A high-speed context-free marker controlled and minima imposition-free watershed transform is proposed for efficient multi-object detection and segmentation from a complex background. The context-free markers are extracted from a complex backgrounded multi-object image using a noise tolerant attention operator. These make high speed marker-controlled watershed possible without over-segmentation and region merging. The proposed method presents a marker-constrained labeling that can speed up the segmentation of the marker-controlled watershed transform by eliminating the necessity of the minima imposition. Simulation results show that the proposed method can efficiently detect and segment multiple objects from a complex background while reducing the over-segmentation and computation time.

Method invocation mechanism is one of the essential features in object-oriented programming languages. This mechanism contributes to data encapsulation and code reuse, but there is a risk of runtime type errors. In the case of object-oriented databases (OODBs), a runtime error causes rollback. Therefore, it is desirable to ensure that a given OODB schema is consistent, i.e., no runtime error occurs during the execution of queries under any database instance of the OODB schema. This paper discusses the computational complexity of the type-consistency problem. As a model of OODB schemas, we adopt update schemas introduced by Hull et al., which have all of the basic features of OODBs such as class hierarchy, inheritance, complex objects, and so on. The type-consistency problem for update schemas is known to be undecidable. We introduce a subclass of update schemas, called acyclic schemas, and show that the type-consistency problem for acyclic schemas is in coNEXPTIME. Furthermore, we show that the problem for recursion-free acyclic schemas is coNEXPTIME-hard and the problem for retrieval acyclic schemas is PSPACE-complete.

The hardware-software codesign of distributed embedded systems is a more challenging task, because each phase of codesign, such as copartitioning, cosynthesis, cosimulation, and coverification must consider the physical restrictions imposed by the distributed characteristics of such systems. Distributed systems often contain several similar parts for which design reuse techniques can be applied. Object-oriented (OO) codesign approach, which allows physical restriction and object design reuse, is adopted in our newly proposed Distributed Embedded System Codesign (DESC) methodology. DESC methodology uses three types of models: Object Modeling Technique (OMT) models for system description and input, Linear Hybrid Automata (LHA) models for internal modeling and verification, and SES/workbench simulation models for performance evaluation. A two-level partitioning algorithm is proposed specifically for distributed systems. Software is synthesized by task scheduling and hardware is synthesized by system-level and object-oriented techniques. Design alternatives for synthesized hardware-software systems are then checked for design feasibility through rapid prototyping using hardware-software emulators. Through a case study on a Vehicle Parking Management System (VPMS), we depict each design phase of the DESC methodology to show benefits of OO codesign and the necessity of a two-level partitioning algorithm.

This paper describes how the image sequences taken by a stationary video camera may be effectively processed to detect and track moving objects against a stationary background in real-time. Our approach is first to isolate the moving objects in image sequences via a modified adaptive background estimation method and then perform token tracking of multiple objects based on features extracted from the processed image sequences. In feature based multiple object tracking, the most prominent tracking issues are track initialization, data association, occlusions due to traffic congestion, and object maneuvering. While there are limited past works addressing these problems, most relevant tracking systems proposed in the past are independently focused to either "occlusion" or "data association" only. In this paper, we propose the KL-IMMPDA (Kanade Lucas-Interacting Multiple Model Probabilistic Data Association) filtering approach for multiple-object tracking to collectively address the key issues. The proposed method essentially employs optical flow measurements for both detection and track initialization while the KL-IMMPDA filter is used to accept or reject measurements, which belong to other objects. The data association performed by the proposed KL-IMMPDA results in an effective tracking scheme, which is robust to partial occlusions and image clutter of object maneuvering. The simulation results show a significant performance improvement for tracking multi-objects in occlusion and maneuvering, when compared to other conventional trackers such as Kalman filter.

This paper deals with a quantitative inversion algorithm for reconstructing the permittivity and conductivity profiles of bounded inhomogeneous buried objects from measured multifrequency and multiincidence backscattered field data. An Edge-Preserving regularization scheme is applied leading to a significant enhancement in the profiles reconstructions. The applications concern civil engineering and geophysics as well as mine detection and localization. The performance of the reconstructions are illustrated with different synthetic data.

Most distributed systems are based on either the C/S (Client/Server) model or the P-to-P (Peer to Peer) model. In C/S based distributed systems, a client invokes a server and waits for the server reply. Because of this sequential nature, C/S based distributed systems can be implemented by the RPC (Remote Procedure Call) scheme. Most tools for developing distributed objects are based on the RPC scheme. Whereas, in P-to-P based distributed systems, each distributed objects work concurrently, by exchanging asynchronous messages, without waiting for the receiver's action. To implement these P-to-P distributed systems, the RPC scheme is not powerful enough, and the active object model using asynchronous messages is suitable. This paper explains the pure Java library CAPE for developing P-to-P based distributed active object systems.

