Software components are one reusable asset which can contain other kinds of software assets like ... more Software components are one reusable asset which can contain other kinds of software assets like requirement specifications, design patterns, source codes, documents, and so on. It can be used for designing software architecture or implementing a software system as an element like a building block. Therefore, software can be developed easily and quickly by assembling those building blocks. Focused on this nature of component-based development, energy-efficient software development can also be achieved with reusable software components. In particular, low-energy software has become a critical component for embedded and mobile software systems. Therefore, we have to consider energy efficiency to develop embedded software when developing the software based on reusable components. This paper, firstly, proposes how to represent the energy characteristics of the components and how to select a component for energy-efficient software development. We developed a component repository, ECoReS ...
Reusing software artifacts is not limited to only source codes, but also various artifacts which ... more Reusing software artifacts is not limited to only source codes, but also various artifacts which are created in software projects. However, traditional artifacts reuse approach has some problems of difficulties to find an appropriate artifact and to choose suitable terms as search keywords. To reduce the difficulties and enhance reusability of software artifacts, this paper presents some novel techniques based on context-aware reuse; which are context-based automatic keyword generation, ontology-based keyword extension, context-aware retrieval and learning-based result visualization. To realize the techniques, we firstly defined microComponent with the smaller unit (section) of a document as the reusable unit. And then we focus on to how can we retrieve and reuse the microComponents with the concept of context-aware. Our technique can precisely control the reusable unit, and enhance reusability of software artifacts based on the microComponents.
Code refactoring technique focuses on enhancing the maintainability of software to extend its lif... more Code refactoring technique focuses on enhancing the maintainability of software to extend its lifetime. However, there are other efforts to improve software qualities like performance or reliability as well as maintainability by using code refactoring techniques. Recently, as low-power software has become one of the critical issues in mobile environments, developing energyefficient software through code refactoring becomes an important one. This paper aims to investigate whether the existing refactoring techniques can support energy-efficient software generation or not. The refactored codes generated by the existing techniques can consume more power than original codes because they did not consider the power consumption in their refactoring processes. This paper analyzes the power consumption to investigate the energy efficiency of M. Fowler’s refactoring techniques. Our analysis result can provide useful information about energy-efficient refactoring techniques to software engineer...
KIPS Transactions on Software and Data Engineering, 2016
While the services of mobile devices like smart phone, tablet, and smart watch have been increase... more While the services of mobile devices like smart phone, tablet, and smart watch have been increased and varied, the software embedded into such devices has been also increased in size and functional complexity. Therefore, increasing operation time of mobile devices for serviceability became an important issue due to the limitation of battery power. Recent studies focus on the software development having efficient behavioral patterns because the energy consumption of mobile devices is caused by software behaviors which control the hardware operations. However, it is often difficult to develop the embedded software with considering energy-efficiency and behavior optimization due to the short development cycle of the mobile services in many cases. Therefore, this paper proposes the refactoring techniques for reducing energy consumption, and enables to fulfill the energy requirements during software development and maintenance. We defined energy bad smells with the code patterns that can excessively consume the energy, and our refactoring techniques are to remove these bad smells. We performed some case studies to verify the usefulness of our refactoring techniques.
KIPS Transactions on Software and Data Engineering, 2014
Code refactoring focuses on enhancing the maintainability of software to extend its lifetime. How... more Code refactoring focuses on enhancing the maintainability of software to extend its lifetime. However as software applications were varied and the range of its usage becomes broaden, there are some efforts to improve software qualities like performance or reliability as well as maintainability using code refactoring techniques. Recently, as low-energy software has become one of critical issues in mobile environment, developing energy efficient software through code refactoring becomes an important one. Therefore this paper has its goal to investigate whether the existing refactoring techniques can support energy efficient software generation or not. That is to say, the existing code refactoring techniques can cause the minus of energy efficiency because they did not considered the energy consumption in their refactoring process. This paper experiments and analyzes to check whether the M. Fowler's code refactoring techniques can support the energy efficient software generation or not. Our research result can give to software developer some informations about energy-efficient refactoring techniques, and can support the development of software that has high maintainability and good energy efficiency.
