• Journal of Korean Tunnelling and Underground Space Association
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• 제19권6호
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• pp.845-856
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• 2017

In the long railway tunnel, in order to secure safety in case of fire, it is required a emergency station. However, there is no standard or research results on smoke exhaust method and exhaust flow rate in emergency station, so it is necessary to study the smoke exhaust system for emergency station. In this study, we are created a numerical analysis model for emergency station where the evacuation cross passage connected to the service tunnel or the relative tunnel was installed at regular intervals (40 m intervals). And the fire analysis are carried out by varying the fire intensity (15, 30MW), the smoke exhaust method (only air supply, forced air supply and exhaust, forced air exhaust only), and the air flow rate (7, 14, $40m^3/s$). From the results of fire analysis, temperature and CO concentration are analyzed and ASET based on the limit temperature are compared at various condition. As a result, in the case with fire intensity of 15 MW, it is shown that a sufficiently safe evacuation environment can be ensured by applying forced air supply and exhaust method or forced air exhaust only method when the air flow rate is $7m^3/s$ above. In case of fire intensity of 30 MW, it is impossible to maintain the safety evacuation environment for more than 900 seconds when the exhaust air volume is below $14m^3/s$. And when the air flow rate is $40m^3/s$, the exhaust port is disposed at the side portion of the upper duct, which is most advantageous for securing the temperature-based safety.

• Transactions of the Korean Society of Mechanical Engineers A
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• 제40권9호
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• pp.835-842
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• 2016

In Korea, urban railway cars are typically maintained using the strategy of predictive maintenance. In an effort to overcome the limitations of the existing strategy, there is increased interest in adopting the condition-based maintenance strategy. In this study, a novel method is proposed to detect faults in the solenoid valves of the braking system in urban railway vehicles. We determined the key component (i.e., solenoid valve) that leads to braking system faults through the analysis of failure modes, effects, and criticality. Then, an equivalent circuit model was developed with the compensation of the temperature effect on solenoid coils. Finally, we presented how to detect faults with the equivalent circuit model and current signal measurements. To demonstrate the performance of the proposed method, we conducted a case study using real solenoid valves taken from urban railway vehicles. In summary, it was shown that the proposed method can be effective to detect faults in solenoid valves. We anticipate the outcome from this study can help secure the safety and reliability of urban railway vehicles.

• Journal of the Korea Society of Computer and Information
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• 제15권7호
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• pp.57-66
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• 2010

Due to the advancement of IPTV technologies, open IPTV services are a step closer to becoming reality. In such service environment, users are able to enjoy IPTV services using a variety of devices available at their home domain. However, it is impossible to get such flexible services at their convenience unless each of devices is individually connected to Set-Top-Box (STB) because of Conditional Access System (CAS) or service providers otherwise allow STB to freely distribute decoded contents to every user devices attached to STB. In this paper, we propose a key management scheme for securely distributing contents from STB to multiple user devices at home domain. The proposed scheme also makes the service providers be able to control the access rights to each of user devices without installing individual STBs. It is achieved by computationally dividing a private key of RSA signature scheme into three parts and thus makes possible to distribute the contents scrambled through a underlying CAS mechanism without re-encrypting them that the existing scheme should employ. It improves significantly computation and communication complexities, maintaining it as secure as the existing schemes. Additionally, it prevents misbehaving users from illegally distributing the contents from STB to their devices available at home domain.

• Korean Journal of Hospice Care
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• 제5권1호
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• pp.50-62
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• 2005

