Miracle-dz/UniFAR-FTUs huggingface dataset:
Modeling growth kinetics of thin films made by atomic layer deposition in lateral high-aspect-ratio structures

The conformality of thin films grown by atomic layer deposition (ALD) is studied using all-silicon test structures with long narrow lateral channels. A diffusion model, developed in this work, is used for studying the propagation of ALD growth in narrow channels. The diffusion model takes into account the gas transportation at low pressures, the dynamic Langmuir adsorption model for the film growth and the effect of channel narrowing due to film growth. The film growth is calculated by solving the diffusion equation with surface reactions. An efficient analytic approximate solution of the diffusion equation is developed for fitting the model to the measured thickness profile. The fitting gives the equilibrium constant of adsorption and the sticking coefficient. This model and Gordon's plug flow model are compared. The simulations predict the experimental measurement results quite well for Al2O3 and TiO2 ALD processes.
Modelling turbulence generation in solitary waves on shear shallow water flows

We derive a dispersive model of shear shallow water flows which takes into account a non-uniform horizontal velocity. This model generalizes the Green–Naghdi model to the case of shear flows. Besides the classical dispersion term in the Green–Naghdi model related to the acceleration of the free surface, it also contains a new dispersion parameter related to the flow structure. This parameter is related to the second moment of the velocity fluctuation with respect to the vertical coordinate. The distinction between shearing and turbulence based on the scale of variation of the velocity fluctuation is proposed. In particular, an equation for the turbulence generation is derived. Solitary waves for this model are obtained in explicit form. Comparison of solitary wave profiles with experimental ones is also performed. The agreement is very good apart from the small region near the top of the wave.
High temperature annealing and CVD growth of few‐layer graphene on bulk AlN and AlN templates

Graphene and AlN are promising materials, interesting to combine together. In this study, we will present first results for direct growth of graphene on bulk AlN and on AlN templates using chemical vapor deposition, including the annealing of these substrates at high temperatures. Atomic force microscopy (AFM) enabled us to study the evolution of the AlN surface morphology after annealing and growth. Few‐layer graphene deposition is demonstrated on the basis of X‐ray photoemission and Raman spectroscopy.
Laser-induced contamination of space borne laser systems: impact of organic contamination and mitigation by oxygen

Laser-induced contamination (LIC) is still a major risk for space based laser systems. In this paper the mitigation of LIC by oxygen is investigated. Tests were performed with a pulsed laser at 355 nm. The partial pressure of the contamination material was in the range of 10-5 -10-4 mbar. The mitigation effect showed a threshold behavior concerning the ratio between contamination and oxygen pressure. Also a cleaning effect was successfully demonstrated: previously created depositions were completely removed by irradiation at several tens Pa oxygen pressure without any remaining degradation of the optical surface.
Molecular Mechanics Simulations of Instabilities in 3D Deformations of Gold Nanospecimens

We use molecular mechanics (MM) simulations with th e ight-binding (TB) potential to study local and global instabilities in initially defectfree finite specimens of gold crystals deformed in shear, simple shear, tension/compression, simple te nsion/compression, and triaxial tension/compression. The criteria used to delineat e local instabilities in a system include the following: (i) a second order spatial derivative of the displace ment field having large values relative to its average value in the body, ( ii) the minimum eigenvalue of the Hessian of the potential energy of an atom becoming nonpositive, ( iii) and structural changes represented by a high value of the common neighborhood parameter. A specimen becomes globally unstable when its potential energy decreases significantly w ith a small increase in its deformations. It is found that the three criteria for local instability are satisfied essentially simultaneously at the same atomic position. Deformations of a specimen ar quite different when it is deformed with some bounding surfaces free from external forces as opposed to essential boundary conditions prescribed on all bounding surfaces. It is found t hat the initial unloaded configuration (or the reference configuration) of the minimum potential e nergy has significant in-plane stresses on the bounding surfaces and nonzero normal stresses at in terior points. In tensile/compressive deformations of a rectangular prismatic nanobar the yield stress defined as the average axial stress when the average axial stress vs. the averag e axial strain curve exhibits a sharp discontinuity depends upon the specimen size; a sim ilar result holds for simulations of shear deformations. Specimens deformed with essential bo undary conditions on all bounding surfaces experience instabilities at a higher value of the a v r ge strain than identical specimens deformed similarly but with one or more pairs of opposite bo unding surfaces traction free. For the former set of deformations, the response of a specimen pri or to the onset of instability is the same as that
Causal Inference of Repeated Observations: A Synthesis of the Propensity Score Methods and Multilevel Modeling

