1,721,145 research outputs found
Reduce Operation Voltage of Polymer-Dispersed Liquid Crystal with pattern-glass substrate
No full text在我們現在的生活中，液晶材料已廣泛地被應用在許多方面上，但由於傳統使用的水平或垂直配向液晶仍然需要配備偏光片，這使得背光源的使用效率降低。為了克服此問題，高分子聚合物分散型液晶這種由液晶和高分子聚合物單體所組成的材料應運而生。因其特殊的光電特性，高分子聚合物分散型液晶不需要使用到偏光片。但為人詬病的是高分子聚合物分散型液晶的操作電壓較一般液晶高。高分子聚合物分散型液晶的操作電壓會較高是因其液晶分子被高分子聚合物單體所包覆，而形成一顆顆的液晶微滴，在此微滴中液晶分子與高分子聚合物單體的介面間有表面錨定力而造成液晶分子不易因電場的施予而轉動。故降低高分子聚合物分散型液晶的操作電壓是我們首要的課題。 在本論文裡，我們希望藉由微影技術設計出不同地圖案化玻璃基板使高分子聚合物分散型液晶的液晶微滴能在圖案化玻璃基板上排列整齊並且更均勻，進而能降低高分子聚合物分散型液晶的操作電壓。因光學顯微鏡的解析度不夠觀察高分子聚合物分散型液晶的液晶微滴排列情形與是否均勻，故需利用電子顯微鏡來做觀察。但是因為電子顯微鏡是電子束去掃描表面結構來拍攝，因此須將做好的高分子聚合物分散型液晶元件拆開，在拆開的過程中會碰到高分子聚合物分散型液晶膜被破壞的情形所以我們利用全氟十二烷基三氯矽烷來當作脫膜劑幫助將高分子聚合物分散型液晶膜脫落。最後在此實驗中，我們成功地將週期10um，air duty cycle 85%的圖案化玻璃基板高分子聚合物分散型液晶的閥值電壓下降11%與飽和電壓下降2.5%。比較掃描式電子顯微鏡的拍攝結果，推論在ridge上無微滴時，會使液晶微滴在ridge與trench的邊界處產生較大的液晶微滴，並且排列整齊，而根據高分子聚合物分散型液晶的理論可以得知，若液晶微滴較大時的在液晶分子與高分子聚合物介面上的錨定力弱，故液晶分子較易受到電場的影響而轉向
Study on the Iron-related Molecules in Iron Homeostasis：Mutation Spectrum and Low Oxygen Effect
No full text鐵能幫助細胞電子傳遞、呼吸作用、氧氣輸送等正常生理功能，故鐵質對維持生物存活是必須物質。但因為鐵在體內沒有代謝管道，使得生物體對鐵的調控必須非常嚴密，防止鐵質含量不平衡所引起組織細胞損傷與疾病。近年來，研究人員陸續找到了與鐵相關的新蛋白群，這使得鐵在生物體內循環與調控更加清楚，也能以不同的角度看待鐵相關的機制與疾病。 Hepcidin是包含25個胺基酸的短鏈荷爾蒙，主要由肝臟製造，目前被認為是體內鐵質平衡的主要調控者。為了控制腸道細胞對於鐵質的吸收，以及巨噬細胞對於鐵質的釋放，hepcidin會降解細胞膜上的輸鐵蛋白ferroportin。目前已知有許多基因牽涉hepcidin表現調控，例如transferrin receptor 1 (TfR1)、transferrin receptor 2(TfR2)、hemojuvelin(HJV)、hemochromatosis (HFE)等。研究人員又發現難治性缺鐵性貧血患者與TMPRSS6變異相關，而找到TMPRSS6最重要的生理功能是藉由切割m-HJV，影響BMP/SMAD訊息傳遞來調節hepcidin的表現。 相較於國外對於HAMP(hepcidin gene)、HJV、FPN1(ferroportin gene)等基因變異有不少研究，台灣地區對於鐵相關的報告卻很少。鐵相關的疾病在於各種族之間發生的頻率與類型皆有不同，本研究針對台灣地區鐵質失衡患者，如鐵質缺乏的病患，以直接定序法直接定序分析TMPRSS6與其它相關基因的變異狀況。以47位缺鐵性貧血病患進行分析，在TMPRSS6重要的serine protease區域中，除了基因多型性變異外，並沒有發現有意義突變。此外，生物體含氧量與含鐵量為調控體內鐵平衡的兩大要素，本研究也針對TMPRSS6表現是否受到氧分壓改變所影響進行研究，TMPRSS6的啟動子區域上，確實包含數個HBS (Hypoxia-inducing factor binding sequence)；將Hep G2與Huh 7細胞培養於氧氣21 %(正常氧)與3 %(低氧)環境下，相較之下，發現當氧濃度降低，且經時越長，TMPRSS6的mRNA表現量越高。另外，也發現HAMP的mRNA在低氧狀況下，表現量有明顯上升。在Hep G2細胞的低氧實驗中，發現ceruloplasmin隨低氧處理的時間越長，轉錄明顯增多；TfR1的轉錄則是先下降後上升。Iron is essential for living organisms to survive, e.g. it is involved in electron transport and energy metabolism. There is no excretory pathway for iron, the regulation of iron homeostasis should be tightly controlled. To prevent unbalanced iron concentration causing cells and tissues damage, the systemic iron metabolism is regulated by iron absorption, utilization, and recycling. Recently, several novel studies of iron-related moleculars and genes make