• Journal of the Korean Society of Hazard Mitigation
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• v.3 no.3 s.10
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• pp.173-181
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• 2003

Because of the gravitation of population toward large cities, a number of masonry buildings have been constructed since 1960's. They have been rapidly deteriorated as time passed by. Therefore the purpose of this paper is to present basic data on timeworn masonry buildings which were managed by the Jung, Mapo and Dobong district in Seoul Metropolitan and to analyse their deterioration factors as well as interrelation. Through this study, masonry buildings have many problems with foundation and crack is the most effective to deterioration. Also, the store buildings are the weakest structure type and the structure grade have an interrelation with occupancy type mere than any other factors.

• Geomechanics and Engineering
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• v.25 no.2
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• pp.123-134
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• 2021

In this paper, the carbon fiber reinforced plastic (CFRP) grids embedded in polymer cement mortar (PCM) shotcrete (CFRP-PCM method) was conducted to repair the degraded tunnel linings with a cavity. Subsequently, the reinforcing effect of the CFRP-PCM method under different degrees of lining deterioration was quantitatively evaluated. Finally, the limit state design method of the M-N interaction curve was conducted to determine whether the structure reinforced by the CFRP-PCM method is in a safe state. The main results indicated that when the cavity is at the shoulder, the lining damage rate is more serious. In addition, the remarkably reinforcing effect on the degraded tunnel linings could be achieved by applying a higher grade of CFRP grids, whereas the optimization effect is no longer obvious when the grade of CFRP grids is too high (CR8); Furthermore, it is found that the M-N numerical values of the ten reinforcing designs of the CFRP-PCM method are distributed outside the corresponding M-N theoretical interaction curves, and these designs should be avoided in the corresponding reinforcing engineering.

• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.367-377
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• 2022

The purpose of this study was to analyze the deterioration of trail conditions and to obtain information for desirable maintenance and restoration of a trail in Deogyusan National Park. The physical characteristics of a trail were surveyed at a total of 412 sites over 79.8 km length. The average trail degree and width were found to be 14.31° and 1.60 m, respectively, while the average bare trail width was 1.40 m and the average maxim trail depth was 5.66 cm. Major deterioration types of trail were trail deepening (36.6%), rock exposure (33.9%), and root exposure (12.5%) in order of frequency. Deterioration classes of the trail were 0.626 km (0.8%), 3.110 km (3.9%) and 8.935 km (11.2%) for heavily, moderately, and lightly deteriorated, respectively, with a deterioration rate of 12.671 km (15.9%). Compared to other national parks, the ratio damaged trail to the total trail was 15.9%, which is slightly higher than other, including Jirisan National Park 9.6% (2019), Bukhansan National Park 13.6% (2019), Sokrisan National Park 11.7% (2019), Chiaksan National Park 12.3% (2015), and Woraksan National Park 10.5% (2015). The section of trail in Deokyusan National Park where the damage grade is analyzed as "Heavy" should therefore be restored in consideration of the field conditions. In particular, the damage status of the trail is expected to be greatly improved when the trail surface maintenance level is restored.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.3
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• pp.64-72
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• 2015

Risk Based Inspection (RBI) Period was proposed for highway bridges in Korea. Hazard factors affecting bridge condition deterioration were found by analyzing condition data from Highway Bridge Management System (HBMS). Certain level of correlations between those factors and condition deterioration were found. They are used to evaluate hazard score. Summarizing several hazard factors, final hazard is classified as three level;high, moderate, low. Vulnerability is assessed only by the current state of bridge. Then, risk matrix is suggested for inspection periods. Inspection periods of the bridges with grade C, D, and E are maintained the same as before. But, those of grade A and B with moderate and high hazard score are elongated to maximum 6 years while the maximum inspection period is three years at present. By adjusting inspection period according to risk assessment, it was shown that 27% of average inspection manpower can be saved.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.3
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• pp.331-339
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• 2010

Purpose : Cervical spondylotic myelopathy is a varied clinical syndromes and the most serious condition of cervical spondylosis. Spinal cord dysfunction is often caused by the compression on spinal cord. The purpose of this report was to describe physical examination and the process of disorders on cervical spondylotic myelopathy(CSM). Methods : Three cases with cervical myelopathy were presented with magnetic resonance image(MRI), Nurick's grade and Japanese Orthopaedic Association(JOA) score. Results : This studies showed a variable clinical course with gradual neurological deterioration in two cases. but one case was improved by operation and a regular aerobic exercise. MRI, Nurick's grade, JOA score are a useful adjunct for CSM evaluation. Conclusion : The state of CSM is variable, which may affect conservative treatments and surgery. It is needed to be a carefull approach and studies for a conservative treatment and management on CSM.

