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Displaying 1-50 out of 104 total
Schedulability and Safety Analysis in the Graphical Communicating Shared Resources
Found in: Object-Oriented Real-Time Dependable Systems, IEEE International Workshop on
By Hanene Ben-Abdallah, Insup Lee, Young Si Kim
Issue Date:February 1996
pp. 25
Graphical Communicating Shared Resources is a formal language for the specification and analysis of real-time systems, including their functional, temporal and resource requirements. GCSR supports the explicit representation of system resources and priorit...
 
Formal Methods Based Development of a PCA Infusion Pump Reference Model: Generic Infusion Pump (GIP) Project
Found in: Joint Workshop on High Confidence Medical Devices, Software, and Systems and Medical Device Plug-and-Play Interoperability
By David Arney, Raoul Jetley, Paul Jones, Insup Lee, Oleg Sokolsky
Issue Date:June 2007
pp. 23-33
As software becomes ever more ubiquitous and complex in medical devices, it becomes increasingly important to assure that it performs safely and effectively. The critical nature of medical devices necessitates that the software used therein be reliable and...
 
Modeling Distributed Autonomous Robots Using CHARON: Formation Control Case Study
Found in: Object-Oriented Real-Time Distributed Computing, IEEE International Symposium on
By Yerang Hur, Rafael Fierro, Insup Lee
Issue Date:May 2003
pp. 93
We present the modeling and analysis of distributed autonomous robots using the specification language for hybrid systems, called CHARON. Coordination between distributed autonomous robots has attracted researchers of embedded and hybrid systems, since the...
 
The Specification and Schedulability Analysis of Real-Time Systems using ACSR
Found in: Real-Time Systems Symposium, IEEE International
By Jin-Young Choi, Insup Lee, Hong-Liang Xie
Issue Date:December 1995
pp. 266
To engineer reliable real-time systems, it is desirable to detect timing anomalies early in the development process. However, there is little work addressing the problem of accurately predicting timing properties of real-time systems before implementations...
 
A Reliable, Safe, and Secure Run-Time Platform for Cyber Physical Systems
Found in: 2013 IEEE 6th International Conference on Service-Oriented Computing and Applications (SOCA)
By Sung-Soo Lim,Eun-Jin Im,Nikil Dutt,Kyung-Woo Lee,Insik Shin,Chang-Gun Lee,Insup Lee
Issue Date:December 2013
pp. 268-274
This paper introduces a global research collaboration project performed by a Korean-USA research group. The project aims at designing and implementing a run-time platform for reliable, safe, and secure cyber physical systems (CPS). The project consists of ...
 
Overhead-aware compositional analysis of real-time systems
Found in: 2013 IEEE 19th Real-Time and Embedded Technology and Applications Symposium (RTAS)
By Linh T. X. Phan,Meng Xu,Jaewoo Lee,Insup Lee,Oleg Sokolsky
Issue Date:April 2013
pp. 237-246
Over the past decade, interface-based compositional schedulability analysis has emerged as an effective method for guaranteeing real-time properties in complex systems. Several interfaces and interface computation methods have been developed, and they offe...
 
Extending Task-level to Job-level Fixed Priority Assignment and Schedulability Analysis Using Pseudo-deadlines
Found in: 2012 IEEE 33rd Real-Time Systems Symposium (RTSS)
By Hoon Sung Chwa,Hyoungbu Back,Sanjian Chen,Jinkyu Lee,Arvind Easwaran,Insik Shin,Insup Lee
Issue Date:December 2012
pp. 51-62
In global real-time multiprocessor scheduling, a recent analysis technique for Task-level Fixed-Priority (TFP) scheduling has been shown to outperform many of the analyses for Job-level Fixed-Priority (JFP) scheduling on average. Since JFP is a generalizat...
   