This letter empirically evaluates the way how to calculate the complexity of methods, that is used in the definition of WMC(Weighted Method per Class), one of the Chidamber and Kemerer's metrics. With respect to the results of our experiment, Halstead's Software Science metric is the most appropriate one to evaluate the complexity of the methods.

In this paper, we describe a distributed transactional workflow system named ICU/COWS, which supports multiple workflow types of large scale enterprises. The system aims to support the whole workflow for large scale enterprises effectively within a single workflow system and the system is designed to satisfy several design goals such as availability, scalability, and reliability. Transactional task and special tasks such as alternative task and compensating task are developed and utilized to achieve the design goals in task model level and the system is constructed with distributed transactional objects to achieve the design goals in distributed system environment. In this paper, structured ad hoc workflow is defined as a special type of ad hoc workflow that should be automated by workflow management system because many benefits can be obtained by automating it and connector facility is proposed as a means to support structured ad hoc workflow effectively. Some characteristics of a workflow system can be identified by monitoring the system behavior on different conditions like workloads or system configurations. An early version of the system has been implemented and the performance data of the system is illustrated.

In this paper, a method of fusing ground-based laser range image and CCD images for the reconstruction of textured 3D urban object is proposed. An acquisition system is developed to capture laser range image and CCD images simultaneously from the same platform. A registration method is developed using both laser range and CCD images in a coarse-to-fine process. Laser range images are registered with an assumption on sensor's setup, which aims at robustly detecting an initial configuration between the sensor's coordinate system of two views. CCD images are matched to refine the accuracy of the initial transformation, which might be degraded by improper sensor setup, unreliable feature extraction, or limited by low spatial resolution of laser range image. Textured 3D model is generated using planar faces for vertical walls and triangular cells for ground surface, trees and bushes. Through an outdoor experiment of reconstructing a building using six views of laser range and CCD images, it is demonstrated that textured 3D model of urban objects can be generated in an automated manner.

This paper describes a new method for detection and tracking of moving objects from a moving camera image sequence using robust estimation and active contour models. We assume that the apparent background motion between two consecutive image frames can be approximated by affine transformation. In order to register the static background, we estimate affine transformation parameters using LMedS (Least Median of Squares) method which is a kind of robust estimator. Split-and-merge contour models are employed for tracking multiple moving objects. Image energy of contour models is defined based on the image which is obtained by subtracting the previous frame transformed with estimated affine parameters from the current frame. We have implemented the method on an image processing system which consists of DSP boards for real-time tracking of moving objects from a moving camera image sequence.

In visual servoing, most studies are concerned with robotic application with known objects. In this paper, the problem of controlling a motion by visual servoing around an unknown object is addressed. In this case, the approach is interpreted as an initial step towards a perception goal of an unmodeled object. The main goal is to perform motion with regard to the object in order to discover several viewpoint of the object. An adaptive visual servoing scheme is proposed to perform such task. The originality of our work is based on the choice and extraction of visual features in accordance with motions to be performed. The notion of invariant feature is introduced to control the navigational task around the unknown object. During experimentation, a cartesian robot connected to a real time vision system is used. A CCD camera is mounted on the end effector of the robot. The experimental results present a linkage of desired motion around different kind of objects.

For plasma simulations, we developed a one-dimensional (1d) Object-Oriented Particle-in-Cell code for X11-based Unix workstations (XOOPIC) by modifying the current two-dimensional version which was originally developed by PTSG (Plasma theory and simulation group) in the University of California at Berkeley. We implemented a simplified field solve and current deposition in the code. We retained three components of particle velocity, although the spatial variation for particle position and field components is limited to one dimension. To verify the function of the 1d code, we perform simulations with typical models such as the Child-Langmuir current model and electromagnetic wave propagation in plasma. In both cases, the simulation results quantitatively agree with the theory.

Design patterns which Erich Gamma advocates is expected as an effective approach for the reuse of designs. So, design patterns are predicted to be used frequently in object-oriented software development. In such circumstance, tools to support applying design patterns to the design diagrams of the system under development are thought to be useful. This research develops Object-Oriented Pattern Applying Support tool OOPAS. It consists of a library of Gamma design patterns with very familiar examples and adrem explanation, and of a function to generate the correctly modified design diagrams of the application system when a design pattern was applied to evolve that system. Actually, these functions are installed in the structured object modeling environment SOME, which is an object-oriented design diagram editor made previously in our laboratory. This design diagram evolving function is formalized as a Join operation of the recursive graph. As a result of the evaluation experiment, the join operation can be applied to the almost of the twenty three Gamma design patterns excluding the six patterns such as Iterator and Command, which are stated at too abstract level to be represented by the design diagrams.

In this paper, a program generator for communication protocol software will be presented. Our program generator takes an extended finite state machine as a domain model and generates a group of C++ classes needed for an implementation. For each state of the FSM, a C++ class is generated, where the interface events are implemented as member functions of the corresponding state object. Protocol data units (PDUs) are embedded as Message objects and specified in the same way as packet filter and is interpreted to generate necessary PDU definition statements and PDU manipulation statements. Also, protocol objects from different layers can be linked together by using an organization model, where a protocol entity is invoked by its upper layer entity or lower layer entity by member function calls.

