bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parameter estimation for binary time series using partial likelihood
Authors: Nadiya I , Widyaningsih Y , Sarwinda D 
Published: January 2021

Abstract
A time series with binary response variable is called a binary time series. Binary time series can be modelled using the Autoregressive general model and nonlinear regression approach. Kedem & Fokianos introduced a binary time series model through the Autoregressive and logistic regression approach. The parameters of binary time series are estimated using the Partial Likelihood method. The Partial Likelihood method is performed by determining the Partial Likelihood function derived from the marginal probability density function (pdf) of Bernoulli distribution. However, in the process of parameter estimation using this method, the form of final function to obtain parameters is not in the closed form equation. To face this problem, Fisher scoring iterations are performed. The application of parameter estimation of the model uses the data about boat racing competition between the University of Cambridge and Oxford University from 1946 to 2011. Based on the data application, parameter estimation of the binary time series model using partial likelihood with different amounts of data resulting in a relatively same or no significant parameter estimator.
Lindley–exponential slash distribution
Authors: Dwiki M , Nurrohmah S , Novita M 
Published: January 2021

AbstractThere is a problem arising when Lindley distribution is used to model right–skewed and unimodal data, which lies in its inability to model data with its peak farther from 0. A modification is required to increase the flexibility of this distribution, with “transformed–transformer” being one of the proposed method. This method is done by making a composition of two random variables through their respective distribution functions, with random variable T being the “transformed”, and random variable X being the “transformer”. In this paper, Lindley distribution was chosen to be the “transformed” and exponential distribution was chosen to be the “transformer”, constructing the Lindley–exponential distribution. However, there is a trouble using distribution if the data has a heavier tail. An alternative distribution is required while maintaining the properties of the Lindley-Exponential Distribution. Through transformation of variables method, a new distribution, Lindley-Exponential Slash Distribution is introduced, which is unimodal, right–skewed, heavier tailed. This paper covered some of its statistical characteristics, such as pdf, cdf, survival function, hazard rate,kthmoment, mean, variance, skewness, and kurtosis. Parameter estimation was carried out with maximum likelihood estimation through numerical method. An application of distribution was illustrated on maximum annual precipitation data of Durham City.
The size Ramsey and connected size Ramsey numbers for matchings versus paths
Authors: Vito V , Nabila A C , Safitri E , Silaban D R 
Published: January 2021

Abstract
Given simple graphs F, G, and H, we write F → (G, H) if for every red-blue coloring of the edges of F, there exists either a red subgraph G or a blue subgraph H in F. The size Ramsey number for G and H, denoted by

r

^

(G, H), is the smallest size of a graph F which satisfies F → (G, H). If in addition F must be connected, then the resulting number is called the connected size Ramsey number for G and H, denoted by

r

^

c

(G, H). In this paper, we obtain upper bounds for

r

^

(
t

K

2

,

P

m

)

,

r

^

c

(
t

K

2

,

P

m

)

,

r

^

(
t

K

2

,

P

4

+
a leaf
)

, and

r

^

c

(
t

K

2

,

P

4

+
a leaf
)

for t ≥ 1 and m ≥ 3. We also determine the exact values of

r

^

c

(
2

K

2

,

P

m

)

and

r

^

(
t

K

2

,

P

3

)

. In addition, the exact values of

r

^

c

(
t

K

2

,

P

3

)

for t = 3,4 are given.
Bühlmann credibility model with correlated risk parameters
Authors: Angelica  , Nurrohmah S , Fithriani I 
Published: January 2021

