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Background: Pancreatic cancers are the common digestive system tumors with poor prognosis and due to its late diagnosis, surgical resection does not remain a viable treatment option in about 80% of patients. Amongst different treatment options, radioactive 125I seed implantation therapy has also emerged as a good alternative in non-resectable pancreatic cancer patients.Purpose: The present review describes the efficacy and safety of iodine-125 seed implantation in unresectable pancreatic cancers in preclinical and clinical studies.Results: In this technique, small radioactive particles are implanted inside the tumor cells to produce the sustain effects. Due to the short radial distance of these radiations, there is a selective and efficient killing of cancer cells without any significant injury to the neighboring cells. Amongst the different methods for implanting 125I seeds in the pancreatic tissues, CT scan or ultrasound-guided percutaneous seed implantation is preferred as it offers shorter operative time, lesser bleeding, early recovery, lesser complications, and low medical costs. The clinical studies have shown that radioactive 125I seed implantation is a good option for the management of local tumor growth, pain palliation, and improvement in the life span of patients suffering from unresectable pancreatic cancer.Conclusion: It may be employed either alone or in combination with cryotherapy, existing chemotherapy, bypass surgery or radiations to achieve the optimal results in these patients. Nevertheless, there is a need to formulate a uniform dose and procedure to achieve homogeneity and develop references for clinical practices.

An efficient protocol for the synthesis of 2-arylsulfonyl quinolines has been developed via a metal-free catalyzed cross-coupling reaction of chloroquinoline with sodium arylsulfinates in moderate-to-good yields under microwave irradiation. The reactions proceed with a wide range of substrates with good functional group tolerance.

This paper presents network coding based reliable disjoint and braided multipath routing (NC-RMR ) for sensor networks, which forms multipath by hop-by-hop method and only maintains local path information of each node without establishing end-to-end paths. Neighbors of each local node are divided into groups according to their hops to sink nodes to improve the network load balancing. For further performance improvement of NC-RMR with disjoint multipath model, local nodes select their own backup nodes in neighbor nodes to form additional logical paths, which implement a braided multipath model. Security advantages of NC-RMR with multipath and network coding mechanisms are analyzed. Analytical and simulation results prove that braided multipath routing model has better performance over disjoint model, and NC-RMR protocol can reduce the required number of transmission paths, ensure load balance of sensor network system, reduce the energy consumption of nodes.

This paper presents a new scheduling method for a flexible manufacturing system (FMS) in a Petri net framework. Petri nets can concisely model multiple lot sizes for each job, the strict precedence constraint, multiple kinds of resources, and concurrent activities. To decrease the likelihood of rejecting the critical markings, our algorithm adopts an improved checking method for previous generated marking. To reduce the computation complexity, an elaborate scheme is applied, which performs A* search locally and backtracking search globally in the reachability graph of the Petri net. Some numerical experiments are carried out to demonstrate usefulness of the algorithm.

Motivated by the problem of simplifying the manual operation of the composition process, we propose an approach to automatically compose available Web services to fulfill user’s goal based on the assumption that there are a set of alternative Web services with similar functionality and different QoS properties. A formal model (i.e. semantic links matrix, SLM for short) is proposed to store semantic links values for the Web services with semantic relationship and QoS of Web services. The SLM provides a search place for a backward-search planning algorithm, at the same time; the QoS criteria make a rational and effective decision among a number of similar Web services. The function and some properties of the algorithm are analyzed. The approach can improve the correctness and flexibility for Web services composition and satisfy the local QoS attribute.

This paper proposes and evaluates a hybrid search strategy and its application to flexible manufacturing system (FMS) scheduling in a Petri net framework. Petri nets can concisely model multiple lot sizes for each job, the strict precedence constraint, multiple kinds of resources, and concurrent activities. To cope with the complexities for FMS scheduling, this paper presents a hybrid heuristic search strategy, which combines the heuristic A* strategy with the DF strategy based on the execution of the Petri nets. The search scheme can invoke quicker termination conditions, and the quality of the search result is controllable. To demonstrate this, the scheduling results are derived and evaluated through a simple FMS with multiple lot sizes for each job. The algorithm is also applied to a set of randomly generated more complex FMSs with such characteristics as limited buffer sizes, multiple resources, and alternative routings.

