Dynamic reasoning in a knowledge-based system

Any space based system, whether it is a robot arm assembling parts in space or an onboard system monitoring the space station, has to react to changes which cannot be foreseen. As a result, apart from having domain-specific knowledge as in current expert systems, a space based AI system should also have general principles of change. This paper presents a modal logic which can not only represent change but also reason with it. Three primitive operations, expansion, contraction and revision are introduced and axioms which specify how the knowledge base should change when the external world changes are also specified. Accordingly the notion of dynamic reasoning is introduced, which unlike the existing forms of reasoning, provide general principles of change. Dynamic reasoning is based on two main principles, namely minimize change and maximize coherence. A possible-world semantics which incorporates the above two principles is also discussed. The paper concludes by discussing how the dynamic reasoning system can be used to specify actions and hence form an integral part of an autonomous reasoning and planning system

Effects of Partial Homogenization of Milk on Yield and Quality of Cheddar Cheese

In the past decade, the cheese industry in the United States (US) has grown rapidly, with cheese sales increasing by 33% (36). The cheese industry, in 1983, utilized 29.2% of total US milkfat supply as compared to 20.3% utilization in 1973 (36). Compared to the total cheese production of 2,059,2Z8 kg (4,539,822 lb) in 1982, 2,185,611 kg (4,818,449 lb) of cheese were manufactured in 1983 in the .US (36). The increased production of cheese was made possible by modifications in the cheese making process and advent of modern equipment; and it was fostered by increased demand .and higher prices. One of the recent concepts in the cheese industry is use of preconcentrated milk for cheese making. Preconcentration of cheesemilk lessens the problems related to whey disposal. With reduced bulk and increased solids level in the raw material, increase in cheese production can be attained without increase in labor or equipment. Research also has indicated increased cheese yields can be obtained by preconcentrating cheesemilk (6). Since ultrafiltration is not legal for treating milk to be used in Cheddar cheese manufacture, vacuum concentration is employed. Vacuum concentration of milk involves considerable amount of agitation by pumping. This physical abuse of milk has a shattering effect on milk fat globules, which is similar in nature to homogenization, but not to as great an extent. Since the natural distribution of milk fat globules and milk proteins is modified by homogenization, it is presumed that this process modifies the properties of cheese curd. Even though some researchers (15,30,38) found increased cheese yields with homogenized milk, the reports (18,39) of its adverse effects on flavor and body of cheese cast doubt on the feasibility of homogenization of milk in Cheddar cheese making. As earlier research with homogenized milk was not totally applicable to cheese making with the modern equipment used in the dairy industry, it seemed practical to investigate the effects of homogenization of milk at various pressures on the properties of the resultant Cheddar cheese during making and curing

Flavor development in lactic fermentation of ultrafiltered cottage cheese whey

Fermented dairy products based on ultrafiltered proteins often seem lacking in flavor particularly if the protein is washed by diafiltration. A model system based on protein collected from cottage cheese whey was used to investigate this phenomenon;The whey proteins were concentrated 10-fold by ultrafiltration through a membrane with 30,000 MW cutoff, diluted 1:1 with water and reconcentrated to a final concentration of 6-7% of the initial whey volume. This resulted in approximately 15-fold concentration of whey. The whey protein concentrate was diluted to 3.5% protein, various constituents were added, and the mixtures fermented with Leuconostoc dextranicum for 16 h at 32°C. The fermented samples were heat-coagulated in a water bath at 90°C for 10 min and cooled to room temperature. The resulting products were evaluated for flavor by a trained panel, who tasted three replicates of each sample;Retentate diluted with distilled water lacked flavor and developed a gritty texture after fermentation and coagulation. When permeate was used to dilute the whey protein before fermentation, the product had a much more intense flavor than when water was used as a diluent;Various techniques were used to isolate and identify components of whey permeate that were responsible for flavor development in the mixture. Constituents in the permeate that were important for flavor development were: ions (sodium, potassium, calcium, magnesium, phosphorus, chlorine, and citrate), dihydroxyacetone, lactose, and acetic acid. Addition of dihydroxyacetone prior to fermentation increased the production of glyoxal, methylglyoxal, and diacetyl as detected by high performance liquid chromatography

