Matching Items (207)
Description
Modern-day automobiles are becoming more connected and reliant on wireless connectivity. Thus, automotive electronics can be both a cause of and highly sensitive to electromagnetic interference (EMI), and the consequences of failure can be fatal. Technology advancements in engineering have brought several features into the automotive field but at the expense of electromagnetic compatibility issues. Automotive EMC problems are the result of the emissions from electronic assemblies inside a vehicle and the susceptibility of the electronics when exposed to external EMI sources. In both cases, automotive EMC problems can cause unintended changes in the automotive system operation. Robustness to electromagnetic interference (EMI) is one of the primary design aspects of state-of-the-art automotive ICs like System Basis Chips (SBCs) which provide a wide range of analog, power regulation and digital functions on the same die. One of the primary sources of conducted EMI on the Local Interconnect Network (LIN) driver output is an integrated switching DC-DC regulator noise coupling through the parasitic substrate capacitance of the SBC. In this dissertation an adaptive active EMI cancellation technique to cancel the switching noise of the DC-DC regulator on the LIN driver output to ensure electromagnetic compatibility (EMC) is presented. The proposed active EMI cancellation circuit synthesizes a phase synchronized cancellation pulse which is then injected onto the LIN driver output using an on-chip tunable capacitor array to cancel the switching noise injected via the substrate. The proposed EMI reduction technique can track and cancel substrate noise independent of process technology and device parasitics, input voltage, duty cycle, and loading conditions of the DC-DC switching regulator. The EMI cancellation system is designed and fabricated on a 180nm Bipolar-CMOS-DMOS (BCD) process with an integrated power stage of a DC-DC buck regulator at a switching frequency of 2MHz along with an automotive LIN driver. The EMI cancellation circuit occupies an area of 0.7 mm2, which is less than 3% of the overall area in a standard SBC and consumes 12.5 mW of power and achieves 25 dB reduction of conducted EMI in the LIN driver output’s power spectrum at the switching frequency and its harmonics.
ContributorsRay, Abhishek (Author) / Bakkaloglu, Bertan (Thesis advisor) / Garrity, Douglas (Committee member) / Kitchen, Jennifer (Committee member) / Seo, Jae-Sun (Committee member) / Arizona State University (Publisher)
Created2023
Description
Three models have been created to visualize and characterize the voltage response of a standing wave accelerating cavity system. These models are generalized to fit any cavity with known values of the quality factor, coupling factor, and resonant frequency but were applied to the Arizona State Universities Compact X-ray Free Electron Laser. To model these systems efficiently, baseband I and Q measurements were used to eliminate the modeling of high frequencies. The three models discussed in this paper include a single standing wave cavity, two cavities coupled through a 3dB quadrature hybrid, and a pulse compression system. The second model on two coupled cavities will demonstrate how detuning will impact two cavities with the same RF source split through a hybrid. The pulse compression model will be used to demonstrate the impact of feeding pulse compression into a standing wave cavity. The pulse compressor will demonstrate more than a 50\% increase of the voltage inside the cavity.
