bluuebunny/crossref_metadata_2025 huggingface dataset:
Cui bono? An empirical investigation into risk benefits of corporate diversification
Authors: Haug Jonas P , Pidun Ulrich , zu Knyphausen-Aufseß Dodo
Published: November 2017

While the diversification–performance link is well covered in strategy research, we know much less about the link between firm diversification and risk. This article draws from modern portfolio theory and corporate diversification theory to derive a comprehensive set of hypotheses on the impact of related and unrelated diversification on the systematic risk, total risk, and bankruptcy risk of a firm. Based on a large international sample, we find the portfolio effect to be more important than previously thought, while synergy effects appear to be largely counterbalanced by the direct and indirect costs of diversification. Specifically, we find that systematic risk is not reduced by corporate diversification, while bankruptcy risk is significantly lower in diversified firms, possibly leading to conflicts between shareholders and other stakeholder groups.
The causal ambiguity paradox: Deliberate actions under causal ambiguity
Authors: McIver Derrick , Lengnick-Hall Cynthia
Published: November 2017

Causal ambiguity describes a lack of understanding of cause-and-effect interactions between resources and competitive advantage. As a central construct in strategic management, causal ambiguity constrains a firm’s ability to replicate valuable capabilities internally, yet, simultaneously, offers a means of protecting those capabilities from imitation by external agents. This analysis shifts the paradigm from looking at casual ambiguity as a given characteristic within organizations and examines the causal ambiguity paradox by looking at how organizations can strategically act on causal ambiguity as a mechanism for extending advantages. Specifically, we suggest actions that deliberately manage causal ambiguity can be a strategic capability and extend competitive advantages.
Using qualitative comparative analysis and system dynamics for theory-driven business model research
Authors: Täuscher Karl
Published: November 2017

The business model has evolved as an important concept in strategic management. While recent years have seen substantial progress in the business model’s conceptual development, empirical progress remains limited. I argue that this limited progress might be due to a mismatch between the business model’s characteristics and the methods applied to study it. This essay introduces two methods—qualitative comparative analysis and system dynamics simulation—that share key characteristics with the business model concept. The essay introduces these methods and discusses five directions for applying them in business model research. In doing so, I hope to contribute to a stronger harmonization of conceptual and empirical business model research.
Cultural codes and education in Poland – a plea for a new educational imaginary
Authors: Zamojski Piotr
Published: November 2017

The twofold aim of this paper is to describe the specificity of education in Poland and to explore the potential and the limitations of the concept of cultural codes for investigating this specificity. With reference to Max Weber’s methodology of ideal types, and following the inquires of Sowa (2011), Leder (2014) and Hryniewicz (2015), as well as with reference to contemporary research on education in Poland, I distinguish three types of cultural codes: the folwark, the totalitarian and the modernisation code. The analysis using the concept of cultural codes consists of reinterpreting the existing empirical data on education in Poland. Its potential lies, therefore, in providing a framework for gathering and understanding diverse phenomena, analysed separately in many dispersed studies. The argument conducted in the paper leads to the conclusion of the exhaustion of educational imaginary in Poland. However, the concept of cultural codes is found to be useful in the work leading towards rejuvenation of this imaginary.
Next Steps: Valuing, Supporting, and Promoting the Intersection of HRD Theory and Practice
Authors: Packard Carol B.
Published: November 2017

The Problem

The need to apply theory and research to practice has been expressed and argued for in the field of human resource development (HRD) and organization development for over two decades. The field of human resource development has sought to address this issue since the mid-2000s, yet not enough progress has been made.

The Solution

This article highlights some of the fundamental barriers that have led to low levels of scholar-practitioner collaboration. Successful models used by other professional organizations and publications to overcome the theory–practice gap will be presented. Their process of integrating traditional scholarship with practitioner applications are described, along with other recommendations for creating borderlands where both HRD scholars and practitioners work together to solve workplace and society problems.

The Stakeholders

There are many stakeholders who would benefit from and can actively participate in increasing collaborations between scholars and practitioners. These include traditional academic scholars, consultants, and professionals in businesses, government, schools, and health care.
Fighting Fire With Fire
Authors: Berg Carla J. , Haardörfer Regine , Getachew Betelihem , Johnston Teresa , Foster Bruce , Windle Michael
Published: November 2017

