Matching Items (140)
Description
For many pre-health and graduate programs, organic chemistry is often the most difficult prerequisite course that students will take. To alleviate this difficulty, an intelligent tutoring system was developed to provide valuable feedback to practice problems within organic chemistry. This paper focuses on the design and use of an intelligent input parser for nomenclature questions within this system. Students in Dr. Gould's Fall 2014 organic chemistry class used this system and their data was collected to analyze the effectiveness of the input parser. Overall the students' feedback was optimistic and there was a positive relationship between test scores and student use of the system.
ContributorsHusarcik, Edward Andrew (Author) / Gould, Ian (Thesis director) / VanLehn, Kurt (Committee member) / Beerman, Eric (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2015-05
Description
Understanding the relationships between chemistry students' motivation, performance, and gender can help identify and inform ways in which chemistry education might be improved. Students from four CHM 101 classes with two different instructors were surveyed using an adapted Science Motivation Questionnaire II, and motivation data was analyzed with respect to final course performance. Gender data was available for two of these classes, and motivation results analyzed by gender for these classes. Exam scores and gender data was obtained from one of the instructors for CHM 101 courses taught over the past five years and were also analyzed. The motivational study involved small sample sizes, especially in the motivation by gender study. Career motivation, grade motivation, self-efficacy, and total motivation declined over the course of the semester in the four classes combined. Self-efficacy and career motivation were found to predict final course performance only at the end of the semester. Self-efficacy strongly predicted performance, and career motivation was negatively correlated with performance. Female students had higher grade motivation at the end of the semester and lost more self-efficacy over the course of the semester than male students. Gender-performance analysis showed that male students scored slightly higher on exams on average, but that female students received a higher percentage of "A"s and a lower percentage of "D"s, "E"s, and "W"s in the majority of the semesters.
ContributorsJohnson, Walter Gregory (Author) / Gould, Ian (Thesis director) / Wolf, George (Committee member) / Austin, Ara (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Life Sciences (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2015-05
Description
Due to its difficult nature, organic chemistry is receiving much research attention across the nation to develop more efficient and effective means to teach it. As part of that, Dr. Ian Gould at ASU is developing an online organic chemistry educational website that provides help to students, adapts to their responses, and collects data about their performance. This thesis creative project addresses the design and implementation of an input parser for organic chemistry reagent questions, to appear on his website. After students used the form to submit questions throughout the Spring 2013 semester in Dr. Gould's organic chemistry class, the data gathered from their usage was analyzed, and feedback was collected. The feedback obtained from students was positive, and suggested that the input parser accomplished the educational goals that it sought to meet.
ContributorsBeerman, Eric Christopher (Author) / Gould, Ian (Thesis director) / Wilkerson, Kelly (Committee member) / Mosca, Vince (Committee member) / Barrett, The Honors College (Contributor) / Computer Science and Engineering Program (Contributor)
Created2013-05
Description
Distributed inference has applications in fields as varied as source localization, evaluation of network quality, and remote monitoring of wildlife habitats. In this dissertation, distributed inference algorithms over multiple-access channels are considered. The performance of these algorithms and the effects of wireless communication channels on the performance are studied. In a first class of problems, distributed inference over fading Gaussian multiple-access channels with amplify-and-forward is considered. Sensors observe a phenomenon and transmit their observations using the amplify-and-forward scheme to a fusion center (FC). Distributed estimation is considered with a single antenna at the FC, where the performance is evaluated using the asymptotic variance of the estimator. The loss in performance due to varying assumptions on the limited amounts of channel information at the sensors is quantified. With multiple antennas at the FC, a distributed detection problem is also considered, where the error exponent is used to evaluate performance. It is shown that for zero-mean channels between the sensors and the FC when there is no channel information at the sensors, arbitrarily large gains in the error exponent can be obtained with sufficient increase in the number of antennas at the FC. In stark contrast, when there is channel information at the sensors, the gain in error exponent due to having multiple antennas at the FC is shown to be no more than a factor of 8/π for Rayleigh fading channels between the sensors and the FC, independent of the number of antennas at the FC, or correlation among noise samples across sensors. In a second class of problems, sensor observations are transmitted to the FC using constant-modulus phase modulation over Gaussian multiple-access-channels. The phase modulation scheme allows for constant transmit power and estimation of moments other than the mean with a single transmission from the sensors. Estimators are developed for the mean, variance and signal-to-noise ratio (SNR) of the sensor observations. The performance of these estimators is studied for different distributions of the observations. It is proved that the estimator of the mean is asymptotically efficient if and only if the distribution of the sensor observations is Gaussian.
