34254 research outputs found
Sort by
A Study of Infusing Culture into School-based STEAM Curriculum
No full textAbstract
This study explores why the indigenous science curriculum lacks and interprets who is the main character to lead the curriculum. By designing how to integrate culture into school-based STEAM curriculum, the research organizes the review of school-based curriculum development and narrows the gap in science learning. Since 2017, the curriculum model and lesson plan for this research were designed, and the formal interview was conducted with 12 school teachers and staff. The research implemented the curriculum teaching and recording in 2022. Both qualitative and quantitative data were collected, including interviews, worksheets, and teaching reflection.The results of this study found:
1. Based on cultural leadership, the research cooperated with the main character from each school, combined with administrative and teaching leadership, and increased teachers\ue2 culture-integrated professional development knowledge and skills. To connect with indigenous life experiences, designing the science curriculum conforms to indigenous characteristics.
2. By executing the school\ue2s SWOT analysis, communication and cognition, persuasion, decision, and implementation, the study established the development of the school-based STEAM curriculum. Moreover, the research conducted the ABCDIE model, including analysis, business, construction, design, implementation, and evaluation.
3. Through the curriculum teaching implementation and recording, the quantitative scale and qualitative interview data showed that students\ue2 advanced learning motivation, interest, and attitude, and narrowed the gap in science learning. The ethnic identity and cultural confidence were also increased and established.
Lastly, based on the research results, this study recommends that school administrations adopt the advanced training of culture-integrated school-based curriculum, and teachers in indigenous areas should accept training of multicultural integration into the science curriculum, providing the class and teaching with multi-sensory learning assessment
Thermoelectric properties of ternary rare earth chalcogenides XAgZ2 (X = Sc or Y; Z = S, Se, or Te) predicted using first-principles calculations
No full textResearchers seek innovative thermoelectric materials to reduce fossil fuel dependency and boost energy efficiency. Ternary rare earth chalcogenides with a chemical formula of XYZ2 offer high Seebeck coefficient, outstanding electrical conductivity, and low thermal conductivity, making them ideal for various applications. In this research, a comprehensive exploration employing first-principles calculations was conducted to assess the structural stability, electronic characteristics, and thermoelectric properties of 6 bulk compounds denoted as XAgZ2, where X represents either Sc or Y, and Z corresponds to S, Se, or Te. Phonon dispersion and molecular dynamics computations affirm the thermodynamic stability of these bulk materials. The electronic characteristics, determined using the hybrid functional approach, reveal the presence of a multi-band feature and multiple band valleys in ScAgTe2 and YAgTe2. These features contribute to a notable Seebeck coefficient, consequently yielding a high-power factor. Furthermore, the calculations of the phonon transport under third-order perturbation theory predicted a low lattice thermal conductivity of 0.36 W/mK for ScAgSe2 and 0.43 W/mK for YAgSe2 at 900 K. Interestingly, the n-type ScAgTe2 and YAgTe2 achieve remarkable ZT values of 1.62 and 1.51 at 800 K, indicating potential for thermoelectric applications. The results we obtained offer essential proof underscoring the structural stability, resilient electronic characteristics, and remarkable thermoelectric capabilities within XAgZ2 materials, especially for utilization in thermoelectric applications. This is anticipated to spur interest in additional experimental synthesis and exploration
Yu-Han Fang Piano Recital Notes
No full textThis report is Yu-Han Fang's Piano Recital Notes on April, 26, 2023. The four pieces on the program include Piano Sonata in B-flat major, Op. 24 No. 2 by Muzio Clementi (1752-1832) , Aria detto Balletto by Girolamo Alessandro Frescobaldi (1583-1643) , 10 Bagatelles, Op. 5 by Alexander Nikolayevich Tcherepnin (1899-1977) , and Hungarian Dances, No. 1-6 by Johannes Brahms (1833-1897). These notes will introduce the lives of the four composers, the compositional backgrounds of individual work, and the analysis of the structure, including design and thematic materials in each work
Amorphous InGaZnO Thin-Film Transistors for Display and Memory Applications via Heterojunction Channels
No full textAmorphous indium-gallium-zinc oxide thin-film transistors are crucial components in display products owing to their exceptional material properties, including high carrier mobility, extremely low off-state leakage current, large-area uniformity, and high transparency to visible light. Therefore, they play essential roles in pixel switches of displays and driving current sources of organic light emitting diodes. Furthermore, owing to its advantage of low fabrication temperature, indium-gallium-zinc oxide semiconductors have become indispensable devices in the back-end-of-line of logic chips. However, despite the outstanding performances of indium-gallium-zinc oxide semiconductors, their long-term stability remains a challenging issue. To date, numerous studies have elucidated the deterioration of indium-gallium-zinc oxide semiconductors after long-term operation. These studies include analysis of stress conditions under direct current bias stresses, light irradiation, self-heating effects, or environmental atmospheres. Nevertheless, with the evolution of new-generation technologies such as augmented reality/virtual reality displays and its applications in advanced logic chips, their reliability under high-frequency/high-switching-rate conditions have become particularly significant. Therefore, this dissertation will focus on analyzing the deterioration of indium-gallium-zinc oxide semiconductor devices under these conditions and propose corresponding physical models. Additionally, within this dissertation, we will discuss the reliability challenges faced when varying the device structure to enhance their operating speed. Ultimately, our aim is to develop high- performance and reliability amorphous indium gallium zinc oxide semiconductor devices that are suitable for diverse applications.
