Anti-Jamming GPS 시스템을 위한 적응형 디지털 신호 처리에 관한 분석

한정수,김석중,김현도,최형진,김기윤,Han, Jung-Su,Kim, Seok-Joong,Kim, Hyun-Do,Choi, Hyung-Jin,Kim, Ki-Yun 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.8c

본 논문에서는 GPS 수신기로 유입되는 간섭 및 재밍 신호를 효율적으로 제거 또는 억압하기 위해 배열 안테나(way antenna)를 적용한 항 재밍(anti-jamming) GPS 시스템을 설계하고 운용 방안을 제시하였다. 특히 제안하는 안테나 구조 및 운용 방안은 전통적인 6 원형 배열 안테나(6 circular array antenna) 구조에서 중앙에 1개의 소자를 추가한 7 배열 원형 안테나 구조로써 주어진 간섭 및 재밍 환경 하에서 전력 효율적으로 운용된다. 아울러 적응형 배열 안테나를 사용하여 디지털 신호처리를 수행할 경우 성능이 우수한 것으로 잘 알려진 STAP(Space Time Adaptive Process)와 SFAP(Space Frequency Adaptive Process)를 적용하고 두 방식의 구조 및 복잡도에 관한 분석, 그리고 동일한 복잡도(Complexity) 조건에서 다양한 재밍 환경에서의 BER 성능 비교를 수행하였다. In this paper, we propose a design of GPS anti-jamming system and its operational method, which can effectively suppress interference and jamming signals induced in GPS receiver. The 7-array antenna used in the proposed system is composed of conventional 6 equi-spaced circular elements with one element on the center of antenna and can be efficiently operated under power-constrained conditions. Futhermore, in this paper, we analyze the structure and complexity of STAP and SFAP which are well known techniques in adaptive array antenna signal processing, and we compare the BER performances between STAP and SFAP in various jamming environment based on the same complexity.

2.45GHz LR-WPAN 수신기를 위한 Coherent 기반의 Symbol Detector

한정수,도주현,박타준,최형진,Han Jung-Su,Do Joo-Hyun,Park Tha-Joon,Choi Hyung-Jin 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.2A

본 논문에서는 2.45GHz 대역 IEEE 802.15.4 LR-WPAN(Low-Rate Wireless Personal Area Network; ZigBee) 시스템의 수신기를 위한 개선된 방식의 symbol detector 알고리즘을 제안한다. 저가 구현을 지향하는 LR-WPAN 시스템의 특성상 규격에서 권고하는 frequency tolerance는 $\pm$80ppm(196KHz, 송수신 각각 $\pm$40ppm)으로서 이러한 큰 주파수 옵셋 환경에서도 안정된 동작이 가능한 symbol detector 알고리즘이 요구된다. 일반적으로 LR-WPAN의 수신 모뎀을 위해 주파수 옵셋에 강인한 noncoherent 기반의 symbol detector 사용되나 noncoherent 방식은 I/Q 제곱 과정에서의 제곱 손실에 의해 성능 열화 및 구현의 복잡도 증가를 유발하게 된다. 따라서 본 논문에서는 단일 preamble 심볼을 이용한 주파수 옵셋 추정기를 통해 주파수 옵셋을 보상해주는 coherent 방식의 symbol detector를 제안한다. 제안된 방식은 noncoherent 방식의 제곱 손실을 제거하여 성능을 향상시킴과 동시에 복잡도를 감소시켜 초소형, 저전력, 저가를 지향하는 LR-WPAN 수신기에 보다 적합하도록 설계되었으며, 다양한 채널 환경에서의 성능 평가를 통하여 제안된 알고리즘이 differential detection 기반의 noncoherent 방식보다 1dB의 향상된 성능을 보임을 입증하였다 In this paper, we propose an enhanced symbol detector algorithm for 2.45GHz LR-WPAN(Low-Rate Wireless Personal Area Network) receiver. Because the frequency offset of $\pm$80ppm on 2.45GHz band is recommended in IEEE 802.15.4 LR-WPAN(Low-Rate Wireless Personal Area Network) specification, a symbol detector algorithm having stable operation in the channel environment with large frequency offset is required. For robustness to the frequency offset, non-coherent detection-based symbol detector algorithm is typically applied in the LR-WPAN receiver modem. However, the noncoherent symbol detector has increased performance degradation and hardware complexity due to squaring loss of I/Q squaring operation. Therefore we propose a coherent detection-based symbol detector algorithm with frequency offset compensation using a preamble symbol. The proposed algorithm is more suitable for LR-WPAN receiver aimed at low-cost, low-power and low-complexity than the non-coherent symbol detector, since it can reduce performance degradation due to squaring loss of I/Q squaring operation and implementation complexity. Simulation results show that the proposed algorithm has performance improvement of about 1dB in various channel environments.

