bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of glutathione antioxidant addition in maturation medium on the morphology of Garut sheep (Ovis aries) oocytes after vitrification
Authors: Gunawan M , Nuriza N , Kaiin E M , Sjahfirdi L
Published: January 2021

The study regarding the addition of glutathione antioxidants in the maturation medium in Garut sheep oocytes has been done. The purpose of this study was to evaluate the addition of glutathione antioxidants on oocyte morphology at post-vitrification. A total of 129 oocytes were matured in vitro using TCM-199 medium combined with glutathione antioxidants with a concentration of 0 mM (KK); 0.5 mM (KP1); 1 mM (KP2); and 1.5 mM (KP3). Oocytes were then vitrified using a combination of 15 % ethylene glycol and 15 % dimethyl sulfoxide as cryoprotectants. Oocyte evaluation was carried out after 7 days of storage in liquid nitrogen, including oocyte maturity and oocyte morphology. The percentages of mature oocytes are 53.13 % (0 mM), 55.88 % (0.5 mM ), 59.38 % (1 mM ), and 67.74 % (1.5 mM ) and the percentages of normal oocytes are 56.25 % (0 mM ), 64.71 % (0.5 mM ), 71.88 % (1 mM ) and 87.10 % (1.5 mM ). The results of ANOVA tests showed that the data were not significantly different between groups (P > 0.05), but the percentage tends to increase with the increase of antioxidants concentration. The addition of glutathione antioxidants in the maturation medium seems to help maintain oocyte morphology until post-vitrification, although not significant.
Phylogenetic study of Sumatran Microhyla heymonsi Vogt, 1911 (Anura: Microhylidae) based on 16S rRNA mitochondrial gene
Authors: Akbari G W , Hamidy A , Maryanto A E , Munir M , Smith E N
Published: January 2021

Microhyla heymonsiis a species that has a very wide distribution, ranging from Taiwan, China, India, Indochina, Peninsular Malaysia, to Sumatra. Species with a very wide distribution often contain cryptic species due to the geographical barrier resulting in reproductive isolation, gene mutation, and evolution. This study aims to determine the phylogenetic relationship betweenM. heymonsispecies from Sumatra and outside Sumatra, as well as the value of genetic distance between the two groups of species. The genetic distance threshold as a species delimitation is 3 %. DNA sequences were obtained through the process of DNA barcoding and then phylogenetic studies were performed through analysis of Unweighted Pair Group Method with Arithmatic Mean, Neighborhood Joining, Maximum Likelihood, and Bayesian Inference. The results show that theM. heymonsispecies from Sumatra form a large single clade on the phylogenetic tree of all analytical methods with significant bootstrap values. The genetic distance value ofM. heymonsiSumatra withM. heymonsiSingapore and Malaysia is still below 3 %. The genetic distance values betweenM. heymonsiSumatra andM. heymonsiThailand, Myanmar, Vietnam and China have exceeded 3 %.
The effect of addition alpha tocopherol antioxidant on slow freezing medium to the quality of Garut sheep oocyte (Ovis aries)
Authors: Kaiin E M , Salmah E N , Gunawan M , Sjahfirdi L
Published: January 2021

This study has evaluated the ability of alpha tocopherol antioxidant in maintaining the quality of Garut sheep oocytes post-cryopreservation using slow freezing method. Total of 226 oocytes with two different qualities (A and B) are matured in vitro in TCM-199 medium added with 150 µM alpha tocopherol. Afterwards, the oocytes were cryopreserved in the slow freezing medium with the addition of 0 µM (KK), 100 µM (KP1), 150 µM (KP2) and 200 µM (KP3) alpha tocopherol. Combination of cryoprotectant 10 % ethylene glycol (EG) and 0.1 M sucrose were also added to the medium slow freezing. Oocyte evaluation was carried out after 7 days of storage in liquid nitrogen (-196 °C), including oocyte morphology and oocyte viability using Hoechst and Propidium Iodide (PI) dyes. Based on the results of the study, the percentage of normal oocyte post-cryopreservation are 0 µM (67.86 %), 100 µM (68.42 %), 150 µM (74.58 %) and 200 µM (61.11 %). The percentage of viable oocyte post-cryopreservation are 0 µM (76.79 %), 100 µM (80.70 %), 150 µM (86.44 %), and 200 µM (70.37 %). The results shows that the addition of alpha tocopherol did not have an effect to the quality of oocytes post-cryopreservation, but there was a tendency for quality improvement with increasing doses of alpha tocopherol. In this study, addition of 150 µM alpha tocopherol into slow freezing medium is the best dose for maintaining the quality of Garut sheep oocytes until post-cryopreservation, although not significant (P > 0.05).
The effect of glutathione antioxidant addition in slow freezing medium on oocyte viability of Garut sheep (Ovis aries)
Authors: Kaiin E M , Febriani D S , Gunawan M , Sjahfirdi L
Published: January 2021