Realizing Compositional Scheduling through Virtualization
Found in: Real-Time and Embedded Technology and Applications Symposium, IEEE
By Jaewoo Lee,Sisu Xi,Sanjian Chen,Linh T.X. Phan,Chris Gill,Insup Lee,Chenyang Lu,Oleg Sokolsky
Issue Date:April 2012
pp. 13-22
We present a co-designed scheduling framework and platform architecture that together support compositional scheduling of real-time systems. The architecture is built on the Xen virtualization platform, and relies on compositional scheduling theory that us...
 
Removing Abstraction Overhead in the Composition of Hierarchical Real-Time Systems
Found in: Real-Time and Embedded Technology and Applications Symposium, IEEE
By Sanjian Chen, Linh T. X. Phan, Jaewoo Lee, Insup Lee, Oleg Sokolsky
Issue Date:April 2011
pp. 81-90
The hierarchical real-time scheduling framework is a widely accepted model to facilitate the design and analysis of the increasingly complex real-time systems. Interface abstraction and composition are the key issues in the hierarchical scheduling framewor...
 
A Safety-Assured Development Approach for Real-Time Software
Found in: Real-Time Computing Systems and Applications, International Workshop on
By Eunkyoung Jee, Shaohui Wang, Jeong Ki Kim, Jaewoo Lee, Oleg Sokolsky, Insup Lee
Issue Date:August 2010
pp. 133-142
Guaranteeing timing properties is an important issue as we develop safety-critical real-time systems such as cardiac pacemakers. We present a safety assured development approach of real-time software using a pacemaker as our case study. Following the model...
 
Dynamic Trust Management
Found in: Computer
By Matt Blaze, Sampath Kannan, Insup Lee, Oleg Sokolsky, Jonathan M. Smith, Angelos D. Keromytis, Wenke Lee
Issue Date:February 2009
pp. 44-52
Trust management forms the basis for communicating policy among system elements and demands credential checking for access to all virtual private service resources—along with careful evaluation of credentials against specified policies—before a party can b...
 
High-Confidence Medical Device Software and Systems
Found in: Computer
By Insup Lee, George J. Pappas, Rance Cleaveland, John Hatcliff, Bruce H. Krogh, Peter Lee, Harvey Rubin, Lui Sha
Issue Date:April 2006
pp. 33-38
Given the shortage of caregivers and the increase in an aging US population, the future of US healthcare quality does not look promising and definitely is unlikely to be cheaper. Advances in health information systems and healthcare technology offer a trem...
 
The MIDdleware Assurance Substrate: Enabling Strong Real-Time Guarantees in Open Systems with OpenFlow
Found in: 2014 IEEE 17th International Symposium on Object/Component/Service-Oriented Real-Time Distributed Computing (ISORC)
By Andrew L. King,Sanjian Chen,Insup Lee
Issue Date:June 2014
pp. 133-140
Middleware designed for use in Distributed Real-Time and Embedded (DRE) systems enable cost and development time reductions by providing simple communications abstractions and hiding operating system-level networking API details from developers. While curr...
 
Functional Alarms for Systems of Interoperable Medical Devices
Found in: 2014 IEEE 15th International Symposium on High-Assurance Systems Engineering (HASE)
By Krishna K. Venkatasubramanian,Eugene Y. Vasserman,Oleg Sokolsky,Insup Lee
Issue Date:January 2014
pp. 247-248
Alarms are essential for medical systems in order to ensure patient safety during deteriorating clinical situations and inevitable device malfunction. As medical devices are connected together to become interoperable, alarms become crucial part in making t...
 
Cache-Aware Compositional Analysis of Real-Time Multicore Virtualization Platforms
Found in: 2013 IEEE 34th Real-Time Systems Symposium (RTSS)
By Meng Xu,Linh T.X. Phan,Insup Lee,Oleg Sokolsky,Sisu Xi,Chenyang Lu,Christopher Gill
Issue Date:December 2013
pp. 1-10
Multicore processors are becoming ubiquitous, and it is becoming increasingly common to run multiple real-time systems on a shared multicore platform. While this trend helps to reduce cost and to increase performance, it also makes it more challenging to a...
 
