Digital Commons Network^™

Design And Development Of Alumni Career Information System Using Php Mysql, Mustofa Abi Hamid, Didik Aribowo, Rini Anggraini

Elinvo (Electronics, Informatics, and Vocational Education)

Alumni data collection at the Electrical Engineering Vocational Education Universitas Sultan Ageng Tirtayasa was still performed manually and there were no career information media about soft skills training and development, tracer studies, and job vacancies information. Therefore, media is needed to accommodate career information and alumni data collection quickly and effectively. The web-based information system using PHP MySQL was developed and tested for feasibility as an information medium for soft skills training and development, tracer studies, job vacancies information, as well as career counseling and consulting. This study used a Modify R&D as a development method and the waterfall method …

Implementation Of Switching Algorithm For Svpwm Inverter In Induction Motor Drive System On Electric Vehicle Applications, Bayu Praharsena, Mohammad Jauhari, Era Purwanto, Mentari Putri Jati, Angga Wahyu Aditya, Aries Alfian Prasetyo

Elinvo (Electronics, Informatics, and Vocational Education)

Electric cars are the way to reduce global warming and fuel shortages. Performance variable speed drive is needed for various drive electric vehicle applications. Unfortunately, high performance is still being investigated with a variety of drive systems. This paper presents a design, analysis, and implementation of the SV-PWM inverter motor drive system. The SV-PWM algorithm in design using Matlab, to analyze the system include signal response, THD-V, THD-I. All algorithms are embedded in STM32F4, as the main controller. The hardware uses a 3-phase motor control Steval power module. Response speed and output signal inverters are shown in chart form for …

A Comparison Of K-Means And Agglomerative Clustering For Users Segmentation Based On Question Answerer Reputation In Brainly Platform, Puji Winar Cahyo, Landung Sudarmana

Elinvo (Electronics, Informatics, and Vocational Education)

Brainly is a question and answer (Q&A) site that students can use as a media for questions and answers. Students can also use Brainly to find and share educational information that helps students solve their homework problems. In Brainly, users can answer questions according to their interests. However, it could be that the interest is not necessarily following the competencies possessed. It causes many answers to the questions given not to have a high rating because the answers given are of low quality to be prioritized as the main answer. This study aims to apply the K-Means and Agglomerative Clustering …

Forecasting Locational Marginal Prices In Electricity Markets By Using Artificial Neural Networks, Kim Jay R. Rosano, Allan C. Nerves

Journal of Economics, Management and Agricultural Development

Electricity price forecasting is an important tool used by market players in decision-making and strategizing their participation in the electricity market. In most studies, market-clearing price is forecasted as it gives an aggregated overview of system price. However, locational marginal price (LMP) gives better outlook of the price particular to the customer location in the electrical power grid. This study utilizes Artificial Neural Networks to forecast weekday LMP of generator and load nodes. Various inputs such as historical prices and demand, and temporal indices were used. Using data for selected nodes of the Philippine Wholesale Electricity Spot Market, forecast Mean …

User Experience Design Practices In Industry (Case Study From Indonesian Information Technology Companies), Isnan Nugraha, Agung Fatwanto

Elinvo (Electronics, Informatics, and Vocational Education)

User Experience (UX) is a term that has received a lot of attention in the last decade. The number of industries whose consider the importance of implementing the UX design process within their development cycle has increased. Therefore, we think it is important to investigate how UX design processes are implemented in the industries. In this research, we take a qualitative approach with descriptive methods by investigating six information technology companies in Indonesia. As a result, we found that most of these information technology companies implement the UX design process as part of their operation and consider that the UX …

Mathematical Model Of Cholera Spread Based On Sir: Optimal Control, Noer Hidayati, Eminugroho Ratna Sari, Nur Hadi Waryanto

PYTHAGORAS : Jurnal Matematika dan Pendidikan Matematika

The bacterium Vibrio cholerae is the cause of cholera. Cholera is spread through the feces of an infected individual in a population. From a mathematical point of view, this problem can be brought into a mathematical model in the form of Susceptible-Infected-Recovered (SIR), which considers the birth rate. Because outbreaks that occur easily spread if not treated immediately, it is necessary to control the susceptible individual population by vaccination. The vaccine used is Oral Vibrio cholera. For this reason, the purposes of this study were to establish a model for the spread of cholera without vaccination, analyze the stability of …

Penggunaan Goal Programming Dalam Perencanaan Menu Untuk Lansia Penderita Hipertensi, Diana Islamiyati, Dwi Lestari, Nur Insani

