Design of the 12-bit Delta-Sigma Modulator using SC Technique for Vibration Sensor Output Processing

The work deals with the design of the 12-bit Delta-Sigma modulator using switched capacitors (SC) technique. The modulator serves to vibration sensor output processing. The first part describes the Delta-Sigma modulator parameters definition. Results of the proposed topology ideal model were presented as well. Next, the Delta-Sigma modulator circuitry on the transistor level was done. The ONSemiconductor I2T100 0.7 um CMOS technology was used for design. Then, the Delta-Sigma modulator nonidealities were simulated and implemented into the MATLAB ideal model of the modulator. The model of real Delta-Sigma modulator was derived. Consequently, modulator coefficients were optimized. Finally, the corner analysis of the Delta-Sigma modulator with the optimized coefficients was simulated. The value of SNDR = 82.2 dB (ENOB = 13.4 bits) was achieved

Logistic Knowledge Tracing: A Constrained Framework for Learner Modeling

Adaptive learning technology solutions often use a learner model to trace learning and make pedagogical decisions. The present research introduces a formalized methodology for specifying learner models, Logistic Knowledge Tracing (LKT), that consolidates many extant learner modeling methods. The strength of LKT is the specification of a symbolic notation system for alternative logistic regression models that is powerful enough to specify many extant models in the literature and many new models. To demonstrate the generality of LKT, we fit 12 models, some variants of well-known models and some newly devised, to 6 learning technology datasets. The results indicated that no single learner model was best in all cases, further justifying a broad approach that considers multiple learner model features and the learning context. The models presented here avoid student-level fixed parameters to increase generalizability. We also introduce features to stand in for these intercepts. We argue that to be maximally applicable, a learner model needs to adapt to student differences, rather than needing to be pre-parameterized with the level of each student's ability

Effective Recruitment Strategies to Attract Orthopaedic Surgeons to Rural Nebraska

Rural communities have difficulty establishing and maintaining a quality healthcare workforce. Twenty percent of Americans compose the rural populations in this country, but only nine percent of physicians practice in these rural areas. From 2000 to 2020, the demand for orthopaedic physicians is expected to increase by 23%, mainly due to the aging population of the United States. Although the demand for orthopaedic surgeons to these underserved, aging rural populations is increasing, there is a shortage which continues to grow in rural areas. One possible driving force of this shortage could be the recruitment strategies exercised by the healthcare managers in these rural communities. Orthopaedic surgeons may avoid work in a rural area due to its remoteness, lack of new technology, and few opportunities for family members. The objective of this study was to identify factors that could enhance recruitment of orthopaedic surgeons to health care facilities in rural Nebraska using Lexington Regional Health Center (LRHC), one of Nebraska’s critical access hospitals, as a case study. Strategies such as loan repayment plans, competitive pay, “humanizing” the work environment, and motivational analysis show promising solutions to recruitment strategies in rural healthcare

Expanding Haptic Workspace for Coupled-Object Manipulation

Haptic force-feedback offers a valuable cue in exploration and manipulation of virtual environments. However, grounding of many commercial kinesthetic haptic devices limits the workspace accessible using a purely position-control scheme. The bubble technique has been recently presented as a method for expanding the user’s haptic workspace. The bubble technique is a hybrid position-rate control system in which a volume, or “bubble,” is defined entirely within the physical workspace of the haptic device. When the device’s end effector is within this bubble, interaction is through position control. When exiting this volume, an elastic restoring force is rendered, and a rate is applied that moves the virtual accessible workspace. Existing work on the bubble technique focuses on point-based touching tasks. When the bubble technique is applied to simulations where the user is grasping virtual objects with part-part collision detection, unforeseen interaction problems surface. This paper discusses three details of the user experience of coupled-object manipulation with the bubble technique. A few preliminary methods of addressing these interaction challenges are introduced

Eliminating helper phage from phage display

Phage display technology involves the display of proteins or peptides, as coat protein fusions, on the surface of a phage or phagemid particles. Using standard technology, helper phage are essential for the replication and assembly of phagemid particles, during library production and biopanning. We have eliminated the need to add helper phage by using 'bacterial packaging cell lines' that provide the same functions. These cell lines contain M13-based helper plasmids that express phage packaging proteins which assemble phagemid particles as efficiently as helper phage, but without helper phage contamination. This results in genetically pure phagemid particle preparations. Furthermore, by using constructs differing in the form of gene 3 that they contain, we have shown that the display, from a single library, can be modulated between monovalent (phagemid-like) and multivalent display (phage-like) without any further engineering. These packaging cells eliminate the use of helper phage from phagemid-based selection protocols; reducing the amount of technical preparation, facilitating automation, optimizing selections by matching display levels to diversity, and effectively using the packaged phagemid particles as means to transfer genetic information at an efficiency approaching 100%

Student Modeling Based on Fine-Grained Programming Process Snapshots

ICER '17 Proceedings of the 2017 ACM Conference on International Computing Education Research. New York, NY, USA : ACM, 2017 ISBN: 978-1-4503-4968-0I am studying the use of fine-grained programming process data for student modeling. The initial plan is to construct different types of program state representations such as Abstract Syntax Trees (ASTs) from the data. These program state representations could be used for both automatically inferring knowledge components that the students are trying to learn as well as for modeling students' knowledge on those specific components.Peer reviewe

IS900 Restriction Fragment Length Polymorphism (RFLP) Analysis of Mycobacterium avium subsp. paratuberculosis Isolates from Goats and Cattle in Norway

In Norway, paratuberculosis has been frequently diagnosed in goats, while cattle have been almost free of the infection. This difference in prevalence between goats and cattle has led to speculations about the existence of a Mycobacterium avium subsp. paratuberculosis (M. a. paratuberculosis) isolate that is non-pathogenic for cattle. There is little information available on genotypic variation of M. a. paratuberculosis isolated from animals in Norway. In the present study, genotypic information on 51 isolates from goats and four isolates from cattle in Norway was obtained by use of IS900 restriction fragment length polymorphism (RFLP) analysis. All isolates from cattle and 84% of the isolates from goats had the same RFLP pattern (B-C1). Five RFLP patterns not previously detected were found. No genotypic variation that could explain a difference in host origin was found between the isolates from cattle and the majority of the Norwegian goat isolates. This lack of difference indicates that the most common M. a. paratuberculosis isolates in Norway may infect both cattle and goats

A Multi-Proxy Approach to Archaeobotanical Research: Archaic and Fremont Diets, Utah

New analytical techniques in archaeobotany allow researchers to examine human plant use by developing interrelated, yet independent lines of evidence. Here we outline the results of a two-method archaeobotanical approach to investigate Archaic and Fremont Great Basin diets. We conducted both macro- and microbotanical (starch granule) analyses at nine archaeological sites located in central and southwestern Utah. Our results show that in contexts where macrobotanical remains are poorly preserved, the application of microbotanical methods can produce additional sets of information, thus improving interpretations about past human diets. In this study, macrobotanical remains represented seed-based dietary contributions, while microbotanical remains came primarily from geophytes. Results suggest largely overlapping diets for Archaic and Fremont residents of Utah