Midori Sugaya

Constructing a multi-OS platform with minimal engineering cost

Constructing an embedded device with a real-time and a general-purpose operating system has attracted attention as a promising approach to let the device balance real-time responsiveness and rich functionalities. This paper introduces our methodology for constructing such multi-OS platform with minimal engineering cost by assuming asymmetric OS combinations unique to embedded systems. Our methodology consists of two parts. One is a simple hypervisor for multiplexing resources to be shared between operating systems. The other is modifying operating systems to allow them to be aware of each other. We constructed an experimental system executing TOPPERS and Linux simultaneously on a hardware equipped with an SH-4A processor. The modification to each operating system kernel limited to a few dozen lines of code and do not introduce any overhead that would compromise real-time responsiveness or system throughput.

Accounting system: a fine-grained CPU resource protection mechanism for embedded system

In ubiquitous computing environments, our daily lives will be made convenient by embedded intelligent devices. Those devices, such as car navigation systems, personal digital assistances, and cellular phones, provide various kinds of the complex services. Those devices are networked with each other and provide complicated services, through the Internet. While they provide useful services, there is an increasing possibility of security attacks, which include the unexpected execution of unsecure codes. Current information appliances have not yet fully embodied a resource protection mechanism that prevents misbehaved applications from consuming the whole CPU capacity of system resources. In this paper, we propose accounting system, and describe its design and implementation. The system is a resource monitoring and restriction system that has the purpose of improving the systems reliability and security. We developed the system on Linux. Our system is a very generic to offer various services, such as security improvement, overload control, and class-based accounting, that require CPU resource control

Task Grain Scheduling for Hypervisor-Based Embedded System

The emergence of functional embedded systems such as cell-phones and digital appliances brought up a new issue, building a system supporting both real-time and rich services. One of the solutions is leveraging a hypervisor to integrate an RTOS and a commodity OS into a single device. However, this approach induces the limitation of application deployment; all the high priority tasks should reside in the RTOS. In this paper, we propose a task grain scheduling for a real-time hypervisor, which enables a flexible application deployment between an RTOS and a commodity OS. We constructed a prototype system with an existing hypervisor, an RTOS, and a commodity OS. We measured some basic overheads, and fixed some tasks which were missing their deadlines using the task grain scheduling to meet their deadlines. The overheads were small and the task grain scheduling achieved a flexible real-time scheduling for the hypervisor based system.

A Lightweight Anomaly Detection System for Information Appliances

In this paper, a novel lightweight anomaly and fault detection infrastructure called Anomaly Detection by ResourceMonitoring (Ayaka) is presented for Information Appliances.Ayaka provides a general monitoring method for detecting anomalies using only resource usage information onsystems independent of its domain, target application, and programming languages. Ayaka modifies the kernel to detectfaults and uses a completely application black-box approach based on machine learning methods. It uses the clustering method to quantize the resource usage vector data and learn the normal patterns with a hidden Markov Model. In the running phase, Ayaka finds anomalies by comparing the application resource usage with the learned model. The evaluation experiment indicates that our prototype system is able to detect anomalies, such as SQL injection and buffer overrun, without significant overheads.

A Mobile Robot for Fall Detection for Elderly-Care☆

Abstract In 2015, the population of people over the age of 65 is 25.0% in Japan. This means that Japan has already become a super-aging society. In such society, the number of elderly people living alone has been also increased. For such people, a fall accident is serious because it can lead to serious injury or death. Researches and services to monitor behaviours of such people have been proposed. For example, by monitoring the status of use of home appliances, something unusual happened to them can be predicted. However, such systems cannot recognize the detailed behaviours like fall. Surveillance cameras have been introduced only outside the house because of the privacy issues. In this paper, we propose a mobile robot to detect human fall and report it to their observers. The mobile robot consists of a household mobile robot (Yujin Robots Kobuki), a sensor (Microsofts Kinect), and a computer (PC) to detect a human and control the robot. For simplicity of the robot and accurate fall detection, the sensor is installed on the robot to follow the target harmoniously. Thus, the sensor can move around with the robot to minimize blind area. The results of our experiments show that improvement of up to 80% in fall detection rate compared to a conventional monitoring technique using position-fixed sensors. Finally, we discuss the capabilities and future works of the robot.

Towards a Language for Communication among Stakeholders

Computers are now present almost everywhere and connected into ever more complex networks. This means not only that embedded systems are more complicated, but also that communication among the diverse stakeholders of systems is much harder than before. This paper introduces the D-Case approach to a systematic explanation of embedded-systems dependability. A D-Case is a structured document that argues for the dependability of a system, supported by evidence. This extends the notion of •textit{safety cases} •cite{BB98} commonly used in (European) safety-critical sectors. The goal is to develop the D-Case language for communication systems dependability among the stakeholders. The paper reports the experience in constructing a D-Case for the remote test surveillance system developed to demonstrate certain dependability system components. D-Case construction is shown to be an effective method in explaining how each system component contributes to the overall dependability of the system. Another experiment shows how the D-Case approach can promote dependability through the life cycle of a larger system. Finally, the paper presents some comments on the difficulties and insights for future work.

Towards an Open Dependable Operating System

This paper introduces a new dependable operating system project, called DEOS, started in 2006, and scheduled to continue for six years. In this project, a safety extension mechanism called P-Bus is to be designed, and implemented in the Linux kernel so that a future dependability attribute is implemented with P-Bus. A hardware abstraction layer, called SPUMONE, is introduced so that a light-weight operating system, called ArcOS, and a monitoring service on top of ArcOS monitors the Linux kernel to provide a safety-net for the Linux kernel. New dependability metrics are being designed to enable developers and users to decide which hardware or software solution meets their dependability requirements, and thus can be used.

An Operating System Architecture for Future Information Appliances

A software platform for developing future information appliances requires to satisfy various diverse requirements. The operating system architecture presented in this paper enhances the flexibility and dependability through virtualization techniques. The architecture allows a system to use multiple operating systems simultaneously, and to use multi-core processors in a flexible way. Also, dependability mechanisms in our architecture will avoid crashing or hanging a system as much as possible in order to improve the user experience when defects in the software are exposed. We present a brief overview of each component in the operating system architecture and some sample scenarios that illustrate the effectiveness of the architecture.

Using virtualized operating systems as a ubiquitous computing infrastructure

The personalization of computing environments is one of the key aspects of ubiquitous computing, and such personalization requires isolated computing environments for better security and stability. This paper describes our ubiquitous computing infrastructure architecture that is based on virtualized operating systems in order to enable ubiquitous devices and servers to be shared securely and reliably. Our architecture also includes CPU resource management mechanisms to support time sensitive applications and to make the execution of applications stable on shared devices.

A structure of a c# framework ContextCS based on context-oriented programming

Context-oriented programming (COP) treats context explicitly and provides mechanisms to adapt behavior dynamically in reaction to changes in context at runtime. These languages are desirable to context-sensitive embedded software since such software usually works in various contexts of heterogeneous devices and complex environments. Moreover, a practical development requires proper handling of legacy programs and product lines. To realize these characteristics, we have developed a C# framework called Con-textCS that contains the following features: layer creation at runtime, separation of layer managing program, and the layer with annotation. The article presents the structure of ContextCS.