A5012886088- Distributed systems and fault tolerance
- Real-Time Systems Scheduling
- Distributed and Parallel Computing Systems
- Energy Efficient Wireless Sensor Networks
- Vehicular Ad Hoc Networks (VANETs)
- Advanced Database Systems and Queries
- Context-Aware Activity Recognition Systems
- Advanced Data Storage Technologies
- Petri Nets in System Modeling
- Indoor and Outdoor Localization Technologies
- Opportunistic and Delay-Tolerant Networks
- Mobile Ad Hoc Networks
- Parallel Computing and Optimization Techniques
- Software System Performance and Reliability
- Cloud Computing and Resource Management
- Security and Verification in Computing
- Embedded Systems Design Techniques
- Traffic control and management
- IoT and Edge/Fog Computing
- Mobile Agent-Based Network Management
- Data Management and Algorithms
- Service-Oriented Architecture and Web Services
- Video Surveillance and Tracking Methods
- Autonomous Vehicle Technology and Safety
- Smart Grid Security and Resilience
Sangji University
2025
Daegu Gyeongbuk Institute of Science and Technology
2014-2024
University of Virginia
2004-2016
Ajou University
2016
China National Offshore Oil Corporation (China)
2014
Charlottesville Medical Research
2005-2012
Catholic University of Daegu
2011
Catholic University of Korea
2010
Cheongju University
2007-2009
University of Skövde
2002-2008
Preventing denial-of-service attacks in wireless sensor networks is difficult primarily because of the limited resources available to network nodes and ease with which are perpetrated. Rather than jeopardize design requirements call for simple, inexpensive, mass-producible devices, we propose a coping strategy that detects maps jammed regions. We describe mapping protocol surround jammer allows applications reason about region as an entity, rather collection broken links congested nodes....
This paper presents the first study on scheduling for cooperative data dissemination in a hybrid infrastructure-to-vehicle (I2V) and vehicle-to-vehicle (V2V) communication environment. We formulate novel problem of (CDS). Each vehicle informs road-side unit (RSU) list its current neighboring vehicles identifiers retrieved newly requested data. The RSU then selects sender receiver corresponding V2V communication, while it simultaneously broadcasts item to that are instructed tune into I2V...
Optimal scheduling of real-time tasks on multiprocessor systems is known to be computationally intractable for large task sets. Any practical algorithm assigning a system presents trade-off between its computational complexity and performance. In this study, new schedulability conditions are presented homogeneous where individual processors execute the rate-monotonic algorithm. The used develop strategies processors. performance shown significantly better than suggested by existing...
The paper presents the design, implementation, and evaluation of an adaptive architecture to provide relative delay guarantees for different service classes on Web servers under HTTP 1.1. first contribution is based a feedback control loop that enforces desired delays among via dynamic connection scheduling process reallocation. second our use theory design with proven performance guarantees. In contrast ad hoc approaches often rely laborious tuning iterations, approach enables us...
Distributed sensor networks are quickly gaining recognition as viable embedded computing platforms. Current techniques for programming cumbersome, inflexible, and low-level. We introduce EnviroTrack, an object-based distributed middleware system that raises the level of abstraction by providing a convenient powerful interface to application developer geared towards tracking physical environment. EnviroTrack is novel in its seamless integration objects live time space into computational...
Despite the significant body of results in real-time scheduling, many real world problems are not easily supported. While algorithms such as Earliest Deadline First, Rate Monotonic, and Spring scheduling algorithm can support sophisticated task set characteristics (such deadlines, precedence constraints, shared resources, jitter, etc.), they all "open loop" algorithms. Open loop refers to fact that once schedules created "adjusted" based on continuous feedback. open-loop perform well static...
Despite the significant body of results in real-time scheduling, many real world problems are not easily supported. While algorithms such as Earliest Deadline First, Rate Monotonic, and Spring scheduling algorithm can support sophisticated task set characteristics (such deadlines, precedence constraints, shared resources, jitter etc.), they all "open loop" algorithms. Open loop refers to fact that once schedules created "adjusted" based on continuous feedback. open-loop perform well static...
