bluuebunny/crossref_metadata_2025 huggingface dataset:
The Pulsating White Dwarf G117-B15A: Still the Most Stable Optical Clock Known
Authors: Kepler S. O. , Winget D. E. , Vanderbosch Zachary P. , Castanheira Barbara Garcia , Hermes J. J. , Bell Keaton J. , Mullally Fergal , Romero Alejandra D. , Montgomery M. H. , DeGennaro Steven , Winget Karen I. , Chandler Dean , Jeffery Elizabeth J. , Fritzen Jamile K. , Williams Kurtis A. , Chote Paul , Zola Staszek
Published: December 2020

The pulsating hydrogen atmosphere white dwarf star G 117-B15A has been observed since 1974. Its main pulsation period at 215.19738823(63) s, observed in optical light curves, varies by only (5.12 ± 0.82) × 10−15 s s−1 and shows no glitches, as pulsars do. The observed rate of period change corresponds to a change of the pulsation period by 1 s in 6.2 million yr. We demonstrate that this exceptional optical clock can continue to put stringent limits on fundamental physics, such as constraints on interaction from hypothetical dark matter particles, as well as to search for the presence of external substellar companions.
Multiwavelength Analysis and the Difference in the Behavior of the Spectral Features during the 2010 and 2014 Flaring Periods of the Blazar 3C 454.3
Authors: Amaya-Almazán Raúl A. , Chavushyan Vahram , Patiño-Álvarez Victor M.
Published: December 2020

Over the years, the flat-spectrum radio quasar 3C 454.3 has presented phases of very high activity (flares) in which the different wave bands increase their flux dramatically. In this work, we perform multiwavelength analysis from radio to gamma-rays and study the Mg ii λ2798 emission line and the UV Fe ii band from 2008 to 2018. We found that an increase in the 43 GHz flux density of the quasi-stationary component C coincides with the estimated time at which a superluminal blob ejected from the radio core (which caused the brightest flare of 2010) collides with the quasi-stationary component (at a projected distance of ∼4.6 pc from the radio core). The different behavior of the spectral index in the first (5000 < JD − 2,450,000 < 5600) and second (6600 < JD − 2,450,000 < 7900) flaring periods suggests changes in the physical conditions. The complex nature of the second period can be a result of a superposition of multiple events at different locations. The Mg ii line has an anticorrelation with the UV continuum while Fe ii correlates positively, except at the time of the brightest flare of 2010, when both have a strong response at high continuum luminosities. Our results suggest that the dominant gamma-ray emission mechanism for the first flaring period is external Compton. For the second flaring period the region emitting seed photons is co-spatial with that emitting gamma-rays. However, a study of the spectral energy distribution using a multizone jet emission model is required to confirm the nature of each significant flare during the second period.
Energy Distribution of Small-scale Flares Derived Using a Genetic Algorithm
Authors: Kawai Toshiki , Imada Shinsuke
Published: December 2020

To understand the mechanism of coronal heating, it is crucial to derive the contribution of small-scale flares, the so-called nanoflares, to the heating up of the solar corona. To date, several studies have tried to derive the occurrence frequency distribution of flares as a function of energy to reveal the contribution of small-scale flares. However, there are no studies that derive the distribution with considering the following conditions: (1) evolution of the coronal loop plasma heated by small-scale flares, (2) loops smaller than the spatial resolution of the observed image, and (3) multiwavelength observation. To take into account these conditions, we introduce a new method to analyze small-scale flares statistically based on a one-dimensional loop simulation and a machine-learning technique, that is, the genetic algorithm. First, we obtain six channels of Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) light curves of the active-region coronal loops. Second, we carry out many coronal loop simulations and obtain the SDO/AIA light curves for each simulation in a pseudo-manner. Third, using the genetic algorithm, we estimate the best combination of simulated light curves that reproduce the observation. Consequently, the observed coronal loops are heated by small-scale flares with energy flux larger than that typically required to heat up an active region intermittently. Moreover, we derive the occurrence frequency distribution which has various power-law indices in the range from 1–3, which partially supports the nanoflare heating model. In contrast, we find that 90% of the coronal heating is done by flares that have energy larger than 1025 erg.
A Pre-explosion Extended Effervescent Zone around Core-collapse Supernova Progenitors
Authors: Soker Noam
Published: December 2020

I propose a scenario according to which the dense compact circumstellar matter (CSM) that the ejecta of many core-collapse supernovae (CCSNe) collide with within several days after explosion results from a dense zone where in addition to the stellar wind there is gas that does not reach the escape velocity. In this effervescent zone around red supergiant (RSG) stars, there are dense clumps that are ejected from the vicinity of the RSG surface, rise to radii of tens of astronomical units, and then fall back. I consider two simple velocity distributions of the ejected clumps. I find that the density of the bound mass can be tens of times that of the escaping wind, and therefore can mimic a very high mass-loss rate. The dense effervescent compact CSM zone can (1) explain the collision of the ejecta of many CCSNe with a dense compact CSM days after explosion, (2) facilitate very high mass-loss rate if the star experiences powerful pre-explosion activity, (3) form dust that obscures the progenitor in the visible band, and (4) lead to an efficient mass transfer to a stellar companion at separations of tens of astronomical units, if it exists. The effervescent zone might exist for thousands of years and more, and therefore the effervescent CSM model removes the requirement from many type II CCSN progenitors to experience a very strong outburst just years to months before explosion.
Differential Chromatic Refraction in the Context of the Legacy Survey of Space and Time
Authors: Yu Weixiang , Richards Gordon T. , Yoachim Peter , Peters Christina
Published: December 2020

