• The Journal of the Korea Contents Association
• /
• v.16 no.12
• /
• pp.310-326
• /
• 2016

A lot of colleges have made continued efforts to help freshmen adapt themselves to a new school life and environment and build a decent relationship with faculty and other students. Therefore, this study attempted to figure out the effectiveness of team teaching(team teaching by academic advisor, standard textbook-centered guidance vs. autonomous mentoring) on strategic cultural curriculum as a way to help freshmen adapt themselves to a school life. For research subjects, 31 enrolled freshmen and 5 professors from a college in Chungbuk were selected. In terms of research tools, 'Communication Competence Assessment Sheet' provided by Strategic Cultural Curriculum Development Team and a simple questionnaire on 'curriculum satisfaction, adaptation to school and intimacy' were applied. For data analysis, paired t-test, independent samples t-test and rating scale were conducted. The study results found the followings: First, according to analysis on the effects of two different types of team teaching on the goal of strategic cultural curriculum('improvement of communication competence'), significant effects were found in a standard curriculum(textbook)-centered team. Second, when adaptation to a school life(school adaptation, intimacy) perceived by the students who completed the strategic cultural curriculum according to two different types of team teaching curriculum was analyzed, significant changes were found at standard textbook-centered guidance team. Third, this study has examined other changes, satisfaction, opinions and perception(strength, weakness, opinions for improvement) on the curriculum perceived by the students(learners) and faculty regarding about team teaching curriculum. Based on these results, educational implications of this study were reviewed. And a suggestion and limits were presented.

• Journal of the Korea Concrete Institute
• /
• v.14 no.3
• /
• pp.307-314
• /
• 2002

Utilization of demolished-concrete as recycled aggregate has been researched for the purpose of substituting for insufficient natural aggregate, saving resources and protecting environment. There, however, are some Problems not only the large difference of dualities in recycled aggregates but also a little deterioration of mechanical properties in recycled aggregate concrete in comparison with that of natural aggregate concrete. In this study, the test results of freez and thaw durability of concrete with demolished-concrete recycled aggregate(DRA) arc as follows. Improvement of crushing process is an important assignment because that adhered mortar on source-concrete recycled aggregate(SRA) and DRA highly affects thc qualifies of recycled aggregate. The compressive strength of recycled aggregate concrete was not highly different in comparison with that of control concrete. But the resistance to penetration of Cl in recycled aggregate concrete was shown smaller than that of control concrete because of adhered mortar on recycled aggregate. The resistance to frcezing and thawing of recycled aggregate concrete was highly different due to adhered mortar on recycled aggregate, and durability factor of concrete with NA-SRA and DRA was more decreased than that of control concrete. On the other hand, durability factor of concrete with AA-SRA was larger than that of control concrete. It, therefore, is necessarily required that recycled aggregate including adequate entrained air should be used for satisfying the freez and thaw durability of recycled aggregate concrete.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.6 no.1
• /
• pp.111-119
• /
• 2011

Recently, urban redevelopment programs and expansion of social infrastructure have caused massive amounts of construction waste in construction fields, and the mounds of it keep increasing every year. The disposal of construction waste is emerging as a national and social issue and the recycled powder generated by the treatment process of waste concrete is all being abolished or buried. Therefore, the purpose of this study is to utilize waste sludge generated by the wet-type treatment process of waste concrete as materials(binder, filler) for cement composite. This study evaluates physical and mechanical properties of mortar using recycled powder according to heating temperature, contents and applications. As a result of the chemical analysis, recycled powder is composed mainly of CaO and $SiO_2$, and that it is even lower in the content of CaO than OPC. The charateristics of mortar using recycled powder, according to drying and heating temperature, shows that as the heating temperature increases, flow decreases. Also, compressive strength and porosity of mortar using recycled powder was superior when heating temperature was $600^{\circ}C$. Thus, it is revealed that an effective development of recycled powder is possible since the binder by cement composite recovers a hydraulic property during heating at $600^{\circ}C$.

