• Journal of the Korean Institute of Gas
• /
• v.20 no.4
• /
• pp.33-43
• /
• 2016

Grinding, weld deposition, type A sleeve, type B sleeve, composite sleeve, hot tapping and clamp are used as the method to repair the buried pipelines in the United States, UK and Europe. In the event of defect to the pipeline, they have repaired the pipeline through the fitness-for-service assessments. In addition, they have guidelines for the possible repair methods to apply to each type of damage, which is occurred due to the 3rd party construction or corrosion. According to the KGS FS551, Safety Validation in Detail including ECDA(External Corrosion Direct Assessment) as one method of integrity management should be carried out for the old pipeline which supply natural gas as the middle pressure in Korea. Where a defect on the pipelines is found, on the result of Safety Validation in Detail, the pipelines should be repaired or replaced by new piping. However, there are no guidelines or regulations regarding the repair and reinforcement of pipeline, so that, cutting the damaged pipeline and replacing it as a segment of new pipe is the only way in Korea until now. We have suggested pipeline repair methods including type A, B sleeve, composite sleeve, after the survey of foreign repair method and standards including the method of United States and the United Kingdom, and after analysis of the results on pipeline repair test including type A, type B sleeve and composite sleeve.

• Journal of Information Technology Applications and Management
• /
• v.26 no.4
• /
• pp.51-69
• /
• 2019

One of the most considerate phenomena of the era of the Fourth Industrial Revolution is the use of digital devices. Digitalization is rapidly advancing through all areas of industry and life. Customer journey with digitalization is looking totally different from previous customer journey. The research targets were users of fashion, automobiles, cosmetics and online shopping malls. We analyzed 300 people for each valid questionnaire. The results of the study are as follows. First, it has been proven that digital experience affects positive (+) impact on purchasing intention and positive (+) impact on recommending intention and negative impact (-) on switching intent and subsequently affects positive impact (+) to purchase and incase of switching intent, negative impact (-) to purchase. Unlike traditional methods such as SPC(Service Profit Chain), the Digital experience to Purchase process Chain (DPC) has been identified to be suitable in the digital age. Second, the digital satisfied group (5 score-very satisfaction) has shown same result as above. However the digital neutral group (even though 4 score- satisfaction in five-point scale), specially in a highly competitive industry, has different from the satisfied group and 3 score-normal is same as dissatisfied group. It means that this group is that If there is a high level of attractiveness of substitute goods, there is a high possibility of switching them. It has supported Jones and Sasser [1995] that there have been two types of loyalty of true long-term loyalty and what we call false loyalty in the highly competitive industry zone which is commoditization or low differentiation, many substitutes, low cost of switching. Identifying true loyalty and false loyalty is crucial to establishing a customer experience strategy. it is necessary to actively utilize long-term digital experiences strategy to increase the total satisfaction of digital experience through all of customer purchasing journey in order to enhance the digital customer experience. It is difficult to see the effect as a one-time event. It should be scaled over the entire customer purchase process over a long period of time, which can positively affect purchase intention, recommendation intention, and conversion intention. This is also why it is difficult for second-runners to overtake first-runners in a short period.

• 한국정보통신설비학회:학술대회논문집
• /
• 2008.08a
• /
• pp.211-217
• /
• 2008

Recently, there are many efforts to support seamless mobility in 802.11 WLANs using IP Layer mobility protocols. The IP layer mobility protocols are the most efficient mechanism to guarantee the service session continuity when IP subnet is changed during handover. Even if the IP layer mobility protocols are quite efficient, the feature of the protocols that had been designed to consider only L3 layer makes it difficult to improve the performance of hand over more and more. Nowadays, to overcome this limitation of IP mobility protocols, many researchers have worked on the mobility protocols integration of different layers (e.g., L2 layer). In this paper, we propose the enhanced Proxy MIPv4 to minimize the latency of handover using MIH protocol in 802.11 WLANs. The proposed mechanism minimizes the latency of authentication by exchanging security keys between Access Routers during handover. Moreover, it also minimizes packet losses by Inter-AP Tunneling and data forwarding.

