Colorado State University System

Peer Reviewed

During the past twenty years the Domain Name System (DNS) has sustained phenomenal growth while maintaining satisfactory user-level performance. However, the original design focused mainly on system robustness against physical failures, and neglected the impact of operational errors such as mis-configurations. Our measurement efforts have revealed a number of mis-configurations in DNS today: delegation inconsistency, lame delegation, diminished server redundancy, and cyclic zone dependency. Zones with configuration errors suffer from reduced availability and increased query delays up to an order of magnitude. The original DNS design assumed that redundant DNS servers fail independently, but our measurements show that operational choices create dependencies between servers. We found that, left unchecked, DNS configuration errors are widespread. Specifically, lame delegation affects 15% of the measured DNS zones, delegation inconsistency appears in 21% of the zones, diminished server redundancy is even more prevalent, and cyclic dependency appears in 2% of the zones. We also noted that the degrees of mis-configuration vary from zone to zone, with the most popular zones having the lowest percentage of errors. Our results indicate that DNS, as well as any other truly robust large-scale system, must include systematic checking mechanisms to cope with operational errors.

Abstract This paper presents a new approach to architecture optimization for an enterprise or System of Systems (SoS) with the goal of enhancing individual system acquisition programs and the operational effectiveness of the enterprise as a whole. Replacing the current common practice of utilizing one or two technical parameters serially to evaluate candidate architectures is a better method that employs a fuller set of technical and programmatic variables in a Model‐Based Systems Engineering (MBSE) context. Integrated architecture modelling and optimization is performed in a tool‐supported MBSE process to identify an optimum architecture solution. This specifically addresses the predesign phases of a system acquisition program where leverage on total program cost is the greatest. We seek to improve the ability to deal with challenges such as management independence, technical diversity, and lack of synchronization across the programs involved in a SoS. This implementation results in a higher quality optimization with a more informed, and traceable selection decision. An example satellite communications SoS case study is used to develop the approach and highlight its utility.

Architecture-centric practices are gaining wide-spread acceptance in systems engineering. This process involves capturing the structure, behavior, and rules and their relationships to create an abstract representation of a system, often termed a model of the system. Central to the rules that govern a system are the requirements that are placed on it, often by various stakeholders. These requirements help guide the system development process of a complex entity. In this paper, we discuss an approach for extending the idea of structured requirements (requirements defined through an orderly structure with specific pieces of content that must be filled in) to SysML through customized stereotypes that help enforce the requirement structure through model-based attributes. This approach helps move requirements modeling and management further into the model-based paradigm from the classical textual definitions. In addition, requirements often are customized by the organization defining them through additional attributes. These additional attributes are added to the model-based structured requirement (MBSR) to create a well-defined organizational requirement stereotype. Several examples of the MBSRs are presented using a notional thrust reverser actuation system (TRAS). Several points are made on how this approach can help support more rigorous requirements modeling, analysis, management, and communication throughout the system development process. Future work will involve automatic generation of the textual requirement statements from the attributes, customized validation rules, and customized classifiers for the various attributes.

INTRODUCTION: Cities have long been known to be society's predominant engine of innovation and wealth creation, yet they are also hotspots of pollution and disease partly due to current urban and transport practices. The aim of the European Urban Burden of Disease project is to evaluate the health burden and its determinants related to current and future potential urban and transport planning practices and related exposures in European cities and make this evidence available for policy and decision making for healthy and sustainable futures. METHODS AND ANALYSIS: Drawing on an established comparative risk assessment methodology (ie, Urban and Transport Planning Health Impact Assessment) tool), in nearly 1000 European cities we will (1) quantify the health impacts of current urban and transport planning related exposures (eg, air pollution, noise, excess heat, lack of green space) (2) and evaluate the relationship between current levels of exposure, health impacts and city characteristics (eg, size, density, design, mobility) (3) rank and compare the cities based on exposure levels and the health impacts, (4) in a number of selected cities assess in-depth the linkages between urban and transport planning, environment, physical activity and health, and model the health impacts of alternative and realistic urban and transport planning scenarios, and, finally, (5) construct a healthy city index and set up an effective knowledge translation hub to generate impact in society and policy. ETHICS AND DISSEMINATION: All data to be used in the project are publicly available data and do not need ethics approval. We will request consent for personal data on opinions and views and create data agreements for those providing information on current and future urban and transport planning scenarios.For dissemination and to generate impact, we will create a knowledge translation hub with information tailored to various stakeholders.

