bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using Force‐Field Analysis as Part of Systems Engineering Strategy to Achieve Goals
Authors: Smartt Clement , Casey William , Ferreira Susan 
Published: August 2018

AbstractThis paper provides an overview of Force‐Field Analysis (FFA) and how to employ it within a defined systems engineering strategy framework to help achieve systems engineering goals. The systems engineering strategy framework has previously been introduced; it includes a high‐level model and a set of classes and attributes to facilitate systems engineering strategic decision‐making. However, no specific methods have been presented for how to use that framework to help achieve goals. FFA provides such a method, considering enablers and barriers related to achieving a goal. A strategist uses FFA to identify actions an organization can take to address the defined enablers and barriers. An example is provided to illustrate the use of FFA in the context of a systems engineering organization.
A UAV Case Study with Set‐based Design
Authors: Small Colin , Buchanan Randy , Pohl Edward , Parnell Gregory S. , Cilli Matthew , Goerger Simon , Wade Zephan 
Published: August 2018

AbstractThe DoD and Engineered Resilient Systems (ERS) community seek to leverage the capabilities of model‐based engineering (MBE) early in the design process to improve decision making in AoAs. Traditional tradespace exploration with point‐based design often converges quickly on a solution and engineering changes are required after this selection. Set‐based design considers sets of all possible solutions and enables down‐selecting possibilities to converge at a final solution. Using an Army case study and an open source excel add‐in called SIPMath, this research develops an integrated MBE model and example that simultaneously generates numerous designs through physics models into the value and cost tradespace allowing exploration for set‐based design analysis and producing a better efficient frontier than traditional point‐based design AoAs. Grouping design decisions into sets based on their characteristic decision, and simultaneously evaluating the value and cost tradespace, allows for a set‐based design approach that provides insight into the design decisions.
Concept Maturity Levels
Authors: Wheatcraft Louis S. , Lewis Layne 
Published: August 2018

AbstractIn this paper, the authors introduce and expand on a method first proposed in a paper: “Space Mission Concept Development Using Concept Maturity Levels (CMLs)” (Wessen, R. R. et al 2013). CMLs are a tool to help organizations access and mature a system concept in order to mitigate risks inherent in moving in to later development lifecycles when the feasibility of a concept has not been established. In the first part of the paper, we introduce the benefits and need for organizations to include the concept of CMLs in their systems engineering processes. We then go into more detail defining and explaining the activities and outcomes for each CML. A key application of CMLs is presented by the authors that maps CMLs to the Systems Engineering (SE) development lifecycles as well as to the concept of Technology Readiness Levels (TRLs). Next, we show how CMLs are an implementation of an older concept referred to as “The Doctrine of Successive Refinement.” Tools to help implement, manage, and mature the project through the various CMLs are presented. Lastly, several organizational approaches are described to help organizations initially mature system concepts faster than more traditional approaches.
Enhancing Automated Trade Studies using MBSE, SysML and PLM
Authors: Chadzynski Pawel Z. , Brown Barclay , Willemsen Patrick 
Published: August 2018

AbstractOne of the critical tasks of Systems Engineering MBSE methodology is execution of Trade Studies. Trade Studies are key to identifying the best‐in‐class architectural and realization alternatives. These studies often rely on physical characteristics of the available system elements represented by the “P” in the core system elements called RFLP (Requirements‐Functional‐Logical‐Physical). Such realization alternatives are not always easy to find for the Systems Engineers and often require tedious manual definition of the implementation elements in a system model. That information, however, often already resides within the enterprise design data and product configuration platforms – most likely a PLM (Product Lifecycle Management) system. This paper discusses how a proper integration between system model authoring tools (e.g. SysML) and PLM, can interactively and in real‐time deliver all relevant “P” information of the RFLP core used in trade studies and therefore save Systems Engineers a significant amount of time, eliminate incorrect assumptions, and maximize reuse.
Systems Engineering Pathology: Comprehensive Characterization of Systems Engineering Dysfunction
Authors: Davidz Heidi L. , Jackson Scott , Thomas Dale 
Published: August 2018

