bluuebunny/crossref_metadata_2025_split huggingface dataset:
Restricted Ridge Regression estimator as a parameter estimation in multiple linear regression model for multicollinearity case
Authors: Rumere F A O , Soemartojo S M , Widyaningsih Y 
Published: January 2021

AbstractMultiple Linear Regression analysis is one of the techniques in statistics that is used to analyse the relationship between a dependent variable and two or more independent (regressor) variables. Ordinary Least Square method is commonly used to estimate the parameters. Most frequently occurring problem in multiple linear regression analysis is the presence of multicollinearity. Multicollinearity in the least square estimation produces estimation with a large variance, so another method is needed to overcome the multicollinearity. The method is called ridge regression. In this method, a constant bias ridgekis added toX′Xmatrix. A study had developed the method by using the prior information of the parameter β and introduced the Restricted Ridge Regression method. Prior information of the parameter β was defined as a non-sample information arising from past experiences and the opinions of an expert with similar situations and containing the same parameters β. This study explains the use of Restricted Ridge Regression method in overcoming the multicollinearity in regression model. Based on an application on a data set, β of Restricted Ridge Regression has smallest mean square error (MSE) than β of Ordinary Least Square.
Predicting readmission risk after coronary artery bypass graft surgery using logistic regression model
Authors: Febriani V , Lestari D , Mardiyati S , Devila S 
Published: January 2021

Abstract
Coronary Artery Bypass Graft (CABG) post-operative readmission has a high incidence rate compared to other health cases. This particular case contributes to an increase in morbidity and hospital costs of patients. Therefore, an appropriate prediction model is needed while the model can be beneficial to the health financing institutions. There are many risk factors that will be used to predict CABG post-operative readmission. Of the many risk factors observed, some factors that have a significant influence on construction the Logistic Regression model will be determined. This model is developed to generate probabilities which are then called Created Readmission Risk Scores (CRRS).
Odd graceful labeling on the Ilalang graph (Sn
, 3) it’s variation
Authors: Amri Z , Irvan I , Maryanti I , Sumardi H 
Published: January 2021

Abstract
A graph called odd graceful graph if there is an injective mapping f:V(G) → {0,1,2,…,2q − 1} such that for each edge xy 6 E(G) labeled by |f(u) − f(v)|, and the results willform a label on the edge {1,3,5, …,2q − 1} which is bijective. Variabel q is the number of edges. This paper purpose is to construct the formula of odd graceful labelling on the ilalang graph (Sn
, 3) and it’s variation.
The relation between prior knowledge and students’ mathematics reflective thinking ability
Authors: Muntazhimah M , Turmudi T , Prabawanto S 
Published: January 2021

Abstract
The reflective thinking ability is one of the higher order thinking skills (HOTS), and mathematics reflective thinking is one of the abilities needed in learning mathematics. This study aims to reveal the relation between prior knowledge and mathematics reflective thinking ability which studied by quantitative method. Data collection used instruments of mathematics reflective thinking test. Samples in this study were students of class VIII at junior high school. The results showed that there was a positive relation between prior knowledge and students’ mathematics reflective thinking ability with the correlation coefficient 0.49. The regression equation shows that each addition of one prior knowledge score was followed by change in increase in students’ mathematics reflective thinking ability by 0.5539. It can be concluded that the prerequisite material as a prior knowledge must be thoroughly learned so as to have a large contribution to the success of learning further material.
Development of learning device oriented problem based learning to improve student’s mathematical problem solving skill
Authors: Siagian T A , Armanto D , Siagian P 
Published: January 2021

Abstract
This research study is research and development learning devices. The purpose of this study were: 1) Developed problem-based on learning tools with criteria are valid, practical, and effective; 2) Described the improvement of mathematical problem solving skills of student using learning device based on problem based learning developed. Learning device development using 4-D model which developed by Thiagarajan, Semmel and Semmel, was done in two stages: 1) the development of learning devices; and 2) testing devices. The subject in this study were students of class X SMAN 1 Pematangsiantar, while the objects is the PBL developed, mathematical problem solving skill students. The results were obtained: 1) The learning devices based on PBL that developed have valid criteria, practical and effective; 2) There is an increased ability of mathematical problem solving skill of student using learning device based PBL developed.
The effect of doping variation on band gap energy and crystal structure of Biochar/TiO2 thin layer
Authors: Fahyuan H D , Deswardani F , Nurhidayah N , Afrianto M F , Heriansyah H , Nazaruddin N , Nelson N 
Published: January 2021

