bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of Active Power Cycling Combined With Passive Thermal Cycles on Discrete Power Electronic Devices for Automotive Applications
Authors: Otto Alexander , Rzepka Sven , Wunderle Bernhard
Published: November 2018

Active power cycling is a standardized and well-established method for reliability assessment and product qualification in power electronics technologies. Repetitive pulses of load current are applied to cause cyclic thermal swings in the p-n junction and in the whole semiconductor device. They induce thermo-mechanical stresses, which ultimately leads to the typical interconnect failure in the ‘devices under test’.

However, these tests are insensitive with respect to new automotive system architectures, in which power electronics devices are exposed to additional loads besides the intrinsic thermal swings. The trends in power electronics towards miniaturization, higher power density, heterogeneous system integration, and the deployment of power electronics in harsher environments combined with longer lifetime and higher uptime requirements strongly increase the reliability demands in general and the need for more improved reliability assessment methodologies in particular. The new testing methods shall be more comprehensive and more efficient, i.e., they shall simultaneously cover the real service conditions better and reduce testing time. One promising approach is the combination of loading factors — such as the superposition of active power cycling by passive thermal cycles. Both loading factors are well-known to cause most relevant failure mechanisms in power electronics. In reality, the power electronic devices are exposed to both factors simultaneously. Hence, this load case should also be replicated in the test.

The paper will report a systematic investigation of such superimposed test schemes, which cover the case of self-heating and passive heating (from neighboring elements) of the power electronics devices under real service conditions. Typical discrete power electronics components in TO-200 packages are selected as test vehicles as they are likewise relevant for the domains of consumer or automotive electronics. The paper details the test concept and discuss the quantitative and qualitative test results.
Feasibility of PCB-Integrated Vibration Sensors for Condition Monitoring of Electronic Systems
Authors: Brinkfeldt Klas , Wetter Göran , Lövberg Andreas , Tegehall Per-Erik , Andersson Dag , Strandberg Jan , Goncalves Johnny , Söderlund Jonas , Kwarnmark Mikael
Published: November 2018

The increasing complexity of electronics in systems used in safety critical applications, such as for example self-driving vehicles requires new methods to assure the hardware reliability of the electronic assemblies. Prognostics and Health Management (PHM) that uses a combination of data-driven and Physics-of-Failure models is a promising approach to avoid unexpected failures in the field. However, to enable PHM based partly on Physics-of-Failure models, sensor data that measures the relevant environment loads to which the electronics is subjected during its mission life are required. In this work, the feasibility to manufacture and use integrated sensors in the inner layers of a printed circuit board (PCB) as mission load indicators measuring impacts and vibrations has been investigated. A four-layered PCB was designed in which piezoelectric sensors based on polyvinylidenefluoride-co-trifluoroethylene (PVDF-TrFE) were printed on one of the laminate layers before the lamination process. Manufacturing of the PCB was followed by the assembly of components consisting of BGAs and QFN packages in a standard production reflow soldering process. Tests to ensure that the functionality of the sensor material was unaffected by the soldering process were performed. Results showed a yield of approximately 30% of the sensors after the reflow soldering process. The yield was also dependent on sensor placement and possibly shape. Optimization of the sensor design and placement is expected to bring the yield to 50 % or better. The sensors responded as expected to impact tests. Delamination areas were present in the test PCBs, which requires further investigation. The delamination does not seem to be due to the presence of embedded sensors alone but rather the result of a combination of several factors. The conclusion of this work is that it is feasible to embed piezoelectric sensors in the layers of a PCB.
Air Flow Pattern and Path Flow Simulation of Airborne Particulate Contaminants in a High-Density Data Center Utilizing Airside Economization
Authors: Thirunavakkarasu Gautham , Saini Satyam , Shah Jimil , Agonafer Dereje
Published: November 2018

The percentage of the energy used by data centers for cooling their equipment has been on the rise. With that, there has been a necessity for exploring new and more efficient methods like airside economization, both from an engineering as well as business point of view, to contain this energy demand. Air cooling especially, free air cooling has always been the first choice for IT companies to cool their equipment. But, it has its downside as well. As per ASHRAE standard (2009b), the air which is entering the data center should be continuously filtered with MERV 11 or preferably MERV 13 filters and the air which is inside the data center should be clean as per ISO class 8. The objective of this study is to design a model data center and simulate the flow path with the help of 6sigma room analysis software. A high-density data center was modelled for both hot aisle and cold aisle containment configurations. The particles taken into consideration for modelling were spherical in shape and of diameters 0.05, 0.1 and 1 micron. The physical properties of the submicron particles have been assumed to be same as that of air. For heavier particles of 1 micron in size, the properties of dense carbon particle are chosen for simulating particulate contamination in a data center. The Computer Room Air Conditioning unit is modelled as the source for the particulate contaminants which represents contaminants entering along with free air through an air-side economizer. The data obtained from this analysis can be helpful in predicting which type of particles will be deposited at what location based on its distance from the source and weight of the particles. This can further help in reinforcing the regions with a potential to fail under particulate contamination.
Facility Cooling Failure Analysis of Direct Liquid Cooling System in Data Centers
Authors: Alkharabsheh Sami , Puvvadi Udaya L. N. , Ramakrishnan Bharath , Ghose Kanad , Sammakia Bahgat
Published: November 2018

