10,737 research outputs found
Stochastic Simulation of Photon Propagation in Si for Extreme-Ultraviolet Mask-Defect Inspection
No full textA Study of ANobii Users’ Preference Structure on Their Leisure Reading Seeking Behavior
No full text本研究以aNobii網路書櫃為研究平台，探討網路書櫃使用者以不同瀏覽管道尋找有興趣的休閒讀物時，其主觀評價與客觀成效表現是否有差異。本研究試圖採用精確性與非精確性概念的評估指標，希望能更貼近休閒讀物尋書之需求。研究中導入行銷學偏好結構的概念，以讀者閱讀的偏好結構作為使用者變項，探討讀者個人偏好結構是否會影響其使用不同推薦工具瀏覽尋書的結果。研究採用準實驗設計，自變項為aNobii上三種導覽工具（朋友書櫃、相似書櫃、同作者書籍）以及受試者個人偏好結構（偏好發展程度、偏好同質性、閱讀涉入程度）；依變項為實驗後問卷搜集的受試者主觀評價，以及在實驗中系統自動於背景搜集的客觀檢索成效。
研究結果發現：一、不同導覽工具的確有所差異。使用者認為同作者書籍較符合其偏好，實際檢索成效亦較佳，但瀏覽起來最無趣；而最不符合偏好的朋友書櫃，卻是三者中瀏覽過程最有趣、亦最能擴展讀者閱讀視野的管道。二、讀者對不同導覽工具的主觀評價結果與客觀檢索成效並不完全一致，但若細就精確性與非精確性的概念區分，可發現主觀與客觀的結果有接近的趨勢。三、讀者的個人偏好結構的確會影響其瀏覽尋書的評價與成效，如偏好發展程度與偏好同質性愈高者，使用同作者書籍瀏覽尋書的客觀成效明顯較佳；閱讀涉入程度愈高者，朋友書櫃中愈容易遇到重覆的已知書籍等等。因此，若此類平台未來能建立讀者的個人偏好結構資訊檔，集有足夠的研究資訊，或許對使用者的服務能更切合所需，也能令使用者的偏好結構與其閱讀需求之間的關係更為清晰。This study aimed to explore how users search books they are interested in with different browsing tools in online bookshelf, aNobii, and whether the performance in subjective perspective and objective results will be different. To meet the demands of users’ leisure reading, we use accuracy and novelty as evaluation indicators. Besides, applying the concept of preference structure widely used in marketing as our independent variable, we attempted to investigate whether readers’ preference structure will influence results of book selection with different recommendation tools.
A quasi-experimental design was adopted where all 40 participants searched alternately with the three book finding tools. There are two independent variables in the research, three browsing tools in aNobii-- friends, similar readers, and the author, and preference structure including preference development, preference homogeneity, and degree of reading involvement. The dependent variables are subjective perspective collected by questionnaires after the experiment and objective search results retrieved by the computer during the experiment.
Some major findings are as follows. First, different browsing tools were found to affect users’ book selection behaviors. Users thought that browsing by author could help them find books better matching their reading preference. It produced a higher accuracy. However, users felt it was less interesting when choosing books by authors. On the contrary, users considered browsing friends’ bookshelf to be most interesting. Books found in friends’ bookshelf may not fit their reading preference but helped users broaden their horizon. Second, performance in subjective perspective and objective search results did not align with each other , which suggested they captured different aspects of user experience . Furthermore, readers’ preference structures were found to affect their browsing results. For instances, search results were better when the reader’s preference is highly developed and homogenous. Also, the reader with high reading involvement was found to be more likely to find books they had already known during browsing friends’ bookshelf.
