• Title/Summary/Keyword: SIR

Search Result 496, Processing Time 0.033 seconds

SIR CPW bandpass filter with folded feed structure for suppressing spurious harmonics (고조파 억압을 위한 피드 구조를 가진 SIR CPW 대역통과 여파기)

  • Park, Kwang-Sun;Shin, Chull-Chai
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
    • /
    • 2003.11a
    • /
    • pp.265-268
    • /
    • 2003
  • In this paper, we introduce the SIR typed bandpass filters in CPW structures for shifting spurious harmonic frequency into higher frequency band. And we proposed the effective feed structures for suppressing spurious frequency in the SIR typed CPW bandpass filters. The designed folded feed structures have lowpass filtering characteristic. They are very effective feed types in the CPW bandpass filters for suppressing harmonics. The measured results of the CPW bandpass filter with folded feed line shows that it has suppressed and wide out-of-band up to 5.8fo.

  • PDF

Role of Chromatin Structure in HMRE Mediated Transcriptional Repression of the HSP82 Heat Shock Gene

  • Lee, See-Woo;Gross, David S.
    • Journal of Microbiology
    • /
    • v.34 no.1
    • /
    • pp.40-48
    • /
    • 1996
  • We have examined the chromatin structure of the HMRE/HSP82 and HMRa/HSP82 allels using three complementary approaches : DNase I chromating footprinting, micrococcal nuclease (MNase) nucleosome-protected ladder assay, and an in vivo E. coli dam methylase accessibility assay. The footprinting results indicate that the promoter and silencer sequences are assembled into nucleoprotein complexes which exhibit no detectable change in structure, despite a 70-fold range in expression levels. In addition, the promoter region of the HMRa/HSP82 allele is cleaved randomly by MNase in all cases, indicating the absence of anonical nucleosomes over this region irrespective of SIR4 or heat-shock. Finally, no discernible difference in the accessibility of the HMRE/HSP82 locus to dam methylase in SIR4 vs. sir4 cells was seenm which again suggests that the chromatin structure of HMRE/HSP82 allele is identical regardless of SIR4. Altogether, our results indicate that in contrast to other observations of the silent mating-type loci, no discernible structural alteration is detected at either HMR/HSP82 allele regardless of SIR genetic background or transcriptional state of the gene.

  • PDF

Surface Characteristics of Silicone Rubber Processes by Corona Discharges (코로나 방전에 따른 실리콘 고무의 표면 특성)

  • 한동희;조한구;강동필;민경은
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.15 no.2
    • /
    • pp.133-140
    • /
    • 2002
  • This paper aims to investigate the effect of silicone oils as processing agent affecting the loss and recovery of hydrophobicity. The recovery of hydrophobicity was evaluated by the measurement of the surface electrical resistivity and the contact angle on the SIR surface. Two kinds of silicone oils (1 and 2) having different molecular weight were selected under a consideration of hydrophobicity and processability. SIR specimens were exposed to corona discharges in air and the specimens were analyzed with contact angle and surface resistance measurements. It was observed that the contact angle and the surface resistivity of SIR increase gradually with testing time. The fast recovery of hydrophobicity of SIR, expressed by the increment of contact angle and surface resistivity, was showed in SIR2 containing silicone oil 2.

Effects of Particle Size of $Al(OH)_3$ on the Electrical Properties of Silicone Rubber ($Al(OH)_3$의 입자크기에 따른 실리콘 고무의 전기적 특성 연구)

  • Park, Hoy-Yul;Kang, Dong-Pil;Ahn, Myeong-Sang;Na, Moon-Kyong
    • Proceedings of the KIEE Conference
    • /
    • 2005.07c
    • /
    • pp.1936-1938
    • /
    • 2005
  • $Al(OH)_3$ is added to the silicone rubber for improvement of its resistance against surface discharge. In this paper, four kinds of $Al(OH)_3$ were added to the SIR during compounding. SIR was deteriorated by a corona treatment. Hydrophobicity recovery rate after corona treatment and arc resistance of SIR were investigated. Hydrophobicity recovery rate of SIR was evaluated by the measurement of contact angle. Arc resistance was evaluated by measuring weight loss of SIR after arc resistance test.

  • PDF

An Empirical Study on Dimension Reduction

  • Suh, Changhee;Lee, Hakbae
    • Journal of the Korean Data Analysis Society
    • /
    • v.20 no.6
    • /
    • pp.2733-2746
    • /
    • 2018
  • The two inverse regression estimation methods, SIR and SAVE to estimate the central space are computationally easy and are widely used. However, SIR and SAVE may have poor performance in finite samples and need strong assumptions (linearity and/or constant covariance conditions) on predictors. The two non-parametric estimation methods, MAVE and dMAVE have much better performance for finite samples than SIR and SAVE. MAVE and dMAVE need no strong requirements on predictors or on the response variable. MAVE is focused on estimating the central mean subspace, but dMAVE is to estimate the central space. This paper explores and compares four methods to explain the dimension reduction. Each algorithm of these four methods is reviewed. Empirical study for simulated data shows that MAVE and dMAVE has relatively better performance than SIR and SAVE, regardless of not only different models but also different distributional assumptions of predictors. However, real data example with the binary response demonstrates that SAVE is better than other methods.

