Indonesia Conference Directory

Corresponding Author
Yohanes Raymond Adikarta

Institutions
Magister Management Universitas Indonesia

Abstract
In this modern era brings a significant changing on life style. The modern people think of how important that the status is. Indicator to measure how high people status is by looking at the attribute they wear, called fashion. Fashion brings confident to somebody. One of the fashion icon that became trend nowadays is Nike product. Luxury brand is high quality product and also service that expensive, exclusive, presticious, authenthic, offering high level of emotional value through consumer experience. Based on several of luxury brand above that has already done with social media marketing strategy, Nike React Element 87, will try this strategy. Through social media, consumers can easily and quickly access User Generated Content (UGC) that contain review and information related to the product. The indicator to measure in choosing the right vlogger based on total subscribers or viewers. So, this paper made to help marketer of Nike shoes to select the right Vlogger for Nike React Element 87.

Keywords
Digital Marketing, Youtuber, Vlogger, Social Media, Luxury product, Shoes, Nike

Topic
Marketing Management

Link: https://ifory.id/abstract/QjnHEy8vWK7M

Corresponding Author
Edi Supardi

Institutions
Universitas Pendidikan Indonesia

Abstract
The Purpose of this research is to examine the impact of Value Equity, Relationship Equity and Affective Commitment to Loyalty Intention on Go-Jek Indonesia. Sample is selected from student at several Polytechnics and Universities in Bandung Who use to utilize Go-Jek services throught their mobile phone application. 91 Questionnaires were analyzed in order to get a meaningful conclusion. The hypotheses which are tested based on the Value Equity, Relationship Equity, Affective Commitment and Loyalty Intention. All the hypotheses was accepted. Hypotheses were tested using SPSS SmartPLS. Result indicated that Almost of young people in bandung use to utilize Go-Jek Services while they will keep loyal in the future as Go-Jek, Value Equity, relationship Equity and Affective Commitment have a positive impact to Go-Jek Customer Loyalty Intention.

Keywords
Value Equity, Relationship Equity, Affective Commitment, Loyality Intention

Topic
Marketing Management

Link: https://ifory.id/abstract/ra2TVREnZuq8

Corresponding Author
Pantjanita Novi Hartami

Institutions
Trisakti University,

Abstract
The selection of appropriate rock support system in accordance with rock properties and rock mass classification should be applied to get the underground mine stability. Underground gold mine of Pongkor Indonesia use friction bolt (split set) and H-beam. For efficiency of rock support system, it is planned to replace the previous rock support system with Mechanical Anchor Bolt as an alternative rock support system. The trial of Mechanical Anchor Bolt was conducted on Cross Cut 519 to Southern on Kubang Kicau vein. The lithology of location dominantly consists of andesite tuff, tuff breccias and quartz veins. The mapping of geological structure was applied to obtained the structural condition. In line with the scanline, the laboratory testing is also carried on in order to get the physical and mechanical properties of rock. By using Rock Mass Classification and the viability index wedge analysis, the technical performance of both supporting was compared and evaluated. The duration of installation of Mechanical Anchor Bolt is observed during the trial and its was compared to previous supporting system. Numerical modeling using Dips, Un-wedge and Examine are applied to model the underground stability. Based on the trial results, the use of Mechanical Anchor Bolt was evaluated to be applied in production stope (Ciguha Flat Back 475 and Gudang Handak Sill Drift Vein C Ramp Down Connect 450) and development access (Pasir Jawa Access Ramp Up to South)

Keywords
friction bolt, H-beam, mechanical anchor bolt, rock mass classification, numerical modelling

Topic
Mining and Metallurgy Engineering

Link: https://ifory.id/abstract/fKtwBhjcz2kC

Corresponding Author
Afiat Anugrahadi

Institutions
a) Geological Engineering Department, FTKE Universitas Trisakti, Jakarta, Indonesia
*afiat[at]trisakti.ac.id
b) Mining Engineering Department, FTKE Universitas Trisakti, Jakarta, Indonesia

Abstract
The Palu earthquake on 28 October 2018 not only destroyed the facilities and infrastructure of human life in the Palu area and its surroundings, but also geological aspect. The earthquake geologically not only caused land and rock movements, tsunamis, and geological damage such as the formation of new faults and fractures, but liquefaction also occurred. The geological survey was carried out five days after the earthquake, the data and information obtained were used to analyze geological impacts of the earthquake. Visually, it is clear the movement of land and rocks on the surface of the earths earth around Palu with the collapse and collapse of houses, hotels and various human settlements. Activation of faults and fractures has caused a shift in the road lane in Palu - Donggala. Subsidence was caused by active faults, especially Palu-Koro fault, as an impact of the Palu tectonic earthquake between 0.5 - 2.5 meters.

Keywords
Earthquake; Palu; Fault; Subsidence.

