Kyoung-Don Kang

Learn More
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 is desirable to execute transactions within their deadlines, i.e., before the real-world status changes, using fresh (temporally consistent) data. However, meeting these(More)
The demand for real-time database services has been increasing recently. Examples include sensor data fusion, decision support, web information services, e-commerce, online trading, and data-intensive smart spaces. In these applications, it is desirable to execute transactions within their deadlines using temporally consistent data. Due to the high service(More)
The demand for real-time database services has been increasing recently. Examples include sensor data fusion, stock trading, decision support, web information services, and data-intensive smart spaces. In these systems, it is essential to execute transactions in time using fresh (temporally consistent) data. Due to the high service demand, many transactions(More)
Due to the relatively high node density and source-to-sink communication pattern, wireless sensor networks (WSNs) are subject to congestion and packet losses. Further, the availability of low-cost hardware, such as Cyclops cameras, is promoting wireless multimedia sensing to support, for example, visual surveillance. As a result, congestion control is(More)
Localization is a fundamental operation in mobile and self-configuring networks such as sensor networks and mobile ad hoc networks. For example, sensor location is often critical for data interpretation; moreover, network protocols, such as geographic routing and geographic storage require individual sensors to know their coordinates. Existing research(More)
Most existing real-time protocols for sensor data dissemination use packet scheduling schemes to prioritize packets according to their deadlines. However, packet prioritization by itself cannot completely support real-time data dissemination requirements. In this paper, we propose new just-in-time scheduling (JiTS) algorithms that take advantage of the(More)
GPGPUs (General Purpose Graphic Processing Units) provide massive computational power. However, applying GPGPU technology to real-time computing is challenging due to the non-preemptive nature of GPGPUs. Especially, a job running in a GPGPU or a data copy between a GPGPU and CPU is non-preemptive. As a result, a high priority job arriving in the middle of a(More)
Providing quality-of-service guarantees for data services in a distributed environment is a challenging task. The presence of multiple sites in distributed environments raises issues that are not present in centralized systems. The transaction workloads in distributed real-time databases may not be balanced and the transaction access patterns may be(More)
In this paper, we consider the security of geographic routing (GR) protocols. In GR, neighbors exchange their location information. Based on this information, a node forwards packets to the neighbor that is closest to the destination. Although GR is widely used in ad hoc and wireless sensor networks, its security has rarely been studied; there are a number(More)
It is challenging to process transactions in a timely fashion using fresh data, e.g., current stock prices, since database workloads may considerably vary due to dynamic data/resource contention. Further, transaction timeliness and data freshness requirements may compete for system resources. In this paper, we propose a novel feedback control model to(More)