• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 춘계학술대회 논문집
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• pp.443-450
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• 2001

This paper shows the reduction effect of tile earthquake-induced liquefaction potential of soils that improved by Vibro-Replacement Stone Columns. The Vibro-Replacement Stone Columns method transforms soft cohesive soils into a composite mass of compacted granular or crushed stone columns by using vibrating equipment and water jets. This study investigated and analyzed the behavior of the stone columns and composite ground using the results of in situ test and measurement at the job-site. This paper shows the evaluation of the earthquake-induced liquefaction potential of soils using in situ test. There are different types of in situ test used in the evaluation the liquefaction potential. In the particular study the Standard penetration test, and Cone penetration test were used. The N value of Standard Penetration test has been used all over for a very long time. The evaluation of the liquefaction of soil was performed using the worldwide renewed Cone penetration test

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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• pp.308-315
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• 1996

The utilization of high flowing concrete in construction sites is a world wide trend, and it will be increase to need for high flowing concrete in our construction sites. While it is quite easy to make high-flowing concrete in the laboratory, controlling slump in the field long enough to ensure easy placement once the concrete arrives at job site can be difficult. This study is the experimental study on the high-flowing and engineering properties of high flowing concrete using river sand and crushed stone according to the replacement percentage of fly-ash. As a results of this study is the mix proportion of replacement percentage of fly-ash 30% better than the others. And it is confirm to possibility of manufacture of the high flowing concrete.

• STI Policy Review
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• 제8권2호
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• pp.75-93
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• 2017

Recently, global competition in the manufacturing sector is driving firms in the manufacturing sector to conduct product innovation projects to maintain their competitive edge. The key points of product innovation projects are 1) what the purpose of the project is and 2) what expected results in the target market can be achieved by implementing the innovation. Therefore, this study focuses on the performance of innovation projects with a business viewpoint. In this respect, this study proposes the "achievement rate" of product innovation projects as a measurement of project performance. Then, this study finds the best strategies from various innovation activities to optimize the achievement rate of product innovation projects. There are three major innovation activities for the projects, including three types of R&D activities: Internal, joint and external R&D, and five types of non-R&D activities - acquisition of machines, equipment and software, purchasing external knowledge, job education and training, market research and design. This study applies decision tree modeling, a kind of data-mining methodology, to explore effective innovation activities. This study employs the data from the 'Korean Innovation Survey (KIS) 2014: Manufacturing Sector.' The KIS 2014 gathered information about innovation activities in the manufacturing sector over three years (2011-2013). This study gives some practical implication for managing the activities. First, innovation activities that increased the achievement rate of product diversification projects included a combination of market research, new product design, and job training. Second, our results show that a combination of internal R&D, job training and training, and market research increases the project achievement most for the replacement of outdated products. Third, new market creation or extension of market share indicates that launching replacement products and continuously upgrading products are most important.

• Advances in concrete construction
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• 제6권5호
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• pp.545-560
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• 2018

The ever-increasing cost of natural sand and the environmental impacts of extracting manufactured sand (quarry sand) calls for exploring the potential to use alternative materials as fine aggregates in concrete. Copper slag and ferrous slag are industrial by products obtained from the smelting process of copper and iron respectively. A large quantity of copper slag and ferrous slag end up being disposed as waste in landfills and this poses a serious threat to the environment. Copper slag and ferrous slag have similar physical and chemical properties as natural sand and also exhibit pozzolanic activity. This paper studies the technical feasibility of industrial by-products such as copper slag and ferrous slag to replace the fine aggregate in concrete by evaluating the workability, strength and durability characteristics of concrete. The test results indicate that the strength properties are not affected by 40% or 100% replacement of quarry sand with iron slag or copper slag. However, 40% replacement of quarry sand with iron slag or copper slag in concrete is recommended considering the durability aspects of concrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.373-376
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• 2008

The objective of this study is to investigate the properties of fresh concrete with recycled fine aggregates. Three different kinds of fine aggregate with natural, high and low quality recycled aggregates were prepared. The concrete mixtures were produced with test parameters of replacement ratio of recycled fine aggregate. The properties of the fresh concrete were measured by means of slump and air content according to elapsed time. Quality control method to maintain the constant total mixing water for recycled aggregate concrete was suggested. The all concrete mixtures were produced with approximately the same slump on the job site after an hour. Test results indicated that compressive strength of the concrete mixtures with constant slump is not affected by the replacement ratio of recycled fine aggregate. Therefore, the practical way for the quality control of recycled aggregate concrete is to maintain the constant total mixing water.

