• Title/Summary/Keyword: RCS Reduction

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Dynamic Control of Random Constant Spreading Worm using Depth Distribution Characteristics

  • No, Byung-Gyu;Park, Doo-Soon;Hong, Min;Lee, Hwa-Min;Park, Yoon-Sok
    • Journal of Information Processing Systems
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    • v.5 no.1
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    • pp.33-40
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    • 2009
  • Ever since the network-based malicious code commonly known as a 'worm' surfaced in the early part of the 1980's, its prevalence has grown more and more. The RCS (Random Constant Spreading) worm has become a dominant, malicious virus in recent computer networking circles. The worm retards the availability of an overall network by exhausting resources such as CPU capacity, network peripherals and transfer bandwidth, causing damage to an uninfected system as well as an infected system. The generation and spreading cycle of these worms progress rapidly. The existing studies to counter malicious code have studied the Microscopic Model for detecting worm generation based on some specific pattern or sign of attack, thus preventing its spread by countering the worm directly on detection. However, due to zero-day threat actualization, rapid spreading of the RCS worm and reduction of survival time, securing a security model to ensure the survivability of the network became an urgent problem that the existing solution-oriented security measures did not address. This paper analyzes the recently studied efficient dynamic network. Essentially, this paper suggests a model that dynamically controls the RCS worm using the characteristics of Power-Law and depth distribution of the delivery node, which is commonly seen in preferential growth networks. Moreover, we suggest a model that dynamically controls the spread of the worm using information about the depth distribution of delivery. We also verified via simulation that the load for each node was minimized at an optimal depth to effectively restrain the spread of the worm.

Development of radar cross section analysis system of naval ships

  • Kim, Kook-Hyun;Kim, Jin-Hyeong;Choi, Tae-Muk;Cho, Dae-Seung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.4 no.1
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    • pp.20-32
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    • 2012
  • A software system for a complex object scattering analysis, named SYSCOS, has been developed for a systematic radar cross section (RCS) analysis and reduction design. The system is based on the high frequency analysis methods of physical optics, geometrical optics, and physical theory of diffraction, which are suitable for RCS analysis of electromagnetically large and complex targets as like naval ships. In addition, a direct scattering center analysis function has been included, which gives relatively simple and intuitive way to discriminate problem areas in design stage when comparing with conventional image-based approaches. In this paper, the theoretical background and the organization of the SYSCOS system are presented. To verify its accuracy and to demonstrate its applicability, numerical analyses for a square plate, a sphere and a cylinder, a weapon system and a virtual naval ship have been carried out, of which results have been compared with analytic solutions and those obtained by the other existing software.

Update on the APJCP and the APOCP in 2013 - What is Going to be Achieved in the Future

  • Moore, Malcolm A.
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.4
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    • pp.2151-2153
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    • 2013
  • The history of the APOCP/APJCP goes back to 1999 when a number of interested scientists joined together to form the organization and to launch a new journal to support cancer prevention research in the Asian-Pacific area. Since the initial Founding Conference, some six General Assemblies (GAs) and ten Regional Conferences (RCs) and Special Study Sessions have been organized. Already the decisions have been made for two further GAs and at least three RCs. As of the April issue of 2013, a total of nearly 3,700 papers have already been published in regular issues of the APJCP or special supplements. With support of the Korean National Cancer Center, housing the Chief Editorial Office, the journal is now including approximately 100 papers a month. Although it experienced a set-back by reduction in the Impact Factor (IF) from 1.29 in 2010 to 0.67 in 2011, there are good grounds to expect an improvement in 2012. However, the future of the APOCP/APJCP will continue to depend on its membership, making continuous efforts to attend our conferences and submit good quality manuscripts. It is particularly important to cite papers in the APJCP wherever possible, if the wish is for an IF commensurate with our long term aims. In that sense it is up to all authors, since the journal will continue to have a very positive ploicy towards accepting papers from all countries within the Asian-Pacific, with continue to varied levels of resources. The editorial team looks forward to your considered support. The APOCP also hopes to see you in person at future meeetings, so that you have a more active voice in deciding the best way forward in our cooperative enterprise.

Researches on Microstrip Reflectarray Antennas (마이크로스트립 리플렉트어레이 안테나에 관한 연구)

  • Yoon, Young Joong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.11
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    • pp.937-950
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    • 2015
  • Microstrip reflectarray is an antenna which controls its radiation pattern with a number of reflective elements. Conventionally, the reflectarray has been researched to replace curved reflector antennas. In this paper, design theories of reflectarray is briefly introduced, and research trends of high gain and broadband reflectarrays are reviewed. To improve the gain of the reflectarrays, it is required that the reflection phase errors on the reflectarray surface be minimized. For this purpose, sufficiently wide reflection phase range and low phase sensitivity should be realized with the designed element. For bandwidth improvement, the reflection phase of the element should be linear with the frequency variation. In this paper, various researches to improve the reflection phase characteristics of the element for high gain and broadband reflectarrays, such as multi-layer and single-layer multi-resonant structures, are reviewed. Also, dual-reflectarray configuration for compact antenna design is reviewed. Finally, various applications of reflectarrays such as contoured beam, near-field focusing, and RCS reduction are reviewed.

