Two-way calling public CT2 telepoint system

In most current implementations of CT2 telepoint systems, only handset initiated calls are allowed. This paper describes a design to allow two-way calling for the CT2 public telepoint system with minimal modifications to the current CT2 infrastructure and the public switched telephone network (PSTN). The design makes use of centralized databases in the home location register (HLR) and visitor location registers (VLR) to track the location of handsets. This location information is stored in the VLR and HLR, and is used by the PSTN to route incoming calls destined for CT2 handsets to the appropriate CT2 telepoint base station (TBS). The TBS connect to the PSTN local exchanges (LE) through the integrated services digital network (ISDN) basic rate interfaces (BRI) for fast out-of-band signaling. We present simulation results of the system with the objective of determining where congestion might occur within the system and to understand the impact of the new implementation on the PSTN. The results indicate that the performance of the system will be limited by the VLR processing speed and the number of ISDN BRI's connecting the ISDN front end (IFE) to the PSTN     

Serum DDT and DDE levels in Singapore general population

Stimulation of afferents in the superior laryngeal nerve (SLN) leads to apnea and evokes reflexes in sympathetic neurons. It is not clear whether these reflexes are secondary to changes in the brainstem respiratory network or due directly to the afferent input on neurons belonging to central sympathetic pathways. To clarify this question, single thoracic preganglionic sympathetic neurons projecting into the cervical sympathetic trunk (CST) were classified as described previously and then tested for their responses to electrical stimulation of the superior laryngeal nerve (SLN) in chloralose-anesthetized, paralysed and artificially ventilated cats. SLN stimulation was performed with intensities sufficient to suppress central inspiratory activity detected by phrenic and recurrent laryngeal nerve recordings. Sympathetic neurons were tested under different levels of respiratory drive. Thirteen group I (putative muscle vasoconstrictor) neurons were mostly activated by SLN stimulation when respiratory drive was low, but depressed when it was high; this was due to the change in inspiration-related activity. Ten of eleven group II (putative cutaneous vasoconstrictor) neurons were depressed during SLN stimulation. This inhibition was independent of central respiratory drive. Inhibition also occurred in those neurons which predominantly discharged during postinspiration. Eight group III neurons which showed a discharge confined to inspiration were inhibited but mostly not silenced by SLN stimulation. Group IV (functionally unclassified) neurons either showed no response (n = 5) or were slightly inhibited (n = 2). The responses of group I neurons, but not the responses of group II and group III neurons, showed a significant positive correlation with those of systemic blood pressure. The observed responses corroborate the classification made previously. The results also demonstrate that the responses of sympathetic neurons to SLN stimulation are not merely due to the respiratory modulation of their activity, but rather consist of two components, one occurring independently of and the other secondary to, the changes in respiration.     

Parallel implementation of backpropagation neural networks on aheterogeneous array of transputers

This paper analyzes parallel implementation of the backpropagation training algorithm on a heterogeneous transputer network (i.e., transputers of different speed and memory) connected in a pipelined ring topology. Training-set parallelism is employed as the parallelizing paradigm for the backpropagation algorithm. It is shown through analysis that finding the optimal allocation of the training patterns amongst the processors to minimize the time for a training epoch is a mixed integer programming problem. Using mixed integer programming optimal pattern allocations for heterogeneous processor networks having a mixture of T805-20 (20 MHz) and T805-25 (25 MHz) transputers are theoretically found for two benchmark problems. The time for an epoch corresponding to the optimal pattern allocations is then obtained experimentally for the benchmark problems from the T805-20, TS805-25 heterogeneous networks. A Monte Carlo simulation study is carried out to statistically verify the optimality of the epoch time obtained from the mixed integer programming based allocations. In this study pattern allocations are randomly generated and the corresponding time for an epoch is experimentally obtained from the heterogeneous network. The mean and standard deviation for the epoch times from the random allocations are then compared with the optimal epoch time. The results show the optimal epoch time to be always lower than the mean epoch times by more than three standard deviations (3sigma) for all the sample sizes used in the study thus giving validity to the theoretical analysis.     

Robustness analysis of matrices with highly structureduncertainties

Lyapunov's method is used to analyze the robustness of system matrices with structured uncertainties. In particular, the 2-norm matrix measure is used to give less conservative stability results     

Universal one‐pot,one‐step synthesis of core–shell nanocomposites with self‐assembled tannic acid shell and their antibacterial and catalytic activities

Facile synthesis of metal@polymer nanocomposites were achieved using self‐assembled tannic acid (TA) shells without crosslinkers. The TA shell was assembled under mildly alkaline conditions in reaction time of 20 min under constant vortexing. Universal synthesis method was demonstrated by the synthesis of Ag@TA and Au@TA nanocomposites. We propose that the shell formation is due to TA undergoing oxidative self‐polymerization to poly(tannic acid) or a supramolecular aggregate of oxidized TA held together by charge transfer, hydrogen bond, and π–π interactions, similar to dopamine polymerization. Gibbs free energy calculations suggest that polymerization is energetically favorable. Synthesized Ag@TA exhibited antibacterial functionality with Escherichia coli minimum inhibitory concentration of 100 µg mL^?1 up to 48 h. The population of E. coli was also reduced by 99% within 5 h when incubated with 100 µg mL^?1 of Ag@TA nanocomposite. Au@TA also functions as a reduction catalyst. It reduces 4‐nitrophenol to 4‐aminophenol in the presence of NaBH₄ with a rate constant of k = 0.63 min^?1 μmol^?1. For comparison, using Au nanoparticles yields a rate constant of 0.14 min^?1 μmol^?1. The ease of synthesis renders the nanocomposites superior to others, with potential for large‐scale application. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45829.     

