• Tunnel and Underground Space
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• v.27 no.6
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• pp.343-350
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• 2017

Amid increasingly saturated ground space, development of underground space has been booming throughout the world and excavation has been underway near the structure above or under the ground level. But the ground subsidence caused by improper or poor construction technologies, underground water leakage, sudden changes of stratum and the problem with earth retaining system component has been emerged as hot social issue. To deal with such problems nationwide, establishment of preventive and proactive disaster management and rapid restoration system has been pushed now. In this study, collection of the data on technology development trend to secure the underground safety was made, taking into account of internal change elements (changing groundwater level, damage to underground utilities, etc) and external change elements (vehicle load, earthquake and ground excavation, etc) during excavation. Amid the growing need of ground behavior analysis, ground subsidence evaluation technology, safe excavation to prevent ground subsidence and reinforcement technology, improvement of rapid restoration technology in preparation for ground subsidence and development of independent capability, this study is intended to introduce the technology development in a bid to prevent the ground subsidence during excavation. It's categorized into prediction/evaluation technology, complex detect technology, waterproof reinforcement technology, rapid restoration technology and excavation technology which, in part, has been in process now.

• Fire Science and Engineering
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• v.31 no.6
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• pp.47-52
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• 2017

The recent tragic outbreak of fire at the Grenfell Tower in the United Kingdom compels all branches of government to reexamine and reassess the safety measures against fires in high-rise buildings from a broad perspective. Accordingly, this study examined what problems stem from the current evacuation codes by comparative analysis of the high-rise apartment evacuation codes that range over various individual laws before introducing a new evacuation code. The outcome of this study can be utilized as basic data for amending the existing evacuation codes for high-rise buildings. The codes related to high-rise building evacuation include the Building Act, the Housing Act, the Skyscraper Disaster Management Act, and the Fire-Fighting System Act. Some local governments have also drawn up their own codes and put them into practice. Comparative analysis of the major evacuation codes has helped identify a variety of problems, such as different codes being applied to each individual law and ordinance, the use of additional codes other than the provisions of laws and ordinances, and the in effectiveness of evacuation codes. Most of these problems occur when diverse codes are applied to a single building, which means that cooperation among the relevant ministries is urgently needed to improve the related codes in the future.

• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.423-430
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• 2021

In order to evaluate the fire risk and fire risk rating of wood for construction materials, this study focused on fire performance index-III (FPI-III), fire growth index-III (FGI-III), and fire risk index-IV (FRI-IV) according to Chung's equations-III and -IV. Western red cedar, needle fir, ash, and maple were used as the specimens. The fire characteristics were investigated using a cone calorimeter (ISO 5660-1) equipment on the specimen. The FPI-III measured after the combustion reaction was 0.86 to 12.77 based on polymethylmethacrylate (PMMA). The FGI-III was found to be 0.63 to 5.26 based on PMMA. The fire rating according to the FRI-IV, which is the fire rating index, was 0.05 to 6.12, and the western red cedar was 122.4 times higher than that of the maple. The fire risk rating according to the FRI-IV increased in the order of maple, ash, needle fir, PMMA and western red cedar. The CO peak concentration of all specimens was measured as 103 to 162 ppm, and it was 2.1 to 3.2 times higher than 50 ppm, the permissible exposure limits of the US occupational safety and health administration. Materials such as western red cedar, which have a low bulk density and contain a large amount of volatile organic substances, have a low FPI-III and a high FGI-III, so they have a high fire risk rating.

• Journal of the Korean GEO-environmental Society
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• v.15 no.1
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• pp.53-62
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• 2014

In Korea, in general, separation distance between existing parallel tunnels was set at two to five times as distant as the diameter of the tunnels according to ground conditions. Recently, however, actual applicability of closely spaced parallel tunnels whose distance between tunnel centers was shorter than the diameter has increased due to environmental damages resulting from massive cutting, restriction in purchase of required land, and maintenance of linear continuity. In particular, when the pillar width of tunnel decreases, the safety of pillars affects behaviors of the tunnel and therefore the need for diverse relevant studies has emerged. However, research so far has been largely confined to analysis of behavior characteristics of pillars, or parameters affecting design, and actually applicable and quantitative data have not been presented. Accordingly, in order to present a stability evaluation method which may maximally reflect construction conditions of spots, this study reflected topographical and stratigraphic characteristics of the portal part with the highest closeness between the tunnels, simulated multi-layer conditions with rock mass and complete weathering, and assessed the degree of effect the stability of pillars had on the entire tunnels through numerical analysis according to changes in pillar width by ground strength. This study also presented composite analysis result on ground surface settlement rates, interference volume rates, and average strength to stress and a formula, which may be applicable to actual work, to evaluate safety rates of closely spaced parallel tunnel pillars and minimum pillar width by ground strength based on failure criteria by Hoek-Brown (1980).

• Fire Science and Engineering
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• v.27 no.6
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• pp.104-114
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• 2013

This study is intended to figure out the effects of supervisors' transformational leadership on organizational culture and innovation in the fire fighting organization. To achieve this, a survey was carried out to fire officers from the National Emergency Management Agency and Seoul Metropolitan Fire & Disaster Headquarters. The results are as follows. First, the effect of supervisors' transformational leadership on organizational culture showed that supervisors' transformational leadership had an effect on group culture, norm culture and rational culture by sub-factors of organizational culture in the fire fighting organization. Second, the effect of organizational culture on organizational innovation showed that group culture and rational culture had an effect on organizational innovation. Third, the effect of supervisors' transformational leadership on organizational innovation showed that supervisors' transformational leadership had an effect on organizational innovation. As for findings stated above, supervisors' transformational leadership had positive effects on organizational culture and innovation in the fire fighting organization. Consequently, supervisors' energetic and change-seeking leader-ship for junior staffs with existing organization-and new generation-oriented new thinking system can contribute to rational culture and development-oriented innovation based on norms in the group.

