bluuebunny/crossref_metadata_2025_split huggingface dataset:
Entrepreneurial orientation as a driver of brokerage in external networks: Exploring the effects of risk taking, proactivity, and innovativeness
Authors: Rank Olaf N. , Strenge Michael 
Published: March 2018

Research Summary: In this article, we examine to what extent a firm's propensity to acquire brokerage positions in its external knowledge networks is driven by its entrepreneurial orientation. Specifically, we compare the influence of a firm's overall entrepreneurial orientation (EO) to the effects that the individual EO dimensions (i.e., risk taking, proactivity, and innovativeness) have on brokerage. Using a case study design, survey data was gathered from a company cluster in the German photonics industry. Applying a class of exponential random graph models, our results suggest that a firm's overall level of EO does not affect its propensity to obtain a brokerage position. In contrast, brokerage is positively influenced by a firm's willingness to take business‐related risks, whereas a pronounced orientation toward innovation seems to reduce brokerage.Managerial Summary: While it has often been claimed that a pronounced orientation toward entrepreneurship helps firms succeed, the results of our study suggest that the individual dimensions of entrepreneurial orientation in fact differently influence the ability of firms to obtain brokerage positions in their external collaboration networks with partners. Specifically, obtaining brokerage positions seems to depend on the willingness of firms to take business‐related risks. In contrast to our theoretical considerations, we were unable to find empirical support for our assumption that proactivity would be a similarly important antecedent to network brokerage. Finally, firms should be careful with respect to an extensive orientation toward innovativeness, as they run the risk of neglecting the importance of an advantageous strategic position in their external networks.
Flexible Film Bulk Acoustic Wave Filters toward Radiofrequency Wireless Communication
Authors: Jiang Yuan , Zhao Yuan , Zhang Lin , Liu Bohua , Li Quanning , Zhang Menglun , Pang Wei 
Published: March 2018

AbstractThis paper presents a flexible radiofrequency filter with a central frequency of 2.4 GHz based on film bulk acoustic wave resonators (FBARs). The flexible filter consists of five air‐gap type FBARs, each comprised of an aluminum nitride piezoelectric thin film sandwiched between two thin‐film electrodes. By transfer printing the inorganic film structure from a silicon wafer to an ultrathin polyimide substrate, high electrical performance and mechanical flexibility are achieved. The filter has a peak insertion loss of −1.14 dB, a 3 dB bandwidth of 107 MHz, and a temperature coefficient of frequency of −27 ppm °C−1. The passband and roll‐off characteristics of the flexible filter are comparable with silicon‐based commercial products. No electrical performance degradation and mechanical failure occur under bending tests with a bending radius of 2.5 mm or after 100 bending cycles. The flexible FBAR filters are believed to be promising candidates for future flexible wireless communication systems.
A New Strategy for Maximizing the Storage Capacity of Lithium in Carbon Materials
Authors: Kang Jun , Kim Han‐Vin , Chae Seen‐Ae , Kim Kwang‐Ho 
Published: March 2018

AbstractA novel strategy for maximizing the lithium storage capacity of carbon materials is reported. To redesign the interior structure, a large amount of Li, 4 wt%, is doped into the carbon during its synthesis. The Li‐doped carbon is subsequently annealed, during which the diffusion of Li induces a disordered structure, thereby generating many nanocavities. The diffused Li atoms aggregate into a superdense state within the carbon structure; when the Li agglomerates escape from the carbon during the delithiation process, new void spaces are created at their location. Thus, the interior of carbon is evacuated to form a new structure capable of storing a large amount of Li, realizing a high reversible capacity during charging. At a rate of 1 C, the average reversible capacity of the material is three times higher than that of commercial graphite, with a stable cycling performance over 300 cycles. This is a remarkably improved Li storage performance for pure carbon, without the need for the silicon, tin, or transition metal oxide, that are becoming popular as next‐generation materials. Therefore, this novel strategy can potentially aid in the design of high‐performance materials via better carbon material design and combinations with other types of materials.
Design and Realization of 3D Printed AFM Probes
Authors: Alsharif Nourin , Burkatovsky Anna , Lissandrello Charles , Jones Keith M. , White Alice E. , Brown Keith A. 
Published: March 2018

