Van der Waerden's Theorem and Avoidability in Words

Pirillo and Varricchio, and independently, Halbeisen and Hungerbuhler considered the following problem, open since 1994: Does there exist an infinite word w over a finite subset of Z such that w contains no two consecutive blocks of the same length and sum? We consider some variations on this problem in the light of van der Waerden's theorem on arithmetic progressions.Comment: Co-author added; new result

Diplomatic style as foreign policy insight : a case study of South Korea

Diplomatic style is problematic. In academic research it is dismissed, misconstrued, treated perfunctorily, or wholly absented. Despite substantial expansion in the field of diplomatic studies, it has attracted scant attention. Yet, practitioners maintain a faith-like confidence in it. They allude to its importance in memoirs and instructional texts, and assume it gives them an advantage over scholars in analyzing foreign policy. For scholars and analysts, this raises the question, does diplomatic style really provide additional insight into foreign policy? This study assesses whether the ability to recognize and comprehend diplomatic style provides additional analytical insight above and beyond that which is available through academic research. I first explore the concept of diplomatic style and present a framework for its analysis. I construct four Weberian ideal types of diplomatic style - purposive-rational, value-rational, traditional, and emotional, which provide a means to contrast and compare concrete examples. Using South Korea as a case study, I elicit experiential narratives of diplomatic style from practicing and retired South Korean diplomats, and practicing and retired members of the Seoul foreign diplomatic corps. I then analyze, contrast, and compare these narratives with the Weberian ideal types. I find a tendency towards emotionalism, and concerns regarding status, generational change, cosmopolitanism, and estrangement, to be characteristics of the South Korean diplomatic style. While these phenomena are featured in academic research, I argue that focusing on diplomatic style highlights their relevance to foreign policy. In particular, the relevance of estrangement is difficult to ascertain from academic research alone. Therefore I also argue that the ability to recognize and comprehend diplomatic style does not provide additional analytical insight into a state's foreign policy, above and beyond that which is normally available through scholarly research, but rather narrows the vast range of information analysts must cover, and thus is an important guide to the factors which are 'policy relevant'. Hence the study makes three core contributions. First, it contributes to the field of diplomatic studies by presenting a comprehensive framework for the conceptualization of style in diplomatic practice. Second, it contributes to the field of Korean studies by highlighting influences on South Korean foreign policy, which were previously disparate and difficult to isolate. And finally, it presents a tangible policy solution to address the scholar-practitioner gap through a focus on diplomatic style

Organisational culture and public diplomacy in the digital sphere: The case of South Korea

Digital diplomacy is the latest technological advance to push change in diplomatic practice. It relates to the application of digital technologies, including information and communication technologies, software engineering and big data, and artificial intelligence, to the practice of diplomacy. Positioned in the top ranks of connectivity, internet speed, smartphone ownership, and social media usage, South Korea should be a leader in the use of digital technologies in diplomatic practice. However, South Korea is not a leader; indeed, it has been left behind. I explore digital diplomacy as a “disruptive technology” and look at criteria for organizational adaptation. I then use these criteria to assess South Korea's adaptation and draw from these the specific policy challenges facing South Korea. To conclude, I propose four core criteria to aid digital diplomacy adaptation in South Korea and other similar states

Application of the Trio-Tri-Star Carpal Wrist for use in a Solar Array Tracking Mechanism for the Momentum-eXchange/Electrodynamic Reboost (MXER) Tether Concept

This paper describes the application of the Trio-Tri-Star Carpal Wrist to the Momentum Exchange Electro-Dynamic Re-boost (MXER) tether, an advanced space transportation concept being developed by the In-Space Propulsion Technology Office at NASA s Marshall Space Flight Center in Huntsville, Alabama. Dr. Joseph Bonometti and Mr. Kirk Sorensen are the principal engineers. In the paper, a brief overview of the MXER concept is given, with an emphasis on the design problem that this wrist is designed to address. The Trio-Tri-Star Carpal Wrist, a three degree of freedom parallel manipulator, invented by Dr. Stephen J. Canfield of Tennessee Tech University, is described with an overview of wrist geometry, kinematics, and stress analysis. A working model of the wrist was assembled at MSFC using Dr. Canfield s prototype to demonstrate its operation. Finally, a design description and supporting analysis of a MXER flight concept wrist is given, with recommendations for future development work

Fostering Effective Parent Engagement

We would like to submit our collaboration model poster from SPED 867 VC as a consideration for SACAD 2020