This work experimentally studies the impact of facility cooling failure of a direct liquid cooling (DLC) system on the IT equipment (ITE). The facility side of a DLC system removes the heat from a secondary loop — in direct contact with the ITE — and discard it in a chiller loop or ambient. The CPU utilization and coolant set point temperature (SPT) are varied to understand the effect of failure under different operating conditions. The ITE response is studied in terms of chip temperature and power, and fan speed. It was found that failure of the facility cooling system is not hazardous to the IT operation. The rate of change in temperature after failure is low and is sufficient to turn the ITE off safely. This is attributed to the surrounding air in the data center and the thermal mass of the cooling system.
Practical Concerns for Adoption of Microjet Cooling
Authors: Walsh Stephen M. , Smith James P. , Browne Eric A. , Hennighausen Timothy W. , Malouin Bernard A.
Published: November 2018

As power densities in advanced electronics continue to rise, the need for high performance thermal solutions becomes increasingly important. Liquid jet impingement has been applied to cooling high power-density electronics due to its ability to dissipate large heat fluxes while maintaining an acceptable operating temperature in the device. Recently, microjets have been embedded within the device substrate, forming a compact solution that is highly scalable. Many practical questions remain, however, on whether microjet technology is ready for actual implementation. In this work, we address several important questions that impede adoption of the technology. Numerical analysis and experimental data are provided to demonstrate the tradeoff between thermal performance and driving pressure requirements through pumping analysis. Additional mechanical concerns regarding robustness to clogging and resistance to erosion are addressed through a 1000-hour extended lifetime test.
Robust and accurate measurements of gold nanoparticle concentrations using UV-visible spectrophotometry
Authors: Shard Alexander G. , Wright Louise , Minelli Caterina
Published: November 2018

This paper provides an empirical formula to calculate the extinction efficiencies of gold nanoparticles over the size range 1–1000 nm in fluids with refractive indexes which extend from n = 1 to n = 1.62. The formula contains a shape factor to account for nonspherical particles and aggregates. The empirical curves are fitted to values calculated from accurate Mie and T-Matrix theory and confirm previous descriptions which are restricted to nearly spherical particles in water of diameter between 5 and 100 nm. This paper demonstrates that these previous descriptions will be in error for fluids other than water and for nonspherical particles greater than 100 nm in size. An empirical description is provided which matches calculated values to within a few percent across most of the range. The description also matches experimental data to within the standard relative error, currently 5% at best, using other methods which directly measure the particle concentration. These extinction efficiencies can be used to validate the concentration of gold nanoparticles in a wide range of situations to support the drive for reproducibility in nanoparticle research.
The transmembrane adaptor protein NTAL limits mast cell chemotaxis toward prostaglandin E
2
Authors: Halova Ivana , Bambouskova Monika , Draberova Lubica , Bugajev Viktor , Draber Petr
Published: November 2018

Mast cell chemotaxis toward prostaglandin E
2
is inhibited by the transmembrane adaptor protein NTAL.
The basics of mechanotransduction
Authors: Williams Erin R.
Published: November 2018

Basic residues in the transmembrane domain of the T cell receptor α chain promote its association with CD3 signaling chains.
Cyanophage A-1(L) Adsorbs to Lipopolysaccharides of
Anabaena
sp. Strain PCC 7120 via the Tail Protein Lipopolysaccharide-Interacting Protein (ORF36)
Authors: Xiong Zhenzhen , Wang Yali , Dong Yanling , Zhang Qiya , Xu Xudong
Published: November 2018

Cyanophages play an important role in regulating the dynamics of cyanobacterial communities in aquatic environments. Hitherto, the mechanisms for cyanophage infection have been barely investigated. In this study, the first cyanophage tail protein that binds to the receptor (LPS) on cell surface was identified and shown to be essential for the A-1(L) infection of
Anabaena
sp. strain PCC 7120. The protein-LPS interaction may represent an important route for adsorption of cyanophages to their hosts.
Importance of Pyruvate Sensing and Transport for the Resuscitation of Viable but Nonculturable
Escherichia coli
K-12
Authors: Vilhena Cláudia , Kaganovitch Eugen , Grünberger Alexander , Motz Magdalena , Forné Ignasi , Kohlheyer Dietrich , Jung Kirsten
Published: November 2018

Viable but nonculturable (VBNC) bacteria do not form colonies in standard medium but otherwise retain their metabolic activity and can express toxic proteins. Many bacterial genera, including
Escherichia
,
Vibrio
, and
Listeria
, have been shown to enter the VBNC state upon exposure to adverse conditions, such as low temperature, radiation, and starvation. Ultimately, these organisms pose a public health risk with potential implications for the pharmaceutical and food industries, as dormant organisms are especially difficult to selectively eliminate and VBNC bacteria can be resuscitated if placed in an environment with appropriate nutrition and temperature. Here we used a microfluidic system to monitor the resuscitation of single VBNC cells over time. We provide new molecular insights into the initiation of resuscitation by demonstrating that VBNC
E. coli
cells rapidly take up pyruvate with an inducible high-affinity transporter, whose expression is triggered by the BtsSR-YpdAB sensing network.
Premature small for gestational age infants fed an exclusive human milk-based diet achieve catch-up growth without metabolic consequences at 2 years of age
Authors: Visuthranukul Chonnikant , Abrams Steven A , Hawthorne Keli M , Hagan Joseph L , Hair Amy B
Published: November 2018

Objective

To compare postdischarge growth, adiposity and metabolic outcomes of appropriate for gestational age (AGA) versus small for gestational age (SGA) premature infants fed an exclusive human milk (HM)-based diet in the neonatal intensive care unit.

