• Fibers and Polymers
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• 제2권2호
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• pp.98-107
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• 2001

The phase transition behavior isothermal micro-phase separation kinetics of polyester-based thermoplastic elastomer were studied using the synchrotron X-ray scattering(SAXS) method. The structural changes occurring during heating period were investigated by determining the changes of the one-dimensional correlation function, interfacial thickness and Porod constant. Based on the abrupt increases of the domain spacing and interfacial thickness, a major structural change occurring well below the melting transition temperature is suggested. Those changes are explained in terms of melting of the thermodynamically unstable hard domains or/and the interdiffusion of the hard and soft segments in the interfacial regions. SAXS profile changes during the micro-phase separation process were also clearly observed at various temperatures and the separation rate was found to be sensitively affected by the temperature. The peak position of maximum scattering intensity stayed constant during the entire course of the phase separation process. The scattering data during the isothermal phase separation process was interpreted with the Cahn-Hilliard diffusion equation. The experimental data obtained during the early stage of the phase separation seems to satisfy the Cahn-Hilliard spinodal mechanism. The transition temperature obtained from the extrapolation of the diffusion coefficient to zero value turned out to be about 147$\pm$$2^{\circ}$, which is close to the order-disorder transition temperature obtained from the Porod analysis. The transition temperature was also estimated from the inveriant growth rate. By extrapolating the inveriant growth rate to zero, a transition temperature of about 145$\pm$$\pm$$2^{\circ}$ was obtained.

• 방송공학회논문지
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• 제16권5호
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• pp.801-810
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• 2011

본 논문에서는 디지털 영상을 위한 공간 영역에서의 무손실 데이터 삽입 방법을 제안한다. 제안하는 방법은 데이터 삽입 및 추출을 위해 위치 지도 등의 부가 정보를 삽입하는 대신에 단 한 개의 파라미터 만을 필요로 한다. 삽입 과정에서는 $3{\times}3$ 크기의 창이 대상 영상 위를 한 화소 단위로 움직이며 각 위치에서 한 비트의 데이터를 삽입 할 수 있다. 따라서, 이상적인 삽입 용량은 영상의 화소수와 동일하다. 또한, 추가적인 실제 삽입 용량의 증가를 위해, 삽입 대상 화소의 예측을 위한 새로운 계수를 적용하였다. 그 결과 기존의 방법에 비해 삽입 용량이 매우 큰 폭으로 증가하고, 고용량 데이터 삽입 시의 영상 화질 또한 향상되었다. 제안 방법은 컴퓨터 시뮬레이션을 통해 검증하였다.

• 대한기계학회논문집A
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• 제39권2호
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• pp.235-240
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• 2015

디지털 기기의 발달과 더불어 능동안전시스템 또한 비례적으로 발달됨에 따라 4.5 톤 이상 중대형상용차에도 능동안전시스템에 대한 요구가 대두되고 있다. 승용차량과 달리 중대형 상용차량 경우 카메라 장착 위치가 상대적으로 높아 차선 인식에 불리한 조건을 가지고 있다. 본 논문에서는 공간영역처리 기반 중 하나인 소벨 에지(Sobel Edge) 추출과 허프 변환(Hough Transform) 기법과 색 변환보정 기법으로 국내 도로 환경에 맞는 차선 인식에 대한 방법을 제시하고, 영상을 통한 전방의 차량을 인식하는 객체 인식 기법 중에 Haar-like 기법, Adaboost 기법, SVM 기법, Template Matching 기법 등을 적용 및 분석을 통하여 검출 오류를 줄이기 위한 전방 차량 인식 방법을 제안한다. 성능검증을 위해서 실차평가를 실시하였으며, 차선 인식에 대해 98% 이상의 높은 인식률을 얻었다.

• 한국산업정보학회논문지
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• 제17권2호
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• pp.19-27
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• 2012

In railway tunnel environment, the reliability of a high-data-rate and real-time train-to-wayside communication should be maintained especially when high-speed train moves along the track. In China and Europe, the communication frequency around 900 MHz is widely used for railway applications. At this carrier frequency band, both of the solutions based on continuously laid leaky coaxial cable (LCX) and discretely installed base-station antennas (BSAs), are applied in tunnel radio coverage. Many available works have concentrated on the radio-wave propagation in tunnels by different kinds of prediction models. Most of them solve this problem as natural propagation in a relatively large hollow waveguide, by neglecting the transmitting/receiving (Tx/Rx) components. However, within such confined areas like railway tunnels especially loaded with train, the complex communication environment becomes an important factor that would affect the quality of the signal transmission. This paper will apply a full-wave numerical method to this case, for considering the BSA or LCX, train antennas and their interacted environments, such as the locomotive body, overhead line for power supply, locomotive pantograph, steel rails, ballastless track, tunnel walls, etc.. Involving finite-difference time-domain (FDTD) method and uni-axial anisotropic perfectly matched layer (UPML) technique, the entire wireless RF downlinks of BSA and LCX to tunnel space to train antenna are precisely modeled (so-called integrative modeling technique, IMT). When exciting the BSA and LCX separately, the field distributions of some cross-sections in a rectangular tunnel are presented. It can be found that the influence of the locomotive body and other tunnel environments is very significant. The field coverage on the locomotive roof plane where the train antennas mounted, seems more homogenous when the side-laying position of the BSA or LCX is much higher. Also, much smoother field coverage solution is achieved by choosing LCX for its characteristic of more homogenous electromagnetic wave radiation.

