• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.601-605
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• 2020

In large ships with complex structures, it is difficult to locate workers. In particular, it is not easy to detect when a worker falls down, making it difficult to respond quickly. Thus, research is being conducted to detect fallen workers using a camera or by attaching a device to the body. Existing image-based fall detection systems have been designed to detect a person's body parts; hence, it is difficult to detect them in various ships and postures. In this study, the entire fall area was extracted and deep learning was used to detect the fallen shipworker based on the image. The data necessary for learning were obtained by recording falling states at the shipyard. The amount of learning data was augmented by flipping, resizing, and rotating the image. Performance evaluation was conducted with precision, reproducibility, accuracy, and a low error rate. The larger the amount of data, the better the precision. In the future, reinforcing various data is expected to improve the effectiveness of camera-based fall detection models, and thus improve safety.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.8
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• pp.23-32
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• 2007

We propose a group-based security scheme for hierarchical wireless sensor networks. We model the network for secure routing with 3-tier sensor network comprised of three types of nodes: Base Station, Group Dominator and ordinary Sensor Nodes. Group-based deployment is performed using Gaussian (normal) distribution and show that more than 85% network connectivity can be achieved with the proposed model. The small groups with pre-shared secrets form the secure groups where group dominators form the backbone of the entire network. The scheme is devised for dealing with sensory data aggregated by groups of collocated sensors; i.e., local sensed data are collected by the dominating nodes and sent an aggregated packet to the base station via other group dominators. The scheme is shown to be light-weight, and it offers a stronger defense against node capture attacks. Analysis and simulation results are presented to defend our proposal. Analysis shows that robustness can significantly be improved by increasing the deployment density using both the dominating and/or ordinary sensor nodes.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.477-482
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• 2022

The structure of the turnout track is very complex, so it is a facility that is more difficult to maintain and requires detailed management than a general track type. The purpose of this study is to analyze the effect on the deformation of the turnout system of the ground section due to the excavation work adjacent to the serviced urban railways. In this study, based on finite element analysis for each stage of adjacent excavation, the track deformation for each major location of turnout system was analyzed in consideration of the layout of the turnout system installed on the ground section, and the safety and stability was confirmed by comparing it with the track irregularity regulation. As a result of the study, it was found that the major construction stage affecting the track deformation of the turnout system on the ground section was the final stage of excavation. In addition, although the vertical displacement which is a vertical irregularity occurred relatively large, it was analyzed that the horizontal deformation was dominant overall, because of the excavation site is located on the side of the turnout system. In addition, it was analyzed that the amount of displacement at each major location of the turnout system is different, and there is a possibility that there may be a twist irregularity due to the deviation of the track deformation for each location according to the distance from the excavation site. Therefore, it was analyzed that it is necessary to classify and manage the importance of the track deformation of the turnout system of actual operating line, including additional displacement due to adjacent excavation, based on the track irregularity that has occurred at each location where the major deformation characteristics occur.

• Economic and Environmental Geology
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• v.51 no.2
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• pp.185-201
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• 2018

Nuclear power plants(NPP) are constructed and operated to ensure safety against natural disasters and man-made disasters in all processes including site selection, site survey, design, construction, and operation. This paper will introduce a series of efforts conducted in Korea Hydro and Nuclear Power Co. Ltd., to assure the safety of nuclear power plant against earthquakes and other natural hazards. In particular, the present status of the earthquake, fault, and slope safety monitoring system for nuclear power plants is introduced. A earthquake observatory network for the NPP sites has been built up for nuclear safety and providing adequate seismic design standards for NPP sites by monitoring seismicity in and around NPPs since 1999. The Eupcheon Fault Monitoring System, composed of a strainmeter, seismometer, creepmeter, Global Positioning System, and groundwater meter, was installed to assess the safety of the Wolsung Nuclear Power Plant against earthquakes by monitoring the short- and long-term behavioral characteristics of the Eupcheon fault. Through the analysis of measured data, it was verified that the Eupcheon fault is a relatively stable fault that is not affected by earthquakes occurring around the southeastern part of the Korean peninsula. In addition, it was confirmed that the fault monitoring system could be very useful for seismic safety analysis and earthquake prediction study on the fault. K-SLOPE System for systematic slope monitoring was successfully developed for monitoring of the slope at nuclear power plants. Several kinds of monitoring devices including an inclinometer, tiltmeter, tension-wire, and precipitation gauge were installed on the NPP slope. A macro deformation analysis using terrestrial LiDAR (Light Detection And Ranging) was performed for overall slope deformation evaluation.

