Abstract: Shoreline erosion problems caused by global warming and sea level rising may result in losing of land areas, so it should be examined regularly to reduce possible negative impacts. Initially in this study, three sets of survey images obtained from the years of 1990, 2001, and 2010, respectively, are digitalized by using graphical software to establish the spatial coordinates of six major beaches around the island of Taiwan. Then, by overlaying the known multi-period images, the change of shoreline can be observed from their distribution of coordinates. In addition, the neural network approximation is used to develop a model for predicting shoreline variation in the years of 2015 and 2020. The comparison results show that there is no significant change of total sandy area for all beaches in the three different periods. However, the prediction results show that two beaches may exhibit an increasing of total sandy areas under a statistical 95% confidence interval. The proposed method adopted in this study may be applicable to other shorelines of interest around the world.
Abstract: P2P Networks are highly dynamic structures since
their nodes – peer users keep joining and leaving continuously. In the
paper, we study the effects of network change rates on query routing
efficiency. First we describe some background and an abstract system
model. The chosen routing technique makes use of cached metadata
from previous answer messages and also employs a mechanism for
broken path detection and metadata maintenance. Several metrics are
used to show that the protocol behaves quite well even with high rate
of node departures, but above a certain threshold it literally breaks
down and exhibits considerable efficiency degradation.
Abstract: Functional gastrointestinal disorders affect millions of people spread all age regardless of race and sex. There are, however, rare diagnostic methods for the functional gastrointestinal disorders because functional disorders show no evidence of organic and physical causes. Our research group identified recently that the gastrointestinal tract well in the patients with the functional gastrointestinal disorders becomes more rigid than healthy people when palpating the abdominal regions overlaying the gastrointestinal tract. Aim of this study is, therefore, to develop a diagnostic system for the functional gastrointestinal disorders based on ultrasound technique, which can quantify the characteristic above related to the rigidity of the gastrointestinal tract well. Ultrasound system was designed. The system consisted of transmitter, ultrasonic transducer, receiver, TGC, and CPLD, and verified via a phantom test. For the phantom test, ten soft-tissue specimens were harvested from porcine. Five of them were then treated chemically to mimic a rigid condition of gastrointestinal tract well, which was induced by functional gastrointestinal disorders. Additionally, the specimens were tested mechanically to identify if the mimic was reasonable. The customized ultrasound system was finally verified through application to human subjects with/without functional gastrointestinal disorders (Normal and Patient Groups). It was identified from the mechanical test that the chemically treated specimens were more rigid than normal specimen. This finding was favorably compared with the result obtained from the phantom test. The phantom test also showed that ultrasound system well described the specimen geometric characteristics and detected an alteration in the specimens. The maximum amplitude of the ultrasonic reflective signal in the rigid specimens (0.2±0.1Vp-p) at the interface between the fat and muscle layers was explicitly higher than that in the normal specimens (0.1±0.0Vp-p). Clinical tests using our customized ultrasound system for human subject showed that the maximum amplitudes of the ultrasonic reflective signals near to the gastrointestinal tract well for the patient group (2.6±0.3Vp-p) were generally higher than those in normal group (0.1±0.2Vp-p). Here, maximum reflective signals was appeared at 20mm depth approximately from abdominal skin for all human subjects, corresponding to the location of the boundary layer close to gastrointestinal tract well. These results suggest that newly designed diagnostic system based on ultrasound technique may diagnose enough the functional gastrointestinal disorders.
Abstract: There are various overlay structures that provide
efficient and scalable solutions for point and range query in a peer-topeer
network. Overlay structure based on m-Binary Search Tree
(BST) is one such popular technique. It deals with the division of the
tree into different key intervals and then assigning the key intervals to
a BST. The popularity of the BST makes this overlay structure
vulnerable to different kinds of attacks. Here we present four such
possible attacks namely index poisoning attack, eclipse attack,
pollution attack and syn flooding attack. The functionality of BST is
affected by these attacks. We also provide different security
techniques that can be applied against these attacks.
Abstract: Toxoplasma gondii is an intracellular parasite capable
of infecting all nucleated cells in a diverse array of species.
Toxoplasma plaque assay have been described using Bacto Agar.
Because of its experimental advantages carboxymethyl cellulose
overlay, medium viscosity was choosing and the aim of this work
was to develop alternative method for formation of T. gondii plaques.
