Cells sense and interact with their microenvironment to retrieve signals which include cell-matrix and cell-cell contacts. These signals account for the influence of culturing conditions and often control the local cellular phenotype and global functions of tissues. Here, I sought to understand if there is any information processed by cells in guiding cellular phenotype given the control of cell shapes and substrate rigidities. If there is, would these phenotypic changes achieve biomedical purposes? What is the strategy to engineer platforms that can handle the longstanding challenges in those fields? In this dissertation, the first chapter serves as an introduction which involves the origin of motivations, which mainly came from current challenges in biomedical researches of kidney podocytes. I have attempted to understand if it is possible to control podocyte differentiation through cell shape control which mimics their in vivo morphology. On the other hand, I have tried to reveal if it is possible that tissue stiffness can affect podocyte phenotype as a result of stiffness sensing. These two topics were rarely investigated for kidney podocytes, which is the critical component of human filtration barrier to perform renal functions. The effort that addresses the question how shape and substrate rigidity as in- formation repositories affect kidney podocytes phenotype has profound meaning in the understanding of renal physiological system and pathological mechanisms. The second chapter will focus on the methods to achieve successful long-term shape control on cells. Engineered cell-device interface using cross-linking biomaterial SU-8 plays a key role in this study. Compared with other previously used approaches summarized in this chapter, SU-8 provides various advantages both in the fabrication of micro- pattern architecture as well as its sustaining effectiveness in controlling cell shape. This approach has been proved very efficient and economic to facilitate single cell level manipulation. The chapter will describe in details the interface micro-fabrication and encountered technical challenges. The results that kidney podocytes were in good compliance with the micro-pattern proved the successful application of this technique. The third chapter will then transfer from micro-fabrication to biological experiments, which discusses in details how in intro kidney podocytes responded to their shapes by enforcing protein localization which characterizes a phenotype found in vivo. This phenotype among in vitro podocytes was further verified that it may contribute to podocytes differentiation and physiological functions. The information processed by shape was proved independent of tension-related processes and thus shape and tension could be regarded as separate contributors in cellular development. The interpretation of shape’s contribution could be referred to my previous publication in the journal of Cell: ”Decoding Information in Cell Shape”. In this study, the motifs of research were applied to other cell lines (Human vascular smooth muscle cell) as a step to generalize the ubiquity of shape’s contribution to cell differentiation. The study here was to differentiate shape and tension through investigating the difference between two major mechanosensors: β3 and β1 integrin receptors. The difference in cell phenotypes through integrin inhibition experiments demonstrated critical but unique role of integrin-based shape sensing in vitro. This chapter in dissertation covers most of the content in a previously submitted paper to Nature Cell Biology. In the fourth chapter, I further carried out a study that investigated if stiffness sensing can influence kidney podocyte phenotype. The fourth chapter will basically review the techniques in the fabrication of hydrogel-based cell culture platforms. In a similar manner to previous study using biomimetic shape for podocytes and find its phenotype, the target of this analysis was to use hydrogel-based biomimetic substrate with renal physiological stiffness and find if there is a differentiation phenotype. Since numerous materials have been reported in hydrogel studies, I will focus on the introduction to representative ones that have been most widely used. Their characteristics will be compared with the demands of kidney podocyte reasearch. Methodologies were the key to a successful research, and in this chapter I will describe in details what choices I made in choosing experimental methods that improved the efficiency and quality of cell culture platforms. A natural enzyme (microbial transglutaminase) cross-linked gelatin hydrogel was adopted here to provide ideal substrate rigidity control for podocytes. This method has demonstrated high efficiency and stability in making large cell culture surface. Moreover, it provides the hydrogel platform with an ideal range of elastic moduli suitable for renal tissue culture. The results will be discussed in detail in the fifth chapter. I successfully found a differentiation phenotype for podocytes cultured on the hydrogel platforms with a physiological stiffness. Similar phenotype, on the contrary, were not found in podocytes on platforms which were either too soft or too stiff. These resutls have formed one of my submitted paper to Scientific Report. The differentiation phenotype for kidney podocytes was characterized by up-regulation of differentiation markers. These findings were in a similar manner to a series of stem cells differentiation guided by regulated substrate stiffnesses. This phenotype of kidney podocytes was verified by microarray technique which confirmed the stiffness sensing using transcription factors. The enrichment analysis of kinases also showed significant response of Src, Fyn etc, of which the activities have been shown critical for podocytes to preserve their physiological functions. These results have successfully suggested the close relations between stiffness changes of glomeruli basement membrane (GBM) and progressive podocyte dysfunction. In summary, this dissertation covers interdisciplinary researches that decoded the information processed by cells from two separate aspects: shape and stiffness sensing. The details in each chapter cover a broader scope than the content selected for publications. Through this dissertation, readers will get in touch with the technique developed for plat- form and their applications to biomedical researches. I wish this will help people new in the field to get my hands-on experience.