Research has been conducted on the addition of glutathione antioxidants in slow freezing medium on the oocyte viability of garut sheep (Ovis aries) after-cryopreservation. The study aimed to evaluate the effect of adding glutathione antioxidants in slow freezing medium with a concentration of 0.5 mM; 1 mM; 1.5 mM on the oocyte viability of garut sheep. Cryopreservation of 136 oocytes was carried out using cryoprotectant, such as 10 % ethylene glycol and 0.1 M sucrose. Viability of oocytes was evaluated using Hoechst and propidium iodide dyes, after 7 days of storage in liquid nitrogen (-196 °C). Based on the results of the study, the percentage of viable oocytes after-cryopreservation was 68.40 % (0 mM), 69.76 % (0.5 mM ), 75.55 % (1 mM ) and 83.08 % (1.5 mM ). Based on ANOVA statistical test, there were no significant differences between treatment groups (P > 0.05), but results showed an increase pattern with the addition of glutathione antioxidant concentrations. In conclusion the results showed that the addition of glutathione antioxidants in the slow freezing medium did not affect the oocyte viability of Garut sheep after cryopreservation.
Potential of mangrove ecosystem as coastal tourism based on biophysical conditions and water quality in Cilamaya Wetan, Karawang Regency
Authors: Wicaksono A A , Handayani T , Pin T G
Published: January 2021

Mangrove ecosystem is the ecosystems that has an important role not only for the life of flora and fauna, but also for the society around the ecosystem. This ecosystem needs to be considered for its sustainability as an effort to utilize the ecosystem. Cilamaya Wetan Sub-district is one of the sub-districts in Karawang Regency which has a very wide mangrove forest that reaches 1,019 ha. Biophysical condition and water quality, and also location factors for accessibility and its distance from the settlement need to consider, in which to develop mangrove ecosystem into tourism. Biophysical variables were analyzed using the suitability of mangroves for tourism, then water quality variables were analyzed using Pollution Index (PI), and location aspects were analyzed spatially using buffer method. The results of the potential of mangrove ecosystems for coastal tourism based on biophysical conditions and water quality obtained three zones that suitable to develop into tourism. Those zones are Maryamah-Tunut zone, Tarsip-Ci lamaya zone, and Cilamaya zone. Then based on spatial analysis using locational factors based on accessibility and distance from settlements, Tarsip-Ci lamaya zone and Ci Lamaya zone have the potential to be used as mangrove marine tourism. Besides those 2 zones area are suitable based on the biophysical conditions and water quality, the accessibility is quite good due to the main road is provided towards the ecosystem and also the distance from the settlement is in ideal distance, so that the ecosystem can be kept in good condition. Good accessibility and suitability mangrove ecosystem can increase the potential of the ecosystem to be used as coastal tourism.
Mapping water inundation and inundated landuse which will formed due to development of Karian dam, Ci Berang Sub-Basin, Lebak Regency, Banten Province
Authors: Bennabi J , Pin T G , Wibowo A
Published: January 2021

Overpopulation and development in Java Island have caused changes in land use from productive into non-productive land. One of the changes occurring in Indonesia is the development of the Karian Dam as a Multi-Purpose Dam in the Ci Berang Sub-Basin. This study aims to determine the area of inundated water will covering land use and many villages caused by the construction of Karian Dam. The dam was started the construction in the year 2015 and will complete in the year 2019. The variables used in this study is the elevation of inundated water and the land use of the Ci Berang Sub-Basin. The data for inundated are water level at minimum, normal, and maximum, which combined with digital elevation model (DEM). The research used the landcover data generated from Landsat 8 OLI. The results explained that the Ci Berang Sub-Basin area would be affected by the inundated water is 1,479 Ha. The changes caused by the water inundation will affect the land use in the northern area of Ci Berang Basin those are shrubs, wetlands, plantations, and urban areas more than 54.57 Ha and vacant lots 16,14 Ha. The land use, which has the highest area of inundated water coverage was shrubs 53 % and wetlands 22 %. The inundated water caused many villages covered by water with the highest land use change was Tambak Village with 335.48 Ha, and the lowest was Sindangsari Village with 3.73 Ha.
Premium calculation on health insurance implementing deductible
Authors: Anggraini N A , Nurrohmah S , Sari S F
Published: January 2021

Implementation of deductibles on insurance contracts is one of many ways to solve the adverse selection and moral hazard problems that often arise in health insurance. Deductibles will make the amount of expected loss for insurance companies lower. However, the deductible will also affect the amount of net premium. The higher the deductible, the lower the net premium that insurance company will get. If the claims amount are very large, then the insurance company would not be able to pay the claims because the amount of net premium that have been earned is small. Thus, the net premium principle is less suitable to use when the insurance companies. Then, they must find more suitable premium calculation method and in this paper, Proportional Hazard (PH) transform principle proposed by Wang being analyzed as an alternative premium when the insurer applies deductibles. The amount of PH transform premium will be higher than net premium and it has more slightly decrease when deductibles are applied compared to the amount of net premium.
Bayesian gaussian finite mixture model
Authors: Mirra J , Abdullah S
Published: January 2021

