6076549
Executable JVM model for analytical reasoning: a study
To study the properties of the Java Virtual Machine(JVM) and Java programs, our research group has produced a series of JVM models written in a functional subset of Common Lisp. In this paper, we present our most complete JVM model from this series, namely, M6, which is derived from a careful study of the J2ME KVM [16] implementation.On the one hand, our JVM model is a conventional machine emulator. M6 models accurately almost all aspects of the KVM implementation, including the dynamic class loading, class initialization and synchronization via monitors. It executes most J2ME Java programs that do not use any I/O or floating point operations. Engineers may consider M6 an implementation of the JVM. It is implemented with around 10K lines in 20+ modules.On the other hand, M6 is a novel model that allows for analytical reasoning besides conventional testing. M6 is written in an applicative (side-effect free) subset of Common Lisp, for which we have given precise meaning in terms of axioms and inference rules. A property of M6 can be expressed as a formula. Rules of interference can be used analytically to derive properties of M6 and the Java programs that run on the model, using a mechanical theorem prover.We argue that our approach of building an executable model of the system with an axiomatically described functional language can bring benefits from both the testing and the formal reasoning worlds.
1363024
Java Program Verification via a JVM Deep Embedding in ACL2
In this paper, we show that one can “deep-embed” the Java bytecode language, a fairly complicated language with a rich semantics, into the first order logic of ACL2 by modeling a realistic JVM. We show that with proper support from a semi-automatic theorem prover in that logic, one can reason about the correctness of Java programs. This reasoning can be done in a direct and intuitive way without incurring the extra burden that has often been associated with hand proofs, or proofs that make use of less automated proof assistance. We present proofs for two simple Java programs as a showcase.
23957657
Terminology model discovery using natural language processing and visualization techniques
Medical terminologies are important for unambiguous encoding and exchange of clinical information. The traditional manual method of developing terminology models is time-consuming and limited in the number of phrases that a human developer can examine. In this paper, we present an automated method for developing medical terminology models based on natural language processing (NLP) and information visualization techniques. Surgical pathology reports were selected as the testing corpus for developing a pathology procedure terminology model. The use of a general NLP processor for the medical domain, MedLEE, provides an automated method for acquiring semantic structures from a free text corpus and sheds light on a new high-throughput method of medical terminology model development. The use of an information visualization technique supports the summarization and visualization of the large quantity of semantic structures generated from medical documents. We believe that a general method based on NLP and information visualization will facilitate the modeling of medical terminologies.
2849722
Consistency-based search in feature selection
Feature selection is an effective technique in dealing with dimensionality reduction. For classification, it is used to find an "optimal" subset of relevant features such that the overall accuracy of classification is increased while the data size is reduced and the comprehensibility is improved. Feature selection methods contain two important aspects: evaluation of a candidate feature subset and search through the feature space. Existing algorithms adopt various measures to evaluate the goodness of feature subsets. This work focuses on inconsistency measure according to which a feature subset is inconsistent if there exist at least two instances with same feature values but with different class labels. We compare inconsistency measure with other measures and study different search strategies such as exhaustive, complete, heuristic and random search, that can be applied to this measure. We conduct an empirical study to examine the pros and cons of these search methods, give some guidelines on choosing a search method, and compare the classifier error rates before and after feature selection.
507681
A Novel Approach to Model Generation for Heterogeneous Data Classification
Ensemble methods such as bagging and boosting have been successfully applied to classification problems. Two important issues associated with an ensemble approach are: how to generate models to construct an ensemble, and how to combine them for classification. In this paper, we focus on the problem of model generation for heterogeneous data classification. If we could partition heterogeneous data into a number of homogeneous partitions, we will likely generate reliable and accurate classification models over the homogeneous partitions. We examine different ways of forming homogeneous subsets and propose a novel method that allows a data point to be assigned multiple times in order to generate homogeneous partitions for ensemble learning. We present the details of the new algorithm and empirical studies over the UCI benchmark datasets and datasets of image classification, and show that the proposed approach is effective for heterogeneous data classification.
45781537
Lower bounds on the signed k-subdomination number of graphs
17120587
Combination methods in microarray analysis
Microarray technology and experiment can produce thousands or tens of thousands of gene expression measurements in a single cellular mRNA sample. Selecting a list of informative differential genes from these measurement data has been the central problem for microarray analysis. Many methods to identify informative genes have been proposed in the past. However, due to the complexity of biological systems, each proposed method seems to perform nicely in a particular data set or specific experiment. It remains a great challenge to come up with a selection method for a wider spectrum of experiments and a broader variety of data sets. In this paper, we take the approach of method combination using data fusion and rank-score graph which have been used successfully in other application domains such as information retrieval, pattern recognition and tracking, and molecular similarity search. Our method combination is efficient and flexible and can be extended to become a general learning system for microarray gene expression analysis.