• Smart Structures and Systems
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• v.29 no.4
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• pp.589-598
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• 2022

Timber structures are susceptible to structural damages caused by variations in moisture content (MC), inducing severe durability deterioration and safety issues. Therefore, it is of great significance to detect MC levels in timber structures. Compared to current methods for timber MC detection, which are time-consuming and require bulky equipment deployment, Lead Zirconate Titanate (PZT)-enabled stress wave sensing combined with statistic machine learning classification proposed in this paper show the advantage of the portable device and ease of operation. First, stress wave signals from different MC cases are excited and received by PZT sensors through active sensing. Subsequently, two non-baseline features are extracted from these stress wave signals. Finally, these features are fed to a statistic machine learning classifier (i.e., naïve Bayesian classification) to achieve MC detection of timber structures. Numerical simulations validate the feasibility of PZT-enabled sensing to perceive MC variations. Tests referring to five MC cases are conducted to verify the effectiveness of the proposed method. Results present high accuracy for timber MC detection, showing a great potential to conduct rapid and long-term monitoring of the MC level of timber structures in future field applications.

• Journal of the Korea Safety Management & Science
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• v.25 no.2
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• pp.9-15
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• 2023

The Severe Disaster Punishment Act had recently been established in order to promote safety and health (OSH) management system for severe accident prevention. OSH management system is primarily designed based on risk assessments; however, companies in industries have been experiencing difficulties in hazard identification and selecting proper measures for risk assessments and accident prevention. This study intended to introduce an accident analysis method based on epidemiological model in finding hazard and preventive measures. The accident analysis method employed in this study was proposed by the U.S. Department of Energy. To demonstrate the effectiveness of the accident analysis method, this study applied it to two accident cases occurred in construction and manufacturing industries. The application process and results of this study can be utilized in improving OSH management system and preventing severe accidents.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.450-454
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• 2007

In line with the construction projects, which have been increasingly getting larger and complex, safety accident has been on the rise, particularly those in association with the construction equipment. In a bid to prevent the safety accident, it's needed to analyze the cause of such accidents. The thesis was intended to identify the cause of safety accident by reviewing the cases of construction disaster complied by Korea Occupational Safety and Health Agency. The cases subject to study were limited to the accident by excavator. Summarizing the study is as follows. 1) Among the cause of accidents caused by excavator were, in order of high frequency, being caught in equipment or machine, falling, being crashed or bumped. 2) Among the causes of accident were, in order of high frequency, worker's unauthorized presence within the range of equipment operation. inappropriate use, failure of equipment inspection prior to starting work and inappropriate work method. The study is highly expected to pave the foundation for further study as well as to make commitment to mitigating the safety accident.

• Journal of the Korean Society of Safety
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• v.35 no.5
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• pp.106-114
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• 2020

The two major trends that have emerged in recent years in relation to disaster recovery and recovery are 'regional infrastructure', 'regional leadership' and 'community recovery'. In the former case, it is to avoid disaster recovery and recovery by using external personnel and resources, and to maximize the resources in the area under the initiative of the residents of the affected area. And through this process, it is to prepare a new growth engine for disaster-affected areas. In addition, the latter expands disaster recovery targets to the general population living in affected areas and is not limited to victims. Through this, we can expect to recover the 'community' beyond the individual's recovery. In the Ansan of Gyeonggi-do, where many families of 'Sewolho' live, and in the Heunghae-eup of Pohang, Gyeongbuk-do, where the damage was severe, projects are underway to restore communities. And In these areas local activists and civic groups are actively utilized to efforts are being made to increase efficiency. Nevertheless, in the case of the community recovery program being promoted in Korea, there are limitations that it can be promoted only on the basis of special laws and that participation of various actors is necessary. This study intends to propose the limitations of current projects and ways to solve them by analyzing domestic and foreign cases related to the community recovery program for disaster-affected communities using local resources. we suggest two way. One is the relaxation of the national dependence of the community recovery program, and the other is to expand the area of disaster relief through.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.3102-3113
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• 2023

Following the Fukushima nuclear disaster, the simulation of accidents in the spent fuel pool has become more noticeable. Despite the low amount of decay heat power, the consequences of the accidents in a spent fuel pool (SFP) can be severe due to the high content of long-lived radionuclides and lack of protection by the pressure vessel. In this study, the loss-of-cooling accident (LOFA) for the VVER-1000/V446 spent fuel pool is simulated by employing RELAP5 and MELCOR 1.8.6 as the best estimate and severe accident analysis codes, respectively. For two cases with different total power levels, decay heat of spent fuels is calculated by ORIGEN-II code. For modeling SFP of a VVER-1000, a qualified nodalizations are considered in both codes. During LOFA in SFP, the key sequences such as heating up of the pool water, boiling and reducing the water level, uncovering the spent fuels, increasing the temperature of the spent fuels, starting oxidation process (generating Hydrogen and extra power), the onset of fuel melting, and finally releasing radionuclides are studied for both cases. The obtained results show a reasonable consistency between the RELAP5 and MELCOR codes, especially before starting the oxidation process.

