目的 探讨CD25单抗在无血缘关系造血干细胞移植（UHSCT）中对干细胞植入和移植物抗宿主病（GVHD）的作用。方法 27例UHCST中，移植后1、4d给予CD25单抗1mg/kg。结果 27例中，除1例早期死亡外，26例患者造血全部重建。17例发生急性GVHD，其中Ⅱ度以上急性GVHD6例（23％）。复发3例，严重感染3例。26例可评价患者中，19例无病生存（73％）。结论 CD25单抗在UHSCT中对保证干细胞植入和预防GVHD有肯定的作用，白血病复发并不增加。此研究为UHCST和HLA不合的造血干细胞移植提供一个可选择的途径。

The migration to wireless network from wired network has been a global trend in the past few decades. The mobility and scalability brought by wireless network made it possible in many applications. Among all the contemporary wireless networks, Mobile Ad hoc NETwork (MANET) is one of the most important and unique applications. On the contrary to traditional network architecture, MANET does not require a fixed network infrastructure; every single node works as both a transmitter and a receiver. Nodes communicate directly with each other when they are both within the same communication range. Otherwise, they rely on their neighbors to relay messages. The self-configuring ability of nodes in MANET made it popular among critical mission applications like military use or emergency recovery. However, the open medium and wide distribution of nodes make MANET vulnerable to malicious attackers. In this case, it is crucial to develop efficient intrusion-detection mechanisms to protect MANET from attacks. With the improvements of the technology and cut in hardware costs, we are witnessing a current trend of expanding MANETs into industrial applications. To adjust to such trend, we strongly believe that it is vital to address its potential security issues. In this paper, we propose and implement a new intrusion-detection system named Enhanced Adaptive ACKnowledgment (EAACK) specially designed for MANETs. Compared to contemporary approaches, EAACK demonstrates higher malicious-behavior-detection rates in certain circumstances while does not greatly affect the network performances.

EAACK—A Secure Intrusion-Detection System for MANETs

Mobile Ad Hoc Networks (MANETs) are generating a lot of interests due to 3G and 4G activities. The dynamic nature of these networks demands new set of network routing strategy protocols to be implemented in order to provide efficient end-to-end communication. Due to the diverse applications that use MANETs, such as battlefield, emergency services, and disaster discovery, MANETs offer many advantages to many organizations that need wireless roaming. For efficient and timely use, routing and synchronization are essential. Both are hot research topics in MANETs. This paper concentrates on routing, which is a challenging task and has seen a huge number of different strategies proposed, each claiming to provide an improvement over other strategies. These competing strategies make it quite difficult to determine which one may perform optimally under a number of different sets of network conditions as defined by their Quality of Service (QoS) offerings. This paper reviews some of the state-of-the-art and widely investigated MANET routing strategies in the literature. Moreover, a performance comparison of discussed routing protocol strategies is provided and suggestions are made to achieve improvement in performance of these protocols. This research is followed by presenting further research that will be pursued to define a radically most optimum set of strategies to satisfy different types of application domains.

Comparative review study of reactive and proactive routing protocols in MANETs

Summary Ad hoc networks are characterized by multi-hop wireless connectivity, frequently changing network topology and the need for efficient dynamic routing protocols plays an important role. We compare the performance of two prominent on-demand routing protocols for mobile ad hoc networks: Dynamic Source Routing (DSR), Ad Hoc Ondemand distance Vector Routing (AODV). A detailed simulation model with MAC and physical layer models is used to study the interlayer interactions and their performance implications. We demonstrate that even though DSR and AODV share similar on-demand behavior, the differences in the protocol mechanisms can lead to significant performance differentials. In this paper we examine two on demand routing protocols AODV and DSR based on packet delivery ratio, normalized routing load, normalized MAC load, average end to end delay by varying the number of sources, speed and pause time.