Abstract
Credibility theory is one of the tools to predict the amount of future claims by combining the experience of the claims in the past of a particular policyholder and external information, which is called manual rate, obtained from the experience of a large group of policyholders. One of the credibility theory that is widely used is Bühlmann credibility, which accommodates the heterogeneity of risk exposures, noted by unique risk parameters for each individual. However, Bühlmann credibility requires an assumption that the risk parameters are independent, which almost surely cannot be fulfilled by individuals living in the same area. Therefore, the Bühlmann credibility estimator with correlated risk parameters is formed by utilizing the orthogonal projection in Hilbert space. Also, the parameters included in the model are estimated. In addition, the standard Bühlmann credibility estimator and the Bühlmann credibility estimator assuming correlated risk parameters are compared to predict the amount of future claims based on data from a life insurance company. Comparing the root mean square error, the credibility estimator with correlated risk parameters is better in predicting the amount of future claim, meaning that the predicted amount of claim is closer to the original amount of claim. Also, as the correlation increases, the root mean square error becomes smaller. Moreover, the credibility estimator applied to the data that is partitioned based on the amount of past claims shows better performance than when applied to unpartitioned data.
Generalized exponential Marshall-Olkin distribution
Authors: Mohammad R , Lestari D , Devila S 
Published: January 2021

Abstract
The distribution of generalized exponential was invented by Rameshwar D. Gupta and Debasis Kundu in 2007. The distribution was the result of a generalized transformation of the exponential distribution. This paper explained the generalized exponential Marshall-Olkin distribution which is the result of the expansion of the generalized exponential distribution using the Marshall-Olkin method. The generalized exponential Marshall-Olkin distribution has a more flexible form than the previous distribution, especially in its hazard function which has various forms so that it can represent survival data better. The flexibility characteristic is due to the addition of new parameters to the generalized exponential Marshall-Olkin distribution. We explained some characteristics of the Marshall-Olkin generalized exponential distribution such as the probability density function (PDF), cumulative distribution function (CDF), survival function, hazard function, mean, and moments. Parameter estimation was conducted using the maximum likelihood method. In the application, it was shown data with generalized exponential Marshall-Olkin (GEMO) distribution. The GEMO distribution was modelled to the waiting time data until the damage to a lamp. The data was taken from Aarset data (1987). The results of modelling the waiting time data until the damage to a lamp on the distribution of GEMO and was compared to the distribution of alpha power Weibull. A comparison of models using Akaike information criteria (AIC) and Bayesian information criteria (BIC) shows that the distribution of GEMO is more suitable in modelling the lamp damage waiting time data than the distribution of alpha power Weibull.
Characterization of microalgae from lowlands in South Sumatera (Indonesia) as a potential source for biodiesel production
Authors: Jumiarni D , Anggraini N 
Published: January 2021

Abstract
Biodiesel production technology from microalgae is widely considered as a potential and efficient method. This research was conducted to characterize microalgal species isolated from some lowlands in South Sumatera and investigated their potential for biodiesel production. Five microalgal culture isolate were selected and identified as strains of Chlorella sp PKB, Chlorella sp PPP, Chlorella sp SB, Crucigenia quadrata PTA and Scenedesmus sudetica PTA. These isolates were determined the growth rates, biomass and total lipid content. Under similar environmental condition, dried weight biomass of isolate were 1,30; 0,88; 0,74; 0,5; 0,26 respectively. Total lipid content of isolates were 35,2; 28,5; 25,6; 17,8; 8,4 respectively. Chlorella sp PKB showed the highest lipid content comparison others, whereas Chlorella sp SB showed the highest dried biomassa. The results suggest that only Chlorella sp PKB can be a possible candidate species for biodiesel production.
Development of higher order thinking skills based problem solving questions on the nervous system concept
Authors: Zen D , Huzaifah S , Santoso L M , Dewi S P 
Published: January 2021

Abstract
Research on the development of higher order thinking skills (HOTS) questions based on problem solving on neural system material aims to produce valid and reliable HOTS questions. The development of higher order thinking skills questions refers to Anderson & Karthwohl and Polya frameworks. The questions that developed are a multiple choice problem with five alternative answers. The evaluation process includes self-assessment, expert review, one-to-one and small groups. Readability questions are tested at the one-to-one stage. The results of the small group stages are then analysed item items, namely item validity and item reliability. The validity of items is calculated based on expert review validation, while the reliability of the questions is calculated using Anates 4.0. The results of the research conducted showed that the questions developed were valid (86,1%) and reliable (0,35). The results of this study can be used as a reference for teachers to provide HOTS questions and familiarize students with solving problems with these characteristics.
Students’ achievement and teachers’ perception in the implementation of lesson study-based cooperative learning
Authors: Hasan R , Lukitasari M , Ernawati Y 
Published: January 2021