An Ant-based Routing Method using Enhanced Path Maintenance for MANETs (MANET에서 향상된 경로 관리를 사용한 개미 기반 라우팅 방안)

  • Woo, Mi-Ae
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.9B
    • /
    • pp.1281-1286
    • /
    • 2010
  • Ant-based routing methods belong to a class of ant colony optimization algorithms which apply the behavior of ants in nature to routing mechanism. Since the topology of mobile ad-hoc network(MANET) changes dynamically, it is needed to establish paths based on the local information. Subsequently, it is known that routing in MANET is one of applications of ant colony optimization. In this paper, we propose a routing method, namely EPMAR, which enhances SIR in terms of route selection method and the process upon link failure. The performance of the proposed method is compared with those of AntHocNet and SIR. Based on he analysis, it is proved that the proposed method provided higher packet delivery ratio and less critical link failure than AntHocNet and SIR.

Pilot Hopping Scheme for Massive Antenna Systems in Cellular Networks (극다중 안테나 셀룰러 시스템을 위한 파일럿 도약 기법)

  • Kim, Seong Hwan;Ban, Tae-Won;Lee, Wongsup;Ryu, Jong Yeol
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.21 no.4
    • /
    • pp.718-723
    • /
    • 2017
  • We propose a pilot hopping scheme that improves the limited system capacity due to pilot contamination in multi-cell environment with large-scale antenna arrays at a base station, assuming the infinite number of antennas. In the conventional fixed pilot scheme, each user obtains the same signal-to-interference ratio (SIR) over a long period of time. Therefore, a user with strong interference has continuously low SIR which degrades its service quality. In the proposed pilot hopping scheme, different pilot signals are used for each time slot, and different amounts of interference are received every time. When such a pilot hopping technique is applied, the SIR fluctuates at every time slot. When the Hybrid Automatic Repeat & reQuest (HARQ) technique is applied in such a channel, the outage probability and transmission rate are improved. We show that there is the performance gain of the proposed scheme over the conventional scheme through computer simulations.

Compact UWB Band-pass Filter with Open-Stub Using Impedance Mismatching and SIR (임피던스 부정합 및 SIR을 적용한 개방형 광대역 소형 스터브 대역통과 여파기)

  • Lee, Won-Seok;Yoon, Ki-Cheol
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.51 no.6
    • /
    • pp.282-289
    • /
    • 2014
  • In this paper, the UWB (Ultra Wide Band) band-pass filter (BPF) with compact-size using impedance mismatching in transmission line and SIR (Stepped Impedance Resonator) instead of open stubs is presented. The proposed BPF have 103 % of bandwidth and 11.2 GHz of center frequency, respectively. In additional, the operation frequencies of the suggested BPF are 4.8 GHz to 16 GHz. In this structure, the length of the transmission line is reduced to half compared with the original one by impedance mismatching technique with low frequency band (sub harmonics) and harmonic components. Also, the open stub can be used for SIR due to reduced size. Experimental results show that the insertion and return losses are 0.35 dB and 15.1 dB, respectively and the filter size is $8.92{\times}10.6mm^2$. The proposed BPF is in good agreement.

Lack of any Association of the CTLA-4 +49 G/A Polymorphism with Breast Cancer Risk in a North Indian Population

  • Minhas, Sachin;Bhalla, Sunita;Shokeen, Yogender;Jauhri, Mayank;Saxena, Renu;Verma, Ishwar Chandra;Aggarwal, Shyam
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.5
    • /
    • pp.2035-2038
    • /
    • 2014
  • Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is an important protein involved in the regulation of the immune system. The +49 G/A polymorphism is the only genetic variation in the CTLA-4 gene that causes an amino acid change in the resulting protein. It is therefore the most extensively studied polymorphism among all CTLA-4 genetic variants and contributions to increasing the likelihood of developing cancer are well known in various populations, especially Asians. However, there have hiterto been no data with respect to the effect of this polymorphism on breast cancer susceptibility in our North Indian population. We therefore assayed genomic DNA of 250 breast cancer subjects and an equal number of age-, sex- and ethnicity-matched healthy controls for the CTLA-4 +49 G/A polymorphism but no significant differences in either the gene or allele frequency were found. Thus the CTLA-4 +49 G/A polymorphism may be associated with breast cancer in other Asians, but it appears to have no such effect in North Indians. The study also highlights the importance of conducting genetic association studies in different ethnic populations.

A Study on Interference Cancelling Receiver with Adaptive Blind CMA Array (적응 블라인드 CMA 어레이를 이용한 간섭 제거 수신기에 관한 연구)

  • 우대호;변윤식
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.27 no.4A
    • /
    • pp.330-335
    • /
    • 2002
  • In the direct sequence code division multiple access system, the problem of multiple access interference due to multiple access is generated. A interference cancelling receiver is used to solve this problem. The conventional interference cancelling receiver is structure of successive interference canceller using antenna array. In this structure, the difference of between method I and method II depends on updating weight vector. In this paper, the adaptive blind CMA array interference cancelling receiver using cost function of constant modulus algorithms is proposed to update weight vector at conventional structure. The simulation compared the proposed interference cancelling receiver with two conventional interference cancelling receivers by signal to interference ratio and bit error rate curve under additive white Gaussian noise environment. The simulation results show that the proposed receiver has about the gain of SIR of 1.5[dB] more than method I which is conventional receiver at SIR curve, and about the gain of SIR of 0.5(dB) more than method II. In BER curve, the proposed IC receiver about the gain of SNR of 2[dB] more than method I and about the gain of SNR of 0.5[dB] more than method If, Thus, the proposed interference cancelling receiver has the higher performance than conventional interference cancelling receivers.