Indonesia Conference Directory

Corresponding Author
Vita Deviantri

Institutions
a*) Program Studi Magister Pengajaran Matematika, Fakultas Matematika dan Ilmu Pengetahuan Alam, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia
*deviantoritori[at]gmail.com

b) Kelompok Keahlian Analisis dan Geometri, Fakultas Matematika dan Ilmu Pengetahuan Alam, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia

Abstract
Makalah ini mengkaji sejumlah definisi garis singgung pada kurva untuk mengetahui apakah definisi tersebut telah disusun secara tepat. Definisi-definisi yang akan dikaji terlebih dahulu dikelompokkan ke dalam tiga pendekatan, yakni pendekatan geometri dasar, analisis, dan pendekatan yang lebih umum. Berdasarkan kajian definisi tersebut, makalah ini juga mengusulkan definisi baru garis singgung pada kurva, namun masih dapat dipelajari oleh siswa SMA.

Keywords
Garis Singgung, Kurva, Definisi

Topic
Pembelajaran

Link: https://ifory.id/abstract/a4eRJcA6DryE

Corresponding Author
Sparisoma Viridi

Institutions
11Department of Physics, Faculty of Mathematics and Natural Sciences, Institut
Teknologi Bandung, Jalan Ganesha 10, Bandung, 40132, Indonesia

2Department of Food Industrial Technology, Faculty of Agro-industrial Technology, Universitas Padjadjaran, Jalan Raya Bandung Sumedang KM 21, Sumedang 45363, Indonesia

a)dudung[at]fi.itb.ac.id (corresponding author)
b)souvia[at]unpad.ac.id

Abstract
Pertumbuhan populasi beberapa jenis mikroorganisme dalam suatu lingkungan yang sama dimoldelkan dengan beberapa persamaan logistik yang saling tidak berinteraksi, yang perbedaan satu persamaan dengan lainnya adalah pada syarat awal, koefisien pertumbuhan, dan kapasitas maksimumnya. Pembedaan ketiga parameter ini menggambarkan perbedaan jenis mikroorganisme yang berinteraksi dengan sistem yang dibahas.Diasumsikan bahwa jumah mikroorganisme pada suatu waktu t hanya dapat diketahui jumlah totalnya dan apa saja jenisnya, tanpa dapat mengetahui jumlah masing-masing jenisnya. Dengan menjalankan simulasi untuk beberapa saat dapat diperoleh kurva pertumbuhan masing-masing jenis mikroorganisme dan juga kurva pertumbuhan totalnya yang merupakan data agregat dari masing-masing jenis. Ditunjukkan bahwa suatu keadaan awal dan akhir tertentu sistem total dapat dibentuk oleh berbagai keadaan awal dan akhir dari masing-masing jenis, yang akan dapat membuat bias penafsiran dari data yang diperoleh. Suatu batasan diusulkan agar hasil yang diperoleh dapat bersifat lebih spesifik.

Keywords
model pertumbuhan, multi-spesies, populasi mikroba

Topic
Komputasi dan Pemodelan

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

Corresponding Author
Andrian Haro

Institutions
a) Faculty of Economics, State University of Jakarta (UNJ), Jakarta, Indonesia
*andrianharo[at]feunj.ac.id
b) Bank of Indonesia (BI), Jakarta, Indonesia

Abstract
The purpose of this study is to examine the influence of brand image and service quality towards purchase intention and its impact on the purchase decision of Samsung smartphone. The sample size of this study is 150 Samsung smartphone users who already visit to the Samsung outlet. The analysis data was used Structural Equation Modeling (SEM) through AMOS software. The results show that brand image has an influence on purchase intention, quality of service has effect on purchase intention, and purchase intention has an influence towards purchase decisions.

Keywords
Brand Image; Service Quality; Purchase Intention; Purchase Decision

Topic
Management

Link: https://ifory.id/abstract/7r4VMQuyNnhA

Corresponding Author
Diana Suzana Mandar

Institutions
UNJ, ISTN, Universitas Surya

Abstract
In mathematics, there is a graph theory. One of them is the tree theory. Tree is a term for an abstract data structure that is widely used. The problem in this research is how to determine the simulation of data in a hierarchical manner for the form of a tree. The method used in this study is literature study. The first step taken in this study was to find a problem. Then formulate the problem, then by using solving analysis using a data tree structure method that can be defined recursively as a collection of nodes. In the discussion, each node is part of a data structure that has a value. Based on the results of these studies, the nodes in the tree are always endeavored to be balanced on each side, in balancing the tree there are several algorithms that can be used, one of them is red-black tree.