• Journal of the Korea Institute of Building Construction
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• v.8 no.3
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• pp.127-133
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• 2008

Safety accident resulting from construction projects getting larger and complex day by day has occurred more often than ever. Particularly, the accident caused by construction equipment, among others, has been on the rise. To prevent such accidents, it's necessary to come up with the measures for reducing the accident. In this study, the cause of safety accidents was analyzed, reviewing the cases of safety accident maintained by Korea Occupational Safety & Health Agency, and the measures for reducing the accident was suggested with computerized safety checklist. The scope of study was limited to excavator, and the result is summarized as below. 1) Investigation was conducted to identify the cases of accident by excavator with the primary causes. 2) Reduction measures were suggested by category of cause of excavator-caused accident. 3) Checklist to prevent the safety accident, which was based on primary causes, was suggested. 4) The measures to stir up safety consciousness and monitor the safety were suggested, making use of computerized system. This study is expected to lay the foundation for further study in future as well as make a great commitment to reducing the safety accident.

• Journal of the Korean Geographical Society
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• v.43 no.6
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• pp.858-872
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• 2008

This study examined the meteorological disaster of Jeju Island in Chosun Dynasty based on historical documents, and analyzed how its government and Jeju Islanders responded to this. Recording cases of abnormal weather days of Jeju Island in Chosun Dynasty were most in 17th Century, and then in 18th Century, 16th Century, 15th Century, and 19th Century in order. For the type of meteorological disaster, storm damage was most serious, and then flood disaster, drought disaster, and snow damage were in order. For the region, Jejumok was mostly damaged from storm and flood, and Daejeonghyeon was mostly from drought. Once meteorological disaster occurred, it was a common thing that it continued with famine. The Chosun government relieved Jeju Islanders by moving the grains of mainland into Jeju Island, and for this, installed Galdujin warehouse, Naripo warehouse, and Jemin warehouse. Also, it tried to resolve chronic famine by moving Jeju people into mainland such as Pyeong'an-do. Corresponding to severe weather, the farmers of Jeju Island implemented agricultural methods such as Dapjeon, Baryeong, molding, and wind-breaking; and the seamen conducted unique arts of navigation such as Hwanjeon, and gravel shipment.

• Journal of Korean Society of Disaster and Security
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• v.15 no.3
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• pp.57-66
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• 2022

According to the official letter of the Ministry of Employment and Labor (recent guidance on the status of deaths in the construction industry and thorough safety management, April 4, 2022), 17 deaths occurred in construction works worth more than 5 billion won until March 31, 2022. In terms of the size of the construction, 7 cases of 5 billion won to 12 billion won, 5 cases of 12 billion won to 80 billion won, and 5 cases of more than 80 billion won occurred. The causes of death accidents were found to be nine cases (50%), five cases (28%), two cases of collapse (11%), one case of entrapment (5%), and one case of drowning (5%). Safety facilities need to be strengthened to reduce deaths caused by falling, which accounts for most of the deaths, and if fall prevention nets, openings, and safety rails are completely installed, most falling accidents can be prevented. Therefore, this paper intends to present cases of development and use of patent technology through improvement of safety facilities in order to prevent accidents corresponding to the fall of new urban living housing sites, which are small apartment houses.

• Korean Journal of Ecology and Environment
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• v.41 no.4
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• pp.423-430
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• 2008

As of September 2008,45 Automatic Water Quality Monitoring Systems (AWQMS) have been installed at different sites on the 4 rivers to detect early the presence of pollutants in water and to issue an alarm. We count the number of issuing alarms by AWQMS, however, we will find the alarm has hardly been issued. The reasons for the scarcity of alarm issue are extensively being examined. The National Institute of Environmental Research attributes wrong alarm criteria for each AWQMS station to one the reasons. In this study, a suggestion has been made to modify the current alarm criteria to correspond with characteristics of river water quality. The current system with only two criteria (low and high) should be replaced as four-criteria systems (low, medium, high, and severe) based on cases of other advanced countries and stream conditions of Korea. The highest value of data collected for 5 years was suggested as the alarm criteria for each parameter. Meanwhile the alarm criteria for VOCs, phenol and heavy metals were established as same as drinking water quality criteria.

• Environmental Analysis Health and Toxicology
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• v.31
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• pp.25.1-25.9
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• 2016

Objectives After the initial investigations by the Korea Centers for Disease Control in 2011, over 1000 suspicious cases of humidifier disinfectant (HD) victims were subsequently reported by 2015, and numbers are still increasing dramatically in 2016 in the midst of the prosecutors' office investigation. This study attempts to summarize the current understandings of the related health effects of HD based upon a systemic review of published epidemiologic studies and toxicology investigations. Methods Published studies of HDs were searched through PubMed and TOXLINE under the search words 'humidifier disinfectant,' and related reports were identified from the references and published report list of regulatory agencies including the Korean National Institute of Environmental Research, US Environmental Protection Agency, and EU European Chemicals Agency. Results Case reports and epidemiologic studies have reported the clinical features of severe forms of HD lung damage, together with epidemiologic findings of seasonal occurrence and demographic variations, including the heightened susceptibility of young children. Toxicological studies have reported inhalation toxicities together with positive findings of in vitro genotoxicity studies. Conclusions This study examined unsolved issues based on cases of upper respiratory diseases and diseases of other organs, including cancers, among suspected victims of HDs. These issues should be clarified in future research for the management and prevention of health effects from HDs and chemicals of other related household products.