• Korean Journal of Construction Engineering and Management
• /
• v.12 no.6
• /
• pp.3-13
• /
• 2011

The construction industry is still the most risky industry and labor accident is a significant management factor on construction site. Safety management has been studied for improving the safety performance on construction sites. However, Almost all of them have been considered on the site safety management for the contractors and evaluation of accident rate. To resolve the limitation of current research, this study is focused on considering accident result and effort by performing the evaluation of safety level of the head office and site in construction companies. By studying the research about a safety management and interviewing with specialists in safety management, 7 items were selected and weighted based on the KOSHA18001 List. Consequently, The checklist was developed to evaluate safety performance management in construction company and Safety Management Index was suggested to coordinate 1) the score of results in accident rate and 2) the effort to evaluate a safety performance management. Safety Management Index is more helpful to evaluate the safety management results and effort. As a result of considering the score of the accident rate and the safety performance management, the outcome of prequalification was changed. Using this index, contractors will attempt to prevent accidents and owners will be able to discriminate individual differences in bidding process.

• Korean Journal of Construction Engineering and Management
• /
• v.17 no.5
• /
• pp.108-119
• /
• 2016

Since the introduction of the converted accident rate in Pre-Qualification(PQ) process in 1992, the safety evaluation system has contributed to a reduction of construction accidents and development of the safety management system in public construction projects. As the comprehensive evaluation method the government plans to introduce includes the indicators 'accident rate' and 'death rate per 10,000 workers', the influences on the safety evaluation in the bidding process would be broader in public sector construction projects. However, the current safety evaluation system is operated by different estimating standards in the bidding process. At this point, a study of improvement on the safety evaluation index is required to review its current conditions and to propose its efficient operating method. Therefore, the purpose of this study is to analyze problems of the current safety evaluation system through the questionnaire survey on the qualified workers in construction safety management and to propose an improvement plan for the problems noticed. Our results suggest the standards of the unified process for the safety evaluation index, the size of construction firms needed for accident rate estimation, and the improvement plan for unreported accidents. The proposed improvement plan enables the reasonable estimation and efficient operation of the safety evaluation index, and further, it would contribute to reducing construction accidents through the activation of voluntary safety management by construction firms.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.38 no.6
• /
• pp.671-679
• /
• 2020

In order to increase the food self-sufficiency rate, monitoring and analysis of crop conditions in the cultivated area is important, and the existing measurement methods in which agricultural personnel perform measurement and sampling analysis in the field are time-consuming and labor-intensive for this reason inefficient. In order to overcome this limitation, it is necessary to develop an efficient method for monitoring crop information in a small area where many exist. In this study, RGB images acquired from unmanned aerial vehicles and vegetation index calculated using RGB image were applied as deep learning input data to classify complex upland crops in small farmland. As a result of each input data classification, the classification using RGB images showed an overall accuracy of 80.23% and a Kappa coefficient of 0.65, In the case of using the RGB image and vegetation index, the additional data of 3 vegetation indices (ExG, ExR, VDVI) were total accuracy 89.51%, Kappa coefficient was 0.80, and 6 vegetation indices (ExG, ExR, VDVI, RGRI, NRGDI, ExGR) showed 90.35% and Kappa coefficient of 0.82. As a result, the accuracy of the data to which the vegetation index was added was relatively high compared to the method using only RGB images, and the data to which the vegetation index was added showed a significant improvement in accuracy in classifying complex crops.