Limited public health research has used psychographic profiling to segment young adults and examine their substance use behaviors. We aimed to conduct market research to identify young adult market segments at risk for alternative tobacco products (ATPs), alcohol, and marijuana use. Substance use; psychographics per the Values, Attitudes, and Lifestyle Scale (VALS); and other key variables were assessed at baseline in a longitudinal study of 3,418 students aged 18–25 from seven colleges/universities in the state of Georgia. Cluster analysis was conducted on VALS factors to identify distinct segments. Regression examined segments in relation to substance use risk. Past 30-day use prevalence for each substance was as follows: cigarettes, 13.3%; little cigars/cigarillos (LCCs), 11.2%; smokeless tobacco (SLT), 3.6%; e-cigarettes, 10.9%; hookah, 12.2%; alcohol, 63.1%; and marijuana, 19.0%. Five segments were identified, created, and named: Conventionals, Simple Lifes, Open Minds, Confident Novelty-seekers, and Stoic Individualists. Controlling for sociodemographics, Open Minds, Confident Novelty-seekers, and Stoic Individualists (vs. Conventionals [referent]) were more likely to smoke cigarettes. Confident Novelty-seekers were more likely to use LCCs. Simple Lifes were less likely to use SLT. Open Minds and Confident Novelty-seekers were more likely to use e-cigarettes. Open Minds were more likely and Simple Lifes were less likely to use hookah. Open Minds were more likely to use alcohol; Simple Lifes and Stoic Individualists were less likely to use alcohol. Open Minds were more likely to use marijuana. Market research is an effective strategy for identifying young adults at risk for using distinct ATPs and can inform targeted health campaigns and cessation interventions.
A Qualitative Analysis of Selected Stakeholders’ Viewpoints on Tobacco Control in Nigeria
Authors: Adebiyi Akindele Olupelumi , Popoola Oluwafemi Akinyele
Published: November 2017

Nigeria is a signatory to the Framework Convention on Tobacco Control. However, tobacco control efforts have been fraught with challenges. These challenges cannot be presumed to be independent of tobacco industry manipulation. We examined submissions and viewpoints from prominent tobacco control stakeholders across social, administrative, and political strata to identify convergence with tobacco industry viewpoints. We illustrate how these convergences pose a threat to effective tobacco control in Nigeria. A thematic analysis of stakeholder viewpoints was conducted on submissions to the national assembly during the Tobacco Control Bill public hearings and various industry documents. Areas of convergence with tobacco industry narratives were then explored. Significant convergence in views was observed between government agencies, social groups, and the tobacco industry. These were for narratives on constitution of a National Tobacco Control Committee, use of automated vending machines, designation of smoking areas, report to regulatory agencies, and negative effect of tobacco control on trade and poverty. There was evidence of tobacco industry interference in tobacco control efforts, which manifested in some prominent tobacco control stakeholders adopting the narratives of the tobacco industry. We advocate a constant watchfulness over the activities of these stakeholders and a proactive engagement with evidence-based antitobacco dialogue.
Antibiotic Resistance in Diabetic Foot Soft Tissue Infections: A Series From Greece
Authors: Demetriou Maria , Papanas Nikolaos , Panagopoulos Periklis , Panopoulou Maria , Maltezos Efstratios
Published: November 2017

Diabetic foot infections are a common and serious problem for all health systems worldwide. The aim of this study was to examine the resistance to antibiotics of microorganisms isolated from infected soft tissues of diabetic foot ulcers, using tissue cultures. We included 113 consecutive patients (70 men, 43 women) with a mean age of 66.4 ± 11.2 years and a mean diabetes duration of 14.4 ± 7.6 years presenting with diabetic foot soft tissue infections. Generally, no high antibiotic resistance was observed. Piperacillin-tazobactam exhibited the lowest resistance in Pseudomonas, as well as in the other Gram-negative pathogens. In methicillin-resistant Staphylococcus aureus isolates, there was no resistance to anti-Staphylococcus agents. Of note, clindamycin, erythromycin, and amoxycillin/clavulanic acid exhibited high resistance in Gram-positive cocci. These results suggest that antibiotic resistance in infected diabetic foot ulcers in our area is not high and they are anticipated to prove potentially useful in the initial choice of antibiotic regimen.
The Effect of Transarterial Chemoembolization in Combination With Kang’ai Injection on Patients With Intermediate Stage Hepatocellular Carcinoma: A Prospective Study
Authors: Wan Yue-Meng , Li Yu-Hua , Xu Zhi-Yuan , Wu Hua-Mei , Xu Ying , Yang Mei , Wu Xi-Nan
Published: November 2017

Background: The outcome of patients with intermediate stage hepatocellular carcinoma (HCC) treated by transarterial chemoembolization (TACE) remains poor. Search for a more effective therapy is still necessary. Objective: This study aimed to investigate the effect of combining TACE with Kang’ai (KA) injection for treating patients with intermediate stage HCC. Methods: A total of 89 patients with intermediate stage HCC were enrolled and divided into TACE +KA group (n = 48) receiving repeated TACE plus KA injection, and TACE group (n = 41) receiving repeated TACE alone. All patients were prospectively studied. Primary endpoints were overall survival (OS) and time to radiologic progression (TTP). Results: The TACE + KA group had significantly longer median OS (27.0 vs 21.0 months, P = .038) and TTP (12.0 vs 10.0 months, P = .028) than TACE group. The 1-, 2-, and 3-year OS rates in the TACE + KA group were markedly higher than in TACE group (88.5%, 58.8%, and 20.8% vs 81.3%, 44.9%, and 6.7%, respectively, P = .038), while the 1- and 2-year TTP rates in the TACE + KA group were significantly lower than in TACE group (49.3% and 86.9% vs 75.3% and 100%, P = .028). TACE + KA group displayed significantly lower incidences of intrahepatic and extrahepatic metastases, as well as postembolization syndrome than TACE group ( P < .05). Multivariate analyses revealed group ( P = .023), maximum tumor size ( P = .019), and tumor number ( P = .034) as significant predictors for OS, and group ( P = .046), maximum tumor size ( P = .002) and α-fetoprotein level ( P = .020) as significant predictors for TTP. Both TACE and KA injection were well tolerated. Conclusion: TACE plus KA injection is more effective than TACE alone for treating patients with intermediate stage HCC in this nonrandomized study. Further research is warranted.
Mouse population-based evaluation of urinary protein and miRNA biomarker performance associated with cisplatin renal injury
Authors: Harrill Alison H , Lin Haixia , Tobacyk Julia , Seely John C
Published: November 2017