Tachyzoites were inoculated onto monolayers of Vero cells and
cultured at 37° C under 5 % CO2. The cultures were followed up by
microscopy inspection. Small plaques were visible by naphtol blue
stain 4 days after infection. Larger plaques could be observed by day
10 of culture. The carboxymethyl cellulose is a cheap reagent and the
methodology is easier, faster than assays under agar overlay. This is
the first description of the carboxymethyl cellulose overlay use for
obtaining the formation of T. gondii plaques and may be useful in
consequent obtaining tachyzoites for detailed studies.
Abstract: The disaster from functional gastrointestinal disorders has detrimental impact on the quality of life of the effected population and imposes a tremendous social and economic burden. There are, however, rare diagnostic methods for the functional gastrointestinal disorders. Our research group identified recently that the gastrointestinal tract well in the patients with the functional gastrointestinal disorders becomes more rigid than healthy people when palpating the abdominal regions overlaying the gastrointestinal tract. Objective of current study is, therefore, identify feasibility of a diagnostic system for the functional gastrointestinal disorders based on ultrasound technique, which can quantify the characteristics above. Two-dimensional finite difference (FD) models (one normal and two rigid model) were developed to analyze the reflective characteristic (displacement) on each soft-tissue layer responded after application of ultrasound signals. The FD analysis was then based on elastic ultrasound theory. Validation of the model was performed via comparison of the characteristic of the ultrasonic responses predicted by FD analysis with that determined from the actual specimens for the normal and rigid conditions. Based on the results from FD analysis, ultrasound system for diagnosis of the functional gastrointestinal disorders was developed and clinically tested via application of it to 40 human subjects with/without functional gastrointestinal disorders who were assigned to Normal and Patient Groups. The FD models were favorably validated. The results from FD analysis showed that the maximum displacement amplitude in the rigid models (0.12 and 0.16) at the interface between the fat and muscle layers was explicitly less than that in the normal model (0.29). The results from actual specimens showed that the maximum amplitude of the ultrasonic reflective signal in the rigid models (0.2±0.1Vp-p) at the interface between the fat and muscle layers was explicitly higher than that in the normal model (0.1±0.2 Vp-p). Clinical tests using our customized ultrasound system showed that the maximum amplitudes of the ultrasonic reflective signals near to the gastrointestinal tract well for the patient group (2.6±0.3 Vp-p) were generally higher than those in normal group (0.1±0.2 Vp-p). Here, maximum reflective signals was appeared at 20mm depth approximately from abdominal skin for all human subjects, corresponding to the location of the boundary layer close to gastrointestinal tract well. These findings suggest that our customized ultrasound system using the ultrasonic reflective signal may be helpful to the diagnosis of the functional gastrointestinal disorders.
Abstract: High purity hydrogen and the valuable by-product of carbon nanotubes (CNTs) can be produced by the methane catalytic decomposition. The methane conversion and the performance of CNTs were determined by the choices of catalysts and the condition of decomposition reaction. In this paper, Ni/MgO and Ni/O-D (oxidized diamond) catalysts were prepared by wetness impregnation method. The effects of reaction temperature and space velocity of methane on the methane conversion were investigated in a fixed-bed. The surface area, structure and micrography were characterized with BET, XPS, SEM, EDS technology. The results showed that the conversion of methane was above 8% within 150 min (T=500) for 33Ni/O-D catalyst and higher than 25% within 120 min (T=650) for 41Ni/MgO catalyst. The initial conversion increased with the increasing temperature of the decomposition reaction, but their catalytic activities decreased rapidly while at too higher temperature. To decrease the space velocity of methane was propitious to promote the methane conversion, but not favor of the hydrogen yields. The appearance of carbon resulted from the methane decomposition lied on the support type and the condition of catalytic reaction. It presented as fiber shape on the surface of Ni/O-D at the relatively lower temperature such as 500 and 550, but as grain shape stacked on and overlayed on the surface of the metal nickel while at 650. The carbon fiber can form on the Ni/MgO surface at 650 and the diameter of the carbon fiber increased with the decreasing space velocity.
Abstract: Multiparty voice over IP (MVoIP) systems allows a group of people to freely communicate each other via the internet, which have many applications such as online gaming, teleconferencing, online stock trading etc. Peertalk is a peer to peer multiparty voice over IP system (MVoIP) which is more feasible than existing approaches such as p2p overlay multicast and coupled distributed processing. Since the stream mixing and distribution are done by the peers, it is vulnerable to major security threats like nodes misbehavior, eavesdropping, Sybil attacks, Denial of Service (DoS), call tampering, Man in the Middle attacks etc. To thwart the security threats, a security framework called PEERTS (PEEred Reputed Trustworthy System for peertalk) is implemented so that efficient and secure communication can be carried out between peers.