This work presents a TDMA based multi-channel MAC protocol called TMMAC for Ad Hoc Networks. requires only single half-duplex radio transceiver on each node. In addition to explicit frequency negotiation which is adopted by conventional protocols, introduces lightweight time negotiation. two-dimensional enables exploit the advantage of both multiple channels and TDMA, achieve aggressive power savings allowing nodes that are not involved in communication go into doze mode. Moreover,...
This paper presents the design and implementation of an adaptive Web server architecture to provide relative absolute connection delay guarantees for different service classes. The first contribution this is based on feedback control loops that enforce desired delays via dynamic scheduling process reallocation. second use theoretic techniques model with performance. In contrast heuristics-based approaches rely laborious hand-tuning testing iteration, approach enables systematic established...
One of the primary requirements in many cyber-physical systems (CPS) is that sensor data derived from physical world should be disseminated a timely and reliable manner to all interested collaborative entities. However, providing dissemination services especially challenging for CPS since they often operate highly unpredictable environments. Existing network middleware has limitations such services. In this paper, we present novel publish/subscribe-based architecture called Real-time Data...
Extensive empirical studies presented in this article confirm that the quality of radio communication between low-power sensor devices varies significantly with time and environment. This phenomenon indicates previous topology control solutions, which use static transmission power, range, link quality, might not be effective physical world. To address issue, online power adapts to external changes is necessary. presents ATPC, a lightweight algorithm for Adaptive Transmission Power Control...
Recent advances in autonomous vehicles and vehicular communications are envisioned to enable novel approaches managing controlling traffic intersections. In particular, with intersection controller units (ICUs), passing can be instructed cross the safely without signals. Previous efforts on control mainly focused guaranteeing safe passage of improving throughput, considering quality travel experience from passengers' perspective. this paper, we aim design an enhanced mechanism, which not...
In addition to maintaining database consistency as in conventional databases, real-time systems must also handle transactions with timing constraints. While transaction response time and throughput are usually used measure a system, the percentage of satisfying deadlines or time-critical value function is often evaluate system. Scheduling far more complex than traditional scheduling sense that (1) worst case execution times typically hard estimate, since not only CPU but I/O requirement...
While early research on real-time computing was concerned with guaranteeing avoidance of undesirable effects, such as overload and deadline misses, adaptive systems are designed to handle effects dynamically. Various efforts have addressed the characterization improvement dynamic behavior systems. However, authors' knowledge, no unified framework exists for designing adaptive, software based specifications desired behavior. We propose a control theory. Using theory, designer can (i) specify...
The demand for real-time data services is increasing in many applications including e-commerce, agile manufacturing, and telecommunications network management. In these applications, it desirable to execute transactions within their deadlines, i.e., before the real-world status changes, using fresh (temporally consistent) data. However, meeting fundamental requirements challenging due dynamic workloads access patterns applications. Further, transaction timeliness freshness may conflict. We...
A new concurrency control algorithm for real-time database systems is proposed, by which scheduling and can be integrated. The founded on a priority-based locking mechanism to support time-critical adjusting the serialization order dynamically in favor of high priority transactions. Furthermore, it does not assume any knowledge about data requirements or execution time each transaction, making very practical.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Standard upper-limb motor function impairment assessments, such as the Fugl-Meyer Assessment (FMA), are a critical aspect of rehabilitation after neurological disorders. These assessments typically take long time (about 30 min for FMA) clinician to perform on patient, which is severe burden in clinical environment. In this paper, we propose framework automating that uses low-cost sensors collect movement data. The sensor data then processed through machine learning algorithm determine score...
This work aims at proposing a transfer learning (TL)-based framework to enhance system scalability of fingerprint-based indoor localization by reducing offline training overhead without jeopardizing the accuracy. The basic principle is reshape data distributions in target domain based on transferred knowledge from source domains, so that those belonging same cluster will be logically closer each other, whereas others further apart other. Specifically, TL-based consists two parts, metric and...
Vehicle-to-vehicle/vehicle-to-infrastructure (referred to as V2X) communications have potential revolutionize current road transportation systems with respect vehicle safety, efficiency, and travel experience. This paper puts the first effort on applying network coding in cooperative V2X communication environments improve bandwidth efficiency enhance data service performance. Specifically, we investigate new arising challenges network-coding-assisted dissemination by considering both...