Abstract
The biochar/TiO2 thin layer has been made by using the sol-gel method and the coating technique by Doctor Blade method. The variation of biochar on TiO2 were 0%, 1%, 2%, 3% and 4%. The characterization was done by using XRD (X-Ray Diffractometer) to see the crystal structure of samples and UV-Vis spectrophotometer to obtain the value of band gap energy. Based on XRD data, it was obtained that the crystal structure of all samples is anatase TiO2. The crystalline size of all samples has no significant difference by the increasing of doping percentage. The smallest crystal size was at the addition of 3% and 4% bio char which was 118.22 nm. The results of UV-Vis characterization showed the lowest value of band gap energy was at sample doping 1% bio char which was 3.25 eV. Band gap energy value for doping sample above 1% showed an increase of band gap energy of Biochar-TiO2.
Driving energy to accelerate the adiabatic electron dynamics in quantum Hall system
Authors: Setiawan I , Syarkowi A , Syatyatuhu A , Gunara B E 
Published: January 2021

Abstract
We study a scheme of accelerated adiabatic quantum dynamics. This scheme was originally proposed by Masuda-Nakamura. The strategy of combining two opposite idea: infinitely-large time-magnification factor (ᾱ) and infinitely-small growth rate (ɛ) of adiabatic parameter was elucidated. We apply the proposed method to the Hall system with electric and magnetic field and obtain regularization term, driving potential VFF
and driving Hamiltonian HFF
to accelerate the system. The driving potential VFF
and the driving Hamiltonian HFF
to be able to accelerate adiabatic electron dynamics in the ground state trapped in the plane xy and electric field in the x direction and a constant magnetic field in y direction.
Development of ARIMA technique in determining the ocean climate prediction skills for pre-service teacher
Authors: Rosmiati R , Liliasari S , Tjasyono B , Ramalis T R 
Published: January 2021

Abstract
The lack of community understanding of the predictions of the ocean climate is key to addressing the impacts and crisis of the ocean climate. The aims of this study is to explain the stages of ocean climate prediction skills using the ARIMA technique for pre service teacher students as beginner learners and provide solutions to build a conscious and responsive attitude to the ocean climate. The data used is Sea Surface Temperature (SST) Niǹo 3.4, analysis the stages of the Autoregressive Integrated Moving Average (ARIMA) model used MINITAB 16.0 and Microsof Excel that has been developed then applied by 3 respondents. Based on the results of the study, more detailed stages of the arima model and n 3 respondents both got a correlation value of 0.96 for Nino SST 3.4 original value and model value, correlation 0.92 for 1 year validation and correlation 0.99 ENSO prediction for 1 year (12 months) ahead. Thus the development of the ARIMA model stage is very effective to be used to predict climate such as ENSO events and other ocean climate phenomena.
Improving activities and learning outcomes of biology education students through learning Problem-Based Learning model of entrepreneurship
Authors: Yani A P , Parlindungan D , Yennita Y 
Published: January 2021

Abstract
This study aims to describe the activities of lecturers, student activities and student learning outcomes on creative thinking material in biology study programs, by applying the Problem-Based Learning (PBL) learning model. This type of research is classroom action research (CAR) with descriptive methods. This research was conducted in 2 cycles, each cycle consisting of 4 stages: planning, implementing, observing and reflecting. Research subjects are lecturers and all semester 5th students of biology study programs. The research variable is the learning model Problem-Based Learning and student learning outcomes. Data collection techniques used are observation and tests. While the research instruments consisted of observation sheets and test sheets. The results of the analysis of lecturer activity data in cycle 1 obtained an average of 33.5 (good) and cycle 2 rose to 35 (good). The results of the analysis of student learning activity data cycle 1 obtained an average score of 29 (good) cycle 2 increased to 34 (good). Student learning outcomes tested by the T-test showed that significantly showed an increase in the value of learning outcomes in cycle 1 (3.02439) and in cycle 2 (7.26829). It was concluded that the Problem-Based Learning (PBL) learning model can improve student learning activities as well as student learning outcomes that take entrepreneurship courses in Biology education courses.
An experimental study on tribological properties and air tightness of co-textured cylinder liner-piston ring on an engine tester
Authors: Miao Chenwei , Guo Zhiwei , Yuan Chengqing 
Published: January 2021

