• Journal of the Korean GEO-environmental Society
• /
• v.17 no.2
• /
• pp.13-22
• /
• 2016

Accurate settlement estimation of dredged soft soil deposits is significantly important to prevent potential disasters during land reclamation. An application of the non-linear finite strain consolidation theory is inevitable in dealing with a very soft ground formation such as dredged fill. In this paper, a series of the sedimentation-consolidation test, self-weight consolidation test and CRS test were conducted to clarify sedimentation and consolidation characteristics of dredged fill in the Songdo area, Incheon. In addition, the settlement of dredged fill was numerically simulated using the PSDDF program. The dredged soil obtained from the Songdo area was classified as low-compressible silt (ML) based on USCS (Unified Soil Classification System), and the final bulking factors were estimated to be 1.56 and 1.17 by Yano's method and the numerical simulation, respectively. This difference is attributable to relatively high reclaimed height and large permeability of dredged soil in this region.

• Journal of the Korean GEO-environmental Society
• /
• v.25 no.4
• /
• pp.5-12
• /
• 2024

In the case of creating a site in the reclaimed land (public waters), due to the nature of the coastal sedimentary ground, large-scale construction materials are required, It is necessary to utilize soft clay, which is inevitably generated during construction of the complex, as a fill material in terms of resource recycling and economic aspects (reducing the amount of embankment required). In this study, changes in the consolidation characteristics of cut-out disturbed soft clay due to the recycling of soft clay soil were identified, and a consolidation settlement design plan was proposed. Through the results of the consolidation test of the study site, the change in consolidation characteristics (compression index reduction, precede load uncountable) due to disturbance (cutting) was confirmed, the method of calculating (consolidation settlement) the filling clay layer as the composite target layer (consolidation target layer, loading load layer) was analyzed as a result consistent with the actual behavior.

• Nuclear Engineering and Technology
• /
• v.54 no.3
• /
• pp.1136-1144
• /
• 2022

The effects of nearby residents and the public by the residual contamination from the decommissioning of nuclear facilities should comply with the dose criteria, and whether additional remediation action is necessary from the ALARA perspective must be determined. Therefore, we analyzed the requirements of ALARA action levels and performed preliminary ALARA evaluation. The ratio of residual contamination concentration to DCGL was calculated for the basement fill and the building occupancy mode. The results showed that the additional remediation actions below DCGL are not justified. In addition, we analyzed the effect of remediation area. It was noted that the increase of the remediation area showed a positive correlation with the Conc/DCGL value in the basement fill mode. On the other hand, in the building occupancy mode, since the floor area of the building is the target of remediation and has the effect of increasing the same as the evaluation area of the building occupants, but due to the difference in the amount of increase, the Conc/DCGL showed a negative correlation. We expect the approach and method of ALARA evaluation can be utilized for concrete cost-benefit calculation during the decommissioning or at the time of remediation.

• Restorative Dentistry and Endodontics
• /
• v.47 no.1
• /
• pp.5.1-5.11
• /
• 2022

Objectives: This study aimed to assess the clinical longevity of a bulk-fill resin composite in Class II restorations for 3-year. Materials and Methods: Patient record files acquired from the 40 patients who were treated due to needed 2 similar sizes Class II composite restorations were used for this retrospective study. In the experimental cavity, the flowable resin composite SDR was inserted in the dentinal part as a 4 mm intermediate layer. A 2 mm coverage layer with a nano-hybrid resin composite (CeramX) was placed on SDR. The control restoration was performed by an incremental technique of 2 mm using the nano-hybrid resin composite. The restorations were blindly assessed by 2 calibrated examiners using modified United States Public Health Service criteria at baseline and 1, 2, and 3 years. The data were analyzed using non-parametric tests (p = 0.05). Results: Eighty Class II restorations were evaluated. After 3-years, 4 restorations (5%) failed, 1 SDR + CeramX, and 3 CeramX restorations. The annual failure rate (AFR) of the restorations was 1.7%. The SDR + CeramX group revealed an AFR of 0.8%, and the CeramX group an AFR of 2.5% (p > 0.05). Regarding anatomical form and marginal adaptation, significant alterations were observed in the CeramX group after 3-years (p < 0.05). The changes in the color match were observed in each group over time (p < 0.05). Conclusions: The use of SDR demonstrated good clinical durability in deep Class II resin composite restorations.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.22 no.6
• /
• pp.179-184
• /
• 2022

As public data opened its doors in line with the era of the 4th Industrial Revolution, agricultural public data also increased. Currently, the majority of farmers are writing farming diaries due to eco-friendly certification and basic public interest direct payment projects. However, it is a difficult task for busy farmhouses in the aging agricultural community to write farming diaries. Therefore, there have been cases where farming diaries have been filled out on behalf of the farmhouses. However, one may get disadvantaged in terms of receiving eco-friendly certification and public interest direct payment projects. In succession, this paper proposes a system to conveniently write farming diaries by checking the farming diary data stored in the server via categories of crops and dates and finding farming diary public data suitable for the user to automatically fill out the diary.

