• Journal of the Korean Geotechnical Society
• /
• v.40 no.2
• /
• pp.105-113
• /
• 2024

Underground buried cables can cause disconnections during the construction of roads and other subterranean structures due to uncertain designs. This paper describes experiments conducted to detect and verify the locations of these cables utilizing ground penetrating radar (GPR). The experiments were carried out at an active road construction site, where cable burial was anticipated. The GPR used operated within a frequency range of 400 MHz to 900 MHz to probe underground structures. The exploration methodology consisted of an initial GPR test to survey the entire area, followed by a secondary test informed by the results of the initial experiment, incorporating a diverse and increased number of lines. The findings confirmed the hyperbolic reflection patterns of cables at consistent locations along the same lines. These patterns were then compared to existing designs to corroborate the presence of cables at the identified locations. This research establishes an effective GPR methodology based on the electromagnetic wave reflection pattern, specifically the hyperbola, to detect difficult-to-locate underground buried cables.

• Journal of Wetlands Research
• /
• v.19 no.1
• /
• pp.45-51
• /
• 2017

Nepal is a landlocked mountainous country in South Asia, located between China to the north and India to the south, east, and west. As such, wastewater management has become one of the most significant problems in urban area of Nepal. In Nepal, the centralized wastewater treatment systems were dysfunctional due to high cost of operation, discontinuous power supply, lack of proper maintenance and proper technical workforce to address the issues. As such, constructed wetlands (CW) were applied to treat various secondary wastewater as alternative to wastewater treatment facilities. Generally, efficiency and sustainability of CW technology depends on proper operation and maintenance and active community involvement. This study summarizes information about 26 CW in Nepal. Specifically, factors including data banking, removal efficiency, quality of discharged water, compliance to water quality standard of Nepal and operation and maintenance were investigated. Considering removal efficiency per pollutant, Ka-1 achieved the greatest reduction for most pollutant followed by B-1, L-3, Ka-5 and K-1. Nepal has practiced CW technology for more than 2 decades but currently, development of technology was interrupted by the inefficient performance of existing facilities. Public awareness about the technology, natural disaster, unavailability of specified substrate materials, lack of fund for further research and experiments has hindered the expansion of technology. In spite of these concerns, CW was still proven as an alternative solution to the present wastewater problems in urban areas of Nepal.

• Journal of The Geomorphological Association of Korea
• /
• v.20 no.1
• /
• pp.85-96
• /
• 2013

This study collected national secondary and tertiary nationwide natural environment survey data of the National Institute of Environmental Research as well as the National Park's secondary and tertiary natural resource research data executed by the Korea National Park Service. The data collection is aimed at reclassification the geomorphological landscape resources of each park in varying types. The results generated a total of 3,169 geomorphological landscape resources within all the national parks. Among all the geomorphological landscape resources, 794 landscape resources were judged as Level I, which accounts for 36.9%. Next, 546 landscape resources were judged as Level II, or 25.3%, and 459 landscape resources judged as Level III, or 21.3%. Lastly, 191 landscape resources were judged as Level IV, having the lowest conservation level, or 8.9%. The number of Level I landscape resources for each national park includes 207 sites on Seoraksan, 92 sites on Dadohaehaesang Park, 84 sites on Jirisan, and 60 sites at the Taeanhaean, respectively. Dadohaehaesang National Park, Seoraksan National Park, Taeanhaean National Park, Jirisan National Park, Songnisan National Park, and Gyeryongsan National Park were evaluated as national parks having excellent landscape resources. To use these excellent landscape resources, there is a need to increase visitors' satisfaction and increase their interest in and understanding of landscape resources. To achieve this, a landscape viewpoint map must be composed and installed at the entrance or at certain points to provide visitors with useful information regarding the geomorphological landscape resources.

