Optimization of a Non-traditional Unsupervised Classification Approach for Land Cover Analysis

The conditions under which a hybrid of clustering and canonical analysis for image classification produce optimum results were analyzed. The approach involves generation of classes by clustering for input to canonical analysis. The importance of the number of clusters input and the effect of other parameters of the clustering algorithm (ISOCLS) were examined. The approach derives its final result by clustering the canonically transformed data. Therefore the importance of number of clusters requested in this final stage was also examined. The effect of these variables were studied in terms of the average separability (as measured by transformed divergence) of the final clusters, the transformation matrices resulting from different numbers of input classes, and the accuracy of the final classifications. The research was performed with LANDSAT MSS data over the Hazleton/Berwick Pennsylvania area. Final classifications were compared pixel by pixel with an existing geographic information system to provide an indication of their accuracy

Analytical model of brittle destruction based on hypothesis of scale similarity

The size distribution of dust particles in nuclear fusion devices is close to the power function. A function of this kind can be the result of brittle destruction. From the similarity assumption it follows that the size distribution obeys the power law with the exponent between -4 and -1. The model of destruction has much in common with the fractal theory. The power exponent can be expressed in terms of the fractal dimension. Reasonable assumptions on the shape of fragments concretize the power exponent, and vice versa possible destruction laws can be inferred on the basis of measured size distributions.Comment: 10 pages, 3 figure

The Mannitol-Fermenting Group of Dysentery Bacilli

The term dysentery was originally used to describe any condition having as a symptom diarrhoea with stools containing blood and mucus. The discovery of Entamoeba histolytica by Losch (1875) and its incrimination as a cause of dysentery was the first step in the more accurate classification of this group of diseases. In 1898 Shiga described a non-lactose fermenting coliform bacillus and produced convincing evidence that infection with this organism gives rise to acute inflammatory and ulcerative colitis. Closely related bacilli, differing from Shiga's organism in their biochemical reactions and antigenic pattern, were isolated from cases of dysentery by Plexner (1900), Strong (1900) and others. In 1915 Sonne found yet another type, and In 1917 Schmitz added one more to the list. A critical review by Murray in 1918 gave convincing confirmation of the existence of four main types of dysentery bacilli. Three of these, Shiga's bacillus, Sonne's bacillus, and Schmitz's bacillus, were clearly defined in their biochemical reactions and antigenic structure. The fourth type - or more correctly, group - embracing the organisms named after Flexner, Strong, Hiss, Russell, and Lentz, had identical biochemical reactions, but,*though closely related, were not wholly alike in their antigenic pattern. This latter group was investigated by Andrewss and Inman (1919) and divided into five types, which they named V, W, X, Y and Z. According to their conception, these types shared four main antigens. Each of the strains, V, W, X and Z was believed to contain a dominant quantity of one of these antigens and minor quantities of the other three, while Y contained approximately equal amounts of all four. For purposes of identification, a polyvalent antiserum was prepared from all five strains, and it was hoped that this would enable all organisms of the Flexner "spectrum" to be recognised with certainty. This hope did not materialise. Experience in India revealed that about 30io of all strains having the general and biochemical characters of the group failed to react with this 'polyvalent' antiserum. For purposes of diagnosis these inagglutinable strains were regarded as atypical but none the less pathogenic Flexner-group bacilli, but this compromise had many disadvantages, and failed to carry conviction to many who at that time still believed in the widespread occurrence of amoebic dysentery. IDENTIFICATION OF NEW TYPES OF MANNITOL-FERMENTING DYSENTRY BACILLI. In view of this state of affairs, an investigation was started which had as its object the differentiation by serological methods of these inagglutinable strains, and the confirmation, or otherwise, of their pathogenic action. Annexures I and II cover the initial part of this work. In all, nine distinct strains were identified which had the biochemical characters of the Flexner group but could be recognised as separate entities by virtue of their antigenic structure. These nine strains could be divided into two groups. The first, consisting of three members, not only resembled Andrewss' types biochemically, but also exhibited a certain degree of cross-agglutination with them. There was no reasonable doubt that they were members of this series, and would have been recognised as such by Andrewes had they found their way into his collection, which contained only one strain emanating from India. The remaining six strains fell into a different category, as they had no demonstrable antigenic relationship with the Flexner group. Their claims to be considered pathogenic are discussed in detail, and at the date of publication of Annexure II, it was considered that three of them could be incriminated. (Abstract shortened by ProQuest.)

Stability of Magneto-optical Traps with Large Field Gradients: Limits on the Tight Confinement of Single Atoms

We report measurements of the stability of magneto-optical traps (MOTs) for neutral atoms in the limit of tight confinement of a single atom. For quadrupole magnetic field gradients at the trap center greater than ∼1 kG/cm, we find that stochastic diffusion of atoms out of the trapping volume becomes the dominant particle loss mechanism, ultimately limiting the MOT size to greater than ∼5 μm. We measured and modeled the diffusive loss rate as a function of laser power, detuning, and field gradient for trapped cesium atoms. In addition, for as few as two atoms, the collisional loss rates become very high for tightly confined traps, allowing the direct observation of isolated two-body atomic collisions in a MOT

Relation between socioeconomic deprivation and death from a first myocardial infarction in Scotland: population based analysis

No abstract available

Strong nonlinear optical response of graphene flakes measured by four-wave mixing

We present the first experimental investigation of nonlinear optical properties of graphene flakes. We find that at near infrared frequencies a graphene monolayer exhibits a remarkably high third-order optical nonlinearity which is practically independent of the wavelengths of incident light. The nonlinear optical response can be utilized for imaging purposes, with image contrasts of graphene which are orders of magnitude higher than those obtained using linear microscopy.Comment: 4 pages, 5 figure

The effect of composition on the mechanism of stress-corrosion cracking of titanium alloys in nitrogen tetroxide, and aqueous and hot- salt environments Annual summary report, 1 May 1967 - 30 Apr. 1968

Stress corrosion data for titanium alloys in aqueous, hot salt, and nitrogen dioxide environment

Measurement and analysis of a small nozzle plume in vacuum

Pitot pressures and flow angles are measured in the plume of a nozzle flowing nitrogen and exhausting to a vacuum. Total pressures are measured with Pitot tubes sized for specific regions of the plume and flow angles measured with a conical probe. The measurement area for total pressure extends 480 mm (16 exit diameters) downstream of the nozzle exit plane and radially to 60 mm (1.9 exit diameters) off the plume axis. The measurement area for flow angle extends to 160 mm (5 exit diameters) downstream and radially to 60 mm. The measurements are compared to results from a numerical simulation of the flow that is based on kinetic theory and uses the direct-simulation Monte Carlo (DSMC) method. Comparisons of computed results from the DSMC method with measurements of flow angle display good agreement in the far-field of the plume and improve with increasing distance from the exit plane. Pitot pressures computed from the DSMC method are in reasonably good agreement with experimental results over the entire measurement area