Photoplethysmography (PPG) has become widely accepted as a valuable clinical tool for performing non-invasive biomedical monitoring. The dominant clinical application of PPG has been pulse oximetry, which uses spectral analysis of the peripheral blood supply to establish haemoglobin saturation. PPG has also found success in screening for venous dysfunction, though to a limited degree. Arterial Disease (AD) is a condition where blood flow in the arteries of the body is reduced,a condition known as ischaernia. Ischaernia can result in pain in the affected areas, such as chest pain for an ischearnic heart, but does not always produce symptoms. The most common form of AD is arteriosclerosis, which affects around 5% of the population over 50 years old. Arteriosclerosis, more commonly known as 'hardening of the arteries' is a condition that results in a gradual thickening, hardening and loss of elasticity in the walls of the arteries, reducing overall blood flow. This thesis investigates the possibility of employing PPG to perform vascular assessment, specifically arterial assessment, in two ways. PPG based perfusion monitoring may allow identification of ischaernia in the periphery. To further investigate this premise, prospective experimental trials are performed, firstly to assess the viability of PPG based perfusion monitoring and culminating in the development of a more objective method for determining ABPI using PPG based vascular assessment. A complex interaction between the heart and the connective vasculature, detected at the measuring site, generates the PPG signal. The haemodynamic properties of the vasculature will affect the shape of the PPG waveform, characterising the PPG signal with the properties of the intermediary vasculature. This thesis investigates the feasibility of deriving quantitative vascular parameters from the PPG signal. A quantitative approach allows direct identification of pathology, simplifying vascular assessment. Both forward and inverse models are developed in order to investigate this topic. Application of the models in prospective experimental trials with both normal subjects and subjects suffering PVD have shown encouraging results. It is concluded that the PPG signal contains information on the connective vasculature of the subject. PPG may be used to perform vascular assessment using either perfusion based techniques, where the magnitude of the PPG signal is of interest, or by directly assessing the connective vasculature using PPG, where the shape of the PPG signal is of interest. it is argued that PPG perfusion based techniques for performing the ABPI diagnosis protocol can offer greater sensitivity to the onset of PAD, compared to more conventional methods. It is speculated that the PPG based ABPI diagnosis protocol could provide enhanced PAD diagnosis, detecting the onset of the disease and allowing a treatmenpt lan to be formed soonert han was possible previously. The determination of quantitative vascular parameters using PPG shape could allow direct vascular diagnosis, reducing subjectivity due to interpretation. The prospective trials investigating PPG shape analysis concentrated on PVD diagnosis, but it is speculated that quantitative PPG shaped based vascular assessment could be a powerful tool in the diagnosis of many vascular based pathological conditions.

In this thesis, a novel fully self-aligned bulk-Si device named dual-channel source/drain-tied (DC-SDT) MOSFET with extremely thin (ET) body is proposed. The process utilizes the multiple epitaxial growths of SiGe/Si layers, so the starting material is bulk-Si wafer instead of the SOI wafer. We have investigated the RF/analog performance, and the high temperature induced device stability degradation has also been also investigated. Moreover, we have compared this structure with the other similar transistors such as: body-tied MOSFET (DC-BT MOSFET) and conventional dual-channel MOSFET (DC-SOI MOSFET). Based on the simulation results, for the DC-BT MOSFET, our proposed DC-SDT MOSFET has improved the device performances such as: Ioff decreased 47.6%, switching speed increased 18.1%, S.S. improved 13%, and voltage gain increased 25%. Whereas for the DC-SOI MOSFET, our proposed DC-SDT MOSFET has also improved the device performances such as: Ion increased 11.3%, reduction of lattice temperature 35.7% and 35.5 in the top and bottom channels, voltage gain increased 15%. We not only compared with the above two similar transistors, but also compared to the other mainstream devices, such as: FinFET and Gate-all-around. After the comparisons, we confirm that the proposed DC-SDT MOSFET has better ON-state current and short-channel behaviors. For the scaling, DC-SDT MOSFET can truly become one of the strong candidates.

