• Journal of Labour Economics
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• v.26 no.2
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• pp.31-59
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• 2003

This paper analyzes a social insurance system that integrates unemployment insurance with a pension program, allowing workers to borrow against their future wage income to finance consumption during an unemployment episode and thus improving their search incentives while reducing risks. This paper identifies the conditions under which the integration improves welfare and the factors which determine the optimal degree of integration. A fully integrated system is one in which no reliance is placed at all on a separate tax-funded unemployment insurance program. We show that when the duration of unemployment is very short compared to the period of employment or retirement, the optimal system involves an exclusive reliance on pension-funded self-insurance. This system imposes a negligible risk burden for workers while avoiding attenuating search incentives. We also argue that a joint integration of several social insurance programs with a pension program through an individual account is desirable unless the risks are perfectly correlated to each other.

• Journal of Educational Research in Mathematics
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• v.17 no.2
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• pp.91-109
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• 2007

This study deals with the problem of transition from arithmetic to algebra and the relationship between elementary and secondary school mathematics for systems of linear equations. In elementary school, activity for solving word problems related to systems of linear equations in two variables falls broadly into using two strategies: Guess and check and making a table. In secondary school, those problems are solved algebraically, for example, by solving systems of equations using the technique of elimination. The analysis of mathematics textbooks shows that there is no link between strategies of elementary school mathematics and secondary school mathematics. We devised an alternative way to reinforce link between elementary and secondary school mathematics for systems of linear equations. Drawing a diagram can be introduced as a strategy solving word problems related to systems of linear equations in two variables in elementary school. Moreover it is closely related to the idea of the technique of elimination of secondary school mathematics. It may be a critical juncture of elementary-secondary school mathematics in the case of systems of linear equations in two variables.

• Journal of Conservation Science
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• v.10 no.1 s.13
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• pp.31-37
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• 2001

The metallurgical investigation of four lumps of bronze from the third building site of the northern workshop site at the Neungsan-ri temple site in Buyeo was performed. The microstructures of a section of sample was observed by SEM and qualitative and quantitative analysis of the sample was performed by EDS. The results are as follows: Sample 1 of the lump of bronze from northern workshop site in the third building site at Neungsan-ri temple site and sample 2 are speculated to be low-quality bronze resulting from refinery of matte which formed on the process of bronze refinery. Sample 3 is speculated as a lump of bronze which is one of Cu-Sn system and the one made by alloy only with pure bronze and tin on the process of bronze refinery. Sample 4 is confirmed as a lump of bronze which is one of Cu-Sn-Pb system from alloy of tin and lead into pure bronze. It is believed that the third building site at Neungsan-ri temple site in Buyeo produced bronze matte by refinery of copper ore or produced low-quality bronze by melting matte imported from outside.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.3
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• pp.127-136
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• 2011

The typical unit infrastructure cost estimation techniques adopted so far in implementing the Korean Impact Fee Zoning have rather been centered around the unilateral simple cost models. The techniques, as such, have frequently been criticized for their lack of flexibility in properly reflecting the regional differences as well as the peculiarities of individual development projects. The Ministry of Land, Transport, and Maritime Affairs (MLTM), in this regard, has recently introduced an enhanced alternative technique. Using the NGIS data, the study probes the viability of the MLTM's new technique by testing the entire estimation process based on the case area in Ansung City. Reflecting the City's characteristics, the study assumes a composite land use plan that accommodates the industrial area in addition to typical residential areas. As an extensive empirical case study, the research has found from the new technique considerable technical merits to overcome the existing shortcomings and summarized its significant policy implications.

• Journal of the Economic Geographical Society of Korea
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• v.17 no.4
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• pp.759-770
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• 2014

The aim of this study is to examine how time-use and activities are affected by work hours. To achieve this, we focused on the weekday time-use of full-time workers in Seoul Metropolitan Area(SMA). The long 'work hours' are under active discussions since it is related to the quality of life. However, many Social researcher thought that problem of Korean working hours is linked to quality of life in the abstract. Because activity connects time-use and quality of life, the key point is activity under time constraints. Therefore, travel patterns should be understood by time-use and activity patterns. This study composes trip-chains from travel data of 2010 Household Travel Survey(HTS). Grouping trip-chains by activity patterns, we could make sure that a few of activities after work is affected by a short free time. This study has potential implications for the policy of work hours and traffic problems in the evening, and will provide new geographical perspective related to measuring quality of life.

