230 results on '"Yang, Yu"'
Search Results
52. A Time-Modulated Array With Digitally Preprocessed Rectangular Pulses for Wireless Power Transmission.
- Author
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Yang, Yu-Qian, Wang, Hao, and Guo, Yong-Xin
- Subjects
- *
WIRELESS power transmission , *PARTICIPATORY design , *SIGNAL processing - Abstract
A cooperative design of the advanced time-modulated array (TMA) and the retrodirective (RD) array is introduced to act as a transmitting array for multiuser wireless power transmission (WPT) applications. The conventional rectangular-pulse based TMA is lack of harmonic beamforming flexibility limited by its frequency spectral properties. By preprocessing the rectangular pulses with the sinusoid-based control signal, harmonic beams are independently steerable. The proposed array is enabled with self-phasing capability by taking advantage of the RD technique. Besides, to avoid the unexploited radiation caused by unscannable fundamental beam and specular harmonic beams, the single sideband (SSB) modulator is utilized to enable the transmitting array with high-efficiency beamforming capacity. The numerical results verify that the presented array performs well in various charging scenarios, which brings a highly potential insight for far-field WPT. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
53. Beam-Deflection Short Backfire Antenna Using Phase-Modulated Metasurface.
- Author
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Zhou, Gao-Nan, Sun, Bao-Hua, Liang, Qiu-Yan, Yang, Yu-Hang, and Lan, Jiang-Hong
- Subjects
DIRECTIONAL antennas ,ANTENNAS (Electronics) ,ELECTRICAL conductors ,UNIT cell ,LIGHTING reflectors - Abstract
This communication presents a beam-deflection short backfire antenna (BD-SBA). The proposed BD-SBA differs from the conventional SBA in that the main reflector of the BD-SBA is a phase-modulated metasurface instead of a perfect electric conductor (PEC). The phase-modulated metasurface consists of 15 columns of unit cells which are designed to change the phase of the reflected waves. Therefore, the beam of the BD-SBA can be deflected to a certain angle. First, several BD-SBAs with linear phase-modulated metasurfaces are studied, which indicates that the beam of antennas point at different directions. Second, the BD-SBAs with nonlinear phase-modulated metasurfaces are studied to compare the difference between metasurfaces with linear and nonlinear width variation of patch. The simulated results show that the metasurface with nonlinear variation can obtain better performance than the former. To verify this design method, the BD-SBA with $\Delta \theta = 10^{\circ }$ was fabricated and measured at ${X}$ -band. The overall height of the proposed antenna is 0.35 wavelength at 10 GHz. The measured and simulated results are in good agreement; the measured beam-deflection angle, realized gain, and aperture efficiency are 10°, 14.8 dBi, and 68.3% at the center frequency, respectively. Due to the beam-deflection function, medium-to-high gain characteristics, and low profile, the proposed BD-SBA can be expected to find potential applications in wireless backhauling. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
54. Amplitude Estimation and Source Separation for Harmonics Within Two Mixtures Based on a Min-Rank Criterion.
- Author
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Yang, Yu, Yao, Hongwei, Dong, Jiyang, Qu, Xiaobo, and Chen, Zhong
- Subjects
- *
AMPLITUDE estimation , *PERTURBATION theory , *BLIND source separation , *ELECTRICAL engineering , *BIOMEDICAL engineering - Abstract
Exponentially decaying sinusoidal signal model is generally applied in a wide range of engineering and research fields. In order to analyze the signal components quantitatively, we need to extract the important parameters, i.e., amplitudes, frequencies, and damping factors, from the signals. In some practical applications, we can obtain multiple signals from multiple sensors or with multiple procedures. In such a way, the acquired signals are composed of similar sources or components but with different intensities. How to separate different sources and estimate the intensities of each source within the signals is essential for further analysis. In this paper, we separated different sources within two mixtures by estimating the relative intensities of the sources within mixtures. First, to evaluate a “clean” separation result, we proposed a minimum rank criterion, i.e., the Hankel matrices of the isolated sources should have the minimum rank, which corresponds to a simplified signal composition. Second, in order to minimize the rank of the Hankel matrices, we reformulated the objective function as a generalized eigenvalue decomposition problem, which can be solved based on the minimum perturbation theory. By this method, we can detect the number and intensities of common harmonic components within two mixtures, and isolate two complicated source signals with highly overlapped spectra from the mixtures. The proposed method can be applied for signal simplification or component quantification in a wide range of areas, such as biomedical or electrical engineering, where the signals are usually modeled as a sum of sinusoidal components. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
55. Experimental Observation of Dynamic Transmission Lineshapes in a Robust SNAP Microbottle-Taper Coupling System.
- Author
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Wang, Mengyu, Zeng, Sifan, Meng, Lingjun, Yang, Yu, Jin, Xueying, Dong, Yongchao, Zhang, Lei, Xu, Wenbin, and Wang, Keyi
- Abstract
Fano-like lineshapes in whispering-gallery modes (WGMs) microresonators are of critical for many actual applications, such as high-sensitivity sensors, slow light, and optical switches. In this paper, we theoretically and experimentally demonstrate dynamic transmission lineshapes, including Lorentzian lineshapes, Fano-like lineshapes and gain-like lineshapes, with a simple system, where a surface nanoscale axial photonic (SNAP) microbottle is coupled to the transition of a tapered fiber by carefully choosing tapered fiber diameters. Controlled and robust coupling with a clean and almost equidistant spectrum for different axial modes is achieved while maintaining contact between the resonator and the taper. Our device offers five similar dynamic transmission lineshapes arranged in order simultaneously, demonstrating stable tuning and a high number of potential degrees of freedom in contrast to other coupling systems for single- or double-coupled microresonators. By using coupled-mode theory, these transmission lineshapes are fitted to explain these experiment observations. We also explore a tunable transmission spectra obtained by increasing the powers of the input laser. Our approach hold unique potential in sensitivity-enhanced sensing, quantum information processing, and all-optical switching. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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56. A hysteresis model and parameter identification for MR pin joints using immune particle swarm optimization
- Author
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Jianchun Li, Yang Yu, Quang Phuc Ha, Sayed Royel, and Yancheng Li
- Subjects
Engineering ,business.industry ,Gaussian ,Particle swarm optimization ,Angular velocity ,Displacement (vector) ,Hysteresis ,symbols.namesake ,Control theory ,Magnetorheological fluid ,Curve fitting ,symbols ,Torque ,business - Abstract
© 2015 IEEE. A novel hybrid model is proposed in this paper to describe the highly-nonlinear hysteretic relationship between the torque and angular velocity in a magnetorheological pin joint (MRP). The MRP's hysteresis loop is modelled by a mixture of hyperbolic and Gaussian functions using the curve fitting technique, resulting in a significant reduction of the model parameters. To identify the model parameters, an immune particle swarm optimization (IPSO) algorithm is employed using torque-angular displacement/velocity experimental data recorded under various loading conditions. To demonstrate the accuracy of the proposed model and the effectiveness of parameter identification process, characterization test data of the smart pin torque and angular velocity are utilized for comparison.