Discovery and qualification of novel biomarkers with improved specificity and sensitivity for detection of xenobiotic-induced injuries is an area of active research across multiple sectors. However, the majority of efforts in this arena have used genetically limited rodent stocks that lack variability in xenobiotic responses inherent to genetically heterogeneous human populations. In this study, genetically diverse Diversity Outbred (DO) mice were used as a surrogate for human clinical populations to investigate performance of urinary kidney biomarkers against classical preclinical kidney injury biomarkers (blood urea nitrogen [BUN] and serum creatinine). In this study, cisplatin was used as a paradigm kidney toxicant, with female adult DO mice exposed to a single injection (5 mg/kg) of cisplatin or vehicle and necropsied 72 h post-exposure and 18 h following overnight urine collection. Interindividual variability in kidney toxicity was observed, with DO mice experiencing either no tubule cell necrosis or minimal-mild necrosis. A panel of urinary protein biomarkers and profiled miRNAs were assessed by receiver-operating characteristic curves as to their ability to distinguish non-responder versus responder animals, as defined by histopathological evidence of renal tubule cell necrosis. A surprising outcome of these studies was that BUN was elevated alongside of urinary miRNA and protein biomarkers in animals with grade 2 proximal tubular cell necrosis; but not elevated with grade 1 necrosis. These studies demonstrate a novel approach for using a rodent population to better assess sensitivity of candidate biomarkers, especially for proposed clinical applications.

Impact statement

Recent studies have indicated that several urinary proteins and miRNA species may be suitable as biomarkers for acute kidney injury. A major focus on biomarker qualification is demonstrating improved specificity and sensitivity over gold standard tests. In this study, a mouse population model, Diversity Outbred mice, was used to demonstrate that neither the urinary protein markers nor the miRNA species assayed in urine could reliably detect low severity kidney injury better than blood urea nitrogen. This study has implications for use of these biomarkers in the clinic, where interindividual heterogeneity is present within patient populations and for which the underlying tissue pathology may not be known.
Noninvasive Imaging of Immune Checkpoint Ligand PD-L1 in Tumors and Metastases for Guiding Immunotherapy
Authors: Chatterjee Samit , Lesniak Wojciech G. , Nimmagadda Sridhar
Published: November 2017

Immunotherapy holds great promise in cancer treatment. The challenges in advancing immunotherapies lie in patient stratification and monitoring therapy. Noninvasive detection of immune checkpoint ligand PD-L1 can serve as an important biomarker for guidance and monitoring of immunotherapy. Here in, we provide an overview of our efforts to develop clinically translatable PD-L1-specific imaging agents for quantitative and real-time assessment of PD-L1 expression in tumor microenvironment.
Exploration of the Pathophysiology of Chronic Pain Using Quantitative EEG Source Localization
Authors: Prichep Leslie S. , Shah Jaini , Merkin Henry , Hiesiger Emile M.
Published: November 2017

Chronic pain affects more than 35% of the US adult population representing a major public health imperative. Currently, there are no objective means for identifying the presence of pain, nor for quantifying pain severity. Through a better understanding of the pathophysiology of pain, objective indicators of pain might be forthcoming. Brain mechanisms mediating the painful state were imaged in this study, using source localization of the EEG. In a population of 77 chronic pain patients, significant overactivation of the “Pain Matrix” or pain network, was found in brain regions including, the anterior cingulate, anterior and posterior insula, parietal lobule, thalamus, S1, and dorsolateral prefrontal cortex (DLPFC), consistent with those reported with conventional functional imaging, and extended to include the mid and posterior cingulate, suggesting that the increased temporal resolution of electrophysiological measures may allow a more precise identification of the pain network. Significant differences between those who self-report high and low pain were reported for some of the regions of interest (ROIs), maximally on left hemisphere in the DLPFC, suggesting encoding of pain intensity occurs in a subset of pain network ROIs. Furthermore, a preliminary multivariate logistic regression analysis was used to select quantitative-EEG features which demonstrated a highly significant predictive relationship of self-reported pain scores. Findings support the potential to derive a quantitative measure of the severity of pain using information extracted from a multivariate descriptor of the abnormal overactivation. Furthermore, the frequency specific (theta/low alpha band) overactivation in the regions reported, while not providing direct evidence, are consistent with a model of thalamocortical dysrhythmia as the potential mechanism of the neuropathic painful condition.
Genetic optimization–based scheduling in maritime cyber physical systems
Authors: Yang Tingting , Feng Hailong , Zhao Jian , Deng Ruilong , Wang Ying , Su Zhou
Published: November 2017

