检索结果-内蒙古大学图书馆

Device Research Conference

作者： Amrita Masurkar Ioannis Kymissis Columbia University New York City NY USA

ISBN: (纸本)9781509028290

Overview Bottom-contact (BC) organic field-effect transistors (OFETs), though more industry-relevant than top-contact (TC) OFETs, are prone to low source-drain currents. The underlying mechanisms behind this remain debated. Thus, our work uses photocurrent microscopy (PCM) to examine charge injection in BC and TC geometries. PCM maps were generated first for OFETs with no electrode or gate dielectric treatments. Potential plots were quantitatively derived from the results using a method from previous work. [1] PCM maps were then collected for devices treated with 1. pentafluorobenzenethiol (PFBT), known to improve semiconductor morphology [2], and 2. UV-ozone, which is thought to enhance trap-assisted carrier transport. [3] These treatments were chosen, because they significantly increase source-drain current in BC devices, but in vastly different ways. In addition, unlike other photocurrent studies, we used a range of illumination wavelengths so as to probe various exciton states.

关键词： photoemission electron traps organic field effect transistors photoconductivity Organic field-effect transistors electron traps photoelectric emission Photoconductivity Drain current Photocurrent pulse code modulation BC charge injection Carrier transport

来源：评论

学校读者我要写书评

暂无评论

Novel device structure for phase change memory toward low-current operation

引用

JAPANESE JOURNAL OF APPLIED PHYSICS 2015年第9期54卷 94302.1-94302.1页

作者： Kim, Eunha Kang, Nam Soo Yang, Hyung-Jun Sutou, Yuji Song, Yun-Heub Hanyang Univ Dept Elect Engn Seoul 133791 South Korea Tohoku Univ Dept Mat Sci Sendai Miyagi 9808579 Japan

We present a novel device architecture for low set and reset currents in phase change random access memory (PCRAM). In this structure, the sidewall of phase-change film is contacted with the vertical heating layer. In particular, to realize a small contact area of under 50 nm(2) for low reset current, this structure includes stacked layers consisting of extremely thin phase change material (PCM) and conduction films, the fabrication method of which is proposed. We estimated set and reset currents for the proposed structure by the device simulation method. Here, we confirmed that a contact area of 30 nm(2) in this structure, where Ge2Sb2Te5 is used as PCM, provides a reset current of 13.5 mu A and a set current of 4 mu A, which are promising for the scaling down of PCM. Furthermore, it is confirmed that the thinner PCM in this structure provides less thermal disturbance to the neighboring cell. From the results, we expect this structure to be a promising candidate for a high-density nonvolatile memory architecture with PCM. (C) 2015 The Japan Society of Applied Physics

关键词： CONTACT AREA Phase change memory Phase change random access memory pulse code modulation low currents proposed structure reset current

来源：评论

学校读者我要写书评

暂无评论

Fine-Grained Write Scheduling for PCM Performance Improvement under Write Power Budget 20

Fine-Grained Write Scheduling for PCM Performance Improvemen...

引用

IEEE/ACM International Symposium on Low Power Electronics and Design (ISLPED)

作者： Lai, Chun-Hao Yu, Shun-Chih Yang, Chia-Lin Li, Hsiang-Pang Natl Taiwan Univ Dept Comp Sci & Informat Engn Taipei Taiwan Natl Taiwan Univ Grad Inst Networking & Multimedia Taipei Taiwan Natl Taiwan Univ Grad Inst Elect Engn Taipei Taiwan Macronix Int Co Ltd Emerging Syst Lab Hsinchu Taiwan

ISBN: (纸本)9781467380096

Phase-change memory (PCM) has gained much attention recently since it offers several advantages over DRAM, such as high cell density and low leakage power. PCM has similar read power and latency as DRAM;however, its write power and latency are significantly higher than DRAM. Therefore, one challenge with PCM is how to increase write throughput under write power budget constraints. To increase write concurrency, PCM often adopts division programming, where a write occurs in a series of divisions, so that writes to different banks proceed concurrently. In this study, we observe that since the write scheduling granularity in the memory controller differs from the actual write granularity in PCM chips, i.e., requests vs. divisions, the available power budget cannot be fully utilized. We therefore propose enhancing the interface between the memory controller and PCM chips to allow the memory controller to schedule writes in the division granularity. To further increase power budget utilization, we design a variable-length division mechanism to allow the division granularity to be adjusted at runtime according to the available write power budget. Our experimental results show that these techniques improve system performance by up to 65%.