• Korean Security Journal
• /
• no.16
• /
• pp.357-371
• /
• 2008

Currently, the security operations in nation's key foundations in Korea are performed by private police and special security guard in accordance with the Private Police Act and Security Business Act, respectively. In 1960s, The Korean Government introduced the private police system in terms of the national security issues, but it was just a hurriedly-set plan on the basis of Japanese Sunsa system as by that time there was no such system revitalized. However, the special security guards could offer wider range of security services including those of the private police with the enactment and revision of the Security Business Act 1976 and April 2001, respectively. Moreover, the expectations and interests rose over the special security guards in nation's key foundations after 9.11Terror Event in the U. S. 2001. However, as we investigated the current education/training system for the special security guard, we found that such education/training which is not activating the specialty of special security guard will not respond to the social demands. Special security guard owns its own characteristics other than those of general security guard as they are in service in nation's key foundations. Thus, the effcient management and training for the special security guard is the most important matter for the safety and security of nation's key foundations. Therefore, the well-educated special security guard through the reorganized and specialized education/training for the protection of nation's key foundations is expected to offer qualitatively improved security services.

• Journal of Korea Multimedia Society
• /
• v.9 no.5
• /
• pp.671-680
• /
• 2006

As a mathematical technique with which we can find the minimum duration time needed to fire all the transitions at least once and coming back to the initial marking in a timed net, the minimum cycle time method has been widely used in computer system analysis. A timed net is a modified version of a Petri net where a transition is associated with a delay time. A delay time used in a timed net is a constant even though the duration time associated with an event in the world is a stochastic number in general. In the consequence, the result of minimum cycle time analysis is not realistic. Therefore, we propose ‘Stochastic Timed Net' where a transition can be associated with a stochastic number and introduce a minimum cycle time analysis method for ‘Stochastic Timed Net’ As an example of the application of ‘Stochastic Timed Net’, we introduce a ‘Stochastic Timed Net' model of a Location Based Service Providing Multimedia System and the result of minimum cycle time analysis of it. Whereas the typical form of the result of the existing minimum cycle time analysis is 'It takes at least 10 time units', the typical form of the result of minimum cycle time analysis of a ‘Stochastic Timed Net' is in the probability form such as "The probability of the events in which it finishes its job within 10 time units is 85%."

• Journal of Korea Water Resources Association
• /
• v.52 no.10
• /
• pp.719-728
• /
• 2019

Valve in water distribution network (WDN), that controls the flow in pipes, is used to isolate a segment (a part of WDN) under abnormal water supply conditions (e.g., pipe breakage, water quality failure event). The segment isolation degrades pressure and water serviceability in neighboring area during the water service outage of the segment. Recent hydraulic and water quality failure events reported encouraging WDN valve installation based on various abnormal water supply scenarios. This study introduces a scenario-based optimal valve installation approach to optimize the number of valves, the amount of undelivered water, and a shortest water supply path indicator (i.e., Hydraulic Geodesic Index). The proposed approach is demonstrated in the valve installation of Pescara network, and the optimal valve sets are obtained under multiple scenarios and compared to the existing valve set. Pressure-driven analysis (PDA) scheme is used for a network hydraulic simulation. The optimal valve set derived from the proposed method has 19 fewer valves than the existing valve set in the network and the amount of undelivered water was also lower for the optimal valve set. Reducing the reservoir head requires a greater number of valves to achieve the similar functionality of the WDN with the optimal valve set of the original reservoir head. This study also compared the results of demand-driven analysis (DDA) and the PDA and confirmed that the latter is required for optimal valve installation.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.24 no.6
• /
• pp.745-756
• /
• 2022

