Browsing by Author "Kuo, Chia-Chen"

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A 3T1R Nonvolatile TCAM Using MLC ReRAM for Frequent-Off Instant-On Filters in IoT and Big-Data Processing
(2017-06-01)
Chang, Meng-Fan
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Lin, Chien-Chen
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Lee, Albert
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Chiang, Yen-Ning
;
Kuo, Chia-Chen
Existing nonvolatile ternary content-addressable-memory (nvTCAM) suffers from limited word-length (WDL), large write-energy (E-W) and search-energy (E-S), and large cell area (A). This paper develops a 3T1R nvTCAM cell using a single multiple-level cell (MLC)-resistive RAM (ReRAM) device to achieve long WDL, lower E-W and E-S, and reduced cell area. Two peripheral control schemes were developed, dual-replica-row self-timed and invalid-entry power consumption suppression (IEPCS), for the suppression of dc current in 3T1R nvTCAM cells in order to reduce E-S. Two versions of the IEPCS scheme were developed (basic and charge-recycle-controlled) to alter the tradeoff between area overhead and power consumption in the updating of invalid-bits. A 128 b x 64 b 3T1R nvTCAM macro was fabricated using back-end-of-line ReRAM under 90-nm CMOS process. The fabricated MLC-based 3T1R nvTCAM macro achieved sub-1-ns search-delay and sub-6-ns wake-up time with supply voltage of 1 V and WDL = 64 b.
A 3T1R Nonvolatile TCAM Using MLC ReRAM with Sub-1ns Search Time
(2015-01-01)
Chang, Meng-Fan
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Lin, Chien-Chen
;
Lee, Albert
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Kuo, Chia-Chen
;
Yang, Geng-Hau
A drawdown solution for constant-flux pumping in a confined anticline aquifer
(2011-08-05)
Chen, Yen-Ju
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Yeh, Hund-Der
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Kuo, Chia-Chen
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環境工程研究所
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Institute of Environmental Engineering
An An anticline, known as a convex-upward fold in layers of rock, commonly is formed during lateral compression, which may be elected as a potential site for carbon sequestration. A mathematical model is developed in this study for describing the steady-state drawdown distribution in an anticline aquifer in response to the constant-flux pumping. The topographical shape of the anticline is mimicked by three successive blocks. The solution is obtained by applying the infinite Fourier transform and the finite Fourier cosine transform in each blocks and acquiring the hydraulic continuities between the blocks. Simulated results reveal that the introduction of a thin-limbs or narrow-ridged anticline would produce a much greater head drop in the ridge zone. For a well of constant pumping rate, the dimensionless drawdown around the well increases with decreasing well screen length or/and aquifer anisotropy ratio. An examination of the effect of well location on the drawdown reveals that the partially penetrating well located at the top-middle of the ridge zone produces the largest drawdown. The simulation of the flow in an anticline aquifer based on MODFLOW results in slightly smaller drawdown values in most regions when compared with those predicted by the present solution. The present solution can also be used to simulate the flow in a slab-shaped aquifer or a hillslope aquifer. It can be applied to determine the aquifer parameters if coupled with an optimization scheme and to provide the basis for selecting a potential site for carbon sequestration in the future as well. (C) 2011 Elsevier B.V. All rights reserved.
A ReRAM-Based 4T2R Nonvolatile TCAM Using RC-Filtered Stress-Decoupled Scheme for Frequent-OFF Instant-ON Search Engines Used in IoT and Big-Data Processing
(2016-11)
Chang, Meng-Fan
;
Huang, Lie-Yue
;
Lin, Wen-Zhang
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Chiang, Yen-Ning
;
Kuo, Chia-Chen
This paper outlines the RC-filtered stress-decoupled (RCSD) 4T2R nonvolatile TCAM (nvTCAM) with the following benefits: 1) reduced NVM-stress; 2) reduced ML parasitic load; and 3) suppression of match-line (ML) leakage current from match cells. The RCSD-4T2R cell achieves a 6x reduction in NVM-stress, a 2x increase in maximum wordlength, and a 2x reduction in search delay. In this paper, we also outline two search schemes, referred to as dynamic source-line pulse controlled (DSL-PC) search and dataline-pulse controlled (DL-PC) search, which were developed specifically for the RCSD-4T2R nvTCAM. We fabricated a 128 x 32 b RCSD-4T2R nvTCAM macro with HfO ReRAM using a 180 nm CMOS process. Using the DSL-PC and DL-PC schemes, the measured search delay of the RCSD-4T2R nvTCAM macro was 1.2 ns under typical VDD.
An analytical solution for heterogeneous and anisotropic anticline reservoirs under well injection
(2010-04-01)
Yeh, Hund-Der
;
Kuo, Chia-Chen
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環境工程研究所
;
Institute of Environmental Engineering
This study develops a mathematical model for describing the steady-state head response to fluid injection into a fully penetrating well in a heterogeneous and anisotropic anticline reservoir. In the model, the upper boundary of the anticline reservoir is approximated by a form of step change in reservoir thickness and the domain of the reservoir is divided into two regions with different hydraulic conductivities. By virtue of the properties of Fourier series, the method of separation of variables is employed to develop the analytical solution of the model. This new solution can be applied to estimating head distributions or injection rates for various geometrical conditions of the reservoir. If the trap is absent, the solution can be utilized to analyze head distributions in the reservoir system with two concentric transmissivity zones. Moreover, if the upper boundary becomes flat and the reservoir is homogeneous and isotropic, the solution reduces to the Thiem equation. (C) 2010 Elsevier Ltd. All rights reserved.
Transient analysis for fluid injection into a dome reservoir
(2011-12-01)
Kuo, Chia-Chen
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Huang, Ching-Sheng
;
Yeh, Hund-Der
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環境工程研究所
;
Institute of Environmental Engineering
A dome-shaped layer can be selected as a storage site for fluid injection. In this study, we develop a mathematical model for simulating transient head distribution in a heterogeneous and anisotropic dome-shaped layer due to a constant-head injection in a fully penetrating well. In the model, a form of step change is adopted to approximate the upper and lower boundaries of the dome and then the layer is split into two regions. The Laplace-domain solution of the model is developed using the Laplace transform and method of separation of variables. The transient injection rate at wellbore can then be obtained based on Darcy's law and Bromwich integral method. The predicted head contours from the head solution show significant vertical flow components near the location of step change in the dome reservoir. The results of sensitivity analysis indicate that the hydraulic conductivity is the most sensitive parameter and the specific storage is the least sensitive one to the injection rate after a short period of injection time. In addition, the injection rate for a dome reservoir is also very sensitive to the change of the height for the reservoir near the injection well (first region) at a very early injection time. In contrast, the injection rate is more sensitive to the change of the height of the second region than that of the first region at late time. This analytical solution may be used as a primary tool to assess the capacity of fluid injection to various dome reservoirs. (C) 2011 Elsevier Ltd. All rights reserved.