Keywords
graph theory, tree, node, red-black tree

Topic
STEM EDUCATION

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

Corresponding Author
Nur Wahyuni

Institutions
Unimed

Abstract
This study aims to: (1) produce character-based student worksheets that are suitable to be used for thematic learning in the sub-themes of singing and dancing for grade 1 elementary school; (2) knowing the large increase in students interest in learning by applying the participants worksheets in the class; and (3) knowing the increase in student learning outcomes through character-based student worksheets. This student worksheet is compiled using the 4D model of Research & Development. Data retrieval research was conducted at SDN 10187 Tanjung Morawa. The research phase is define, design, develop, and disseminate. The level of feasibility of student worksheets is obtained from expert validator and practitioner validator analyzed. After being validated and revised, the product is tested on a limited basis on students. The results of limited trials were then analyzed to determine the feasibility of student worksheets from the students point of view. Extensive tests are conducted after making improvements from the results of limited trials. The final results of the extensive test in the form of pretest and post test values were then analyzed and obtained standard gain values 0.85 with the high category.

Keywords
Development, Worksheets, Thematics, Characters

Topic
Curriculum, Research and Development

Link: https://ifory.id/abstract/PpGtMy4qE7bW

Corresponding Author
Andrian Haro

Institutions
a) Faculty of Economics, State University of Jakarta (UNJ), Jakarta, Indonesia
*andrianharo[at]feunj.ac.id
b) Bank of Indonesia (BI), Jakarta, Indonesia

Abstract
This study aims to examine and determine consumer behavior in creating halal value chain creation through religiosity, lifestyle and attitude toward their purchase intention on Muslim fashion products. By using the purposive sampling method, the research sample is both of Muslim men and women with total sample 200 respondent who domiciled in Jakarta which having bought and using Muslim fashion products. Multiple liniear regression was used to analyze the data and to test the research hypotheses through SPSS. The result indicate that attitude and lifestyle have an influence toward purchase intention on Muslim fashion products. Surprisingly, there is no influence between religiousity toward their purchase intention.

Keywords
Religiousity; Attitude; Lifestyle; Purchase Intention

Topic
Marketing Management

Link: https://ifory.id/abstract/JUdWBvR7NGmb

Corresponding Author
Umi Zuraida

Institutions
a) Universitas Pendidikan Indonesia, Bandung, Indonesia
b) Sekolah Bisnis dan Manajemen, Institut Teknologi
Bandung, Indonesia
Email : umi.zuraida[at]upi.edu

Abstract
To improve the quality of the university in order to become a World Class University (WCU), Indonesia has changed several State Uni-versities to become autonomous public university (PTN-BH). Using the concept of human capital management that treats employees as assets rather than cost, it will be a revolutionary way of managing employees. This is because human capital is a concept related to the value added of people to organizations. This paper is a literature review that later will be followed up in empirical research. Using Ulrichs theory (1997 ) is expected to be known the role of HCM in increasing PTN-BH performance .

Keywords
World Class University (WCU), Autonomous Public University (PTN-BH), Human Capital Management (HCM), Performance

Topic
Organizational Behavior, Leadership and Human Resources Management

Link: https://ifory.id/abstract/v2FjVnDqz8He

Corresponding Author
Kusdianto Kusdianto

Institutions
Department of Chemical Engineering, Institut Teknologi Sepuluh Nopember, Sukolilo, Kampus ITS Sukolilo, Surabaya, Indonesia 60111

*Email: swinardi[at]chem-eng.its.ac.id

Abstract
Flame pyrolysis is widely used for fabrication of nanoparticles due to high crystallinity and narrow size distribution of the products. In this study, ZnO-Ag nanocomposite materials have been successfully fabricated by a flame pyrolysis. The effects of Ag loading ranging from 0 to 20 wt% in the ZnO-Ag nanocomposites on the photocatalytic activity under UV and sunlight irradiations were also studied. ZnO and Ag nanoparticles were synthesized based on zinc acetate dihydrate 0.1 M and silver nitrate inside a flame reactor. Morphologies and crystallinity of ZnO-Ag nanoparticles were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). SEM analysis showed that nanoparticles have irregular sphere-like shapes. The XRD patterns indicated that the produced ZnO had a wurtzite structure with varying crystallite sizes. XRD analysis also confirmed the existence of Ag nanoparticles in ZnO-Ag nanocomposites when the concentration of Ag as much as 5 wt% indicated by the appearance of XRD peak at 38.1º. The peak at 38.1º increased with the increase of Ag content. Finally, the photocatalytic activity was evaluated by measuring the degradation of methylene blue aqueous solution under UV and sunlight irradiations. It showed that the best photocatalytic performance was obtained at 5 wt% Ag content for both irradiations.