• Journal of the Korean GEO-environmental Society
• /
• v.16 no.8
• /
• pp.13-20
• /
• 2015

Due to the population growth and exhaustion of resource, the development on the harsh environment such as cold weather is emerging as an alternative for new resource development. The permafrost area covers about 14 percent of the world's land area and the global construction market for such area is rapidly expanded. Whereas the developed countries have already recognition of the need for research of coldest place and invested heavily in technology development, the domestic technology for the coldest place development is less developed and related research has rarely been performed. There is not a detailed national specification standard for the strength and deformation properties of the earthworks at sub-zero temperature but simple field directions. Therefore, the D compaction tests were conducted on the sand with fine contents of 0%, 5%, 10% and 15% at room temperature ($18^{\circ}C$), $-3^{\circ}C$ and $-8^{\circ}C$ to investigate the effect of the compaction energy on the compacted soils at sub-zero temperatures. Based on the test results, the larger compaction energy, the larger maximum dry unit weight under sub-zero temperature and D type compaction at $-3^{\circ}C$ show similar max. dry unit weights as those obtained from the compaction at the room temperature. However, compaction at $-8^{\circ}C$ showed significant performance degradation regardless of the compaction energy.

• KOMUNHWA
• /
• no.70
• /
• pp.35-62
• /
• 2007

Songguk-ri site gained academic recognition by the excavation of stone coffin tomb with a bronze dagger in 1974. And it is confirmed that this site is epoch-making in Korean bronze age through the following excavation started in 1975. But the excavation reports published until now do not have even overall view of this site, thus it is difficult to get the whole picture of this site. Thus, in this paper the author reexamined all reports on this site and by making the map of overall view and distribution of archaeological features as a basic research. Moreover, I analyzed also artifacts from this site, and compared with the recent papers written by other researchers about the chronology and character. Songguk-ri site has livelihood domain which consists of dwelling pits, attached features, storage pits, pot-firing features, wood fence, abatises, buildings above ground, as well as cemetery which consists of stone-coffins, jar-coffins, pit tombs. Trace of making large terrace was also excavated. These features seem to belong to the same archaeological stage, dated about B.C.850-550, according to C14 dating. On the other hand, the intensification of wet-rice cultivation made this group more productive. Based on this financial strength, some influential group emerged they constructed defensive settlement to protect their products safely. Besides it seems that there were frequent occurrence of conflicts. However, we can know that they kept their stable life, through the expansion of living space. Consequently, Songguk-ri site played a role of the summit among some settlement in this area.

• Resources Recycling
• /
• v.23 no.3
• /
• pp.30-36
• /
• 2014

A large amount of waste copper slag containing about 35 ~ 45% iron has been generated and discarded every year from pyrometallurgical processes for producing copper from copper concentrate. Thus, recovery of iron from the waste copper slag is of great interest for comprehensive use of mineral resource and reduction of environment problems. In this study, a physico-chemical separation process for upgrading iron from the waste copper slag discharged as an industrial waste has been developed. The process first crushes the waste copper slag below 1 mm (first crushing step), followed by carbon reduction at $1225^{\circ}C$ for 90 min (carbon reduction step). And then, resulting material is again crushed to $-104{\mu}m$ (second crushing step), followed by wet magnetic separation (wet magnetic separation step). Using the developed process, a magnetic product containing more than 66 wt.% iron was obtained from the magnetic separation under a magnetic field strength of 0.2 T for the waste copper slag treated by the reduction reaction. At the same conditions, the percentage recovery of iron was over 72%. The iron rich magnetic product obtained should be used as a iron resource for making pig iron.

• Management & Information Systems Review
• /
• v.39 no.3
• /
• pp.53-82
• /
• 2020

Daejeon Metropolitan City has the best innovation capability infrastructure (ICT) required for the 4th industry. Nevertheless, there are scattered factors that hinder the industrial ecosystem. In this study, the factor of job creation was approached from the viewpoint of organizational ecology in consideration of regional characteristics during the 4th Industrial Revolution.That is, the case of job creation through overseas ICT-based clusters (or cities) was examined. Then, the factors of organizational ecology, 'niche', 'variation', 'selection', and 'retention' were derived. Through this process, we explored the environment surrounding Daejeon Metropolitan City and benchmarked lessons from existing overseas cluster cases. As a result, we discover the 'niche' of ICT-based job creation and suggest strategies for the 'variation' process to survive in the ecosystem and how to be 'retention' in the ecosystem. n conclusion, the strategy of the organizational ecological approach to establish itself as a metropolitan city as the strength of Daejeon city and the 'innovation hub' that is evident, such as '4th Industrial Revolution City', 'Innovation City Designation', and 'Secure Excellent Capability of SW' Insist on need. Through this study, we hope that there will be a theoretical contribution to the prior research lacking from original research such as the scarcity of ICT-based job creation research in response to the era of the fourth industrial revolution, recognition of the importance of the region in job creation, and presentation of an organizational ecological approach of sustainable clusters.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
• /
• 1995.12a
• /
• pp.9-21
• /
• 1995