ContributorsBanavar, Mahesh Krishna (Author) / Tepedelenlioğlu, Cihan (Thesis advisor) / Spanias, Andreas (Thesis advisor) / Papandreou-Suppappola, Antonia (Committee member) / Duman, Tolga (Committee member) / Zhang, Junshan (Committee member) / Arizona State University (Publisher)
Created2010
Description
To establish reliable wireless communication links it is critical to devise schemes to mitigate the effects of the fading channel. In this regard, this dissertation analyzes two types of systems: point-to-point, and multiuser systems. For point-to-point systems with multiple antennas, switch and stay diversity combining offers a substantial complexity reduction for a modest loss in performance as compared to systems that implement selection diversity. For the first time, the design and performance of space-time coded multiple antenna systems that employ switch and stay combining at the receiver is considered. Novel switching algorithms are proposed and upper bounds on the pairwise error probability are derived for different assumptions on channel availability at the receiver. It is proved that full spatial diversity is achieved when the optimal switching threshold is used. Power distribution between training and data codewords is optimized to minimize the loss suffered due to channel estimation error. Further, code design criteria are developed for differential systems. Also, for the special case of two transmit antennas, new codes are designed for the differential scheme. These proposed codes are shown to perform significantly better than existing codes. For multiuser systems, unlike the models analyzed in literature, multiuser diversity is studied when the number of users in the system is random. The error rate is proved to be a completely monotone function of the number of users, while the throughput is shown to have a completely monotone derivative. Using this it is shown that randomization of the number of users always leads to deterioration of performance. Further, using Laplace transform ordering of random variables, a method for comparison of system performance for different user distributions is provided. For Poisson users, the error rates of the fixed and random number of users are shown to asymptotically approach each other for large average number of users. In contrast, for a finite average number of users and high SNR, it is found that randomization of the number of users deteriorates performance significantly.
ContributorsBangalore Narasimhamurthy, Adarsh (Author) / Tepedelenlioğlu, Cihan (Thesis advisor) / Duman, Tolga M. (Committee member) / Spanias, Andreas S (Committee member) / Reisslein, Martin (Committee member) / Papandreou-Suppappola, Antonia (Committee member) / Arizona State University (Publisher)
Created2010
Description
Thousands of high-resolution images are generated each day. Segmenting, classifying, and analyzing the contents of these images are the key steps in image understanding. This thesis focuses on image segmentation and classification and its applications in synthetic, texture, natural, biomedical, and industrial images. A robust level-set-based multi-region and texture image segmentation approach is proposed in this thesis to tackle most of the challenges in the existing multi-region segmentation methods, including computational complexity and sensitivity to initialization. Medical image analysis helps in understanding biological processes and disease pathologies. In this thesis, two cell evolution analysis schemes are proposed for cell cluster extraction in order to analyze cell migration, cell proliferation, and cell dispersion in different cancer cell images. The proposed schemes accurately segment both the cell cluster area and the individual cells inside and outside the cell cluster area. The method is currently used by different cell biology labs to study the behavior of cancer cells, which helps in drug discovery. Defects can cause failure to motherboards, processors, and semiconductor units. An automatic defect detection and classification methodology is very desirable in many industrial applications. This helps in producing consistent results, facilitating the processing, speeding up the processing time, and reducing the cost. In this thesis, three defect detection and classification schemes are proposed to automatically detect and classify different defects related to semiconductor unit images. The first proposed defect detection scheme is used to detect and classify the solder balls in the processor sockets as either defective (Non-Wet) or non-defective. The method produces a 96% classification rate and saves 89% of the time used by the operator. The second proposed defect detection scheme is used for detecting and measuring voids inside solder balls of different boards and products. The third proposed defect detection scheme is used to detect different defects in the die area of semiconductor unit images such as cracks, scratches, foreign materials, fingerprints, and stains. The three proposed defect detection schemes give high accuracy and are inexpensive to implement compared to the existing high cost state-of-the-art machines.