INTRODUCTION: Cities have long been known to be society's predominant engine of innovation and wealth creation, yet they are also hotspots of pollution and disease partly due to current urban and transport practices. The aim of the European Urban Burden of Disease project is to evaluate the health burden and its determinants related to current and future potential urban and transport planning practices and related exposures in European cities and make this evidence available for policy and decision making for healthy and sustainable futures. METHODS AND ANALYSIS: Drawing on an established comparative risk assessment methodology (ie, Urban and Transport Planning Health Impact Assessment) tool), in nearly 1000 European cities we will (1) quantify the health impacts of current urban and transport planning related exposures (eg, air pollution, noise, excess heat, lack of green space) (2) and evaluate the relationship between current levels of exposure, health impacts and city characteristics (eg, size, density, design, mobility) (3) rank and compare the cities based on exposure levels and the health impacts, (4) in a number of selected cities assess in-depth the linkages between urban and transport planning, environment, physical activity and health, and model the health impacts of alternative and realistic urban and transport planning scenarios, and, finally, (5) construct a healthy city index and set up an effective knowledge translation hub to generate impact in society and policy. ETHICS AND DISSEMINATION: All data to be used in the project are publicly available data and do not need ethics approval. We will request consent for personal data on opinions and views and create data agreements for those providing information on current and future urban and transport planning scenarios.For dissemination and to generate impact, we will create a knowledge translation hub with information tailored to various stakeholders.

Wheat (Triticum aestivum) is an important crop worldwide, contributing to about one third of the global caloric intake. In June 2021, leaves with bacterial blight symptoms, including yellow and necrotic lesions running parallel to veins, were found in several fields across five counties in eastern Colorado (Weld, Morgan, Sedgwick, Baca, and Kit Carson). Plants exhibiting these symptoms were scattered throughout fields, but symptoms appeared consistent across counties. To determine the causal agent and complete Koch's postulates, a 1 cm2 symptomatic leaf area was excised and macerated in 0.5 mL of sterilized water from four field samples. The lysate was spread on yeast extract dextrose calcium carbonate medium (YDC agar, 1% yeast extract, 2% dextrose, 2% calcium carbonate, 1.5% agar) to isolate bacteria. Single colonies of yellow, mucoid morphology were selected and streaked on new YDC plates. Isolate genomic DNA was extracted (Zymo Research Quick-DNA Fungal/Bacterial Miniprep Kit, #D6005), and ~30 ng of gDNA was used to amplify the 16S rRNA, gyrB, and rpoB genes of all four isolates (Barret et al., 2015; Delétoile et al., 2009; Krawczyk et al., 2020; Ogier et al., 2019). Amplified PCR products were cleaned (Zymo DNA Clean & Concentrator kit, #D4033) and Sanger sequenced, and all sequences have been deposited in NCBI (16S rRNA: OR707336, OR707337, OR707338, OR707339), (gyrB: PP407951, PP407952, PP407953, PP407954), (rpoB: PP407955, PP407956, PP407957, PP407958). A BLAST search against whole genomes identified one isolate from Kit Carson county (CO314) and two isolates from Baca county (CO316 and CO317) as Pantoea agglomerans with 100% identity for the 16S rRNA, gyrB, and rpoB genes, and one isolate from Weld county (CO315) was 100% identical to Pantoea allii for all three genes. To complete Koch's postulates and confirm Pantoea sp. as the causal disease agents, isolates were grown as lawns on DifcoTM Nutrient Agar (NA) medium (48h, 28℃), suspended in 10 mM MgCl2 using a final optical density of 0.1 (~109 colony forming units per milliliter (CFU/mL)), and syringe-infiltrated into the entire leaf area of 10-day-old wheat seedling leaves (var. Hatcher). Treatments of 10mM MgCl2 and a field isolate that does not cause symptoms, identified as Pseudomonas synxantha by 16S rRNA and gyrB sequencing, were negative controls. Inoculated wheat plants were transferred to a growth chamber (22℃, 90% relative humidity). Symptoms developed 14 days post inoculation (dpi), with the most severe appearing 21 dpi. Each of the four Pantoea isolates were re-isolated from symptomatic leaves by grinding them in a Tissue Lyser II (Qiagen) with two metal beads and diluting with 0.4 mL of sterile water. A 20 µL sample of each isolate was plated on NA (24h, 28℃). The colonies appeared phenotypically identical to the original isolates, and Sanger sequencing confirmed the identities of the isolates. To our knowledge, this is the first report of P. agglomerans causing disease in wheat in the United States, and the first report of P. allii as a wheat disease-causing agent. This report is consistent with previous communications showing P. agglomerans causing wheat disease in China (Gao et al., 2023), and P. ananatis in Poland (Krawczyk et al., 2020). The growing numbers of reports of Pantoea spp. as pathogens in recent years suggests increasing novel disease emergence on cereals worldwide.