Resource Devolution from the Centre to States: Enhancing the Revenue Capacity of States for Implementation of Essential Health Interventions

Access to adequate health care services is an important component of empowering people with human capital. This, however, can be achieved only when the spending on health care is adequate and delivery systems efficient. Improving health indicators is an important component of the Millennium Development Goals (MDGs) set by the United Nations. There are also important targets on health status achievements set for the Tenth Plan. The Common Minimum Programme of the ruling UPA government also seeks to increase the public expenditure by the Centre and States on health and family welfare schemes from the present level of less than 1% to 2%-3% of the gross domestic product (GDP). The provision of health and family welfare services falls in the realm of concurrent responsibility of the Centre and the States, but the latter have a predominant role in the delivery of these services. However, fiscal pressures at the State level lead to compression of expenditures by the State Governments resulting in an increase in Central financing of these services, particularly for some prioritized programmes implemented through the Centre and Centrally sponsored schemes. Thus, over 85% of the public expenditure on medical and public health is incurred by the State Governments, though the proportion of financing the expenditure by the State Governments is lower. This paper identifies the resource gap between the desired and the actual health expenditure in 15 major States in India (14 large, non-special category States and Assam), and highlights the extent to which the gap can be reduced by augmenting resources at the State level. Further, it estimates the resource gap that cannot be met through States’ own resources and therefore, requires Central transfers. The design of Central transfers needed for meeting the required health expenditure of various States is also discussed.Federal Transfers to Provinces; Public Expenditure on Health

Elliptic supersonic jet morphology manipulation using sharp-tipped lobes

Elliptic nozzle geometry is attractive for mixing enhancement of supersonic jets. However, jet dynamics, such as flapping, gives rise to high-intensity tonal sound. We experimentally manipulate the supersonic elliptic jet morphology by using two sharp-tipped lobes. The lobes are placed on either end of the minor axis in an elliptic nozzle. The design Mach number and the aspect ratio of the elliptic nozzle and the lobed nozzle are 2.0 and 1.65. The supersonic jet is exhausted into ambient at almost perfectly expanded conditions. Time-resolved schlieren imaging, longitudinal and cross-sectional planar laser Mie-scattering imaging, planar Particle Image Velocimetry, and near-field microphone measurements are performed to assess the fluidic behavior of the two nozzles. Dynamic Mode and Proper Orthogonal Decomposition (DMD and POD) analysis are carried out on the schlieren and the Mie-scattering images. Mixing characteristics are extracted from the Mie-scattering images through the image processing routines. The flapping elliptic jet consists of two dominant DMD modes, while the lobed nozzle has only one dominant mode, and the flapping is suppressed. Microphone measurements show the associated noise reduction. The jet column bifurcates in the lobed nozzle enabling a larger surface contact area with the ambient fluid and higher mixing rates in the near-field of the nozzle exit. The jet width growth rate of the two-lobed nozzle is about twice as that of the elliptic jet in the near-field, and there is a 40\% reduction in the potential core length. Particle Image Velocimetry (PIV) contours substantiate the results.Comment: 19 pages, 16 figures. Revised version submitted to Physics of Fluids for peer review. URL of the Video files (Fig. 6 & Fig. 14) are given in the text files (see in '/anc/*.txt'

