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A Study on RF Calibration Method of Next Generation Mobile Communication System (차세대 이동통신 시스템의 RF Calibration 기법에 관한연구)

  • Kim, Wan-Tae;Cho, Sung-Joon
    • Journal of Advanced Navigation Technology
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    • v.14 no.6
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    • pp.859-864
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    • 2010
  • In the next generation system, a study on realization of Multi-Core system is in progress for applying it in multi service network. Therefore some mobile systems are expected to be appeared. These systems can support WiBro, WCDMA, CDMA, etc with single terminal. These systems have to support various FA using broadband frequency and hand over to other service network. Especially, in the telecommunication system composed of cell, the transmit power can be interference at adjacent system, has effect on system channel capacity and cell size. In this paper, we improve the unstable transmit power caused by unsettled system operation, propose the RF(Radio Frequency) Calibration method which can use the transmit power stably even during hand over between heterogeneous networks causing unstable power change. Also we used proposed method and analysed used electricity of system during hand over between heterogeneous networks.

Blind Adaptive Receiver based on Constant Modulus for Downlink MC-CDMA Systems (하향링크 MC-CDMA 시스템을 위한 CM 기반의 블라인드 적응 수신기)

  • Seo, Bangwon
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.5
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    • pp.47-54
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    • 2019
  • In this paper, we consider a constant modulus (CM) based blind adaptive receiver design for downlink multi-carrier code-division multiple access (MC-CDMA) systems employing simple space-time block coding (STBC). In the paper, filter weight vectors used for the detection of the transmitted symbols are partitioned into its subvectors and then, special relations among the optimal subvectors minimizing the CM metric are derived. Using the special relations, we present a modified CM metric and propose a new blind adaptive stochastic-gradient CM algorithm (SG-CMA) by minimizing the modified CM metric. The proposed blind adaptive SG-CMA has faster convergence rate than the conventional SG-CMA because the filter weight vectors of the proposed scheme are updated in the region of satisfying the derived special relations. Computer simulation results are given to verify the superiority of the proposed SG-CMA.

Analysis of Multi-Core mobile system structure and nonlinear characteristic (Multi-Core Mobile 시스템구조와 비선형 특성 분석)

  • Kim, Wan-tae;Park, Bee-ho;Cho, Sung-joon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.959-962
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    • 2009
  • Recently, a multi-core system is studied for single terminal's operations on various service networks for mobile systems. Therefore, it is expected that mobile systems capable of supporting WCDMA, GSM, and WiBro would be developed. Mobile systems for supporting various service networks is able to be implemented on a single chipset via SoC(System on Chip) technology, thus a noble modem design proper for SoC technology is necessary. As those systems shall be operated at different frequency band with only a single terminal, a problem that a nonlinear characteristic according to the system and its frequency band is occurred. In this paper a noble modem design for multi-core systems is proposed and the nonlinear characteristics for those systems is analysed. The proposed modem design is based on OFDM(Orthogonal Frequency Division Multiplexing) and MC-CDMA scheme. And nonlinear characteristic analysis is done by PSD measurement.

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Seismic Access of Offshore Subsea Manifold using RSA and THA Seismic Analysis Results for Simplified Model (단순화 모델에서의 응답스펙트럼과 시간이력 내진해석 결과를 활용한 해양플랜트용 매니폴드 실제품의 내진강도 평가)

  • Lee, Eun-Ho;Kwak, Si-Young
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.32 no.1
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    • pp.7-16
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    • 2019
  • In this paper, for a seismic analysis of an offshore subsea manifold, Response Spectrum Analysis(RSA) and Time History Analysis(THA) were conducted under a various analysis conditions. Response spectrum and seismic design procedure have followed ISO19901-2 code. In case of THA, The response spectrum were converted into artificial earthquake history and both of Explicit and Implicit solvers were used to examine the characteristics of seismic analysis. For the verification, Various seismic analysis methods were applied on a single degree of freedom beam model and a simplified model of the actual manifold. The difference between the results of RSA and THA on the simplified manyfold model evaluated for the analysis of the actual manifold. Because THA is impossible in case of real complex structure such as a manifold, Safety of the actual manifold structure was accessed by using the RSA and the difference between the results of RSA and THA from the simplified model.

RaspberryPi board control with GPIO (GPIO를 사용한 RaspberryPi 보드 제어)

  • Lee, Sung-jin;Choi, Chul-kil;Choi, Byeong-yoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.429-431
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    • 2014
  • Raspberry Pi is in the UK (Paspberry Pi) Foundation created a compact / Cheap PC and was developed as part of the educational project. RCA connection jack and has been released in March 2012 was also sold out in one hour. Raspberry Pi Linux kernel based operating system called Raspberry Pi using optimized Raspbian Debian-based operating systems are often used to be free. Raspberry Pi is currently in the field of IoT with the board quite Cubie limelight and Cubie board holds more data. Arduino is quite easy to reach and access to the avr but impossible to include any custom code associated to a library and customize drawbacks must be solved only. Raspberry Pi using the Raj Caribbean and limitations of low cost, but there is a small output. So, for a combination of the two, with GPOI was reminiscent of hardware control. In this paper, using GPIO Cooking Hacks RaspberryPi board for controlling input and output by using the shield is insufficient expansion raspberry pie was confirmed that the good operation was verified.

