100 research outputs found

    Critique of rationalism in the epistemology of modality

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    In this thesis, I critically discuss rationalism in epistemology of modality. Rationalism claims that our a priori intuition or conceivability gives us knowledge about metaphysical possibility. I examine this claim by considering Bealerā€™s moderate rationalism and Chalmersā€™s modal rationalism. In particular, I argue that Bealerā€™s moderate rationalism is not successful in responding to Kripkeā€™s and Putnamā€™s counterexamples which sever the link between a priori intuition and modal knowledge. Also, it is argued that given Chalmersā€™s modal rationalism, our a priori conceivability entails more than metaphysical possibility from the perspective of our world. After providing some preliminary points in Introduction, I assess Bealerā€™s moderate rationalism in Chapter 2. Specifically, I argue that our a priori intuition about epistemic possibility concerning property-identities does not give us knowledge about metaphysical possibility. In arguing this point, Russellian and Fregean theories of phenomenal content are discussed. Also, a priori unknowability of necessary properties of a substance is examined. In Chapter 3, I discuss an issue untouched by Bealerā€™s moderate rationalism: a priori knowability of metaphysical possibility concerning property-possession of a substance. I argue that given Bealerā€™s moderate rationalism, our a priori intuition does not give us knowledge about metaphysical possibility concerning that. In arguing this point, categoricalism and dispositionalism about the nature of properties are discussed. I examine Chalmersā€™s modal rationalism in Chapter 4 and argue that our a priori conceivability can entail metaphysical possibility from perspectives of other worlds. Then, I derive a claim that we must be cautious not to commit a modal error of regarding what is not metaphysically possible from the perspective of our world as possible when we depend on a priori conceivability to know metaphysical possibility

    Demonstration of P-Type Stack-Channel Ternary Logic Device Using Scalable Dntt Patterning Process

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    A p-type ternary logic device with a stack-channel structure is demonstrated using an organic p-type semiconductor, dinaphtho[2,3-b:2\u27,3\u27-f]thieno[3,2-b]thiophene (DNTT). A photolithography-based patterning process is developed to fabricate scaled electronic devices with complex organic semiconductor channel structures. Two layers of thin DNTT with a separation layer are fabricated via the low-temperature deposition process, and for the first time, p-type ternary logic switching characteristics exhibiting zero differential conductance in the intermediate current state are demonstrated. The stability of the DNTT stack-channel ternary logic switch device is confirmed by implementing a resistive-load ternary logic inverter circuit

    Dual-Channel P-Type Ternary Dntt-Graphene Barristor

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    P-type ternary switch devices are crucial elements for the practical implementation of complementary ternary circuits. This report demonstrates a p-type ternary device showing three distinct electrical output states with controllable threshold voltage values using a dual-channel dinaphtho[2,3-b:2\u27,3\u27-f]thieno[3,2-b]-thiophene-graphene barristor structure. to obtain transfer characteristics with distinctively separated ternary states, novel structures called contact-resistive and contact-doping layers were developed. The feasibility of a complementary standard ternary inverter design around 1 V was demonstrated using the experimentally calibrated ternary device model

    Individual participant data meta-analysis of LR-5 in LI-RADS version 2018 versus revised LI-RADS for hepatocellular carcinoma diagnosis

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    Background A simplification of the Liver Imaging Reporting and Data System (LI-RADS) version 2018 (v2018), revised LI-RADS (rLI-RADS), has been proposed for imaging-based diagnosis of hepatocellular carcinoma (HCC). Single-site data suggest that rLI-RADS category 5 (rLR-5) improves sensitivity while maintaining positive predictive value (PPV) of the LI-RADS v2018 category 5 (LR-5), which indicates definite HCC. Purpose To compare the diagnostic performance of LI-RADS v2018 and rLI-RADS in a multicenter data set of patients at risk for HCC by performing an individual patient data meta-analysis. Materials and Methods Multiple databases were searched for studies published from January 2014 to January 2022 that evaluated the diagnostic performance of any version of LI-RADS at CT or MRI for diagnosing HCC. An individual patient data meta-analysis method was applied to observations from the identified studies. Quality Assessment of Diagnostic Accuracy Studies version 2 was applied to determine study risk of bias. Observations were categorized according to major features and either LI-RADS v2018 or rLI-RADS assignments. Diagnostic accuracies of category 5 for each system were calculated using generalized linear mixed models and compared using the likelihood ratio test for sensitivity and the Wald test for PPV. Results Twenty-four studies, including 3840 patients and 4727 observations, were analyzed. The median observation size was 19 mm (IQR, 11ā€“30 mm). rLR-5 showed higher sensitivity compared with LR-5 (70.6% [95% CI: 60.7, 78.9] vs 61.3% [95% CI: 45.9, 74.7]; P < .001), with similar PPV (90.7% vs 92.3%; P = .55). In studies with low risk of bias (n = 4; 1031 observations), rLR-5 also achieved a higher sensitivity than LR-5 (72.3% [95% CI: 63.9, 80.1] vs 66.9% [95% CI: 58.2, 74.5]; P = .02), with similar PPV (83.1% vs 88.7%; P = .47). Conclusion rLR-5 achieved a higher sensitivity for identifying HCC than LR-5 while maintaining a comparable PPV at 90% or more, matching the results presented in the original rLI-RADS study

