Why Open Source?: Exploring the Motivations of Using an Open Model for Hardware Development

Following the successful adoption of the open source model in the software realm, open source is becoming a new design paradigm in hardware development. Open source models for tangible products are still in its infancy, and many studies are required to demonstrate its application to for-profit product development. It is an alluring question why entrepreneurs decide to use an open model to develop their products under risks and unknowns, such as infringement and community management. The goal of this paper is to investigate the motivations of entrepreneurs of open source hardware companies. The leaders and founders of twentythree companies were interviewed to understand their motivation and experiences in creating a company based on open source hardware. Based on these interviews, we generated a hierarchical framework to explain these motivations, where each level of the framework has been defined, explained and illustrated with representative quotes. The motivations of open source action are framed by two categories in the paper: 1) Intrinsic Motivation, which describes the motivations of an entrepreneur as an individual, who needs personal satisfaction, enjoyment as well as altruism and reciprocity; 2) Extrinsic Motivation, which describes motivations of an entrepreneur whose identity is as a for-profit company leader

Spartan Daily, October 14, 1986

Volume 87, Issue 33https://scholarworks.sjsu.edu/spartandaily/7490/thumbnail.jp

Novel insights into echocardiographic assessment of cardiac function following heart surgery

Assessment of cardiac function is a fundamental in everyday clinical decision making and is essential diagnostic tool for choosing therapy in patients with cardiac disease. Currently, echocardiography is the integral part in management of patients with different cardiac disease and the most established imaging tool in the assessment of cardiac function. Coronary artery bypass grafting (CABG) is an effective treatment in selected patients suffering from advanced coronary artery disease (CAD). Improvement in symptoms, functional status and cardiac function is often used to evaluate the success of CABG. Evaluation of cardiac function often is divided in assessment of systolic and diastolic function. However, systole and diastole are integrated and interconnected parts of cardiac cycle. Thus, a method for quantifying cardiac function which incorporates both systole and diastole is to be preferred. Myocardial performance index (MPI) assessed by pulsed-wave Doppler tissue imaging (PW-DTI) is combining systole and diastole, easy to acquire and is independent of cardiac geometry. The aim of this thesis is to evaluate the feasibility of MPI measured by PW-DTI in assessment of left and right ventricular performance in patients with CAD treated with CABG. In addition, to explore the role of B-type natriuretic peptide (BNP) in predicting long-term major adverse outcomes following CABG and exploring its association with MPI. Finally, this thesis aims to evaluate the impact of conventional aortic valve surgery in comparison to minimally invasive aortic valve surgery (MIAVR) on right ventricular function (RV) assessed by echocardiography. Methods and Results Study I, forty six patients who were accepted for CABG were included. They all were investigated by dobutamine stress-echocardiography (DSE) prior to CABG and 3 month after CABG. Several methods for evaluation of left ventricular systolic and diastolic function had been applied, i.e. EF, longitudinal systolic and diastolic velocities as well as MPI. All the measurements were performed at rest and at peak DSE. The values from pre-CABG were compared to those after CABG. At baseline, MPI was prolonged both at rest (0.61 ±0.13) and at peak DSE (0.78±0.16). Accordingly, ejection fraction (EF) was also impaired at rest (42.7±8%) and at peak DSE (49.2±9). Similarly, wall-motion score index WMSI was impaired at rest (1.1±0.2) and at peak DSE (1.4±0.2). After CABG, MPI improved significantly both at rest (0.45±0.08; P < 0.001) and at peak DSE (0.56±0.1; P < 0.001). On the other hand, EF and WMSI did not improve at rest (43.7±8% and 1.1±0.2, respectively). However, at peak DSE an improvement of both EF (54.2±9; P < 0.05) and WMSI (1.1±0.16; P < 0.001) was observed. Study II: The same patient cohort as in study I was used for analyzing the impact of CABG on RV function. Coronary angiography, DSE and exercise bicycle test were performed 1 month before and 3 months after CABG. Right ventricular index of myocardial performance (RIMP), right ventricular systolic velocity (RVS) and displacement (TAPSE) at the lateral tricuspid annulus were all assessed. The RIMP improved following CABG both at rest (0.45 ± 0.11 vs. 0.38 ± 0.08 CABG, P = 0.013) and during DSE (0.75 ± 0.23 vs. 0.49 ± 0.14, P < 0.001). Compared to baseline, TAPSE reduced substantially after CABG both at rest (23.9 ± 4.46 vs. 14.6 ± 3.67, P < 0.001) and during DSE (20.9 ± 4.16 vs 11.9 ± 3.60, P < 0.001). A significant decline in RVS was also observed following CABG both at rest (11.9 ± 2.40 vs. 8.5 ± 1.93, P < 0.001) and during DSE (15.6 ± 4.30 vs. 10.5 ± 3.21, P < 0.001). On contrary, compared to pre-CABG values exercise capacity improved significantly following CABG (128.4 ± 40.12W vs 142.1 ± 46.73 W, P = 0.014). Study III was a predefined post hoc analysis of CMILE study (Cardiac Function after Minimally Invasive Aortic Valve Implantation including 40 patients with severe aortic stenosis and eligible for isolated aortic valve replacement. The patients were randomized 1:1 either to conventional aortic valve replacement (AVR) or minimally invasive aortic valve replacement (MIAVR). The impact of these two surgical techniques on right ventricular mechanics and contractility was evaluated by echocardiography. Compared to baseline RV strain rate (RV-LSR) was preserved after MIAVR (-1.52±0.5 vs -1.49±0.4 1/s, p=0.84) but declined following AVR (-1.67±0.3 vs -1.38±0.3 1/s, p<0.01). RV longitudinal strain (RV-LS) was deteriorated after AVR (˗27.4±2.9% vs ˗18.8±4.7%, p<0.001) and MIAVR (˗26.5±5.3% vs ˗20.7±4.5%, p<0.01). Peak systolic velocity of the lateral tricuspid annulus (RVS) declined by 18.8% in the MIAVR group (10.1±2.9 vs 8.2±1.4 cm/s, p<0.01) and 36.6% in the AVR group (9.3±2.1 vs 5.9±1.5 cm/s, p<0.01) when values from before surgery were compared to after surgery. In Study IV, 99 patients with CAD who underwent CABG were evaluated by a biomarker BNP and Echocardiography. In a subpopulation of 40 patients DTI and MPI were obtained. Patients were followed-up for 5 years and during this period death, myocardial infarction, stroke and hospitalization due to heart failure were recorded. The role of postoperative BNP for predicting major outcomes was assessed and its association with MPI was determined. Seventeen patients experienced major adverse outcomes during the follow-up. Univariate analysis revealed that creatinine clearance (P<0.01), body mass index (BMI, P<0.01), postoperative BNP (P<0.001) and preoperative LV-MPI (P=0.04) were all significantly associated with major outcomes at follow-up. However, after correcting for cofactors in multivariate analysis only postoperative BNP (P=0.003) and BMI (P=0.025) were associated with major outcomes. CONCLUSIONS: Myocardial performance index and right ventricular index of myocardial performance improved significantly following CABG in patients with CAD both at rest and peak DSE and appear to be a sensitive measure of myocardial function in patients with CAD. Postoperative BNP obtained in a stable clinical condition, 3 month after CABG is a predictive of major outcomes 5 years after CABG. Load-independent contractility is preserved following MIAVR but reduced following AVR. Load-dependent measures of myocardial function all declined following both MIAVR and AVR however, to a much lesser extent following MIAVR