We investigate how measurements of differential chromatic refraction might influence choices for survey strategy in the Legacy Survey of Space and Time.
Diversity and composition of plant species in the forest over limestone of Rajah Sikatuna Protected Landscape, Bohol, Philippines
Authors: Aureo Wilbert , Reyes Tomas , Mutia Francis Carlo , Jose Reizl , Sarnowski Mary Beth
Published: December 2020

Rajah Sikatuna Protected Landscape (RSPL), considered the last frontier within the Central Visayas region, is an ideal location for flora and fauna research due to its rich biodiversity. This recent study was conducted to determine the plant species composition and diversity and to select priority areas for conservation to update management strategy. A field survey was carried out in fifteen (15) 20 m x 100 m nested plots established randomly in the forest over limestone of RSPL from July to October 2019. Three hundred and sixty eight (368) species of plants were identified up to species level. This represented 327 angiosperms, one gymnosperm and 40 pteridophytes. Common plant families with more than 10 representative species were Moraceae, Meliaceae, Lauraceae, Dipterocarpaceae, Rubiaceae, Myrtaceae, Phyllanthaceae, Annonaceae, Araceae and Lauraceae. There were 93 (28%) endemic and 46 (14%) threatened species (vulnerable to critically endangered) observed. The cluster analysis and species accumulation curve suggests that plant species are not homogeneously distributed which implies that different management and conservation strategies should be implemented across RSPL. These results not only indicate the importance of RSPL, but also highlights areas with higher diversity and concentration of threatened and endemic species as a special area of concern. Furthermore, areas with high biodiversity value were recommended for immediate protection, while areas with low biodiversity value were recommended for reforestation programmes using species with high importance value.
First record of the carpenter bee Xylocopa pubescens (Hymenoptera, Apidae) in the Canary Islands confirmed by DNA barcoding
Authors: Ruiz Carlos , Suárez Daniel , Naranjo Manuel , De la Rúa Pilar
Published: December 2020

Island ecosystems are particularly vulnerable to the introduction of exotic species that can have an impact on local fauna and flora. Here, the carpenter bee Xylocopa pubescens is reported in Gran Canaria (Canary Islands, Spain) for the first time. This species is native to North Africa and the Near East and shows a rapid dispersion across the city of Las Palmas de Gran Canaria, together with a single record in the southernmost tip of the island. Different hypotheses about its arrival to the island are discussed.
Figures du traumatisme durant l’enfance au cinéma : une analyse comparée de quatre films classiques américains
Authors: Ménochet Laurent , Chaput Corinne
Published: December 2020

Par une analyse comparée de quatre films classiques américains, l’auteur aborde le traumatisme psychologique vécu par des enfants. Que ce soit par la perte d’un parent ou la séparation physique d’un être cher, chaque personnage vit ces séparations comme de véritables chocs traumatiques. Cette analyse montre que l’enfance est une étape primordiale du développement de l’être futur et que toute déchirure peut entamer ce développement et laisser des traces indélébiles.
Inconsistency of Bone Mineral Density Between Femoral Head and Proximal Femur After Femoral Neck Fracture Surgery Indicates Great Possibility of Femoral Head Necrosis
Authors: Chu Kai , Cheng Gong , Yu Guo-Zheng , Ning Bin , Jia Tang-Hong
Published: December 2020

On clinical observation, it was found that the bone mineral density (BMD) of the femoral head and proximal femur was not consistent in some patients with femoral neck fracture after surgery. The current study was performed to explore whether this phenomenon was associated with femoral head necrosis after surgery for femoral neck fracture. Bone mineral density inconsistency is when the difference of the sum of pixel values on both sides of the fracture line has exceeded 30%. Statistical analysis was performed on the clinical characteristics of 271 patients who had received the operation for femoral neck fracture. Chi-square test, Spearman rank correlation, independent sample
t
test, Kaplan–Meier method, and log-rank test, as well as univariate Cox regression and multivariate Cox regression, were used to analyze the potential relationship among related factors. It was revealed that the incidence of inconsistency in BMD between the femoral head and proximal femur was significantly increased in patients with femoral head necrosis after surgery for femoral neck fracture, and that the consistency was considerably high between BMD inconsistency and femoral head necrosis. The inconsistent BMD occurred 11.1 months earlier than the necrosis of the femoral head. Cox multivariate regression analysis indicated that the inconsistency in BMD between the femoral head and proximal femur after surgery for femoral neck fracture was an independent prognostic factor affecting femoral head necrosis. The inconsistent changes in BMD between the femoral head and proximal femur after surgery for femoral neck fracture indicate a great possibility of femoral head necrosis. [
Orthopedics
. 2021;44(2):e223–e228.]
Feedback synchronization of FHN cellular neural networks
Authors: Skrzypek Leslaw , You Yuncheng
Published: December 2020