It is difficult to give an accurate judgement of whether the traffic model fit the actual traffic. The traditional method is to compare the Hurst parameter, data histogram and autocorrelation function. The method of comparing Hurst parameter cannot give exact results and judgement. The method of comparing data histogram and autocorrelation only gives a qualitative judgement. Based on linear discriminant analysis we proposed a novel arithmetic. Utilizing this arithmetic we analysed some sets of data with large and little differences. We also analysed some sets of data generated by network simulator. The analysis result is accurate. Comparing with traditional method, this arithmetic is useful and can conveniently give an accurate judgement for complex network traffic trace. Copyright © 2005 John Wiley & Sons, Ltd.

It is not a simple and trivial work to set up an appropriate network traffic model. A fractional Alpha model is proposed in this paper and two proofs based on flow and session level, respectively, are given. Based on this model, the lower bound for the residual of the queueing distribution is deduced. Comparing the residual distribution function (RDF) based on our model with it based on other models, we find our formula matches the real RDF better. Based on this formula, we can predict the need for forwarding performance. Then a novel QoS routing algorithm based on this prediction is proposed. Last we demonstrate a simple example to denote how our algorithm can effectively improve the utility of bandwidth and amount of traffic and guarantee QoS.

As a NP-Complete problem, multicast routing with delay constraint is a research difficulty in routing problem. Tabu Search is artificial intelligence algorithm, which is an extension of local search algorithm and has simple realization and well properties. In this paper, an efficient algorithm based on Tabu Search for Delay-Constrained Low-Cost Multicast Routing is proposed to solve delay-constrained multicast routing problem. This problem is known to be NP-Complete. The proposed heuristic algorithm makes use of the characteristics of flexible memory function and tabu rule in TS algorithm, generates neighborhood structure base on 'paths-switching' operations, and finds multicast tree satisfying constraint. A large number of simulations demonstrate that the algorithm performs excellent performance of cost, rapid convergence and stable performance of delay.

Urban traffic systems are usually complex systems which require dedicated modeling methodologies. In this paper, the "traffic flows" in the urban traffic systems is modeled as continuous variable dynamic systems (CVDS) and the "decision maker + traffic lights" of the traffic systems is modeled as discrete event dynamic systems (DEDS). So the entire urban traffic system can be modeled in the unified hybrid frame. Based on the unified hybrid frame, we propose a candidate hybrid model of extended fluid stochastic Petri net (EFSPN) with rule-based transitions for urban traffic systems. A simple example of urban traffic system is also presented to illustrate the modeling approach.

Multicast can bring many attractive multimedia applications to network service and save the bandwidth. In the paper we address the issue of multicast support for mobile host using mobile IPv6 (MIPv6). MIPv6 offers two basic multicast methods for mobile host called bi-direction tunneling (BT) and remote subscription (RS), but each one has its complementary advantages and limitations. Firstly, the operations of BT and RS were analyzed in detail based on MIPv6. Then a multicast simulation model for mobile host was designed based on the mesh random network. Finally the cost performance and the delay characteristic of RS and BT were analyzed by using the random model. We also drew a conclusion that RS is more suitable for multicast than BT when the network resource optimization and the end-to-end delay were mainly considered for multicast communication

Many industrial systems are governed by discrete state digital controllers, whose internal states interact mutually with the value of some continuous physical quantities. We model, continuous quantities of industrial systems and their mutual interaction with the systems' discrete part by using two formalisms of Petri nets: first order and second order fluid stochastic Petri net (FO-FSPN and SO-FSPN). Simulative and numerical methods are used to analyze these models. As an example, an industrial mixing tank with digital controllers is modeled. The continuous physical quantities (fluid level) in the tank are calculated for both FO-FSPN and SO-FSPN models. Lastly, the benefits and limitations of each approach are discussed.

IP routing lookup schemes using single-step TCAM used in core routers demand entries being sorted according to prefix lengths in descending order relative to TCAM addresses. The sorting operations related to addresses have disadvantageous affections to the entry updating speed and lookup continuity. This paper provides a novel IPv4/IPv6 dual-stack routing lookup method based on BSPL (bi-search on prefix length), which using multi-step TCAM pipelining based on bi-search on prefix length. Its outstanding advantages include that no entry sorting is needed, lookup speed is high, entry updating is completed fast with pipelining, and lookup continuity is enhanced. It satisfies wire-speed (48B-packet) forwarding of OC-768 (40Gbps) interfaces of IPv4/IPv6 dual-stack core routers.