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宇宙參數之統計分析與研究 -宇宙微波背景輻射與宇宙殘陷
No full text觀測、理論及統計分析乃宇宙學與日俱進之三大要角,
正確解讀觀測資料是統計分析所被賦予的任務,
而我們的工作即是從宇宙微波背景輻射中,
擷取出攸關宇宙演化的宇宙參數,
此有賴於理論模型資料庫的建立,
以進一步篩選出各個參數值。
我們從宇宙微波背景輻射之統計性質切入,
逐步呈現統計分析中之問題,
並綜合整理此門先驅奮鬥所提之解決之道,
最後將運算方案化為具體之程式碼,
在此我們亦介紹如何加入宇宙殘陷之效應,
此工作可用以了解宇宙殘陷對參數分析之影響程度,
而近來宇宙微波背景輻射之研究,
已轉至對其偏極化之偵測,
若能確定宇宙為波背景輻射偏極化之存在,
這將是對宇宙大霹靂理論的進一步證據。1 統計策略 8
1.1 前言 8
1.2 估計量之評價準則 8
1.3 最大概似估計量 9
1.3.1 Fisher矩陣 12
1.3.2 高斯常態隨機分布 13
1.4 區間估計 16
1.4.1 Frequentist統計 16
1.4.2 Bayes統計 17
1.5 結論 19
2 宇宙微波背景輻射之資料分析 20
2.1 實際的計算問題 20
2.2 宇宙微波背景輻射向異性之統計性質 21
2.3 角冪譜與資料壓縮 22
2.3.1 Fisher矩陣的轉換 22
2.3.2 角冪譜的Fisher矩陣 24
2.4 應用與問題 25
2.4.1 理想化的實驗 25
2.4.2 雜訊 25
2.4.3 Beam-smoothing and Chopping 26
2.5 概似函數的非高斯性 28
3 宇宙參數之估計 30
3.1 前言 30
3.2 X2統計量 32
3.3 宇宙殘陷的影響 33
3.4 偏極化的去簡併效應 34
參考文獻 42
附錄 44
A 宇宙微波背景輻射之資料分析-Fortran 程式碼 44
A.1 準備工作 44
A.2 Program Main 45
A.3 Subroutine Likelihood 45
A.4 Module Calculator 46
A.5 Module Figure 52
A.6 Subroutine Analysis 66
A.7 Module Chi-square 69
A.8 Subroutine Frequentist 72
A.9 Module Graphics 73
A.10 Function Initialsettings 77
A.11 Module IO 77
A.12 Module String 84
A.13 Module global 86
A.14 Module numerical 86
A.15 Module typedef 8
Design and Implementation of a Low-Jitter 6GHz Spread Spectrum Clock Generator for Serial-ATA
No full textEMI (Electro-Magnetic Interference) causes more destruction to the transmitting signal since the operating frequency is higher than before. Spread spectrum clocking (SSC) is a method that can reduce the EMI effectively. This method is more and more popular since it is easy to design and suitable for integrated IC. Serial ATA is a high speed external mass storage device having the SSC specifications as following: a triangular modulation profile with down spread, a 5000 ppm frequency deviation, a 30~33KHz modulation frequency, an EMI reduction larger than 7dB, and a 3ps RMS jitter @ 250 cycles.
Our research is stressed on low-jitter design. Due to the higher operating frequency requirement, design with low-jitter performance becomes more and more important and thus more difficult to realize. VCO phase noise dominates the jitter performance of PLLs. Therefore, we proposed a LC tank VCO with low phase noise characteristic. The simulation results show that the phase noise is -119.8dBc/Hz @1MHz offset voltage and FoM is -190.8.