Design

Premature infants (birth weight ≤1250 g) fed an exclusive HM-based diet were examined at 12–15 months corrected gestational age (CGA) (visit 1) for anthropometrics, serum glucose and non-fasting insulin, and at 18–22 months CGA (visit 2) for body composition by dual-energy X-ray absorptiometry.

Results

Of 51 children, 33 were AGA and 18 were SGA at birth. The SGA group had weight gain (g/day) equal to AGA group during the follow-up period. SGA had a significantly greater body mass index (BMI) z-score gain from visit 1 to visit 2 (0.25±1.10 vs −0.21±0.84, p=0.02) reflecting catch-up growth. There were no significant differences in total fat mass (FM) and trunk FM between groups. SGA had significantly lower insulin level (5.0±3.7 vs 17.3±15.1 µU/mL, p=0.02) and homeostatic model of assessment-insulin resistance (1.1±0.9 vs 4.3±4.1, p=0.02). Although regional trunk FM correlated with insulin levels in SGA (r=0.893, p=0.04), they had lower insulin level compared with AGA and no difference in adiposity.

Conclusions

SGA premature infants who received an exclusive HM-based diet exhibited greater catch-up growth without increased adiposity or elevated insulin resistance compared with AGA at 2 years of age. An exclusive HM-based diet may improve long-term body composition and metabolic outcomes of premature infants with ≤1250 g birth weight, specifically SGA.
Therapeutic hypothermia initiated within 6 hours of birth is associated with reduced brain injury on MR biomarkers in mild hypoxic-ischaemic encephalopathy: a non-randomised cohort study
Authors: Montaldo Paolo , Lally Peter J , Oliveira Vânia , Swamy Ravi , Mendoza Josephine , Atreja Gaurav , Kariholu Ujwal , Shivamurthappa Vijayakumar , Liow Natasha , Teiserskas Justinas , Pryce Russell , Soe Aung , Shankaran Seetha , Thayyil Sudhin
Published: November 2018

Objective

To examine the effect of therapeutic hypothermia on MR biomarkers and neurodevelopmental outcomes in babies with mild hypoxic-ischaemic encephalopathy (HIE).

Design

Non-randomised cohort study.

Setting

Eight tertiary neonatal units in the UK and the USA.

Patients

47 babies with mild HIE on NICHD neurological examination performed within 6 hours after birth.

Interventions

Whole-body cooling for 72 hours (n=32) or usual care (n=15; of these 5 were cooled for <12 hours).

Main outcome measures

MRI and MR spectroscopy (MRS) within 2 weeks after birth, and a neurodevelopmental outcome assessment at 2 years.

Results

The baseline characteristics in both groups were similar except for lower 10 min Apgar scores (p=0.02) in the cooled babies. Despite this, the mean (SD) thalamic NAA/Cr (1.4 (0.1) vs 1.6 (0.2); p<0.001) and NAA/Cho (0.67 (0.08) vs 0.89 (0.11); p<0.001) ratios from MRS were significantly higher in the cooled group. Cooled babies had lower white matter injury scores than non-cooled babies (p=0.02). Four (27%) non-cooled babies with mild HIE developed seizures after 6 hours of age, while none of the cooled babies developed seizures (p=0.008). Neurodevelopmental outcomes at 2 years were available in 40 (85%) of the babies. Adverse outcomes were seen in 2 (14.3%) non-cooled babies, and none of the cooled babies (p=0.09).

Conclusions

Therapeutic hypothermia may have a neuroprotective effect in babies with mild HIE, as demonstrated by improved MRS biomarkers and reduced white matter injury on MRI. This may warrant further evaluation in adequately powered randomised controlled trials.
Distribution of diabetes, hypertension and non-communicable disease risk factors among adults in rural Bangladesh: a cross-sectional survey
Authors: Fottrell Edward , Ahmed Naveed , Shaha Sanjit Kumer , Jennings Hannah , Kuddus Abdul , Morrison Joanna , Akter Kohenour , Nahar Badrun , Nahar Tasmin , Haghparast-Bidgoli Hassan , Khan A K Azad , Costello Anthony , Azad Kishwar
Published: November 2018

Background

Non-communicable diseases (NCDs) are increasing in low-income settings. We conducted a survey of risk factors, blood pressure and blood glucose in rural Bangladesh and assessed variations by age, sex and wealth.

Methods

We surveyed a random sample of 12 280 adults aged>30 years in 96 villages in rural Bangladesh. Fieldworkers measured blood glucose and conducted an glucose tolerance test with a repeat blood test 120 min post glucose ingestion. Blood pressure, anthropometric, socioeconomic, lifestyle and behavioural risk factors data were also collected. Data were analysed to describe the prevalence of diabetes, intermediate hyperglycaemia, hypertension and NCD risk factors by age, sex and wealth.

