• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.160-166
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• 2011

It is difficult to clarify the dynamic response characteristics of trackbed because of various environmental conditions. However, track irregularity be affected by ununiformed bearing capacity and its dynamic response, study for dynamic response characteristics is required to investigate the cause of track irregularity and countermeasure. In this paper, the response variation for dominant frequency and vibration energy by trackbed structure and material stiffness are investigated. The analysis section is two layered ground structure that is comprised of trackbed and soft rock. This structure amplifies the energy of dominant range easily. It is evaluated to affect track irregularity on comparing by theoritical, analytical and empirical method for dynamic response of the trackbed.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.5
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• pp.60-70
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• 2007

As Republic of Korea community nears to old age society rapidly, various kinds problem about old mans is risen. Can speak that item connected with medical treatment is more serious in the importance aspect among them Therefore, many-sided effort is consisting to ready countermeasure in reply, but economical method is not presented clearly as being realistic yet. Also, medical treatment service that more users through diffusion of fast internet are little more better effort that serve consist. But, in the case of old age, by difficulty of the use, restriction condition happens. In this paper proposed system that is prevailing already and user-friendly can cope curtly in old mans' emergency situation more rapidly and conveniently using mobile phone of CDMA way relatively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.588-593
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• 2011

The airpollutant may accelerate degradation of power line facilities, and may reduce the life of the electric facilities. In case of korea, there are a tendency that the density of air pollution may be increased by industrial development. while lack of research activity and establishment of a countermeasure on this issue. Recently the occurrence of electricity failure have been reduced on the power transmission and distribution lines. but the occurrence of electricity failure by insulator itself has been increased. It means that we should have develop more clear technique for detection of the wrong insulator. In this study to provide a method for detection of the insulator failure or effective management of the troubled insulator, we analyze the chemical composition of the insulator which used on power distribution line at the sea side locations. To define the relation between insulation and corona intensity, we design and develop an corona detector. We define the variation of insulation by pollution changes on the insulator and verify quantitative relation between corona and insulations using the corona detector.

• Journal of the Society of Disaster Information
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• v.5 no.1
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• pp.10-27
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• 2009

The fear briefly became reality in the U.S. after 9/11, as man-made anthrax spores were found in letters and in east coast post offices on a number of occasions. Anthrax attacks must be related to the terrorist attacks of September 11. These two accidents changed the situation completely. Characteristics are summarized as belows. First, it is necessary for all countries to create each own appropriate countermeasures against bioterrorism. In addition, it is urgent to consider countermeasures focusing on bioterror characteristics that terrorists may use biological agents because they can be extremely difficult to detect and do not cause illness for several hours to several days. Otherwise, those attacks will also show the panic and very real danger posed by the release of such toxins on an unsuspecting public. Second, it is crucial to manage the result thoroughly. A biological weapon is useful to a terrorist group mainly as a method of creating mass panic and disruption to a society. Because it is not easy to predict and collect information about how terrorists utilize pathogenic microbe as well as terror measures in their activities, more realistic approach should be taken to reduce damage. Third, to expand investment in research and development is necessary. Considering advances in microbiology and genetic engineering lately, it is likely that new pathogenic microbe would be created by the enemy. For that matter, it is imperative that medical countermeasures should be devised.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.4
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• pp.721-726
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• 2000

The remarkable progress of electronics and radio communications technology has made our life abundant. On the other hand, the countermeasure of EMC becomes more important socially according to the increased use of electromagnetic waves. It had been required that the absorbing ability of an electromagnetic wave absorber is mote than 20 dB, the bandwidth of which is required through 30 MHz to 1,000 MHB for satisfying the international standard about an anechoic chamber lot EMl/EMS measurement. From November of 1998, however, the CISPR11 has accepted the extended frequency band from 30 MHz to 18 GHz in the bandwidth of EMI measurement. In this paper, we proposed the cutting corn-shaped type satisfying the above requirements and carried out broadband design using the equivalent material constants method. Moreover, we have fabricated it and compared its characteristics with simulated one.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.125-127
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• 2012

