Abstract Nowadays, knowledge management is considering an essential part of organizations to use the expertise, and bright ideas to prepare and equip itself with a vision to foresee the future. The knowledge management has started to be the main entry to the governments. Many reasons for this development (i.e. emergence of information and communication technologies in the last decade, the emergence of knowledge worker, and the knowledge economy). Read More Read Less

Abstract The wood production is an activity of fundamental importance for Brazilian economy. Studies show that the illegality in wood production is around 80% of the total production. This illegal wood becomes legalized in its supply chain due to the failures in controlling and monitoring systems. This paper analyzes some computational problems existing in managing and monitoring the production process in Amazon Forest and identifies new requirements to create a traceability system more efficient and appropriate to the region’s characteristics. Read More Read Less

Abstract This paper addresses the Information Retrieval issues by today’s hierarchical systems such as file systems. They usually contain substantial amount of redundant items. Maintaining the structure becomes difficult when large amount of items exist and ambiguity occurs in the structure. In this study, a conceptual method is presented that replaces the “containment” principle involved in current systems by “membership” principle. The proposed Conceptual File Management (CFM) method allows a file to be accessed from multiple folders; furthermore, it keeps the current hierarchical structure with minor changes. CFM reduces the ambiguity and redundancy, therefore the quality of information retrieval is improved. A Conceptual File Manager based on the above-mentioned principle has been developed. Experiments show that it improves the quality of the system in terms of maintaining the structure and retrieving the desired items easier and faster based on users’ viewpoints. CFM is applicable to not only traditional file systems on computers, but also file systems on cell phones (and message storage systems), site maps in Web sites, Content Management Systems, taxonomies, and in general, classification based structures. Read More Read Less

Abstract It has been demonstrated through simulation and experimental studies that TCP protocol suffers from a significant drop of performance when communicating over wireless networks. In general, packets can be lost for three main reasons: 1) Congestion 2) Link failure due to node mobility, and 3) Losses due to transmission errors. However, TCP doesn’t distinguish between these three types of packet losses. It considers any packet loss as a sign of network congestion; and therefore triggers its exponential back off as a mean to control congestion. In this paper, we study the impact of providing TCP with explicit information extracted from the physical, link and network layers to make it possible to identify the cause of the packet loss. There are three information of interest to this study: maximum probability to drop a packet, signal strength of the wireless node, and explicit handover notification when the mobile node transits to a new access point. We show in the experimental section that by providing TCP sender with only the information regarding the queues states, the performance can be improved by 500% over a lossy wireless link (with 60% error rate). Read More Read Less