Indonesia Conference Directory

Corresponding Author
Erdawaty Kamaruddin

Institutions
(a) Vocational Education Program, Informatics Education Studies Program, State University of Jakarta, Jakarta, Indonesia
*erda_kamaruddin[at]yahoo.com
(b) Graduate Program, Education Research and Evaluation Program, State University of Jakarta, Jakarta, Indonesia

Abstract
Scoring is a process of converting test answers into numbers which are quantitative values of an answer to an item in an instrument. The numbers of the scoring results will then be converted into values through a certain processing process. The scoring model is a way of scoring a test. The scoring models can result in inappropriate score, where students cannot answer the easy items correctly but successfully answer difficult items. The research data were analyzed using the Donlon and Fisher method through biserial correlation. The study used the experimental method. The study population was high school students in DKI Jakarta, samples of seven hundred students were taken using proportional random sampling techniques. Data collection is done through Mathematics tests in the form of multiple choices using the correct score and punishment score scoring model. The results of data analysis showed the value of thit = 13.0750 and ttab = 1.645. Because of thit > ttab, it was decided to reject the null hypothesis. Thus it can be concluded that in the five option multiple choice objective test, the punishment score scoring model produces a more reasonable score than the correct score scoring model.

Keywords
scoring model, correct score, punishment score, math test

Topic
Mathematics

Link: https://ifory.id/abstract/ZK923Bv4LQ6V

Corresponding Author
Hasbullah Hasan

Institutions
Universitas Pendidikan Indonesia

Abstract
This study aims to determine the voltage losses on the 150 KV transmission line in Cibatu and Mandirancan Sub-systems in the PLN APB West Java region. This study utilizes the effect of the installation of Static VAR Compensator on voltage losses on a 150 KV transmission line during peak load conditions. By knowing the characteristics of the system on a channel that utilizes sensitivity to the addition of loads, the installation of SVC will have an impact on the improvement of voltage losses on the transmission network. This study uses simulations using ETAP software version 12.6. From the calculation simulation results that use the actual data of APB APB West Java in the amount of voltage loss on the channel. While based on the ETAP simulation results, there were improvements in voltage losses at Dawuan substation by 13.56%. This proves that SVC installation on transmission lines can reduce voltage losses in the Cibatu and Mandirancan Sub Systems.

Keywords
losses of voltage, transmission line, Static Var Compensator

Topic
Sample Topic

Link: https://ifory.id/abstract/CdaYyjTtn9Gv

Corresponding Author
Diena Rauda Ramdania

Institutions
a-e) Department of Informatics, UIN Sunan Gunung Djati Bandung
Jl. A.H. Nasution No.105 Cibiru, Bandung, West Java, 40614, Indonesia
*diena.rauda[at]uinsgd.ac.id

Abstract
A hospital is a labor-intensive organization that requires many personnel and professions from various disciplines. Employees are one of the determinants of the success of a company. One way that agencies use to obtain qualified employees is by making a selection at the time of employee recruitment. The problem that is often encountered is that part-time employee selection is done manually so that it is less efficient and accurate in the selection process. Decision support systems with the TOPSIS method are considered suitable to assist the personnel section of the public hospital in selecting prospective part-time employees. TOPSIS is a multicriteria decision-making method based on a concept where the chosen alternative has the closest distance from a positive ideal solution and also has the farthest distance from a negative ideal solution. The completion criteria applied to the selection of employees include the results of written tests, psychological tests, health tests, and interviews. The results of the tests show that the TOPSIS method can be used well in selecting and sorting from the largest to the smallest value with an accuracy rate of 85% in the amount of 20 data.

Keywords
hospital, employee selection, TOPSIS, decision support system

Topic
Information Engineering

Link: https://ifory.id/abstract/B2EeTyJGwjYn

Corresponding Author
Selly Anastassia Amellia Kharis

Institutions
a) Faculty of Mathematics and Science, Universitas Negeri Jakarta
Jalan Rawamangun Muka, Jakarta 13220, Indonesia
*sellyanas[at]yahoo.com

Abstract
Dengue virus is a member of the genus Flavivirus of the family Flaviviridae. The global incidence of dengue has grown dramatically in recent decades. The dengue virus has 10 viral proteins, 3 structural proteins and 7 nonstructural proteins. To perform the molecular functions required for invasion, replication, and spread of the virus, proteins encoded by dengue virus must interact with and alter the behavior of protein networks in both hosts. In this paper, we present a clustering dengue virus based on Tribe Markov Clustering (T-MCL). T-MCL is a graph clustering method which is the modification of Markov Clustering Algorithm (MCL). T-MCL process is built using R programming language is applied to PPI networks of 26 dengue virus genes data obtained from Virus Pathogen Database and Analysis Resource (ViPR) in 2010-2014. Because data processed in bioinformatics usually have a vast amount of information and have high sparsity, a method to save memory usage and make the computing process faster is needed. This research concludes that T-MCL method produces 7 groups of 26 dengue viral protein sequences with groups having one or more group centers using sparse matrix.

