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A Low-Offset Low-Noise Sigma-Delta Modulator with Pseudorandom Chopper-Stabilization Technique
No full textThis paper presents a low-offset low-noise sigma-delta modulator with pseudorandom chopper-stabilization technique. The comparison of the noise-cancellation ability with the correlated double sampling and chopper-stabilization techniques is demonstrated; also, the noise performance of these cancellation techniques is observed and discussed. Using the proposed technique, the modulator achieves 92 dB of dynamic range and -135 dB of noise floor while consuming 950 ¿W from a 3-V supply. Based on the experimental results, the pseudorandom chopper-stabilization technique has a DC offset voltage that is 6 dB lower than that of the chopper-stabilization technique, and retains a thermal noise floor that is 1.6 dB lower than that of the correlated double sampling technique.補正完畢US
The future of hotel check-ins: Evaluating generation Z's acceptance of facial recognition technology using AIDUA-PMT model approach
No full textResearch background: The use of facial recognition services (FRS) is growing rapidly, yet there is a lack of research examining the impact of a protective perspective on individual acceptance. Thus, it is necessary to comprehensively understand the perceptions of tourists toward utilizing artificial intelligence (AI) devices within the hospitality industry.
Purpose of the article: This study aims to examine the influence of protective behavior on individuals’ adoption of hotel FRS via a theoretical framework that integrates the Protection Motivation Theory with the AI Device Use Acceptance model, in the context of FRS.
Methods: Partial least squares structural equation modelling is employed to test the proposed model, utilizing data from Generation Z tourists in Taiwan.
Findings & value added: The findings reveal Generation Z's willingness to use hotel FRS is significantly influenced by their emotions and self-efficacy elicited by using FRS. The results also recognize the crucial significance of hedonic motivation, as it affects Generation Z's performance expectancy and emotions, resulting in their increased willingness to use hotel FRS. Conversely, perceived vulnerability has a negative effect on willingness to use hotel FRS, identifying security concerns as a significant barrier. These insights emphasize the importance of addressing security concerns, enhancing user confidence, and leveraging the hedonic aspects of FRS to foster acceptance among Generation Z tourists in the hotel sector.補正完畢PO
Equivariant CR Yamabe problem
No full textAs a generalization of the Yamabe problem, Hebey and Vaugon considered the equivariant Yamabe problem: for a subgroup G of the isometry group, find a G-invariant metric whose scalar curvature is constant in a given conformal class. In this paper, we introduce the equivariant CR Yamabe problem and prove some related results.補正完畢US
Noncompactness of the constant scalar curvature and constant boundary mean curvature equation
No full textTaiwanese Mathematical Society補正完畢國內台北，臺灣TW
Source-Free Domain Adaptation via Enhanced Self-Supervised Learning
No full textThis paper addresses the challenge of Source-free Domain Adaptation (SFDA), where knowledge is transferred from a labeled source domain to an unlabeled target domain without requiring access to the source data during adaptation. Traditional Unsupervised Domain Adaptation (UDA) methods typically depend on source data availability during training, which raises concerns related to privacy, security, and scalability. Our proposed approach eliminates this dependency by leveraging only a pre-trained source model for adaptation to the target domain. We introduce a comprehensive framework that incorporates iterative centroid refinement for pseudo-labeling, enhanced self-supervised learning strategies, advanced regularization techniques, and dynamic loss weighting mechanisms. These innovations improve feature alignment and classification performance in the target domain. Extensive experiments conducted on diverse datasets, including digital and object benchmarks, demonstrate that our method consistently outperforms state-of-the-art techniques in both accuracy and robustness. Additionally, this study delves into the theoretical foundations of SFDA, providing insights into its efficacy and exploring its practical applications across various domains.補正完畢SG
Analysis of CO2 absorption in gas/liquid membrane contactors with inserted descending hydraulic diameters of 3D-printed turbulence promoters