Machining of Tungsten Heavy Alloy under Cryogenic Environment

AbstractThe machining of tungsten heavy alloy is very difficult as it has high strength and hardness, which requires special cutting tools and cutting process. Though carbide tools are extensively used in conventional cutting, these lead take high machining time and tool failures which cause to decrease in productivity. To overcome the above, special techniques are being practiced in machining of tungsten alloys, one such technique is machining under cryogenic environment. In this paper, liquid nitrogen is used as coolant in machining of tungsten heavy alloys, because it is cost effective, safe, non flammable and environmental friendly gas, in addition to that it cannot contaminate the work piece and no separate mechanism required for disposal. An experimental investigation has been carried out on machining of tungsten heavy alloys by the solid carbide cutting tools under cryogenic and conventional coolants. The material removal rate, surface integrity and cutting forces were studied for both the coolants. The chip morphology also measured for evaluation of shear stress and shear strain. The cryogenic coolant has enhanced the machinability of tungsten heavy alloys. It is observed that the material removal rate was three times higher in cryogenic cooling method when compared with conventional coolant method and the surface finish of the machined surfaces are extremely good and the magnitude of cutting forces are lesser in cryogenic coolant

Research Notes : United States : Screening for cytoplasmic/maternal effects in resistance to soybean cyst nematode

With the discovery of soybean cyst nematode (SCN) in the U.S. in 1954, the research for resistance was initiated. Ross and Brim (1957) identified several soybean plant introductions resistant to the North Carolina SCN populations. Epps and Hartwig (1972) reported PI lines resistant to race 4

Electrical and Magnetic behaviour of PrFeAsO0.8F0.2 superconductor

The superconducting and ground state samples of PrFeAsO0.8F0.2 and PrFeAsO have been synthesised via easy and versatile single step solid state reaction route. X-ray & Reitveld refine parameters of the synthesised samples are in good agreement to the earlier reported value of the structure. The ground state of the pristine compound (PrFeAsO) exhibited a metallic like step in resistivity below 150K followed by another step at 12K. The former is associated with the spin density wave (SDW) like ordering of Fe spins and later to the anomalous magnetic ordering for Pr moments. Both the resistivity anomalies are absent in case of superconducting PrFeAsO0.8F0.2 sample. Detailed high field (up to 12Tesla) electrical and magnetization measurements are carried out for superconducting PrFeAsO0.8F0.2 sample. The PrFeAsO0.8F0.2 exhibited superconducting onset (Tconset) at around 47K with Tc({\rho} =0) at 38K. Though the Tconset remains nearly invariant, the Tc({\rho} =0) is decreased with applied field, and the same is around 23K under applied field of 12Tesla. The upper critical field (Hc2) is estimated from the Ginzburg Landau equation (GL) fitting, which is found to be ~ 182Tesla. Critical current density (Jc) being calculated from high field isothermal magnetization (MH) loops with the help of Beans critical state model, is found to be of the order of 103 A/cm2. Summarily, the superconductivity characterization of single step synthesised PrFeAsO0.8F0.2 superconductor is presented.Comment: 15 Pages Text + Fig

QoS Constrained Optimal Sink and Relay Placement in Planned Wireless Sensor Networks

We are given a set of sensors at given locations, a set of potential locations for placing base stations (BSs, or sinks), and another set of potential locations for placing wireless relay nodes. There is a cost for placing a BS and a cost for placing a relay. The problem we consider is to select a set of BS locations, a set of relay locations, and an association of sensor nodes with the selected BS locations, so that number of hops in the path from each sensor to its BS is bounded by hmax, and among all such feasible networks, the cost of the selected network is the minimum. The hop count bound suffices to ensure a certain probability of the data being delivered to the BS within a given maximum delay under a light traffic model. We observe that the problem is NP-Hard, and is hard to even approximate within a constant factor. For this problem, we propose a polynomial time approximation algorithm (SmartSelect) based on a relay placement algorithm proposed in our earlier work, along with a modification of the greedy algorithm for weighted set cover. We have analyzed the worst case approximation guarantee for this algorithm. We have also proposed a polynomial time heuristic to improve upon the solution provided by SmartSelect. Our numerical results demonstrate that the algorithms provide good quality solutions using very little computation time in various randomly generated network scenarios