Keywords
Ag content, Characterizations, Photocatalytic Activity, ZnO/Ag

Topic
Chemical Engineering

Link: https://ifory.id/abstract/b9ryV2tGnZjq

Corresponding Author
Kusdianto Kusdianto

Institutions
1Department of Chemical Engineering, Institut Teknologi Sepuluh Nopember, Kampus ITS Sukolilo, Surabaya, Indonesia 60111
2Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 4-1, Kagamiyama 1-chome, Higashi-Hiroshima, Hiroshima 739-8527, Japan


*Email: swinardi[at]chem-eng.its.ac.id

Abstract
The development of nanoparticle technology is growing continuously for wide range applications, one of which is fabrication of semiconductor materials as photodegradation of organic pollutants using photocatalyst method. ZnO is the most widely used as a catalyst material for photocatalytic application due to a suitable band gap energy and the chemical stability. It was also reported by our previous study that the photocatalytic performance was significantly affected by the Ag content. In this study, ZnO-Ag nanocomposite materials have been successfully fabricated by a flame pyrolysis and the effects of catalyst weight ranging from 2 to 10 mg on the photocatalytic performance were also investigated. Zin acetate and silver nitrate were used as precursors for producing ZnO-Ag nanocomposites. The catalyst products, ZnO-Ag nanocomposite, were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). While, UV Vis spectrometry was used to measure the concentration of methylene blue (MB) before and after irradiations. Photocatalytic performances of nanocomposites were performed by evaluating the degradation of MB under UV and sunlight irradiations. The photocatalytic tests showed that the best performance was attained when the Ag content was 5 wt% and the weight of catalyst as much as 2 mg after irradiation with sunlight, where the degradation rate of MB was 98 % and the rate constant was 0.0512 /min.

Keywords
Catalyst Weight, Photocatalytic Activity, ZnO/Ag Nanoparticle

Topic
Chemical Engineering

Link: https://ifory.id/abstract/THvpUbutF3XA

Corresponding Author
Wayan Widhiada

Institutions
University of Udayana

Abstract
Abstract The development of prosthetic limbs in Indonesia is still conventional. Users still have difficulty to move fake legs and spend a lot of energy. These problems can be reduced by using the robotic prosthetic limbs. Bionic robot leg movements can be regulated by the implementation of a control system on the Microcontrolle. The auto tuning parameters of PID control system design is using to achieve the optimal of the responses. Beside that this research is also using the intelligence control system that is Fuzzy Logic makes it easy to create a motion control system program from a dc motor mounted on the robotic foot joint. The purpose of this study is to compare the results of the performance of the use of PID control systems and fuzzy controls. The bionic robot leg control system produce the optimal motions, accurate movement and fast response by reducing signal errors, maximum overshoot, and faster settle time.

Keywords
Bionic robot leg, PID, Fuzzy Logic, Intelligent Control, Performance of motions

Topic
Mechanical Engineering

Link: https://ifory.id/abstract/bH4qWg3AatDN

Corresponding Author
Kazuyo Futaesaku

Institutions
Graduate School of Asian and African Area Studies, Kyoto University.

Abstract
My most recent research has focused on the province of Bangka Belitung, Indonesia. This province has been an important global tin mining center since the 18th century, but tin has been depleted in recent years and there is a big demand for new industries to replace tin mining. In recent years, the province has begun to focus on tourism development to replace tin mining, and tourism in the province, especially in Belitung Island, is attracting attention in Indonesia. Although ethnically, the Melayu people are in the majority, other ethnic groups such as Chinese have flowed into the region as tin miners since the Dutch colonial era, which is why this province is a multi-ethnic/multi-cultural area . In this time I will talk about how local government try to develop tourism in this region by using local power. Using Informal interviews and collecting data in Bangka-Belitung islands and Jakarta, I found that the role of central/local government and local residents in tourism there. We can see how local government try to make the region more attractive by seeing some movements such as holding cultural event and supporting local residents with commodities, and so forth. Interestingly there are some differences between Bangka and Belitung regarding to the conditions of tourism development. However, both islands are now trying to use multi-cultural characteristic, like Melayu culture and Chinese Indonesian culture, in each touristic event or spot to show how their province is "unique" and attractive.Also, the mine site itself has the potential to be a regional cultural resource. Recently there are some local residents who struggle to construct a new leisure spot near the tin mine. I believe that these results provide new insight into our understanding into the development of tourism in mining area which have various ethnics in Southeast Asia.