This dissertation looks closely at deployment of thin-film integrated inductors within power electronics, including details on the state-of-the-art technology for such inductors and related packaging techniques. Design challenges for systems using these inductors are discussed in detail, including the current outlook on magnetics development and the impact of these non-linearities on system design. In particular, this work looks closely at effects often left behind in modern discrete-component-based power module design, such as soft core saturation and significant high-frequency losses. In conjunction with the magnetics, a well-known non-linear controller for buck converters is analyzed in-depth for the first time, using frameworks from variable structure and sliding-mode control. This allows for development of a more profound rationale for the heuristic design guidelines that have been heretofore provided for this class of controllers. To verify the theoretical development, a testbench integrated CMOS front-end for a switched-inductor step-down, or buck converter is used to investigate departures of system behavior from the general wisdom around buck converter performance. Two packaging methodologies are explored for integration, and their impact on the design cycle and module lifetimes are discussed in some detail.

"January 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

在世界各地，自然或人為災難隨時可能發生。災難回應作為災難處理的重要環節顯得尤為重要，隨著科學技術的進步和提高，人們希望通過使用各種科學手段來提高災難的回應效率。機器人技術作為21世紀高科技結合的產物被廣泛應用於這一領域。一般情況下，設計者會採用功能集成的思想對機器人進行設計，他們的主要設計思想是根據自己對環境的理解和認知得到機器人的設計需求，然後針對設計需求，通過功能集成和疊加的方式來完成對機器人的設計，採用這種方式機器人一旦設計完畢，其功能也隨之確立並不可更改，這種設計思想是基於環境狀況的，即一旦災難現場的環境不符合預先的設定，機器人的執行能力將大幅下降，同時功能疊加的設計方式會產生功能與功能之間相互約束，影響其專業性。 / 本文介紹了一種基於分散式設計思想的全新設計理念，並且根據這一理念設計了一套基於任務需求的救援機器人系統。機器人系統不會根據設計者對災難現場的預先理解和認知而被一體化設計，相反根據"如何到達"和"如何操作"把機器人系統拆分成移動單元和操作單元兩個環節，針對每個環節分別設計了符合現場需求的通用移動模組和任務執行模組，救援人員可以根據災難現場的即時任務需求而迅速搭建出有針對性的機器人系統任務解決方案，和傳統的機器人系統相比，具適應性廣、靈活性高、針對性強等特點。 / 在本論文中，對三種通用的移動平臺和兩種通用的模組化關節以及一個快速連接器分別進行了結構設計、理論分析及樣機設計，並採用基本的通用模組，根據即時的任務需求構建出有針對性的多個機器人系統。實驗表明該機器人系統可以提供對災難環境有針對性的系統解決方案，具有一定容錯性、經濟性及災難環境的適應性。文章的創新點如下，首次針對于救援機器人提出分散式的設計思想，並以該思想為基礎設計了基於通用模組的救援機器人系統，針對不同任務對移動性能的不同要求設計了三種移動平臺，為滿足不同的救援操作要求設計了兩種模組化關節以及快速連接器。同時，文中為實際的地震救援任務提出了一套救援機器人系統解決方案。 / Natural and man-made disasters nowadays still present a large amount of risk. Disaster response is an important phase of disaster management, and the enhancement of its effectiveness and accountability has attracted an increasing amount of attention. Robots can help rescuers in doing this task because of its wide range of applications. In general, the rescue robot concept assumes one or more targeted tasks while design, and one or a set of robot(s) is/are designed by integrating different functions to accomplish those tasks. Once the design of a robot is finished, its function cannot be changed. However, this kind of design is environment-dependent, as once a disaster environment changes, the execution performance of the robot will reduce. Furthermore the function-integrated design concept may cause internal constraints between functions, and fail to provide a targeted solution for different disaster environments. / This dissertation introduces a novel design concept, based on which a requirement-oriented rescue robot system is developed. This design concept adopts a distributed strategy, according to which tasks are no longer seen as a whole but divided into two parts: traversability and operation. Several functional modules are designed to meet the different requirements of the two parts separately, and the entire robot system can be assembled using different functional modules according to the real-time requirements of the disaster environment. Compared with the traditional rescue robot