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Validation on Solar-array Drive Assembly of GEO-KOMPSAT-2A Through In-orbit Operation (천리안2A호 태양전지판구동기 궤도상 운영 검증)

  • Park, Young-Woong;Park, Keunjoo;Park, Bong-Kyu
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.47 no.4
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    • pp.283-288
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    • 2019
  • In this paper, there is summarized the validation of ground test results through the telemetry acquired during on-orbit initial activation on solar-array drive assembly(SDA) of GK2A launched at Dec-5, 2018. Especially, the decision logic of SDA initial position and the compensation logic are validated and confirmed. The SDA initial position is needed when GK2A enter to geostationary orbit from transfer orbit and the compensation logic is for the accumulated position error due to the open-loop control. Up to now, it is normal operating. Also the periodic offset between the geostationary orbit and Sun position is found that it is not checked on design phase, and then the proper threshold value is applied.

Network Forensic Evidence Generation and Verification Scheme (효율적인 인터넷 범죄수사를 위한 범행호스트 탐지 및 범죄행위 입증기술)

  • Kim, Hyung-Seok;Kim, Eun-Jin;Kim, Huy-Kang
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.22 no.4
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    • pp.719-731
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    • 2012
  • One of the most important point in the Internet crime investigation is tracing back and pointing out a criminal host. However, criminals can forge a crime record stored in the crime host, or can utilize malicious applications in order not to leave a crime record. In addition, criminals can change the source IP address of a crime host and deny their involvement. In this study, we suggests the Network Forensic Evidence Generation and Verification Scheme (NFEGVS) to rectify the current limitation of Network Forensic technologies. This scheme can prove who and when the crime has occurred. In addition, this prevents leaking of symmetric key for guaranteeing certification and integrity of Forensic Evidence by proposing the Timestamp Secret Key Distribution Scheme, and minimizes performance degradation of router when generating forensic evidence with the Flow-Based Selection Scheme. In this paper, we implement the proposed scheme and evaluate overall performance of the proposed system.

Services analysis and improvement of MKE(Ministry of Knowledge Economy) Cyber Security Center (지식경제사이버안전센터의 대응활동분석과 개선방안)

  • Lee, Seung-Won;Roh, Young-Sup
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.22 no.2
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    • pp.249-258
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    • 2012
  • Cyber attacks expose sensitive information and cause fatal damage in both the public and the private sectors. Therefore, MKE (Ministry of Knowledge Economy) Cyber Security Center was founded on July 25, 2008, to perform three major roles. First, it detects and analyzes cyber attacks for the both sectors. Second, its ISAC (Information Sharing & Analysis Center) service analyzes and evaluates the vulnerability of the communication and network infrastructure to security threats, including control systems. Third, it provides CERT/CC (Computer Emergency Response Team Coordination Center) service to prevent and to respond to computer security incidents. This study focuses on the MKE Cyber Security Center's service analysis, which is playing an increasingly larger role in the both sectors. Based on this analysis, after grasping the response services activity and pointing out the problems, this study suggests improvements to the MKE Cyber Security Center.

Trace Metal Distribution and Ecological Risk Assessment in Marine Sediments from the Southeast Coastal Areas of Korea (남동해 연안 퇴적물 내 미량금속 분포 및 생태위해도 평가)

  • Dong-Woon Hwang;Minkyu Choi;Jae-Hyun Lim;In-Seok Lee;Garam Lee;Sujin Na
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.56 no.4
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    • pp.438-448
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    • 2023
  • The concentrations of trace metals and organic matters in marine sediments collected from southeast Korean coastal areas were investigated. The primary purpose of this study was to evaluate the contamination status, spatial distribution and potential ecological risks associated with the physiochemical composition in the studied areas. We found that the concentrations of trace metals in marine sediments were as follows: Fe > Mn > Zn > Cr > Pb > Cu > As > Cd > Hg. According to the sediment quality guidelines (SQGs) of Korea, concentrations of Zn, Cr, Cu and Cd at all sampling sites were below threshold effect levels (TEL). However, concentrations of As, Hg, and Pb (i.e., at the 94-98% of sampling sites), were below the TEL. In addition, concentration factors (CF) in the surveyed area were found to be associated with low ecological risks, whereas As, Hg, and Cu showed moderate to high risk levels in some inner parts of the studied bays. Finally, the pollution load index (PLI) and ecological risk index (ERI) of the elucidated metals were linked to moderate ecological risk, pointing to the possibility of being deleterious to some benthic organisms.