- Published
- 2015
57. TFSIW-Excited Dual-Polarized Array Antenna With 30° Beam-Pointing for Millimeter-Wave Applications.
- Author
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Yang, Yu-Hang, Sun, Bao-Hua, Zhang, Guan-Xi, and Shen, Long
- Subjects
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ANTENNA arrays , *COAXIAL cables , *DIPOLE antennas , *PRINTED circuits , *ANTENNAS (Electronics) , *PORT districts , *SURFACE preparation , *POWER dividers - Abstract
This communication presents a dual-polarized series-fed array antenna with 30° beam-pointing for millimeter-wave (MM-Wave) applications. The 45° and −45° polarized subarrays share the aperture in an interdigital shape. The spacing between subarrays with the same polarization orientation is set to $0.56\lambda _{0}$ through the use of narrower T-type folded substrate integrated waveguide (TFSIW) instead of substrate integrated waveguide (SIW). The substrate integrated coaxial line (SICL) is adopted to design the array feeding network. To validate the proposed design, a $4 \times 6$ (single polarization) dual-polarized array antenna operating at 28 GHz with 30° beam-pointing is fabricated. Based on the measurement, the return losses are lower than −10 dB from 27.5 to 28.5 GHz, the isolations between the two polarization ports are higher than 30.0 dB in the frequencies mentioned above, the maximum gain at the center frequency is 15.7 dBi, and the cross-polarization levels are lower than −18.5 dB. The proposed antenna only needs one-step processing with the standard PCB technology without additional stitching assembly. Simulated and measured results of the proposed antennas were compared. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
58. A 4.2 nW and 18 ppm/°C Temperature Coefficient Leakage-Based Square Root Compensation (LSRC) CMOS Voltage Reference.
- Author
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Huang, Chao-Jen, Lai, Yan-Jiun, Yang, Yu-Jheng Ou, Chen, Hung-Wei, Kuo, Chun-Chieh, Chen, Ke-Horng, Lin, Ying-Hsi, Lin, Shian-Ru, and Tsai, Tsung-Yen
- Abstract
State-of-the-art CMOS-based voltage reference suffer from a trade-off between power dissipation and temperature coefficient (TC) due to the limited order of compensation in an advanced process which features a low supplied voltage (1~1.2 V). The proposed voltage reference with leakage-based square root compensation (LSRC) technique bias the substrate to offset TC with ultra-low leakage current (100~300 pA). On the other hand, the architecture provides an extensible order of compensation which is independent of voltage headroom. The two LSRC branches voltage reference implemented in 40 nm CMOS process achieves a within-wafer $ {\sigma }/ {\mu }$ of 0.204 and a TC of 18 ppm/°C with a power consumption of 4.2 nW. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
59. Wireless Cloaking System Based on Time-Reversal Multipath Propagation Effects.
- Author
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Ding, Shuai, Fang, Yong, Zhu, Jin-Feng, Yang, Yu, and Wang, Bing-Zhong
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TIME reversal ,ELASTIC wave propagation ,WAVE packets ,INTERSYMBOL interference ,FREQUENCY selective surfaces ,WIRELESS communications - Abstract
In this communication, we present a new method of encoding /decoding information contained in a wave packet using multipath effect. A signal is mixed with an auxiliary signal and sent into an enclosed cavity. The strongly distorted signal transmitted through the cavity is then sent to a receiver, where it is time reversed and sent to a second enclosed metallic cavity that is strictly identical to the first one. As a result, the waveform of the initial signal is reconstructed at a point of the second cavity that is equivalent to the point of the first cavity due to the spatial and temporal focusing. Using the mechanism, secure wireless data transmission is carried out. Finally, the impact of the size of the cavity on intersymbol interference and the frequency dispersion caused by frequency selective fading are discussed. Such a communication system ensures a high level of security. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
60. The Design of Dual Circularly Polarized Series-Fed Arrays.
- Author
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Yang, Yu-Hang, Guo, Jing-Li, Sun, Bao-Hua, Cai, Yuan-Ming, and Zhou, Gao-Nan
- Subjects
- *
CIRCULAR polarization , *ANTENNA radiation patterns , *MICROSTRIP antenna arrays , *PARAMETERS (Statistics) , *ROTATIONAL motion - Abstract
This paper presents the design of dual circularly polarized (CP) series-fed arrays based on the sequential rotation (SR) technique with uniform radiation elements. The radiation elements and feeding network used in the array are uniform, which leads to the possibility of dual-CP radiation by series-fed SR arrays. Meanwhile, the elements radiate unequal powers due to this arrangement. The relationship between the axial ratio and four key parameters of the array is derived and thoroughly discussed. Good polarization purity and port isolation can be realized by optimizing these parameters. A dual-CP array working at 10 GHz is designed with the help of the analysis. The experimental results show that the proposed antenna has good properties. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
61. Analysis of Resonance Between a VSC-HVDC Converter and the AC Grid.
- Author
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Zou, Changyue, Rao, Hong, Xu, Shukai, Li, Yan, Li, Weiwei, Chen, Jun, Zhao, Xiaobin, Yang, Yu, and Lei, Bo
- Subjects
HIGH-voltage direct current transmission ,ALTERNATING currents ,ELECTRIC impedance ,RESONANCE ,ELECTRIC power distribution grids - Abstract
A 1270 Hz resonance occurred between ±350 kV/ 1000 MW Luxi back-to-back voltage source converter based high-voltage dc transmission (VSC-HVDC) converter and the 525 kV ac grid after disconnection of several ac transmission lines. To understand the resonance and find a solution, the impedance-based stability analysis model considering different equipment is first established. Then, the resonance is analyzed and repeated in the simulation based on the established model. The system stability can be judged by the ratio of grid impedance to the equivalent impedance of all parallel-connected equipment with the converter. To evaluate the occurrence and risk of resonance, the frequency range where the impedance has a negative-real-part has been searched and studied. In order to narrow the negative-real-part region to avoid potential resonance, solutions such as control strategy improvement and passive or active impedance adapter may be applicable and are discussed. For a complex system containing various equipment, the equipment can be divided into several subsectors to avoid modeling all possible combinations of equipment, which can be exhausting. And analysis has shown sufficient but not necessary condition to stabilize the system is to avoid the negative-real-part region in each sector. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
62. PreventDark:Automatically detecting and preventing problematic use of smartphones in darkness
- Author
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Ruan, Wenjie, Sheng, Quan Z., Yao, Lina, Tran, Nguyen Khoi, Yang, Yu Chieh, Ruan, Wenjie, Sheng, Quan Z., Yao, Lina, Tran, Nguyen Khoi, and Yang, Yu Chieh
- Abstract
Smartphone adoption has increased significantly and users can access the Internet, communicate, and entertain themselves anywhere and anytime. However, the negative aspects of smartphone overuse on young adults are being increasingly recognized recently. One such serious problematic usage is peering at brightly lit screens in dark, which can cause sleep loss and resultant health problems. In this paper, we investigate the potential of exploiting sensors embedded in smartphones to detect and prevent such unhealthy habit by measuring the ambient light intensity and detecting the smartphone motion. We implement our system through an Android APP, called PreventDark. We show the feasibility and accuracy of our developed system by experiments on different android smartphones. Field experimental results indicate our system can significantly prevent and decrease the problematic use after intervention with up to 93.6%, particularly in the dark residential environments.
- Published
- 2016
63. A Genetic Programming approach to distributed QoS-aware web service composition
- Author
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Hui Ma, Mengjie Zhang, and Yang Yu
- Subjects
Web standards ,medicine.medical_specialty ,computer.internet_protocol ,Service delivery framework ,Computer science ,Distributed computing ,Service level requirement ,computer.software_genre ,medicine ,Web application ,Enterprise application integration ,Service (business) ,WS-Addressing ,business.industry ,Quality of service ,Service design ,Mobile QoS ,Service-oriented architecture ,Differentiated service ,Middleware (distributed applications) ,The Internet ,Web service ,business ,WS-Policy ,computer ,Web modeling - Abstract
Web service composition has emerged as a promising technique for building complex web applications, thus supporting business-to-business and enterprise application integration. Nowadays there are increasing numbers of web services are distributed across the internet. For a given service request there are many ways of service composition that can meet the service functional requirements (inputs and outputs) but have different qualities of Services (QoS), like response time or execution cost. QoS-aware web service composition seeks to find a service composition with optimized QoS properties. Genetic Programming is an efficient tool for tacking such optimization problems efficiently. This paper proposes a novel GP-based approach for distributed web service composition where multiple QoS constraints are considered simultaneously. A series of experiments have been conducted to evaluate the proposed approach with test data. The results show that our approach is efficient and effective to find a near-optimal service composition solution in the context of distributed service environment.