Abstract
Lesson study (LS) initially developed in Japan with over a century is a form of teacher inquiry in which teachers in small groups undertake collectively a cycle of “plan-do-see” activities to improve pedagogy and learning practice. LS has been practiced in many countries worldwide as well as developing countries in South East Asia region. This paper reported the implementation of LS on enhancement students’ activeness in classroom and concept comprehension in biological class as well as teacher’s perception in improving their quality as LS applied. We used cooperative learning model in three cycles of LS practice of this study. The results showed that students’ activeness during LS in cycle I was 1.9% of excellent, 46.3% of good, 50.6% of fair and 1.2% of poor. The students’ activeness was better in cycle II become 7.4% of excellent, 56.2% of good, 36,4% of fair and 0% of poor. In cycle III students’ activeness rise to 11.7% of excellent, 71.6% of good, 16.7% of fair and 0% of poor. Student’s comprehension on biological concept in this study was increased from 64.2 to 75.8 and 82.7 in cycle I, II and III of LS, respectively. Those results reflected that LS implementation improved students’ activeness on biology lesson and concept comprehension in biology. On the other hand, all teachers evolved in this study perceived that LS implementation can improve teachers’ professional quality and promote teacher’s professional development. They strongly agreed that LS be beneficial for them to become a better-quality biological teacher.
Realistic mathematic education of students worksheet (LKS) for reasoning ability of mathematical reflection of class XI High School number 1 Lubuklinggau
Authors: Yanto Y , Luthfiana M 
Published: January 2021

Abstract
This research aims to develop high quality PMR based on Student Worksheet (LKS) to facilitate mathematical reasoning ability of grade XI students of SMA Negeri 1 Lubuklinggau. This research used research and development method (Research and development) and the stage of Analysis Design, Development, Implementation, and Evaluation. In the development stage, there are two kinds of processes, namely the development of LKS and LKS validation, then evaluated LKS by the experts of linguists, and media experts. Validity of LKS was developed categorized “Valid” with an average score of 3.09 was determined based on the LKS assessment result by 3 experts (material experts, linguists, and media experts) maximum score was 4.00. Data analysis used LKS Practicality analysis developed “Praktis” with an average score of 3.38 is determined based on the result of student response to LKS. Descriptive and statistical analysis. The effectiveness can be seen from the results of students achievement tests. Based on the results of the Test Achievement shows that the percentage mastery learning class XI SMA Negeri 1 Lubuklinggau was 87%. Thus, learning mastery reaches good criteria, In shortly, LKS that used in teaching and learning was effective.
Improving student learning activities in microbiology through lesson study activities
Authors: Irwandi I , Hasan R 
Published: January 2021

Abstract
Lesson study is an educator development program through collaborative and continuous learning based on the principles of collegiality. Lesson study can be implemented at various levels of education from primary schools to universities. The 4 cycles-lesson study presented here is aimed to improve students’ learning activities in microbiology subject in the Biology Education Department, Universitas Muhammadiyah Bengkulu. Students who engaged in this activity as much as 28 students. The lesson study activities were conducted in three stages: plan (plan), implementation (do) and reflection (see). Selected topics in this activity were infection and viruses. In addition to those topics, a practical class for (1) preparation of microorganism culture media and its sterilization; and (2) the proliferation of fungi and bacteria was also accomplished. The results showed that there is an improvement in the students learning activity by conducting a lesson study program on a microbiology course. The obtained results prove that lesson study can improve lecturer professionalism. This improvement in lecturer professionalism then will have an impact on the effectiveness of learning activities and on improving the quality of education overall.
The significance of Maillard reaction for species-specific detection gelatine in food industry
Authors: Ismarti I , Triyana K , Fadzillah N A , Nordin N F H 
Published: January 2021