INTRODUCTION: Postoperative pulmonary complications (PPCs) represent a significant cause of postoperative morbidity and even mortality. However, there is a lack of consensus regarding this composite endpoint, the definition of the individual components, classification and optimal outcome measures. This study aims to refine the PPCs composite framework by evaluating its construct validity, assessing the necessity and risks of a composite measure and exploring the feasibility of differentiating severity categories. METHODS: A Delphi consensus process will be conducted, engaging an international multidisciplinary group of 30-40 panellists, including clinicians, researchers, patients, public representatives and health economists. Through iterative rounds, the study will seek agreement on the individual components of the PPCs composite. Additionally, consensus will establish a framework for a composite outcome measure based on a standardised severity classification, appropriate timeframes and weighted grading of PPCs. ANALYSIS: tests or the Kruskal-Wallis test. ETHICS AND DISSEMINATION: The study will be conducted in strict compliance with the principles of the Declaration of Helsinki and will adhere to ACCORD guidance for reporting. Ethics approval has been obtained for this study from the University of Wolverhampton, UK (SOABE/202425/staff/3). Informed consent will be obtained from all panellists before the commencement of the Delphi process. The results of the study will be published in a peer-reviewed journal with the authorship assigned in accordance with ICMJE requirements. TRIAL REGISTRATION NUMBER: NCT06916598 (clinicaltrials.gov).

Youth-onset type 2 diabetes (T2D) is on the rise and may be associated with more adverse health outcomes than adult onset. Latinx adolescents are disproportionately at risk for T2D yet are underrepresented in prevention efforts. Extant interventions to prevent T2D in Latinx adolescents show limited effectiveness. Comprehensive understanding of Latinx adolescent/family needs is lacking, but necessary for cultural tailoring of T2D prevention. Researchers conducted focus groups with 32 Latinx adolescents (age 10-18 years) from Northern Colorado and 31 Spanish-speaking parents/caregivers, with 2.5-hr semistructured youth-specific and parent-specific discussions, respectively. No participants included in this study had T2D. Qualitative data were analyzed for emergent themes about barriers/facilitators of healthy living and T2D prevention preferences. Thematic content analysis yielded eight themes within three categories: barriers to healthy living, facilitators of healthy living, and program preferences. Barriers to healthy living included individual motivational factors/food preferences; financial cost and time demands of healthy eating/exercise; negative emotions; and external/relational factors such as parent feeding pressure and peer pressure/bullying. Facilitators of healthy living included individual motivational factors/enjoyment of healthy living and supportive family structure. Program preferences were for family-based programming with adolescent breakout sessions and for facilitation by culturally competent facilitators. T2D is recognized as a serious health concern among Latinx families. There is a need for culturally tailored prevention programming that, in order to be acceptable, should address cultural and socioeconomic considerations, provide coping skills for adolescent-specific psychosocial stressors, and utilize a family-based programming framework with adolescent breakout sessions and culturally competent facilitators.

Abstract The mechanical loss of amorphous thin films of germania (GeO 2 ) and titania-doped germania (Ti:GeO 2 ) deposited by ion-beam sputtering onto silicon double-paddle oscillators was studied from 10 K to 290 K. Undoped germania was found to show a wide cryogenic mechanical loss peak centered at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mo>∼</mml:mo> </mml:mrow> <mml:mn>60</mml:mn> </mml:math> K with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>ϕ</mml:mi> <mml:mo>=</mml:mo> <mml:mn>3.1</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:msup> </mml:math> , which decreases to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>1.1</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:msup> </mml:math> as Ti-concentration increases to 44%. In addition to decreasing the height of this low-temperature peak, Ti-doping increases its width, and shifts its position toward lower temperatures. Annealing reduces the room temperature mechanical loss of Ti:GeO 2 and increases its cryogenic mechanical loss, which is consistent with trends observed in most amorphous oxides.

A model is developed to describe trace gas uptake and reaction with applications to aerosols and microdroplets. Gas uptake by the liquid is formulated as a coupled equilibria that links gas, surface and bulk regions of the droplet or solution. Previously, this framework was used in explicit stochastic reaction-diffusion simulations to predict the reactive uptake kinetics of ozone with droplets containing aqueous aconitic acid, maleic acid and sodium nitrite. Using prior data and simulation results, a new equation for the uptake coefficient is derived, which accounts for both surface and bulk reactions. Lambert W functions are used to obtain closed form solutions to the integrated rate laws for the multiphase kinetics; similar to previous expressions that describe Michaelis–Menten enzyme kinetics. Together these equations couple interface and bulk processes over a wide range of conditions and don’t require many of the limiting assumptions needed to apply resistor model formulations to explain trace gas uptake and reaction.