Keywords
Tribe Markov Clustering; Sparse Matrix; Dengue Virus

Topic
Mathematics

Link: https://ifory.id/abstract/wU6ZATKFRDcj

Corresponding Author
Shinta DORIZA, M.Pd., M.S.E.

Institutions
Universitas Negeri Jakarta

Abstract
The aim of this study is to develop media learning for Children Counselling Subject using application Appypie (android application based) at Family Welfare Education Department. In addition, this study also aims to measure the improvement of student-s learning when using this application. When developing the application, the ten stages of research and development method by Borg & Gall was employed in the study. To test the effect of the application, 30 students were involved in this research. We conducted a pre-test to find out their initial score level on Children Counselling Subject. Afterwards, students learned with Appypie application. By the end of the learning, we administer a post test. This research found that student learning result increased from 75% in the pre-test score to 88% (post-test) through quiz method which is provided in that application.

Keywords
Appypie application, android-based, children counselling subject

Topic
Computer Science

Link: https://ifory.id/abstract/bMJpyQaCGkqw

Corresponding Author
Teguh Budi Prayitno

Institutions
Universitas Negeri Jakarta

Abstract
We investigated the implications when introducing the higher order tensor in the Einstein field equations for the Schwarzschild metric on the vacuum condition and non de Sitter. Since the components of this tensor contain the fourth-order derivative, the solution of the Einstein field equations was solved by the Frobenius method. To see the implications, we tested two cases, i.e., the deviation of light and the time delay of light. We found that the deviation of light has no correction while the time delay of light needs correction.

Keywords
Higher order tensor, Schwarzschild metric

Topic
Physics

Link: https://ifory.id/abstract/Zpm3uJ4j9Rvc

Corresponding Author
Dedi sadudin Taptajani

Institutions
a) Department of Industial Engineering
b) Department of Informatics Engineering
Sekolah Tinggi Teknologi Garut

Abstract
There are many strategies that can be carried out by the company that will have implications / implications, which in general, namely the principal actors or network members in the chain of supply chains of red bricks that consist of five organizations or parties namely suppliers, manufacturers, distributors, retailers, and consumers. The five principal actors must be as a totality. Next The nature of competition between supply chain networks is then the phasing implications of the supply chain process where the evolutionary process requires phasing, so it needs to be detailed, differentiated, and planned about what, who, and how for each element such as drivers, focus, benefits, tools, areas of action, guidelines, models, alliances, and training, The key to supply chain management is network integration or management among all related companies, the company is still owned by the owner, and there are no acquisitions so that the strategies developed are total and collective, not the strategy of individual companies. All relevant parties need to be included in order to produce a plan believed and implemented together, which will then be carried out by several targets which are specific performance benchmarks, as well as improving customer relations. the SCOR model (Supply Chain Operations Reference) is used to issue performance measurement standards in the supply chain so that it can be used for comparison with other industries. In this research, it is expected to get a solution to declare the impact of the red brick supply chain seen in terms of total effort in improving and or creating competitive advantage (new) so that competition no longer occurs between companies, but between one supply chain and another supply chain , or between one company network and another company network.

Keywords
Supply Chain, Strategic, Management, Supplier

Topic
Industry Engineering

Link: https://ifory.id/abstract/WMPcQBJe79v6

Corresponding Author
Prasojo Pribadi

Institutions
(a) Student of Ph.D Program, Universitas Gadjah Mada
Universitas Muhammadiyah Magelang
(b,c,d) Universitas Gadjah Mada

Abstract
Improvement of service quality, customer satisfaction and loyalty give significant contribution to business performance and profitability. This study aims to identify the most critical factors related to hospital service quality in predicting the patients satisfaction and to examining the effect of patient satisfaction on patient loyalty. This research is a quantitative study with a cross sectional approach, involving 280 outpatients and valid questionnaire conducted in two hospital. Finally, the SPSS 21 and AMOS 22 (structural equation modeling) were performed to analyze the data. The lowest index performance is outcome quality (62.10) and highest is quality of personnel (78.89). Meanwhile, the calculation of the patient satisfaction index (PSI) is 75.60. Patient satisfaction is positively influenced by quality of personnel, outcome quality, social responsibility, administrative procedures, and physical aspects. Patients satisfaction has a positive effect on patient loyalty. However, health insurance, quality of medical care, and quality of pharmaceutical care did not influence patient satisfaction. Importance-performance analysis found the hospital institution needs to improve the administrative procedures and outcome quality. Overall the patient is satisfied with the performance of hospital services. Patients are objective controls of an organization. Therefore, hospital managers must be focus on strategies to building relationships with patients.