In the first section of this study, we investigate the degradation model of etch-stop- layer type amorphous-indium-gallium-zinc-oxide thin-film transistors under dynamic switching operations. We observe a severe degradation of the threshold voltage in devices after alternating current operations, while the devices exhibit high stability under direct current operations. To further analyze the degradation model, we systematically discuss the stress with different switching waveform, geometry of devices, and temperatures. The results indicate that during the transition from accumulation to depletion, electrons will perform trapping behaviors at the rear interface of the active layer. This is due to the insufficient time for the channel layer to deplete carriers under a short falling time. Then, these residual carriers in the channel are further trapped at the rear interface of the channel when switching to the off-state voltage.
In the second section of this study, we investigate the instability of amorphous-indium-gallium-zinc-oxide thin-film transistors with copper electrodes under positive gate bias stress. To elevate the operating frequency of displays, copper metal is often chosen over aluminum metal for lower resistance-capacitance delay in the metal wiring. However, we realized that the devices will experience severe copper ion migration at the oxide layer after positive gate bias stress. We analyze the gate leakage throughout the stress duration by the carrier transport behavior in insulators to understand the degradation model. Additionally, to further observe the copper ions within the insulator layer, we used the focus ion beam system to prepare the cross-section of devices, followed by material analysis through the transmission electron microscopy system. The copper signals obtained from the material analysis directly confirm the diffusion behavior.
In the third section of this study, we integrated heterojunction channels into top-gate amorphous-indium-gallium-zinc-oxide thin-film transistors and achieved a high-performance/high-reliability transistor. The heterojunction channel is composed of two layers of indium-gallium-zinc oxide thin films with different metal ratios. The introduction of a zinc-rich layer as the front channel layer not only serves as a diffusion barrier layer which effectively suppresses the hydrogen diffusion behavior in short channel devices, but also reduces the vertical electric field in the gate insulator. To further validate this phenomenon, Silvaco TCAD simulations are conducted to systematically discuss the device characteristic and reliability of heterojunction channel thin-film transistors.
