1,130 research outputs found
A Study of Over-education of College Recent Graduates in Taiwan
No full text本論文主要探討高等教育的過度教育之情形以及薪資的關係，研究對象為台灣地區大學畢業後一年的專職工作者。過去多以著重在分析過度教育人數之比例和過度教育與薪資的關係，而判斷是否為過度教育的衡量方式多種，各有優缺點，故本研究以Jensen(2003)的所得面方式衡量，則以潛在薪資與實際薪資的差距做為過度教育的程度指標，再進一步探討過度教育程度之分配差異。
實證結果有以下重要發現：(一)學校類型以技職體系畢業生的薪資表現較差，在所得面上過度教育程度也最高。(二)全部樣本上，過度教育確實對薪資產生負面影響，且隨著學校類型的不同，過度教育對薪資的影響幅度也不同。但男性樣本上，對於過度教育較無顯著情形。(三)而性別會影響薪資，以全部樣本而言，女性薪資顯著低於男性，但以Jensen過度教育指標，男女不存在過度教育程度差異。(四)在校的學習變數會影響薪資也會造成過度教育程度的差異，以科技領域薪資最高，但過度教育程度也最為嚴重。The main purpose of this thesis is to analyze the relationship between over-education and wage in higher education of Taiwan. We focus on the college graduates who graduated from college within one year in Taiwan. Most previous over-education studies concentrate on issues of incidence of over-education and its effect on wage. The over-education has been determined by several different measures. This article adopts the income ratio measure proposed by Jensen. It is a degree index of over-education that measures the gap between the potential and actual wage.
Empirical findings from our analysis conclude: (1) polytechnic college graduates perform low in wage where their among four school types, degree of over-education tends to be higher than university graduates. (2) The over-education has negative impact on wage, and such effect varies by school type. However, such effect is not significant in male sample. (3) Wage differs by gender. However, it doesn’t make difference between male and female by Jensen over-education index. (4) The learning at school variables will significantly affect wage and the degree of over-education. College graduates in sciences tend to have the highest wage among different fields of graduates, however they also suffer the most serious degree of over-education
The Effects of Brief Light Pulse and Intracerebroventricular Injection on Sleep-Wake Activity in Rats
No full textThe Effects of a Brief Light Pulse and Intracerebroventricular Injection on Sleep-Wake Activity in Rats
No full text
Infection of ENU Mutant Mice With Human Herpes Simplex Virus-1 (HSV-1) to Probe Immune Deviations in the Host Predominantly Expressing IL-15 Splice Variants
No full text介白質-15 (interlukine-15, IL-15) 是細胞激素的一種。除了參與重要的免疫反應之外，同時也涉及了宿主體內其他的生理反應，諸如:骨骼肌的代謝亦或是角質細胞的增生。基於作用的多效性以及分佈的廣泛性，IL-15生物活性的調控就顯得相當的重要。近幾年來，科學界在自然情況下發現人體內的許多細胞激素選擇性剪接異構體，並且藉用體外實驗的方式觀察到這些異構蛋白對於原型細胞激素的生物活性扮演了抑制調控的角色。然而，這些細胞激素剪接異構體的免疫生物活性尚未在體內實驗裡得到進一步的証實。本論文利用由國家型基因突變鼠核心實驗室以ENU誘導突變所建立的突變鼠品系191(P191)，經過人類疱疹一型病毒(Human Herpes Simplex Virus-1，HSV-1)的感染模式，希望能進一步地了解IL-15選擇性剪接異構體對原型IL-15調控下的免疫機制的影響。 我們將小鼠皮膚經過HSV-1感染後，藉由組織切片染色的方法比較突變鼠與正常鼠對病毒感染的反應結果發現:P191小鼠比野生型小鼠(C57BL/6，B6)能更快地產生病毒感染所引起的典型皮層細胞的病理變化並且顯示較嚴重程度的細胞破壞。經由免疫組織化學染色的結果得知這些皮膚組織的破壞程度和病毒蛋白表現的豐富程度相關。此外，從免疫組織螢光染色的結果觀察到，B6小鼠經過HSV-1 病毒感染後雖然能在皮膚組織誘發表現IL-15及IL-15Rα，但是這些因子在P191小鼠的皮膚表現卻相對地降低。雖然小鼠的皮膚經過病毒的感染會發生皮層細胞的壞死，正常鼠卻能在感染後七天內開始出現皮膚修復的現象，同時伴隨表現Gr-1抗原的細胞的浸潤與聚集。