In this article, we attempt to solve the issue of optimal scheduling for vessels monitoring video data uploading in maritime cyber physical systems, during the period of sailing from the origin port to destination port. We consider the terrestrial infrastructure-based networking, delivering video packets assisted by the shoreside infostations to the authorities on land. Each video packet has respective elements (i.e. release time, deadline, processing time, and weight) to describe, in which deadline is utilized to demonstrate the time domain limitation before that to upload it successfully. In order to cope with the computation complexity of traditional scheduling algorithms in intermittent infostations scenario, time-capacity mapping method is exploited to transfer it to a continue scenario when classic scheduling algorithms could be utilized with lower time complexity. An ingenious mathematic job-machine scheduling formulation is indicated with the goal of minimizing the total penalties of tardiness of uploaded video packets, taking into account the tardiness and the weights of jobs simultaneously. A genetic based algorithm, as well as an improved genetic algorithm–based optimization scheme, is proposed to target this optimization formulation. Specially, the genetic based algorithm as well as the improved genetic based algorithm are described in detail, including a novel chromosome representation, a heuristic initialization procedure, as well as a modified crossover and mutation process. The effectiveness of the proposed schemes is verified by the simulation results.
An improved belief entropy–based uncertainty management approach for sensor data fusion
Authors: Tang Yongchuan , Zhou Deyun , He Zichang , Xu Shuai
Published: November 2017

In real applications, sensors may work in complicated environments; thus, how to measure the uncertain degree of sensor reports before applying sensor data fusion is a big challenge. To address this issue, an improved belief entropy–based uncertainty management approach for sensor data fusion is proposed in this article. First, the sensor report is modeled as the body of evidence in Dempster–Shafer framework. Then, the uncertainty measure of each body of evidence is based on the subjective uncertainty represented as the evidence sufficiency and evidence importance, and the objective uncertainty measure is expressed as the improved belief entropy. Evidence modification of conflict sensor data is based on the proposed uncertainty management approach before evidence fusion with Dempster’s rule of combination. Finally, the fusion result can be applied in real applications. A case study on sensor data fusion for fault diagnosis is presented to show the rationality of the proposed method.
See the Connections? Addressing Leadership and Supervision Challenges to Support Improved Student Achievement in a Small Rural School
Authors: Hartman Jenifer J.
Published: November 2017

This case study was developed for educational leadership courses addressing supervision and school improvement. Various data are presented for students to analyze and identify key concerns at a low-performing, rural, racially diverse, K-8 school. It challenges leadership candidates to recognize interrelated problems and solutions in a school. Students are asked to prioritize responses to issues of changing school leadership, professional development to address teacher expectations, English Language Arts achievement, instructional and disciplinary practices, student behaviors and attendance, and parent engagement practices. They will develop a specific schoolwide professional development plan within an overall School Improvement Plan to address these concerns.
Review on application of phase change material in water tanks
Authors: Xie Ling , Tian Liu , Yang Lulu , Lv Yifei , Li Qianru
Published: November 2017

Latent heat storage with phase change material is a superior way of storing thermal energy because of its high thermal storage density, isothermal nature of the storage process, and easy control. In recent years, latent heat storage systems have been increasingly used in building energy conservation, solar heating systems, and waste heat recovery systems. The water tank as a key component of solar heating systems has been widely applied in practical applications. This article first reviews the research on the water tank integrated with phase change material in terms of existing research methods and heat transfer enhancing technologies and then summarizes the applications of various phase change material–based water tanks. Finally, the further research suggestions on the phase change material–based water tank are proposed in this article. The successful completion of this review will not only deepen the understanding on the research development of phase change material–based water tank but also promote practical applications of such water tanks in solar heating systems.
Improvement of coordination performance of fractional-order systems based on weighted state and relative state information
Authors: Liu Xueliang , Liu Huazhu , Wang Shanjin , Zhang Zhi , Liu Yonggui
Published: November 2017

The weighted state and relative state information feedback is introduced into the existing coordination control protocol aiming to improve the robustness of fractional-order multi-agent systems against fractional-order [Formula: see text]. By applying frequency-domain method and Nyquist stability theorem, a sufficient condition is given to ensure the fractional-order coordination. It is shown that the proposed coordination control protocol can improve the robustness of fractional-order multi-agent systems against fractional-order under directed communication topology. Two numerical examples are given and the corresponding simulation results show that compared with the existed coordination control protocols, the proposed weighted state and relative state information feedback control protocol is feasible and effective for improving the robustness performance.
In situ measurement of fatigue crack opening stresses by nonlinear vibro-acoustic modulation testing
Authors: Jia Jun , Hu Haifeng , Tao Limin , Hu Yongpan
Published: November 2017