Keywords
Indonesia, Tourism, Tin mining, Culture

Topic
Local Politics and Decentralization

Link: https://ifory.id/abstract/7jDt3bcnL4dN

Corresponding Author
Gunawan, S.Pd.I

Institutions
Mathematics Education Program Post Graduate IKIP Siliwangi, Cimahi

Abstract
This study was a descriptive survey having a goal to examine attainment of student-s mathematical reasoning (MR) and self regulated learning(SRL) according to student-s cognitive stage. The survey implicate 36 eleventh grade students of 17 years old, test of logical thinking (TOLT), an essay MR test,a SRL scale. By using TOLT, the survey investigated many students with 17 years old had not reached formal cognitive stage, namely 19 % students at formal stage, 25 % students at transition stage, and rest 56% students at concrete stage. In addition, survey invented that entirely students obtained MR at very low grade level, and according to student-s cognitive stage, formal students obtained higher grade MR than the grade of transisiton students and concrete students. Even if, those grades were still at low and very low level. Either entirely or based on student-s cognitive stage there were no different grades on student-s SRL and those grade were fairly good level. SRL at fairly good grade level, transistion stage students attained MR and SRL at medium grade Other finding, there was medium association between cognitive stage and MR, but therewere no association between cognitive stage and MR, and SRL and between MR and SRL. In general, these findings were, that in normal condition formal cgnitive stage will reach by students in 12 -13 years old, or in 13-14 years old, even in specific condition in 19 – 20 years old; and that formal students possess higher abilities than concrete students on completing HOT tasks such as MR tasks which needed formal operational thinking.

Keywords
cognitive stage, TOLT, mathematical reasoning, self regulated learning.

Topic
Mathematics Education

Link: https://ifory.id/abstract/FX3dmhkUNKZL

Corresponding Author
Ida Nuraida

Institutions
Jl.R.E Martadinata No. 150. Ciamis. Universitas Galuh.
ida.nuraidamath[at]gmail.com

Abstract
This research is backed by the difficulties of junior high school students in linear equation system material. The focus of this research is to produce the Hypothetical Learning Trajectory (HLT) system of linear equations based on the development of Learning Trajectory (LT) with the aim of research to improve students mathematical communication skills. Research method used design Research with 3 phases:, Preliminary design, teaching experiment, and retrospective analysis. The subject of study in SMP grade VII in Tasikmalaya district. This research uses the instrument of communication skills test students. Processing of research data using test-T, Test-T, Mann-Whitney U test, and Kruskal-Wallis test. Based on the results of the research obtained: (a) HLT results from the development of LT linear alignment system in RME to improve student mathematical communication skills; and (b) students who acquire RME learning have increased mathematical communication skills greater than those who acquire conventional learning.

Keywords
Hypothetical learning trajectory, mathematical communication, learning trajectory, design research, realistic mathematics education

Topic
Mathematics Education

Link: https://ifory.id/abstract/6uZD7Rtgrxvm

Corresponding Author
Upik Nurbaiti

Institutions
a) Physics Department, Universitas Negri Semarang, Jl. Raya Sekaran Gunungpati, Semarang 50221, Indonesia
*upik_nurbaiti[at]mail.unnes.ac.id
b) Physics Department, Institut Teknologi Sepuluh Nopember Surabaya, Jl. Arief Rahman Hakim, Surabaya 60111, Indonesia

Abstract
Nano forsterite powders have been successfully synthesized via ultrasonic assistant for the starting materials and followed by solid reaction and calcination steps. The synthesis products were greenish powders with forsterite as the dominating phase as revealed by XRD data analysis. The formation of forsterite was also confirmed by FTIR spectrometry and supported by SEM images. The phase composition after calcination at 950 °C for 4h was 93.9wt% forsterite and 6.1wt% periclase. The forsterite crystal was nanometric according to the XRD data, while the density of the powder was 2.88g/cm3. UV-Vis spectrum of the powder showed relatively strong absorption peaks particularly at 635, 660, 670, 680, 695 and 705 nm which can be associated with the greenish color of the product and is different from previous studies. Therefore, it can be concluded that high purity greenish forsterite can be formed at 950 °C calcination temperature as previously reported, except that the raw materials were subjected to ultrasonic treatment.

Keywords
nano-forsterite; optical characteristics; silica sand; ultrasonic treatment

Topic
Synthesis and Characterization Techniques

Link: https://ifory.id/abstract/Fajm8tVCQHbE

Corresponding Author
Muhammad Reza Ramadhani Raharjo

Institutions
Fakultas Matematika dan Ilmu Pengetahuan Alam
Institut Teknologi Bandung
Jl. Ganesa 10 Bandung, 40132, Indonesia

Abstract
Router adalah sebuah alat jaringan komputer yang mengirimkan paket data melalui sebuah jaringan atau internet menuju tujuannya, melalui proses yang dikenal sebagai routing. Dengan keadaan router yang harus dinyalakan selama 24 jam non-stop, sebuah router harus didesain agar tidak cepat rusak, oleh karena itu, produsen router merancang router buatan mereka agar tidak bekerja secara berlebihan, namun kita bisa mengganti operating system dari router kita menjadi openwrt yang berbasis LINUX. Keuntungan dari mengganti operating system dari sebuah router adalah kita dapat memaksimalkan sistem kerja dari sebuah router, tanpa ada yang menghalangi, dan menggunakan router sebagai wifi radio. Pada percobaan kali ini, akan dijelaskan bagaimana mengganti operating system dari sebuah router menjadi openwrt, serta menggunakan router sebagai mp3 player.

