• Journal of Microbiology and Biotechnology
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• 제29권3호
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• pp.367-372
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• 2019

Deactivation of aminoglycosides by their modifying enzymes, including a number of aminoglycoside O-phosphotransferases, is the most ubiquitous resistance mechanism in aminoglycoside-resistant pathogens. Nonetheless, in a couple of biosynthetic pathways for gentamicins, fortimicins, and istamycins, phosphorylation of aminoglycosides seems to be a unique and initial step for the creation of a natural defensive structural feature such as a 3',4'-dideoxy scaffold. Our aim was to elucidate the biochemical details on the beginning of these C3',4'-dideoxygenation biosynthetic steps for aminoglycosides. The biosynthesis of istamycins must surely involve these 3',4'-didehydroxylation steps, but much less has been reported in terms of characterization of istamycin biosynthetic genes, especially about the phosphotransferase-encoding gene. In the disruption and complementation experiments pointing to a putative gene, istP, in the genome of wild-type Streptomyces tenjimariensis, the function of the istP gene was proved here to be a phosphotransferase. Next, an in-frame deletion of a known phosphotransferase-encoding gene forP from the genome of wild-type Micromonospora olivasterospora resulted in the appearance of a hitherto unidentified fortimicin shunt product, namely 3-O-methyl-FOR-KK1, whereas complementation of forP restored the natural fortimicin metabolite profiles. The bilateral complementation of an istP gene (or forP) in the ${\Delta}forP$ mutant (or ${\Delta}istP$ mutant strain) successfully restored the biosynthesis of 3',4'-dideoxy fortimicins and istamycins, thus clearly indicating that they are interchangeable launchers of the biosynthesis of 3',4'-dideoxy types of 1,4-diaminocyclitol antibiotics.

• 한국항공우주학회지
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• 제47권4호
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• pp.283-288
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• 2019

본 논문은 천리안위성 2A호가 2018년도 12월 5일에 발사되고 태양전지판구동기의 초기운영을 수행하면서 획득된 텔레메트리를 통해 지상에서 개발하고 시험한 결과에 대한 우주검증 결과를 정리하였다. 특히, 전이궤도 이후 정지궤도에 진입하면서 태양전지판구동기의 위치 설정 로직과 open-loop 제어에 의한 누적오차 보상 로직에 대한 결과를 검증하고 정상 운영이 되고 있음을 확인할 수 있었다. 또한, 설계 단계에서 확인되지 못했던 정지궤도 대비 태양의 위치가 시간에 따라 주기적인 오프셋이 있음을 발견하고 그에 적합한 보정 threshold 값을 설정하게 된 결과도 정리하였다.

• 정보보호학회논문지
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• 제22권4호
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• pp.719-731
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• 2012

인터넷범죄를 수사함에 있어 가장 중요한 점은 범행호스트의 범행을 입증하는 것이다. 그러나 범죄자들은 범행부인을 위해 범행호스트의 IP주소를 변경하거나 패킷의 출발지 IP주소를 조작한다. 또한 악의적인 어플리케이션을 이용하여 범행기록을 남기지 않는다. 본 논문은 인터넷범죄수사의 한계를 극복하기 위한 Network Forensic Evidence Generation and Verification Scheme을 제안한다. 이 기술은 인터넷범죄수사를 위해 패킷의 생성위치와 전송과정에 주소필드가 조작되지 않았음을 보장하는 증거를 생성하여, 범행기록이 부재하여도 패킷을 통해 입증한다. 그리고 증거생성에 의한 라우터의 성능저하를 최소화하기 위해 Timestamp SecretKey Distribution Scheme과 Flow-Based Selection Scheme을 추가 제안한다. 마지막으로 제안한 기술들을 활용하기 위한 시스템을 구현하고 패킷전송률을 실험한다.

• 정보보호학회논문지
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• 제22권2호
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• pp.249-258
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• 2012

최근 사이버 테러는 국가와 민간을 넘나들며 그 경계가 제한되지 않고 있으며, 현대전의 양상은 사이버 공격을 활용하여 관련 정보를 유출하고 그 정보를 악의적으로 이용하여 국가 및 기업에 치명적인 피해를 끼치고 있다. 이에 정부는 2008년 7월 25일부터 지식경제부 산하 공공기관의 보안과 사고예방을 위하여 지식경제사이버안전센터를 운영하고 있다. 지식경제사이버안전센터는 보안관제센터로서 사이버공격 정보를 탐지 분석하여 즉시 대응 조치를 수행하고, 수집 탐지한 정보를 국가 사이버안전센터 및 회원기관과 공유한다. 또한 정보공유분석센터(ISAC, Information Sharing & Analysis Center)로서 전자적 제어 관리시스템을 포함한 주요정보통신기반시설에 대한 취약점분석 및 평가를 실시하고, 침해사고대응센터(CERT/CC, Computer Emergency Response Team/Coordination Center)로서 보안사고 예방활동 및 보안사고 대응서비스를 수행하고 있다. 이에 본 논문에서는 나날이 그 역할이 커지고 있는 지식경제사이버안전센터의 설립 목적 및 역할, 수행업무에 대한 서비스를 분석하고 문제점을 파악한 후에 개선 방안을 제시한다.

• 한국수산과학회지
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• 제56권4호
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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.

• Korean Journal of Acupuncture
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• 제40권2호
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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.

• International journal of advanced smart convergence
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• 제11권4호
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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.

• 천문학회보
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• 제44권2호
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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.

• 영어영문학
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• 제56권6호
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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.

• 영어영문학
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• 제55권3호
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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.