• Archives of design research
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• v.12 no.4
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• pp.99-108
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• 1999

The interior space in a passenger car is consisted with many partial elements, and the instrument panel is the most important part from all of them, which is designate the total image of the interior design and the space variation, drivability and safety of the interior space. ] The instrument panel of a passenger car in the early age had the concept of a wall between the engine room and the passenger cabin on which the instrument for the driver were fitted. Therefore the central mounting of the instruments was the typical feature regardless of the position of a driver seat. As the automobiles became more functional with many equipments, driver oriented instrument panel with energy absorbing materials had been developed, and that was the beginning of the various instrument panel design of these days. The recent instrument panels of passenger car have the tendency of going back to the central instrument mounting as it was at the past on a few cars for the strict safety regulation, a new production technology and for the enhanced drivability. It can be summarized into a few results as these with the analysis of a few recent instrument panels. -minimizing the total volume for the better frontal visibility. -energy absorbing and passive structures for the strict impact regulations. -revival of central instrument mounting for the convenience and safety through minimizing the difference of the focal length of a driver.

• Journal of Navigation and Port Research
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• v.38 no.3
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• pp.233-238
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• 2014

With the increasing needs on various leisure activities, the users of passenger ships and cruisers have been increased year by year. Although over 15 accidents per year betide on domestic passenger ships for last decade, the researches on the safety of crews and guests on boards are difficult to find. This study performed the comparative analysis by experiments on the evacuation characteristics between experience levels on board a training ship. The followings are the results. From the seniors' experiments, it is found that more various evacuation scenarios have to develope and drill as a part of education contents. And from the freshmen's trials, the importances of the evacuation education and the roles of existing crews on evacuation guides are pointed out as to increase the safety of new crews and/or guests who are not accustomed to onboard a ship. On the other, it is explained that the communications between evacuees are worthy and useful, and also save more evacuation times. And on the viewpoint of evacuation methodology, it is clear that captain and evacuation-related crews have to control all the evacuation passages and evacuees of each passages to save more lives.

• The Korean Journal of Archival Studies
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• no.27
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• pp.89-118
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• 2011

This paper considers the relationship between memory and archives by exploring the concepts and meaning of archivist and archival description. The author considers the metaphor of archives as memory and relates our understanding of creation, arrangement, preservation, description, and use of records and archives. The author argues that archivists demonstrate their knowledge and background when they organizing and preserving records and archives.

• Magazine of the Korea Concrete Institute
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• v.6 no.5
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• pp.140-148
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• 1994

RCI 318-8!4 recommends that when the specified cornpresslve strength of concrete In a column is greater than 1.4 times thdt spec~f~ed for a floor svsttm. top surface of the colunm concrete shall extend 2ft(600mm) into the slab from the face of colurnn to avoid unexpected brittle failure. Six test specimens were cast arid tested on 2/3 scale frame specmiens havlng different extension distances and compressive strength of concrete as the major variables. The paper discusses the performance of the frames in terms of ductility and also presents the assessment of the ACI 318-89 provisions.The test results showed that the ductility index were incrrased with increasing of compressive strength of concrete and extension distance. And top surface of the column concrete should extend 2h(h overall depth of beam) into the beam from the face of the column to avoid unexpected brittle failure in frame.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2581-2587
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• 2013

This paper aims at the design of wheel and axle with cap. The cap is conceptually designed by using TRIZ/CAE. Wheel axle is used at railway vehicle to safety and it is always investigated to reduce the railway vehicle weight. The cap has hollow shaft with the material of SM45C. Cap is located in the bearing seat of wheel and axle. The cap becomes durable within the allowable stress of EN13103, 13104 standard. In this study, the strength of wheel and axle with cap becomes higher than that of hollow shaft. The weight of wheel and axle with cap becomes lower by about 6.75 percent than that of solid shaft. The confidence of wheel and axle with cap can be improved by comparing with solid and hollow shafts.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.425-431
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• 2020

The market for small unmanned aerial vehicles (SUAVs) is growing rapidly as technology advances and makes it possible to use them in various fields. However, due to the rapid increase in small drones, breakdowns, collisions and falls are also increasing year by year, and technologies for reducing accident and securing safety are being actively researched. In particular, the application of a fault tolerance system to cope with unexpected failures during flight is essential. According to data released by the US Department of Defense, accidents caused by errors in flight control computers account for about 28% of all accidents. This paper describes the proposal of flight control computer system's dual structure design to tolerate flight control system failure.