AbstractIn order to characterize dysfunction in the execution of the Systems Engineering (SE) process in a more methodical and systematic way, the Systems Science concept of Systems Pathology is extended to Systems Engineering Pathology. Poor SE execution can be due to inadequate execution, insufficient budgets, deficient interfacing, and other factors. These can be addressed by program/project audits and lessons learned. However, applying the science of Systems Pathology can provide a more integrated and methodical approach to address poor SE execution. SE Pathology can provide the holistic approach needed to better characterize dysfunction, for a better chance at intervention, prevention, and ultimately program success. Through a literature review, the logic behind Systems Engineering Pathology is explained and existing Systems Engineering Pathology work is discussed. These sources are aggregated to provide an expanded list of typical SE dysfunctions. Next steps for empirical study are proposed. Transfer of SE Pathology research findings to SE practice is discussed. As medicine has been gradually accumulating an understanding of causes, detection and treatment of diseased states, perhaps SE can begin to accumulate an understanding of causes, detection and treatment of dysfunctional execution. The objective would be to better achieve affordable, healthy SE functions enabled to positively influence program outcomes.
Retracted: microRNA‐590‐5p targets transforming growth factor β1 to promote chondrocyte apoptosis and autophagy in response to mechanical pressure injury
Authors: Wang Jun , Zhang Yumin , Song Wei , Ma Tao , Wang Kunzheng 
Published: August 2018

AbstractThis study aimed to investigate the role of miR‐590‐5p in chondrocyte apoptosis and autophagy in response to mechanical pressure injury in vitro, as well as to elucidate its regulatory mechanism in the pathogenesis of osteoarthritis. We applied mechanical pressure of 10 MPa to chondrocytes for 60 minutes to establish the chondrocyte model of experimentally induced mechanical injury. We then investigated the expression of miR‐590‐5p in the injury model and the effects of miR‐590‐5p dysregulation on the expression of cell apoptosis–related and autophagy‐related proteins. Cell apoptosis was detected by flow cytometry. Moreover, the potential targets of miR‐590‐5p were investigated. Mechanical pressure injury resulted in a significantly increased expression of miR‐590‐5p. Suppression of miR‐590‐5p significantly increased chondrocytes viability, inhibited chondrocytes apoptosis and autophagy in response to mechanical pressure injury. In addition, mechanical pressure injury led to a decreased expression of transforming growth factor β1 (TGFβ1). Moreover, TGFβ1 was confirmed as a direct target of miR‐590‐5p. Knockdown of TGFβ1 significantly induced chondrocytes apoptosis and autophagy in response to mechanical pressure injury, which was contrary to the effects of miR‐590‐5p suppression. Furthermore, overexpression of TGFβ1 and miR‐590‐5p at the same time significantly reversed the effects of overexpression of miR‐590‐5p alone on chondrocytes apoptosis and autophagy. Our results indicate that upregulation of miR‐590‐5p may target TGFβ1 to promote chondrocyte apoptosis and autophagy in response to mechanical pressure injury, thus contributing to the pathogenesis of osteoarthritis.
Hybrid reactive distillation using polyoctylmethylsiloxane membrane for isopentyl acetate production from mixed PVA by products
Authors: Wang Chen , Wang Chao , Guang Chao , Gao Jun , Zhang Zhishan 
Published: August 2018

AbstractBACKGROUNDThe transesterification of methyl acetate and isoamyl alcohol catalyzed by ionic liquids is a new environment‐friendly method for isopentyl acetate (iso‐AmAc) production, and also appropriate for the recovery of polyvinyl alcohol (PVA) byproducts. Therefore, it is of great significance for iso‐AmAc production from PVA byproducts to explore alternative processes with the goal of improving the conversion of the chemical equilibrium reaction and energy efficiency, including reactive distillation (RD), dividing‐wall reactive distillation (RDWC) and pervaporation (PV)‐based hybrid reactive distillation.RESULTThis article proposed four novel reactive hybrid processes with feedstock of mixed PVA byproducts and made a comparison with two conventional processes of RD and RDWC in terms of the minimum total annual cost (TAC) and CO2 emissions. The results revealed that the RDWC‐PV can give a 35.61% saving in TAC and a 40.27% reduction in CO2 emissions compared with the RD, and the other three RD‐PV hybrid processes have less CO2 emissions and equivalent TAC compared with the RDWC.CONCLUSIONIn summary, all hybrid processes proposed were more energy‐saving and economical than the conventional RD, especially the RDWC‐PV, due to synergistic advantages of various process intensification methods. © 2018 Society of Chemical Industry
One skull to rule them all? Descriptive and comparative anatomy of the masticatory apparatus in five mouse species
Authors: Ginot Samuel , Claude Julien , Hautier Lionel 
Published: August 2018

