• Title/Summary/Keyword: EAM

Search Result 117, Processing Time 0.021 seconds

Nonlinearity Compensation of Electroabsorption Modulator by using Semiconductor Optical Amplifier (반도체 광증폭기를 이용한 전계흡수 광변조기 비선형성 보상)

  • Lee, Chang-Hyeon;Son, Seong-Il;Han, Sang-Guk
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.37 no.5
    • /
    • pp.23-30
    • /
    • 2000
  • To compensate the nonlinearity of electroabsorption modulator(EAM) resulting from its near exponential transfer function, a semiconductor optical amplifier(SOA) that has a log transfer function is used. Since the transfer function of SOA is inverse to that of EAM, the intermodulation distortion(IMD) of EAM can be reduced by cascading SOA to EAM. Also, the RF gain can be increased by the optical gain of SOA. For these reasons, spurious free dynamic range(SFDR) of EAM is enhanced by connecting SOA to EAM in series and operating in gain salutation region. To improve the nonlinearity compensation of EAM, the increased gain of SOA is required and the slope of gain saturation, the ratio of gain to input SOA power, needs to be steep. However, signal spontaneous beat noise that is the dominant system noise increases in proportion to the gain such that the SFDR of EAM is reduced. The higher the gain of SOA is, the more ASE is increased. Thus the noise level of system is increased and the following SFDR of EAM is decreased. The slope of gain saturation region and ASE of have trade-off relation and the optimization is achieved at 8㏈ optical gain. 9㏈ enhancement of SFDR of EAM is obtained. This scheme is easy to embody the linear EAM and the integration with three components (DFB-LD, EAM and SOA) offers many merits, such as low insertion loss, low chirping and low polarization sensitivity.

  • PDF

Induction of Apoptosis by Ethyl Acetate Fraction of Astragalus membranaceus in Human Non-small Cell Lung Cancer Cells - Apoptosis Induction by Astragalus membranaceus -

  • Park, Hyun-Ji;Park, Shin-Hyung
    • Journal of Pharmacopuncture
    • /
    • v.21 no.4
    • /
    • pp.268-276
    • /
    • 2018
  • Objectives: The purpose of this study is to investigate the anti-cancer effects of different fractions of Astragalus membranaceus (AM) in human non-small cell lung cancer (NSCLC) cells. Methods: We isolated hexane, ethyl acetate, and butanol fractions from crude ethanol extract of AM. The cell death was examined by MTT assay and trypan blue exclusion assay. Apoptosis was detected by DAPI staining, annexin V-PI double staining and cell cycle analysis. The expression of apoptosis-related proteins and mitogen-activated protein kinases (MAPKs) was examined by western blot. Results: Among various fractions of AM, the ethyl acetate fraction of AM (EAM) showed the strongest cytotoxic effect in NSCLC cells. EAM reduced the cell proliferation in a time- and dose-dependent manner in NSCLC cells. In addition, EAM induced the chromatin condensation, and increased the population of sub-G1 phase and annexin V-positive cells in a time-dependent manner, indicating that EAM induced apoptosis in NSCLC cells. Consistently, EAM enhanced the expression of cleaved caspase-8 and -9, and induced the accumulation of cleaved- poly (ADP-ribose) polymerase (PARP). Among MAPK proteins, only ERK was dephosphorylated by EAM, suggesting that ERK might be related with EAM-induced apoptosis. Conclusion: Our results clearly demonstrate that EAM exhibited anti-cancer effects in NSCLC cells by induction of apoptosis. We provide a valuable evidence which suggests that AM could be a desirable therapeutic option for treatment of NSCLC.

Rheological Properties of Ethylene-Propylene Rubber Modified Nylon-6 (EP 고무로 개질한 Nylon-6의 유변학적 성질)

  • Haw, Jung-Rim;Lee, Sung;Kim, Byeong-Cheol;Lee, Dai-Soo
    • The Korean Journal of Rheology
    • /
    • v.5 no.2
    • /
    • pp.144-148
    • /
    • 1993
  • Nylon-6의 내충격성을 개선하기 위한 개질제로써 에틸렌-프로필렌 고무(EPR)와 에 틸렌-아크릴 에스터-무수말레산 공중합체(EAM)를 첨가한 nylon-6/EPR/EAM 블렌드 시스 템의 유변학적 특성을 24$0^{\circ}C$에서 조사하였다. 개질제중 EAM의 점도는 조성물 가운데 가장 낮음에도 불구하고 첨가량을 증가함에 따라 블렌드의 점도는 증가하였다. 또한 EPR(I)의 점 도가 EPR(II)의 점도보다 낮지만 EAM 함량이 증가함에 따라 nylon-6/EPR(I)/EAM의 점도 는 nylon-6/EPR(II)/EAM의 점도보다 높아지는 현상이 관찰되었다. 이러한 특성을 분산상의 morphology 변화와 전단력하에서 변형이 어려워지기 때문인 것으로 해석하였다.

