• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1407
  • 599
  • 402
  • 195
  • 145
  • 140
  • 129
  • 118
  • 112
  • 37
  • 29
  • 24
  • 17
  • 16
  • 15
  • Tagged with
  • 3935
  • 579
  • 548
  • 336
  • 273
  • 266
  • 262
  • 214
  • 207
  • 205
  • 196
  • 191
  • 191
  • 184
  • 172
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Utveckling av modell för kvalitetsstyrning av polyetenreaktor

Larsson, Katarina January 2003 (has links)
No description available.
82

Towards measurement of the ratio BR(η → 3π<sup>0</sup>) / BR(η → π<sup>+</sup> π<sup>- </sup>π<sup>0</sup>)

Heijkenskjöld, Lena January 2010 (has links)
<p>This diploma thesis presents a preliminary study of the ratio of branching ratio r = BR(η → 3π<sup>0</sup>) / BR(η → π<sup>+</sup> π<sup>- </sup>π<sup>0</sup>). The experimental data used is collected by WASA-at-COSY which is a 4π sr detector optimised to detect light mesons and their decay products and is situated in Jülich, Germany.The focus of the work is to see how different reconstruction methods for the detected particles can alter both the measured values of the  branching ratios and the luminosity dependence of these branching ratios. The results show that for some of the methods, the measured branching ratios have a clear luminosity dependence. Depending on method, the extracted branching ratios vary differently. A few different methods have been studied, so the results provides a qualitative understanding of the behaviour of the measured branching ratios for different luminosities.</p>
83

none

Chuang, Che-ming 06 September 2007 (has links)
Abstract Since the open of domestic financial market recent years, the financial products have become more and more various. In six years, there has been 2.7 funds issued every month on average. For investors, how to choose a good fund company and an appropriate fund from plenty of new offered funds is uneasy. Particularly new offered fund has no history data to examine the performance, and also lacks the regular benchmarks like £]and Sharp ratio. This thesis uses the data of the domestic stock funds which were offered over 1 year from 1997 January 1 to 2006 December 31.The data resources is from TEJ. The study will distinguish all data from whether the prospectuses regulate the funds¡¦ stock holding percentage over 70 ¢H or not. Then we want to investigate the behavior in the first year and to discuss if the fund managers¡¦ experiment will result in the abnormal performance. The study results shows that the stock holding percentage of the domestic stock funds have been over 70¢H on average since offered 3 months, but the percentage of the funds with free investment period of 3 months is less than 60¢H. However the percentage of the funds with free investment period of 6 months would rise to be 70¢H early in the second or third month. We try to use a statistic way and set a dummy variable to test whether there is different between the performance of the funds with free period and those with limited period. The result shows that there is no fund performance difference between these two period. From the second month after the fund is offered, turnover rare is close or even over the average of one year. The average level is about 30¢H and it shows the domestic stock funds have changed stocks frequently since it is offered . The tenure of Fund managers¡¦ after domestic stock funds raised is 20 months on average from 95 months to 1 month.13¢Mof fund managers will be taken place less than half year after the fund offered, 39¢Mwill be less than 1 year. 60¢Mof the fund managers have ever managed other funds before the newly one which he manage now, but 40¢Mhave no such experiment. The statistics shows that there is no significant different between fund managers¡¦ experiment and fund¡¦s abnormal returns.
84

A High CMRR Instrumentation Amplifier for Biopotential Signal Acquisition

Muhammad Abdullah, Reza 2011 May 1900 (has links)
Biopotential signals are important to physicians for diagnosing medical conditions in patients. Traditionally, biopotentials are acquired using contact electrodes together with instrumentation amplifiers (INAs). The biopotentials are generally weak and in the presence of stronger common mode signals. The INA thus needs to have very good Common Mode Rejection Ratio (CMRR) to amplify the weak biopotential while rejecting the stronger common mode interferers. Opamp based INAs with a resistor-capacitor feedback are suitable for acquiring biopotentials with low power and low noise performance. However, CMRR of such INA topologies is typically very poor. In the presented research, a technique is proposed for improving the CMRR of opamp based INAs in RC feedback configurations by dynamically matching input and feedback capacitor pairs. Two instrumentation amplifiers (one fully differential and the other fully balanced fully symmetric) are designed with the proposed dynamic element matching scheme. Post layout simulation results show that with 1 percent mismatch between the limiting capacitor pairs, CMRR is improved to above 150dB when the proposed dynamic element matching scheme is used. The INAs draw about 10uA of quiescent current from a 1.5 dual power supply source. The input referred noise of the INAs is less than 3uV/sqrt(Hz).
85