AbstractMurine rodents display a unique cranial morphology and masticatory musculature. Yet detailed myological descriptions are scarce, especially considering the great diversity of the subfamily and the use of the house mouse and brown rat as model organisms. The masticatory musculature in these two species has been thoroughly described, which allows comparisons with other wild species. Description and comparison of a wide range of species constitutes a necessary step to fully understand how ecological factors may influence the morphology and myology of the skull in the Murinae and vice versa. In this study, we describe the masticatory musculature of five mouse species: Mus caroli, Mus cervicolor, Mus pahari, Mus fragilicauda, and Mus minutoides. For each species, one to five specimens were dissected, and their muscle weights and volumes calculated. One specimen was selected for iodine‐enhanced CT‐scanning, which allowed us to digitally reconstruct the musculature. We then compared the different masticatory arrangements between these species, as well as with the previous descriptions of the house mouse and brown rat. We show that interspecific differences especially involved the temporalis muscle and zygomatico‐mandibularis muscular groups, although some differences were also seen in the pterygoid muscle and masseter muscle groups. We then propose some ecological interpretations for these differences, by interpreting them in terms of functional differences.
The larval ontogeny of Coryphaeschna perrensi (McLachlan, 1887): Supporting monophyletic groups in Aeshnidae dragonflies (Insecta: Odonata: Anisoptera)
Authors: Carvalho Alcimar L. 
Published: August 2018

AbstractThe development of the larval external morphology of Coryphaeschna perrensi is reported based primarily on a comparison of successive exuviae of reared specimens, with the second stadium larvae first described separately. Accentuated changes observable throughout successive moltings occur in some structures, such as the head capsule, labium, and anal appendages, allowing for the definition of characters with naturally ordered, polarized, and linear states (transformation series) by ontogenetic evidence. The terminal (less general) and nonterminal (more general) states of the described transformation series correspond by primary homology to the conditions found in larvae of other dragonfly species. Consequently, as the result of a parsimony analysis and subsequently ontogenetic rooting, the disposition of the states of 17 characters in a sample of final‐stadium larvae of 23 species, representatives of the six Aeshnidae tribes (21) and Austropetaliidae (2), results in a hierarchical network comprising six distinct taxonomic levels of inclusion of C. perrensi. The levels correspond to Aeshnidae, Aeshninae, Aeshnini (part) + Gynacanthini, Coryphaeschna + Remartinia, Coryphaeschna, and Coryphaeschna except C. adnexa, which are groups previously recognized as monophyletic resulting from analyses considering adult morphology. Immature insect morphology coupled with ontogenetic observation presenting great potential to hypothesize phylogenetic relationships and investigate heterochronic events.
Diagnostic Performance of Ultrasound Elastography for Evaluating Portal Hypertension in Children: A Systematic Review and Meta‐analysis
Authors: Kim Dong Wook , Yoon Hee Mang , Jung Ah Young , Lee Jin Seong , Oh Seak Hee , Kim Kyung Mo , Cho Young Ah 
Published: August 2018