The difficulty of accurately measuring crack closure regions has hindered measurements of opening or closure stresses, and ultrasonic methods have shown great potentialities in evaluating closure area. Many recent researches have confirmed the advantages of nonclassical nonlinear acoustic approaches in detecting short cracks and even micro- or meso-cracks. However, there are few reports on using nonclassical nonlinear acoustic approaches to measure crack closure. The aim of this article is to verify the applicability of vibro-acoustic modulation approach in estimating opening stresses of fatigue cracks. A procedure of approximating the opening stress by the applied tensile load of the inflection point of the modulation intensity curve is proposed. To study the performance of this measuring method experimentally, in situ vibro-acoustic modulation tests were carried out on a central cracked 5052-H32 aluminum alloy fatigue sample. The experimental estimations match well with other researches. Analysis of the experimental results suggests that the vibro-acoustic modulation technology is not only capable of measuring the fatigue cracks opening stresses, but also capable of analyzing the crack closure behavior, even for physically short cracks.
Determination of appropriate level of detail of a three-dimensional computer-aided design model from a permissible dissimilarity for fully automated simplification
Authors: Kwon Soonjo , Kim Hyungki , Mun Duhwan , Han Soonhung
Published: November 2017

The level of detail required for a three-dimensional computer-aided design model varies according to its purpose. Thus, it is necessary to develop an automated method for controlling the level of detail of three-dimensional computer-aided design models to facilitate the use of three-dimensional computer-aided design models in different application areas. When multiple three-dimensional computer-aided design models need to be simplified in a batch mode without user intervention, it would be advantageous if the appropriate level of details for the models were automatically determined. This study proposes a new and automated method to determine the appropriate level of detail of each three-dimensional computer-aided design model during the simplification phase. To achieve this goal, the concept of an “appropriate level of detail for simplification” was defined from the viewpoint of shape dissimilarity. After that, an algorithm was developed to determine the appropriate level of detail of a model by adopting the feature-based simplification method and the shape distribution–based comparison method. Finally, a prototype system was invented to verify the proposed method through experiments, in which the appropriate level of details for test cases were determined by the system.
Parallel genetic algorithms on the graphics processing units using island model and simulated annealing
Authors: Li Cheng-Chieh , Lin Chu-Hsing , Liu Jung-Chun
Published: November 2017

To solve a non-deterministic polynomial-hard problem, we can adopt an approximate algorithm for finding the near-optimal solution to reduce the execution time. Although this approach can come up with solutions much faster than brute-force methods, the downside of it is that only approximate solutions are found in most situations. The genetic algorithm is a global search heuristic and optimization method. Initially, genetic algorithms have many shortcomings, such as premature convergence and the tendency to converge toward local optimal solutions; hence, many parallel genetic algorithms are proposed to solve these problems. Currently, there exist many literatures on parallel genetic algorithms. Also, a variety of parallel genetic algorithms have been derived. This study mainly uses the advantages of graphics processing units, which has a large number of cores, and identifies optimized algorithms suitable for computation in single instruction, multiple data architecture of graphics processing units. Furthermore, the parallel simulated annealing method and spheroidizing annealing are also used to enhance performance of the parallel genetic algorithm.
A geometric error tracing method based on the Monte Carlo theory of the five-axis gantry machining center
Authors: Fan Jinwei , Tang Yuhang , Chen Dongju , Wu Changjun
Published: November 2017

This article proposes a tracing method to identify key geometric errors for a computer numerical control machine tool by cutting an S-shaped test piece. Adjacent part relationships and machine tool errors transform relationships are described by topology of the machining center. Global sensitivity analysis method based on quasi-Monte Carlo was used to analyze machining errors. Using this method, key geometric errors with significant influence on machining errors were obtained. Compensation of the key errors was used to experimentally improve machining errors for the S-shaped test piece. This method fundamentally determines the inherent connection and influence between geometric errors and machining errors. Key geometric errors that have great influence on machining errors can be determined quickly with this method. Thus, the proposed tracing method could provide effective guidance for the design and use of machine tools.
Identifying the stiffness parameters of a structure using a subspace approach and the Gram–Schmidt process in a wavelet domain
Authors: Su Wei-Chih , Huang Chiung-Shiann , Lien Ho-Cheng , Le Quang-Tuyen
Published: November 2017

This article presents a procedure to improve the accuracy of calculated stiffness matrix of a structure based on the identified modal parameters from its measured responses. First, a continuous wavelet transform is applied to the measured responses of a structure, and the state–space model can be reconstructed by the wavelet coefficients of acceleration that can be obtained from the measured noisy responses. The modal parameters are identified using the subspace approach. Second, the identified mode shapes are corrected via Gram–Schmidt process. Finally, the identified natural frequencies and the corrected mode shapes in previous steps are utilized to build the stiffness matrix of structure. The accuracy of the proposed approach is numerically confirmed, and the noise effects on the ability to precisely identify the stiffness matrix are also investigated. The measured data of two eight-story steel frames in a shaking table test are analyzed to demonstrate the applicability of the procedure to real structures.
Research on energy-saving operation control model of the multi-type configuration centrifugal pump system with single invert
Authors: Luo Yin , Xiong Zhixiang , Sun Hui , Guo Yihang
Published: November 2017