PYTHAGORAS : Jurnal Matematika dan Pendidikan Matematika

Penelitian ini bertujuan untuk membangun suatu model goal programming untuk mengoptimalkan perencanaan menu harian lansia penderita hipertensi. Fungsi tujuan model ini yaitu untuk memaksimumkan kandungan gizi makanan lansia sesuai Angka Kecukupan Gizi (AKG), meminimumkan biaya pangan, memaksimumkan kuantitas pangan, dan meminimumkan konsumsi pangan yang mengandung natrium. Berdasarkan eksperimen komputasi yang dilakukan dengan menerapkan model weighted goal programming ini, dihasilkan solusi optimal kebutuhan gizi lansia penderita hipertensi yang sesuai dengan AKG. Adapun perencanaan optimal menu makanan untuk lima hari yaitu terdiri dari 12 jenis pangan dengan pengeluaran biaya sebesar Rp 11.236,- untuk hari pertama, 13 jenis pangan dengan pengeluaran biaya …

Drought-Prone Areas Mapping Using Fuzzy C-Means Method In Gunungkidul District, Kismiantini Kismiantini, Fajra Husniyah, Osval Antonio Montesinos-López

PYTHAGORAS : Jurnal Matematika dan Pendidikan Matematika

Gunungkidul district is one of the districts in the Special Region of Yogyakarta that is frequently affected by drought disasters. The purpose of this study is to map drought-prone areas in Gunungkidul district using the fuzzy c-means method, making it easier for the government to allocate water-dropping assistance to drought-affected areas. The research variables include rainfall, soil type, infiltration, slope, and land use. The type of variables is an ordinal scale, so they must be transformed using the successive interval method before being analyzed using the fuzzy c-means method. The cluster validity indexes of the Xie and Beni index, partition …

A Novel Arabic Corpus For Text Classification Using Deep Learning And Word Embedding, Roua A. Abou Khachfeh, Islam El Kabani, Ziad Osman

BAU Journal - Science and Technology

Over the last years, Natural Language Processing (NLP) for Arabic language has obtained increasing importance due to the massive textual information available online in an unstructured text format, and its capability in facilitating and making information retrieval easier. One of the widely used NLP task is “Text Classification”. Its goal is to employ machine learning technics to automatically classify the text documents into one or more predefined categories. An important step in machine learning is to find suitable and large data for training and testing an algorithm. Moreover, Deep Learning (DL), the trending machine learning research, requires a lot of …

A Poisson-Akash Inrar(1) Model For Over Dispersed Count Time Series, Emmanuel W. Okereke, Sunday N. Gideon

BAU Journal - Science and Technology

In this paper, a Poisson-Akash INAR(1) model was proposed in order to improve on the modelling of overdispersed stationary count time series. The estimators of the parameters of the model were derived using the Yule-Walker (YW) method and the conditional least squares (CLS) method. An expression for the conditional log-likelihood and the r-step ahead forecast were obtained for the model. Three overdispersed nonseasonal stationary count time series were modelled to illustrate the applicability of the proposed model as well as its capacity to outperform the competing INAR (1) models in modelling overdispersed stationary count time series and the result showed …

Walking Diagonally: A Simple Proof Of Countability Of The Set Of All Finite Subsets Of Naturals, Miroslav Kures

BAU Journal - Science and Technology

The countability of the set of finite subsets of natural numbers is derived. In addition to the derivation itself, the use of diagonal method is illustratively presented; thinking about infinite sets relate to the name of Georg Ferdinand Ludwig Philipp Cantor, the creator of set theory, which has become a fundamental theory in mathematics. The proof of the claim is original, although the theorem is an analogy with the famous theorem about the countability of rational numbers. A certain insight into the subsets of natural numbers is given. Anyway, the technique could be considered already at high school level as …

Role Of Technological Revolution In Transport And Communications Development, Mohamad B. Chami

BAU Journal - Science and Technology

The arousal of technology has changed a lot of aspects in human life and has drastically changed its path through a revolution that changed the whole world. This revolution took place in various aspects while affecting significantly the global economy and from those fields that considerably affect the life of human beings in the previous and current centuries are Information and Communication Technology (ICT) and transportation. It is these two factors that play a major role in the economy of countries and dominate the lives of societies in the world. Thus, this paper studies the impact of the technology revolution …

The Inhibition Activity Of Tert-Butylhydroquinone Towards Corrosion Of Aluminum, Copper And Stainless Steel In Biodiesel Blend B20 Alternative Fuel, Chaza Joumaa, Ibtissam Saad, Ghassan Younes