ContributorsFalconer, Jasmin (Author) / Graves, William (Thesis director) / Kitchen, Jennifer (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2023-05
Description新世纪以来中国电影的产业化改革与探索愈发呈现良好的态势，国产院线电影也在实践中努力赢得观众和票房市场。其中类型喜剧电影，最符合商业电影规律、最顺应影视市场需求、最能获得票房收益而备受影视创投机构、制作公司青睐。本论文研究对象聚焦类型喜剧电影，通过“欢声笑语里的财富”现象，探究类型喜剧电影内部本体构成要素与外部客观促成要素的关联；以通过分析自变量与因变量因素对中国电影票房之类型喜剧影响因素进行实证研究，为影视创投和影视制作总结并提供可靠建议。
本论文整体结构包括：第一部分为导论，包括研究背景、目的意义，相关文献综述与文献评述和论文创新性。第二部分聚焦类型喜剧本身，从电影学范畴的电影本体出发，探究“笑”的心理、社会与文化内涵，并分析将“笑”对经济领域的延伸。第三部分以影视投资、票房为依托，从现象和数据中探寻影响类型喜剧电影的因素，为展开中国电影票房之类型喜剧影响因素实证研究做好理论的铺垫。第四与第五部分则基于上述理论进行实证检验，选用2013-2020年电影样本，采用多元线性回归模型研究喜剧类型对票房的吸引力，以及不同种类型喜剧对电影票房的提振效果作用差异。研究发现喜剧电影对电影票房有显著的提振作用；以及研究电影的外部影响因素（续集效应）对电影票房的作用。发现续集电影有更好的票房表现，续集效应的票房提升作用在喜剧电影中表现的更加明显。
本论文研究成果最终将回归到“欢声笑语里的财富”本身；即“类型复合喜剧”对促进电影与金融产业的互动关联、实现更加可持续化发展，以及进而推动经济及文化业的发展。
ContributorsLiu, Yongqian (Author) / Shen, Wei (Thesis advisor) / Zhu, Ning (Thesis advisor) / Dong, Xiaodan (Committee member) / Arizona State University (Publisher)
Created2022
Description人口的老龄化不仅对养老事业提出更高的要求，也对养老服务产业人才的培养提出要求。但是青年学生选择涉老服务专业的意愿却非常低。因此，为了探究职业学院如何增强涉老服务专业吸引力这一问题，本文以学生为主体视角，利用相关理论，对于影响青年学生选择涉老服务专业的因素进行全面的分析，并结合深度访谈和调查法，提出并建构了相关的理论模型。首先，通过深度访谈和焦点小组讨论，结合对现有的文献的分析，本文提出了影响青年学生选择职业院校涉老服务专业的各种因素，主要包括：个人未来风险感知、家庭经济资本、社会信息评价、校企合作水平、专业课程建设水平、学生激励水平、师资队伍建设水平。之后，本文通过调查法，基于社会认同理论构建了本文的研究模型，并通过结构方程模型对所构建的模型进行检查。
本文的研究结果表明：个人未来风险感知对学生专业认同度产生负面影响；家庭经济资本对学生专业认同度产生负面影响；社会信息评价对学生专业认同度产生正面影响；校企合作水平对学生专业认同度产生正面影；专业课程建设水平对学生专业认同度产生正面影响；学生激励水平对学生专业认同度产生正面影响；师资队伍建设水平对学生专业认同度产生正面影响；学生专业认同度对学生专业选择意愿产生正面影响。
基于上述研究结论，本文选取了个人未来风险感知、家庭经济资本、社会信息评价、校企合作水平、专业课程建设水平、学生激励水平、师资队伍建设水平等因素对于广东岭南职业技术学院涉老服务专业的现有吸引力进行了分析和评估，并从这些视角进一步了对如何提升招生吸引力问题进行探讨，为提高涉老服务专业对于青年学生的吸引力，得出了相关管理建议。
ContributorsZhou, Lanqing (Author) / Shen, Wei (Thesis advisor) / Wu, Fei (Thesis advisor) / Pei, Ker-Wei (Committee member) / Arizona State University (Publisher)
Created2021
Description
The development of portable electronic systems has been a fundamental factor to the emergence of new applications including ubiquitous smart devices, self-driving vehicles. Power-Management Integrated Circuits (PMICs) which are a key component of such systems must maintain high efficiency and reliability for the final system to be appealing from a size and cost perspective. As technology advances, such portable systems require high output currents at low voltages from their PMICs leading to thermal reliability concerns. The reliability and power integrity of PMICs in such systems also degrades when operated in harsh environments. This dissertation presents solutions to solve two such reliability problems.The first part of this work presents a scalable, daisy-chain solution to parallelize multiple low-dropout linear (LDO) regulators to increase the total output current at low voltages. This printed circuit board (PCB) friendly approach achieves output current sharing without the need for any off-chip active or passive components or matched PCB traces thus reducing the overall system cost. Fully integrated current sensing based on dynamic element matching eliminates the need for any off-chip current sensing components. A current sharing accuracy of 2.613% and 2.789% for output voltages of 3V and 1V respectively and an output current of 2A per LDO are measured for the parallel LDO system implemented in a 0.18μm process. Thermal images demonstrate that the parallel LDO system achieves thermal equilibrium and stable reliable operation.
