• Fire Science and Engineering
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• v.25 no.6
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• pp.136-145
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• 2011

One of a large proportion among the causes of fire is electrical factors, and of fire by electric factors, the accident which accounted for over certain percentage is electric leakage and ground fault. In order to reduce the electric leakage and ground fault, the technical guidelines on the protection of ground fault in the low-voltage electrical line (KECG 1091-2011) was amended for reflecting recent international standard, IEC 60364-4-41, and new conservation methods, which improved the reliability by recovering the facility's all-time use operation and breakdown defect, was on the rise. Accordingly, in this paper, after grasping the fire's status for last 10 years and analyzing the risk of electrical fires, and as a way to improve the electric leakage and ground fault accident which accounted for more than certain percentage, the revision of KECG 1091-2011 will be reviewed. And then, after applying to the preventive conservation methods in order to enhance the protection reliability of electric leakage and ground fault detection, the problems at issue routine inspection scheme and durable years scheme in time-scheduled conservation method are listed, along with suggestion of the problem-solving scheme, and the leakage current integrated monitoring systems and digital electric leakage devices by status monitor conservation method will be proposed.

• Journal of Navigation and Port Research
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• v.45 no.1
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• pp.9-15
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• 2021

According to IMO, MASS is defined as a vessel operated at various levels independent of human interference. The safety navigation support service for MASS is designed to improve the safety and efficiency of MASS by developing public services on shore for ship arrivals/departures and for cargo handling. The safety navigation support service consists of a total of six types of services: autonomous operation, berthing/unberthing/mooring, cargo handling and ship arrival/departure service, PSC inspection, condition monitoring, and accident response support services. In order to support accident response service, the relative importance of a bridge navigational equipment was assessed by stratifying the navigation system to provide safe and efficient support services by objective judgment through specific and quantitative methods using AHP, one of decision-making methods used by an expert group. The survey was conducted by dividing the bridge navigational equipment into depth, location, and speed information. As a result of applying the AHP method, the importance of depth, location, and speed information was assessed. The relative importance of each equipment for providing location information was also assessed in order of Radar, DGPS, ECDIS, Gyro compass, Autopilot, and AIS. This was similar to survey results on the utilization of each operator's preference and its impact on marine accidents.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.5
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• pp.515-528
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• 2020

Underground concrete structures are usually designed to be used for decades, but in recent years, many of them are nearing their original life expectancy. As a result, it is necessary to promptly inspect and repair the structure, since it can cause lost of fundamental functions and bring unexpected problems. Therefore, personnel-based inspections and repairs have been underway for maintenance of underground structures, but nowadays, objective inspection technologies have been actively developed through the fusion of deep learning and image process. In particular, various researches have been conducted on developing a concrete crack detection algorithm based on supervised learning. Most of these studies requires a large amount of image data, especially, label images. In order to secure those images, it takes a lot of time and labor in reality. To resolve this problem, we introduce a method to increase the accuracy of crack area detection, improved by 0.25% on average by applying adversarial learning in this paper. The adversarial learning consists of a segmentation neural network and a discriminator neural network, and it is an algorithm that improves recognition performance by generating a virtual label image in a competitive structure. In this study, an efficient deep neural network learning method was proposed using this method, and it is expected to be used for accurate crack detection in the future.

• Korean Journal of Remote Sensing
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• v.38 no.5_2
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• pp.793-810
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• 2022

Synthetic Aperture Radar (SAR) is considered to be suitable for near real-time inundation monitoring. The distinctly different intensity between water and land makes it adequate for waterbody detection, but the intrinsic speckle noise and variable intensity of SAR images decrease the accuracy of waterbody detection. In this study, we suggest two modules, named 'morphology module' and 'edge-enhanced module', which are the combinations of pooling layers and convolutional layers, improving the accuracy of waterbody detection. The morphology module is composed of min-pooling layers and max-pooling layers, which shows the effect of morphological transformation. The edge-enhanced module is composed of convolution layers, which has the fixed weights of the traditional edge detection algorithm. After comparing the accuracy of various versions of each module for U-Net, we found that the optimal combination is the case that the morphology module of min-pooling and successive layers of min-pooling and max-pooling, and the edge-enhanced module of Scharr filter were the inputs of conv9. This morphologic and edge-enhanced U-Net improved the F1-score by 9.81% than the original U-Net. Qualitative inspection showed that our model has capability of detecting small-sized waterbody and detailed edge of water, which are the distinct advancement of the model presented in this research, compared to the original U-Net.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.2
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• pp.91-111
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• 2024

