• Title/Summary/Keyword: Low noise

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Table-Based Fault Tolerant Routing Method for Voltage-Frequency-Island NoC (Voltage-Frequency-Island NoC를 위한 테이블 기반의 고장 감내 라우팅 기법)

  • Yoon, Sung Jae;Li, Chang-Lin;Kim, Yong Seok;Han, Tae Hee
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.8
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    • pp.66-75
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    • 2016
  • Due to aggressive scaling of device sizes and reduced noise margins, physical defects caused by aging and process variation are continuously increasing. Additionally, with scaling limitation of metal wire and the increasing of communication volume, fault tolerant method in manycore network-on-chip (NoC) has been actively researched. However, there are few researches investigating reliability in NoC with voltage-frequency-island (VFI) regime. In this paper, we propose a table-based routing technique that can communicate, even if link failures occur in the VFI NoC. The output port is alternatively selected between best and the detour routing path in order to improve reliability with minimized hardware cost. Experimental results show that the proposed method achieves full coverage within 1% faulty links. Compared to $d^2$-LBDR that also considers a routing method for searching a detour path in real time, the proposed method, on average, produces 0.8% savings in execution time and 15.9% savings in energy consumption.

Digital Logic Extraction from QCA Designs (QCA 설계에서 디지털 논리 자동 추출)

  • Oh, Youn-Bo;Kim, Kyo-Sun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.1
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    • pp.107-116
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    • 2009
  • Quantum-dot Cellular Automata (QCA) is one of the most promising next generation nanoelectronic devices which will inherit the throne of CMOS which is the domineering implementation technology for large scale low power digital systems. In late 1990s, the basic operations of the QCA cell were already demonstrated on a hardware implementation. Also, design tools and simulators were developed. Nevertheless, its design technology is not quite ready for ultra large scale designs. This paper proposes a new approach which enables the QCA designs to inherit the verification methodologies and tools of CMOS designs, as well. First, a set of disciplinary rules strictly restrict the cell arrangement not to deviate from the predefined structures but to guarantee the deterministic digital behaviors is proposed. After the gate and interconnect structures of. the QCA design are identified, the signal integrity requirements including the input path balancing of majority gates, and the prevention of the noise amplification are checked. And then the digital logic is extracted and stored in the OpenAccess common engineering database which provides a connection to a large pool of CMOS design verification tools. Towards validating the proposed approach, we designed a 2-bit adder, a bit-serial adder, and an ALU bit-slice. For each design, the digital logic is extracted, translated into the Verilog net list, and then simulated using a commercial software.

The Performance Comparison of the MMA and SCA Algorithm for Self Adaptive Equalization (자기 적응 등화를 위한 MMA와 SCA 알고리즘의 성능 비교)

  • Lim, Seung-Gag
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.2
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    • pp.159-165
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    • 2012
  • This paper deals with the performance comparison of adaptive equalization algorithm, MMA and SCA, that is used for the minimization of the distortion and noise effect in the communication channel.. The transmitting signal will be distorted and received due to the nonlinearties of magnitude and phase transfer characteristics of communication channel, the compensation of it by using the self adaptive equalizer. The constant modulus has important metric in the self adaptive equalizer, the MMA uses the 2nd and 4th high order statistics of transmitting signal, the SCA uses the 2nd order statistics of transmitting signal only in order to the calculation of it. We compared to the compensation performance of the MMA and SCA by the computer simulation that are possible to the compensation of the two kinds of transfer characteristics at same times by the relatively simple arithmatic operation. We used to the recovered constellation, residual isi and MSE, SER that are the essential index for the comparison of the adaptive equalizer. The result of performance comparison of algorithms, the MMA which uses the high order statistics of transmitting signal has good performance in the MSE and SER compared to the SCA which is using the low order statistics. But in the recovered costellation and residual isi, the SCA has a good than the MMA.

Accuracy Evaluation of the FinFET RC Compact Parasitic Models through LNA Design (LNA 설계를 통한 FinFET의 RC 기생 압축 모델 정확도 검증)

  • Jeong, SeungIk;Kim, SoYoung
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.11
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    • pp.25-31
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    • 2016
  • Parasitic capacitance and resistance of FinFET transistors are the important components that determine the frequency performance of the circuit. Therefore, the researchers in our group developed more accurate parasitic capacitance and resistance for FinFETs than BSIM-CMG. To verify the RF performance, proposed model was applied to design an LNA that has $S_{21}$ more than 10dB and center frequency more than 60GHz using HSPICE. To verify the accuracy of the proposed model, mixed-mode capability of 3D TCAD simulator Sentaurus was used. $S_{21}$ of LNA was chosen as a reference to estimate the error. $S_{21}$ of proposed model showed 87.5% accuracy compared to that of Sentaurus in 10GHz~100GHz frequency range. The $S_{21}$ accuracy of BSIM-CMG model was 56.5%, so by using the proposed model, the accuracy of the circuit simulator improved by 31%. This results validates the accuracy of the proposed model in RF domain and show that the accuracies of the parasitic capacitance and resistance are critical in accurately predicting the LNA performance.

