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The resolution of excess investment in Fuzzy portfolio selection using piecewise linear function
No full textFuzzy portfolio selection on the guaranteed return rate has been proposed to study excess investment in different dimensions of risk preferences. However, the theory of behavioural finance proposes that the investment proportions of securities are not only determined by the intrinsic value of the security but also largely affected by the behaviour of investors. Therefore, the investment behaviour of an investor in the fuzzy portfolio selection should be considered in the excess investment for different securities at different return rates. In this study, we propose a piecewise linear function for the fuzzy expected return rates and use the new decision variables for investment proportion in each security. In addition, considering the investment behaviours of decision-makers, we use the concept of fuzzy contingent strategy to take into account the relationships of investment proportion among the securities in the fuzzy portfolio selection. Analysis results indicated that we can find the investment proportions in the portfolio with the possible results of shortage investment, full investment, or excess investments by the fuzzy constraint of total investment proportions. Finally, in the illustration with two experiments, investors could individually select the portfolio by the piecewise linear function in shortage investment, full investment, or excess investment.補正完畢GB
Influence of Fe doping on the electrochromic properties of co-sputtered V2O5 thin films
No full textVanadium pentoxide (V2O5) attracts considerable attention in electrochromism due to its multicolor aspects and high ion storage capacity for the counter electrode. In this work, pure and Fe-doped V2O5 films are deposited by radiofrequency magnetron co-sputtering. The influence of Fe doping on the structural and electrochemical properties of V2O5-based thin films is investigated. Thin films containing up to 7.8 atom % of Fe are obtained without phase impurities. Although this high Fe doping is detrimental to V2O5 electrochromic properties, a proper amount of about 1.7 atom% of Fe leads to an enhancement of V2O5 crystallinity and electrochemical capacity. The higher capacity of a 1.7 atom % Fe-doped V2O5 film is associated with a stronger memory effect property, described as a reversible color persistence in open-circuit conditions. This work contributes to the exploration of Fe doping through co-sputtering and highlights the relevant role of the doping amount on the physicochemical properties of V2O5.補正完畢US
Manipulability-Aware Task-Oriented Grasp Planning and Motion Control with Application in a Seven-DoF Redundant Dual-Arm Robot
No full textTask-oriented grasp planning poses complex challenges in modern robotics, requiring the precise determination of the grasping pose of a robotic arm to grasp objects with a high level of manipulability while avoiding hardware constraints, such as joint limits, joint over-speeds, and singularities. This paper introduces a novel manipulability-aware (M-aware) grasp planning and motion control system for seven-degree-of-freedom (7-DoF) redundant dual-arm robots to achieve task-oriented grasping with optimal manipulability. The proposed system consists of two subsystems: (1) M-aware grasp planning; and (2) M-aware motion control. The former predicts task-oriented grasp candidates from an RGB-D image and selects the best grasping pose among the candidates. The latter enables the robot to select an appropriate arm to perform the grasping task while maintaining a high level of manipulability. To achieve this goal, we propose a new manipulability evaluation function to evaluate the manipulability score (M-score) of a given robot arm configuration with respect to a desired grasping pose to ensure safe grasping actions and avoid its joint limits and singularities. Experimental results demonstrate that our system can autonomously detect the graspable areas of a target object, select an appropriate grasping pose, grasp the target with a high level of manipulability, and achieve an average success rate of about 98.6%.補正完畢CH
Unsupervised domain adaptation with deep network based on discriminative class-wise MMD