• Fire Science and Engineering
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• v.33 no.3
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• pp.63-73
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• 2019

This study examined the activity of the simulated training scenarios and special rescue crew assuming a chemical accident inside the building. To improve the response ability and safety of rescue personnel in the event of a chemical accident, a total of eight stages of simulated training scenarios were conducted and the activity was measured. As a result of the activity measurement according to the simulation training scenario, the average maximum heart rate of the rescuers was the highest at 177.50 ppm in the 4^th stage, and then 176.67 ppm for the 5^th step, 171.17 ppm for the 2^nd step, 169.33 ppm for the 3^rd step, 162.17 ppm for the 6^th step, 159.58 ppm for the 7^th step, 148.75 ppm for the 8^th step, and 139.33 ppm for the 1^st step. The mean maximum respiratory rate was the highest at 38.17 rpm in the 4^th stage, followed by 37.58 rpm in the 5^th stage, 32.00 rpm in the 6^th stage, 31.58 ppm in the 7^th stage, 31.33 rpm in the 3^rd stage, 31.08 rpm in the 2^nd stage, and 28.00 rpm in the 8^th stage. The 1^st stage was 22.67 rpm. In addition, body water reduction measurements were reduced by up to 0.7 g due to the training intensity.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.713-723
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• 2023

Climate change is significantly affecting coastal areas, and its impacts are expected to intensify. Recent studies on climate change adaptation and risk assessment in coastal regions increasingly integrate the concepts of recovery resilience and vulnerability. The aim of this study is to develop a measurement model for coastal hazard recovery resilience in the context of climate change adaptation. Before constructing the measurement model, a comprehensive literature review was conducted on coastal hazard recovery resilience, establishing a conceptual framework that included operational definitions for vulnerability and recovery resilience, along with several feedback mechanisms. The measurement model for coastal hazard recovery resilience comprised four metrics (MRV, LRV, RTSPV, and ND) and a Coastal Resilience Index (CRI). The developed indices were applied to domestic coastal erosion cases, and regional analyses were performed based on the index grades. The results revealed that the four recovery resilience metrics provided insights into the diverse characteristics of coastal erosion recovery resilience at each location. Mapping the composite indices of coastal resilience indicated that the areas along the East Sea exhibited relatively lower coastal erosion recovery resilience than the West and South Sea regions. The developed recovery resilience measurement model can serve as a tool for discussions on post-adaptation strategies and is applicable for determining policy priorities among different vulnerable regional groups.

• Journal of the Korean Geotechnical Society
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• v.36 no.11
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• pp.119-133
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• 2020

Underground utility tunnel, the most representative cut and cover structure, is subjected to seismic force by displacement of the surrounding soil. In 2020, Korea Infrastructure Safety Corporation has published "Seismic Performance Evaluation Guideline for Existing Utility Tunnel." This paper introduces two seismic evaluation methods, RDM (Response Displacement Method) and RHA (Response History Analysis) adopted in the guide and compares the methods for an example of an existing utility tunnel. The test tunnel had been constructed in 1988 and seismic design was not considered. RDM is performed by single and double cosine methods based on the velocity response spectrum at the base rock. RHA is performed by finite difference analysis that is able to consider nonlinear behavior of soil and structure together in two-dimensional plane strain condition. The utility tunnel shows elastic behavior for RDM, but shows plastic hinge for RHA under the collapse prevention level earthquake.

• Korean journal of applied entomology
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• v.59 no.1
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• pp.73-78
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• 2020

The fall armyworm, Spodoptera frugiperda (Smith, 1797), originated from tropical and subtropical America is one of sporadic agricultural pests in the world. Since the moth has high migration capacity, it rapidly expanded the world distribution such as Africa in 2016, India in 2018, and East-Asian countries in 2019. In Korea, this species was firstly found at maize fields of Jeju Island, in early June 2019, and subsequently detected at many counties of Jeolla-do and Gyeongsang-do in June and July 2019. The first invaded populations of S. frugiperda in Korea were genetically confirmed as one species, S. frugiperda by using a mitochondrial cytochrome oxidase subunit I (COI) gene, and analyzed to be comprised of two haplotypes (hap-1 and hap-2) each belonging to different clades. Among 31 COI sequences, the hap-1 sequence was predominant, accounting for 93.5%.

• Fire Science and Engineering
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• v.28 no.6
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• pp.13-21
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• 2014

Forest fire has a number of variables and since the effects of wind fields are bigger than any other variables, it is essential to know wind direction and velocity for the forest fire extinguishing techniques and the prediction of fire spread. With regards to the local area that has a high chance of forest fire, the data from meteorological observatory in the area is used for the estimation of wind velocity. It is relatively easy to obtain automatic weather station (AWS) data which are available for the whole nation. There is a chance that the data from the weather station may be different with the actual data at the mountain areas. In this study simply shaped hills (Sae-byeol hill of Jeju Island and port Ma-geum in An-myeon Island in the sea side) were selected as the experimental locations to minimize the distortion of the wind field by the adjacent geographic features. Spot measurements and analysis of computational fluid dynamics (CFD) for the given geographic features were conducted to examine and compare their consistency. As a conclusion It is possible to predict wind patterns in these simple locations.