Neuropsychobiology of affective disorders. Some methodological considerations

Amine hypothesis is neither an adequate nor a sufficient postulate in understanding the neuropsychobiology of affective disorders. Interactions and balance between various mechanisms and factors may be important. Better techniques and methodology need to be used and a more comprehensive approach seems to be necessary in formulating meaningful research strategies. The present paper reexamines someaspects of the available data and suggests a few approaches in the sutdy and elucidation of neruophychobiology of affective disorders.     

Cooking at low temperatures: energy and time requirements

A flat plate solar collector can easily supply hot water at temperatures upto 90–95°C. At these temperatures, rice, potatoes and vegetables can be cooked without much difficulty. However, to design an efficient solar system for cooking, one must know the exact energy and time required for cooking at these temperatures. Our experiments show that the actual energy consumed in cooking rice, potatoes or green vegetables is only 0.06 to 0.10 kWh/kg at cooking temperatures of 82–88°C and the cooking time at these temperatures is 30–45 min.     

Error Probability of a Binary Signal Perturbed by Intersymbol Interference and Impulsive Atomopheric Noise

This paper analyzes the performance of baseband polar signals in the presence of impulsive atmospheric noise and intersymbol interference (ISI). Different levels of ISI have been considered to make the analysis more meaningful. Possible explanations for the results are offered. A comparison has also been made with the system operating in Gaussian noise.     

Multilevel difference schemes for the heat conduction equation and its application to the dirichlet problem in two and three dimensions

In this paper we have discussed a general method of deriving high order multilevel schemes for the heat conduction equation in higher dimensions. The application of the three level parabolic schemes for the solution of the steady state Dirichlet problem in two and three dimensions is discussed by introducing two parameters. The error bounds given by Hadjidimos are further refined which drastically reduces the theoretical estimate of the number of iteration cycles required for a given accuracy η. We have also defined a new set of iteration parameters. A numerical example is computed and it is seen that the present methods produce accurate results.     

Binary baseband polar signals in combination with continuous and impulsive noise with i.s.i.

This letter presents the performance of a binary baseband polar system in the presence of a mixture of continuous and impulsive noise and intersymbol interference (i.s.i.). The results obtained are very general and the system performance in special cases like purely continuous noise or purely impulsive noise with or without i.s.i. can be easily derived from the general results.     

Critical magnetic fields of Cu-Pb-Cu proximity-effect sandwiches studied by acoustic surface waves

The temperature dependence of the surface-wave attenuation in Cu-Pb-Cu sandwiches, in the absence of a magnetic field, agrees well with the BCS expression. We compare the temperature dependence of the parallel and perpendicular critical fields with expressions derived from the Ginzburg-Landau theory. We get satisfactory agreement, provided that for the thinner specimens we take the mean free paths in the proximity-effect sandwich to be somewhat smaller than the values found for monitor strips. This implies that some interdiffusion between the Pb and the Cu is taking place.     

Validity studies in clustering methodologies

Clustering algorithms tend to generate clusters even when applied to random data. This paper provides a semi-tutorial review of the state-of-the-art in cluster validity, or the verification of results from clustering algorithms. The paper covers ways of measuring clustering tendency, the fit of hierarchical and partitional structures and indices of compactness and isolation for individual clusters. Included are structural criteria for validating clusters and the factors involved in choosing criteria, according to which the literature of cluster validity is classified. An application to speaker identification demonstrates several indices. The development of new clustering techniques and the wide availability of clustering programs necessitates vigorous research in cluster validity.     

IP mobility issues for a mobile tele-robotic system—NEPWAK

The network-centric applied research team (N-CART) is continuing its work on an ambitious project known as the network-enabled powered wheelchair adaptor kit (NEPWAK). It introduces techniques for modifying and using powered wheelchairs as mobile platforms enabling communication and remote control. The wheelchair is equipped with a laptop computer, a CCD camera and a wireless network interface card (NIC) for 802.11b Internet access. The laptop acts as a server allowing network clients to gain access through a custom control interface on the chair. The remote controlling client receives a video and audio feed from the chair and sends control signals for maneuvering. While traveling, the chair is able to change its network association from one access point (AP) to another within the same subnet–the process is known as handoff. However, there is no inter-network handoff mechanism presently available in IP networks. This restricts the mobility of the wheelchair to within the coverage area of the subnet APs. This paper shows that the Internet engineering task force’s(IETF) network layer mobility protocol—Mobile IP[1] suffers from large handoff latencies that can hinder communication between the client and the wheelchair during handoff. Mobile IP alone is not a suffcient solution for a mobile telebotic system such as NEPWAK. An interesting solution to the handoff latency problem comes from the Fast-handover protocol[2] described in Section 4.4 with simulation results in Section 6.2.