Reconstruction of poloidal magnetic field profiles in field-reversed configurations with machine learning in laser-driven ion-beam trace probe

The diagnostic of poloidal magnetic field(B_(p))in field-reversed configuration(FRC),promising for achieving efficient plasma confinement due to its highβ,is a huge challenge because B_(p)is small and reverses around the core region.The laser-driven ion-beam trace probe(LITP)has been proven to diagnose the B_(p)profile in FRCs recently,whereas the existing iterative reconstruction approach cannot handle the measurement errors well.In this work,the machine learning approach,a fast-growing and powerful technology in automation and control,is applied to B_(p)reconstruction in FRCs based on LITP principles and it has a better performance than the previous approach.The machine learning approach achieves a more accurate reconstruction of B_(p)profile when 20%detector errors are considered,15%B_(p)fluctuation is introduced and the size of the detector is remarkably reduced.Therefore,machine learning could be a powerful support for LITP diagnosis of the magnetic field in magnetic confinement fusion devices.

NATIONAL FIELD TRIAL OF THE CHINESE CLASSIFICATION AND DIAGNOSTIC CRITERIA OF MENTAL DISORDERS: COMPREHENSIBILITY, ACCEPTABILITY AND APPLICABILITY

The Chinese Neurology and Psychiatry Association conducted a national field trial of its Chinese Classification and Diagnostic Criteria of Mental Disorders (CCMD-2) involov-ing 26 provinces and municipalities, 80 psychiatric institutes, and 224 professionals. The results were as follows: (1)95.2% of researchers considered the comprehensibility of the CCMD-2 diagnstic criteria good. Within the ten major categories, comprehensibility ranged from 85.7% to 100%. (2) Of those surveyed concerning the acceptibility of the CCCMD-2 diagnostic criteria, 85.9% considered them acceptable. In individual classifications, the rate ranged from 74.1% to 95.2%. (3) 1498 cases were tested. The overall applicability rate which indicated the consistency between the CCMD-2 result and the actual clinical diagnoses was found to be 87.6%, (averaging Kappa = 0.82,P<0.01), better than those obtained from non-Chinese systems of diagnosis.

Acoustic field distribution posterior to a tumor in B-Mode diagnostic ultrasonography

The image features, such as enhancements, shadows and lateral shadows, posterior to a tumor in a B-Mode diagnostic ultrasonography, are studied. The tumor is simplified as a homogeneous cylinder in an inhomogeneous medium. Using the ray theory we derive the intensity in the region behind the cylinder. Taking the influences of sound attenuation and the time gain compensation of the B-Mode displyer into acount , we simulate with a computer five images corresponding to our experiments conducted with a tissue equivalent phantom. The theoratical images seem to be in good qualitative agreement with the experimental results.

The study of complex focussing acoustic field of a convex phased array probe used in ultrasonic diagnostic B-scanner

This paper reports a study of complex focussing acoustic fields of a convex phased array probe widely used in ultrasonic diagnostic B-scanner. The time delay necessary for electronic focussing and for geometric focussing of complex focussing is given. By means of Helmholtz's integral formula, the expressions of acoustic fields were obtained for the electronic focussing and complex focussing.With Simpson's numerical integral, a great deal of computations was carried out with an 86 / 330 computer. By means of using different parameters, an optimum focal range and beam width of a 4 sequences electronic and complex focussing acoustic system was selected. With an EUB-40 ultrasound diagnostic B-scanner produced by the Hitachi company, the lateral focussing acoustic field and lateral resolution in an echoic tank were photographed by latticing method and the experimental result is consistent with the theory.