In the fourth section of this study, we demonstrate a nonvolatile optoelectronic memory through utilizing a heterojunction channel in amorphous-indium-gallium-zinc- oxide thin-film transistors. By exploiting the carrier confinement effect of heterojunction interfaces, we separated the carrier conduction and the charge storage at the front and back bulk layers of the active region, respectively. This device exhibits a memory window of 4.6 V, a read window of 106, and an operating voltage requirement below 20 V. In terms of charge storage capability, the memory retains its state for over 10 years and endures more than 1000 cycles of repeated operations
Novel Impedance Estimation for Distribution Systems with Voltage Magnitude Measurements
No full textIn recent years, concerns regarding grid stability have steadily risen, underscoring the increasing significance of smart grids in ensuring immediate and accurate system responses. Accurate grid impedance information plays a crucial role in distribution status estimation, decentralized power control within smart grid technology, and is indispensable for the impact analysis of new and renewable energy sources. The traditional impedance estimation method typically involves measuring each bus through a phase measurement unit (PMU) and then calculating the system impedance using complex values of voltage and current. Although this method is relatively straightforward in calculation, it demands high accuracy from the PMU.This paper introduces an impedance estimation method based on bus voltage. In this method, the phase angle of each bus is preset to 0\uc2\ub0, and the power and voltage of the bus are converted into current. Through parameter estimation, the line impedance is obtained using the bus voltage magnitude and line current. Forward iteration is then performed, and the current is recalculated after obtaining the phase angle of each bus bar. The system line impedance can be determined through continuous iteration until convergence. This method liberates the estimation of grid impedance from the reliance on PMUs, enabling smart grids to acquire more real-time impedance information for distribution status estimation and power control, especially when significantly impacted by environmental factors or when system parameters are unknown.The paper analyzes impedance estimation errors based on the accuracy of different measuring instruments and the accumulated information for the proposed impedance estimation method. In a 16-bus system with 24 pieces of measurement information, voltage measurement error \uc2\ub10.03%, line power measurement error \uc2\ub15%, and injected power measurement error \uc2\ub11%, the average absolute value of the error rate for the estimated impedance magnitude of all lines is 3.87%, with an average absolute angle error of 2.46\uc2\ub0.Furthermore, the paper considers the feasibility of installing PMUs in the system and integrating them into the calculation. Under the scenario of installing 5 PMUs with an error of \uc2\ub10.01\uc2\ub0, the average absolute value of the error rate for the estimated impedance magnitude of all lines is 2.35%, with an average absolute angle error of 1.55\uc2\ub0.This paper successfully overcomes challenges posed by the high cost and necessity of PMUs in power grid impedance estimation. It effectively addresses errors arising from changes in system parameters during power distribution status estimation and provides a more accurate solution. The decentralized power control equips the system with the line impedance matrix, enhancing its capability to manage a substantial influx of renewable energy in the future
Revisiting the Ego in Freudian Psychoanalytic Metapsychology: Based on the Problematic Axis from the Narcissism to the Topological Formation
No full textThis study directly re-examines Freud\ue2s psychoanalysis through psychoanalyst Jean Laplanche\ue2s contention of \ue2returning to Freud,\ue2 a method based on analytical clinical principles. This move bypasses the post-Freudian discourse space opened up by the incongruity caused by a large number of conceptual \ue2revisions\ue2 and \ue2supplements\ue2 in psychoanalytic metapsychology, and brings the core of the problem back to the original path for interpretation.
This thesis proposes a (re)constructive approach to reorganize metapsychology by the use of ego, in order to achieve a programmatic elucidation of related concepts that are usually considered ungraspable. This explanation will give a trajectory of transformation through the first and second topographies, and will also complete the general explanation of the ego form per se. The axis of argumentation takes the textual concept of narcissism that appeared in his monograph in 1914 as a leading clue, by using the structural shortcomings of the article to redraw the boundaries of problems, and traces the construction of metapsychology based on the dialectical elements from the libido theory. Based on this preliminary guideline, this thesis examines the development of ego as described by Freud, and uses the constitutive tension of the object-choice as a guide to deepen the formal construction of the organization of ego. Furthermore, this form can provide two types of construction problems in order to meet the apparatus problems of memory and consciousness represented by the experiences of satisfaction as well as the reality problems represented by the two principles of economy. The former addresses the correspondence between the agency levels and its defensive content in the early construction to the integrated structure in his late stage; the latter is related to the evolutionary discussion of the primary and secondary processes from which the pleasure principle is proposed, from the early neuron model and the overlapping schema of The Interpretation of Dreams to the final completion of the reality principle. The two meet each other under the judgment function of the ego that inspects representation. On the one hand, it creates a transformation from instinct to agencies that guides itself towards the ego; on the other hand, it leads to the differentiation of ego from the critical supervisory function.