• 한국의사학회지
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• 제33권1호
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• pp.79-97
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• 2020

We discovered various sides of Lee Jema's tenure as the governor of Jinhae by looking at recently found historical materials of the central government of Joseon. Lee Jema went to his appointed post in Jinhae in February of 1887 and was replaced before the termination of his office in June of 1888. Since his replacement did not immediately arrive at Jinhae, Lee Jema continued to perform his duties until the first half of 1889. The difference between the date of his resignation and the arrival of his replacement reveals why various historical materials disagree about when he left office. After Lee Jema's official resignation in June of 1888, he was appointed to the honorary posts of Naegeumjang and Cheomji, which indicates the termination of his career as an official. Two superior officials conducted job assessments on Lee Jema three times during his service (once every six months) and these are the rare evaluations which were performed during his lifetime. Lee Jema was highly regarded in terms of job competency by two superiors in succession, which was unique for a local government official in the late Joseon dynasty. One of the job assessments referred to the potential of his performance as an official which usually implied that he was a suitable candidate for higher rank. This might have derived from Lee Jema's study of statecraft. Lee Jema's love for the people as an official was also mentioned in one of the job assessment reports. This is borne out by his quelling the revolt of Hamheung Province in 1896.

• Asian Journal for Public Opinion Research
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• 제10권3호
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• pp.200-229
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• 2022

The purpose of this study is to analyze the effects of youth job policy measures, set forth in Korea's 2016-2020 Third Basic Plan for Low Fertility and Aging Society (December 2015), on marriage and fertility among young people. Based on the results, we provide theoretical explanations for the findings and suggest policy alternatives to overcome the low fertility phenomenon in Korea. Previous studies have shown that employment is an important factor for marriage among youth, and a job policy could increase marriage and fertility rates. To test this assumption, we performed an exact matching between Statistics Korea's Employee-Enterprise Linkage DB and the Newlyweds DB from 2011 to 2019, in order to identify all young people aged 15-34. Then, linear spline regression analysis was used to examine the impact of the youth job policy on marriage and fertility. Comparing the period before the implementation of the employment policy (2011-2015) and after (2016-2019), the fertility rate increased as the number of young people looking for work increased. In addition, it was found that these impacts were greater after the implementation of the measures (2016-2019) than before (2011-2015). It is interesting to note that job growth among young people did not lead to an increase in marriage. However, the number of births significantly increased when young people who occupy jobs got married, which seems to be related to the delay in marriage among young people who are employed. Survey results about the intentions to marry and views on fertility are utilized for the explanation of the study results.

• 한국조리학회지
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• 제14권4호
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• pp.27-40
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• 2008

This study focused on retraining programs for cuisiniers and drawing attention to the necessity of retraining and the new method of retraining for cuisiniers as a professional in a knowledge based society. Case study review and interviews followed by thorough review of related literatures were taken place to give suggestions and comments for the improvement of job performance enhance training for cuisiniers. Interviews were done with current participants and institutional trainers in March, 2008. Result from the interviews showed that retraining was really necessary. It was concluded that various retraining programs organized and developed by an association could be the solution. Methods of retraining can take formats of distance learning, classroom learning, and blended learning. However, working condition for most cuisiniers at present would allow them to squeeze some time off to attend higher education and most restaurant companies are not big enough to offer systematic job training on site or not stable enough to arrange replacement workers. It is therefore suggested to adopt a blended learning method and further study on this subject is highly recommended.

• 품질경영학회지
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• 제14권2호
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• pp.40-46
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• 1986

The decision maker has the job of torecasting capital investments and operating expenses to aid the decision making in choosing and evaluating present and future alternatives. The estimating function eventually analysis, evaluates and choose the alternatives. The analysis stemmed originally from a preliminary design of some sort, and eventually plans are started to investigate investment possibilites. This study provide the descounted cash flow and the present worth method. Despite any choice of an analytical method, there remains the problem of predicting certain future events. Therefore, these models dealing with optimum plant sizing, equipment replacement, and lease or buy will be discussed.

• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.43.1-43.12
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• 2023

Background: Gig workers, also known as platform workers, are independent workers who are not employed by any particular company. The number of gig economy workers has rapidly increased worldwide in the past decade. There is a dearth of occupational health studies among gig economy workers. We aimed to investigate the association between exposure to violence and job stress in gig economy workers and depressive symptoms. Methods: A total of 955 individuals (521 gig workers and 434 general workers) participated in this study and variables were measured through self-report questionnaires. Depressive symptoms were evaluated by the Patient Health Questionnaire-9 when the score was greater than or equal to 10 points. The odds ratio with 95% confidence interval was calculated using multivariable logistic regression adjusted for age, sex, working hours, education level, exposure to violence and job stress. Results: 19% of gig economy workers reported depressive symptoms, while only 11% of general workers reported the depressive symptoms. In association to depressive symptoms among gig economy workers, the mainly result of odds ratios for depressive symptoms were as follows: 1.81 for workers type, 3.53 for humiliating treatment, 2.65 for sexual harassment, 3.55 for less than three meals per day, 3.69 for feeling too tired to do housework after leaving work. Conclusions: Gig economic workers are exposed to violence and job stress in the workplace more than general workers, and the proportion of workers reporting depressive symptoms is also high. These factors are associated to depressive symptoms. Furthermore, the gig workers associated between depressive symptoms and exposure to violence, job stress.