The Power Domination Toolbox

Phasor Measurement Units (PMUs) are placed at strategic nodes in an electrical power network to directly monitor nearby transmission lines and monitor further parts of the network through conservation of energy laws.Efficient placement of PMUs is modeled by the graph theoretic process called Power Domination (PD). This paper describes a Power Domination Toolbox (PDT) that efficiently identifies potential PMU locations. The PDT leverages the graph theoretic literature to reduce the complexity of determining optimal PMU placements by: reducing the size of the network (contraction), identification of preferred nodes, elimination of redundant nodes, assignment of a qualitative score to the remaining nodes, and parallel processing techniques. After pre-processing steps to reduce network size, current state-of-the-art PD techniques based on the minimum rank sage library (MRZG) are used to analyze the network. The PDT is an extension of MRZG in Python and maintains the compatibility of MRZG with SageMath. The PDT can identify minimum PMU placements for networks with hundreds of nodes on personal computers and can analyze larger networks on high performance computers. The PDT affords users the ability to investigate power domination on networks previously considered infeasible due to the number of nodes resulting in a prohibitively long run-time.Comment: 12 pages, 9 figure

FTC Rulemaking Through Negotiation

The Federal Trade Commission, along with other administrative agencies, has been especially affected by the current emphasis on deregulation. Some proponents of the free market system view the Commission as an unnecessary and costly impediment to market functioning. In this article, Professor Koch and Ms. Martin review past FTC regulatory efforts in light of the FTC\u27s mandate: to maintain an efficient, competitive free market Although the FTC has deviated from its market maintenance goal, this deviation should not serve as a basis for constricting Commission rulemaking activity. Rather, the authors demonstrate that past Commission practices illustrate the need for an informal rulemaking procedure that is sensitive to the needs of both consumers and industry

Power domination with random sensor failure

The power domination problem seeks to determine the minimum number of phasor measurement units (PMUs) needed to monitor an electric power network. We introduce random sensor failure before the power domination process occurs and call this the fragile power domination process. For a given graph, PMU placement, and probability of PMU failure $q$, we study the expected number of observed vertices at the termination of the fragile power domination process. This expected value is a polynomial in $q$, which we relate to fault-tolerant and PMU-defect-robust power domination. We also study the probability of that the entire graph becomes observed and give results for some graph families.Comment: 20 pages, 6 figure

Toward a Theory of Teacher Education for Justice-Oriented STEM

Among the multiple perspectives as to the focus of education policy, there has been much recent attention paid to both STEM and social justice education. While these approaches are often seen in opposition with each other, in this paper we explore the possibility of combining these two aims as we begin to develop a theory of teacher education for justice-oriented STEM education

Identification of false positive exercise tests with use of electrocardiographic criteria: A possible role for atrial repolarization waves

Atrial repolarization waves are opposite in direction to P waves, may have a magnitude of 100 to 200 mu V and may extend into the ST segment and T wave. It was postulated that exaggerated atrial repolarization waves during exercise could produce ST segment depression mimicking myocardial ischemia. The P waves, PR segments and ST segments were studied in leads II, III, aVF and V4 to V6 in 69 patients whose exercise electrocardiogram (ECG) suggested ischemia (100 mu V horizontal or 150 mu V upsloping ST depression 80 ms after the J point). All had a normal ECG at rest. The exercise test in 25 patients (52% male, mean age 53 years) was deemed false positive because of normal coronary arteriograms and left ventricular function (5 patients) or normal stress single photon emission computed tomographic thallium or gated blood pool scans (16 patients), or both (4 patients). Forty-four patients with a similar age and gender distribution, anginal chest pain and at least one coronary stenosis greater than or equal to 80% served as a true positive control group. The false positive group was characterized by (1) markedly downsloping PR segments at peak exercise, (2) longer exercise time and more rapidmore » peak exercise heart rate than those of the true positive group, and (3) absence of exercise-induced chest pain. The false positive group also displayed significantly greater absolute P wave amplitudes at peak exercise and greater augmentation of P wave amplitude by exercise in all six ECG leads than were observed in the true positive group.« les