The perception system is a safety-critical component that directly impacts the overall safety of ... more The perception system is a safety-critical component that directly impacts the overall safety of autonomous driving systems (ADSs). It is imperative to ensure the robustness of the deep-learning model used in the perception system. However, studies have shown that these models are highly vulnerable to the adversarial perturbation of input data. The existing works mainly focused on studying the impact of these adversarial attacks on classification rather than regression models. Therefore, this paper first introduces two generalized methods for perturbation-based attacks: (1) We used naturally occurring noises to create perturbations in the input data. (2) We introduce a modified square, HopSkipJump, and decision-based/boundary attack to attack the regression models used in ADSs. Then, we propose a deep-autoencoder-based adversarial attack detector. In addition to offline evaluation metrics (e.g., F1 score and precision, etc.), we introduce an online evaluation framework to evaluate t...
The System of Cyber-Physical Systems (SoCPS) comprises several independent Cyber-Physical Systems... more The System of Cyber-Physical Systems (SoCPS) comprises several independent Cyber-Physical Systems (CPSs) that interact with each other to achieve a common mission that the individual systems cannot achieve on their own. SoCPS are rapidly gaining attention in various domains, e.g., manufacturing, automotive, avionics, healthcare, transportation, and more. SoCPS are extremely large, complex, and safety-critical. As these systems are safety-critical in nature, it is necessary to provide an adequate safety analysis mechanism for these collaborative SoCPS so that the whole network of these CPSs work safely. This safety mechanism must include composite safety analysis for a network of collaborative CPS as a whole. However, existing safety analysis techniques are not built for analyzing safety for dynamically forming networks of CPS. This paper introduces a composite safety analysis approach called SafeSoCPS to analyze hazards for a network of SoCPS. In SafeSoCPS, we analyze potential haza...
Proceedings of the 14th International Conference on Software Technologies, 2019
Social network sites have become popular and their popularity is growing exponentially every day.... more Social network sites have become popular and their popularity is growing exponentially every day. From the requirements engineering point of view, social network sites have provided unprecedented opportunities for software development organizations to understand the requirements of unknown end-users. Using social network sites, end-users express their experiences, needs, or concerns about a particular system or a product. Such information can be useful for software developers to address the concerns of users quickly. To get an overview of how social network sites are helping requirements engineering and new research trends in this area, we have surveyed a large number of research papers. We found that social network sites can be a major source that can be used for requirements elicitation, requirements prioritization, and negotiation. We also found that the research in this domain is at its beginning stage, but it is rapidly growing with the passage of time.
The deep neural networks (DNNs)based autonomous driving systems (ADSs) are expected to reduce roa... more The deep neural networks (DNNs)based autonomous driving systems (ADSs) are expected to reduce road accidents and improve safety in the transportation domain as it removes the factor of human error from driving tasks. The DNN based ADS sometimes may exhibit erroneous or unexpected behaviors due to unexpected driving conditions which may cause accidents. It is not possible to generalize the DNN model performance for all driving conditions. Therefore, the driving conditions that were not considered during the training of the ADS may lead to unpredictable consequences for the safety of autonomous vehicles. This study proposes an autoencoder and time series analysis based anomaly detection system to prevent the safety critical inconsistent behavior of autonomous vehicles at runtime. Our approach called DeepGuard consists of two components. The first component, the inconsistent behavior predictor, is based on an autoencoder and time series analysis to reconstruct the driving scenarios. Based on reconstruction error and threshold it determines the normal and unexpected driving scenarios and predicts potential inconsistent behavior. The second component provides on the fly safety guards, that is, it automatically activates healing strategies to prevent inconsistencies in the behavior. We evaluated the performance of DeepGuard in predicting the injected anomalous driving scenarios using already available open sourced DNN based ADSs in the Udacity simulator. Our simulation results show that the best variant of DeepGuard can predict up to 93 percent on the CHAUFFEUR ADS, 83 percent on DAVE2 ADS, and 80 percent of inconsistent behavior on the EPOCH ADS model, outperforming SELFORACLE and DeepRoad. Overall, DeepGuard can prevent up to 89 percent of all predicted inconsistent behaviors of ADS by executing predefined safety guards.