Abstract
Many ingredients derived from animal have been distributed widely in foods, pharmaceutical, and cosmetic formulations which may invites issues due to religious restrictions. Thus, the species-specific detection has become an important issue among Muslims, Jews, Hindus, Vegan, and vegetarian communities. Some methods such as spectroscopy, chromatography, and DNA based method have been applied for this purpose. However, these methods use sophisticated technology, therefore need high skill and cost for industrial practice. Research needs to encourage the development of simple and portable instrument. This paper highlights the potency of the Maillard reaction for species-specific detection of animal derivatives in food, especially for gelatine. Gelatine from different sources revealed different amino acids composition. It will produce various sensory of active compounds such as colour, odour, and taste when subjected to Maillard reaction, depends on reactant substances and conditions of reaction. The differences will be the key principle in species-specific detection of the sources of gelatine.
The effect of civet coffee isolate and time fermentation on Robusta coffee protein profiles
Authors: Uliyandari M , Sumpono S , Muslim C 
Published: January 2021

Abstract
This research aims is to determine the effect of the isolate’s concentration of civet coffee and fermentation time on the protein concentration profile and protein molecular weight profile of Robusta coffee which fermented in vitro, in vivo, and without fermentation. Isolates of civet coffee made from microbial civet feces and made in five variants concentrations (2,91x108 CFU/mL; 2,91x107CFU/mL; 2,91x 106CFU/mL, 2,91x105 CFU/mL; 2,91x104 CFU/mL). In the fermentation process coffee Robusta beans marinated with various concentrations of coarse isolates. The coffee beans are fermented analysed by Uv-Vis spectrophotometer and the results obtained in vitro protein concentration of the lowest 50,95 μg/mL (fermentation time of 60 hours and isolates concentration of 2,91 x 108 mg/mL), coffee fermentation in vivo (167, 44 μg/mL), and coffee without fermentation (217,61 μg/mL). The protein molecular weight profile is determined based on the results of electrophoresis. The higher the concentration of isolates civet coffee in the fermentation process, the more protein bands appear, and vice versa.
New candidate for traditional anti-malarial medicine from Kebiul seed (Caesalpinia bonduc) as a substitute for chloroquine in preclinical testing of mice
Authors: Sundaryono A , Ekolistiono A , Astuti A P , Muryani T S , Febrianti L , Nurleli N , Nurhamidah N 
Published: January 2021

Abstract
Kebiul seeds (Caesalpinia bonduc) are seeds from the Kebiul plant that are widely used by the community of Bengkulu in southern, Indonesia, especially by the Sarawai tribe as a cure for malaria. The purpose of this study was to scientifically prove the efficacy of Kebiul seeds as an anti-malaria medicine through preclinical testing in mice by measuring percent (%) chemosuppresion of crude extract of Kebiul seeds. Twenty-five mice were divided into 5 groups, K-, K +, P1, P2 and P3, each was infected with Palsmodium berghei. Three days after infection, the number of parasitemia of mice was calculated. When the number of parasites had reached 20-30%, mice were treated orally for 3 days according to their group. Group (K-) was treated with olive oil, group (K +) with chloroquine, and group P1, P2 and P3 with crude extract of Kebiul seeds at a dose of 0.028 g / kgbw, 0.056 g / kgbw and 0.084g / kgbw. The average number of parasitaemia developments was calculated from the 1st day of treatment to the 7th day through thin blood smears drawn from the tail. Calculation of the percentage (%) of chemosuppression was done by comparing the mean number of parasitaemia in the negative control (K-) and one in the treated group. As the result, the average percentage (%) of chemosuppresion in the administration of crude extract Kebiul seeds at a dose of 0.028 g / kgbw was 51.21% higher than the administration of chloroquine (50.77%). Moreover, it has been reported in several areas including Bengkulu that malaria is resistant to chloroquine. Therefore, based on this result, Kebiul seed extract at a dose of 0.028 g / kgbw can be developed as a new traditional medicine as a substitute for anti-malaria medicine chloroquine.
Betweenness centrality in corona product of Path and Star graphs
Authors: Haryadi T I , Susilowati L 
Published: January 2021