OBJECTIVE: Although yoga shows some promise as an intervention for post-traumatic stress disorder (PTSD), little is known about how yoga reduces PTSD symptoms. The current study hypothesised that aspects of interoceptive awareness would mediate the effect of a yoga intervention on PTSD symptoms. METHODS: = 141) that offered weekly 90-minute sessions. We conducted a mediation analysis using interoceptive awareness and other variables that were associated with PTSD symptom reduction at mid-treatment and treatment end. RESULTS: Although measures of anxiety, interoceptive awareness, and spirituality were identified in individual mediator models, they were no longer found to be significant mediators when examined jointly in multiple mediator models. When examining the multiple mediator models, the strongest mediator of the yoga intervention on PTSD symptoms was mental well-being at mid-treatment and stigma at the treatment end. The total effect of yoga on CAPS and PCL at the treatment end mediated by stigma was 37.1% (-1.81/-4.88) and 33.6% (-1.91/-5.68), respectively. CONCLUSION: Investigation of mental well-being and mental illness stigma as potential mediators is warranted in future studies of yoga as a treatment for PTSD as they may prove to be important foci for yoga interventions.

Unmanned Aerial Vehicles (UAVs), or drones, are becoming increasingly prevalent in the commercial and defense sectors, operating throughout the continental United States airspace. UAVs have wing sizes ranging from 0.25 centimeters to 61 meters, and they perform a myriad of roles from job site surveillance to 3D mapping of agricultural fields. However, a UAV is not a standalone system, but joins a ground control system, pilot and communications network to form an Unmanned Aircraft System (UAS) platform. With the various UAS platforms of different UAV sizes and missions, the Federal Aviation Administration (FAA) is developing a UAS Traffic Management (UTM) system to safely integrate them into the airspace. UAS ground systems require ingestion, processing, compilation and dissemination of weather data specific to a local area. The NOAA Advanced Quantitative Precipitation Information (AQPI) system has proven to reliably perform these functions. Expanding the mission for a system changes the requirements originally used to design the system. The ability of a system to adjust is the foundation of System Adaptability. Using the concept of System Adaptability and leveraging the existing Digital Twin of the Bay Area AQPI, this paper presents the theoretical application of adapting the San Francisco Bay Area AQPI system to provide meteorological information to UAS platforms operating under the Bay Area UTM.

Abstract Communication skills are one of several professional skills that are required for engineering graduates that pose difficulties for engineering educators. The issues around these skills include what to teach, how to teach them, and how to assess students’ abilities. As part of a curriculum reform project that is a component of a larger department change effort, three required classes of the third year curriculum of an Electrical and Computer Engineering program have added a knowledge integration component that occurs approximately every five weeks. During these integration efforts, students are required to integrate knowledge from the three courses to evaluate the design of a cell phone. The goal of these efforts is to have the students connect the knowledge across the three courses using a practical real-world device. Additionally, students are required to produce short video presentations to demonstrate their abilities in integrating the knowledge and the ability to communicate this via a video presentation. The video presentation assignment includes several components. To provide scaffolding for the student efforts, a couple of high-quality example video presentations are made available. These videos were developed by graduate students involved with the knowledge integration project. After the graduate students developed initial versions of their videos, they were critiqued by several faculty and then finalized and made available to the students. A time limit of 7.5 minutes was given for each video. After producing the videos, students were required to perform an anonymous peer review of three classmates’ presentations. Additionally, one graduate student, not responsible for an example video, then also performed an assessment of the videos. The students were also required to provide guided self-reflections on their communication skills after they had completed their videos and performed and received peer reviews. Herein we present results of the assessment data collected for this project. There are a couple of goals related to the assessment of the videos. First, a comparison is made between the assessments of the GTA and peer assessments with the students’ self-reflections –looking for areas of consistency. Then a second evaluation was performed where a random selection of videos were evaluated by members of an industry advisory board to look for similarities and differences between their evaluation and the in-house, or academic, evaluations. The methodology for this work includes collecting the text-based evaluations from each constituents. These texts were then coded for emergent themes that are compared across the various constituents. The results of this work demonstrate the efficacy of combining peer reviews with self-reflections in the development of students’ communication skills.