In data analysis it is common to assume that data are generated from one population. However, due to some underlying factors, data might come from several sources that should be considered as several sub-populations. Partitioning methods such as k-means clustering, as well as hierarchical clustering, are two commonly used methods for identifying data grouping. The grouping is done based on distance between observations. We discuss alternative means of data grouping, based on data distribution, known as Finite Mixture Model. Parameter estimation will be done using the Bayesian approach. Incorporation of prior distribution on the parameter of interest will complete data information from the sample, resulting in updated information in the form of posterior distribution. Gaussian distribution is assumed for the sampling model. Markov Chain Monte Carlo with Gibbs Sampling algorithm is implemented for sampling from the posterior distribution. Data on wave sensitivity on monkeys’ eyes were used to illustrate the method.
Pricing catastrophe reinsurance risk premium using Peaks Over Threshold (POT) model
Authors: Jaladri A S , Nurrohmah S , Fithriani I
Published: January 2021

An incident that cost more lives than a certain threshold is called a catastrophic event. In the world of insurance, the incidence of catastrophe causes many policies to make a claim together, so it can cause big losses for insurance companies. The risk of catastrophic events can be minimized by purchasing a catastrophic reinsurance contract. The reinsurance company then calculates the amount of risk premium for catastrophic reinsurance to be paid by the insurance company. The model used to calculate the risk premium is the peaks over threshold (POT) model. The POT model is generally used to model extreme events. In this model, the number of catastrophic events is modeled using the Poisson distribution. Then, the number of casualties is modeled using the discrete generalized Pareto distribution (DGPD). To estimate the parameters of the model, the maximum likelihood method is used and the data on the number of fatalities resulting from a particular event in Indonesia is collected and compiled. Furthermore, the number of claims is modeled with the Beta-Binomial distribution and the size of claims resulting from a catastrophic event is modeled by Exponential distribution. Numerical simulations are then performed to obtain the total size of claims resulting from all catastrophic events within 1 year of catastrophic reinsurance contracts. Ultimately the risk premium can be calculated using the standard deviation premium principle by utilizing the expected value and the variance of the total amount of the claim.
Harmonious labeling of the union of m-cycle and n-path graph
Authors: Ng S , Alwie F , Marjadi T P , Sugeng K A
Published: January 2021

A graph G is called harmonious graph if there is an injective mapping f from the set of vertices of G to the set Zq
so that the mapping induced a bijection mapping f
∗ from the set of edges of G to Zq
, which is defined as f*(xy) = f(x)+ f(y) for each edge xy∈ E(G). The mapping f is called harmonious labeling. Harmonious labeling concept has been developed since 1980. At that time, harmonious labeling is inspired by channel assignment problems. Nowadays, harmonious labeling has been known for various classes of graphs. However, there are still many certain classes of graphs that have not been determined yet whether they can be harmonious labeled or not. One of the class of graphs that have not been determined yet whether it can be harminous labeled or not is graph Cm
∪ Pn
In this paper, we prove that there is a harmonious labeling of graph Cm
∪ Pn
for some values m and n.
The odd harmonious labelling of nhair-kC
4-snake graph
Authors: Mumtaz K , Silaban D R
Published: January 2021

Let G(p,q) be graph that consists of p = |V| vertices and q = |E| edges, where is the set of vertices and E is the set of edges of G. A graph G(p,q) is odd harmonious if there exist an injective function f: V → {0, 1, 2, …, 2q − 1} that induced a bijective function f
∗:E → {1, 3, 5, …, 2q − 1} defined by f
∗(uv) = f(u) + f(v). The function f is called harmonious labelling of graph G(p,q). A hair-kC
4 snake graph is a graph obtain by attaching n leaves to vertices of degree two in kC
4-snake graph. In this paper we prove that nhair-kC
4-snake graph is odd harmonious.
The measure strength of predictive in the poisson regression model with regression correlation coefficient case study of maternal mortality rate in Central Java Province in 2015
Authors: Nisa K , Nurrohmah S , Novita M
Published: January 2021

RCC which stands for regression correlation coefficient is an alternative measure strength of predictive that can be applied to the GLM model in which the distribution of response variable is not only normal. The RCC is constructed based on the definition of correlation coefficient by using generalized linear model (GLM). So, the RCC can be defined as a value that states the strength of the relationship between response variable Y and its conditional expectation given predictor variables E[Y|
X
]. The RCC is one measure of predictable power that can satisfies the property like applicability, interpretability, consistency, and affinity. In general, the explicit form of RCC on GLM is difficult to find. However, when RCC is applied to the Poisson regression model and the predictor variables are assumed to be a normal multivariate distribution, an explicit form is found. This explicit form still contains the unknown parameters derived from the Poisson regression model. Therefore, we need to find an estimate of these parameters to obtain an estimator from the RCC. The Poisson regression model which still contains the unknown parameters are estimated using maximum likelihood method. Application of regression correlation coefficient is done in case of maternal mortality rate in Central Java Province in 2015.
Analysis of factors affecting employee loyalty of PT X in Jakarta region
Authors: Karimah R P , Abdullah S , Setiadi R
Published: January 2021