Keywords
Service quality; Satisfaction; Loyalty; Hospital; Importance-performance analysis

Topic
Management Science

Link: https://ifory.id/abstract/NcwVYpJjkWLh

Corresponding Author
Vingky Zulfa Asria

Institutions
Departemen Pendidikan Matematika, Universitas Pendidikan Indonesia, Jl. Dr. Setia Budhi No. 229, Bandung 40154, Indonesia
*vingky22[at]upi.edu

Abstract
This study aims to investigate whether or not there the difference between students- mathematics concept comprehension ability by using Think Pair Share (TPS) approach and by using direct learning reviewed based on their preliminary ability (high, medium, and low level). This research was a quasi experiment by using posttest only control group design that aimed to investigating the cause and effect by treating one of classes, and comparing the result of the class that was treated differently. Methods of data collection in this study through observation, documentation and test, involving 42 students of senior high school in Pekanbaru in the even semester of 2017. T test was used to analyzed the data. The results showed that there are difference between students- mathematics concept comprehension ability by using TPS approach and by using direct learning reviewed on their preliminary ability to learning outcomes. Classes with TPS approach give better learning outcomes than the ones in direct learning classes. Thus, in general the implementation of TPS approach influenced students- mathematics concept comprehension ability reviewed based on their preliminary ability at Senior High School in Pekanbaru.

Keywords
Think Pair Share, Students- Mathematics Concept Comprehension Ability, Mathematics Preliminary Ability

Topic
Mathematics

Link: https://ifory.id/abstract/fhqPwbxcRuDm

Corresponding Author
Azizah Zahra Jenar Suwarni

Institutions
Universitas Pendidikan Indonesia

Abstract
The aims of this study was to improve writing and storytelling skills of second grade elementary school students. Through digital literacy, students can have a meaningful experience when they learn to make and tell a story they have made. Students will be able to explore their competences while using a lot of audiovisual media for finishing writing and storytelling assignment. This research conducted with a qualitative research design by using observation and students- assessment as research instruments. Based on the findings, a conclusion can be drawn that digital literacy is able to improving second grade students- writing and storytelling skills

Keywords
digital literacy, elementary student, writing skills, storytelling skills

Topic
Computer Science

Link: https://ifory.id/abstract/AmZ7Lhd9aFJj

Corresponding Author
Mirsa Umiyati

Institutions
Universitas Warmadewa

Abstract
Since its establishment in 2009, the Faculty of Medicine and Health Sciences, University of Warmadewa has implemented a competency-based curriculum, in which teaching materials are grouped into block based on systems or themes. By this way, learning is expected to be more meaningful because clinical sciences can be introduced to student earlier. The study design was cross-sectional analytic where all students of the years 2016 and 2017 who underwent block 1.6 (Nervous System and Special Senses) were involved. From the present study we concluded that E-learning in combination with conventional learning method (blended learning) increased student achievement in final students assessment of the block Nervous System and Special Senses, hence E-learning can be applied as a supporting tool for conventional learning method.

Keywords
Learning Achievement; Block of Nervous System; Special Senses; Blended Learning

Topic
Computer and Communication Engineering

Link: https://ifory.id/abstract/cVGMAYQDmtek

Corresponding Author
Devi Nurrahma Wulandari

Institutions
(a) Jl. Maulana Hasanudin No.63, Cipondoh, Kota Tangerang, Banten 15148, Indonesia
(b) Physics Education Study Program, University of Jakarta,
The way the Youth No.10, Rawamangun - East Jakarta, 13220

Abstract
STEM learning provides students with knowledge and concepts that have relationships and applications in everyday life. In addition, students are given many opportunities to develop the ability to think and literate through the process of engineering design based on scientific knowledge. The purpose of this study was to identify the effects of STEM learning in improving scientific literacy of students at high school level. This study explores the integration of STEM performance to develop students scientific literacy. Learning Physics on the topic of global warming is implemented to produce solar cooker products. Data was collected from field notes, and scientific literacy tests with the value of student can describe and carry out experimental procedures 50%, student can demonstrate logical reasoning in explaining natural phenomena, experimental procedures or outcomes, and application of scientific or technological concepts 100%. Finally, the implementation of the STEM project in physics has provided opportunities for students in physics learning involvement and the development of scientific literacy.