不過，這些表現Gr1抗原的細胞卻無法在病毒感染後各個時間點所收集的P191小鼠皮膚中觀察到，同時P191小鼠需要經過較長的時間才能修復受到病毒感染而破壞的皮膚組織。雖然不論是正常鼠或是突變鼠的皮膚在病毒感染後都能觀察到CD3+ T 細胞的浸潤，它們對於二種品系的小鼠在控制病毒感染的作用與角色還需要進一步地研究與探討。總之，本實驗結果發現，在基因轉錄水平上表現較高程度IL-15異構體的P191小鼠經過HSV-1的表皮感染後，不但比正常鼠容易產生病毒的複製並且造成較嚴重的組織破壞，對於控制病毒感染與進行組織修復的時間與機智也與正常鼠有許多的差異。究竟這些差異如何由IL-15異構體轉錄本所造成以及該異構體轉錄本是否能在體內轉譯為蛋白質後並且進一步地影響原型IL-15的生物活性,或是同時能影響其它多項控制疱疹病毒感染的免疫機制，仍有待未來更進一步的實驗證明與探討。Interlukine-15 (IL-15) is one of important cytokines and exhibits a high degree of pleiotropy, controlling a wide range of functions including immune responses, metabolism of skeletal muscle and proliferation of keratinocytes. However, very little is known about the mechanisms by which the expression and bioactivity of IL-15 are controlled. Whereas several forms of IL-15 alternative splice variants are identified in normal mice, their roles in the control of IL-15 expression remain unclear. In this study, we used an ENU mutant mouse model generated by the MMPCF (Mouse Mutagenesis Program Core Facility) to investigate how the immune responses against virus infection are affected when the host predominantly expresses IL-15 splice variants. Normal C57BL/6 (B6) and mutant pedigree 191 (P191) were infected with Human Herpes Simplex Virus-1 (HSV-1) via epicutanous route. Skin samples with lesional areas were collected and sectioned for further analysis. Results from H & E stain showed that HSV-1 induced typical pathological changes in skin tissues of both types of mice including cell ballooning, vesicular degeneration and epidermal cytolysis. However, these changes appeared earlier and more severe in P191 than in wild type B6 skin. Expression of HSV-1 proteins was also more abundant in P191 than in B6 skin by immunohistochemical stain. Whereas expressions of IL-15 and IL-15R were induced in the subdermal area of B6 skin after HSV-1 infection, they were much reduced in P191 lesional skin. In addition, the time for the skin to be healed after HSV-1 infection was longer for P191 than B6 mice. While significant numbers of Gr-1+ cells were detected on day 5 and peaked at day 10 in the dermis of infected B6 skin, they were nearly detected at all times in P191 skin after HSV-1 infection. Although CD3+ T cells were all detected in B6 and P191 skin after HSV-1 infection, their roles in the control of virus infection remain clarified. In summary, results from our study have shown that infection of P191 mice with HSV-1 resulted in altered immune responses as compared with wild type B6 mice. The differences at least but not limited include the susceptibility to HSV-1 infection, time for skin healing and recruitment of immune cells to lesional areas. How does the elevated level of IL-15 splice variants in P191 mice contribute to these deviations is not clear. More experiments will be done to understand whether IL-15 splice variants are expressed as variant proteins to antagonize prototype IL-15 and/or acquire novel functions in regulating host immune responses.