Improving schedulability of fixed-priority real-time systems using shapers
Found in: 2013 IEEE 19th Real-Time and Embedded Technology and Applications Symposium (RTAS)
By Linh T. X. Phan,Insup Lee
Issue Date:April 2013
pp. 217-226
In this paper, we introduce a technique for improving the schedulability of real-time embedded systems with fixed-priority scheduling. Our technique uses shapers to reduce the resource interference between higher-priority and lower-priority tasks, and thus...
 
Security and Interoperable-Medical-Device Systems, Part 2: Failures, Consequences, and Classification
Found in: IEEE Security & Privacy
By Eugene Y. Vasserman,Krishna K. Venkatasubramanian,Oleg Sokolsky,Insup Lee
Issue Date:November 2012
pp. 70-73
Interoperable medical devices (IMDs) face threats due to the increased attack surface presented by interoperability and the corresponding infrastructure. Introducing networking and coordination functionalities fundamentally alters medical systems' security...
 
Security and Interoperable-Medical-Device Systems, Part 1
Found in: IEEE Security & Privacy
By Krishna K. Venkatasubramanian,Eugene Y. Vasserman,Oleg Sokolsky,Insup Lee
Issue Date:September 2012
pp. 61-63
Interoperable medical devices (IMDs) face threats due to the increased attack surface presented by interoperability and the corresponding infrastructure. Introducing networking and coordination functionalities fundamentally alters medical systems' security...
 
From Verification to Implementation: A Model Translation Tool and a Pacemaker Case Study
Found in: Real-Time and Embedded Technology and Applications Symposium, IEEE
By Miroslav Pajic,Zhihao Jiang,Insup Lee,Oleg Sokolsky,Rahul Mangharam
Issue Date:April 2012
pp. 173-184
Model-Driven Design (MDD) of cyber-physical systems advocates for design procedures that start with formal modeling of the real-time system, followed by the model's verification at an early stage. The verified model must then be translated to a more detail...
 
Rationale and Architecture Principles for Medical Application Platforms
Found in: Cyber-Physical Systems, IEEE/ACM International Conference on
By John Hatcliff,Andrew King,Insup Lee,Alasdair Macdonald,Anura Fernando,Michael Robkin,Eugene Vasserman,Sandy Weininger,Julian M. Goldman
Issue Date:April 2012
pp. 3-12
The concept of
 
An empirical analysis of scheduling techniques for real-time cloud-based data processing
Found in: Service-Oriented Computing and Applications, IEEE International Conference on
By Linh T. X. Phan,Zhuoyao Zhang,Qi Zheng,Boon Thau Loo,Insup Lee
Issue Date:December 2011
pp. 1-8
In this paper, we explore the challenges and needs of current cloud infrastructures, to better support cloud-based data-intensive applications that are not only latency-sensitive but also require strong timing guarantees. These applications have strict dea...
 
Video Quality Driven Buffer Sizing via Frame Drops
Found in: Real-Time Computing Systems and Applications, International Workshop on
By Deepak Gangadharan,Linh T.X. Phan,Samarjit Chakraborty,Roger Zimmermann,Insup Lee
Issue Date:August 2011
pp. 319-328
We study the impact of video frame drops in buffer constrained multiprocessor system-on-chip (MPSoC) platforms. Since on-chip buffer memory occupies a significant amount of silicon area, accurate buffer sizing has attracted a lot of research interest latel...
 
Towards a Compositional Multi-modal Framework for Adaptive Cyber-physical Systems
Found in: Real-Time Computing Systems and Applications, International Workshop on
By Linh T.X. Phan,Insup Lee
Issue Date:August 2011
pp. 67-73
Among the key characteristics of cyber-physical systems are the ability to adapt to changes during operation, the multidimensional complexity of multi-functionality and the underlying heterogeneous distributed architecture, as well as resource use efficien...
 
A Semantic Framework for Mode Change Protocols
Found in: Real-Time and Embedded Technology and Applications Symposium, IEEE
By Linh T. X. Phan, Insup Lee, Oleg Sokolsky
Issue Date:April 2011
pp. 91-100
We present a unified framework for the specification and analysis of mode-change protocols used in multi-mode real-time systems. We propose a highly expressive formalism, called MCP, to model the system behavior during mode transitions, and show how variou...
 