Results

Women had higher levels of overweight or obesity and lower levels of physical activity and fruit and vegetable consumption than men; 63% of men used tobacco compared with 41.3% of women. Overweight or obesity and abdominal obesity (waist to hip ratio) increased with socioeconomic status (least poor vs most poor: OR (95% CI) 3.21 (2.51 to 4.11) for men and 2.83 (2.28 to 3.52) for women). Tobacco use, passive smoke exposure and salt consumption fell with increasing socioeconomic status in both sexes. Clustering of risk factors showed more than 70% of men and women reported at least three risk factors. Women in the least poor group were 33% more likely to have three or more risk factors compared with women in the most poor group (1.33 (95% CI 1.17 to 1.58)). The combined prevalence of impaired fasting glucose, impaired glucose tolerance and diabetes was 26.1% among men and 34.9% among women, and increased with age. The prevalence of prehypertension and hypertension was 30.7% and 15.9% among men and 27.2% and 22.5% among women, with similar rising prevalence with age.

Conclusion

NCD risk factors, hyperglycaemia and raised blood pressure are an immediate health threat in rural Bangladesh. Initiatives to improve detection, treatment and prevention strategies are needed.
Community palliative medicine out-of-hours needs and the 7-day week: a service evaluation
Authors: Doré Matthew , Willis Derek
Published: November 2018

Background

Evidence regarding out-of-hours (OOH) community palliative care provision is required to inform the need for a 7-day work.

Aim

This paper seeks to provide evidence for this discussion by defining general practitioners’ (GPs) OOH workload and patients’ demographics, symptomology and interventions. By quantifying the challenges faced, we can understand current practice and focus on what provision is required.

Design

Using Shropshire Doctors Co-operative’s recorded data, the authors have collated a representative picture of the OOH GP palliative care practice over a year from 161 OOH GP–patient interactions.

Setting

Primary care.

Results

Palliative care makes up 11.4% of the total OOH GP home visits (HV). Overall 56% of OOH GP HVs are for patients who are expected to die within 48 hours, with 80% of the symptoms being agitation, secretions and pain. Overall 5.7% of OOH GP palliative HVs resulted in hospital admission; however, this decreased to 0.6% adjusting for the last 48-hour prognosis.

Conclusion

OOH Shropshire GPs deal with a wide variety of scenarios in a heterogeneous population. The greatest demand is from 17:00 to 00:00 (65% of the total shift) on weekdays, and from 09:00 to 00:00 on weekends (82% of the shift). These data begin to quantify the role being performed by OOH GPs, have implications for service provision and support 7-day work.
Virtual patient educational intervention for the development of shared decision-making skills: a pilot study
Authors: Jacklin Simon , Chapman Stephen , Maskrey Neal
Published: November 2018

Background

Shared decision-making (SDM) involves a healthcare professional and a patient forming a congruent partnership, within which information is shared and decisions are made which align with the patient’s values. SDM does not occur to the extent it ought to; SDM requires practice. Virtual reality could help facilitate this practice.

Objective

To pilot an interactive, high-fidelity virtual patient (VP) who simulates SDM within a primary care consultation.

Method

Academic pharmacists and doctors were recruited from the Keele University. Participants completed prequestionnaires and postquestionnaires.

Results

18 participants (14 pharmacists and 4 medical doctors) completed the study. 89% (n=16) suggested the VP was ‘enjoyable’ or ‘highly enjoyable’ to use and 72% (n=13) suggested it was ‘very accessible’. There were diverse views about the way in which the user made their reply to the VP with ratings ranging from ‘very poor’ (n=2) to ‘very good’ (n=5); the modal rating was indifference (n=7). It seemed the multiple choice system caused the participants to feel restricted but it was unclear why those who liked the system did so.

Conclusions

The VP was found to be enjoyable and thought-provoking. The data suggest that this type of intervention could be useful at many different stages of a professional’s career although the multiple-choice conversation style may be too restrictive for more experienced consulters.
Use of ultrasonography to identify a periocular plant foreign body in a dog
Authors: Wait Courtney , Meekins Jessica Marie , Tucker‐Mohl Katherine , Biller David
Published: November 2018

A one‐year‐old female spayed miniature schnauzer was referred to the Kansas State University Veterinary Health Center Ophthalmology Service for evaluation of chronic purulent discharge and conjunctival hyperaemia of the right eye. Two months before presentation, the dog was treated by its primary veterinarian for grass awn foreign bodies in the periocular area. Three visible grass awns were removed, and an associated superficial corneal ulcer healed without complication. However, ocular discharge and conjunctival hyperaemia persisted. Due to the patient’s history and the focal pattern of conjunctival hyperaemia, diagnostic imaging (ultrasound) was recommended to screen for retained plant foreign material. The dog was anaesthetised, and a hyperechoic linear structure was identified in the dorsolateral periocular space on ultrasound examination. The plant material was successfully extracted during a brief conjunctival exploration, and the previously reported clinical signs subsequently resolved over the course of one  week.
Fatal systemic toxoplasmosis in a rock hyrax (Procavia capensis)
Authors: Dervas Eva , Hatt Jean‐Michel , Hilbe Monika
Published: November 2018