誌謝 1文摘要 2文摘要 4一章 緒論 6一節 細胞激素與免疫反應 6. 調控細胞激素表達的機制 7. IL-2 cytokine family異構體的生物性特色 7IL-2 cytokine family 7IL-2 cytokine family與選擇性剪接異構體 8. 細胞激素異構體的應用發展性 10二節 動物模式在生物學研究上的重要性 10. ENU的致突變機轉 11. 從表型篩選到基因探索 13. ENU突變鼠在免疫學研究上的應用 13Pedigree 191 (P191) 14. P191 基因突變鼠免疫偏差(Immune Deviation)之探討 16三節 人類單純性疱疹一型病毒(Human Herpes Simplex Virus-1，HSV-1)的感染與免疫反應 16. HSV-1的特性與致病機轉 17. 宿主的防禦機制 18.1. 補體連鎖反應的活化 18.2. 免疫細胞與細胞激素的相互作用 19. 利用HSV-1病毒感染的模式探討P191小鼠的免疫偏差 20二章 材料與方法 22三章 實驗結果 34. 利用RT-PCR的方式確認Pedigree 191(P191)所表現的IL-15選擇性剪接異構體 34. 人類疱疹一型病毒感染小鼠上皮組織之感染動物模式的建立 35. 人類疱疹一型病毒感染小鼠上皮組織之病理現象 35. 人類疱疹一型病毒感染後，小鼠皮膚組織內病毒蛋白的偵測 36. 人類疱疹一型病毒感染皮膚後誘導的免疫反應 37.1. IL-15 與 IL-15Rα 37.2. Gr1+浸潤細胞 38.3. CD3+浸潤細胞 38. 總結 39四章 討論 41. 比較人類疱疹一型病毒感染野生型 B6 與 P191小鼠後皮膚組織病理變化差異之原因 41. 人類疱疹一型病毒的感染引誘皮膚組織CD3+ T 細胞的浸潤 42. HSV-1的清除和Gr-1+ 細胞的浸潤 43. IL-15的表達與Neutrophils的浸潤在抗HSV-1感染上的相關性 44五章 圖表 47六章 參考資料 60表目次. Detection of IL-15 mRNA splice variant in p191 by RT-PCR 47. Development of HSV-1 zosteriform model in B6 mice 49. HSV-1 induced cytopathological changes in mouse skin by H&E stain 50. Demonstration of expressions of HSV-1 proteins in skin by immunohistochemical staining 52. Expressions of IL-15 and IL-15 Rα in mouse skin after HSV-1 infection by immunofluorescence analysis 54. Detection of Gr-1 expressing cells within the cellular infiltration in HSV-1 infected skin by confocal microscopy 56. Detection of CD3 expressing cells within the cellular infiltration in HSV-1 infected skin by confocal microscopy 5
Electro-Optical Properties of Nano-structured Indium Nitride
No full text本論文中研究氮化銦一維結構尺度上光學、電性與光電導的效應。使用有機金屬化學沈積技術成長具有單晶烏采結構氮化銦奈米結構。接著製作單根氮化銦奈米元件。光學量測中，20K下氮化銦發光位置約為0.84 eV。溫度由20K到100K時光致發光位置開始有異常藍移的現象接著升至室溫時由於一般的能隙收縮造成紅移。此一光致發光機制為能帶與能階間復合機制與電子在表面上累積有關。氮化銦一維奈米結構的高載子濃度(2.7x1019 1.65x1020 cm-3)可由傅立葉轉換紅外光譜儀證實。在電性量測上，所有單根氮化銦奈米元件的導電率在50到8000 -1cm-1之間。變溫電導量測中顯示其具有類金屬的傳輸特性。光電導量測中對其尺寸的影響，我們發現其最大的光電流反應可以達到1000 A/W，這是氮化銦中第一次被發現的現象。當氮化銦奈米帶的直徑改變由60至230 nm，光電流有非常明顯的增加。由於一維結構的尺寸效應形成明顯的表面電子累積造成較短的載子生命期和較低的載子移動率，使得光電流對尺寸有明顯的效應。We have studied optical, transport, and photoelectric properties on dimensionality of one-dimensional (1D) nanostructure of InN. Single-crystalline InN nanobelts with wurtize structure have been synthesized using metalorganic chemical vapor deposition (MOCVD). The fabrication of single nanobelt device has been also demonstrated. For optical measurement, we found that the photoluminescence (PL) peak position of the samples is observed at around 0.84 eV at 20 K. In addition, the PL peak position reveals anomalous blueshift as temperature increases from 20K to 100K and then follows redshift from 100K to 300K due to normal bandgap shrinkage. The PL emission mechanism in InN nanobelts can be explained by the combination of the model of free-to-bound recombination and electron surface accumulation. The high carrier concentration of InN nanobelts in the range of 2.7x1019 1.65x1020 cm-3 has been further