Thus, if we can build users’ reading preference profile to collect enough information for research, we can supply service that meet users’ needs in the future. Moreover, it can help us understand the relation between readers’ preference structure and reading needs
Development of small interfering RNA delivery system using PEI-PEG-APRPG polymer for antiangiogenic vascular endothelial growth factor tumor-targeted therapy
No full textZong-Xia Lu1, Li-Ting Liu1,2, Xian-Rong Qi11Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Beijing, People's Republic of China; 2Department of Pharmacy, School and Hospital of Stomatology, Peking University, Beijing, People's Republic of ChinaBackground: Small interfering RNA (siRNA) can silence target genes in the cytoplasm and be a major tool in gene therapy. Vascular endothelial growth factor (VEGF), a potent regulator of angiogenesis, is overexpressed in most tumors and is closely associated with tumor growth and metastasis. It has been shown that inhibition of VEGF expression by siRNA is an effective and useful method for antiangiogenic tumor therapy.Methods: In the present study, we synthesized a targeted delivery system of PEI-PEG-APRPG incorporating angiogenic vessel-homing Ala-Pro-Arg-Pro-Gly (APRPG) peptide into cationic polyethylenimine (PEI) via a hydrophilic poly(ethylene glycol) (PEG) spacer.Results: PEI-PEG-APRPG effectively condensed siRNA into 20–50 nm nanoparticles with a positive surface charge using a suitable N/P ratio. The siRNA/PEI-PEG-APRPG complex effectively enhanced the stability of siRNA in RNase A, and improved the proliferation-inhibiting ability and transfection efficiency of siRNA in vitro and tumor accumulation in vivo. In addition, the siRNA/PEI-PEG-APRPG complex exhibited high efficiency as antitumor therapy with regard to tumor growth, microvessel density, and VEGF protein and mRNA levels.Conclusion: These findings suggest that PEI-PEG-APRPG effectively delivers siRNA to tumors overexpressing VEGF and thereby inhibits tumor growth.Keywords: PEI-PEG-APRPG, VEGF siRNA, gene delivery, tumor-targeted, antiangiogenic therap
Síntese de polietilenoiminas ramificadas decoradas com grupos hidrofóbicos e nucleosídeos e estudos de sua interação com dodecilsulfato de sódio e DNA
Full text linkTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciencias Fisicas e Matematicas, Programa de Pós-Graduação em Química, Florianópolis, 2012A poli(etilenoimina) (PEI) foi modificada por meio da alquilação com grupos n-alquila (n = 4, 6, 8 e 12 carbonos). O espalhamento de raios X a baixos ângulos (SAXS), tensão superficial, emissão de fluorescência do pireno, viscosidade e medidas de pH foram as técnicas usadas para investigar a conformação e agregação das PEIs hidrofobicamente modificadas em solução aquosa, na ausência e na presença de dodecil sulfato de sódio (SDS). Medidas de SAXS mostraram que o raio de giro diminui com o aumento do comprimento da cadeia alquílica, enquanto que os dados de viscosidade indicaram uma diminuição na viscosidade intrínseca. A PEI não modificada não apresentou atividade na superfície, enquanto as PEIs modificadas mostraram atividade pronunciada na superfície e presença de domínios hidrofóbicos. Na presença de SDS, o início da formação do complexo polímero-surfactante foi determinado, indicando uma diminuição na concentração de agregação crítica (cac) com o aumento no comprimento da cadeia alquílica substituída na PEI. A PEI também foi decorada com o grupo uridina com dois graus de substituição (5% e 15%). A formação de complexos das PEIs, decoradas com uridina ou hidrofobicamente modificadas, com o DNA do timo de bezerro foi investigada através das técnicas de emissão de fluorescência do brometo de etídio, espectrofotometria de UV-Vis, dicroísmo circular (CD), potencial zeta, viscosidade, espalhamento de luz dinâmico (DLS) e SAXS, na ausência e na presença de SDS. Todas as PEIs apresentaram três etapas na formação de complexos com o DNA: a primeira, quando uma pequena quantidade de polieletrólito foi adicionada, as cadeias do DNA são parcialmente condensadas; a segunda, quando mais polieletrólito foi adicionado, apresenta complexos com densidade de carga nula, com tamanho micrométrico; a terceira, em concentrações mais altas da PEI, o DNA foi completamente condensado pelas cadeias das PEIs, formando complexos positivamente carregados com valores de RH,ap na faixa de 51 a 88 nm. Análises de viscosidade e SAXS sugerem que o a PEI não modificada teve a interação mais forte e que melhor condensa o DNA.Abstract : The polyethylene imine (PEI) was modified by means of the alkylation with n-alkyl groups (n = 4, 6, 8 and 12 carbons). Small-angle X-ray scattering (SAXS), viscosity, surface tension, and pyrene fluorescence emission were then used as techniques to examine the conformation and aggregation of the hydrophobically modified PEIs in aqueous