The present report describes a case of fatal toxoplasmosis in a two‐year‐old female rock hyrax (Procavia capensis). Major histopathological findings consisted of multifocal acute necrotising hepatitis, enteritis and adrenalitis, glial nodule formation in the brain, and suppurative splenitis with numerous intralesional protozoan tachyzoites and tissue cysts. Infection with Toxoplasma gondii was confirmed via immunohistochemical examination in the liver, adrenal gland, spleen, intestine, brain and the lung. To the authors’ knowledge this is the first case report of a systemic toxoplasmosis in a rock hyrax and in the family of Procaviidae.
Comparative digestibility of energy and nutrients in four fibrous ingredients fed to barrows at three different initial body weights
Authors: Xie F. , Li Y.K. , Zhao J.B. , Li Z.C. , Liu L. , Cao Y.H. , Zhang S.
Published: November 2018

This study was conducted to determine the digestible energy (DE) and metabolizable energy (ME) values and apparent total tract digestibility (ATTD) of nutrients in four fibrous ingredients [corn distillers’ dried grains with solubles (DDGS), soybean hull, wheat bran, and corn bran] fed to barrows at three different growth stages. Thirty growing barrows, 30 finishing barrows, and 30 fattening barrows (initial body weights of 29.04, 58.57, and 105.65 kg, respectively) were individually housed in metabolism crates and allotted to one of four test diets or a basal corn–soybean meal diet in a 3 × 5 factorial design. Fecal and urine samples were collected for 5 d after a 12 d adaption period. The DE and ME values and ATTD of gross energy (GE), organic matter (OM), crude protein, and acid detergent fiber (ADF) in wheat bran, as well as the ATTD of GE, OM, neutral detergent fiber (NDF), and ADF in corn DDGS, and ATTD of NDF and ADF in soybean hull, were greater (P < 0.05) in pigs at stage 3 compared with those at stages 1 and 2. In conclusion, both body weight and fibrous ingredients have effects on energy values and nutrient digestibility in barrows.
Aeolian activity during Late Glacial time, with an example from Mongo, Indiana, USA
Authors: Fisher Timothy G. , Horton Jennifer , Lepper Kenneth , Loope Henry
Published: November 2018

The last aeolian activity of a significant number of inland sand dunes in the southern Great Lakes region (SGLR) was several thousands of years after deglaciation. At Mongo, Indiana, a field of parabolic sand dunes with a variety of morphologies are within the channel bottom of the Pigeon River meltwater channel, with some dunes having climbed up the channel wall onto the adjacent upland surface. The optically stimulated luminescence (OSL) samples from the channel-bottom dunes have a mean age of 14.2 ± 1.6 ka (n = 2) and the OSL samples from upland dunes have a mean age of 12.3 ± 1.6 ka (n = 4). Dunes and outwash ages and geomorphic setting constrain both the position of the Huron-Erie and Saginaw lobes. The oldest dune age is also a minimum age for cessation of local meltwater flow from the Huron-Erie Lobe of the Laurentide Ice Sheet and formation of the adjacent Sturgis Moraine of the Saginaw Lobe. The final activity of the dunes is coincident with late glacial stadial and interstadial events as recorded in the Greenland ice core records, a similar finding to all other studies of dunes in the SGLR. It is now well recognized that many dunes were last active before, during, and after the Younger Dryas stadial, presumably in response to a climate that was windier and less favorable for vegetation.
Controller Design for Different Electric Tail Rotor Operating Modes in Helicopters
Authors: Tang Peng , Wang Fei , Dai Yuehong
Published: November 2018

The nonlinear aerodynamics and new kinds of operation associated with helicopter electric tail rotors (ETRs) make accurate speed tracking control under complex flight conditions a key challenge confronting designers. In this paper, we present an electric propulsion system for tail rotors that uses a high-power-density permanent magnet motor. The management of aerodynamic disturbance rejection and accurate speed control are aspects of ETR design that require particularly close attention. To this end, we have developed a speed controller that is based on an active disturbance rejection control (ADRC) technique that can handle fixed speed and adjustable pitch-angle modes. We have also applied a linear extended state observer (LESO) with a self-tuning bandwidth to estimate fluctuations in the drive system. For variable speeds, a simple controller combined with an adaptive radial basis function (RBF) observer and nonlinear state error feedback using ADRC was designed to replace LESO while avoiding any dependence on the system parameters. The stability of the controllers was analyzed and their effectiveness was verified using a simulation platform. Test results showed that the propulsion system is able to achieve fast dynamic response and aerodynamic disturbance rejection.
Spreading speeds of KPP-type lattice systems in heterogeneous media
Authors: Liang Xing , Zhou Tao
Published: November 2018