• Journal of Korea Water Resources Association
• /
• v.33 no.1
• /
• pp.111-121
• /
• 2000

A numerical model which can analyze the flow and bed topography characteristics of a single bend and continuous one was suggested using the equations of mass, momentum, the vertical distribution of secondary flow, and the transverse bed slope. The calculated flow and bed topography characteristic values were compared with the experimental data in a single bend, and the predicted path of maximum streamwise velocity in continuous bends also compared with the Vadnal and Chang's data. The comparisons gave good results. A curved channel with 180 degrees was used. Sand and anthracite were selected as bed materials in the movable bed experiments. The model application of this model to the sand bed and the anthracite one accorded well with the observed values in the experiments. This model was proved to be useful for predicting the flow and bed topography with the change of bed materials. The results of this research could be used to construct and control curved channels as a fundamental information.mation.

• Health Policy and Management
• /
• v.17 no.4
• /
• pp.99-112
• /
• 2007

The purpose of this study was to analyze the effect of fire fighters' duty type on occurrence and severity of low back pain. Data were collected with questionnaire to 450 fire fighters working at 119 safety center and rescue unit of 30 fire stations in Gyeonggi-do. Finally the study was analyzed for 360 persons among them. The risk of experiencing of lower back pain occurred in the order of Rescue[odds ratio(OR) 3.36, 95% confidence interval(95% CI) 1.18-9.52], Vehicle operation(OR 2.63, 95% CI 1.26-5.50), First aid(OR 2.18, 95% CI 1.03-4.59), and Putting out a fire. The risk on severity of lower back pain occurred in the order of Vehicle operation(OR 4.00, 95% CI 1.57-9.80), First aid(OR 1.88, 95% CI 1.00-4.81), Putting out a fire, and Rescue. These result suggest that duty type of fire fighters may be a prognostic factor for occurrence and severity of low back pain. The potential implications of these findings are discussed about different approach for primary and secondary prevention by duty type of fire fighters.

• Spatial Information Research
• /
• v.18 no.2
• /
• pp.35-44
• /
• 2010

This research intended to estimate the damage information from torrential rainfalls using airphotos and spatial data which have been rapidly increasing their applicability recently. The study area was Bonghwagun of Gyungsangbukdo where the large amount of damages were occurred from torrential rainfall in July, 2008. For this study, the database was constructed for the study area by collecting usable data. The interpretable items from the airphotos of 40cm spatial resolution were selected. Also, the useful GIS layers such as road were selected in the digital map to extract the damage information more accurately and rapidly. The damaged area was easily identified through the comparison of pre- and post-disaster airphotos. The recovery cost was estimated by applying unit cost to the damaged area. GIS's overlay function was used to extract the damage information of for individual items damaged. The method for extracting damages information using GIS and airphotos could be more efficient and cost effective in case of relatively wide and unapproachable damaged areas. It is also expected that the method using high resolution imagery would lead to minimize the secondary damages as well since it can facilitate the damage estimation within short period of time thereby supporting early securing budget for recovery.

• Geomechanics and Engineering
• /
• v.9 no.1
• /
• pp.57-81
• /
• 2015

Water inrush and mud outburst always restricts the tunnel constructions in mountain area, which becomes a major geological barrier against the development of underground engineering. In view of the complex disaster-causing mechanism and difficult quantitative predictions of water inrush and mud outburst, several theoretical methods are adopted to realize dynamic assessment of water inrush in the progressive process of tunnel construction. Concerning both the geological condition and construction situation, eleven risk factors are quantitatively described and an assessment system is developed to evaluate the water inrush risk. In the static assessment, the weights of eight risk factors about the geological condition are determined using Analytic Hierarchy Process (AHP). Each factor is scored by experts and the synthesis scores are weighted. The risk level is ultimately determined based on the scoring outcome which is derived from the sum of products of weights and comprehensive scores. In the secondary assessment, the eight risk factors in static assessment and three factors about construction situation are quantitatively analyzed using fuzzy evaluation method. Subordinate levels and weight of factors are prepared and then used to calculate the comprehensive subordinate degree and risk level. In the dynamic assessment, the classical field of the eleven risk factors is normalized by using the extension evaluation method. From the input of the matter-element, weights of risk factors are determined and correlation analysis is carried out to determine the risk level. This system has been applied to the dynamic assessment of water inrush during construction of the Yuanliangshan tunnel of Yuhuai Railway. The assessment results are consistent with the actual excavation, which verifies the rationality and feasibility of the software. The developed system is believed capable to be back-up and applied for risk assessment of water inrush in the underground engineering construction.