Topic
Disaster Management and Environmental Issues

Link: https://ifory.id/abstract/3ZGnN4uP9LDA

Corresponding Author
Gracio Haggai

Institutions
1
Program Studi Teknik Pertambangan, Fakultas Teknologi Kebumian dan Energi,
Universitas Trisakti, Jalan Kyai Tapa No.1, Tomang, Grogol Petamburan,
Jakarta Barat, Daerah Khusus Ibukota Jakarta 11440

2.
Dosen Program Studi Teknik Pertambangan, Fakultas Teknologi Kebumian dan Energi,
Universitas Trisakti, Jalan Kyai Tapa No.1, Tomang, Grogol Petamburan,
Jakarta Barat, Daerah Khusus Ibukota Jakarta 11440

Abstract
According to Landslide Threat Map 2016 prepared by BPBD-s Keumen, all districts in Kebumen is a high-potential areas of landslides. Therefore, we need more detailed mapping area regarding the area prone to landslide. In this study, Anbaagan method (1992) is used to analyze landslide zoning prone. Anbalagan method calculates six factors causing landslides, such as slope degre, wetness, vegetation density, structure, rocks, and relatif relief. Kedungwaru is a villagelocated in District Karangsambung, Kebumen, Central Java and geographically S 7 ° 35 557 , E 109 ° 40 011.The research result in Kedungwaru village tells there are two zones prone to landslides. First, the 48,5% low hazard prone zone in Kerajan, Rawajmambe, Kaliwadas and Gayam village. Second, the 51,5% medium hazard prone zone in Tegalsari village.

Keywords
Landslide, Photogrametry,GIS

Topic
Disaster Management and Environmental Issues

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

Corresponding Author
Melisa Tabi Padang

Institutions
Environmental Engineering UPN "Veteran" Yogyakarta

Abstract
Oil spill is one of the pollution which has a serious impact on the water and land area. Marine pollution has an impact on changing the marine environment. The purpose of this study is: (1) analyzing intensity potentials of oil spills, (2) Analyzing the direction of the spread of oil spills, (3) Formulate environmental sensitivity to oil spills based on ESI, (4) Determine strategies for handling oil spills. The initial stage of the research is literature study and survey of observation locations. The research observation point is based on consideration of tentative maps. The ESI parameters (Vulnerability Index, Ecological Index and Social Index) that have been obtained are then calculated to obtain the sensitivity level of the research area. The magnitude of the sensitivity value of the coastal environment is known based on the results of interpretation, digitization, direct observation in the field and calculations. Natural factors that are more dominant influence on coastal conditions obtained from the results of the analysis are then described. The value of coastal ESI is used as the basis for determining direction and management techniques for handling oil spills in Pari Island, Kepulauan Seribu Regency.The results showed that the level of environmental sensitivity was divided into 2 categories. These two categories are sensitive levels (ESI II zones) and quite sensitive (ESI III zones). The intensity of the potential for an oil spill is quite high, supported by the presence of 200 vessel owned by residents which almost every day operates. The direction of the spread of the oil spill tends towards the northeast and northwest. Appropriate handling techniques use technical approaches, socio-economic approaches and institutional approaches.

Keywords
environmental sensitivity index, oil spill, zone of mangrove, oil boom, oil absorbent, oil skimmer, APO.

Topic
Disaster Management and Environmental Issues

Link: https://ifory.id/abstract/ewb9aNxrV8JF

Corresponding Author
LH Wiryanto

Institutions
Department of Mathematics, Bandung Institute of Technology

Abstract
Two-fluid system of finite depth is considered in this talk. The fluids have different density and the height is also possible different. The interface between them is presented as the lower fluid height measured from the bottom. Because of a disturbance, that height changes at any time and position, so that it presents interfacial wave with KdV equation as the model. The wave propagation and deformation are observed for same various values of the physical parameters, such as density and height of the fluids. A finite difference method is shown successfully in performing the wave propagation. When the density and the height of the upper fluid tend to zero, the result confirms to the surface wave.

Keywords
KdV equation, interfacial wave, finite difference method

Topic
Coastal and Ocean Dynamics

Link: https://ifory.id/abstract/MZpUzHrj9aFu

Corresponding Author
Rinta Bi Tari Erdyanti

Institutions
Department of Geophysical Engineering, Faculty of Civil, Environmental and Geo Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia

Abstract
Vibrating- sample magnetometer (VSM) is a magnetic measurement method to calculate the induction magnetization by observing magnetic moment (M) which is response of applying ascending and descending magnetic field (H) to the material. Initially from zero magnetic field, ascending magnetic field was applied until Hmax. Then the applied field was decayed to zero and switched polarity till approaches -Hmax (descending). The field was then ascended again until Hmax. The observed magnetic moments were plotted versus magnetic field so that they form a kind of loop called hysteresis loop. This paper introduces an approach to process hysteresis loop by creating MATLAB program. It is conducted by subtracting the magnetic moment between descending and ascending (Δm). Then, the first derivative and second derivative of Δm is applied. The behavior of these derivative curves can be used to evaluate type and domain of magnetic mineral.