Most of utility cable tunnels are constructed utilizing shield TBM as part of the underground transmission line project. The TBM chamber is the only space inside the tunnel that encounters rock and soil, and is the place with the highest frequency of accident exposure, such as collapse and collision accidents. Since there is currently no way to measure the disc cutter wear from outside the chamber, frequent inspection by workers is essential. Accordingly, in this study, in order to prevent safety accidents inside the TBM chamber and expect the effect of shortening the construction period by reducing the number of chamber openings, the concept of disk cutter wear measurement technology was established and a prototype was produced. By considering prior technology and determining that magnetic sensors are most suitable for the excavation environment, wear measurement sensor package were developed integrating magnetic sensors, wireless communication modules, power supply, external casing, and monitoring systems. To verify the performance of the prototype in an actual excavation environment, a full-scale tunnelling test was performed using a 3.6 m EPB shield TBM. Based on the full-scale tests, five prototypes were operated normally among eight prototypes. It was analyzed that sensor measurement, wireless communication, and durability performance were secured within a maximum thrust of 3,000 kN and a rotation speed of 1.5 RPM.

• Journal of Environmental Impact Assessment
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• v.6 no.1
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• pp.5-31
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• 1997

Strategic Environmental Assessment (SEA) is an assessment process integrated with policy and planning processes considering environmental impacts, not at the level of individual project, but at higher level of policy and plan. Presently, two systems for the SEA are being implemented in Korea. One is "the consultation of environmental investigation into a change in national land utilization", which is to be pre-discussed with the head of the related central administrative organizations, based on the respective individual code. The other is "the consultation of environmental investigation into an administrative plan and project", which is to be pre-discussed with the minister of the environments for the administrative plan. However, these two systems are not integrated procedures with the planning process. In other words, there is a separate post-environmental assessment after planning. Also concrete proposal is not yet prepared for the method and procedure of environmental investigation about details of the planning. Therefore, they do not playa role in taking precautions for environmentally sustainable development. In this study, for the effective environmental investigation at the level of planning, environmental assessment model to be integrated with urban comprehensive plans was developed. The results of this study can be summarized as follows: First, based on the analysis of systematic problems in environmental investigation of this country, the study compared and analysed the SEA method of foreign countries. derived the potential limitations in its applications to this country. Also, the new method in this study, is integrated into planning process by improving the limitations. Thus, we developed the SEA model for this country, which consists of seven steps ; Phase 1; establishing a work program, Phase 2; defining the scop. of the SEA, Phase 3; analyzing an existing environmental situation, Phase 4; examining the consistency with environmental policy, Phase 5; appraising and synthesizing the plan content, Phase 6; proposing recommendations, Phase 7; monitoring and feedback. Second, the two types of application program of the developed assessment model were proposed. One is to integrate this model into planning process, and the other is for the institute and ministry of environments to implement SEA after planning. An aim of this study was developing an environmental assessment model at the planning level which was not yet established in this country and was to apply the model to urban comprehensive plan for inspection. This research will make the effective operation of environmental investigation system possible at the planning level in this country and contribute to the environmental protection at the global level.

• The Journal of Society for e-Business Studies
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• v.23 no.3
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• pp.159-171
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• 2018

The imported foods, which are imported and sold domestically, are on the rise every year, and the scale is expected to be larger, including processing the imported raw materials. However, the origin of raw materials is indicated when declaring cargo for finished products of agricultural products, but the standardization of inspection information management system for raw materials is insufficient. In addition, there is a growing concern about the presence of residual pesticides or radioactivity in raw materials or products, and customer want to know production history information when purchasing agrifoods. It manages the hazard analysis of imported agricultural products, but most of them are global issues such as microorganisms, residual pesticides, food additives, and allergy components, etc. Therefore, it is necessary to share among the logistics entities in the entire transportation process the related data. Additionally, to do this, it needs to design an architecture and standardize business model. In this paper, it defines the architecture and the work-flow that occurs between the business process for collecting, processing, and processing information for tracking the status of imported agricultural products by steps, and develops XML message with UBL and the extracted conceptual information model. It will be easy to exchange and share information among the logistics entities through the defined standard model and it will be possible to establish visibility, reliability, safety, and freshness system for transportation of agricultural products requiring real-time management.