Cyber-physical systems have emerged as a new engineering paradigm, which combine the cyber and ph... more Cyber-physical systems have emerged as a new engineering paradigm, which combine the cyber and physical world with comprehensive computational and analytical tools to solve complex tasks. In cyber-physical systems, components are developed to detect failures, prevent failures, or mitigate the failures of a system. Sensors gather real-time data as an input to the system for further processing. Therefore, the whole cyber-physical system depends on sensors to accomplish their tasks and the failure of one sensor may lead to the failure of the whole system. To address this issue, we present an approach that utilizes the Failure Modes, Effects, and Criticality Analysis, which is a prominent hazard analysis technique to increase the understanding of risk and failure prevention. In our approach, we transform the Failure Modes, Effects, and Criticality Analysis model into a UML(Unified Modeling Language) class diagram, and then a knowledge base is constructed based on the derived UML class d...
As service-oriented software is considered as one of solutions to fulfill the users` needs in int... more As service-oriented software is considered as one of solutions to fulfill the users` needs in internet service environment, it has been increased the demands of reliable service development by the composition of internet services. However a critical issue in the service development approach is to satisfy the performance requirement as well as the functional correctness for the developing services, because impatient user multiply clicks the request-button of service without a short waiting. This paper proposes a framework to examine the performance of composite service. Our testing framework provides the data of service response time to service developer by measuring the service execution time. We develope an Aspect-based timer service, and weave the service with existing services to measure the execution time. Additionally, we perform some experiments to confirm the usefulness of performance test for composite service. This framework can support to develop a good performance service...
In company with the demand of powerful processing units for embedded systems, the method to devel... more In company with the demand of powerful processing units for embedded systems, the method to develop embedded software is also required to support the demand in new approach. In order to improve the resource utilization and system performance, software modeling techniques have to consider the features of hardware architecture. This paper proposes a partitioning technique of UML-based software models, which focus the generation of the allocatable software components into multiprocessor architecture. Our partitioning technique, at first, transforms UML models to CBCFGs(Constraint-Based Control Flow Graphs), and then slices the CBCFGs with consideration of parallelism and data dependency. We believe that our proposition gives practical applicability in the areas of platform specific modeling and performance estimation in model-driven embedded software development.
In spite of the various techniques on the testing of embedded software, operation failures of emb... more In spite of the various techniques on the testing of embedded software, operation failures of embedded systems such as robot or satellite applications, are occurred frequently. The critical reason of these failures is due to the fact that software is embedded into a target system with inherent faults. Therefore, in order to prevent the failure owing to such faults, it needs a technique to test the embedded software which operates in real environment. In this paper, we propose a testing technique, aspect-based On-the-Fly testing that is to test the functionality and performance at real operation time. Our proposed technique gives some benefits of real test of unexpected input conditions, prevention of software malfunction, and reusability of aspect components for the testing.
Along with the complexity and size growth of embedded software, it is critical to meet the nonfun... more Along with the complexity and size growth of embedded software, it is critical to meet the nonfunctional requirements such as power consumption as well as functional requirements such as correctness. This paper, apart from the existing studies of source code-based power analysis, proposes an approach of model-based power analysis using UML 2.0. Specially, we focus on the development of energy library to analyze the power consumption of embedded software. Our energy library supports model-based power analysis, and also supports the easy adaption for the change of embedded application.
Proceedings of the 2020 European Symposium on Software Engineering
Cyber-Physical Systems solve complex problems through their tight integration between the physica... more Cyber-Physical Systems solve complex problems through their tight integration between the physical and computational components. Therefore, the reliability of a complex system is the most critical requirement for the cyber-physical system because an unreliable system often leads to service disruption, property damage, financial loses and sometimes lead to fatality. In order to develop more reliable CPS, this paper proposes a generic framework for reliability modeling and analysis for our ongoing work on cyber-physical systems. Research Method: This paper, at first defines an architecture for general CPS which is comprised of three layers; environment layer, communication layer, and computational layer. Secondly, we formalize a reliability model for the architectural components, and then propose a framework for the reliability of CPS with the consideration of how to capture the reliability. Results: Based on the research method, we demonstrate the proposed framework with an illustrative example by using different reliability values from "offshore and onshore reliability data" library. We confirmed that the reliability model covers almost all possible reliabilities required to general cyber-physical systems.
