A novel approach was proposed to recognize the non-rigid 3D objects from their corresponding 2D images by combining the benefits of the principal component analysis and the geometric hashing. For all of the object models to be recognized, we calculated the statistical point features of the training shapes using principal component analysis. The results of the analysis were a vector of eigenvalues and a matrix of eigenvectors. We calculated invariants of the new shapes that undergone a similarity transformation. Then added these invariants and the label of the model to the model database. To recognize objects, we calculated the necessary invariants from an unknown image and used them as the indexing keys to retrieve any possible matches with the model features from the model database. We hypothesized the existence of an instance of the model in the scene if the model's features scored enough hits on the vote count. This approach allowed us to store the rigid and the non-rigid object models in a model database and utilized them to recognize an instance of model from an unknown image.

A multimedia coding standard, MPEG4 has frozen its Committee Draft (CD) as the MPEG4 version 1 CD, last October. It defines Audio-Visual (AV) coding Algorithms and their System Multiplex/Composition formats. Founding on Object-base concept, Video part adopts Shape Coding technology in addition to conventional Texture Coding skills. Audio part consists of voice coding tools (HVXC and CELP core) and audio coding tools (HILN and MPEG2 AAC or Twin VQ). Error resilience technologies and Synthetic and Natural Hybrid Coding (SNHC) technologies are the MPEG4 specific features. System part defines flexible Multiplexing of audio-visual bitstreams and Scene Composition for user-interactive re-construction of the scenes at decoder side. The version 1 standardization will be finalized in 1998, with some possible minute changes. The expected application areas are real-time communication, mobile multimedia, internet/intranet accessing, broadcasting, storage media, surveillance, and so on.

We consider linearizable implementations of shared FIFO queues and general deterministic objects on a distributed message-passing system which provides a real-time timer. The efficiency of an implementation is measured by the worst-case response time res_time(op) for each operation op of the implemented objects. We show the following results under the assumption that all message delays are in the range [d-u,d] for some constants d and u (0 u d). We first present an implementation of deterministic objects with res_time(opa)=u for any ack-type operation opa and res_time(opv)=2d for any val-type operation opv, where an ack-type operation is an operation which always returns a unique response and a val-type operation is an operation which is not ack-type. We also consider an implementation of FIFO queues, which have two kinds of operations, enq(v) and deq. We show that, for any implementation of FIFO queues, (1) res_time(enq(v)) u(n-1)/n holds for some v where n is the number of processes, and (2) res_time(deq) d+u/2 holds in the case of u (2/3)d.

Method schemas were proposed as a formal model of object-oriented languages. A method schema S is called consistent if, for each method invocation during the execution of S, a method definition to be bound to the invoked method name is uniquely determined. However, the consistency testing problem is known to be undecidable in general. This paper presents an algorithm which analyzes the consistency of a given method schema. The algorithm decides the consistency problem in polynomial time for monadic method schemas. We also provide an incremental algorithm for testing consistency after updates of a method schema.

When a set of objects is shared among several applications, multiple implementations for the set are required in order to suit each application as much as possible. Furthermore, if a set of objects could have multiple implementations, the following issues arise: (1) how to select the best implementation when processing queries on the set, and (2) how to propagate updates on an implementation of the set to the others. In this paper we propose a mechanism of multiple implementations for a set, and also give a solution for the latter issue. In the proposal a set can be of multiple types, and each of the types corresponds to an implementation already contained within the set. Update propagation can be achieved by a rewriting technique at compilation time. We also present a performance study in which the feasibility and effectiveness of our proposal were examined.

We show that moving objects can be detected from optical flow without using any knowledge about the magnitude of the noise in the flow or any thresholds to be adjusted empirically. The underlying principle is viewing a particular interpretation about the flow as a geometric model and comparing the relative "goodness" of candidate models measured by the geometric AIC.

This paper deals with two different quantitative inversion algorithms for reconstructing the complex permittivity profile of bounded inhomogeneous objects from measured scattered field data. The first algorithm involves an imaging method with single frequency excitation and multiincidence illumination and the second algorithm involves a method with synthetic pulse (multifrequency mode) excitation for objects surrounded by freespace or buried in stratified half-space media. Transmission or reflection imaging protocols are considered depending on aimed applications: microwave imaging in free-space from far-field data for target identification, microwave imaging from near-field data for nondestructive testing (NDT), microwave tomography of buried objects for mine detection and localization, civil engineering and geophysical applications. And Edge-Preserving regularization scheme leading to a significant enhancement in the image reconstructions is also proposed. The methods are illustrated with synthetic and experimental data.