- Published
- 2014
64. High-Performance Three-Phase PWM Converter With a Reduced DC-Link Capacitor Under Unbalanced AC Voltage Conditions.
- Author
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Ren, Chunguang, Han, Xiaoqing, Wang, Lei, Qin, Wenping, Yang, Yu, and Wang, Peng
- Subjects
PULSE width modulation transformers ,AC DC transformers ,DISTRIBUTED power generation ,HIGH performance computing ,ELECTRIC currents - Abstract
A high-performance three-phase pulse width modulation (PWM) converter with reduced dc-link capacitor under unbalanced ac voltage conditions is proposed in this paper. The unique feature of the converter lies in that sinusoidal symmetrical ac currents and ripple free dc voltage can be achieved simultaneously without using a bulky capacitor, which was thought to be a dilemma in the past. The control scheme is implemented in an α–β frame, so the complex rotate transformations are avoided, and it does not require the extraction of positive and negative sequence currents, which simplifies the control algorithm. A two-quadrant operation active power compensator together with its controller is developed to suppress the voltage ripple in the dc-link. Compared with the passive compensation method, the compensator is equipped with a smaller capacitor to reduce the system size, weight, and cost. Moreover, the compensator could be integrated with the conventional three-phase three-leg PWM converter seamlessly. The effectiveness of the proposed control schemes is verified by the experiment results. [ABSTRACT FROM PUBLISHER]
- Published
- 2018
- Full Text
- View/download PDF
65. Diversity-Promoting Deep Structural Metric Learning for Remote Sensing Scene Classification.
- Author
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Zhiqiang Gong, Ping Zhong, Yang Yu, and Weidong Hu
- Subjects
REMOTE-sensing images ,ARTIFICIAL neural networks ,DEEP learning ,IMAGE registration ,MULTIPLE correspondence analysis (Statistics) - Abstract
Deep models with multiple layers have demonstrated their potential in learning abstract and invariant features for better representation and classification of remote sensing images. Moreover, metric learning (ML) is usually introduced into the deep models to further increase the discrimination of deep representations. However, the usual deep ML methods treat the training samples in each training batch in the stochastic gradient descent-based learning procedure independently, and thus, they neglect the important contextual (structural) information in the training samples. In this paper, we first introduce deep structural ML (DSML) into the literature of remote sensing scene classification and specifically capture and use the structural information during the training on the remote sensing images. Further analysis demonstrates that DSML usually makes many learned metric parameters similar. This similarity leads to obvious model redundancy and thus decreases the representational ability of the model. To address this problem, this paper proposes a new diversity-promoting DSML (D-DSML) method by regularizing the learning procedure by a diversity-promoting prior over the parameter factors. The proposed D-DSML encourages the parameter factors to be uncorrelated, such that each factor can model unique information, and thus, the model's description ability and classification performance would be significantly improved. Experiments over six real-world remote sensing scene data sets demonstrate that the proposed method obtains much better results than those obtained by the original deep models and has comparable or even better performances when compared with state-of-the-art methods. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
66. A Modified One-Cycle-Control-Based Active Power Filter for Harmonic Compensation.
- Author
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Wang, Lei, Han, Xiaoqing, Ren, Chunguang, Yang, Yu, and Wang, Peng
- Subjects
ELECTRIC power filters ,ELECTRICAL harmonics ,ELECTRIC currents ,ENERGY consumption ,CLOSED loop systems - Abstract
This paper proposes a modified one cycle control (OCC) for active power filter (APF) to compensate only harmonic components of load currents. The conventional OCC-based APF cannot differentiate between the harmonic and reactive components of load currents, which leads to the increment in device current rating because of compensation of large reactive currents besides harmonics. The reference signals of the OCC control core have been reconstructed and the associated control equations have been developed, following the control philosophy of simplicity. The modified scheme is easy to implement and only three more sensors are required for measuring load currents compared with the conventional OCC. This modified OCC guarantees the excellent performance of harmonic compensation alone and retains the advantages of the conventional OCC, such as no phase locking loop and the constant switching frequency. The feasibility and performance of the proposed OCC has been validated by experimental studies on a 5 kVA APF hardware platform developed in laboratory. [ABSTRACT FROM PUBLISHER]
- Published
- 2018
- Full Text
- View/download PDF
67. Activity Maximization by Effective Information Diffusion in Social Networks.
- Author
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Wang, Zhefeng, Yang, Yu, Pei, Jian, Chu, Lingyang, and Chen, Enhong
- Subjects
- *
SOCIAL networks , *SOCIAL influence , *HEURISTIC , *ALGORITHMS , *MATHEMATICS theorems - Abstract
In a social network, even about the same information the excitement between different users are different. If we want to spread a piece of new information and maximize the expected total amount of excitement, which seed users should we choose? This problem indeed is substantially different from the renowned influence maximization problem and cannot be tackled using the existing approaches. In this paper, motivated by the demand in a few interesting applications, we model the novel problem of activity maximization, and tackle the problem systematically. We first analyze the complexity and the approximability of the problem. We develop an upper bound and a lower bound that are submodular so that the Sandwich framework can be applied. We then devise a polling-based randomized algorithm that guarantees a data dependent approximation factor. Our experiments on four real data sets clearly verify the effectiveness and scalability of our method, as well as the advantage of our method against the other heuristic methods. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
68. Tracking Influential Individuals in Dynamic Networks.
- Author
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Yang, Yu, Wang, Zhefeng, Pei, Jian, and Chen, Enhong
- Subjects
- *
WEIGHTED graphs , *BIG data , *SOCIAL influence , *SOCIAL networks , *INTERNET users , *WIRELESS sensor networks - Abstract
In this paper, we tackle a challenging problem inherent in a series of applications: tracking the influential nodes in dynamic networks. Specifically, we model a dynamic network as a stream of edge weight updates. This general model embraces many practical scenarios as special cases, such as edge and node insertions, deletions as well as evolving weighted graphs. Under the popularly adopted linear threshold model and independent cascade model, we consider two essential versions of the problem: finding the nodes whose influences passing a user specified threshold and finding the top-$k$
- Published
- 2017
- Full Text
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69. Fuzzy comprehensive approach based on AHP and entropy combination weight for pipeline leak detection system performance evaluation
- Author
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Yinfeng Wu, Jiangwen Wan, Yang Yu, and Ning Yu
- Subjects
Engineering ,business.industry ,Weighted average operator ,Fuzzy set ,Analytic hierarchy process ,computer.software_genre ,Fuzzy logic ,Reliability engineering ,Pipeline transport ,Evaluation methods ,Entropy (information theory) ,Leak detection ,Data mining ,business ,computer - Abstract
Recently research on the evaluation of pipeline leak detection systems has been developing due to the widespread of natural gas supply through pipeline transportation in urban areas. This paper presents an improved fuzzy comprehensive evaluation method for assessing the performance of leak detection systems. In this method, the weights of different indexes are calculated by combining entropy weight with AHP weight. Weighted average operator is introduced to replace the fuzzy operator in traditional evaluation models. And interval evaluation according to comment rank is also adopted for final evaluation results. Simulation experiments verify the effectiveness of new approach. Compared with other common evaluation methods, new approach could effectively enhance evaluation resolution, satisfying the requirement of pipeline leak detection application. © 2012 IEEE.