After examining its own results, this thesis has the following contributions: a general explanation of the formation of the ego in Freud\ue2s metapsychology. Following the preceding rationale, the thesis also explains the entangled relationship between auto-erotism and narcissism, proposes Freud\ue2s own theorem of association theory, and makes a dialectical use of actuality to combine the concepts of introversion and frustration in an attempt to clarify the composition of reality. Then, the researcher reaffirms the errors submerged in post-Freudian theory arise from narcissistic pathology. Finally, the thesis raises an alternative perspective on the ego that develops in the primal phantasy, primal repression and the complex
Enhancing Masked Face Recognition through Adaptive Margin Quality
No full textIn practical applications, such as in medical institutions where masks are worn, the recognition success rate of faces may decrease due to obstruction. While it is possible to ask users to remove their masks for each recognition, this may affect user experience. Therefore, a more intelligent and practical solution is needed. Additionally, there are situations where users cannot be asked to remove masks, such as when identifying suspects from surveillance videos. Simultaneously, low-resolution images can lead to information loss and distortion, increasing the difficulty of recognition tasks, especially when dealing with complex conditions such as obstructions and changes in lighting. The research in this thesis aims to enhance the face recognition model\ue2s ability to cope with mask-wearing and handling low-quality images.
In recent years, the rapid development of deep learning has significantly advanced the field of face recognition, making it an indispensable technology in various practical appli- cations. To overcome the adverse effects of low-quality images on the training process, we consider using a loss function adapted to image quality to train the face recognition model. The advantage of this approach is the reduction of uncertainty in the training of low-quality images, such as blurry or low-resolution images, as these images often lack sufficient in- formation to recognize faces and learn key features of recognition. Furthermore, consid- ering the lack of images with individuals wearing masks in existing face datasets, we aim to augment the training data by synthesizing images with individuals wearing masks. To validate the feasibility of this approach, we generate test images with masks from common face test datasets such as LFW, CFP-FP, CPLFW, CALFW, and AgeDB, demonstrating that our method outperforms existing methods in these test datasets
Investigation of the Diffusion and Electric Conductivity of Alcohol Aqueous Solutions in Proton Exchange Membrane Nafion 117 by Variable Temperature Nuclear Magnetic Resonance and Electrochemical Impedance Spectroscopy
No full textTo address the pertinent problems such as methanol crossover, improvement and stability of electric conductivity and membrane degradation facing direct methanol fuel cells (DMFCs) which are regarded as the most promising alternative energy sources, some fundamental problems need more investigation such as a more comprehensive understanding of the interactions among fuel, water and the proton exchange membrane. Because Nafion has been widely used in DMFCs as their proton exchange membrane (PEM), this work aims at a better understanding on fuel crossover in Nafion. A series of alcohol solutions (methanol, ethanol) were used each to prepare 5 concentrations ( 10%, 20%, 30%, 40%, 50% ( w/w )) before introduced into Nafion samples. The 1H spectra, diffusion coefficients of alcohol and water were then measured and compared with the results of proton conductivity at different temperatures measured with electrochemistry impedance spectroscopy (EIS). We also employed FT-IR, UV-Vis as well as quantum chemistry calculation and molecular dynamics simulation to acquire supplementary data. It is found that not only the significantly different diffusion behavior of alcohol aqueous solutions in Nafion than that in the bulk state can be clearly revealed and quantified by these techniques, the correlations between diffusion, chemical shift and conductivity in Nafion samples filled with alcohol-water binary systems of different concentrations of alcohols can provide invaluable information on understanding the fuel crossover as well as proton conductivity mechanism, demonstrating the power of combining NMR spectra, diffusion and EIS in the studies of sustainable energy related functional materials
The constructed Utopia of Kang youwei\ue2s Thought of Datong
No full textThis thesis focuses on \ue2The constructed Utopia of Kang youwei\ue2s Thought of Datong\ue2. The germ of Kang youwei\ue2s thoughts on the great unity sprouted early on in his life. During the onset of the Sino-French war, he felt the plight of his nation and the misfortunes of its citizens, In response he wrote \ue2The universal principles of humanity\ue2 and \ue2The works of Kang youwei\ue2s\ue2 envisioning a world marked by equality. However, he witnessed China experiencing oppression from the western powers. He understood that for China to progress, it was necessary to break free from the constraints of traditional Chinese feudalism. Hence, he repeatedly submitted memorials to emperor Guangxu, eventually gaining him the approval from emperor Guangxu. Kang led the Hundred days\ue2 reform which was declared failed due to the strong opposition of the entrenched conservative forces, causing him without a choice but to become a fugitive in exile.
