A content-based image retrieval system for outdoor ecology learning: a firefly watching system

[[abstract]]We devote to provide teachers and students with short-range wireless learning environment. The wireless learning platform consists of wireless handheld devices (PDA, notebook, etc.) carried by the guide and learners. A content-based image retrieval system (CBIR) is constructed to provide learner with required information using image recognition and wireless transmission technologies, such that the objective of outdoor ecology learning can be achieved. A firefly database is used as an instance to illustrate the operations of CBIR system. Instead of learning from textbook, a real firefly in natural environment can be observed and learned through digital camera and image recognition system. During the learning activity, the teacher can use this CBIR system to control the learning progress, evaluate the learning effects and provide necessary assistances to students in order to have a flourish learning environment.[[conferencetype]]國際[[conferencedate]]20040329~20040329[[conferencelocation]]Fukuoka, Japa

Congestion control of bluetooth radio system by piconet restructuring

[[abstract]]Bluetooth is a low-cost and short-range wireless communication technology. Two or more bluetooth devices connected form a piconet and two or more piconets connected form a scatternet through relay devices. Without the consideration of traffic flows, a scatternet may operate with serious congestion problem. Congestion problem can be resolved by either reduced traffic flows or increased bandwidth provision. In bluetooth, new piconet can be dynamically constructed to increase system bandwidth. However, as the number of piconet is increased, collision problem among piconets becomes a serious problem. The objective of this paper is to resolve the congestion problems in a scatternet through piconet restructuring which perform both flow analysis and distributed role-switching technique. Advantages of the proposed piconet restructuring mechanism includes the following: (1) the communication bottleneck can be released; (2) the communication path is shortened; (3) the transmission latency is reduced; and (4) the lifetime of piconets can be increased. Experimental results demonstrated that the proposed method could effectively increase the transmission efficient in each piconet and increase the performance of an entire scatternet.[[incitationindex]]SC

Mean Quantization-based Fragile Watermarking for Image Authentication

[[sponsorship]]資訊科學研究所,資訊科技創新研究中心[[note]]已出版;[SCI];有審查制度;具代表性[[note]]http://gateway.isiknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=Drexel&SrcApp=hagerty_opac&KeyRecord=0091-3286&DestApp=JCR&RQ=IF_CAT_BOXPLO

An efficient cluster-based multi-channel management protocol for wireless Ad Hoc networks

[[abstract]]In Ad Hoc networking, cluster-based communication protocol can reduce large amount of flooding packets in route establishment process. However, the 802.11 medium access control (MAC) protocol is not dedicated to cluster-based network architecture. Applying 802.11 MAC protocol to cluster-based network introduces problems of inefficient channel utilization in announcement traffic indication message (ATIM) and data sub-windows for gateway nodes, heavy channel contention in some channels, large power consumption of mobile hosts, and poor utilization of multi-channel resources. In this paper, we propose a MAC layer multi-channel management protocol which takes power saving issues into consideration in a cluster-based network topology. The proposed protocol aims at effective utilization of multi-channel bandwidth for data communications among mobile hosts. Features of the proposed protocol includes: (1) preserving the property of fair channel contention in original 802.11 protocol, (2) constructing a proper contention condition for mobile hosts, (3) reducing power consumption for idle mobile hosts, (4) reducing probability of collision and unnecessary power consumption due to heavy contention, and (5) decreasing the transmission delay of gateway node through proper management of inter-cluster traffic. Experimental results reveal that the proposed protocol has good performance in network throughputs, average transmission delay time and energy consumption.[[notice]]補正完畢[[incitationindex]]SC

Relay reduction and disjoint routes construction for scatternet over Bluetooth radio system

[[abstract]]Bluetooth is a new technology for low-cost, low-power, and short-range wireless communication. By constructing a piconet, Bluetooth device establishes link and communicates with other device in a master–slave manner. Relay is a Bluetooth device that joins two or more piconets and forwards data from one piconet to another, providing multi-hop (or inter-piconet) communication services. In a Bluetooth scatternet, the number of relays and the degree of each relay are factors that significantly affect the performance of entire network. Unnecessary relays raise the difficulty of scheduling, leading to frequent packet loss. Relay switching among several piconets in turns also creates guard time overhead and increases the transmission delay. This study presents an effective protocol that can dynamically adjust the network topology by reducing the unnecessary relays. An efficient scatternet environment thus can be constructed with characteristics of connected, high bandwidth utilization and low maintenance cost. Additionally, a routing protocol is developed to reduce the path length and generate two disjoint routes for any pair of source and destination devices located in different piconets. Experimental results demonstrate that the proposed protocols perform well in terms of route length, bandwidth consumption, and transmission delay.[[incitationindex]]SC

A Content-Based Image Retrieval System for Outdoor Ecology Learning: A Firefly Watching System

Abstract In this paper, we devote to provide teachers and students with short-range wireless learning environment. The wireless learning platform consists of wireless handheld devices (PDA, notebook, etc.

New fuzzy linear mapping technique for facial feature extraction and recognition

[[abstract]]Fast feature matching process and high recognition rates are two important issues in face recognition systems. In this paper, a fuzzy neural network based face recognition system which addresses on these two subjects is proposed. This face recognition system uses a fuzzy linear mapping (FLM) for feature extraction and a fuzzy neural network (FNN) for fuzzy feature matching. Experimental results show that the proposed face recognition system has two advantages. First, higher recognition rates are achieved in comparison with statistical feature extraction methods. Second, feature matching process using fuzzy neural network is faster than minimum distance classifier.[[fileno]]2030224030018[[department]]資訊工程學

Antihyperglycemic drugs use and new-onset atrial fibrillation: A population-based nested case control study.

Currently, the potential risk of atrial fibrillation associated with antihyperglycemic drug use has been a topic of considerable interest. However, it remains uncertain whether different classes of antihyperglycemic drug therapy are associated with the risk of atrial fibrillation risk. Here, we investigated the association between different classes of antihyperglycemic drugs and new-onset atrial fibrillation (NAF). A case-matched study was performed based on the National Health Insurance Program in Taiwan. Patients who had NAF were considered the NAF group and were matched in a 1:4 ratio with patients without NAF, who were assigned to the non-NAF group. Patients were matched according to sex, age, diabetes mellitus duration, index date, and Charlson Comorbidity Index score. We used multivariate logistic regression controlling for potential confounders to examine the association between different classes of antihyperglycemic drug use and the risk of NAF. Overall, we identified 2,882 cases and 11,528 matched controls for the study. After adjusting for sex, age, comorbidities, and concurrent medications, users of biguanides or thiazolidinediones were at a lower risk of developing NAF when compared with non-users (odds ratio [OR] 0.81, 95% confidence interval [CI] 0.71-0.95 and OR 0.72, 95% CI 0.63-0.83, respectively). In contrast, users of insulin were at a higher risk of developing NAF than were non-users (OR 1.19, 95% CI 1.06-1.35). Sulfonylureas, glinides, α-glucosidase inhibitors, and dipeptidyl peptidase-4 inhibitors were not associated with developing the risk of NAF. In conclusion, the use of biguanides or thiazolidinediones may be associated with a low risk of NAF, whereas insulin may be associated with a significant increase in the risk of NAF in patients with type 2 diabetes mellitus during long-term follow-up. Further prospective randomized studies should investigate which specific class of antihyperglycemic drug treatment for diabetes mellitus can prevent or postpone NAF