- Published
- 2012
70. Detecting abnormal data for ontology based information integration
- Author
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Jeff Heflin and Yang Yu
- Subjects
Information retrieval ,Relation (database) ,Computer science ,Statement (logic) ,Predicate (mathematical logic) ,Ontology (information science) ,Object (computer science) ,Semantics ,Semantic Web ,Information integration - Abstract
To better support information integration on Semantic Web data with varying degrees of quality, this paper proposes an approach to detect triples which reflect some sort of error. In particular, erroneous triples may occur due to factual errors in the original data source, misuse of the ontology by the original data source, or errors in the integration process. Although diagnosing such errors is a difficult problem, we propose that the degree to which a triple deviates from similar triples can be an important heuristic for identifying errors. We detect such “abnormal triples” by learning probabilistic rules from the reference data and checking to what extent these rules agree with the triples. The system consists of two components for two types of abnormal relational descriptions that a Semantic Web statement could have, whether accidentally or maliciously: a statement could relate two resources that are unlikely to have anything in common or an inappropriate predicate could be used to describe the relation between the two resources. The classification technique is adopted to learn statistical characteristics for detecting a suspect resource pair, i.e. there is no significant relation between the subject and the object in the statement. For the suspect usages of a predicate, the system learns semantic patterns for each predicate from indirect semantic connections between the subject / object pairs.
- Published
- 2011
71. Subjective well-being, personality and environmental satisfaction in urban China
- Author
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Mike Willis, Zhai Qing-guo, Yang Yu-wen, and Bob O'Shea
- Subjects
Agreeableness ,Economic growth ,Extraversion and introversion ,media_common.quotation_subject ,Personality ,Conscientiousness ,Job satisfaction ,Big Five personality traits ,Subjective well-being ,Psychology ,Social psychology ,Hierarchical structure of the Big Five ,media_common - Abstract
The aim of this study is to examine the influence of environmental satisfaction, job satisfaction, and Big Five personality traits on subjective well-being. Data were collected from white-collar workers across four Chinese cities in 2009. All the research variables were measured with multi-item instruments with good psychometric properties. The research found that environmental satisfaction, job satisfaction, conscientiousness and extraversion have a positive effect on subjective well-being. In addition, individuals married, managers and working in state sector were found to be happier in their lives than individuals who are single, in non-managerial position and in private sector. However, the research found no relationship between neuroticism, agreeableness and subjective well-being. The finding of a positive relationship between environmental satisfaction and subjective well-being suggests that by pursuing a balance between economic development and environmental protection, urban residents' SWB could be enhanced.
- Published
- 2010
72. Validity of job satisfaction survey scale in Chinese
- Author
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Zhai Yu-bo, Luan Xiu-yun, Zhai Qing-guo, Yang Yu-wen, and Wang Zhi-hong
- Subjects
Chinese population ,Knowledge management ,business.industry ,media_common.quotation_subject ,Factor structure ,Confirmatory factor analysis ,Promotion (rank) ,Convergent validity ,Facet (psychology) ,Scale (social sciences) ,Job satisfaction ,Psychology ,business ,Social psychology ,media_common - Abstract
The aim of this study is to examine the factor structure of the scale of Job Satisfaction Survey (JSS), and its divergent and convergent validity in Chinese population. Data were collected with JSS from 1073 urban employees in Liaoning. Four alternative models were tested with confirmatory factor analysis. The first two models are models validated in the US, while the third and fourth models are composed of five commonly used dimensions of job satisfaction taken from JSS. The research found a poor model fit for the first two models, suggesting a possible national difference between China and the US. However, model three and model four displayed a good model fit, suggesting that the five dimensions in JSS (satisfaction with nature of work, with supervision, with co-worker, with promotion, and with pay) are five distinct dimensions. The correlations between these five facet job satisfaction and PA and NA demonstrated convergent and divergent validity of the scales for these five dimensions of job satisfaction.
- Published
- 2010
73. Automatic image annotation using group sparsity
- Author
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Yang Yu, Shaoting Zhang, Hongsheng Li, Junzhou Huang, Dimitris N. Metaxas, and Yuchi Huang
- Subjects
business.industry ,Computer science ,Feature extraction ,Relevance feedback ,Image processing ,Pattern recognition ,Feature selection ,Annotation ,Text mining ,Automatic image annotation ,Feature (computer vision) ,Histogram ,Artificial intelligence ,Cluster analysis ,business ,Image retrieval - Abstract
Automatically assigning relevant text keywords to images is an important problem. Many algorithms have been proposed in the past decade and achieved good performance. Efforts have focused upon model representations of keywords, but properties of features have not been well investigated. In most cases, a group of features is preselected, yet important feature properties are not well used to select features. In this paper, we introduce a regularization based feature selection algorithm to leverage both the sparsity and clustering properties of features, and incorporate it into the image annotation task. A novel approach is also proposed to iteratively obtain similar and dissimilar pairs from both the keyword similarity and the relevance feedback. Thus keyword similarity is modeled in the annotation framework. Numerous experiments are designed to compare the performance between features, feature combinations and regularization based feature selection methods applied on the image annotation task, which gives insight into the properties of features in the image annotation task. The experimental results demonstrate that the group sparsity based method is more accurate and stable than others.
- Published
- 2010
74. A Framework for Querying Sensor Networks Using Mobile Devices
- Author
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Yang Yu, Sol M. Shatz, and Shourui Tian
- Subjects
Mobile radio ,Computer science ,business.industry ,Distributed computing ,Mobile wireless sensor network ,business ,Mobile device ,Wireless sensor network ,Computer network - Abstract
An interplay between mobile devices and static sensor nodes is envisioned in the near future. This will enable a heterogeneous design space that can offset the stringent resource and power constraints encountered in traditional static sensor networks by taking advantage of the more powerful mobile devices. As such, we present a systematic framework for end-to-end query processing, using a two-layer architecture that consists of mobile devices at the upper layer and static sensor nodes at the bottom layer. One of our key goals is to achieve energy-efficient query injection and data collection by leveraging the mobility and transmission flexibility of objects at the upper layer. We propose a pull query model that contains staged operations including query generation, query routing, query injection, and query result routing. In the context of this model, we investigate a suite of techniques for the scenario with location-ignorant sensor nodes.
- Published
- 2007
75. Numerical Simulations of AC Losses in Multifilamentary Superconducting Tapes Under Bending Strain.
- Author
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Yang, Yu, Yong, Huadong, and Zhou, Youhe
- Subjects
- *
ALTERNATING currents , *MULTIFILAMENTARY superconductors , *STRAINS & stresses (Mechanics) , *MAGNETIC field effects , *CRITICAL currents - Abstract
AC loss has become a key problem for practical applications of high-temperature superconductors. It is well known that mechanical deformation will affect the critical current and ac loss as the superconductor is subjected to the magnetic field or transport current. In this paper, the ac losses in Bi2Cr2Ca2Cu 3O10 (Bi2223)/Ag tapes under bending deformation are investigated. Bi2223 tape consists of Ag matrix and Bi2223 filaments, and the ac losses are generated by transport current and external field. By considering the plastic deformation of Ag matrix and residual strain, the simplified mechanical fracture model is established. Then, the finite element method analysis is used to investigate the relation of critical current and ac loss with bending deformations, and the losses are presented for different transport current and external magnetic field conditions. The influences of filament fracture on the ac loss are discussed for transport current and external magnetic field cases, respectively. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
76. An Advanced 2.5-D Heterogeneous Integration Packaging for High-Density Neural Sensing Microsystem.
- Author
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Hu, Yu-Chen, Huang, Yu-Chieh, Huang, Po-Tsang, Wu, Shang-Lin, Chang, Hsiao-Chun, Yang, Yu-Tao, You, Yan-Huei, Chen, Jr-Ming, Huang, Yan-Yu, Lin, Yen-Han, Duann, Jeng-Ren, Chiu, Tzai-Wen, Hwang, Wei, Chuang, Ching-Te, Chiou, Jin-Chern, and Chen, Kuan-Neng
- Subjects
NEURAL chips ,ELECTRODES ,WIRE bonding (Electronic packaging) ,SILICON ,SEMICONDUCTORS - Abstract
In the traditional neural sensing microstructure, the limited metal line pitch and the metal layer numbers restrict the neural signal routing ability from electrodes to circuit chips. Miniature packaging and excessive noise interference bottlenecks are some of the challenges faced by the electrodes and circuit chips integration with traditional wire bonding. This paper proposes a 2.5-D heterogeneous integration neural sensing microsystem based on the silicon substrate to overcome these issues. With standard semiconductor and 3-D integration processes, high-channel-density (256 channels at 25 mm2) neural sensing microsystem is achieved. Through silicon via provides the shortest vertical interconnection and dramatically minimizes the packaging. Furthermore, the interposer can carry multiple chips to enhance the function of the biosensor. Electrical characteristics and reliability examinations reveal its high quality and great performance as compared to traditional approaches. This novel highly integrated neural sensing microsystem is expected to contribute to the biomedical field for exploring and solving unknown biological mysteries. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
77. HySense: A Hybrid Mobile CrowdSensing Framework for Sensing Opportunities Compensation under Dynamic Coverage Constraint.
