• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.54-62
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• 2010

A novel harpin-like protein, HpaXm, was described from cotton leaf blight bacteria, Xanthomonas citri subsp. malvacearum. The hpaXm was found to be localized between hrp2 and hrcC. A phylogenetic analysis of the complete amino acid sequence or solely the 13 highly conserved residues $H_2N$-SEKQLDQLLTQLI-COOH in the N-terminal $\alpha$-helix indicates that HpaXm is evolutionarily closer to HpaGXag and HpaXac than to Hpa1Xoo and Hpa1Xoc. A synthesized peptide containing two heptads, 39-LDQLLTQLIMALLQ-52, from the N-terminal a-helical region of HpaXm displayed comparable activity in inducing a hypersensitive response, but two other synthesized derivatives, $HpaXm{\Delta}T44C$ and $HpaXm{\Delta}M48Q$, showed reduced HR-triggering activity. The data from a GST trap test revealed that HpaXm was released into the extracellular medium, hpaXm mutant deficient for the leader peptide (1-MNSLNTQIGANSSFL-15) was unable to be secreted outside cells but still induced HR in tobacco leaves.

• Membrane Journal
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• v.16 no.1
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• pp.9-15
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• 2006

PVA/SSA/HPA composite membranes were prepared by the addition of SSA as a crosslinking agent and HPA such as PWA or SiWA. The water uptake decreased and the IEC increased as the HPA contents increased in PVA/SSA/HPA composite membranes. XRD results showed that HPA distributed well into the composite membranes as the HPA concentration increased, and SiWA dispersed better than PWA in the composite membranes. TGA results showed that PVA/SSA composite membranes were more heat-resistant than PVA due to the crosslinking of PVA, and the heat stability of the composite membranes improved much more as the concentration of HPA increased. The methanol barrier property of PVA/SSA/HPA composite membranes was superior to Nafion, and the methanol permeability of the composite membranes decreased as the concentration of HPA increased.

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.318-324
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• 2006

In order to develop an oral vaccine to prevent H. pylori infection, we have expressed the hpaA gene of H. pylori K51 isolated from Korean patients, encoding 29-kDa HpaA that is known to be localized on the cell surface and flagella sheath, in a live delivery vector system, Lactococcus lactis. The hpaA gene, amplified by PCR using the genomic DNA of H. pylori K51, was cloned in the pGEX-2T vector, and the DNA sequence analysis revealed that the hpaA gene of H. pylori K51 had 99.7% and 94.8% identity with individual hpaA genes of the H. pylori 26695 strain (U.K) and the J99 strain (U.S.A). A polyclonal anti-HpaA antibody was raised in rats using GST-HpaA fusion protein as the antigen. The hpaA gene was inserted in an E. coli-L. lactis-shuttle vector (pMG36e) to express in L. lactis. Western blot analysis showed that the expression level of HpaA in the L. lactis transformant remained constant from the exponential phase to the stationary phase, without extracelluar secretion. These results indicate that the HpaA of H. pylori K51 was successfully expressed in L. lactis, and suggest that the recombinant L. lactis expressing HpaA may be applicable as an oral vaccine to induce a protective immune response against H. pylori.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.12
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• pp.948-953
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• 2017

When using a high-power amplifier(HPA) for high-speed communication, the nonlinear characteristics of the HPA deteriorate power efficiency, bit error rate(BER) performance, and spectral efficiency. Because it is inevitable to use the HPA to obtain sufficient transmission power for high-speed communication, it is necessary to compensate for nonlinearity of the HPA by using a predistorter. In this study, a predistorter was used to compensate for the nonlinearity of the HPA, and the nonlinear distortion was compensated using the predistorter. Simulation results show that the compensation of the nonlinearity of the HPA using the predistorter achieves a BER performance similar to that of an ideal linear amplifier, and that the spectral mask is also satisfied.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.850-853
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• 2011

HPA(Host Protected Area) 영역과 DCO(Device Configuration Overlay) 영역은 사용자가 일반적으로 접근할 수 없는 영역이며 이 위치에 데이터를 저장하거나 은닉할 수 있다. HPA/DCO 영역은 저장 장치와의 통신을 위해 만들어진 규약인 ATA-4와 ATA-6에서 제시되었다. 디지털 포렌식 조사시 HPA/DCO 영역을 고려하지 않은 디스크 이미징 및 데이터 추출 방법은 해당 영역에 숨겨진 유용한 정보를 획득할 수 없다. 따라서 디지털 포렌식 관점에서 HPA/DCO 영역은 중요한 의미를 가지고 있으며, 해당 영역에 존재하는 데이터를 인식하여 획득하는 절차를 통해 디스크 이미징 또는 데이터 추출이 이루어져야 한다. 본 논문은 HPA/DCO 영역에 관한 기존 연구를 활용하여 포렌식 조사에서 해당 영역을 확인하고 접근할 수 있는 방법을 제시하며, HPA/DCO 영역에 저장되어 있는 데이터를 획득하여 디지털 포렌식 조사시 활용할 수 있도록 한다.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.341-346
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• 2016