关键词： Memory Controller pulse code modulation power budget DRAM1 gene Writing Latency Cell Density divisions

来源：评论

学校读者我要写书评

暂无评论

Response of a Hybrid Supercapacitor - PEM Fuel Cell System to Fast Fuel Cell Energy Dips 6

Response of a Hybrid Supercapacitor - PEM Fuel Cell System t...

引用

IEEE International Workshop on Applied Measurements for Power Systems (AMPS) Proceedings

作者： Ferrero, R. Toscani, S. Dotelli, G. Stampino, P. Gallo Latorrata, S. Univ Liverpool Dept Elect Engn & Elect Brownlow Hill Liverpool L69 3GJ Merseyside England Politecn Milan Dip Elettron Informaz & Bioingn I-20133 Milan Italy Politecn Milan Dept Chem Mat & Chem Engn G Natta I-20133 Milan Italy

ISBN: (纸本)9781479999989

PEM fuel cell (FC) operation is likely to be characterized by voltage dips on time scales shorter than 1 s, arising from temporary flooding of gas channels or porous layers, particularly when the FC is operated at high humidity levels. If supercapacitors are employed together with the FC as energy storage systems, they can make up for the temporary lack of energy produced by the FC. However, the steep slopes of the voltage dips affect the energy that can be actually delivered by the supercapacitor because of the frequency dependence of its capacitance, and this should be taken into account in sizing the supercapacitor. In this paper, the supercapacitor response to a FC voltage dip is simulated and discussed, based on an experimentally identified supercapacitor model and a typical voltage dip measured on a single PEM FC.

关键词： energy storage fuel cell power plants hybrid power systems porous materials proton exchange membrane fuel cells supercapacitors PEM fuel cell system energy storage systems fast fuel cell energy dips gas channel flooding hybrid supercapacitor porous layers supercapacitor model voltage dips Capacitance Fuel cells Humidity Supercapacitors Voltage fluctuations Voltage measurement voltage sags Supercapacitors fuel cell power plants energy storage Proton exchange membrane fuel cells fuel cell power systems Voltage fluctuations fuel batteries Hybrid power systems voltage measurement capacitance Porous materials Energy storage systems mucin 1 pulse code modulation

来源：评论

学校读者我要写书评

暂无评论

Linear Encoder-Decoder-Controller Design over Channels with Packet Loss and Quantization Noise

Linear Encoder-Decoder-Controller Design over Channels with ...

引用

European Control Conference (ECC)

作者： Dey, S. Chiuso, A. Schenato, L. Uppsala Univ Dept Signals & Syst SE-75121 Uppsala Sweden Univ Padua Dept Informat Engn I-35131 Padua Italy

ISBN: (纸本)9783952426937

In this paper we consider the problem of designing coding and decoding schemes for linear control design of a scalar unstable stochastic linear system in the presence of a wireless communication channel between the sensor and the estimator. In particular, we consider a communication channel which is prone to packet loss and includes quantization noise due to its limited capacity. We first study the case of perfect channel feedback, where the transmitter is aware of the quantization noise and the packet loss history of the channel. We show that in this case, the optimal strategy among all possible linear encoders corresponds to the transmission of the Kalman filter innovation (the difference between the filtered state estimate at the transmitter and the predicted state estimate at the receiver) similarly to the differential pulse-code modulation (DPCM). Although the critical Signal-to-Quantization Noise Ratio (SQNR) required for stabilizing the system is the same for innovation forwarding as well as measurement forwarding at the transmitter, the latter is strictly suboptimal in terms of control performance. For the case of imperfect feedback, we assume that the channel feedback or acknowledgement is randomly lost with a certain erasure probability, rendering the transmitter ignorant of the control action taken by the receiver and subsequently applied to the plant. We propose several heuristic strategies for a suboptimal Kalman filter design at the transmitter based on estimation of the channel feedback status and compare their performances via numerical simulation studies.

