• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.37-46
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• 2024

This study investigates the evolution of concrete damage due to chloride-induced steel corrosion through Impact-echo (IE) testing. Three reinforced concrete specimens, each measuring 1500 mm in length, 400 mm in width, and 200 mm in thickness, were fabricated using three concrete mixture proportions of blended cement types: ordinary Portland cement, ground granulated blast-furnace slag and fly ash. Steel corrosion in the concrete was accelerated by impressing a 0.5 A current following a 35-day cycle of wet-and-dry saturation in a 3% NaCl solution. Initial IE data collected during the saturation phase showed no significant changes, indicating that moisture had a minimal impact on IE signals and highlighting the slow progress of corrosion under natural conditions. Post-application of current, however, there was a noticeable decline in both IE peak frequency and the P-wave velocity in the concrete as the duration of the impressed current increased. Remarkably, progressive monitoring of IE proves highly effective in capturing the critical features of steel-corrosion induced concrete deterioration, such as the onset of internal damages and the rate of damage propagation. These results demonstrate the potential of progressive IE data monitoring to enhance the reliability of diagnosing and prognosticating the evolution of concrete damage in marine environment.

• Journal of Ecology and Environment
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• v.47 no.4
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• pp.272-281
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• 2023

Ecosystem observatories are burgeoning globally in an endeavour to detect national and global scale trends in the state of biodiversity and ecosystems in an era of rapid environmental change. In this paper we highlight the additional importance of regional scale outcomes of such infrastructure, through an introduction to the Great Western Woodlands TERN (Terrestrial Ecosystem Research Network) SuperSite, and key findings from three gradient plot networks that are part of this infrastructure. The SuperSite was established in 2012 in the 160,000 km² Great Western Woodlands region, in a collaboration involving 12 organisations. This region is globally significant for its largely intact, diverse landscapes, including the world's largest Mediterranean-climate woodlands and highly diverse sandplain shrublands. The dominant woodland eucalypts are fire-sensitive, requiring hundreds of years to regrow after fire. Old-growth woodlands are highly valued by Indigenous and non-Indigenous communities, and managing impacts of climate change and the increasing extent of intense fires are key regional management challenges. Like other TERN SuperSites, the Great Western Woodlands TERN SuperSite includes a core eddy-covariance flux tower measuring exchanges of carbon, water and energy between the vegetation and atmosphere, along with additional environmental and biodiversity monitoring around the tower. The broader SuperSite incorporates three gradient plot networks. Two of these represent aridity gradients, in sandplains and woodlands, informing regional climate adaptation and biodiversity management by characterising biodiversity turnover along spatial climate gradients and acting as sentinels for ecosystem change over time. For example, the sandplains transect has demonstrated extremely high spatial turnover rates in plant species, that challenge traditional approaches to biodiversity conservation. The third gradient plot network represents a 400-year fire-age gradient in Eucalyptus salubris woodlands. It has enabled characterisation of post-fire recovery of vegetation, birds and invertebrates over multi-century timeframes, and provided tools that are directly informing management to reduce stand-replacing fires in eucalypt woodlands. By building regional partnerships and applying globally or nationally consistent methodologies to regional scale questions, ecological observatories have the power not only to detect national and global scale trends in biodiversity and ecosystems, but to directly inform environmental decisions that are critical at regional scales.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.7-16
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• 2008

The immigration procedure at airports is vital to making passenger and cargo transport faster. The rapid procedure of immigration could be an important determining factor when passengers select an air transport company, one that should have high satisfactory in terms of their service level and efficiency. Therefore, the advanced airport makes it easy for customers and their cargo to proceed. The coordination between authorities related to the Korean international airport is not satisfactory for customers. This paper analyzes the factors necessary to enhance the airport immigration procedure with the movement of aircrafts, passengers, cargo, and post, using the CK(Cook and Kress) model of DEA(Data Envelopment Analysis). From this study, the author found that research and development will be needed to improve the immigration procedure, especially on facilities and their operating systems. There are needed, also, performance indicators and a continuous monitoring system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.1
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• pp.21-28
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• 2010