In this Thesis, a spread spectrum clock generator (SSCG) modulated by a divider is presented. The PLL is fabricated in a 0.18μm CMOS process and the whole SSCG system is integrated and tested on an FPGA board. The simulation results show that all specifications of the Serial ATA have been achieved in our system and the jitter measurement shows that the RMS jitter is 0.4ps @ 250 cycles.TABLE OF CONTENTS
ABSTRACT i
LIST OF FIGURES v
LIST OF TABLES ix
CHAPTER 1 INTRODUCTION 1
1.1 Motivation 1
1.2 Thesis Organization 2
CHAPTER 2 BASIC OF SPREAD SPECTRUM CLOCKING 5
2.1 Specification of Serial ATA for SSC 5
2.2 Fundamental Theory of SSC 6
2.3 Types of SSC Implementation 8
2.4 Jitter Performance 10
CHAPTER 3 FRACTIONAL-N PLL USING Δ-Σ MODULATOR 13
3.1 Principle of Phase-Locked Loop 13
3.2 Analysis of Phase-Locked Loop 14
3.2.1 Voltage Controlled Oscillator 14
3.2.2 PFD with Charge Pump and Loop Filter 15
3.2.3 Linear Model of PLL 17
3.2.4 Phase Noise in PLL 19
3.3 Fractional-N Frequency Synthesis 21
3.3.1 Pulse Swallow 22
3.3.2 Fractional Spurs 24
3.4 Δ-Σ Modulator 26
3.5 Third-Order MASH Δ-Σ Modulator 29
CHAPTER 4 DESIGN OF SPREAD SPECTRUM CLOCK GENERATOR 33
4.1 System Architecture 33
4.2 Voltage Controlled Oscillator 34
4.2.1 LC-VCO Versus Ring-VCO 35
4.2.2 VCO Phase Noise 35
4.2.3 LC-VCO Technique 37
4.2.4 A New LC-VCO with Back-Gate Tuning Technique 39
4.3 Phase/Frequency Detector 40
4.4 Charge Pump 41
4.5 Programmable Charge Pump 43
4.6 Multi-Modulus Divider 44
4.7 Loop Filter 45
4.8 MASH 1-1-1 Δ-Σ Modulator 49
4.9 Triangular Generator 52
CHAPTER 5 SIMULATION RESULTS OF SPREAD SPECTRUM CLOCK GENERATOR 55
5.1 SSCG Behavior Simulation 55
5.2 Circuit Level Simulation 58
5.2.1 Voltage Controlled Oscillator 59
5.2.2 Phase/Frequency Detector and Charge Pump 62
5.2.3 Prescaler 64
5.2.4 Multi-Modulus Divider 64
5.2.5 Closed-Loop Simulation of PLL 65
5.2.6 PLL Implementation 67
5.3 MASH 1-1-1 and Triangular Generator 69
5.4 Closed-Loop Simulation of SSCG 71
CHAPTER 6 CONCLUSION 75
REFERENCE 7
Comparative Nephrotoxicity and Efficacy of antibiotics for the treatment of Gram-Positive Bacterial Infections -- A systematic review and network meta-analysis
No full text細菌的抗藥性在最近這幾十年中不斷的上升，尤其是在革蘭氏陽性菌的抗藥性上的改變造成了醫院內敗血症病人的增加。在美國，革蘭氏陽性菌在加護病房中有高達百分之六十為抗藥性金黃色葡萄球菌。而在台灣，根據2008年全國院內感染偵測系統的報告指出，在醫學中心的加護病房中革蘭氏陽性菌已經有高達百分之八十為抗藥性金黃色葡萄球菌。萬古黴素(Vancomycin)是標準的治療抗藥性金黃色葡萄球菌的藥物，但它的副作用所造成的腎臟毒性卻為人所詬病。隨著藥物發展的日新月異，有多種治療抗藥性金黃色葡萄球菌的抗生素陸續問世，臨床上常使用的藥物包括vancomycin，teicoplanin，linezolid，tigecycline以及telavancin。經過文獻回顧後，我們發現之前的研究多著重於一對一藥物配對分析。然而，對於臨床決策而言，我們更希望知道這些藥物的臨床治療效力及副作用上，彼此之間的差異性。於是，我們設計了這個研究來針對革蘭氏陽性菌感染的病人，使用不同的抗生素，所造成的腎毒性及治療效力的網路統合分析。
研究方法：
我們搜尋了Medline，Cochrane Library，Pubmed資料庫中與vancomycin，teicoplanin，linezolid，teicoplanin，tigecycline以及telavancin所有相關用來治療革蘭氏陽性菌感染的臨床試驗及統合性分析。收錄的研究時間從1988年1月起到2011年12月為止。除此之外，我們也從美國衛生研究院的臨床研究註冊系統中找尋與這些藥相關的研究結果並加入我們的系統性回顧中。從這些研究內容裡面，我們收集了作者，研究設計，性別，平均年齡，病人數，感染部位，藥物的種類及用量，臨床治療成功率，微生物清除率，藥物副作用及腎毒性。我們以腎毒性作為藥物安全性的評估，以臨床治療成功率及微生物清除率作為藥物療效的評估，把收錄到的研究，進行直接與間接統合性分析。
研究結果：
根據系統性文獻搜尋，我們找出390篇相關研究，符合納入條件後共有26篇隨機臨床試驗，共計8094位參加者。在直接比較的統合性分析結果方面，teicoplanin比起vancomycin所造成的腎毒性來的低(勝算比為0.37, 95%信頼區間為0.19-0.70)。但在臨床治癒率上，這些藥物皆無統計學的差異。而在微生物清除率上，linezolid 比起vancomycin有更好的效果(勝算比為1.29, 95%信頼區間為1.02-1.63)。
經過間接的網路統合分析發現，在這些抗生素中，telavancin造成腎毒性的風險最高。Telavancin比起teicoplanin (勝算比為8.63, 95%信頼區間為2.26-66.47)跟linezolid (勝算比為6.88, 95%信頼區間為1.50-58.15)的腎毒性都來的高出許多。而這五種抗生素之中，teicoplanin是腎毒性最低的藥物，不管是間接比較或直接比較法都支持這樣的結果。而linezolid不只在臨床療效上優於vancomycin(勝算比為1.4, 95%信頼區間為1.01-1.93)，在微生物清除率上也比起傳統的vancomycin有更好的表現(勝算比為1.32, 95%信頼區間為1.03-1.7)。