    CT/MRI and CEUS LI-RADS Major Features Association with Hepatocellular Carcinoma: Individual Patient Data Meta-Analysis

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    Background The Liver Imaging Reporting and Data System (LI-RADS) assigns a risk category for hepatocellular carcinoma (HCC) to imaging observations. Establishing the contributions of major features can inform the diagnostic algorithm. Purpose To perform a systematic review and individual patient data meta-analysis to establish the probability of HCC for each LI-RADS major feature using CT/MRI and contrast-enhanced US (CEUS) LI-RADS in patients at high risk for HCC. Materials and Methods Multiple databases (MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Scopus) were searched for studies from January 2014 to September 2019 that evaluated the accuracy of CT, MRI, and CEUS for HCC detection using LI-RADS (CT/MRI LI-RADS, versions 2014, 2017, and 2018; CEUS LI-RADS, versions 2016 and 2017). Data were centralized. Clustering was addressed at the study and patient levels using mixed models. Adjusted odds ratios (ORs) with 95% CIs were determined for each major feature using multivariable stepwise logistic regression. Risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) (PROSPERO protocol: CRD42020164486). Results A total of 32 studies were included, with 1170 CT observations, 3341 MRI observations, and 853 CEUS observations. At multivariable analysis of CT/MRI LI-RADS, all major features were associated with HCC, except threshold growth (OR, 1.6; 95% CI: 0.7, 3.6; P = .07). Nonperipheral washout (OR, 13.2; 95% CI: 9.0, 19.2; P = .01) and nonrim arterial phase hyperenhancement (APHE) (OR, 10.3; 95% CI: 6.7, 15.6; P = .01) had stronger associations with HCC than enhancing capsule (OR, 2.4; 95% CI: 1.7, 3.5; P = .03). On CEUS images, APHE (OR, 7.3; 95% CI: 4.6, 11.5; P = .01), late and mild washout (OR, 4.1; 95% CI: 2.6, 6.6; P = .01), and size of at least 20 mm (OR, 1.6; 95% CI: 1.04, 2.5; P = .04) were associated with HCC. Twenty-five studies (78%) had high risk of bias due to reporting ambiguity or study design flaws. Conclusion Most Liver Imaging Reporting and Data System major features had different independent associations with hepatocellular carcinoma; for CT/MRI, arterial phase hyperenhancement and washout had the strongest associations, whereas threshold growth had no association. Ā© RSNA, 2021 Online supplemental material is available for this article

    Fabrication of SiCf/Ti3SiC2 by the electrophoresis of highly dispersed Ti3SiC2 powder

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    This paper reports the processing details and important phenomena occurred during the fabrication of a SiC fiber-reinforced Ti3SiC2 matrix composite (SiCf/Ti3SiC2). Because both SiC and Ti3SiC2 are microwave absorbing materials, the fabrication of SiCf/Ti3SiC2 deserves extensive study, where an improved mechanical property is expected due to the SiC fibers incorporated in the Ti3SiC2 matrix. To fabricate the composite, a highly dispersed Ti3SiC2 slurry was prepared by considering both steric and electrostatic dispersion mechanisms after adding different types of dispersants and polymeric processing additives. Electrophoresis was performed under a DC electric field to infiltrate the Ti3SiC2 particles into the voids of Tyranno (TM)-SA grade 3 woven fabric, followed by hot pressing at 1350 degrees C under 20 MPa. High energy milling of the starting material accelerated the decomposition of Ti3SiC2 during sintering due to mechano-chemical activation. By adopting mild ball milling, however, SiCf/Ti3SiC2 with a density >= 90% and a flexural strength >= 100 MPa could be fabricated, retaining the most of Ti3SiC2 matrix phase

