1,720,984 research outputs found
Formal construction and verification of home service robots: A case study
No full textHome service robots have attracted much attentions to anticipate improved quality of human life. Considering that malfunctions of home service robots can directly threat the safety of human users, the assurance of robot's safe operation is a crucial prerequisite for the wide deployment of home service robots. Current practice of robot development, however, often fails to satisfy this requirement. Robot developers tend to concentrate on technical components only and fail to consider how these components will integrate to create the service. This practice frequently causes feature interaction problems. Furthermore, reactive nature of the robot applications adds to further complexity. Traditional testing is unsuccessful with this setting due to the difficulty of testing embedded systems and uncertainty caused by sensor devices. These situations make formal construction and verification essential to ensure safe operation of home service robots. In this paper, we present our experience of formally constructing and verifying the core of Samsung Home Robot (SHR) with the use of Esterel. First, we reverse-engineered SHR to identify and analyze the core of SHR. Then, we re-implemented the core part in Esterel and verified SHR to satisfy safety properties regarding stopping behaviors through model checking. Through the verification, we detected and solved a feature interaction problem which caused the robot to ignore a stop command.X112sciescopu
Morphology control of BaMgAl10O17 : Eu particles: The use of colloidal solution obtained from alkoxide precursor in spray pyrolysis
No full textThe morphology of BaMgAl10O17:Eu2+ phosphor particles was controlled by changing the precursor solution used in the spray pyrolysis. The colloidal and aqueous solutions were obtained using aluminum isopropoxide and aluminum nitrate as the source of aluminum. The characteristics of particles prepared from colloidal solution were compared with those of particles prepared from aqueous solution. The particles prepared from colloidal solution maintained their spherical structure and nonaggregation characteristics of as-prepared particles even after post-treatment at 1400 degrees C while aggregation was observed to take place in the particles pre pared from aqueous solution. The high thermal stability of particles prepared from colloidal solution was attributed to the stable intermediate, MgAl2O4. For the highest crystallinity and brightness of particles, the optimum post-treatment temperature was found to be 1200 degrees C. The particles prepared from colloidal solution had higher crystallinity than those prepared from aqueous solution. (C) 2000 The Electrochemical Society. S0013-4651(99)07-066-4. All rights reserved
Feature dependency analysis for product line component design
No full textAnalyzing commonalities and variabilities among products of a product line is an essential activity for product line asset development. A feature-oriented approach to commonality and variability analysis (called feature modeling) has been used extensively for product line engineering. Feature modeling mainly focuses on identifying commonalities and variabilities among products of a product line and organizing them in terms of structural relationships (e.g., aggregation and generalization) and configuration dependencies (e.g., required and excluded). Although the structural relationships and configuration dependencies are essential inputs to product line asset development, they are not sufficient to develop reusable and adaptable product line assets. Other types of dependencies among features also have significant influences on the design of product line assets. In this paper, we extend the feature modeling to analyze feature dependencies that are useful in the design of reusable and adaptable product line components, and present design guidelines based on the extended model. An elevator control software example is used to illustrate the concept of the proposed method.X1130sciescopu
Feature binding analysis for product line component development
No full textFeature analysis, which provides commonality and variability information of a product line, is essential for product line asset development. Moreover, feature binding information (i.e., when and how product features are included to products and delivered to customers) also drives product line component design. Feature binding can be examined from three perspectives: what features are bound (feature binding unit), when features are bound (feature binding time), and how features are bound (feature binding techniques), and this information must be made available to component design so that composition of components for feature binding becomes feasible. In this paper, we introduce an approach to analyzing feature binding from the three perspectives (i.e., what, when, and how) and illustrate how the analysis results can be used for component development of a product line.X113sciescopu
ASADAL/PROVER: A toolset for verifying temporal properties of real-time system specifications in statechart
No full textCritical properties of real-time embedded systems must be verified before these systems ale deployed as failing to meet, these properties may cause considerable property damages and/or human, casualties. Although Statechart is one of the most popular languages for modeling behavior of real-time systems, proof systems[5], [9], [14] and analysis tools[1], [2] for Statechart so far are in research and do not fully support the semantics of the original Statechart [8], or have limited capabilities for proving real-time properties. This paper introduces a toolset ASADAL/PROVER for verifying temporal properties of Statechart extended with justice and compassion properties. ASADAL/PROVER is composed of two subsystems, RTTL-Prover and Model-Checker. The RTTL-Prover converts Statechart specifications into real-time temporal logic (RTTL) formulas of Ostroff [18], [19], and then checks if the formulas satisfy a temporal property (also in RTTL) using theorem proving techniques. The Model-Checker supports verification of a predefined set of real-time properties using a model checking technique. The RTTL-Prover can support verification of any real-time properties as long as they can be specified in RTTL and, therefore, messages generated by the tool are general and may not be of muck help in debugging Statechart specifications. The Model-Checker, however, can provide detailed information for debugging. ASADAL/PROVER has been applied successfully to some experimental systems. One of on-going researches in this project is to apply the symbolic model-checking technique by [3]. to support Statecharts with a much larger global-state space. We are also extending the types of temporal properties supported by the Model-Checker.open111sciescopu