結論：
本研究發現在藥物安全性上，telavancin造成腎毒性的風險最高，teicoplanin造成腎毒性的風險最低。在療效上，linezolid有最佳的臨床治療效果與微生物清除率。Background：Bacterial resistance has risen dramatically during the last few decades and infections caused by Gram-positive organisms constituting nowadays the main cause of sepsis in in-hospital patients. In the United States, more than 60% of the Gram-positive organisms isolates in intensive care units are methicillin resistance Staphylococcus aureus now (MRSA). In Taiwan nosocomial surveillance system reports, the prevalence of MRSA in Gram-positive organisms is up to 80% in medical centers. There is uncertainty as to whether vancomycin in cause permanent or temporary kidney damage. Many studies have shown an increased risk of kidney failure after vancomycin treatment. At least five agents of antibiotics, including vancomycin, teicoplanin, linezolid, tigecycline and telavancin can against MRSA infection. The efficacies and nephrotoxicity of different antibiotics have been studies by traditional meta-analysis method. However, for clinical decisions, we need to know the safety and effective of each possible in comparison with all relevant alternatives, not just one. We conducted a network meta-analysis study of comparative nephrotoxicity and efficacy of antibiotics for the treatment of Gram-positive bacterial infections.
Method： We searched the Medline, Cochrane Library, PubMed databases to identify published clinical trials in which vancomycin, linezolid, telavancin, teicoplanin and tigecycline were used to treat Gram positive infection from January 1988 to December 2011. We also searched trials in “clnicaltrials.gov” which is a service of clinical trial registry in U.S. National institutes of Health. Among included articles, the following variables were abstracted and collected in a standardized form: authors; year of publication ; study design; gender; mean age; number of patients ; site of infection; antimicrobial agents and dosages used ; microorganism species and susceptibility; clinical cure outcome; microbiological eradication; survival; adverse events; and serious adverse events. The safety outcome is nephrotoxicity and efficacy outcomes are clinical cure and microbiological eradication. We analyzed direct and indirect comparisons of different treatments using Bayesian network meta-analysis.
Results：Literature searching and systematic review identified 390 non-duplicate citations, of which 26 trials comprising 8094 participants were included. In direct comparison, lower risk of nephrotoxicity in teicoplanin compared with vancomycin (OR: 0.37, 95% C.I: 0.19-0.70). There was no statistical difference in clinical cure between these antibiotic agents. In microbiological eradication, linezolid is significant more effective than vancomycin (OR: 1.29, 95%C.I: 1.02-1.63). In indirect comparison, telavancin was the antibiotics of most high risk nephrotoxicity than others, compare with teicoplanin (OR: 8.63, 95% credible interval (CrI): 2.26-66.47) and linezolid (OR: 6.88, 95%CrI: 1.50-58.15). The lower risk of nephrotoxicity with teicoplanin was observed. Compared with vancomycin, teicoplanin showed significant decrease the risk of nephrotoxicity (OR: 0.29, 95%CrI: 0.11-0.67). Linezolid was superior to vancomycin in clinical cure (OR: 1.4, 95%CrI: 1.01-1.93) and microbiological eradication (OR: 1.32, 95%CrI: 1.03-1.7).