BAU Journal - Science and Technology

Tert-butylhydroquinone (TBHQ) has been investigated as corrosion inhibitor for aluminum; copper and stainless steel in biodiesel blend B20 by using electrochemical impedance spectroscopy (EIS) method. The results showed that the inhibition efficiency increases with an increase in the concentration of TBHQ but decreases with increasing temperature from 30℃ to 60℃. A maximum inhibition efficiency of about 61.52% for aluminum was recorded for THBQ in biodiesel blend B20 at temperature 30℃ and at a concentration of 4x10^-6 M which is the lowest concentration used compared to the concentrations of TBHQ used for the other metals (copper and stainless steel). Theoretical …

Physical And Magnetic Properties Of Nanosized Mn0.5ni0.5¬Fe2-Xprxo4 Prepared By Co-Precipitation Method, Douaa El-Said Bakeer, Khulud Habanjar, Ghassan Youness, Mohammad Abou Ghoush

BAU Journal - Science and Technology

Nanosized Mn_0.5Ni_0.5Fe_2-xPr_xO₄, x=0.0, 0.02, 0.04, 0.06, 0.08, 0.1 and 0.15 are prepared by co-precipitation method at calcination temperature 650^oC for 4 hours. X-ray diffraction patterns show the presence of the cubic (Mn-Ni)- ferrite phase and anti-ferromagnetic a-Fe₂O₃. The variation in the lattice parameter “a” is due to the replacement of smaller radius ions Fe⁺³ by larger radius ions Pr⁺³. Transmission electron micrographs indicate that the particles are spherical in shape. The moderately agglomerated particles are present due to the …

Mercury Contamination In Selected Edible Plants And Soil From Artisanal And Small-Scale Gold Mining In Sukabumi Regency, Indonesia, Grace Serepina Saragih, Ely Rahmi Tapriziah, Yunesfi Syofyan, Siti Masitoh, Yohana Sari Hotmatua Pandiangan, Andriantoro Andriantoro

Makara Journal of Science

Artisanal and small-scale gold mining (ASGM) activities often pollute soil, water, and air, thereby achieving widespread proliferation, and contaminating the surrounding biota including plants. Mercury contamination on agricultural land around ASGM areas has been widely reported. This study aims to determine the total mercury contamination in plants and soil around active ASGM sites in Sukabumi Regency, Indonesia, namely, Waluran, Lengkong, and Ciemas Districts. Total mercury (Hg) content was measured from 27 plant samples (including cassava [Manihot utilisima], rice [Oryza sativa], and papaya [Carica papaya]), 7 rhizosphere soil samples, and 7 non-rhizosphere soil samples. Data …

Effect Of Dry Oxidation And Thermal Annealing On Aln/Gan/Aln/Si (111) And Evaluation Of Its Electrical Characteristics, Mohd Zaki Mohd Yusoff, Azzafeerah Mahyuddin, Zainuriah Hasssan, ‪Muhammad Syarifuddin Yahya

Makara Journal of Science

We proposed a technique for improving the platinum (Pt) Schottky contact dark current of the AlN/GaN/AlN/Si(111) substrate. The AlN/GaN/AlN/ heterostructure sample was successfully grown on a silicon substrate by radio frequency molecular beam epitaxy. The high quality of the interlayer heterostructure sample was verified by transmission electron microscopy (TEM). From the TEM image, a good quality single interface layer with spacing less than 1 nm was detected. The strong significant peaks obtained by X-ray diffraction measurement indicated that the sample has a high structural quality for each grown layer. Dry oxidation and thermal annealing were used in conjunction to effectively …

Bioaccumulation Of Trace Metals For Daily Fish Consumption From Selected Former Tin Mining Ponds In Peninsular Malaysia: A Review On Safety Of Fish Consumption, Mohd Hafiz Rosli, Amirul Azuan Md Joni, Nur Khaliesah Abdul Malik

Makara Journal of Science

Tin mining was the predominate mining industry in Malaysia, especially during the mid-19th century. Most of the former mining areas have been reused for aquaculture purposes. Fish produced from former mining areas have been misunderstood as a high health risk if consumed due to their likelihood of containing high heavy metal content in their tissue. Therefore, we review national information on trace metals levels in the tissue of fish from selected former mining ponds in Peninsular Malaysia, together with background concentration of trace metals in their surroundings and food security and human health implications. Seven trace metals (Cu, Zn, As, …

Magnetically Separable Fe3o4/Sio2/Tio2 Photocatalyst Composites Prepared Through Hetero Agglomeration For The Photocatalytic Degradation Of Paraquat, Jarnuzi Gunlazuardi, Adel Fisli, Ridwan Ridwan, Yuni Krisyuningsih Krisnandi, Didier Robert