• Korean journal of applied entomology
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• v.56 no.2
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• pp.135-145
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• 2017

A sampling survey was conducted at three reservoirs of Junam wetland ($6.02km^2$) in Korea to identify the wetland insect fauna along with their dominance, diversity, richness and evenness. Methods of monitoring were visual inspection and sweeping in 2010, Malaise trapping in 2011, light trapping and pitfall trapping in 2012. In total, 9,269 individuals (36.3% coleopterans, 21.3% lepidopterans and 13.9% odonates) were collected, belonging to 574 species, 141 families and 14 orders. For the number of species, lepidopterans shared the highest (31.2%), followed by coleopterans (28.0%) and hemipterans (12.9%). Dominant species were Enochrus simulans (Coleoptera) (7.9% of total individuals) followed by Hydaticus grammicus (Coleoptera) (4.3%), Galerucella nipponensis (Coleoptera) (4.1%), Elophila interruptalis (Lepidoptera) (3.1%) and Apis mellifera (Hymenoptera) (2.2%). Total counts of coleopterans, lepidopterans and odonates in the three reservoirs were quite high, but the counts were not significantly different among the reservoirs. Insect diversity index (H') and richness index (RI) of the Junam wetland were 5.04 and 59.10, respectively.

• Journal of the Korean Institute of Gas
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• v.25 no.3
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• pp.27-38
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• 2021

We devised the system to automatically shutdown the boiler and to fundamentally block the harmful gases, including carbon monoxide, into the indoor when the exhaust system swerves: (1) The discharge pressure of the exhaust gas decreases when the exhaust pipe is disconnected. The monitoring system of the exhaust pipe is implemented by measuring the output voltage of APS(Air Pressure Sensor) installed to control the amount of combustion air. (2) The operating software was modified so that when the system recognizes the fault condition of a flue pipe, the boiler control unit displays the fault status on the indoor regulator while shutting down the boiler. In accordance with the ventilation facility standards in the "Rules for Building Equipment Standards" by the Ministry of Land, Infrastructure and Transport, experiments were conducted to ventilate indoor air. When carbon monoxide leaked in worst-case scenario, it was possible to prevent poisoning accidents. However, since 2013, the number of indoor air exchange times has been mitigated from 0.7 to 0.5 times per hour. We observed the concentration exceeding TWA 30 ppm occasionally and thus recommend to reinforce this criterion. In conclusion, if the flue pipe fault detection and the indoor air ventilation system are introduced, carbon monoxide poisoning accidents are expected to decrease significantly. Also when the manufacturing and inspection steps, the correct installation and repair are supplemented with the user's attention in missing flue, it will be served to prevent human casualties from carbon monoxide poisoning.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.335-340
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• 2010

In accordance with the increasing possibility that the new and reoccurring epidemics continuously appearing abroad flow into Korea, it is very important to evaluate the efficiency of quarantine management projects of National Quarantine Station. This study adopted the pairwise comparison approach using the analytical hierarchy process(AHP) that has been recognized with its scientific adequacy for allocating the weight, the relative importance of evaluation components. AHP technique is evaluated to be distinguished in measuring the impact by making hierarchy of, simplifying and systemizing the complicated multi-criteria decision making problems. The weights by evaluation indexes were 0.2 in the organization evaluation field and 0.8 in the service and program field. The quarantine business showed the highest value, 0.45, in the service and program field. The indexes were classified into the upper category (organization evaluation field, service and program evaluation field) and lower category (input/process/result/quarantine field, inspection field, hygiene management field, pathogenic organ investigation and monitoring field, epidemics prevention promotion/education field). The evaluation indexes that were finally selected were applied to the actual businesses in National Quarantine Station. Next, the minimum evaluation indexes were selected and so the evaluation system on the businesses in National Quarantine Station was more systemized.