PARTS - A TEMPORAL LOGIC-BASED REAL-TIME SOFTWARE SPECIFICATION METHOD SUPPORTING MULTIPLE VIEWPOINTS
No full textAreas of computer application are being broadened rapidly due to the rapid improvement of the performance of computer hardware. This results in increased demands for computer applications that are large and have complex temporal characteristics. This paper introduces a real-time systems anlaysis method named PARTS. PARTS supports analyses from two viewpoints: external viewpoint, a view of the system from the user's perspective, and internal viewpoint, a view from the developer's perspective. These viewpoints are specified using formal languages, which are Real-Time Events Trace (RTET) for the external viewpoint, and Time Enriched Statechart (TES) and PARTS Data Flow Diagram (PDFD) for the internal viewpoint. All PARTS languages are based on the Metric Temporal Logic (MTL), and consistency of the specifications made from the two different viewpoints are analyzed based on the same MTL formalism.X11sci
Phase-sensitive Kondo effect in a quantum dot
No full textThe phase-sensitive Kondo effect in the transmission through a quantum dot is investigated. It is shown that the Kondo-resonant tunneling through a quantum dot coupled to two arms is characterized by a high transmission probability with a constant phase shift. The Kondo-assisted persistent current flowing through a quantum dot embedded in an Aharonov-Bohm ring is also considered. It is shown that the strongly correlated nature of the ground state leads to a novel parity effect.This work was supported by the Creative Research Initiatives
of the Korean Ministry of Science and Technology,
and by the Brain Korea 21 Project of the Korean
Ministry of Education
Effort estimation of component-based software development - a survey
No full textEffort estimation of software development is an important sub-discipline in software engineering. It has been the focus of much research mostly over the last couple of decades. In recent years, software development turned into engineering through the introduction of component-based software development (CBSD). The industry has reported significant advantages in using CBSD over traditional software development paradigms. However, the introduction of CBSD has also brought a host of unique challenges to software effort estimation which are quite different from those associated with traditional software development. Owing to the increasing tendency to use the CBSD approach in recent years, it is clear that effort estimation of CBSD is particularly an important area of research with a direct relevance to industry. In this study, the authors survey the most up-to-date research work published on predicting the effort of CBSD. The authors analyse the surveyed approaches in terms of modelling technique, the type of data required for their use, the type of estimation provided, lifecycle activities covered and their level of acceptability with regard to any validation. The aim of this survey is to provide a better understanding of the cost and schedule estimation approaches for CBSD.X1149sciescopu
Concepts and guidelines of feature modeling for product line software engineering
No full textProduct line software engineering (PLSE) is an emerging software engineering paradigm, which guides organizations toward the development of products from core assets rather than the development of products one by one from scratch. In order to develop highly reusable core assets, PLSE must have the ability to exploit commonality and manage variability among products from a domain perspective. Feature modeling is one of the most popular domain analysis techniques, which analyzes commonality and variability in a domain to develop highly reusable core assets for a product line. Various attempts have been made to extend and apply it to the development of software product lines. However, feature modeling can be difficult and time-consuming without a precise understanding of the goals of feature modeling and the aid of practical guidelines. In this paper, we clarify the concept of features and the goals of feature modeling, and provide practical guidelines for successful product line software engineering. The authors have extensively used feature modeling in several industrial product line projects and the guidelines described in this paper are based on these experiences.X1197sciescopu
A real world object modeling method for creating simulation environment of real-time systems
No full textMost real-time embedded control software feature complex interactions with asynchronous inputs and environment objects, and a meaningful simulation of a real-time control software specification requires realistic simulation of its environment. Two problems that need to be addressed in the simulation of a target software system and its environment: First, integration and simulation of the specifications of a target software system and its artificial environment are often performed too late in the lifecycle to provide any significant value. Second, real world objects in the environment usually have spatial characteristics (form) such as shape, motion, etc. that must be specified for simulation, and there is no method to express these spatial characteristics at various levels of abstraction that are adequate for the required simulation fidelity. To address these problems, we have developed a method that supports incremental specification and simulation of both the target software system and its environmental objects. The method includes: (1) a specification method for behavior, function, and form integrated objects; (2) form specification primitives that abstract common spatial characteristics of real world objects, their typical spatial relations, and spatial interactions; and (3) a methodology that refines, verifies, and validates behavior, function, and form specification of both the real-time embedded control software and its environment in a systematic and incremental manner. The proposed specification, verification, and validation method has been applied to a robot control system example to demonstrate its effectiveness and usefulness.X11sciescopu
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