Cyber-physical systems (CPSs) that interact with each other to achieve common goals are known as ... more Cyber-physical systems (CPSs) that interact with each other to achieve common goals are known as collaborative CPSs. Collaborative CPSs can achieve complex goals that individual CPSs cannot achieve on their own. One of the examples of collaborative CPSs is the vehicular cyber-physical systems (VCPSs), which integrate computing and physical resources to interact with each other to improve traffic safety, situational awareness, and efficiency. The perception system of individual VCPS has limitations on its coverage and detection accuracy. For example, the autonomous vehicle’s sensor cannot detect occluded objects and obstacles beyond its field of view. The VCPS can combine its own data with other collaborative VCPSs to enhance perception, situational awareness, accuracy, and traffic safety. This paper proposes a collaborative perception system to detect occluded objects through the camera sensor’s image fusion and stitching technique. The proposed collaborative perception system combi...
Since embedded software is very dependent for target hardware architecture, characteristics of th... more Since embedded software is very dependent for target hardware architecture, characteristics of the platform must be considered when designing the software. Furthermore, MPSoCs consists of heterogeneous hardware components that are specified in micro level. Thus mapping of embedded software for MPSoCs should be considered the characteristics. In this paper, we provide an approach to automatic mapping PIM (Platform Independent Model) of an embedded software to PSM(Platform Specific Model) for MPSoC(Multi Processor System On Chip) and verify its effectiveness with simulation. In the proposed approach, tasks are derived from an object oriented model based on the UML (Unified Modeling Language). And then the types of the derived tasks are identified. With the identified types and inter relationship between tasks, the tasks are assigned to appropriate heterogeneous hardware components. We expect that the approach improve accuracy of the assigning and concurrency of the deployed software.
Collaborative Cyber-Physical Systems (CCPS) are those systems in which several Cyber-Physical Sys... more Collaborative Cyber-Physical Systems (CCPS) are those systems in which several Cyber-Physical Systems (CPSs) collaborate to achieve a common goal. However, safety verification for collaborative CPSs is a significant challenge. The challenges occur due to unexpected operating conditions which are, by definition, unknown at development time or due to the lack of composite hazard analysis for collaborative CPSs. In this paper, we present an approach to perform safety analysis for collaborative CPSs by introducing an enhanced Fault Traceability and Propagation Graph based on composite hazard analysis. This graph enables to determine the fault source, propagation scope and required safety guards to mitigate the faults. We use the platooning system as a case study and modify the original VEhicular NeTwork Open Simulator (VENTOS) to verify safety for the platooning driving system in a variable environment (an unexpected event). Our simulation results show that after applying our defined sa...
Background/Objectives: Software engineering community has been studied extensively on large-sized... more Background/Objectives: Software engineering community has been studied extensively on large-sized software organizations and has provided suitable and interesting solutions. However, small software companies that make a large part of the software industry have been overlooked. Methods/Statistical analysis: The current requirement engineering practices are not suitable for small software companies. We propose a social network-based requirement engineering approach that will complement the traditional requirement engineering approaches and will make it suitable for small software companies. Findings: We have applied our SNS-based requirements determination approach to knowing about its validity. As a result, we concluded that 33.06 % of invited end-users participated in our approach and figured out 156 distinct user requirements. It has been seen that it was not necessary for users to have requirements engineering knowledge to participate in our proposed SNS-based approach that made m...
Collaborative Cyber-Physical Systems (CCPS) are systems where several individual cyber-physical s... more Collaborative Cyber-Physical Systems (CCPS) are systems where several individual cyber-physical systems collaborate to perform a single task. The safety of a single Cyber-Physical System (CPS) can be achieved by applying a safety mechanism and following standard processes defined in ISO 26262 and IEC 61508. However, due to heterogeneity, complexity, variability, independence, self-adaptation, and dynamic nature, functional operations for CCPS can threaten system safety. In contrast to fail-safe systems, where, for instance, the system leads to a safe state when an actuator shuts down due to a fault, the system has to be fail-operational in autonomous driving cases, i.e., a shutdown of a platooning member vehicle during operation on the road is unacceptable. Instead, the vehicle should continue its operation with degraded performance until a safe state is reached or returned to its original state in case of temporal faults. Thus, this paper proposes an approach that considers the res...