Abstract
Betweenness centrality is a concept in graph theory which is currently widely used in network analysis. The network can be a computer network, a criminal network, social interaction network, etc. The concept of betweenness centrality studies the potential ability of a point to exert influence on a network. If there is a point
x
in the shortest path between two points, then point
x
has the potential to influence information passing through that path. This paper will investigate the concept of betweenness centrality in the corona operation between path and star graph. Corona operation is one of the operations on graph theory that works between two graphs. The corona operation will duplicate the second graph and connect each copy to the first graph.
The comparison of the ordinal logistic model with the classical regression model
Authors: Yensy N A 
Published: January 2021

Abstract
This research’s aims was to provide an alternative for statistical user who were interested in analysing the functional relationship between ordinal response and explanatory variable. The data used was the data of Students on Generation 2017 JPMIPA FKIP Bengkulu University. The test statistic from the modified probability ratio in ordinal logistic had a higher test power than the F test in the classical linear regression. Overall the probability of rejection of ordinal logistic tended to be lower than the classical regression. At condition of p close to one, the test power of the ordinal logistic would be the same as the classical regression. Ordinal logistic model tended to be more selective in choosing variables that significantly affect the response, resulting in a simpler model than the classical regression. The results of the research with the classical linear model obtained variables that influence the student GPA were UN score, High School Report, UNIB admission pathway, High School Status and interaction of UN Score and High School Status. While the ordinal logistic model produced influential independent variables were the UN Score, High School Report, High School Status and the interaction of UN Score and High School Status.
Practicality test of student worksheet (SWS) based on: Action, Process, Object, Schema (APOS model) assisted on Geogebra the subject of Riemann sum
Authors: Hanifah H 
Published: January 2021

Abstract
The APOS Model is a Mathematical Learning Model Based on Theory: Action, Process, Object, and Schema (APOS). The APOS Model is a refinement of the Calculus Learning Model Based on APOS Theory. The APOS Model has syntax with phases: Orientation, Practicum, Small Group Discussion, Class Discussion, Exercise or Evaluation. Development of SWS based on APOS Model assisted on Geogebra in the subject of Riemann Sum developed using Plomp design which consists of three stages: 1) preliminary research, 2) prototyping phase, and 3) assessment phase. The purpose of this research was to find out how practicality of SWS was being developed, and how the criteria of practicing SWS based on the APOS Model assisted by Geogebra in the Riemann Sum discussion topic. The instrument used to collect data was the SWS practicality instrument in the form of a Likert scale. Research subjects were: one-to-one test conducted by a lecturer, a teacher, 3 senior students. Small group test by 3 groups of senior students with 3 students in each group. Large group test by 30 students in class B on the 3rd semester of Program Studi Pendidikan Matematika Universitas Bengkulu. After processing the data, the average score of practicality test of SWS was: one to one trial = 82.5%; according to the small group test = 77.63%; according to the large group test = 79.0%. The average value of practicality of SWS by users was 79.71 and belongs to the practical category.
The enhancement of mathematical reasoning and problem solving ability through metaphorical thinking approach
Authors: Purwasi L A , Fitriyana N 
Published: January 2021

Abstract
The objective of this study was to determine the effect of metaphorical thinking learning approach on mathematical reasoning and problem solving ability. This research used quasi-experimental method. The population of this study was the third-semester students of mathematics education study program at STKIP PGRI Lubuklinggau. The sample selection was done by using saturated samples. Based on the analysis of the t-test, the results of the study showed that 1) tobtained (2.351) of the ability of mathematical reasoningwas more thanthe ttable(2.06), so H0was rejected and Hawas accepted.It can be concluded that there was significant influence of the metaphorical thinking learning approach on the students’mathematical reasoning ability; and 2) tobtained(2.311) of the problem solving skill was more than the ttable(2.06), so H0was rejected and Hawas accepted. It can be concluded that there was a significant effect of the metaphorical thinking approach on the students’problem solving skill. In short, metaphorical thinking approach has influenced the students’ mathematical reasoning and problem solving ability significantly.