In this work we study the synchronization of ring-structured cellular neural networks modeled by the lattice FitzHugh-Nagumo equations with boundary feedback. Through the uniform estimates of solutions and the analysis of dissipative dynamics, the synchronization of this type neural networks is proved under the condition that the boundary gap signal exceeds the adjustable threshold.
Semi-compatible mappings and common fixed point theorems of an implicit relation via inverse $ C- $class functions
Authors: Zhou Mi ,   School of Science and Technology, University of Sanya, Sanya, Hainan, 572022, China, Jain Mukesh Kumar , Khan Mohammad Saeed , Secelean Nicolae Adrian ,   J. N. V. Udalguri Assam, India,   College of Science, Department of Mathematics and Statistics, Sultan Qaboos University, Al-Khod, Muscat, Oman,   Department of Mathematics and Computer Science, Faculty of Sciences, Lucian Blaga University of Sibiu, Romania
Published: December 2020

In this paper, we prove some common fixed point theorems by exploring a new kind of generalized semi-compatibility and an implicit relation via inverse $ C- $class functions. The results generalize, extend and improve the main results of [19, 21, 22, 23]. Moreover, some examples are given to illustrate the validity of our results.
E-Government Adoption Among Employees
Authors: Bhaskar Preeti , Vinay Muddu , Joshi Amit
Published: December 2020

The United Nations have sustenance e-government to promote good governance for achieving Sustainable Development Goals – 2030 by fostering environmental, technological, socio-cultural, and political sustainability. Many countries are making sincere efforts to create an ecosystem for fostering e-government to contribute to Sustainable Development Goals. The government is investing a huge amount in e-government projects, but most of them are not able to meet the desired results. It has been reported that most of the e-government is failing due to the non-adoption behavior of employees. This chapter seeks to understand the employee's perspectives by discussing benefits, barriers, and enablers to adopting e-government through a systematic literature review.
Identifying Innovations in Human Resources
Authors: Singh Amrik , Kumar Sanjeev
Published: December 2020

HR is evolving into a more technology-based profession because organizations needs to streamline HR processes and reduce administrative burden, reducing administrative cost; compete more effectively with global talent; improve services and access data to the employees and managers; provide real-time metrics in order tom on spot decisions for the decision makers; and manage the workforce more effectively and enable the HR to transform so it can play more strategic role in the business and operations. The purpose of this chapter is to develop a meaningful debate on the innovations in human resource in terms of new ideas, methods, and technology to better meet the evolving requirement of the organization and workforce. Anticipating and exploring the future needs and circumstances rather than simply finding some responses to the situation, this chapter highlights challenges and prospects related to innovations in HR.
Technology Applications in Managing Talents
Authors: Kataria Pushpa
Published: December 2020

Human resource (HR) management is all about people; there is no doubt about it. However, in the contemporary era inbuilt by the technological revolution and transformative development, the tenets of HR are finding a new footing. Technology applications have changed facets of corporate houses from restructuring organizations to resources to manpower. It has been seen that HR technologies are playing a major role in managing talents in organizations. Artificial intelligence, robotic process automation, and machine learning add an edge to talent acquisition and management. Machine learning tools are primarily being used in acquiring talents and enabling the hiring process effectively and efficiently. Today, as every company is moving to a new era of digitalization and data management, managing and mapping talents pose a challenge to C-suite and board-level management. The present study highlights the role of technology in managing talents in a series of HR processes.
Determination of Poverty Indicators Using Roc Curves in Turkey
Authors: Çiçek Zübeyde , Demirgil Hakan
Published: December 2020

The present study was conducted to determine the reasons affecting poverty in Turkey and specify the level of significance of these reasons to explain poverty. The data which was analyzed in the study were retrieved from the Household Budget Research which was published by the Turkish Statistical Institute. In the study, logit models have been established by taking into account the demographic and socioeconomic indicators and the characteristics of the household. For each of these models, ROC curves were drawn, and the best model was found with the help of the areas under the curve. The results showed that the model which was developed based on the variables related to housing and the model according to consumption expenditure were determined to be more significant to explain poverty. Also, the rental value of the house, the floor type of the house and household's head educational level were found to be the most significant determinants of poverty according to the analysis of the results.
Decision Making and Data Analysis
Authors: Jakóbczak Dariusz Jacek
Published: December 2020

The proposed method, called probabilistic nodes combination (PNC), is the method of 2D curve modeling and handwriting identification by using the set of key points. Nodes are treated as characteristic points of signature or handwriting for modeling and writer recognition. Identification of handwritten letters or symbols need modeling, and the model of each individual symbol or character is built by a choice of probability distribution function and nodes combination. PNC modeling via nodes combination and parameter γ as probability distribution function enables curve parameterization and interpolation for each specific letter or symbol. Two-dimensional curve is modeled and interpolated via nodes combination and different functions as continuous probability distribution functions: polynomial, sine, cosine, tangent, cotangent, logarithm, exponent, arc sin, arc cos, arc tan, arc cot, or power function.
A Decadal Walk on BCI Technology
Authors: Chatterjee Ahan , Mandal Aniruddha , Roy Swagatam , Sinha Shruti , Priya Aditi , Gupta Yash
Published: December 2020

In this chapter, the authors take a walkthrough in BCI technology. At first, they took a closer look into the kind of waves that are being generated by our brain (i.e., the EEG and ECoG waves). In the next section, they have discussed about patients affected by CLIS and ALS-CLIS and how they can be treated or be benefitted using BCI technology. Visually evoked potential-based BCI technology has also been thoroughly discussed in this chapter. The application of machine learning and deep learning in this field are also being discussed with the need for feature engineering in this paradigm also been said. In the final section, they have done a thorough literature survey on various research-related to this field with proposed methodology and results.
A Fusion-Based Approach to Generate and Classify Synthetic Cancer Cell Image Using DCGAN and CNN Architecture
Authors: Chatterjee Ahan , Roy Swagatam
Published: December 2020