To develop distributed applications requires to consider not only functional requirements but also non-functional requirements such as distributions, synchronizations, and scheduling policies. Specifying such non-functional requirements is necessary for supporting on-line capabilities of Autonomous Decentralized Systems (ADS). However, the existing design notations and methods do not address such needs sufficiently enough to develop ADS applications systematically using object-oriented technique. In this paper, we propose an object-oriented design-level support for specifying concurrent, distributed, and autonomous object behaviors in developing dynamic distributed applications. We develop a high-level meta-object protocol called diMOP to deal with object distributions, method synchronizations, and method scheduling policies. In addition, we develop Class Diagram Supporting diMOP (CDSM) and Dynamically Configurable Object Statemachine (DCOS) for specifying non-functional behaviors and dynamic configuration behaviors, by extending the ordinary class diagram and state diagram of UML. A development environment called diMOPer is implemented to support our approach.

Standard client-server workflow management systems have an intrinsic scalability limitation, the central server, which represents a bottleneck for large-scale applications. This server is also a single failure point that may disable the whole system. We propose a fully distributed architecture for workflow management systems. It is based on the idea that the case (an instance of the process) migrates from host to host, following a process plan, while the case activities are executed. This basic architecture is improved so that other requirements for Workflow Management Systems, besides scalability, are also contemplated. A CORBA-based implementation of such architecture is discussed, with its limitations, advantages and project decisions described.

Efficient content-based retrieval of complex images is a challenging task since the detected object may appear in various scale, rotation and orientation with a wide variety of background colors and forms. In this paper, we propose a novel representation of objects with multiple colors, the spatial neighborhood-adjacency graph(SNAG), which can serve as a basis for detecting object by color contents from the candidate image. The SNAG consists of a set of main-vertices and two sets of edges. Each main-vertex represents a single color region of multi-colored object, and edges are divided into two classes: Neighborhood edges representing neighborhood relationship between two main-vertices with similar color, and adjacency edges representing adjacency relationship between a main-vertex and another vertex with different color. By investigating whether SNAG of object image is an isomorphic subgraph of SNAG of a candidate image, we can determine whether the similar object exists in the candidate image. In addition, we have also applied the proposed approach to a range of different object detection problems involving complex background, and effectiveness has been proved.

This paper proposes a Space-Time Object Model, an object oriented model that possesses space and time management mechanisms. The goal of this object model is to provide a common software infrastructure for implementing large-scale moving object simulations efficiently, such as car traffic simulations and disaster evacuation simulations, using a direct mapping scheme on a parallel and distributed computing environment. In this object model, the software infrastructure provides two principal functions, "Space Management" and "Time Management," which allows programmers to focus on application programming instead of parallel programming. Although there are several known infrastructure software, which provide the environment needed to develop and execute parallel and distributed simulations, they only provide a "Time Management" mechanism. In this paper, we present a Space-Time Object Model and an overview of a program called OSim, which is an implementation of the Space-Time Object Model. Then, we demonstrate the applicability and efficiency of this model by introducing the overview and evaluation results of a parallel car traffic simulation system using OSim.

This paper proposes a reference model of CAD system generation, and describes its prototype implementation. The problems encountered in using CAD systems in industry involve complicated data handling and unsatisfied demands for domain knowledge because of the lack of a way of extracting and adopting it in the system. In the example domain of architecture, the authors have already defined domain-specific BDL (Building Design Language) for architecture experts to describe modelers of architectural structure in CAD systems by themselves. Moreover, the authors have developed a CAD system generator based on BDL descriptions. However, the different domain-specific languages required for individual domains create difficulty in developing various CAD system generators. The proposed reference model solves this problem by applying a common intermediate language based on the object model. Moreover, the model allows the creation of an integrated CAD system which contains multiple domains required by a field of industry. Its prototype implementation demonstrates its feasibility.

To bridge a wide gap between the end users and the requirements engineers, we propose a business flow diagram for acquiring users' requirements of the object oriented software development in the business application domain. Each field of this diagram shows either a role or a responsibility of a particular person or an organization. This paper proposes a development method that the engineers acquire the requirements by using our diagrams. We have implemented a supporting tool based on this study for collaborating the requirements engineers with their users. At first, the end users of an information system to be developed draw diagrams representing the flows of information and physical objects in their work from their own points of view. Sometimes the engineers write them with the users. If all users submit their diagrams, then our tool collects them and constructs a total diagram. The requirements engineers analyze the total diagram for improving the business flow. After the engineers complete this diagram, our tool can automatically transform it into an initial version of the class diagram. We show the effectiveness of our approach with some experiments. Comparing the related works, we discuss some issues of the practical aspects of this proposal.