The elderly people was over 8.3% in 2003. This seament is projected to grow to 14.4% by 2019(Aged society) and over 20% by 2026(Super aged society). As the elderly population is increasing and young population is declined social issues around elderly care are emerged in Korea. As a result of that, they are in the condition of poor system of the welfare of the old and it is the worst one in Korea. And because of the worst financial independence and difficulty in Korea, welfare facilities and medical instruments are so insufficient and deteriorated, so the quality of service is getting low. Furthermore the mortality of cancer is rapidely increased in recent years. So it is expected that the number of families who are caring for terminal cancer patient will be increased. We can not solve those problems only with government's policy such as to secure ample budget and to enlarge the aged welfare institutions. Definitely, to acheve the suggetions persistence concern about old people is most important, and family, community and national government should be linked to accomplish to goal. Accordingly, for this study attempts to provide conceptual framework of the respite care, spiritual care and home hospice, nursing home for the elderly. And this study is to discuss the necessity and effect about the construction of housing welfare infrastructure and to make a cooperation and linkage system among the aged welfare institutions, government and the aged welfare programs. As is well known, the issue of the increasing aged people is neither a matter of individuals nor of the family, but rather a complex matter of whol society. Therefore it can be resolved by the active participation of government. Conclusively this study tries to provide an direction of the improvement with regard to the welfare policy for the elderly. The study is as follwos: Chapters 1: The theological base, conception, essentiality, respite care, spiritual care and home hospice, nursing home for the elderly. Chapters 2: Definitions of respite care, spiritual care, hospice, patient of termina cancer and quality of life. And relations between respite care and nursing home. Chapters 3: The necessity of long-term care insurance and the perspectives of spiritual care. Chapters 4: Conclusions and summarizing(The directions of improvement of welfare policy for the elderly). To sum up, the problems of the aged people has not effects only to the aged people. This means that the problems of aged is the problems of the young generation today. Because young generation will be the old generation in the near future.

• Journal of National Security and Military Science
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• 통권4호
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• pp.289-350
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• 2006

The world has been rapidly restructured in an agenda of national security from center of military strength to that of economic strength since the post cold-war era China military leadership-division carried out RMA through learning of a lesson from Gulf war in 1990 -1991 and Iraq war in 2003, thus the leadership-division made an attempt to convert the military system to a technical intensive system. The principle based on RMA of China military is (National defense strategy) drafted by the central military committee 1985 and (Four modernization general principles) 1978. China has introduced Russian high-technological arms and equipment in order to build up the military arms greatly thanks to an economical development, and they take pragmatism line as chinese socialism with their strategy to make secure a position as military powers such as they successfully launched a manned spacecraft and are building an air-craft carrie and soon. USA has a theory of dichotomy whether a country is a cooperator for USA, or not. and also enemy or friend since 9.11terror, thus USA is different from their direction of police. This is because USA stands a position as the superpower of the supremacy hegemony of the world. We must be carefully aware that USA considers as important area for Middle east, West south Asia, Central Asia and Northwest Asia to meet the demands of 2lcentury. Accordingly, the focus of USA's military strategy will be probably concentrated at the above mentioned four areas. On the other hand, USA enjoys such a superpower position due to collapse of USSR which was the past main enemy since the post cold war era. We could give an conclusive example as fact that USA has recurred to unilateralism But USA carry on the military operations to the terror groups at global around by converting thje military strike strategy to pre-emptive strike strategy since9.11 terror, 2001. USA seeks for transformation to the mobile military forces with light-quantity oriented in order to carry on such the military operations and makes progress GPR, And the USA forces in Korea makes progress a military renovation as part of such a military strategy. On the other hand, USA promotes the measures of choose for the countries standing at the crossroads of strategy and carries forward a main scheme of provision for four priority aims that the leaders of a hostile country and mis-country shall be prohibited from use and obtainment of weapons of mass destruction. Accordingly, this treatise found out a significant meaning to have an effect on the national security in the korean peninsula.

• Korean Journal of Social Welfare
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• 제50권
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• pp.87-108
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• 2002

According to Neo-liberalism, the privatization of social security systems is pivotal for a country's economic growth and the wellbeing of its people, because such systems hinder the full operation of the market, eventually leading the national economy to collapse. The Chilean case of pension privatization is often cited as a good evidence for the Neo-liberal argument. Neo-liberalists say that Chile has experienced a rapid economic growth and retirees have enjoyed a much more pension payment since the national pension system was successfully privatized in 1981. The primary purpose of this article is to provide a critical review on the results of the Chilean pension privatization reform implemented in 1981. This study is intended to give an objective understanding of the reform because the existing evaluations, particularly those from the neo-liberalism, over-emphasize the bright sides of the reform. for this purpose, this article will pay a particular attention to the change in the level of pension payment after the reform. The conclusion of this study is that, contrary to the argument of Neo-liberalism, the pension reform has lowered the level of pension payment and, compared to the old public pension, has made the lives of ordinary retirees less secure. Reorganization of the social security system is more desirable than privatization as a remedy for the current problems of the welfare state.