Keywords
HYSITS; hysteresis loop; magnetic; MATLAB; VSM

Topic
Computation and Other Related Field

Link: https://ifory.id/abstract/AxT4jFnLEUPW

Corresponding Author
Adika Bagaskara

Institutions
Department of Geophysical Engineering, Faculty of Civil, Environmental and Geo Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia

Abstract
Isothermal Remanent Magnetization (IRM) is a method used to observe the magnetization of materials by applying DC magnetic field in a constant temperature. The observed values of magnetization is used to distinguish the magnetic minerals contained in samples e.g. rocks, sediments, soils. This paper proposes IRMITS, a novel MATLAB program for analyzing the IRM data set acquired. This program uses several integrated approaches to analyze each mineral, called Linear Acquisition Plot (LAP), Gradient of Acquisition Plot (GAP), and Standardised Acquisition Plot (SAP). In order to be able to analyze the data on a broader range, we provide LAP, GAP, and SAP on semilog axes. The x-axis represents applied magnetic field on logarithmic scale, while the y-axis illustrates linear-scaled IRM value. The LAP values normalize IRM values, which is done automatically by this program. The GAP values are found through the differentiation of the normalized IRM values, and the SAP values are found by converting the normalized IRM values into z-score values and probability distribution. Then, the generated value of those functions are plotted to get the curves that could be interpreted. Plots from LAP, GAP, and SAP can complement each other in analysis process. After plotting the results and analyzing the trends of the graphs, different minerals can be distinguished. This is possible because different trends represent different mineral. For further research, the analyzed data from this paper could be used to determine the saturation point of minerals and discover different types of composing mineral. Our program can also be used as a quicklook to be validated in the future with other methods such as X-Ray Diffraction (XRD) analysis.

Keywords
IRMITS, IRM, magnetic, MATLAB

Topic
Computation and Other Related Field

Link: https://ifory.id/abstract/9nDxJTg2AC4t

Corresponding Author
Zulfah Zulfah

Institutions
Mathematics Education, Universitas Pahlawan Tuanku Tambusai, Jalan Tuanku Tambusai No 23, Bangkinang, 28412, Riau, Indonesia, zulfahasni670[at]gmail.com

Abstract
The purpose of this study is to produce the valid, practical, and effective problem-based questions to measure the mathematical problem-solving abilities of eighth-grade students of junior high school. The materials used as the basis of development are system of linear equation in two variables and the Pythagorean theorem. The development model used is the Plomp model consisting of three stages; preliminary research, prototyping phase, and Assessment phase. Based on the results of these stages, 16 problem-based questions were obtained which are valid to the criteria of content, constructs and determined language, practically used by the teacher, and effective for measuring students mathematical problem solving abilities because they can direct students to identify problems, plan solutions, implement solutions, and need to carry out evaluations as indicators of problem-solving abilities.

Keywords
Math Questions, Evaluation, Mathematical Problem Solving Skills

Topic
Mathematics Education

Link: https://ifory.id/abstract/JYxqRCXApa8T

Corresponding Author
SRI ULFA INSANI

Institutions
Mathematics Education, Universitas Pahlawan Tuanku Tambusai, Jl. Tuanku Tambusai No. 23, Bangkinang, Riau, Indonesia.

Abstract
Abstract. The aim of this research is to produce mathematics instructional package based on problem in senior high school students oriented to student-s critical thinking skills and curiosity based on aspects of validity, practicality, and effectiveness. This study was research and development with used ADDIE-s model (Analyze, Design, Develop, Implement, and Evaluate). The research subjects were 10th grade students of MAN 4 Kampar. The research instruments were validation sheets, teacher assessment sheets, student assessment sheets, learning implementation observation sheets, critical thinking skills test, and curiosity questionnaires. The instructional packages were valid if the experts judgment were categorized minimum as valid. Then the instructional packages were practical if the teachers assessment and students assessment were categorized minimum as practical. Furthermore, the instructional packages were effective if the percentage of students who completed in the test of critical thinking skills reaches at least 70% and if the percentage of the results of the students curiosity questionnaire reaches at least 75%. The results of this research show that mathematics instructional package was very valid. Then based on the results of learning implementation show that mathematics instructional package was very practical. Furthermore, the mathematics instructional package was effective based on the results of evaluation of critical thinking skills and student curiosity questionnaires.

Keywords
instructional package, critical thinking skill, curiosity

Topic
Mathematics Education

Link: https://ifory.id/abstract/ML7rydEGRuQx

Corresponding Author
Novia Lusiana

Institutions
Study program of environmental engineering, agricultural engineering department, faculty of agricultural technology, university of brawijaya

Abstract
Industrialization and domestic activities are very potentially towards water pollution contribution. One of kind domestic activities which producing wastewater is a hospital activity. Public Regional Hospital in Tulungagung is located at Kedungwaru District that will developed in order to further support the existing infrastructure. Assessment towards water quality and load pollution capacity of Ngrowo river as wastewater receiver is very important before hospital development began. The method used in this research was Mass Balance method, Pollution Index to determine of water pollution status in which the analyzed parameters were temperature, pH, TSS, DO, BOD, COD, Nitrate, Phosphate, and then the results of the parameter testing were compared with the water quality standard class II, then the maximum pollutant load was calculated to determine the pollution load capacity. Result show that water quality of Ngrowo River categorized in low pollution (around 3.75 – 3.99 for index pollution) based on class of II of water quality standard. Load pollution capacity at downstream have exceeded 28673.3 kg.day-1 for BOD, 34339.3 kg.day-1 for COD in existing condition. We recommend when a hospital development does exist should find other place to throw away their wastewater because Ngrowo River have polluted even in upstream area.