system, this system can provide a more targeted solution for different disaster situations, and is more adaptable and flexible. / This dissertation details the basic functional modules, including three kinds of mobile bases for traversability and two sets of modular joints for operation, and analyzes a quick connector that makes the connection easier and more convenient. Several possible combinations of the rescue robot system are displayed to show how to construct a rescue robot system according to different requirements. This kind of rescue robot system can provide targeted solutions to different disaster tasks. Robustness is also enhanced, as the replacement of the functional modules is flexible and easy to overhaul. Furthermore, the functional modules can be decomposed and reused to make the robot system more economical. This dissertation makes several contributions. It presents a systematic solution for rescue robot, develops three mobile bases for high traversability and two kinds of modular joints and a quick connector for rescue operation. Furthermore, it also develops a rescue robot system for missions in earthquake. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Yang, Yong. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 226-236). / Abstracts also in Chinese.

The goal of this dissertation is to demonstrate the utility of portable, small-scale diffuse optical spectroscopic (DOS) systems for the diagnosis and treatment monitoring of various diseases. These systems employ near-infrared light (wavelength range of 650nm to 950nm) to probe human tissue and are sensitive to changes in scattering and absorption properties of tissues. The absorption is mainly influenced by the components of blood, namely oxy- and deoxy-hemoglobin (HbO2 and Hb) and parameters that can be derived from them (e.g. total hemoglobin concentration [THb] and oxygen saturation, StO2). Therefore, I focused on diseases in which these parameters change, which includes vascular diseases such as Peripheral Atrial Disease (PAD) and Infantile Hemangiomas (IH) as well as musculoskeletal autoimmune diseases such as Rheumatoid Arthritis (RA). In each of these specific diseases, current monitoring techniques are limited by their sensitivity to disease progression or simply do not exist as a quantitative metric. As part of this project, I first designed and built a wireless handheld DOS device (WHDD) that can perform DOS measurements at various tissue depths. This device was used in a 15-patient pilot study for infantile hemangiomas (IH) to differentiate diseased skin from normal skin and monitor the vascular changes during intervention. In another study, I compare the ultra-small form- factor WHDD’s ability to monitor synovitis and disease progression during a patient’s treatment of RA against the capabilities of a proven frequency domain optical tomographic (FDOT) system that has shown to differentiate patients with and without RA. Learning from clinical utility of the WHDD from these two studies, I adapted the WHDD technology to develop a compact multi- channel DOS measurement system to monitor perfusion changes in the lower extremities before and after surgical intervention for patients with peripheral artery disease (PAD). Using this multi- channel system, which we called the vascular optical spectroscopic measurement (VOSM) system, our group conducted a 20-subject pilot study to quantify its ability to monitor blood perfusion before and after revascularization of stenotic arteries in the lower extremities. This proof-of- concept study demonstrated how DOS may help vascular surgeons perform revascularization procedures in the operating room and assists in post-operative treatment monitoring of vascular diseases.