• Korean Journal of Social Welfare
• /
• v.57 no.1
• /
• pp.271-297
• /
• 2005

Since the 1980s, the western welfare states have experienced a wide spectrum of socio-economic changes; changes in population composition, the economic globalization, the post-industrialization, an increasing flexibility in the labor market. etc. This study examines the trend of poverty in welfare states, and analyzes how those socio-economic changes are related to it. For these purposes, this study first calculates the poverty indices for several years in 10 welfare states using the Luxembourg Income Study database, and then decomposes the index by subpopulation and income sources. Major findings of this study can be summarized as follows. First of all, the welfare state in general has experienced an increasing trend in the degree of poverty since the 1980s. In particular, poverty has greatly intensified in the United Kingdom and the Netherlands. Many other welfare states including Canada, Germany, Sweden, and Norway have also experienced substantial increases in poverty. The increasing trend of poverty is not wholly due to changes in population composition such as increases in the aging population and one-parent(mother) families. Contrary to the traditional belief, these population groups are not as much poor as the working-age population. In particular, the degree of poverty in the elderly is less severe than in the working-age group. Furthermore, since the 1980s the market income poverty in the aging population has shown a decreasing trend in many welfare states. The degree and trend of poverty in one-parent families vary greatly across countries, owing to the labor market and income transfer policies. The most important reason for the increasing poverty trend in the welfare state is that the degree of poverty has been deepening in the working-age population. Especially, the market income poverty of the working-age population has considerably increased in every country except the Netherlands. Structural changes in the economy and the labor market may drive the increasing trend of poverty. Further studies and deliberate anti-poverty policies are needed to tackle the factors relating to the increase in the market income poverty.

• Horticultural Science & Technology
• /
• v.16 no.4
• /
• pp.517-519
• /
• 1998

This experiment was carried out to find out the effects of heat conservation materials (burying in soil, lagging, lagging +straw, nonwoven fabric, nonwoven fabric+straw) on freezing damage, labor saving, and crown gall occurrence of 'Kyoho' grapes. Temperature differences in burying in soil and lagging with $2.8^{\circ}C$ and $6.4^{\circ}C$, respectively and were considered favorable for over-wintering of grapevines. Heat conservation index in lagging +straw and burying in soil calculated from degree-hours below $-10^{\circ}C$ was 5 to 7 times higher than that of open field. Budbreak started earlier in lagging with+straw and nonwoven fabric+straw covering, and percent budbreak was increased by 22% and 7%, respectively, as well as higher than burying in soil. Diameter of bearing mother branch and length of internode and daughter branch were gross or long with soil and lagging straw and nonwoven fabric+straw. Cane growth was enhanced by burying in soil and lagging with+straw treatment. Crown gall occured higher in soil covered grape vines Labor saving was obtained in lagging with as much as 44% compared to burying in soil.

• Korean Journal of Health Education and Promotion
• /
• v.7 no.1
• /
• pp.54-63
• /
• 1990

This study aims to find out the prevalence of smoking, and to analyze the effect of smoking for health status, and then to emphasize the necessity of stop smoking. The data used in this study are obtained from periodic health care programe at Health Care Center in a suburban hospital, and selected 435 males who have occupation. The independent varibles chosen for the analysis are general charactersitic variables and smoking habit. The dependent variables are designed to cover the health status of individual cases, and include blood pressure, blood cholesterol level with HDL-cholesterol and blood triglyceride level, recent symptoms and recently being managed diseases. The result of this study are summarized as follows. 1) Percentage of smoker by the age groups is highest in 4th decade, being 71.1%. The second and third ranks are 6th and 7th decades, being 53.5% and 44.4%, respectively. 2) In the view of socio-economic levels, smoking rate is higher in the groups who live at rural area and whoes occupation is labor or merchant. Smoking rate is significantly higher in the heavy drinking group. 3) Among the atherosclerotic risk factors, which include hypertension, HDL-cholesterol by total cholesterol ratio lower than 0.2 and triglyceride level higher than 200gm/dl, hypertension was not statistically associated with smoking, but others revealed statistically high association with smoking. 4) The groups who have the symptoms of severe fatigue, gastrointestinal symptoms, pulmonary symptoms, palpitation and chest tightness havepositive association with smoking. 5) The groups who have hypertension with cardiovascular diseases and gastrointestinal diseases showed highly significant association with non-smoking. 6) In relation of the smoking habit to the atherosclerotic risk factor index, smokers have more atherosclerotic risk factors, but that is not statistically significant. 7) In relation of the smoking habit to the recent symptom index, smokers have more symptoms than non-smokers with statistical significance. In conclusion, smokers have worse health status than non-smokers especially in the atherosclerotic risk factors such as hypertension or abnormal blood lipid status and have more symptoms such as severe fatigue, gastrointestinal symptoms, pulmonary symptoms, palpitation and chest tightness. And the campaingn against smoking should direct for the male in 4th decade because they have highest smoking rate.