The multipass rendering method based on the global illumination model can generate the most photo-realistic images. However, since the multipass rendering method is very time consuming, it is impractical in the industrial world. This paper discusses a massively parallel processing approach to fast image synthesis by the multipass rendering method. Especially, we focus on the performance evaluation of the view-dependent object-space parallel processing on the (Mπ)2 which has been proposed in our previous paper. We also propose two kinds of distributed frame buffer system named cached frame buffer and multistage-interconnected frame buffer. These frame buffer systems can solve the access conflict problem on the frame buffer. The simulation results show that the (Mπ)2 has a scalable performance. For example, the (Mπ)2 with more than 4000 processing elements can achieve an efficiency of over 50%. We also show that both of the proposed distributed frame buffer systems can relieve the overhead due to frame buffer access in the (Mπ)2 in the case that a large number of high-performance processing elements are adopted in the system.

A new scheme based on hierarchical information organization and situation awareness to support network manager in failure localization is proposed. This paper integrates the situation theory for the needs of fault management to model the states and events. As the result, the proposed information model includes four fault management viewpoints to support situational, functional, logical and physical analysis within the respective networks. Object-oriented analysis is applied to construct the information. The correlation of network situation is derived by description logic. The proposed classification algorithm is applied to solve the situation awareness problem. By using this proposal the correlation performance is enhanced to logarithmic order.

Key technologies are presented for enhancing the reusability of software in communication switching node systems along with the results obtained from porting software between several types of node systems, including N-ISDN, B-ISDNs, and Intelligent Networks. A reusable software platform based on object-oriented designing and programming techniques has been established and mechanisms for reusing object classes has been developed. Analysis of the reusability showed that this platform can be applied to various types of communication systems and that an average of more than three quarters of a system's programs can be ported. By using our software reuse framework to develop software components, we were able to reduce the time needed to develop device management programs by about 30%. Furthermore, about 80% of these programs can be ported to other systems, so introducing this platform improves software programming productivity.

Recently, the spatio-temporal filter using linear analog Cellular Neural Network (CNN), called CNN filter array, has been proposed for the purpose of dynamic image processing. In this paper, we propose a design method of descrete-time cellular neural network filter which selectively extracts the particular moving object from other moving objects and noise. The CNN filter array forms a spatio-temporal filter by arranging cells with a same function. Each of these cells is a simple linear analog temporal filter whose input is the weighted sum of its neighborhood inputs and outputs and each cell corresponds to each pixel. The CNN filter is formed by new model of discrete time CNN, and the filter parameters are determined by applying backpropagation algorithm in place of the analytic method. Since the number of connections between neurons in the CNN-type filter is relatively few, the required computation in the learning phase is reasonable amount. Further, the output S/N ratio is improved by introducing nonlinear element. That is, if the ratio of output to imput is smaller than a certain value, the output signal is treated as a noise signal and ought to be rejected. Through some examples, it is shown that the target object is enhanced in the noisy environment.

In this paper, we propose a method to construct structure models of articulated objects from multiple local observations of their motion using state transition analysis of local geometric constraints. The object model is constructed by a bottom-up approach with three levels. Each level groups sensor data with a constraint among local features observed by the sensor, and constructs the local model. If the sensor data in current model conflict, the model is reconstructed. In each level, the first level estimates a local geometric feature from the local sensor data (eg. edge, feature point) The second level estimates a rigid body from the local geometric feature. The third level estimates an object from the rigid bodies. In the third level, the constraint between rigid bodies is estimated by transition states, which are motions between rigid bodies. This approach is implemented on a blackboard system.

Modern database systems have to support complex data objects, which appear in advanced data models such as object-oriented data models and nested relational data models. Set-valued objects are basic constructs to build complex structures in those models. Therefore, efficient processing of set-valued object retrieval (simply, set retrieval) is an important feature required of advanced database systems. Our previous work proposed a basic scheme to apply superimposed coded signature files to set retrieval and showed its potential advantages over the B-tree index based approach using a performance analysis model. Retrieval with signature files is always accompanied by mismatches called false drops, and proper control of the false drops is indispensable in the signature file design. This study intensively analyzes the false drops in set retrieval with signature files. First, schemes to use signature files are presented to process set retrieval involving "has-subset," "is-subset," "has-intersection," and "is-equal" predicates, and generic formulas estimating the false drops are derived. Then, three sets of concrete formulas are derived in three ways to estimate the false drops in the four types of set retrieval. Finally, their estimates are validated with computer simulations, and advantages and disadvantages of each set of the false drop estimation formulas are discussed. The analysis shows that proper choice of estimation formulas gives quite accurate estimates of the false drops in set retrieval with signature files.