Pen-based interactions are becoming widely popular on a variety of devices, including tabletPCs, mobile devices and tabletop systems. The digital pens and tablets have evolved considerably and served users in creative industries. A digital pen can sense various auxiliary inputs, such as tilt, pressure and roll. Researchers have explored properties of each channel in isolation of another. Since the human wrist and fingers can operate multiple input channels simultaneously, a natural progression warrants examination of controllability when these channels are operated simultaneously. In this thesis, I explore a class of interaction techniques, a-coord input, which requires users to control two auxiliary channels simultaneously. Through experiments, I explore the design space of a-coord input and investigate the effect of changing the order in which the channels are combined. Furthermore, I investigate its effectiveness for discrete and continuous selection tasks. Finally, this thesis shows the value of a-coord input through several applications.

Pen-based interactions are becoming widely popular on a variety of devices, including tabletPCs, mobile devices and tabletop systems. The digital pens and tablets have evolved considerably and served users in creative industries. A digital pen can sense various auxiliary inputs, such as tilt, pressure and roll. Researchers have explored properties of each channel in isolation of another. Since the human wrist and fingers can operate multiple input channels simultaneously, a natural progression warrants examination of controllability when these channels are operated simultaneously. In this thesis, I explore a class of interaction techniques, a-coord input, which requires users to control two auxiliary channels simultaneously. Through experiments, I explore the design space of a-coord input and investigate the effect of changing the order in which the channels are combined. Furthermore, I investigate its effectiveness for discrete and continuous selection tasks. Finally, this thesis shows the value of a-coord input through several applications.

Master’s thesis contains the theory for realization of the researched software. Besides other, it describes Fourier transform, frequency response function, coherence, impulse response and group delay. Real life application of the software is discussed. Software is invented in the MatLab environment. Further, thesis provides testing of the software and shows its commented outcomes.

Sales are central to retail companies. One of the main problems for these companies is when products are sold later than expected, causing overstock due to lower inventory turnover, which increases inventory levels. Therefore, for many retailers, it is important to solve this problem. This is mostly applicable to companies engaged in sales; however, if we take into account the main supplier and the way they act within the supply chain, we must also consider an additional approach. Since online sales are a major innovation brought about by the new digital era, it is standard for sales strategies to focus on this new requirement of customers. In this way, the main supplier takes a leap forward on Internet sales, creating another sales channel. This is when companies under the supply chain start losing sales. According to the above, a dual supply chain model was suggested using the SCOR model and drop shipping. After the improvement proposal was implemented, the company reported a reduction of approximately S/13,000 when comparing the first quarter of 2018 to that of 2019.

The advent of the Internet has not only enabled traditional brick-and-mortar retailers to open online channels, but also provided a platform that facilitated consumer-to-consumer information exchange on retailers and/or products. As a result, the purchasing decisions of today's consumers are often affected by the purchasing decisions of other consumers. In this dissertation, we adopt an interdisciplinary approach that brings together tools and concepts from operations management, economics, systems dynamics and marketing literatures to create analytical models in order to address a dual-channel retailer's optimal demand shaping strategy, through e-commerce advertisement efforts, store service levels, and pricing, in this new environment. Our findings show that the retailer's optimal demand shaping strategy, in terms of store service levels and e-commerce advertisement effort, critically depends on the product's e-commerce adoption phase. We also show that in the presence of higher operating costs for the store channel compared to the online channels, a channel-tailored pricing policy always dominates a uniform pricing strategy. Our work sheds light on the benefits of channel integration for multi-channel retailers. We show that the retailer can leverage the online channels to provide in-store pricing and inventory availability information in order to enable a more transparent shopping experience for consumers, and this strategy results in a "win-win" situation for all parties. / Ph. D.