The Clinical Usefulness Evaluation of Normal Saline Injection in Coronary Artery Computed Tomography Angiography(Coronary CTA) (관상동맥 전산화단층촬영 조영검사에서 생리식염수 투여를 통한 임상 유용성 평가)

  • Jung, Kang-Kyo;Lee, Mi-Hwa;Cho, Pyong-Kon
    • Journal of radiological science and technology
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    • v.37 no.4
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    • pp.307-313
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    • 2014
  • The purpose of this study is that in coronary artery angiography computed tomography (coronary CTA), to gain high quality of image and to use low dose radiation by administrating normal saline and converting the mode of scanning heart rate (HR) characteristics before infusing contrast media. All patients data (total specimens: 200, male: 108, female: 92) were measured by using appropriate mode of scanning the heart rate (HR) after injection of saline. in addition we measured radiation dose (CTDIvol, effective dose) in all examinations. CT number and noise, and blurring of coronary artery (proximal RCA, middle RCA, proximal LCA) were measured and compared. The result of this study after injection of saline, mean heart rate was decreased about $4.8{\pm}0.3bpm$ (beats per minute). 33 patients (13%) got converting scan mode due to reducing heart rate (HR). In prospective gating mode, radiation dose were measured less $6.0{\pm}1.0mSv$ (54.1%) than retrospective gating mode. Also showed a significant difference in heart rate decrease in image evaluation.

An Analysis on the Determining Factors of Satisfaction for Environmental Improvement of Trails around Recreation Park - Focused on Suseong Recreation Park in Daegu - (유원지 주변 산책로의 환경개선을 위한 이용만족도 결정요인 분석 - 대구광역시 수성유원지를 대상으로 -)

  • Kim, Dong-Seok;Lee, Woo-Sung;Jung, Sung-Gwan
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.5
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    • pp.28-39
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    • 2015
  • The purpose of this study is to analyze users' behavior and facility satisfaction and to suggest the practical solution plans for environmental improvement of trails in Suseong recreation park in Daegu. Therefore, satisfaction factor analysis on trails was carried out based on a field and questionnaire survey in Suseong recreation park. First, from users' behavior, 48% of users visited Suseong recreation park for walking. The greatest response to number of visits was once or twice a week, and average use time per visit was 80.4 minutes. In terms of trails, the greater responses to the number of visits were once(38.1%) or more than 5 times(23.8%), and average use time was 45.4 minutes. According to the results from the analysis of facility satisfaction, management condition, length, slope, and adjacent natural landscape of trails were evaluated at a satisfaction rate higher than 3.4 points. However, water pollution, and number of exits and parking lots were analyzed at a low rate of 2.75 and 2.78 points, respectively. In terms of analyzing determining factors of facility satisfaction for trails, use of facilities, walking convenience, surrounding landscapes, amenities, and noise had a significantly positive effect on satisfaction. In particular, walking convenience was the highest effect factor; its standardized coefficient was 0.533. The findings from this study can contribute to the improvement of the physical environment for trails of Suseong recreation park and provide basic data for plan and maintenance of similar waterside trails.

The Direction of School Forest Plans Considering Satisfaction of Elementary Students (초등학생들의 만족 유형을 고려한 학교숲 조성방향)

  • Jang, Cheol-Kyu;Jung, Sung-Gwan;Jang, Jung-Sun;Kim, Kyung-Tae;Oh, Jeong-Hak
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.4
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    • pp.42-51
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    • 2009
  • The purpose of this study is to analyze the actual conditions of school forests using a field survey and to establish the construction methods considering satisfactions of students using a satisfaction inquiry. The results of the this study are as follows: many trees had the highest score whereas reduction of noise had the lowest score in the satisfaction analysis of 15 items. According to the result of the factor analysis, 3 factors were determined to be most important from 15 items of satisfaction, and they were Environmental Function, Educational and Recreational Function, and Ecological Function. Next, students were classified into 4 groups using factor scores by cluster analysis. Group I had very high effectiveness in the Environmental Function and group II had low effectiveness in all factors. Also, group III had very high effectiveness in the Educational and Recreational Function, and group IV had very high effectiveness in the Ecological Function. According to the analysis results of the character of the school on students' group, the satisfaction of school forests was high when students of group II were few and other group's students were similar. As these schools use a lot of parts of the playground for green space, there was more school forest than at other schools. Also, students of these schools were experiencing the school forest through educational programs. Therefore, school forests should be constructed by increasing the green area and considering the satisfaction factors of students through various experience and education programs and by the way utilizing wide space than adding the tree in the garden.