Effectiveness of Instructor-Led Discussion versus Simulation to Prepare Students for Fieldwork

Occupational therapy students do not always feel prepared to start fieldwork. The study purposes were to 1) measure the effectiveness of refresher sessions on students’ perceived self-efficacy, knowledge, and skills related to fieldwork preparedness and 2) determine whether using simulation with standardized patients (SPs) was more effective than a discussion-based format. The participants (N=34) were entry-level occupational therapy doctoral (OTD) students. Four students acted as a control group while the remaining 30 students were randomly assigned to experimental groups (discussion or simulation). Outcome measures included a readiness for fieldwork survey (quantitative self-reported ratings and qualitative questions), a knowledge-based exam, and a competency evaluation. The experimental groups’ total mean differences were greater than the control group, although these were not statistically significant (p = .551). However, there were statistically significant differences between the groups for two survey items (p = .010; p = .045). There were also statistically significant differences for within-group measures for each experimental group related to self-efficacy (simulation group, p = .006; discussion group, p = .001), but not for the control group. This suggests that both discussion and simulation were effective in increasing student fieldwork readiness. The qualitative data provided additional insight into student perceptions about fieldwork, patient interactions, and level of confidence. Study findings supported the implementation of refresher sessions and demonstrated that using either discussion or simulation were effective options. Further research examining specific strategies for both interventions and combining the two for optimal student preparation would be beneficial

Influence of calcium administration on the short-term hemodynamic and anti-ischemic effects of nifedipine

This prospective study investigated whether pretreatment with intravenously administered calcium would influence the effect of nifedipine on rest hemodynamics and treadmill performance in patients with ischemic heart disease. Seventeen patients were studied after undergoing a qualifying treadmill exercise test that revealed ST segment depression indicative of ischemic heart disease. Study subjects performed three additional treadmill tests as part of the protocol. One treadmill test was obtained from each patient to provide baseline measurements without a preceding intravenous infusion and in the absence of all antianginal drugs including nifedipine two additional exercise tests were preceded by an infusion and 10 mg of bite-and-swallow nifedipine. The infusions, administered in a randomized, double-blind, crossover fashion, consisted of either 10 ml of 10% calcium chloride (13.6 mEq) in 50 ml of 5% dextrose in water or 5% dextrose in water alone. Rest systolic blood pressure (134 +/- 4.6 mm Hg) was unchanged after placebo infusion (135 +/- 4.6 mm Hg) but decreased to 124 +/- 4.1 mm Hg (p less than 0.01) 25 min after nifedipine administration. Rest systolic blood pressure increased after calcium infusion (from 139 +/- 4.3 to 148 +/- 4.8 mm Hg, p less than 0.01) and then decreased significantly 25 min after nifedipine administration to 135 +/- 4.2 mm Hg (p less than 0.01). Despite a decrease at the time of peak nifedipine effect after either infusion, systolic blood pressure was significantly lower after administration of nifedipine alone than after administration of calcium and nifedipine (124 +/- 4.1 vs. 135 +/- 4.2 mm Hg, p less than 0.01)

Investigating the Academic and Social Benefits of Extended New Student Orientations for First-Year Students

In this study, researchers examined the benefits of college students’ participation in an extended new student orientation at a large, public research university. Framed within social identity theory, this study extends a hypothesis that extended new student orientations promote the institutional social identity of first-year students and facilitate their sense of belonging through supportive community development; consequently, the findings suggested that first-year students who participated in an extended new student orientation had a greater sense of belonging, higher academic performance (as measured through students’ fall and spring cumulative grade point averages), and higher retention to their second year. Recommendations for new student orientation practitioners, directors, and administrators are discussed

The Lantern Vol. 11, No. 1, December 1942

• Friends of the Aquarium • Espionage • Fuss-Budget • Dress Blues • Alone • One Easy Lesson in How Not to Study • A Thumbtack Sketch • One Star • A Colonial Inn • Thoughts on a Dark Day • Query • Paul Revere and the World He Lived In • Sunsetshttps://digitalcommons.ursinus.edu/lantern/1028/thumbnail.jp