Compositional Analysis of Multi-mode Systems
Found in: Real-Time Systems, Euromicro Conference on
By Linh T.X. Phan, Insup Lee, Oleg Sokolsky
Issue Date:July 2010
pp. 197-206
The paper presents a model for multi-mode real-time applications and develops new techniques for the compositional analysis of systems that contain multiple such applications. An algorithm for constructing an interface for a single multi-mode application i...
 
Model-Based Programming of Modular Robots
Found in: Object-Oriented Real-Time Distributed Computing, IEEE International Symposium on
By David Arney, Sebastian Fischmeister, Insup Lee, Yoshihito Takashima, Mark Yim
Issue Date:May 2010
pp. 66-74
Modular robots are a powerful concept for robotics. A modular robot consists of many individual modules so it can adjust its configuration to the problem. However, the fact that a modular robot consists of many individual modules makes it a highly distribu...
 
Generating Reliable Code from Hybrid-Systems Models
Found in: IEEE Transactions on Computers
By Madhukar Anand, Sebastian Fischmeister, Yerang Hur, Jesung Kim, Insup Lee
Issue Date:September 2010
pp. 1281-1294
Hybrid systems have emerged as an appropriate formalism to model embedded systems as they capture the theme of continuous dynamics with discrete control. Under this paradigm, distributed embedded systems can be modeled as a network of communicating hybrid ...
 
A Compositional Scheduling Framework for Digital Avionics Systems
Found in: Real-Time Computing Systems and Applications, International Workshop on
By Arvind Easwaran, Insup Lee, Oleg Sokolsky, Steve Vestal
Issue Date:August 2009
pp. 371-380
ARINC specification 653-2 describes the interface between application software and underlying middleware in a distributed real-time avionics system. The real-time workload in this system comprises of partitions, where each partition consists of one or more...
 
Strong and Weak Policy Relations
Found in: Policies for Distributed Systems and Networks, IEEE International Workshop on
By Michael J. May, Carl A. Gunter, Insup Lee, Steve Zdancewic
Issue Date:July 2009
pp. 33-36
Access control and privacy policy relations tend to focus on decision outcomes and are very sensitive to defined terms and state. Small changes or updates to a policy language or vocabulary may make two similar policies incomparable. To address this we dev...
 
Resource Scopes: Toward Language Support for Compositional Determinism
Found in: Object-Oriented Real-Time Distributed Computing, IEEE International Symposium on
By Madhukar Anand, Sebastian Fischmeister, Insup Lee
Issue Date:March 2009
pp. 295-304
Complex real-time embedded systems should be compositional and deterministic in the resource, time, and value domains. Determinism eases the engineering of correct systems and compositionality simplifies the assembly of complex systems out of smaller modul...
 
Hierarchical Scheduling Framework for Virtual Clustering of Multiprocessors
Found in: Real-Time Systems, Euromicro Conference on
By Insik Shin, Arvind Easwaran, Insup Lee
Issue Date:July 2008
pp. 181-190
Scheduling of sporadic task systems on multiprocessor platforms is an area which has received much attention in the recent past. It is widely believed that finding an optimal scheduler is hard, and therefore most studies have focused on developing algorith...
 
Compositional Feasibility Analysis of Conditional Real-Time Task Models
Found in: Object-Oriented Real-Time Distributed Computing, IEEE International Symposium on
By Madhukar Anand, Arvind Easwaran, Sebastian Fischmeister, Insup Lee
Issue Date:May 2008
pp. 391-398
Conditional real-time task models, which are generalizations of periodic, sporadic, and multi-frame tasks, represent real world applications more accurately. These models can be classified based on a tradeoff in two dimensions - expressivity and hardness o...
 