Keywords
STEM Learning, Science Literacy

Topic
Physics

Link: https://ifory.id/abstract/3bDaWkyPKcAw

Corresponding Author
Ni Komang Alit Astiari

Institutions
a Agrotechnology Study Program, Faculty of Agriculture,Warmadewa University, Denpasar, Bali.
b Agroecotechnology Study Program, Faculty of Agriculture,Udayana University, Denpasar, Bali.
* E-mail: alit.astiari[at]gmail.com

Abstract
This study aims to improve the quality of citrus cv. Siam through fertilization and pruning. This experiment used factorial randomized block design consisting of 2 factors. The first factor is fertilization consisting of 3 levels (P0 = only fertilized with manure/control, P1 = manure,N,P,K,Ca, and P2 = manure,N,P,K,Ca,Zn,Cu). The second treatment is pruning consisting of 3 levels (M0 =without pruning, M1 =pruning young shoots, and M2 =pruning young shoots, leaves and twigs that are protected and affected by disease). Fertilization treatment with P2 improved fruit quality, which was reflected by the increase of harvested fruit weight per tree (99.79%); weight per fruit (35.69%) and total dissolved solids (30.22%). Harvested fruit weight, weight per fruit, and total dissolved solids on treatment with P2 were 3442.76g, 173.58g, and 9.48obrix, respectively, but on control that were only 1673.13g; 127.92g and 7.28obrix. In the pruning treatment, the best results were obtained in M2 which was reflected in the increase in weight of fruit harvested per tree (40.91%), weight per fruit (19.56%) and total dissolved solids (25.55%). Fruit weight per tree, weight per fruit, and total dissolved solids in M2 treatment were 3638.77g, 173.58g, and 9.63obrix respectively, but in controls only 2582.34g, 145.92g, and 7.67obrix

Keywords
fruit quality, off-season, fertilization, pruning, Citrus cv. Siam

Topic
Biology

Link: https://ifory.id/abstract/weq3vDjfG2hF

Corresponding Author
Yani Suryani

Institutions
Department of Biology
Faculty of Science and Technology
UIN Sunan Gunung Djati
Bandung

Abstract
In-silico study of kaempferol has been performed to determine its potential as a natural estrogen competitor in an effort to suppress the growth of endometrial cancer. This study used a method of molecular decelerating of kaempferol against estrogen receptor alpha, which is compared with natural estrogen in the body. The research process was conducted at the Laboratory of Biology Department of Science and Technology Faculty of UIN Sunan Gunung Djati Bandung, from December 2017 until February 2018. The software used in this study is PyRx-Virtual Screening Tools (for molecular docking process) and Discovery Studio (for pose visualization and data analysis). The results showed that kaempferol is a potential natural estrogen competitor. It is indicated by the lower binding affinity value of kaemperol (-7.0 kcal / mol) than the binding affinity of natural estrogen (-6.7 kcal / mol). The low affinity binding value shows a stable interaction.

Keywords
Binding Affinity, Molecular Deceleration, Kaempferol, Estrogen Receptor Alpha, RMSD

Topic
Computer Science

Link: https://ifory.id/abstract/U8DmYk4EMNKG

Corresponding Author
Jajang Sugiat

Institutions
STIE Yasa Anggana Garut
Jl.Otto Iskandardinata No.278 A Garut

Abstract
Increasing Student Trust through the Service Marketing Mix Strategy with Value Services as an intervening variable (Study in Private High Schools in Garut Regency) This study aims to find out, analyze, and test the Service Marketing Mix Strategy, Service Value and Student Trust, and the Effect of Service Marketing Mix Strategy on Service Value and Effect of Service Value on Student Trust in Private Colleges in Garut Regency. The method used in this research is explanatory survey method. Data were analyzed using the Path Method analysis technique to explain the relationship and influence between manifest variables and confirmation analysis Based on the results of the study, the findings obtained include: The Marketing Mixing Strategy is in the Enough to Good category. Value of Service is in the category of Enough for Good, and Student trust is in the Enough for Good category. The Service Marketing Mix Strategy significantly affects the Value of Services and Value of Services significantly influencing Student Trust in Private Universities in Garut Regency. Keywords: Service Marketing Mix Strategy, Service Value, and Student Trust

Keywords
Service Marketing Mix Strategy, Service Value, and Student Trust

Topic
Management Science

Link: https://ifory.id/abstract/hq3YXmkNHDLb

Corresponding Author
rohman dijaya

Institutions
Universitas Muhammadiyah Sidoarjo

Abstract
UMSIDA Eprints is a repository of student and lecturer publication documents at the Muhammadiyah Sidoarjo University (UMSIDA). The collection of documents is still random and the search can only detect from the title keywords. The increasing culture of writing and research makes it possible for more and more documents as literature. Documents in Eprints are grouped by subject provided by the repository manager and grouped by the admin who uploaded the document. Automatic document grouping can be done by grouping documents based on the contents of the document using the Information Retrieval (IR) approach. The retrieval process is carried out by document processing with tokenization to obtain data tokens, the data tokens are processed through a stemming process to obtain the stem value of each word. The stem value is processed using the indexing process and word stem to get sentence indexes through the weighting process. The index results stored in the database become document variables that are the features or characteristics of each document. The index of all documents is grouped through the Kmeans Genetic Algorithm (GA-Kmeans) by determining the similarity of the document or the proximity of the centroid with the index of each data. The cluster data will be in accordance with the groups grouped from the closest distance to the cluster.