The most talked about disease of our era, cancer, has taken many lives, and most of them are due to late prognosis. Statistical data shows around 10 million people lose their lives per year due to cancer globally. With every passing year, the malignant cancer cells are evolving at a rapid pace. The cancer cells are mutating with time, and it's becoming much more dangerous than before. In the chapter, the authors propose a DCGAN-based neural net architecture that will generate synthetic blood cancer cell images from fed data. The images, which will be generated, don't exist but can be formed in the near future due to constant mutation of the virus. Afterwards, the synthetic image is passes through a CNN net architecture which will predict the output class of the synthetic image. The novelty in this chapter is that it will generate some cancer cell images that can be generated after mutation, and it will predict the class of the image, whether it's malignant or benign through the proposed CNN architecture.
Project Control
Authors: Caron Franco
Published: December 2020

The capability to elaborate a reliable estimate at completion for a project since the early stage of project execution is the prerequisite in order to provide an effective project control. The non-repetitive and uncertain nature of projects and the involvement of multiple stakeholders increase project complexity and raise the need to exploit all the available knowledge sources in order to improve the forecasting process. Therefore, drawing on a set of case studies, this chapter proposes a Bayesian approach to support the elaboration of the estimate at completion in those industrial fields where projects are denoted by a high level of uncertainty and complexity. The Bayesian approach allows the authors to integrate experts' opinions, data records related to past projects, and data related to the current performance of the ongoing project. Data from past projects are selected through a similarity analysis. The proposed approach shows a higher accuracy in comparison with the traditional formulas typical of the earned value management (EVM) methodology.
Job Scheduling in Cloud Using Seagull Optimization Algorithm
Authors: Garg Meenakshi , Dhiman Gaurav
Published: December 2020

In recent years, cloud computing technology has gained a great deal of interest from both academia and industry. Cloud computing's success benefited from its ability to offer global IT services such as core infrastructure, platforms, and applications to cloud customers around the web. It also promises on-demand offerings and new ways of pricing packages. However, cloud job scheduling is still NP-complete and has become more difficult due to certain factors such as resource dynamics and on-demand customer application requirements. To fill this void, this chapter presents the seagull optimization algorithm (SOA) for scheduling work in the cloud world. The efficiency of the SOA approach is compared to that of state-of-the-art job scheduling algorithms by having them all implemented in the CloudSim toolkit.
Integrating Business Intelligence With Cloud Computing
Authors: Jaswal Shivani
Published: December 2020

Cloud Computing has emerged as an expression that has described various other computing concepts that involve computers that are interconnected virtually. It is so prominent that it has modified the architecture by incorporating new design principles. Also, the present economic crisis, which is being experienced by most of the world, has oriented us towards cloud computing and its efficient services. Here, business intelligence plays a pivotal role in extraction of valuable information and identifying hidden patterns of data. Also, any organization in striving stage can also act smartly with the use of various business intelligence solutions. Various benefits are also offered by the BI solutions such as working together as a team and identifying various resolutions. The contribution of this chapter is to show how the cloud computing environment has been merged with business intelligence to fulfil the future need of uplifting of economy.
Migrating Complex Applications From On-Premises to Cloud Interface
Authors: Pawar Lokesh , Bathla Gaurav
Published: December 2020

Migrating applications on the cloud storage from the systems physically available on the premises is a difficult task. There are a lot of research articles providing solutions for the current problem of migration of applications by software industry. The chapter is shedding light on how to migrate the application efficiently using mathematical approach. The dependency of migration is directly proportional to the size of the data and the speed of the network. There are a number of storage options available on cloud for easy accessibility, cache-ability, and consistency. This chapter focuses on difficult migration of an application.
mHealth for Illness Self-Management for People With Schizophrenia
Authors: Simões de Almeida Raquel
Published: December 2020

People with schizophrenia and other related disorders experience great difficulties in getting the appropriate treatment regarding not only the type of interventions available but also the conditions that required for a proper treatment, mainly cost, locale, and frequency. The use of gamified mHealth applications for this population is a proven way to provide a set of tools that may help patients to manage their condition using applications on mobile devices, like smartphones, that implement game-like strategies and elements that transform unpleasant tasks into virtual challenges. This chapter addresses the impact and implications that the use of gamified mHealth applications have for people with schizophrenia, a comprehensive guide of recommendations and standards used by the industry on the development of gamified applications and provides a literature review on the subject.
A validated audio-visual educational module on examination skills in ophthalmology for undergraduate medical students in the COVID-19 season - An observational longitudinal study
Authors: Rose Jeyanth S , Lalgudi Sharmili , Joshua R Aarwin , Paul Joshua , Susanne M Aishwarya , Phillips Ashna C , Jeyaraj Chriset , Abraham Greeni , Joshua R , Vinay Samuel , Paul Padma , Amritanand Anika , Nadaraj Ambily
Published: December 2020

Purpose:

The aim of this study was to assess the impact of an audio visual (AV) teaching module on basic torchlight examination of the eye and direct ophthalmoscopy for undergraduate medical students.

