A high efficiency driver circuit is proposed for Light Emitting Diode (LED) lamps with dimming feature. The current regulation is accomplished by processing partial power of the power conversion circuit so that a high overall efficiency can be realized. The detailed description and analysis of circuit operation are provided. The dimming feature can be accomplished by means of linear current regulation, pulse-width modulation (PWM) or double pulse-width modulation (DPWM). Based on the circuit analyses and derived equations, a laboratory circuit is designed for an LED lamp which is composed of 40 high-brightness white LEDs in series. The performances with three dimming schemes are compared from the measured results. LEDs dimmed by DPWM have less color shift than those dimmed by linear current regulation and PWM. On the other hand, the dimming scheme with linear current regulation has the highest light efficiency over the entire dimming range. The circuit efficiency can be as high as 95.5% at the rated output and deteriorates slightly to 90.5% as the lamp is dimmed to 10% of the rated power.

This thesis aims to construct a semantic system for the disparate uses of peh in TSM and peh¡¦s pragmatic functions in actual language uses in terms of cognitive accounts. Firstly, based on the data collected from dictionaries of the Ministry of Education, the present study divided the various meanings of peh into two main types, i.e., prototypical meaning and extended meanings. Prototypical meaning is further classified into perception-based type. How peh is perceived in perception-based type is in close relationship with the actual environment where we interact with. On the other hand, the main category under extended meanings is conception-based type, which is divided into four subcategories of cognitive mechanisms. That is, the diverse meanings of peh in conception-based type will be interpreted in the perspective of four subcategories of cognitive mechanisms. They are metonymic extension, metaphorical extension, the interaction of metaphor and metonymy, and culturally-related extension. Then, to better understand peh¡¦s pragmatic functions in TSM, the study shifts its foucus to the examination of the interrelationship between peh and the shared Taiwanese cultural background knowledge in actual language uses. Basically, the function which peh serves in discourse depends mainly on the context where it is used, and the world or the community will determine and pick up the most appropriate wordings for us (Mey, 2008). There is no definite answer as to which linguistic expression bears which meaning or interpretation when we try to sort out all possible interpretations and meanings for each linguistic expression containing peh. We need both contextual clues and cultural background knowledge to decipher peh¡¦s underlying meanings. The encodings of color perception do not lie in our biology; instead, it is structured socially (Lucy, 1997). In addition, certain uses of peh, e.g., pe̍h-pau (¥Õ¥]), pe̍h-thiap-á (¥Õ©«¥J), etc., in real life discourse make the function of peh more than a representation of the color itself but bridge the gap and create interpersonal relationship between their language users at the same time. On the whole, this research may shed light on the cognitive understanding of peh in TSM not only semantically but also pragmatically.

Whereas research related to the experience of faculty of color is increasing, little attention has been focused on Chinese faculty's career experience in the United States. The purpose of this study was: (1) to identify and describe factors which influence Chinese faculty decisions to apply for, accept, and remain in faculty positions at a Research Extensive University in Texas; and (2) to determine the challenges and support Chinese faculty have experienced with respect to promotion, tenure and recognition at a Research Extensive University in Texas. To address the purpose of the study, four research questions were used as guidance for collecting and analyzing the data. The purposive sample consisted of sixteen Chinese faculty members (four female and twelve male) across different disciplines, ranks and genders, from seven different colleges at the studied university. All participants are first generation Americans who obtained at least a bachelor's degree in China, received their doctoral degree or postdoctoral training in the United States, and found faculty positions in the United States. This study used a qualitative research design with in-depth interviews, observations and document reviews as the major tools for data collection. Constant comparative method was adopted to analyze data. Major findings concluded that factors such as traditional Chinese culture, family influence, the ability to access American academic freedom, advanced research environments, flexibility and job security, have significant influences in determining Chinese faculty decisions to work within academia in the United States. Additionally, Chinese faculty tended to regard individual barriers (i.e. challenges in mastery of English language, a lack of teaching experience, no undergraduate educational background in the United States, an unfamiliarity with the American culture, and insufficient communications skills in general) rather than institutionalized barriers (i.e. occupational discrimination, stereotypes and prejudice) as primary factors that impeded their professional development. Furthermore, Chinese women faculty experienced racial and gender issues in their lives and faced more challenges than their male counterparts in developing their career in the United States. The researcher hoped that this study could contribute to the scant literature on Chinese faculty's career experiences in the United States, shed some light on understanding what factors influenced their career development, and provide some implications for practice and recommendations for further research.