Keywords
Automatic Optimation,Eprints,Genetic Algorithm, Index, Information Retreival

Topic
Computer Science

Link: https://ifory.id/abstract/vB3XDFuKnErV

Corresponding Author
Susilawati -

Institutions
Universitas Wijaya Kusuma Surabaya

Abstract
Rhizosphere microorganisms such as phosphate solubilizing bacteria have been widely reported as bacteria that have the ability as phosphate solvents and promote growth. The purpose of this research was to isolate the indigenous bacteria from waste Maja fruit and evaluate whether these could enhance the viability of deteriorating rice seeds. The method used in the first stage of isolation, and evaluation of germination of rice seeds using a completely randomized design. It was revealed that three isolates are isolate 1-1, isolat1-2, and isolate 1-4 were able to solubilise phosphate and produce indole. The Result showed that the three isolates were able to increase the persentage of germination by up to 39,33%, the uniformity of germination by up to 40,76% and germination rate by up 10,46%/d.

Keywords
Phosphate solubilizng bacteria; Waste maja fruit; Viability; Rice seeds

Topic
Material Science

Link: https://ifory.id/abstract/fYE3n8pZwRTX

Corresponding Author
Mujiarto Mujiarto

Institutions
a) Department of Electrical Engineering, Universitas Muhammadiyah Tasikmalaya
*hani.rubiani[at]umtas.ac.id
b) Department of Information Technology Education, Universitas Muhammadiyah Tasikmalaya
c) Department of Mechanical Engineering, Universitas Muhammadiyah Tasikmalaya, Jl. Tamansari Km. 2,5, Mulyasari, Tamansari, Tasikmalaya 46196, Indonesia
*mujiarto[at]umtas.ac.id

Abstract
Estimating the location of Object in an indoor environment poses a fundamental challenge in ubiquitous computing. Indoor localization based on signal strength by utilizing devices in buildings such as WiFi signals is increasingly being done. To determine the user-s position using the algorithm of the received signal strength. This paper shows that contrary to popular belief an indoor localization system based on WiFi fingerprints using Support Vector Machine (SVM) method. The performed experiments using 14480 datasets and 302 classes, collected from real world environments in building, and the comparison with Naïve Bayes confirm the effectiveness of SVM-based localization proposal. Experimental results show that the system achieves a correct classification rate of around 88% and minimum average error distance 4.61 meters compared to Naïve Bayes for correct classification rate of around 67% and minimum average error distance 6.21 meters.

Keywords
Support vector machine; SVM; Naive bayes; Indoor localization

Topic
Computer and Communication Engineering

Link: https://ifory.id/abstract/aGe6gb7THEcx

Corresponding Author
sri susilawati islam

Institutions
a) Industrial Engineering Program Study, Sampoerna University, Jl. Raya Pasar Minggu No.Kav. 16, Jakarta 12780, Indonesia
*sri.islam[at]sampoernauniversity.ac.id
b) Accounting Program Study, Sampoerna University, Jl. Raya Pasar Minggu No.Kav. 16, Jakarta 12780, Indonesia
c) Industrial Engineering Program Study, Borobudur University, Jl. Raya Kalimalang No.1, Jakarta 031018, Indonesia

Abstract
The research aims to examine factors that may cause inventory mismanagement in a Small Medium Enterprises (SME), which is a market leader in the Heavy Equipment after sales business, is selected. The company is selected because despite its status as market leader, the company deals with various inventory problems, for examples slow moving stocks, delivery delays to customers, etc. Those problems, at the end, may reduce companys profit. In order to determine the main causes, this study applies quantitative and qualitative methods. Quantitative method, specifically Pareto diagram and Inventory Turnover Ratio (ITR) is mainly used to evaluate sales and inventory management. ITR is affected by spare part quantity, warehouse area used, and the material amount. The top five ITR ratings are examined further through observation, interview, and questionnaire techniques. Meanwhile, the qualitative method is applied to evaluate the companys inventory information systems, procedures and coordinations among departments, and human resources. Our findings suggest that the unintegrated companys information system and lack of qualified human resources are the main factors affect inefficient inventory management. The research benefits to industry by suggesting the importance of information systems and human resources to inventory management. As for academics, this research enriches inventory management literature.