Having loyal employees, i.e. those who desire to do their best in their work to achieve the company’s target, is important for the company. This study is conducted to identify factors that explain loyalty of employees in PT X, Jakarta. Furthermore, we also aim to generate profiles of the most loyal employees. Questionnaires were used to collect data from the central office and 12 branches of the company, using purposive sampling scheme, giving 467 respondents in total. Data processing was conducted using Partial Least Square (PLS) and Classification and Regression Tree (CART) methods. The results showed that job satisfaction and gender directly influence employees’ loyalty. Moreover, physiological needs, safety needs, love needs, and self-actualization needs indirectly influence loyalty of employees through job satisfaction. Highly loyal employees are those with either high job satisfaction and low physiological needs or low job satisfaction and low level of love needs.
Laterality condition analysis on non-arteritic anterior ischemic optic neuropathy patient in one of the hospital in Jakarta with medical data mining
Authors: Unggul D B , Abdullah S , Rachman A
Published: January 2021

Non-arteritic Anterior Ischemic Optic Neuropathy (NAION) is a disease caused by blood shortages in the artery that supplies the optic disc. Risk factors for NAION are hypertension, obesity, diabetes, dislipidemia, smoking, hypercoagulable state, cardiovascular disease, and stroke. NAION can result from unilateral or bilateral conditions. This study will focus on the identification of important factors that could distinguish characteristics between unilateral and bilateral patients. Random forest method is applied to obtain factors that can consistently distinguish characteristic between each laterality condition. Decision trees and the logistic regression method are added to obtain the visualization of the role of each important factors in the form of classification tree and the risk comparison of patients for experiencing a certain laterality condition by using odds ratios. The important factors based on random forest model are onset, fasting blood glucose levels, high density lipoprotein levels, age, two-hour postprandial glucose levels, and low density lipoprotein levels. Based on the odds ratio, advancing age and high density lipoprotein levels will decrease the risk of patients experiencing bilateral condition; on the other hand, the risk of bilateral condition will increase if other important factors are also increased.
Quota-share and stop-loss reinsurance combination based on Value-at-Risk (VaR) optimization
Authors: Putri A D , Nurrohmah S , Fithriani I
Published: January 2021

Every insurance companies have a capacity limit related to the maximum claim that can be borne. Therefore, insurance companies need to reinsure risks to reinsurance companies. Besides of quota-share, types of reinsurance contracts that commonly used is stop-loss. The quota-share reinsurance premium is proportional based on the amount claim that is covered, but not safe against a large claim. While for stop-loss, the reinsurance premium is relatively large but safe for a large claim. So, this paper combines both types of reinsurance to cover the shortcomings with their respective strengths. After being combined, it is necessary to determine the optimal quota-share proportion and stop-loss retention. One criterion of determines optimal proportion and retention is based on Value-at-Risk (VaR) optimization. With the reinsurance premium as a constraint, this optimization problem is solved for each type of reinsurance combination, be it quota-share before stop-loss or stop-loss before quota-share. From each of these types combinations, the result is optimal quota-share proportion and stop-loss retention, so as produce a minimum VaR value from the borne risk by insurance companies. by comparing the results of VaR optimization of these combinations, stop-loss before quota-share is obtained resulting in a more minimum VaR value.
Prediction of the reported but not settled (RBNS) claims reserves and the incurred but not reported (IBNR) claims reserves using the double chain ladder method
Authors: Addini F F , Nurrohmah S , Fithriani I
Published: January 2021

An insurance company is required to set up a claims reserve to pay claims reported by the policyholders. There are two types of claims reserve: Reported but Not Settled (RBNS) claims reserve and Incurred but Not Reported (IBNR) claims reserve. Insurance company predicts a claims reserve using run-off triangle data. There are two types of data in a run-off triangle: claims amount and number of claims. The Chain Ladder (CL) Method is often used to estimate the claims reserve. In CL method, the claims reserve determined using the run-off triangle claims amount by calculated development pattern from the data and then calculated a predictive value of the claims reserve using that development pattern. But CL method unable to estimate the RBNS and IBNR reserves separately. The method used in this paper is closely related to CL method and is called a Double Chain Ladder (DCL) method. The DCL method applies the CL algorithm to two run-off triangles, the run-off triangle of claims amount and number of claims. The additional information from the run-off triangle of the number of claims enable the DCL method to estimate the RBNS and IBNR reserves separately. Based on numerical application, claims reserves obtained from CL and DCL methods are significantly different when there are many zero values in incremental run-off triangle.
Assessment of Indramayu batik based on Outstanding Universal Value (OUV) and Geographical Indications (GI)
Authors: Maiyang F , Taqyuddin
Published: January 2021