Forest fire is one of the main factor disturbing the environment of forest, and it influences greatly the structure and function on forest. The process of vegetation recovery could be decided according to the extent of the damage. It is required a lot of man powers and budgets to understand born severity and process of vegetation rehabilitation at the damaged area after large-fire. However, the analysis of born severity in the forest area using satellite imagery can acquire rapidly information and more objective results remotely in the large-fire area. In this study, the space sensors have been used to map area burned, assess characteristics of active fires. For classifying fire damaged area and analyzing severity of Cheongyang-Yesan fire in 2002, in this paper we use pre- and post-fire imagery from the Landsat TM and ETM+ to compute the evaluate large-scale patterns of burn severity, use the digital stock map to calculate the damaged condition about the forest fires damaged regions and use the NDVI to monitoring the situation of the revegetation.

• Journal of Broadcast Engineering
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• v.19 no.2
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• pp.205-214
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• 2014

Minimization of visual fatigue is important for production of high quality stereoscopic 3D contents. Vertical disparity of stereo images occurred during contents production is considered as the main factor of visual fatigue. To ensure correct stereoscopy vertical disparity needs to be eliminated. In this paper, a method for automated image alignment was proposed for Stereoscopic 3D contents generation and post-processing steps. The proposed method consists of two parts: rectification for image alignment and camera motion detection. The proposed method showed that its rectification performance was the most superior among the existing methods tested and that camera motion detection had a success rate of 98.35%. Through these evaluations, we confirmed that the proposed method can be effectively applied to 3D contents production.

• Tunnel and Underground Space
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• v.22 no.2
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• pp.130-143
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• 2012

Cablebolts used to be employed as auxiliary supports where long or high capacity bolts are needed, but become competitive by the improvements in supportability and easiness in handling. Based on the test results obtained from various researches, the performance of the cablebolts was analyzed numerically while varying lengths and fixing conditions. The supporting effecte is assessed by monitoring displacements and stress taken place in shotcrete. When cablebolts are grouted without being tensioned, supporting effect was not as good as that of rockbolts. But, their supportability was good enough to substitute rockbolts if tensioned properly. Post grouting right after tensioning of the cablebolts shows reduction in supportability, but long term stability could be achieved without losing supportability if grouted when the bolt is far enough from the face. Further study is necessary including laboratory and in-situ tests under various conditions to use cablebolts as main support in tunnels.

• Journal of Soil and Groundwater Environment
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• v.17 no.6
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• pp.9-22
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• 2012

Though geologic storage of $CO_2$ (GS) is considered as an attractive technological option to enormously reduce greenhouse gases emission into the atmosphere, many concerns on potential environmental and health risks associated with $CO_2$ leakage have been raised. In particular, groundwater contamination due to the brine displacement by a pressure build-up and the acidification by leaked $CO_2$ is paid a special attention. Therefore, integrated regulatory frameworks have been established by law in many countries to secure the permanent containment of injected $CO_2$. Regulatory frameworks deal with entire processes of GS, including site selection, monitoring and post-closure environmental management. This review paper provides a summary of regulatory frameworks in USA (U.S. EPA Geologic Sequestration Rule) and EU (Geologic $CO_2$ Sequestration Directive). The regulatory framework to properly address environmental issues should be established for the deployment of CCS projects in Korea.