• Journal of the Korean Chemical Society
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• v.47 no.6
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• pp.559-568
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• 2003

A procedure based on liquid liquid extraction(LLE)-GC/MS has been developed for the simultaneous analysis of antioxidants and insecticides known as endocrine disrupters. The endocrine disrupters investigated in this study are butylated hydroxy anisole(BHA) and butylated hydroxy toluene(BHT), and the insecticides are allethrin and fenvalerate. The limit of detection(LOD) was 0.071~0.159 ng/ml with RSD of 1.41~5.34% for the standard sample. From water reservior of Han river, Geum river, Nakdong river and Sumjin river, these compounds were not detected. For the synthesized sample, the LOD is 0.051~0.132 ng/ml with RSD of 6.39~13.4%.

• Informatization Policy
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• v.23 no.1
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• pp.20-37
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• 2016

As the numbers of various cyber-crimes have sharply increased, the importance of securing information has also been emphasized. Despite the government's constant efforts to solve the issue, they hardly work in practice, and cases related to information security are still on the rise. This study investigates the reasons for the discrepancy that occurs when a solution is put to action. The research analyzes the recent shift in the administrative system with regard to information security and officials' awareness of the shift, focusing on members of local government. The results of the study confirm a steady attempt including changes in institutions at the level of the central government. However, there is still a lack of personnel and budget support at the local government level as well as not much change in the awareness of information security.

• The Journal of the Korea Contents Association
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• v.16 no.12
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• pp.492-506
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• 2016

This study is aimed to investigate the factors predicting the responses after volunteering activities among corporate volunteers. While positive responses to volunteering are conceptualized as both the degree of satisfaction from volunteering and the perceived contribution of volunteering, negative responses are conceptualized as the degree of burnout. Family supports, the volunteering support system of corporation, various human relations in volunteering sites are selected and empirically tested as variables predicting the differential responses after volunteer activities. Questionnaire data were collected from 250 corporate volunteers and analyzed through hierarchical regression analysis. The results showed that while family supports have no significant effects on volunteering responses, corporate support system of volunteering have significant effects. Additionally, human relations with clients and volunteers managers have strong and positive significant effects on positive responses including the degree of satisfaction and the perceived contribution. However, no significant effect has been found on negative responses represented by burnout. Findings from this study emphasized the importance of human relations management in volunteering sites for corporate and nonprofit volunteer managers to increase the positive response from corporate volunteers.

• Journal of Life Science
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• v.25 no.4
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• pp.385-389
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• 2015

In this study, it is reported that a large polyprotein can be stoichiometrically cleaved by the use of caspase-3-dependent proteolysis. Previously, it has been shown that the proteolytic IETD motif was partially processed when treated with caspase-3, while the DEVD motif was completely cleaved. The cleavage efficiency of the DEVD-based substrate was approximately 2.0 times higher than that of the IETD substrate, in response to caspase-3. Based on this, 3 protein genes of interest were genetically linked to each other by adding two proteolytic cleavage sequences, DEVD and IETD, for caspase-3. Particularly, glutathione-S transferase (GST), maltose binding protein (MBP), and red fluorescent protein (RFP) were chosen as model proteins due to the variation in their size. The expressed polyprotein was purified by immobilized metal ion affinity chromatography (IMAC) via a hexa-histidine tag at the C-terminal end, showing 93 kDa of a chimeric GST:MBP:RFP fusion protein. In response to caspase-3, cleavage products, such as MBP:RFP (68 kDa), MBP (42 kDa), RFP (26 kDa), and GST (25 kDa), were separated from a large precursor GST:MBP:RFP (93 kDa) via SDS-PAGE. The results obtained from this study indicate that a multi-protein can be stoichiometrically produced from a large poly-protein by using proteolytic recognition motifs, such as DEVD and IETD tetra-peptides, for caspase-3.

• Resources Recycling
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• v.14 no.1
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• pp.26-32
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• 2005

A study on the preparation of Ag fine particles was performed through a reduction reaction using ascorbic acids as a reductant, which is one of the indispensable processes for the recycling of silver-bearing wastes. Silver nitrate solution in the range of 10~120 mmole/l was used and Tamol NN8906 or PVP was also used as a dispersant in the preparation of Ag fine particles size analyze, SEM, and TEM to determine the particle size and morphology of them. As a result, the reduction reaction of silver ions with ascorbic acid reached equilibrium within 10 min. It was found that about 60% excess of ascorbic acid was required in order to reduce completely silver ions in the solution. The particle size distribution of Ag particles prepared through the reduction reaction showed typically biomodal or trimodal distribution. Especially, initial Ag concentration in the solution, the type and amount of dispersant added during the reduction reaction played an important role in determining the mean particle size of Ag particles.