The multi-type pump configuration equipped with one invert scheme is suitable for the system to operate over a wide range of flow and head at different time periods. Its optimization may be the result of relatively low regulation capability. As a result, a synchronous switch control model was adopted to overcome this defect and to save further energy operation of the pump system. The hardware of synchronous switch control could be achieved by a simple logic control circuit which could be easily programmable and a phase discriminator control circuit which could eliminate the impact current. The software of synchronous switch control could be achieved by the minimum shaft power scheduling model group based on every type pump as variable-speed pump could calculate the optimal operation condition and the minimum switch number could ensure the optimal control regulation scheme. In conclusion, the single invert with synchronous switch control technology was used in an energy-saving reconstruction project of a circulating pump station; it could achieve the gain almost as same as the two invert scheme with the payback time almost the same as the single invert with pony pump scheme. Such is a particularly high quality and reasonable price scheme.
Deployment behavior control using cables and bi-shape memory alloy convex tape booms
Authors: Katsumata Nobuhisa , Kume Masaru , Higuchi Ken
Published: November 2017

This study aims to demonstrate the synchronous and stable deployment of a newly proposed boom system that consists of cables, a rotary damper, and shape memory alloy with a memorized convex tape shape. Through a shaft, a rotary damper is connected to a reel, and cables wound around the reel are connected to the shape memory alloy boom tips. The deployed part consists of bi-shape memory alloy convex tape booms in which two shape memory alloy convex tapes are combined to form a convex lens cross section, and the outside of the bi-shape memory alloy convex tape is wrapped by a sheet-type heater and polyimide film. The boom is deployed using only the shape recovery force of the shape memory alloy. By installing cables and a rotary damper, the deployment behavior of each boom is controlled, and each boom is deployed synchronously owing to the resistance force of the damper to a leading deploy boom. Moreover, the structural stiffness control concept of the proposed shape memory alloy bi-convex tape boom is discussed considering that Young’s modulus becomes almost half in the martensitic phase.
Connectivity of a modular electric vehicle by the use of a mobile device
Authors: Urbina Coronado Pedro Daniel , Ahuett-Garza Horacio , Morales-Menendez Ruben , Orta Castañón Pedro , Dávila Luis Daniel , Flores Escalera Mendoza Rubén
Published: November 2017

This work presents results from the project EvTec, which focus on the design, construction, and testing of an electric vehicle with special features such as modular design, multimotor, power source, digital control, autonomy, and connectivity. The proposed architecture explores the use of the Android-based Control Ecosystem, which integrates the Operating System Android, as part of the open-source control of the vehicle. The objective of this work is to design a platform that enables connectivity with the cloud for monitoring and remote controlling purposes. Results are reported about the feasibility of sending and storing information and in general interacting with a remote server. Vehicle control signals and sensor data were shared remotely at a rate of 200 ms per cycle. The data sent for storage in the cloud reconstructed very well the signals, with no data loss, proving its potential for monitoring purposes. This work also presents a brief discussion about the weakness and strengths of the concept, and the future work toward the potential impact and integration with autonomous driving.
Investigation of effect on cross-flow heat exchanger with air flow non-uniformity under low Reynolds number
Authors: Shen Kai , Zhang Zhendong , Zhang Ziqing , Yang Youwen
Published: November 2017

In this study, the theoretical and experimental study of a cross-flow heat exchanger is carried out based on the theory of porous media under low Reynolds number. The accuracy of the mathematical calculation model is verified by experiments. Pressure drop in air side and efficiency of heat exchanger are analyzed with mathematical models of various non-uniform air flows under low Reynolds number. The responses are found influences of air flow non-uniformity on pressure drop and efficiency of heat exchanger have certain rules. The difference in pressure drops between non-uniform air flows and evenly distributed air flows is linearly related to variance [Formula: see text] of non-uniformity. And the increasing rate of resistance energy consumption difference between non-uniform air flows and evenly distributed air flows is approximately linearly related to the relatively non-uniform coefficient squared [Formula: see text] of non-uniformity. The descent range of heat transfer efficiency has exponential relation to the relatively non-uniform coefficient [Formula: see text].
Influence of the volute cross-sectional shape on mixed inflow turbine performances
Authors: Meghnine Mohamed Amine , Hamidou Mohammad Kamal , Hamel Mohammed
Published: November 2017

