bluuebunny/crossref_metadata_2025 huggingface dataset:
Methods for acoustic desensitization of fiber optic interferometer
Authors: Vlasov A A , Plotnikov M Yu , Aleinik A S , Varlamov A V
Published: October 2019

Methods for acoustic desensitization of fiber optic interferometer were studied as applied to the compensation interferometer (CIF) of a fiber optic phase sensor system. Materials with high mechanical loss factor were used for the fiber optic interferometer rack case. Also case acoustic conditioning measures and vibration isolation system based on steel springs were developed. Different types of fiber coating for acoustic desensitization were investigated. The best implementation provided up to 30 times (-29.8 dB) suppression of CIF undesirable acoustic sensitivity level.
Acousto-optic frequency shift modulators with acoustic and optic waveguides on X-cut lithium niobate substrates
Authors: Varlamov A V , Lebedev V V , Agruzov P M , Ilichev I V , Shamrai L V , Shamrai A V
Published: October 2019

An optimal configuration of the waveguide acousto-optic frequency shift modulators on the X-cut lithium niobate substrates was analyzed. The conditions for efficient excitation of surface acoustic waves (SAW) and their interaction with the guided light in integrated optical structures were found. The influence of acoustic waveguide presence and interdigital transducer (IDT) geometry and material on the SAW resonance excitation was investigated. An acoustic waveguide configuration was proposed for increasing the TE-TM optical mode conversion efficiency. A low power (about 15 dBm) high frequency modulation signal was required for full TE-TM mode conversion in the proposed modulator configuration.
Features of the signal registration and processing in the study of liquid flow medium by the refraction method
Authors: Grebenikova N M , Davydov R V , Rud V Yu
Published: October 2019

Features of image formation and registration of the light-shadow boundary in flow refractometer are considered. A new design of refractometer was developed for the state control of poorly transparent and turbid flowing media containing big insoluble particles. A new algorithm for processing the image recorded on a photodiode array for determining of liquid flow parameters has been developed. A new method for contrast degree determining of the light-shadow border has been proposed taking into account features of registration and processing of optical signals. Experimental results are presented.
Tunable optical delay lines based on a system of coupled whispering gallery mode resonators
Authors: Markvart A A , Liokumovich L B , Ushakov N A
Published: October 2019

The paper presents an analysis of optical delay lines based on coupled whispering gallery mode resonators. The induced optical delay is caused by slow light regime in high finesse resonators. The analysis is based on slowly varying envelopes approach and includes evaluation of possibilities to adjust the induced delay time. We also investigate the properties of transfer coefficient of system of coupled whispering gallery mode resonators.
Image filtering for the nanosatellite vision system
Authors: Andryakov A A
Published: October 2019

This paper provides an overview of the basic methods for filtering images. The main sources of the noise component in the image, which should be shooted by camera based on nanosatellite, the criteria for assessing the quality of filtering and the main digital filters for image recovery are given. The comparative characteristics are presented.
Theoretical analysis of averaging methods for intermodal fiber interferometer
Authors: Petrov A V , Chapalo I E , Kotov O I
Published: October 2019

Theoretical expressions describing the signal of an intermodal fiber interferometer are presented. Two methods of signal averaging are investigated theoretically: the ensemble averaging and the averaging over a “long realization”. The methods are examined by conducting numerical experiments. The averaging efficiency is analyzed depending on number of realizations and the fiber length increment.
Development and implementation of accelerated methods of data access
Authors: Ermakov N V , Molodyakov S A
Published: October 2019

In this paper we address the problem of organizing a permission-conscious access to files and their metadata. A large amount of data is required to be stored and analyzed in medicine, bioinformatics, astronomy, and banking. For effective data storage, it is necessary to apply different technologies depending on the data. We have developed a system that consists of the following components: a relational DBMS to store user permissions and file metadata; an off-the-shelf distributed search engine to store activity logs; a distributed cache with permissions; a file system; a special application that interacts with all the respective components. We describe the overall architecture of our approach and discuss each component in detail. To offload database server and to speed up the permission checking we have devised a simple data caching scheme that is performed on an application server. The idea was to manually rewrite queries that are used by our application to check permissions. As a result, queries that use several tables request only non-cached tables from the database. We conclude our paper with the experimental evaluation of our system and the proposed caching approach.
Geodesic distance numerical computation on compliant mechanical parts in the aircraft industry
Authors: Popov N P , Pogarskaia T A
Published: October 2019

The problem of geodesic distance computation in the Aircraft industry is considered in the paper. While simulating the assembly process, in some computational problems the calculation of the shortest distances between different objects is required. The aim of the work is to compare several approaches to geodesic distance numerical computation on test geometry and some of the most common joints of aircraft. The first considered approach represents graph-based algorithms. In the paper, geodesic distances are calculated in the constructed graph using Dijkstra’s algorithm or its modification with binary heap. The second approach is the fast marching method, which is based on the solution of the Eikonal equation and provides efficient geodesic distance computation on triangulated surfaces.
Improving the effectiveness of the multi-frequency signals application under conditions of amplitude limitation
Authors: Nguyen D C , Zavjalov S V , Ovsyannikova A S , Nguyen C M
Published: October 2019