• Asian Pacific Journal of Cancer Prevention
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• 제14권7호
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• pp.4279-4282
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• 2013

Background: The activation and inactivation of receptor tyrosine kinases are tightly regulated to ensure faithful replication of cells. After having transduced extracellular growth activating signals, activated EGFR is subjected to downregulation either by clathrin mediated endocytosis or c-Cbl mediated proteasome degradation depending on the ligand concentration. c-Cbl is an ubiquitin ligase which requires a phosphorylated tyrosine residue at position 1045 in the cytoplasmic domain of EGFR to interact and add ubiquitin molecules. While activating mutations in exons 19 and 21 have been associated with the development of several cancers, the status of mutations at tyrosine 1045 coding exon 27 of EGFR remain to be investigated. Consistently, defective phosphorylation at 1045 has been associated with sustained phosphorylation of EGFR in non-small lung carcinomas. Hence in the present study we investigated the genetic status of the tyrosine 1045 coding site within exon 27 of EGFR gene to explore for possible occurrence of mutations in this region, especially since no studies have addressed this issue so far. Materials and Methods: Tumor chromosomal DNA isolated from thirty five surgically excised oral squamous cell carcinoma tissues was subjected to PCR amplification with intronic primers flanking the tyrosine 1045 coding exon 27 of EGFR gene. The PCR amplicons were subsequently subjected to direct sequencing to elucidate the mutation status. Results: Sequence analysis identified no mutations in the tyrosine 1045 codon of EGFR in any of the thirty five samples that were analyzed. Conclusions: The lack of identification of mutation in the tyrosine 1045 codon of EGFR suggests that mutations in this region may be relatively rare in oral squamous cell carcinomas. To the best of our knowledge, this study is the first to have explored the genetic status of exon 27 of EGFR in oral squamous cell carcinoma tissue samples.

• 대한전자공학회논문지TC
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• 제40권1호
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• pp.37-46
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• 2003

임의로 결선된 디지털 전송선로의 과도응답을 효율적인 노드분할 기법을 사용하여 분석하였다. 제시한 노드분할 기법은 전송선로를 분할하여 해석할 수 있도록 하므로서 연결선의 임의 위치에서의 과도파형을 쉽게 예측할 수 있다. 일반성을 보이기 위해 임의로 연결된 분산특성을 갖는 마이크로스트립 다도체 전송선로들을 예로 들어 분석하였다. 결합선로의 주파수의존성 등가 회로정수들은 스펙트럼 영역 기법(SDA)을 사용하여 도출하였다. 고속 마이크로스트립 결합선로 상에 인가되는 펄스의 펄스폭 변화가 누화에 미치는 영향도 동시에 검토하였다. 선로의 길이와 기판 유전율이 증가하면 누화 피크값이 단조롭게 증가한다는 기존의 결과와는 달리 펄스폭이 수 ps에 이르면 오히려 감소하는 특성을 볼 수 있었다. 제시한 노드분할 기법을 사용한 결과를 일반화된 S-행렬 기법을 사용한 결과와 비교하므로서 타당성을 보였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1997-1998
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• 2008

Pulse diagnosis is the one of the most important diagnostic process to traditional medical doctors. Although the pulse diagnosis position, Gwan is apart from Chon or Cheok by 10$\sim$20mm at most, traditional medical doctors applies different indent pressures and even they states different pulse images are felt at Chon, Gwan and Cheok. One the other hand, the education on pulse diagnosis behavior includes tantalizing problem caused by no tool for communication between trainer and trainee. On account of this situation, we tried to develop a system which can measure the hold-down pressure during a pulse diagnosis and compare the hold-down pressure profile of trainer and that of trainee. This system can be divided into three parts - pulse pressure sensing part, signal acquisition part and data storing part. A correction curve was generated by the relation between output voltages and standard weights. Using this system, 3 channel hold-down pressure profile of a oriental medical doctor were recorded three times. In the profile, three period were observed and all period included two process for searching the depth of pulsation and for classifying the pulse feeling into one or more of 28 pulse types. The maximum value of pulse profile was 1.3$kg{\cdot}f$ which was more than reported by previous chinese groups and the mean values of three channel ranged from 240$g{\cdot}f$ to 430$g{\cdot}f$. In frequency domain, each channel has some dominant frequency components - about 10Hz, 35Hz and 75Hz. In further study, we want to collect more profiles from lage number of oriental medicine doctors and hope to develop a measuring system which can measure the hold-down pressure on subject's skin directly.