AbstractThe fundamental problem of causal inference is that an individual cannot besimultaneously observed in both the treatment and control states. The propen-sity score matching methods that compare the treatment and control groupsby discarding the unmatched units is now widely used to deal with this prob-lem. In some situations, however, it is possible to observe the same individualor unit of observation in the treatment and control states at di erent pointsin time. The data has the structure that is often refer to as time-series crosssectional (TSCS) data. While multilevel modeling is often applied to analyzeTSCS data, synthesizing the propensity score methods and multilevel modelingis preferable.The paper conduct a Monte Carlo simulation with 36 di erent scenariosto test the performance of the two combined methods. The result shows thatsynthesizing the propensity score matching with multilevel modeling is prefer-able in that such method yield less biased and more ecient estimates. Anempirical case study that reexamine the model of Przeworski et al. (2000) ondemocratization and development also shows the advantage of this synthesis.Keywords: causal inference, balancing score, multilevel modeling, propensityscore, time-series cross-sectional data
The Risk of Acute Suicidality in Psychiatric Inpatients Increases with Low Plasma Cholesterol

--? p-Several studies suggest that the reductlon of total cholesterol in blood by lipid-lowering agents is accompanied by a decrease in the incidence of coronary heart disease, but not in total mortality. Likewise, epidemiological studies show that low total cholesterol concentrations appear to be associated with an increased risk of death from suicide and injuries. There is little information with respect to acute suicidality and cholesterol in psychiatric inpatients; therefore the aim of the present study was to examine exactly this relation between plasma cholesterol and acute suicidality. The study comprised 45 acutely suicidal psychiatric inpatients. 95 nonsuicldal inpatients with affective disorder, and 20 healthy subjects. Psychopatholo-gical measures (Brief Psychiatric Rating Scale, Hamilton Depression Rating Scale, Beck's Suicide Intent Scale) were established in these patients as well as the plasma concentrations of cholesterol in patients and healthy subjects. The most important finding of this study is that the risk of acute suicidality decreases with Increasing total cholesterol levels irrespective of age, gender, and nutritional status (i.e. body mass index). comparison of total cholesterol levels between age-and sex-matched suicidal and nonsuicidal patients with affective disorder supports this observation: Despite the slightly higher body mass index, suicidal patients have significantly lower cholesterol levels than nonsuicidal patients. Our findings support the notion that acute suicidafity is associated with low plasma cholesterol: this observation needs to be further studied in the context of a biological marker for suicide risk.
Spatially adapted second-order total generalized variational image deblurring model under impulse noise

Image deblurring under impulse noise is a typical ill-posed problem which requires regularization methods to guarantee high-quality imaging. L1-norm data-fidelity term and total variation (TV) regularizer have been combined to contribute the popular regularization method. However, the TV-regularized variational image deblurring model often suffers from the staircase-like artifacts leading to image quality degradation. To enhance image quality, the detailpreserving total generalized variation (TGV) was introduced to replace TV to eliminate the undesirable artifacts. The resulting nonconvex optimization problem was effectively solved using the alternating direction method of multipliers (ADMM). In addition, an automatic method for selecting spatially adapted regularization parameters was proposed to further improve deblurring performance. Our proposed image deblurring framework is able to remove blurring and impulse noise effects while maintaining the image edge details. Comprehensive experiments have been conducted to demonstrate the superior performance of our proposed method over several state-of-the-art image deblurring methods.
Tunable Q-switched erbium-doped fiber laser based on curved multimode fiber and graphene oxide saturable absorber