The Development and Effectiveness Verification of Integrative Psychotherapy Program for Relieving Depression among the Symptoms of Conversion Disorder : For Elderly Women in their 60s (전환장애 증상 중 우울감 감소를 위한 통합심리학적 치료 프로그램 개발 및 효과성 검증: 60대 노년 여성 대상)

  • Hwang, Tamija;Lee, Min Sun
    • Journal of Digital Convergence
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    • v.22 no.2
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    • pp.11-20
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    • 2024
  • The aim of this study was to develop a group counseling program as an integrative psychotherapy program to alleviate depression and physical symptoms of 22 women in 60s who experience depression as a symptom of conversion disorder and also tried to prove the effectivity of the program by using comparative analyze of pre-post changes. The Korean-style Elderly Depression Test(K-GDS), Symptom Interpretation Questionnaire(SIQ), Hamilton Depression Assessment Scale Questionnaire, PHQ-9 and interpersonal relationship scale (RCS) were conducted and pre-post-corresponding sample t-test, correlation analysis and multiple regression analysis were performed. The results showed depression reduction, physical symptoms alleviation, decreases in negative emotions and beliefs, and positive changes in interpersonal relationships. The implications and limitations of this study were discussed.

A Retro-Directive Array System for Reduction of Electromagnetic Wave Reflection (전자기파 반사 감소를 위한 역지향 배열 안테나 시스템)

  • Ha, Jungje;Jang, Sunghoon;Lee, Yongshik
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.1
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    • pp.113-118
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    • 2015
  • In this paper, a cancellation technique for electromagnetic waves is realized based on a retrodirective antenna array system. The system re-transmits a signal to the direction of the incoming signal, with the same frequency and opposite phase. For the experimental verification, a $2{\times}2$ retrodirective array system is designed and fabricated. Experimental results for a metallic cylinder show as much as 26-dB reduction in reflection.

Application of Transformation Electromagnetics to Cloak Design and Reduction of Radar Cross Section

  • Mittra, Raj;Zhou, Yuda
    • Journal of electromagnetic engineering and science
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    • v.13 no.2
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    • pp.73-85
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    • 2013
  • In this paper we present an alternative approach to addressing the problem of designing cloaks for radar targets, which have been dealt with in the past by using the transformation optics (TO) algorithm. The present design utilizes realistic materials, which can be fabricated in the laboratory, and are wideband as well as relatively insensitive to polarization and incident angle of the incoming wave. The design strategy, presented herein, circumvents the need to use metamaterials for cloak designs that are inherently narrowband, dispersive and highly sensitive to polarization and incident angle. A new interpretation of the TO algorithm is presented and is employed for the design of radar cross section-reducing absorbers for arbitrary targets, and not just for canonical shapes, e.g., cylinders. The topic of performance enhancement of the absorbers by using graphene materials and embedded frequency structure surfaces is briefly mentioned. The design procedure for planar absorbing covers is presented and their performance as wrappers of general objects is discussed. A number of test cases are included as examples to illustrate the application of the proposed design methodology, which is a modification of the classical TO paradigm.

Effects of Green Manure Crops on Tomato Growth and Soil Improvement for Reduction of Continuous Cropping Injury through Crop Rotation in Greenhouse (토마토 시설재배지 토양에서 단기 녹비작물 재배가 연작장해 토양 개량 및 토마토 생육에 미치는 영향)

  • Jung, Yu Jin;Nou, III Sup;Kang, Kwon Kyoo
    • Korean Journal of Plant Resources
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    • v.28 no.2
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    • pp.263-270
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    • 2015
  • To reduce the injury by continuous cropping system of tomato cultivation, green manure crops (GMCs) such as hairy vetch and rye were applied, Nutrient contributions of N, P2O5, K2O, CaO, and MgO in hairy vetch were 26.2, 5.8, 10.2, 6.6, and 1.5 ㎏/10a, respectively. Nutrient contributions of N, P2O5, K2O, CaO, and MgO in rye were 9.1, 4.2, 11.8, 3.8, and 3.1 ㎏/10a, respectively. After incorporation of GMCs into soil, bulk density in soil with GMCs was lower than that in soil without GMCs (control). In soil after incorporation of GMCs, pH was not different in all treatment conditions, and ranged from 6.37~6.52. EC in soil after incorporation of GMCs was lower than that in soil without GMCs. The OM, T-N, and avail. P2O5 contents in soil with GMCs were higher than those in soil without GMCs. The tomato growths were increased in the rotational cropping system (RCS) as compared to continuous cropping system (control and without NPK). Also the density of Pseudomonas corrugata in soil with GMCs was lower than that in soil without GMCs (control). This study suggest that the RCS using GMCs showed lower disease outbreak density in soil for tomato cultivation as compared to RCS without GMCs. Especially, the GMCs was good effect for reduction of continuous cropping injury of tomato.

Radar Cross Section Reduction by Planar Array of Dielectric Barrier Discharge Plasma under Atmospheric Pressure (평면 배열 유전체 장벽 방전 플라즈마 발생기의 대기압에서의 레이다 단면적 감소 효과)

  • Kim, Yuna;Kim, Sangin;Kim, Doo-Soo;Lee, Yongshik;Yook, Jong-Gwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.8
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    • pp.646-652
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    • 2017
  • The effect of plasma on mono-static radar cross section under atmospheric pressure is demonstrated when the dielectric barrier discharge actuator has plasma layer. The volume of plasma layer is increased by using planar array of electrodes. Because the incident wave has electric field which is perpendicular to the electrode array, the undesired effect on radar cross section caused by structure of plasma actuator is minimized. In experiments, mono-static radar cross section is measured at the frequencies from 2 GHz to 25 GHz. The generated plasma reduces the radar cross section at frequencies above 18 GHz, and the amount of reduction reaches to 8 dB in maximum. The reduction can be controlled by changing the peak-to-peak voltage from high voltage generator. The result shows the possibility of plasma as a flexible radar cross section controller.