AbstractAtomic force microscope (AFM) probes and AFM imaging by extension are the product of exceptionally refined silicon micromachining, but are also restricted by the limitations of these fabrication techniques. Here, the nanoscale additive manufacturing technique direct laser writing is explored as a method to print monolithic cantilevered probes for AFM. Not only are 3D printed probes found to function effectively for AFM, but they also confer several advantages, most notably the ability to image in intermittent contact mode with a bandwidth approximately ten times larger than analogous silicon probes. In addition, the arbitrary structural control afforded by 3D printing is found to enable programming the modal structure of the probe, a capability that can be useful in the context of resonantly amplifying nonlinear tip–sample interactions. Collectively, these results show that 3D printed probes complement those produced using conventional silicon micromachining and open the door to new imaging techniques.
MapReduce functions to remote sensing distributed data processing—Global vegetation drought monitoring as example
Authors: Zou Quan , Li Guoqing , Yu Wenyang 
Published: March 2018

SummaryGlobal change models for different applications are developed, according to the principle of remote sensing technology. Data for these models are generally remote sensing image, which is multiplatform, multidimentional, multiband, and multisource. Moreover, such data may be in different parts of the world and perhaps up to terabyte or petabyte level. Therefore, a data‐intensive computing problem in the global change has emerged. Distributed computing infrastructures are suitable to store large‐scale datalike satellite images that have to be written only once and read frequently. The emergence of the cloud computing technology brings new information architecture, and global change models implemented in the cloud platform provide users with stable, effective, on‐demand cloud computing services. In this paper, the experiment is carried out on the cloud framework based on open cloud computing platform‐Hadoop. In addition, on this framework, it achieves a prototype example for monitoring global vegetation drought conditions. Oriented to a variety of remote sensing data, we propose an abstract data format to achieve the unified description of remote sensing data. The data abstraction is to discretize the multidimensional remote sensing data for easy‐distributed storage and computation. Using MapReduce paradigm, the complexity of remote sensing algorithms is resolved. Experimental results show that based on the parallel programming method, good scalability changing with the amount of processed data in the Hadoop distributed environment.
PGD2/PTGDR2 Signaling Restricts the Self-Renewal and Tumorigenesis of Gastric Cancer
Authors: Zhang Bin , Bie Qingli , Wu Peipei , Zhang Jie , You Benshuai , Shi Hui , Qian Hui , Xu Wenrong 
Published: March 2018

AbstractThe antitumor effect of prostaglandin D2 (PGD2) on gastric cancer (GC) has been known for decades. However, the mechanism of PGD2's control of GC growth is unclear. Cancer stem cells (CSCs) are implicated in tumor neovascularization, invasiveness, and therapeutic resistance. Herein, we discovered that signaling between PGD2 and its receptor (PTGDR2) has the ability to restrict the self-renewal of GC cells in vitro and suppress tumor growth and metastasis in vivo. To obtain these findings, we first determined that PGD2 synthase (L-PTGDS) and PTGDR2 expression were lower in GC tissues than adjacent tissues and was associated with the patients’ prognosis. Moreover, the expression of L-PTGDS and PTGDR2 was negatively correlated with the GC-CSC markers Sall4 and Lgr5 in GC tissues. Second, L-PTGDS and PTGDR2 expression were knocked down in CSC-like cells, resulting in enhanced expression of CSC markers and self-renewal ability. Direct PGD2 stimulation and L-PTGDS overexpression produced the opposite effect. Thirdly, PGD2 inhibited tumor growth and incidence rate in a subcutaneous tumor model and suppressed liver and mesenteric metastasis in a peritoneal metastasis model. Interfering with the expression of PTGDR2 reversed these effects in vivo. Last, a mechanistic study found that PGD2 inhibited STAT3 phosphorylation and nuclear expression. Further experiments revealed that the inhibitory effect of PGD2 on the expression of CSC markers disappeared after mutations were introduced into STAT3 phosphorylation (Thr705) site. In short, this study reveals a novel function of PGD2/PTGDR2 signaling on CSC regulation and provides a new way to control the development of GC.
Stem Cell Defect in Ubiquitin-Green Fluorescent Protein Mice Facilitates Engraftment of Lymphoid-Primed Hematopoietic Stem Cells
Authors: Faltusová Kateřina , Szikszai Katarína , Molík Martin , Linhartová Jana , Páral Petr , Šefc Luděk , Savvulidi Filipp , Nečas Emanuel 
Published: March 2018

