The ecology of distance learning: Bridging the gap between university and student

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Utilizing Online Exams: A Case Study

Technology has opened a wide range of possibilities for the college classroom.  Thus, the classroom has changed in a variety of ways.  Some courses have been converted to fully online courses.  Students and instructors do not have any face-to-face contact in these courses.  Other courses have converted a portion of their courses to online.  These classes are generally referred to as Hybrid classes.  Students and instructors meet face-to-face for a portion of the course and complete online assignments for the remainder of the course.  Some other courses have maintained their face-to-face course but have integrated technology into those courses.   Instructors have utilized a variety of technologies that include but are not limited to:  Live Chats, Threaded Discussions – Forums, Powerpoint Presentations, Email, Videos, Software, Spreadsheets, Word Processors, Online Portals, Electronic Portfolios/Projects, Online Exams. This is a case study of the implementation of online exams in a traditional classroom.  Students are given a paper and pencil exam that has been utilized previously in other courses as the midterm.  Then an online exam was utilized in the courses.  The case study looks at the success of the exam from the point of view of the students and instructors.  Students overwhelmingly indicated that the online exam was superior to the paper exam. Students indicated that the online exams provided an opportunity for students to complete the exam at a time that was best for them.  They were able to pick a time that reduced anxiety.  The online exam also provided immediate feedback on how they did.  Faculty indicated that although the online exam does have a few glitches and there are concerns about cheating, it was effective and proved useful.  Further studies need to be done regarding the online exam to assure that it is an accurate evaluation of student learning

Mitigating NPD And R&D Risks Via A Portfolio Effect In Country Choice

New Product Development as well as Research and Development projects tend to be inherently risky investments.  Most MNC’s today have great latitude in choosing site and country locations to build or contract Research or Development projects.  MNC R&D risks, corporate wide, can be moderated via a diversification of NPD/R&D projects across multiple cultures and countries.  In fact there is some evidence that R&D global diversification can generate synergies.  (Fast track projects that work around the clock via work being done in three locations each 8 hours off from the other.) Foreign R&D facilities can help serve as outposts to facilitate the entrance into strategic foreign markets. This paper attempts to develop decision methodologies for allocating NPD/R&D globally with the goal of both reducing risks and increasing global competitiveness

Search of low-contrast liver lesions in abdominal CT: the importance of scrolling behavior.

Purpose: Visual search using volumetric images is becoming the standard in medical imaging. However, we do not fully understand how eye movement strategies mediate diagnostic performance. A recent study on computed tomography (CT) images showed that the search strategies of radiologists could be classified based on saccade amplitudes and cross-quadrant eye movements [eye movement index (EMI)] into two categories: drillers and scanners. Approach: We investigate how the number of times a radiologist scrolls in a given direction during analysis of the images (number of courses) could add a supplementary variable to use to characterize search strategies. We used a set of 15 normal liver CT images in which we inserted 1 to 5 hypodense metastases of two different signal contrast amplitudes. Twenty radiologists were asked to search for the metastases while their eye-gaze was recorded by an eye-tracker device (EyeLink1000, SR Research Ltd., Mississauga, Ontario, Canada). Results: We found that categorizing radiologists based on the number of courses (rather than EMI) could better predict differences in decision times, percentage of image covered, and search error rates. Radiologists with a larger number of courses covered more volume in more time, found more metastases, and made fewer search errors than those with a lower number of courses. Our results suggest that the traditional definition of drillers and scanners could be expanded to include scrolling behavior. Drillers could be defined as scrolling back and forth through the image stack, each time exploring a different area on each image (low EMI and high number of courses). Scanners could be defined as scrolling progressively through the stack of images and focusing on different areas within each image slice (high EMI and low number of courses). Conclusions: Together, our results further enhance the understanding of how radiologists investigate three-dimensional volumes and may improve how to teach effective reading strategies to radiology residents

Dynamical Structure Factor for the Alternating Heisenberg Chain: A Linked Cluster Calculation

We develop a linked cluster method to calculate the spectral weights of many-particle excitations at zero temperature. The dynamical structure factor is expressed as a sum of exclusive structure factors, each representing contributions from a given set of excited states. A linked cluster technique to obtain high order series expansions for these quantities is discussed. We apply these methods to the alternating Heisenberg chain around the dimerized limit ($\lambda=0$), where complete wavevector and frequency dependent spectral weights for one and two-particle excitations (continuum and bound-states) are obtained. For small to moderate values of the inter-dimer coupling parameter $\lambda$, these lead to extremely accurate calculations of the dynamical structure factors. We also examine the variation of the relative spectral weights of one and two-particle states with bond alternation all the way up to the limit of the uniform chain ($\lambda=1$). In agreement with Schmidt and Uhrig, we find that the spectral weight is dominated by 2-triplet states even at $\lambda=1$, which implies that a description in terms of triplet-pair excitations remains a good quantitative description of the system even for the uniform chain.Comment: 26 pages, 17 figure

