Open Source Software Information Triangulation: A Design Science Study

Open source components are a promising way for creating and delivering software to the market fast. However, challenges arise when assessing the quality of open source software. While frameworks to assess these components exist, the open source market is neither governed nor regulated and the use of these frameworks is labor-intensive and complex. This research aims to solve this problem by selecting quality indicators for open source software on GitHub and realizing a tool for automatically supporting the evaluation of information about open source software from other available sources. These sources include StackExchange.com for external support and the National Vulnerability and Exposure database for security incident history. Feedback on the developed prototype supports our view that automatic checks of open source software claims is possible and useful

The NLstart2run study: running related injuries in novice runners:Running related injuries in novice runners

Hardlopen is wereldwijd een populaire sport welke vaak wordt beoefend voor de positieve gezondheidseffecten. Er is echter een keerzijde. Hardlopers worden vaak geplaagd door blessures. Een probleem waar veelal beginners tegenaan lopen. Dit proefschrift beschrijft de NLstart2run studie, een onderzoek waarin een groep van 1.700 beginnende hardlopers gedurende een 6-weekse “Start to Run” cursus is gevolgd. Doel van dit onderzoek was de kennis betreffende incidentie en risicofactoren voor hardloopblessures te vergroten. Dit zal uiteindelijk moeten bijdragen aan de introductie van blessurepreventieve maatregelen. Tijdens de loopcursus liep 10,9% van de deelnemers een blessure op wat gelijk was aan een incidentie van 27,5 blessures per 1.000 uur hardlopen. De meeste blessures ontstonden rond de knie (38,4%) en kuit (20,0%). Hardlopers zonder hardloopervaring, met vroegere beweeg klachten, een hogere leeftijd en hogere BMI hadden een verhoogd risico op het ontstaan van een blessure. Daarnaast bleek trainingsfrequentie geen significante relatie met blessure ontstaan te hebben en trainen op hogere intensiteit in de voorafgaande week het blessurerisico te verhogen. Meer dan 60 minuten hardlopen in de voorgaande week bleek het blessurerisico te verlagen. Dit is verrassend, omdat dit betekent dat minder hardlopen het blessurerisico verhoogd. Waarschijnlijk liggen andere factoren hieraan ten grondslag. In toekomstige studies moeten we ons daarom realiseren dat de relatie tussen training en blessure verandert door persoonsfactoren. Dit inzicht moet gebruikt gaan worden om persoonspecifieke trainingsprogramma’s aan te kunnen bieden met als doel het blessurerisico te verlagen. Vanuit dit oogpunt kan een digitale coaching app veel mogelijkheden voor zowel onderzoek als implementatie

Experimentally Determine the Impact of Jacking-Oil Pockets on the Rotordynamic Characteristics of a Four-Pad, LBP, Tilting-Pad Journal Bearing

Test results that examine the influence of jacking-oil ports on a tilting pad journal (TPJ) bearing are presented. The static and dynamic characteristics before and after adding jacking-oil ports are compared. The test bearing is a four-pad, rocker-pivot, 57% pivot offset TPJ bearing in load between pad configuration. This original bearing was modified to include jacking-oil ports on the two loaded pads and retested at the same operating conditions. The ports occupy 5% of the pad’s surface area and have an approximate depth of 25 times the radial clearance. Pressurized jacking-oil was not used during testing; however, oil supply lines complete with check valves were added to emulate a typical industrial bearing assembly. This thesis compares both the static and dynamic bearing characteristics to determine the effects jacking-oil ports had. Rotordynamic coefficients are presented as dimensionless values, using a frequency-independent [K][C][M] model. The added jacking-oil ports caused a decrease in direct damping and increase in virtual-mass. Direct damping coefficients were reduced by an average of -26% in the loaded y-direction, and -9% in the orthogonal x-direction. The original bearing had all negative direct virtual-mass coefficients (stiffening with increasing frequency). The modified bearing had negative coefficients that were smaller in magnitude, and some virtual-mass coefficients that were positive. No significant changes were observed in any of the cross-coupled coefficients or the direct stiffness coefficients. The added jacking-oil ports has no significant impact on the static characteristics of the TPJ bearing. Static characteristics included the steady-state journal eccentricity, attitude angle, minimum film-thickens, and pad temperature. A predictive bearing code was modified to account for the jacking-oil port geometry but was unable to produce predictions matching the measured change in dynamic performance. Contrary to measurements, the code predicted frequency-dependent direct rotordynamic coefficients and no reduction in direct stiffness or damping for the bearing with jacking-oil ports. The influence of jacking-oil ports on a simple rotor-bearing system is presented. Rotordynamic predictions were made for a rigid rotor symmetrically supported by two TPJ bearings. Predictions showed that jacking-oil ports can significantly lower the first critical speed. This was attributed to the change in virtual-mass coefficients. There was only a small reduction in damping ratio predicted

Corn Yield Response to Water Availability

Drought-tolerant technologies have become popular in hybrids for low-yielding corn environments across central and western Kansas and are marketed for their ability to produce higher grain yields with less water. The objective of this study was to compare water use, yield, and water use efficiency (WUE) of two types of drought-tolerant (DT) corn hybrids and a high-yielding non-DT hybrid. Water use and yield of two DT and one non-DT, high-yielding hybrid were compared in both dryland and irrigated situations. The average yield for the irrigated corn was 217 bu/a, and the average was 127 bu/a in dryland, representing a yield increase of 90 bu/a. The irrigated corn received a total of 10 in. more water than the dryland corn over the course of the growing season, resulting in 9 bu for each additional inch of water use averaged across the three hybrids. The irrigated corn used a mean of 20.85 in. of water, and the dryland corn used a mean of 11.66 in. of water. The WUE was 10.71 bu/in. and 10.43 bu/in. for dryland and irrigated corn, respectively. Although hybrid yields differed in the irrigated environment, water use and WUE were similar for all hybrids in both dryland and irrigated environments. One DT hybrid exhibited more stable yields across dryland and irrigated environments compared with the other DT hybrid and the non-DT hybrid