16,449 research outputs found
She ji kuan dai jin ling xiang ying chao cai liao zhi ce lüe
No full textNg, Ka Ki = 設計寬帶近零響應超材料之策略 / 吳嘉麒.Thesis M.Phil. Chinese University of Hong Kong 2015.Includes bibliographical references (leaves 107-111).Abstracts also in Chinese.Title from PDF title page (viewed on 29, September, 2016).Ng, Ka Ki = She ji kuan dai jin ling xiang ying chao cai liao zhi ce lüe / Wu Jiaqi
Valuing Ecosystem Services in the Bang Ka Chao Green Area, Thailand
No full textBang Ka Chao, the largest green area in the Bangkok metropolitan area, delivers significant ecosystem services to sustain society free of charge. It is therefore difficult to achieve socially optimal services because of inefficient allocation of resources, over-consumption, and negative externalities resulting from market failures. This study assesses the value, or consumers’ willingness to pay (WTP), for enhanced ecosystem services from the Bang Ka Chao Green Area and to investigate factors influencing the WTP of Bangkok residents. The choice experiment approach was applied by interviewing 200 respondents living in the Bangkok metropolitan area. The data were collected between July and September 2016 and analyzed using a conditional logit model. The results reveal that the respondents are willing to pay USD41.5 per year to improve the ecosystem services provided by the Green Area. The respondents identified air purification as the most important service, while food products and recreational benefits were somewhat important, and bird habitat was the least important. We therefore suggest that the government take immediate steps to establish restoration projects with the concrete objective of enhancing regulating services, especially air purification. Traditional agricultural practices (mixed fruit orchards), agroforestry, and agritourism should also be implemented and promoted in the green area. Therefore, a payment for ecosystem services (PES) scheme funded by Bangkok and recreational users should be a possible approach to guarantee the quality of the ecosystem services provided by the landowners within the Bang Ka Chao Green Area
Ti du de ge xiang yi xing chao cai liao de guang jiao du de Gusi-han xin wei yi
No full textHui, Ka Shing = 梯度的各向異性超材料的廣角度的古斯-漢欣位移 / 許嘉誠.Thesis (M.Phil.)--Chinese University of Hong Kong, 2013.Includes bibliographical references (leaves 78-82).Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.Abstracts also in Chinese.Hui, Ka Shing = Ti du de ge xiang yi xing chao cai liao de guang jiao du de Gusi-han xin wei yi / Xu Jiacheng
San zhong chao jian dai teng hu dui gao wen de sheng li fan ying ji zhuan lu ti yan jiu
No full textWong, Ka Wing Karen.Thesis M.Phil. Chinese University of Hong Kong 2014.Includes bibliographical references (leaves 143-157).Abstracts also in Chinese.Title from PDF title page (viewed on 30, November, 2016).Wong, Ka Wing Karen
Research on Broadband Power Amplifiers in Ka Band
No full text大部分已發表的Ka頻段寬頻功率放大器功率頻寬都是窄頻的，但寬頻功率放大器在大訊號操作下應該也要是寬頻的，而不是僅由增益與返回損耗認定。這篇論文提出了在Ka頻段的射頻功率放大器以及緩衝放大器之研究。為了驗證電路設計的方法，我們設計並實作了兩個Ka頻段放大器。
我們介紹了一個20 dBm單晶微波積體電路功率放大器，它的操作頻率涵蓋了整個Ka頻段，製程使用砷化鎵假型高速電子移動電晶體，並採用了疊接組態以提供高增益。量測中出現了振盪，可使用晶片外旁路電容以及調高共閘極電晶體的閘極端偏壓消去振盪。量測結果顯示輸出功率1 dB功率壓縮點為19.3 dBm，功率附加效益15.5%以上；在整個Ka頻段中量測的峰值功率附加效益達到22.5%，並有22.7 dBm的飽和輸出功率。因為量測結果和模擬相去甚遠，我們發現是電晶體模型在操作的偏壓不精確，因而提出了修正過的模型。因為電路有振盪的問題，所以我們提出了Q值的分析以穩定電路，並重新設計了放大器。
我們使用65奈米CMOS製程設計並製造了一個頻寬27-34 GHz的緩衝放大器，量測結果顯示輸出功率1 dB功率壓縮點為7.7 dBm，此時能維持21.8 dB的小訊號功率增益，以及13%以上的功率附加效益，峰值功率附加效益達到23.3%並有10.6 dBm的飽和輸出功率。這在所知已發表的Ka頻段緩衝放大器中有最寬的功率頻寬。Most reported broadband power amplifiers in Ka band have narrowband power characteristics. A broadband power amplifier should have wideband characteristics which include not only gain and return losses but also power performance. In this dissertation, the design and analysis of broadband amplifiers is demonstrated. To verify the proposed method, two Ka-band amplifiers are designed and implemented.