AbstractTransgenic mice expressing green fluorescent protein (GFP) are useful in transplantation experiments. When we used ubiquitin-GFP (UBC-GFP) transgenic mice to study the availability of niches for transplanted hematopoietic stem and progenitor cells, the results were strikingly different from the corresponding experiments that used congenic mice polymorphic in the CD45 antigen. Analysis of these unexpected results revealed that the hematopoiesis of UBC-GFP mice was outcompeted by the hematopoiesis of wild-type (WT) mice. Importantly, UBC-GFP mice engrafted the transplanted bone marrow of WT mice without conditioning. There was a significant bias toward lymphopoiesis in the WT branch of chimeric UBC-GFP/WT hematopoiesis. A fraction of immature Sca-1+ cells in the spleen of UBC-GFP mice expressed GFP at a very high level. The chimeric hematopoiesis was stable in the long term and also after transplantation to secondary recipient mice. The article thus identifies a specific defect in the hematopoiesis of UBC-GFP transgenic mice that compromises the lymphoid-primed hematopoietic stem cells in the bone marrow and spleen.
Optimized synthesis of cost‐effective, controllable oil system architectures for turbofan engines
Authors: Hambley Christopher J. , Jones Bryn L. , Griffin Ian , Mills Andrew R. , Kadirkamanathan Visakan 
Published: March 2018

AbstractTurbofan oil systems are used to provide lubrication and cooling in the engine . There is an increasing interest in oil system architectures which utilize electric pumps and/or valves to give optimized control of flows to individual oil chambers, leading to improved thermal management of oil and lubrication efficiency. The challenges here lie in the trade‐off between increasing controllability and minimizing the addition of new components, which adds unwanted production and maintenance costs. This paper formulates the oil system architecture design as a constrained, multiobjective optimization problem. An architecture is described using a graph with nodes representing components and edges representing interconnections between components. A fixed set of nodes called the architecture template is provided as an input and the edges are optimized for a multicriteria objective function. A heuristic method for determining similarities between the different oil chamber flow requirements is presented. This is used in the optimization to evaluate the controllability objective based on the structure of the valve architecture. The methodology provides benefits to system designers by selecting cheaper architectures with fewer valves when the need to control oil chambers separately is small. The effect of manipulating the cost/controllability criteria weightings is investigated to show the impact on the resulting architecture.
Harnessing expert knowledge: Defining a Bayesian network decision model with limited data–Model structure for the vibration qualification problem
Authors: Rizzo Davinia B. , Blackburn Mark R. 
Published: March 2018