Keywords
hospital, load pollution capacity, wastewater

Topic
WASTE AND ENVIRONMENTAL MANAGEMENT

Link: https://ifory.id/abstract/jk973vK8uTmM

Corresponding Author
Sogandi Sogandi

Institutions
a) Department of Pharmacy, University of 17 Augustus 1945, Jakarta,14356, Indonesia
*Corresponding author: sogandi[at]uta45jakarta.ac.id

Abstract
Endophytic bacteria have been recognized as a microorganism that has an important role as the producer of bioactive compounds. In the literature, endophytic bacteria from Noni fruits (Morinda citrifolia l.) with their antioxidant activities have been rarely studied. This research aimed at isolating endophytic bacteria associated with Noni fruits to investigate their antioxidant activity, to identify potential endophytic bacteria with16s rRNA and to detect bioactive compounds they produce. Based on morphological characteristics of bacterial colonies, six endophyte bacteria were isolates from Noni fruits. The isolates were observed and evaluated in terms of their antioxidant activities by using 1,1-Diphenyl -2-picryl-hydrazyl (DPPH) radical scavenging activity. Results of this study discovered supernatant from isolate ACP3 to have the highest DPPH free-radical scavenging activity at up to 68.90%. In addition, molecular identification conducted by applying PCR amplification on 16S rRNA gene showed isolate ACP3 (Acc. No. MN068816) to belong to Staphylococcus sp. with 100% sequence similarities. Looking at GCMS analysis, ethyl acetate fraction from the secondary metabolites of isolate ACP3 contained pyrazine alkaloids, which have been known as a bioactive compound. Based on these results, the ACP3 strain was considered as a good and sustainable resource for natural antioxidants.

Keywords
16s rRNA; Antioxidant; Endophyitic Bacteria; Morinda citrifolia

Topic
HEALTH, NUTRITION AND MEDICAL MICROBIOLOGY

Link: https://ifory.id/abstract/d4Lt7BvaPeEA

Corresponding Author
Putri Setiani

Institutions
Environmental Engineering, Faculty of Agricultural Technology, Brawijaya Universityty

Abstract
Plastic has been widely used as single-use package and carrier material due to its low price, strength, practicality, and versatility. On the other hand, plastic require a very lengthy period to naturally decompose. The enormous number of plastic waste has caused serious threat to our global environment, hence a more environmentally benign substance is of significant importance. In this study, we propose the production of biodegradable material from nata de soya, which is composed from whey waste and coconut water. This environmentally-friendly substance is mainly obtained from tofu industry byproduct, through fermentation process using Acetobacter xylinum bacteria. To obtain desired texture and characteristic, the fermented product is mixed with chitosan, acetic acid, glycerol, and tapioca starch, with various range of concentration. The mixed component then underwent milling and drying process for finalization. As for characteristic of the materials, tested parameters include water resistance, heat resistance, tensile strength, and natural degradability in the environment. Our preliminary result shows the potential of this material to substitute the use of plastic, and is applicable for versatile purposes.

Keywords
bioplastic, waste treatment, sustainability

Topic
WASTE AND ENVIRONMENTAL MANAGEMENT

Link: https://ifory.id/abstract/Yzfhca9dbXAV

Corresponding Author
Wike Agustin Prima Dania

Institutions
Agroindustrial Technology Department, Faculty of Agricultural Technology
University of Brawijaya
Jl. Veteran No 1 Malang, East Java, Indonesia
wikedania[at]ub.ac.id

Abstract
Apple as one of the fresh fruit commodities needs specific treatment in material handling to keep the freshness of the product from farm to the consumers. One of the critical process to maintain the quality of the product is the inventory system. Inventory is one of the major cost components in the production system. Therefore, the inventory system must be controlled to propose the optimal inventory level at the minimum cost. The objective of this paper is to minimise the inventory costs of apple inventory in one of supermarket in Indonesia by using a multi-supplier Basnet-Leung formulation model since the retailer replenishes his inventory from several suppliers. This model allows the system to apply multi-product, multi-period lot sizing and multi-suppliers. The result shows by comparing the costs components between the current company inventory system and the proposed Basnet Leung inventory system; the total cost is reduced up to 40.68%. It results in the total saving in purchasing costs, ordering costs, and holding costs up to 43.20%, 6.44%, and 45.99% respectively. To sum up, controlling the inventory level by using Basnet Leung model will result in a more effective way of purchasing management.

Keywords
Inventory control; Basnet and Leung; multi-supplier

Topic
AGROINDUSTRIAL PRODUCTION SYSTEM MANAGEMENT AND REGULATION

Link: https://ifory.id/abstract/QxCtyJmf73wd

Corresponding Author
Tunjung Mahatmanto

Institutions
a) Jurusan Teknologi Hasil Pertanian, Fakultas Teknologi Pertanian, Universitas Brawijaya
Jl. Veteran, Malang 65145, Jawa Timur, Indonesia
*tjmahatmanto[at]ub.ac.id
b) PT PG Rajawali I
Jl. Undaan Kulon no. 57-59, Surabaya 60274, Jawa Timur, Indonesia

