bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Logistic Regression to Determine The Quality of Foreign Tourists to Indonesia
Authors: Agustina Neli , Puspita Chaterina D. , Arifatin Dini , Yordani Ricky 
Published: April 2021

Abstract
Tourism has become a priority sector in the development of the Indonesian economy. Tourism is expected to be a prime mover in accelerating economic growth in Indonesia through job creation and business opportunities, foreign exchange earnings, and infrastructure development. The role of tourism in the Indonesian economy is increasing, in 2018 the contribution of the tourism sector to GDP reached $16.426 million. In terms of quantity, the number of foreign tourists visiting Indonesia in the past five years shows a rising trend. The number of foreign tourists visiting 2018 reached 15.81 million visits, up 12.61 percent compared to the number of visits during 2017. In terms of the quality of foreign tourists, the average expenditure of foreign tourists during the last five years per visit while in Indonesia shows an increasing trend, but growth is still relatively small. This study aims to analyze the determinants in improving the quality of foreign tourists in supporting the tourism sector as the main driver in accelerating economic growth. By using logistic regression analysis, the results show that foreign tourists with the purpose of business visits is 1.41 times greater odds to spend their expenses above the average expenditure than with the purpose of personal visits. Furthermore, based on their nationality, foreign tourists who come from ASEAN continent have greater odds to spend their expenses above the average than the tourist who come from Asia (exclude ASEAN) and Non-Asia countries.
Churn Analysis in Telecommunication Industry Customers Using Semiparametric and Non Parametric Survival Method
Authors: Monika Ade Vreyyuning , Indahwati  , Aidi Muhammad Nur 
Published: April 2021

Abstract
One of the challenges faced by Customer Relationship Management (CRM) of Telecommunication Company is customer retention efforts. The success rate of customer retention can be seen by the customer switching or churn process. Using the background and usage data related to the loyalty of the customers, it can be known the probability that customers will churn at a certain time. To overcome the problem, survival analysis will be carried out with parametric model using Cox Proportional Hazard and non-parametric using Support Vector Machine (SVM) for customer data. The data used in this study are customer data from telecommunication company who subscribe bundling package Internet and IPTV which are taken from 1000 customers in the Jabodetabek area. The time a customer is registered for the first time is defined as the start time and the last observation date is the end time. During the observation period, customer churn time is recorded. Based on the Kaplan Meier curve and log rank test, it is shows that there is a significant difference curve between customers with six different age categories. The results of the analysis found that SVM survival is able to compensate for Cox Proportional Hazard. Based on the result of the concordance index, the performance of the SVM survival has a better performance than Cox Proportional Hazard. One possibility that survival of SVM give a better performance is because the assumption of Cox Proportional Hazard is not met.
Cox Model Survival Analysis to Evaluate Treatment of Electro-Capacitive Cancer Therapy (ECCT) For Cancer Patients
Authors: Purnami S W , Putra R S , Edina A I , Pertiwi I N , Sukur E , Soraya N 
Published: April 2021

AbstractCancer is a disease caused by uncontrolled growth of abnormal cells in the body. Lung cancer, brain cancer and breast cancer are a deadly threat to sufferers. Cancer treatment using a therapy called Electro-Capacitive Cancer Therapy (ECCT) has received a lot of medical attention. Since 2012, the C-Tech Labs Edwar Technology Cancer Research Tangerang has applied ECCT to the therapeutic treatment more than 11,000 cancer patients. In this study, the Cox Proportional Hazard model was used to asses factors that affects survival of cancer patients. Some prognostic factors are evaluated included age of patient and type treatments such as herbs therapy, chemotherapy, radiotherapy and monitoring frequency of ECCT. The all three survival models (breast cancer, brain cancer, and lung cancer) identified the same prognostic factors. The study showed that monitoring frequency of ECCT is significant factor that influenced in cancer survival for all three survival models. Based on the Cox survival model, the hazard ratio (HR) value ranges from are 0.8 – 0.9. It means that each additional one time the frequency of monitoring, the risk of experiencing death decreased by 0.8 – 0.9 times.
Quality of Water Production Process Using Mixed Multivariate EWMA-CUSUM (MEC) Control Chart
Authors: Asmara N H D , Wibawati  , Ahsan M , Mashuri M , Khusna H 
Published: April 2021