System Architectural Design for DeliveringVideo Mail over the World-Wide-Web

This paper examines the feasibility of providing multimedia mail,in particular video mail,on the existing World-Wide-Web platform.In this instance, the Web browser will act as the user agent of the mailing system.With this,users will be able to compose,send and read video mail directly on the Web, This paper examines a number of different system architectures which can be employed for the development of Video Mail.Based on the following key issues:portability of system,flexibility of system,Internet standard support,security and authentication,and message compression and storage,a final architecture was chosen to build Video Mail.The approach taken is that the system will be interfaced to the Web using a standard Hyper Text Transfer Protocol(HTTP) server and a standard Web brower.This is achieved through the use of Common Gateway Interface(CGI) programs and forms which reside in a standard HTTP server to provide the functionality of video mail,and a separaete mail server for the storage and management of messages.This will cause the HTTp server to behave as if it is an electronic mail system.The paper also addresses implementation issues pertaining to the use of CGI programs,mail server development,and video and auidio composition and playback.     

Aggregate Interference of Equidistant Cognitive Radios

In spite of spectrum sensing, aggregate interference from cognitive radios (CRs) remains as a deterring factor to the implementation of spectrum sharing strategies. We provide a systematic approach of evaluating the aggregate interference (I _aggr) experienced at a victim primary receiver (PR). In our approach, we model the received power versus distance relations between a primary transmitter (PT), PR, and CRs. CRs can spatially reuse a channel and thus two adjacent CRs are separated by the co-channel reuse distance (R). Our analytical framework differs from the existing ones in that we have formulated I _aggr in terms of R and sensing inaccuracy. Energy detector is assumed for the purpose of spectrum sensing. I _aggr is expressed explicitly as a function of the number of energy samples collected (N) and the threshold SNR level used for comparison (SNR _ε ). This allows us to assess their impacts on I _aggr. A numerical example is constructed based on the scenario of spectrum sharing between DTV broadcast and IEEE 802.22 Wireless Regional Area Network. Our analysis demonstrates the extents of which I _aggr can be restricted, by increasing R or sensing accuracy (either by increasing N or decreasing SNR _ε ), and the amount of increment required. Conditioned on the example scenario, the critical {N, SNR _ε , R} values that fulfill certain regulatory requirement are revealed.     

Synthesis of mass exchange network for batch processes—Part I: Utility targeting

Synthesis of optimal mass exchange network (MEN) for continuous processes based on Pinch Analysis has been rather well established. In contrast, very little work has been done on mass exchange network synthesis (MENS) for batch process systems. The batch process systems referred to in this work can be defined as processes which operate discontinuously and deliver the products in discrete amounts, with frequent starts and stops. There is a clear need to develop a MENS procedure for batch process systems which are industrially very common as well as important. Techniques developed in this paper for the batch MENS involved the first key steps in the synthesis task, i.e. setting the utility targets ahead of batch MEN design. The utility-targeting approach employs the vertical and horizontal cascading approaches in a newly developed tool, i.e. time-dependent composition interval table that has been adapted from heat exchange network synthesis for batch processes. Prior to MEN design, the targeting procedure establishes the minimum utility (solvent) and mass storage targets for a maximum mass recovery network. These targets are essential for network design and batch process rescheduling.     

Networked LQG control over unreliable channels

In this article, the linear quadratic Gaussian (LQG) optimal control problem for networked control systems when data is transmitted through a transmission control protocol (TCP)‐like network and both measurement and control packets are subject to random packet dropouts, is addressed for two cases. In the ?rst case, it is assumed that the control acknowledgment packets in TCP‐like protocols are always available, that is, they always reach the ?lter‐controller unit on time and without fail, and we propose how to design a linear optimal ‘hold‐input’ control law for this case. In the second problem, we assume the acknowledgement packets may go missing with a known probability. This case is known to be di?cult and the optimal control law would be nonlinear. Hence, we derive a suboptimal linear estimation‐control law instead. Simulation results are presented to demonstrate the effectiveness of the proposed approaches. Copyright © 2011 John Wiley & Sons, Ltd.     

Development,implementation, and analysis of direct integration offline programming method

Wire bond programming (WBP) consists of information required to drive a wire bond machine’s movement during the wire bonding process. Wire bond programs consist of three key components: material handling, bonding parameter, and bonding path instructions. Of the three components, the bonding path component requires effort and time the most to prepare, as the preparation of bond path is currently being carried out manually. The manual process is tedious and error prone. In comparison to a manual process, offline programming (OLP) of bonding path creation provides a much more reliable and a less tedious method as it is error proof. OLP can be categorized into two versions, mainly vendor specific OLP and direct integration offline programming (Di-OLP), which is presented in this paper. Vendor specific OLP utilizes bonding diagrams created by a computer-aided design program to generate wire bonding paths. Di-OLP on the other hand utilizes the numeric coordinate data extracted from the bonding diagram creation software to generate the bonding path component of the wire bond program. Di-OLP is a more flexible method as it has the potential to be adapted to different machine platforms. This paper explains the challenges in the implementation of Di-OLP. The effectiveness and efficiency of the program created by Di-OLP are evaluated as compared to a manual programming method. Final results indicate that the offline programming is more efficient as it greatly reduces the time required to create the bonding paths for wire bond programs as compared to the manual methodology.