Comparative Literature Review of Floating Acupuncture: Compared to Meridian Muscle, Myofascial Pain Syndrome and Wrist-Ankle Acupuncture (부침 이해를 위한 문헌 비교: 경근, 근막동통이론, 완과침 그리고 부침)

  • Cheoung Su Kim;Yeon Kyeong Nam;Piao Quanyu;Seung Bum Yang;Jae-Hyo Kim;O Sang Kwon
    • Korean Journal of Acupuncture
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    • v.40 no.2
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    • pp.33-43
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    • 2023
  • Objectives : Floating acupuncture (FA) is a kind of newly developed acupuncture technique that contains its own apparatus. The technique has unique points that the body of the acupuncture needle stays intradermal space and manipulation is performed by shaking the needle horizontally; after manipulation, part of the needle remained in the intradermal space for 2~3 days. FA is not a common acupuncture methodology while various clinical study claims its efficacy on musculoskeletal disorders. In this study, the authors aimed to enhance the use of FA by comparing related theories. Methods : The authors reviewed classics, books, and articles related to FA, Meridian Muscle (MM), Myofascial Pain Syndrome (MPS), and Wrist-Ankle Acupuncture (WAA), and compared its characteristics by related theory, related symptoms, apparatus, and performing procedures. Results : FA was related and had various common parts with MM, MPS, and WAA, however, there were unique parts in the manipulation, apparatus, and stimulation location. FA is based on MM and MPS which pointing 'ashi points' or 'trigger points' as a treating target while FA does not stimulate the points directly. FA also targets subcutaneous space by inserting the needle horizontally as WAA does, while FA remains the needle handle part in the subcutaneous area for 2~3 days for more stimulation. Conclusions : FA has a unique manipulation procedure and potential benefit for musculoskeletal disorders despite the crude theological base written by Fu himself. Thus, developing a new explanation and patient-friendly methodology/apparatus is required for further down-to-earth studies.

A Study of 0.5-bit Resolution for True-Time Delay of Phased-Array Antenna System

  • Cha, Junwoo;Park, Youngcheol
    • International journal of advanced smart convergence
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    • v.11 no.4
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    • pp.96-103
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    • 2022
  • This paper presents the analysis of increasing the resolution of True-Time-Delay (TTD) by 0.5-bit for phased-array antenna system which is one of the Multiple-Input and Multiple Output (MIMO) technologies. For the analysis, a 5.5-bit True-Time Delay (TTD) integrated circuit is designed and analyzed in terms of beam steering performance. In order to increase the number of effective bits, the designed 5.5-bit TTD uses Single Pole Triple Throw (SP3T) and Double Pole Triple Throw (DP3T) switches, and this method can minimize the circuit area by inserting the minimum time delay of 0.5-bit. Furthermore, the circuit mostly maintains the performance of the circuit with the fully added bits. The idea of adding 0.5-bit is verified by analyzing the relation between the number of bits and array elements. The 5.5-bit TTD is designed using 0.18 ㎛ RF CMOS process and the estimated size of the designed circuit excluding the pad is 0.57×1.53 mm2. In contrast to the conventional phase shifter which has distortion of scanning angle known as beam squint phenomenon, the proposed TTD circuit has constant time delays for all states across a wide frequency range of 4 - 20 GHz with minimized power consumption. The minimum time delay is designed to have 1.1 ps and 2.2 ps for the 0.5-bit option and the normal 1-bit option, respectively. A simulation for beam patterns where the 10 phased-array antenna is assumed at 10 GHz confirms that the 0.5-bit concept suppresses the pointing error and the relative power error by up to 1.5 degrees and 80 mW, respectively, compared to the conventional 5-bit TTD circuit.

Development of the Command and Data Handling System and Flight Software of BITSE

  • Park, Jongyeob;Baek, Ji-Hye;Jang, Bi-ho;Choi, Seonghwan;Kim, Jihun;Yang, Heesu;Kim, Jinhyun;Kim, Yeon-Han;Cho, Kyung-Suk;Swinski, Joseph-Paul A.;Nguyen, Hanson;Newmark, Jeffrey S.;Gopalswamy, Natchumuthuk
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.57.4-57.4
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    • 2019
  • BITSE is a project of balloon-borne experiments for a next-generation solar coronagraph developed by a collaboration with KASI and NASA. The coronagraph is built to observe the linearly polarized brightness of solar corona with a polarization camera, a filter wheel, and an aperture door. For the observation, the coronagraph is supported by the power distribution unit (PDU), a pointing system WASP (Wallops Arc-Second Pointer), telemetry & telecommand system SIP (Support Instrument Package) which are developed at NASA's Goddard Space Flight Center, Wallops Flight Facility, and Columbia Scientific Balloon Facility. The BITSE Command and Data Handling (C&DH) system used a cost-off-the-shelf electronics to process all data sent and received by the coronagraph, including the support system operation by RS232/422, USB3, Ethernet, and digital and analog signals. The flight software is developed using the core Flight System (cFS) which is a reusable software framework and set of reusable software applications which take advantage of a rich heritage of successful space mission of NASA. The flight software can process encoding and decoding data, control the subsystems, and provide observation autonomy. We developed a python-based testing framework to improve software reliability. The flight software development is one of the crucial contributions of KASI and an important milestone for the next project which is developing a solar coronagraph to be installed at International Space Station.