Keywords
Linux, OpenWRT, router

Topic
Instrumentasi

Link: https://ifory.id/abstract/Yf2ptDGc6L9E

Corresponding Author
Al Muizzuddin Fazaalloh

Institutions
Brawijaya University

Abstract
This paper examines the effect of foreign direct investment (FDI) to economic growth and domestic investment in 6 Southeast Asia countries (Indonesia, Thailand, Malaysia, Brunei Darussalam, Philippines, and Laos) over the period 2000-2017. Using panel data regression analysis with panels corrected standard errors (PCSEs) approach, we find that FDI has a significant positive effect on economic growth. In addition, the interaction effect of FDI and education shows a significant negative effect. Meanwhile, the interaction effect of FDI and financial development indicates an insignificant effect. These results imply that education and financial development may not be a good channel for FDI in boosting economic growth.

Keywords
FDI, economic growth, Southeast Asia, panel data regression

Topic
Economics

Link: https://ifory.id/abstract/qUYMPxQVDh9X

Corresponding Author
Ismail Hanif Batubara

Institutions
Universitas Muhammadiyah Sumatera Utara

Abstract
This research is aimed to know: (1) Whether the increasing student-s critical thinking ability through guided discovery learning methods assisted by autograph higher than the students who were given guided discovery learning methods without autograph (2) How the interaction between learning and early math ability of student mathematical learning result. This study was a quasi-experimental study. The population of this study approximately 122 peoples. Randomly, two classes were selected from four classes. The first experimental class was given autograph assisted discovery method and the second experimental class was not given autograph. The data analysis has been done by analysis of two-way variance (ANOVA). The results showed (1) the increasing student-s critical thinking ability through guided discovery learning methods assisted by autograph were better than the students who were given guided discovery learning methods without autograph. (2) There was no Interaction between learning and early math ability of student mathematical learning result.

Keywords
Critical Thinking, Guided Discovery Learning, Autograph

Topic
STEM EDUCATION

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

Corresponding Author
Putri Reno Kemala Sari

Institutions
Faculty Economic and Business, Universitas Teknologi Sumbawa

Abstract
Women participation in economic activities is often limited by social norms, especially in moslems majority societies like Poto village of Sumbawa. Nevertheless, the burden of poverty is forced many women to work in several jobs. This paper aims to investigate how women in Poto involve in reducing their poverty and how it linked to islamic paradigm. This research is using qualitative method to collect and analyze the data through interview, FGD, and direct observation. Respondents were chosen by purposive sampling, while key informants were chosen by snowball technique. The results show that the main strategies of Poto-s women to reduce their poverty are being producer of Kre Alang and labor of on farm agribusiness. Those two jobs are related to islamic values which require some limitation for women to work in public. Furthermore, such kind of women participation in economy has a significant contribution to reduce poverty in the village

Keywords
Women-s Participation, Reducing Poverty, Islamic Perspective

Topic
Sustainable Development in Islamic Perspective

Link: https://ifory.id/abstract/TpWtvJEq7nbe

Corresponding Author
Didied Haryono

Institutions
1Department of Metallurgical Engineering, University of Sultan Ageng Tirtayasa,
Cilegon 42435, Banten, Indonesia 1
2Department of Metallurgical and Materials Engineering, Universitas Indonesia,
Depok 16424, Jawa Barat, Indonesia
3 Center for Non-Destructive Testing and Process Imaging (CNDTPI), CTECH Labs Edwar Technology,
Tangerang 15235, Banten, Indonesia

Abstract
Metallurgical performance in flotation process can be expressed by recovery or grade. In column flotation process, recovery is affected by several factors including particle size and air flow rate. Particle size and air flow rate affect the interaction of mineral particles with air bubbles. Metallurgical performance of column flotation process can be determined by monitoring. Electrical capacitance volume tomography (ECVT) used as a monitoring technology by utilizing the difference in permittivity values of objects in column flotation and producing volumetric and real-time images. Monitoring column flotation process was carried out to observe the effect of particle size and air flow rate on recovery and 3D image resulted by monitoring. Column flotation experiments were carried out on a column flotation laboratory scale with particle size variations of -80+100

Keywords
Column flotation, recovery, particle size, air flow rate, ECVT.

Topic
Metallurgy Engineering

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

Corresponding Author
Wahyuni Martiningsih

Institutions
Universitasity of Sultan Ageng Tirtayasa

Abstract
This research to design a wireless electric power transfer system by utilizing a used TV flyback transformer. Flyback TV is used as a Tesla coil power supply with a flyback converter circuit. The principle of wireless in this study is the resonance of electromagnetic waves produced by the Tesla coil. Experiments are carried out by providing switching frequencies and changing distances. The results showed that the power produced was 31.24 W (highest) at a switching frequency of 6.8 kHz and at a distance of 10 m. Efficiency at the same condition is 56,768%.