The remainder of the thesis deals with time-domain switching regulators for high-reliability applications. A time-domain based buck and boost controller with time as the processing variable is developed for use in harsh environments. The controller features adaptive on-time / off-time generation for quasi-constant switching frequency and a time-domain comparator to implement current-mode hysteretic control. A triple redundant bandgap reference is also developed to mitigate the effects of radiation. Measurement results are showcased for a buck and boost converter with a common controller IC implemented in a 0.18μm process and an external power stage. The converter achieves a peak efficiency of 92.22% as a buck for an output current of 5A and an output voltage of 5V. Similarly, the converter achieves an efficiency of 95.97% as a boost for an output current of 1.25A and an output voltage of 30.4V.
ContributorsTalele, Bhushan (Author) / Bakkaloglu, Bertan (Thesis advisor) / Garrity, Douglas (Committee member) / Seo, Jae-Sun (Committee member) / Kitchen, Jennifer (Committee member) / Arizona State University (Publisher)
Created2021
Description本文在对分子诊断与基因测序相关概念以及文献进行分析和整理的基础上，通过批判分析找到当前研究的空白之处。在此基础上，从理论角度对研发投入、团队背景、应用场景等因素对公司财务绩效的作用机理以及销售模式对研发投入与公司财务绩效关系的调节机理进行分析并提出相关研究假设。利用华大基因、达安基因、凯普生物、金域医学、迪安诊断、艾德生物、透景生命、贝瑞基因等8家分子诊断与基因测序领域上市公司的数据实证了上述研究假设。研究发现：（1）研发投入能够显著促进分子诊断与基因测序公司的财务绩效，但是这种作用效力较小。公司规模和债务水平的提高会降低公司财务绩效，机构投资人持股比例和市场推广费用对公司财务绩效的影响不显著。
（2）创业团队背景的不同并不会导致分子诊断与基因测序公司财务绩效产生差异。
（3）采取直销模式的分子诊断与基因测序公司财务绩效要优于代销和混合模式，后两者公司财务绩效没有显著差异；与代理模式相比，采取直销模式的公司其研发对公司财务绩效的促进作用更加明显，混合模式公司则没有显著差异。
（4）不同产品应用场景的分子诊断与基因测序公司财务绩效，肿瘤的最好，传染病其次，遗传病的排在最后。
ContributorsGuan, Jian (Author) / Shen, Wei (Thesis advisor) / Jiang, Zhan (Thesis advisor) / Sun, Tianshu (Committee member) / Arizona State University (Publisher)
Created2022
Description
Entrepreneurship entails a transition from status quo to a founder/leader of a new organization, and the dominant view in the literature focuses on opportunities in a hypothetical situation, namely an entrepreneurial option. This study shifts the attention from an entrepreneurial option to a current situation and proposes that a perception of costliness in status quo as a driver of entrepreneurial decisions and strategies. Specifically, I propose that a perception of inequality due to the local hierarchy of an organization engenders motivation of disadvantaged employees to become a leader of his/her own entrepreneurial organization. Utilizing hierarchy-based power dynamics and attribution biases, I theorize that i) status gap between a leader and a member and ii) status distinctiveness of a leader in the current organization affect an entrepreneurial decision because of inequality perception. Furthermore, I hypothesize that entrepreneurial organizations driven by such status inequality are more likely to replicate the local structure of the previous employer in terms of status hierarchy to compensate for the perceived disadvantages in the previous employer. The empirical analyses of this study investigate entrepreneurial decisions and entrepreneurial team formation of jazz musicians from jazz discographies between 1950 and 2018, and I found supportive results. This study contributes to the entrepreneurship and inequality literature by bridging two research spaces. It first uncovers the roles of a negative perception of the status quo in entrepreneurship, in addition to the established idea of a positive perception of an alternative option. It also suggests a novel explanation of the long-standing question of inequality reproduction by looking at whether and how inequality spreads via entrepreneurship.
ContributorsJeon, Chunhu (Author) / Shen, Wei (Thesis advisor) / Bundy, Jonathan N (Thesis advisor) / Certo, S. Trevis (Committee member) / Arizona State University (Publisher)
Created2022
Description
The Compact X-ray Light Source is an x-ray source at ASU that allows scientists to study the structures and dynamics of matter on an atomic scale. The radio frequency system that provides the power to accelerate electrons in the Compact X-ray Light Source must operate with a high degree of precision. This thesis measures the precision with which that system performs.
