Highly reliable testing of ULSI memories with on-chip voltage-downconverters

Two testing techniques for ultra-large-scale integrated (ULSI) memories containing on-chip voltage downconverters (VDCs) are described. The first in an on-chip VDC tuning technique that adjusts internal V_CC to compensate for the monitored characteristics of the process parameters during repair analysis testing. The second is an operating-voltage margin test, performed at various internal V_CC levels during the water sort test (WT) and the final shipping test (FT)     

Partitioning large networks without breaking communities

The identification of cohesive communities is a key process in social network analysis. However, the algorithms that are effective for finding communities do not scale well to very large problems, as their time complexity is worse than linear in the number of edges in the graph. This is an important issue for those interested in applying social network analysis techniques to very large networks, such as networks of mobile phone subscribers. In this respect, the contributions of this paper are twofold. First, we demonstrate these scaling issues using a prominent community-finding algorithm as a case study. Then, we show that a two-stage process, whereby the network is first decomposed into manageable subnetworks using a multilevel graph partitioning procedure, is effective in finding communities in networks with more than 10⁶ nodes.     

Augmented reality using personal projection and retroreflection

The support of realistic and flexible training simulations for military, law enforcement, emergency response, and other domains has been an important motivator for the development of augmented reality technology. An important vision for achieving this goal has been the creation of a versatile “stage” for physical, emotional, and cognitive training that combines virtual characters and environments with real world elements, such as furniture and props. This paper presents REFLCT, a mixed reality projection framework that couples a near-axis personal projector design with tracking and novel retroreflective props and surfaces. REFLCT provides multiple users with personalized, perspective-correct imagery that is uniquely composited for each user directly into and onto a surrounding environment, without any optics positioned in front of the user’s eyes or face. These characteristics facilitate team training experiences which allow users to easily interact with their teammates while wearing their standard issue gear. REFLCT can present virtual humans who can make deictic gestures and establish eye contact without the geometric ambiguity of a typical projection display. It can also display perspective-correct scenes that require a realistic approach for detecting and communicating potential threats between multiple users in disparate locations. In addition to training applications, this display system appears to be well matched with other user interface and application domains, such as asymmetric collaborative workspaces and personal information guides.     

Pramila Rao · D. Sujatha · K. Rathina Raj · S. Vishwanatha · K. Narasimhamurthy · P. Saibaba · D. Narasimha Rao · S. Divakar

 Subchronic toxicity dietary studies were conducted in albino rats on the safety aspects of residual β-cyclodextrin in egg samples treated for cholesterol removal at concentrations of 250, 125 and 20 ppm for a period of 90 days. Daily food intake, body weight gain, relative organ weights, histopathology, haematology and serum enzyme activities were studied. The study however, did not reveal any toxicity at any of the levels tested. It can therefore be concluded from the present study that β-cyclodextrin-treated egg samples do not cause any toxicity. Received: 28 September 1999     

Long-term feeding effects of thermally oxidised oils on the absorption, storage and excretion of fat in rats

 The long term effects of feeding heated and fried vegetable oils namely peanut, sesame and coconut oils, at levels of 5% and 20% for 20 weeks on the absorption, storage and excretion of fat were studied in laboratory rats. Although no significant difference in the absorption rate of heated fats was observed, a marginal increase in the levels of fecal fat excretion was noted in heated/fried oil-fed rats. Deposition of fat in the perirenal adipose tissue indicated higher levels of palmitic and oleic acid in heated/fried oil-fed rats. Received: 14 June 1999 / Revised version: 2 August 1999     

Exact analysis of Marangoni convection with throughflow

Summary The onset of Marangoni convection with throughflow in a horizontal fluid layer with upper boundary free and insulating to temperature perturbations and the lower boundary rigid and either conducting or insulating to temperature perturbations is investigated. The resulting eigenvalue problem is solved exactly. The Prandtl number arising due to throughflow plays a crucial role in determining the stability of the system. It is found that a small amount of throughflow in one particular direction destabilizes the system depending on the Prandtl number and temperature boundary conditions.     

Cardiac Arrival Time Analyzer

The sequence of excitation of cardiac muscles is greatly affected by any abnormality in the conduction system of the heart. Epicardial mapping for the measurement of activation time at different points is helpful for the diagnosis of such abnormalities. For the measurement of activation time at different points of the epicardial surface, a number of sophisticated instruments, including microcomputer-based ones, have been reported. However, the need for a reliable, low-cost, and easy to operate instrument cannot be denied. In this note, such a cardiac arrival time analyzer is described.     

Effects of throughflow and internal heat generation on the onset of convection in a fluid layer

Summary The throughflow and internal heat generation effects on the onset of convection in an infinite horizontal fluid layer are investigated. The boundaries are considered to be rigid (however permeable) and perfectly conducting. The resulting eigenvalue problem is solved by using the Galerkin method, and the effects of various parameters in the stability results are analyzed. The results indicate that the stability of the system is significantly affected by both throughflow and internal heat generation in the fluid layer. The Prandtl number comes into play due to the presence of throughflow and it has a profound effect on the stability of the system. It is found that, in the presence of internal heating, throughflow in one direction supresses convection while throughflow in the other direction encourages it.     

Broadband cylindrical dielectric resonator antenna excited by modified microstrip line

The impedance bandwidth of a high permittivity cylindrical dielectric resonator antenna excited by a microstrip line was significantly improved by modifying the feed geometry. The 10 dB return loss bandwidth is enhanced from 12 to 26% without much affecting the gain and other radiation properties of the antenna. Good agreement has been observed between the predicted and measured results.