No full textGeneral learning algorithms trained on a specific dataset often have difficulty generalizing effectively across different domains. In traditional pattern recognition, a classifier is typically trained on one dataset and then tested on another, assuming both datasets follow the same distribution. This assumption poses difficulty for the solution to be applied in real-world scenarios. The challenge of making a robust generalization from data originated from diverse sources is called the domain adaptation problem. Many studies have suggested solutions for mapping samples from two domains into a shared feature space and aligning their distributions. To achieve distribution alignment, minimizing the maximum mean discrepancy (MMD) between the feature distributions of the two domains has been proven effective. However, this alignment of features between two domains ignores the essential class-wise alignment, which is crucial for adaptation. To address the issue, this study introduced a discriminative, class-wise deep kernel-based MMD technique for unsupervised domain adaptation. Experimental findings demonstrated that the proposed approach not only aligns the data distribution of each class in both source and target domains, but it also enhances the adaptation outcomes.補正完畢US
Energy storage chemistry: atomic and electronic fundamental understanding insights for high-performance supercapacitors
No full textThe scarcity of fuels, high pollution levels, climate change, and other major environmental issues are critical challenges that modern societies are facing, mostly originating from fossil fuels-based economies. These challenges can be addressed by developing green, eco-friendly, inexpensive energy sources and energy storage devices. Electrochemical energy storage materials possess high capacitance and superior power density. To engineer highly efficient next-generation electrochemical energy storage devices, the mechanisms of electrochemical reactions and redox behavior must be probed in operational environments. They can be studied by investigating atomic and electronic structures using in situ x-ray absorption spectroscopy (XAS) analysis. Such a technique has attracted substantial research and development interest in the field of energy science for over a decade. The mechanisms of charge/discharge, carrier transport, and ion intercalation/deintercalation can be elucidated. Supercapacitors generally store energy by two specific mechanisms—pseudocapacitance and electrochemical double-layer capacitance. In situ XAS is a powerful tool for probing and understanding these mechanisms. In this Review, both soft and hard x rays are used for the in situ XAS analysis of various representative electrochemical energy storage systems. This Review also showcases some of the highly efficient energy and power density candidates. Furthermore, the importance of synchrotron-based x-ray spectroscopy characterization techniques is enlightened. The impact of the electronic structure, local atomic structure, and electronically active elements/sites of the typical electrochemical energy storage candidates in operational conditions is elucidated. Regarding electrochemical energy storage mechanisms in their respective working environments, the unknown valence states and reversible/irreversible nature of elements, local hybridization, delocalized d-electrons spin states, participation of coordination shells, disorder, and faradaic/non-faradaic behavior are thoroughly discussed. Finally, the future direction of in situ XAS analysis combined with spatial chemical mapping from operando scanning transmission x-ray microscopy and other emerging characterization techniques is presented and discussed.補正完畢US
Magnetization dynamics and domain reversal in electrodeposited permalloy thin films: impact of thickness and annealing treatment