solution, in the absence and presence of sodium dodecylsulfate (SDS). Analysis of the SAXS data showed that the radius of gyration decreases with an increase in the alkyl chain length of the polymer, while the viscosity data indicated a decrease in the intrinsic viscosity under the same conditions. The nonmodified PEI was not surface active, while the hydrophobically modified samples showed pronounced surface activity and the presence of hydrophobic domains. On addition of SDS, the onset of the formation of polymer#surfactant complexes was determined, indicating a decrease in the critical aggregate concentration (cac) with an increase in the alkyl chain length of the polymer backbone. The PEI also was decorated with uridine groups with two substitution degrees (5% and 15%). The complex formation of the decorated or hydrophobically modified PEI with calf thymus DNA was investigated through of the ethidium bromide fluorescence emission, UV-Vis spectrophotometry, circular dichroism (CD), potential zeta, viscosity, dynamic light scattering (DLS) and SAXS techniques, in the absence and presence of SDS. All versions of PEI showed three steps in complexes formation with DNA: first, when a small amount of polyelectrolyte was added, DNA chains were partially condensed; second, when more polyelectrolyte was added, the complexes had a null charge density and micrometric size; third, at higher concentration of PEI, the DNA was fully condensed by PEI chains, leading to positively charged complexes with RH,ap values in the range of 51-88 nm. Viscosity and SAXS analyses suggested that the unmodified PEI had the stronger interaction and promoted the best DNA condensation
我國公司治理與獨立董事監察人制度之研究
No full text「公司治理」，在近幾年來是企業重視的議題，除由於國際環境變化劇烈影響外，與整體企業監控制度有密切的關聯。為了協助上市上櫃公司建立良好的公司治理制度，財政部證期會（現金管會證期局）於民國九十一年二月二十日宣佈即日起，凡申請上市、上櫃的股票公開發行公司，要求必需強制設立獨立董監事，聘請二席以上獨立董事、一席以上獨立監察人，否則不准上市上櫃且不溯及既往。
基此，本論文將探討我國企業之特性及實施公司治理、獨立董監制度前後所面臨之相關問題。其主要目的有下列四項：
一、闡述我國公司治理及獨立董監制度之要義，以加強社會大眾對於我國公司治理及獨立董監制度之了解。
二、研究我國公司治理之架構及公司治理之特性，以分析國內施行公司治理前所面臨之獨立董監之相關問題。
三、探討公司治理守則之特色，並分析國內施行公司治理後已解決之問題，及其後所衍生之獨立董監制度之相關問題。並參考OECD 之改善公司治理策略及規定，以作為我國公司治理改革之方向。
四、提出改善之建議，以供政府單位改善公司治理及獨立董監制度之相關單位研究國內公司治理及獨立董監議題之參考。
經本論文研究，發現我國公司治理制度及獨立董監制度之範疇尚有不足之處，如業界之抗拒、人才之不足、缺乏獨立性、獨立董監之功能重疊等，甚而有論者認為引進獨立董監事缺乏適當之激勵機制，難期望其能用心於公司之事務上，另外，在推動公司治理初期，是否應以法律強制設置獨立董監事？審計委員會的設置是否必要？
針對目前公司治理不足之處，本論文建議應積極推動獨立董監事的改革，包括：建立監督約束機制，以增強獨立董監事之獨立性、明確劃分獨立董監事之權責、強制投保獨立董監事之責任險、建立獨立董監之專業人力資源市場、考慮各功能委員會的設置及落實公司評等系統等。公司應落實公司治理制度之建立與執行、強化機構投資人參與公司治理機制、加強投資人之再教育、健全會計環境等，而最重要是要匡正企業文化和領導者心態，讓企業發自內心的推動公司治理制度。Abstract
Corporate governance has become an important issue recently. In order to assist listed companies to build good corporate governance systems, Securities and Futures Commission has requested that all public offering companies should set up the independent director systems in order to become listed companies.
The purpose of this study is to explore the characteristics of Taiwan’s enterprises and the problems they face both before and after practicing corporate governance, independent directors and supervisors. The five main objectives of this thesis are as follows:
A. To illustrate the system of corporate governance, independent directors and supervisors in Taiwan in order to enhance public understanding of corporate governance, independent directors and supervisors system in Taiwan.
B. To study the framework and characteristics of corporate governance, independent directors and supervisors in Taiwan in order to analyze related problems before corporate governance, independent directors and supervisors was practiced.
C. To discuss the features of corporate governance rules and analyze resolved problems after corporate governance, independent directors and supervisors was applied in Taiwan. Furthermore, to discuss problems arisen after the application. And to indicate the direction which corporate governance, independent directors and supervisors reform in Taiwan should take by referring to OECD strategies for improving corporate governance, independent directors and supervisors.
D. To raise improvement suggestions that will serve as a reference for the government when devising improvement methods for Taiwan’s corporate governance, independent directors and supervisors.
This research reveals that independent directors and supervisors. The obstacles in establishing a system include industry resistance, shortage of talented candidates, independence needs, overlapping functions of independent directors and independent supervisors, and as some critics have mentioned,lack of an appropriate encouragement mechanism. Without this mechanism,independent directors and supervisors cannot be expected to devote themselves to the company.
Furthermore, should the appointment of independent directors and supervisors be made mandatory by law in the first stages of promoting corporate governance? Is it necessary to set up an audit committee?
