• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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• pp.71-71
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• 2003

For fast MRI, the number of phase encoding steps has to be reduced. However, the reconstructed image is aliased if the phase encoding steps don't satisfy Nyquist sampling theory. SENSE is used in order to eliminate the aliasing effect as well as to reduce imaging time. SENSE is a linear algebraic technique applied to the multiple receiver data. In this study, we implement a tool to reconstruct the original image (SENSE image) with Sensitivity Encoding (SENSE)

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.343-346
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• 2005

In this study, a basic concept of wavelet encoding and its advantages over Fourier based phase encoding application. Wavelet encoding has been proposed as an alternative way to Fourier based phase encoding in magnetic resonance imaging. In wavelet encoding, the RF pulse is designed to generate wavelet-shaped excitation profile of spins. From the resulting echo signals, the wavelet transform coefficients of spin distribution are acquired and an original spin density is reconstructed from wavelet expansion. Wavelet encoding has several advantages over phase encoding. By minimizing redundancy of the data acquisition in a dynamic series of images, we can avoid some encoding steps without serious loss of quality in reconstructed image. This strategy may be regarded as data compression during imaging. Although there are some limitations in wavelet encoding, it is a promising scheme in a dynamic imaging.

• 한국산업정보학회논문지
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• 제12권1호
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• pp.9-18
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• 2007

모바일 기기 사용 환경에서 디지털 콘텐츠에 대한 권리를 보호하고 안전하게 사용하기 위한 방법으로 PKI 기술을 이용하였다. 암호화는 TripleDES를 전자서명은 RSA를 사용하였으며 효과적 관리를 위한 구조로 암호화된 콘텐츠와 서비스를 위한 정보를 연계하는 메카니즘을 제시하였으며 이를 바탕으로 콘텐츠를 안전하게 유통하는 모바일 환경을 제시하였다. 본 연구를 통하여 콘텐츠에 대하 권리를 효과적으로 보호할 수 있으며, 안전한 모바일 콘텐츠 유통 환경을 제시하였다.

• ETRI Journal
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• 제27권6호
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• pp.814-817
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• 2005

Fast binary dilation and erosion algorithms using run-length encoding (RLE) are proposed. RLE is an alternative way of representing a binary image using a run, which is a sequence of '1' pixels. First, we derive the run-based representation of dilation and erosion and then present the full steps of the proposed algorithms in detail.

• 한국융합학회논문지
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• 제8권8호
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• pp.225-230
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• 2017

시조는 우리의 삶에 역동적이고 정격화 된 치유의 활력을 제공한다. 본 연구는 시조가 명사로 끝나는 부분에서 발화하는 문학치료의 기능을 살펴보고자 하였다. 연구의 결과 시조의 종장에 사용된 명사는 서술어의 기능을 발화시키는 것이었다. 이 시조는 한 음보 단축된 11음보로 응집되면서도 12음보의 기능으로 발화되는 것이다. 이러한 시조의 기능 발화는 문학치료의 부호화에 대한 치료적 서술이다. 그래서 시조나 언어에서 서술하지 않고 명사만 언급해도 치유적인 부호화를 활성화시킬 수 있다. 그 이유는 시조의 명사가 인체에 끼어들어 주어가 되고 인체의 뉴런이 서술어가 되어 문장을 만들어내기 때문이다. 이때 뉴런의 핵이 명사로 들어온 정보를 분석하여 새로운 문장을 만들어낸 것을 인체가 인식하는 것으로 판단된다. 이러한 인식이 또한 인체에서 발화하는 치료의 기능인 부호화의 과정이다.

• 대한의용생체공학회:의공학회지
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• 제17권1호
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• pp.93-98
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• 1996

The purpose of this paper is to propose a new localized imaging method of reduced imaging time luting a locally-linear gradient. Since most fast MR(Magnetic Resonance) imaging methods need the whole $\kappa$-space(Spatial frequency space) data corresponding to the whole imaging area, there are limitstions in reducing the minimum imaging time. The imaging method proposed in this paper uses a specially-made gradient coil generating a local ramp-shape field and uniform field outside of the imaging areal Conventional imaging sequences can be used without any RF/gradient pulse sequence modifiestions except the change in the number of encoding steps and the field of view.

• Current Optics and Photonics
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• 제3권6호
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• pp.548-554
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• 2019

A binary encoding method for grayscale images is proposed to address their unsatisfactory decryption results from joint transform correlator (JTC) encryption systems. The method converts the encryption and decryption of grayscale images into that of binary images, and effectively improves decrypted-image quality. In the simulation, we replaced unencoded grayscale images with their binary encoded counterparts in the JTC encryption and decryption processes, then adopted a median filter to suppress saturation noise while keeping other settings unchanged. Accordingly, decrypted-image quality was clearly enhanced as the correlation coefficient (CC) between a decrypted image and its original rose from 0.8237 to 0.9473 initially, and then further to 0.9937, following the above two steps respectively. Finally, optical experimental results confirmed that the proposed encryption system works correctly.

• 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.

• Genomics & Informatics
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• 제6권4호
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• pp.227-230
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• 2008

Compounds of polyketide origin possess a wealth of pharmacological effects, including antibacterial, antifungal, antiparasitic, anticancer and immunosuppressive activities. Many of these compounds and their semisynthetic derivatives are used today in the clinic. Most of the gene clusters encoding commercially important drugs have also been cloned and sequenced and their biosynthetic mechanisms studied in great detail. The area of biosynthetic engineering of the enzymes involved in polyketide biosynthesis has recently advanced and been transferred into the industrial arena. In this work, we introduce a computational system to provide the user with a wealth of information that can be utilized for biosynthetic engineering of enzymes involved in post-PKS tailoring steps. Post-PKS tailoring steps are necessary to add functional groups essential for the biological activity and are therefore important in polyketide biosynthesis.

• BMB Reports
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• 제34권3호
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• pp.230-236
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• 2001

dTDP-rhamnose is synthesized from dTTP and glucose-1-phosphate by four enzymatic steps in the gram-negative bacteria. By using a homologous PCR product, a gene cluster encoding four genes (rfbA, rfbB, rfbC, rfbD) involved in L-rhamnose biosynthesis by Acinetobacter calcoaceticus was isolated and sequenced. The four genes were clustered on the biosynthetic operon in the order of rfbB, D, A, C. A gene, rfbA, encoding glucose-l-phosphate thymidylyltransferase (RfbA), was cloned from A. calcoaceticus pathogenic and encapsulated in the gram-negative bacterium. This enzyme catalyzes the formation of dTDP-D-glucose From $\alpha$-D-glucose-1-phosphate and dTTP.RfbA was amplified by PCR and inserted into the $T_7$ expression system. The activity of RfbA was determined by the capillary electrophoresis. The $K_m$ values for dTTP and $\alpha$-D-glucose-1-phosphate were calculated to be 1.27 mM and 0.80 mM, respectively by using the Line-Weaver Burk plot. RfbA is inactivated by diethylpyrocarbonate.