Chen, Xijun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 72-77). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Design Challenges --- p.2 / Chapter 1.2 --- Wireless Sensor Network Applications --- p.6 / Chapter 1.2.1 --- Military Applications --- p.7 / Chapter 1.2.2 --- Environmental Applications --- p.9 / Chapter 1.2.3 --- Health Applications --- p.11 / Chapter 1.3 --- Wireless Biomedical Sensor Networks (WBSN) --- p.12 / Chapter 1.4 --- Text Organization --- p.13 / Chapter Chapter 2 --- Design a Wearable Platform for Wireless Biomedical Sensor Networks --- p.15 / Chapter 2.1 --- Objective --- p.17 / Chapter 2.2 --- Requirements for Wireless Medical Sensors --- p.19 / Chapter 2.3 --- Hardware design --- p.21 / Chapter 2.3.1 --- Materials and Methods --- p.21 / Chapter 2.3.2 --- Results --- p.24 / Chapter 2.3.3 --- Conclusion --- p.27 / Chapter 2.4 --- Software design --- p.28 / Chapter 2.4.1 --- TinyOS --- p.28 / Chapter 2.4.2 --- Software Organization --- p.28 / Chapter Chapter 3 --- Wireless Medical Sensors --- p.32 / Chapter 3.1 --- Sensing Physiological Information --- p.32 / Chapter 3.1.1 --- Pulse Oximetry --- p.32 / Chapter 3.1.2 --- Electrocardiograph --- p.36 / Chapter 3.1.3 --- Galvanic Skin Response --- p.41 / Chapter 3.2 --- Location Tracking --- p.43 / Chapter 3.2.1 --- Outdoor Location Tracking --- p.43 / Chapter 3.2.2 --- Indoor Location Tracking --- p.44 / Chapter 3.3 --- Motion Tracking --- p.49 / Chapter 3.3.1 --- Technology --- p.50 / Chapter 3.3.2 --- Motion Analysis Sensor Board --- p.51 / Chapter 3.4 --- Discussions --- p.52 / Chapter Chapter 4 --- Applications in Medical Care --- p.54 / Chapter 4.1 --- Introduction --- p.54 / Chapter 4.2 --- Wearable Wireless Body Area Network --- p.56 / Chapter 4.2.1 --- Architecture --- p.58 / Chapter 4.2.2 --- Deployment Scenarios --- p.62 / Chapter 4.3 --- Application in Ambulatory Setting --- p.63 / Chapter 4.3.1 --- Method --- p.64 / Chapter 4.3.2 --- The Software Architecture --- p.66 / Chapter Chapter 5 --- Conclusions and Future Work --- p.69 / References --- p.72 / Appendix --- p.78

空間站探索是世界熱點研究問題，空間站巨大因此往往在外太空在軌建造和組裝，因此需要由宇航員和機器人開展大量的艙外工作（ Extra-Vehicular Activities，EVAs）。目前，宇航員的艙外工作存在以下三個方面的問題：（1）宇航員在移動攀爬和任務操作相互衝突的問題， 宇航員在艙外工作時不能一邊沿著扶手攀爬，一邊搬運載荷；（2）當前的空間機器人工作空間有限，在空間站表面有許多地方無法達到開展艙體檢查等在軌服務；（3）當前的空間機器人在狹窄空間裡操作效率不高，不能很好地避開障礙物和做精細化靈巧操作。 / 本論文針對以上問題提出了2 個機器人系統，四腿行走機器人（ Four-legged Robot Walker, FLRW ） 和圓弧軌道機器人（Circular Rail Robot System , CRRS）。四腿行走機器人擅長多退的扶手攀爬和操作，攀爬和操作可同時開展。四腿行走機器人還有一個可旋轉頭部（可旋轉的視覺系統）來增強攀爬過程中的視覺範圍。圓弧軌道機器人通過移動機器人在圓弧軌道的運動能完全覆蓋空間站的所有工作空間，該系統是在太空應用的第一個弧形軌道系統，同時也有最小的轉彎半徑。 / 本論文對提出的2 個機器人系統的移動性進行了深入的研究，四腿機器人側重在雙臂攀爬的策略、攀爬步態，並開展了全艙攀爬的在軌任務模擬驗證。圓弧軌道機器人開展了艙體軌道系統、多艙體軌道切換器、移動基座平臺、移動平臺驅動和轉彎半徑的深入設計與分析，並且完成了移動軌道平臺的原型樣機試製驗證。 / 本論文對提出的2 個機器人系統的操作臂開展了非球形腕部掛接、冗餘操作臂奇異點辨識研究，提出了一種雅克比初等變換（MJET）演算法進行操作臂奇異分析，該演算法可以將冗餘機械臂的6x7 奇異矩陣轉化到3x4 的子矩陣，大大提高了運算效率。論文還開展了在多移動物體環境下的避障研究，提出了一種即時的多移動物體障礙回避（MMOA）演算法，該演算法採用超曲面函數描述障礙物的包絡，採用偽距離即時計算與移動障礙物距離，取得了控制精度和即時性的平衡。 / 本論文對提出的2 個機器人系統的操作臂開展了動力學建模和在軌裝配研究，採用拉格朗日建模方法對操作臂建模，並與商務軟體ADAMS 對比驗證建模準確度。同時，並運用阻抗控制演算法針對ORU 的在軌抓取、安裝和轉移等在軌任務的實現驗證。 / 最後論文進行了總結和後續工作展望。 / Space station exploration is a global hot research topic. The space stations are usually large in scale so that they have to be fabricated and assembled in space, which involves a large number of Extra-Vehicular Activities (EVAs) by astronauts and robots. There are three main problems of EVA mission. (1) Astronauts experience a conflict between climbing and manipulation during EVA missions, as they cannot carry payloads while handrail climbing. (2) Current space robots have workspace limitations and cannot reach the whole exterior of a space station, making it challenging to carry out inspection and servicing. (3) It is also difficult for robots to avoid obstacles and perform fine manipulation tasks in a compact workspace. / Two robotics systems, the Four-Legged Robot Walker (FLRW) and the Circular-Rail Robot System (CRRS), are proposed to address the above problems. The FLRW is good at handrail climbing as it has multiple, identical legs. It also has a rotatable vision system to enhance its field of view during climbing. The CRRS provides full coverage of the space station workspace, as it is a mobile robot that drives on a circular rail system around the space station. This system is the first design of robotic system with circular-rail in space and also has the smallest turning radius. / The mobility of both robots is addressed. The FLRW analysis focuses on the climbing strategy and climbing gait analysis. The circular rail system, rail switch, mobile platform, driving force and turning radius of CRRS are carefully designed and analyzed. A prototype of the CRRS mobile platform is implemented for verification. / The proposed manipulator is designed with redundant joint and non-spherical-wrists. A Modified Jacobian Elementary Transformation (MJET) approach is proposed to determine all of the singularity conditions. This approach has a singularity isolation feature to reduce the computational workload. A Multiple Moving Obstacle Avoidance (MMOA) approach is proposed for manipulator path planning in a compact workspace. A super-quadric surface function is used to describe the shape of an obstacle, and the pseudo-distance from the manipulator to the obstacle is measured and controlled in real time. This approach achieves a good balance between computational complexity and accuracy. / The proposed manipulator is modeled using the Lagrangian dynamics formulation and the dynamics of the proposed manipulator is verified with the commercial software ADAMS (Automatic Dynamic Analysis of Mechanical Systems). The mathematics model has similar output in ADAMS under a constant torque input and a sine torque input. The Orbital Replacement Unit (ORU) assembly task is implemented using impedance control. Both simulation and hardware tests are completed for verification, and the experimental results show that the controller is good for on-orbit servicing tasks. / The contributions of the thesis are summarized and future work is proposed. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Chen, Yongquan. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 131-148). / Abstracts also in Chinese.