A Study on the Resistance Against Environmental Loading of the Fine-Size Exposed Aggregate Portland Cement Concrete Pavements (소입경 골재노출콘크리트포장의 환경하중 저항성에 대한 연구)

  • Chon, Beom-Jun;Lee, Seung-Woo;Chae, Sung-Wook;Bae, Jae-Min
    • International Journal of Highway Engineering
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    • v.11 no.2
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    • pp.99-109
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    • 2009
  • Fine-size exposed aggregate portland cement concrete pavements (FEACP) have surface texture of exposed aggregate by removing upper 2$\sim$3mm mortar of surface of which curing is delayed by using delay-setting agent. FEACPs have advantages of maintaining low-noise and adequate skid-resistance level during the performance period than general portland cement concrete pavements. It is necessary to ensure the durability environmental loading to prevent unexpected distress during the service life of FEACP. In the process of curing, volume change accompanied change in by moisture and temperature could be an important cause of crack in concrete to construct for successful FEACP, The use of chloride containing deicer may accelerate defects of concrete pavement, such as crack and scaling. This study aim to evaluate environmental loading resistance of FEACP, based on the estimation of shrinkage-crack-control-capability by moisture evaporation and scaling by deicer in freeze-thaw reaction.

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Evaluation of a signal segregation by FDBM (FDBM의 음원분리 성능평가)

  • Lee, Chai-Bong
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.12
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    • pp.1793-1802
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    • 2013
  • Various approaches for sound source segregation have been proposed. Among these approaches, frequency domain binaural model(FDBM) has the advantages of low computational load and effective howling cancellation. A binaural hearing assistance system based on FDBM has been proposed. This system can enhance desired signal based on the directivity information. Although FDBM has been evaluated in terms of signal-to-noise ratio (SNR) and coherence function, the evaluation results do not always agree with the human impressions. These evaluation methods provide physical measures, and do not take account of perceptual aspect of human being. Considering a binaural hearing assistance system as a one of major applications, the quality of segregated sound should keep level enough. In the paper, signal segregation performance by means of FDBM is evaluated by three objective methods, i.e., SNR, coherence and Perceptual Evaluation of Speech Quality(PESQ), to discuss the characteristic of FDBM on the sound source segregation performance. The simulation's evaluation results show that FDBM improves the quality of the left and right channel signals to an equivalent level. And the results suggest the possibility that PESQ provides a more useful measure than SNR and coherence in terms of the segregation performance of FDBM. The evaluation results by PESQ show the effects from segregation parameters and indicate appropriate parameters under the conditions. In the paper, signal segregation performance by means of FDBM is evaluated by three objective methods, i.e., SNR, coherence and PESQ, to discuss the characteristic of FDBM on the sound source segregation performance. The simulation's evaluation results show that FDBM improves the quality of the left and right channel signals to an equivalent level. And the results suggest the possibility that PESQ provides a more useful measure than SNR and coherence in terms of the segregation performance of FDBM. The evaluation results by PESQ show the effects from segregation parameters and indicate appropriate parameters under the conditions.

Analysis of Geomagnetic Field measured from KOMPSAT-1 Three-Axis Magnetometer (다목적위성 삼축자력계로부터 관측된 지구자기장에 관한 연구)

  • 김정우;황종선;김성용;이선호;민경덕;김형래
    • Economic and Environmental Geology
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    • v.37 no.4
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    • pp.401-411
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    • 2004
  • The Earth's total magnetic field was calculated from on board TAM(Three-Axis Magnetometer) observations of KOMPSAT-1 satellite between June 19th and 21st, 2000. The TAM's telemetry data were transformed from ECI(Earth-Centered Inertial Frame) to ECEF(Earth-Centered Earth-Fixed Frame) and then to spherical coordination. Self-induced field from the satellite bus were removed by the symmetric nature of the magnetic field. The 2-D wavenumber correlation filtering and quadrant-swapping method were applied to eliminate the dynamic components and track-line noise. To test the validity of the TAM's geomagnetic field, ${\phi}$rsted satellite's magnetic model and IGRF2000 model were used for statistical comparison. The correlation coefficients between KOMPSAT-1/${\phi}$rsted and KOMPSAT-1/IGRF2000 models are 0.97 and 0.96, respectively. The global spherical harmonic coeffi-cient was then calculated from the KOMPSAT-1 data degree and order of up to 19 and compared with those from IGRF2000, $\phi$rsted, and CHAMP models. The KOMPSAT-1 model was found to be stable to degree & order of up to 5 and it can give new information for the low frequency components of the global geomagtic field.