A full Ka-band 20-dBm power amplifier is implemented in 0.15-um GaAs pHEMT technology. The cascode configuration is adopted to provide higher gain. Spurious oscillations are observed in measurement and can be suppressed by off-chip bypass and raising the gate bias of CG transistor. The measurement result shows a power added efficiency (PAE) at 1-dB compression point (P1dB) up to 15.5% and 19.3-dBm OP1dB. Peak PAE higher than 22.5% and saturation output power (Psat) higher than 22.7 dBm are obtained at 27 GHz. Since the measurement results differ from simulation, we find that the transistor model is not precise at the desired bias, thus a modified model is introduced. Because the amplifier suffers from oscillations, the Q factor of bypass network is analyzed to stabilize the amplifier, and the proposed amplifier is redesigned.
A 27-34 GHz buffer amplifier (BA) is fabricated in 65-nm CMOS process. The measurement results show a PAE at P1dB up to 13% while maintaining 21.8-dB gain and 7.7-dBm OP1dB at 30 GHz. The peak PAE and Psat are higher than 23.3% and 10.6 dBm, respectively. To the best of our knowledge, the 27-34 GHz BA has the highest PAE among reported Ka-band CMOS BAs
Visualizing the online reputations of particular targets via static, animated and interactive visual techniques
No full textWith the progress made in the Web 2.0 technology, people are more likely to share their opinions, status and feelings via social media. But due to the explosion of data in volume on the Internet, people are being overwhelmed by the overloading information and begin to get lost and confused. Since people are used to find and read the online reviews before making their further decisions recently, a tool which is able to summarize the opinion data and reveal the explicit social image of a particular target should be proposed and introduced.
According to the previous work, Ting-Ying Huang has proposed a visual representation which is able to display the overall summarization of targets’ reputations. However, in most situations, people are likely to be interested in a specific aspect of individuals. Therefore, some additional visual approaches should be proposed to gain the meaningful clues. In this thesis, we aim at refining both the reputation evaluation methods and the visual representations which are suggested by Ting-Ying Huang. To accurately estimate the explicit social images of several particular targets, we analyze the opinion data at sentence level by incorporating the knowledge of Natural Language Processing. Additionally, we propose several static visualizations to reveal the detailed information such as the temporal evolutions, topical summarizations, content diversity among various features and social mediums. Moreover, to enhance the graphical perception and comprehension, we create an animated bubble chart which is able to exhibit the trends and changing patterns over time. Furthermore, we offer a fully interactive mean for users to examine and explore the opinion data via any viewing aspects.1. Introduction ………………………………………………………………………….... 1
1.1 Backgrounds and Motivations ………………………………………………. 1
1.2 Our Contributions ………………………………………………………….... 3
2. Related Works ……………………………………………………………………….... 4
2.1 The Definitions of Reputation …………………………………………….… 4
2.2 Opinion Analysis and Feature Extraction …………………………………….7
2.2.1 Opinion Analysis ………………………………………………….. 7
2.2.2 Chinese words analysis ………………………………………….… 8
2.2.3 Feature Extraction …………………………………………….…… 9
2.2.4 Brief Summary …………………………………………………… 10
2.3 Information Visualization ………………………………………………….. 11
2.3.1 Textual Data and Document Visualizations ……………………... 12
2.3.2 Temporal Data Visualizations ……………………………………. 16
2.3.3 Visualizations of Social Network ………………………………... 18
2.3.4 Brief Summary …………………………………………………… 23
2.4 Animated Visualization ……………………………………………………. 24
2.4.1 Introduction of Animated Visualization …………………………. 24
2.4.2 The applications of Animated Visualization ……………………... 26
2.4.3 Brief Summary …………………………………………………… 30
3. Methodology ………………………………………………………………………… 31
3.1 Method Overview and Data Pre-processing ……………………………….. 31
3.2 Opinion Analysis Method ………………………………………………..… 33
3.3 Estimations of Reputation and Social Image ………………………………. 35
3.4. Visual Analysis ………………………………………………………….… 37
3.4.1 To Display the Overall Summarization ………………………..… 37
3.4.2 Animated Visualization ………………………………………..… 38
3.4.3 To Display the Temporal Information …………………………… 40
3.4.3.1 To Display the Temporal Hierarchical Structures …...… 40
3.4.3.2 Using Timeline to Display the Evolutions …………...… 41
3.4.4 Textual Data Summarization …………………………………….. 43
3.4.5 Variations among Different Mediums …………………................ 44
3.4.6 Content Diversity among Various Features …………………….... 45
3.4.7 Interactive Force Bubble Chart …………………………………... 46
3.5 Summary ………………………………………………………………….... 48
4. Results and Discussions ……………………………………………………………... 49
4.1 Experimental Data …………………………………………………………. 49
4.2 Experiments ………………………………………………………………... 50
4.2.1 Case 1: Cell Phones …………………………………………....… 50
4.2.2 Case 2: Movies ………………………………………………...…. 67
4.3 User Interviews …………………………………………………………..… 81
5. Conclusions ……………………………………………………………….…………. 85
5.1 Conclusions ………………………………………………………………… 85
5.2 Suggestions and Limitations ……………………………………………..… 86