In this paper, simulation modelling of information transmission using spectrally efficient multi-frequency (SEFDM) signals with an amplifier and a limiter on transmission has been held. SEFDM signals have a high peak-to-average power ratio (PAPR). Therefore, we need to limit the value of PAPR to increase the efficiency of the amplifier stages of transceiver devices. An effective value for PAPR limiting has been found. For signal-to-noise ratio 7 dB, level of bit error rate reaches minimum value when the PAPR limit value is within 4.5-5.5 dB. Besides that, a comparison of the effectiveness of detection algorithms with and without feedback has been made. The results showed that detection algorithm with feedback increases the effectiveness of the multi-frequency signals application under conditions of amplitude limitation.
Experimental research of receiver based on SEFDM-signals with optimal envelopes
Authors: Smirnova E N
Published: October 2019

This article describes a research of receiver which is part of SDR-modem based on SEFDM-signals (Spectrally Efficient Frequency Division Multiplexing) with optimal envelopes. Three envelope types and two values of frequency spacing between subcarriers in SEFDM-signals are implemented. Influence of combined use of methods of increasing spectral efficiency on BER performance is considered. Receive algorithm of SEFDM-signals is symbol-by-symbol coherent detection algorithm.
Study of the stability of the fiber-optic current sensor
Authors: Temkina V S , Mayzel A V
Published: October 2019

Optical fiber sensors are of particular interest for applications in the high-voltage environments of the electric power industry due to their characteristic properties including dielectric nature, immunity to electro-magnetic interference, and small size and weight. We have studied current sensor that employs the Faraday effect in the spun fiber and signal processing based on the additional harmonic modulation of the self-consistent polarization interferometer. We replaced the traditional PZT transducer with the LiNbO3 waveguide electro-optical modulator that allowed to increase significantly the modulation frequency and to reduce the length of the fiber delay line. Original error compensation methods allowed us to achieve the accuracy of ±0.2% in amplitude in the temperature range of about 50 °C.
Comparative analysis of the virtual and physical experiments with a snake robot’s rectilinear movement
Authors: Varlashin V V , Shmakov O A
Published: October 2019

The paper describes virtual and physical experimental studies of the “rectilinear movement” locomotion of a snake robot. Software for controlling the robot movements and registering the modules movements was developed in MATLAB and Simulink. A parameterized virtual model of a snake robot was implemented in the MSC Adams. Authors propose a method for processing experimental data and demonstrate the comparison results of the virtual and physical experiments.
Trellis channel joint equalization and demodulation of SEFDM signals
Authors: Gorbunov S V
Published: October 2019

An algorithm of channel joint equalization and demodulation of multicarrier signals with nonorthogonal frequency spacing (spectrally efficient frequency division multiplexing, SEFDM) is proposed. It is based on DFT (Discrete Fourier Transform) and BCJR (Bahl, Cocke, Jelinek and Raviv) algorithm adapted to work with frequency samples of received signal. The performance of proposed receiver is comparable with performance of classic OFDM-signal receivers.
Copoly Eugenol Crosslinked Dialylphthalate 8% as a Carrier in Phenol and Pb(II) Metal Transport
Authors: Kiswandono A A , Hadi S , Mudasir  , Sinjia F , Sari M Y , Irfan M
Published: October 2019

Synthesis of polyeugenol derivatives, copoly-eugenol-dialylphthalate (co-EDAF) through polymerization process between eugenol and diene compounds, dialyl phthalate (DAF) with boron triflouride diethyl ether (BF3.O(C2H5) as catalyst have been developed. Synthesized compounds were characterized using FT-IR, SEM, and TG-DTA. Furthermore, this compound was applied as a phenol transport carrier compound using the polymer inclusion membrane (PIM) method. The results showed that the co-EDAF compound has been successfully synthesized. The success parameters of the synthesis were indicated by the loss of the vinyl group (-CH = CH2) in eugenol at wavenumber 995.27 cm−1 and loss of allyl group at a wavenumber of 1636 cm−1. The results also showed that co-EDAF can function as a carrier compound for transporting phenols and Pb (II) metals. Pb (II) metal transport is smaller compared to phenol transport.
Synthesis 4-Piperoilmorpholine from Piperine
Authors: Bahri S , Ambarwati Y , Iqbal M , Baihaqy A A
Published: October 2019

Piperine was isolated from black pepper by soxhletation method using technical grade ethanol as a solvent. This compound was used as precursor for the synthesis of 4-piperoilmorpholine. The synthesis was carried out via a pre-target piperoilchloride, where the piperine was initially hydrolyzed using KOH ethanolate for 24 hours, added SOCl2 and then mixed with morpholine at 0-5° C. The result of synthesis was obtained 4-piperoilmorpholine with yield of 40,80%.
The Effect of Sugarcane Bagasse to Rubber Seed Oil Ratios on The Chemical Composition of Liquid Fuels Produced by Zeolite-y Catalyzed Pyrolysis
Authors: Simanjuntak A , Simanjuntak W , Pandiangan K D. , Sembiring Z
Published: October 2019