the association between iron homeostasis and diseases more clear. Hepcidin, a 25-amino acid peptide hormone, is mainly produced in the liver and is considered to be the principal regulator of systemic iron concentration. To limit iron absorption in enterocytes and control iron release from macrophages, hepcidin would bind to the iron-exporter protein ferroportin and trigger entrocytosis to degrade ferroportin. The hepcidin expression is regulated through erythropoietic activity pathway, iron store pathway, and inflammation pathway. Additionally, severl moleculars are also involved in, such as transferring receptor 1 (TFR1), transferring receptor 2 (TFR2), hemochromatosis (HFE), hemojuvelin (HJV), bone morphogenetic protein (BMP), etc. Recently, the TMPRSS6 mutation is revealed to be related to iron-refractory iron deficiency anemia, subsequent reporters showed that the main function of TMPRSS6 is to inhibit hepcidin activation by cleaving m-HJV. The mutation of these genes were reported somewhere, however, there are few reporters to discover the mutations of HAMP, HJV, FPN1 and TMPRSS6 in Taiwan. The aim of the present research is to study iron-related genes in 47 patients with iron deficiency, especially the TMPRSS6. We didn’t find any meaningful mutations in the functional serine protease domain, besides some SNPs. Further, the second aim is to know the effect of differ oxygenation concentrations. We measured several genes mRNA of Hep G2 and Huh7 cell lines which are incubated in normoxia or hypoxia conditions. Compared with normoxia, hypoxia can induce the expression of TMPRSS6 and HAMP mRNA in both cell lines. As expected, we found ceruloplasmin mRNA increased under hypoxia in Hep G2 cells. Furthermore, hypoxia decreased TfR1 mRNA at first and then increased its expression.口試委員審定書 謝 i次 ii寫表 iv文摘要 vi文摘要 viii一章 前言 1二章 研究目的 7三章 材料與方法 8四章 實驗結果 23五章 討論 28六章 結論 34考文獻 35圖 42 45表 58 5
CEO ability, equity incentives, and earnings manipulation
No full text本論文以台灣高科技公司為樣本檢驗CEO能力、股權誘因與盈餘操弄之關係。和先前盈餘操弄文獻一致，本研究將盈餘操弄區分為應計基礎盈餘操弄和實質盈餘操弄。研究結果顯示CEO能力與應計基礎(實質)盈餘操弄呈現顯著正向(負向)關聯。此外，研究也顯示高股權誘因會導致CEO使用較多(少)的應計基礎(實質)盈餘操弄。更特別的是，能力較高的CEO相較於能力較低的CEO更會專注於實質盈餘操弄造成的長期後果，所以CEO能力與實質盈餘操弄之負向關聯在高股權誘因之下更為強烈。此現象的合理解釋是因為能力較高的CEO有更多的知識以瞭解實質盈餘操弄之下背離正常營運活動所造成的負面後果。因此，當能力較高的CEO擁有高的股權誘因時他們比較不會使用實質盈餘操弄此種方式以拉抬盈餘。整體來說，本研究指出CEO能力和股權誘因都會影響盈餘操弄，而且高股權誘因對於CEO能力和盈餘操弄的關係具有一個調節效果。