On the strength of saturated cement-treated soil reconstituted by wet-mixing

Lewsley, Gregory 11 1900 (has links)
Cutter Soil Mixing (CSM) is a recently developed deep mixing technique that has grown to include the treatment of sandy and silty soils. This study seeks to investigate the influence of (i) sand-silt ratio, (ii) cement content, (iii) water content and (iv) time on the unconfined compressive strength of saturated cement-treated soil specimens. A new test device and method of specimen reconstitution were conceived in order to obtain a saturated mix of soil and cement. A comparison of results show strength increases non-linearly to decreasing total water-cement ratio, and that this trend is largely independent of sand-silt ratio. Furthermore, strength increases non-linearly with time and is independent of sand-silt ratio. Lastly, it is recommended that the strength be correlated with total water-cement ratio rather than cement content, in order to improve data reporting and provide design guidance to engineering practice.
86

Utveckling av modell för kvalitetsstyrning av polyetenreaktor

Larsson, Katarina January 2003 (has links)
No description available.
87

Towards measurement of the ratio BR(η → 3π0) / BR(η → π+ π- π0)

Heijkenskjöld, Lena January 2010 (has links)
This diploma thesis presents a preliminary study of the ratio of branching ratio r = BR(η → 3π0) / BR(η → π+ π- π0). The experimental data used is collected by WASA-at-COSY which is a 4π sr detector optimised to detect light mesons and their decay products and is situated in Jülich, Germany.The focus of the work is to see how different reconstruction methods for the detected particles can alter both the measured values of the  branching ratios and the luminosity dependence of these branching ratios. The results show that for some of the methods, the measured branching ratios have a clear luminosity dependence. Depending on method, the extracted branching ratios vary differently. A few different methods have been studied, so the results provides a qualitative understanding of the behaviour of the measured branching ratios for different luminosities.
88

Analyzing and classifying the jumping spider of Eugaria albidentata

Lin, Shih-hua 28 July 2010 (has links)
Under the mechanism of natural selection, creatures are forced to evolve naturally in order to survive. Keen-sighted jumping spiders have long been considered as the main predation pressure of terrestrial arthropod. Many species benefit from mimicking the appearance of jumping spider. In this study according to the experimental data from Wang (2009b), a data analysis is undertaken concerning male Ptocasius strupifer¡¦s behavior to different subject groups, namely, male Ptocasius strupifer, female Ptocasius strupifer, male Plexippus paykulli, female Plexippus paykulli, Cataclysta angulata and Eugauria albidentata, so as to investigate the jumping spider mimicry of Eugauria albidentata. In this work, our interest is to compare the behavior of male Ptocasius strupifer on Eugauria albidentata with there of the other five groups mentioned above, and identify which one is the most similar to there of Eugauria albidentata . We use different statistical methods, i.e. likelihood ratio test, factor analysis and cluster analysis to evaluate the closeness of the behavior between different groups. According to the analysis result, it shows that the behavior of Ptocasius strupifer towards Eugauria albidentata is more similar to those of both female Ptocasius strupifer and female Plexippus paykulli. Moreover there is a wide discrepancy between Eugauria albidentata and Cataclysta angulata, although both of them belong to Musotiminae.
89

Viewing angle switchable displays based on three-dimension control of liquid-crystal orientation

Chen, Chia-Wei 08 September 2010 (has links)
In this study, a liquid-crystal display (LCD) with the capability of switchable viewing-angle is proposed. The contrast ratio of the LCD mainly depends on the transmittance of the bright state and the dark state. By using the improved structure of the pixel electrodes, the viewing angle of the LCD can be switched between the wide viewing-angle mode and the narrow-viewing angle mode. Based on the proposed three-electrode structure, the liquid-crystal orientation of the LCD is controlled to generate different light-leakage conditions at large viewing angles, thus, resulting in the switch of the viewing angle of the LCD. The proposed structure, which has the slim outline and low-cost of the LCD, is a simple way to control the viewing angle of the LCD. Potential applications for the protection of personal privacy are emphasized.
90

Investment Decision of the Electronics Industry

Kuo, Sheng-cheng 17 July 2012 (has links)
Since our current economic environment is getting more and more competitive, enterprises must continuously improve and strengthen their ability in order to maintain their competitiveness. Therefore, investment activities of firms are the key elements to drive business growth. This article tries to discuss whether three different investment dimensions can help to boost firm¡¦s future growth of profitability. This research uses investment spending of listed firms in domestic electronics industry (including capital expenditure, intangible assets and R&D expenditures) as variable to explore the effects of these three investment expenditures on corporate P/B ratio as well as ROA (Return on Asset). This study attempts to analyze whether firm¡¦s investment activities can impose significantly positive influence on its future profitability. We use panel data to run regression analysis and further divide Taiwan electronics industry into five sectors to analyze the effects of firm¡¦s investment expenditure on P/B and future profitability among different sectors. The empirical results show that investment spending imposes significantly positive effect on firm¡¦s profits, but this relationship exist time lags.

Page generated in 1.3575 seconds