Abstract
Human life is highly dependent on clean and freshwater. Therefore, the quality of water used by humans must be properly monitored and controlled. Based on the regulations of the Ministry of Health, the quality of clean water can be monitored from the parameters of physics, chemistry, and microbiology. The main characteristics of water quality are turbidity level, organic substance, and chlorine residual which are correlated with each other. This research proposes the combination of MEWMA and MCUSUM charts called MEC control chart for monitoring the process mean of water quality with the variables used are turbidity level, organic substance, and chlorine residual. This charting method is divided into two-part, namely MEC1 and MEC2. Further, the water production process is characterized by dry and rainy seasons. Based on the analysis results, it is found that the optimum λ in the production process during the dry and rainy season for the MEC1 control chart is 0.3. Meanwhile, the optimum λ in the production process during the dry and rainy season for the MEC2 control chart is 0.1. In this condition, the MEC1 control chart is more sensitive than the MEC2 control chart because of the higher number of out of control observations. Moreover, the organic substance is the main issue causing the out of control observations during the dry and rainy season. In the capability process analysis, the process of water production during the dry and rainy season is said to be capable because the capability index of the turbidity level is larger than the specification limit. On the other hand, the water production process with organic substance and chlorine residual are not capable due to the lower capability index compared to the specification limit.
Generalized Structural Equations Approach in the of Elderly Self-rated Health
Authors: Bagheri Arezoo , Saadati Mahsa 
Published: April 2021

Abstract
To model classified and ordinal data, the Generalized Structural Equation Model (GSEM), which is based on the integration of two generalized linear model (GLM) and Structural Equation Modeling (SEM) algorithms, is applied. Unlike the SEM, this model does not require the normality assumption. The main purpose of this paper is to introduce and compare weighted (WLSMV) and unweighted (ULSMV) least squares mean and variance adjusted methods, two of the most applicable estimators of GSEM, for studying factors affecting the elderly self-rated health in 2015 in Tehran, Iran. 600 elderly people aged 60 years and above from 22 regions of Tehran were selected using multi-stage sampling. Self-rated health of the elderly variable (a 5-point Likert scale) was analyzed as an ordinal variable and was modeled considering the variables of social support, financial and environment security, spirituality, mental and physical health, functional health and health-related behaviors by Mplus software. The results showed that WLSMV outperformed ULSMV according to the smaller values of RMSEA and larger values for CFI and TLI indexes (RMSEA WLSMV = 0.04, CFI WLSMV = 0.965, and TLI WLSMV = 0.936). To prevent concluding invalid results in studying ordinal data due to considering them as a continues variable, it is important selecting correct statistical method according to the type of variables.
Spatial Clustered Regression Analysis of 2017 Getis Score Indonesian Malaria Prevalence Data
Authors: Sukmawati Suci , Djuraidah Anik , Wigena Aji Hamim 
Published: April 2021

AbstractMalaria is a disease that is still endemic to Indonesia. In the national scale, morbidity rate related to malaria continued to decline from 2009 to 2017. Eastern areas of Indonesia (namely Papua, West Papua, and East Nusa Tenggara) still have high endemic levels of malaria, while western areas (Islands Sumatera and Java) mostly have low endemic levels or even free of malaria. This indicates that malaria has a clustering pattern. This research used the Annual Parasite Incidence (API) data as the dependent variable and Slide Positivity Rate (SPR), Annual Blood Examination Rate (ABER), number of positive cases on children aged 1-14 years, and the number of Plasmodium falciparum cases and Plasmodium vivax cases data as the independent variables. Since they contain spatial autocorrelation, Getis Ord G_i were employed in the clustered regression analysis. Finite Mixture Model was employed as the clustering method. This study resulted in the forming of 3 clusters. Cities/regencies belonging to Cluster-1 were neither hotspots nor coldspots. Elements of Cluster-2 are SPR hotspots. Elements of Cluster-3 are hotspot areas of API, ABER, number of Plasmodium falciparum cases, number of Plasmodium vivax cases, and number of cases on children aged 1-14 years. Cluster-1 consists of 360 cities/regencies located in Islands Kalimantan, Sulawesi, Sumatera, and Java, and North Maluku Province. Cluster-2 consists of 88 cities/regencies, mostly located in provinces South Sumatera, Bengkulu, Lampung, Banten, DKI Jakarta, and West Java. Cluster-3 consists of 66 cities/regencies located in the Papua Island and East Nusa Tenggara Province.
Clustering of Commodity Inflation Pattern based on Estimated ARIMA Model
Authors: Hendrawati T , Wigena A H , Sumertajaya I M , Sartono B 
Published: April 2021