The road tunnel is a semi-closed space that is blocked on all sides except the entrance and exit, and in the event of a fire, the smoke of the fire spreads longitudinally due to heat buoyancy caused by the fire and air currents that always exist in the tunnel. To solve this problem, smoke removal facilities are installed in road tunnels to secure a safe evacuation environment by controlling the direction of movement of smoke or directly smoking at fire points. In urban areas, the service level of urban roads decreases due to the increase in traffic due to the increase in population, and as a solution, the construction of underground roads in urban areas is increasing. When a fire occurs during hydrogen leakage through TPRD of a hydrogen fuel cell vehicle (FCEV), the fire intensity depends on the amount of leakage, and the maximum fire intensity depends on the orifice diameter of the TPRD. Considering the TPRD orifice diameter of 1.8 mm, this study analyzed the diffusion distance of fire smoke according to the wind speed of the roadway and the opening interval of the large exhaust port when the maximum fire intensity was 15 MW. As a result, it was analyzed that air flow in the tunnel could be controlled if the wind speed of the road in the tunnel was less than 1.25 m/s, and smoke could be controlled within 200 m from the fire if the damper interval was 50 m and 100 m.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.4
• /
• pp.564-570
• /
• 2019

Although some studies have been attempted to utilize 3D spatial information for fire safety and disaster management, it is still not enough to apply it to actual work. Especially, in case of multi-use facilities, many facilities are more vulnerable to rapid response in the event of a disaster due to complexity of facilities, diversity of usage, and specificity of users. In this paper, we propose a method to develop a 3D safety status information platform that combines 3D spatial information and time - varying safety status information for efficient disaster management of multi-use facilities. In detail, first, we analyze the use cases of existing disaster management platform and the needs of business users. Second, based on the analyzed results, target facilities were selected and possible scenarios were created. Finally, we developed platform architecture design and service development strategy. The research results will be used as a basis for future 3D safety status information platform development. This will contribute to improving the safety of multi-use facilities and minimizing damage to disaster vulnerable groups.

• The Korean Journal of Archival Studies
• /
• no.15
• /
• pp.219-262
• /
• 2007

Business organization have developed in close association with the society afterward. Moreover, under capitalism business archives, though they are created in private sector, have started to have public characteristics and be used in public domain beyond internal use in business organization. Records and Archives management at a corporate level increasingly become indispensible. Business organization can use archive management to improve job efficiency and customer service and to facilitate legal matters, marketing, advertising, property management, personnel management and publicity. Additionally, They can secure corporate identity and social reliability as well as transparency in management. This is turn helps secure corporate competitiveness to play as a medium for creating new profit, which will enhance corporate brands. The records and Archives management, which recently kicks off among business organization, are to collect scattered archives and seek systemic management through archives management systems. This study present ways to collect archives scattered before archives management systems were adopted according to archives management. As a prior investigation, the scope and characteristics of business archives are defined. Visit to business organization to collect data and interview with officials responsible were carried out as a preliminary investigation to conduce acquisition policy. Based on the results of the investigation, acquisition policy of Meritz was conducted. into internal and external collection activities, event collection activities. Value appraisal and display appraisal of archives were established as a appraisal policy for efficient management and utilization of collected business archives. This study takes the case of Metitz Fire & Marine Insurance Co, Ltd (Meritz) as a example to present ways to manage business archives specifically.

• 재활복지
• /
• v.17 no.4
• /
• pp.127-149
• /
• 2013

This study analyzed the hazard of unemployment and the influencing factors on the rate. Data came from the Panel Survey of Employment for the Disabled(PSED), 2010-2012, which is a longitudinal survey for 5,092 disabled people in Korea. For the main purpose of this study, the life-table method was used for describing the patterns of unemployment duration by disabled, and the cox proportional hazard model was used to identify significant factors on the unemployment duration. The results were as follows. First, according to the life table analysis, the unemployment rate to remain until the longest period of unemployment(25month) is 90.5%, and the rate of entry into the labor market was only 9.5%. Overall, the unemployment maintenance rate was high, the unemployment escape rate decreased after 12month. Second, looking at the results from the cox proportional hazards model, the unemployment escape possibility were increased for those who are male, are non-public benefit recipient with disability, have mild disability, and have less discrimination experiences. With these results, disability discrimination act which can reduce the disability discrimination in employment site should be strengthened. Also, the scheme of Nation Basic Protection Program should be modified to attract the employment of recipients with disability. Finally, policy targets having employment escape difficulty, such as women with disability, people with severe disabilities should be departmentalized. And employment service is provided in accord with the individual needs and characteristics.