- Author
-
Han, Guangjie, Liu, Li, Chan, Sammy, Yu, Ruiyun, and Yang, Yu
- Subjects
REMOTE sensing ,REMOTE sensing devices ,SOFTWARE frameworks ,WIRELESS sensor nodes ,SERVICE-oriented architecture (Computer science) ,COMPUTER software - Abstract
Mobile crowdsensing is a novel sensing paradigm enabled by the proliferation of mobile devices. Since crowdsensing applications are driven by sufficient users, advanced incentive mechanisms have been designed to enhance users' willingness to participate in sensing tasks. However, incentive mechanisms only provide adequate sensing opportunities on the condition that the available user base is large. If existing users are fewer than the required number of participants, incentive mechanisms will lose efficacy. This article proposes a hybrid framework called HySense to compensate for inadequate sensing opportunities solely provided by incentive mechanisms. Within each sensing cycle, HySense combines mobile devices with static sensor nodes to generate uniformly distributed space-time data under the constraint of field coverage. To balance sensing opportunities among different geographic regions, redundant users are efficiently migrated from densely populated areas to sparsely populated areas. HySense utilizes calibration mode for checking whether the participants' behavior patterns are consistent with the sensing task queue. Therefore, any change caused by unforeseen accidents can be dealt with in advance. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
78. Micromagnetic Study for Magnetic Properties of Exchange-Coupled Nanocomposite Magnetic Systems With $\alpha$ -Fe Grains Embedded in Nd2Fe14B Matrix.
- Author
-
Ryo, Hyok-Su, Hu, Lian-Xi, Kim, Jin-Guk, and Yang, Yu-Lin
- Subjects
MICROMAGNETICS ,MICROSTRUCTURE ,FINITE element method ,GRAIN size ,MAGNETIC coupling - Abstract
In this paper, the relationship between the magnetic properties and microstructures of nanocomposite isotropic exchange-coupled systems with the structure of \alpha -Fe crystalline grains embedded in Nd2Fe14B matrices has been estimated by micromagnetic finite-element method. And then, the results have been analyzed by means of the effectiveness of exchange coupling between the magnetically hard Nd2Fe14B and soft \alpha -Fe phase of the exchange-coupled Nd2Fe 14\text{B}/\alpha -Fe magnetic systems. The effectiveness of interphase exchange coupling has been estimated by the volume fractions of exchange coupling area near phase boundaries between \alpha -Fe grains and Nd2Fe14B matrix. The results have shown the micromagnetic mechanism of the advanced magnetic properties of the exchange coupled magnetic systems with the structure of $\alpha $ -Fe grains embedded in Nd2Fe14B matrix. In addition, the optimal magnetic properties can be expected in the case of comparatively the large grain sizes of $\alpha $ -Fe and Nd2Fe14B phase due to the characteristic structure of those magnetic systems. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
79. Far-Field Super-Resolution Imaging of Scatterers With a Time-Reversal System Aided by a Grating Plate.
- Author
-
Gong, Zhi-Shuang, Wang, Bing-Zhong, Yang, Yu, Zhou, Hong-Cheng, Ding, Shuai, and Wang, Xiao-Hua
- Abstract
A time-reversal imaging system for far-field super-resolution imaging of scatterers is proposed. First, a grating plate, similar to the optical far-field super lens, is designed to convert near-field evanescent waves to propagative waves with wavevector modulation. Then, the scattered signals are processed by a time-reversal (TR) technique and retransmitted back. Finally, the images of the targets are reconstructed by doing demodulation operations in the k-domain to the TR field at the refocusing time. Imaging results show that two scatterers separated by 0.1 λ can be distinguished clearly. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
80. Dual-Band Slot Helix Antenna for Global Positioning Satellite Applications.
- Author
-
Yang, Yu-Hang, Guo, Jing-Li, Sun, Bao-Hua, and Huang, You-Huo
- Subjects
- *
MICROSTRIP transmission lines , *PRINTED circuits , *MICROELECTRONICS , *ELECTRONIC circuits , *MINIATURE electronic equipment - Abstract
A slot helix antenna working in Global Positioning System (GPS) L1 and L2 bands is proposed in this paper. Adopting sequential rotation technique, the proposed antenna is equipped with six helix radiation arms and fed by a microstrip line with folded shape. The whole antenna can be built on a full printed circuit board; so, it is easy to process the proposed antenna. The circularly polarized radiation mechanism of a circular array is analyzed in a new perspective to guide the design. A double-faced slot radiation structure is also established for dual-band operation. Additionally, a traveling wave feeding network suitable for the proposed antenna is presented. The experimental results show that the proposed antenna has good properties in GPS L1 and L2 bands. [ABSTRACT FROM PUBLISHER]
- Published
- 2016
- Full Text
- View/download PDF
81. Substructural Regularization With Data-Sensitive Granularity for Sequence Transfer Learning.
- Author
-
Sun, Shichang, Liu, Hongbo, Meng, Jiana, Chen, C. L. Philip, and Yang, Yu
- Subjects
MACHINE learning ,ARTIFICIAL neural networks ,ARTIFICIAL intelligence - Abstract
Sequence transfer learning is of interest in both academia and industry with the emergence of numerous new text domains from Twitter and other social media tools. In this paper, we put forward the data-sensitive granularity for transfer learning, and then, a novel substructural regularization transfer learning model (STLM) is proposed to preserve target domain features at substructural granularity in the light of the condition of labeled data set size. Our model is underpinned by hidden Markov model and regularization theory, where the substructural representation can be integrated as a penalty after measuring the dissimilarity of substructures between target domain and STLM with relative entropy. STLM can achieve the competing goals of preserving the target domain substructure and utilizing the observations from both the target and source domains simultaneously. The estimation of STLM is very efficient since an analytical solution can be derived as a necessary and sufficient condition. The relative usability of substructures to act as regularization parameters and the time complexity of STLM are also analyzed and discussed. Comprehensive experiments of part-of-speech tagging with both Brown and Twitter corpora fully justify that our model can make improvements on all the combinations of source and target domains. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
82. A metric and mixed-integer-programming-based approach for resource allocation in dynamic real-time systems
- Author
-
Yang Yu, Viktor K. Prasanna, Jong-Kook Kim, Shoukat Ali, Anthony A. Maciejewski, Howard Jay Siegel, Shriram B. Gundala, and Sethavidh Gertphol
- Subjects
Mathematical optimization ,Computer science ,Distributed computing ,Real-time computing ,Metric (mathematics) ,Resource allocation ,Resource allocation (computer) ,Resource management ,Heuristics ,Integer programming ,Performance metric ,Software metric ,Task (project management) - Abstract
Dynamic real-time systems such as embedded systems operate in environments in which several parameters vary at run time. These systems must satisfy several performance requirements. Resource allocation on these systems becomes challenging because variations of run-time parameters may cause violations of the performance requirements. Performance violations result in the need for dynamic re-allocation, which is a costly operation. A method for allocating resources such that the allocation can sustain the system in the light of a continuously changing environment is developed. We introduce a novel performance metric called MAIL (maximum allowable increase in load) to capture the effectiveness of a resource allocation. Given a resource allocation, MAIL quantifies the amount of additional load that can be sustained by the system without any performance violations. A mixed-integer-programming-based approach (MIP) is developed to determine a resource allocation that has the highest MAIL value. Using simulations, several sets of experiments are conducted to evaluate our heuristics in various scenarios of machine and task heterogeneities. The performance of MIP is compared with three other heuristics: integer-programming based, greedy, and classic min-min. Our results show that MIP performs significantly better when compared with the other heuristics.
