Behaviour of Thiosulphate in Electrodialysis in the Presence of Photographic Gelatin

Electrodialysis of a 10 per cent solution of gelatin containing 30 /M of thiosulphate labelled 3,S in the outer sulphur atom was carried out with a brentzinger apparatus. Forty-five per cent of the radioactivity appeared in the anodic liquid, thirty per cent in the cathodic and the remaining twenty-five per cent in the gelatin solution. The validity of these results is discussed also in relation to other experiments carried out with ,SS labelled sulphate and :aP labelled phosphate.     

FAULT DIAGNOSIS APPROACH BASED ON HIDDEN MARKOV MODEL AND SUPPORT VECTOR MACHINE

Aiming at solving the problems of machine-learning in fault diagnosis, a diagnosis approach is proposed based on hidden Markov model (HMM) and support vector machine (SVM). HMM usually describes intra-class measure well and is good at dealing with continuous dynamic signals. SVM expresses inter-class difference effectively and has perfect classify ability. This approach is built on the merit of HMM and SVM. Then, the experiment is made in the transmission system of a helicopter. With the features extracted from vibration signals in gearbox, this HMM-SVM based diagnostic approach is trained and used to monitor and diagnose the gearbox's faults. The result shows that this method is better than HMM-based and SVM-based diagnosing methods in higher diagnostic accuracy with small training samples.     

The Photographic Lens in Medical Photography

The author reports on a number of specific applications of photography in medicine for which the normally available lenses for amateur cameras do not suffice. To begin with, the problems involved in ultra-violet and infra-red photography are dealt with. In ultra-violet photography the spectral transmission of the lenses is of importance whereas in infra-red photography the chromatic correction is decisive. Further, attention is drawn to the rble stereo-photography is playing in medical tuition. To conclude, the reasons are given for the superiority of lens-optical systems in radiography.     

The Quantum Sensitivity of Photographic Emulsion Grains

A method is described of obtaining the response curves of individual size classes of a photographic emulsion in which the exposure scale is expressed in absorbed quanta per grain. No assumptions of any significance are involved. The method is applied to the derivation of sensitivity characteristics of grains in modern emulsions of high speed for their average grain size, and to other emulsions not chemically-sensitized to such a high level. It is found that the sensitivity spread among grains of a single size may vary from about 1.0 to 2.0 log units, depending on the emulsion, but does not vary greatly for grains of different size in the same emulsion. The numbers of absorbed quanta involved are such that the greater part of this spread must be attributed to the fact that within a single size class grains differ widely in the numbers of quanta which they must absorb in order to be rendered developable; quantum fluctuations make only a small contribution to the spread in exposures over which grains become developable. Grains of the highest sensitivity encountered become developable after absorption of about 4 quanta, which suggests that a latent image of minimum developable size consists of 4 silver atoms.     

Photofabricated Focussing Diffracting Optics

Optical components such as zone plates which operate by diffraction can be formed from a recording, in a photosensitive layer, of the intensity distribution created by the interaction of two coherent wavefronts.

This paper describes some examples of such components and discusses the practical aspects of photofabrication. Examples of wavefront aberration introduced by a wavelength change and two methods of aberration correction are shown.     

Parallel Implementations of Block-Based Motion Vector Estimation for Video Compression on Four Parallel Processing Systems

Parallel algorithms, based on a distributed memory machine model, for an exhaustive search technique for motion vector estimation in video compression are being designed and evaluated. Results from the execution on a 16,384 processor MasPar MP-1 (an SIMD machine), a 140 node Intel Paragon XP/S and a 16 node IBM SP2 (two M IMD machines), and the 16 processor PASM prototype (a partitionable SIMD/MIMD mixed-mode machine) are presented. The trade-offs of using different modes of parallelism (SIMD, SPMD, and mixed-mode) and different data partitioning schemes (the rectangular and stripe subimage methods) are examined. The analytical and experimental results shown in this application study will help practitioners to predict and contrast the performance of different approaches to parallel implementation of this important video compression technique. The results presented are also applicable to a large class of image and video processing tasks. Case studies, such as the one presented here, are a necessary step in developing software tools for mapping an application task onto a single parallel machine and for mapping a set of independent application tasks, or the subtasks of a single application task, onto a heterogeneous suite of parallel machines.     

Closed-loop form quantization algorithm with bounded accumulative error

This paper proposes a closed-loop form quantization algorithm that guarantees the boundness of accumulative error. The algorithm is particularly useful for mobile robot navigation that is usually implemented on embedded systems. If the wheel command of the mobile robot is given by velocity or positional increments at every control instant that are quantized due to the finite word length of the controller's CPU, the quantization error accumulates to produce large position error. Such an error is critical for wheeled mobile robots or autonomous vehicles with non-holonomic constraints. To solve this problem, a non-error accumulative quantization algorithm with a closedloop form is presented. We can extend it to a generalized form corresponding to the nth-order accumulation. The boundness of the accumulative quantization error is proven via mathematic processes and verified by a series of computer simulations. The proposed method is effective to accurately control the autonomous mobile robot, particularly with embedded systems.     

An authenticated secure image hiding scheme

Abstract

Image hiding involves the concealment of an embedded secret image within a cover image to form a stego-image. The secret image can be used for transmission across the public networks without its presence being detected. Image hiding thus serves as a way of secure message communication; therefore, except for the platitudinous issues of image quality and hiding capacity, it is necessary to pay more attention to the means to assure the origin and integrity of the delivered content. In this paper, a digital signature scheme is skillfully applied so as to guarantee the integrity and the origin of the transmitted message and a behind-the-scenes guide to recover the hidden secret. Our idea launches realistic feints and ambushes to enhance the effect of camouflage.     

Photographic Action of Complex Cyanides

The electronic configuration of complex cyanides of the transition elements is briefly outlined. It is shown that those complexes possessing an unpaired electron, like ferricyanide, produce fog or, in greater concentration desensitize silver-digested emulsion. Diamagnetic complexes studied did not produce fog and, with one exception, did not desensitize appreciably. An explanation, based on the coupling of unpaired electrons of the complex ions with silver sensitizing specks, is put forward.     

The Electrophotographic Properties of Zinc Oxide

Measurements on the light dependence of the conductivity of zinc oxide in various gases have provided new information about the important role of ionised donors as charge carriers, in addition to free electrons. These results enable one to understand the mechanism of the corona charging process and the flow of charge from the surface to the grounded electrode during exposure.