This study examines the relation of CEO ability, equity incentives, and earnings manipulation in Taiwanese high-tech firms. Following the recent literatures on earnings manipulation, this study divides earnings manipulation into accrual-based earnings manipulation (AEM) and real earnings manipulation (REM). The results show that CEO ability is positively (negatively) associated with AEM (REM). The results also suggest that AEM (REM) is increasing (decreasing) with high equity incentives. Specifically, high-ability CEOs are more concerned about long-term implication of aggressive REM than low-ability CEOs are when they have high equity incentives, thereby high equity incentives result a relatively greater negative association between CEO ability and REM. The reasonable explanation is that high-ability CEOs have more knowledge to recognize the negative consequences of abnormal business practice with REM activities. Therefore, high-ability CEOs with high equity incentives appear to be less likely to use REM activities to boost reported income. Collectively, this study finds that CEO ability and equity incentives can and do impact earnings manipulation. In addition, high equity incentives have moderation effect on the relation between CEO ability and earnings manipulation
Chondrogenic Differentiation Potential of Human Adipose Stem Cell Spheroid Forming on Glycol Chitosan and Gelatin Hydrogel
No full text軟骨組織由於缺乏血管和神經系統，遭受損傷後極難修復，且由於其多於關節等骨頭相鄰處作為緩衝，受損未經修復容易惡化致使整個關節失去功能，因此修復軟骨組織為組織工程中一重要課題。人類脂肪幹細胞可發現於成人脂肪組織中，具有多種諸如脂肪、硬骨和軟骨等分化潛力，易於取得且可用於自體移植避免免疫反應之發生，已成為組織工程研究中一重要之細胞來源。乙二醇幾丁聚醣擁有和幾丁聚醣相似的特性且可溶於中性的水中，其結構和軟骨組織中的糖胺聚醣相似。此研究將其和明膠混合形成之水凝膠作為人類脂肪幹細胞之載體，觀察細胞生長情形和型態，並分析其軟骨分化之潛力。 明膠的存在可增進水凝膠的細胞貼附性質，然而明膠會隨著時間從膠中釋出。經觀察，幹細胞會逐漸在水凝膠表面聚集最後形成球狀，推測其原因可能為水凝膠之貼附性質降低，且幾丁聚醣的表面有助於幹細胞球的生成，即有研究是以幾丁聚醣形成之薄膜使幹細胞於其表面成球。細胞球的結構已被證實可以增進幹細胞的分化能力，傳統形成細胞球的技術諸如液滴、模具和幾丁聚醣膜等，其中細胞的聚集和避免細胞的攤平貼附為重要之因素。 細胞球之外觀和性質由顯微鏡和螢光染色等觀察之。而後以軟骨分化培養液對細胞球進行軟骨分化的刺激，在一定的天數以螢光染色和測量基因表現來分析軟骨分化的傾向。在水凝膠上以一定的細胞密度培養，可在一至兩天形成細胞聚集進而成球，然而由於明膠的脫離，水凝膠難以支持長時間的培養。 在軟骨分化方面，細胞的聚集成球對於幹細胞在SOX9和COL II兩者的基因表現有所助益，顯示對於軟骨分化的潛力。The repair of damaged cartilage is a challenge due to its hard self-repair in cartilage tissue engineering. Human adipose stem cells are proved that have the ability to differentiate into different linage including adipogenic, osteogenic and chondrogenic lineage. They are considered to be the cell sources in cartilage tissue engineering. Glycol chitosan, which is a soluble derivative of chitosan, is studied for cartilage repairing due to its similar structure to glycosaminoglycans in cartilage and keeps the properties of biocompatibility and degradability