Methods:

This observational longitudinal study was done on 33 consecutive medical interns during their Ophthalmology posting from December 2019 to March 2020 at a medical college in South-India. An AV-module was created using animation graphics, narratives, demonstrations on normal individuals and on patients with positive signs. All interns had a pretest consisting of Multiple-choice questions, (MCQs) and an Objective Structured Clinical Examination (OSCE) on torchlight examination and direct ophthalmoscopy (DO). They were then shown the 20-minute AV-module. A posttest was performed immediately and after one week.

Results:

The mean pretest MCQ score was 5.84 ± 1.98. It improved to 8.81 ± 1.15 in the immediate posttest and 8.87 ± 1.66 in the one-week posttest. The mean pretest OSCE score was 12.21 ± 3.39. It improved to 23.21 ± 3.39 in the immediate posttest and 23.90 ± 3.7 in the one-week posttest. Using Generalized Estimating Equation, MCQ score improved by 2.97 units and 3.03 units and the OSCE score improved by 11 units and 11.69 units in the immediate posttest and one-week posttest respectively when compared to the pretest corresponding to the MCQ score and OSCE score (p < 0.001).

Conclusion:

AV teaching modules-for torchlight examination and DO has a significant benefit in improving knowledge and skill in undergraduate medical students. These significant results have the great translatory capacity in the current COVID-19 pandemic, where physical demonstrations involving close proximity and groups of students are highly risk prone.
Neuroinflammation in Alzheimer's Disease Continuum
Authors: Taskiran-Sağ Aslihan , Yemişçi Müge
Published: December 2020

Aging population brings an ever-increasing global burden of dementia, and Alzheimer's disease (AD) is the most frequent type worldwide. Many years of research have introduced characteristic cerebral histopathological and molecular changes in this disease. However, all attempts to establish an effective treatment have failed. In this review, we aim to address the basic evidence regarding the role of inflammatory mediators in AD and their link to the other pathogenetic pathways. Novel findings based on advanced biotechnology and bioinformatics are covered briefly, as well.
Identification of a Novel CSNK2A1-PDGFRB Fusion Gene in a Patient with Myeloid Neoplasm with Eosinophilia
Authors: Xu Xiaoyu , Lu Qiongyu , Wang Zheng , Cai Ping , Zeng Zhao , Zhang Ling , Wang Man , Ma Liang , Ruan Changgeng , Chen Suning
Published: December 2020

Platelet-derived growth factor receptor beta (PDGFRB) rearrangements play an important role in the pathogenesis of eosinophilia-associated myeloid/lymphoid neoplasms. Up to now, more than 70 PDGFRB fusions have been identified. Here, a novel PDGFRB fusion gene CSNK2A1-PDGFRB has been identified in myeloproliferative neoplasm (MPN) with eosinophilia by RNA-sequencing, which has been verified by reverse transcription polymerase chain reaction and Sanger sequencing. The new PDGFRB fusion partner gene CSNK2A1 encoded one of the two catalytic subunit of casein kinase II (CK2). To our knowledge, this is the first report on the involvement of CSNK2A1 in fusion genes, especially fusion with another kinase PDGFRB in MPN. In addition, the CSNK2A1-PDGFRB fusion retained the entire kinase domain of PDGFRB and response to imatinib at low concentration. The patient with CSNK2A1-PDGFRB was sensitive to imatinib treatment and acquired sustained complete remission.
Subgroups of word hyperbolic groups in rational dimension 2
Authors: Arora Shivam , Martínez-Pedroza Eduardo
Published: December 2020

A result of Gersten states that if

G

is a hyperbolic group with integral cohomological dimension

\mathsf{cd}_{\mathbb{Z}}(G)=2

then every finitely presented subgroup is hyperbolic. We generalize this result for the rational case

\mathsf{cd}_{\mathbb{Q}}(G)=2

. In particular, the result applies to the class of torsion-free hyperbolic groups

G

with

\mathsf{cd}_{\mathbb Z}(G)=3

and

\mathsf{cd}_{\mathbb Q}(G)=2

discovered by Bestvina and Mess.
Temporal properties of aftershock sequences of large earthquakes in Iran - Analysis of primary and secondary aftershocks of the Ezgeleh sequence
Authors: Lavasani Mahdieh , Shabani Elham
Published: December 2020

In this study, the decay of earthquake aftershock sequences of some major earthquakes in different tectonic regimes in the Iranian plateau is discussed. The studied earthquakes are Rigan [2010], Ahar-Varzaghan [2012], Goharan [2013], Sefidsang [2017] and Ezgeleh [2017]. The spatial and temporal windows are considered based on the method proposed by Gardner and Knopoff [1974] to compute decay parameters for each sequence. The decay rates of sequences were compared to well-known models to find the best fit for each sequence. The results showed that the modified Omori is the best fit for Ahar-Varzaghan and Ezgeleh sequences, for Rigan and Sefidsang sequences the modified Omori and the Kisslinger ones found as the best fits. The values of the p parameter of the Reasenberg and Shcherbakov models were larger compared to the Omori model, but the parameter of the Kisslinger model was slightly smaller compared to the Omori one. The c parameter showed an inverse relation to the threshold magnitude. The correlation between the p and c parameters and also the and the Gutenberg and Richter (G-R) parameters were investigated. In addition, we made use of a graphical method to analyze the seismic sequence of the Ezgeleh earthquake during 13 months after the main event. The graphical method was successful to estimate the occurrence of an event with an approximate magnitude of M=6.4 in the sequence.
Muon Tomography sites for Colombian volcanoes
Authors: Vesga-Ramírez Alejandra , Sierra Porta David , Peña Rodríguez Jesús , Sanabria-Gómez José , Valencia-Otero Martha , Sarmiento-Cano Christian , Suárez-Durán Mauricio , Asorey Hernán , Núñez Luis
Published: December 2020