• Journal of Korean Academy of Nursing
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• v.30 no.5
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• pp.1303-1317
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• 2000

This study was conducted to identify a effect of the comprehensive self-regulation program for hypertensives as a nursing intervention on self-care performance and the physiologic parameters in rural areas. For this purpose, a nonequivalent control group and a pre and post-test quasi- experimental design was used. Fifty-four were evaluated subjects from two Community Health Practitioner Posts in the suburbs of Taejon City. The subjects of the control and experimental groups were matched for age and sex. The self-regulation program developed by author given to the experimental group. The program consisted of group education on hypertension and self-care, self-regulation including the blood pressure self-monitoring, recording of self-care activities, and encouraging and reinforcing self-efficacy. The whole program was carried out from September to November of 1999. The data were analyzed by repeated measure ANCOVA, t-test, and ANCOVA. The results were as follows ; There was significant improvement in the scores on knowledge (F=.68, P=.004), perceived self-efficacy (F=26.39, P=.000), self-care performance (F=26.11, P=.000) of the experimental group compared with those of the control group. There was no significant change on the score of locus of control, perceived benefits and perceived barrier, blood cholesterol level, body weight between two groups (P>.05). From these results, it can be concluded that the self-regulation program is an effective nursing strategy to promote self-care performance of hypertensives in rural area.

• Journal of Korean Clinical Nursing Research
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• v.23 no.3
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• pp.376-387
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• 2017

Purpose: This study was to systematically review the contents and effects of nurse-led transitional care programs for discharged patients from hospital to home. Methods: Randomized controlled trials published between 2005 and 2015 were searched in Pubmed, Embase, Cochrane(Central Register of Controlled Trials) and CINAHL. Data were analyzed using Cochrane Review Manager(Revman) software 5.3. Results: Nine studies were selected and analyzed. Patient assessment, education and discharge planning were included in pre-discharge phase. Referring, communication and care planning were performed by nurses in transition phase. Home and phone visits, monitoring and multidisciplinary advices were included in post-discharge phase. Various outcome measures such as hospital utilization(30 days readmission and emergency department visit), quality of life, and cost were used to identify effectiveness of nurse-led transitional care programs. 30 days readmission(OR=.73, 95% CI 0.54, 0.98; p=.03) and emergency department visit(OR=.67, 95% CI 0.50, 0.88; p=.005) were statistically significant in meta-analysis. However, participant blinding was not done in seven studies which put at the risk of performance bias. Conclusion: The results indicated that nurse-led transitional care program is effective in reducing unnecessary hospital utilization. Nevertheless, small sample size and risk at performance bias are the limitation of this study. Thus, we suggest that well-designed randomized controlled trials need to be conducted.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.73-86
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• 2004

The purpose of this study is the identification of (N-2-hydroxy-3-butenyl) valine(HBVal adduct) and (N-2,3,4-trihydroxy-butyl)valine(THBVal adduct)with mice inhalation exposure with 1,3-butadiene for 3 weeks($6\;hr/day\;{\times}\;5\;days/week$). Body weights were significantly lower from 4 or 9 exposure post-day in 1000 or 500ppm inhalation group than in control. The levels of HBVal adducts are 1.8, 3.7 and 6.2 pmol/mg globin in $1^{st}$, $2^{nd}$ , and $3^{rd}$ week for 500 ppm 1,3-butadiene(BD), and 5.7, 7.4 and 16.0 pmol/mg globin in $1^{st}$, $2^{nd}$ , and $3^{rd}$ week for 1000 ppm BD inhalation exposure. The levels of THBVal adducts are 32.0, 42.0 and 55.0 pmol/mg globin in $1^{st}$, $2^{nd}$ , and $3^{rd}$ week for 500 ppm BD, and 67.8, 72.7 and 83.5 pmol/mg globin in $1^{st}$, $2^{nd}$ , and $3^{rd}$ week for 1000 ppm BD inhalation exposure. Their ratios of THBVal and HBVal adducts are higher at earlier exposure and lower concentration. They are17.8, 11.4 and 8.87 in $1^{st}$, $2^{nd}$ , and $3^{rd}$ week for 500 ppm BD, and 11.9, 9.8 and 5.2 in $1^{st}$, $2^{nd}$ , and $3^{rd}$ week for 1000 ppm BD inhalation exposure. In conclusion, THBVal and HBVal adducts are a important hemoglobin adduct for monitoring of BD exposure, and the latter is more biomarker than the other.