A planning support system enhances our ability to use water capacity expansion as an urban growth management strategy. This paper reports the development of capacity expansion modeling of water supply as part of the continuing development of such a planning support system (PEGASUS: Planning Environment for Generation and Analysis of Spatial Urban Systems) to incorporate water supply, This system is designed from the understanding that land use and development drive the demand for infrastructure and infrastructure can have a significant influence on the ways in which land is developed and used. Capacity expansion Problems of water supply can be solved in two ways: 1) optimal control theory, and 2) mixed integer nonlinear programming (MINLP). Each method has its strengths and weaknesses. In this study the MINLP approach is used because of its strength of determining expansion sizing and timing simultaneously. A dynamic network optimization model and a water-distribution network analysis model can address the dynamic interdependence between water planning and land use planning. While the water-distribution network analysis model evaluates the performance of generated networks over time, the dynamic optimization model chooses alternatives to meet expanding water needs. In addition, the user and capacity expansion modeling-to-generate-alternatives (MGA) can generate alternatives. A cost benefit analysis module using a normalization technique helps in choosing the most economical among those alternatives. GIS provide a tool for estimating the volume of demanded water and showing results of the capacity expansion model.

• Journal of Advanced Marine Engineering and Technology
• /
• v.40 no.9
• /
• pp.836-841
• /
• 2016

An indoor positioning system using Wi-Fi is essential to produce a radio map that combines the indoor space of two or more dimensions, the information of node positions, and etc. in processing for constructing the radio map, the measurement of the received signal strength indicator(RSSI) and the confirmation of node placement information counsume substantial time. Especially, when the installed wireless environment is changed or a new space is created, easy installation of the node and fast indoor radio mapping are needed to provide indoor location-based services. In this paper, to reduce the time consumption, we propose an algorithm to distinguish the straight and curve lines of a corridor section by RSSI visualization and Sobel filter-based edge detection that enable accurate node deployment and space analysis using cable-type Wi-Fi node installed at a 3 m interval. Because the cable type Wi-Fi is connected by a same power line, it has an advantage that the installation order of nodes at regular intervals could be confirmed accurately. To be able to analyze specific sections in space based on this advantage, the distribution of the signal was confirmed and analyzed by Sobel filter based edge detection and total RSSI distribution(TRD) computation through a visualization process based on the measured RSSI. As a result to compare the raw data with the performance of the proposed algorithm, the signal intensity of proposed algorithm is improved by 13.73 % in the curve section. Besides, the characteristics of the straight and the curve line were enhanced as the signal intensity of the straight line decreased by an average of 34.16 %.

• Journal of Fisheries and Marine Sciences Education
• /
• v.27 no.4
• /
• pp.1129-1135
• /
• 2015

The stow net is a stationary gear made from netting, usually in shape like trawl net without wings. The nets are fixed by means of anchors, placed according to the direction and strength of the current. And the commercial fishing is associated with high rate of fatal and non-fatal occupational injury. The hazard factors analysis for the fishermen's safety of offshore stow nets vessel was conducted to serve as a basic data for improving the healthy and safe working environment of fishermen using fishermen's occupational accidents of the national federation of fisheries cooperatives (NFFC) from 2012 to 2014 (n=1,144). As a result, the average occupational accident occurrence rate of this fishery was 206.9‰ in all industries 36.9 times the rate of that. In addition, average death and missing rate was found to have a very serious level management to 50.4‰ in all industries of death of 42.0 times. The accident occurred in 84.5 to 94.6% was happened at sea. The struck by object, slipping, contact with machinery, contact by object or gear and others occurred more frequently in order on the frequency of accident occurrence pattern. However, the occurrence rate of death and missing did not match the frequency of accident pattern. In other words, slipping occurred frequently higher while death and missing risk was not high. And the contact with fishing gear and fall in the waters was low while death and missing risk was high. The results are expected to contribute for identification and assessment of safety hazard occurred in offshore stow nets vessel.