/pdf/performance-comparison-of-mobile-ad-hoc-network-routing-1gg050vrbm.pdf

Performance Comparison of Mobile Ad-hoc Network Routing Protocol

There has been a tremendous growth in the use of wireless communication in the past few decades Mobile Ad hoc NETwork (MANET) is one of the most important one among various wireless communication mechanisms In MANET, each node in a network performs as both a transmitter and a receiver They rely on each other to store and forward packets Its unique infrastructureless network and self-configuring capability makes it ideal for many mission critical applications, including military use and remote exploration However, these characteristics also make MANET vulnerable to passive and active attacks due to its open medium, changing topology and lack of centralized monitoring To address the new security challenges, Intrusion Detection System (IDS) is required to detect the malicious attackers before they can accomplish any significant damages to the network Many existing IDSs for MANETs are based upon Watchdog mechanism In this paper, we propose a new IDS called Enhanced Adaptive ACKnowledgement (EAACK) that solves four significant problems of Watchdog mechanism, which are ambiguous collisions, receiver collisions, limited transmission power and false misbehavior report We use Network Simulator 2 to simulate the proposed mechanism and compare the results with existing mechanisms

Detecting misbehaving nodes in MANETs

Mobile ad hoc networks(MANET) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self organize into arbitrary and temporary ad-hoc network topologies, allowing people and devices to seamlessly internet work in areas with no preexisting communication infrastructure e.g., disaster recovery environments. An ad-hoc network is not a new one, having been around in various forms for over 20 years. Traditionally, tactical networks have been the only communication networking application that followed the ad-hoc paradigm. Recently the introduction of new technologies such as Bluetooth, IEEE 802.11 and hyperlan are helping enable eventual commercial MANET deployments outside the military domain. These recent revolutions have been generating a renewed and growing interest in the research and development of MANET. To facilitate communication within the network a routing protocol is used to discover routes between nodes. The goal of the routing protocol is to have an efficient route establishment between a pair of nodes, so that messages can be delivered in a timely manner. Bandwidth and power constraints are the important factors to be considered in current wireless network because multi-hop ad-hoc wireless relies on each node in the network to act as a router and packet forwarder. This dependency places bandwidth, power computation demands on mobile host to be taken into account while choosing the protocol. Routing protocols used in wired network cannot be used for mobile ad-hoc networks because of node mobility. The ad-hoc routing protocols are divided into two classes: table driven and demand based. This paper reviews and discusses routing protocol belonging to each category.

Ad Hoc Mobile Wireless Networks Routing Protocols - A Review

Ad hoc networks are characterized by multihop wireless connectivity, frequently changing network topology and the need for efficient dynamic routing protocols plays an important role. We compare the performance of two prominent on-demand routing protocols for mobile ad hoc networks: Dynamic Source Routing (DSR), Ad Hoc On-demand distance Vector Routing (AODV). A detailed simulation model with MAC and physical layer models is used to study the interlayer interactions and their performance implications. We demonstrate that even though DSR and AODV share similar on-demand behavior, the differences in the protocol mechanisms can lead to significant performance differentials. In this paper we examine two on demand routing protocols AODV and DSR based on packet delivery ratio, normalized routing load, normalized MAC load, average end to end delay by varying the number of sources, speed and pause time.

/pdf/performance-comparison-of-two-on-demand-routing-protocols-t7qn4o8j8z.pdf

Performance Comparison of Two On-demand Routing Protocols for Ad-hoc Networks based on Random Way Point Mobility Model

Modern database management systems (DBMSs) expose hundreds of configuration knobs that collectively determine their runtime behavior. Those knobs control, for example, the amount of memory used for cache and the maximum number of concurrent reads. If the knobs are optimally configured, the database systems can achieve higher performance and efficiency. The traditional practice for manual DBMS tuning is where the database administrators (DBAs) use their expertise and manually experiment by changing individual knobs to understand their effectiveness on the entire workload. However, manual DBMS tuning is a daunting task even for expert DBAs because of the following reasons: (1) Complexity: Modern DBMSs have hundreds of interdependent configuration knobs, and most knobs take in continuous values. As a result, the configuration space for DBMS tuning is orders of magnitude larger than those of traditional systems (e.g., file systems) [8]. (2) Hardwaredependent: Different hardware might have different optimal configurations. e.g. a configuration that is good for SSD might not work for HDD [1]. (3) Workloaddependent: The optimal configuration for one application might be sub-optimal for another [19]. (4) DBMSdependent: Two DBMSs may use different names for the same knob [19]. (5) Inter-dependent: The knobs are also dependent of each other (configuring one knob could impact the other knobs). Moreover, different DBMSs use different internal structures, so optimal configurations are not generic across different DBMSs. As a result, recent research has focused on the automatic tuning of the configuration knobs.

G. Gopinath

Papers

Ad Hoc Mobile Wireless Networks Routing Protocols - A Review

Performance Comparison of Two On-demand Routing Protocols for Ad-hoc Networks based on Random Way Point Mobility Model

Comparing Black-Box Optimization Methods for Online DBMS Tuning