Abstract
The performance of cylinder liner-piston ring (CLPR) affects the efficiency of marine engine greatly. An experimental study on textured CLPR was conducted to seek insight into the operation reliability of CLPR. Three types of surface texture, groove texture on cylinder liner, dimple texture on piston ring, and co-texture on both sides, were processed. A series of tests were then carried out on an engine tester. Three characterization parameters, contact resistance, worn surface topography on cylinder liner, and cylinder pressure were used to describe the CLPR tribological properties and air tightness. The results showed that the three textures all improved tribological properties. Compared to the non-textured surface, the contact resistance of the three textures increased 30.7%, 71.7% and 98.4% on average. The wear resistance of dimple texture was weaker than that of groove texture. Air tightness was closely related to oil film pressure. At dead centre, the cylinder pressure of the three textures respectively was optimized by 4.6 kPa, 7.8 kPa and 12.3 kPa averagely. The co-texture was shown to combine the advantages of groove texture with the advantages of dimple texture, which provided the surface with improved oil film distribution and more efficient debris trapping, resulting in the optimum tribological properties and air tightness among the three textures.
Parametric optimization and analysis of cavitation erosion behavior of Ni-based + 10WC microwave processed composite clad using Taguchi approach
Authors: Bansal Sandeep , Mago Jonty , Gupta Dheeraj , Jain Vivek 
Published: January 2021

Abstract
This study aims to develop cavitation erosion-resistant clads on stainless steel (SS-316) using the microwave cladding technique. Ni-based alloy powder (EWAC) was reinforced with tungsten carbide (10% by wt) powder to obtain composite clads. The cladding process was carried out in a domestic microwave applicator of 2.45 GHz frequency with 900 W power. The microstructure, crystal structure (phase identification and quantification), and microhardness of the developed clad were investigated with scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), x-ray diffraction (XRD), and Vickers microhardness tester, respectively. It was found that the deposited clad has a uniform thickness of ∼520 μm, and the microstructure mainly consists of equally dispersed and agglomerated carbides in cellular like Ni-Matrix. XRD analysis reveals that the composite clad was composed of various intermetallic, carbide, and oxide phases. The EWAC + 10WC clad (625 ± 81 HV0.3) has a hardness ∼3.5 times higher than the stainless steel substrate (195 ± 15 HV0.3). The cavitation erosion behavior of the SS-316 and EWAC + 10WC clad was examined by using a vibratory cavitation test apparatus. The parametric cavitation erosion testing was conducted according to the Taguchi L9 orthogonal array (OA) to study the effects of variations in amplitude (AMP), immersion depth (ID), and standoff distance (SOD) on mass loss in SS-316 and composite clad. The parametric study results show that SOD was the most influential test parameter, followed by AMP and ID. SOD contributes more than 50% in the mass loss of SS-316 and clad specimens, whereas AMP and ID contribution was around 32%–37% and 7%–11%, respectively. The developed EWAC + 10WC clad performed ∼6.7 times better than the SS-316. Nevertheless, the SS-316 and EWAC + 10WC clad specimens got severely damage in the form of pits, craters, plastic deformation, lip formation, impingement marks, and secondary cracks.
HUNTER: precision massive-neutrino search based on a laser cooled atomic source
Authors: Martoff C J , Granato F , Palmaccio V , Yu X , Smith P F , Hudson E R , Hamilton P , Schneider C , Chang E , Renshaw A , Malatino F , Meyers P D , Lamichhane B 
Published: January 2021