Abstract
Cellulases are enzymes that catalyse the degradation of cellulose–the most abundant renewable biomaterial–and are used in a wide range of applications including healthcare, textiles, detergents, food, feed, and biorefinery. Different industrial applications require specific properties of cellulases with regard to their compatibility with the conditions in which they are applied. While efforts to engineer cellulases with improved properties can meet the demand for more benign and efficient processes, screening provides a valuable resource for discovering unique properties of cellulases. Here, we report the screening of cellulase-producing microbes from sugarcane bagasse and filter cake–waste products of sugar industry. Samples collected from a local sugar factory were cultured in selective media containing carboxymethyl cellulose. One hundred colonies from each sample were grown on selective agar for cellulase activity detection using Congo red staining and four were selected based on their cellulase activity index. Extracellular cellulase activity was determined by dinitrosalicylic acid method using carboxymethyl cellulose as a substrate. The cellulase activity ranged from 0.003 to 0.016 U/mL and appeared to increase and plateau with culturing time. Gram and lactophenol cotton blue staining suggest that the cellulase-producing microbes were bacteria and fungi. Strategically, high-throughput large scale screening to select the best candidates for further characterization should be performed. However in a low-resource setting, we believe that concerted discovery efforts, albeit at the grass-root level, could serve as initial steps toward the realization of a green bioeconomy in Indonesia–an archipelago where diverse microbial potential awaits to be untapped.

Keywords
Cellulase; industrial microbes; sugarcane; bagasse; filter cake

Topic
INDUSTRIAL BIOTECHNOLOGY AND BIOPROCESSING

Link: https://ifory.id/abstract/fM8X2nBdeWqb

Corresponding Author
Sri Rahwany Marbun

Institutions
a) Mathematics Education, State University of Medan
Jl. Willem Iskandar / Pasar V, Medan 20221, Indonesia
*srirahwanymarbun15[at]gmail.com
b) Faculty of Mathematics, State University of Medan
Jl. Willem Iskandar / Pasar V, Medan 20221, Indonesia

Abstract
The purpose of this study is to analyze whether there is an enhancement difference of mathematic conceptual understanding ability (MCUA) of student which is taught by guided discovery learning (GDL) and which is taught by direct learning (DL). This study is quasi experimental study. The population of this study is the eighth grade students of Madrasah Tsanawiyah Negeri Barus. The sample of this study is taken randomly, which consisted of two classes. The experiment class is taught by guided discovery learning (GDL) and the control class is taught by direct learning (DL). The result of study showed that there is enhancement difference of mathematic conceptual understanding ability (MCUA) of student which is taught by guided discovery learning (GDL) and student which is taught by direct learning (DL). The N-gain of mathematical concept understanding ability of student which is taught by guided discovery learning (GDL) is higher than student which is taught by direct learning (DL).

Keywords
Mathematical Conceptual Understanding; Guided Discovery Model, Direct Learning Model

Topic
Mathematics,Science and Nursing Education

Link: https://ifory.id/abstract/ErM38nbaRYeh

Corresponding Author
yusnina nina

Institutions
Educational Of Technology

Abstract
This research aims to discover: (1)The results of mathematics learning students who are taught by using the STAD Learning Model and Mathematics learning outcomes of students who are taught with a Guided Inquiry Learning Model, (2)Mathematics learning outcomes between students who have more kinesthetic learning styles and learning outcomes of students who have a visual learning style, (3)Are there interactions between Learning Models (STAD and Guided Inquiry) and Learning Styles in influencing Mathematics learning outcomes. The research was carried out in the Public School 5 of Tanjungbalai and a population of 129 students. For the study sample, 66 students were 34 students in the experimental class and 32 students in the control class. The research method used quasi-experimental with 2 x 2 factorial design, the data analysis technique used was two-way ANOVA with significant significance &

Keywords
Result Of Learning, Attitude, STAD Method, Direct Method

Topic
Teachers Education Model in Future

Link: https://ifory.id/abstract/gVaQGAL4EHFj

Corresponding Author
Yohanes Hariaman Nada

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

Abstract
Facts in the field show that there are still many students who have difficulty in understanding concepts of algebra and have a low ability in algebraic thinking. One of the factors that influence the situation is because students find it difficult to change their thinking processes from arithmetic thinking to algebraic thinking. Students who are accustomed to operating in arithmetic terms of reference tend not to see the relational aspects of operations, but their focus is on calculations. The purpose of this study was to analyze the characteristics of students mathematical representation in solving problems related to algebraic thinking. This research is a qualitative research conducted on 6th grade students of elementary school and 7th grade students of junior high school. Based on the analysis of the results of written tests and interviews, it was found that elementary and high school students have similarities and differences in the mathematical representations they use to solving algebraic thinking problems. In addition, the researcher found that both elementary school students and junior high school students tended to use a combination of several representations to express mathematical ideas found in the problem.

Keywords
Mathematical representation; algebraic thinking; algebraic thinking problems.

Topic
Mathematics Education

Link: https://ifory.id/abstract/UrP6ZB2gmTkM

Corresponding Author
Naniek Utami Handayani

Institutions
Industrial Engineering Department, Faculty of Engineering, Diponegoro University
*naniekh[at]ft.undip.ac.id

Civil Engineering Department, Faculty of Engineering, Diponegoro University

Abstract
Climate change due to rising greenhouse gas (GHG) emissions and resource depletion is one of the major challenges of the twenty-first century. Construction waste is not only associated with energy use and waste of materials in the construction process, but also other activities that do not add value such as repair, waiting time and delays. Concepts such as waste and value are not well understood by construction personnel. They often do not realize that many activities they carry out do not add value to the work. These issues contribute to a reduction in the value of construction productivity and could reduce company performance. The aim of this GSCM study on the construction sector are to identify the drivers/motives of stakeholders are for implementing green practices; and the barriers/ challenges faced by stakeholders are in the implementation of these practices. The research methods are literature study (deductive methods) and fields observation (inductive methods) where the experts are going to be asked to contribute their opinions related to barrier and driver to implement the Green Supply Chain management (GSCM) in construction.