• BMB Reports
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• 제34권5호
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• pp.402-407
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• 2001

Based on the currently proposed toxicity model for the different Bacillus thuringiensis Cry $\delta$-endotoxins, their pore-forming activity involves the insertion of the ${\alpha}4-{\alpha}5$ helical hairpin into the membrane of the target midgut epithelial cell. In this study, a number of polar or charged residues in helix 4 within domain I of the 65-kDa dipteranactive Cry11A toxin, Lys-123, Tyr-125, Asn-128, Ser-130, Gln-135, Arg-136, Gln-139 and Glu-141, were initially substituted with alanine by using PCR-based directed mutagenesis. All mutant toxins were expressed as cytoplasmic inclusions in Escherichia coli upon induction with IPTG. Similar to the wild-type protoxin inclusion, the solubility of each mutant inclusion in the carbonate buffer, pH 9.0, was relatively low When E. coli cells, expressing each of the mutant proteins, were tested for toxicity against Aedes aegypti mosquito-larvae, toxicity was completely abolished for the alanine substitution of arginine at position 136. However, mutations at the other positions still retained a high level of larvicidal activity Interestingly, further analysis of this critical arginine residue by specific mutagenesis showed that conversions of arginine-136 to aspartate, glutamine, or even to the most conserved residue lysine, also abolished the wild-type activity The results of this study revealed an important determinant in toxin function for the positively charged side chain of arginine-136 in helix 4 of the Cry11A toxin.

• 한국항행학회논문지
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• 제14권2호
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• pp.151-160
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• 2010

미래 지능형교통시스템에서 각 차량의 차선별 주행 정보를 관측 및 제어하는 기능은 반드시 선결되어야 할 요소 기술에 해당된다. 본 논문에서는 미래 지능형교통시스템 구현에 있어서 선결되어야 할 정밀측위 기반 주행차선 구분을 위하여 위성항법 수신기망 구성요소들을 설계하고, 실험을 통하여 제안된 방식에 의한 차선 구분의 가능성을 평가하였다. 설계된 수신기망 구성 요소는 기준국 서버, 방송기, 그리고 이동국 클라이언트로 구분되며 설계된 구성요소들은 추후 유연한 확장을 위하여 국제 표준 RTCM SC-104 version3.0 메시지 규격을 활용하는 특징을 가진다. 또한, 항공 및 해양 분야와는 달리 가시위성의 출몰이 빈번한 상황을 고려하여 이동체 클라이언트는 정밀 위치의 추출을 위하여 저가의 단일 주파수 수신기와 위치영역 위상평활화필터를 활용하도록 설계 하였다. 선 조사된 왕복 4차선 도로에 대한 주행 실험을 통하여 제안된 방식의 성능을 평가하였으며, 수평에서 20cm 이내의 측위 정확도를 보임을 확인 할 수 있었다.

• 대한의생명과학회지
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• 제11권2호
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• pp.135-141
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• 2005

A Jopock (Jpk), a trans-acting factor associating with the position-specific regulatory element of murine Hoxa-7, has shown to have a toxicity to both prokaryotic and eukaryotic cells when overexpressed. Since Jpk protein harbors a transmembrane domain and a putative endoplasmic reticulum (ER)-retention signal at the N-terminus, a subcellular localization of the protein was analyzed after fusing it into the green fluorescent protein (GFP): Both N-term (Jpk-EGFP) and C-term tagged-Jpk (EGFP-Jpk) showed to be localized in the ER when analyzed under the fluorescence microscopy after staining the cells with ER- and MitoTracker. Since ER stress triggers the ER-stress mediated apoptosis to eliminate the damaged cells, we analyzed the expression pattern of Jpk under ER-stress condition. When MCF7 cells were treated with the ER-stress inducer such as DTT and EGTA, the expression of Jpk was upregulated at the transcriptional level like that of Grp78, a molecular chaperone well known to be overexpressed under ER-stress condition. In the presence of high concentration of ER-sterss inducer (10 mM), about 70 (DTT) to $95\%$ (EGTA) of cells died stronly expressing ($10\~12$ fold) Jpk. Whereas at the low concentration ($0.001\~1.0\;mM$) of the inducer, the expression of Jpk was increased about 2.5 (EGTA) to 5 fold (DTT), which is rather similar to those of ER chaperone protein Grp78. These results altogether indicate that the ER-stress upregulated the expression of Jpk and the excess stress induces the ER-stress induced apoptosis and the concomitant expression of Jpk.