By using a very detailed simulation scheme, we have calculated the cosmic ray background flux at 13 active Colombian volcanoes and developed a methodology to identify the most convenient places for a muon telescope to study their inner structure. Our simulation scheme considers three critical factors with different spatial and time scales: the geo-magnetic effects, the development of extensive air showers in the atmosphere, and the detector response at ground level. The muon energy dissipation along the path crossing the geological structure is modeled considering the losses due to ionization, and also contributions from radiative Bremßtrahlung, nuclear interactions, and pair production. By examining each particular volcano topography and assuming reasonable statistics for different instrument acceptances, we obtained the muon flux crossing each structure and estimated the exposure time for our hybrid muon telescope at several points around each geological edifice. After a detailed study from the topography, we have identified the best volcano to be studied, spotted the best points to place a muon telescope and estimated its time exposures for a significant statistics of muon flux. We have devised a mix of technical and logistic rules –the “rule of thumb” criteria– and found that only Cerro Machín, located at the Cordillera Central (4°29'N 75°22'W), can be feasibly studied today through muography. Cerro Negro and Chiles could be good candidates shortly.
Rarity, proximity, and design actions: mapping strong earthquakes in Italy
Authors: Cito Pasquale , Iervolino Iunio
Published: December 2020

At the state-of-the-art of structural codes, seismic design actions are based on probabilistic seismic hazard analysis (PSHA). In the performance-based earthquake engineering framework, the return period of exceedance of the reference ground motion is established based on the desired performance of the structure. It is easy to show and recognize that exceedance of elastic spectra, for the most common return periods considered for design, is very likely for some earthquakes if they occur close to the site of interest, and that this does not necessarily contradict the results of PSHA. Therefore, it might be relevant to gather insights about: (i) the probability that the site is in proximity of earthquakes of magnitude that can imply exceedance; (ii) the probability that earthquakes occurring close cause exceedance of design actions; (iii) the minimum magnitude of close-by events that are likely to cause exceedance of design actions, which are then referred to as the strong earthquakes; (iv) the accelerations that structures could be exposed to in the case of exceedance of design spectra. These results, which are produced for Italy in this study, may be considered by-products of PSHA, and are helpful in determining what to expect in terms of elastic actions for code-conforming structures in countries where probabilistic seismic hazard lies at the basis of structural design.
PREDICTING COST CONTINGENCY FOR PRIVATE PROJECTS: CASE STUDY IN VIETNAM
Authors: TUAN KIET NGUYEN , KIM SOO-YONG , TRUONG LUU VAN , VAN HUNG LE , HUU DAT LE
Published: December 2020

Actual cost in construction projects has tended to exceed the project budgets. Thus, cost contingency from the initial of the project is the significant budget to complete project activities. Cost contingency is an important element of  cost estimation to protect project stakeholders such as owners, contractors, and architects from the risks of the project. This paper reviewed the previous studies to find the factors affecting cost contingency and proposed a regression model to predict the cost contingency for private projects in Vietnam. Through industry survey, project performance information from a total of 48 private projects in Vietnam was gathered. The research also compared with other studies to have an overview about cost contingency predicting methods. The key benefit of this research is that the project managers can use this model as another forecasting method to get a better quality cost management. The further research can be focused on developing the model for other project types in Vietnam.
IT IS NECESSARY TO UNDERSTAND THE VALUE OF K DENSITY WHEN TESTING THE QUALITY OF NATURAL AGGREGATE LAYER IN ROAD COAT STRUCTURE IN THE SOUTH
Authors: TAN LE
Published: December 2020

Density is an important parameter reflects the quality of the foundation and base construction. Therefore, the exact determination of density parameters is extremely necessary in the work of checking and accepting the work items. The paper presents the results of the research to determine the density of the natural mix layer in the road coat structure with flexible and rational adjustment of the oversized grain content - during standard compaction as well as sampling for field test of density to overcome difficulties and obstacles when implementing the inspection of road structure.
COMPARISION AND STUDY OF NUMERICAL METHODS FOR DYNAMIC RESPONSE EVALUATION OF SDOF
Authors: PHUONG TRUC THAI
Published: December 2020