Compositional Analysis Framework Using EDP Resource Models
Found in: Real-Time Systems Symposium, IEEE International
By Arvind Easwaran, Madhukar Anand, Insup Lee
Issue Date:December 2007
pp. 129-138
Compositional schedulability analysis of hierarchical scheduling frameworks is a well studied problem, as it has wide-ranging applications in the embedded systems do- main. Several techniques, such as periodic resource model based abstraction and compositi...
 
A Verifiable Language for Programming Real-Time Communication Schedules
Found in: IEEE Transactions on Computers
By Sebastian Fischmeister, Oleg Sokolsky, Insup Lee
Issue Date:November 2007
pp. 1505-1519
<p><b>Abstract</b>—Distributed hard real-time systems require predictable communication at the network level and verifiable communication behavior at the application level. At the network level, communication between nodes must be guarant...
 
Improving the Safety of Patient-Controlled Analgesia Infusions with Safety Interlocks and Closed-Loop Control
Found in: Joint Workshop on High Confidence Medical Devices, Software, and Systems and Medical Device Plug-and-Play Interoperability
By Philippe-Antoine Cortès, Shankar M. Krishnan, Insup Lee, Julian M. Goldman
Issue Date:June 2007
pp. 149-150
Patient-Controlled Analgesia (PCA) treatment for postoperative pain management is commonly employed in hospitals and its usage is steadily increasing. However, despite the apparent ?inherent? safety strategy of requiring active participation of the patient...
   
Composition Techniques for Tree Communication Schedules
Found in: Real-Time Systems, Euromicro Conference on
By Madhukar Anand, Sebastian Fischmeister, Insup Lee
Issue Date:July 2007
pp. 235-246
A critical resource in a distributed real-time system is its shared communication medium. Unrestrained concurrent access to the network can lead to collisions that reduce the system?s reliability. Therefore in this area, one goal is to develop effective mo...
 
Use Case Demonstration: X-Ray/Ventilator
Found in: Joint Workshop on High Confidence Medical Devices, Software, and Systems and Medical Device Plug-and-Play Interoperability
By David Arney, Julian M. Goldman, Insup Lee, Ersel Llukacej, Susan Whitehead
Issue Date:June 2007
pp. 160
Patients who need an x-ray while under anesthesia are at risk because clinicians turn off the anesthesia ventilator for an x-ray and may forget to turn it back on afterwards. This problem occurred in a case study reported by the Anesthesia Patient Safety F...
   
Compositional Schedulability Analysis of Hierarchical Real-Time Systems
Found in: Object-Oriented Real-Time Distributed Computing, IEEE International Symposium on
By Arvind Easwaran, Insup Lee, Insik Shin, Oleg Sokolsky
Issue Date:May 2007
pp. 274-281
Embedded systems are complex as a whole but consist of smaller independent modules interacting with each other. This structure makes them amenable to compositional design. Real-time embedded systems consist of real-time workloads having deadlines. Composit...
 
Privacy APIs: Access Control Techniques to Analyze and Verify Legal Privacy Policies
Found in: Computer Security Foundations Workshop, IEEE
By Michael J. May, Carl A. Gunter, Insup Lee
Issue Date:July 2006
pp. 85-97
There is a growing interest in establishing rules to regulate the privacy of citizens in the treatment of sensitive personal data such as medical and financial records. Such rules must be respected by software used in these sectors. The regulatory statemen...
 
Formal Modeling and Analysis of the AFDX Frame Management Design
Found in: Object-Oriented Real-Time Distributed Computing, IEEE International Symposium on
By Madhukar Anand, Steve Vestal, Samar Dajani-Brown, Insup Lee
Issue Date:April 2006
pp. 393-399
The Avionics Full Duplex Switched Ethernet (AFDX) has been developed to provide reliable data exchange with strong data transmission time guarantees in internal communication of the aircraft. The AFDX design is based on the principle of a switched network ...
 
Network-Code Machine: Programmable Real-Time Communication Schedules
Found in: Real-Time and Embedded Technology and Applications Symposium, IEEE
By Sebastian Fischmeister, Oleg Sokolsky, Insup Lee
Issue Date:April 2006
pp. 311-324
Distributed hard real-time systems require guaranteed communication. One common approach is to restrict network access by enforcing a time-division multiple access (TDMA) schedule.The typical data representation of offlinegenerated TDMA schedules is table-...
 
