A high-resolution PAC and BAC map of the SCA2 region

DNA sequence changes induced in the vermilion gene of Drosophila following in vivo treatment of postmeiotic male germ cells with vinyl carbamate (VCA), an etheno-adduct-forming carcinogen, are primarily deletions. With VCA, 65% (13/20) of the vermilion mutants isolated from crosses of NER+ (nucleotide excision repair) males with NER+ females and 40% (6/15) obtained from matings with NER- females were intra- or multi-locus deletions. Due to the insufficiently low mutagenic activity in NER+ genotypes of vinyl bromide (VB), another epsilon-adduct-forming carcinogen, vermilion mutants could only be isolated from crosses of VB-treated males with NER- females. Of 14 vermilion mutants induced by VB, three carried large deletions. Twenty-two of 23 base substitutions derived from either VCA or VB experiments fell into one of the four categories expected from epsilon-adducts: three vermilion mutants had GC-->AT transitions, five had AT-->GC transitions, 7 carried GC-->TA transversions, and 7 were AT-->TA transversions. In view of the similarities in the response of mouse and Drosophila germ lines to several classes of alkylating agents, a high incidence of deletions is predicted to occur as well in postmeiotic germ cells of mice exposed to these types of agents.     

Design and implementation of a practical semi‐lumped high power low‐pass filter

In this article, a compact, semi‐lumped and high power low‐pass filter in VHF band frequency is designed, fabricated, and measured. A semi‐lumped structure is used to decrease the size of the filter and improve its power handling. In high power analysis, all effects of critical points in distributed and lumped structures are considered. The experimental measurements show close agreement with the simulation results. This filter has a cut off frequency at 180 MHz, 0.02 dB ripples in pass band, return loss better than 21 dB in the pass band, 0.2 dB insertion losses, 1.6 dB/MHz shape factor, a 75% miniaturization against conventional structures with distributed elements, and wide out of band rejection. Moreover, 10 and 1 KW are the peak power and the average power handling of the filter. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:605–614, 2014.     

Two-dimensional energy-dependent models for the simulation ofsubstrate current in submicron MOSFET's

Two-dimensional energy-dependent substrate current models are described for NMOS and PMOS devices that have been developed using a multi-contour approach. The new models offer a significant improvement in the calculation of substrate current due to a more accurate calculation of the average energy as compared to the local-field model. The models are implemented in a post-processing manner by applying a one-dimensional energy conservation equation to each of many current contours in order to generate a two-dimensional representation of average energy and impact ionization rate, that is then integrated to calculate the substrate current. The new models have been compared to substrate current characteristics of a variety of NMOS and PMOS devices for a wide range of bias conditions and channel lengths, and very good agreement has been obtained with a single set of model parameters. An additional significance of this work is the enhancement of the standard multi-contour model by an energy-sink term that results in an improved prediction of the impact ionization process in PMOSFET's     

Microgrid dynamic responses enhancement using artificial neural network‐genetic algorithm for photovoltaic system and fuzzy controller for high wind speeds

The microgrid (MG) is described as an electrical network of small modular distributed generation, energy storage devices and controllable loads. In order to maximize the output of solar arrays, maximum power point tracking (MPPT) technique is used by artificial neural network (ANN), and also, control of turbine output power in high wind speeds is proposed using pitch angle control technic by fuzzy logic. To track the maximum power point (MPP) in the photovoltaic (PV), the proposed ANN is trained by the genetic algorithm (GA). In other word, the data are optimized by GA, and then these optimum values are used in ANN. The simulation results show that the ANN‐GA in comparison with the conventional algorithms with high accuracy can track the peak power point under different insolation conditions and meet the load demand with less fluctuation around the MPP; also it can increase convergence speed to achieve MPP. Moreover, pitch angle controller based on fuzzy logic with wind speed and active power as inputs that have faster responses which leads to have flatter power curves enhances the dynamic responses of wind turbine. The models are developed and applied in Matlab/Simulink. Copyright © 2015 John Wiley & Sons, Ltd.     

Design,implementation and performance evaluation of a proactive overload control mechanism for networks of SIP servers

The extent and diversity of systems, provided by IP networks, have made various technologies approach integrating different types of access networks and convert to the next generation network (NGN). The session initiation protocol (SIP) with respect to facilities such as being in text form, end-to-end connection, independence from the type of transmitted data, and support various forms of transmission, is an appropriate choice for signalling protocol in order to make connection between two IP network users. These advantages have made SIP be considered as a signalling protocol in IP multimedia subsystem (IMS), a proposed signalling platform for NGNs. Despite having all these advantages, SIP protocol lacks appropriate mechanism for addressing overload causing serious problems for SIP servers. SIP overload occurs when a SIP server does not have enough resources to process messages. The fact is that the performance of SIP servers is largely degraded during overload periods because of the retransmission mechanism of SIP. In this paper, we propose an advanced mechanism, which is an improved method of the windows based overload control in RFC 6357. In the windows based overload control method, the window is used to limit the amount of message generated by SIP proxy server. A distributed adaptive window-based overload control algorithm, which does not use explicit feedback from the downstream server, is proposed. The number of confirmation messages is used as a measure of the downstream server load. Thus, the proposed algorithm does not impose any additional complexity or processing on the downstream server, which is overloaded, making it a robust approach. Our proposed algorithm is developed and implemented based on an open source proxy. The results of evaluation show that proposed method could maintain the throughput close to the theoretical throughput, practically and fairly. As we know, this is the only SIP overload control mechanism, which is implemented on a real platform without using explicit feedback.     