• Journal of the Ergonomics Society of Korea
• /
• v.34 no.4
• /
• pp.327-334
• /
• 2015

Objective: The purpose of this study was to evaluate Korean workers' work ability and to identify its contributing factors. Background: In order for Korea to overcome the phenomena of becoming an aged society, older adults must participate in the workforce to balance out the population; workers' work ability must also be maintained. In addition, influential factors in employees' capabilities and degrees of importance thereof should be identified in advance to maintain work ability. Method: The Work Ability Index (WAI) questionnaire was completed by 5,708 Korean workers. Survey questionnaire consisted items of current work ability, physical and mental demands of the job, numbers of diseases, work impairment due to diseases, sick leaves, work ability in 2 years and mental resources. Results: Results indicated that work ability and length of service increased with age. It was also found that employees in administrative positions had greater work ability than site workers, workers directly managed by a supervisor had greater work ability than workers in cooperative firms, and workers who performed intellectual tasks had greater work ability than workers who performed physical labor. Job stress was additionally observed to contribute towards overall work ability. And musculoskeletal disorders (MSDs) were found to negatively affect work ability. Conclusion: The strongest determining factors in the work ability of Korean workers were stress level and mental state. Therefore, when the WAI is used to assess Korean workers, the weighting of WAI items pertaining to physical and mental abilities should be adjusted accordingly to account for these factors. Application: The result is expected to suggest that workers maintain work ability in an aged society.

• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.449-451
• /
• 2007

In the commercially managed timber lands, the information such as height, age, stand density, canopy closure and leaf area index need to be collected periodically. Stand volume is the most fundamental information in the valuation of timber, however, stand age information is the primary element of forest inventory and these two are highly correlated. Conventional method of collecting stand age information by field surveys such as ring count method is accurate; however, it is expensive, labor-intensive and time consuming. In the present study it was aimed to collect stand age information using modem techniques in a commercially managed timberland situated in Tennessee, USA. The Landsat Thematic Mapper (TM), Enhanced Thematic Mapper (ETM+) of three different periods, Shuttle Radar Topography Mission (SRTM), National elevation dataset (NED) and field inventory data were used. Normalized difference vegetation index (NDVI) and Tasselled Cap (TC) transformation techniques were applied on the TM and ETM+ data. The regression analysis was carried out to identify the correlation between stand age and NDVI, TC. In the present study about 2,469 datasets were analyzed. The $R^{2}$ value for stand age estimation was 0.713. The NDVI, TC2 and TC3 were found to produce accurate timber age information.

• International Journal of Highway Engineering
• /
• v.7 no.3 s.25
• /
• pp.63-69
• /
• 2005

For many years, the compressive strength of concrete has been regarded as an important index in determining concrete pavement quality. The compressive strength of the sample cores from the field has been used as quality index of concrete pavement. However, this process is time consuming and requires a lot of labor. Recently, the M-E Design Methodology in the pavement design based on the elastic modulus has been adopted. Therefore, several NDT methodologies have been adopted for QA/QC in the field and for the pavement design. Among various NDT methods, the wave propagation method can be used to measure the elastic modulus of concrete because the wave velocity is directly related to the elastic modulus. Therefore, in this study the wave propagation method was used for estimating the concrete modulus. The relationship between the compressive strength measured in he laboratory and the elastic modulus measured by the wave propagation method was analyzed, and the compressive strength was estimated from the elastic modulus for various mix types. The results showed that the relationship between the elastic modulus and the compressive strength was observed and the relationship varied depending on the aggregate types.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.21 no.4
• /
• pp.373-379
• /
• 2019

Smart-farm has been spreading across Korea to improve the labor efficiency and productivity of greenhouse crops. Although notable improvements have been made in the monitoring technologies and environmental-controlling systems in greenhouses, only a few simple decision-support systems are available for predicting the optimum environmental conditions for crop growth. In this study, a tomato growth model (GreenTom), which was developed by Seoul National University in 1997, was calibrated and validated to examine if the model can be used as a decision-supporting system. The original GreenTom model was not able to simulate artificial defoliation, which resulted in overestimation of the leaf area index in the late growth. Thus, an algorithm for simulating the artificial defoliation was developed and added to the original model. The node development, leaf growth, stem growth, fruit growth, and leaf area index were generally well simulated by the modified model indicating that the model could be used effectively in the decision-making of smart greenhouse.