In this research, co-pyrolysis of sugarcane bagasse and rubber seed oil using zeolite-Y as catalyst was carried out, with the main purpose to study the effect of raw material compositions on chemical composition of liquid fuel produced. For this purpose, the mixture of sugarcane bagasse and rubber seed oil with different mass ratios of bagasse to oil of 1 : 1; 1: 2; 1: 3: and 1: 4 was subjected to pyrolysis at 450 ° C in the presence of zeolite-Y as catalyst, and the liquid fuels were analyzed by GC-MS. The results show that liquid fuel contains hydrocarbons as main components, with several additional components include alcohols, esters, ketones, aldehydes, and acids. The liquid fuel produced from the raw material with the ratio of 1 : 3 was found to contain hydrocarbon with the highest relative percentage (87.91%), and consists of gasoline fraction (42.60%), kerosene fraction (43.59%), and residual fraction (1.72%).
The potential of derivatives of organotin(IV) benzoate compounds in medicinal chemistry
Authors: Samsuar  , Simanjuntak Wasinton , Qudus Hardoko Insan , Hadi Sutopo
Published: October 2019

This paper deals with short review about the application of organotin(IV) compounds. The discovery of bacterial resistance to antibiotics drew the attention of chemists to discover new types of chemical compounds that have the antibacterial activity to overcome the resistance. Increased antibiotic resistance is a consequence of the evolution and adaptation of microbes, caused by excessive anthropogenic antibiotic consumption. Increased cases of bacterial resistance will be a bigger problem if not treated with the discovery of new antibiotics. The discovery of medicinal chemicals may contribute to the advancement of treatment, especially antibiotic resistant. Organotin(IV) compounds are part of organometallic compounds that have been studied their pharmacological effects on several types of bacteria. The derivatives of organotin(IV) benzoate compounds proven to have biological activity against some types of bacteria. The type and structure of the ligand in the compound derivative of organotin(IV) benzoate gives the influence of different biological activity against bacteria.
The Deposition of Silver (Ag) on a Glass Substrate (Sio2) using Direct Current Sputtering Method
Authors: Rumiyanti L , Ginting E S B , Aziz I , Sembiring S , Warsito
Published: October 2019

The research’s aims are to calculate the absorbance and the thickness value of the silver (Ag) thin layer formed on the glass substrate (SiO2) at various visible wavelengths. The silver (Ag) thin layer was formed using Direct Current Sputtering method. The research showed that the highest absorbance value on the glass (SiO2) substrate was 4.000 with wavelengths 287.50 nm. While, the lowest absorbance value on the glass (SiO2) substrate was -4.000 with wavelengths 262.50 nm and 243 nm. The lowest absorbance value is estimated because of the part of the substrate that has not been completely coated so that the part is not absorbed at all. Using Swanepoel equation we obtained the thickness value of the thin layer equal to 4.692663316 nm with sputtering time of 15 minutes.
Measuring of Cassava Starch Content by Using Strain Gauge
Authors: Surtono A , Aprilliana P , Supriyanto A , Pauzi G A , Junaidi  , Suciyati S W , Warsito
Published: October 2019

It has been realized an instrument for measuring cassava starch content digitally based on specific gravity method. The instrument is designed using strain gauge, which packing in load cell as a mass sensor, HX711 (Analog to Digital Converter), Arduino Uno as a data processor, LCD, and personal computer. The principles of this instrument are using specific gravity method, which is based on differences of cassava mass in the air and the water. Cassava starch content calculated by Arduino using Sungzikaw equation and displayed in LCD screen. The result showed that the instrument capable measure cassava starch content with the maximum capacity of 2,0 kg and average percentage error of less than 1,5 %.
Smart Patrol as Monitoring System In Resort Way Nipah Bukit Barisan Selatan National Park
Authors: Efendi A A , Fitria E , Haryanto S P , Charles Y , Rustiati E L
Published: October 2019

SMART is new aplication developed to measure, evaluate, an improve effectivity of monitoring and activity of conservation based of location. The research be held on march-april 2018, in Resort Way Nipah Bukit Barisan Selatan National Park (BBSNP), under program and collaboration with WWF-Indonesia Southern Sumatran Program. This research to understand effort security conservation area with SMART Patrol in Resort Way Nipah Bukit Barisan Selatan National Park. In this research use data patrol period July 2015-July 2017 as discussion material. Data devided into some groups (data series) consists of 4 groups is group 1 (period patrol September-December 2015), group 2 (period patrol March-June 2016), group 3 (period patrol September-December 2016) and group 4 (period patrol March-June 2017). High threat findings in period patrol March-June 2016 and 2017, while low threat findings in period patrol September-Desember 2015 and 2016. Wild animal findings increased in 3 first period and decreased in fourth period. Resort Way Nipah had over land function as plantation of coffee (Coffea sp), cocoa (Theobroma cacao), peper (Piper nigrum) and banana (Musa paradisiaca). Has been identified 25 species wild animal findings in Resort Way Nipah based on direct findings and indirect findings. Based on 25 species wild animal has identified, divided based on conservation status is Least Concern (9 species) Near Threatnes (4 species) Vulnerable (4 species) Endangered (5 species) and Critically Endangered (3 species).
Cytotoxic Activity Assay of N-Hexane Extract of Solanum nigrum L. Fruits Fermented by Kombucha against MCF-7 Breast Cancer Cell Line
Authors: Ziska R , Agustina A , Supriadi
Published: October 2019