Written for senior-year undergraduates and first-year graduate students with solid backgrounds in differential and integral calculus, this paper is oriented toward engineers and applied mathematicians. Consequently, this paper should be useful to senior-year undergraduates the finite element method [1]. The scaled direct approach is adopted for this purpose and each step in the finite element solution process is given in full detail. For this reason, all students must be exposed to (and indeed should master). This paper provides the general framework for the development of nearly all (nonstructural) finite element models. The finite element method of analysis is a very powerful, modern computational tool. Applications range from deformation and stress analysis of automotive, aircraft, building, and bridge structures to field analysis of beat flux, fluid flow, magnetic flux, seepage, and other flow problems. This paper presents study and comparison of numerical methods which are used for evaluation of dynamic response. A Single Degree of Freedom (SDF)-linear problem is solved by means of Newmark’s Average acceleration method [2], Linear acceleration method [2], Central Difference method [6,7] with the help of MATLAB. The advantages, disadvantages, relative precision and applicability of these numerical methods are discussed throughout the analysis.
KIỂM ĐỊNH VÀ ĐÁNH GIÁ THANG ĐO TÁC ĐỘNG CỦA VIỆC SỬ DỤNG RUBRICS TRONG ĐÁNH GIÁ KẾT QUẢ HỌC TẬP CỦA SINH VIÊN
Authors: KHOA THÚY KHA ĐỖ
Published: December 2020

Trong những năm gần đây, việc đổi mới phương pháp dạy học và đổi mới phương pháp đánh giá sinh viên là một trong những ưu tiên của Trường Đại học Công nghiệp Thành phố Hồ Chí Minh nhằm nâng cao chất lượng đào tạo của các chương trình. Các bài kiểm tra viết với các câu hỏi truyền thống đang dần được thay thế bằng các hình thức đánh giá phi truyền thống như đánh giá sự thực hiện các nhiệm vụ học tập của sinh viên. Ngoài đào tạo và đánh giá mức độ lĩnh hội kiến thức, hiện nay giảng viên còn tiến hành rèn luyện và đánh giá các k năng mềm của sinh viên. Công cụ được nhiều giảng viên lựa chọn để đánh giá sự thực hiện nhiệm vụ và kỹ năng mềm của sinh viên hiện nay tại trường Đại học Công Nghiệp thành phố Hồ Chí Minh là rubrics. Rubrics là công cụ đặc biệt hữu dụng khi dùng để đánh giá các chuẩn đầu ra ở mức độ nhận thức cao trong thang Bloom, các chuẩn về kỹ năng mềm hay về thái độ của sinh viên khi mà các công cụ đánh giá khác phụ thuộc nhiều vào cảm nhận chủ quan của người chấm và không đảm bảo độ tin cậy và tính công bằng. Bài báo kiểm định và đánh giá thang đo tác động của việc sử dụng Rubrics trong đánh giá kết quả học tập của sinh viên trong phạm vi Trường Đại học Công nghiệp Thành phố Hồ Chí Minh.
NGHIÊN CỨU SỬ DỤNG XƠ DA THUỘC PHẾ LIỆU ĐỂ CHẾ TẠO VẬT LIỆU COMPOSITE NỀN NHỰA POLYESTER KHÔNG NO
Authors: THỊ MỸ LINH NGUYỄN , THỊ HỒNG PHƯỢNG PHẠM
Published: December 2020

Nghiên cứu này trình bày các kết quả khảo sát ảnh hưởng của nồng độ dung dịch polyester không no (UPE), hàm lượng chất đóng rắn methyl ethyl ketone peroxide (MEKP), hàm lượng xơ da, tỷ lệ khối lượng phối trộn xơ da với sợi thủy tinh và mùn cưa trong cốt gia cường đến thời gian đóng rắn, độ bền cơ học, sự phân bố các pha và màu sắc của vật liệu composite thu được. Xơ da sử dụng trong nghiên cứu là các loại xơ được nghiền từ phế liệu da thuộc phát sinh trong quá trình sản xuất giầy dép. Trong khoảng khảo sát về nồng độ dung dịch UPE (40 – 60%), chất đóng rắn MEKP (1 – 2%), hàm lượng xơ da (7 – 11%), tỷ lệ khối lượng phối trộn xơ da/sợi thủy tinh (50/50), xơ da/mùn cưa (50/50) và xơ da/sợi thủy tinh/mùn cưa (40/30/30) trong cốt gia cường, điều kiện thích hợp để chế tạo vật liệu composite là UPE 60%, MEKP 1% và xơ da 7%. Điều kiện này đảm bảo thu đƣợc vật liệu có tính chất cơ học (độ bền kéo, độ bền va đập và độ bền nén) tương đối tốt. Mẫu có tỷ lệ khối lượng phối trộn xơ da/sợi thủy tinh (50/50) có độ bền cơ học và phân bố pha tốt nhất. Kết quả từ nghiên cứu này bước đầu cho thấy khả năng sử dụng xơ da thuộc phế liệu để chế tạo các loại vật liệu mới có khả năng ứng dụng trong dân dụng và công nghiệp.
Autoregressive Integrated Moving Average Model for Polar Seas Ice Prediction
Authors: Kayikci Safak
Published: December 2020

Sea ice predictions are very important for the future of polar climates and play a significant role in ecosystems. Models are the simulated representations that have been set up to research systems. To advance model forecasts, researchers require improved parameterizations that are formed by the assembling and analysis of convenient observations. In this study, an Autoregressive Integrated Moving Average (ARIMA) model is proposed to predict the Arctic and Antarctic sea ice extent. The data is gathered from the National Snow and Ice Center (NSIDC) between 01. Jan.1979 and 30. Jun.2020. The fitted data between 2017 and 2020 matches the observed data very closely with the overlap is firmly within the 95% confidence band shows the success of the model.
IKM-NCS: A Novel Clustering Scheme Based on Improved K-Means Algorithm
Authors: Wang Weipeng , Tu Shanshan , Huang Xinyi
Published: December 2020

