11 research outputs found

    Automatic Construction of a Korean Toxic Instruction Dataset for Ethical Tuning of Large Language Models

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    Caution: this paper may include material that could be offensive or distressing. The advent of Large Language Models (LLMs) necessitates the development of training approaches that mitigate the generation of unethical language and aptly manage toxic user queries. Given the challenges related to human labor and the scarcity of data, we present KoTox, comprising 39K unethical instruction-output pairs. This collection of automatically generated toxic instructions refines the training of LLMs and establishes a foundational framework for improving LLMs' ethical awareness and response to various toxic inputs, promoting more secure and responsible interactions in Natural Language Processing (NLP) applications.Comment: NeurIPS 2023 Workshop on Instruction Tuning and Instruction Followin

    Role of Si Doping in Reducing Coercive Fields for Ferroelectric Switching in HfO2

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    The ferroelectricity of HfO2 thin films is technologically useful with various advantages compared to conventional ferroelectrics. However, the application of orthorhombic HfO2 has been limited by its large coercive field compared to perovskite-based ferroelectrics. Using first-principles calculations, we extensively search for 34 dopant elements to reduce the problematic coercive fields and discover that the coercive fields exhibit a simple volcano shape against the dopant's size. We also discover that the Si dopant is a critical element in stabilizing tetragonal phase HfO2 (transition state) because of its intrinsic sp(3) bond favoring characteristics with oxygen, thereby notably lowering the coercive fields. We provide an atomic scale picture to understand the excellent role of Si in effective ferroelectric switching and a simple rule to tune coercive fields with various doping agents

    Facile Ferroelectric Phase Transition Driven by Si Doping in HfO2

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    The recently discovered ferroelectricity in thin-film orthorhombic HfO2, which can be directly integrated into complementary metal-oxide semiconductor technology, has become an important research target. However, the use of orthorhombic HfO2 in practical devices has been limited by undesirable mixing with the monoclinic phase, which is nonpolar and thus degrades the ferroelectric properties. Here, we demonstrate that a Si dopant significantly stabilizes the ferroelectric phase because of its unique bonding characteristics, particularly its intrinsic tendency to form strong covalent bonds with O, thereby weakening the phase boundary to stabilize the ferroelectric orthorhombic phase over 20 the nonpolar monoclinic phase, relatively. On the basis of our theoretical predictions, we conducted transmission electron microscopy measurements and confirmed that Si substitution doping indeed induced monoclinic structural components into the orthorhombic phase, which is a strong indication of the weakened phase boundary and subsequent facilitation of the ferroelectric transition. This work thus provides an atomic-scale picture for understanding the unique role of Si in promoting the ferroelectric phase and the dopant dependence on the wake-up effect in HfO2, offering a substantial advancement toward integrating ferroelectrics into practical devices

    Scale-free ferroelectricity induced by flat phonon bands in HfO2

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    Discovery of robust yet reversibly switchable electric dipoles at reduced dimensions is critical to the advancement of nanoelectronics devices. Energy bands flat in momentum space generate robust localized states that are activated independently of each other. We determined that flat bands exist and induce robust yet independently switchable dipoles that exhibit a distinct ferroelectricity in hafnium dioxide (HfO2). Flat polar phonon bands in HfO2 cause extreme localization of electric dipoles within its irreducible half-unit cell widths (~3 angstroms). Contrary to conventional ferroelectrics with spread dipoles, those intrinsically localized dipoles are stable against extrinsic effects such as domain walls, surface exposure, and even miniaturization down to the angstrom scale. Moreover, the subnanometer-scale dipoles are individually switchable without creating any domain-wall energy cost. This offers unexpected opportunities for ultimately dense unit cell???by???unit cell ferroelectric switching devices that are directly integrable into silicon technology

    Super-resolution visible photoactivated atomic force microscopy

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    Imaging the intrinsic optical absorption properties of nanomaterials with optical microscopy (OM) is hindered by the optical diffraction limit and intrinsically poor sensitivity. Thus, expensive and destructive electron microscopy (EM) has been commonly used to examine the morphologies of nanostructures. Further, while nanoscale fluorescence OM has become crucial for investigating the morphologies and functions of intracellular specimens, this modality is not suitable for imaging optical absorption and requires the use of possibly undesirable exogenous fluorescent molecules for biological samples. Here we demonstrate super-resolution visible photoactivated atomic force microscopy (pAFM), which can sense intrinsic optical absorption with similar to 8 nm resolution. Thus, the resolution can be improved down to similar to 8 nm. This system can detect not only the first harmonic response, but also the higher harmonic response using the nonlinear effect. The thermoelastic effects induced by pulsed laser irradiation allow us to obtain visible pAFM images of single gold nanospheres, various nanowires, and biological cells, all with nanoscale resolution. Unlike expensive EM, the visible pAFM system can be simply implemented by adding an optical excitation sub-system to a commercial atomic force microscope.117sciescopu

    Radial probe endobronchial ultrasound using a guide sheath for peripheral lung lesions in beginners

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    Abstract Background The diagnostic yields and safety profiles of transbronchial lung biopsy have not been evaluated in inexperienced physicians using the combined modality of radial probe endobronchial ultrasound and a guide sheath (EBUS-GS). This study assessed the utility and safety of EBUS-GS during the learning phase by referring to a database of performed EBUS-GS procedures. Methods From December 2015 to January 2017, all of the consecutive patients who underwent EBUS-GS were registered. During the study period, two physicians with no previous experience performed the procedure. To assess the diagnostic yields, learning curve, and safety profile of EBUS-GS performed by these inexperienced physicians, the first 100 consecutive EBUS-GS procedures were included in the evaluation. Results The overall diagnostic yield of EBUS-GS performed by two physicans in 200 patients with a peripheral lung lesion was 73.0%. Learning curve analyses showed that the diagnostic yields were stable, even when the procedure was performed by beginners. Complications related to EBUS-GS occurred in three patients (1.5%): pneumothorax developed in two patients (1%) and resolved spontaneously without chest tube drainage; another patient (0.5%) developed a pulmonary infection after EBUS-GS. There were no cases of pneumothorax requiring chest tube drainage, severe hemorrhage, respiratory failure, premature termination of the procedure, or procedure-related mortality. Conclusions EBUS-GS is a safe and stable procedure with an acceptable diagnostic yield, even when performed by physicians with no previous experience
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