Background: Breast cancer is the second leading cause of cancer-related deaths among women worldwide. Anticancer drugs therapy cause unwanted side effects problems that occur when treatment affects healthy tissues or organs. It is quite essential to find potential herbal as alternative cancer treatments. Glycoalkaloid (β2-solanin), solamargin, solasodine, dan solasonin of Solanum nigrum L. are potentially inhibit proliferation of leukemia and tumor cell: hepatic, intestinal, breast and cervic. On the other hand, kombucha as symbiotic culture of bacteria and yeast (SCOBY) has ability to increase activity of substrate by fermentation process. Objective: To determine cytotoxicity activity of n-hexane fruits extract of Solanum nigrum L. against MCF-7 breast cancer cell line after fermented by kombucha. Method: n-hexane fruits extract of Solanum nigrum L. was fermented for eight days at 25 ºC with 20% of combucha and addition of 20% of sucrose. Citotoxic activity was performed by using MTT(3-(4,5-dimethyltiazole-2-yl)-2,5-diphenyltetrazolium bromide) assay. Phytochemical of n-hexane extract was analyzed by GC-MS. Total acid and total phenol were characterized quantitatively. Results: IC50 of n-hexane fruits extract and fermentation product were 544,30 ppm and 1386,39 ppm, respectively. Flavonoids and steroids were identified from the extract and GC-MS shown seven compounds have been extracted from n-hexane fraction. Conclusion: condition of kombucha fermentation required optimization to improve cytotoxic activity of n-hexane fruits extract of Solanum nigrum L. against MCF-7 breast cancer cell line.
The Implementationof Digital Text Coding Algorithm Through A Three Dimensional Mapping Derived From Generalized ΔΔ-mKdV Equation Using Mathematica
Authors: Notiragayu  , Zakaria L
Published: October 2019

Encryption-decryption algorithm using a mapping can be done for encoding a digital text, such as two dimensional mapping ΔΔ-sine Gordon equation. In this article, we will be given an encryption-decryption algorithm to a digital text through a three dimensional mapping that derived from the generalized ΔΔ-mKdV equation. Implementation of Encryption-decryption algorithm in this article using MATHEMATICA.
Ethnomathematics batik design Bali island
Authors: Irawan A , Lestari M , Rahayu W , Wulan R
Published: October 2019

Aims of this study is to make an application to detect Balinese batik that has an etnomatematics elements using backpropagation method and to observe etnomatematics elements on Balinese batik. This study using qualitative descriptive methods with ethnographical approach, literature study, and expert study on etnomatematics issues. This paper shows that in typical Balinese batik there are several elements in the transformation of mathematics that are translation, reflection, rotation, while in other batik shows dilation elements In addition from the ethnography there are elements of spiritual and distinctiveness of the Balinese society that upholds local culture values.
Analysis of Internet Service Quality Using Internet Control Message Protocol
Authors: Hafiz A , Susianto D
Published: October 2019

Quality measurement needs to be done to determine the level of quality possessed by the system. Quality of Service is a measurement method issued by the European Telecommunications Standard Institute (ETSI). All activities at AMIK DCC utilize internet facilities, such as teaching and learning activities, administrative activities, student unit activities, and libraries. Because to support all these activities need a good and reliable of network. Some students complained about the lack of satisfaction of the internet network on campus. this research will analyze the Quality of Service internet network both wired or wireless in AMIK DCC Building by using Internet Control Message Protocol (ICMP). The data obtained will then be processed for analyzed throughput, packet loss, delay, and jitter to know how the quality of internet services. Based on the measurement, the results obtained that the throughputis 79%, the packet loss under 5%, the delay is below 175 ms and the jitter at 1%. From the results of research, it can be concluded that the Quality Of Service internet network in AMIK DCC included in the category satisfactory by TIPHON standards, but need to add repeaters to defeat the Internet network coverage for every floor and room.
Assessment of Science Teacher Competence in Teaching Secondary Science with Spiral Progression Approach
Authors: Maing Emily M. , Mangadang Almaira T. , Salic-Hairulla Monera A. , Canalita Everlita E. , Sequente Fernando R. , Yuenyong Chokchai
Published: October 2019

This study aimed to assess the competence of science teacher in teaching secondary science with spiral progression approach in terms of their knowledge on subject matter, teaching strategies, personality traits and teaching approach. Science teachers in both public and private schools within Lanao del Sur and Lanao del Norte served as the respondents of this study. The study used questionnaire as methodology and utilized the frequency distribution, correlation coefficient and regression analysis method. The result showed that the profile of the respondents specifically age, tenure and year in teaching science, and salary grade are correlated with science teacher’s competence in knowledge of subject matter. The result also showed that aside from age and tenure rank or position of the respondents is also correlated with the teaching strategies. Length of service correlates only with the personality traits of the respondents. Civil status, years in teaching, highest educational attainment correlates with the respondents teaching approach.
Magnet and Pin kit: Connection Symbolic and Submicroscopic Representations of Lewis dot structure and Molecular geometry
Authors: Kamkhou Phalakorn , Yuenyoung Chokchai
Published: October 2019