Abstract
We describe a project that brings together researchers from atomic physics, nuclear physics and sub-atomic particle physics, to develop a high-precision laboratory-scale experiment able to search for very weakly coupled sterile neutrinos in the mass range extending from 5–10 keV/c
2 to several 100 keV/c
2. Observed neutrino flavor eigenstates are known to be quantum mixtures of at least three sub-eV/c
2 mass eigenstates. There is a strong theoretical belief that there may exist further neutrino mass eigenstates at higher mass levels, and which, if in the keV/c
2 mass range, might form all or part of the galactic dark matter. This has led to many searches for anomalous events in both astrophysical and particle physics experiments, and searches for distortions in beta decay spectra. The present experiment will utilize K-capture events in a population of 131Cs atoms suspended in vacuum by a magneto-optical trap (MOT). Using AMO and nuclear physics techniques, individual events will be fully reconstructed kinematically. Normally each event would be consistent with an emitted neutrino mass close to zero, but the existence of a sterile neutrino of keV/c
2 mass that mixes with the electron type neutrino produced in the decay would result in a separated population of events with non-zero reconstructed missing mass (up to the Q = 352 keV available energy of the reaction). Detailed calculations and simulations of all significant background processes have been made, in particular for scattering in the source itself, radiative K-capture, local radioactivity, cosmic ray muons, and knock-out of electrons by x-rays. A phase 1 of the experiment, under construction with funding from the W M Keck Foundation, has the potential to reach sterile neutrino mixing angles down to sin2
θ ∼ 10−4. With further upgrades this technique could be progressively improved to eventually reach much lower coupling levels ∼10−10, in particular reaching the level needed to be consistent with galactic dark matter below the astrophysical x-ray limits.
Photonic nanojets and their applications
Authors: Darafsheh Arash 
Published: January 2021

Abstract
Dielectric microelements with circular symmetry have shown interesting optical properties: photonic nanojets (PNJs) and whispering gallery modes (WGMs). They can confine light inside the cavity, forming WGMs, or focus the light in their proximity, forming PNJs. Both WGMs and PNJs have found numerous applications, including sensing and imaging. In this work, a review of PNJs and their applications in contemporary literature is provided.
Enantiomeric Separation and Thermodynamic Investigation of (R)-N-Tert-Butoxy Carbonyl-Piperidine-3-Carboxylic Acid Hydrazide, a Key Starting Material of Zidebactam
Authors: Rane Vipul P , Ahirrao Vinod K , More Kiran B , Yeole Ravindra D 
Published: January 2021

Abstract
A new selective, accurate and precise chiral high-performance liquid chromatography method for the separation of (R)-N-tert-butoxy carbonyl-piperidine-3-carboxylic acid hydrazide (RE) and its enantiomer was developed. RE is a key starting material of novel β-lactam enhancer drug Zidebactam. Chiral resolution of more than 10 was achieved on Chiralpak IA column using mobile phase consisting of n-hexane, ethanol in the ratio of 70:30, v/v. The flow rate of the mobile phase was 1.0 mL min−1 and the column oven temperature was 30°C. Detection was carried out at 225 nm. The developed method was validated as per the International Conference on Harmonization guideline. Limit of detection and limit of quantification of the enantiomeric impurity (S)-N-tert-butoxy carbonyl-piperidine-3-carboxylic acid hydrazide (SE) was 2.5 and 7.5 μg mL−1, respectively. Mean recovery of the SE was 96.83 ± 1.4%. The effect of thermodynamic parameters on the chiral separation was evaluated.
Esophagectomy combined with off-pump coronary artery bypass grafting through left posterolateral incision is safe and feasible for esophageal cancer associated with coronary artery disease
Authors: Ding C-Z , Wang G-L , Wang H-T , Wang W-G , Wang L , Wang P-F , Zhu R-J , Liu X , Wang J-H , Wang J , Zhao S 
Published: January 2021

Summary
Controversy still exists as to whether surgical treatment has any impact on the long-term survival of esophageal cancer (EC) patients with coronary artery disease treated with curative esophagectomy combined with off-pump coronary artery bypass grafting (OPCABG). Therefore, the aim of this study was to introduce and assess the effect of esophagectomy combined with OPCABG on both short- and long-term outcomes. From January 2010 to January 2015, 1428 EC or esophagogastric junction cancer patients underwent surgical treatment at Henan Chest Hospital, Zhengzhou, China. The clinical data of 25 patients who underwent EC resection through a left thoracotomy following OPCABG and the perioperative characteristics and follow-up results were analyzed. The majority of the patients were male, and the EC stage was predominantly cT2N0-1M0 II. The most common pathological types were squamous cell carcinoma. The EC surgeries consisted of 15 chest anastomosis procedures and 10 cervical anastomosis procedures with aortocoronary graft implantation (mean: 2.36 grafts per patient). The mean total operative time was 330.8 ± 83.5 minutes. The median intensive care unit and hospital lengths of stay were 1.72 and 21.16 days, respectively. Resection without macroscopic residual disease (R0) was achieved in all of the patients. The most frequent complications included pulmonary infections (24%), arrhythmias (24%), pleural effusion (12%), and esophageal anastomotic leakage (8%). There were no postoperative deaths or myocardial infarctions within 30 days after the surgery. The overall 1-, 3-, and 5-year survival rates were 88%, 40%, and 24%, respectively, with a median survival time of 43 months. In the short-term, radical resection of EC following OPCABG is a safe and feasible treatment with low postoperative mortality rates. In the long-term, simultaneous surgery is acceptable and is associated with favorable overall and disease-free survival.
Factors influencing development of non-cardiac chest pain after endoscopic submucosal dissection for esophageal neoplasms: a retrospective case–control study of 309 patients from a single center
Authors: Zhao Dian , Liu Ying , Wang Lei , Xu Guifang , Lv Ying , Ling Tingsheng , Zhang Xiaoqi , Liang Ying , Wang Erhua , Zhang Yiyang , Zou Xiaoping , Zhang Bin 
Published: January 2021