manifested by the study of plasma edge absorption in the Fourier Transform Infrared (FTIR) examination. For electrical measurement, the overall conductivity of the nanobelts is in the range of 50 8000 -1cm-1. The temperature dependence of dark conductivity has indicated the metallic transport behavior of the single InN nanobelt. Size-dependent hotoconductivity (PC) has been observed on the InN nanobelts and the maximal photocurrent responsivity reaching to 1000 A/W has been demonstrated for the first time. It is found that the responsivity has increased significantly as nanobelt size increases from 60 to 230 nm. The size-effect on the PC performance could be explained by the electron surface accumulation in the size-confined 1D nanostructure of InN giving rise to shorter lifetime and lower mobility of carrier.Chapter 1 Introduction 1
1.1 Introductory Remarks 1
1.2 Important Properties of InN 3
Chapter 2 Fabrication and Characterization of InN Nanostructures 7
2.1 Experimental System 7
2.1.1 Metalorganic Chemical Vapor Deposition System(MOCVD) 7
2.1.2 DC Sputtering 9
2.1.3 E-gun Evaporator 10
2.2 Experimental Steps 10
2.2.1 Growth Processes of InN Nanostructure 10
2.2.2 Fabrication of single InN Nanobelt Device 10
2.3.1 Scanning Electron Microscopy (SEM) 11
2.3.2 Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Analysis (EDS) 12
2.3.4 X-ray Diffraction (XRD) 13
2.3.5 Photoluminescence Spectroscopy (PL) 13
2.3.6 Fourier Transform Infrared (FTIR) Measurements 17
2.3.7 Photoconductivity Measurement and Temperature-dependent Electrical Measurement 18
Chapter 3 Analysis and Discussion 28
3.1 Structure Analyze of InN Nanobelts 28
3.1.1 SEM Characterization 28
3.1.2 XRD Characterization 28
3.1.4 TEM Characterization 28
3.2 Optical Properties 29
3.2.1 Power-dependence of PL Mechanism 29
3.2.2 Temperature-dependence of PL Mechanism 32
3.2.3 Estimation of Carrier Concentration by FTIR Measurements 34
3.3 Electronic and Photoelectronic Properties 38
3.3.1 Two Terminal Measurement of Single InN Nanobelt and its Temperature -dependence 38
3.3.2 Size-dependent Photoconductivity of Single InN Nanobelt 38
Chapter 4 Conclusion 41
Reference 5
Prescription sequence symmetry analysis: assessing risk, temporality, and consistency for adverse drug reactions across datasets in five countries
Get PDFAbstract not availableNicole Pratt, Esther W. Chan, Nam-Kyong Choi, Michio Kimura, Tomomi Kimura, Kiyoshi Kubota, Edward Chia-Cheng Lai, Kenneth K.C. Man, Nobuhiro Ooba, Byung-Joo Park, Tsugumichi Sato, Ju-Young Shin, Ian C.K. Wong, Yea-Huei Kao Yang, and Elizabeth E. Roughea
PLL Clock Generator with Phase Error Detector
No full text本論文探討以深次微米金氧半(CMOS)技術實現之鎖相迴路(PLL),針對以下兩主題提出新的方法.第一,使用相位誤差偵測器進行相位誤差偵測.第二,利用相位誤差偵測值與數位控制延遲電路進行校正,取得相位誤差最佳化
我們先討論鎖相迴路頻寬最佳化問題,首先,若要減少輸出信號受輸入的雜訊的影響,則迴路的頻寬要愈小愈好,其次,若要減少輸出的信號受內部振盪器的雜訊影響,則迴路的頻寬要愈大愈好.此二種要求是相互抵觸的,需要某種程度的妥協.
當鎖相迴路系統頻寬取得最佳化時,用於實體晶片製造下,因製程過程會有偏移而產生誤差,因而造成相位誤差.利用相位誤差偵測器,可取出相位誤差平均值.