Investigational echocardiography for the detection of heart involvement in rheumatic musculoskeletal diseases

Introduction. Patients with rheumatic musculoskeletal diseases (RMDs) face a risk of cardiovascular disease (CVD) that is significantly higher than the general population. It has long been recognised that RMDs can affect the musculoskeletal system as the heart. However, RMDs-primary heart involvement (RMDs-pHI) has been poorly characterised, and it is difficult to ascertain its contribution to the increased CVD risk of RMDs patients. Other than the effect of traditional cardiovascular risk factors, several factors that are disease-specific may contribute to RMDs-pHI, such as a chronic inflammatory insult to the vessels, pro-inflammatory lipids, the effects of anti-rheumatic therapies, and autoimmune or post-repairing biological processes. Detection of RMDs-pHI has prognostic implications. Aim. This doctoral thesis aimed to investigate by ultrasound the plethora of cardiac abnormalities in patients with RMDs and to correlate those findings with the clinical characteristics of the diseases. Methods. This was a prospective observational study based at the Division of Rheumatology, University of Verona (Italy). We recruited outpatients with established diagnoses of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and systemic sclerosis (SSc). All patients underwent a baseline assessment of cardiovascular and disease-related data. We also used standard transthoracic echocardiography (TTE) and additional investigational TTE techniques to determine cardiac abnormalities. Study outcomes were: 1) left ventricular (LV) volumes and mass, including an assessment of LV hypertrophy (LVH); 2) myocardial strain, using speckle-tracking echocardiography (STE); 3) arterial stiffness, as measured by the aortic stiffness index (AoSI); 4) myocardial fibrosis, identified by pulse-cancellation imaging (eSCAR). Results. We found that among RA patients, women were more likely to progress to LVH than men, irrespective of their CVD risk profile. Patients with RA also had an increased AoSI, but the use of tumor necrosis factor-alpha inhibitors compared to csDMARDs was protective against the progression of aortic stiffness, especially with accumulating CVD risk factors. SLE patients had myocardial fibrosis detected by eSCAR in the inferior and inferoseptal basal segments in 17%, which was associated with the long-term exposure to glucocorticoids. Patients with SSc had myocardial scars with a similar pattern to SLE patients in 25%, but also with ischemic patterns. However, digital ulcers were independently associated with non-ischemic fibrosis. In both SLE and SSc patients, myocardial fibrosis localized in areas of impaired myocardial deformation as shown by STE, suggesting that myocardial fibrosis was associated with subclinical myocardial dysfunction. Conclusion. We showed that myocardial abnormalities are frequent in RMDs patients and can be effectively detected with manageable TTE techniques. Moreover, specific cardiac lesions were associated with features of disease severity in SLE and SSc patients. The implementation of echocardiography studies in the Rheumatology core assessment could allow cardiovascular risk stratification of patients with RMDs. This could help reduce costs and optimise resources