No full textThe decline in absorption flux across membrane modules is attributed to the increase in concentration polarization resistance in flat-plate membrane contactors for CO2 absorption using monoethanolamine (MEA) as the absorbent. Researchers have discovered that this effect can be mitigated by inserting turbulence promoters, which enhance turbulence intensity at the cost of increased power consumption, thereby improving CO2 absorption flux. The performance of flat-plate membrane contactors for CO2 absorption was further enhanced by reducing the hydraulic diameters of embedded 3D-printed turbulence promoters, considering the increased power consumption. The mass-balance modeling, incorporating chemical reactions, was developed theoretically and conducted experimentally on a flat-plate gas/liquid polytetrafluoroethylene/polypropylene (PTFE/PP) membrane module in the present study. A one-dimensional theoretical analysis, based on the resistance-in-series model and the plug-flow model, was conducted to predict absorption flux and concentration distributions. An economic analysis was also performed on modules with promoter-filled channels, considering different array configurations and geometric shapes of turbulence promoters, weighing both absorption flux improvement and power consumption increment. Device performances were evaluated and compared with those of modules using uniform promoter widths. Additionally, the Sherwood number for the CO2 membrane absorption module was generalized into a simplified expression to predict the mass transfer coefficient for modules with inserted 3D-printed turbulence promoters. Results showed that the ratio of absorption flux improvement to power consumption increment in descending hydraulic-diameter operations is higher than in uniform hydraulic-diameter operations.補正完畢CH
Intelligent Guardian: Key Technology Research and Development for an Outdoor Leisure Activity Positioning Application and Communication System
No full text計畫編號：NSTC112-2622-8032-002-SP研究期間：11212 ~ 11311研究經費：400千元本計劃旨在導入LoRa通訊技術與GPS衛星定位系統於運動手錶中，應用於戶外休閒活動參與者，提升運動產業科技應用成效及戶外活動安全性。方法：本計劃分三階段進行：首先，建置LoRa通訊平台與GPS衛星定位系統的軟硬體條件，包括購置科技裝置、建置資料庫及串聯資料表單。接著，分析戶外休閒活動客群資料，設計精準配套定位系統，並測試不同行銷策略，收集回饋後微調。最後，推出智能守護者手錶服務，並進行產品實證，定期報告並調整產品數目和內容。結果：本計畫產出的智能守護者具有下列特點：(1) 精準掌握戶外活動參與者位置；(2) 全雙工語音通訊對講，讓登山者在無訊號區域與隊友或外界通話；(3) 通訊距離無限制，構成網狀智能網絡，隨時掌握聯繫資訊；(4) 輔助救援單位監控成效，降低戶外活動危險性。結論：智能守護者運動手錶將促進運動產業與科技結合，提供安全的運動環境，減少戶外休閒活動危險性，打造友善且安全的戶外運動環境，並在學術知識與產業實務層面提供具體貢獻，深化運動產業實質效益。國家科學及技術委員會補正完
Acid-Catalyzed Synthesis and CO2 Adsorption of Cu and Cu-Zn Bimetallic Imidazolate Frameworks
No full textCopper and copper-zinc imidazolate frameworks were successfully synthesized using improved mild acid catalyzed method. Imidazolates were directly reacted with metal oxides and formed copper or copper-zinc imidazolate frameworks. Copper-based mono- and bi-metallic imidazolate catalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption, Fourier transform infrared spectra (FTIR), thermogravimetry (TG), XANES/EXAFS and CO2 adsorption capacities were measured. XANES spectra confirmed the presence of Cu(II) in Cu(im)2, Cu(mim)2, Cu(bim)2 and Cu2Zn(im)6, while Cu(I) in Cu2Zn(im)4. The Cu–O bond distance in Cu(im)2 sample was 2.00 Å with the coordination number of 2.4. It has been found that the CO2 adsorption capacity is directly related to the total pore volume and the specific surface area of the metal imidazolates. Cu(im)2 showed the highest CO2 adsorption capacity of 8.3 mmol g−1 measured at 273 K and 25 bar. The BET specific surface area of Cu(im)2 was 83.94 m2g−1 with the total pore volume of 22.2 cm3g−1.補正完畢US
The resolved star-formation efficiency of early-type galaxies
No full textUnderstanding how and why star formation varies between galaxies is fundamental to our comprehension of galaxy evolution. In particular, the star-formation efficiency (SFE; star-formation rate or SFR per unit cold gas mass) has been shown to vary substantially both across and within galaxies. Early-type galaxies (ETGs) constitute an extreme case, as about a quarter have detectable molecular gas reservoirs but little to no detectable star formation. In this work, we present a spatially resolved view of the SFE in 10 ETGs, combining state-of-the-art Atacama Large Millimeter/submillimeter Array (ALMA) and Multi Unit Spectroscopic Explorer (MUSE) observations. Optical spectroscopic line diagnostics are used to identify the ionized emission regions dominated by star formation, and reject regions where the ionization arises primarily from other sources. We identify very few regions where the ionization is consistent with pure star formation. Using Ha as our SFR tracer, we find that previous integrated measurements of the star-formation rate based on UV and 22 um emission are systematically higher than the SFR measured from Ha
. However, for the small number of regions where ionization is primarily associated with star formation, the SFEs are around 0.4 dex higher than those measured in star-forming galaxies at a similar spatial resolution (with depletion times ranging from
108 to 1010yr). Whilst the SFE of ETGs is overall low, we find that the SFEs of individual regions within ETGs can be similar to, or higher than, similar sized regions within star-forming galaxies.補正完畢GB