    Multitask Siamese Network for Remote Photoplethysmography and Respiration Estimation

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    Heart and respiration rates represent important vital signs for the assessment of a personā€™s health condition. To estimate these vital signs accurately, we propose a multitask Siamese network model (MTS) that combines the advantages of the Siamese network and the multitask learning architecture. The MTS model was trained by the images of the cheek including nose and mouth and forehead areas while sharing the same parameters between the Siamese networks, in order to extract the features about the heart and respiratory information. The proposed model was constructed with a small number of parameters and was able to yield a high vital-sign-prediction accuracy, comparable to that obtained from the single-task learning model; furthermore, the proposed model outperformed the conventional multitask learning model. As a result, we can simultaneously predict the heart and respiratory signals with the MTS model, while the number of parameters was reduced by 16 times with the mean average errors of heart and respiration rates being 2.84 and 4.21. Owing to its light weight, it would be advantageous to implement the vital-sign-monitoring model in an edge device such as a mobile phone or small-sized portable devices.11Ysciescopu

    The effect of touch-key size on the usability of In-Vehicle Information Systems and driving safety during simulated driving

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    Investigating the effect of touch-key size on usability of In-Vehicle Information Systems (IVISs) is one of the most important research issues since it is closely related to safety issues besides its usability. This study investigated the effects of the touch-key size of IVISs with respect to safety issues (the standard deviation of lane position, the speed variation, the total glance time, the mean glance time, the mean time between glances, and the mean number of glances) and the usability of IVISs (the task completion time, error rate, subjective preference, and NASA-TLX) through a driving simulation. A total of 30 drivers participated in the task of entering 5-digit numbers with various touch-key sizes while performing simulated driving. The size of the touch-key was 7.5 mm, 12.5 mm, 17.5 mm, 22.5 mm and 27.5 mm, and the speed of driving was set to 0 km/h (stationary state), 50 km/h and 100 km/h. As a result, both the driving safety and the usability of the IVISs increased as the touch-key size increased up to a certain size (17.5 mm in this study), at which they reached asymptotes. We performed Fitts&apos; law analysis of our data, and this revealed that the data from the dual task experiment did not follow Fitts&apos; law. (C) 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.X111514sciessciscopu

    Photoelectrochemical Hydrogen Generation Using C-dot/ZnO Hierarchical Nanostructure as an Efficient Photoanode

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    In this study, we have developed a stable and environmental-friendly photoelectrode of carbon nanodots (C-dots) coupled with a 3 dimensional ZnO structure. Our C-dots are synthesized hydrothermally with a high yield of 40%, and they are successfully anchored onto the ZnO backbone via a facile solution procedure. The as-prepared C-dot/ZnO photoelectrodes have exhibited reasonable photocurrent density and remarkable photostability under the 1 sun irradiation condition without any sacrificial reagent. We have studied the chemistry beneath the C-dot/ZnO interface through various spectroscopic and electrochemical techniques. This work could shed light on future application of C-dots in efficient and toxin-free solar water-splitting systems. (C) 2015 The Electrochemical Society. All rights reserved.X1165sciescopu

    Cytologic Characteristics of Thymic Adenocarcinoma with Enteric Differentiation: A Study of Four Fine-Needle Aspiration Specimens

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    Thymic adenocarcinoma is extremely rare. Although its histologic features have been occasionally reported, a lack of description of the cytologic features has hampered the prompt and accurate diagnosis of this condition. Herein, we describe the cytologic findings and histology of four aspiration cytology specimens of thymic adenocarcinoma. The specimens were obtained from primary tumors, metastatic lymph nodes, and pericardial effusions. All four specimens showed three-dimensional glandular clusters with a loss of polarity and nuclear overlapping. One specimen had extensive extracellular mucinous material. Three specimens contained tumor cells with intracytoplasmic vacuoles. While the specimen with extracellular mucin showed relatively mild cytologic atypia, other specimens exhibited more atypical cytologic changes: irregular nuclear membranes, a coarse chromatin pattern, and prominent nucleoli. The cytologic features were correlated with the histologic features in each case of enteric type thymic adenocarcinoma. The differential diagnosis included other thymic carcinomas, yolk sac tumors, and metastatic adenocarcinoma from the lung or colorectum
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