关键词： Kalman filters control system synthesis feedback linear systems packet radio networks probability pulse code modulation stability stochastic systems telecommunication channels telecommunication control DPCM Kalman filter innovation SQNR channel feedback differential pulse-code modulation erasure probability imperfect feedback linear encoder-decoder-controller design numerical simulation packet loss scalar unstable stochastic linear system signal-to-quantization noise ratio stabilization wireless communication channel Channel estimation Encoding Packet loss Quantization (signal) Receivers Transmitters

来源：评论

学校读者我要写书评

暂无评论

Electrical Circuit Modeling of A PEM Fuel Cell Including Compressor Effect 58

Electrical Circuit Modeling of A PEM Fuel Cell Including Com...

引用

IEEE 58th International Midwest Symposium on Circuits and Systems (MWSCAS)

作者： Nabag, Mahmoud Fardoun, Abbas A. Hejase, Hassan A. N. Al-Marzouqi, Ali UAE Univ POB 15551 Al Ain U Arab Emirates

ISBN: (纸本)9781467365574

This study aims to investigate the development of an Electrical Circuit Model (ECM) that represents the behavior of a PEM fuel cell system. The ECM parameters are identified based on sets of impedance data obtained by using a characterization process known as Electrochemical Impedance Spectroscopy (EIS). The measured impedance is fitted to an ECM using a nonlinear least-square fitting method. The proposed ECM is able to represent the effect of the compressor. The proposed model is validated using a commercial fuel cell power module. In general, such model representation is useful for analyzing the effects of the operating conditions on the fuel cell performance, efficiency and durability.

关键词： Polymer electrolyte membrane fuel cells Exceptional Case Marking electronic countermeasures fuel cell power systems mucin 1 pulse code modulation Compressors fuel batteries Electricity Operating conditions Durability COMMERCIAL FUELS

来源：评论

学校读者我要写书评

暂无评论

Secret Key Watermarking in WAV Audio file in Perceptual Domain 1

Secret Key Watermarking in WAV Audio file in Perceptual Doma...

引用

International Conference On Futuristic Trends in Computational Analysis and Knowledge Management

作者： Bibhu, Vimal Kushwaha, P. K. Kohli, Rashi Singh, Divya Amity Univ Dept CSE Greater Noida UP India

ISBN: (纸本)9781479984336

Digital audio watermarking is a system of insertion and detection of the key which called watermarking key in host audio to prove the intellectual property right of the audio files. In this paper I proposed an enhanced method for watermark generation and embedding according to input audio clip. The generated key is embedded in audio clip with sampling rate of 44.1 KHz with consideration of properties of perceptual domain of human auditory system. Audio clip sequences particularly uses th direct sequence spread spectrum by utilizing the concept of watermark key. The embedding algorithm creates 128 samples and calculates masking threshold value. The Fast Fourier Transform operates at 128 points at each samples and single bit of key is added. After that 128 point reverse mode of Fast Fourier Transformation is taken to write the audio samples in output sequences. The extraction algorithm reads both original and watermarked audio clips and matches each bits from both input audio samples to determine the differences. If there is difference, it is considered as key bit difference and extracted.

关键词： Human Auditory System Discrete Fourier Transform Fast Fourier Transform Signal to Mask Ratio pulse code modulation

来源：评论

学校读者我要写书评

暂无评论

Thermal Time Shifting: Leveraging Phase Change Materials to Reduce Cooling Costs in Warehouse-Scale Computers 15

Thermal Time Shifting: Leveraging Phase Change Materials to ...

引用

ACM/IEEE 42nd Annual International Symposium on Computer Architecture (ISCA)

作者： Skach, Matt Arora, Manish Hsu, Chang-Hong Li, Qi Tullsen, Dean Tang, Lingjia Mars, Jason Univ Michigan Ann Arbor MI 48109 USA Adv Micro Devices Inc Sunnyvale CA 94088 USA Univ Calif San Diego San Diego CA 92103 USA

ISBN: (纸本)9781450334020

Datacenters, or warehouse scale computers, are rapidly increasing in size and power consumption. However, this growth comes at the cost of an increasing thermal load that must be removed to prevent overheating and server failure. In this paper, we propose to use phase changing materials (PCM) to shape the thermal load of a datacenter, absorbing and releasing heat when it is advantageous to do so. We present and validate a methodology to study the impact of PCM on a datacenter, and evaluate two important opportunities for cost savings. We find that in a datacenter with full cooling system subscription, PCM can reduce the necessary cooling system size by up to 12% without impacting peak throughput, or increase the number of servers by up to 14.6% without increasing the cooling load. In a thermally constrained setting, PCM can increase peak throughput up to 69% while delaying the onset of thermal limits by over 3 hours.

