39814897
An Object Relational Database for Brain Aging Research
36409029
Object testing in ITEE
To assure the quality of software by running test cases and evaluating the results is one of the difficult parts of the entire software development project. The difficulty usually comes from the lack of appropriate supporting tools and the complexity of the software. In the past ad hoc supporting tools were made for each project and test results were usually not used across projects. This conventional way of test and evaluation (T & E) is time consuming, and the most important decision "When is this software ready to ship?" is left to the engineers depending on his/her experience. Our objective is to build a knowledge-based T & E environment such that test cases, test results, object snapshots and other information are accumulated in a database. These longitudinal data can be automatically tracked and analyzed to provide decision support information. As a result, test results can be reviewed repeatedly and software quality can be assured by analyzing these data from various perspectives. We describe the details of object testing in our testing environment.
42475732
An object-oriented approach to visual databases
As the demand for virtual reality systems increases, a new approach is needed to meet the following requirements: a world consists of a large number of objects; a camera is allowed to move and a world should be displayed in near real-time depending on the position of the camera as well as the angle of its lens; and minimum effort should be needed when objects are moving. We satisfy these requirements with the following: an object-oriented rendering approach is developed; and an approach based on spatial indexing (specifically R/sup +/-tree) is developed to manage operations on objects (i.e., retrieval, insertion and deletion) effectively.
5688593
A Cluster-Based TMO-Structured Scalable Approach for Location Information Systems
Location-based service (LBS) systems have recently become a subject of active research and development. A key issue in such systems is efficient management of current and past location information of moving items. In the past two years, we have been establishing a new LBS system architecture, named the GALIS (Gracefully Aging Location Information System), which is based on the new approach of using a cluster of database server nodes and effecting efficient distributed and parallel computing in both real-time update of location records of moving items and processing of location-related queries. Each server node is dedicated to keeping records relevant to a different geographical zone and a different temporal zone. Each subsystem in GALIS is structured as a TMO network for the sake of easy analysis and expansion. A prototype implementation of GALIS has been realized only partially, and its full implementation is under way. In this paper, major features of GALIS are presented together with discussions on trade-off considerations which led to the adoption of those features. Issues remaining for further research are also briefly discussed.
28214269
Active rule processing in the BioCompose database
BioCompose is an object-relational database query tool that runs on top of any relational database and provides an intelligent and complete object-relational interface to the user. Unlike the traditional approach, which is completely table driven, queries in BioCompose are structured along the lines of natural language and sentences. In BioCompose, the database server continuously monitors the triggers and integrity constraints which are expressed as logical rules and are evaluated based on incoming events which include real time events, value events, transaction events, abstract events, and message events. The paper presents a novel approach that compiles triggers and integrity constraints into an asynchronous network to minimize the rule evaluation effort under different kinds of events.
42266951
TMO-structured cluster-based real-time management of location data on massive volume of moving items
A major challenge in the field of location based service (LBS) system engineering, is to establish a highly scalable system architecture which can be instantiated in moderate-size configurations handling thousands of moving items as well as in upper-end configurations handling millions of moving items. We are exploring an approach of using a cluster of database server nodes and effecting efficient distributed and parallel computing in both real-time update of location records of moving items and processing of location-related queries. The approach of developing efficient middleware which is layered on a cluster of nodes running commercial off-the-shelf database servers, has been adopted. The middleware design is substantially based on the TMO scheme for real-time distributed object programming and real-time distributed computing system design, which enables low-overhead coordination of distributed computations and highly abstract distributed programming styles.
33719933
Possibilistic C-Template Clustering and Its Application in Object Detection in Images
We present in this paper a new type of alternating-optimization based possibilistic c-shell clustering algorithm called possibilistic c-template (PCT). A template is represented by a set of line segments. A cluster prototype consists of a copy of the template after translation, scaling, and rotation transforms. This extends the capability of shell clustering beyond a few standard geometrical shapes that have been studied so far. We use a number of 2-dimensional data sets to illustrate the application of our algorithm in detecting generic template-based shapes in images. Techniques taken to relax the requirements of known number of clusters and good initialization are also described. Results for both synthetic and actual image data are presented.
9613111
Strategies for distributed search
The problem of locating information among cooperating agents within a distributed computing environment is considered. Such collections of agents can be collectively thought of as a single distributed application providing a single set of services; the X.500 distributed directory is an example of such an application. A central problem in such applications is the cooperative search for certain information which might be located at one of the agents. One approach to this problem relies on flooding messages throughout the distributed environment, such as that which might be used in routing algorithms to locate entries. Although the use of such algorithms, in principle, takes advantage of reaching many different agents via parallel data communication paths, the additional number of messages may be a distinct disadvantage in “higher layer” applications. This paper presents a variant of such approaches which rely on a depth-first method of distributing messages. Results of simulations illustrating the savings in messages of this approach to one relying on traditional flooding are presented for different network configurations.
14267974
Sample Rate Conversion Technology in Software Defined Radio
In this paper, a reconfigurable integer factor sample rate converter is proposed for software defined radio (SDR) receivers. A general principle for digital filter design in sample rate conversion (SRC) in SDR receivers can be summarized as that implementation efficiency is emphasized in the front stages, while high performance must be emphasized in the back stages. Based on this principle, a cascaded integrate comb (CIC) filter with factor-16 down sampler is used to realize large-factor and multiplier-free decimation in the front stage, while a multistage decimator is implemented together with the CIC filter to provide finer integral down sample rate. The multistage decimator is consisted of three stages, with each stage serving as a factor-2 down sampler. The Nyquist filters are used as anti-aliasing filter in the first two stages, and the linear phase equiripple filter is used in the last stage. In the end, the results of the sample rate conversion in SDR receiver are provided in this paper
566237
Regularized discriminant analysis for high dimensional, low sample size data
Linear and Quadratic Discriminant Analysis have been used widely in many areas of data mining, machine learning, and bioinformatics. Friedman proposed a compromise between Linear and Quadratic Discriminant Analysis, called Regularized Discriminant Analysis (RDA), which has been shown to be more flexible in dealing with various class distributions. RDA applies the regularization techniques by employing two regularization parameters, which are chosen to jointly maximize the classification performance. The optimal pair of parameters is commonly estimated via cross-validation from a set of candidate pairs. It is computationally prohibitive for high dimensional data, especially when the candidate set is large, which limits the applications of RDA to low dimensional data.In this paper, a novel algorithm for RDA is presented for high dimensional data. It can estimate the optimal regularization parameters from a large set of parameter candidates efficiently. Experiments on a variety of datasets confirm the claimed theoretical estimate of the efficiency, and also show that, for a properly chosen pair of regularization parameters, RDA performs favorably in classification, in comparison with other existing classification methods.
5669766
Automatic Estimation of 3D Transformations using Skeletons for Object Alignment
An algorithm for automatic estimation of 3D transformations between two objects is presented in this paper. Skeletons of the 3D objects are created using a fully parallel thinning technique, feature point pairs (land markers) are automatically extracted from skeletons, and a least squares method is applied to solve an over determined linear system to estimate the 3D transformation matrix. Experiments show that this method is quite accurate when the translations and rotation angles are small, even when there is some noise in the data. The estimation process requires about 2 seconds on an Intel Centrino Laptop with 512 MB memory, for a complex model with about 37,000 object points and 500 object points for its skeletons