• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.802-811
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• 1996

Farmers need alternatives for weed control due to the desire to reduce chemicals used in farming. However, conventional mechanical cultivation cannot selectively remove weeds located in the seedline between crop plants and there are no selective heribicides for some crop/weed situations. Since hand labor is costly , an automated weed control system could be feasible. A robotic weed control system can also reduce or eliminate the need for chemicals. Currently no such system exists for removing weeds located in the seedline between crop plants. The goal of this project is to build a real-time , machine vision weed control system that can detect crop and weed locations. remove weeds and thin crop plants. In order to accomplish this objective , a real-time robotic system was developed to identify and locate outdoor plants using machine vision technology, pattern recognition techniques, knowledge-based decision theory, and robotics. The prototype weed control system is composed f a real-time computer vision system, a uniform illumination device, and a precision chemical application system. The prototype system is mounted on the UC Davis Robotic Cultivator , which finds the center of the seedline of crop plants. Field tests showed that the robotic spraying system correctly targeted simulated weeds (metal coins of 2.54 cm diameter) with an average error of 0.78 cm and the standard deviation of 0.62cm.

• Journal of the Korean housing association
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• v.26 no.3
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• pp.45-54
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• 2015

The purpose of this research is to analyze the wealth effects of home-owning baby-boomers on household consumption on non-durable goods in the Seoul Metropolitan Area. In so doing, this empirical study utilized the Korean Labor and Income Panel Study (KLIPS) of 2002 and 2012. The statistical findings reveal that household wealth in the period had sharply risen in household income, asset, debt and consumption, and the substantial increase came from growing income and consumption embedded into an expansionary stage of the family life cycle. Further, housing wealth had a much greater effect on consumption expenditure than did financial asset in 2012 while financial wealth effect was larger than housing wealth effect in 2002. Housing wealth effects had become far stronger as the age of the baby-boomer householders increased. As the baby-boomers are close to the retirement stage, post-retirement income security becomes of concern, so that the wealth effect of real estate income as an income alternative for retirees is explicit. The results imply that retirement of baby-boomers is likely to reduce consumer spending, aggravating slowdown of the real economy. Thus, diversification of household asset portfolio in a pre-retirement period is of great significance in maintaining adequate household consumption in later life.

• Korean Journal of Construction Engineering and Management
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• v.4 no.4 s.16
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• pp.69-79
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• 2003

About 93$\%$ of domestic teal estate construction firms registered as the end of 2001 recorded net profits of only less than 500 million won(including firms in the red) for the term. As a result of having analyzed the ratios of sales costs and the structural ratios of sales costs for the past 10 years, it was found that there have been great changes in structural ratios of sales costs. Material costs and labor costs have gradually decreased, but outsourcing costs of processing have greatly increased. In order to find activity points which are fundamental to cost control, the methods of new activity based cost management have been pursued. The characteristics of real estate construction industry lie in the fact that contract prices (sales in) are fixed and amounts of profits differ depending on the use of costs. In order to create maximum profits from fixed contract prices, the new activity based cost management has been proposed. The control of operation budgets and management costs is designed to control their schedules and expenses in different respects. Operation budgets ate executed with specific activities and management costs are controlled as a form of material costs, labor costs, out sourcing costs and expenses which are details of expenditure. In order to execute them by using the methods of new activity based cost management, first of all, we have to analyze what activity drivers ale and how much added values such activities can create. It is considered as a method of cost management which is necessary far the survival management of real estate construction industry.

• Korean Journal of Social Welfare
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• v.65 no.2
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• pp.79-102
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• 2013

This study aimed at empirically analysing the double discrimination on the elderly with disabilities due to both age and disabilities in the labor market. To achieve this research goal, real employment probabilities and hourly wages of the elderly disabled(below "ED") were compared with those of the young disabled(below "YD") and those of the elderly non-disabled(below "END") to calculate empirical differentials between ED's and YD's, and ED's and END's. The differential decompositions between groups were applied by the Oaxaca(1973). The study results were as followings. First, the real gaps of the employment probabilities between ED and YD only appeared at the regular jobs and the gaps due to the characteristics between ED and YD were bigger than those due to the age discrimination. Second, on the contrary, the gaps of the hourly wages were caused by age discrimination more than characteristics between YD and ED. Third, it was not true that the elderly with disabilities take double discriminations in the labor market. It is therefore required to give the additional incentives to ED workers with government subsidies of employment promotion for the disabled provided. Second, it is proposed that the integrations the employment policies for the disabled with those for the aged because the disability as dependent valuable didn't have statistically significant effects on the employment probabilities and the hourly wage levels.

• Korean Journal of Microbiology
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• v.47 no.1
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• pp.87-91
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• 2011

The aim of this study was to compare the performance of conventional culture and real-time PCR for detection of Cronobacter spp. in powdered foods. Infant formula, baby food and Misugaru inoculated with Cronobacter were enriched in distilled water as first enrichment step, followed by incubating in Enterobacteriaceae enrichment (EE) broth as second enrichment step. A loopful of enriched sample was streaked onto Druggan-Forsythe-Iversen agar, followed by incubating at $37^{\circ}C$ for 24 h. One milliliter of the enriched distilled water and EE broth were used in real-time PCR assay. No statistical differences were observed in the number of positive samples between culture method and real-time PCR (p>0.05) in all types of food samples. The number of positives of real-time PCR was higher in the first enrichment media (distilled water) than the second enrichment media (EE broth), though there was no significant difference (p>0.05). It appears that some components of the second enrichment broth, EE broth, inhibit the reaction of real-time PCR. These results show that real-time PCR using a single enrichment with distilled water could be useful as an effective screening method for detection of Cronobacter while saving much time and labor compared to conventional culture method.