Abstract
Clustering is the stage that is carried out before further data analysis. There are many approach method that can be used for clustering time series data, one of which is the model-based approach. In this study, we clustering inflation data used the ARIMA model. The cluster model is carried out after obtaining the clusters. The similarity between time series is measured using the development of Piccolo distance. Furthermore, the Ward hierarchical method is used for clustering. The Silhouette averaging method is used to determine the optimal number of clusters. The cluster model can be used to represent individual models. The cluster model is more effective than creating all individual models.
State Mapping of the Public Health Development Index in Aceh Province using K-Medoids method
Authors: Rahayu L , Rusdiana S , Mahdi S , Safitri W D , Ikhwan M , Sari N , Akhdansyah T 
Published: April 2021

Abstract
Health level mapping is necessary to obtain information on the state of public health in Aceh Province. The study analyzed the clustering of districts/cities in Aceh Province using the Aceh Province Public Health Development Index (PHDI) in 2013 and 2018, which was sourced from the Aceh Health Office. The analytical method used is the K-Medoids grouping method. The results of this study indicate that 4 clusters are consisting of 3 conditions, namely the district/city cluster with a good health level, the district/city cluster with a medium health level, the district/city cluster with a low health level. Districts/cities that experienced significant changes in health levels in 2013 and 2018 are Aceh Besar, Lhokseumawe, Aceh Jaya, Pidie Jaya, Aceh Timur, Gayo Lues, and Simeulue. Meanwhile, Banda Aceh, Sabang, and Langsa city always occupy a cluster position with a high level of health.
Adjustment Pattern of pH Using Random Forest Regressor for Crop Modelling of NFT Hydroponic Lettuce
Authors: Mara M N , Helmy  , Nursyahid A , Setyawan T A , Sriyanto A 
Published: April 2021

Abstract
IoT makes it possible to automatically adjust pH based on sensor numerical data for NFT hydroponic lettuce. In this research, we use sensors of light intensity, farm temperature, farm humid, reservoir level, reservoir temperature, humid on the outside farm, outside farm temperature at Kartika Farm and Turus Asri. Data were taken for five cropping periods. We got different adjustment pattern of pH based on these sensors and Total Dissolved Solids (TDS) control. Furthermore, Kartika Farm’s cropping was different from Turus Asri. In a kilogram of Kartika Farm cropping ingredient seven holes of hydroponic lettuces while Turus Asri cropping ingredient ten holes of hydroponic lettuces. Economically, Kartika Farm harvests more benefits than Turus Asri. In this research, we modeling the pattern of pH adjustment at Kartika Farm using random forest regression. The result showed that the important variable for pH adjustment modeling is water level, TDS and green house humidity. We got an accurate value for the model is 78,37% with MAE and MSE consecutively 0.19 and 0.15.
Research of gel systems stability in relation to additive technologies
Authors: Pokusaev B G , Vyazmin A V , Karlov S P , Zakharov N S , Sulyagina O A 
Published: April 2021

AbstractThe study of thermokinetics and rheology of gel systems based on agarose gel was performed. The dependences of the spectral characteristics of both pure gels and gels with special additives in the conditions of the “cooling-heating-cooling” transition process are obtained. The effect of hysteresis of the studied samples during the transition from a liquid solution to a gel and back was found. The presented results can be useful for the development of a promising 3D-bioprinting technology, for the design and selection of operating modes of printing devices.
On Spiral Turbulent Flow in an Annular Concentric Channel
Authors: Ignatenko Ya S , Gavrilov A A , Bocharov O B 
Published: April 2021