Batik is an Indonesian cultural heritage that has been known since the early 19th century until now. Batik art in each region can be seen from the manufacturing process, batik quality, ornament, and color arrangement. A product to be crowned a world heritage needs to meet the criteria for Outstanding Universal Value (OUV) that has been set by UNESCO and Geographical Indications (GI) by the Directorate General of Intellectual Property Rights. This study discusses which ornaments of Indramayu batik represent the production area the most, then Indramayu batik is assessed on two grounds, namely Outstanding Universal Value (OUV) and Geographical Indication (GI). Also, with this assessment, it can be seen that spatial patterns formed from the results of the assessment of Indramayu batik based on OUV and GI. This study used a qualitative method in which the data collection was carried out through interviews using a list of questions to representatives of Indramayu batik business owners and Indramayu batik craftsmen spread across 22 locations of Indramayu batik producers. The results of this study are sekar niem and kapal kandas ornaments get the highest value based on OUV and GI, while merak berunding, liris, parang teja, and banji are the ornaments with the lowest value.
Analysis of pre-service biology teachers’ metacognitive skills on invertebrate zoology
Authors: Madang K , Tibrani M M , Santoso L M
Published: January 2021

This study aims at obtaining pre-service biology teachers’ metacognitive skills in invertebrate zoology. A number of pre-service biology teachers that take invertebrate zoology course at a state university in Sumatera, Indonesia, were involved as participants in this study. Data on metacognitive skills were collected using metacognitive skills instrument test that have been developed. The data obtained were processed by calculating the percentage (%) for each indicator of metacognitive skills. Results show that the value of pre-service biology teachers’ metacognitive skills on invertebrate zoology are 4.86. For each indicator of metacognitive skill composition were no logic, no systemic, no analyse/evaluate/create (64.56%); no logic, no systemic, less analyse/evaluate/create (31.60%); no logic, no systemic, have analyse/evaluate/create (2.53%), and no logic, have systemic, have analyse/evaluate/create (1.27%). Based on the results of this study, it is suggested that pre-service biology teachers’ metacognitive skills in invertebrate zoology was very low. In order to repair pre-service biology teachers’ metacognitive skills, it is needed revision on instructional strategies for invertebrate zoology course.
Problem-based learning (PBL) and blended learning in improving critical thinking skills and student learning activities in biochemistry courses
Authors: Yennita Y , Zukmadini A Y
Published: January 2021

This study aims at improving students’ critical thinking skills and student learning activities in biochemistry courses. The efforts in improving critical thinking skills are carried out by applying the problem-based learning model using “blended learning” method. Blended learning method is implemented by integrating the face-to-face learning with online learning into the syntax of problem base learning. Face-to-face learning is done in the classroom, while the form of online learning is done by utilizing internet facilities and online discussion forums. Data from observations of learning activities are also calculated using a range of values that appear and determine the criteria. The results showed that the percentage of students’ critical thinking skills in the first cycle was 52.29% (quite critical), while in the second cycle it increased to 64.43% (critical). The teaching activities of lecturers in the first cycle and the second cycle were 36 (good category). Student learning activities in the first cycle is 35 (good category) and in the second cycle is 34 (good category). The conclusion of this study is the application of problem-based learning (PBL) using the blended learning method can improve critical thinking skills and student learning activities in biochemistry courses.
Students’ scientific articles writing ability based on lacertilia inventory results in the conservation area Bengkulu University
Authors: Karyadi B , Astuti A P , Listiono A E , Sundaryono A , Ruyani A
Published: January 2021

Writing scientific articles is a problem for teachers especially in elementary, junior and high school levels. This study aimed to determine student ability to write scientific articles based on the results of lacertilia suborder inventory in the conservation area of Bengkulu University. This study used Research and Development method. Participants in this research was teachers who being students of graduated school of science education on 2018 academic year who enroll biology environment subject. Students in 7 groups has made 7 articles based on lacertilia inventory research. From the scientific articles writing, there are 7 indicators that indicate in good score, including the ability to write title, identity, article components, abstracts, introduction, results and discussion, and conclusions with highest average score as much as 3.42 in ability to write results and discussion, and lowest average score as much as 2,14 in ability to write method.
Lesson study at Bengkulu Iqro IT High School to improve learning outcomes and the role of teachers in supporting Biology learning
Authors: Zukmadini A Y , Rochman S
Published: January 2021

Iqro IT High School is one of the high school level schools based on Islam in the city of Bengkulu. This study aims to improve the learning outcomes of class XI students and enhance the role of teachers in enhancing collaborative biology learning. This type of research is action research conducted using the lesson study method. Lesson studies are carried out collaboratively by involving the roles of teachers, peers, and lecturers. Lesson study activities carried out in two open lessons, where each open lesson consists of 3 sessions namely plan, do, and see. The instrument used in this study was the observation sheet of the implementation of lesson study and the test sheet of learning outcomes. The results showed an additional increase in the study of lessons from open lesson 1 to open lesson 2. In addition, there was also an increase in learning outcomes from open lesson 1 to open lesson 2. The conclusion of this study is that lesson study can help teachers to enhance their role in teaching and learning and be able to improve student learning outcomes in biology subjects.
Lesson study stimulated students critical thinking in Cell Biology courses
Authors: Hidayat T , Santoso S
Published: January 2021