Fly-By-Wireless 비행제어 기술의 연구 동향

한정수,하철수,오수헌,강승은,고상호,Han, Jung-Soo,Ha, Chul-Su,O, Su-Hun,Kang, Seung-Eun,Ko, Sangho 한국항공운항학회 2014 한국항공운항학회지 Vol.22 No.1

This paper deals with recent research cases and directions of Fly-By-Wireless (FBWLS) flight control technology. FBWLS is a new type of flight control system technology with the aim of solving the problems mainly caused by the increasing amount of wires in aircraft to which Fly-By-Wire (FBW) technology applies. Therefore, in FBWLS flight control system the wired communication system is replaced with a wireless communication system. Currently the FBWLS flight control technology is at an initial development stage and thus this paper surveys deals with the cases in the viewpoint of technology feasibility. In this context, this paper analyzes technology that needs further studies to secure the reliability, stability and accuracy to the similar level of the corresponding FBW system. Since the major problems of FBWLS technology are packet losses and time delays so that this paper suggests the research direction of wireless communication protocol selection, optimization of wireless communication network and controller design considered communication environment.

WCDMA 단말 모뎀을 위한 개선된 SIR 측정 알고리즘 설계

한정수,도주현,최형진,Han, Jung-Su,Doo, Joo-Hyun,Choi, Hyung-Jin 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.2a

본 논문에서는 WCDMA(Wideband Code Division Multiple Access) 단말 모뎀을 위한 개선된 SIR 측정 알고리즘을 제안한다. 제안된 알고리즘은 속도 적응형 IIR 타입의 channel estimator를 적용함으로써 DPCH(Dedicated Physical Channel)의 채널 보상으로 인한 처리 지연을 최소화하였으며, 파일럿 채널인 CPICH(Common Pilot Channel)를 사용하여 페이딩 채널 환경에서 발생하는 신호 전력 감쇄를 보상함으로써 페이딩 환경에서 SIR 측정시 발생하는 SIR 측정 오차를 대폭 감소시켰다. 또한 fading의 변화를 적절히 반영할 수 있도록 IIR 필터를 신호 전력 및 간섭 전력 측정 시에 추가함으로써 SIR 측정에 대한 안정도를 향상시켰다. 제안된 알고리즘과 기존의 SIR 측정 알고리즘과의 성능 비교를 통하여 무선 이동 채널, 특히 고속 이동체 환경에서 제안된 알고리즘의 측정된 SIR의 mean은 최대 약 8dB, jitter는 약 2dB의 향상된 우수한 성능을 보임을 입증하였다. In this paper, we propose an enhanced SIR measurement algorithm for WCDMA mobile station modem. The proposed algorithm minimizes processing delay by applying velocity estimation-based channel estimator with IIR filter and reduces measured SIR offset by compensating attenuated signal power by using pilot channel(CPICH) in fading channel environment. To improve stability of SIR measurement, we also adopt an IIR filter which can properly reflect variation of fading channel in signal and interference power measurement. We prove that the proposed algorithm outperforms conventional SIR measurement algorithm in mean and jitter of measured SIR. Computer simulation shows that performance results using the proposed algorithm have improvement of approximately 8dB for measured mean and 2dB for measured jitter in the wireless mobile channel, especially in fast mobile speed environment.