Top ten risk factors for morbidity and mortality in patients with chronic systolic heart failure and elevated heart rate: the SHIFT risk model

Aims We identified easily obtained baseline characteristics associated with outcomes in patients with chronic heart failure (HF) and elevated heart rate (HR) receiving contemporary guideline-recommended therapy in the SHIFT trial, and used them to develop a prognostic model. Methods We selected the 10 best predictors for each of four outcomes (cardiovascular death or HF hospitalisation; all-cause mortality; cardiovascular mortality; and HF hospitalisation). All variables with p &#60; 0.05 for association were entered into a forward stepwise Cox regression model. Our initial analysis excluded baseline therapies, though randomisation to ivabradine or placebo was forced into the model for the composite endpoint and HF hospitalisation. Results Increased resting HR, low ejection fraction, raised creatinine, New York Heart Association class III/IV, longer duration of HF, history of left bundle branch block, low systolic blood pressure and, for three models, age were strong predictors of all outcomes. Additional predictors were low body mass index, male gender, ischaemic HF, low total cholesterol, no history of hyperlipidaemia or dyslipidaemia and presence of atrial fibrillation/flutter. The c-statistics for the four outcomes ranged from 67.6% to 69.5%. There was no evidence for lack of fit of the models with the exception of all-cause mortality (p = 0.017). Similar results were found including baseline therapies. Conclusion The SHIFT Risk Model includes simple, readily obtainable clinical characteristics to produce important prognostic information in patients with chronic HF, systolic dysfunction, and elevated HR. This may help better calibrate management to individual patient risk.</p

Extended Life Testing of Duplex Ball Bearings

Sierra Nevada Corporations Space Systems performed bearing life testing for the Scan Mirror Motor/Encoder Assembly (SMMA), part of the Scan Mirror Assembly on-board the Aerosol Polarimetry Sensor (APS) on the NASA Glory Spacecraft. The baseline bearing life test duration extended beyond the launch date for the Glory Spacecraft; a risk that the program was willing to undertake with the understanding that if any anomalies or failures occurred before the required life was achieved, then the mission objectives or operating profile could be modified on orbit to take those results into account. Even though the Glory Spacecraft failed to reach orbit during its launch in March of 2011, the bearing life testing was continued through a mutual understanding of value between Sierra Nevada Corporation and our customer; with a revised goal of testing to failure rather than completing a required number of life cycles. Life testing thus far has not only exceeded the original mission required life, but has also exceeded the published test data for Cumulative Degradation Factor (CDF) from NASA/CR-2009-215681. Many lessons were learned along the way regarding long life testing. The bearing life test has been temporarily suspended due to test support equipment issues

Effect of visit-to-visit variation of heart rate and systolic blood pressure on outcomes in chronic systolic heart failure: results from the Systolic Heart Failure Treatment With the If Inhibitor Ivabradine Trial (SHIFT) trial

Background: Elevated resting heart rate (HR) and low systolic blood pressure (SBP) are related to poor outcomes in heart failure (HF). The association between visit-to-visit variation in SBP and HR and risk in HF is unknown. Methods and Results: In Systolic Heart Failure Treatment with the If inhibitor ivabradine Trial (SHIFT) patients, we evaluated relationships between mean HR, mean SBP, and visit-to-visit variations (coefficient of variation [CV]=SD/mean×100%) in SBP and HR (SBP-CV and HR-CV, respectively) and primary composite endpoint (cardiovascular mortality or HF hospitalization), its components, all-cause mortality, and all-cause hospitalization. High HR and low SBP were closely associated with risk for primary endpoint, all-cause mortality, and HF hospitalization. The highest number of primary endpoint events occurred in the highest HR tertile (38.8% vs 16.4% lowest tertile; P&lt;0.001). For HR-CV, patients at highest risk were those in the lowest tertile. Patients in the lowest thirds of mean SBP and SBP-CV had the highest risk. The combination of high HR and low HR-CV had an additive deleterious effect on risk, as did that of low SBP and low SBP-CV. Ivabradine reduced mean HR and increased HR-CV, and increased SBP and SBP-CV slightly. Conclusions: Beyond high HR and low SBP, low HR-CV and low SBP-CV are predictors of cardiovascular outcomes with additive effects on risk in HF, but with an unknown effect size. Beyond HR reduction, ivabradine increases HR-CV. Low visit-to-visit variation of HR and SBP might signal risk of cardiovascular outcomes in systolic HF. Clinical Trial Registration: URL: http://www.isrctn.com/. Unique identifier: ISRCTN70429960