Application of fuzzy control algorithms for electric vehicle antilock braking/traction control systems

The application of fuzzy-based control strategies has gained enormous recognition as an approach for the rapid development of effective controllers for nonlinear time-variant systems. This paper describes the preliminary research and implementation of a fuzzy logic based controller to control the wheel slip for electric vehicle antilock braking systems (ABSs). As the dynamics of the braking systems are highly nonlinear and time variant, fuzzy control offers potential as an important tool for development of robust traction control. Simulation studies are employed to derive an initial rule base that is then tested on an experimental test facility representing the dynamics of a braking system. The test facility is composed of an induction machine load operating in the generating region. It is shown that the torque-slip characteristics of an induction motor provides a convenient platform for simulating a variety of tire/road /spl mu/-/spl sigma/ driving conditions, negating the initial requirement for skid-pan trials when developing algorithms. The fuzzy membership functions were subsequently refined by analysis of the data acquired from the test facility while simulating operation at a high coefficient of friction. The robustness of the fuzzy-logic slip regulator is further tested by applying the resulting controller over a wide range of operating conditions. The results indicate that ABS/traction control may substantially improve longitudinal performance and offer significant potential for optimal control of driven wheels, especially under icy conditions where classical ABS/traction control schemes are constrained to operate very conservatively.     

A Cross Layer Metric for Discovering Reliable Routes in Mobile Ad Hoc Networks

Host mobility in mobile ad hoc networks causes failure of wireless links between nodes and breaks all the routes that use these links. Consequently, route reconstructions are needed, which is one of the most critical problems for this type of wireless networks. The number of route reconstructions can be reduced if more reliable wireless links are used. Also by these links, stable clusters can be constructed as is needed in cluster based protocols. Reliable routing protocols for mobile ad hoc networks use many link reliability metrics for finding these links; four of the most commonly used are ??Link Expiration Time??, ??Probabilistic Link Reliable Time??, ??Link Packet Error Rate?? and ??Link Received Signal Strength??. It is shown that these metrics enhance the reliability and reduce the number of route reconstructions, but to the best of our knowledge there is no report that compare their efficiencies. In this paper, we make this comparison in different network conditions and discuss their optimal applications. Then, a new cross layer metric is proposed that combines the aforementioned metrics according to their efficiency by means of a unit weight function. Simulation results show that by using all these metrics, the number of route reconstructions is reduced, and for the proposed one the result is better than the others.     

Integrated Design of Undepressed Collector for Low Power Gyrotron

A 42 GHz, 200 kW continuous wave (CW) gyrotron, operating at TE₀₃ mode is under development for the electron cyclotron resonance plasma heating of the Indian TOKAMAK system. The gyrotron is made up of an undepressed collector. The undepressed collector is simple to design and cost effective. In this paper, a detailed design study of the undepressed collector for the 42 GHz gyrotron is presented. The EGUN code is used to analyze the spent electron beam trajectory for the maximum spread to reduce the power loading on the collector surface. To achieve wall loading ≤1 kW/cm², a collector with a length of 800 mm and a radius of 42.5 mm is designed. The design also includes the three magnet systems around the collector for maximum and uniform beam spread. The thermal and the structural analyses are done using the ANSYS code to optimize the collector structure and dimensions with tolerance.     

Induction of labor by intracervical prostaglandin gel and oxytocin infusion in primigravid women with unfavorable cervix

The rate of Cesarean Section for failed induction of labor and maternal and fetal compilations are high when labor is induced in a nulliparas women with an unripe cervix by amniotomy and oxytocin infusion. Prostaglandins (PG) in different forms have been used for ripening the cervix with an aim of reducing these problems. A prospective randomized trial was performed on one hundred primigravid women between 37 and 42 weeks of gestation with singleton pregnancy, cephalic presentation and unfavorable cervix (Modified Bishop Score < or = 5) in the department of Obstetrics & Gynaecology of Institute of Postgraduate Medicine & Research from 1st May 1996 to 30th April 1997. In this study the efficiency of prostaglandin E2 intracervical (PGE2 IC) gel in induction of labor in a group of primigravid women with unripe cervix was assessed and compared with another group with similar characteristics using oxytocin infusion and artificial rupture of membrane (ARM). The Modified Bishop Score (MBS), interval between IOL and onset of labor and the duration of labor after insertion of PGE2 gel was significantly different from those of oxytocin infusion group. But the Apgar Score at 1 & 5 min had shown no statistically significant difference. Any significant difference could also not be detected in the mode of delivery between the two induction group. The proportion of emergency Cesarean Section (CS) was high in the oxytocin infusion group than that of in the prostaglandin group. There was also no significant difference regarding the acceptability of both the induction methods.     

