578 research outputs found

    Analysis of Anechoic Chamber Testing of the Hurricane Imaging Radiometer

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    The Hurricane Imaging Radiometer System (HIRAD) is a new airborne passive microwave remote sensor developed to observe hurricanes. HIRAD incorporates synthetic thinned array radiometry technology, which use Fourier synthesis to reconstruct images from an array of correlated antenna elements. The HIRAD system response to a point emitter has been measured in an anechoic chamber. With this data, a Fourier inversion image reconstruction algorithm has been developed. Performance analysis of the apparatus is presented, along with an overview of the image reconstruction algorith

    Simulations of CMOS pixel sensors with a small collection electrode, improved for a faster charge collection and increased radiation tolerance

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    CMOS pixel sensors with a small collection electrode combine the advantages of a small sensor capacitance with the advantages of a fully monolithic design. The small sensor capacitance results in a large ratio of signal-to-noise and a low analogue power consumption, while the monolithic design reduces the material budget, cost and production effort. However, the low electric field in the pixel corners of such sensors results in an increased charge collection time, that makes a fully efficient operation after irradiation and a timing resolution in the order of nanoseconds challenging for pixel sizes larger than approximately forty micrometers. This paper presents the development of concepts of CMOS sensors with a small collection electrode to overcome these limitations, using three-dimensional Technology Computer Aided Design simulations. The studied design uses a 0.18 micrometer process implemented on a high-resistivity epitaxial layer.Comment: Proceedings of the PIXEL 2018 Worksho

    Do paranoid delusions exist on a continuum with subclinical paranoia? A multi-method taxometric study

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    Background There is widespread interest in whether psychosis exists on a continuum with healthy functioning. Previous research has implied that paranoia, a common symptom of psychosis, exists on a continuum but this has not been investigated using samples including both patients and non-patients and up-to-date taxometric methods. Aim To assess the latent structure of paranoia in a diverse sample using taxometric methods. Method We obtained data from 2836 participants, including the general population as well as at-risk mental state and psychotic patients using the P-scale of the Paranoia and Deservedness Scale. Data were analysed using three taxometric procedures, MAMBAC, MAXEIG and L-MODE (Ruscio, 2016), and two sets of paranoia indicators (subscales and selected items from the P scale), including and excluding the patient groups. Results Eleven of the twelve analyses supported a dimensional model. Using the full sample and subscales as indicators, the MAMBAC analysis was ambiguous. Overall, the findings converged on a dimensional latent structure. Conclusions A dimensional latent structure of paranoia implies that the processes involved in sub-clinical paranoia may be similar to those in clinical paranoia

    A randomised controlled trial of a brief online mindfulness-based intervention on paranoia in a non-clinical sample

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    Paranoia is common and distressing in the general population and can impact on health, emotional well-being and social functioning, such that effective interventions are needed. Brief online mindfulness-based interventions (MBIs) have been shown to reduce symptoms of anxiety and depression in non-clinical samples, however at present there is no research investigating whether they can reduce paranoia. The current study explored whether a brief online MBI increased levels of mindfulness and reduced levels of paranoia in a non-clinical population. The mediating effect of mindfulness on any changes in paranoia was also investigated. One hundred and ten participants were randomly allocated to either a two week online MBI including 10 minutes of daily guided mindfulness practice or to a waitlist control condition. Measures of mindfulness and paranoia were administered at baseline, post-intervention and one-week follow-up. Participants in the MBI group displayed significantly greater reductions in paranoia compared to the waitlist control group. Mediation analysis demonstrated that change in mindfulness skills (specifically the observe, describe and nonreact facets of the FFMQ) mediated the relationship between intervention type and change in levels of paranoia. This study provides evidence that a brief online MBI can significantly reduce levels of paranoia in a non-clinical population. Furthermore, increases in mindfulness skills from this brief online MBI can mediate reductions in non-clinical paranoia. The limitations of the study are discussed