Spartan Daily, March 30, 1984

Volume 82, Issue 43https://scholarworks.sjsu.edu/spartandaily/7161/thumbnail.jp

Advanced water iodinating system

Potable water stores aboard manned spacecraft must remain sterile. Suitable sterilization techniques are needed to prevent microbial growth. The development of an advanced water iodinating system for possible application to the shuttle orbiter and other advanced spacecraft, is considered. The AWIS provides a means of automatically dispensing iodine and controlling iodination levels in potable water stores. In a recirculation mode test, simulating application of the AWIS to a water management system of a long term six man capacity space mission, noniodinated feed water flowing at 32.2 cu cm min was iodinated to 5 + or - ppm concentrations after it was mixed with previously iodinated water recirculating through a potable water storage tank. Also, the AWIS was used to successfully demonstrate its capability to maintain potable water at a desired I2 concentration level while circulating through the water storage tank, but without the addition of noniodinated water

Identification of acute coronary syndrome in the era of high-sensitivity troponin assays

Bakgrunn: Det er mulig å bedre pasientflyt og diagnostisk presisjon ved utredning av pasienter med mistenkt akutt koronarsyndrom (AKS). Konsentrasjonen av kardialt troponin (cTnT eller cTnI) kan benyttes til å forutse langsiktig risiko for kardiovaskulære hendelser dersom visse utfordringer blir avklart, for eksempel om de etablert persentilene innen normalområdet er biologisk like for alle tilgjengelige analyseapparater. Avhandlingen vurderer viktige diagnostiske og prognostiske verktøy i utredningen av pasienter med mulig AKS: troponin-algoritmer, kliniske risikoskalkulatorer og prognostisk betydning av kronisk forhøyede troponin-verdier over 99-percentilen, definert som kronisk myokardskade (KMS). Metode: Pasienter innlagt på Haukeland Universitetssykehus med symptomer på AKS ble inkludert i WESTCOR-studien (n=1506). Blodprøver ble tatt ved innkomst og etter 3 og 8-12 timer. Artikkel 1 (n=1506) beregner diagnostiske presisjonen for diagnosen NSTEMI basert på brystsmertenes karakter og plassering, og tilleggssymptomer. Artikkel 2 (n=984) vurderer diagnostisk presisjon av troponin-baserte 0/3-timersalgoritmer og 11 ulike risiko-kalkulatorer. Artikkel 3 (n=1147) vurderer prevalens av troponin-verdier over 99-persentilen og prognostisk verdi av KMS sammenlignet mot å bruke lavere troponin-grenser for risikovurdering. Resultater: Det var små forskjeller mellom kjønn og aldersgrupper i risiko for akutt koronarsykdom basert på spesifikke symptomer. Pasienter med lav risiko for AKS basert på risikokalkulatorer kombinert med lave troponin-konsentrasjoner har svært lav korttidsrisiko for kardiale hendelser. Pasienter med KMS har økt langtidsrisiko for kardiovaskulær død eller uønskede koronare hendelser, men prevalensen av KMS varierer mellom analyseapparater som analyserer cTnT og cTnI. Konklusjon og implikasjoner: Pasienter med lav risiko for AKS basert på symptomer, kliniske risikokalkulatorer og høy-sensitive troponin-analyser har svært lav kortsiktig risiko for kardiovaskulære hendelser og kan vurderes for tidlig utskrivelse fra sykehus. Klinikere bør være kjent med den forhøyede langtidsrisikoen for fremtidige kardiovaskulære hendelser forbundet med KMS, men også den svake korrelasjonen mellom 99-persentilene for ulike troponin-analyseapparater.Background: There is potential for future improvements in patient flow and diagnostic precision in patients presenting to hospital with suspected acute coronary syndrome (ACS). Long-term risk of cardiovascular (CV) events may be assessed by cardiac troponin (cTn) levels if certain concerns are addressed and resolved, like whether the established percentiles of normal range are biological equal between all commercially available assays. The thesis evaluates important diagnostic and prognostic tools in cardiac workup of patients with possible ACS: troponin (cTn) algorithms, clinical risk scores, and prognostic relevance of chronically elevated cTn. above the 99th percentile, termed chronic myocardial injury (CMI). Methods: Patients admitted to Haukeland University Hospital with symptoms suggestive of ACS were included in the WESTCOR study (n=1506). Blood samples were collected at presentation and after 3 and 8-12 hours. Paper 1 (n=1506) calculate the diagnostic precision of chest pain characteristics and additional symptoms for the diagnosis of NSTEMI. Paper 2 (n=984) assess the short-term risk of adverse events when troponin-based 0/3-hour algorithms are combined with 11 different clinical risk scores. Paper 3 (n=1147) evaluate the prevalence of having cTn concentrations above the 99th percentile and long-term prognostic power of CMI compared to using lower cutoff values for risk stratification. Results: The risk of having an NSTEMI based on specific symptoms were overall similar across sex and age groups. Low-risk patients identified by a risk score combined with low concentrations of cTn have very low short-term risk of adverse cardiac events. Patients with CMI have elevated risk for cardiovascular death and coronary events, but the prevalence of CMI is highly dependent on cTn assay. Conclusions and implications: Patients classified as low risk based on the presentation of symptoms, clinical risk scores and hs-cTn assays had a very low short-term risk of CV events and could be considered for early discharge from hospital. Physicians should be aware of the increased long-term risk of CV events associated with CMI, but also the low concordance between the 99th percentile URLs of different cTn assays.Doktorgradsavhandlin