• 보존과학연구
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• s.34
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• pp.64-81
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• 2013

It is not easy to define the priority criteria of the need of conservation treatment for stone cultural heritage, although many of them have been treated and restored over the past decade. This study approached the correlation between damage grade and the need of conservation treatment based on damage diagnosis of stone cultural heritage carried out from 2001 to 2005. The number of Third-graded (from First to Fifth-grade) stone heritage in deterioration was the highest among state-designated stone cultural heritage. The Fourth-graded stone cultural heritage (143 in total) was mostly influenced by high physiochemical deterioration, whereas the Fifth-graded ones (61 in total) was dominantly affected by biological colonization. It was estimated that total 211 stone cultural heritage were treated for conservation and restoration from 2002 to 2011. They were usually cleaned (total 134, 26.1%), joined and consolidated, and maintenance works as shelter construction, drainage installation and surrounding cleaning were carried out for some of them. The number of conservation intervention increased with the high deterioration grade, and the case number of metamorphic and sedimentary rocks. By age, the stone cultural heritage in Three-kingdom Period were treated the most, and other heritage in Unified Shilla, Goryeo and Joseon showed an approximate ratio. The stone cultural heritage fallen in the fifth-grade in deterioration demonstrated the highest ratio, approximately 80% of conservation intervention. These results can be used as preliminary data to define the emergency criteria for conservation intervention policy.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.4
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• pp.181-189
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• 2003

Because of the gravitation of population toward large cities, a number of masonry buildings have been constructed since 1960. They have been rapidly deteriorated as time passed by. Therefore the purpose of this paper is to present basic data on timeworn masonry buildings which have been managed by metropolitan government and to analyse their deterioration factors. And then, the results of this paper can be used to establish the policy of managing timeworn masonry buildings. According to this study, the crack of masonry wall is the most effective deterioration factor and timeworn masonry buildings have a problem with foundation. The structure grade have an interrelation with occupancy type more than building age. Also, the longer building age becomes, the sooner deterioration speeds. A timeworn masonry building is in urgent need of reinforcement on a thirty-year period of building age.

• Economic and Environmental Geology
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• v.52 no.6
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• pp.617-626
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• 2019

In this study, we investigated the petrographic characteristics and physical property of the Rock-carved Seated Buddha at Bugmireugam hermitage of Daeheungsa temple in Haenam. The Buddha Statue was carved on micrographic granite, and the rock was composed of the fine quartz encircled by orthoclase. The results of diagnosis for deterioration evaluation have shown a highly damage rate of black contaminants (8.4%) and crack index (6.6). The ultrasonic velocity have detected SW (slightly weathered) grade of weathering coefficient (mean 0.18). Various weathering factor on the surface of the Buddha Statue was affected by precious shelter, and physical property with ultrasonic was directly influenced by the structural characteristics and fissure of host rock.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1416-1418
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• 2002

In order to examine the thermal properties of the wire materials, we analyzed the shrinkage, the expansion and the form transformation, the surface structure according to the thermal deterioration temperature through the testing method for a heating shrinkage of Korean Industrial Standard(KS C 3004). For IV(600V grade polyvinyl chloride insulated wires), we measured the shrinkage and the expansion rate, analyzed the surface structure using SEM(Scanning Electron Microscope). In the result of this experiment, the shrinkage rate of IV 2.0mm covering was high in comparison with other wires. As the deterioration temperature rises gradually, the covering is molten and harden.

• Journal of Microbiology and Biotechnology
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• v.4 no.2
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• pp.141-145
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• 1994

Conventional commercial thermal process for preparing Sikhae (Rice beverage) in a hermetically sealed container was evaluated to solve the nutritional deterioration and organoleptic inferiority problem caused by severe heat treatment. A milder thermal process with an aid of Nisin, a GRAS-grade, selectively germicidal compound, was introduced to destroy the putrefactive microorganisms. In this experiment, hot-filling method with Nisin, and thermal processing (at 110$^{\circ}C$ for 15 minutes with Nisin, at 121$^{\circ}C$ for 25 minutes without Nisin) were compared. The quality of Sikhae could be enhanced and over 90% of the thermal process could be conserved by this process in terms of sterilizing value without quality deterioration when processing the bottled Sikhae at 110$^{\circ}$ for 15 minutes $\{(F^{10}{_{121})_{process}=1.54\}$.