ContributorsSaid, Asaad F (Author) / Karam, Lina (Thesis advisor) / Chakrabarti, Chaitali (Committee member) / Tepedelenlioğlu, Cihan (Committee member) / Patel, Nital (Committee member) / Arizona State University (Publisher)
Created2010
Description
Background: Vascular brachytherapy (VBT) is an established treatment for the management of in-stent restenosis (ISR). However, whether VBT is associated with improved patient-reported outcomes is unknown and not been previously studied.
Methods: The authors evaluated 51 consecutive patients, age 18 years and older undergoing VBT in one or more coronary arteries from January 2018 to September 2019. Data on baseline characteristics, procedural outcomes, and occurrence of adverse events were obtained. All patients completed the Seattle Angina Questionnaire – 7 (SAQ-7) form before and after the intervention at 1 month and 6 months.
Results: The mean age was 69 ± 9 years and 29 (57%) of patients were males. Most patients had hypertension (n = 44, 86%) and diabetes (n = 29, 57%). The use of aspirin was 90% while 96% of patients were on P2Y12 inhibitors. 48 (94%) patients were on antianginal therapy. The procedural success was 94.1%. The mean summary SAQ-7 score improved significantly (53.2 ± 21 vs. 83 ± 19, p<0.001) at 30-days. The median Quality of Life (QoL) component of the SAQ-7 score at baseline was 31.3 (Interquartile Range [IQR]: 18.8, 62.5) and improved to 82.5 (IQR: 62.5, 100), p<0.001 at 30 days and 87.5 [IQR: 75, 100), p<0.001 at last follow up. Likewise, the median angina frequency component of the SQL-7 score pre-VBT was 55 (IQR: 45, 80) and improved significantly to 90 (IQR: 60, 100) at 30-days, p<0.001 and 100 [IQR: 68.8, 100], p=0.02 at last follow up. Lastly, the median activity component of the SAQ-7 score improved from 83.3 (IQR: 60 – 100) to 100 (IQR: 83, 100), p = 0.01 at 30-days.
Conclusion: This study demonstrated improvement in patient-reported outcome measures following vascular brachytherapy that are evident as early as 1 month after the intervention and sustained at a median follow up of 17 months.
Methods: The authors evaluated 51 consecutive patients, age 18 years and older undergoing VBT in one or more coronary arteries from January 2018 to September 2019. Data on baseline characteristics, procedural outcomes, and occurrence of adverse events were obtained. All patients completed the Seattle Angina Questionnaire – 7 (SAQ-7) form before and after the intervention at 1 month and 6 months.
Results: The mean age was 69 ± 9 years and 29 (57%) of patients were males. Most patients had hypertension (n = 44, 86%) and diabetes (n = 29, 57%). The use of aspirin was 90% while 96% of patients were on P2Y12 inhibitors. 48 (94%) patients were on antianginal therapy. The procedural success was 94.1%. The mean summary SAQ-7 score improved significantly (53.2 ± 21 vs. 83 ± 19, p<0.001) at 30-days. The median Quality of Life (QoL) component of the SAQ-7 score at baseline was 31.3 (Interquartile Range [IQR]: 18.8, 62.5) and improved to 82.5 (IQR: 62.5, 100), p<0.001 at 30 days and 87.5 [IQR: 75, 100), p<0.001 at last follow up. Likewise, the median angina frequency component of the SQL-7 score pre-VBT was 55 (IQR: 45, 80) and improved significantly to 90 (IQR: 60, 100) at 30-days, p<0.001 and 100 [IQR: 68.8, 100], p=0.02 at last follow up. Lastly, the median activity component of the SAQ-7 score improved from 83.3 (IQR: 60 – 100) to 100 (IQR: 83, 100), p = 0.01 at 30-days.
Conclusion: This study demonstrated improvement in patient-reported outcome measures following vascular brachytherapy that are evident as early as 1 month after the intervention and sustained at a median follow up of 17 months.