Software components are one reusable asset which can contain other kinds of software assets like ... more Software components are one reusable asset which can contain other kinds of software assets like requirement specifications, design patterns, source codes, documents, and so on. It can be used for designing software architecture or implementing a software system as an element like a building block. Therefore, software can be developed easily and quickly by assembling those building blocks. Focused on this nature of component-based development, energy-efficient software development can also be achieved with reusable software components. In particular, low-energy software has become a critical component for embedded and mobile software systems. Therefore, we have to consider energy efficiency to develop embedded software when developing the software based on reusable components. This paper, firstly, proposes how to represent the energy characteristics of the components and how to select a component for energy-efficient software development. We developed a component repository, ECoReS ...
Reusing software artifacts is not limited to only source codes, but also various artifacts which ... more Reusing software artifacts is not limited to only source codes, but also various artifacts which are created in software projects. However, traditional artifacts reuse approach has some problems of difficulties to find an appropriate artifact and to choose suitable terms as search keywords. To reduce the difficulties and enhance reusability of software artifacts, this paper presents some novel techniques based on context-aware reuse; which are context-based automatic keyword generation, ontology-based keyword extension, context-aware retrieval and learning-based result visualization. To realize the techniques, we firstly defined microComponent with the smaller unit (section) of a document as the reusable unit. And then we focus on to how can we retrieve and reuse the microComponents with the concept of context-aware. Our technique can precisely control the reusable unit, and enhance reusability of software artifacts based on the microComponents.
Code refactoring technique focuses on enhancing the maintainability of software to extend its lif... more Code refactoring technique focuses on enhancing the maintainability of software to extend its lifetime. However, there are other efforts to improve software qualities like performance or reliability as well as maintainability by using code refactoring techniques. Recently, as low-power software has become one of the critical issues in mobile environments, developing energyefficient software through code refactoring becomes an important one. This paper aims to investigate whether the existing refactoring techniques can support energy-efficient software generation or not. The refactored codes generated by the existing techniques can consume more power than original codes because they did not consider the power consumption in their refactoring processes. This paper analyzes the power consumption to investigate the energy efficiency of M. Fowler’s refactoring techniques. Our analysis result can provide useful information about energy-efficient refactoring techniques to software engineer...
KIPS Transactions on Software and Data Engineering, 2016
While the services of mobile devices like smart phone, tablet, and smart watch have been increase... more While the services of mobile devices like smart phone, tablet, and smart watch have been increased and varied, the software embedded into such devices has been also increased in size and functional complexity. Therefore, increasing operation time of mobile devices for serviceability became an important issue due to the limitation of battery power. Recent studies focus on the software development having efficient behavioral patterns because the energy consumption of mobile devices is caused by software behaviors which control the hardware operations. However, it is often difficult to develop the embedded software with considering energy-efficiency and behavior optimization due to the short development cycle of the mobile services in many cases. Therefore, this paper proposes the refactoring techniques for reducing energy consumption, and enables to fulfill the energy requirements during software development and maintenance. We defined energy bad smells with the code patterns that can excessively consume the energy, and our refactoring techniques are to remove these bad smells. We performed some case studies to verify the usefulness of our refactoring techniques.
KIPS Transactions on Software and Data Engineering, 2014
Code refactoring focuses on enhancing the maintainability of software to extend its lifetime. How... more Code refactoring focuses on enhancing the maintainability of software to extend its lifetime. However as software applications were varied and the range of its usage becomes broaden, there are some efforts to improve software qualities like performance or reliability as well as maintainability using code refactoring techniques. Recently, as low-energy software has become one of critical issues in mobile environment, developing energy efficient software through code refactoring becomes an important one. Therefore this paper has its goal to investigate whether the existing refactoring techniques can support energy efficient software generation or not. That is to say, the existing code refactoring techniques can cause the minus of energy efficiency because they did not considered the energy consumption in their refactoring process. This paper experiments and analyzes to check whether the M. Fowler's code refactoring techniques can support the energy efficient software generation or not. Our research result can give to software developer some informations about energy-efficient refactoring techniques, and can support the development of software that has high maintainability and good energy efficiency.