The purpose of this study was to investigate the perceptions of African American and Hispanic students who dropped out of school while exploring their schooling experiences and the factors they believe contributed to their decision to drop out. The case study approach was used in an effort to capture the informants’ voices and the meanings they hold as students of color about the experience of dropping out. The findings from this study will contribute to the existing body of literature by contextualizing a student of color’s choice to dropout of school. The informants in this study were members of a large, diverse suburban high school, in a large school district in Southeast Texas. The 12 informants were purposefully selected resulting in seven Hispanic, five African American, seven female, and five male dropout students. A one-on-one interview with the informants generated data for this study. Additional data consisted of observations made by the researcher as a school administrator at the last school the informants attended and by prior knowledge about some of the informants from school records. The interpretational analysis process selected was based on Glaser and Strauss’ constant comparative approach to analysis. The constant comparative data analysis generated three major themes of the factors that informants attributed to dropping out of school: (1) challenging home situations, (2) personal realities, and (3) school related factors that reflected a lack of support systems. The theoretical framework that grounded this study was based on Mehan’s Contextual Factors Surrounding Hispanic Dropouts. His construct suggested that for students of color dropping out was a function of social reproduction and deficit thinking. He further asserted that such outcomes were a result of school factors controlled and institutionalized by schools. However, contrary to Mahen’s theory, my informants noted challenging home situations as the primary consideration in their decision to drop out. My findings, based on the context of the Horizon High School, suggest that while the school as an institution is not responsible or accountable for the family factors that contribute to students’ decision to drop out, it can provide systems of support for students to assist them in overcoming the causes outside of the school walls that contribute to their decision to leave.

Vertical alignment liquid crystal display has the advantages of wide view angle, high contrast and good response time. Today vertical alignment liquid crystal display get flourishing development, and Multi-Domain Vertical Alignment (MVA) technology is progressive. In this report we would find an alignment materiel which could be fabricated easily, low cost and good E-O characteristic. The use of dimenthysiloxane (PDMS) in fabrication of microfluidic channels technology in biotechnology has the advantages of characteristics foregoing. In this study PDMS was used as LC vertical alignment materiel. We used the MVA structure and ASV structure to align LC direction because PDMS cannot be rubbed. In experiment we found that PDMS exhibited different surface energies when it was baked in different temperature. The results of measuring the pre-tilt angle in the different surface energy conditions are similar. ASV LC samples were fabricated using PDMS alignment layer. MVA LC cells were made using high viscosity PDMS. We found the characteristic of paper white at CIE chromaticity diagram in the ASV LC sample without any color filter and color correction technology.

Turkish speakers differentiate the blue region of color spectrum into mavi (blue) and lacivert (dark blue) / whereas non-Turkish speakers in this study had only one color term in the blue region. The present study aimed to explore the predictions of the Linguistic Relativity Hypothesis. Operationally, Categorical Perception (CP) effects were used. In Experiment 1, Turkish speakers performed a naming task to determine an average category boundary between mavi and lacivert. In Experiment 2, both Turkish and non-Turkish speakers&rsquo / color-difference detection thresholds were estimated on the average boundary as well as within the mavi and lacivert categories. The thresholds were also estimated in the green region, in which both groups had only one color term. 2-TAFC method, which eliminates the effects of memory or labeling and isolates the perceptual processes, was used to estimate the thresholds. Turkish speakers, and not non-Turkish speakers, were predicted to show CP effects only in the blue region: thresholds should be lower on the boundary than within-category. The result revealed that Turkish speakers&rsquo / color-difference detection thresholds were lower than those of non-Turkish speakers both in the blue and the green regions. The difference in the green region does not rule out the LRH. It is possible that this difference resulted from the limitations of the study. Finally, in Experiment 3, Turkish speakers&rsquo / thresholds were also estimated on their individual boundaries. The patterns of the thresholds revealed by Experiment 3 were similar to the pattern of the thresholds in Experiment 2.