Through travels to various countries, Kang youwei gained a deeper and broader understanding of the world. His perspectives expanded beyond China, and it was during this time that his "Datong thought" matured, culminating in the writings of the utopian "Datongshu". Perceiving the sufferings of the world with a compassionate heart, Kang Youwei addressed various inequalities and aspired to chart a path of "evolution." He integrated Confucian concepts of "benevolence" and "Datong" with Buddhist notions of "compassion" and "great love," blending them with Western humanitarianism and concepts of human rights. Constructing a perfect world of equality and perfection known as \ue2The great world of unity\ue2.
In \ue2The great world of unity,\ue2 there exists no class oppression or exploitation, no suppression of the weak, no wars, and no restrictions of family and country. Both politics and the economy serve for its own people, and individuals receive comprehensive social welfare caring them from birth to death. Nevertheless, in a society where wisdom is not yet awakened and human nature is not inherently virtuous, this seemingly perfect social model appears to be a far-fetched and optimistic ambition.
In the "Datongshu," Kang Youwei proposed the sequence of "Subduing Chaos (traditional autocracy)," "Achieving Peace and Prosperity (constitutional monarchy)," and "Attaining Great Unity and Peace (democratic republic)." He believed that these three stages must be carried out gradually and in order, without radical changes. While this theory is open to discussion and controversy, it indeed provides a hopeful vision for the world's development and represents one of the positive values of Kang Youwei's "Datong thought" in his contemporaries and even in posterity.
Therefore, through the exploration of " The constructed Utopia of Kang youwei\ue2s Thought of Datong " this study aims to analyze Kang Youwei's ideas from different aspects such as human rights, politics, economy, and society. It is hoped that through this research, we can gain insights into his vision of the "The great world of unity.
Study on the microstructure and electrical property of electrochemical deposited cuprous oxide thin films
No full textThis study aims at characterizing the microstructure of cuprous oxide (Cu2O) epilayers deposited by an electrochemical method and the electronic property of the Cu/Cu2O, and ZnO/Cu2O junction samples. Cu2O films were deposited from a sulfate solution on copper or silver substrates in a galvanostatic or potentiostatic mode. Part of the samples were annealed in the air after deposition. The deposited films were characterized by scanning electron microscopy, x-ray diffraction, electron back scattering diffraction, and x-ray photoelectron spectroscopy. The I-V characteristics of the junction samples were also studied under dark and AM1.5 solar illumination.
Results indicated that the deposited potential (current density) increased with the increasing current density (potential) in deposition in a galvanostatic (potentiostatic) mode. In addition, the onset time for nucleation decreased with the increasing current density (potential). The films were mainly composed of Cu2O as deposited at 0.25 mA/cm2 to 4.0 mA/cm2 in a galvanostatic mode, and at 0.245 V to 0.40 V in a potentiostatic mode, though CuO was occasionally observed. Cu2O was deposited epitaxially on both copper and silver grains regardless of their orientations. Four out of five orientation relationships reported by D. Dai were observed in the galvanostatically deposited samples [1]. An additional orientation relationship R*: {102} Ag// {101} Cu2O was observed in the sample deposited at 0.50 mA/cm2. R1 was the dominant orientation relationship at 4.0 mA/cm2. Moreover, both (100)- and (110)-oriented Cu2O were observed in the films deposited on the (110)-oriented single-crystalline copper substrates. The deposited Cu2O were all composed of crystals in a size of 100 ~ 500 nm which increased with the increasing deposition potential. The FWHMs of (110) reflection of the epilayer deposited on the (110)-oriented single crystalline copper substrates were distributed in a range of 1.62 ~ 1.99 \uc2\ub0 whereas that of the substrate was 0.81 \uc2\ub0.
The as deposited films contained excess Cu which results in a Cu/O ratio higher than 2. The Cu2O thin film deposited at 0.30 V possesses a Cu/O ratio very close to 2. In addition, Cu in a metallic state (Cu0) was found in the Cu LMM Auger spectrum. Quantitative analysis indicated that the film deposited at 0.40 V contained the lowest amount of Cu0. Films annealed at temperatures of 300 ~ 350 \ue2 in air exhibited a Cu/O ratio of ~ 2. However, all the Cu/Cu2O samples failed to show Schottky barrier behavior in the second measurement, though Schottky barrier behavior was observed in the first one, indicating that the interface structure is unstable. All the ZnO/Cu2O heterojunction samples also failed to show power output under illumination