The perception system is a safety-critical component that directly impacts the overall safety of ... more The perception system is a safety-critical component that directly impacts the overall safety of autonomous driving systems (ADSs). It is imperative to ensure the robustness of the deep-learning model used in the perception system. However, studies have shown that these models are highly vulnerable to the adversarial perturbation of input data. The existing works mainly focused on studying the impact of these adversarial attacks on classification rather than regression models. Therefore, this paper first introduces two generalized methods for perturbation-based attacks: (1) We used naturally occurring noises to create perturbations in the input data. (2) We introduce a modified square, HopSkipJump, and decision-based/boundary attack to attack the regression models used in ADSs. Then, we propose a deep-autoencoder-based adversarial attack detector. In addition to offline evaluation metrics (e.g., F1 score and precision, etc.), we introduce an online evaluation framework to evaluate t...
The System of Cyber-Physical Systems (SoCPS) comprises several independent Cyber-Physical Systems... more The System of Cyber-Physical Systems (SoCPS) comprises several independent Cyber-Physical Systems (CPSs) that interact with each other to achieve a common mission that the individual systems cannot achieve on their own. SoCPS are rapidly gaining attention in various domains, e.g., manufacturing, automotive, avionics, healthcare, transportation, and more. SoCPS are extremely large, complex, and safety-critical. As these systems are safety-critical in nature, it is necessary to provide an adequate safety analysis mechanism for these collaborative SoCPS so that the whole network of these CPSs work safely. This safety mechanism must include composite safety analysis for a network of collaborative CPS as a whole. However, existing safety analysis techniques are not built for analyzing safety for dynamically forming networks of CPS. This paper introduces a composite safety analysis approach called SafeSoCPS to analyze hazards for a network of SoCPS. In SafeSoCPS, we analyze potential haza...
Proceedings of the 14th International Conference on Software Technologies, 2019
Social network sites have become popular and their popularity is growing exponentially every day.... more Social network sites have become popular and their popularity is growing exponentially every day. From the requirements engineering point of view, social network sites have provided unprecedented opportunities for software development organizations to understand the requirements of unknown end-users. Using social network sites, end-users express their experiences, needs, or concerns about a particular system or a product. Such information can be useful for software developers to address the concerns of users quickly. To get an overview of how social network sites are helping requirements engineering and new research trends in this area, we have surveyed a large number of research papers. We found that social network sites can be a major source that can be used for requirements elicitation, requirements prioritization, and negotiation. We also found that the research in this domain is at its beginning stage, but it is rapidly growing with the passage of time.
The deep neural networks (DNNs)based autonomous driving systems (ADSs) are expected to reduce roa... more The deep neural networks (DNNs)based autonomous driving systems (ADSs) are expected to reduce road accidents and improve safety in the transportation domain as it removes the factor of human error from driving tasks. The DNN based ADS sometimes may exhibit erroneous or unexpected behaviors due to unexpected driving conditions which may cause accidents. It is not possible to generalize the DNN model performance for all driving conditions. Therefore, the driving conditions that were not considered during the training of the ADS may lead to unpredictable consequences for the safety of autonomous vehicles. This study proposes an autoencoder and time series analysis based anomaly detection system to prevent the safety critical inconsistent behavior of autonomous vehicles at runtime. Our approach called DeepGuard consists of two components. The first component, the inconsistent behavior predictor, is based on an autoencoder and time series analysis to reconstruct the driving scenarios. Based on reconstruction error and threshold it determines the normal and unexpected driving scenarios and predicts potential inconsistent behavior. The second component provides on the fly safety guards, that is, it automatically activates healing strategies to prevent inconsistencies in the behavior. We evaluated the performance of DeepGuard in predicting the injected anomalous driving scenarios using already available open sourced DNN based ADSs in the Udacity simulator. Our simulation results show that the best variant of DeepGuard can predict up to 93 percent on the CHAUFFEUR ADS, 83 percent on DAVE2 ADS, and 80 percent of inconsistent behavior on the EPOCH ADS model, outperforming SELFORACLE and DeepRoad. Overall, DeepGuard can prevent up to 89 percent of all predicted inconsistent behaviors of ADS by executing predefined safety guards.