• Journal of Digital Convergence
• /
• v.10 no.1
• /
• pp.1-10
• /
• 2012

In this paper, we review recently emerging smart applications, and analyzed policy implications in light of digital convergence perspective. While extant literatures on smart applications mainly dealt with consumer behaviors based in technology acceptance model or innovation adoption, the research on digital management policy is rather limited. We intend to fill this research gap. As such, we first organize two categories of smart work and smart commerce, and investigate the representative service models, four service models were reviewed for each category respectively. Next, the three policy related constructs are extracted, which are QoL(Quality of Life), public impacts in both the positive and negative ways. Finally, empirical analysis following the Delphi principle was conducted to investigate the policy implications. The results offer useful insights for the further research in digital convergence related policy areas.

• Journal of environmental and Sanitary engineering
• /
• v.19 no.3 s.53
• /
• pp.13-21
• /
• 2004

This study was focused on the evaluation of Nanjido landfill site by leachate analysis. Several parameters, for example pH, BOD, $COD_{Mn},\;COD_{Cr}$, SS, TP, $NH_3-N$, Color, were selected as major leachate quality parameters. $BOD/COD_{Cr}$. was used to estimate the biodegradable portion in organic matter. Samples were collected at the leachate storage wells and leachate treatment facility inflow in each quarter of 2003. The results were as follows : 1. Inflow quality of treatment plant in 2003 was analysed as $pH\;7.3\~8.0,\;BOD\;12.4\~30.0mg/L,\;COD_{Mn}\;101.2\~130.3mg/L,\;COD_{Cr}\;122.5\~238.0mg/L,\;SS\;16.1\~115.3mg/L$, $T-P\;0.27\~0.80mg/L,\;NH_3-N\;208.0\~~354.0mg/L$, Color $110.3\~129.0$ unit. 2. $BOD/COD_{Cr}$ of inflow ranged between $0.07\~0.16$ indicating that the landfill had the properties of old-fill and organic portion in leachate was mostly persistent organic matter. 3. Though concentrations of BOD, COD, $NH_3-N$, Color in leachate storage wells were mostly higher in first landfill than in second landfill, $BOD/COD_{Cr}$ ranging from 0.03 to 0.20, showed reversely. 4. Correlation coefficient$(R^2)$ between color and other parameters related to organic matter showed mostly above 0.7 and especially highest value with $COD_{Mn}$ of 0.7985.

• Journal of Preventive Medicine and Public Health
• /
• v.39 no.3
• /
• pp.205-212
• /
• 2006

Objectives: In spite of the recent increased concern for Asian dust storms, there are few studies concerning how dangerous the general public recognizes these dust storms to be. This study examined the public's perceptions of the risk of the Asian dust storms and also the source of the information concerning the risk. Methods: A telephone interview survey using a standardized questionnaire was done for the adults living in Seoul and its metropolitan area from May 15th, 2003 to May 16th, 2003. The contents of the questionnaire were the sociodemographic characteristics, the perceptions of risk to the Asian dust storms, and the coping strategy of the study participants. Results: The study participants get their information on Asian dust storms mainly from TV newscasts and they have a good knowledge of them. They regard it as one of the most dangerous health risks, along with dioxin. They think that it is associated with allergic rhinitis, conjunctivitis and bronchial asthma, etc. Of the 500 study participants, 201 (40.2%) persons suffered bodily discomforts during the Asian dust storm period. Conclusions: Although there are uncertainties about the health risks of Asian dust storms, the public thinks these dust storms are very dangerous to health in many ways This negative perception will not disappear easily. To fill the gap of the public's perceptions of the risk and the objective evidence of its health effects, more studies about its health effects and the methods to reduce exposure are required.

• The Journal of Engineering Geology
• /
• v.28 no.2
• /
• pp.277-295
• /
• 2018

As it has become difficult to secure new water resources through dam construction due to the critical social public opinions on dam construction from 10 years ago, it is necessary to review the existing water resources through the review of existing dams. Accordingly, access methods, such as planning, construction and management, were carried out using technologies already accumulated in relation to the repair and reinforcement of the dam. As a result of the repair and reinforcement, permeation grouting has been performed in many dams, but the establishment of the technology is insufficient so far, and the published paper at home and abroad is extremely rare. In this thesis, low-pressure penetration and grouting reinforcement technologies for the YC dam are analyzed in detail. As a result, penetration grouting has shown that it can be effectively applied to the improvement in the constallability of the core fill-like a YC dam. In addition, the technical details of the experience-proven penetration grouting are given in relation to the injection criteria. It is deemed that the specific analysis data of the Fill Dam penetration grouting technology through this study can be used as useful data for strengthening the repair of Fill Dam and reservoir.

• Journal of the Korean Society for Library and Information Science
• /
• v.45 no.1
• /
• pp.103-124
• /
• 2011

The 21st century society is becoming globalized rapidly due to mass immigration and South Korea has become a multicultural nation since 2007 with over one million foreigners living here. Due to these social environmental changes, there was a need to provide multicultural programs and services in public libraries. In order to develop multicultural library services, we need to look into what librarians and users of public libraries know of the existing services. We assumed that comparing the two groups, librarians and users, and establishing a fit model would be the most effective way to provide information. According to the survey, there were differences in understanding between the two groups. By providing services that help fill in the gap, public libraries could be closer to multicultural families, and help them become integrated into Korean society. We have presented a multicultural service model based on the results of the survey.