as chitosan. In this study, the hydrogel was combined by glycol chitosan and gelatin which made cells able to attach on and its performance in cell culture was researched. This hydrogel could make cells adhere on its surface and make the hASCs form a sphere structure after culturing for several days. The formation of spheroids was attributed to the releasing of gelatin and the main material, glycol chitosan. These spheroids were observed by SEM and fluorescence and tested their properties and gene expression of differentiation. There were studies showing that the stem cells in spheroids were viable mostly and had better differentiation ability. Moreover, the material we used was usually studied for cartilage tissue engineering. Therefor the chondrogenic differentiation potential of cells in spheroids was researched. We hope the GAGs-like glycol chitosan in hydrogel and formation of spheroids are able to promote the chondrogenic differentiation. The results showed the chondrogenic differentiation performance appeared in spheroids. Moreover, the spheroids formed with induction medium were larger and had more complete shape of sphere. They also had higher performance in chondrogenic differentiation
A Gaming Model of Capacity Strategy Analysis in an Oligopoly Industry of Uncertain Demand and High Investment Cost
No full text高科技產業是台灣目前在世界的競爭主力，而高科技製造業中的需求不確定、產能投資成本高、技術更迭快速，導致廠商經營風險高、企業間競爭激烈，弱勢廠商容易被市場所淘汰，產業結構會由產業發展初期的眾多廠商角逐的情況，逐漸演變為寡佔競爭，半導體製造與液晶顯示面板產業是近年明顯的例子。高科技寡佔競爭的產業景氣循環現象非常明顯且劇烈，產能供給與需求經常發生失衡，產能投資的決策不僅決定經營獲利，也會影響廠商的長期競爭力，因此產能投資是廠商的在考量永續經營時的重要決策。在產業發展初期，由於市場成長快，各家廠商的產能計畫大致可以依據本身的成本、價格、需求等資料而制訂，但是寡佔競爭逐漸成形後，各廠商的價格與需求都會發生密切的互動，賽局模式因此將成為廠商產能規劃的重要情境考量。由於我國許多高科技製造產業逐漸變成寡占市場，相關產能策略的制訂是企業發展的重要研究需求。
針對上述之產業發展現況，本文以營收為產能擴充之績效指標發展出產能策略選取模式。利用廠商之售價、成本、市場佔有率等資料，搭配市場需求情況，分析在市場上產能供給與需求不均衡時廠商的策略選取，並提出賽局模式，當市場中不同競爭條件的廠商面臨不確定需求及龐大不可逆成本時，採取不同策略之預期營收，並歸納出基本競爭原則，結果得出技術領先廠商與技術落後廠商都會採取積極的策略，但技術落後的廠商營收較低，不利長期經營。Many high-tech manufacturing industries can be characterized by intense competition, high capacity investment cost, rapid technology advancement and uncertain demand. These characteristics tend to weed out weaker firms and drive an industry toward an oligopoly as it passes the embryonic stage. Examples of such industries include semiconductor manufacturing and liquid crystal display manufacturing. In an oligopoly, a firm can not afford to make capacity decisions based on cost-benefit analysis alone; potential actions of the opponents must also be taken into consideration.