AbstractAs systems become more complex, systems engineers rely on experts to inform decisions. There are few experts and limited data in many complex new technologies. This challenges systems engineers as they strive to plan activities such as qualification in an environment where technical constraints are coupled with the traditional cost, risk, and schedule constraints. Bayesian network (BN) models provide a framework to aid systems engineers in planning qualification efforts with complex constraints by harnessing expert knowledge and incorporating technical factors. By quantifying causal factors, a BN model can provide data about the risk of implementing a decision supplemented with information on driving factors. This allows a systems engineer to make informed decisions and examine “what‐if” scenarios. This paper discusses a novel process developed to define a BN model structure based primarily on expert knowledge supplemented with extremely limited data (25 data sets or less). The model was developed to aid qualification decisions—specifically to predict the suitability of six degrees of freedom (6DOF) vibration testing for qualification. The process defined the model structure with expert knowledge in an unbiased manner. Validation during the process execution and of the model provided evidence the process may be an effective tool in harnessing expert knowledge for a BN model.
A historical perspective on systems engineering
Authors: Honour Eric C. 
Published: March 2018

AbstractWith 20 years of theSystems Engineeringjournal completed, this short article considers its impact on the discipline of systems engineering (SE) as a whole. It reviews the founding principles of this journal and assesses how well it has advanced those principles. In a broader sense, it also reviews 70 years of existence of the SE discipline and then looks ahead for its promises. After several decades of rapid growth, SE appears to have partially stagnated in the 1990s and 2000s in the face of process control pressures. The use of first principles has dwindled. Resurgence in the field, however, has been coincident with the time frame of this journal, as first principles are being redeveloped and new methods are arising. This journal successfully acts as a stimulus for that resurgence.
Can Single‐Pass Electrofishing Replace Three‐Pass Depletion for Population Trend Detection?
Authors: Hanks R. Daniel , Kanno Yoichiro , Rash Jacob M. 
Published: March 2018

AbstractSince changes in climate and land use operate at broad spatial scales, efficient monitoring of temporal trends in fisheries resources over large geographic areas is vital to appropriate management. We compared the statistical power of single‐ versus three‐pass electrofishing surveys in detecting temporal trends of age‐1 and older Brook Trout Salvelinus fontinalis populations in western North Carolina. Empirical estimates of abundance and capture probabilities were obtained from annual three‐pass depletion surveys at 14 headwater stream sites between 2012 and 2017. The CVs in abundance averaged 26% (SD = 14.2%) across study sites, and the mean capture probability per pass was 0.72 (range = 0.57–0.84, SD = 0.09). Captures from single‐pass sampling and abundance estimates from three‐pass removal sampling were highly correlated (r2 = 0.98). In simulations, under the range of years sampled (5–25 years) and annual declines (2.5–7.5%) considered, the power to detect temporal trends was similar (∆ power < 0.1) between the two methods when five or more sites were monitored. An additional set of simulations with varying capture probabilities demonstrated that differences in power between the two methods increased as mean capture probabilities decreased (0.8, 0.5, and 0.2) accompanied by larger variation in capture probabilities among the samples, indicating results obtained with Brook Trout populations in North Carolina might not be applicable to other habitat types or species. Variation in fish abundance did not affect the difference in power between the two methods. Single‐pass electrofishing surveys can be an efficient survey method to monitor temporal population trends for habitat types and species characterized with high capture probabilities and low variation among samples. However, single‐pass data would not typically allow for inferences of capture probabilities and thus abundance. This can be problematic when environmental factors vary and when data sets collected using different protocols are compared. This trade‐off should be carefully considered when designing monitoring programs.
STEM career aspirations in Black, Hispanic, and White ninth‐grade students
Authors: Gottlieb Jessica J. 
Published: March 2018