References ……………………………………………………………………………...… 8
Una interpretación de a-ka-na-jo ( a3-ka-na-jo)
No full textThe author studies the word a-ka-na-jo in the PY Cn 328 tablet and taking into account some factors she proposes αγναιος as the reading of this word.The author studies the word a-ka-na-jo in the PY Cn 328 tablet and taking into account some factors she proposes αγναιος as the reading of this word
Environmental influences over the last 16 ka on compound-specific δ13C variations of leaf wax n-alkanes in the Hani peat deposit from northeast China
No full textCompound-specific carbon isotope ratios (δ13C) of leaf wax n-alkanes (C21-C33 odd carbon numbered n-alkanes) were measured in the Hani peat sequence from northeast China. These data were compared with lipid biomarker compositions to assess changes in local vegetation and paleoclimate for the last 16 ka The δ13C values of n-alkanes range between -36.6 and -30.7‰, showing that the compounds originate from C3 plants. Much larger variations (∼5.4‰) in the n-alkane δ13C values than those of atmospheric CO2 during the last 16 ka (< 0.5‰) indicate that the isotopic values were affected by environmental factors in addition to the postglacial δ13C variations in the atmospheric reservoir. The stratigraphic records of δ13C reveal decoupled fluctuations among the individual n-alkanes, particularly between 15.5 to 11.4 ka. Synchronous excursions in the δ13C offsets among individual n-alkanes (Δδ13C) and lipid biomarker paleoplant proxies (Paq, and C23/C31 and C27/C31) from 14.9 to 13.2 ka and 12.7 to 11.6 ka suggest that vegetational changes are the most likely causes for the decoupled δ13C variations. Parallel fluctuations of the δ13C values of terrestrial higher plant-derived C29 and C31 n-alkanes and the n-alkane average chain-length (ACL) from 11 to 6 ka indicate that the δ13C variations responded to net evaporation changes. Negative shifts in the n-alkane δ13C values coinciding with the ACL decreases at 10.5-9.3 ka and 8.1 ka indicate the short-term onset and fluctuations of the summer monsoon strength in eastern China during the early Holocene
NRF2 and chemoprevention: signaling, epigenetics and role in intestinal carcinogensis
No full textPrevention is better than cure. The carcinogenesis could take as long as 20 to 30 years to develop from initiated cells to malignant tumor, therefore providing us various opportunities to prevent the appearance of tumors with the use of chemopreventive compounds in the early stage. Chemoprevention becomes an increasing important concept and has led to the intense research about the mechanisms of actions of various chemopreventive compounds. They can be generally classified into blocking agents and suppressing agents. The chemopreventive compounds usually prevent or slow progression of cancer by maintaining a low oxidative stress and inflammatory environment in cells. This is brought about by the activation of Nrf2, the key protein being investigated in our lab. In this dissertation, I will be discussing the use of compounds as suppressing agents and blocking agents, how compounds activates Nrf2 signaling, how novel Nrf2 interaction partner IQGAP1 mediates Nrf2-Keap1 signaling axis, how expression level of Nrf2 could be regulated epigenetically, apart from the well-known post-translational control by Keap1-Ubiquitinase-Protesome axis and finally how loss of Nrf2 could enhance intestinal tumorigenesis in Apc(min/+) mice.Ph.D.Includes bibliographical referencesIncludes vitaby Ka Lung Cheun
Nearby fibroblasts' response to multiple acupuncture needle revolutions on fibroblast populated collagen gels
No full textAcupuncture is an ancient Chinese healing practice, and an alternative therapy for alleviating pain and chronic disorders. For over twenty years, research is trying to understand the mechanisms that lead to its therapeutic effect. Our laboratory investigates the cellular and molecular events in the connective tissue that occur by acupuncture needling. An in vitro assay was developed to evaluate some of the potential contributors to acupuncture’s effects using a cellular collagen gel as a loose connective tissue mimic. It was hypothesized besides immediate changes to cells under mechanical loading from an acupuncture needle, there were chemical factors released to nearby cells in acupuncture. This thesis investigates whether mechanically stimulating collagen gels with fibroblasts at different revolutions would release chemical factors to nearby fibroblasts where flow cytometry was used to observe cell proliferation as an indicator. Results reveal mechanically stimulating cellular collagen gels at different revolutions does not cause any changes in cell proliferation to nearby cells. However, dead stained mechanically stimulated cellular collagen gels showed cell death occurs around the acupuncture needle. It is possible there were no effects in cell proliferation because when a cellular collagen gel was needle manipulated, some chemical factors were released into the nearby cells. Then as needle manipulation increased, more chemical factors were released, but restricted by the larger amount of cell death around the needle from the increasing rotation.M.S.Includes bibliographical referencesby Ka Po Ch
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