Makara Journal of Science

A photocatalyst supported on magnetic material allows the simple technique by using an external magnetic material to separate photocatalyst from the treated water. Thus, it is a magnetically separable nanoparticles photocatalyst (MSNP). The use of superparamagnetic nanoparticles that do not pose spontaneous magnetic moment thus could be dispersed in water and can be recollected easily by an external magnetic bar. We prepare Fe₃O₄/SiO₂/TiO₂ composite by hetero agglomeration of Fe₃O₄/SiO₂ and TiO₂ at a pH range of 3 to 6.2 in an aqueous slurry_.The Fe_{3 …}

Self-Assembly Of Black Cumin Oil-Based Nanoemulsion On Various Surfactants: A Molecular Dynamics Study, Aulia Fikri Hidayat, Taufik Muhammad Fakih

Makara Journal of Science

Black cumin is commonly used as traditional medicine due to its wide range of pharmacological potential. Black cumin oil (BCO) was often prepared as nanoemulsion to improve its solubility, stability, and bioavailability. This study was conducted to investigate the molecular behavior as well as structural evolution of BCO-surfactant systems during self-assembly micellization using molecular dynamics (MD) simulations. Several BCO constituents and variations of surfactants were employed to model BCO-surfactant systems. 50 ns of MD simulations were performed to elucidate their evolution of structures and physicochemical properties during formation. Results showed that BCO-tween20 and BCO-lecithin were able to form spherical-shaped micelles …

Scale Model Equations And Optimization For Annular Flow Of Non-Newtonian Fluids Between Eccentric And Rotating Cylinders, Wei Zhang, Pooya Khodaparast, Amin Mehrabian Dr., Amir Shojaei

Progress in Scale Modeling, an International Journal

A broad range of engineering applications involves helical flow of non-Newtonian fluids between two eccentric cylinders. These applications often require estimation of the frictional pressure losses along the axes of the cylinders. Laboratory flow loops are commonly used to study the flow characteristics at smaller scales of investigation. This study uses the laws of similarity and dimensional analysis to obtain a set of scaling equations between the laboratory and prototype scales of the described annular flow. These equations are derived for four types of fluid rheology including Newtonian, power-law, Bingham-plastic, and yield power-law.

Results are expressed through a set of …

Decomposable Model Spaces And A Topological Approach To Curvature, Kevin M. Tully

Rose-Hulman Undergraduate Mathematics Journal

This research investigates a model space invariant known as k-plane constant vector curvature, traditionally studied when k=2, and introduces a new invariant, (m,k)-plane constant vector curvature. We prove that the sets of k-plane and (m,k)-plane constant vector curvature values are connected, compact subsets of the real numbers and establish several relationships between the curvature values of a decomposable model space and its component spaces. We also prove that every decomposable model space with a positive-definite inner product has k-plane constant vector curvature for some integer k>1. In …

Winning Strategy For Multiplayer And Multialliance Geometric Game, Jingkai Ye

Rose-Hulman Undergraduate Mathematics Journal

The Geometric Sequence with common ratio 2 is one of the most well-known geometric sequences. Every term is a nonnegative power of 2. Using this popular sequence, we can create a Geometric Game which contains combining moves (combining two copies of the same terms into the one copy of next term) and splitting moves (splitting three copies of the same term into two copies of previous terms and one copy of the next term). For this Geometric Game, we are able to prove that the game is finite and the final game state is unique. Furthermore, we are able to …

Hurwitz Actions On Reflection Factorizations In Complex Reflection Group G₆, Gaurav Gawankar, Dounia Lazreq, Mehr Rai, Seth Sabar

Rose-Hulman Undergraduate Mathematics Journal

We show that in the complex reflection group G₆, reflection factorizations of a Coxeter element that have the same length and multiset of conjugacy classes are in the same Hurwitz orbit. This confirms one case of a conjecture of Lewis and Reiner.

Lie-Derivations Of Three-Dimensional Non-Lie Leibniz Algebras, Emily H. Belanger

Rose-Hulman Undergraduate Mathematics Journal

The concept of Lie-derivation was recently introduced as a generalization of the notion of derivations for non-Lie Leibniz algebras. In this project, we determine the Lie algebras of Lie-derivations of all three-dimensional non-Lie Leibniz algebras. As a result of our calculations, we make conjectures on the basis of the Lie algebra of derivations of Lie-solvable non-Lie Leibniz algebras.