ContributorsBabic, Gregory (Author) / Graves, William (Thesis director) / Kitchen, Jennifer (Committee member) / Holl, Mark (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor) / Department of Physics (Contributor)
Created2022-05
Description
This paper analyzes China's transformative changes over the past four decades through a microeconomic lens focused on enterprises. Market-oriented non-state-owned enterprises have emerged as a pivotal force driving China's economic development within this context. The article investigates the determinants of their development. Notably, more than half of market-oriented non-state-owned enterprises have entered the inheritance stage, necessitating the exploration of novel attributes for sustained growth.The study's research scope is defined across four dimensions, with a specific focus on approximately 4,000 market-oriented non-state-owned enterprises. It investigates the driving factors behind sustained performance growth at various stages of these enterprises, emphasizing five variables: "partnership governance, entrepreneurial spirit, development strategy, incentive mechanisms, and innovation capability." Employing a combination of "typical case studies" and "group validation" methods, the research examines the factors influencing sustained growth in these enterprises and their interrelationships. The goal is to construct a model for enterprise succession and development, ultimately offering recommendations to foster sustained growth.
The research paper is structured into an introduction, literature review and theoretical foundation, typical case studies, empirical research on a group, and a conclusion.
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Key findings include: Partnership governance positively impacts partners' entrepreneurial spirit, promoting sustained performance growth. Trajectory-oriented development strategies, effective incentive mechanisms, and leading innovation capabilities have a positive moderating effect on entrepreneurial spirit, fostering sustained performance growth. During the innovation development phase, partnership governance significantly influences entrepreneurial spirit with a noteworthy environmental moderation effect.
The paper recommends implementing a "Dual-Factor Improvement Model" that enhances both partnership governance systems and the selection and functioning mechanisms of entrepreneurial spirit partners. This approach aims to boost partners' entrepreneurial spirit and facilitate high-quality succession in market-oriented non-state-owned enterprises，，ultimately achieving sustained high-quality growth.
In conclusion, this research contributes to a deeper understanding of sustained performance growth in enterprises. It offers valuable insights for the succession and development of market-oriented non-state-owned enterprises and innovation-driven entrepreneurship. This research holds significant value in advancing sustained high-quality development among market-oriented non-state-owned enterprises in China, optimizing resource allocation, and nurturing talented individuals.
ContributorsDeng, Cheng (Author) / Shen, Wei (Thesis advisor) / Cheng, Shijun (Thesis advisor) / Wu, Fei (Committee member) / Arizona State University (Publisher)
Created2023
Description
With the increasing aging population in China, the public's emphasis on health has been on the rise. Many innovative pharmaceutical companies have undertaken multiple rounds of financing, with some going public through IPOs. As a high-tech industry, it is essential to study the relationship between the level of corporate publicity and the financing process.This study collected information on the number of promotional articles, timing, and platforms of dozens of pharmaceutical companies that have already gone public through IPOs using Python. An analysis was conducted on the temporal variations of promotional articles for ten representative companies. It was found that the number of promotional articles experienced a significant increase in the month of IPO or the month before, and remained relatively high even after the IPO.
Furthermore, the Pearson correlation coefficient method was used to analyze the correlation between the number of promotional articles and various stages of financing. The study found a positive correlation between the daily average number of promotional articles before IPO and the final financing amount. Additionally, a strong positive correlation was observed between the daily average number of promotional articles from 7 days before IPO to IPO day and the turnover rate on IPO day. Grey correlation analysis was also employed to analyze the impact of publicity on the financing amount of each
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financing round, revealing that the financing round and the Shanghai Composite Index had a significant influence.
Finally, a multiple regression analysis was conducted to examine the relationship between the pre-IPO financing scale, IPO-day trading amount, and the level of corporate publicity. The regression results indicated that the pre-IPO financing scale was mainly influenced by the number of promotional articles in the 7 days preceding IPO, particularly for pharmaceutical companies listed on the A-share market. Moreover, a negative correlation was observed between the financing round and the financing amount, particularly among companies that experienced a decline in share price on the IPO day. However, the study found a weak association between the IPO-day trading amount and the level of corporate publicity, primarily observed among pharmaceutical companies listed on the A-share market.
ContributorsMiao, Yujia (Author) / Shen, Wei (Thesis advisor) / Jiang, Zhan (Thesis advisor) / Cheng, Shijun (Committee member) / Arizona State University (Publisher)
Created2024