ObjectivesTo assess the diagnostic performance of ultrasound (US) elastography in evaluating portal hypertension in children and compare the liver and spleen stiffness values between the portal hypertension and control groups.MethodsStudies in the MEDLINE and Embase databases were selected that investigated the diagnostic performance of US elastography in children with portal hypertension up to December 21, 2017. Pooled sensitivity and specificity data were assessed by hierarchical logistic regression modeling.ResultsEleven studies were included in the systematic review, and a meta‐analysis could be conducted in 7 of these publications to evaluate the diagnostic performance of US elastography. The summary sensitivity and specificity of this method for liver stiffness were 90% (95% confidence interval [CI], 83%–94%) and 79% (95% CI, 73%–84%), respectively, and the area under the hierarchical summary receiver operating characteristic curve was 0.92 (95% CI, 0.90–0.94). A subgroup analysis of 5 transient elastographic studies revealed similar diagnostic performance (sensitivity, 90%; specificity, 78%). In 10 of the 11 studies that investigated liver stiffness and 2 of the 3 studies that also measured spleen stiffness, patients in the portal hypertension group had a significantly higher stiffness value than the control group (P < .05).ConclusionsUltrasound elastography shows good performance in diagnosing portal hypertension and can identify significant differences in liver and spleen stiffness in children with this condition. This method thus has considerable potential as a noninvasive tool for screening portal hypertension–related complications in children with chronic liver disease.
Silicon consumption kinetics by marine sponges: An assessment of their role at the ecosystem level
Authors: López‐Acosta María , Leynaert Aude , Grall Jacques , Maldonado Manuel 
Published: August 2018

AbstractThe silicic acid (DSi) is a dissolved nutrient used by diverse marine organisms to build their skeletons of biogenic silica (BSi). This consumption, mostly due to diatoms, largely determines the availability of DSi in the photic ocean. Yet growing evidence suggests that Si consumers traditionally disregarded, such as the siliceous sponges, may also play a role. This study investigated the kinetics of DSi utilization by two demosponges as a function of both DSi availability and duration of the incubation period (24 h vs. 48 h). Consumption increased with increasing DSi availability following a saturable Michaelis–Menten kinetics. Haliclona simulans saturated at about 70 μM (Km = 45.9) and Suberites ficus around 130 μM (Km = 108.2). Forty‐eight hour incubations yielded more conservative consumption rates than 24 h incubations, particularly when DSi availability was far below saturation. DSi concentrations in the sponge natural habitats (0.2–15 μM) were consistently much lower than required for efficient elaboration of the BSi skeleton, suggesting a chronic DSi limitation. The DSi consumption kinetics was combined with quantifications of sponge biomass in the Bay of Brest (France), which was used as case study. In this system, sponges consume daily 0.10 ± 0.19 mmol Si m−2 and about 6.4 × 106 mol Si yearly. This activity represents 7.6% of the net annual BSi production in the Bay, a figure overlooked in previous nutrient balances based only on diatoms. Since the world marine Si cycle does not yet incorporate the contribution of sponges, its global BSi production budget may also be underestimated.
Photoinitiated Seeded RAFT Dispersion Polymerization: A Facile Method for the Preparation of Epoxy‐Functionalized Triblock Copolymer Nano‐Objects
Authors: Li Xueliang , Tan Jianbo , Xu Qin , He Jun , Zhang Li 
Published: August 2018

AbstractIn this study, a novel photoinitiated seeded reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization is developed for the preparation of epoxy‐functionalized triblock copolymer nano‐objects at room temperature. Epoxy‐functionalized worms and vesicles prepared by photoinitiated RAFT dispersion polymerization of glycidyl methacrylate are used as seeds for chain extension by photoinitiated seeded RAFT dispersion polymerization of methacrylic and acrylic monomers. Good control is maintained during the polymerization with a high polymerization rate. Pure triblock copolymer worms can be prepared by the photoinitiated seeded RAFT dispersion polymerization with a broad degree of polymerization range of the third block. The room temperature feature of photoinitiated seeded RAFT dispersion polymerization is critical to ensure the survival of epoxy moiety after the polymerization. The obtained triblock copolymer nano‐objects can be cross‐linked by reacting with a diamine. Finally, cross‐linked worms are used as the stationary phase of chromatography for selective separation of organic dyes from water.
Functional Precision Polymers via Stereo‐ and Regioselective Polymerization Using Group 6 Metal Alkylidene and Group 6 and 8 Metal Alkylidene N‐Heterocyclic Carbene Complexes
Authors: Buchmeiser Michael R. 
Published: August 2018