Keywords
Tesla Coil, Flyback Converter, Trafo Flyback, NE555, Wireless Power Transfer

Topic
Electrical Engineering

Link: https://ifory.id/abstract/U23wHqFBbCAM

Corresponding Author
B. Handoko Purwojatmiko

Institutions
(a) Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Skudai, Johor Bahru, Malaysia 81310
djokosetyowidodo[at]gmail.com

(b) Department of Industrial Engineering, Universitas Indonesia, Kampus Baru UI Depok, West Java, Indonesia 16424
*h.purwojatmiko[at]gmail.com

Abstract
Acoustic performance in classroom is important especially in speech communication. In order to make learning process more effective, the acoustic quality must be considered. There are two factor considered in this experiments that is frequency and air conditioner condition. Design of experiment is a systematic method used in this experiments to describe or explain the variation of information that are hypothesized to reflect the variation. General factorial design was used to determine all possible effect for factor combination. This paper propose to analyze how to know the significant effect from factors influence the intensity level. ANOVA was introduced to analyze significant factors and the interaction both factors. Analyze was completed with 5% significance level and the results show that frequency is the most significance factor that influence sound intensity level. Air Conditioner is other effect that increase sound intensity level since the additional ambient noise. Sound factors indirectly affect a person-s comfort in activities. Related to speech communication when the lecturer want to give clear information in classroom then should speak more louder than usual. The more participants in the room will have an impact on one-s performance in carrying out their activities.

Keywords
Design of Experiment; General Factorial Design; Acoustic Performance; Classroom; Frequency; Air Conditioner; ANOVA

Topic
Industrial Engineering

Link: https://ifory.id/abstract/NgPZLJT2HDMu

Corresponding Author
Anantya Novega Santoso

Institutions
Universitas Indonesia

Abstract
Increased population and economic capacity of the community indirectly affects the amount of household waste produced by the community. Unfortunately, this is not accompanied by good waste management from the community level. Management of household waste at the community level can be done by sorting waste. The habit of people to dispose of garbage without sorting can be a problem in implementing 3R activities (Recycling, Reducing, Reusing). The purpose of this study is to find out what factors influence the community in sorting household waste. This research is based on the Theory of Planning Behavior (TPB) which considers several factors such as attitudes, subjective norms, and behavioral controls to influence someone to make intentions in behavior and expand the TPB conceptual model to overcome gaps. The results of this study came from a survey with 301 respondents in two locations namely DKI Jakarta and Depok. The results of this study indicate that attitudinal factors have the most significant influence on the intention and behavior of sorting garbage. While other factors such as demographics, subjective norms and perceptions of behavioral control do not have a significant effect.

Keywords
Waste Separation; Theory of Planned Behavior (TPB); Partial Least Square (PLS)

Topic
Industrial Engineering

Link: https://ifory.id/abstract/DRUNagde8W7u

Corresponding Author
Nabila Yuraisyah Salsabila

Institutions
Department of Industrial Engineering, Institut Teknologi Sepuluh Nopember, Kampus ITS Sukolilo-Surabaya 60111, Indonesia

Abstract
A maintenance strategy is an important factor in the production activities of the process industry. Since the process industry consists of many components, the failure mode is relatively complex. This paper observes one of the petrochemical companies in Indonesia which produces Pythalic Anhydride. The company is able to produce in 20.69 days every month. In reality, during 2017, the company produced 23 days every month on average. Production, known as the calendar day, which cannot achieve the target can affect customer service level. This research focuses on evaluating availability in order to minimize Mean Time to Repair (MTTR). One of the best strategies is to control the spare part inventory policy so that the spare part must be available when an equipment downtime occurs. We will use two modelling techniques to solve the problem: (a) reliability block diagram will be used to model the failure mode and (b) the simulation model will be used to model the entire system, including random variables and variable inter-dependency. After conducting scenario analysis by varying some parameters, the availability increased to 91.8% and average calendar days decreased to 22.64 days per month.