Cyber-physical systems have emerged as a new engineering paradigm, which combine the cyber and ph... more Cyber-physical systems have emerged as a new engineering paradigm, which combine the cyber and physical world with comprehensive computational and analytical tools to solve complex tasks. In cyber-physical systems, components are developed to detect failures, prevent failures, or mitigate the failures of a system. Sensors gather real-time data as an input to the system for further processing. Therefore, the whole cyber-physical system depends on sensors to accomplish their tasks and the failure of one sensor may lead to the failure of the whole system. To address this issue, we present an approach that utilizes the Failure Modes, Effects, and Criticality Analysis, which is a prominent hazard analysis technique to increase the understanding of risk and failure prevention. In our approach, we transform the Failure Modes, Effects, and Criticality Analysis model into a UML(Unified Modeling Language) class diagram, and then a knowledge base is constructed based on the derived UML class d...
As service-oriented software is considered as one of solutions to fulfill the users` needs in int... more As service-oriented software is considered as one of solutions to fulfill the users` needs in internet service environment, it has been increased the demands of reliable service development by the composition of internet services. However a critical issue in the service development approach is to satisfy the performance requirement as well as the functional correctness for the developing services, because impatient user multiply clicks the request-button of service without a short waiting. This paper proposes a framework to examine the performance of composite service. Our testing framework provides the data of service response time to service developer by measuring the service execution time. We develope an Aspect-based timer service, and weave the service with existing services to measure the execution time. Additionally, we perform some experiments to confirm the usefulness of performance test for composite service. This framework can support to develop a good performance service...
In company with the demand of powerful processing units for embedded systems, the method to devel... more In company with the demand of powerful processing units for embedded systems, the method to develop embedded software is also required to support the demand in new approach. In order to improve the resource utilization and system performance, software modeling techniques have to consider the features of hardware architecture. This paper proposes a partitioning technique of UML-based software models, which focus the generation of the allocatable software components into multiprocessor architecture. Our partitioning technique, at first, transforms UML models to CBCFGs(Constraint-Based Control Flow Graphs), and then slices the CBCFGs with consideration of parallelism and data dependency. We believe that our proposition gives practical applicability in the areas of platform specific modeling and performance estimation in model-driven embedded software development.
In spite of the various techniques on the testing of embedded software, operation failures of emb... more In spite of the various techniques on the testing of embedded software, operation failures of embedded systems such as robot or satellite applications, are occurred frequently. The critical reason of these failures is due to the fact that software is embedded into a target system with inherent faults. Therefore, in order to prevent the failure owing to such faults, it needs a technique to test the embedded software which operates in real environment. In this paper, we propose a testing technique, aspect-based On-the-Fly testing that is to test the functionality and performance at real operation time. Our proposed technique gives some benefits of real test of unexpected input conditions, prevention of software malfunction, and reusability of aspect components for the testing.
Along with the complexity and size growth of embedded software, it is critical to meet the nonfun... more Along with the complexity and size growth of embedded software, it is critical to meet the nonfunctional requirements such as power consumption as well as functional requirements such as correctness. This paper, apart from the existing studies of source code-based power analysis, proposes an approach of model-based power analysis using UML 2.0. Specially, we focus on the development of energy library to analyze the power consumption of embedded software. Our energy library supports model-based power analysis, and also supports the easy adaption for the change of embedded application.
Proceedings of the 2020 European Symposium on Software Engineering
Cyber-Physical Systems solve complex problems through their tight integration between the physica... more Cyber-Physical Systems solve complex problems through their tight integration between the physical and computational components. Therefore, the reliability of a complex system is the most critical requirement for the cyber-physical system because an unreliable system often leads to service disruption, property damage, financial loses and sometimes lead to fatality. In order to develop more reliable CPS, this paper proposes a generic framework for reliability modeling and analysis for our ongoing work on cyber-physical systems. Research Method: This paper, at first defines an architecture for general CPS which is comprised of three layers; environment layer, communication layer, and computational layer. Secondly, we formalize a reliability model for the architectural components, and then propose a framework for the reliability of CPS with the consideration of how to capture the reliability. Results: Based on the research method, we demonstrate the proposed framework with an illustrative example by using different reliability values from "offshore and onshore reliability data" library. We confirmed that the reliability model covers almost all possible reliabilities required to general cyber-physical systems.
