The performance of the support vector machine (SVM) on a speaker verification task is assessed. Since speaker verification requires binary decisions, support vector machines seem to be a promising candidate to perform...
详细信息
The performance of the support vector machine (SVM) on a speaker verification task is assessed. Since speaker verification requires binary decisions, support vector machines seem to be a promising candidate to perform the task. A new technique for normalising the polynomial kernel is developed and used to achieve performance comparable to other classifiers on the YOHO database. We also present results on a speaker identification task.
Attenuation of high frequency ultrasound (10-55 MHz) by skin layers and subcutaneous fat was studied in vivo using 16 normal subjects aged 19 to 34. Attenuation values at several frequencies were obtained by computing...
详细信息
ISBN:
(纸本)0780363655
Attenuation of high frequency ultrasound (10-55 MHz) by skin layers and subcutaneous fat was studied in vivo using 16 normal subjects aged 19 to 34. Attenuation values at several frequencies were obtained by computing the slope of spectra vs. depth (dB/mm). Diffraction effects were eliminated using axial translation of the focal zone within the tissue. Data were collected from three sites in the body: fingertip, dorsal side of forearm near the wrist, and dorsal side of forearm near the elbow. At 25 MHz, significant differences in attenuation were found between dermis at the fingertip and the two forearm regions (9.5/spl plusmn/2.5 vs. 2.7/spl plusmn/2.6 and 1.8/spl plusmn/2.1 dB/mm, Mean/spl plusmn/SD among the subjects). The corresponding mean attenuation coefficients were 0.32, 0.21 and 0.20 dB/mm/MHz respectively. Significant differences were not found between the dermis and fat at the forearm regions. These results are expected to aid future studies on quantitative characterization of skin tissues using high frequency ultrasound.
Investigating virtual environments has become an increasingly interesting research topic for engineers, computer and cognitive scientists, and psychologists. Although there have been several recent studies focused on ...
详细信息
Investigating virtual environments has become an increasingly interesting research topic for engineers, computer and cognitive scientists, and psychologists. Although there have been several recent studies focused on the development of multimodal virtual environments (VEs) to study human-machine interactions, less attention has been paid to human-human and human-machine interactions in shared virtual environments (SVEs), and to our knowledge, no attention paid at all to what extent the addition of haptic communication between people would contribute to the shared experience. We have developed a multimodal shared virtual environment and performed a set of experiments with human subjects to study the role of haptic feedback in collaborative tasks and whether haptic communication through force feedback can facilitate a sense of being and collaborating with a remote partner. The study concerns a scenario where two participants at remote sites must cooperate to perform a joint task in an SVE. The goals of the study are (1) to assess the impact of force feedback on task performance, (2) to better understand the role of haptic communication in human-humaninteractions, (3) to study the impact of touch on the subjective sense of collaborating with a human as reported by the participants based on what they could see and feel, and (4) to investigate if gender, personality, or emotional experiences of users can affect haptic communication in SVEs. The outcomes of this research can have a powerful impact on the development of next-generation human-computer interfaces and network protocols that integrate touch and force feedback technology into the Internet, development of protocols and techniques for collaborative teleoperation such as hazardous material removal, space station repair, and remote surgery, and enhancement of virtual environments for performing collaborative tasks in shared virtual worlds on a daily basis such as cooperative teaching, training, planning and design
We present the system called Takealook, which personalizes information presentation according to the user's interests and knowledge. The system infers the user's interests from her/his question-and-answer inte...
详细信息
We present the system called Takealook, which personalizes information presentation according to the user's interests and knowledge. The system infers the user's interests from her/his question-and-answer interactions and the information presenters' conceptual spaces by using the related method of collaborative filtering. It then provides additional information about current contents and also recommends other related contents. The user's interests are represented by her/his own individual conceptual space (i.e., a set of related keywords) which is adapted to her/his preferences. In this paper we describe a method for personalizing the information presentation, implementating the system at reviewing an exhibition, and experimental results.
The adoption of 3D virtual interfaces is becoming more widespread. Although design guidelines and usability evaluation methods exist for the conventional 2 dimensional Graphical User Interface (GUI), they may or may n...
详细信息
The adoption of 3D virtual interfaces is becoming more widespread. Although design guidelines and usability evaluation methods exist for the conventional 2 dimensional Graphical User Interface (GUI), they may or may not however, be appropriate in the design and the evaluation of 3 dimensional virtual interfaces. This paper describes the on-going research to find appropriate ways to evaluate virtual reality (VR) systems for usability.
Inspection is a fundamental means of achieving software usability. Past research showed that the current usability inspection techniques were rather ineffective. We developed perspective-based usability inspection, wh...
详细信息
Inspection is a fundamental means of achieving software usability. Past research showed that the current usability inspection techniques were rather ineffective. We developed perspective-based usability inspection, which divides the large variety of usability issues along different perspectives and focuses each inspection session on one perspective. We conducted a controlled experiment to study its effectiveness, using a post-test only control group experimental design, with 24 professionals as subjects. The control group used heuristic evaluation, which is the most popular technique for usability inspection. The experimental design and the results are presented, which show that inspectors applying perspective-based inspection not only found more usability problems related to their assigned perspectives, but also found more overall problems. Perspective-based inspection was shown to be more effective for the aggregated results of multiple inspectors, finding about 30% more usability problems for 3 inspectors. A management implication of this study is that assigning inspectors more specific responsibilities leads to higher performance. Internal and external threats to validity are discussed to help better interpret the results and to guide future empirical studies.
The Reorderable Matrix is a simple visualization method for quantitative tabular data. This paper examines how first-Time users interact with the Reorderable Matrix and how well they perform a simple task of finding c...
详细信息
Mandala is a system for using images to represent, access, and organize web information. Images from a web page represent the content of the page. Double-clicking on an image signals a web browser to display the assoc...
详细信息
作者：
B.B. BedersonA. BoltmanComputer Science Department
Human-Computer Interaction Laboratory Institute for Advanced Computer Studies University of Maryland College Park MD USA College of Education
Human-Computer Interaction Laboratory Institute for Advanced Computer Studies University of Maryland College Park MD USA
We examine how animating a viewpoint change in a spatial information system affects a user's ability to build a mental map of the information in the space. We found that animation improves users' ability to re...
详细信息
We examine how animating a viewpoint change in a spatial information system affects a user's ability to build a mental map of the information in the space. We found that animation improves users' ability to reconstruct the information space, with no penalty on task performance time. We believe that this study provides strong evidence for adding animated transitions in many applications with fixed spatial data where the user navigates around the data space.
暂无评论