Perturbation theories for the S=1/2 spin ladder with four-spin ring exchange

The isotropic S=1/2 antiferromagnetic spin ladder with additional four-spin ring exchange is studied perturbatively in the strong coupling regime with the help of cluster expansion technique, and by means of bosonization in the weak coupling limit. It is found that a sufficiently large strength of ring exchange leads to a second-order phase transition, and the shape of the boundary in the vicinity of the known exact transition point is obtained. The critical exponent for the gap is found to be $\eta\simeq1$, in agreement both with exact results available for the dimer line and with the bosonization analysis. The phase emerging for high values of the ring exchange is argued to be gapped and spontaneously dimerized. The results for the transition line from strong coupling and from weak coupling match with each other naturally.Comment: 8 pages, 4 figures, some minor changes in text and reference

Phase Diagram of the BCC S=1/2 Heisenberg Antiferromagnet with First and Second Neighbor Exchange

We use linked-cluster series expansions, both at T=0 and high temperature, to analyse the phase structure of the spin-\half Heisenberg antiferromagnet with competing first and second-neighbor interactions on the 3-dimensional body-centred-cubic lattice. At zero temperature we find a first-order quantum phase transition at $J_2/J_1 \simeq 0.705 \pm 0.005$ between AF$_1$ (Ne\'el) and AF$_2$ ordered phases. The high temperature series yield quite accurate estimates of the bounding critical line for the AF$_1$ phase, and an apparent critical line for the AF$_2$ phase, with a bicritical point at $J_1/J_2\simeq 0.71$, $kT/J_1\simeq 0.34$. The possibility that this latter transition is first-order cannot be excluded.Comment: 10 pages, 4 figure

Reduzierung von Missing Wedge Artefakten mit DIRECTT

Wir stellen eine Prozedur vor, mit der typische Missing Wedge MW Artefakte in CT Rekonstruktionen effektiv unterdrückt werden können. Dazu wird der iterative DIRECTT Algorithmus Direkte Iterative Rekonstruktion Computertomographischer Trajektorien mit einigen Zyklen diskreter Rekonstruk tion eingesetzt. Die Kernfunktionen des Algorithmus , die wiederholte Auswahl und Gewichtung von Elementen einer Zwischenrekonstruktion, werden beibehalten. Abgesehen von Sonderfällen der Röntgen und Neutronentomographie tritt die MW Restriktion neben einer Vielzahl anderer in Standardkonfigurationen der Elektronentomographie auf. Um den MW Effekt isoliert zu untersuchen und beurteilen zu können, werden hier vollständige experimentelle Datensätze einer bekannten Porenstruktur um einen Sektor beschnitten sowie MW Rekonstruktionen von Porenmodellen erzeugt. Die Ergebnisse werden mit zurzeit verbreiteten Algorithmen Gefilterte Rückprojektion FBP und ART Varianten verglichen. Die Bewertung im Fourierraum zeigt, dass DIRECTT die fehlende Information im MW erfolgreich ergänzt. Zur quantitativen Bewertung der lokalen Rekonstruktions qualität werden Methoden der räumlichen Statistik eingesetz

From Greenland to Canada in Ten Days: Tracks of Bowhead Whales, Balaena mysticetus, across Baffin Bay

Five bowhead whales (Balaena mysticetus) were instrumented with satellite transmitters in northwestern Disko Bay, West Greenland, in May 2001. Best results were obtained when tags were deployed with a pole rather than a pneumatic gun. At least three of the tagged whales remained in the northwestern part of the bay for one to two weeks after tagging. A male and a female whale moved from Disko Bay to northern Canada. They left Disko Bay 11 days apart and took different routes across Baffin Bay to the southern part of the North Water polynya, just east of the entrance to Lancaster Sound. The whales crossed the central part of Baffin Bay relatively rapidly (travel time of 9-10 days, 3.1 and 4.5 km/h). Dive behaviour of one whale was monitored and showed changes in dive depths, dive rates, and surfacing times in different localities, indicating behavioural changes probably related to feeding. The whales were presumably feeding in both Disko Bay in May and in the southern part of the North Water (southeast of Bylot Island) in June. This study confirms whalers' observations that bowhead whales move between West Greenland and the east coast of Baffin Island.En mai 2001, cinq baleines boréales (Balaena mysticetus) ont été équipées d'émetteurs spatiaux dans le nord-ouest de la baie de Disko (Groenland occidental). Les meilleurs résultats ont été obtenus lorsque les marqueurs ont été apposés avec une perche plutôt qu'avec un fusil à air comprimé. Au moins trois des baleines marquées sont restées dans la partie nord-ouest de la baie pendant une à deux semaines après le marquage. Deux individus, un mâle et une femelle, se sont déplacés de la baie de Disko au nord du Canada. Ils ont quitté la baie à 11 jours d'écart et ont emprunté des trajets différents pour traverser la baie de Baffin et rejoindre la partie méridionale de la polynie de l'Eau du Nord, située juste à l'est de l'entrée du détroit de Lancaster. Les baleines ont traversé la partie centrale de la baie de Baffin assez vite (en 9 et 10 jours, soit 3,1 et 4,5 km/h). On a suivi le comportement de plongée d'une baleine, qui a montré des changements dans la profondeur des plongées, leur fréquence et le temps en surface à divers endroits, révélant des modifications du comportement probablement associées au nourrissage. On suppose que les baleines s'alimentaient dans la baie de Disko en mai aussi bien que dans la partie méridionale de l'Eau du Nord (au sud-est de l'île Bylot) en juin. Cette étude confirme les observations des baleiniers à l'effet que les baleines boréales se déplacent entre l'ouest du Groenland et la côte est de l'île de Baffin