Keywords
Inventory Management, Small Medium Enterprise, Inventory Turnover Ratio

Topic
Industry Engineering

Link: https://ifory.id/abstract/JkVN2wr3acxt

Corresponding Author
Saroso Saroso

Institutions
Universitas Negeri Malang

Abstract
The aim of this study are, to determine the influence of achievement motivation, the inspiration of the learning model, service satisfaction, career expectations, to the achievement of learning and self-confidence graduate Polytechnic of Road Transport Safety. The sample in this research consist of 308 students of Polytechnic of Road Transport Safety. The data obtained from questionnaires distributed to the respondents. After the data collected continued with the validity and reliability test by using the formula Confirmatory Factors Index then the data were analyzed by using SEM technique. The results showed in general, the conclusion of this research there is influence of achievement motivation, inspiration from learning model, service satisfaction, and career expectation toward learning achievement and self-confidence of graduate of Polytechnic of Road Transport Safety

Keywords
achievement motivation, the inspiration of the learning model, service satisfaction, career expectation, achievement of learning and self-confidence of graduates

Topic
Management Science

Link: https://ifory.id/abstract/PEYGMB6ZVyf2

Corresponding Author
Eddy Soeryanto Soegoto

Institutions
Departemen Teknik dan Ilmu Komputer, Universitas Komputer Indonesia, Indonesia
Departemen Teknik dan Ilmu Komputer, Universitas Komputer Indonesia, Indonesia
Departemen Teknik dan Ilmu Komputer, Universitas Komputer Indonesia, Indonesia

Abstract
The purpose of this research is to explain the influence and advantages of artificial intelligence in the automotive industry. This research uses descriptive research method where data is obtained from existing facts. The results of this research is explain how important driverless cars technology is in the application of artificial intelligence in the automotive industry, and how the advantages and disadvantages of driverless cars technology are applied nowadays. The results of the research were obtained because the increase of human needs in the era of technology industry 4.0, so some companies developed driverless cars technology. This research was conducted to discuss the influence of artificial intelligence in the automotive industry by applying driverless cars technology.

Keywords
Artificial , Automotive Industry,

Topic
Computer Science

Link: https://ifory.id/abstract/GVruZHaK6tX9

Corresponding Author
Siska Titik Dwiyati

Institutions
Pendidikan Teknik Mesin, Universitas Negeri Jakarta

Abstract
The purpose of this research was to study tensile properties of 3D printing ABS material with axial and lateral direction. The specimen was printed according to ASTM D 632-02 by layer thickess variations around 0.1 mm, 0.2 mm and 0.3 mm. Moreover, three specimens was made for each printing direction. Tensile test was performed using Zwick Roell Series Z 021 machine. Then, the fracture surface was studied with scanning electron microscope (SEM). Based on the research from 6 variations layer of 3D printing, the optimal result was found on the axial direction of 0,3 mm thickness layer with tensile strength 30,6 MPa and ultimate tensile strength 550,81 N. The voids were seen at the fracture surface.

Keywords
3D printing, tensile properties

Topic
Material Science

Link: https://ifory.id/abstract/9V7Xjr3wJKbz

Corresponding Author
Butje Alfonsius Louk Fanggi

Institutions
a) Civil Engineering Department, Politeknik Negeri Kupang, 85000, Jl. Adi Soecipto-Penfui, NTT 85000, Indonesia
*butje2017[at]gmail.com
b) Dry Land Agriculture Departement, Politeknik Pertanian Negeri Kupang, Jl. Prof. Dr. Herman Johanes, NTT, 85001, Indonesia

Abstract
It is well known that rice husks ash can be used as cementitous material. However, different climate and geographical conditions could provide different quality of the ash. Therefore, this study aimed to investigate the effect of different percentage of local rice husk ash (RHA) taken from Oesao village in Nusa Tenggara Timur-Indonesia on compressive strength of normal-strength concrete. Eight specimens with diameter of 150 mm and height of 300 mm made of normal-strength concrete with replacement of .0%, 5.0%, 10%, 15% of Portland cement with RHA were cast, prepared, and tested until failure. It is found that the maximum strength was observed on specimen with replacement of 10% of the ash.

