Matching Items (4)

Using Bag of Words Approach for Classifying Native Arizona Snakes in Images as Venomous or Non-Venomous

Description

Uninformed people frequently kill snakes without knowing whether they are venomous or harmless, fearing for their safety. To prevent unnecessary killings and to encourage people to be safe around venomous

Uninformed people frequently kill snakes without knowing whether they are venomous or harmless, fearing for their safety. To prevent unnecessary killings and to encourage people to be safe around venomous snakes, a proper identification is important. This work seeks to preserve wild native Arizona snakes and promote a general interest in them by using a bag of features approach for classifying native Arizona snakes in images as venomous or non-venomous. The image category classifier was implemented in MATLAB and trained on a set of 245 images of native Arizona snakes (171 non-venomous, 74 venomous). To test this approach, 10-fold cross-validation was performed and the average accuracy was 0.7772. While this approach is functional, the results could be improved, ideally with a higher average accuracy, in order to be reliable. In false positives, the features may have been associated with the color or pattern, which is similar between venomous and non-venomous snakes due to mimicry. Polymorphic traits, color morphs, variation, and juveniles that may exhibit different colors can cause false negatives and misclassification. Future work involves pre-training image processing such as improving the brightness and contrast or converting to grayscale, interactively specifying or generating regions of interest for feature detection, and targeting reducing the false negative rate and improve the true positive rate. Further study is needed with a larger and balanced image set to evaluate its performance. This work may potentially serve as a tool for herpetologists to assist in their field research and to classify large image sets.

Contributors

Agent

Created

Date Created
  • 2017-05

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WCAG 2.0 success criterion 1.1.1 compliance: using accessibility checkers to find empty alt attributes in university home-pages

Description

With 285-million blind and visually impaired worldwide, and 25.5 million in the United States, federally funded universities should be at the forefront when designing accessible websites for the blind community.

With 285-million blind and visually impaired worldwide, and 25.5 million in the United States, federally funded universities should be at the forefront when designing accessible websites for the blind community. Fifty percent of the university homepages discussed in my thesis failed accessibility checker tests because alternative text was not provided in the alt-attribute for numerous images, making them inaccessible to blind users. The images which failed included logos, photographs of people, and images with text. Understanding image content and context in relation to the webpage is important for writing alternative text that is useful, yet writers interpret and define the content and context of images differently or not at all. Not all universities follow legal guidelines of using alternative text for online images nor implements best practices of analyzing images prior to describing them within the context of the webpage. When an image used in a webpage is designed only to be seen by sighted users and not to be seen by screen reader software, then that image is not comparably accessible to a blind user, as Section 508 mandates.

Contributors

Agent

Created

Date Created
  • 2018

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See yourself in history: using imagery and journaling to promote historical thinking in secondary world history

Description

ABSTRACT

Learning world history has the potential to develop adolescents into thoughtful, active citizens. This is especially true when students are taught in ways that engage them with complex issues and

ABSTRACT

Learning world history has the potential to develop adolescents into thoughtful, active citizens. This is especially true when students are taught in ways that engage them with complex issues and help them make connections between what they learn and their personal goals and experiences. However, instructional time in social studies is limited because of the current emphasis on standardized achievement testing in other content areas. Furthermore, in the specific field of world history, the scope of material covered, coupled with debate over what should be taught, has made it difficult to present a curriculum that is meaningful and relevant to students. As a result, the study of world history may be seen as tangential or incoherent.

The purpose of this action research study was to introduce an innovation aimed at helping students think deeply and find personal relevance in the study of world history. Specifically, visual imagery and reflective journaling were used to help students to become proficient in historical thinking and to fully engage in the study of world history. The study was developed according to a mixed-methods design: the quantitative data collection tools were pre- and posttests and a student survey, and the qualitative data collection tools included discussion transcripts, reflective journals, student-created presentations, and observations.

Results showed that the use of images and reflective journaling enabled students to develop some critical thinking skills, such as making claims, supporting claims with evidence, and considering divergent perspectives. Furthermore, students' awareness of their connections to the world around them increased, as did student performance on tests about historical events and concepts. Unfortunately, students did not reach proficiency in factual knowledge on post-tests in the class, despite these increases. However, this study highlights the benefits of explicitly connecting students to historical thinking through the use of images and journaling that allow students to explore their own thoughts and deductions.

Contributors

Agent

Created

Date Created
  • 2015

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The reality of directed forgetting in the item-method paradigm: suppression, not selective search or decay

Description

It has been suggested that directed forgetting (DF) in the item-method paradigm results from selective rehearsal of R items and passive decay of F items. However, recent evidence suggested that

It has been suggested that directed forgetting (DF) in the item-method paradigm results from selective rehearsal of R items and passive decay of F items. However, recent evidence suggested that the passive decay explanation is insufficient. The current experiments examined two theories of DF that assume an active forgetting process: (1) attentional inhibition and (2) tagging and selective search (TSS). Across three experiments, the central tenets of these theories were evaluated. Experiment 1 included encoding manipulations in an attempt to distinguish between these competing theories, but the results were inconclusive. Experiments 2 and 3 examined the theories separately. The results from Experiment 2 supported a representation suppression account of attentional inhibition, while the evidence from Experiment 3 suggested that TSS was not a viable mechanism for DF. Overall, the results provide additional evidence that forgetting is due to an active process, and suggest this process may act to suppress the representations of F items.

Contributors

Agent

Created

Date Created
  • 2011