• Annual Conference of KIPS
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• 2008.11a
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• pp.1462-1464
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• 2008

본 논문에서는 정보시스템 운영시 발생하는 사용자 취약성(Human Vulnerability) 문제의 심각성에 대해 알아보고 이를 개선하기 위한 교육 및 훈련 프로그램을 다루고 있는 기존 관련 연구들을 조사 분석 한다. 아울러 기존 연구에서 보완되어야 할 개선 요구사항 들을 도출하여 향후 효과적인 취약성 개선 프로그램 제공을 위한 가상머신에 기반한 보안 훈련장 시스템 아키텍쳐를 제안한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.117-120
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• 2008

In this paper, we developed the EM wave absorber for eliminating false images in collision-avoidance radar. First of all, we fabricated some samples in different composition ratio of $TiO_2$ and CPE. And the relative permittivities of samples are calculated from S-parameter of samples by using 1-port method. We designed and fabricated the EM wave absorber by using the calculated relative permittivity. As a result, the EM wave absorber with composition of $TiO_2$:CPE=70:30 wt% has thickness of 1.85 mm and absorption ability higher than 20 dB in the frequency range 76-77 GHz.

• Journal of the korean veterinary medical association
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• v.47 no.2
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• pp.165-176
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• 2011

구제역은 우제류 동물이 걸리는 급성열성전염병으로, 본 병에 걸린 동물은 발열이나 식욕부진을 지나 병명대로 구강과 혀 점막, 발굽 주위나 유방의 피부에 수포를 형성한다. 이후 이환된 가축은 섭취 장애나 보행장애가 일어나고, 산육능력이나 비유량이 저하됨에 따른 경제동물로서의 가치를 현저하게 떨어지게 한다. 또한 본 병의 전파는 극히 빠르고 동물이나 축산물에 대하여 엄격한 이동제한이나 방역조치가 본 병의 전파나 확대를 막기 위해 실시하기 때문에 본 병에 의해 생기는 경제적 피해는 농가의 지역단위 뿐만 아니라 국가단위에도 미쳐 심각하다. 그 때문에 자유무역을 표방하는 WTO체재하에 있어서도 구제역의 만연방지를 목적으로 한 무역제한은 국제적으로 용인되어져 오고 있고, 세계동물보건기구에 의해 국가나 지역단위의 청정도 구분이 장해져 각국의 법에 반영되어져 있다. 구제역의 병원체로 있는 바이러스는 숙주역이 넓고, 적지 않은 바이러스양에도 감염이 성립, 감염동물체내에서 바이러스가 신속하게 복제, 감염동물로부터 다량의 바이러스가 배설, 접촉전파만이 아닌 공기전파를 일으킨다는 등이 본 병의 전파나 확대에 유리한 복잡한 성성을 가질 경우에 구제역의 방역 및 박멸을 어렵게 하기 때문에 수의학영역에서 가장 경계해야할 전염병의 하나이다. 따라서 본 필자는 최근의 국내 구제역 발생상황속에서 관련자료정리를 하다가 대동물 임상수의사가 알아야 부분과 일본 동물위생연구소 등에서 구제역바이러스 인공감염 및 화학물질(T-1105)투여시험 결과 내역를 정리하여 소개해두고 저 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10B
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• pp.1876-1884
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• 1999

The next generation of wireless LAN AND PBX systems will make use of the unlicensecd band at 2.5 GHz. Deployment of these systems inside buildings requires and understanding of propagation characteristics within buildings. Because the wavelength is small compared to building dimensions, ray methods can be used to predict propagation, but they require knowledge of the transmission and reflection properties of walls. This paper reports on transmission measurements made at walls made of gypsum board on metal studs, and at concrete block walls using directive antennas. The measurements are found to give good agreement with theoretical results that account for the periodic nature of the wall structure.

• Journal of Navigation and Port Research
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• v.28 no.6
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• pp.503-507
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• 2004

We prepared EM wave absorbers by using recycled Sr ferrite for GHz frequency, and investigated the effects of carbon additions and preparation temperatures on their EM wave absorption properties. A Sr ferrite EM wave absorber with the ratio of Sr ferrite: silicon rubber: carbon = 80 : 13.6: 6.4 wt% prepared at 7$0^{\circ}C$ showed -24 dB at 9.4 GHz and -23 dB at 5.5 GHz for 2 mm and 3 mm thickness, respectively.

• Journal of Advanced Navigation Technology
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• v.20 no.6
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• pp.568-573
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• 2016

Since the existing analog village broadcasting system has some technical problems in applying and degradations in performance due to its old equipments, it had been required to be changed to a digital system and to develop the standardization from now. Therefore, we have analyzed the service coverage in various environments in order to construct an effective digital wireless village broadcasting system. Also, a precise prediction of field strength should be set up in various propagation environments to design a digital radio stations with reliable transmit power. Using these results the received power and the propagation characteristics in various environments can be predicted to establish a standard and the testing service will be deployed in the near future.

• Journal of the Korean Institute of Navigation
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• v.25 no.2
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• pp.119-129
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• 2001

Along with the increase of demand of radio communications and with the rapid progress of communication systems, the radio frequency interference of neighbor nations is a matter of argue. This problem is a delicate matter which must be dealt diplomatically with by having a distinct technical back ground. After the radio interference has been experienced in the Korean TRS service on the south seashore due to the base stations including the Fukuoka station in Japan, the radio interference problem between neighbor nations has become the matter of conflict. For the purpose to solve this problem, we has measured the radio waves that come from Fukuoka in Japan mainly to Pusan in Korea and also collected data in real-time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1A
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• pp.16-22
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• 2006

This papers described with the analysis for electric Field strength on ground level transmitted from DMB transponder in stratosphere HAPS. It is compare with horizontal propagated ground wave. Resultly we confirm the equal strength a electric field on ground level between hish altitude vertical propagated wave and horizontal ground wave, also, is only 1W compare with terrestrial facility as transmitted output power for the DMB transponder in stratosphere HAPS. It is corresponding to 1Kw as same power value in ground propagated wave. Lastly it is new material wave source and also we concluding remarks as ubiquitous communication networking media.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.6 no.2
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• pp.19-26
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• 1995

The design of broad-band, thin layer electromagnetic wave absorbers usually employs magnetic materials. The common absorber consists of a magnetic material layer bonded to a metal plate at the back. For such structure, a theoretical expression involving six parameters defines the allowable material shape and values of electromagnetic parameters that will produce zero reflection or more practically more than 99% absorption (20dB attenuation). The Secant Method was employed to compute the matching boundary values corresponding to 20dB attenuation. In addition, a search algorithm coupled with the Secant Method was developed to obtain allowable range of material parameters for the design of wave absorbers. These numerical methodes applicable to any six parameters effectively yielded accurate solutions in the least iterations.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.4
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• pp.18-24
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• 1999

The design method of a wave absorber for a perfectly conducting sphere is presented. The backscattered field from a coated sphere can be represented as the sum of the reflected field and the creeping wave. The wave absorber for a curved surface has been designed from that the reflection coefficient of the reflected field is zero. For the design of wave absorber for a small sized conducting sphere, the creeping wave should be considered as well as the reflected field. The perfect absorbing conditions are numerically searched using the Newton-Raphson method from the backscattered field of the eigenfunction series solution from a coated sphere. The wave absorber designed by this method exhibits a superior performance of absorption to that designed from the plate type absorbing condition.