In this paper, we investigated spreading properties of the solutions of the Kolmogorov–Petrovsky–Piskunov–type (KPP-type) lattice system [Formula: see text] Motivated by the work in [H. Berestycki and G. Nadin, Spreading speeds for one-dimensional monostable reaction–diffusion equations, J. Math. Phys. 53(11) (2012) 115619, 23 pp.], we develop some new discrete Harnack-type estimates and homogenization techniques for the lattice system [Formula: see text] to construct two speeds [Formula: see text] such that [Formula: see text] for any [Formula: see text], and [Formula: see text] for any [Formula: see text]. These speeds are characterized by two generalized principal eigenvalues of the linearized systems of [Formula: see text]. In particular, we derive the exact spreading speed when the coefficients are random stationary ergodic or almost periodic (where [Formula: see text]). Finally, in the case where [Formula: see text] is almost periodic in [Formula: see text] and the diffusion rate [Formula: see text] is independent of [Formula: see text], we show that the spreading speeds in the positive and negative directions are identical even if [Formula: see text] is not invariant with respect to the reflection.
Speaking to Theory and Speaking to the China Field
Authors: O’BRIEN KEVIN J.
Published: November 2018

Bringing knowledge about China to the disciplines has reduced the outsized role that research on Europe and America has on many topics. But mainstreaming China studies also leads to certain tradeoffs. How should we manage these tradeoffs and produce research that is both true to China and contributes to the social sciences? In the last 40 years, China scholars have developed many strategies to navigate the territory between area studies and the social sciences. I myself have vacillated about how China studies and political science should interact and inform each other. How are scholars addressing this issue now, in an era of mixed methods, sophisticated quantitative research, experiments and “big data?”
Improved dielectric energy storage performance of Pb-free 0.5Na0.5Bi0.5TiO3-0.5SrTiO3 ceramics modified with CaO
Authors: Chen Peng , Zhang Leiyang , Wang Ziyang , Wang Yifei , Song Chunlin , Hu Jinzhu , Liu Gang , Yan Yan
Published: November 2018

CaO doped 0.5Na[Formula: see text]Bi[Formula: see text]TiO3 (NBT)-0.5SrTiO3 (ST) were prepared by a traditional solid-reaction method under various sintering temperatures. X-ray diffraction (XRD), electron scanning microscopy (SEM), and electrical measurements were employed to check the phases, microstructures, and energy storage properties. The doping of CaO can deeply affect the relaxation nature of NBT-ST ceramics. So the energy storage performance could be modified. Specially, sample with 1 at.% CaO exhibits a high energy storage density of 1.51[Formula: see text]J/cm3. Any further details can be found within this study.
Factors affecting investment decision-making in Pakistan stock exchange
Authors: Mumtaz Adeel , Saeed Tahir , Ramzan M.
Published: November 2018

This study analyzes the impact of various factors like heuristic, risk aversion, financial tools and techniques, firm’s corporate governance, and day-to-day experience on the investor’s decision-making. The sample consisted of 701 individual investors trading in the Pakistan Stock Exchange. The Ordinary Least Square (OLS) is used for the estimation of research models. The findings revealed that heuristics, risk aversion, financial tools and techniques have a significant positive effect on the investment decisions of investors. The day-to-day experience and corporate governance (CG) play an important role in investment decision-making of the financial sector in Pakistan. This study will contribute to creating awareness in a diversity of investors for investing in the equity market and increases the investors’ confidence.
Word Segmentation for Burmese Based on Dual-Layer CRFs
Authors: Zhang Shaoning , Mao Cunli , Yu Zhengtao , Wang Hongbin , Li Zhongwei , Zhang Jiafu
Published: November 2018

Burmese is an isolated language, in which the syllable is the smallest unit. Syllable segmentation methods based on matching lead to performance subject to the syllable segmentation effect. This article proposes a word segmentation method with fusion conditions of double syllable features. It combines word segmentation and segmentation of syllables into one process, thus reducing the impact of errors on the syllable segmentation of Burmese. In the first layer of the conditional random fields (CRF) model, Burmese characters as atomic features are integrated into the Burma section of the Barkis Speech Paradigm (Backus normal form) features to realize the Burma syllable sequence tags. In the second layer of the CRFs model, with the syllable marked as input, it realizes the sequence markers through building a feature template with syllables as atomic features. The experimental results show that the proposed method has a better effect compared with the method based on the matching of syllables.
Arabic Authorship Attribution
Authors: Altakrori Malik H. , Iqbal Farkhund , Fung Benjamin C. M. , Ding Steven H. H. , Tubaishat Abdallah
Published: November 2018

Law enforcement faces problems in tracing the true identity of offenders in cybercrime investigations. Most offenders mask their true identity, impersonate people of high authority, or use identity deception and obfuscation tactics to avoid detection and traceability. To address the problem of anonymity, authorship analysis is used to identify individuals by their writing styles without knowing their actual identities. Most authorship studies are dedicated to English due to its widespread use over the Internet, but recent cyber-attacks such as the distribution of Stuxnet indicate that Internet crimes are not limited to a certain community, language, culture, ideology, or ethnicity. To effectively investigate cybercrime and to address the problem of anonymity in online communication, there is a pressing need to study authorship analysis of languages such as Arabic, Chinese, Turkish, and so on. Arabic, the focus of this study, is the fourth most widely used language on the Internet. This study investigates authorship of Arabic discourse/text, especially tiny text, Twitter posts. We benchmark the performance of a profile-based approach that uses
n
-grams as features and compare it with state-of-the-art instance-based classification techniques. Then we adapt an event-visualization tool that is developed for English to accommodate both Arabic and English languages and visualize the result of the attribution evidence. In addition, we investigate the relative effect of the training set, the length of tweets, and the number of authors on authorship classification accuracy. Finally, we show that diacritics have an insignificant effect on the attribution process and part-of-speech tags are less effective than character-level and word-level
n
-grams.
How to Live in a Post-Meltdown and -Spectre World
Authors: Bennett Rich , Callahan Craig , Jones Stacy , Levine Matt , Miller Merrill , Ozment Andy
Published: November 2018