No full textThe domain reversal and magnetization dynamics of electrodeposited permalloy (Fe20Ni80) thin films on conducting ITO/glass substrate was investigated using Magneto-optic Kerr effect microscopy and ferromagnetic resonance. Permalloy thin films were electrodeposited with thickness ranging from 66 nm to 330 nm. Synchrotron XRD confirmed the deposited permalloy in FCC phase without any impurity. The squared hysteresis with very low coercivity (Hc ∼ 5 Oe) established soft magnetic nature of the films. Further, angular MOKE hysteresis measurements with simultaneous domain imaging revealed four-fold surface anisotropy in as-deposited film ensuing magnetization reversal via branched and ripple domains. The annealing treatment in Ar+H2 atmosphere removed surface anisotropy and renovated the magnetization reversal through 180° branched domains with rapid magnetization switching. Ferromagnetic resonance spectroscopy discloses reduction in the gyromagnetic ratio (γ) as well as in Gilbert damping parameter (α) as the film thickness increases. The lowest Gilbert damping for 330 nm film measured at 0.022, which further reduced to 0.018 after annealing. The combination of rapid magnetization switching and low Gilbert damping in the electrodeposited permalloy thin films render them promising for implementation in high-frequency microwave devices devices and magnetic sensors.補正完畢GB
CEO Past Distress Experience and Risk‐taking: Evidence from US Property–Liability insurance firms
No full textWe investigate the relationship between CEOs' past distress experience and risk-taking in US property–liability insurance companies. Our evidence shows that CEOs' past distress experience is negatively associated with insurers' risk-taking behavior, suggesting that CEOs with distress experiences tend to take lower levels of risk in making financial decisions for their firms. The results are robust to using alternative measures of risk-taking, including value at risk, expected shortfall, volatility of stock return, idiosyncratic volatility, systematic volatility, underwriting risk, and investment risk. Additionally, our results pass a placebo test, and we mitigate endogeneity concerns with the propensity score matching method.補正完畢GB
Enhancing Specific Detectivity and Device Stability in Vacuum-Deposited Organic Photodetectors Utilizing Nonfullerene Acceptors
No full textOrganic photodetector (OPD) studies have undergone a revolutionary transformation by introducing nonfullerene acceptors (NFAs), which provide substantial benefits such as tunable band gaps and enhanced absorption in the visible spectrum. Vacuum-processed small-molecule-based OPD devices are presented in this study by utilizing a blend of boron subphthalocyanine (SubPc) and chlorinated subphthalocyanine (Cl6SubPc) as the active layer. Four different active layer thicknesses are further investigated to understand the intrinsic phenomena, unveiling the suppression of dark current density while maintaining photoexcitation and charge separation efficiency. Experimental results reveal that, at an applied bias of −3 V, the 50-nm-thick active layer achieves a remarkably low dark current density of 1.002 nA cm–2 alongside a high external quantum efficiency (EQE) of 52.932% and a responsivity of 0.226 A W–1. These impressive performance metrics lead to a specific detectivity of 1.263 × 1013 Jones. Furthermore, the findings offer new insights into intrinsic phenomena within the bulk heterojunction (BHJ), such as thermally generated current and exciton quenching. This integration is potentially well-heeled to revolutionize display technology by combining high-sensitivity photodetection, offering new possibilities for novel display panels with sensing applications.補正完畢US
Research on the Relationship Between ESG and Corporate Financial Performance Considering Endogeneity - A Case Study of Listed Companies in China
No full text本研究在考量內生性下，探討ESG（環境、社會、公司治理）對中國大陸上市公司財務績效是否具顯著影響，實證資料選自2018至2022年間的300家大陸上市公司。由於縱橫資料迴歸模型（Panel Data Regression Model）常存在內生性問題，透過Wu-Hausman檢定內生性問題後，進一步應用二階段最小平方法（Two-Stage Least Squares，2SLS）及廣義動差法（Generalized method of moments，GMM）模型進行參數估計及分析。結果顯示，ESG投入與ROA資產報酬率在2SLS模型及差分GMM與系統GMM模型估計均呈現顯著正關係，意謂企業落實執行ESG政策可激勵財務績效正成長。補正完畢TW
Examining national Paralympic sports development through the SPLISS model: Perspectives on Taiwan's future from global experiences
No full text隨著自由民主的時代演進，重視人權的理念與制度逐漸成為普世價值，處於相對弱勢的身心障礙族群，其追求健康與運動的權利越來越受到先進國家與社會的關注，而推動與發展帕拉運動即是倡議生存、自由、尊重、平等的最佳證明。儘管臺灣在推展帕拉運動已有近四十年的歷史，但如何與國家競技運動的政策方向與管理制度相互配合，甚至建構屬於身心障礙族群的帕拉運動系統，有賴借鏡世界上在帕拉運動取得成就的國家。本文探討在De Bosscher等（2006）提出的「國際運動成功之運動政策因素」（Sport Policies Leading to International Sporting Success framework, SPLISS）模式，探討該模式對各政策面向的定義與相互關係，分析世界各國競技運動政策的實例，進而探究SPLISS模式在帕拉運動中的獨特性，及指出臺灣帕拉運動的發展現況與挑戰，為回應這些挑戰，結合SPLISS模式對帕拉運動政策的分析，本研究提出七項建議：臺灣應增加帕拉運動經費支持的多元化，整合國內與帕拉運動相關的體育行政單位，建構完善的帕拉運動選才與培訓制度，提供帕拉運動員訓練、參賽與退役後的各種必要支持，積極參與或申辦國際帕拉運動賽事，提升運動教練與技術人員對帕拉運動的專業知能，並鼓勵帕拉運動科學研究，以建構一個適合臺灣國情的高效能帕拉運動系統，並成為引領國際體育運動成功的政策模式。補正完畢TW