Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Publication Type
Articles 1 - 4 of 4
Full-Text Articles in Computer Engineering
Faster Multidimensional Data Queries On Infrastructure Monitoring Systems, Yinghua Qin, Gheorghi Guzun
Faster Multidimensional Data Queries On Infrastructure Monitoring Systems, Yinghua Qin, Gheorghi Guzun
Faculty Research, Scholarly, and Creative Activity
The analytics in online performance monitoring systems have often been limited due to the query performance of large scale multidimensional data. In this paper, we introduce a faster query approach using the bit-sliced index (BSI). Our study covers multidimensional grouping and preference top-k queries with the BSI, algorithms design, time complexity evaluation, and the query time comparison on a real-time production performance monitoring system. Our research work extended the BSI algorithms to cover attributes filtering and multidimensional grouping. We evaluated the query time with the single attribute, multiple attributes, feature filtering, and multidimensional grouping. To compare with the existing prior …
Link Scheduling In Multi-Transmit-Receive Wireless Networks, Hong-Ning Dai, Soung Chang Liew, Liqun Fu
Link Scheduling In Multi-Transmit-Receive Wireless Networks, Hong-Ning Dai, Soung Chang Liew, Liqun Fu
Hong-Ning Dai
This paper investigates the problem of link scheduling to meet traffic demands with minimum airtime in a multitransmit-receive (MTR) wireless network. MTR networks are a new class of networks, in which each node can simultaneously transmit to a number of other nodes, or simultaneously receive from a number of other nodes. The MTR capability can be enabled by the use of multiple directional antennas or multiple channels. Potentially, MTR can boost the network capacity significantly. However, link scheduling that makes full use of the MTR capability must be in place before this can happen. We show that optimal link scheduling …
On Collision-Tolerant Transmission With Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu
On Collision-Tolerant Transmission With Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu
Hong-Ning Dai
The application of directional antennas in wireless networks brings numerous benefits, such as increased spatial reuse and mitigated interferences. Most MAC protocols with directional antennas are based on the RTS/CTS mechanism which works well in wireless networks using omni-directional antennas. However, RTS/CTS frames cannot mitigate the interfering nodes completely. Besides, they also contribute a lot to the performance overhead. This paper studies the problem from a new perspective. We analyze the transmission success probability under directional transmission and directional reception when the antenna beamwidth is quite narrow. Motivated by the analytical results, we design a lightweight MAC protocol without RTS/CTS …
On The Capacity Of Multi-Channel Wireless Networks Using Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Raymond Chi-Wing Wong, Min-You Wu
On The Capacity Of Multi-Channel Wireless Networks Using Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Raymond Chi-Wing Wong, Min-You Wu
Hong-Ning Dai
The capacity of wireless ad hoc networks is affected by two key factors: the interference among concurrent transmissions and the number of simultaneous transmissions on a single interface. Recent studies found that using multiple channels can separate concurrent transmissions and greatly improve network throughput. However, those studies only consider that wireless nodes are equipped with only omnidirectional antennas, which cause high collisions. On the other hand, some researchers found that directional antennas bring more benefits such as reduced interference and increased spatial reuse compared with omnidirectional antennas. But, they only focused on a single-channel network which only allows finite concurrent …