AbstractThis study identifies factors that are significantly related to student intentions to enter science, technology, engineering, and mathematics (STEM) occupations by age 30, and examines how those factors differ across definitions of STEM occupation, educational attainment levels, and student demographics. Data from 2009 High School Longitudinal Study base year were used, and were analyzed using multinomial logistic regression. Expectancy‐value theory is the theoretical framework for this study. The findings from this study suggest that depending on the definition of STEM careers operationalized in the analysis, variation can be observed in the impact of gender, while the role of the expectancy‐value constructs remains largely consistent across multiple definitions of STEM careers. The results also suggest that while expectancy‐value constructs such as utility, interest, and attainment value are significantly related to the STEM career plans of White students, fewer significant relationships between expectancy‐value constructs and the STEM career plans of Black and Hispanic students were identified. Additionally, findings from this study raise questions about the extent to which STEM career choices at the sub‐bachelor's degree level can be understood as achievement‐related choices, and thus the extent to which expectancy‐value theory is a suitable framework for understanding those choices.
Scaffolding Evidence‐Based Writing for English Learners in Three Steps
Authors: Lee Soyoung 
Published: March 2018

AbstractEvidence‐based writing is a complex standard in the Common Core State Standards that has taken center stage in the writing curriculum. Students must demonstrate proficiency in making claims based on evidence and explain how the evidence supports their claim. This is a challenging task for all students, but for English learners, it can be especially overwhelming. The author describes a series of lessons that teachers can use to introduce evidence‐based writing in three steps to English learners. The author developed the three‐step lessons for use with English learners after observing teachers and students struggling with evidence‐based writing in linguistically diverse settings. The lessons incorporate literature on best practices in writing development for second‐language learners, and the descriptions of the lessons are supported with examples from a sixth‐grade English as a Second Language classroom.
Reconstruction of high‐resolution climate data over China from rainfall and snowfall records in the Qing Dynasty
Authors: Hao Zhixin , Yu Yingzhuo , Ge Quansheng , Zheng Jingyun 
Published: March 2018

In recent years, researchers studying historical climates have given an increasing amount of attention to the Yu‐Xue‐Fen‐Cun record of the Qing Dynasty of China. These records play an important role in the quantitative reconstruction of the climate from the past 300 years in China due to their uniform recording formats and measurement methods. As a result of collective effort, methods for climate reconstruction are constantly improving, and regions with reconstructed high‐resolution historical climate data are expanding. This study reviews the features of the Yu‐Xue‐Fen‐Cun record and summarizes the progress and primary results achieved over the past 20 years. Studies showed that temperature variations over eastern China had three stages: a relatively cold phase in the 18th century, the coldest phase in the 19th century, and the warmest phase during and after the 20th century. However, the amplitudes between the maximum and minimum temperatures differed from 4.2 to 5.7 °C among different regions and sites. The variation in annual precipitation in North China showed an opposite phase to the Meiyu rainfall in the middle and lower reaches of the Yangtze River in the periods of 1736–1767, 1916–1948, and after 1955, and a consistent phase in the periods of 1792–1836 and 1845–1885. The rainband regularly moved away from South China in early May to the middle and lower reaches of the Yangtze River in mid‐June, and then finally arrived in North China in early July.This article is categorized under:

Paleoclimates and Current Trends > Modern Climate Change
Harmonic balance Navier‐Stokes aerodynamic analysis of horizontal axis wind turbines in yawed wind
Authors: Drofelnik Jernej , Da Ronch Andrea , Campobasso Michele Sergio 
Published: March 2018

AbstractMultimegawatt horizontal axis wind turbines often operate in yawed wind transients, in which the resulting periodic loads acting on blades, drive‐train, tower, and foundation adversely impact on fatigue life. Accurately predicting yawed wind turbine aerodynamics and resulting structural loads can be challenging and would require the use of computationally expensive high‐fidelity unsteady Navier‐Stokes computational fluid dynamics. The high computational cost of this approach can be significantly reduced by using a frequency‐domain framework. The paper summarizes the main features of the COSA harmonic balance Navier‐Stokes solver for the analysis of open rotor periodic flows, presents initial validation results on the basis of the analysis of the NREL Phase VI experiment, and it also provides a sample application to the analysis of a multimegawatt turbine in yawed wind. The reported analyses indicate that the harmonic balance solver determines the considered periodic flows from 30 to 50 times faster than the conventional time‐domain approach with negligible accuracy penalty to the latter.