ContributorsRawal, Sahil (Author) / Gould, Ian (Thesis director) / Sawant, Abhishek C. (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
This study seeks to determine whether female and male students in general chemistry courses differ in exam and course-based performance. Using data from previous semesters of CHM 101 (Marks), CHM 101 (Bauer), CHM 114 (Seo, Windman), CHM 113/116 (Cabirac), and CHM 117/118 (Williams) courses taught at Arizona State University, the total exam scores and final course grades for each student were recorded and analyzed. The results of this study differ greatly by course type, as each course corresponded to a different STEM major. While CHM 113/116, the pre-medicinal majors course, saw evidence of stereotype threat via lower female exam performance, the other courses saw no statistical difference between male and female performance on their exam scores or overall course grades. For CHM 101, this was understandable, as the majority of students were nursing majors, who likely did not experience tokenism or feel stereotyped negatively in their science classes. However, CHM 114, the engineering majors course, and CHM 117/118, the research science course, saw parity with respect to male and female student performance. This suggests the possibility that female students face adversity in science and math courses before college that cause only those with high self-efficacy to advance to a career in these fields.
ContributorsWoner, Victoria Elaine (Author) / Gould, Ian (Thesis director) / Saenz, Delia (Committee member) / Austin, Ara (Committee member) / Department of Psychology (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
The main objective of this project is to create a hydrogel based material system to capture and release CCRF-CEM Leukemia cancer cells via chemo-mechanical modulation. This system is composed of an aptamer-functionalized hydrogel thin film at the bottom of a microfluidic channel, which changes its film thickness as the temperature of the fluid in the system changes. The functionalized hydrogel film has been created as the primary steps to creating the microfluidic device that could capture and release leukemia cells by turning the temperature of the fluid and length of exposure. Circulating tumor cells have recently become a highly studied area since they have become associated with the likelihood of patient survival. Further, circulating tumor cells can be used to determine changes in the genome of the cancer leading to targeted treatment. First, the aptamers were attached onto the hydrogel through an EDC/NHS reaction. The aptamers were verified to be attached onto the hydrogel through FTIR spectroscopy. The cell capture experiments were completed by exposing the hydrogel to a solution of leukemia cells for 10 minutes at room temperature. The cell release experiments were completed by exposing the hydrogel to a 40°C solution. Several capture and release experiments were completed to measure how many cells could be captured, how quickly, and how many cells captured were released. The aptamers were chemically attached to the hydrogel. 300 cells per square millimeter could be captured at a time in a 10 minute time period and released in a 5 minute period. Of the cells captured, 96% of them were alive once caught. 99% of cells caught were released once exposed to elevated temperature. The project opens the possibility to quickly and efficiently capture and release tumor cells using only changes in temperature. Further, most of the cells that were captured were alive and nearly all of those were released leading to high survival and capture efficiency.
ContributorsPaxton, Rebecca Joanne (Author) / Stephanopoulos, Nicholas (Thesis director) / He, Ximin (Committee member) / Gould, Ian (Committee member) / Materials Science and Engineering Program (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
The Effect of ZnS and Other Metal Sulfides on cis-1,2-dimethylcyclohexane at Hydrothermal Conditions
Description
Reactions between minerals and organic compounds in hydrothermal systems (high temperature and presence of H2O) are critical in the Earth’s deep carbon cycle and may have implications in the origins of life. Previous work demonstrated that in the absence of a mineral, hydrothermal reaction of cis- and trans-1,2-dimethylcyclohexane is extremely slow and resulted in the formation of many products. However, in the presence of sphalerite (ZnS), the reaction rate is significantly increased and it results in the formation of one main product, the corresponding stereoisomer. Following similar methods, we demonstrated that the sphalerite used in the reaction of cis-1,2-dimethylcyclohexane to the trans- stereoisomer visually changes structure via SEM. Additionally, we ran the experiments in sealed glass tubes, which unlike previously used gold tubes, do not react with the organics and provides more volume for larger amounts of mineral to be used. Finally, we investigated the role of other metal sulfides (FeS and PbS) in organic transformation reactions and analyzed their resulting physical structure. We found the role of FeS catalysis to be ambiguous and that PbS seemed to have no effect in the transformation reactions. We also found the glass tube data using ZnS to track previously published data with the same reactions in gold tubes. Our reactions were run without pressurizing the reaction vessels and at 300°C indicating pressure is not main factor in product formation (compare 1000 bar and 300°C).
ContributorsMchenry, Austin Ryan (Author) / Gould, Ian (Thesis director) / Johnson, Kristin (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05