Conclusion：Telavancin is associated with a greater risk of renal toxicity than other comparators. It is a novel concept in traditional and network meta-analysis study. Teicoplanin appear the lower risk of nephrotoxicity in treatment of Gram positive bacterial infection. Linezolid showed a significant superior efficacy in clinical cure and microbiological eradication than others. Better performed randomized trials on antibiotic treatment of Gram-positive infection are needed to build a more robust network meta-analysis
Study of Optoelectronic Properties of Nano Structure InGaN/GaN Light Emitting Diodes
No full text在奈米製程技術的進步發展下，有許多新奇的發光二極體結構被提出並表現出較好的元件特性，例如：奈米柱、奈米桿以及光子晶體元件等等。為了分析這些特殊的結構，我們利用了原子價力場模型與一致性的帕松、飄移擴散以及薛丁格方程式去設計、分析不同奈米結構下的氮化銦鎵/氮化鎵量子井發光二極體。首先，我們計算並描述了光譜能量藍移與應力釋放在不同尺寸的多重量子井奈米柱下的關係。並且，我們也研究了不同深度的蝕刻奈米洞陣列之氮化銦鎵/氮化鎵量子井發光二極體，而當奈米洞相當接近或穿透過量子井區域的時候，應力釋放效應與表面狀態效應對元件發光性質的影響被我們所分析。我們相信應力的釋放與奈米結構維度的尺寸將主要的影響其發光二極體的發光頻譜。在本篇論文中，我們將非常詳細地討論這些訊息。而應力鬆弛、壓電效應、表面狀態效應以及非輻射性複合機制等等在發光二極體中的作用都將被本篇論文所包含。我們的結果對於分析這類發光二極體之奈米結構的元件性質而言，可以提供許多有用的資訊。In the advance of nano technologies, many novel LED structures such as nanocolumn, nanorod, and photonic devices have been proposed to show better device performance. In order to analyze these structures, we have applied the valence force field model and self-consistent Poisson, drift-diffusion, and Schrodinger to analyze the InGaN/GaN quantum well LEDs with different nano structures. We first describe the correlation between the energy blue shifts and the strain relaxation of multiple quantum wells embedded in nanorods with different averaged sizes. We also studied the emission properties of InGaN/GaN quantum well light emitting diodes when the etching depths of nanohole arrays are close to or penetrate the quantum well structures. The effects of strain relaxation and surface states are analyzed, which could possibly influence the diode emission properties. Our results suggest that the effects of strain relaxation and sizes of nano structure dimensions strongly influence the emission properties of the nanorod LEDs. In this thesis, we will discuss these information in great detail. The roles of strain relaxation, piezoelectric effect, surface states, and non-radiative recombination mechanism will all be included in this thesis. Our calculation results can provide useful information in analyzing emission properties of these imilar nano structure LEDs.口試委員會審查表. . . . . . . . . . . . . . . . . . . . . . . . . i謝. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii文摘要. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv文摘要. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v錄. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii目錄. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x目錄. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvi Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1 Prologue . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 III-V Nitride Compound Semiconductors . . . . . . . . 1.3 Quantum Confined Effect . . . . . . . . . . . . . . . . 4.4 Characteristics of the InGaN/GaN QuantumWell Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4.1 Defect Density and High P-type Doping in In-aN and GaN Materials . . . . . . . . . . . . . 7.4.2 Spontaneous Polarization and Strain-induced Piezoelectricolarization Effects . . . . . . . . . . . 9.4.3 Quantum Confined-Stark Effect . . . . . . . . . 14.4.4 Spontaneous Emission . . . . . . . . . . . . . . 16.5 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 17 Formalism . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19.1 Electrical Properties of InGaN/GaN LEDs . . . . . . . 19.1.1 Valence Force Field (VFF) Model . . . . . . . . 19.1.2 The Total Polarization Charge Model . . . . . . 21.1.3 Self-Consistent Model . . . . . . . . . . . . . . 23.1.4 Fermi Distribution . . . . . . . . . . . . . . . . 