• Journal of the Korea Society for Simulation
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• 제20권3호
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• pp.69-78
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• 2011

A large-scale sensor network usually operates in open and unattended environments, hence individual sensor node is vulnerable to various attacks. Therefore, malicious attackers can physically capture sensor nodes and inject false reports into the network easily through compromised nodes. These false reports are forwarded to the base station. The false report injection attack causes not only false alarms, but also the depletion of the restricted energy resources in a battery powered network. The statistical en-route filtering (SEF) mechanism was proposed to detect and drop false reports en route. In SEF, the choice of routing paths largely affect the energy consumption rate and the detecting power of the false report. To sustain the secure routing path, when and how to execute the path re-selection is greatly need by reason of the frequent network topology change and the nodes's limitations. In this paper, the regional path re-selection period determination method is proposed for efficient usage of the limited energy resource. A fuzzy logic system is exploited in order to dynamically determine the path re-selection period and compose the routing path. The simulation results show that up to 50% of the energy is saved by applying the proposed method.

• Journal of Navigation and Port Research
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• 제39권4호
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• pp.319-327
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• 2015

This study can be summarized as follows : First, main participant, procedure and method of redevelopment of Inner port shall be additionally reviewed. Demands of stakeholder of Incheon Inner Port are actively accommodated to avoid the disruption in undertaking the project. Second, it must ensure the adequacy and appropriateness of policies regarding the redevelopment of the Inner Port in Incheon. It is necessary to obtain consent of people on this project. Third, appropriate system must be established to undertake the project. For this purpose, the governance system shall be built to collect the opinions of the people. The conclusions of this study are as follows. The national master plan and modify plans of Port redevelopment have been being undertaken based on Port Act. Incheon Inner Port redevelopment has been showing slight discrepancy with that of other ports. It's the essential part to coordinate the opinions and needs between the parties prior to the establishment of a redevelopment plan. This can be settled when it's warranted for dock workers to secure the job, and for port companies to provide replaceable piers as the precondition. In addition, eco-friendly waterfront leisure space shall be planned and alternative policies shall be arranged with accommodating the needs of local residents and merchants.

• Journal of Navigation and Port Research
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• 제41권6호
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• pp.451-466
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• 2017

Deep-sea fishing vessel No. 501 Oryong was fully flooded through its openings and sunk to the bottom of the sea due to the very rough sea weather on the way of evasion after a fishing operation in the Bearing Sea. As a result, many crew members died and/or were missing. In this study, a full-scale ship flooding sinking simulation was conducted, and the sinking process was analyzed for the precise and scientific investigation of the sinking accident using highly advanced Modeling & Simulation (M&S) system of Fluid-Structure Interaction (FSI) analysis technique. To objectively secure the weather and sea states during the sinking accident in the Bering Sea, time-based wind and wave simulation at the region of the sinking accident was carried out and analyzed, and the weather and sea states were realized by simulating the irregular strong wave and wind spectrums. Simulation scenarios were developed and full-scale ship and fluid (air & seawater) modeling was performed for the flooding sinking simulation, by investigating the hull form, structural arrangement & weight distribution, and exterior inflow openings and interior flooding paths through its drawings, and by estimating the main tank capacities and their loading status. It was confirmed that the flooding and sinking accident was slightly different from a general capsize and sinking accident according to the simple loss of stability.

• Journal of the Society of Disaster Information
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• 제10권2호
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• pp.294-303
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• 2014

The state has the constitutional duty to secure the safety of its citizens and provide protection against any physical dangers. The Republic of Korea has a high threat of nuclear, biological and or chemical(hereafter referred to as NBC) attack from the Democratic People's Republic of Korea. Thus, the state has a responsibility to form a legislation to provide the protection for its citizens and implement duty to guarantee the human rights. Under the current legislation, the 'United Defense Act', 'Framework Act on Civil Defense' that are applied under wartime conditions are insufficient in providing the protection of the citizens of the state in the occurrence of NBC attack. Therefore, it is necessary that the 'Act for the Protection of Citizens in the occurrence of NBC Attack' is legislated to provide a system that protects the nation's citizens under the wartime conditions mentioned above. This paper incorporates a theoretical analysis of the need for the constitutional responsibility of the state to provide protection for its citizens under wartime conditions, the necessity of a specific measure to protect citizens during NBC attack, the relationship between 'Act for the Protection of Citizens in the occurrence of Nuclear, Chemical and or Biological Attack' and current legislations that are applied under wartime conditions, and the particulars of the proposed act.