Abstract: Among the numerous economic evaluation techniques currently available, Multi-criteria Spatial Analysis lends itself to solving localization problems of property complexes and, in particular, production plants. The methodology involves the use of Geographical Information Systems (GIS) and the mapping overlay technique, which overlaps the different information layers of a territory in order to obtain an overview of the parameters that characterize it. This first phase is used to detect possible settlement surfaces of a new agglomeration, subsequently selected through Analytic Hierarchy Process (AHP), so as to choose the best alternative. The result ensures the synthesis of a multidimensional profile that expresses both the quantitative and qualitative effects. Each criterion can be given a different weight.
Abstract: The overlay approach has been widely used by many service providers for Traffic Engineering (TE) in large Internet backbones. In the overlay approach, logical connections are set up between edge nodes to form a full mesh virtual network on top of the physical topology. IP routing is then run over the virtual network. Traffic engineering objectives are achieved through carefully routing logical connections over the physical links. Although the overlay approach has been implemented in many operational networks, it has a number of well-known scaling issues. This paper proposes a new approach to achieve traffic engineering without full-mesh overlaying with the help of integrated approach and equal subset split method. Traffic engineering needs to determine the optimal routing of traffic over the existing network infrastructure by efficiently allocating resource in order to optimize traffic performance on an IP network. Even though constraint-based routing [1] of Multi-Protocol Label Switching (MPLS) is developed to address this need, since it is not widely tested or debugged, Internet Service Providers (ISPs) resort to TE methods under Open Shortest Path First (OSPF), which is the most commonly used intra-domain routing protocol. Determining OSPF link weights for optimal network performance is an NP-hard problem. As it is not possible to solve this problem, we present a subset split method to improve the efficiency and performance by minimizing the maximum link utilization in the network via a small number of link weight modifications. The results of this method are compared against results of MPLS architecture [9] and other heuristic methods.
Abstract: With optimized bandwidth and latency discrepancy ratios, Node Gain Scores (NGSs) are determined and used as a basis for shaping the max-heap overlay. The NGSs - determined as the respective bandwidth-latency-products - govern the construction of max-heap-form overlays. Each NGS is earned as a synergy of discrepancy ratio of the bandwidth requested with respect to the estimated available bandwidth, and latency discrepancy ratio between the nodes and the source node. The tree leads to enhanceddelivery overlay multicasting – increasing packet delivery which could, otherwise, be hindered by induced packet loss occurring in other schemes not considering the synergy of these parameters on placing the nodes on the overlays. The NGS is a function of four main parameters – estimated available bandwidth, Ba; individual node's requested bandwidth, Br; proposed node latency to its prospective parent (Lp); and suggested best latency as advised by source node (Lb). Bandwidth discrepancy ratio (BDR) and latency discrepancy ratio (LDR) carry weights of α and (1,000 - α ) , respectively, with arbitrary chosen α ranging between 0 and 1,000 to ensure that the NGS values, used as node IDs, maintain a good possibility of uniqueness and balance between the most critical factor between the BDR and the LDR. A max-heap-form tree is constructed with assumption that all nodes possess NGS less than the source node. To maintain a sense of load balance, children of each level's siblings are evenly distributed such that a node can not accept a second child, and so on, until all its siblings able to do so, have already acquired the same number of children. That is so logically done from left to right in a conceptual overlay tree. The records of the pair-wise approximate available bandwidths as measured by a pathChirp scheme at individual nodes are maintained. Evaluation measures as compared to other schemes – Bandwidth Aware multicaSt architecturE (BASE), Tree Building Control Protocol (TBCP), and Host Multicast Tree Protocol (HMTP) - have been conducted. This new scheme generally performs better in terms of trade-off between packet delivery ratio; link stress; control overhead; and end-to-end delays.
Abstract: The survey and classification of the different security
attacks in structured peer-to-peer (P2P) overlay networks can be
useful to computer system designers, programmers, administrators,
and users. In this paper, we attempt to provide a taxonomy of
structured P2P overlay networks security attacks. We have specially
focused on the way these attacks can arise at each level of the
network. Moreover, we observed that most of the existing systems
such as Content Addressable Network (CAN), Chord, Pastry,
Tapestry, Kademlia, and Viceroy suffer from threats and vulnerability
which lead to disrupt and corrupt their functioning. We hope that our
survey constitutes a good help for who-s working on this area of
research.