- Published
- 2002
83. Utilization-based heuristics for statically mapping real-time applications onto the HiPer-D heterogeneous computing system
- Author
-
Shriram B. Gundala, Anthony A. Maciejewski, Viktor K. Prasanna, Howard Jay Siegel, S. Aliy, Sethavidh Gertphol, Yang Yu, and J.-K. Kimy
- Subjects
Set (abstract data type) ,Computer science ,Distributed computing ,Real-time computing ,Testbed ,Resource allocation ,Workload ,Symmetric multiprocessor system ,Heuristics ,Application software ,computer.software_genre ,computer - Abstract
Real-time applications continue to increase in importance as they are employed in various critical areas, such as command and control systems. These applications have traditionally required custom-made systems to execute them. Recently, with the widespread use of increasingly powerful commercial off-the-shelf (COTS) products, some real-time system designers have started a shift from custom development to COTS-based systems to achieve lower costs and more flexible systems. This research investigates the problem of allocating real-time applications to a set of COTS heterogeneous machines connected together by a COTS high-speed network. The heuristics were implemented on the High Performance Distributed Computing Program's (HiPer-D) Naval Surface Warfare Center (NSWC) testbed. At the specification of NSWC, the goal of this study is to design static resource allocation heuristics that balance the utilization of the computation and network resources in the HiPer-D system based on the system information provided. The broader goal is to maximize the time before dynamic reallocation is required for managing an increased workload at runtime.
- Published
- 2002
84. Coherent control of acoustic phonon oscillations in InGaN/GaN multiple-quantum-wells
- Author
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Amber C. Abare, Chi-Kuang Sun, Steven P. DenBaars, Christopher J. Stanton, Xiang-Yang Yu, and Jian-Chin Liang
- Subjects
Physics ,Phonon ,business.industry ,Oscillation ,Laser ,law.invention ,Condensed Matter::Materials Science ,law ,Coherent control ,Femtosecond ,Optoelectronics ,Coherent spectroscopy ,business ,Spectroscopy ,Ultrashort pulse - Abstract
Summary form only given. Progress in femtosecond lasers and ultrafast spectroscopy technology has enabled us to generate and directly observe the coherent oscillations of phonon modes. We demonstrate the coherent control of the initiated coherent acoustic phonon oscillation using a separate control UV pulse. The experiments were performed at room temperature on 14 periods InGaN-GaN MQWs.
- Published
- 2000
85. The Impact of Weather Condition on Radio-Based Distance Estimation: A Case Study in GSM Networks With Mobile Measurements.
- Author
-
Fang, Shih-Hau and Yang, Yu-Hsuan Sylvia
- Subjects
- *
WEATHER , *MEASUREMENT of distances , *GSM communications , *WIRELESS communications , *WIND speed - Abstract
Distance estimation based on the received signal strength (RSS) of wireless radio has been extensively studied; however, the estimation accuracy is susceptible to radio propagation conditions, particularly during periods of precipitation. This study performed experiments on the 1.8-GHz band of Global System for Mobile Communications (GSM) networks at Yuan Ze University, Taoyuan, Taiwan, sensing actual radio power signals using mobile phones and recording transmission conditions during various weather events. The aim was to compare RSS performance under dry and wet weather conditions and study the dynamics of distance estimation from theoretical and empirical perspectives. Traditional rain attenuation models have largely discounted the impact of precipitation on GSM signals due to the relatively low frequency band; however, on-site experimental results demonstrated that dynamic weather significantly degrades accuracy in distance estimation. This study employed a typical rain attenuation model and a radio propagation model to evaluate errors in distance estimation under various rain conditions, i.e., heavy rain, extremely heavy rain, torrential rain, and extremely torrential rain, in accordance with the standards set out by the Central Weather Bureau, Taiwan. This study also investigated the RSS attenuation under various wind speeds. The Cramer–Rao lower bound (CRLB) was used as a benchmark for comparison. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
86. Distributed State Estimation With Dimension Reduction Preprocessing.
- Author
-
Ma, Hang, Yang, Yu-Han, Chen, Yan, Liu, K. J. Ray, and Wang, Qi
- Subjects
- *
BANDWIDTH research , *LOSSLESS data compression , *SIGNAL processing , *DETECTORS , *MEAN square algorithms - Abstract
System state estimation relies heavily on the measurements. With the advance of sensing technology, the ability to measure is no longer a bottleneck in many systems, and more and more researchers now focus on the rich-information setting, i.e., big data. However, although information never hurts, it does not help unconditionally. How to make the most of it depends on whether we can process the data efficiently. In some systems, the inherent constraint such as the bandwidth and cost makes it necessary to reduce the dimension of the measurement before further processing. The problem that the raw measurements are first preprocessed to reduce size and then used for estimation is addressed in this paper. It is shown that there is a lower bound on the size of the preprocessed data such that if the size is beyond the bound, there exists a closed-form estimator design that the linear minimum mean-square estimation can be obtained. Moreover, we propose an algorithm that is guaranteed to converge to a stationary point to design an estimator in the conditions that the lower bound cannot be reached. Besides convergence, the proposed algorithm guarantees bounded performance loss compared with the global optimal solution under some additional conditions. Finally, simulation results in three different applications are shown to demonstrate the effectiveness of the proposed algorithm. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
- View/download PDF
87. PushPull: Short-Path Padding for Timing Error Resilient Circuits.
- Author
-
Yang, Yu-Ming, Jiang, Iris Hui-Ru, and Ho, Sung-Ting
- Subjects
- *
INTEGRATED circuit design , *TIMING circuits , *LINEAR programming , *HEURISTIC programming , *ELECTRONIC circuit design - Abstract
Modern IC designs are exposed to a wide range of dynamic variations. Traditionally, a conservative timing guardband is required to guarantee correct operations under the worst-case variation, thus leading to performance degradation. To remove the guardband, resilient circuits are proposed. However, the short-path padding (hold time fixing) problem in resilient circuits is far severer than conventional IC design. Therefore, in this paper, we focus on the short-path padding problem to enable the timing error detection and correction mechanism of resilient circuits. Unlike recent prior work adopts greedy heuristics with a local view, we determine the padding values and locations with a global view. Moreover, we utilize spare cells and a dummy metal to further achieve the derived padding values at physical implementation. Experimental results show that our method is promising to validate timing error-resilient circuits. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
- View/download PDF
88. Bathymetry Retrieval From Hyperspectral Remote Sensing Data in Optical-Shallow Water.
- Author
-
Sheng Ma, Zui Tao, Xiaofeng Yang, Yang Yu, Xuan Zhou, and Ziwei Li
- Subjects
WATER depth ,WATER levels ,HYPERSPECTRAL imaging systems ,IMAGING systems ,PEARSON correlation (Statistics) ,BATHYMETRY ,MARINE geophysics - Abstract
In this paper, an algorithm for estimating shallow-water depth from hyperspectral data is proposed. This methodology is based on the different responses of shallow-water reflectance on depth and substrate type. Two parameters-similarity coefficient and Pearson correlation coefficient-are introduced to describe the different types of responses, and a linear logarithm ratio model is established. Using Hyperion data over the coastal regions of O'Ahu Island and Saint Thomas Island, the retrieved bathymetry is compared with the airborne LIDAR data. The validation results show that the proposed method has good performance, and the root mean square error is less than 1.5 m over shallow water (shallower than 20 m). [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