The purpose of this study is a lesson study joint learning forum for mutual learning from experience in order to stimulate critical thinking of students in the Cell Biology course in the Biology Education Study Program FKIP Muhammadiyah University of Bengkulu. This research is an action research with a qualitative-descriptive approach carried out for 4 cycles. The stages of the lesson study are learning planning (plan), Implementation of learning (Do) and Reflection (See). The results showed that students critical thinking skills in learning Biology Cells through the implementation of lesson studies gained an average score of 85% in either category. The development of the ability to manage classes that have been done through the implementation of lesson studies to stimulate students’ critical thinking has increased.
Domain-specific critical thinking skills: Designing and analysis the instrument test on thermochemistry
Authors: Nursa’adah E , Sari D , Affifah I
Published: January 2021

Chemistry learning needs an assessment to evaluate ways of students’ thinking. One them is critical thinking skill test. The purpose of this study is designing domain-specific critical thinking (DS-CT) skill on thermochemistry concept. There are 29 DS-CT Skills test to measure students’ DS-CT skills. Content Validity Ratio (CVR) and Confirmatory Factor Analysis (CFA) were evaluated to analysis the validity of DS-CT Skills test. Cronbach’s Alpha evaluated to analysis the reliability. Research and Development was used as research design. The participants of this study are 185 senior high school students in Cilegon-Banten-Indonesia. Data are obtained from expertise judgment, empirical test, and interview. The results showed that validity of DS-CT skills test on thermochemistry concept based on CVR and CFA is 0,723 (good criteria). Cronbach’s Alpha test showed 0,652 (high criteria). It can be conclude that this DS-CT Skills test is feasible to measure students’ DS-CT skills on thermochemistry domain knowledge. Students’ CT skill on domain thermochemistry are 46% on present and provide arguments, 27% make and assess claims, and 21% analysis arguments.
Application of fractal principles in redesigning an arabic calligraphy and rafflesia flower motif in Batik Besurek
Authors: Mayasari Z M
Published: January 2021

Batik besurek is one of Indonesia’s cultural heritages from Bengkulu Province. This batik is different from another batik in general because it has the characteristics of Arabic calligraphy. There are seven types basic of motifs in batik besurek, one of them is the Arabic calligraphy motif. In this paper explained the development of the pattern of the Arabic calligraphy and rafflesia flower motif in batik besurek. The pattern development is done by applying the fractal principles. The results is a new motif of batik besurek that are expected to enrich the style, shape, diversity of motifs, and enhance the beauty and selling value of the batik itself.
Critical thinking ability through student worksheet development based on Missouri Mathematics project learning model using think talk write
Authors: Efuansyah E , Wahyuni R
Published: January 2021

This study aims to describe the mathematical critical thinking skills of class VIII students through the development of Student Worksheets based on the Missouri Mathematics Project learning model using Think Talk Write strategies. This research was conducted at junior high school number 11 Lubuklinggau in the Even semester of the 2018/2019 school year with research population were all students of class VIII at junior high school number 11 Lubuklinggau. Data collection technique used was a test technique to measure students’ critical thinking skills on the material of Cubes and Cuboid. While the data analysis uses descriptive qualitative analysis. Based on the results of data analysis, it was found that the average percentage of students’ thinking abilities in class VIII was 76.97 and was in the Good category.
The influence of computer-based Multimedia materials on learning outcomes of class VII students on the set material in SMP N 6 Bengkulu Selatan
Authors: Syafri F S , Sari I T S , Isran D
Published: January 2021

This research is a quantitative study aimed at knowing the multimedia teaching materials based on SMP 06 Kota Bengkulu in the results of mathematics learning. Sampling in this study used random sampling techniques with a research sample of 20 class VII. The collection of data used in this research is poll and test. Data in the study was further analyzed using Test T, based on the results of the analysis came to the conclusion that computer-based multimedia teaching materials have a positive influence on the results of the mathematics of students in SMP N 06 Bengkulu South.
Analysis of junior high school students ‘capability on completing mathematical problems of the PISA model using the Lubuklinggau context reviewed from the PISA level
Authors: Elly A , Rosalina E
Published: January 2021