This work aims to connect the symbolic and submicroscopic representations of covalent compound’s Lewis dot structure and molecular geometry by using the Magnetic and Pin kit (MP-kit), which was constructed from magnets and pins. The MP-kit was created to facilitate the students. The kit has two sets, the first set, called Magnet set, consists of a 30x30 cm iron plate, an alphabet A with magnet (refer to central atom), 6 alphabets B with magnet (refer to surrounding atom), 18 white circular magnets (refer to valence electron of A), 42 black circular magnets (refer to valence electron of B) and 3 yellow circular magnets (refer to extra electron of molecule, from ion generation). Which was used to create the Lewis dot structure of covalent molecules. The second set, called Pin set, consists of a spherical eraser (refer to central atom), 6 pins (refer to bond and surrounding atom) and 3 droplet pins (refer to lone pair electron of central atom). Which was used to make the molecular geometry of covalent compounds, that predicted by using VSEPR theory. The users can use the Magnet set to create the Lewis dot structure without frequent drawing and rubbing on the papers. The magnets on the plate are moved for anytime when the users know it’s wrong. Moreover, this set can be used to show the number of bond pair electrons, types of bond and number of lone pair electrons on central atom. The Pin set is used to build the 3D molecular structure and specify the bond angles. The kit was used to link the symbolic and submicroscopic representations and encourage the student’s understanding. Finally, the teacher can use the MP-kit to check the student’s misconception, leading to solve problems immediately.
Challenges of implementing Lesson Study in Cambodia: Mathematics and Science Teaching by using Lesson Study at Happy Chandara School
Authors: Kim Visa , Douch Makara , Thy Savrin , Yuenyong Chokchai , Thinwiangthong Sampan
Published: October 2019

This study diagnoses the challenges of implementing Lesson Study (LS) in teaching mathematics and science at the junior high school and the senior high school of Happy Chandara School (HCS), Cambodia. This action research was selected during July 2017 to July 2018. The study seeks to answer two main questions: 1) what are the advantages of implementing LS? 2) What are the challenges of implementing LS? To collect the data, we carried out 5 steps: classroom observation, assessments of pedagogical content knowledge (PCK), surveys of teachers and school directors, introducing LS, and implementing LS. As the result, it found that LS helped teachers: to clarify the level of learning outcomes to which the instruction should be directed; to make a qualified lesson plan (it is not individual work); to become more cooperative to improve their teaching and students’ learning; and to build up the professional capacity among the group work of their colleagues with the same subject. Furthermore it sheds light on content and instruction, instructional support systems, the implementation of teacher standards, and time management as the challenges.
Formulating Refreshment Drink Activity Utilizing STEM Education for Grade 8 Learners
Authors: Guarin Rica Mae , Buan Amelia T. , Malicoban Elesar , Barquilla Manuel B. , Yuenyong Chokchai
Published: October 2019

This article is a qualitative study using literature review to create a lesson plan in STEM education. The lesson plan employs the pedagogy of purposeful design and inquiry. This proposes combining elements of design, art, geography and marketing into the disciplines in scientific inquiry of the STEM education in order to further strengthen it. The embedded lesson plan focused on identifying and solving social issues while hitting as many as possible learning competencies along the way. This lesson plan will serve as a contextualize application of learning competencies in Grade 8 Integrated science: biology, chemistry and physics as well as mathematics’ topic on statistics and social sciences’ topic on local geography. This study also include innovation and humanities so students learn skills such as communication, marketing and entrepreneurship. This will also be implemented with the goal of steering students’ interests towards a career in STEM and developing more 21st century as well as life skills that they can use in the future. The student activity in this lesson plan will be assisted and evaluated by the teacher through questions that are framed to encourage deep thinking about the concepts integrated in the activity and how it would be used to produce quality product that would solve the social issue presented at the beginning of the lesson.
Indonesian Students’ Attitude and Interest in STEM: An Outlook on The Gender Stereotypes in The STEM Field
Authors: Suwono Hadi , Fachrunnisa Rifka , Yuenyong Chokchai , Hapsari Linda
Published: October 2019