• Korean Journal of Construction Engineering and Management
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• v.14 no.4
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• pp.24-34
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• 2013

Since 2004, the government decided to gradually introduce Actual Cost Data into cost estimate for improving problems of below-cost tendering and to reflect fair market price through competition and carry contract efficiently. However, there are many concerns that Actual Cost Data has not reflected real market price, even that has contributed to reduce the government's budget. General construction firm's burden for labor cost is imputed to specialty contractors and eventually it becomes construction worker's burden. Therefore, realization of Actual Cost Data is very important factor to settle this system. To understand realization level and make short term forecast, this paper drew construction group of which labor cost constitutes more than 95% of direct cost, and compares their Actual Cost Data with relevant skilled workers's unit wage and predicts using time series analysis. The bid price which is not be reflected market price accelerates work environment changes and leads to directly affect such as late disbursement of wages, bankruptcy to workers. Therefore this paper is expected to be used to the preliminary data for solving the problem and establishing improvement of Actual Cost Data.

• Journal of Korean Philosophical Society
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• v.146
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• pp.115-135
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• 2018

This article attempts to deal with the problem that science and technology function as a mechanism to oppress and exploit humans rather than to release humans from labor. To explore this subject, it is necessary to consider the difference between the theory of labor value and the theory of 'technology value'. In addition, it is also important to refer to Marx's critical view of the 'capitalist' use of technology. Above all, Marx' concepts of relative surplus value and special surplus value, and his analysis of organic composition of capital are still valid in explaining that development of technology tightens control over workers and intensity of labor, and worsens instability of employment. Reflection of the limitations of capitalist development of technology is also important for realization of its usefulness. Industry 4.0 in Germany therefore deserves to be noticed as a good example because it shows a different way from extreme capitalist exploitation. The model suggests also some points that shouldn't be overlooked, when we try to actualize the tremendous slogan of the current fourth industrial revolution as real innovation and progress in human life. In this matter, the most important point is the possibility of technological development that doesn't oppose workers' interests.

• International Area Studies Review
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• v.15 no.2
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• pp.77-100
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• 2011

The Korean economy have experienced the remarkable decreases in factor prices such as bond yields, real wage since the IMF foreign exchange crisis. This paper investigates the effects of the price changes in the factor markets on determining the level and cyclicality of industrial markups in the manufacturing industry. For this purpose, we construct a markup equation in the small open economy based on the production function including foreign intermediate goods and assuming constant returns to scale technology and AR(1) process of technological coefficient. Empirical results are summarized as the followings. The empirical results shows that the increased markups after the IMF crisis can be explained by the price decreases in the factor markets which result in lowering marginal costs. And we also observed counter cyclicality of markup, labor share and interest rates while real wages, technical coefficients, and production price index proved to be pro-cyclical. In conclusion, the price changes in factor market have contributed to the stickiness in markup fluctuation in the manufacturing industry.

• Journal of Korea Game Society
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• v.9 no.1
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• pp.33-41
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• 2009

In this paper we tried to figure out the types of real money trade of game items, and in order to study it we examined the Leveling System of MMORPG which is a perfect competitive market and how the closed structure of the game economy emits real money trade. The over production of the MMORPG's leveling system which is a perfect competitive market increases the amount of currency in circulation and then induces arbitrage due to mudfalation inside the game. In order to improve this problem, there are three methods of resolutions. The first is stabling the game economy by spontaneous order among the game users, but this is much local than the artificial order which takes a long time and evokes discrepance in MMORPG competitive characteristic. Secondly, legislational regulations from the government could improve the problem, but this method doesn't grant information or services as non-material labor in which it couldn't follow up the developing speed of the game market. Finally, delicate modulation among game items by the designer isn't possible to constrain them, and there is a limited reason that it couldn't control the increase of currency which is the main factor of arbitrage.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.211-220
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• 2017

The application of the theoretical model to real assembly lines has been one of the biggest challenges for researchers and industrial engineers. There should be some realistic approach to achieve the conflicting objectives on real systems. Therefore, in this paper, a model is developed to synchronize a real system (A discrete event simulation model) with a theoretical model (An optimization model). This synchronization will enable the realistic optimization of systems. A job assignment model of the assembly line is formulated for the evaluation of proposed realistic optimization to achieve multiple conflicting objectives. The objectives, fluctuation in cycle time, throughput, labor cost, energy cost, teamwork and deviation in the skill level of operators have been modeled mathematically. To solve the formulated mathematical model, a multi-objective simulation integrated hybrid genetic algorithm (MO-SHGA) is proposed. In MO-SHGA each individual in each population acts as an input scenario of simulation. Also, it is very difficult to assign weights to the objective function in the traditional multi-objective GA because of pareto fronts. Therefore, we have proposed a probabilistic based linearization and multi-objective to single objective conversion method at population evolution phase. The performance of MO-SHGA is evaluated with the standard multi-objective genetic algorithm (MO-GA) with both deterministic and stochastic data settings. A case study of the goalkeeping gloves assembly line is also presented as a numerical example which is solved using MO-SHGA and MO-GA. The proposed research is useful for the development of synchronized human based assembly lines for real time monitoring, optimization, and control.