This study aims to describe the ability of junior high school students to solve PISA mathematical problems using the Lubuklinggau context in terms of the PISA level. The subjects in the study were students of class IX.5 Middle School 5 Lubuklinggau. The method in this research is descriptive qualitative method. The instruments and data collection techniques used were test sheets and questionnaires as well as interview guidelines. Data analysis of data through 3 channels, namely data reduction, data presentation, and drawing conclusions. The results obtained indicate that the level I PISA Problem in the category is excellent with an average value of 91.07, level II in the category is excellent with an average value of 91.96, level III in the good category with an average value of 72.45, level IV in the good category with an average value of 61.61, level V in fair category with an average value of 58.16, and level VI in poor category with an average value of 38.10.So it can be concluded that the ability of class IX students of SMP Negeri 5 Lubuklinggau in solving mathematical problems using the PISA model Lubuklinggau context in terms of PISA level is included in both categories with an overall average value of 68.89.
Problem-based learning model to improve mathematical reasoning ability
Authors: Mandasari N
Published: January 2021

Reasoning ability is very important to note because it is able to train students’ thinking activities to be able to solve mathematical problems. This ability is also a benchmark in determining student achievement in the field of mathematics, one of which is in the international event TIMSS and PISA. However, the competitiveness of Indonesian students is still very low compared to other countries. This can be caused by the lack of giving questions that practice the ability of reasoning by the teacher. Therefore, there is a need for improvement in the process of learning mathematics. In the learning process, students should be given the opportunity to explore all their potential. The teacher can offer problems that are able to train and develop mathematical reasoning abilities. Problem-based learning is problem-centered learning. Problems given can be related to real-life students and can practice the ability to reason and solve mathematical problems.
Development of students’ worksheets based on a scientific approach for set concept in grade VII Junior High Schools 10 Bengkulu City
Authors: Wulandari S , Syafri F S
Published: January 2021

This research is to develop a mathematics learning tool for Student Worksheet (students worksheets) based on a scientific approach that is valid, effective, and practical. The research method used is the development research with the Plom Model consisting of 3 stages, namely the initial investigation phase (preliminary research), the development phase or making a prototype (development or prototyping phase), and the assessment phase (assessment phase). The subjects of this study were students of class VII SMP 10 Bengkulu city consisting of 32 students. Data collection techniques in the preliminary stage are document analysis, while the formative evaluation stage is walk through, observation, and students worksheets tests. The results of this study are in the form of products, namely: Student Worksheet (students worksheets). The results showed that the students worksheets in the valid category based on the score obtained 3.50 was stated to meet the criteria, for practicality tests a score of 3.55 met the criteria stated practical, whereas for the effectiveness test a score of 83 had met the completeness criteria, so it can be said that the learning kit students worksheets mathematics based on a scientific approach to class VII material can already be used.
Improving monoid concept understanding ability through problem posing learning model at abstract algebra course
Authors: Yumiati Y , Haji S
Published: January 2021

This study aims to improve the ability to understand monoid concepts through Problem Posing learning. The method used is a quasi-experiment. The research design used was pre-test post-test group design. The research sample was 32 undergraduate students of the Mathematics Education Study Program FKIP Universitas Bengkulu at the Algebra Abstract course of even semester of 2018-2019 academic year. The instrument used was a 4 item test about the concept of monoid. Data were analysed qualitatively and quantitatively. The results of the study are as follows: 1) an increase in the ability to understand the monoid concept of students by 0.67, including the medium category; 2) the achievement of the ability to understand the monoid concept is 74.75 in the high category. The results of this study have implications for the importance of the role of questions in learning mathematics.
The cognitive process of students understanding quadratic equations
Authors: Herawaty D , Widada W , Gede W , Lusiana D , Pusvita Y , Widiarti Y , Anggoro A F D
Published: January 2021

Algebra is mandatory learning in junior high school. That is a continuation of arithmetic with the bridge being variable. Students often have difficulty in understanding it, especially quadratic equations. The purpose of this study is how students’ cognitive processes in understanding the principles of quadratic equations. It was an exploratory study conducted on research subjects. The subjects were junior high school students selected based on their ability to understand concepts and principles about quadratic equations. That’s done through tests about understanding quadratic equations. There were 16 selected research subjects. They were interviewed in-depth by researchers using interview guides. Interview data were analyzed qualitatively based on genetic decomposition. The results of this study are that students can use square, rectangular and unit square cards to determine the principle of factorization of quadratic equations. Students can generalize until completing a perfect quadratic equation. The conclusion is that the cognitive process of students who learn to use learning media based on square and rectangular able to reach a high level (trans-level).
The design of furnace for biochar production by using vacuum pump and temperature manual control
Authors: Nurhidayah N , Peslinof M , Afrianto M F , Fahyuan H D , Heriansyah H , Damris M
Published: January 2021

Temperature control is very prominent to be done in producing biochar, because the quality of biochar depends on combustion temperature and the amount of oxygen existing when the combustion process is happening. In this research, the designing of furnace for biochar production by using vacuum pump and temperature manual control had been done. The fuel used was LPG gas. The furnace was designed by having two parts which are cylinder tube for biochar production and tube feet as the holder of the kiln. The calibration of the furnace for biochar production was done to find out the temperature and the pressure that can be generated and its effect toward produced biochar. The calibration was done by using vacuum pump to vacuum the combustion chamber and temperature manual control as temperature indicator. There were two steps for this furnace calibration, first, the leakage test and second, combustion test of biochar production. The leakage test was done by using bubble test method. The result showed that there were still some leakages happened, but they were fixed with glue on the leak parts. As the final result of the leakage calibration, the vacuum condition obtained was -25 cmHg. And as the result of biochar combustion as long as one and two hour, the temperature reached 2800C and 2500C.
Design of hydraulic’ tools for students’ practicum
Authors: Maison M , Ilfan F , Triyanto J H
Published: January 2021