The volute is an essential element in the centrifugal machines. Improving its performance is an effective way to improve the total performance of the turbine. The purpose of this study is to replace the accelerating and guiding nozzle vanes by exploring different design possibilities on the cross-sectional area convergence of the volute, since a decreasing area is then associated with expansion in the subsonic regime. The work is extended to a mixed inflow turbine using the new volute cross sections under pulsating regimes for turbocharging. The numerical simulation results show larger accelerations [Formula: see text] and lesser losses in the case of sections with flatter area in the radial direction and without vaneless space between the volute and the rotor; but this combination has an effect on the exit absolute flow angle which is less uniform.
Investigation on the impact-contact between droplet and rough surface in mechanical polishing using atomic modeling method
Authors: Han Xuesong , Ding Heming
Published: November 2017

Investigation on the mechanism of impact-contact occurred at multiphase interface is of great importance in technique control of mechanical polishing as it is the basic dynamic process connected with mass transfer and interfacial pressure. Classical continuum mechanics is not fit for study the physical essence of complex dynamic behavior in the impact-spreading at nano length scale because of the small thickness of fluid film and the discrete property of surface morphology. Molecular dynamics method has already been proved to be one of the most efficient toolkit on atomic scale discrete phenomenon and thus being employed in this research to study the complex mechanism of nano-scale impact-spreading. The study shows that the liquid film behaves like a stretched membrane under the unbalanced forces and the real traverse spreading is an anisotropic process resulted by the anisotropic surface structure which also influences the nonuniform distribution of film. The result justifies that boundary lubrication at the interface is resulted by poor spreading behavior on rough surface and will affect the transportation of abrasive particle and materials removal rate. The results also justify that the mechanical similarity can be difficult to hold because of the complexity of surface texture (rough surface) and the different contour profiles resulted by random movement of molecule. Furthermore, energy distribution shows that physical adsorption plays an important role in the impact-contact process which is also justified by the adsorption structure of water. With the increasing of impact velocity, part of outer molecules breaks away the constraints generated by the surface tension and forming a free-state water layer.
An improved dynamic model of preloaded ball screw drives considering torque transmission and its application to frequency analysis
Authors: Li Fuhua , Jiang Yao , Li Tiemin , Du Yunsong
Published: November 2017

A dynamic model of the ball screw drive is proposed in this article. It is revealed that when axial thrust is transmitted between the ball screw and the nut, extra torque is generated synchronously which is not proposed in existing dynamic models. And a physical model for studying the relationship between the thrust and the torque is proposed. A lumped dynamic model is established, and a kinematic compatibility equation describing motion transmission between rotary displacement and axial displacement is established. Then a preload model of a double-nut for analyzing the force and the deformation is built. An approach to analyze the first resonant frequency of the proposed model is described. Meanwhile, a tested bench with a novel preload-adjustable double-nut and two novel loading mechanisms is constructed. The axial stiffness of the supporting bearings and the preloaded double-nut is tested based on a measurement system. Then vibration tests are carried out to measure the first resonant frequency of the ball screw drive. Finally, contrastive analysis between experimental results and simulated results of three models is conducted. The results show that the proposed model agrees much better with the experimental results than the discrete model and the hybrid model do.
Performance of Al2O3 nanofluids in minimum quantity lubrication in hard milling of 60Si2Mn steel using cemented carbide tools
Authors: Minh Duc Tran , The Long Tran , Bao Ngoc Tran
Published: November 2017

In this article, an attempt has been made to explore the potential performance of Al2O3 nanoparticle–based cutting fluid in hard milling of hardened 60Si2Mn steel (50-52 HRC) under different minimum quantity lubrication conditions. The comparison of hard milling under minimum quantity lubrication conditions is done between pure cutting fluids and nanofluids (in terms of surface roughness, cutting force, tool wear, and tool life). Hard milling under minimum quantity lubrication conditions with nanofluid Al2O3 of 0.5% volume has shown superior results. The improvement in tool life almost 177%–230% (depending on the type of nanofluid) and the reduction in surface roughness and cutting forces almost 35%–60% have been observed under minimum quantity lubrication with Al2O3 nanofluids due to better tribological behavior as well as cooling and lubricating effects. The most outstanding result is that the uncoated cemented carbide insert can be effectively used in machining high-hardness steels (>50 HRC) while maintaining long tool life and good surface integrity (Ra = 0.08–0.35 µm; Rz = 0.5–2.0 µm, equivalent to finish grinding) rather than using the costlier tools like coated carbide, ceramic, and (P)CBN. Therefore, using hard nanoparticle–reinforced cutting fluid under minimum quantity lubrication conditions in practical manufacturing becomes very promising.
Evolution dynamic of the expressway toll-free policy impact on the mode choice in a bimodal transportation network during holidays
Authors: Lin Xiao-Mei , Shao Chun-Fu , Qian Jian-Pei , Zhang Ying-Da
Published: November 2017