Spectre and Meltdown create a risk landscape that has more questions than answers. This article addresses how these vulnerabilities were triaged when they were announced and the practical defenses that are available. Ultimately, these vulnerabilities present a unique set of circumstances, but for the vulnerability management program at Goldman Sachs, the response was just another day at the office.
Using Remote Cache Service for Bazel
Authors: Lam Alpha
Published: November 2018

Remote cache service is a new development that significantly saves time in running builds and tests. It is particularly useful for a large code base and any size of development team. Bazel is an actively developed open-source build and test system that aims to increase productivity in software development. It has a growing number of optimizations to improve the performance of daily development tasks.
Multiobjective Collective Decision Optimization Algorithm for Economic Emission Dispatch Problem
Authors: Xu Xinlin , Hu Zhongbo , Su Qinghua , Xiong Zenggang
Published: November 2018

The collective decision optimization algorithm (CDOA) is a new stochastic population‐based evolutionary algorithm which simulates the decision behavior of human. In this paper, a multiobjective collective decision optimization algorithm (MOCDOA) is first proposed to solve the environmental/economic dispatch (EED) problem. MOCDOA uses three novel learning strategies, that is, a leader‐updating strategy based on the maximum distance of each solution in an external archive, a wise random perturbation strategy based on the sparse mark around a leader, and a geometric center‐updating strategy based on an extreme point. The proposed three learning strategies benefit the improvement of the uniformity and the diversity of Pareto optimal solutions. Several experiments have been carried out on the IEEE 30‐bus 6‐unit test system and 10‐unit test system to investigate the performance of MOCDOA. In terms of extreme solutions, compromise solution, and three metrics (SP, HV, and CM), MOCDOA is compared with other existing multiobjective optimization algorithms. It is demonstrated that MOCDOA can generate the well‐distributed and the high‐quality Pareto optimal solutions for the EED problem and has the potential to solve the multiobjective optimization problems of other power systems.
A Classic Herbal Formula Danggui Beimu Kushen Wan for Chronic Prostatitis: From Traditional Knowledge to Scientific Exploration
Authors: Li Hong , Hung Andrew , Yang Angela Wei Hong
Published: November 2018

Chronic prostatitis (CP) is a chronic inflammation in the prostate with unsatisfactory management. Danggui Beimu Kushen Wan (DBKW) is a classic formula developed 1800 years ago for patients with difficult urination and it has been widely utilized for CP in modern days. However, scientific understanding of DBKW on CP has not been systematically reviewed. First, we searched the Encyclopedia of Traditional Chinese Medicine for the etiologies and pathogeneses of CP‐like symptoms and DBKW and compared their similarities and differences from traditional Chinese medicine and conventional medicine perspectives. Then, we searched 21 electronic databases to identify potential clinical and experimental studies. Characteristics of included studies, ingredients, herb frequency, and possible mechanisms of actions were descriptively summarized. Risk of bias of randomized controlled trials (RCTs) was evaluated using the Cochrane risk of bias assessment tool. A total of 290 studies were identified. Six clinical studies, including four RCTs and two case series, and eight experimental studies were included. Clinical studies indicated that DBKW used alone or as an adjunct therapy significantly reduced the CP symptom scores and decreased the expressed prostatic secretions‐pH when compared to antibiotics or α‐blocker. Most RCTs have high or unclear risk of bias. Experimental studies revealed that DBKW may have effects on anti‐inflammation, antibacteria, antioxidation, sex hormone regulation, and immunoregulation. DBKW demonstrated a great potential in the treatment of CP. High‐quality RCTs and network pharmacological studies should be considered for future research.
Network Intrusion Detection Method Based on PCA and Bayes Algorithm
Authors: Zhang Bing , Liu Zhiyang , Jia Yanguo , Ren Jiadong , Zhao Xiaolin
Published: November 2018

Intrusion detection refers to monitoring network data information, quickly detecting intrusion behavior, can avoid the harm caused by intrusion to a certain extent. Traditional intrusion detection methods are mainly focused on rule files and data mining. They have the disadvantage of not being able to detect new types of attacks and have the slow detection speed. To address these issues, an intrusion detection method based on improved PCA combined with Gaussian Naive Bayes was proposed. By weighting the first few feature vectors of the traditional PCA, data pollution can be reduced. The number of final weighted principal components is 2 through sequential selection. The dimensionality reduction of the data is achieved through improved PCA. Finally, the intrusion behaviors were detected by using the Gaussian Naive Bayes classifier. The indexes of detection accuracy, detection time, precision rate, and recall rate were applied to evaluate the results. The experimental results show that, comparing with the traditional Bayes method, the method proposed in this article can reduce the detection time by 60%, shorten it to 0.5s, and increase the detection rate to 91.06%. The mean value of detection accuracy is about 86% by cross-validation.
Temperature Profile Measurement in Simulated Fuel Assembly Structure with Wire-Mesh Technology
Authors: Takiguchi Hiroki , Furuya Masahiro , Arai Takahiro
Published: November 2018