    KHAT USE PREVALENCE, CAUSES AND ITS EFFECT ON MENTAL HEALTH, BAHIR-DAR, NORTH WEST ETHIOPIA

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    The main objectives of this study were to assess the prevalence, causes and effects of khat chewing on levels of anxiety, depression and social-skills of Bahir-Dar University (BDU) students who have an experience of khat chewing. Methods: For this study, 154 (i.e. 112 khat users and 42 non-khat users) participants were selected using repeated survey sampling. The levels of anxiety and depression were assessed using anxiety and depression symptoms inventory and the level of social-skill was assessed using social avoidance and distress scale. The analysis was made using descriptive statistics like frequency, minimum, maximum, mean, correlation; and inferential statistics like one-way ANOVA. Along with, thematic analysis for qualitative data was used. The study revealed that 33% and 67% of khat users were categorized as dependent khat users and non-dependent khat users respectively. Some of the worsening factors of khat chewing were; the high production khat in the area and khat chewing houses in the nearby university villages, and nonattendance of awareness creating opportunities on the psychological, social and economic influence as a result of khat use. The expense was highly affecting the life of students mainly when they were frequent chewers of khat. Statistically significant difference was found in the levels of anxiety (p<0.01) and depression (p<0.05) between dependent khat users, nondependent khat users and non-khat users. However, statistically significant variation was not obtained on the level of social-skills among the three groups (p>0.05). Anxiety and depression are determined by the level of dependence, dependent khat users higher level of experience as compared to nondependent khat users and non-khat users. Therefore, it is not becoming a khat user, but developing dependency on khat which is associated with anxiety and depression. Many factors worsening khat chewing and the usage of khat was uneconomical for university students

    Total Ionizing Dose Effects on CMOS Image Sensor for the ULTRASAT Space Mission

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    ULTRASAT (ULtraviolet TRansient Astronomy SATellite) is a wide-angle space telescope that will perform deep time-resolved surveys in the near-ultraviolet spectrum. ULTRASAT is a space mission led by the Weizmann Institute of Science and the Israel Space Agency and is planned for launch in 2025. The camera implements backside-illuminated, stitched pixel sensors. The pixel has a dual-conversion-gain 4T architecture, with a pitch of 9.59.5 μm\mu m and is produced in a 180180 nmnm process by Tower Semiconductor. Before the final sensor was available for testing, test sensors provided by Tower were used to gain first insights into the pixel's radiation tolerance. One of the main contributions to sensor degradation due to radiation for the ULTRASAT mission is Total Ionizing Dose (TID). TID measurements on the test sensors have been performed with a Co-60 gamma source at Helmholz Zentrum Berlin and CC-60 facility at CERN and preliminary results are presented.Comment: Part of the conference: Frontier Detectors for Frontier Physics: 15th Pisa Meeting on Advanced Detectors, La Biodola - Isola d'Elba Published in: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Available online 15 June 2023, 168463. In Press, Journal Pre-proo

    Skipper-in-CMOS: Non-Destructive Readout with Sub-Electron Noise Performance for Pixel Detectors

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    The Skipper-in-CMOS image sensor integrates the non-destructive readout capability of Skipper Charge Coupled Devices (Skipper-CCDs) with the high conversion gain of a pinned photodiode in a CMOS imaging process, while taking advantage of in-pixel signal processing. This allows both single photon counting as well as high frame rate readout through highly parallel processing. The first results obtained from a 15 x 15 um^2 pixel cell of a Skipper-in-CMOS sensor fabricated in Tower Semiconductor's commercial 180 nm CMOS Image Sensor process are presented. Measurements confirm the expected reduction of the readout noise with the number of samples down to deep sub-electron noise of 0.15rms e-, demonstrating the charge transfer operation from the pinned photodiode and the single photon counting operation when the sensor is exposed to light. The article also discusses new testing strategies employed for its operation and characterization.Comment: 7 pages, 10 figure

    Roles of Cognitive Characteristics in Tinnitus Patients

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    To investigate the cognitive characteristics that affect the emotional and functional distress caused by tinnitus and to decide and test the model to explain their relations, 167 patients with tinnitus, who visited Samsung Medical Center, Seoul, Korea between March 2001 and May 2002 were recruited. To examine their features related to tinnitus, the following scales were administered; Tinnitus-related basic questionnaire including dysfunctional beliefs, Tinnitus Handicap Inventory, State-Trait Anxiety Inventory, Anxious Thought and Tendencies, Self-Consciousness Scale, and modified 'catastrophic thought' from Coping Strategies Questionnaire. The results showed that the duration of experiencing tinnitus was 4.7±7.1 yr, those who com-plained of hearing one sound were the most common (45.5%), and hearing sounds similarly described to whistling were the most common (22.5%). Also, there were significant correlations among tinnitus features, cognitive characteristics, and distresses from tinnitus. As a result of testing the model, Normed fit index, Incremental fit index, Tucker-Lewis index, and Comparative fit index were over .90, indicating that it is a good model, and Root mean square error of approximation showed a reasonable fit. Also, the direct effects of the trait or severity of tinnitus on distress did not appear to be significant, thus it appeared to be affecting indirectly through the cognitive characteristics. This result shows that cognitive interventions can be important for the psychological adaptations of tinnitus patients
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