• Journal of Korean Society for Geospatial Information Science
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• v.18 no.4
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• pp.71-77
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• 2010

Cut Slope Management System(CSMS) is a systematic maintenance and management system designed to prevent the collapse of cut slopes located along national roads. In order to implement safe road operation system, KICT has started the inventory of cut slopes and developed a cut slope database since 2006. Cut slope database management system using GIS technology and navigation system was developed as a Information Technology application. Through the Cut Slope Navigation System(SLOPE-Navi.), the previously developed database was checked and verified. The converted cut slope inventory data and field investigation data of 28,707 cut slopes were loaded on the navigation map. We consider that the Cut Slope Navigation Management System can be useful as in-situ system, which can be systematic and effective DB management and operation to prevent cut slope collapses and establish a remedial countermeasure as mitigation concerning disasters.

• Journal of the Korea Convergence Society
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• v.5 no.3
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• pp.1-5
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• 2014

The development of communication method for a variety of intelligent automobiles are delivering comfortable and safe information. However the development of such communication method must also think about security. Even the update of navigation to be used for intelligent automobiles uses the wireless updating methods but the updating methods currently being used has no reliable security measures. The navigation communications used in the intelligent automobiles are being provided with TTI(Traffic and Travel Information) service using a variety of methods by the countries. In the case of Korea, most are based on T-DMB using the TPEG method for transmitting the information. By identifying the characteristics on the navigation wireless update, a security solution is proposed for delivering the reliable update information after creating the attack scenario.

• Journal of the Korea Convergence Society
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• v.5 no.3
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• pp.23-27
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• 2014

In recent times, there is an increasing interest in wireless charge of smartphones and devices, and many companies are developing wireless charges. The range of application of wireless charge would be expanded to almost all electronics, including not only mobile devices, but also notebook computers and vacuum cleaners. On-line electric vehicles are to be launched in the market this year in a massive scale. As such wireless charge-related markets are inexhaustible. Wireless charge is included in the world's top 10 promising technologies, and its rapid growth is expected to have annual growth by more than 100%. However, there's a need to establish a safe environment, by analyzing security threats to technical limitations and harmfulness to human body, and arrange institutional compliments. The development of communication method for a variety of wireless charging are delivering comfortable and safe information. This paper aims to examine the factors to threaten electric vehicle, which are usually intruded through network system and analyzes security threats to and security requirements for magnetic resonance mode-based wireless charge in mobile devices, and suggests security requirements.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.185-188
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• 2008

Fiber reinforced polymer(FRP) bars are proving to be a valuable solution in the corrosion problem of steel reinforced concrete structures. As such, a number of guidelines for their use have been developed. These guidelines are primarily based on modifications to existing codes of practice for steel reinforced concrete structures. These guidelines are also similar in that though the design equations are presented in the partial factor formats that are often used in probability based design, they are not true probabilistic codes. Instead, they typically make use of already existing design factors for loads and resistances. Thus, when concrete structures reinforced FRP bars are designed, the structural reliability levels are not known. This paper investigates uncertainties of concrete beams reinforced with GFRP bars. Also, the structural reliability levels are evaluated for the flexural failure mode.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.705-708
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• 2008

To obtain tunnel concrete safety in case of fire, this study analyzed fire proof characteristics by fire proof method change, and the results are as follows. As a fire proof characteristics by RABT temperature heating curve, plain concrete experienced severe spalling by initial extremely high temperature. In view of fire proof method, in the cases of organic fiber mixing method and board method, spalling was prevented, and in the case of spray method, severe spalling of over 100mm depth occurred along with exposure of structural concrete including spray coat by heat stress, etc while metal lath, the stiffener, falls off. As for fire proof characteristics by RWS temperature heating curve, in case of organic fiber inclusion, concrete surface experienced fusion of within 5mm, while in the case of spray method, spray coat was severely spalled to a depth of over 100mm causing structural body concrete to expose its reinforcement, and also in the case of board method, board was fused by high temperature, causing structural body concrete be directly exposed to high temperature, which triggered overall fall-off phenomenon, so in such extraordinary high temperature heating condition, establishment of special fire proof measures is needed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.4
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• pp.23-30
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• 2000

