New advances of high-level synthesis for efficient and reliable hardware design

The spectacular CMOS technology scaling will continue to evolve and dominate the semiconductor industry. This will lead to tens of billions of transistors integrated on a single chip by the year 2020. However, one significant problem is that the design productivity for complex designs has been lagging behind. In addition to several proposed techniques for dealing with the widening productivity gap, e.g., IP reuse and integration, virtual platform modeling, formal verification and others, high-level synthesis (HLS) has been touted as an important solution as it can significantly reduce the number of man-hours required for a design by raising the level of design abstraction. However, existing HLS solutions have limitations, and studies show that the design quality of HLS can be inferior compared to that of manual RTL design. In this paper, we will present a set of new techniques developed recently to drastically improve HLS solutions, which not only improve the traditional design metrics such as circuit performance and energy efficiency but also emerging metrics such as hardware security and robustness. We will also discuss how HLS can collaborate with other techniques to provide a holistic design methodology that can enable the delivery of high-quality designs with much less design cost and much faster time-to-market.     

Promoting conceptual change of learning sorting algorithm through the diagnosis of mental models: The effects of gender and learning styles

It has been advocated that pedagogical content knowledge as well as subject matter knowledge are important for improving classroom instructions. To develop pedagogical content knowledge, it is argued that understanding of students’ mental representations of concepts is deemed necessary. Yet assessing and comparing mental model of each individual is very tedious and time consuming. This study attempted to use gender and learning styles to associate mental models in learning sorting algorithm. The Gregorc Style Delineator (GSD) was used to measure learning styles of the participants. Mental models were assessed using the Pathfinder Scaling Algorithm (PSA). Results indicated that females showed greater similarity in mental models than males and concrete learners also exhibited closer resemblance to the expert mental model than abstract learners. These suggest that gender and learning styles can be meaningfully used to associate mental models in order to provide a group-based instead of individual-based diagnosis and thus promote conceptual change in learning.     

TTS技术在外语多媒体教学中的应用

随着电脑语音技术的发展，TTS技术必然会越来越多地应用到教育领域，并发挥越来越大的作用．通过TTS结合Authorware制作一个简单的多媒体英语朗读程序，阐述了TTS在Au—thorware中的实现原理、条件和步骤．     

Scattered context grammars generate any recursively enumerable language with two nonterminals

By showing that two nonterminals are sufficient, we present the optimal lower bound on the number of nonterminals of scattered context grammars being able to generate any recursively enumerable language.     

Querying Documents using Content, Structure and Properties

Much information is nowadays stored electronically in document bases. Users retrieve information from these document bases by browsing and querying. While a large number of tools are available nowadays, not much work has been done on tools that support queries involving all the characteristics of documents as well as the use of domain knowledge during the search for information. In this paper we propose a query language that allows for querying documents using content information, information about the logical structure of the documents as well as information about properties of the documents. Domain knowledge is taken into account during the search as well. We also present an architecture for a system supporting such a language and we describe a prototype implementation together with test results.     

Beyond plagiarism: An active learning method to analyze causes behind code-similarity

Code-similarity is the actual indicator of plagiarism in the context of programming assignments. However, the experiences of practical software development have empirically confirmed the existences of other causes for code-similarity. Existing practices usually overemphasis the casual relationship between code-similarity and plagiarism, but ignore the importance to make students understand other causes that also contribute to code-similarity. This paper presents an active learning method to involve students and instructors collaboratively in finding causes of code-similarity occurred in programming assignments. The result shows that most causes occurred in programming assignments are positive. Students can learn the different causes of code-similarity with pros and cons during conducting the active learning method.     

Accurate garbage collection in uncooperative environments revisited

Implementing a concurrent programming language such as Java by means of a translator to an existing language is attractive as it provides portability over all platforms supported by the host language and reduces development time—as many low‐level tasks can be delegated to the host compiler. The C and C++ programming languages are popular choices for many language implementations due to the availability of efficient compilers on a wide range of platforms. For garbage‐collected languages, however, they are not a perfect match as no support is provided for accurately discovering pointers to heap‐allocated data on thread stacks. We evaluate several previously published techniques and propose a new mechanism, lazy pointer stacks, for performing accurate garbage collection in such uncooperative environments. We implemented the new technique in the Ovm Java virtual machine with our own Java‐to‐C/C++ compiler using GCC as a back‐end compiler. Our extensive experimental results confirm that lazy pointer stacks outperform existing approaches: we provide a speedup of 4.5% over Henderson's accurate collector with a 17% increase in code size. Accurate collection is essential in the context of real‐time systems, we thus validate our approach with the implementation of a real‐time concurrent garbage collection algorithm. Copyright © 2009 John Wiley & Sons, Ltd.     

精益包装管理探析

从对包装本质的认识入手,论述了"包装综合成本"的概念,提出了"精益包装管理"理论与实务体系的框架结构.     

Notes on the case statement

The case statement is one of the newest and one of the least known of the ‘standard’ control structures in higher level languages. Its importance has increased with the greater use of structured and goto-less programming. This paper surveys the development of the case statement and provides two extensions which are natural and intuitive and which, it is claimed, increase the intellectual manageability of the host language.