STEM education could be reckoned as a noble thing in the Indonesian Educational System in the last few years. This paper is a preliminary attempt to investigate the students’ attitude and interest in STEM regarding the gender perspective of Senior High School’s student in Malang, Indonesia. To explore the attitude and interest in the gender stereotypes, this quantitative method study has been conducted. 357 students participated in the survey which comprised 126 males and 231 females. The survey contended 40 items of belief’s indicators in the STEM field such as science, technology, engineering, mathematics and the STEM. Besides, at the end of the survey’s section, there are some options for future study programs and career to be selected by the learner. Unexpectedly, the finding of this project revealed that male has a more positive belief in the most of STEM field, such as technology, engineering, mathematics, and STEM, rather than female. In comparison, the female has a more positive belief than male in the science only. The marked investigation of emerging from the data comparison was both of male and female have a higher interest in the social field and medicine. However, the additional interest of male and female was significantly different. In males, we found that they have more interest in engineering, while females have an interest in biology. This study also disclosed that the factors, namely family support, family financial, friends, teachers, and hobby, determined both attitude and interest in STEM among students in Malang.
Examine Students’ Perception on Their Critical Thinking and Problem-Solving Ability through Journal Writing for Learning about Genetics and DNA Technology
Authors: Wongsila Saranya , Yuenyong Chokchai
Published: October 2019

This study examined grade 12 students’ perception on their critical thinking and problem-solving ability when they participated in the STS genetics and DNA technology unit. The participants were 43 grade 12 students in Maung, Khon Kaen, Thailand. The STS genetics and DNA technology unit were provided learning activities through STS approach in framework of Yuenyong (2006) and has been taught by the first author for 3 weeks. Methodology regarded interpretive paradigm. Students’ perception on their critical thinking and problem-solving ability were interpreted through their reflection as journal writing for their learning about genetics and DNA technology. Students’ journal writing was collected after each class of the STS genetics and DNA technology unit was done. The findings revealed that students perceived on their critical thinking and problem-solving ability when they wrote their journals to reflect what they learned. These reflections provided 4 elements of critical thinking and problem-solving ability. These included reason effectively, used systems thinking, make judgment and decisions, and solve problem. These finding would be a good practices for teaching biology through STS approach to who may take further applications for science teaching and learning.
Ice Cream STEM Education Learning Activity: Inquiry from the Context
Authors: Villaruz Eileen J. , Cardona Maria Cindy F. , Buan Amelia T. , Barquilla Manuel B. , Yuenyong Chokchai
Published: October 2019

The paper will clarify the ice cream making STEM education learning activities which provide through Sutaphan nad Yuenyong [11] context based STEM education learning approach. This approach consists of 7 stages including (1) Identification of social issues, (2) Identification of potential solution, (3) Need for knowledge, (4) Decision-making, (5) Development of prototype or product, (6) Test and evaluation of the solution, and (7) Socialization and completion decision stage. Icecream STEM Education Learning Activity will bring students to practice integrated knowledge among chemistry, mathematics, art, and economics in order to design their products of icecream. This may has implication for organizing STEM education in school setting.
The Influence of vocabulary mastery and reading comprehension towards performance of students in mathematics
Authors: Virgana V , Lapasau M
Published: October 2019

This study aims to find out about the influence of the vocabulary mastery and reading comprehension towards students’ mathematicals performance in PISA, either directly or indirectly. This research uses survey method with a quantitative approach and path analysis as a research design. The respondents are 70 students of Junior High School in Jakarta. Data collection is done through research instrument in the form of tasks about vocabulary and reading comprehension, while the mathematical questions about Space and Shape are taken from PISA 2015. The results of the analysis shows that there are: direct influence of vocabulary mastery towards students’ performance in mastering mathematical problems in PISA; direct influence of reading comprehension towards students’ performance in mastering mathematical problems in PISA; direct influence of vocabulary mastery towards reading comprehension; direct influence of vocabulary mastery towards students’ performance in mastering PISA’ mathematical problems through reading comprehension. It can be concluded that in order to enhance student’ mathematical competence in PISA, we also have to improve their competence in vocabulary mastery and reading comprehension through improvement of teacher’s competence and infrastructures at school such as language laboratory. We hope that this study can be beneficial for further research to improve mathematical competences of the students.
Solid geometry educational game based on student’s mathematical understanding
Authors: Pramuditya S A , Rozak A , Rukmana D
Published: October 2019

The low ability of students in solid geometry material and the lack of use of digital media make students less active and creative in the learning process. One way to solve this problem is to develop valid learning media. It can be used as a supplement by students. The aim of this study is to develop learning media in the form of android-based educational games. This research is a development research, and uses the ADDIE model. This learning media was tested for validity by three validators, and the implementation was tested in one class consisting of 23 students. Based on the validation test obtained a percentage of 94.79% and its implementation has very practical results with a percentage of 97.71%. The percentage is based on the data of the results of the pretest and posttest results, obtained by students in solid geometry material — the ability of mathematical understanding increase in the medium category. From these results it can be concluded that the media based android education game can be used in the learning process in the solid material and easy to use for students.
Measurement of health service performance through machine learning using clustering techniques
Authors: Dana R D , Dikananda A R , Sudrajat D , Wanto A , Fasya F
Published: October 2019