Effect of high hydrostatic pressure (150-200-250 MPa) on the microbial load and quality parameters (pH, color, 5-hydroxymethylfurfural-HMF) of white (Sultaniye) and red (Alicante Bouschet) grape juices with combination of temperature (20-30-40&deg / C) and holding time (5-10-15 min) was studied. Increased pressure and temperature showed significant effect on microbial reduction in white and red grape juices (p&lt / 0.05). The effect of pressure and time on pH drop was found to be insignificant (p&gt / 0.05). HHP resulted in E&lt / 1 for white grape and E&lt / 7 for red grape juice samples. Shelf life analysis for HHP treated white grape juice (200 MPa-40&deg / C-10min) and red grape juice (250 MPa-40&deg / C-10min) revealed no microbial growth up to 90 days when stored at 25&deg / C. Although HMF formation was observed in industrially manufactured, pasteurized samples (65&deg / C for 30 min), no HMF was detected in HHP treated white and red grape juices. HHP at the suggested conditions can be recommended as a better production alternative to heat treatment for white and red grape juice with respect to microbial load and studied quality parameters even at temperatures lower than required for pasteurization.

In this thesis, real time detection of traffic signs using FPGA hardware is presented. Traffic signs have distinctive color and shape properties. Therefore, color and shape based algorithms are chosen to implemented on FPGA. FPGA supports sufficient logic to implement complete systems and sub-systems. Color information of images/frames is used to minimize the search domain of detection process. Using FPGA, real time conversion of YUV space to RGB space is performed. Furthermore, color thresholding algorithm is used to localize the sign in the image/video depending on the color. Edges are the most important image/frame attributes that provide valuable information about the shape of the objects. Sobel edge detection algorithm is implemented on FPGA. After color segmentation, FPGA implementation of Sobel algorithm is used to find the edges of candidate traffic signs in real time. Later, radial symmetry based shape detection algorithm is used to determine circular traffic signs. Each FPGA implemented algorithm is tested by using video sequences and static images. In addition, combined implementation of color based and shape based algorithms are tested. Joint application of color and shape based algorithms are used in order to reduce search domain and the processing time of detection process. Designing architecture on FPGA makes traffic sign detection system portable as a final product and relatively more efficient than the computer based detection systems. The resulting hardware is suitable where cost and compactness constraints are important.

Denim production is one of the leading sub-sectors of textile industry which basically generates highly colored indigo dyeing effluents. In the present study, ozonation was applied to the indigo-dyeing effluent(COD=820 mg/L / color=5500 Pt-Co), and to the whole effluent from a denim-producing plant before(COD=2750 mg/L / color=3950 Pt-Co) and after(COD=800 mg/L,color=3700 Pt-Co) biological treatment for degradation/detoxification purposes. Ozonation was also tried in the wastewater of the plant(COD=3100 mg/L / color=4500 Pt-Co) that would be produced after some foreseen cleaner production measures / caustic recovery and reusing of dyeing process wastewater. When applied to indigo-dyeing wastewater / ozonation provided 95% color and 61% COD removals at 1320 mg/h ozone dose within 60 minutes The optimum pH was evaluated as 4 when indigo-dyeing wastewater exposed to ozonation at different pHs(1.6-12.3). On the other side, ozonation applied as pre-treatment to the plant effluent provided 86% color and 46% COD removals with 3240 mg/h ozone dose in 70 minutes. Less satisfactory results were obtained when ozonation was tried in the wastewater after measures, with 86% color and 31% COD removals at 3960 mg/h ozone dose in 80 minutes. When applied to the biologically-treated effluent / at 420 mg/h ozone dose and within 40 minutes, ozonation removed 47% of influent COD and 96% of influent color indicating better performance of ozonation in postoxidation. In order to assess possible improvements on ozonation with the addition of H2O2, different concentrations were tried, but no significant improvement was obtained. The improvement in BOD5/COD index was also determined for the ozonetreated plant effluent to measure the effects of ozonation on biodegradability and found out that BOD5/COD ratio has improved to 0.39 from 0.22.

SeaWiFS was collecting ocean color data since 1997. This means chlorophyll-a data for more than ten years. Since, SeaWiFS Chl-a data is validated for Black Sea this data set can be used for analysis. Nevertheless, the data is not gap free due to cloud effect. One of the main objectives of this work is to obtain a gap free, complete Chl-a data set for the Black Sea. For this purpose DINEOF method will be used.