With the progress of electronics and radio communication technology, human enjoys greater freedom in communication. However, EMW (Electro-Magnetic wave) environments have became complicate and more difficult to control. Thus, international organizations, such as the American National Standard Institution (ANSI), Federal Communications Commission (FCC), the Comite Internationale Special des Perturbations Radio electrique (CISPR), etc, have provided standard for controlling the EM wave environments and for the countermeasure of the electromagnetic compatibility (EMC). In this paper, the status of EMW absorber and the goal of smart EMW absorber ifor the future were described. Furthermore, design method of the smart EM wave Absorber with heat radiating function was suggested. The designed smart EM wave Absorber has the absoption ability of more than 5 dB from 2 GHz to 2.45 GHz band, one optimum aperture (hole) size of which was 6 mm, 9 mm in adjacent hole space, and 6.5 mm in thickness, respectivly. Thus, it is repected that these results can be applied to various EMC devices in electronic, communication, and controlling systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.7
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• pp.1149-1159
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• 2008

Since the demand for radio wave due to proliferation of radio wave communication is increased rapidly, policy for efficient use of radio wave is a challenge of sustainable research for technology development in this field with focus on service supply and distribution. Therefore, this paper analyzed and reviewed radio wave related international agreements and overseas institutions and policies, and proposed the improvement method for systematic and efficient countermeasure on radio wave management policy and system according to radio wave promotion policy circumstance changes, radio wave environmental change and technology development.

• Journal of the Korean Society for Railway
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• v.18 no.6
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• pp.596-608
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• 2015

Freight transport by railway is gaining more attention at present as a countermeasure against global warming. In keeping with this purpose, the present study examined various methods for promoting railway use through minimization of the transfer resistance of bulk freight at railway stations. First, the transfer-related factors that shippers consider as important when choosing railway as a transport mode were identified. Also, the relative importance and the level of influence of each factor during the transfer stage were evaluated. Policy directions for reducing transfer resistance in railway stations were then proposed based on the analysis of the transfer resistance factors. The policy directions include both hardware and software approaches. The necessary reduction ranges with regard to the transfer cost and time through policy implementation efforts were suggested as well.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.505-508
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• 2015

Soil bulk density is a key parameter for soil physical property. Much root placed in rhizosphere soil lump, especially in grassland and orchard, makes it difficult to measure soil bulk density. This experiment was carried out to countermeasure the above drawbacks. Volume check apparatus using water-filling method was made of acryl for higher accuracy in bulk density measurement. 10 types of land cover, including bare, tall fescue, rye, and soybean, were used for determining the relationships between root and bulk density. In this study, higher root volume resulted in higher differences in bulk density between in-situ core soil and root-ridded core soil, which indicated the volume check apparatus through water-filling could be useful for increasing the accuracy of bulk density of soils with much root.

• Wind and Structures
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• v.28 no.2
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• pp.99-110
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• 2019

Vortex-Induced-Vibration (VIV) is one kind of the wind-induced vibrations, which may occur in the construction and operation period of bridges. This phenomenon can bring negative effects to the traffic safety or can cause bridge fatigue damage and should be eliminated or controlled within safe amplitudes.In the current VIV studies, one available mitigation countermeasure, the horizontal flow-isolating plate, shows satisfactory performance particularly in PI shaped bridge deck type. Details of the wind tunnel test are firstly presented to give an overall description of this appendage and its control effect. Then, the computational-fluid-dynamics(CFD) method is introduced to investigate the control mechanism, using two-dimensional Large-Eddy-Simulation to reproduce the VIV process. The Reynolds number of the cases involved in this paper ranges from $1{\times}10^5$ to $3{\times}10^5$, using the width of bridge deck as reference length. A field-filter technique and detailed analysis on wall pressure are used to give an intuitive demonstration of the changes brought by the horizontal flow-isolating plate. Results show that this aerodynamic appendage is equally effective in suppressing vertical and torsional VIV, indicating inspiring application prospect in similar PI shaped bridge decks.