The health center is the first level public health service center that is run by the Indonesian government. Organizing quality health center services of health center is the hope and satisfaction of every patient. The dimensions of patient satisfaction vary greatly and the scope is very wide. Patient satisfaction can be used as an indicator of quality and service performance of health center. The purpose of this study was to measure the performance of health center services in order to determine the level of patient satisfaction and grouping the Patient Satisfaction Index. With the knowledge of the dimensions of performance and quality of health services provided by the health center, it will facilitate the government in carrying out the function of guidance and control of the health center. This study uses a Machine Learning technology approach with clustering techniques, by grouping the Patient Satisfaction Index with K-Means (Hard Clustering) and Fuzzy C-Mean (Soft Clustering) methods. Based on the subsets produced, clustering techniques can be divided into 2 methods, namely hard clustering techniques and soft clustering techniques. The K-Mean method is widely used in clustering techniques. K-Mean has advantages in computational speed and relatively easy process stages. While the Fuzzy C-Means method has advantages in terms of flexibility in determining clusters so that there is little possibility of converging failure. The experimental results of the Patient Satisfaction Index show that the K-Means method provides better performance with a value of 96% compared to the Fuzzy C-Means method with a value of 76%.
Fuzzy modelling to predict students’ attitudes toward mathematics using mathematical anxiety and self-efficacy data
Authors: Susanto H P , Sutarti T
Published: October 2019

This paper discusses how to predict students’ positive attitudes toward mathematics using mathematical anxiety and self-efficacy data. The dimension is rooted from many researchers concluding that mathematical anxiety, self-efficacy and positive attitudes towards mathematics have relationship each other. We also modelize form to predict students’ attitudes using a fuzzy model. 312 data for training and 68 data for testing models used is from 380 pairs of anxiety, self-efficacy, and positive attitudes data. Further analysis showed that the first fuzzy model within 13 fuzzy sets produces 61 fuzzy rule base and the fuzzy model with 16 fuzzy sets produces 82 fuzzy rule base. Every model is carried out by using MAPE for training and testing the data. The first fuzzy model, the second fuzzy model and regression model with training data successively produced MAPE of 7.35%, 7.06%, and 7.98%. Furthermore, using the testing data of the three models successively produced MAPE values of 7.43%, 7.16%, and 7.45%. Based on the MAPE, it can be concluded that the fuzzy model is better than the regression, and the fuzzy models with 16 fuzzy sets and 82 rules are the best models that can be employed to predict students’ positive attitudes toward mathematics.
Mathematical communication and social skills of the students through learning assurance relevance interest assessment and satisfaction
Authors: Ratnaningsih N , Hermanto R , Kurniati N S
Published: October 2019

The purpose of this research is to analyze mathematical communication skills and find patterns in thinking process of students in terms of social skills through learning Assurance Relevance Interest Assessment and Satisfaction (ARIAS). This research was conducted in Tasikmalaya city with 80 students as research subjects. The research method uses a sequential explanatory combination. Data was collected through tests of mathematical communication skills and social skills questionnaires. Data analysis techniques to test hypotheses using proportion tests. Based on the results of data analysis, it was concluded that mathematical communication skills of the students through ARIAS learning achieved ideal completeness. Subjects from very skilled groups, thinking processes in mathematical communication skills on each indicator written text, drawings, and mathematical expressions have written what is known and asked, equipped with images, the steps are clear, answer in 2 ways, but there are errors in so wrong calculations in the final result. Whereas subject from skilled groups, have not written in full what is known and asked, the stages are incomplete, some use images and are equipped with other alternatives in the process of completion. Subjects from quite skilled groups have deficiencies in each written text, drawing, and mathematical expressions.
Boreal tree-rings are influenced by temperature up to two years prior to their formation: a trade-off between growth and reproduction?
Authors: Tumajer Jan , Lehejček Jiří
Published: October 2019

Large spatial and between-tree variability has recently been observed in the response of boreal forests to ongoing climate change, spanning from growth stimulation by increasing temperatures to drought limitation. To predict future responses of boreal forests, it is necessary to disentangle the drivers modulating the temperature-growth interaction. To address this issue, we established two inventory plots (at a treeline and closed-canopy forest) and assembled site chronologies in Picea glauca stands at the transition between boreal forest and tundra in Northern Quebec, Canada. In addition to site chronologies, we established a set of chronologies containing, for each year, exclusive subsets of tree-rings with specific cambial age (young/old), tree dimensions (small/large) and tree social status (dominant/suppressed). All chronologies were correlated with climatic data to identify the course of climatic conditions driving variability in tree-ring widths. Our results show that the growth of P. glauca correlates significantly with summer temperature in tree-ring formation years and during up to two prior summers. Tree-ring width is positively influenced by summer temperatures in tree-ring formation year and two years prior to tree-ring formation. In addition, climate-growth correlations indicate a negative effect of summer temperature one year before tree-ring formation at the closed-canopy forest site. The pattern of climate-growth correlations is tightly synchronized with previously published patterns of climate-reproduction correlations of P. glauca, suggesting a growth-reproduction trade-off as a possible factor modulating the response of boreal forests to summer temperatures. Climatic signal does not differ between pairs of chronologies based on subsets of cambial ages, stem dimensions or tree competition status at the treeline site. However, the response to summer temperatures one year before tree-ring formation is significant only in mature (old, large and dominant) individuals at the closed-canopy site. The inverse pattern of temperature-growth correlations during a sequence of three years challenges predictions of how boreal forests respond to climate change.
Test Performance and Economic Analysis of Straw Chopper Machine
Authors: Sugandi W , Herwanto T , Handarto  , Juliya
Published: October 2019