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A Study on Web Vulnerability Risk Assessment Model Based on Attack Results: Focused on Cyber Kill Chain (공격 결과 기반의 웹 취약점 위험도 평가 모델 연구: 사이버 킬체인 중심으로)

  • Jin, Hui Hun;Kim, Huy Kang
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.31 no.4
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    • pp.779-791
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    • 2021
  • Common web services have been continuously targeted by hackers due to an access control policy that must be allowed to an unspecified number of people. In order to cope with this situation, companies regularly check web vulnerabilities and take measures according to the risk of discovered vulnerabilities. The risk of these web vulnerabilities is calculated through preliminary statistics and self-evaluation of domestic and foreign related organizations. However, unlike static diagnosis such as security setting and source code, web vulnerability check is performed through dynamic diagnosis. Even with the same vulnerability item, various attack results can be derived, and the degree of risk may vary depending on the subject of diagnosis and the environment. In this respect, the predefined risk level may be different from that of the actual vulnerability. In this paper, to improve this point, we present a web vulnerability risk assessment model based on the attack result centering on the cyber kill chain.

Telemedicine Software Application

  • UNGUREANU, Ovidiu Costica;POPESCU, Marius-Constantin;CIOBANU, Daniela;UNGUREANU, Elena;SARLA, Calin Gabriel;CIOBANU, Alina-Elena;TODINCA, Paul
    • International Journal of Computer Science & Network Security
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    • v.21 no.2
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    • pp.171-180
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    • 2021
  • Currently, hospitals and medical practices have a large amount of unstructured information, gathered in time at each ward or practice by physicians in a wide range of medical branches. The data requires processing in order to be able to extract relevant information, which can be used to improve the medical system. It is useful for a physician to have access to a patient's entire medical history when he or she is in an emergency situation, as relevant information can be found about the patient's problems such as: allergies to various medications, personal history, or hereditary collateral conditions etc. If the information exists in a structured form, the detection of diseases based on specific symptoms is much easier, faster and with a higher degree of accuracy. Thus, physicians may investigate certain pathological profiles and conduct cohort clinical trials, including comparing the profile of a particular patient with other similar profiles that already have a confirmed diagnosis. Involving information technology in this field will change so the time which the physicians should spend in front of the computer into a much more beneficial one, providing them with the possibility for more interaction with the patient while listening to the patient's needs. The expert system, described in the paper, is an application for medical diagnostic of the most frequently met conditions, based on logical programming and on the theory of probabilities. The system rationale is a search item in the field basic knowledge on the condition. The web application described in the paper is implemented for the ward of pathological anatomy of a hospital in Romania. It aims to ease the healthcare staff's work, to create a connection of communication at one click between the necessary wards and to reduce the time lost with bureaucratic proceedings. The software (made in PHP programming language, by writing directly in the source code) is developed in order to ease the healthcare staff's activity, being created in a simpler and as elegant way as possible.

Proposal of a Mutual Authentication and Key Management Scheme based on SRP protocol (SRP 기반의 DCAS 상호인증 및 키 관리 기법의 제안)

  • Choi, Hyun-Woo;Yeo, Don-Gu;Jang, Jae-Hoon;Youm, Heung-Youl
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.20 no.3
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    • pp.53-65
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    • 2010
  • Conditional Access System (CAS) is a core security mechanism of IPTV SCP (Service and Content Protection) which enables only authenticated user to be able to watch the broadcasting contents. In the past, it was general that CAS was built in Set-Top Box (STB) as hardware or as a detachable cable card. However, numerous researches in Downloadable CAS (DCAS), where users can download CAS code in their STB through their network, have been recently conducted widely due to the lack of security and scalability problem. In this paper, the security requirements of OpenCable based DCAS which is typical example of downloadable IPTV SCP will be derived, the novel authentication and key management scheme will be proposed by using the Authentication Proxy (AP) which is the core DCAS. Also, the benefits of the proposed system will be evaluated by comparison and analysis with preceding research.

Secure AKA(Authentication and Key Agreement) Protocol for Binary CDMA Network (Binary CDMA 망을 위한 안전한 AKA 프로토콜)

  • Kim, Yong-Hee;Park, Mi-Ae;Cho, Jin-Woong;Lee, Hyeon-Seok;Lee, Jang-Yeon;Yi, Ok-Yeon
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.20 no.1
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    • pp.51-61
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    • 2010
  • Koinonia system is designed to fully utilize the advantage of Binary CDMA so as to guarantee QoS in wireless networks. In this paper, we propose the new network structure based on this system and refer to it as BLAN(Binary CDMA LAN). Although BLAN is similar structure to IEEE 802.11 WLAN, it will ensure the fast handover and QoS. We also propose the AKA(Authentication and Key Agreement) protocol and Reauthentication protocol to be used for communication in BLAN. These protocols are securely and efficiently designed using the user identity module to support the more powerful authentication. Hence, BLAN, including the proposed protocols, will support the high mobility and security. In conclusion, we expect that BLAN can be applied to future infrastructure on special environment, and it can be helpful showing the new network model which alternate WLAN.

Network separation construction method using network virtualization (네트워크 가상화를 이용한 망 분리 구축 방법)

  • Hwang, Seong-Kyu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.8
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    • pp.1071-1076
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    • 2020
  • The importance of network separation is due to the use of the Internet with existing business PCs, resulting in an internal information leakage event, and an environment configured to allow servers to access the Internet, which causes service failures with malicious code. In order to overcome this problem, it is necessary to use network virtualization to separate networks and network interconnection systems. Therefore, in this study, the construction area was constructed into the network area for the Internet and the server farm area for the virtualization system, and then classified and constructed into the security system area and the data link system area between networks. In order to prove the excellence of the proposed method, a network separation construction study using network virtualization was conducted based on the basis of VM Density's conservative estimates of program loads and LOBs.