셀룰로오스 분자량 조절에 의한 하이드로젤의 성상

한정수(Jung Su Han),서영범(Yung Bum Seo) 한국펄프·종이공학회 2015 한국펄프·종이공학회 학술발표논문집 Vol.2015 No.10

개선된 SIR 측정 알고리즘 적용한 WCDMA 순방향 폐루프 전력 제어

한정수(Jung-Su Han),도주현(Joo-Hyun Do),최형진(Hyung-Jin Choi) 한국통신학회 2005 한국통신학회 학술대회 및 강연회 Vol.2005 No.4

외국유한파트너쉽의 국내원천소득 과세에 대한 개선방안

한정수 ( Han Jung Su ) 연세대학교 법학연구원 글로벌비즈니스와 법센터 2017 연세 글로벌 비즈니스 법학연구 Vol.9 No.1

This study discusses the issues dealt with in the Supreme Court Cases related to the domestic source income taxation of the foreign limited partnerships and the issues in the application of new provisions in the Corporate Income Tax Law related to foreign limited partnerships. First of all, with respect to the issue of substantial ownership, the Supreme Court concluded that domestic source income belongs to the foreign limited partnership based on the fact that it has a character as a separate entity with rights and obligations apart from its partners. According to the new provision introduced in the 2012 Revision of Corporate Income Tax Law, foreign investment vehicle shall submit an application for the reduced tax rate received from the beneficial owner to a withholding agency when the domestic source income is paid through the foreign investment vehicle. However, there is an issue on whether to interpret the investor of the foreign investment vehicle and foreign investment vehicle as a beneficiary of domestic source income. This issue should be resolved through a foregone interpretation because of the ambiguity of tax law interpretation and the possibility of hindering the predictability of foreign investors in domestic investment. Considering the interpretation related to foreign investment vehicle issued by the Internal Revenue Service and the Ministry of Strategy and Finance and the taxation trends of OECD and other major countries for the foreign investment vehicle, it is desirable to interpret the abovementioned provision on submitting an application for reduced tax rate as a substantive regulation to apply the tax treaty to the investors of foreign investment vehicle rather than the simple procedural provision. With respect to the issue on entity classification of foreign limited partnerships, the Supreme Court concluded that the foreign limited partnership is regarded as a foreign corporation because it consists of unlimited liability partners and limited liability partners and has independent existence with rights and obligations apart from its partners. However, in the 2013 Revision of Corporate Income Tax Law, specific standards for determining the foreign corporation were newly established and it stated that the application of entity classification standards of foreign corporation does not affect the determination on whether to apply the tax treaty. In particular, Article 1-(2)(c) of the Enforcement Decree of the Corporate Income Tax Law defines a foreign corporation as an entity that has rights and obligations by possessing assets or becoming a party to a litigation independent from its investors. In this regard, there still is an issue on determining the scope of subject of the rights and obligations due to the unclear definition of ‘independence.’ In addition, Article 1-(2)(d) of the Enforcement Decree of the Corporation Income Tax Law defines a foreign corporation as a foreign entity in case the foreign entity is a corporation subject to domestic laws, such as “Commercial Act”. However, there are difficulties in determination of a foreign corporation if there are several groups or no group in domestic laws similar to foreign limited partnership. These issues can be improved by two remedies; i) enumerating specific criteria to be independent in terms of rights and obligations, and ii) specifying the category (i.e., type of corporation) of each foreign entity through the notification of the National Tax Service. Finally, in relation to the application of the tax treaty, the foreign limited partnership treated as “transparent entity” does not fall under the definition of the residents in the tax treaty even if the foreign limited partnership is a ‘person’ in the tax treaty. If the domestic source income is attributed to the foreign limited partnership which does not meet the definition of resident of tax treaty, the domestic source income will not be covered by the tax treaty. In order to solve this problem, Dongwon Enterprise judgment and TMW judgment decided to apply the tax treaty to the partnership only for the partnership and those of the partners who are residents of the same country. This is not natural in the interpretation of the tax treaty except for the technical description of the US-Korea tax treaty. Based on the OECD partnership report and the US model tax treaty, it is necessary to consider amending the treaty to reflect the tax treaty on the basis of investors of the foreign limited partnership when foreign limited partnerships classified as transparent entity. In addition, it is possible to consider introducing LOB regulations on the BEPS project into the treaty to prevent a tax avoidance of foreign limited partnership treated as a resident of tax treaty. In the last, in relation to the application of the tax treaty, the foreign limited partnership treated as “transparent entity” does not meet the definition of the residents in the tax treaty even if the foreign limited partnership is ‘person’ in the tax treaty. If the domestic source income is attributed to the foreign limited partnership which does not meet the definition of resident of tax treaty, the domestic source income will not be covered by the tax treaty. In order to solve this problem, Dongwon Enterprise judgment and TMW judgment decided to apply the tax treaty to the partnership only for the partnership and those of the partners who are residents of the same country. This is not natural in the interpretation of the tax treaty except for the technical description of the US-Korea tax treaty. In relation to the OECD partnership report and the US model tax treaty, it is necessary to consider amending the treaty to reflect the tax treaty on the basis of investors of the foreign limited partnership when foreign limited partnerships classified as transparent entity. And it is possible to consider introducing LOB regulations on the BEPS project into the treaty to prevent tax avoidance of foreign limited partnership treated as a resident of tax treaty.