The Optimal Double Bubble For Density 𝑟ᵖ, Jack Hirsch, Kevin Li, Jackson Petty, Christopher Xue

Rose-Hulman Undergraduate Mathematics Journal

In 2008 Reichardt proved that the optimal Euclidean double bubble---the least-perimeter way to enclose and separate two given volumes---is three spherical caps meeting along a sphere at 120 degrees. We consider Rⁿ with density r^p, joining the surge of research on manifolds with density after their appearance in Perelman's 2006 proof of the Poincaré Conjecture. Boyer et al. proved that the best single bubble is a sphere through the origin. We conjecture that the best double bubble is the Euclidean solution with the singular sphere passing through the origin, for which we have verified equilibrium (first variation …

Photoelectrochemical Sensing Based On Zr-Mofs For Homocysteine Detection, Wen-Xia Dong, Guang-Ming Wen, Bin Liu, Zhong-Ping Li

Journal of Electrochemistry

Due to the independent form of the light source and detection system, photoelectrochemical (PEC) sensor has the advantages of low background, high sensitivity and simple operation. So far, PEC systems have been widely used in the fields including the actual detection of metal ions, biological antibodies or antigens in environmental pollutants. When the photosensitive material is irradiated by a light source with an energy being equal to or greater than its band gap, electrons (e-) transition occurs from the valence band to the conduction band, leaving a hole (h+), at the same time, the generated electron-hole pair (e-/h+) separate, and …

Formation And Morphological Evolution Of Nanoporous Anodized Iron Oxide Films, Jin-Wei Cao, Nan Gao, Zhao-Qing Gao, Chen Wang, Sheng-Yan Shang, Yun-Peng Wang, Hai-Tao Ma

Journal of Electrochemistry

The preparation of iron oxide films with nanoporous structure by anodization has attracted much attention for its potential applications. However, the formation mechanism of porous structure during anodization is still unclear. In this paper, the composition of anodic current during the formation of nanoporous anodized iron oxide film was analyzed in combination with the current density-potential response (I-V curve) and the derivation of Faraday’s law. The results showed that the anodic current consisted of an ionic current (leading to the migration of ions to form oxide) and an electronic current (leading to the oxygen evolution), and the …

Cyclic Voltammetric Simulations On Batteries With Porous Electrodes, Xue-Fan Cai, Sheng Sun

Journal of Electrochemistry

Lithium-ion batteries (LIBs) are among the most widely used energy storage devices. Whole-cell modeling and simulations of LIBs can optimize the design of batteries with lower costs and higher speeds. The Pseudo-Two-Dimensional (P2D) electrochemical model is among the most famous whole-cell models and widely applied in LIB simulations. P2D model consists of a series of kinetic equations to model Li+/Li diffusion in working/counter electrodes and electrolytes, which are filled in the porous electrodes and separator, and reactions at the interface of electrolyte and active particles. The traditional applications of P2D model, however, are limited to the cases where the current …

Effect Of Aluminum Alloy Surface Modification On Adhesion Of The Modified Polyurethane Coating And Its Corrosion Protective Performance, Xian-Yin Kuang, Shao-Qiang Jin, Yan-Hui Cao, Yan-Mei Zhang, Shi-Gang Dong, Long-Hui Zhu, Li-Wen Lin, Chang-Jian Lin

Journal of Electrochemistry

The ordinary organic coatings on aluminum alloy usually encounter a problem of low adhesion to the substrate, which results in destruction and failure of the long-term protective performance of the anticorrosion systems. The surface modification of aluminum alloy is able to enhance the adhesion of organic coating on aluminum alloys, and to improve their protective performance. In this work, a combined surface modification of anodic oxidation and mussel adhesion protein/CeO₂/3-aminopropyltriethoxysilane composite film (MCA) was developed on the aluminum alloy. The adhesion of modified polyurethane coated on the treated aluminum alloy and its corrosion protective performance were evaluated comprehensively …

Functional Sulfate Electrolytes Enable The Enhanced Cycling Stability Of Nati2(Po4)3/C Anode Material For Aqueous Sodium-Ion Batteries, Shu-Jin Li, Zhi-Kang Cao, Wen-Kai Wang, Xiao-Han Zhang, Xing-De Xiang

Journal of Electrochemistry

Aqueous sodium-ion batteries show promising application in fields of large-scale storage of intermittent renewable energies owing to the earth-abundant sodium resources and incombustible aqueous electrolytes. Primary factors determining whether they can be commercially utilized are low cost and long lifetime. Among current electrode materials, NASICON-type NaTi₂(PO₄)₃ arouses wide interests as an anode material for aqueous sodium-ion batteries as it offers a high specific capacity, fast Na-transport ability and reasonable working potential, however, suffering from insufficient cycling performance caused by severe dissolution of active materials in traditional aqueous electrolytes. In this work, a functional sulfate electrolyte …