In this paper, a gaming analysis method is described for designing capacity strategies in oligopoly competition with high irreversible investment cost and high demand uncertainty. This paper focuses on semiconductor manufacturing. Industry data of average selling price and manufacturing costs are utilized in the analysis. An optimal capacity model that a firm might undertake while disregarding the opponent’s action is first described. This model is based on tradeoff between over-capacity and under-capacity when the demand is highly uncertain and representable as a Brownian motion process and is used to determine myopic capacity decision of individual firms. In the second part of the paper, mathematical formulas are derived for modeling the behavior of the market leader and follower. Finally, a gaming analysis method is presented to analyze the gaming interaction between the players of the game and to compare the outcomes of aggressive and conservative strategies by the leader and the follower. The paper illustrates two results: both the players will take aggressive strategies; the follower cannot keep long-term success for its revenue appreciably lower than the leader.第一章 緒論................................................................................................................1
1.1 研究動機................................................................................................1
1.2 研究目的................................................................................................5
1.3 研究範疇與限制....................................................................................8
1.4 研究流程................................................................................................9
1.5 論文架構..............................................................................................10
第二章 文獻探討......................................................................................................11
2.1 寡佔產業的競爭策略..........................................................................11
2.2 產能擴充模型......................................................................................12
2.2.1 產能規劃(Capacity planning with production, inventory and demand management perspectives).............................................................13
2.2.2 選擇權..........................................................................................13
2.2.3 風險分攤......................................................................................14
2.3 寡佔競爭下之賽局模式......................................................................14
2.4 單一廠商之產能規劃模式..................................................................16
2.5 市場佔有率模型..................................................................................17
2.6 Wilkinson’s Method.............................................................................19
第三章 不確定需求之寡佔市場之競爭分析..........................................................22
3.1 資料分析..............................................................................................22
3.1.1 市場需求分析..............................................................................22
3.1.2 技術差異分析..............................................................................23
3.1.3 成本分析......................................................................................24
3.1.4 市場佔有率分析..........................................................................25
3.2 問題假設..............................................................................................27
3.3 四種供給情境......................................................................................28
3.4 期望營收..............................................................................................30
3.5 廠商策略目標......................................................................................31
3.6 四種供給情境下之期望有效產能......................................................34
3.6.1 產能水準-L1................................................................................35
3.6.2 產能水準-L2................................................................................37
3.6.3 產能水準-L3................................................................................39
3.6.4 產能水準-L4................................................................................41
第四章 產業數據運算與分析..................................................................................45
4.1 激進與保守策略之產能量計算..........................................................45
4.2 期望有效產能與利潤計算..................................................................46
4.2.1 期望有效產能..............................................................................48
4.2.2 營業純益......................................................................................49
4.3 Payoff matrix分析...............................................................................50
第五章 結論..............................................................................................................52
5.1 結論......................................................................................................52