Cyber-physical systems (CPSs) that interact with each other to achieve common goals are known as ... more Cyber-physical systems (CPSs) that interact with each other to achieve common goals are known as collaborative CPSs. Collaborative CPSs can achieve complex goals that individual CPSs cannot achieve on their own. One of the examples of collaborative CPSs is the vehicular cyber-physical systems (VCPSs), which integrate computing and physical resources to interact with each other to improve traffic safety, situational awareness, and efficiency. The perception system of individual VCPS has limitations on its coverage and detection accuracy. For example, the autonomous vehicle’s sensor cannot detect occluded objects and obstacles beyond its field of view. The VCPS can combine its own data with other collaborative VCPSs to enhance perception, situational awareness, accuracy, and traffic safety. This paper proposes a collaborative perception system to detect occluded objects through the camera sensor’s image fusion and stitching technique. The proposed collaborative perception system combi...
Since embedded software is very dependent for target hardware architecture, characteristics of th... more Since embedded software is very dependent for target hardware architecture, characteristics of the platform must be considered when designing the software. Furthermore, MPSoCs consists of heterogeneous hardware components that are specified in micro level. Thus mapping of embedded software for MPSoCs should be considered the characteristics. In this paper, we provide an approach to automatic mapping PIM (Platform Independent Model) of an embedded software to PSM(Platform Specific Model) for MPSoC(Multi Processor System On Chip) and verify its effectiveness with simulation. In the proposed approach, tasks are derived from an object oriented model based on the UML (Unified Modeling Language). And then the types of the derived tasks are identified. With the identified types and inter relationship between tasks, the tasks are assigned to appropriate heterogeneous hardware components. We expect that the approach improve accuracy of the assigning and concurrency of the deployed software.
Collaborative Cyber-Physical Systems (CCPS) are those systems in which several Cyber-Physical Sys... more Collaborative Cyber-Physical Systems (CCPS) are those systems in which several Cyber-Physical Systems (CPSs) collaborate to achieve a common goal. However, safety verification for collaborative CPSs is a significant challenge. The challenges occur due to unexpected operating conditions which are, by definition, unknown at development time or due to the lack of composite hazard analysis for collaborative CPSs. In this paper, we present an approach to perform safety analysis for collaborative CPSs by introducing an enhanced Fault Traceability and Propagation Graph based on composite hazard analysis. This graph enables to determine the fault source, propagation scope and required safety guards to mitigate the faults. We use the platooning system as a case study and modify the original VEhicular NeTwork Open Simulator (VENTOS) to verify safety for the platooning driving system in a variable environment (an unexpected event). Our simulation results show that after applying our defined sa...
Background/Objectives: Software engineering community has been studied extensively on large-sized... more Background/Objectives: Software engineering community has been studied extensively on large-sized software organizations and has provided suitable and interesting solutions. However, small software companies that make a large part of the software industry have been overlooked. Methods/Statistical analysis: The current requirement engineering practices are not suitable for small software companies. We propose a social network-based requirement engineering approach that will complement the traditional requirement engineering approaches and will make it suitable for small software companies. Findings: We have applied our SNS-based requirements determination approach to knowing about its validity. As a result, we concluded that 33.06 % of invited end-users participated in our approach and figured out 156 distinct user requirements. It has been seen that it was not necessary for users to have requirements engineering knowledge to participate in our proposed SNS-based approach that made m...
Collaborative Cyber-Physical Systems (CCPS) are systems where several individual cyber-physical s... more Collaborative Cyber-Physical Systems (CCPS) are systems where several individual cyber-physical systems collaborate to perform a single task. The safety of a single Cyber-Physical System (CPS) can be achieved by applying a safety mechanism and following standard processes defined in ISO 26262 and IEC 61508. However, due to heterogeneity, complexity, variability, independence, self-adaptation, and dynamic nature, functional operations for CCPS can threaten system safety. In contrast to fail-safe systems, where, for instance, the system leads to a safe state when an actuator shuts down due to a fault, the system has to be fail-operational in autonomous driving cases, i.e., a shutdown of a platooning member vehicle during operation on the road is unacceptable. Instead, the vehicle should continue its operation with degraded performance until a safe state is reached or returned to its original state in case of temporal faults. Thus, this paper proposes an approach that considers the res...
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Papers by Jang-Eui Hong