A tunable Q-switched erbium-doped fiber laser using a singlemode-multimode-singlemode fiber structure as a wavelength tuning filter and a graphene oxide saturable absorber is proposed and demonstrated. The system allows the Q-switched laser to be tuned between the wavelengths of 1550.78 nm and 1560.62 nm, giving a tuning range of 9.84 nm. At a Q-switched laser wavelength of 1552.75 nm, a repetition rate of 39.1 kHz and pulse width of 3.6 µs, as well as an average output power of 1.32 mW and pulse energy of 33.8 nJ at a maximum pump power of 79 mW are obtained. Radio frequency analysis shows an average signal-to-noise ratio of 38.8 dB across the measured operating wavelengths, confirming that the system is stable and reliable, with small pulse width and intensity fluctuations.
Performance of progressive generations of GPT on an exam designed for certifying physicians as Certified Clinical Densitometrists

Background: Artificial intelligence (AI) large language models (LLMs) such as ChatGPT have demonstrated the ability to pass standardized exams. These models are not trained for a specific task, but instead trained to predict sequences of text from large corpora of documents sourced from the internet. It has been shown that even models trained on this general task can pass exams in a variety of domain-specific fields, including the United States Medical Licensing Examination. We asked if LLMs would perform as well on a much narrower subdomain tests designed for medical specialists. Furthermore, we wanted to better understand how progressive generations of GPT (generative pre-trained transformer) models may be evolving in the completeness and sophistication of their responses even while generational training remains general. In this study, we evaluated the performance of two versions of GPT (GPT 3 and 4) on their ability to pass the certification exam given to physicians to work as osteoporosis specialists and become a certified clinical densitometrists. Methods: A 100-question multiple-choice practice exam was obtained from a 3rd party exam preparation website that mimics the accredited certification tests given by the ISCD (international society for clinical densitometry). The exam was administered to two versions of GPT, the free version (GPT Playground) and ChatGPT+, which are based on GPT-3 and GPT-4, respectively (OpenAI, San Francisco, CA). The systems were prompted with the exam questions verbatim. If the response was purely textual and did not specify which of the multiple-choice answers to select, the authors matched the text to the closest answer. Each exam was graded and an estimated ISCD score was provided from the exam website. In addition, each response was evaluated by a rheumatologist CCD and ranked for accuracy using a 5-level scale. The two GPT versions were compared in terms of response accuracy and length. Results: The average response length was 11.6 {+/-}19 words for GPT-3 and 50.0{+/-}43.6 words for GPT-4. GPT-3 answered 62 questions correctly resulting in a failing ISCD score of 289. However, GPT-4 answered 82 questions correctly with a passing score of 342. GPT-3 scored highest on the Overview of Low Bone Mass and Osteoporosis category (72% correct) while GPT-4 scored well above 80% accuracy on all categories except Imaging Technology in Bone Health (65% correct). Regarding subjective accuracy, GPT-3 answered 23 questions with nonsensical or totally wrong responses while GPT-4 had no responses in that category. Conclusion: If this had been an actual certification exam, GPT-4 would now have a CCD suffix to its name even after being trained using general internet knowledge. Clearly, more goes into physician training than can be captured in this exam. However, GPT algorithms may prove to be valuable physician aids in the diagnoses and monitoring of osteoporosis and other diseases. Keywords: GPT; LLM; clinical densitometry; CCD;
Drivers of bias in diagnostic test accuracy estimates when using expert panels as a reference standard