Drawing from experiences as a leader at various universities, in this paper, the author discusses the blessings and curses of major intercollegiate athletic programs. Blessings include national attention, contribution to diversity, improved facilities, campus excitement, the ability to recruit top coaches and staff, and academic support. Curses include the considerable national attention, tighter scrutiny, misplaced priorities, a culture of dependency, decreases in faculty and staff morale, the potential for decrease athlete welfare, and a lack of competition. The author then offers potential solutions to these issues.

With continuing scaling of CMOS process, process variations in the form of die-to-die and within-die variations become significant which cause timing uncertainty. This paper proposes a method of analytically analyzing statistical behavior of multiple coupled interconnects with an uncertain signal arrival time at each interconnect input (aggressors and the victim). The method utilizes delay change characteristics due to changes in relative arrival time between an aggressor and the victim. The results show that the proposed method is able to accurately predict delay variations through a coupled interconnect.

Abstract In this paper, we report our progress on integrating a model‐based system engineering methodology with a system architectural trade study applied to flight control systems of a locally owned and operated, cost effective Unmanned Aerial Vehicles (UAV) design utilizing the concepts of Model‐Based Systems Architecture Processes (MBSAP). The primary objective of the UAV is to monitor wildfires and to gather information and to provide surveillance data for predicting and preventing wildfires [1] . We describe our experience with a holistic approach to architect flight controls (the System‐of‐Interest), in a way that is tightly coupled with high‐level stakeholder needs and concerns, operational scenarios, (normal, inadvertent, and mis‐) use cases, Context System, and Enabling Systems. Several architectural variants of the Surface‐less Flight Controls (SFC) were traded. Our systemic approach showed that classical flight controls are feasible for the baseline UAV. It also helped us identify a novel architecture with a potential to drastically improve UAV performance (range, survey time), UAV weight, and specific cost. Our approach has resulted in an architecture that has the potential to significantly reduce the costs of manufacturing as well as operating UAVs, at the same time it drastically improves their performance. This development could mean widely increased availability and improved effectiveness of UAVs in fire detection and prevention.

The Advanced Quantitative Precipitation Information (AQPI) System provides San Francisco Bay Area users with a single source of meteorological observations ranging from national weather model forecasts to local high resolution radar quantitative precipitation estimations (QPE). As a complex and sociotechnical system, AQPI lends itself to following the Complex, Large-scale, Interconnected, Open, Sociotechnical (CLIOS) process defined by Joseph Sussman. Following the CLIOS process and separating the physical model from the institutional sphere, a systems engineering approach naturally aligns with the Model-Based Systems Engineering (MBSE) methodology. Using block diagrams and internal block diagrams to capture the physical system, the engineer expresses the institutional sphere using behavioral modeling of use cases and activity diagrams. An MBSE behavioral analysis model for AQPI was developed in 2021 based upon the project concept. This preliminary model defined a foundation for the development of an AQPI Digital Twin.Systems mature from concept through implementation, and Digital Twins are no different. In 2022, AQPI hosting transitioned from National Oceanic and Atmospheric Administration (NOAA) to the Cooperative Institute for Research in the Atmosphere (CIRA). With the completion of the transition, the AQPI model required an update to match implementation as of April 2023. Using capabilities-based requirements analysis, the updated AQPI model matures a step closer to becoming the Digital Twin of the AQPI system and a single source of truth for development and system evaluation in support of operations and maintenance.

This paper presents a survey of existing literature, standards, methods, and best practices for security requirements elicitation in the field of systems engineering. Despite the abundance of research on requirements engineering, there is a notable scarcity of resources addressing security requirements from a systems engineering perspective. This work integrates insights from both software centric security engineering and traditional systems engineering to offer a consolidated reference for systems engineers. Key areas reviewed include relevant systems engineering standards, Model-Based Systems Engineering (MBSE) methods, Systems Theory approaches, and software security requirements engineering practices. This survey aims to provide a valuable resource for systems engineers striving to enhance security requirements development during system design.

To support further electrification of the aircraft industry, replacements of mechanical with electrical drives for various applications are being considered. Previous research by the authors proposed a drive architecture and control strategy for electromechanical thrust-reverse actuation in aircraft using parallel induction machines in a central-converter multiple-machine architecture, with rotor position synchronization achieved with variable stator resistance circuits controlled with proportional-integral feedback. This paper describes an improved control design employing the H-infinity method. Model linearization and weight function selection for the modified plant in the optimal control synthesis problem are described. Primary findings are that control performance using the proposed approach is improved in terms of maximum and normed position errors and also convergence time compared to the previous design.