89. Ohmic Loss Distribution Analysis of a Coaxial Waveguide With Misaligned Inner Rod.
- Author
-
Liu, Diwei, Li, Xuelian, Yang, Yu, Long, Xiaolan, and Zhang, Ying
- Subjects
WAVEGUIDES ,ELECTRICAL conductors ,ELECTRIC waves ,ELECTROMAGNETIC waves ,GYRATORS - Abstract
The azimuthal distribution of the ohmic loss in the coaxial waveguide with a misaligned inner rod is investigated in this paper. For axially symmetric modes with zero caustic radii, a little misalignment will bring a large change of the azimuthal ohmic loss distribution on the inner rod and the outer wall, and the change is more noticeable for a larger misalignment or a larger ratio of the inner to the outer radii in a coaxial waveguide; for asymmetric volume modes and whispering-gallery modes with nonzero caustic radii, when the inner rod radius is smaller than the caustic radius of a given mode, the azimuthal ohmic loss distribution is almost unchanged with a small misalignment, but when the inner rod radius is larger than the caustic radius, the azimuthal ohmic loss distribution changes obviously with the misalignment, and this change is larger for the coaxial waveguide with a larger ratio of the inner to the outer radii or a larger misalignment of the inner rod. This noticeable change may cause the azimuthal accumulation of heat on the inner rod and the outer wall in a coaxial waveguide or cavity. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
90. Design of Test Structures for the Characterization of Thermal–Mechanical Stress in 3D-Stacked IC.
- Author
-
Minas, Nikolaos, Van der Plas, Geert, Oprins, Herman, Yang, Yu, Okoro, Chukwudi, Mercha, Abdelkarim, Cherman, Vladimir, Torregiani, Cristina, Perry, Dan, Cupak, Miroslav, Rakowski, Michal, and Marchal, Paul
- Subjects
THERMAL analysis ,CRYSTAL structure ,STRAINS & stresses (Mechanics) ,INTEGRATED circuits ,SILICON ,METAL oxide semiconductors ,TEMPERATURE measurements ,HEATING ,DIGITAL-to-analog converters - Abstract
In this paper, we present test structures and measurement techniques that enable the extraction of the significance of the thermal–mechanical stress in 3D-stacked integrated circuit technology. Heaters and integrated diodes have been used to determine the impact of hotspots in 3-D systems. The results obtained showed that in 3-D case, the peak temperature of a hotspot is three times higher compared to a traditional 2-D system. For the characterization of through silicon vias (TSVs)-induced stress and its impact on analog metal-oxide semiconductor (MOS) devices, a 10-bit current steering digital-to-analog converter (DAC) test structure is utilized. The DAC has been optimized to detect ion changes down to 0.5% due to TSV proximity, TSV orientation, thermal hotspots, and wafer thinning or stacking process. The results obtained from stand-alone short-channel MOS devices and the DAC structure clearly indicate the impact of TSV proximity and TSV orientation on the carrier mobility of nearby transistors. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
- View/download PDF
91. Manifold Concept Design for ITER Gas Injection System.
- Author
-
Jiang, Tao, Li, Bo, Li, Wei, Wang, Mingxu, Pan, Yudong, Maruyama, So, and Yang, Yu
- Subjects
GAS injection ,PLASMA beam injection heating ,TOROIDAL plasma ,GAS distribution ,NATURAL gas pipelines - Abstract
The main functions of the ITER gas injection system (GIS) are to provide gas fueling for plasma, wall conditioning operation, and neutral beam injectors. The dedicated manifold, which contains independent tubes for \H2/\D2, \H2, \T2, ^4\He/^3\He, \N2/\Ne, Ar, and evacuation, is the key part of the gas injection lines. It shall deliver gases from the tritium plant to various fueling systems. This paper presents an overview of the GIS manifold design, particularly introducing the solution of the penetration structure and the routing of the manifold from the concept design point of view. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
- View/download PDF
92. INTEGRA: Fast Multibit Flip-Flop Clustering for Clock Power Saving.
- Author
-
Jiang, Iris Hui-Ru, Chang, Chih-Long, and Yang, Yu-Ming
- Subjects
FLIP-flop circuits ,INTEGRATED circuit design ,COORDINATE transformations ,LINE drivers (Integrated circuits) ,TOPOLOGY ,INTERSECTION graph theory - Abstract
Clock power is the major contributor to dynamic power for modern integrated circuit design. A conventional single-bit flip-flop cell uses an inverter chain with a high drive strength to drive the clock signal. Clustering several such cells and forming a multibit flip-flop can share the drive strength, dynamic power, and area of the inverter chain, and can even save the clock network power and facilitate the skew control. Hence, in this paper, we focus on postplacement multibit flip-flop clustering to gain these benefits. Utilizing the properties of Manhattan distance and coordinate transformation, we model the problem instance by two interval graphs and use a pair of linear-sized sequences as our representation. Without enumerating all possible combinations, we identify only partial sequences that are necessary to cluster flip-flops, thus leading to an efficient clustering scheme. Moreover, our fast coordinate transformation also makes the execution of our algorithm very efficient. The experiments are conducted on industrial circuits. Our results show that concise representation delivers superior efficiency and effectiveness. Even under timing and placement density constraints, clock power saving via multibit flip-flop clustering can still be substantial at postplacement. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
93. Subnanosecond Pulse Generators for Impulsive Wireless Power Transmission and Reception.
- Author
-
Yang, Chin-Lung, Yang, Yu-Lin, and Lo, Chun-Chih
- Abstract
This brief describes a novel impulsive wireless power transmission (WPT) and reception system. This new concept enhances the power conversion efficiency (PCE) for low average input power. Low input power is important in several applications, such as biomedical implant devices and energy harvesting from unknown sources. An ultrawideband (UWB) monocycle pulse generator is designed using a shunt step recovery diode. The fabricated pulse generator produces an impulse width of approximately 290 ps. Complete wideband transmitting and receiving systems are implemented to validate the feasibility of impulsive WPT technologies and to assess the improvement of the conversion efficiency of the rectifier circuitry. Finally, UWB impulsive wireless transmission systems demonstrate 59.6% PCE, even when the input power of the rectifier is less than -2.84 dBm. [ABSTRACT FROM PUBLISHER]
- Published
- 2011
- Full Text
- View/download PDF
94. A Loss Inference Algorithm for Wireless Sensor Networks to Improve Data Reliability of Digital Ecosystems.
- Author
-
Yang, Yu, Xu, Yongjun, Li, Xiaowei, and Chen, Canfeng
- Subjects
- *
ALGORITHMS , *BANDWIDTHS , *TOPOLOGY , *TOMOGRAPHY , *SELF-organizing systems , *EQUATIONS , *COMPUTER networks , *SCALABILITY , *SIMULATION methods & models - Abstract
Digital ecosystems (DEs) are based on a large amount of distributed data, and these data are gathered from physical devices, particularly from wireless sensor networks (WSNs). Due to the inherent stringent bandwidth and energy constraints, energy-efficient mechanisms of performance measurement are the key to the proper operation of WSNs and thereby important for the data reliability of DEs. This paper presents a novel algorithm, i.e., Loss Inference based on Passive Measurement (LIPM), to infer WSN link loss performance. The LIPM algorithm passively monitors the application traffic between sensor nodes and the sink (base station), and then uses network tomography technology to infer the network internal performance. Furthermore, contour maps, the well-known representation of data, are first taken into account in WSN loss performance inference, which can help the LIPM algorithm identify lossy areas rapidly. Finally, the algorithm is validated through simulations and exhibits good performance and scalability. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
95. Automating Logic Transformations With Approximate SPFDs.
- Author
-
Yang, Yu-Shen, Sinha, Subarna, Veneris, Andreas, and Brayton, Robert K.