Objectives: To assess the impact of study and expert panel characteristics on index test diagnostic accuracy estimates. Study Design and Setting: Simulations were performed in which an expert panel was used as reference standard to estimate the sensitivity and specificity of an index diagnostic test. Diagnostic accuracy was determined by combining probability estimates of target condition presence, as provided by experts using four component reference tests, through a predefined threshold. Study and panel characteristics were varied in several scenarios: target condition prevalence (20%, 40%, 50%), accuracy of component reference tests (70%, 80%, mixed), expert panel size (2, 3, 10), study population size (360, 1000), and random or systematic differences between expert's probability estimates. Bias in accuracy estimates across all possible true index test values was quantified for all scenarios. The total bias in each scenario was quantified using the mean squared error (MSE). Results: When estimating an index test with 80% sensitivity and 70% specificity, bias in these estimates was hardly affected by the study population size or the number of experts. When one expert was systematically biased, bias in sensitivity and specificity estimates increased, but this effect lessened when the number of experts in the panel was higher. Prevalence had a large effect on bias, scenarios with a prevalence of 0.5 estimated sensitivity between 63.3% and 76.7% and specificity between 56.1% and 68.7%, whereas scenarios with a prevalence of 0.2 estimated sensitivity between 48.5% and 73.3% and specificity between 65.5% and 68.7%. Random and systematic differences between experts also increased bias, with estimated sensitivity between 48.6% and 77.4% and specificity between 59.1% and 69.1% as opposed to scenarios without random or systematic differences, which estimated sensitivity between 58.0% and 77.4% and specificity between 56.1% and 69.1%. More accurate component reference tests also reduced bias. Scenarios with four component tests of 80% sensitivity and specificity estimated index test sensitivity between 60.1% and 77.4% and specificity between 62.9% and 69.1%, whereas scenarios with four component tests of 70% sensitivity and specificity estimated index test sensitivity between 48.5% and 73.4% and specificity between 56.1% and 67.0%. Conclusion: Bias in accuracy estimates when using an expert panel will increase if the component reference tests (combined) are less accurate. Prevalence, the true value of the index test accuracy, and random or systematic differences between experts can also impact the amount of bias, but the amount and even direction will vary between scenarios.
A novel gene-screening approach reveals QSOX1/IL1RAP as promising biomarkers for the severity of non-alcoholic fatty liver disease.

Background and Aims: Non-alcoholic fatty liver disease (NAFLD) is a progressive liver disease that ranges from simple steatosis to inflammation, fibrosis, and cirrhosis. To address the unmet need for new NAFLD biomarkers, we aimed to identify candidate biomarkers using publicly available RNA sequencing (RNA-seq) and proteomics data. Methods: A novel approach involving unsupervised gene clustering was performed using homogeneously processed and integrated RNA-seq data of 625 liver specimens to screen for NAFLD biomarkers, in combination with public proteomics data from healthy controls and NAFLD patients. Additionally, we validated the results in the NAFLD and healthy cohorts using enzyme-linked immunosorbent assay (ELISA) of plasma and immunohistochemical staining (IHC) of liver samples. Results: We generated a database (https://dreamapp.biomed.au.dk/NAFLD/) for exploring gene expression changes along NAFLD progression to facilitate the identification of genes and pathways involved in the disease's progression. Through cross-analysis of the gene and protein clusters, we identified 38 genes as potential biomarkers for NAFLD severity. Up-regulation of Quiescin sulfhydryl oxidase 1 (QSOX1) and down-regulation of Interleukin-1 receptor accessory protein (IL1RAP) were associated with increasing NAFLD severity in RNA-seq and proteomics data. Particularly, the QSOX1/IL1RAP ratio in plasma demonstrated effectiveness in diagnosing NAFLD, with an area under the receiver operating characteristic (AUROC) of up to 0.95 as quantified by proteomics profiling, and an AUROC of 0.82 with ELISA. Conclusions: We discovered a significant association between the levels of QSOX1/IL1RAP and NAFLD severity. Furthermore, the QSOX1/IL1RAP ratio shows promise as a non-invasive biomarker for diagnosing NAFLD and assessing its severity. (ChiCTR2300073940).
Preparation of hollow polymer particles with an opened single pore