Keywords
Availability, Discrete event simulation, Inventory management, Reliability block diagram

Topic
Industrial Engineering

Link: https://ifory.id/abstract/KCBfqQ4vGMN7

Corresponding Author
Sutarsi sutarsi

Institutions
1 Departement of Chemical Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia

Abstract
Curcuma xanthorrhiza Roxb. known as temulawak, Javanese ginger or Javanese turmeric, is a plant species, belonging to the ginger family. This plant is originated from Indonesia, more specifically from Java island, and usually used as medicine. It contain high amount of phenolic compound namely curcumin. Supercritical carbondioxide extraction technique was employed to extract curcumin from temulawak. The objective of this study was to investigate the effects of temperature, pressure and CO2 flow rate to extraction yield and curcumin recovery from C. xanthorrhiza Roxb. extracted using supercritical carbon dioxide and cosolvent ethanol. Box-Behken Design (BBD) experimental design and response surface methodology (RSM) were used to optimize extraction yield and curcumin recovery. The extraction conditions at temperature of 40oC, pressure of 25 MPa and CO2 flow rate of 5.34 ml/min produced the optimum extraction yield of 10.4% and curcumin recovery of 3.2%. From FTIR analysis, although physical-chemical structure in starting material an residue almost similar, but the quantity of all functional grups in residue decreased from the starting material. From SEM analysis, it was confirmed that the cell was broken due to high pressure effect and finally the material structure was altered.

Keywords
curcumin, Curcuma xanthorriza Roxb., phenolic compounds, supercritical CO2 extraction

Topic
Chemical Engineering

Link: https://ifory.id/abstract/R8JnAMd6aHK3

Corresponding Author
Gunawan Saroji

Institutions
Civil Engineering Department, Faculty of Engineering, Universitas Indonesia, Depok 16424, Indonesia

Abstract
The application of transit oriented development (TOD) was felt to be relevant to support the Light rail transit (LRT) Jabodebek. The increase in property value in the area around the LRT line is significant to note in order to find out the potential revenue from the TOD project. This study aims to estimate property income (housing, commercial, office) in the development of TOD-based areas. Interview method used to get the variable characteristics of hedonic price modeling (HPM) suitability of TOD that will be used as benchmarks. The coefficient of increase in the value of the HPM of benchmarking, which has conformance characteristics with TOD Jabodebek will be used to calculate the magnitude of the increased value of the property. Based on the calculation, it was obtained that property income due to the influence of the hedonic coefficient increased by 161 billion rupiah with an internal rate of return (IRR) 11.7% on Ciracas TOD, Bekasi Timur TOD 74 billion rupiah with IRR 11.01%, TOD Cibubur 124 billion rupiah with IRR 19.51% and TOD Jaticempaka IDR 107 billion with IRR 12.01%

Keywords
Property, Transit Oriented Development, Hedonic Price Modeling

Topic
Civil Engineering

Link: https://ifory.id/abstract/eVhkcMW9FnLH

Corresponding Author
Novaldi Dwiputra Prihadi

Institutions
Industrial Engineering, School of Industrial Engineering, Telkom University, Bandung, Indonesia

Abstract
Increased sales in the automotive sector every year, forcing supporting companies to support their production activities. Increased productivity, the potential risks also arise that arise and give a negative impact on the company, one of which is rubber industry, as a supporting company. One area that is very vulnerable to risk is the supply chain scope. The complexity of the supply chain structure that involves many parties is very vulnerable to the emergence of potential risks and becomes a challenge in managing them. Therefore, risk management and proactive actions in the supply chain are needed to minimize the losses that will occur. The model that is suitable in overcoming this problem is House of Risk (HOR). The HOR model is divided into two stages. HOR1 is used to identify and rank each identified risk agent. HOR2 is used to prioritize proactive actions that must be applied by companies with selected risk agents at HOR1. In this case, there are 9 proactive actions that are prioritized in overcoming the identified risk agent.

Keywords
risk management, supply chain, manufacturing, house of risk, proactive actions

Topic
Industrial Engineering

Link: https://ifory.id/abstract/ekbjf3awLUcx

Corresponding Author
Muhammad Iman Santoso

Institutions
a) Electrical Dept. University of Sultan Ageng Tirtayasa, Center for Transport System and Logistics (CTSL)-Untirta
Jl. Jend Sudirman KM. 3 Cilegon 42435 - Indonesia
*iman.santoso[at]untirta.ac.id
b) Electrical Dept. University of Sultan Ageng Tirtayasa
Jl. Jend Sudirman KM. 3 Cilegon 42435 - Indonesia
c) Communication Science Dept. University of Sultan Ageng Tirtayasa
Jl. Jend Raya Jakarta KM. 4 Pakupatan Serang 42111 - Indonesia

Abstract
Congestion has become a common problem in urban. Road growth is always slower than vehicles. City mayor around the world already understands and try to find breakthroughs. Unfortunately, the settlement is often partial and ignore social interests. This paper seeks to solve urban transport problem in urban with information technology, spatial analysis, social plan, and legal formalities. The research began with a survey of public transport routes using mobile apps, a review of the transport regulation, one-way road arrangement study followed by WebGIS Development. This application is a multi-tier client-server architecture consisting of the client-side, the server-side, and the data directory that stored in the VPS (Virtual Private Server). The client-side is powered by HTML-5, which is assisted by the API (Application Programming Interface) from several open-source online mapping. Standard performance test of the application has been set, and every menu is well functioned. Every data on the transport infrastructure could be gathered and stored on the web. Furthermore, every single transport planning should refer to this transport information system. Thus, WebGIS becomes online surveillance system for land use.