- Subjects
- *
MATHEMATICAL transformations , *APPROXIMATION algorithms , *VERY large scale circuit integration , *DEBUGGING , *COMBINATORIAL optimization , *MATHEMATICAL models , *LOGIC machines , *DATA structures , *SIMULATION methods & models - Abstract
During the very large scale integration design process, a synthesized design is often required to be modified in order to accommodate different goals. To preserve the engineering effort already invested, designers seek small logic structural transformations to achieve these logic restructuring goals. This paper proposes a systematic methodology to devise such transformations automatically. It first presents a simulation-based formulation to approximate sets of pairs of functions to be distinguished and avoid the memory/time explosion issue inherent with the original representation. Then, it uses this new data structure to devise the required transformations dynamically without the need of a static dictionary model. The methodology is applied to both combinational and sequential designs with transformations at a single or multiple locations. An extensive suite of experiments documents the benefits of the proposed methodology when compared to existing practices. [ABSTRACT FROM PUBLISHER]
- Published
- 2011
- Full Text
- View/download PDF
96. Multiuser MIMO Downlink Beamforming Design Based on Group Maximum SINR Filtering.
- Author
-
Yang, Yu-Han, Lin, Shih-Chun, and Su, Hsuan-Jung
- Subjects
- *
ELECTRIC interference , *SIGNAL-to-noise ratio , *SIGNAL processing , *LINE receivers (Integrated circuits) , *MIMO systems , *BEAMFORMING , *MULTIUSER computer systems , *ITERATIVE methods (Mathematics) - Abstract
In this paper, we aim to solve the multiuser multi-input multi-output (MIMO) downlink beamforming problem where one multi-antenna base station broadcasts data to many users. Each user is assigned multiple data streams and has multiple antennas at its receiver. Efficient solutions to the joint transmit-receive beamforming and power allocation problem based on iterative methods are proposed. We adopt the group maximum signal-to-interference-plus-noise-ratio (SINR) filter bank (GSINR-FB) as our beamformer which exploits receiver diversity through cooperation between the data streams of a user. The data streams for each user are subject to an average SINR constraint, which has many important applications in wireless communication systems and serves as a good metric to measure the quality of service (QoS). The GSINR-FB also optimizes the average SINR of its output. Based on the GSINR-FB beamformer, we find an SINR balancing structure for optimal power allocation which simplifies the complicated power allocation problem to a linear one. Simulation results verify the superiority of the proposed algorithms over previous works with approximately the same complexity. [ABSTRACT FROM PUBLISHER]
- Published
- 2011
- Full Text
- View/download PDF
97. Capacitance Characteristics Improvement and Power Enhancement for RF LDMOS Transistors Using Annular Layout Structure.
- Author
-
Chiu, Chia-Sung, Chen, Kun-Ming, Huang, Guo-Wei, Chen, Ming-I., Yang, Yu-Chi, and Wang, Kai-Li
- Subjects
TRANSISTORS ,RADIO frequency ,METAL oxide semiconductors ,PERFORMANCE evaluation ,ENERGY consumption ,CAPACITORS ,DIRECT currents - Abstract
This paper presents an annular-structure lateral-diffused metal–oxide–semiconductor (LDMOS) RF transistor using a 0.5-\mum LDMOS process. This paper also examines the dc, small-signal, and large-signal characteristics of RF LDMOS transistors with different closed structures. In particular, the problem of evaluating the LDMOS aspect ratio for annular structure is addressed. The capacitance characteristics improvement in the LDMOS device design using the annular structure was also investigated. The power gain and efficiency of annular structure give nearly 5% enhancement compared to the traditional structure with 80-\mum gatewidth at 1.9 GHz. Results show that the annular structure appears to be a better layout design for RF LDMOS transistors. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
98. A 0.5-V Biomedical System-on-a-Chip for Intrabody Communication System.
- Author
-
Lin, Yu-Tso, Lin, Yo-Sheng, Chen, Chun-Hao, Chen, Hsiao-Chin, Yang, Yu-Che, and Lu, Shey-Shi
- Subjects
MEDICAL electronics ,INTEGRATED circuits ,LOW voltage systems ,MICROCONTROLLERS ,ANALOG-to-digital converters ,RADIO transmitter-receivers ,RADIO frequency - Abstract
A low-voltage (0.5 V) and low-power (4.535 mW) monolithic biomedical system-on-a-chip (SOC) consisting of a receiver, a transmitter, a microcontrol unit, and an analog-to-digital converter (ADC), implemented in a 0.18- \mu\m CMOS technology for intrabody communication is first reported. The SOC can take command through a human body and activate (or turn on) the ADC and transmitter inside the SOC. Then, a biomedical signal is converted to digital format and transmitted to the RF gateway through a human body. With this transmission methodology and the proposed SOC circuit, it is much more power efficient than wireless communication. Moreover, since no antenna is required, the chip size of the SOC is only 1.5 \mm^2, excluding the test pads. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
99. A Compact Repetitive Unipolar Nanosecond-Pulse Generator for Dielectric Barrier Discharge Application.
- Author
-
Tao Shao, Dongdong Zhang, Yang Yu, Cheng Zhang, Jue Wang, Ping Yan, and Yuanxiang Zhou
- Subjects
DIELECTRICS ,ELECTRIC oscillators ,ELECTRIC discharges ,ATMOSPHERIC pressure ,PULSED power systems ,ELECTRIC generators - Abstract
Dielectric barrier discharge excitated by pulsed power is a promising approach for producing nonthermal plasma at atmospheric pressure, but pulsed power generators vary widely in performance and should be chosen according to application requirements. In this paper, a repetitive unipolar nanosecond-pulse generator is constructed using resonant charging and one-stage magnetic compression circuits, where IGBT and magnetic switches are the key units, respectively. The generator is capable of providing repetitive pulses with a voltage of up to 30 kV and duration of 70 ns at a 300 Ω resistive load. Output pulse voltage can be adjusted by varying ac input voltage or trigger pulse-width. This compact and convenient generator has been used successfully to produce stable dielectric barrier discharge. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
100. Surface Treatment of Polyethylene Terephthalate Films Using DBD Excited by Repetitive Unipolar Nanosecond Pulses in Air at Atmospheric Pressure.
- Author
-
Cheng Zhang, Tao Shao, Kaihua Long, Yang Yu, Jue Wang, Dongdong Zhang, Ping Yan, and Yuanxiang Zhou
- Subjects
DIELECTRICS ,POLYETHYLENE terephthalate ,POLYMERS ,MICROSTRUCTURE ,SURFACE roughness - Abstract
Dielectric barrier discharge (DBD) is proved to be an effective method for surface treatment of polymers over the past 20 years and is now widely used in the fields of surface modification. In this paper, surface treatment of polyethylene terephthalate (PET) films for improving the hydrophilicity using DBD excited by unipolar nanosecond pulses is presented. Two typical discharges exhibiting homogeneous and filamentary modes are obtained under certain experimental conditions, and then, they are used to modify the surface of PET films. The microstructure and properties of the film surface before and after treatment are characterized with water contact angle measurement, scanning electron microscope, atomic force microscope, and X-ray photoelectron spectroscope. The results show that, with the treatment power density of 192 and 158 mW/cm2 in filamentary and homogeneous modes, respectively, surface morphology and property after treatment are significantly changed, and the physical etching and introduction of oxygen-containing polar functional groups account for the decease of surface contact angle and the increase of surface roughness. Compared with the filamentary DBD treatment, the homogeneous DBD (HDBD) is more effective in surface treatment, such as lower contact angle, higher roughness, and more oxygencontaining function groups after treatment. It is attributed to the fact that the HDBD can achieve a uniform treatment and canmake the physical and chemical interaction much sufficient. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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