  • PDF

A Study of the interoperability of XACML and PMI to enhance the security on EAM system (EAM시스템 보안을 위한 XACML과 PMI 상호운용에 관한 연구)

  • 박제원;정성우;이남용
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2004.10a
    • /
    • pp.400-402
    • /
    • 2004
  • EAM(Enterprise Access Management)은 SSO(Single Sign On)와 사용자 역할기반의 세분화된 접근관리를 제공하는 적극적 시스템 인증, 제어관리 솔루션으로 EAM 도입을 위해서는 중요한 자원들의 안전한 보관 관리가 필수적이다. 이를 위해 각 기업이나 그룹에서는 XML을 기반으로 한 여러 보안기술을 도입하고 있지만 현재 XML 정보 보안 기술을 중심으로 한 EAM시스템의 구현은 그 기반이 미미한 실정이며 표준에 따른 시스템의 고려도 미약한 실정이다. 특히 XML 정보보호기술과 기존 보안기술인 공개키 기반구조(Public Hey infrastructure, PKI), 권한관리구조 PMI(Privilege Management infrastructure)등과 같은 인증기술과의 상호연동기술에 관한 연구가 부족한 상태이다 이에 본 논문은 표준 XML 정보 보호기술 중 대표적인 기술인 XACML(extensible Access Control Markup Language)과 PMI를 연동한 안전한 EAM 통합 접근 시스템 구축 방안에 대친 연구하였다.

  • PDF

A Study on Mechanical Characteristics of Fiber Modified Emulsified Asphalt Mixture as Environmentally-Friend Paving Material (섬유보강 친환경 상온아스팔트 혼합물의 역학적 특성에 관한 연구)

  • Rhee Suk-Keun;Park Kyung-Won
    • International Journal of Highway Engineering
    • /
    • v.8 no.2 s.28
    • /
    • pp.23-30
    • /
    • 2006
  • Emulsified Asphalt Mixture(EAM) is more environmentally-friendly and cost-effective than typical Hot Mix Asphalt (HMA) because EAM does not produce carcinogenic substances, e.g., naphtha, kerosene, during the both of manufacturing and roadway construction process. Also, it does not require heating the aggregates and asphalt binder. However, EAM has some disadvantages. Generally EAM has a less load bearing capacity and more moisture susceptibility than conventional HMA. The study evaluated a Fiber modified EAM (FEAM) to increase load bearing capacity and to decrease moisture susceptibility of EAM. Modified Marshall mix design was developed to find Optimum Emulsion Contents (OEC), Optimum Water Contents (OWC), and Optimum Fiber Contents (OFC). A series of test were performed on the fabricated specimen with OBC, OWC, and OFC. Tests include Marshall Stability, Indirect Tensile Strength, and Resilient modulus test. Comparison analyses were performed among EAM, Fiber modified EAM (FEAM), and typical HMA to verify the applicability of EAM and FEAM in the field. Test results indicated that both of EAM and FEAM have an enough capability to resist medium traffic volume based on the Marshall mix design criteria. Also the study found that fiber modification is effective to increase the load bearing capacity and moisture damage resistance of EAM.

  • PDF

Reactive Oxygen Species (ROS) Generation Contributes to the Synergistic Anticancer Effect of Astragalus Membranaceus and Adenophora Triphylla Var. Japonica in H1299 Human Lung Carcinoma Cells (H1299 인체폐암세포주에서 활성산소종 생성에 의한 황기와 사삼의 항암 시너지 작용)

  • Min, Tae Rin;Park, Hyun Ji;Park, Shin Hyung
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.32 no.3
    • /
    • pp.157-164
    • /
    • 2018
  • This study was designed to investigate the mechanism of the synergistic anticancer effect of Astragalus membranaceus (AM) and Adenophora triphylla var. japonica (AT) in H1299 human lung carcinoma cells. A combined treatment of ethanol extract of AM (EAM) and AT (EAT) explosively increased the reactive oxygen species (ROS) generation in H1299 cells compared to the single treatment of each of them. Co-treatment of N-acetyl-L-cysteine (NAC) with EAM and EAT markedly enhanced the cell viability and suppressed apoptosis in H1299 cells, suggesting that ROS generation contributed to the anticancer effect of EAM and EAT. Interestingly, the combined treatment of EAM and EAT down-regulated p-AKT in H1299 cells, which was abrogated by NAC treatment. These results clearly indicated that ROS generation mediated the inactivation of AKT. Co-treatment of LY294002 with EAM and EAT significantly reduced the cell viability at a concentration which EAM and EAT didn't show any cytotoxicity. In addition, the recovery of cell viability by co-treatment of NAC with EAM and EAT was quite reversed by LY294002 treatment, which confirmed that the inactivation of AKT played a pivotal role in ROS-mediated apoptosis. Taken together, our results demonstrated that the synergistic anticancer effect of EAM and EAT was mediated by ROS generation and inactivation of AKT. We provide a valuable preclinical data for the development of more effective combination of AM and AT to treat lung cancer.