Keywords
Green Supply Chain Management, Construction, Driver, Barrier

Topic
Civil Engineering

Link: https://ifory.id/abstract/gDcLvKPm7tjr

Corresponding Author
Naniek Utami Handayani

Institutions
a Civil Engineering Department, Faculty of Engineering, Diponegoro University
b Industrial Engineering Department, Faculty of Engineering, Diponegoro University
c Civil Engineering, Vocational School, Diponegoro University

* naniekh[at]ft.undip.ac.id

Abstract
Supply chain is the interconnected hierarchy of supply contracts necessary to procure a built asset. On a traditional building project, design consultants are first tier suppliers, working for the client, and the contractor has a supply chain of sub-contractors and specialist suppliers. The problems in the construction industry is that the first and second tier of the supply chain sign up to impartially difficult arrangements but as the chain develops, so the contractual responsibilities decrease until suppliers at the end of the chain are often not locked in at all. The construction of the Diponegoro University Psychology building began September 29, 2017 with a target of 300 days. The deviation between the realization of project work and the planning timeline is -10.37% in the 7th month. The purpose of this study is to evaluate the supply chain process in building construction project. The Supply Chain Operation References (SCOR) is going to be applied to measures the performance of construction projects based on five material planning processes (plan) and project work schedules, material procurement (source), implementation of construction work (make), material delivery (deliver), and the return process if there is a material return (return). The Matrix (OMAX) and Traffic Light method is going to be used to assess the performance of cement and steel structure as the main material on this building project. The results of the assessment with Omax and traffic light obtained that the supply chain performance of cement material is worth 4.3 of the maximum value is 10. Supply chain performance for iron material worth 5.4 from the maximum value is 10. This shows that supply chain performance is quite good but needs repaired.

Keywords
construction supply chain, SCOR, building project

Topic
Civil Engineering

Link: https://ifory.id/abstract/MKarBLV3yqUN

Corresponding Author
NOORAKMAR BINTI AB WAHAB

Institutions
Faculty of Food Science and Nutrition, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Malaysia.

Abstract
Pindang egg and tea egg were processed by boiling in hot water for a few hours with variety of leaves and spices to provide brownish colour and aroma onto the boiled eggs. The aim of this study was to compare the physicochemical and sensory properties as well as shelf life of the boiled eggs upon storage at room (250C) and chill (40C) temperatures. Therefore, analyses of ash, protein, fat, minerals, tannin content and texture profile analysis were conducted to determine the physicochemical properties of the boiled eggs. Quantitative Descriptive Analysis (QDA) and microbiological study were used to investigate the sensory properties and shelf life of the boiled eggs, respectively. The results showed that pindang egg was higher in protein and ash content compared to tea egg (p<0.05), but there was no significant different in fat content (p>0.05). Pindang egg also had high sodium (Na), calcium (Ca), iron (Fe) and magnesium (Mg) content compared to tea egg and hard-boiled egg (p<0.05). Moreover, tannin content of pindang egg and tea egg were higher than hard-boiled egg (p<0.05), and decreasing in trend of tannin content were found up to four days of storage at room and chill temperatures (p<0.05). At day 0, hardness and cohesiveness of pindang egg and tea egg were higher than hard-boiled egg (p<0.05), but the eggs were adhesive (p>0.05). Upon storage at room and chill temperatures, the hardness, adhesiveness and cohesiveness of all eggs were increased (p<0.05). Both pindang egg and tea egg had strong aroma, darker colour, hard and bitter compared to hard-boiled egg, however tea egg showed better overall acceptance than others (p<0.05). Pindang egg and tea egg could last up to four days at chill storage (40C). In conclusion, pindang egg and tea egg had better chemical values, hard, well accepted and longer shelf life than hard-boiled egg.

Keywords
Egg, physicochemical properties, sensory properties, shelf life

Topic
Biophysics engineering

Link: https://ifory.id/abstract/2NxFPWJ37ype

Corresponding Author
Sitti Nur Faridah Faridah

Institutions
Agricultural Engineering Study Program, Faculty of Agriculture, Hasanuddin University
Add. Perintis Kemerdekaan Tamalanrea Makassar, South Sulawesi, Indonesia

Abstract
Success in implement irrigation area management activities is highly dependent on data availability. The existence of a realtime, fast, and accurate information is very important. The data and information needed must be easily accessible to interested parties. Development of an irrigation network information system is carried out by converting data into coordinate form using ArcGIS software. Visual studio software is used to display all data that has been processed. Spatial-based irrigation network information systems built using ArcGIS and Visual Studio software can easily obtain information about channel conditions, rating curves, channel profiles and channel photos. the availability of spatial-based irrigation network information systems facilitates the management of irrigation networks.