The usage of rice straw as an alternative basic compost fertilizer is needed. Rice straw processing into compost fertilizer through stage chopper. Chopper is the size reducing stage that it is easily decomposed. The chopper processing can be done by using straw chop machine. This research aims for performance test and economic analysis. Research use descriptive analysis. The results of performance test of straw chop machine have actual capacity is 103.32±12.068 kg/h, engine efficiency is 79.59%, power requirement with load and without load are 1.1±0.067 HP and 0.698±0.109 HP, specific load 7.94 W/kg, chopper yield is 94.33±0.97%, the percentage of chopper chunks is 83.55±0.04%, engine noise level 76.6±0.5 dB, and vibration level on the framework, hopper and chopper cylinder are 18±4.9 mm/s2, 53.94±1.3 mm/s2 and 21.6±4.6 mm/s2. Based on the result of economic analysis of rice straw chop machine have the basic cost is Rp.46,159,621.- with gross income Rp.55,792,800.-/year. The breakeven point has been reached when the machine has chopped 41,078 kg of rice straw. This rice straw chopper machine has met the economic feasibility criteria of NPV>0 that is Rp.52,821,891. BC Ratio>1 with value is 1.17. IRR value> MARR interest rate (9%) with IRR 102%.
Actual and Prediction Body Weight Performance from Birth Until of 18 Months of Age in Dairy Cattle Friesian Holstein
Authors: Tasripin D S , Indrijani H , Anang A , Purnamasari H , Nanda E D
Published: October 2019

The aim of this research is to get the body weight performance and growth pattern of Friesian Holstein dairy cows from birth to 18 months. This study used monthly weight data of dairy Friesian Holstein cows from birth to 18 months (508 head). Obtained standard equation of body weight by using logistic regression model ŷ=363.53⁄=1+〖6.57e〗^(-0.21(x)) ) (Se = 14.78; r = 0.989), inflection point occurs at age 10 months (body weight 232.4 kg). The actual body weight of calves at birth until the age of 2 months is lower than the weight of the alleged body. The actual body weight of the calf aged 3 to 6 months is higher than the body weight of the estimation and the actual body weight of the calf above the estimation weight standard. The actual body weight of 7-9 months is still higher than the weight but at 10-12 months the actual body weight is lower than the expected weight, (puberty phase) that will affect growth. Month at 13-16 actual body weight is lower than the weight of the estimation body, as well as the previous month that is the first period of lust and puberty.
Utilization of Fermented Complete Feed Based on Mixed Pennisetum Purpureum and Indigofera Sp on Performance of Garut Male Lambs
Authors: Nurachma S , Nurmeidiansyah A A , Dhalika T , Ramdani D
Published: October 2019

This research was aimed to find out the use of fermented complete feed based on mixed Pennisetum purpureum and Indigofera sp on performance of Garut male lambs during fattening. A completely randomized design was used to compare 5 different complete feeds containing different Pennisetum purpureum (60, 70, 80, 90 and 100%) and Indigofera sp (40, 30, 20, 10, 0%) mixtures using 5 replicates. The measurable parameters were dry matter consumption, body weight gain, as well as feed conversion efficiency. The results showed that different mixtures of Pennisetum purpureum and Indigofera sp had a significant effect (P<0.05) on dry matter consumption with the highest dry matter consumption was obtained by mixture of 80% Pennisetum purpureum and 20% Indigofera sp (1,313.4 gram/head/day). However, the mixtures had no significant effect (P>0.05) on body weight gain and feed conversion efficiency of the lambs.
Performance and Income Over Feed Cost of Rambon Duck that Given the Ration Containing Gold Snail (Pomaceae canaliculata) and Noni Fruit (Morinda citrifolia L) Flour
Authors: Tanwiriah W , Nurlina L , Garnida D , Sujana E
Published: October 2019

The golden snail can breed very quickly and could become a pest for the plants especially rice plants. The Gold snails contains to use as duck feed. One of ducks that developed in West Java, is Rambon duck. In the maintenance of ducks, to improve productivity, usually required additional substances in ration. Noni plant which fruit is very nutritious, and contains anti-microbial that increase the productivity of livestock. This study aims to determine the level of gold snails and the Noni Fruits flour in a ration that gave the best Rambon duck performance and IOFC in the Jatigede Reservoir area. The research was done experimental and all data were analyzed statistically with Anava and further test with Duncan Test. The research used 200 DOD of Rambon duck that given 4 ration treatment containing gold snail flour (K) and noni fruit flour (M). The treatments were P1 (R1+0.45% M), P2 (R1+0.60% M), P3 (R2+0.45% M), dan P4 (R2+0.60% M). Parameters measured were feed consumption, body weight gain, feed conversion, carcass weight and IOFC. The results showed that P2 treatment (gold Snail 5%+0,60% noni fruit) gave the best Rambon duck performance with the value of IOFC Rp. 11,675.74 each bird