When light water reactor (LWR) is subject to a cold shutdown, it needs to be cooled with pure water or seawater to prevent the core melting. To precisely evaluate the cooling characteristics in the fuel assembly, a measurement method capable of installing to the fuel assembly structure and determining the temperature distribution with high temporal resolution, high spatial resolution, and in multidimension is required. Furthermore, it is more practical if applicable to a pressure range up to the rated pressure 16 MPa of a pressurized water reactor (PWR). In this study, we applied the principle of the wire-mesh sensor technology used in the void fraction measurement to the temperature measurement and developed a simulated fuel assembly (bundle) test loop with installing the temperature profile sensors. To investigate the measurement performance in the bundle test section, it was confirmed that a predetermined temperature calibration line with respect to time-average impedance was calculated and became a function of temperature. To evaluate the followability of measurement in a transient temperature change process, we fabricated a 16 × 16 wire-mesh sensor device and measured the hot-water jet-mixing process into the cold-water pool in real time and calculated the temperature profile from the temperature calibration line obtained in advance from each measurement point. In addition, the sensors applied to three-dimensional temperature distribution measurement of a complex flow field in the bundle structure. The axial and cross-sectional profiles of temperature were quantified in the forced flow field with nonboiling when the 5×5 bundle was heated by energization.
Collecting and Using Students’ Digital Well-Being Data in Multidisciplinary Teaching
Authors: Moilanen Hannu , Äyrämö Sami , Jauhiainen Susanne , Kankaanranta Marja
Published: November 2018

This article examines how students (N=198; aged 13 to 17) experienced the new methods for sensor-based learning in multidisciplinary teaching in lower and upper secondary education that combine the use of new sensor technology and learning from self-produced well-being data. The aim was to explore how students perceived new methods from the point of view of their learning and did the teaching methods provide new information that could promote their own well-being. We also aimed to find out how to collect digital well-being data from a large number of students and how the collected big data set can be utilized to predict school success from the students’ well-being data by using machine learning methods (lasso regression and multilayer perceptron). Results showed that sensor-based learning can promote students’ learning and well-being. All upper secondary school (n=37) and 87% of lower secondary school pupils (n=161) argued that when data are produced by their bodies, learning is more interesting, and they mostly found that well-being analysis was useful (upper secondary 97%; lower secondary 78%) and can improve personal well-being (upper secondary 78%; lower secondary 67%). The predictive powers with lasso regression and multilayer perceptron (MLP) were quite weak (correlation: −0.14 and 0.34, respectively).
Increasing Sustainability of Logistic Networks by Reducing Product Losses: A Network DEA Approach
Authors: Lozano S. , Adenso-Díaz B.
Published: November 2018

This paper considers a multiproduct supply network, in which losses (e.g., spoilage of perishable products) can occur at either the nodes or the arcs. Using observed data, a Network Data Envelopment Analysis (NDEA) approach is proposed to assess the efficiency of the product flows in varying periods. Losses occur in each process as the observed output flows are lower than the observed input flows. The proposed NDEA model computes, within the NDEA technology, input and output targets for each process. The target operating points correspond to the minimum losses attainable using the best observed practice. The efficiency scores are computed comparing the observed losses with the minimum feasible losses. In addition to computing relative efficiency scores, an overall loss factor for each product and each node and link can be determined, both for the observed data and for the computed targets. A detailed illustration and an experimental design are used to study and validate the proposed approach. The results indicate that the proposed approach can identify and remove the inefficiencies in the observed data and that the potential spoilage reduction increases with the variability in the losses observed in the different periods.
Influence of Energy State of Montmorillonite Interlayer Cations on Organic Intercalation
Authors: Wu Limei , Cao Shiyue , Lv Guocheng
Published: November 2018

It is well known that the intercalation of montmorillonite (Mt) with organic cations is a fast process. During the intercalation, the interaction between the original cations and the structure layer of Mt keeps changing, and the basal spacing of Mt keeps increasing until an organic environment has been built in the interlayer. Many properties of Mt also change during the intercalation, such as hydrophobic or hydrophilic property and thermal stability. In this research, the impact of intercalation on the properties of Mt was studied by investigating the change in basal spacing and energy that coordinates the interlayer cations during the intercalation of Mt with organic cations. The interaction between interlayer cations and the layers in the Mt structure and the change in the system energy were obtained by using molecular dynamics simulation. All the experiment and calculation results provide a theoretical proof in organic intercalation mechanism.
A Full-Dielectric Chiral Material Based on a Honeycomb Structure
Authors: Barba Ismael , Grande Ana , Molina-Cuberos Gregorio J. , García-Collado Ángel J. , Represa José , Cabeceira Ana C. L.
Published: November 2018

A uniaxial bianisotropic, full-dielectric structure has been designed and numerically studied. The material is based on a previously published 2D-honeycomb structure. A 3D expansion leads to an effective metamaterial showing a typical chiral electromagnetic behavior, i.e., a resonant electromagnetic activity with a small circular dichroism.