• Aerospace Engineering and Technology
• /
• v.10 no.2
• /
• pp.29-36
• /
• 2011

The Science and Technology Satellite-3 (STSAT-3) is based on the KITSAT-1, 2, 3 and STSAT-1, 2 which were Korea micro-satellites for the mission of space and earth science. The objectives of the STSAT-3 are to support earth and space sciences in parallel with the demonstration of spacecraft technology. The STSAT-3 carries an infrared (IR) camera for space & earth observation and an imaging spectrometer for earth observation. The IR payload instrument of the STSAT-3, Multi-purpose Infrared Imaging System (MIRIS), will observe the Galactic plane and North/South Ecliptic poles to research the origin of universe. The secondary payload instrument, Compact Imaging Spectrometer (COMIS), images the Earth's surface. The data acquired from COMIS are expected to be used for various application fields such as monitoring of disaster management, water quality studies, and farmland assessment. In this paper we present the operations concept of STSAT-3 which will be launched into a sun-synchronous orbit at a nominal altitude of 600km in late 2012.

• Journal of the Korean Society of Industry Convergence
• /
• v.22 no.6
• /
• pp.665-671
• /
• 2019

The estimated on-site accident rate in Forestry is relatively high. According to statistics of the accident, in the recent 5 years, from 2014 to 2018, forestry accidents have resulted in 98% of injuries and 87% of fatalities. Especially, there are significant geographical constraints to access to the scene in case of an accident. Even though the capacity of first aid capacity is notably emphasized its importance to minimize the scale of damages, the relevant employees have been educated only basic first aid, which is not considered circumstances or geographic limitations, by Occupation Safety and Health Acts. Therefore, the purpose of this study is to derive a direction for a forest emergency service system to increase forestry workers' survival and prevent secondary injury through securing 'Golden Time.' This study conducts analyzing relevant laws and regulations in domestic and international settings as well as looking at several concerned accident cases. The outcome of analysis presents an issue regarding the implementation of onsite first aid in forestry and existing risk factors depending on the working process. Finally, we suggest two ways to improve the forest emergency service that are 1) an appropriate curriculum and kit for forest first aid; and 2) a system for emergency transfer through sharing information between National Fire Agency (NFA) and emergency medical service center, and emergency and rescue mission using helicopter from NFA and Korea Forest Service.

• Journal of the Korean Society of Safety
• /
• v.34 no.4
• /
• pp.111-118
• /
• 2019

Accidents occurring due to natural disasters in chemical process facilities where technologies are concentrated can cause secondary damage. The concept of the relationship between natural disasters and highly intensive technologies has evolved into the Natech (Natural Hazards Triggered Technological Disaster) research. Currently, the number of earthquakes is increasing all over the Korean peninsula. To assess the risk of Natech when an earthquake has occurred in South Korea, the Rapid Natech Risk Assessment Tool (RAPID-N) developed by the European Commission's Joint Research Center (EC JRC) was used in the present study. The RAPID-N can be used for Natech risk assessment based on mapping and can be utilized for sufficient preparation for reduction of the effects of Natech accidents. A total of 261 chemical facilities actually existing in Pohang were initially analyzed to select eight facilities and the Pohang earthquake that occurred in 2017 was implemented in the RAPID-N utilizing the shake map. High risk areas were selected through Natech risk assessments for the selected eight work places and countermeasures for the areas were suggested. High risk areas exist depending on the location, since the damage influence ranges could be overlapped and each chemical facility has an independent probability of Natech. Therefore, studies on Natech emergency plans and emergency evacuation routes should be actively conducted considering such high risk areas. The present study was conducted to demonstrate the feasibility of Natech risk assessment in South Korea through the RAPID-N. These findings can be used as a reference material to lay a foundation for Natech risk assessment and related policies in South Korea.