A research report submitted to the Faculty of Engineering and Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, Johannesburg 2017 / Depletion of mineral resources is a reality of mining. It is critical that as resources get depleted, new reserves are subsequently opened up continuously if a mine is to continue operating. Failure to open up new reserves will result in a mining operation running out of reserves and ultimately ceasing operations. Besides the economic considerations of an ore reserve such as the grade and tonnage, stability of the mining operation is of equal importance. A mine should remain stable for the entire period that it remains operational. Pillars play a critical role in ensuring the stability of an excavation; actually, regional pillars ensure the overall stability of a mine. It therefore goes without saying, pillar design is an integral component of any successful mine design. This project was undertaken with the objective of ensuring that the new reserves being opened up in the Khuseleka Ore Replacement Project (KORP) section are not only profitable, but also stable. This was done through a) maximisation of extraction ratio, thereby maximising the mines’ profitability. b) designing the regional pillar layout for the KORP section using current empirical and numerical pillar design methods and comparing the results to come up with the most optimal design. c) ensuring the stability of the on and off reef mine infrastructure by determining the Rockwall Condition Factor (RCF) values on the footwall infrastructure due to pillars left above and thus prevent damage to these excavations through stress induced failures. Consideration was given to the standard Khuseleka footwall infrastructure layouts for the design based on the planning department’s layout of haulages and crosscuts for the KORP section. The layout of the footwall excavations indicated that the pillars would be differently sized thereby having an influence on the APS, pillar strength and factors of safety of the regional pillars. d) numerical modelling analysis of the effects of leaving stabilizing pillars on the 27 raise line where the haulages intersect the reef horizon. The methodology employed for this undertaking involved a critical literature review of existing pillar design methods, applying and comparing them, and coming up with an economic and safe design. To be able to design a pillar layout that met the objectives listed above, engineering design principles had to be applied. It involved gathering the relevant geological and geotechnical information required as input parameters for the different empirical and numerical analyses methods. What came out from this project was that each method employed yielded its own set of results. This highlighted the need to understand the context under which a design is carried out and the shortcomings of each method employed. It showed how important it is to have all the relevant information of not only the characteristics of the rock mass in which an excavation will be made, but also on the strengths and limitations of the tools available to design a structure. It highlighted the fact that to minimize uncertainty and have a more robust design, it was necessary to spend time and effort in gathering as much relevant data as possible. In the end engineering judgment was used to decide on the best method or system to employ in the design of the pillars. / XL2018

Catheter-Associated Urinary Tract Infections are considered a clinical indicator of quality of care. A descriptive research study was conducted to identify the strategies used by hospitals to reduce or eliminate CAUTIs. Infection Control Preventionists were surveyed. In a predominately rural southeastern state, this study demonstrated that about 40% of hospitals surveyed are implementing CAUTI prevention processes.

Journal article published in The Qualitative Report 2018 Volume 23, Number 10, How to Article 2, 2264-2275 / This paper describes conditions that led to the use of a smartphone to collect qualitative data instead of using a digital voice recorder as the standard device for recording of interviews. Through reviewing technical documents, the paper defines a smartphone and describes its applications that are useful in the research process. It further points out possible uses of other applications of a smartphone in the research process. The paper concludes that a smartphone is a valuable device to researchers