This paper suggests advancing the reform of independent directors and supervisors in order to eliminate weaknesses in the current corporate governance, independent directors and supervisors. Recommended approaches: create a control mechanism to enhance the independence of independent directors and supervisors, clearly differentiate the responsibilities of independent directors and independent supervisors, introduce a compulsory liability insurance scheme for independent directors and supervisors, establish a human resource market of professional independent directors and supervisors, set up commissions of distinct functions, and implement the company rating system. Aside from reforms in independent directors and supervisors and information disclosure, companies should carry out the establishment and practice of corporate governance, give institutional investors a greater role in corporate operation, put more emphasis on the re-education of investors, and provide a sound accounting environment. Most importantly, corporate culture and operators’ values should be rectified, in order for companies to make a sincere effort in enforcing corporate governance.目 錄
第一章 緒論……………………………………………………… 1
第一節 研究動機………………………………………………… 1
第二節 研究目的………………………………………………… 4
第二章 公司治理之發展與內涵………………………………… 6
第一節 公司治理發展之原因…………………………………… 6
第二節 公司治理之理論架構…………………………………… 8
第三節 公司治理之定義…………………………………………18
第四節 公司治理之原則…………………………………………20
第五節 公司治理之重要性………………………………………21
第三章 我國公司治理之發展與現況……………………………26
第一節我公司治理發展之背景………………………………… 26
一、 環境因素………………………………………………26
二、 我國公司治理制度採行前之問題……………………29
三、 國內上市公司財務危機事件層出不窮………………33
第二節 我國公司治理之現況……………………………………38
第四章 獨立董監制度之引進與發展……………………………46
第一節 獨立董監制度之興起與內涵……………………………46
第二節 外國獨立董監制度之發展及運作………………………48
一、美國外部董事制度之運作………………………………… 48
二、英國獨立董事制度之運作………………………………… 57
三、德國監事會制度之運作…………………………………… 60
四、日本外部監察人制度之運作……………………………… 63
五、韓國獨立董事制度之運作………………………………… 67
六、新加坡獨立董事制度之運作……………………………… 70
七、香港獨立董事制度之運作………………………………… 73
八、大陸獨立董事制度之運作………………………………… 75
第三節 我國獨立董監制度之引進…………………………… 78
第四節 各方之意見………………………………………………81
一、學者之見解………………………………………………… 82
二、主管機關之立場…………………………………………… 86
三、產業界之意見……………………………………………… 91
四、 小結………………………………………………… 99
第五章 我國獨立董監制度之現況問題及解決方法………… 103
第一節 現行法規對於董事監察人之相關規定與缺失……… 103
一、現行法規有關一般董事監察人之相關規定………………103
二、現行法規有關獨立董事監察人之相關規定………………114
三、目前董事監察人運作之缺失………………………………121
第二節 獨立董監與一般董監應予區分……………………… 125
第三節 獨立董監制度之現況問題與解決方法……………… 131
一、強制設立……………………………………………………131
二、法源…………………………………………………………136
三、席次…………………………………………………………138
四、人才來源……………………………………………………139
五、資格及遴選…………………………………………………140
六、報酬…………………………………………………………144
七、權利、義務…………………………………………………146
八、責任…………………………………………………………153
九、保險…………………………………………………………155
十、獨立董事、監察人、獨立監察人間之關係………………158
十一、資訊揭露…………………………………………………164
十二、投資人保護………………………………………………172
十三、小結………………………………………………………175
第六章 結論與建議…………………………………………… 17
Towards the tumble resistant microlight
No full textThe tumble mode is a pitching departure from controlled flight which leads to a pitch autorotation that is generally unrecoverable – resulting in vertical ground impact, usually preceded by in-flight breakup (the mechanism for which, surprisingly, can sometimes prevent loss of life). This was identified in work led by the British Microlight Aircraft Association beginning in 1997 as a response to a number of fatal accidents in Rogallo winged microlight aeroplanes, although the tumble is also known to occur to hang-gliders. This paper explains how this class of aeroplane is controlled, and how it has been found that they can enter the tumble mode. The mechanism by which the tumble can be entered is described. This has led to work showing how flight testing can be used to establish and demonstrate resistance to tumble entry – particularly important with increasing number of very high performance flexwings. These flight tests will be explained, together with the significance of the results. Recent accident investigation work has also shown a new mechanism of tumble entry, through partial failure of the A-frame structure and the pitch-trimmer mechanism. Also described is a possible relevance to well known historical accidents to flying wing aeroplanes– specifically the YB-49 and dH-108, and discovered data on the characteristics of the BKB-1flying wing glider; are also described
Lithics from Hang Trong (clockwise from upper left): Core tool, flake tools (photo by author).
No full textLithics from Hang Trong (clockwise from upper left): Core tool, flake tools (photo by author).</p
URO812316_supplemental_material – Supplemental material for Conservative management and radical treatment in localised prostate cancer: A systematic review with meta-analysis and trial sequential analysis
No full textSupplemental material, URO812316_supplemental_material for Conservative management and radical treatment in localised prostate cancer: A systematic review with meta-analysis and trial sequential analysis by Ka Ting Ng, Pei En Kwok and Wan Yi Teoh in Journal of Clinical Urology</p
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