Keywords
WebGIS, Spatial-Analysis, Transport, Congestion, Urban

Topic
Computer Engineering

Link: https://ifory.id/abstract/eDKHaEjN6URc

Corresponding Author
Ni Luh Gede Ratna Juliasih

Institutions
1 Chemistry Department,
Faculty of Mathematics and Natural Sciences,
University of Lampung, Jl. Sumantri Brojonegoro No. 1 Bandar Lampung 35145, Indonesia.

* ratnagede.juliasih[at]gmail.com

2 Biochemistry Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40231, Indonesia.

Abstract
Diatoms are unicellular photosynthetic microalgae, which dispersed in marine and freshwater environments. More than 200 diatom genus with around 100,000 species found in nature, each with different morphologies and dimensions. Their cell walls are composed of biosilica and exhibit species-specific nanoporous to microporous and macroporous patterning which is a promising renewable material for various applications, such as in catalysis, drugdelivery systems, sensors, and Biophotonics, due to the high surface area, mechanical resistance, unique optical features, and biocompatibility. In this study, biosilica of tropical marine diatom C. striata was used as a material for protein purification. The frustule of C. striata was washed with an acid solution and dried in oven. Remaining organic compounds were removed via calcination in a furnace. The biosilica was modified using 3-Mercaptopropylmethyl-dimethoxysilane (MPTS) and the obtained material was characterized using FTIR and SEM_EDX. The binding test capacity was conducted to evaluate the modified biosilica. The protein binding capacity of the modified biosilica was 14520 µg/mL.

Keywords
microalgae, diatom, Cyclotella striata, biosilica, protein purification

Topic
Materials Science

Link: https://ifory.id/abstract/tYfe9kuBnrvd

Corresponding Author
Endarto Y. Wardhono

Institutions
1 University of Sultan Ageng Tirtayasa, Cilegon, 42435, Banten, Indonesia
2 Sorbonne Universités, Université de Technologie de Compiègne, Integrated Transformations of Renewable Matter Laboratory (EA TIMR 4297 UTC-ESCOM), rue du Dr Schweitzer, 60200 Compiègne, France

Abstract
In this work, the evolution of dispersed droplets formation in a water-in-oil, W/O emulsion was observed using calorimetry technique. The emulsion was prepared by dispersing drop by drop of an aqueous phase into an oil continuous phase at room temperature using rotor-stator homogenizer. The droplets formation during: (1) formulation; (2) stabilization (3) and destabilization were observed using Differential Scanning Calorimertry, DSC. The samples were gently cooled-down below to its solid-liquid equilibrium temperature then heated back above the melting point to determine its solidification temperature. The energy released during the process was recorded in order to get information about the water droplet dispersion state. The mean droplet size distribution of the sample emulsion was correlated to its solidification temperature and the morphology was followed by optical microscopy. The results indicated that the calorimetry technique so far are a very good technique to characterize of W/O emulsion system

Keywords
DSC, W/O emulsion, dispersed droplets, solidification temperature, droplet size distribution

Topic
Chemical Engineering

Link: https://ifory.id/abstract/qY4EnkXAT2u6

Corresponding Author
Misri Gozan

Institutions
Department of Chemical Engineering, Universitas Indonesia, Depok 16421, Indonesia
*mgozan[at]che.ui.ac.id

Abstract
Biogas is one of the alternative energies to overcome the increasing demand of electrical energy in Indonesia due to both population and industrial growths. In the growing cities, one source of biogas is the municipal waste. This study examined a biogas power plant proposal in Bantar Gebang which receives supply of approximately 6500 tonnes of garbage per day from all parts of Jakarta. It is assumed that a mixture of 60-70% CH4, 30-40% CO2 and other gases such as H2S is produced from anaerobic digestion. The overall heating value of this mixture is 6-24 MJ/m3, which is a half of the heating value of natural gas. Iron sponge is used to remove acid gases. The plant size is 2 ha which is located near the Bantar Gebang Integrated Landfill. Both gas and steam turbines are used to produced electricity. The produced electricity is sold to PLN, with price US$ 0.10 per kwh. With the 44.2 MWh/year electricity production, the income of this biogas power plant is around US$6 Million per year. The CAPEX is US$9,935,838 and OPEX is US$1,697,375.09 with the IRR 17%, ROI 32%, NPV US$ 4,471,949.2, and Payback Period in 6.8 years of production. These figures show that the biogas electricity plant is profitable.

Keywords
municipal waste; electricity; biogas; plant design

Topic
Chemical Engineering

Link: https://ifory.id/abstract/LWNnDxa2Ej3b