ABSTRACT Polymer microparticles with size-controlled single pore was synthesized successfully using seeded emulsion polymerization. The pore size can be changed with relevant parameters. A scanning electron microscope(SEM) was used to characterize their pore size and morphology. Through measurement and calculation of SEM images, the change rules of pore size with the amount of monomer and porogen were taken.
An Elastica Model that Describes the Buckling of Cross-sections of Nanotubes

Multi-walled carbon nanotubes (MWNT) are well-known for their superior mechanical properties. Their size, tensile strength, and flexibility make them an attractive choice for a variety of practical applications. Thus numerous studies have been conducted in an effort to better understand the response of MWNT to applied loading. In this paper, we develop a nonlinear continuum model that describes equilibrium configurations of double-walled carbon nanotubes (DWNT). The DWNT is assumed to deform in such a way that enables us to reduce our analysis to a single cross-section perpendicular to the axis of the DWNT. We model the cross-section of a DWNT as 2 circular concentric rings that interact through a van der Waals body force. Utilizing our continuum assumption and the Lennard-Jones 12-6 potential function, we derive an expression for the body force. We apply Euler’s elastica theory to derive a two-point boundary value problem that consist of a system of 4 nonlinear ordinary differential equations with periodic boundary conditions. Using standard techniques of bifurcation theory, we establish a trivial branch of circular solutions and give a complete description of the critical radii at which buckled solutions bifurcate from the trivial branch.
Modeling of a Giant Exoring System Around the Substellar Companion J1407b

Abstract We model the complex light curve of 1SWASP J140747.93-394542.6, a ~16 Myr old star in the Sco-Cen OB association, with a giant ring system that fills a significant fraction of the Hill sphere of an unseen secondary companion, J1407b. The best ring model has 37 rings and extends out to a radius of 0.6 AU (90 million km), and the rings have an estimated total mass on the order of 1 M⊕. The ring system has one clearly defined gap at 0.4 AU (61 million km), which we hypothesize is being cleared out by a < 0.8 M⊕ exosatellite orbiting around the secondary companion.
A Design Method of Robust PID Control by Using Backstepping Control with Time Delay Estimation and Nonlinear Damping