NASA Tech Briefs, December 1999

Topics include: Imaging/Videos/Cameras; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Books and Reports

Spartan Daily, February 1, 1996

Volume 106, Issue 5https://scholarworks.sjsu.edu/spartandaily/8790/thumbnail.jp

Rapid SoC Design: On Architectures, Methodologies and Frameworks

Modern applications like machine learning, autonomous vehicles, and 5G networking require an order of magnitude boost in processing capability. For several decades, chip designers have relied on Moore’s Law - the doubling of transistor count every two years to deliver improved performance, higher energy efficiency, and an increase in transistor density. With the end of Dennard’s scaling and a slowdown in Moore’s Law, system architects have developed several techniques to deliver on the traditional performance and power improvements we have come to expect. More recently, chip designers have turned towards heterogeneous systems comprised of more specialized processing units to buttress the traditional processing units. These specialized units improve the overall performance, power, and area (PPA) metrics across a wide variety of workloads and applications. While the GPU serves as a classical example, accelerators for machine learning, approximate computing, graph processing, and database applications have become commonplace. This has led to an exponential growth in the variety (and count) of these compute units found in modern embedded and high-performance computing platforms. The various techniques adopted to combat the slowing of Moore’s Law directly translates to an increase in complexity for modern system-on-chips (SoCs). This increase in complexity in turn leads to an increase in design effort and validation time for hardware and the accompanying software stacks. This is further aggravated by fabrication challenges (photo-lithography, tooling, and yield) faced at advanced technology nodes (below 28nm). The inherent complexity in modern SoCs translates into increased costs and time-to-market delays. This holds true across the spectrum, from mobile/handheld processors to high-performance data-center appliances. This dissertation presents several techniques to address the challenges of rapidly birthing complex SoCs. The first part of this dissertation focuses on foundations and architectures that aid in rapid SoC design. It presents a variety of architectural techniques that were developed and leveraged to rapidly construct complex SoCs at advanced process nodes. The next part of the dissertation focuses on the gap between a completed design model (in RTL form) and its physical manifestation (a GDS file that will be sent to the foundry for fabrication). It presents methodologies and a workflow for rapidly walking a design through to completion at arbitrary technology nodes. It also presents progress on creating tools and a flow that is entirely dependent on open-source tools. The last part presents a framework that not only speeds up the integration of a hardware accelerator into an SoC ecosystem, but emphasizes software adoption and usability.PHDElectrical and Computer EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/168119/1/ajayi_1.pd