Impact of pilot project of Rural Maintenance Programme (RMP) on destitute women: CARE, Bangladesh

BACKGROUND: The rate of malnutrition among women in Bangladesh is high, but historically there has not been a specific program focusing on the improvement of the nutritional status of Bangladeshi women. OBJECTIVE: To observe changes in the nutritional status of destitute women of the Rural Maintenance Programme (RMP) by incorporating a health and nutrition intervention package with RMP ongoing activities. METHODS: An intervention study involving 1,275 poor destitute women was conducted from July 2004 to June 2005 in 17 districts in Bangladesh under two field offices, Mymensingh and Jessore, covering 8 and 9 districts, respectively. The respondents were divided into intervention, comparison, and control groups. All participants in the intervention and comparison groups were paid as part of the RMP and received weekly 30-minute nutrition interventions for 7 weeks in addition to routine training. The comparison group also received RMP training. The control group consisted of women with similar demographic characteristics to the intervention and comparison groups who did not receive pay or any intervention. The intervention was a unique combination of the three components of the UNICEF triangle model (food security, caring practices, and disease control). Data on socioeconomic and anthropometric characteristics, immunization, and vitamin A capsule intake were also collected with the use of a structured questionnaire. RESULTS: After the intervention, the mean body weight had significantly increased by 1,333 g in the intervention group and had decreased by 277 g in the control group and 147 g in the comparison group. The body mass index of women in the intervention group had also significantly increased at the end of the study (p < .001). There was a significant increase in the intake of iodized salt in the intervention group as well as increased immunization coverage in all groups. Intake of the first vitamin A capsule by children increased (from 60% to 97%) in the intervention group only. CONCLUSIONS: The nutrition pilot intervention was highly effective in improving the nutritional status of women in the RMP.     

Directional Diversity of Smart Antenna in LAS CDMA Systems

The performance of code division multiple access (CDMA) systems can be affected by small scale fading such as Rayleigh fading channel. In this paper, the application of smart antenna and Large Area Synchronous CDMA (LAS CDMA) systems, which introduce directional diversity channel, is presented. A novel interference cancellation scheme through dynamic space code (DSC) algorithm is briefly described. The directional diversity can be realized from the directional gain of smart antenna system. It can be found that when the number of elements in smart antenna is increase the directional gain of antenna system is much higher than single antenna. The system performance analysis in term of error probability is compared between traditional and LAS CDMA systems in both single and smart antenna systems. From the performance analysis it is found that CDMA system is more susceptible to multipath fading channel than interferences from existing users.

Development of a new clinical mastitis detection method for automatic milking systems

This study investigated the potential for accurate detection of clinical mastitis (CM) in an automatic milking system (AMS) using electronic data from the support software. Data from cows were used to develop the model, which was then tested on 2 independent data sets, 1 with 311 cows (same farm but from a different year) and 1 with 568 cows (from a different farm). In addition, the model was used to test how well it could predict CM 1 to 3 d before actual clinical diagnosis. Logistic mixed models were used for the analysis. Twelve measurements were included in the initial model before a backward elimination, which resulted in the following 6 measurements being included in the final model: quarter-level milk yield (MY; kg), electrical conductivity (EC; mS/cm), average milk flow rate (MF; kg/min), occurrence of incompletely milked quarters in each milking session (IM; yes or no), MY per hour (MYH; kg/h), and EC per hour (ECH; mS/cm/h) between successive milking sessions. The other 6 measurements tested but not included in the final model were peak milk flow rate (kg/min), kick-offs (yes or no) in each milking session, lactation number, days in milk (d), blood in milk (yes or no), and a calculated mastitis detection index used by DeLaval (DelPro software; DeLaval International AB, Tumba, Sweden). All measurements were assessed to determine their ability to detect CM as both individual variables and combinations of the 12 above-mentioned variables. These were assessed by producing a receiver operating characteristic curve and calculating the area under the curve (AUC) for each model. Overall, 9 measurements (i.e., EC, ECH, MY, MYH, MF, IM, peak flow rate, lactation number, and mastitis detection index) had significant mastitis detection ability as separate predictors. The best mastitis prediction was possible by incorporating 6 measurements (i.e., EC, ECH, MY, MYH, MF, and IM) as well as the random cow and quarter effects in the model, resulting in 90% sensitivity and 91% specificity with excellent AUC (0.96). Assessment of the model was found to produce robust results (AUC >0.9) in different data sets and could detect CM with reductions in sensitivity and specificity with increasing days before actual diagnosis. This study demonstrated that improved mastitis status prediction can be achieved by using multiple measurements, and new indexes based on that are expected to result in improved accuracy of mastitis alerts, thereby improving the detection ability and utility on farm.     

Improving the multicast state scalability in internet routers by integrating hash algorithm with recursive unicast

In this article, a new protocol called REHASH has been devised that gracefully integrates the idea of recursive unicast with hash algorithm to achieve scalable multicast for improved performance.In this model, data packets have unicast destination addresses. Therefore, REHASH supports pure unicast routers transparently.The key idea of the proposed protocol is to simplify address allocation and implements multicast distribution using recursive unicast hash trees. The branching nodes recursively create packet copies to implement the distribution. REHASH adopts the source-specific channel abstraction to tackle the address allocation and the sender access control problems. Consequently, it provides best routes and is suitable for including QoS and authentication parameters inside hash tree construction algorithm. Additionally, REHASH tree management provides enhanced tree stability in the presence of group dynamics.