Abstract: This study aimed at developing visualization tools for integrating CloudSat images and Water Vapor Satellite images. KML was used for integrating data from CloudSat Satellite and GMS-6 Water Vapor Satellite. CloudSat 2D images were transformed into 3D polygons in order to achieve 3D images. Before overlaying the images on Google Earth, GMS-6 water vapor satellite images had to be rescaled into linear images. Web service was developed using webMathematica. Shoreline from GMS-6 images was compared with shoreline from LandSat images on Google Earth for evaluation. The results showed that shoreline from GMS-6 images was highly matched with the shoreline in LandSat images from Google Earth. For CloudSat images, the visualizations were compared with GMS-6 images on Google Earth. The results showed that CloudSat and GMS-6 images were highly correlated.
Abstract: It is expected that ubiquitous era will come soon. A ubiquitous environment has features like peer-to-peer and nomadic environments. Such features can be represented by peer-to-peer systems and mobile ad-hoc networks (MANETs). The features of P2P systems and MANETs are similar, appealing for implementing P2P systems in MANET environment. It has been shown that, however, the performance of the P2P systems designed for wired networks do not perform satisfactorily in mobile ad-hoc environment. Subsequently, this paper proposes a method to improve P2P performance using cross-layer design and the goodness of a node as a peer. The proposed method uses routing metric as well as P2P metric to choose favorable peers to connect. It also utilizes proactive approach for distributing peer information. According to the simulation results, the proposed method provides higher query success rate, shorter query response time and less energy consumption by constructing an efficient overlay network.
Abstract: Recently, there have been considerable efforts towards the convergence between P2P and Grid computing in order to reach a solution that takes the best of both worlds by exploiting the advantages that each offers. Augmenting the peer-to-peer model to the services of the Grid promises to eliminate bottlenecks and ensure greater scalability, availability, and fault-tolerance. The Grid Information Service (GIS) directly influences quality of service for grid platforms. Most of the proposed solutions for decentralizing the GIS are based on completely flat overlays. The main contributions for this paper are: the investigation of a novel resource discovery framework for Grid implementations based on a hierarchy of structured peer-to-peer overlay networks, and introducing a discovery algorithm utilizing the proposed framework. Validation of the framework-s performance is done via simulation. Experimental results show that the proposed organization has the advantage of being scalable while providing fault-isolation, effective bandwidth utilization, and hierarchical access control. In addition, it will lead to a reliable, guaranteed sub-linear search which returns results within a bounded interval of time and with a smaller amount of generated traffic within each domain.
Abstract: Network layer multicast, i.e. IP multicast, even after
many years of research, development and standardization, is not
deployed in large scale due to both technical (e.g. upgrading of
routers) and political (e.g. policy making and negotiation) issues.
Researchers looked for alternatives and proposed application/overlay
multicast where multicast functions are handled by end hosts, not
network layer routers. Member hosts wishing to receive multicast
data form a multicast delivery tree. The intermediate hosts in the tree
act as routers also, i.e. they forward data to the lower hosts in the
tree. Unlike IP multicast, where a router cannot leave the tree until all
members below it leave, in overlay multicast any member can leave
the tree at any time thus disjoining the tree and disrupting the data
dissemination. All the disrupted hosts have to rejoin the tree. This
characteristic of the overlay multicast causes multicast tree unstable,
data loss and rejoin overhead. In this paper, we propose that each node
sets its leaving time from the tree and sends join request to a number
of nodes in the tree. The nodes in the tree will reject the request if
their leaving time is earlier than the requesting node otherwise they
will accept the request. The node can join at one of the accepting
nodes. This makes the tree more stable as the nodes will join the tree
according to their leaving time, earliest leaving time node being at the
leaf of the tree. Some intermediate nodes may not follow their leaving
time and leave earlier than their leaving time thus disrupting the tree.
For this, we propose a proactive recovery mechanism so that disrupted
nodes can rejoin the tree at predetermined nodes immediately. We
have shown by simulation that there is less overhead when joining
the multicast tree and the recovery time of the disrupted nodes is
much less than the previous works. Keywords
Abstract: Color printing proceeds with multiple halftone
separations overlay. Because of separation overlay misalignment in
printing, the percentage of different primary color combination may
vary and it will result in color shift. In traditional printing procedure
with AM halftone, every separation has different screening angle to
make the superposition pattern in a random style, which will reduce
the color shift. To evaluate the color shift of printing with hybrid
halftoning, we simulate printing procedure with halftone images
overlay and calculate the color difference between expected color and
color in different overlay misalignment configurations. The color
difference for hybrid halftone and AM halftone is very close. So the
color shift for hybrid halftone is acceptable with current color printing
procedure.