We have developed a management agent that adapts the delegation concept to achieve efficient network management. In conventional delegation architecture, a network management operator details management operations in an operation-script that describes management operation flow and such network management functions as event management and path tracing. The operator sends this script to agents to execute. In our delegation architecture, the operator sends only a script skeleton describing management operation flow alone; management functions are built into the agents in the form of fuction objects. This helps keep management traffic low. Each function object is designed by utilizing three operational objects: enhanced, primitive, and communication. Each enhanced operational object (EOO) provides a script skeleton with an individual network management function. A primitive operational object (POO) provides an EOO with managed object (MO) access functions. A communication operational object (COO) provides an EOO with a mechanism for accessing the functions of other remote EOOs. We have tested our design by applying it to a path tracing application, and we have measured the total data transfer size between a manager and an agent and the amount of memory usage in our agent's running environment. Evaluation of our implementation suggests that our design can be applied such network management functions as connection establishment and release, fault isolation, and service provisioning.

Using object-oriented techniques, one can build software that models the real world more closely. In objectoriented analysis and design, two types of closely interrelated models have been built which specify the static structure and the dynamic behavior of objects. Much work based on those models deals with how to use inheritance to support reuse and easy extension more precisely. In this paper, we are concerned with the dynamic aspects of objects, and define a behavior inheritance relationship between a class and its subclass. We present a set of derivation operations based on the incremental design of the behavior model. The operations preserve the behavior inheritance relationship between classes. The result makes a theoretical base for making new classes by reusing the existing classes in objectoriented system development.

The reconstruction of 3-D moving images from transmitted parameters describing position, attitude and shape variation of objects in a virtual 3-D space has been studied as an application of three dimensional (3-D) image communication. The shape information was obtained from a database that was built in advance. Since an appropriate database of 3-D object shapes needs to be developed, efficient storage of the shape data of the actual objects might become a key technology. This paper proposes an efficient entropy coding method of voxel map data obtained with shape measuring equipment. The proposed method converts the voxel map data into an octree and encodes their node information with conditional probability on the state of neighbor nodes sequentially, beginning with the upper hierarchy level. This method has the property of being able to extract information up to a given arbitrary hierarchy level because of its hierarchical characteristic. For implementation, two methods are proposed for reducing the large number of contexts, one uses 3-D isotropism, the other uses sample statistics. The experimental coding results using several sample data sets show that the proposed method can reduce the information volume by about 20% in comparison to the ordinary method using unconditional entropy. The binary voxel map of 512512512 can be represented by approximately 680 kbits.

A formal system-level synthesis model for the concurrent object-oriented design of parallel computer systems, called Multi-token Object-oriented Bi-directional net (MOBnet), is proposed. The MOBnet model extends the standard Petri net by defining (1) multiple tokens to represent different kinds of synthesis control information, (2) object-oriented nodes (places) to denote the system parts under synthesis, and (3) bi-directional arcs to model the design completion check and synthesis rollback operations. In this paper, we first show that MOBnet can serve as a pre-fabrication design methodology analysis tool in ways such as class hierarchy construction, design specification comparison, reachability analysis, and concurrent process management and analysis. We then formally prove MOBnet to be a valid model for concurrent synthesis and give experimental application examples to verify. Finally, solution schemes for the design completion check and synthesis rollback problems are formally validated by analyzing the dynamic behavior of MOBnet, and experimentally illustrated through examples.

Key aspects and technologies of future satellite communications are discussed toward multimedia era. Onboard processing called the switchboard in the sky and networking taking full advantage of features peculiar to satellite communications are pointed out as essential technologies to overcome a variety of big challenges for realizing future satellite communications. Several experimental and commercial systems are introduced as the first step toward multimedia era.

In this paper, we propose a practical and secure electronic voting scheme which meets the requirements of large scale general elections. This scheme involves voters, the administrator or so called the government and some scrutineers. In our scheme, a voter only has to communicate with the administrator three times and it ensures independence among voters without the need of any global computation. This scheme uses the threshold cryptosystem to guarantee the fairness among the candidate's campaign and to provide mechanism for achieving the function that any voter can make an open objection to the tally if his vote has not been published. This scheme preserves the privacy of a voter against the administrator, scrutineers, and other voters. Completeness, robustness, and verifiability of the voting process are ensured and hence no one can produce a false tally, corrupt or disrupt the election.

In this paper, we present a first step for developing a method of verifying both safety and correctness of object-oriented design specification. At first, we analyze the discrepancies, which can occur between requirements specification and design specification, to make clear target faults. Then, we propose a new design review method which aims at detecting faults in the design specification by using three kinds of information tables. Here, we assume that component library, standards for safety and design specification obtained from the Booch's object-oriented design method are given. At the beginning, the designers construct a design table based on a design specification, and the verifiers construct a correctness table and a safety table from component library and standards for safety. Then, by comparing the items on three tables, the verifiers review a given design specification and detect faults in it. Finally, using a small example of object-oriented design specification, we show that faults concerning safety or correctness can be detected by the new design review method.