Variance and Passivity Constrained Fuzzy Control for Nonlinear Ship Steering Systems with State Multiplicative Noises

The variance and passivity constrained fuzzy control problem for the nonlinear ship steering systems with state multiplicative noises is investigated. The continuous-time Takagi-Sugeno fuzzy model is used to represent the nonlinear ship steering systems with state multiplicative noises. In order to simultaneously achieve variance, passivity, and stability performances, some sufficient conditions are derived based on the Lyapunov theory. Employing the matrix transformation technique, these sufficient conditions can be expressed in terms of linear matrix inequalities. By solving the corresponding linear matrix inequality conditions, a parallel distributed compensation based fuzzy controller can be obtained to guarantee the stability of the closed-loop nonlinear ship steering systems subject to variance and passivity performance constraints. Finally, a numerical simulation example is provided to illustrate the usefulness and applicability of the proposed multiple performance constrained fuzzy control method

Nardosinane-Type Sesquiterpenoids from the Formosan Soft Coral Paralemnalia thyrsoides

Five new nardosinane-type sesquiterpenoids, paralemnolins Q–U (1–5), along with three known compounds (6–8), were isolated from the Formosan soft coral Paralemnalia thyrsoides. The structures of new metabolites were elucidated on the basis of extensive spectroscopic methods, and the absolute configuration of 1 was determined by the application of Mosher’s method on 1. Among these metabolites, 1 and 3 are rarely found nardosinane-type sesquiterpenoids, possessing novel polycyclic structures. Compounds 1, 3, 6 and 7 were found to possess neuroprotective activity

Variance and Passivity Constrained Fuzzy Control for Nonlinear Ship Steering Systems with State Multiplicative Noises

The variance and passivity constrained fuzzy control problem for the nonlinear ship steering systems with state multiplicative noises is investigated. The continuous-time Takagi-Sugeno fuzzy model is used to represent the nonlinear ship steering systems with state multiplicative noises. In order to simultaneously achieve variance, passivity, and stability performances, some sufficient conditions are derived based on the Lyapunov theory. Employing the matrix transformation technique, these sufficient conditions can be expressed in terms of linear matrix inequalities. By solving the corresponding linear matrix inequality conditions, a parallel distributed compensation based fuzzy controller can be obtained to guarantee the stability of the closed-loop nonlinear ship steering systems subject to variance and passivity performance constraints. Finally, a numerical simulation example is provided to illustrate the usefulness and applicability of the proposed multiple performance constrained fuzzy control method

Design and Implementation of a Matrix Decomposition based Precoding Parameterization scheme for MIMO-OFDM Systems