Thermionic emission model of electron gate current in submicronNMOSFETs

A thermionic emission model based on a non-Maxwellian electron energy distribution function for the electron gate current in NMOSFET's is described. The model uses hydrodynamic equations to describe more correctly the electron transport and gate injection phenomena in submicron devices. A generalized analytical function is used to describe the high-energy tail of the electron energy distribution function. Coefficients of this generalized function are determined by comparing simulated gate currents with the experimental data. This model also includes the self-consistent calculation of the tunneling component of the gate current by using the WKB approximation, and by using a more accurate representation of the oxide barrier by including the image potential. Good agreement with gate currents over a wide range of bias conditions for three different technological sets of devices are demonstrated by using a single set of coefficients     

A novel congestion control protocol with AQM support for IP-based networks

Multimedia services (Real-time and Non real-time) have different demands, including the need for high bandwidth and low delay, jitter and loss. TCP is a dominant protocol on the Internet. In order to have the best performance in TCP, the congestion window size must be set according to some parameters, since the TCP source is not aware of the window size. TCP emphasizes more on reliability than timeliness, so TCP is not suitable for real-time traffic. In this paper an active Queue management support TCP (QTCP) model is presented. Source rate is regulated based on the feedback which is received from intermediate routers. Furthermore, in order to satisfy the requirements of multimedia applications, a new Optimization Based active Queue management (OBQ) mechanism has been developed. OBQ calculates packet loss probabilities based on the queue length, packets priority and delay in routers and the results are sent to source, which can then regulate its sending rate. Simulation results indicate that the QTCP reduces packet loss and buffer size in intermediate nodes, improves network throughput and reduces delay.     

Centralized Key Management Scheme in Wireless Sensor Networks

Today, key management is widely recognized as an important aspect of security in wireless sensor networks. In these networks, sensor nodes can be either mobile or static. Therefore, supporting the mobility of the nodes can be regarded as a purpose of key management schemes. In our previous work, we presented a key management scheme that was more efficient with respect to security and connectivity compared to the other ones. In that scheme, it is assumed that the nodes are static. In this paper we are going to present a scheme that supports the mobility of the nodes and makes the initial scheme more flexible. The basic criterion for the evaluation of the scheme is the communication overhead. First, the nodes establish a secure link with the cluster heads and then establish a secure link among themselves with the help of the cluster heads. We have analyzed this scheme with regards to the communication overhead and we will compare it with the other schemes.     

Non‐Invasive High‐Throughput Metrology of Functionalized Graphene Sheets

The utilization of fluorescence quenching microscopy (FQM) for quick visualization of chemical functionalization in relatively large regions of graphene, grown via chemical vapor deposition (CVD), is discussed. Through reactive ion plasma etching, patterns of p‐type CVD‐grown graphene functionalized with fluorine are generated. 4‐(dicyanomethylene)‐2‐methyl‐6‐(4‐dimethylaminostyryl)‐4H‐pyran (DCM) is used as the fluorescent agent. The emission of DCM is quenched to a different extent by fluorinated and pristine graphene, which provides the fluorescence‐imaging contrast essential for this metrology. To probe the functionalized surface patterns with DCM, the dye is dispersed in polymethylmethacrylate (PMMA) then the graphene surface is coated, forming a 30‐nm‐thick DCM‐PMMA layer. Fluorescence images of dye‐coated graphene distinctly reveal the difference between the chemically treated and as‐grown regions. The pristine graphene quenches the DCM emission more efficiently than the fluorinated graphene. Therefore, the regions with pristine graphene appear darker on the fluorescence images than the regions with fluorinated graphene, enabling large‐scale mapping of the functionalized regions in CVD grown graphene sheets Due to its simplicity and consistent results, FQM is now poised for widespread adoption by graphene manufacturers as a basis for facile and high throughput metrology of large‐scale graphene sheets.     

Optimized Congestion Management Protocol for Healthcare Wireless Sensor Networks

The application of Wireless Sensor Networks (WSNs) in healthcare is dominant and fast growing. In healthcare WSN applications (HWSNs) such as medical emergencies, the network may encounter an unpredictable load which leads to congestion. Congestion problem which is common in any data network including WSN, leads to packet loss, increasing end-to-end delay and excessive energy consumption due to retransmission. In modern wireless biomedical sensor networks, increasing these two parameters for the packets that carry EKG signals may even result in the death of the patient. Furthermore, when congestion occurs, because of the packet loss, packet retransmission increases accordingly. The retransmission directly affects the lifetime of the nodes. In this paper, an Optimized Congestion management protocol is proposed for HWSNs when the patients are stationary. This protocol consists of two stages. In the first stage, a novel Active Queue Management (AQM) scheme is proposed to avoid congestion and provide quality of service (QoS). This scheme uses separate virtual queues on a single physical queue to store the input packets from each child node based on importance and priority of the source’s traffic. If the incoming packet is accepted, in the second stage, three mechanisms are used to control congestion. The proposed protocol detects congestion by a three-state machine and virtual queue status; it adjusts the child’s sending rate by an optimization function. We compare our proposed protocol with CCF, PCCP and backpressure algorithms using the OPNET simulator. Simulation results show that the proposed protocol is more efficient than CCF, PCCP and backpressure algorithms in terms of packet loss, energy efficiency, end-to-end delay and fairness.