The implementation of expressway toll-free policy during holidays in China has caused serious congestion and frequent accidents on expressways. Many studies have explored the policy’s macroscopic outcome and its countermeasures for policy managers, while limited attention has been paid to the influence mechanism of the policy on the individuals’ travel behavior, especially the mode choice behavior. More insight into the dynamic effects of individuals reacting to policy measure is needed. This study aims at analyzing the adaption progress of the individual’s mode choice behavior and estimating the time-varying influence of the traffic policy on the mode split. With assumptions travelers’ adapting behavior conform to the inertia and myopia principles, a Logit dynamic evolutionary model for mode choice is proposed. A unique globally stable equilibrium state for the model is derived with the strict mathematical analysis. As an application, the influence of the expressway toll-free policy on mode split is evaluated. The travel cost structure, the sensitivity of the travel distance and traffic supply, and the evolutionary dynamics of the mode split are analyzed in scenarios with and without the expressway toll-free policy. The result indicates that travel distance and network’s total supply amount remarkably affect the implementation effect of the policy.
Prediction of long-term gas load based on particle swarm optimization and gray neural network model
Authors: Zhang Zhenwu , Liu Xiantao
Published: November 2017

With the continuous consumption of fossil energy and environmental pollution, natural gas as a clean energy has received more and more attention. How to accurately predict the future of natural gas load has a vital significance. A long-term natural gas load forecasting model based on GBP is established to solve the problem of natural gas load forecasting. First, the method of correlation index is used to optimize the 20 indicators and then the optimized index number is 16; second, combining the advantages of gray neural network (BP) in fitting time series and particle swarm optimization in optimization parameters, a long-term load forecasting model of natural gas based on PSO-BP is established; finally, in order to verify the validity of the model, taking the natural gas load sample from 2005 to 2015 in Anhui Province as an example, the BP and GBP alone prediction models are compared with this model. The results show that compared with BP and GBP alone, the PSO-GBP prediction model improved the mean absolute deviation and mean absolute percentage error values by 0.065 and 0.03485 and 6.67944 and 3.62817, respectively, and increased the calculation time by 0.00726 and 0.00378 s.
Air emission inventory of container ports’ cargo handling equipment with activity-based “bottom-up” method
Authors: Zhang Yan , Peng Yi-qiang , Wang Wei , Gu Jian , Wu Xiao-jing , Feng Xue-jun
Published: November 2017

With the rapid development of China’s container port industry, the emissions of air pollutants in port areas have been increasing. Cargo handling equipment as a non-road mobile source of emissions has become a focus of public attention. This article adopted a full activity-based “bottom-up” method to establish the inventory of emissions by cargo handling equipment at a container port. Drawing on the OFFROAD model, we conducted investigation and analysis of cargo handling equipment holdings, activity levels, and equipment-related parameters and modified the emission factors. The Nanjing Longtan Container Port was taken as a case study. Results show that in 2014, emissions by cargo handling equipment of the Nanjing Longtan Container Port were as follows: PM10 4.25 t, PM2.5 3.91 t, NOx 82.98 t, SOx 1.06 t, CO 23.84 t, and HC 16.39 t, all lower than results from an earlier research based on 2013 fuel consumption data. Cargo handling equipment produced more PM and HC emissions than any other emission source at the port. The method and main conclusions of this article provide support for future work on energy conservation and emission reduction in port areas.
Stabilization of pilot valve system using linear flow resistance
Authors: Peng Jiehong , Youn Chongho , Takeuchi Tomoaki , Kagawa Toshiharu
Published: November 2017

In a pilot valve system, the pressure in the control chamber of the main valve is straightforwardly affected by pressure oscillation in the downstream pipeline or the pilot tube. To solve this problem, an orifice is generally installed in the pilot tube to restrain the oscillation. However, the orifice is a nonlinear flow resistance; the amplitude of the oscillation alters the gain curve of the control pressure response. In this study, a linear flow resistance such as a porous material is employed to stabilize the pilot valve system. A test pilot valve was manufactured, and a pilot valve system was developed in the laboratory of the authors of this article. A mathematical model of the pilot valve system using linear and nonlinear flow resistances was simulated in MATLAB. The linearity of the P–Q characteristics of the linear flow resistance was confirmed, and a series of frequency response experiments were performed to examine the dynamic characteristics of the pilot valve system with various flow resistances. The experimental results were in accord with the simulation results. This implied that when porous materials were used in the pilot valve system, the gain of the pressure response did not vary regardless of the varying pressure vibration amplitude. Therefore, porous materials are suitable to be used in the pilot valve system instead of an orifice to enhance its stability.
Improving force tracking control performance in cooperative robots
Authors: Sánchez-Sánchez Pablo , Arteaga-Pérez Marco A
Published: November 2017

In order to obtain the environment’s information, cooperative robots could need a lot of sensors. A possible solution to reduce the number of sensors might be the use of control–observer structures. In this article, we have designed a control algorithm by using a modified hybrid computed torque method based on the principle of orthogonalization, but in order to avoid the use of tachometers in the implementation, we are including a velocity observer. The stability proof is developed by using the theory of Lyapunov. Simulation of the proposed control structure compared with a well-known control structure via the performance index analysis is presented. Experimental tests are implemented with the control structure that has the best performance index.