In recent years, Multiple-Input and Multiple-output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) systems has been widely used in a variety of wireless communication systems. The closed-loop MIMO-OFDM system is enhanced by the introduction of pre-coding technology, which feedbacks the channel state information obtained from the receiver to the transmitter in order to pre-code the data for transmission. The advantage of pre-coding is that the channel effect can be pre-compensated, thereby reducing multipath interference for a transmission channel consisting of multiple independent parallel sub-channels. The complexity of the MIMO signal detection can be reduced due to the precoding measure as well. Most linear pre-coding schemes are based on the method of channel matrix decomposition. Popular schemes include Singular Value Decomposition (SVD) , Geometric Mean Decomposition (GMD) and so on. In this thesis, we focus on the most efficient GMD scheme. In GMD, the channel matrix is decomposed into the product of three matrices, i.e., the pre-coding matrix, the equivalent channel matrix and the receiver matrix used in signal detection. Among them, the precoding matrix information must be fedback to the transmitter. The amount of feedback data, however, will occupy considerable communication bandwdith. Therefore, it is essential to compress the pre-coding matrix information before feedback, i.e.,. 'parameterization' of the pre-coding matrix. This calls for additional matrix decomposition and parameter quantization. In this thesis, we present a new parameterization algorithm and its hardware implementation. The parameterization is achieved by perfroming the QR decomposition via Givens rotations first and using the rotation angles of the Givens rotations as the feedback to reconstruct the precoding matrix. Since low complexity coordinate rotations digital computer (CORDIC) modules are employed to implement the Givens rotations, the micro-rotation sequence, instead of the real rotation angle information, is recorded. We can thus reduce the amount of feedback data by 75% and the saving is in line with the spec of IEEE 802.11ac. Based on the proposed parameterization scheme, the corresponding hardware circuit design and chip implementation are also developed. The design can support a MIMO system with the number of 4×4 antennas and has a high throughput performance. We follow the specs of IEEE 802.11ac to develop the design. A highly parallel architecture and low complexity CORDIC modules are adopted to enhance the throughput while confining the hardware complexity. Various circuit optimization skills are also introduced to achieve a high operating frequency and a low complexity chip implementation. The 4×4 pre-coding matrix parameterization chip is realized in a TSMC 90nm CMOS process technology. The implementation result indicates that the design, with a chip area of 1.23 mm2 and a working frequency up to 194.93MHz, can parameterize a 4×4 precoding matrix every 4 clock cycles. This corresponds to a throughput of 48.73M matrix parameterizations per second. The total power consumption is 28.3 mW. The gate count efficiency (throughput divided by the gate count) is 644.57, which is much superior to the numbers of similar designs reported in the literatures.近年來多輸入多輸出正交分頻多工系統已被廣泛使用在各種無線通訊系統上。而預編碼技術的引進，透過在接收端所取得的通道狀態資訊回傳到傳送端，以利對傳送資料進行預編碼運算，使得此系統成為一個閉迴路的架構。預編碼的優點可以對通道效應進行預補償，降低多重路徑干擾，使得傳輸通道呈現互相獨立平行的多重子通道，進而降低訊號偵測的運算複雜度。常見的線性預編碼技術多是針對通道矩陣進行分解，方法如奇異值分解演算法、幾何平均值演算法等。 透過以上矩陣分解法將通道矩陣資訊分解為三種矩陣的乘積，分別為預編碼矩陣、等效通道矩陣以及在進行訊號偵測時所使用到的接收矩陣。然而直接回傳預編碼矩陣的資料量過於龐大。因此，如何對預編碼矩陣訊息進行壓縮後回傳也是一個重要的議題。此項訊息壓縮被稱為預編碼矩陣的參數化，包括預編碼矩陣的分解與旋轉係數的量化。本論文透過QR分解之參數化演算法，以分解過程中的Givens Rotation的旋轉角度來代表預編碼矩陣訊息。並利用低複雜度的座標旋轉數位計數器(CORDIC)來進行Givens Rotation的特性實現，以CORDIC運算的旋轉方向序列來取代實際的角度資訊，此法能有效的降低回傳的資料量。以4×4預編碼矩陣為例，總回傳資料量可降低達75%，且符合IEEE 802.11ac中的回傳資料量標準。 針對所提出之預編碼矩陣參數化方法，本論文也開發對應之硬體電路設計以及晶片實作，可支援多輸入多輸出天線數為4×4，並具有高輸出吞吐量的特性。係依循IEEE 802.11ac規範，並根據演算法進行電路的平行化架構設計以及使用低複雜度的座標旋轉數位計算器簡化運算電路。此外也採用許多電路最佳化技巧來達到高工作頻率以及低運算複雜度的晶片。本晶片透過台積電90奈米製程下線，其晶片面積為1.23mm2，工作頻率可達194.93MHz，且每四個時脈週期可以完成一筆預編碼矩陣的參數化運算。晶片的輸出率達每秒執行48.73M個矩陣分解運算，總功率消耗為28.3mW。本晶片設計之Gate count efficiency為644.57，也大幅領先現有文獻之設計。摘要 i Abstract ii 目錄 iv 表目錄 vi 圖目錄 vii 第一章 緒論 1 1.1 研究背景 1 1.1.1 多輸入多輸出技術 2 1.1.2 正交分頻多工技術 3 1.1.3 IEEE 802.11ac簡介 3 1.1.4 預編碼技術簡介 6 1.1.5 IEEE 802.11 ac預編碼回傳技術簡介 7 1.2 研究動機 9 1.3 論文架構 10 第二章 預編碼與參數化技術介紹 11 2.1 預編碼回傳技術介紹 11 2.1.1 Codebook回傳技術介紹 12 2.1.2 參數化回傳技術介紹 13 2.1.3 預編碼回傳技術分析與選擇 14 2.2 預編碼技術對於參數化分解之影響分析及比較 15 2.2.1幾何平均值分解法 16 2.2.2 Generalized幾何平均值分解法 21 2.2.3 D&C幾何平均值分解法 25 2.3 預編碼技術演算法分析與選擇 34 2.3.1 基於不同參數化回傳資料量之分析及選擇 34 2.3.2 不同預編碼技術對參數化回傳之分析及選擇 35 第三章 參數化分解預編碼矩陣演算法 36 3.1 預編碼矩陣參數化分解法 36 3.1.1 參數化分解法 36 3.1.2 參數量化 41 3.1.3座標旋轉數位計數器原理 42 3.2 效能分析 44 3.3 複雜度分析 47 第四章 恆定吞吐量之低複雜度4×4預編碼矩陣參數化電路設計 49 4.1 硬體規格定義 49 4.2 硬體設計與實現 50 4.2.1座標旋轉數位計數器硬體模組設計 50 4.2.2 系統架構 52 4.2.3 系統平行化設計 53 4.2.4 硬體共享設計 55 4.3 功能模組設計 55 4.3.1 前處理硬體模組 56 4.3.2參數化運算模組 57 4.3.3 資料輸出模組 58 4.4 晶片實現 58 4.4.1晶片設計與實作流程 58 4.4.2定點數模擬與分析 60 4.4.3 晶片實作考量 63 4.4.4 硬體驗證 63 4.4.5 晶片規格與總結 64 4.4.6 晶片效能比較 66 第五章 結論與展望 68 參考文獻 7