关键词： data center pulse code modulation cost analysis Thermal loading Servers Computers Phase change materials Overheating thermal time COOLING SYSTEM

来源：评论

学校读者我要写书评

暂无评论

Adaptive Sprinting: How to Get the Most Out of Phase Change Based Passive Cooling 20

Adaptive Sprinting: How to Get the Most Out of Phase Change ...

引用

IEEE/ACM International Symposium on Low Power Electronics and Design (ISLPED)

作者： Kaplan, Fulya Coskun, Ayse K. Boston Univ ECE Dept Boston MA 02215 USA

ISBN: (纸本)9781467380096

CMOS scaling trends lead to elevated on-chip temperatures, which substantially limit the performance of today's processors. To improve thermal efficiency, Phase Change Materials (PCMs) have recently been used as passive cooling solutions. PCMs store large amount of heat at near-constant temperature during phase change, allowing strategies such as computational sprinting. While existing sprinting methods allow short performance boosts, there is significant unexplored potential in improving performance on systems with PCM-enhanced cooling. To this end, this paper proposes a novel run time management policy driven by observations that are not captured by prior techniques: (i) PCM melts non-uniformly due to spatially heterogeneous on-chip heat distribution;(ii) power consumption during sprinting is highly application dependent and assuming a fixed sprinting power leads to lower thermal efficiency;(iii) if we monitor the remaining PCM energy at various locations, we can utilize the PCM heat storage capability much more efficiently. The proposed Adaptive Sprinting policy exploits these observations to extend sprinting duration for increased performance gains. Our policy monitors the remaining PCM energy corresponding to each core at run time, and using this information, it decides on the number, the location and the voltage-frequency (V/f) setting of the sprinting cores. Experimental evaluation including a detailed phase change thermal model demonstrates 29% performance improvement, 22% energy savings, and 43% energy delay product (EDP) reduction on average, compared to prior strategies.

关键词： Phase transtormations performance boost pulse code modulation Runtime Cooling out of phase thermal model core thermal efficiency energy saving system-on-chip Policies

来源：评论

学校读者我要写书评

暂无评论

Greater than 2-bits/cell MLC Storage for Ultra High Density Phase Change Memory Using a Novel Sensing Scheme

Greater than 2-bits/cell MLC Storage for Ultra High Density ...

引用

35th Anniversary of the Symposium on VLSI Technology (VLSI Technology)

作者： Wu, J. Y. Khwa, W. S. Lee, M. H. Li, H. P. Lai, S. C. Su, T. H. Wei, M. L. Wang, T. Y. BrightSky, M. Chen, T. S. Chien, W. C. Kim, S. Cheek, R. Cheng, H. Y. Lai, E. K. Zhu, Y. Lung, H. L. Lam, C. Macronix Int Co Ltd IBM Macronix Joint PCRAM Project Emerging Cent Lab 16 Li Hsin Rd Hsinchu Sci Pk Taiwan IBM T J Watson Res Ctr Yorktown Hts NY USA

ISBN: (纸本)9784863485013

Multi-level-cell (MLC) is a critical technology to achieve low bit cost for phase change memory. However, resistance drift is an intrinsic material property that kills memory window and imposes formidable challenges for MLC. In this work, we report a radically different sensing concept that exploits the non-linear R-V characteristics of PCM that can easily accommodate 8 resistance levels in three independent 10X sensing windows (100K Omega similar to 1M Omega X 3) all on same read speed. Each sensing window only needs to store 2 similar to 3 resistance levels instead of 8 levels needed in conventional MLC method, thus can tolerate resistance drift without closing the memory windows. A maximum of 16 levels of MLC is demonstrated on a 256Mb chip that is suitable for 4-bits/cell application.

关键词： microprocessor logic circuit MLC1 gene Phase change memory Material properties windows windows RXFP2 gene pulse code modulation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：