Two SiGe-on-insulator (SGOI) structures for CMOS application are presented: surface-channel strained-Si on SGOI (SSOI) and dual-channel SGOI structures. Comparisons between two structures are made from both device performance and CMOS process point of view. We have demonstrated both structures on SGOI, and have fabricated n-MOSFET’s and p-MOSFET’s on those two structures respectively. Device characteristics are presented. The devices show enhancement on both electron and hole mobilities. / Singapore-MIT Alliance (SMA)

Pneumatic vacuum systems are today used in automated manufacturing and packaging industries. Before an automated system is allowed to lift an object the control system has to get a good to go signal that informs that the desired vacuum level is reached in the gripper and that it is able to lift the object. The device sending this signal is called a vacuum switch. To reduce the energy consumption of the system the vacuum switch should also send a signal to the energy saving system. The work is conducted for Piab AB in Täby in Sweden. The purpose of this master thesis was to dimension and design a new electromechanical vacuum switch that is able to send a signal from two vacuum levels. The two levels should be adjustable but also dependent of each other to make the switch more reliable. The work resulted in an electromechanical vacuum switch with two dependent and adjustable signals. The switch met 13 of the 15 tested requirements. One of the requirements it failed to meet was the height requirement and the other was a performance parameter which it marginally failed. Further more, all requirements could not be verified. A full verification will have to be done with a later prototype. More work has to be done on the switch before it meets all the requirements and functions as desired, but the purpose can be considered fulfilled since all the basic functions are working as desired. / Pneumatiska vakuumsystem används idag inom automatiserade industrier. Innan ett automatiserat system är tillåtet att lyfta ett objekt måste kontrollsystemet få en OK signal som informerar om att den önskade vakuumnivån är uppnåd i gripdonet. Enheten som skickar OK signalen kallas en vakuumvakt. För att hålla nere på systemets energikonsumtion ska vakuumvakten även skicka en signal till energisparsystemet. Arbetet är utfört på Piab AB i Täby i Sverige. Syftet med det här examensarbetet var att dimensionera och konstruera en ny elektromekanisk vakuumvakt som kan skicka en signal från två olika vakuumnivåer. Dessa två vakuumnivåer ska vara justerbara men också beroende av varandra för att göra vakuumvakten mer pålitlig. Arbetet resulterade i en elektromekanisk vakuumvakt med två justerbara och beroende av varandra vakuumnivåer. Vakten uppfyllde 13 av 15 testade krav. En av de krav den inte klarade av att uppfylla var höjdbegränsningen, det andra kravet missade vakten marginellt och det var ett prestandakrav. Alla krav kunde inte verifieras, en fullständig verifikation av de specifierade kraven bör göras med en senare prototyp. Mer arbete behöver läggas ner på vakten innan den uppfyller alla krav och fungerar som önskat, men syftet med arbetet kan fortfarande anses vara uppfyllt eftersom alla grundläggande funktioner fungerar som det är tänkt.

abstract: A dual-channel directional digital hearing aid (DHA) front-end using a fully differential difference amplifier (FDDA) based Microphone interface circuit (MIC) for a capacitive Micro Electro Mechanical Systems (MEMS) microphones and an adaptive-power analog font end (AFE) is presented. The Microphone interface circuit based on FDDA converts the capacitance variations into voltage signal, achieves a noise of 32 dB SPL (sound pressure level) and an SNR of 72 dB, additionally it also performs single to differential conversion allowing for fully differential analog signal chain. The analog front-end consists of 40dB VGA and a power scalable continuous time sigma delta ADC, with 68dB SNR dissipating 67u¬W from a 1.2V supply. The ADC implements a self calibrating feedback DAC, for calibrating the 2nd order non-linearity. The VGA and power scalable ADC is fabricated on 0.25 um CMOS TSMC process. The dual channels of the DHA are precisely matched and achieve about 0.5dB gain mismatch, resulting in greater than 5dB directivity index. This will enable a highly integrated and low power DHA / Dissertation/Thesis / Ph.D. Electrical Engineering 2011