29.2 Optical Properties of InGaN/GaN LEDs . . . . . . . . 32.2.1 Carrier Recombination Theory . . . . . . . . . . 32.2.2 Formula of Spontaneous Emission Rate . . . . . 37 Size Dependence of Strain Relaxation and Optical Propertiesrom InGaN/GaN Nanorod LEDs . . . . . . . . . . . . . . . 39.1 The Device Structures . . . . . . . . . . . . . . . . . . 41.2 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 43.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . 56 Etching Depth Dependence of Emission Properties from Nanoholetructures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58.1 The Device Structures . . . . . . . . . . . . . . . . . . 60.2 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 61.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . 71 Conclusion and Future Work . . . . . . . . . . . . . . . . . . 73eference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Fast Mode Decision Algorithm in H.264/AVC
No full text多媒體應用已在日常生活中扮演舉足輕重的角色，不論是在家庭可以看見的影音娛樂設備，如DVD播放器、數位電視，或是隨身可攜的各項產品如手機、數位相機、攝影機，甚至在我們的捷運站、公車上，處處都可以看見多媒體應用的身影。
這麼多廣泛應用中，技術核心在於影像的編碼，而在新一代的影像編碼標準中，除了原本運算就相當吃重的移動估計模組外，還另外提供了多重模式選擇的功能，因而增加了及時編碼運算的難度。本篇論文將著重在如何減少多重模式選擇所帶來的運算量，並且搭配已有的快速移動估計，發展出快速演算法。利用各個模式出現的機率分佈的差異，以及鄰近方塊間模式的關連性，加上各種提前終止條件的設立，避免尋找各個模式的移動估計運算來達到演算法加速的目的。單就模式選擇方面來看，與完全搜尋相比，整體編碼速度可提升到1.87-2.5倍，若是搭配上快速移動估計演算法，整體編碼速度甚至可達到約13倍，大幅提昇了及時運算的可能性。Multimedia applications have played an important role in our daily life. We can see them in the family, such as DVD player, digital TV, or portable devices such as mobile phones, digital camera, even in the subway and on the bus. The multimedia applications are everywhere.
The technological core of the different applications is the codec. In the new generation of codec standard, the multi-mode decision is offered and increases the complexity of whole system. So, the real-time applications are not easily to be realized. This thesis focuses on the probability of different modes and the mode correlations of neighboring blocks. With different early termination conditions and the fast motion estimation algorithm, the new algorithm shortens the total encoding time. The fast mode decision algorithm achieves up to 2.5 times speedup and the joint algorithm achieves up to 13 times speedup in total encoding time. It makes real-time application possible.摘要……… ii
Abstract……… iii
Chapter 1 引言 1
1.1 數位影像發展趨勢 1
1.2 H.264/AVC編碼標準概要 3
1.3 H.264/AVC Profiles and Layers 5
1.4 論文各章概述 6
Chapter 2 H.264/AVC編碼標準介紹 7
2.1 數位影像壓縮簡介 7
2.2 Temporal Redundancy 9
2.2.1 多重方塊大小的移動估計和移動補償 9
2.2.2 多重參考畫面 11
2.2.3 Quarter-Pixel-Accurate Motion Compensation 12
2.2.4 移動向量預測 13
2.3 畫面內模式預測 14
2.4 熵編碼 16
2.4.1 Exp-Golomb碼 16
2.4.2 Context-Based Adaptive Variable Length Coding 17
2.5 Lagrangian位元率-失真最佳化 18
2.6 運算複雜度分析 19
Chapter 3 回顧已發展的快速演算法 21
3.1 Fast Mode Decision Algorithm 21
3.1.1 Fast Inter Mode Decision [31] 21
A) 均值方塊預測 22
B) 均值區域和非均值區域的模式選擇 23
3.1.2 Fast Mode Decision for H.264 [30] 23
3.2 畫面內模式預測 24
3.2.1 Fast Mode Decision Algorithm for Intraprediction in H.264/AVC Video Coding [50] 24
A) Primary Edge Direction 25
B) Edge Direction Diagram 25
3.2.2 Fast Three Step Intra Prediction Algorithm for 4x4 blocks in H.264 [51] 27
3.3 快速移動估計演算法 28
3.3.1 Hybrid Unsymmetrical-Cross Multi-Hexagon-Grid Search (UMHexagonS) Algorithm [27] 29
3.3.2 Fast multi-frame motion estimation and mode decision for H.264 encoders [45] 31
Chapter 4 提出的畫面間/畫面內快速模式選擇演算法 35
4.1 提出的快速模式選擇演算法 35
4.1.1 統計特性分析 35
4.1.2 提出的畫面間快速模式選擇 44
4.1.3 提出的畫面內快速模式選擇 50
4.2 整合快速模式選擇和快速移動估計演算法 52
Chapter 5 Simulation Results 53
5.1 提出的畫面間快速模式選擇演算法 53
5.2 提出的畫面內快速模式選擇演算法 61
5.3 整合快速模式選擇和快速移動估計演算法 63
Chapter 6 Conclusion 71
參考書目 7
Size-Dependent Strain Relaxation and Emission Characteristics of InGaN/GaN Nanorod Light Emitting Diodes
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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