我們提出了一個校正系統.此系統利用上述平均值可以校正鎖相迴路的相位誤差,取得其最佳化.最後運用實作的晶片去驗證我們所提出的理論確實可達到我們預計的效果.This thesis describes with the PLL of a CMOS technique, and put forward two topics. First, use phase error detector circuit to detect the phase error. Second, use the phase error detector and digital control delay line (DCDL) circuit to correct the phase error of the PLL.
We discuss the PLL bandwidth optimization problem. first, if reduce the noise influence that the output’s signal to the out of chip, then the bandwidth of the PLL want to be the smaller the better, the next in order, if reduce the noise influence that the output's signal to the inner part, then the bandwidth of the PLL want to be the bigger the better. The two kinds of requests is what conflict with mutually, needing the compromise of a certain degree.
When PLL system bandwidth obtains the optimization, being used for the chip manufacturing will be partial to move and produce the error margin because of the manufacturing process, cause the phase error. Making use of the phase error detector circuit can take out the phase error average values.
We put forward corrects the system. This system makes use of the above the average value can correct the PLL phase error. Finally, the chip made use of to make actually identifies we put forward of theories can reach the result that we anticipate really.摘要---------------------------------------------------------------------------- ii
誌謝---------------------------------------------------------------------------- iv
表目錄-------------------------------------------------------------------------- 3
圖目錄------------------------------------------------------------------------- 4
第一章 緒論 8
1.1 論文架構---------------------------------------------------------- 9
第二章 鎖相迴路架構與設計 10
2.1 鎖相迴路設計概念----------------------------------------------- 10
2.1.1 鎖相迴路定理------------------------------------------------ 11
2.2 鎖相迴路組合元件探討------------------------------------------ 12
2.2.1 相位頻率偵測器--------------------------------------------- 12
2.2.2 電壓控制振盪器--------------------------------------------- 14
2.2.3 “Charge Pump” 與迴路濾波器------------------------------ 15
2.3 鎖相迴路參數設計------------------------------------------------ 17
2.3.1 三階的鎖相迴路--------------------------------------------- 18
2.4 系統模擬--------------------------------------------------------- 22
2.4.1 行為模擬方塊介紹------------------------------------------- 22
第三章 相位誤差偵測器 24
3.1 介紹---------------------------------------------------------------- 24
3.2 概觀---------------------------------------------------------------- 25
3.3 鎖相迴路參數設計------------------------------------------------ 26
3.4 相位誤差偵測器架構---------------------------------------------- 27
3.5 行為模擬---------------------------------------------------------- 31
3.6 電路實現---------------------------------------------------------- 33
3.6.1 架構----------------------------------------------------------- 33
3.6.2 相位頻率偵測器和“Charge pump”電路---------------------- 34
3.6.3 迴路濾波器---------------------------------------------------- 35
3.6.4 電壓控制振盪器---------------------------------------------- 35
3.6.5 除法器--------------------------------------------------------- 37
3.6.6 相位誤差對頻率轉換器-------------------------------------- 38
3.6.7 頻率對數位碼轉換器---------------------------------------- 40
3.7 量測結果----------------------------------------------------------- 40
3.8 摘要---------------------------------------------------------------- 43
第四章 相位誤差校正系統 47
4.1 介紹--------------------------------------------------------------- 47
4.2 概觀---------------------------------------------------------------- 47
4.3 校正架構---------------------------------------------------------- 48
4.4 行為模擬---------------------------------------------------------- 50
4.5 電路實現---------------------------------------------------------- 52
4.5.1 架構---------------------------------------------------------- 52
4.5.2 數位控制延遲線--------------------------------------------- 52
4.6 量測結果--------------------------------------------------------- 54
4.7 摘要--------------------------------------------------------------- 55
結論 59
參考文獻 60
附錄 運用相位誤差偵測器快速鎖定之鎖相迴路 62
A.1 介紹---------------------------------------------------------------- 62
A.2 概觀----------------------------------------------------------------- 62
A.3 電路實現------------------------------------------------------------ 64
A.4 量測結果------------------------------------------------------------ 65
A.5 摘要----------------------------------------------------------------- 6
Electrically Controllable Polarized Emission from CdS Nanorods for Smart Optoelectronic Devices
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