Keywords
Information system, visual studio, irrigation network

Topic
Land and water resources engineering

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

Corresponding Author
Joko Nugroho Wahyu Karyadi

Institutions
a) Department of Agricultural and Biosystem Engineering
Universitas Gadjah Mada
*) Corresponding Author jknugroho[at]ugm.ac.id

Abstract
Edamame (Glycine max. L. Merill) has been consumed due to its savory taste and high nutrient content, such as protein, calcium, vitamin A, and isoflavone. Fresh edamame is usually consumed after steaming. However, steamed edamame has to be consumed really soon because it stale quickly. As an alternative, edamame can be dried and consumed as a crunchy snack through the drying process which is able to retain nutrition loss during it using freeze drying. The objective of this study is to investigate the moisture content decreasing of edamame during freeze drying. Fresh edamame with initial water content of 60-70% was steam blanched to 9 minutes before drying. The freeze dryer has capacity of 1.5 kg was used with freezing temperature was set at -18C and pressure at -76 cmHg. Its parameters was measured at 0 h; 12 h; 18 h; 24 h; 30 ;, and 36 h. The drying rate of edamame freeze drying is 6.94% db per hour.

Keywords
Edamame, freeze drying, kinetics, drying rate

Topic
Postharvest and food engineering

Link: https://ifory.id/abstract/4Vk2REcwzZfr

Corresponding Author
Yoga Murtono

Institutions
Departemen Teknologi Industri Pertanian, Fakultas Teknologi Industri Pertanian
Universitas Gadjah Mada, Yogyakarta, Indonesia

Abstract
Abstract The supply chain of shallot commodities in Bantul Regency involves several business actors including farmers, middleman, collectors, wholesalers, retailers and small traders. In the process of each supply chain, risks will always be encountered. The risks in each tier of shallot supply chain certainly need to be identified and analyzed. The categories of each of these risks will determine the appropriate supply chain risk management steps based on the risk categories obtained. This study was conducted to analyze the risk of shallot supply chains in the three largest shallot producing sub-districts. The Rapid Agricultural Supply Chain Risk Assessment (RapAgRisk) method is used to carry out risk analysis, and the sampling method used was purposive sampling and snowball sampling. The results show that the farmer is the tier with most risks faced compared to the others. Excessive stock is the risk that requires adequate priority to manage, and it is faced by all levels of the shallot supply chain. Meanwhile, farmers are the weakest supply chain actors in bargaining power, and the small traders are the most vulnerable actors in the face of risks associated with quality damage and slow sales rate.

Keywords
shallot, supply chain, risk assessment, risk management

Topic
Other Agricultural and biosystems topic

Link: https://ifory.id/abstract/9k6VUdPh3XZW

Corresponding Author
Yuana Susmiati

Institutions
Politeknik Negeri Jember
Universitas Gadjah Mada

Abstract
Reboiler in the distillation device is a heat exchanger to heat or boil liquid material in the distillation column. In this research vertical tubular baffle heat exchanger was designed and used as an internal reboiler in the distillation device. The aim of the study was to observe the temperature distribution during the liquid heating process in the vertical tubular baffle heat exchanger with different dimensions. The study was conducted by designing heat exchangers (HE) with different dimensions in height, diameter, and surface area (number) of tubes. Times and fuels needed to heat the liquid to a temperature of 78 oC were calculated. Based on observations it was found that the different geometry of the vertical tubular baffle heat exchanger gives different performance. Height, diameter, and the number of tubes (surface area) affect the value of the overall heat transfer coefficient, times and fuels needed for heating liquids at a temperature of 78 oC. In the same surface area but different in height and diameter of the heat exchanger, give a different result in overall heat transfer coefficient (U). HE with the number of tubes 3 and 7 obtained a higher value of U with a tube height of 4 cm and a diameter of 4 cm, compared with the value of U in HE with a tube 8 cm in high and 2 cm in diameter, but the opposite occurs in HE with a number of tubes 5.

Keywords
internal reboiler, heat exchanger, vertical tubular baffle, distillation

Topic
Energy and agricultural machinery

Link: https://ifory.id/abstract/Qyt2dWDCNmKF

Corresponding Author
Hanggar Ganara Mawandha

Institutions
a) Graduate School of Engineering, Kobe University, Japan
*mawandha[at]stu.kobe-u.ac.jp
b) Center for Volcanology and Geological Hazard Mitigation, Geological Agency, Indonesia
c) Research Center for Urban Safety and Security, Kobe University, Japan

Abstract
High-precision of rainfall prediction in a matter of rates and time is significant aspects for such issues in disaster mitigation, irrigation management, public services, and many others. Rainfall in the mountainous region has unique characteristics related to time-varying and spatial distribution. In Mt.Merapi region, located at the border of Special Region of Yogyakarta Province and Central Java Province, Indonesia, rainfalls are typically classified as the deep-convective type which occurs in a short period with high intensity. Therefore short term rainfall predictions in a proper way remain challenging tasks. The use of remote monitoring instruments such as the GNSS (Global Navigation Satellite System) is believed to provide a better measurement accuracy through the identification of water vapor variation in the process of deep convection weather. GNSS observes the geodetic position of the GNSS antenna or receiver while it broadcasts microwave signals continuously through the atmosphere to the ground-based receivers. As they travel through the atmosphere, the microwave signals are mostly influenced by ionospheric and neutral atmospheric effects which cause some delays. By using a sufficiently dense network of GNSS receivers, the impact of the neutral atmosphere delay can be estimated as a by-product of the geodetic processing. These delays can be regarded as an indirect measure of the integrated water vapor along the path and measured as Zenith Total Delay (ZTD). By studying the relationship between time-varying ZTD and rainfall, it can be found that the ZTD level increases sharply before raining. Through the deployment of GNSS receivers, the spatial feature of rainfall characteristics is also depicted. The initial results showed that the increase of ZTD is strongly correlated to rainfall occurrence based on the rain gauges measurement around Mt.Merapi region. The results show that the rate of true forecasted is about 65%, with the lead time recorded is two hours before the actual event.