AbstractThe concepts of functional precision polymers and the latest accomplishments in their synthesis are summarized. Synthetic concepts based on chain growth polymerization are compared to iterative synthetic approaches. Here, the term “functional precision polymers” refers to polymers that are not solely hydrocarbon‐based but contain functional groups and are characterized by a highly ordered primary structure. If insertion polymerization is used for their synthesis, olefin metathesis‐based polymerization techniques, that is, ring‐opening metathesis polymerization (ROMP), acyclic diene metathesis (ADMET) polymerization, and the regio‐ and stereoselective cyclopolymerization of α,ω‐diynes are almost exclusively applied. Particularly with regio‐ and stereospecific ROMP and with cyclopolymerization, the synthesis of tactic polymers and copolymers with high regio‐, stereo‐, and sequence control can be accomplished; however, it requires carefully tailored transition metal catalysts. The fundamental synthetic concepts and strategies are outlined.
Effects of Astragalus membranaceus fiber on growth performance, nutrient digestibility, microbial composition, VFA production, gut pH, and immunity of weaned pigs
Authors: Che Dongsheng , Adams Seidu , Wei Cai , Gui‐Xin Qin , Atiba Emmanuel M. , Hailong Jiang 
Published: August 2018

AbstractAstragalus membranaceus is an herbaceous perennial plant, growing to about 2 feet tall, with sprawling stems and alternate leaves about 12–24 leaflets. In total, 24 cross bred (Duroc × Landrace × Yorkshire) piglets weaned at 4 weeks with an average body weight of 10.84 ± 1.86 kg, were divided into four groups and randomly assigned to dietary treatments containing different AMSLF levels (0.00%, 2.50%, 5.00%, and 7.50%). The piglets in the control group (0.00% AMSLF) were fed basal diet and other treatment groups were fed basal diet in addition to 2.50%, 5.00%, and 7.50% pulverized AMSLF. The results indicated that supplementation with AMSLF significantly (p < 0.05) decreased diarrheal incidence in piglets. There was significant difference between treatment in terms of ADFI, ADG and FCR. Both 5.00% and 7.50% treatments significantly increased growth performance. The digestibility of gross energy and dry matter increased (p > 0.05) with increasing AMSLF level. The level of blood IL‐2 and TNF‐α were significantly affected by AMSLF supplementation with 7.50% AMSLF group having higher (p < 0.05) IL‐2 and TNF‐α levels than the other treatment groups. The 16SrDNA sequencing results from the four treatments showed that the potentially active bacterial microbial population and diversity in pig cecum were dominated by the phyla Bacteriodetes and Firmicutes regardless of the AMSLF supplementation. The Shannon diversity, PD whole tree diversity indices and Chao analyses exhibited significant variability in species richness across the treatments. The principal coordinates analysis (PCoA) showed significant (p < 0.1) differences between bacterial communities in all treatment groups. Results from the current study suggested that AMSLF supplementation increased composition of bacterial microbiota in pig gut. In conclusion, dietary supplements with AMSLF could potentially be used to prevent diarrheal incidence and improved pig production.
Highly precise time integration method for linear structural dynamic analysis
Authors: Xing Yufeng , Zhang Huimin , Wang Zekun 
Published: August 2018

SummaryTo achieve high accuracy, conventional time integration methods require small time steps, especially when applied to large‐scale finite element systems. The use of small time steps calls for a large number of computations. In this paper, a strategy is proposed to construct an efficient and highly precise time integration method for linear time‐invariant systems. Adopting the multi‐substep notion, the highly precise time integration method creates an integrated amplification matrix prior to recursive calculations by multiplying the amplification matrices of N equal substeps, where a 2m algorithm and the method of storing incremental matrix are respectively employed to reduce computational cost and rounding error. On the basis of the Newmark method, two highly precise symplectic schemes and one highly precise dissipative scheme are developed. In addition, the consistent stability of the used Newmark schemes is presented. The free vibration of a three‐dimensional truss, the impact of a particle against a rod, and the forced vibrations of a rectangular thin plate and a stiff system are investigated to validate the performance of the proposed method.