Using In Vivo Confocal Neuroimaging to observe rat retinal wave

過去科學家研究證實在脊椎動物早期發育的視網膜上有神經訊號同步放電的現象，稱之為視網膜波，會影響視網膜與腦部的連結。過去研究神經訊號現象使用電生理學測量活體或離體培養視網膜的電訊號或是使用光學影像技術觀測離體培養視網膜的鈣離子螢光影像，這些都是侵入式的方法或需將動物犧牲。因為眼睛的可穿透性質，身為中樞神經系統一部分的視網膜是唯一可藉由非侵入式光顯微技術觀察的組織，所以我們利用ICON技術去觀察剛出生幼鼠視網膜的神經活動現象。ICON此種觀察方法可以讓同隻幼鼠被重複的觀測而不被犧牲或造成細胞的傷害，且提供了細胞解析度的眼底觀測方法，將可以更深入的研究神經細胞的活動。 我們的實驗雖然因為取樣範圍而無法看出視網膜波的空間性質，但是確認了活體生物內的神經活動現象，並且將可以長時間且重複的觀察同一個樣本的發育，所以對於神經細胞放電訊號研究提供了活體螢光影像的可能，未來可研究規律性自發神經活動作用所引發的神經細胞群間之連線改變（一般在數日或數週後發生）或動作電位引發神經細胞間的突觸可塑性（在數毫秒發生）。It has been shown that the spontaneous activity of neurons, called retinal wave, in immature retina of vertebrate will influence retina growth and connection between CNS.The phenomenon using electrophysiological measurment in vivo or in vitro and observation of optical microscope from cultured retina were successfully detected, but those technology were invasive.Because of the transparency of the eyes, retina is the only part of central nervous system (CNS) that can be investigated noninvasively by optical imaging. In this report, we applied in vivo confocal neuroimaging (ICON) to detect the electrical activities of neurons in postnatal rat retina. ICON permits repeated observation of rats, preventing cell damage as well as rat sacrifice. In addition, ICON has the potential to provide subcellular resolution at fundus, so that the retinal neuron activities can be studied in more detail. Our experiments can’t approve the spatial property of the retinal waves, but confirmed that the neural activity within living organisms. The same rat can be repeatedly observed for a long time, thus provideing a possibility of detcting neural activity in vivo. We can investigate the relationship between the effects triggered by patterned spontaneous activity on the connectivity between different neuron populations (happening from days to weeks after birth) and the plasticity of the synapses between neurons as induced by action potential (occurring in milliseconds to seconds)

Fuzzy Stabilization for Nonlinear Discrete Ship Steering Stochastic Systems Subject to State Variance and Passivity Constraints

For nonlinear discrete-time stochastic systems, a fuzzy controller design methodology is developed in this paper subject to state variance constraint and passivity constraint. According to fuzzy model based control technique, the nonlinear discrete-time stochastic systems considered in this paper are represented by the discrete-time Takagi-Sugeno fuzzy models with multiplicative noise. Employing Lyapunov stability theory, upper bound covariance control theory, and passivity theory, some sufficient conditions are derived to find parallel distributed compensation based fuzzy controllers. In order to solve these sufficient conditions, an iterative linear matrix inequality algorithm is applied based on the linear matrix inequality technique. Finally, the fuzzy stabilization problem for nonlinear discrete ship steering stochastic systems is investigated in the numerical example to illustrate the feasibility and validity of proposed fuzzy controller design method

Fuzzy Stabilization for Nonlinear Discrete Ship Steering Stochastic Systems Subject to State Variance and Passivity Constraints

For nonlinear discrete-time stochastic systems, a fuzzy controller design methodology is developed in this paper subject to state variance constraint and passivity constraint. According to fuzzy model based control technique, the nonlinear discrete-time stochastic systems considered in this paper are represented by the discrete-time Takagi-Sugeno fuzzy models with multiplicative noise. Employing Lyapunov stability theory, upper bound covariance control theory, and passivity theory, some sufficient conditions are derived to find parallel distributed compensation based fuzzy controllers. In order to solve these sufficient conditions, an iterative linear matrix inequality algorithm is applied based on the linear matrix inequality technique. Finally, the fuzzy stabilization problem for nonlinear discrete ship steering stochastic systems is investigated in the numerical example to illustrate the feasibility and validity of proposed fuzzy controller design method

Seismic Analysis of a Viscoelastic Damping Isolator

Seismic prevention issues are discussed much more seriously around the world after Fukushima earthquake, Japan, April 2011, especially for those countries which are near the earthquake zone. Approximately 1.8×1012 kilograms of explosive energy will be released from a magnitude 9 earthquake. It destroys most of the unprotected infrastructure within several tens of miles in diameter from the epicenter. People can feel the earthquake even if living hundreds of miles away. This study is a seismic simulation analysis for an innovated and improved design of viscoelastic damping isolator, which can be more effectively applied to earthquake prevention and damage reduction of high-rise buildings, roads, bridges, power generation facilities, and so forth, from earthquake disaster. Solidworks graphic software is used to draw the 3D geometric model of the viscoelastic isolator. The dynamic behavior of the viscoelastic isolator through shock impact of specific earthquake loading, recorded by a seismometer, is obtained via ANSYS finite element package. The amplitude of the isolator is quickly reduced by the viscoelastic material in the device and is shown in a time response diagram. The result of this analysis can be a crucial reference when improving the design of a seismic isolator