Abstract
The paper presents the results of Newtonian-fluid spiral flow simulation in an annular channel. The simulation parameters were dimeters ratio of 0.5; Re = 100 ÷ 10,000 and dimensionless inner cylinder rotation rate χ = 0.2 ÷ 5. The turbulent flow regimes were simulated using URANS, a non-stationary statistical turbulence model. While simulation, the following flow regimes were detected: homogeneous flow without pronounced structures (Re = 100, χ⩽3 and Re=300, χ⩽0.5); flow with Görtler-type continuous spiral vortices near inner cylinder (Re = 300, χ=1 and Re = 1000 ÷ 10000, χ = 0.5); flow with Taylor-type vortices (Re = 100, χ⩾3 and Re = 300, χ⩾3); flow with small-scale Görtler-type vortices near both channel walls (Re ⩾ 1000 and χ⩾1). The spiral spin of Görtler-type vortices near the outer cylinder was co-directed with the rotation of the inner cylinder, while the vortices near the inner cylinder spin against the rotation. Formation of large Taylor-type vortex structures led to a decrease in the channel skin friction coefficient faRe. Görtler-type vortices interaction near the channel walls triggered the formation of small-scale structures increasing in the channel resistance as the Reynolds number and rotation speed grew.
Experimental study of the effect of surfactants on the characteristics of waves in three-dimensional wave regimes
Authors: Kvon A Z , Guzanov V V 
Published: April 2021

Abstract
Effect of a surfactant Triton X-100 on three-dimensional wave regimes of the falling liquid film flow was experimentally studied. The shadow method and laser induced fluorescence measurements revealed that for surfactant concentrations at which complete suppression of wave motion is not observed, the flow characteristics at the three-dimensional wave regime differ from the characteristics of a pure water flow. Most likely, these differences are associated with differences in the structure of flows under the three-dimensional wave, which were revealed by simultaneous measurements of the thickness and volumetric measurements of the velocity in the wave at the initial section of the flow. For films with the surfactant concentration of 2000 mg/l, the capillary ripples in front of the three-dimensional wave are weakly expressed, there are no backflows, and transverse flows in the area of the capillary precursors are much weaker than in the case of pure water.
The numerical investigation of the oil displacing efficiency from the pore in the rock formation depending on the width and height of the pore
Authors: Lobasov A S , Minakov A V 
Published: April 2021

Abstract
The calculated study of the oil displacing by the water from straight microchannels, which simulate a pore in the rock formation, was carried out. The Reynolds numbers were varied in the range from one to 1000. The channel’s width and height were in the range of 100 μm to 800 μm. The «Volume of Fluid» (VOF) numerical method with the «Continuum Surface Force» (CSF) algorithm was used. It was found that the oil recovery coefficient increases with a decrease in the height of the pore microchannel and with an increase of its width. In case of constant channel width, the oil recovery coefficient: increases in the ranges of Reynolds numbers from 1 to 50 and from 100 to 400 and decreases in the ranges of Reynolds numbers from 50 to 100 and from 400 to 1000. In case of constant channel height, the oil recovery factor behaves as follows: at h = 100 μm it slightly increases in a whole range of Reynolds numbers; at h = 200 μm its behaviour is the same the in case of constant channel width; at h = 400 μm it sharply increases in the ranges of Reynolds numbers from one to 50 and slightly decreases in the ranges of Reynolds numbers from 50 to 1000; at h = 800 μm it sharply increases in the ranges of Reynolds numbers from one to 100 and sharply decreases in the ranges of Reynolds numbers from 100 to 1000. Such behaviour in both cases can be explained by the competition between the forces of inertia and capillary, but further research is needed for a more complete understanding. It was also found that, in almost all cases, the oil recovery coefficient does not exceed 10%. It follows that water is a poor washing agent in terms of oil recovery from reservoirs.
Affordable Housing For the Middle-Income Group in Malaysia
Authors: Abdullah Yusfida Ayu , Jamaluddin Nor Baizura , Yakob Hamizah , Marzukhi Marlyana Azyyati , Zaki Zulkifli Ahmad 
Published: April 2021