5.2 未來研究方向......................................................................................53
參考文獻......................................................................................................................5
Optical-scanning Photoacoustic Microscopy with Acoustic Near-Field Detection
No full text本研究的目的在於設計一個微小且能高速取像的光聲顯微鏡。光聲影像系統為生醫影像的一支，主要探測人體組織吸收度形成對比。目前，光聲成像已廣泛應用在血管及血液的三維型態及功能性造影。前者可觀察腫瘤的血管新生或是創傷的血管癒合，後者則能監控血液中的血氧及血糖濃度，提供診斷和治療的依據；此外，光聲腦部影像和分子影像也有很大的發展潛力。
光聲顯微鏡則是一種高空間解析度的光聲影像系統，它的解析度到達數個微米的等級，可用來取得組織中微血管的影像，甚至可以觀察單一紅血球的運動。然而，目前的光聲顯微鏡成像速度普遍較慢，而且空間及對比解析度受到共軛校準的影響甚鉅。
本研究設計的目標為加速成像、系統微小化和提高解析度。這些技術在探針式光聲顯微系統設計，或是光聲顯微與其他影像系統整合中皆扮演關鍵角色。因此，在先導研究中，使用可調波長的鈦藍寶石雷射、單模光纖和 DVD 雷射頭組成光學系統，並用非聚焦探頭近場偵測光聲信號。對仿體進行造影測試，以探討系統的性能。首先利用毛髮仿體，可得橫向解析度約為 14.0um，而軸向解析度則有 50um 左右的水準，大約是30MHz超音波的波長。使用印刷的灰階仿體，發現經由 gamma 曲線修正後，光聲影像的對比與光學吸收度大致成線性，回歸係數為0.92。透過水聽筒測試，發現雜訊等效聲壓為 28.45Pa，與其他光聲顯微系統相仿。
為了實現系統微小化和加速成像，本研究近一步採用 MEMS 技術的光學微鏡掃描子系統。此掃描鏡透過DSP微處理機及外部電路驅動和回授控制，可用 130Hz 以上的速度導引雷射光束，掃描樣品平面。在應用方面，則是演示了對於石墨型血糖試紙的非破壞性檢測。In this study, a miniature photoacoustic microscopy is designed for rapid image acquisition. Photoacoustic (PA) imaging is a biomedical imaging modality capable of creating images whose contrast is specific on optical absorption. Existing applications of PA imaging includes 3D visualization of vessels, arteries and blood flow. Under PA images, anatomical information such as tumor angiogenesis and vessel wound healing can be visualized. Besides, functional imaging of blood oxygen and sugar levels can also be performed for diagnosis and treatment purposes. Furthermore, PA brain imaging and molecular imaging have become rapidly growing fields. Photoacoustic microscopy (PAM) is a high-resolution version of PA imaging. With micron-order spatial resolution, PAM is capable of visualizing capillaries in tissues, even dynamics of a single RBC. Unfortunately, existing PAM designs suffer from low imaging speed. In addition, both spatial and contrast resolution depends crucially on the confocal alignment. The proposed solution in this study aims to accelerate image acquisition, minimize device size and improve resolution. Such design has great potential in probe-based PAMs, or an integrated multi-modality system including PAM function. In a feasibility study, we present a PAM based on single-mode fiber and DVD pickup head, in order to minimize the optics. Acoustic near-field detection is proposed, with which image resolution is solely determined by laser spot size and near-field behaviour of ultrasound. Phantom studies have been conducted to characterize the performance of this device. With a hair phantom, the lateral resolution is assessed at 14.0um. The axial resolution reaches 50um, corresponding to the wavelength of a 30MHz ultrasound frequency in water. The PA signal amplitude is approximately linear to optical absorption, with a 0.92 correlation coefficient, after fitting a gamma-corrected model. The noise equivalent pressure (NEP) of 28.45(Pa) is comparable to other PAM systems. To make PAM both smaller and faster, a MEMS optical scanning mirror is featured in this study. The mirror, which is controlled by DSP and an analog interface circuit, scans the laser beam across the specimen plane at a 130Hz speed. An application is demonstrated, where non-destructive testing is conducted on glucose test strips used in glucose meters
Mobile Instant Messaging and the Maintenance of Parent-Child Relationships: A Case Study of Taiwan’s Long-Distance Families
No full text親子分隔異地是常見的遠距家庭型態，隨著行動媒體及無線網路普及，行動即時通訊漸成為維繫親子關係的重要管道。 本研究採取深度訪談法訪問22戶遠距家庭，探討當行動即時通訊滲入遠距家庭後，親子溝通與親子關係出現何種轉變。研究發現，父母的性別差異扮演關鍵性的因素：一方面，親職的性別分工深刻影響親子溝通行為；另一方面，行動即時通訊的媒介特質與社會情境因素，也對溝通行為及親密關係產生影響。整體來說，本研究認為行動即時通訊對遠距親子關係而言是利多於弊，與過去文獻不同的是，本研究發現在傳統家庭中，行動即時通訊有助於父親與子女進行親子溝通；比起母親，父親與子女間更能感受到親密關係的改善。Long-distance families, where parents and children live apart, are very common. With the growing popularity of smart phones and wireless networks, mobile instant messaging (MIM) has gradually become an important platform for maintaining parent-child relationships. Conducting in-depth interviews with 22 long-distance families, this thesis explores how parents communicate with their children after the introduction of MIM into long-distance families. The research results that gender differences between father and mother plays a crucial role in parent-child communication. One the one hand, gendered division of parenting deeply affects the parent-child communication behavior. On the other hand, the characteristics of MIM and social factors also affect the communication behavior and intimacy between parents and children. Generally speaking, this paper concludes that MIM does more good than harm to long-distance parent-child relationships. In contrast to the past literature, this thesis finds that MIM help fathers to communicate with their children better in traditional families. Furthermore, the enhancement of relationships between fathers and children is better than that between mothers and children
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
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