Keywords
rice husk ash, compressive strength

Topic
Civil Engineering

Link: https://ifory.id/abstract/KkngHdB2yhjG

Corresponding Author
dhawud sabilur razaq

Institutions
(a) Department of Physics, Universitas Indonesia, Depok 16424, Indonesia
* budhy.kurniawan[at]sci.ui.ac.id
(b) Research Center for Metallurgy and Materials, Indonesian Institute of Sciences (LIPI), Gedung 470, Puspiptek, South Tangerang 15314, Banten, Indonesia

Abstract
A systematic study of the La0.7Ba0.1Sr0.2Mn0.85Cu0.15O3 manganites have been conducted, mainly to understand the influence of sintering temperature on structure, microstructure, and electrical transport properties in the materials. Polycrystalline sample of La0.7Ba0.1Sr0.2Mn0.85Cu0.15O3 were prepared using sol-gel method and sintered at 1100 °C and 1200 °C. X-ray diffraction result shows that sintering temperature does not affect the crystal structure of the materials which remain rhombohedral with R-3c space group. a more detailed examination shows that sintering temperature change the unit cell volume, bond length, and bond angle of the samples. The electrical resistivity decreases followed by the decrease in the grain size with the increase in sintering temperature. Analysis using theoretical model shows that both samples can be well explained using percolation model. Fitting result suggests that the transport properties of the materials at low temperature were governed by the scattering and interaction between electron, phonon, and magnon. At high temperature, the electrical transport of the samples were governed by the hopping of polarons.

Keywords
Structure; Electrical Transport; Sintering; Percolation Model; Manganites

Topic
Material Science

Link: https://ifory.id/abstract/QhkW6jvTfrCw

Corresponding Author
Zulkarnain Jalil

Institutions

1Department of Physics, Syiah Kuala University, Banda Aceh 23111, Indonesia
2Department of Mechanical Engineering, Syiah Kuala University, Banda Aceh 23111, Indonesia
3Department of Physics, Jakarta State University, Jakarta, Indonesia

Abstract
MgH2 is one of the most promising material for hydrogen storage application, since its reversible and able to store hydrogen in large amounts of 7.6wt%. In this study, nickel and silicon oxide catalysts were used to reduce the operational temperature of MgH2. The silicon oxide used in this study was extracted from rice husks ash. The composition of MgH2 + 10wt% SiO2 + 5wt% Ni was prepared by mechanical alloying technique, by varying milling time 1, 5, 10 and 15 hours. XRD results indicate a decrease in particle size with longer milling time. MgH2 was obtained as the main phase followed by Ni and SiO2. SEM results showed that the longer milling time, the more particle size is homogeneous. Furthermore, thermal investigation using DSC showed that the desorption temperature obtained was in the range of values of 331,8 0C to 342,3 0C. The addition of 10wt% SiO2 and 5wt% Ni have improved sorption temperature and kinetic of MgH2.

Keywords
Magnesium, hydrogen storage, mechanical alloying, catalyst, desorption

Topic
Material Science

Link: https://ifory.id/abstract/vkwLmBuVaMyU

Corresponding Author
Muhammad Arsyad

Institutions
a) Mechanical Engineering Department, Politeknik Negeri Ujung Pandang, Jalan Perintis Kemerdekaan KM.10 Tamalanrea, Makassar 90245, Indonesia
b) Mechanical Engineering Department, Univeristas Brawijaya, Jalan M.T. Haryono No.167 Malang 65145, Indonesia
* arsyadhabe[at]poliupg.ac.id

Abstract
The objectives of research is to determine the effect of long soaking of coconut fiber in alkaline solution to the tensile strength of coconut fiber. The testing stages include preparation, soaking, drying, testing, and analysis. The materials used consist of coconut fiber, alkali solution, aquades, tensile test equipment, and furnace. Coconut fiber is soaked in an alkali solution with a concentration of 20% for 1, 5, 7, 9, and 11 hours. Then, the coconut fiber was rinsed with aquades before being dried in a furnace at 90oC for 5 hours. Furthermore, tests of mechanical properties include a single fiber tensile of coconut fiber with ASTM. Based on the results and discussion, it can be concluded that (a) the alkali treatment decreases the amount of hemicellulose and cellulose in coconut fiber, (b) the maximum tensile strength obtained at 7 hour treatment is 223.907 N/mm2.

Keywords
soaking; alkali; tensile; coir

Topic
Material Science

Link: https://ifory.id/abstract/tyupjgePEwFB

Corresponding Author
RINI SETIATI

Institutions
Petroleum Engineering Departement , FTKE, Universitas Trisakti , Jakarta

Abstract
Pore volume of foam cement is a main factor affected compressive strength in the addition axial load design. Foam agent material used in this research is Sika-aer as a replace the nitrogen gasses. This research study used mix composition cement 1 : silica sand 0.25 : water 0.5and foam agent 0.03% - 0.15% BWOC. The purpose of this study is provide alternative cementing product beside lightweight cement in oil and gas industry with foam cement to mitigate loss circulations. Compressive strength testing was carried out with different time periods and pore volume testing were carried out on each addition/change in foam agent concentrations every cement slurry mixture. Characteristics of bubbles on cement slurry is one of many factors that influences compressive strength parameters. Compressive strength foam cement depends on size, diameters and relationship between bubbles on the cement slurry. This laboratory study produced compressive strength values between 1078 psia – 3745 psia and pore volume values between 15 cc – 17 cc in 5 samples core foam cement with different foam agent concentrations Sika-aer.