논문은 시간지연을 이용한 추정(TDE)과 비선형 댐핑(nonlinear damping)을 이용하는 백스테핑 컨트롤(backstepping control)을 기반으로 하는 강인 PID 컨트롤의 디자인 방법을 제안한다. PID 제어기는 귀환 제어기로서 많은 산업 컨트롤 시스템 분야에서 널리 사용되며 비례, 미분, 적분 이득으로 구성되어 있다. PID 제어기는 우리가 원하는 입력과 시스템 출력 사이의 오차를 이용하고, 시스템을 제어하기 위해 요구되는 이득 값을 선택해서 원하는 입력 값을 시스템의 출력 값이 되도록 한다. PID 제어기의 이득 값은 시스템의 성능과 관련하여 물리적인 의미를 가지고 있으며, 이 이득값들이 잘 조절 되었을 때, 과도응답과 정상상태 오차가 동시에 잘 개선됨으로써 만족할만한 성능을 가지게 된다. 만족할만한 성능을 가지는 PID 제어기를 얻기 위해서 이득 값을 조절하는 것에 대한 많은 과거 연구가 이루어 졌다. 그러나 이들 연구는 대부분 선형 플랜트에서 진행되었으며 실제로 비선형 플랜트에서 이득 값을 선택하는 것은 어렵다. 비선형 플랜트에서도 PID 제어기를 구현하기 위한 많은 연구가 있지만 이들 연구에서 제안된 방법은 어렵고 이론적으로 복잡하며 때로는 안정성 분석에 대한 문제가 야기 된다. 그 결과, PID 이득 값은 체험적인 방법을 통하여 조절되는 것이 일반적이다. 이러한 문제에 대해, 디지털 시스템의 관점으로부터 비선형 플랜트에 대한 강건 PID 제어기의 이득 값을 선정하는 것에 대한 체계적인 방법이 제안되었다. 이 연구에서는, 플랜트의 모델을 정확히 알지 못함에도 불구하고, 플랜트가 이차 제어기 표준형으로 나타난다고 고려될 때, 제어기가 이산 시간 영역에서 실행된다면, 시간 지연을 이용한 제어기(TDC)를 이용해서 강건한 PID 제어기의 이득 값을 결정하는 방법이 제시되었다. 시간지연을 이용한 제어기와 PID 제어기의 등가 관계를 이용해서 PID 제어기의 이득 값이 결정 되었다. 시간지연을 이용한 제어기는 시스템의 비선형과 불확실성을 시간지연을 이용해 추정하는 간단하고 효율적인 제어기이다. 현재 시스템의 상태를 추정하기 위하여 한 단계 과거 시점의 시간에서 생성된 시스템 변수들의 정보를 이용하는 방법이다. 이 제어기는 시스템의 정확한 정보를 필요로 하지 않는 이점을 가지는 반면, 강한 비선형으로 인해 야기되는 시간 지연 추정에 의해 생기는 오차(TDE error)를 가진다는 단점 있다. 이 오차에 의해 시스템의 성능과 안정성이 저하된다. 문제는 강한 비선형을 가진 시스템에서 TDC 를 사용하여 PID 제어기의 이득 값을 구할 때, PID 제어기는 시간지연을 이용한 제어기(TDC)와 같은 특징을 가지게 되므로 시스템의 안정성과 성능이 보장되지 못하게 된다. 이러한 이유 때문에 이 연구에서는 시간지연 추정에 의해 생기는 오차(TDE error)를 상쇄시키고 제어기의 생성과정에서 안정성을 보장하는 시간 지연을 이용한 추정(TDE)과 비선형 댐핑(nonlinear damping)을 포함하는 백스테핑 제어기(backstepping control)를 이용한다. 이 제어기를 이용하여 우리는 등가의 PID 제어기를 구현하였고, 백스테핑 방법을 기반으로 하는 제어기의 파라미터를 이용하여 등가 PID 제어기의 이득 값들을 구성하였다. 따라서 PID 제어기는 강한 비선형에도 안정성이 보장되는 우수한 특징을 가지게 되었으며, 비선형 시스템에서 PID 제어기의 이득 값을 조절하는 것에 대한 문제를 해결하게 되었다. 또한, 제안된 PID 제어기는 비선형 댐핑에 의해서 가변 이득을 가지게 되며, 이는 시스템의 파라미터 변화와 외란에 강하다는 장점을 가지게 된다. 따라서 이 논문에서는 시간 지연 추정과 비선형 감쇠를 이용하는 백스테핑 제어기를 간단히 언급하고, 이를 이용해서 등가의 PID 제어기를 구성하고 제어기의 이득 값들을 구할 것이다. 또한, 제안된 PID 제어기에서 이득 값들의 크기와 형태를 분석할 것이며, 추가적으로 시간지연을 이용한 제어기(TDC)를 이용한 PID 제어기와 이 논문에서 제안된 PID 제어기를 비교할 것이다. 이러한 내용들은 모의실험과 실험을 통하여 증명 된다. ⓒ 2013 DGIST
A no reference quality metric to measure the blocking artefacts for video sequences

The need to measure video quality arises in the development of video equipment and in the delivery and storage of video and image information. In this paper, we propose a new perceptually significant video quality metric to estimate the effect of block coding for standards H.264 AVC and MPEG2. Our method operates in the spatial domain and does not require a high complexity of computation. We evaluate the performance of the proposed method by using three sequences CIF ‘common intermediate file’ with different compression rate. We compare it with Suthaharan’s and MSU’s techniques by using ‘LIVE’ and ‘IVP’ databases. Results indicate that the proposed method outperforms Suthaharan’s and MSU techniques in H264 coder. They also indicate that our method is more effective than MSU’s and Suthaharan’s techniques for the H.264 AVC standards with the Spearman Rank Order Correlation Coefficient.