Fluid mechanics and hydraulics subject is a subject that explains the concepts of the nature of fluids (liquids and gases) when stationary or moving, or when interacting with other fluids or solid objects. One of the courses in this subject related to hydraulics is about open channels. Many students have difficulties understanding this material and not able to describe abstract concepts because they were not doing experiments with the open channel. The purpose of this research is to develop hydraulic devices for open channels that can be used by students for practicum. The methods used to develop these tools are the study of literature, determination of design concepts, exploration of design scenarios, toolmaking, testing, evaluation, and improvement the tools. These tools are also equipped with a microcontroller to regulate water flow, the slope of the water-retaining plate to display hydraulic jumps and adjust the pump power. The test results show that the tool can provide consistent results, both from flowrate, weir overflow coefficient, and Froude numbers.
The development of students worksheets is oriented to the higher other thinking skill with problem solving models on electromagnetic induction materials
Authors: Purwanto A , Sakti I , Sindita D
Published: January 2021

This research was aimed to develop a valid Student Worksheet (LKPD) oriented to Higher Order Thinking Skills (HOTS) with a problem solving model on electromagnetic induction material. This research was a type of development research (Research and Development) with type 1 design consisting of 5 stages, namely: 1) potential and problems 2) literature study and information gathering 3) product design 4) design validation 5) tested design. Design validation was carried out by 3 expert judgments and 3 Practitioners to assess products developed from aspects of presentation, content, and language. Based on the results of the validity of the presentation aspects, the results were 76.3% (very good categories), content aspects at 74.4% (good categories), and language aspects at 80.1% (very good categories). Based on these results, it was concluded that the HOTS-oriented LKPD developed was declared valid and was a tested design with a percentage of the total validity test which was 86% (very good category).
Using certainty response index to differentiate lack of knowledge and misconception about basic electrical concepts
Authors: Koto I , Gusma S E
Published: January 2021

The objective of this study was to examine pre-service physics teacher understanding related to physics content knowledge by investigating knowledge of the Basic Electrical Concepts (BECs) test and the student’s certainty in their physics knowledge. Data was collected from 57 preservice physics teachers with the BECs test and Certainty of Response Index (CRI) values. The BECs test with CRI was administered to pre-service physics students following accomplishment of a unit of study on electricity and simple circuit. The results of diagnostic test were classified into correct and incorrect answers, and CRI values were classified into certain and uncertain. High CRI value in incorrect answer on the BECs test implied that 26% preservice physics teachers had misconceptions about basic electrical concepts. Low CRI value in correct or incorrect answer on the BECs test indicated there were 53% preservice physics teachers providing the answer by guessing; due to no understanding or confusion about their understanding. There were 21% preservice physics teachers providing the answer correctly on the diagnostic test with high CRI value. It was concluded that the majority of preservice physics teachers (79%) were either guessing or had misconceptions about every item related to the electric basic concepts.
Collaborative skills of prospective teachers in laboratory activities related to the concept of elasticity
Authors: Malik A , Ubaidillah M , Fatmawati S , Aswirna P , Qaddafi M , Sutarno S
Published: January 2021

The collaborative is a skill needed in facing challenges and opportunities in the era of industrial revolution 4.0. Therefore, universities must prepare prospective graduates to have collaborative skills. The purpose of this study was to describe collaborative skills that are trained and developed through laboratory activities. This study used descriptive quantitative methods. The research sample amounted to 250 teacher candidates from several Islamic Universities in Indonesia. The sampling technique used random sampling, which represents Islamic universities on four islands in Indonesia. The research instrument used was a performance assessment supplemented by a rubric of assessment. The results of research prospective teacher collaboration skills were a good category. Thus, laboratory activities can train and develop collaborative skill skills of prospective teachers.
Profile of pre-service physics teachers’ critical thinking skills related to heat transfer
Authors: Yusal Y , Suhandi A , Setiawan W , Kaniawati I
Published: January 2021

One of the skills needed to meet the challenges of 21sf century is critical thinking skills. This study aims at describing the profile of pre-service physics teachers’ critical thinking skills related to heat transfer. This research is a descriptive research conducted in the physics education program at one of the private universities in Jakarta. Data collection is done through the test of critical thinking skills related to heat transfer. The collected data is analysed quantitatively. The results showed that 0% of students were in the category of high critical thinking skills, 25% on moderate critical thinking skills, and 75% on low critical thinking skills. Thus, the critical thinking skills of pre-service physics teachers still belong to low category.