Aiming at the problems of distorted center selection and slow iteration convergence in traditional clustering analysis algorithm, a novel clustering scheme based on improved k-means algorithm is proposed. In this paper, based on the analysis of all user behavior sets contained in the initial sample, a weight calculation method for abnormal behaviors and an eigenvalue extraction method for abnormal behavior set are proposed and a set of abnormal behaviors is constructed for each user according to the behavior data generated by abnormal users. Then, on the basis of the traditional k-means clustering algorithm, an improved algorithm is proposed. By calculating the compactness of all data points and selecting the initial cluster center among the data points with high and low compactness, the clustering performance is enhanced. Finally, the eigenvalues of the abnormal behavior set are used as the input of the algorithm to output the clustering results of the abnormal behavior. Experimental results show that the clustering performance of this algorithm is better than the traditional clustering algorithm, and can effectively improve the clustering performance of abnormal behavior
Sustainable Communication: Cross-Cultural Management of Higher Education Staff in East Coast of Peninsular Malaysia
Authors: Rosila Ismail Isma , Che Noh Che Hasniza , Mohamad Zaleha
Published: December 2020

This study investigates the ethnic and cultural backgrounds of the University Malaysia Terengganu (UMT) personnel to determine the elements of uncertainty avoidance among the staff. As such, the study examines the respondents’ expectations of rules, changes, and creativity in uncertainty avoidance. This study also investigates the differences between respondents’ behaviour in High Uncertainty Avoidance (HUA) or Low Uncertainty Avoidance (LUA) and the extent to which these differences affect communication. Furthermore, this study employed mixed (qualitative and quantitative) methods as a research design, with ethnography as a research approach.  The study data were analysed using the Statistical Package for Social Science (SPSS Version 20) and thematic analysis for an in-depth exploration of the respondents. The result of the study showed that, regardless of ethnicity, common HUA values were shared in the observation of rules and regulations, which reflected the consensual agreement on the importance of observing rules. Concerning changes and adaptation, all the three ethnic groups indicated LUA, with only a small number indicating HUA in this matter. The Malay personnel indicated an especially high LUA, as the future was believed to be too intricate, ambiguous, unpredictable, and hostile for efficient planning. Regarding workplace creativity, all three ethnic groups indicated LUA, with only a small number indicating HUA in this matter. Nevertheless, it is made aware in this study that the results are not representative of the three ethnic populations in Malaysia.
Dizel İçten Yanmalı Motorlarda Silindir İçindeki Hava Hareketlerinin İncelenmesi ve Ölçüm Metodlarının Karşılaştırılması
Authors: YELKEN Burak , SAVCİ İsmail Hakki , DÜLGER Zafer
Published: December 2020

Dizel motorlarda yanma odası içerisindeki yakıt ve hava karışımı tam olarak homojen değildir. Bu karışımın silindir içinde hareketinin davranış özelliklerini çözebilmek için çeşitli modellemeler yapılmış olsa da henüz tam olarak tamamlanmış ve anlaşılmış değildir. Silindir içindeki hava hareketlerinin özellikle motor yanma performansı ve emisyon çıktılarına etkisi büyüktür. Motor emiş sırasında, hava silindir içerisinde girdap ve takla olmak üzere iki farklı hareket yapabilmektedir. Bu çalışmada özellikle girdap hareketi üzerinde durulacaktır. Son yıllarda gelişen lazer ve kamera teknolojileri sayesinde girdap hareketini gözlemleyebilmek ve kaydedebilmek mümkün olabilmektedir.
Bu çalışma kapsamında, çalışmaya özgü olarak, 9l bir dizel motorun hava emiş portunu temsil eden hızlı prototip parça yaptırılmıştır. 9l motor hava emişi temsil eden bu parça üzerinde balpeteği yöntemi kullanılarak girdap katsayıları ölçülmüştür. Yapılan belirsizlik analizi ile yapılan testin hata mertebesi belirlenmiştir. Parçacık görüntülemeli hız ölçümü (PGHÖ) tekniği ile aynı parça üzerinde girdap ölçümü 2 boyutlu ve 3 boyutlu olarak gerçekleştirilmiş ve sonuçlar karşılaştırılmıştır. PGHÖ tekniği için belirsizlik analizi yapılarak hata mertebesi belirlenmiştir. Yöntemler arasında bir karşılaştırma ve uygunluk konusunda değerlendirilme yapılmıştır.
Classical Deities in Astronomy: The Employment of Verse to Commemorate the Discovery of the Planets Uranus, Ceres, Pallas, Juno and Vesta
Authors: Cunningham Clifford J. , Oestmann Günther
Published: December 2020

From 1781 to 1807 five new planetary objects transformed our basic ideas about the nature of the solar system. The coincidental discovery of these objects during a period when classical ideas permeated European thought produced a rich variety of verse in Latin, German, French, Italian and English. For the first time, they are collected here and put into context.
William Herschel’s Wonderful Decade, 1781-1790
Authors: Hoskin Michael
Published: December 2020

William Herschel was a professional musician for fully half his life, and wished to be remembered as a composer. His achievements in astronomy—as telescope builder, observer, and theoretician—that are recognised by the naming of the current Herschel Space Telescope belong mainly to a single mirabilis decas, and this I discuss.