579393
Chinese input with keyboard and eye-tracking: an anatomical study
Chinese input presents unique challenges to the field of human computer interaction. This study provides an anatomical analysis of today's standard Chinese input process, which is based on pinyin, a phonetic spelling system in Roman characters. Through a combination of human performance modeling and experimentation, our study decomposed the Chinese input process into sub-tasks and found that choice reaction time and numeric keying, two component resulted from the large number of homophones in Chinese, were the major usability bottlenecks. Choice reaction alone took 36% of the total input time in our experiment. Numeric keying for multiple candidates selection tends to take the user's attention away from the computer visual screen. We designed and implemented the EASE (Eye Assisted Selection and Entry) system to help maintaining complete touch-typing experience without diverting visual (spacebar) and implicit eye-tracking to replace the numeric keystrokes. Our experiment showed that such a system could indeed work, even with today's imperfecteye-tracking technology.
17608350
End-user place annotation on mobile devices: a comparative study
Advances in Location-Based Services (LBS) are opening opportunities for using the location of people, places, and things to augment or streamline interaction. While computers work with physical locations like latitude and longitude directly, people usually think and speak in terms of places, which adds personal, environmental and social meaning to a location. To address this conceptual mismatch, location-aware applications must incorporate the notion of place to achieve their full potential. In this paper, we investigate four techniques for collecting end-user place annotations interactively using cell phones. The results from a usability study suggest that while all the four methods receive similar preference ratings in understandability, the "photo memo plus offline editing" method is the most favorite approach in ease of use. In addition, users indicated their desire to adopt more than one place annotation method in location-aware applications.
207156320
Livenotes: a system for cooperative and augmented note-taking in lectures
We describe Livenotes, a shared whiteboard system and educational practice that uses wireless communication and tablet computing to support real-time conversations within small groups of students during lectures, independent of class size. We present an interface design that enables group members to interact with one another by taking lecture notes cooperatively, as well as to augment student note-taking by providing instructor slides in the background to annotate over. Livenotes was designed to facilitate more efficient, stimulating modes of learning that other collaborative approaches do not. We report how the system impacts cooperative learning in an undergraduate class and how students interacted with background slides in the workspace. We conclude with directions for improving the system and learning practice.
12186597
A Power-Saving Multi-Radio Multi-Channel MAC Protocol for Wireless Local Area Networks
Opportunistic spectrum access and adaptive power management are effective techniques to improve throughput, delay performance, and energy efficiency for wireless networks. In this paper, we consider the joint design of opportunistic spectrum access and adaptive power management under the setting of multi-radio nodes and multi-channel wireless local area networks (WLANs) under the distributed coordination function (DCF) mode. This design problem is particularly challenging due to the conflicting nature of the multi-radio capability of a node, i.e., multiple radios improve throughput and delay performance at the cost of increased energy consumption. To address this problem, we propose a power-saving multi-channel MAC protocol (PSM-MMAC), which is capable of reducing the collision probability and the waiting time in the ‘awake’ state of a node, resulting in improved throughput, delay performance, and energy efficiency. The key ideas of PSM-MMAC are the following: we first estimate the number of active links; given this estimation as well as queue lengths and channel conditions, we appropriately select channels, radios, and power states (i.e., awake or doze state); then we optimize the medium access probability in p-persistent CSMA used in the data exchange. Another contribution of this paper is an analytical model that characterizes the throughput performance. Simulation results validate the accuracy of our analytical model and show that our proposed protocol is able to significantly improve both throughput and energy efficiency.
24192218
On point-linear arboricity of planar graphs
The point-linear arboricity of a graph G=(V, E), written as p 0 (G), is defined as p 0 (G)=min{k | there exists a partition of V into k subsets, V=∪=1 V i such that (V i ) is a linear forest for 1 >i>k}. In this paper, we will discuss the point-linear arboricity of planar graphs and obtained following results: p 0 (G)=2 if G is a outplanar graph. p 0 (G)=4 if G is a planar graph.
13917172
iCLEF 2003 at Maryland: Translation Selection and Document Selection
Maryland performed two sets of experiments for the 2003 Cross-Language Evaluation Forum’s interactive track, one focused on interactive selection of appropriate translations for query terms, the second focused on interactive selection of relevant documents. Translation selection was supported using possible synonyms discovered through back translation and two techniques for generating KeyWord In Context (KWIC) examples of usage. The results indicate that searchers typically achieved a similar search effectiveness using fewer query iterations when interactive translation selection was available. For document selection, a complete extract of the first 40 words of each news story was compared to a compressed extract generated using an automated parse-and-trim approach that approximates one way in which people can produce headlines. The results indicate that compressed “headlines” result in faster assessment, but with a 20% relative reduction in the F α= 0.8 search effectiveness measure.
2192459
Curriculum Knowledge Representation and Manipulation in Knowledge-Based Tutoring Systems
A knowledge-based tutoring system (KBTS) is a computer-based instructional system that uses artificial intelligence techniques to help people learn some subjects. We found that the knowledge communication process involving a KBTS and a human student can be decomposed into a series of communication cycles, where each cycle concentrates on one topic and contains four major phases: planning, discussing, evaluating and remedying. The major contributions of this work are the development of a generic architecture for supporting the knowledge communication between a KBTS and a student, and a graphical notation and schema for supporting the curriculum knowledge representation and manipulation during the planning phase of a tutoring process. The curriculum knowledge about a course can help a tutoring system determine the sequences in which the topics will be discussed with the students effectively and diagnose the students' mistakes. The curriculum knowledge base contains the goal structure of the course, prerequisite relations, and multiple ways of organizing topics, among others. As an example, we focus on developing SQL-TUTOR, a KBTS for the domain of SQL programming. This system has features such as an efficient control mechanism, explicit curriculum knowledge representation, and individualized private tutoring. For allowing the students relative freedom to decide how to study the domain knowledge about a subject, the system provides the students with a group of operators to hand-tailor the learning schedules according to their special backgrounds, requests, and interests.
34091874
Incremental architectural modeling and verification of real-time concurrent systems
An incremental approach for architectural modeling and analysis of real-time concurrent systems is presented. The approach integrates existing formal methods, more specifically time Petri nets and real-time computational tree logic, and leverages their complementary strengths in a way that allows us to systematically enforce that architectural design meets the system's timing requirements, and to incrementally verify the conformance. Consequently, our approach is able to provide better assurance to system design and yet reduce the complexity of analysis. The approach is based on a Real-time Architectural Specification (RAS) model, which provides a formal basis to systematically maintain a correlation between the (timing) requirements of a system and its architectural design. Based on RAS, we further present a method to verify timing properties of a system design. This method helps conquer the complexity of analysis in two dimensions. Horizontally at each design level, incremental verification is achieved by introducing TPN reduction rules that allow us to compose analysis results on individual system components. Vertically across design levels, incremental verification is achieved by propagating higher-level constraints to lower-level designs so that we can safely plug a component design into a high-level architecture without having to re-verify the entire model. A naval command and control (C2) system is used throughout the paper to demonstrate the concept and usability of our approach.