Cogeneration systems are seen as a significant innovation for dispersed energy generation since they are both environmentally friendly and has comparatively high degrees of efficiency. It is especially suited for the decentralized provision of electricity and heat. However, it causes operational problems such as voltage regulation, voltage variation, protection and safety. Especially, it is expected that the interconnection/disconnection operation of cogeneration system has an effect on distribution voltage regulation and variation. Recently, with the increased use of customer-owned computers and other sensitive electronic equipment, electric power quality has become an important concerns. Therefore, the voltage quality problems with cogeneration system should be investigated because the voltage quality is an important part of electrical power quality. In this paper, the momentary voltage dips associated with the interconnection/disconnection operation of cogeneration system are analyzed, including restraint solutions at the customer level. In addition, the unit capacity of cogeneration systems per feeder are evaluated from the view point of momentary voltage variations. The results of this paper are useful analysis data for interconnection standards/guidelines of cogeneration systems and dispersed generation (DG)

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.2
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• pp.83-96
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• 2011

Currently, the commonly used tunneling method in Korea is NATM (New Austrian Tunneling Method). This method uses the rock bolt, shotcrete, and supporting system to maintain the strength of original soil and ensures the stability of tunnel by stabilizing the soil using the original strength of the soil in maximum after the excavation. In past years, wire-mesh reinforced shotcrete was common ones but currently steel-fiber reinforced shotcrete is being widely used for the tunnel construction site in Korea to save construction time with the advanced construction technology. The results further indicate that needs for the establishment of not only the specifications for shotcrete but the strengthening methods for the under reinforced shotcrete sections. Therefore, this study deals with the development of a new steel-fiber to ensure the stability of tunnels that are under reinforced with steel-fibers and to overcome the shortcomings of conventional method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1727-1732
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• 2010

Forensic engineering is the area of expertise of people qualified to serve as engineering experts in courts of law or during arbitration proceedings. An aerial-lifter can lift and carry load, including people, using power. Recently, failure of aerial-lifter internal parts while working and sweeping causing injuries and damage to property almost always generates conflict between the automaker and customer. Hence, the investigation of such events generally involves an engineering analysis. One of the possible reasons for accidents, such as a vehicle catching fire is the failure of oil pressure machine and the supporting pin. The results of formal inspections and engineering tests can reveal the cause for the failure of the mechanical parts. Therefore, the failure mechanism is analyzed by adopting fractography methods and by applying an instrumented indentation technique to compare the material properties of the reference part with those of the malfunctioning part.

• Korean Journal of Agricultural Science
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• v.19 no.2
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• pp.136-144
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• 1992

This study was aimed to extend the marketing period through the postharvest application of fruit coating materials in early cultivar 'Tsugaru' apples. Postharvest application of fruit coating materials were effective on remaining freshness during storage and marketing. Prestorage waxing showed higher flesh firmness and weight loss was greatly reduced after storage. This tendency was continued even after marketing period. While no clear effect of prestorage Prolong application on keeping freshness was found, poststorage application of Prolong appeared to be most effective on the prevention of weight loss and keeping firmness during marketing. Parts of fruit developed $CO_2$ injury - like disorder regardless posthavest treatments but no trial was conducted to examine this disorder in this study. Further study should include to determine the cause of this disorder.

• Geotechnical Engineering
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• v.11 no.4
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• pp.125-140
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• 1995

Generally, the groundwater pressure is not considered in the design of concrete lining of bottom drainage tunnel. This design method implies that the phreatic surface is drawdown to the bottom of tullnel. When tile groundwater is continually supplied without changing of groundwater table, there is a possibility at which the groundwater pressure acting on the tunnel lining after the completion of tunnel. Therefore, the safety of tunnel lining must be checked in this case. In this paper, the stability of bottom drainage tunnel which is affected by groundwater discharge is analzed by using of the Finite Element Method at the 2 sections of subway where the groundwater level has a tittle change during the construction. As the result of analysis, the grouting for the water tightness and the permanent monitoring system of tunnel are required for maintaining of long-term stability of bottom drainage tunnel for the case of groundwater plassure acting on the tunnel lining is greater than that of design stage.