We introduce a new scheme of buffer management to handle packet queues in Mobile Ad hoc Networks (MANETs) for fixed and mobile nodes. In this scheme, we try to achieve efficient queuing in the buffer of a centrally communicating MANET node through an active queue management strategy by assigning dynamic buffer space to all neighboring nodes in proportion to the number of packets received from neighbors and hence controlling packet drop probabilities. Our simulation study reveals that the prop...

The reputation-based trust mechanism is a way to assess the trustworthiness of offered services, based on the feedback obtained from their users. In the absence of appropriate safeguards, service users can still manipulate this feedback. Auction mechanisms have already addressed the problem of manipulation by market-trading participants. When auction mechanisms are applied to trust systems, their interaction with the trust systems and associated overhead need to be quantitatively evaluated. T...

Reality over Web (RoW) is a novel concept, where a window on the web corresponds to a window onto a real space. Once the correspondence is established, users should be able to interact or manipulate the objects or people in the real space through the web window. In this paper, we introduce the RoW concept and highlight the principles that govern its design and implementation. A system architecture for realizing the RoW concept is described along with a proof-of-concept prototype that implemen...

Low-Density Parity-Check (LDPC) codes are powerful error correcting codes. LDPC decoders have been implemented as efficient error correction codes on dedicated VLSI hardware architectures in recent years. This paper describes two strategies to parallelize min-sum decoding of irregular LDPC codes. The first implements min-sum LDPC decoders on multicore platforms using OpenMP, while the other uses the Compute Unified Device Architecture (CUDA) to parallelize LDPC decoding on Graphics Processing...

The API interfaces provided by CUDA help programmers to get high performance CUDA applications in GPU, but they cannot support most I/O operations in device codes. The characteristics of CUDA’s mapped memory are used here to create a dynamic polling service model in the host which can satisfy most I/O functions such as read/write file and "printf". The technique to implement these I/O functions has some influence on the performance of the original applications. These functions quick...

Intermediate spoofing can impact most off-the-shelf Global Navigation Satellite Systems (GNSS) receivers, therefore low cost detection of such spoofing is very important to protect the reliability of the GNSS receivers used in critical safety and financial applications. This paper presents two strategies to analyze attacks by intermediate spoofing attackers to identify the weaknesses of such attacks. The analyses lead to a code and carrier phase consistency detection method with simulation re...

With the explosive growth of commercial logos, high quality logo images are needed for training logo detection or recognition systems, especially for famous logos or new commercial brands. This paper focuses on automatic collecting representative logo images from the internet without any human labeling or seed images. We propose multiple dictionary invariant sparse coding to solve this problem. This work can automatically provide prototypes, representative images, or weak labeled training ima...

Performance predictions for database queries allow service providers to determine what resources are needed to ensure their performance. Cost-based or rule-based approaches have been proposed to optimize database query execution plans. However, Virtual Machine (VM)-based database services have little or no sharing of resources or interactions between applications hosted on shared infrastructures. Neither providers nor users have the right combination of visibility/access/expertise to perform ...

Feature selection is a key task in statistical pattern recognition. Most feature selection algorithms have been proposed based on specific objective functions which are usually intuitively reasonable but can sometimes be far from the more basic objectives of the feature selection. This paper describes how to select features such that the basic objectives, e.g., classification or clustering accuracies, can be optimized in a more direct way. The analysis requires that the contribution of each f...

In the upcoming exa-scale era, the exploitation of data locality in parallel programs is very important because it benefits both program performance and energy efficiency. However, this is a hard topic for graph algorithms such as the Breadth First Search (BFS) due to the irregular data access patterns. This study analyzes the exploitation of data locality in the BFS and its impact on the energy efficiency with the Codelet fine-grain dataflow-inspired execution model. The Codelet Model more e...