Numerical Study on Hydrogen Absorption and Expansion Behavior on Palladium (팔라듐에 관한 수소저장과 팽창거동에 관한 수치해석)

  • Kim, S.W.;Hwang, C.M.;Jang, T.I.;Jung, Y.G.
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.18 no.3
    • /
    • pp.256-264
    • /
    • 2007
  • In order to calculate the relation between the hydrogen and the hydrogen absorption metals in the atomic level, Embedded Atom Method(EAM) is recommended. In this study, we had constructed the EAM programs from constitutive formulas and parameters of the hydrogen and palladium for the purpose of predicting the expansion behavior on hydrogen absorbing in the geometric shape of hydrogen absorption metals, as palladium bars and plates. And the EAM analyses data were compared with the experiment data by using electrochemical method. As results, it is note that the expansion rate in thickness of the palladium plate model by EAM analyses is about 4 times larger than width and length, be similar to experiment results. Also, in the microscopic and macroscopic level the expansion behavior through EAM analyses show good agreement with experiment data.

Elliptical Clustering with Incremental Growth and its Application to Skin Color Region Segmentation (점증적으로 증가하는 타원형 군집화 : 피부색 영역 검출에의 적용)

  • Lee Kyoung-Mi
    • Journal of KIISE:Software and Applications
    • /
    • v.31 no.9
    • /
    • pp.1161-1170
    • /
    • 2004
  • This paper proposes to segment skin color areas using a clustering algorithm. Most of previously proposed clustering algorithms have some difficulties, since they generally detect hyperspherical clusters, run in a batch mode, and predefine a number of clusters. In this paper, we use a well-known elliptical clustering algorithm, an EM algorithm, and modify it to learn on-line and find automatically the number of clusters, called to an EAM algorithm. The effectiveness of the EAM algorithm is demonstrated on a task of skin color region segmentation. Experimental results present the EAM algorithm automatically finds a right number of clusters in a given image without any information on the number. Comparing with the EM algorithm, we achieved better segmentation results with the EAM algorithm. Successful results were achieved to detect and segment skin color regions using a conditional probability on a region. Also, we applied to classify images with persons and got good classification results.

Novel Model for Nonlinearity of Traveling-Wave Electroabsorption Modulator according to Microwave Characteristics (마이크로파 특성에 따른 진행파형 전계흡수 변조기의 비선형 모델)

  • 윤영설;이정훈;최영완
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.40 no.8
    • /
    • pp.580-587
    • /
    • 2003
  • In this paper, we introduce a novel model to analyze the linearity of a TW-EAM (traveling-wave electroabsorption modulator). The device length, microwave loss (ML), and internal reflection (IR) due to impedance mismatch have effect on the linearity of a TW-EAM. The longer devices have characteristics of lower biases with minimum IMDS (intermodulation distortions). ML decreases the output power as well as the IMD value. Internal reflection has different nonlinear characteristics according to the wavelength of the input frequency and the device length. There is little change in SFDR (spurious-free dynamic range) due to ML or IR. As a result, for a 50 GHz band RF-optical communication system, a 0.8 mm-long TW-EAM with the lowest ML would have better properties by using n, which is caused by impedance, mismatch at the output port.

Positional symmetry of porion and external auditory meatus in facial asymmetry

  • Choi, Ji Wook;Jung, Seo Yeon;Kim, Hak-Jin;Lee, Sang-Hwy
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.37
    • /
    • pp.33.1-33.9
    • /
    • 2015
  • Background: The porion (Po) is used to construct the Frankfort horizontal (FH) plane for cephalometrics, and the external auditory meatus (EAM) is to transfer and mount the dental model with facebow. The classical assumption is that EAM represents Po by the parallel positioning. However, we are sometimes questioning about the possible positional disparity between Po and EAM, when the occlusal cant or facial midline is different from our clinical understandings. The purpose of this study was to evaluate the positional parallelism of Po and EAM in facial asymmetries, and also to investigate their relationship with the maxillary occlusal cant. Methods: The 67 subjects were classified into three groups. Group I had normal subjects with facial symmetry ($1.05{\pm}0.52mm$ of average chin deviation) with minimal occlusal cant (<1.5 mm). Asymmetry group II-A had no maxillary occlusal cant (average $0.60{\pm}0.36$), while asymmetry group II-B had occlusal cant (average $3.72{\pm}1.47$). The distances of bilateral Po, EAM, and mesiobuccal cusp tips of the maxillary first molars (Mx) from the horizontal orbital plane (Orb) and the coronal plane were measured on the three-dimensional computed tomographic images. Their right and left side distance discrepancies were calculated and statistically compared. Results: EAM was located 10.3 mm below and 2.3 mm anterior to Po in group I. The vertical distances from Po to EAM of both sides were significantly different in group II-B (p=0.001), while other groups were not. Interside discrepancy of the vertical distances from EAM to Mx in group II-B also showed the significant differences, as compared with those from Po to Mx and from Orb to Mx. Conclusions: The subjects with facial asymmetry and prominent maxillary occlusal cant tend to have the symmetric position of Po but asymmetric EAM. Some caution or other measures will be helpful for them to be used during the clinical procedures.