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The Topology of Extimacy in Language Poetry: Torus, Borromean Rings, and Klein Bottle

  • Kim, Youngmin
    • Journal of English Language & Literature
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    • v.56 no.6
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    • pp.1295-1310
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    • 2010
  • In her "After Language Poetry: Innovation and Its Theoretical Discontents" in Contemporary Poetics (2007), Marjorie Perloff spotted Steve McCaffery's and Lyn Hejinian's points of reference and opacity/transparency in poetic language, and theorizes in her perspicacious insights that poetic language is not a window, to be seen through, a transparent glass pointing to something outside it, but a system of signs with its own semiological interconnectedness. Providing a critique and contextualizing Perloff's argument, the purpose of this paper is to introduce a topological model for poetry, language, and theory and further to elaborate the relation between the theory and the practice of language poetry in terms of "the revolution of language." Jacques Lacan's poetics of knowledge and of the topology of the mind, in particular, that of "extimacy," can articulate the way how language poetry problematizes the opposition between inside and outside in the substance of language itself. In fact, as signifiers always refer not to things, but to other signifiers, signifiers becomes unconscious, and can say more than they actually says. The original signifiers become unconscious through the process of repression which makes a structure of multiple and polyphonic signifying chains. Language poets use this polyphonic language of the Other at Freudian "Another Scene" and Lacan's "Other." When the reader participates the constructive meanings, the locus of the language writing transforms itself into that of the Other which becomes the open field of language. The language poet can even manage to put himself in the between-the-two, a strange place, the place of the dream and of the Unheimlichkeit (uncanny), and suture between "the outer skin of the interior" and "the inner skin of the exterior" of the impossible real of definite meaning. The objective goal of the evacuation of meaning is all the same the first aspect suggested by the aims of the experimentalism by the language poetry. The open linguistic fields of the language poetry, then, will be supplemented by The Freudian "unconscious" processes of dreams, free associations, slips of tongue, and symptoms which are composed of this polyphonic language. These fields can be properly excavated by the methods and topological mapping of the poetics of extimacy and of the klein bottle.

Dualism in Carlyle's Sartor Resartus: Descendentalism and Transcendentalism

  • Yoon, Hae-Ryung
    • Journal of English Language & Literature
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    • v.55 no.3
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    • pp.399-413
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    • 2009
  • Pointing out the reality of criticism done mostly on Carlyle s original structure and rhetoric in his Sartor Resartus, this research paper focuses on Carlyle s dualistic philosophy revealed in the work, limiting its focus mostly to the dualistic theme of descendentalism and transcendentalism. The essence of Caryle s descendentalism is his irony and satire on human civilization, not for criticism itself, like other satirists, but rather out of his deep, secret humanism behind his mask. Roughly the two objects of his social criticism in the contemporary, descendentalisitc world, are mechanism and materialism in a variety of new ideologies. To diagnose the Zeitgeist and disillusion man living in contemporary civilization, Carlyle in this work uses a very original metaphor, the clothes-symbol. According to Carlyle, human history and progress can be said to be originated from man s adventitious invention of clothes that was not for biological need or social decency, but for decoration, the instinct of which implies man s innate vanity and desire. Interestingly enough here, however, Carlyle uses the same metaphor of clothes for his vision of transcendence, the world of Everlasting Yea. Man is also God s apparel and Matter is that of Spirit. Carlyle s Everlasting Yea world stresses especially the two attitudes, belief in God and love of man, which have been recently jeopardized in the socalled descendentalistic world. But Carlyle s transcendental and religious vision in Sartor Resartus is, as critics also have agreed, a unique and mysterious vision as something different from orthodox Christianity or other Victorian ideologies, as more like an amalgamation among Calvinism, Romanticism, Platonism and German Idealism. All in all, reading Sartor Resartus is still a valuable experience of an idiosyncratically original vision along with his warning against dehumanizing forces lurking in the name of civilization and with his ultimate eulogy on man, proving descendentalism as just part of transcendentalism, although the reader from time to time can be embarrassed by his male-centered, politically conservative, and individual-oriented dynamism.

Manufacturing and Characteristic Evaluation of Free space Optical Communication Devices in 5G Mobile Base Stations for Emergency Disaster Response (긴급재난 대응용 5G 이동 기지국을 위한 대기공간 광통신 장치의 제작과 특성평가)

  • Jin-Hyeon Chang
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.5
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    • pp.131-138
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    • 2023
  • In this paper, a free space optical communication device that can be used in a mobile base station of several km or less was fabricated and its characteristics were investigated. To overcome the loss due to atmospheric transmission, an optical fiber amplifier (EDFA) with an output of 23 dBm or more was used. In order to increase the focusing speed and miniaturization of the laser beam, an optical lens was manufactured, and a transmission lens was designed to have beam divergence within the range of 1.5 to 1.8 [mrad]. A PT module that controls PAN/TILT was fabricated in order to reduce pointing errors and effective automatic alignment between transceiver devices. In this study, Reed-Solomon (RS) code was used to maintain the transmission quality above a certain level. It was manufactured to be able to communicate at a wireless distance of 300m in a weather situation with visibility of 300m. For performance measurement, it was measured using BERT and eye pattern analyzer, and it was confirmed that BER can be maintained at 2.5Gbps.