Opportunities and Obligations for Physical Computing Systems
Found in: Computer
By John A. Stankovic, Insup Lee, Aloysius Mok, Raj Rajkumar
Issue Date:November 2005
pp. 23-31
Seamlessly integrating computing with the physical world via sensors and actuators, physical computing systems promise to give society an improved living standard, greater security, and unparalleled convenience and efficiency
 
Abstract Slicing: A New Approach to Program Slicing Based on Abstract Interpretation and Model Checking
Found in: Source Code Analysis and Manipulation, IEEE International Workshop on
By Hyoung Seok Hong, Insup Lee, Oleg Sokolsky
Issue Date:October 2005
pp. 25-34
<p>This paper proposes a new approach to program slicing based on abstract interpretation and model checking. First, the notion of abstract slicing is introduced. Abstract slicing extends static slicing with predicates and constraints by using as the...
 
RT-MaC: Runtime Monitoring and Checking of Quantitative and Probabilistic Properties
Found in: Real-Time Computing Systems and Applications, International Workshop on
By Usa Sammapun, Insup Lee, Oleg Sokolsky
Issue Date:August 2005
pp. 147-153
Correctness of a real-time system depends on its computation as well as its timeliness and its reliability. In recent years, researches have focused on verifying correctness of a real-time system during runtime by monitoring its execution and checking it a...
 
Code Generation from Hybrid Systems Models for Distributed Embedded Systems
Found in: Object-Oriented Real-Time Distributed Computing, IEEE International Symposium on
By Madhukar Anand, Jesung Kim, Insup Lee
Issue Date:May 2005
pp. 166-173
Code generation from hybrid system models is a promising approach to producing reliable embedded systems. This approach presents new challenges as the precise semantics of the model are hard to capture in the code. A framework for generating code was intro...
 
Compositional Real-Time Scheduling Framework
Found in: Real-Time Systems Symposium, IEEE International
By Insik Shin, Insup Lee
Issue Date:December 2004
pp. 57-67
Our goal is to develop a compositional real-time scheduling framework so that global (system-level) timing properties can be established by composing independently (specified and) analyzed local (component-level) timing properties. The two essential proble...
 
Periodic Resource Model for Compositional Real-Time Guarantees
Found in: Real-Time Systems Symposium, IEEE International
By Insik Shin, Insup Lee
Issue Date:December 2003
pp. 2
We address the problem of providing compositional hard real-time guarantees in a hierarchy of schedulers. We first propose a resource model to characterize a periodic resource allocation and present exact schedulability conditions for our proposed resource...
 
Data Flow Testing as Model Checking
Found in: Software Engineering, International Conference on
By Hyoung Seok Hong, Sung Deok Cha, Insup Lee, Oleg Sokolsky, Hasan Ural
Issue Date:May 2003
pp. 232
This paper presents a model checking-based approach to data flow testing. We characterize data flow oriented coverage criteria in temporal logic such that the problem of test generation is reduced to the problem of finding witnesses for a set of temporal l...
 
Modular Code Generation from Hybrid Automata based on Data Dependency
Found in: Real-Time and Embedded Technology and Applications Symposium, IEEE
By Jesung Kim, Insup Lee
Issue Date:May 2003
pp. 160
Model-based automatic code generation is a process of converting abstract models into concrete implementations in the form of a program written in a high-level programming language. The process consists of two steps, first translating the primitives of the...
 
Embedded System Design Framework for Minimizing Code Size and Guaranteeing Real-Time Requirements
Found in: Real-Time Systems Symposium, IEEE International
By Insik Shin, Insup Lee, Sang Lyul Min
Issue Date:December 2002
pp. 201
In addition to real-time requirements, the program code size is a critical design factor for real-time embedded systems. To take advantage of the code size vs. execution time tradeoff provided by reduced bit-width instructions, we propose a design framewor...
 
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