Keywords
foam cement, pore volume, compressive strength, bubbles, Sika-aer

Topic
Material Science

Link: https://ifory.id/abstract/9ZCnYUuGRmKD

Corresponding Author
Helfy Susilawati

Institutions
Electrical Engineering Departement, Universitas Garut

Abstract
Availability of a parking place in the shopping center remains a problem since the vehicle that will go into the parking area will be look for an empty parking space with no definite goal. This research intends to design information regarding the possible parking place for the vehicle when entrancing to the shopping center. By doing that, the incoming vehicle just go straight to an empty parking place. This research uses prototyping method using microcontroller as input data processor, Inductive Proximity sensor, Wifi module, and Web application. When vehicles come into the parking lot A, the sensor will provide the data on the Arduino in which the parking place A has a vehicle, and then the data will be sent to the Web application by using Module Wifi so that the web for the parking place A will get information that is already filled. There will be a description where the parking place is available on the other parking places such as the parking lots B and C. By doing this research, the parking place for the vehicle will be more well-organized and can make it easier for the vehicle that will go into the shopping center.

Keywords
Avaliable Parking, Proximity Inductive, IoT

Topic
Electrical Engineering

Link: https://ifory.id/abstract/NbRctDPFTHGM

Corresponding Author
Yosep Septiana

Institutions
Department of Informatics, Sekolah Tinggi Teknologi Garut, Jalan Mayor Syamsu 1, Garut 44151, Indonesia
*yseptiana[at]sttgarut.ac.id

Abstract
Healthcare organizations can use differentiation and cost reduction strategies to gain a competitive advantage and can survive in fierce competition by implementing information system strategies. The research aims to build an information system for strategic planning in healthcare organizations. The information system strategic planning method used is the Ward and Peppard Model with a formulation framework and strategic planning process covering the stages of input, output, and evaluation of information system interpretation. The input stage includes an analysis of the business and information systems environment. Output stages include business information system, information system management strategies and information system strategies. The evaluation phase of information system interpretation is modified by the use of Balance Scorecard Information Technology, and the evaluation stages are carried out after the information system planning and application mapping so that the application portfolio is aligned with the corporate contribution perspective, user orientation, operational excellence, and future orientation. The result of this research produced a recommendation for healthcare organizations in the form of development priorities which include the establishment of an information system unit and the development of an application portfolio that will support the business processes sustainability

Keywords
Balance Scorecard; Healthcare; Information System; Strategic Plan; Ward and Peppard

Topic
Information Engineering

Link: https://ifory.id/abstract/KdTm2eFUzqPg

Corresponding Author
Riser Fahdiran

Institutions
1Department of Biology, Faculty of Mathematics and Natural Science, University of Indonesia, Depok, IDN

2Biology Department, Faculty of Mathematics and Natural Sciences, Universitas Negeri Jakarta, Rawamangun, Jakarta Timur, Indonesia, 13220

Abstract
Microplastics (MPs) is the most contamination problem on the marine environment. Small pelagic fish like anchovies are one of the organism which exposured by microplastics, yet reported contamination on Indonesian anchovies is lacking. Here, the investigation result from anchovies digestive tract (Stolephorus spp.) sampled (n = 15). The total microplastics contamination from Talisayan harbor, East Kalimantan is 366 ± 3,51 particles/individual. Kind of microplastics size range detected as categories: < 20 µm, 20-50 µm, 50-500 µm, 500-1000 µm, and >1000 µm. Most of microplastics shapes from Talisayan harbour are microfilm (50%) and microfiber (29,59%). The type of polymers are confirmed by Fourier transform infrared (FTIR) spectroscopy as polypropylene, high-density polyethylene and foamed polystyrene nylon. Our findings reported that spesific size range (50-500 µm) is the most majority of microplastics size range which are ingested by anchovies from Talisayan harbor. The microplastics are more dangerous if another contamination found together on it. On this investigation, the mercury contamination also tested and the result showed as not detected mercury contaminant. The anchovies are had the economic value and also small pelagic fish which are play as prey for the other big fish. The exposured are possible to the human by contaminated seafood diet.

Keywords
Ingestion; microplastics; anchovies

Topic
Biology

Link: https://ifory.id/abstract/9ezW836LxXCM