Summary
Endoscopic submucosal dissection (ESD) is widely used for early stage esophageal cancer and precancerous lesions. Non-cardiac chest pain (NCCP) is a frequent complication of ESD. However, little is known about its incidence and associated factors. This study investigated the pain incidence and predictive factors for pain development after ESD for esophageal neoplasms. We enrolled a total of 309 patients with esophageal neoplasms, who underwent ESD in our center from January 2018 to June 2019. Sociodemographic and clinicopathological information for all patients was collected, and patients were divided into either a pain-free group (n = 156) or a pain group (n = 153) according to whether there was onset of NCCP 24–48 hours after surgery. We made comparisons between groups using Student’s t test or the χ2 test. Logistic-regression analysis was used to screen for risk factors. There were statistically significant differences in histories of previous surgery (P = 0.039), lesion size (P = 0.026), operation time (P = 0.009), and postoperative fever (P = 0.001). History of previous surgery (P = 0.043) and postoperative fever (P = 0.007) were independent risk factors for chest pain after esophageal ESD treatment. Chest pain and fever prolonged postoperative hospitalization time (P = 0.005, P = 0.001) and increased hospitalization cost (P = 0.034, P &lt; 0.001). A history of previous surgery and postoperative fever was associated with the occurrence of NCCP after ESD in patients with esophageal neoplasms. NCCP and fever after esophageal ESD increased both hospitalization time and cost.
Blood flow characteristics after aortic valve neocuspidization in paediatric patients: a comparison with the Ross procedure
Authors: Secinaro Aurelio , Milano Elena Giulia , Ciancarella Paolo , Trezzi Matteo , Capelli Claudio , Ciliberti Paolo , Cetrano Enrico , Curione Davide , Santangelo Teresa Pia , Napolitano Carmela , Albanese Sonia B , Carotti Adriano 
Published: January 2021

Abstract

Aims
The aortic valve (AV) neocuspidization (Ozaki procedure) is a novel surgical technique for AV disease that preserves the natural motion and cardiodynamics of the aortic root. In this study, we sought to evaluate, by 4D-flow magnetic resonance imaging, the aortic blood flow characteristics after AV neocuspidization in paediatric patients.

Methods and results
Aortic root and ascending aorta haemodynamics were evaluated in a population of patients treated with the Ozaki procedure; results were compared with those of a group of patients operated with the Ross technique. Cardiovascular magnetic resonance studies were performed at 1.5 T using a 4D flow-sensitive sequence acquired with retrospective electrocardiogram-gating and respiratory navigator. Post-processing of 4D-flow analysis was performed to calculate flow eccentricity and wall shear stress. Twenty children were included in this study, 10 after Ozaki and 10 after Ross procedure. Median age at surgery was 10.7 years (range 3.9–16.5 years). No significant differences were observed in wall shear stress values measured at the level of the proximal ascending aorta between the two groups. The analysis of flow patterns showed no clear association between eccentric flow and the procedure performed. The Ozaki group showed just a slightly increased transvalvular maximum velocity.

Conclusion
Proximal aorta flow dynamics of children treated with the Ozaki and the Ross procedure are comparable. Similarly to the Ross, Ozaki technique restores a physiological laminar flow pattern in the short-term follow-up, with the advantage of not inducing a bivalvular disease, although further studies are warranted to evaluate its long-term results.