조사논문 : 한우 사양관리에 있어서 TMF 사료의 경제적 효과 -홍성 지역 사례를 중심으로-

한정수 ( Jung Su Han ),홍승지 ( Seung Jee Hong ) 한국농업정책학회, 한국축산경영학회 2010 농업경영정책연구 Vol.37 No.2

여자유도를 이용한 상지 착용형 로봇의 메커니즘 설계

이영수(Young Su Lee),홍성준(Sung Jun Hong),장혜연(Hye Yeon Jang),장재호(Jae Ho Jang),한창수(Chang Su Han),한정수(Jung Su Han) Korean Society for Precision Engineering 2009 한국정밀공학회지 Vol.26 No.7

주관적 향의 선호도와 뇌파 반응과의 상관관계

민병찬,한정수,정순철,변증남,김지관,김철중,Min, Byeong-Chan,Han, Jeong-Su,Jeong, Sun-Cheol,Byeon, Jeung-Nam,Kim, Ji-Gwan,Kim, Cheol-Jung 대한인간공학회 2001 大韓人間工學會誌 Vol.20 No.3

In the present study, the correlation between subjective assessment and EEG for essential odors were investigated quantitatively. EEG signals were measured from 19 electrodes according to the International 10-20 system (Fp1, Fp2, F3/4, F7/8, Fz, C3/4, Cz, P3/4, Pz, T3/4, T5/6, O1/2) from 8 healthy males subjects for four odor(Rose oil bulgarian, Lemon oil misitano, jasmin abs, Laverder oil france (KIMEX co. Ltd) conditions. The result of the subjective assessment shows the most pleasant odor for each subject. and the power spectrum of ${\alpha}/({\alpha}+{\beta})$ of EEG signals from the most pleasant odor was compared with those from the control condition, which has no odor at all. Power spectrum of ${\alpha}/({\alpha}+{\beta})$ of EEG from the most pleasant odor was increased significantly at T4, T6 compared to the control condition. This result implies that the parameter, power spectrum of ${\alpha}/({\alpha}+{\beta})$, could be an important index for signifying the levels of pleasantness for odors.