Abstract
One of the most fundamental human needs is a house. While urbanization occurs tremendously in the cities of Malaysia, the middle-income groups living in the urban areas are facing greater challenges in house ownership. The middle-income households continuously experience issues of affordability, access to finance and availability. This paper presents a study on the delivery system of affordable housing. In this study, an assessment of affordable housing delivery system was conducted by examining the urban middle-income group in relation to the process of affordable housing provision. The study therefore aims at examining the current affordable housing policies and delivery system, with the focus on the middle-income group, which concentrates on assessing house buyers’ experience and perception in relation to the practice of providing affordable housing for the middle-income. Using a mixed-method approach, the study employs a quantitative and a qualitative technique in conducting the study. A case study approach was exercised by means of investigating the PR1MA Corporation and SPNB as case studies. Results demonstrated that there are many constraints in the delivery system from the qualitative analysis and the respondents’ perspective. The experience by the house buyers can be useful for authorities and other providers in the future development.
The use of Trifloralin Herbicide, cultivation distances and cultivation method to control the weeds accompanying the local barley crop (Hordeum vulgare L.)
Authors: Hayawi Jassim Abdullah , Walid Taha Muhammad Amin , Hamad Abdulmueem Shabeeb 
Published: April 2021

Abstract
The research was conducted in the fields of the Agricultural Technical College / Mosul to combat the weed associated with the barley crop for the winter season 2019/2020 to as a method of integrated control management. The research included three factors: The first factor is the two levels Trifloralin Herbicide (the concentration of 1248 cm3 active substance / e and the comparison treatment) and the second factor is the cultivation distances at two levels (15, 30) cm. As for the third factor, cultivation methods are also at two levels (orthogonal cultivation, conventional cultivation). The experiment was applied according to the system of global experiments in split – split block by designing the complete random sectors with three replicates. The most important results are summarized as follows: The three factors: Trifloralin herbicide and the narrow distance (15) cm between the row and cultivation achieved a significant decrease in the number of narrow-leaf weeds / m2, number of tillers for narrow-leaved weeds / m2, dry weight of the narrow-leaf weeds and the number of broad-leaved weeds, while no significant effect appeared between the two cultivation methods on the dry weight of the broad-leaved weed. The interference between the herbicide and the distance (15) cm, and the interference between the herbicide and orthogonal cultivation, and the interference between the distance (15) cm and orthogonal cultivation, as well as the triple interference between the herbicide and the distance (15) cm orthogonal cultivation, achieved a significant decrease in all studied characteristics.
Study of the Contamination of Soils Irrigated from Diwaniyah River with Lead / Iraq
Authors: Jarallah Raid Shaalan , Al Husseini Huda Mahdi Haraj 
Published: April 2021

Abstract
This study was conducted to find out the effect of adding different pollutants (sewage water, liquid industrial water and heavy water) throwing into the river in Diwaniyah governorate on the concentration of Lead in river water and the effect of irrigation on the presence of this element in the soils during the different seasons of the year.
Soil samples were taken for two dimensions, the first at a distance of 100-150 meters from the source of pollution and for three depths, the first depth 0-30 cm, the second depth 30-60 cm, the third depth 60-90 cm, and the second dimension samples were taken at a distance of 5-5.5 km from the same source and also for three depths and three iterations for all sites and during four seasons: summer (July) 2019, autumn (October) 2019, winter (January) 2020, spring (April) 2020 with three locations, the first site is located at the entrance of Diwaniyah city (Sania area), which represents the control treatment as it is located before the various pollution ports that flow into the river (such as sewage, hospital waste, factory waste, sewage … etc) and the second site in the city center (Rifaat quarter) and the third site in the (Sudair area), which represents the last site of the Diwaniyah city after the end of all estuaries and sources of pollution.
The results of the study were reached that the soil contamination with Lead was highest in the surface layer compared to the other of the depths, and the first dimension (100-150) m from the source of pollution is the highest compared with the second dimension (5-5.5) km, this indicated to a decrease in Lead concentration while moving away from the source of pollution. The highest concentration of Lead in the summer was 3.11 micrograms. Kg−1 in the first depth of the third site at a distance of (100-150 m), while the lowest concentration in the winter was 0.22 micrograms.Kg−1.
At the third depth of the first site at a distance (5-5.5) km, this indicates that Lead contamination of soils is highest in the surface layer and increases with the slope of the river, and the concentration of Lead was decreasing with depth in all four seasons of the year and for all studied sites.