from the survival analysis are as follows: the higher the mother's education level, the shorter is the breastfeeding duration. The mother's work status played a significant role in the early termination of breastfeeding. Women aged 35 or older showed a longer breastfeeding duration than the younger age groups, whereas the maternal age was not a significant factor in affecting whether or not a mother would breastfeed. Conclusions: Reducing the cases of operative delivery (Cesarean section) and low weight births, enlightening young and highly educated women on breastfeeding and improving the environment for breastfeeding on the job are important strategies to encourage women to breastfeed.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.359-366
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• 2013

Although many research efforts have been conducted to address the effect of crew members' work skills (e.g., technical and planning skills) on work performance (e.g., work duration and quality) in construction projects, the relationship between skill and performance has generated a great deal of controversy in the field of management (Inkpen and Crossan 1995). This controversy can lead to under- or over-estimations of the overall project schedule, and can make it difficult for project managers to implement appropriate managerial policies for enhancing project performance. To address this issue, the following aspects need to be considered: (a) work performances are determined not only by individual-level work skill but also by the group-level work skill affected by work team members, each member's role, and any working behavior pattern; (b) work planning has significant effects on to what extent work skill enhances performance; and (c) different types of activities in construction require different types of work, skill, and team composition. This research, therefore, develops a system dynamics (SD) model to analyze the effects of both individual-and group-level (i.e., multi-level) skill on performances by utilizing the advantages of SD in capturing a feedback process and state changes, especially in human factors (e.g., attitude, ability, and behavior). The model incorporates: (a) a multi-level skill evolution and relevant behavior development mechanism within a work group; (b) the interaction among work planning, a crew's skill-learning, skill manifestation, and performances; and (c) the different work characteristics of each activity. This model can be utilized to implement appropriate work planning (e.g., work scope and work schedule) and crew management policies (e.g., work team composition and decision of each worker's role) with an awareness of crew's skill and work performance. Understanding the different characteristics of each activity can also support project managers in applying strategic work planning and crew management for a corresponding activity, which may enhance each activity's performance, as well as the overall project performance.

• Safety and Health at Work
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• v.14 no.1
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• pp.59-65
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• 2023

Objectives: Epidemiological evidence linking long working hours and shift work to metabolic syndrome remains inadequate. We sought to evaluate the impact of reducing working hours on metabolic syndrome. Methods: We compared the prevalence of metabolic syndrome among male manual workers in a manufacturing company (N = 371) before and after the introduction of policy to reduce daily work hours from 10 to 8 hours. Components of metabolic syndrome were measured in periodic health examinations before the intervention, 6-9 months after, and 1.5-2 years after the intervention. Generalized estimating equation models were used to estimate changes in the prevalence of metabolic syndrome. Analyses were stratified by day work versus shift work. Results: The results showed a significantly decreased prevalence of metabolic syndrome 6-9 months following the intervention in day workers (risk ratio = 0.68, 95% confidence interval 0.52-0.88), but the benefit disappeared after 1.5-2 years. Shift workers showed a decreased prevalence of metabolic syndrome for the whole follow-up duration after the intervention, although the change was not statistically significant. Conclusion: Reducing working hours was associated with short-term improvement in metabolic syndrome in male manual workers.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.952-959
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• 2022

Active construction work zones will result in longer travel time and/or longer travel distances for road users because of reduced speed limits and/or detours. This results in increased fuel consumption and increased emissions of harmful gases such as Carbon Monoxide (CO), Nitrogen Oxides (NOx), and Sulfur Oxides (SOx), which causes discomfort to the environment and road users around the work zone. The impact of such emissions should be considered while designing work zones or determining the number of days the roadway will be allowed to be closed partially or fully. This study develops a methodology to compute additional road user costs associated with such work zones. To achieve this goal, a) an extensive literature review is conducted, b) a framework to compute emission cost is developed, c) emission rates are computed for all counties (95) of the state of Tennessee, and d) a case study is conducted to demonstrate the use of the framework to estimate the additional impact of emission because of the work zone. For the case study conducted, the emission cost was computed to be $10,653.60 for the duration of the project. State DOTs can account for such road user costs while selecting contractors using A+B bidding. Accounting for such impact of emission will also indicate the agency's willingness to consider sustainability as a part of the business practices.

• Analytical Science and Technology
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• v.6 no.4
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• pp.363-368
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• 1993

Blood lead concentrations of occupationally exposed workers were measured by the atomic absorption spectrometry with graphite furnace. The concentrations of the unexposed group were also checked and compaired with those of the exposed one. The correlation of smoking habit and work duration with the blood lead concentration was also surveyed.