Keywords
GNSS, ZTD, rainfall, prediction

Topic
Land and water resources engineering

Link: https://ifory.id/abstract/48RpZzBY9vQN

Corresponding Author
hamdi agustin

Institutions
fakultas ekonomi universitas islam riau

Abstract
The purporse of this research to analyze the effects of inflation, Certificates of Indonesian Bank of Sharia (CIBS), deposit funds (DF) and Non Performing Financing (NPF) to murabahah lending. The population and sample consists of 22 Islamic business units, only 10 banks were selected to be the sample. The period of this study is from 2011 to 2015. This study using panel data and using pooled Ordinary Least Squares (OLS). The results showed that Certificates of Indonesian Bank of Sharia has a negative effect on murabahah lending. This suggests that banks have a greater Bank interest rate spread that has also been shown to affect to lending behavior. it is one of the instruments for placing funds at Bank Indonesia which is used to absorb the excess liquidity of Islamic banks in the context of open market operations to control the amount of money in circulation. Deposit funds have a positive effect on murabahah lending. This suggests that deposits what a bank accepts are demand forms which are repayable to depositors on demand. As a result banks may maintain a large amount of customer deposits as a reserve to meet customers demand instead of lending. NPF has a negative effect on ML These results illustrate that the higher Non performing finance is followed by a decrease in the distribution of funds made by the Bank to reduce the risk of bad credit.

Keywords
lending, Islamic business units and Sharia

Topic
Islamic Finance and Banking

Link: https://ifory.id/abstract/TGXquEU83hHQ

Corresponding Author
MOCHAMAD SOCHEH

Institutions
Faculty of Animal Science, Universitas Jenderal Soedirman

Abstract
Abstract. The aim of the research is to investigate the effect of four different energy level in the ration into the calpain activity of Jawarandu does. The research was done during 5 months in the Experimental Farm of the Faculty of Animal Science, Universitas Jenderal Soedirman. The research material used was 16 heads of the Jawarandu doe with the aged 2.5−3 years. All the animals were randomly assigned to the ration treatment which forms four the different energy levels (82.26% TDN, 85, 87.93, dan 90.74% TDN). The replication of each treatment was four times. Variable measured was a calpain activity on the muscle of Longissimus dorsi. General linear model (GLM) of the SPSS was used to analysis variable measured. Energy content 1.63McalME/heads/day and 1.92McalME/heads/day as well as 1.73McalME/heads /day and 2.06McalME/heads/day were increased of the μ-calpain and m-calpain activities at the Longissimus dorsi muscle, respectively. However, there was decreased of the calpastatin activity at the Longissimus dorsi muscle. Different energy content of the ration increased the μ-calpain and m-calpain activities at the Longissimus dorsi muscle and of those decreased calpastatin activity.

Keywords
Calpain activity, Calpastatin activity, Energy level, Jawa Randu Does, Longissimus dorsi

Topic
General animal production and husbandries (ruminants and non-ruminants)

Link: https://ifory.id/abstract/ApB4yTF9YfmX

Corresponding Author
Sigit Prastowo

Institutions
1) Animal Science Department, Faculty of Agriculture, Universitas Sebelas Maret. Surakarta – Indonesia
*prastowo[at]staff.uns.ac.id
2) Artificial Insemination Center Singosari, Singosari, Malang, Indonesia

Abstract
Semen quality is an important factor influencing the success of a cattle breeding program. Efforts to continuously evaluate the semen quality parameter is needed. Indonesia has Bali cattle; it is indigenous, tropically adapted, robust, and has high fertility. Bali cattle need to be developed into meat producer by selecting the best bulls and disseminate their sperm through artificial insemination program. To obtain the desired improvement, one of the key is to ensure the semen quality. This study aimed to determine the factors affecting fresh semen quality of Bali bull. In total, 864 ejaculates were collected from nine bulls from January to October 2016. Semen was collected twice a week, followed with semen quality evaluation as semen volume (ml), sperm concentration (x106/ml), sperm motility (%), and pH. A linear model was built to obtain the significant fixed factor of season and/or age affecting sperm quality followed by mixed model procedure including individual bulls as random effect to estimate the variance components. The result showed that season didn-t give any effect (p>0.05) in all fresh semen quality observed, while there was a significant effect of age (p<0.05) on volume, sperm concentration and pH. There is no interaction (p>0.05) between season and age in this study. The variance component of individual bulls contributed 71.15, 67.92, 48.22, and 11.76% of the total variance of semen volume, sperm concentration, sperm motility, and pH respectively. This study shows that there is a wide variation of semen quality resulted due to the variation between individual of the Bali cattle bull, which mirroring the diverse of Bali cattle genetic. In bulls selection as semen source, careful selection and the application of genetic standard need to be concerned.

Keywords
semen quality, Bali cattle bull, individual variance component

Topic
General animal production and husbandries (ruminants and non-ruminants)

Link: https://ifory.id/abstract/udJce3CvnNrH