The AMY2B gene, encoding human pancreatic ${\alpha}$-amylase isozyme (HPA II), was expressed in Pichia pastoris, and the effects of chloride ions on HPA II activity toward starch substrates were investigated. As seen with chloride ion-dependent ${\alpha}$-amylases-including HPA I, the isozyme of HPA II-chloride ions increased enzyme activity and shifted the optimal pH to an alkaline pH. The activity enhancement by chloride was more significant at pH 8 than that at pH 6, suggesting that the protonation state of the general acid/base catalyst of HPA II was important for the hydrolysis of starches at an alkaline pH because of the increase in its $pK_a$ by chloride ions. The turnover values for cereal starches as the substrates markedly increased in the presence of chloride by up to 7.2-fold, whereas that for soluble starch increased by only 1.7-fold. Chloride inhibited substrate hydrolysis at high substrate concentrations, with $K_i$ values ranging from 6 to 15 mg/mL.

• The korean journal of orthodontics
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• v.39 no.5
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• pp.289-299
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• 2009

Objective: The purpose of the present study was to evaluate the effectiveness of the use of Head Posture Aligner (HPA) during cone-beam computed tomography (CBCT) scan in generation of frontal cephalograms using 3D CBCT images. Methods: CBCT scans and frontal cephalograms were made in 30 adult individuals. While a couple of CBCT scan was made for one subject, one was made with conventional method, without use of HPA, the other was acquired with the use of HPA. After creation of virtual frontal cephalogram from each 3D CBCT image, it was traced and compared with the tracing of real frontal cephalogram. Results: In the comparison of the measurements, the virtual cephalograms with the use of HPA did not show statistically significant differences with the real cephalograms whereas the virtual cephalograms without the use of HPA presented significant differences with real cephalograms in many measurements. In the correlation analysis with the measurements of the real cephalograms, the virtual cephalograms with the use of HPA showed higher correlations in all measurements than the virtual cephalograms without the use of HPA. Conclusions: Measurements from CBCT-generated cephalograms become similar to those from real cephalograms with the use of HPA during CBCT scan. Thus, the use of HPA is suggested during the CBCT scan in order to construct accurate virtual frontal cephalograms using 3D CBCT images.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2A
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• pp.166-173
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• 2004

Satellite communication system uses a high non-linear HPA(high power amplifiers) in the earth station and satellite transponder. Therefore, it is important to consider the nonlinear effect of HPA on the communication system. In this paper, we find the variation of power spectrum density by nonlinearity HPA and the change of harmonic component according to IBO (input back-off). When the BPSK is used for satellite communication system, we analyze BER performance including the external co-channel interference (CCI) and the adjacent channel interference (ACI) resulting from the HPA nonlinearity. BER degrades as ACI magnitude grows up when the uplink SNR, uplink SIR (signal to co-channel interference power ratio) and downlink SIR are constant at some level. In case there is only non-linear HPA in the satellite, it is shown that BER considerably depends on the ACI magnitude ACI. When there are two non-linear HPAs in the both earth station and satellite, much BER degradation results from the CCI and ACI.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.401-406
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• 2004

In this paper, a new time-domain adaptive predistortion scheme is proposed to compensate for the nonlinearity of high power amplifiers (HPA) in OFDM systems. A complex Wiener-Hammerstein model (WHM) is adopted to describe the input-output relationship of unknown HPA with linear dynamics, and a power series model with memory (PSMWM) is used to approximate the HPA expressed by WHM. By using the PSMWM, the compensation input to HPA is calculated in a real-time manner so that the linearization from the predistorter input to the HPA output can be attained even if the nonlinear input-output relation of HPA is uncertain and changeable. In numerical example, the effectiveness of the proposed method is confirmed and compared with the identification method based on PSMWM.

• Journal of Aerospace System Engineering
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• v.3 no.1
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• pp.42-46
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• 2009

The 1st development of "Human Powered Aircraft(HPA)" in Korea has been conducting by KAFA(Korea Air Force Academy) from Aug. 2008 to now. HPA is an aircraft powered by directly human energy. The thrust provided by the human power may be the only source and that is weak. Therefore, light weight and strong structure is first requirement. In this paper, treating a basic conceptual design of HPA and material property and material choice for HPA. Also analysing the structure and checking the safety of HPA.