bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biodiversity Arbuscular Mycorrhizal Fungi in the Former Gold Mine Area in North Sumatra
Authors: Pulungan Ahmad Shafwan S , Nasution Mhd. Yusuf 
Published: March 2021

Abstract
This study aims to determine the diversity of arbuscular mycorrhizal fungi in the area of the former gold mine in North Sumatra. This research was conducted with 5 soil sampling points. The research method used began with calculating the percentage of root colonization, spores density of arbuscular mycorrhizal fungi and types of arbuscular mycorrhizal fungal spores. In addition, physical and chemical conditions of the soil are also measured. The results showed that the rate of root colonization was at moderate to high with an average rate of root colonization at 22.8%. The density of arbuscular mycorrhizal fungi spores in this study averaged 10/50 g of sample soil. the number of spores in this study belongs to the moderate category, however the characteristics of the study location show the uniqueness of its own area that makes the population of mycorrhizal types not too much. Spore types were found in 4 types with each Glomus and Acaulospora. The conclusion obtained that there was a symbiosis between fungi and plants in the former gold mining area in North Sumatra.
Development of Digital Book in Enhancing Students’ Higher-Order Thinking Skill
Authors: Siregar Budi Halomoan , Kairuddin  , Mansyur Abil , Siregar Nurhasanah 
Published: March 2021

Abstract
During the Covid-19 pandemic, the learning process is carried out massively from home, on the other hand, higher-order thinking skills (HOTS) remain a priority for learning objectives, therefore it is necessary to ensure creative solutions to achieve it. Digital book is a learning media that is compiled by combining: 1) text, 2) animation, 3) audio, 4) video, which can be accessed easily and systematically via online. The development of this book aims to facilitate online learning during the covid-19 pandemic, then specifically to measure the level of validity, practically, and effectiveness in increasing students’ HOTS. This research was conducted in five stages: 1) analyzing, 2) designing, 3) development, 4) implementation, and 5) evaluation (ADDIE model), while the instruments used were observation sheets, validation sheets, questionnaires, and essay tests. This research was conducted in class E and F, each consist of 35 students. The results of data analysis indicate that this book is in a valid and practical category. Furthermore, this book is very effective to be used to enhance student HOTS.
Designing Interactive Videos in Online Multivariable Calculus Course to Support Student’s Critical Thinking
Authors: Firdaus M , Mukhtar  , Darari M B , Azis Z 
Published: March 2021

AbstractEmphasizing critical thinking skills in the curriculum of higher education institutions is needed to produce graduates with higher order thinking skills. Given the importance of information technology for critical thinking in learning, it is necessary to understand the key factors related to learning designs that utilize information technology in their learning environment and consider the pedagogical and information technology alignment. This study aims to describe the process of analysing, designing, and developing interactive learning videos as part of the redesign of the multivariable calculus course to support students’ critical thinking skills. This paper will describe the lessons learned from and the next steps in this research and development process.
Development of a Field Guide Book on the Pteridophyta Topic in Padang Lawas Regency
Authors: Siregar Saddam Hamidi 
Published: March 2021

Abstract
This study aimed to determine the feasibility of a field manual guidance for ferns (Pteridophyta) in oil palm and rubber plantations in Padang Lawas District. The subjects in this study were (1) material experts, (2) instructional design experts, (3) layout design experts and (4) 4th semester undergraduate students of Biology Department at Universitas Negeri Medan. This field manual guidance was developed according to Thiagarajan (4D), namely the stages: define, design, development and dissemination, but in this study it was only up to the development stage. The results showed that (1) the assessment of material experts based on material suitability, accuracy and strength of the material, learning systematics, efficiency of field manual guidance in learning and language had an average score of 79.5% with good criteria, (2) the assessment of instructional design experts based on the feasibility and presentation of the content had an average score of 90.86% with very good criteria, (3) the assessment of the layout design experts based on the size aspect, the cover design and the content design of the field manual guidance had an average score namely 82.87% with very good criteria, (4) assessment by 4th semester undergraduate students based on individual trials, small groups and limited groups sequentially had scores 84.04%, 93.63%, 86.86% which showed very good criteria. Therefore it can be concluded that the field guide book for ferns (Pteridophyta) in oil palm and rubber plantations in Padang Lawas Regency which was developed was feasible according to material experts, instructional design experts, layout design experts and students, so that the field manual guidance for ferns (Pteridophyta) in oil palm and rubber plantations in Padang Lawas District could be used as a supplementary book for lecturers, students, readers in general and researchers interested in the field of ferns (Pteridophyta).
Isolation of Nematophagous Fungi from Lau Kawar Lake, North Sumatra, Indonesia
Authors: Hastuti L D S , Yurnaliza Y , Tarigan W E , Hartanto A , Pahlevi S 
Published: March 2021

Abstract
Root-knot nematodes are harmful organisms which cause severe damage to plants and decreasing its productivity. Biocontrol agents isolated from potential environment may solve the intriguing problem of these nematodes. Nematophagous fungi has proven as promising strategy in controlling nematodes when compared to commercial pesticides which may pollute the soil and environment through accumulated residues post-usage. Nematophagous fungi were isolated from several soils or sediments around Lau Kawar Lake using a combination of pour and sprinkle techniques. Nine fungal morphotypes were recovered from soil/sediment samples as revealed from their distinctive morphologies. Two isolates, LK.10.1 and LK.10.3 were designated as potential nematophagous fungal isolates by their effectiveness in killing nematodes within 36 hr of observation. Species-level identification is currently carried out for the isolates to reveal and confirm their identities as nematophagous fungi.
Online Learning in Faculty of Mathematics and Natural Sciences, State University of Medan: Lecturers’ Preferences for Online Learning Media During the Covid-19 Pandemic
Authors: Sipahutar Herbert , Harahap Fauziyah , Mukhtar  , Nasution Muh. Yusuf 
Published: March 2021

Abstract
Online learning has long been promoted by the Faculty of Mathematics and Natural Sciences (FMNS), State University of Medan (SUM). The online learning system (SIPDA) has been developed by Unimed as the backbone of online learning, but the number of lecturers using the system has not been as expected. The covid-19 has succeeded in forcing all lecturers to migrate from classroom face-to-face (offline) to online learning. This research was aimed to study the preferences of lecturers for available online learning media during the Covid-19 pandemic. The data were obtained using questionnaire that distributed online to all lecturers and students who were active in lectures for the even semester of the 2019/2020 academic year. The data shows that all lecturers have implemented online learning to serve all classes. The majority of lecturers serve their class by using more than one online media. The order of the three types of online media which became the main preference of lecturers experienced a shift during the 3 months of observation, namely from WhatsApp (WA) - Email - Google Classroom (GC) in the first, to WA - GC - SIPDA in the second, and to WA - SIPDA - GC in the third month. It can be concluded that, although initially the lecturers’ main preference in learning was social media (WA), they have tried hard to make SIPDA as the main choice among the available e-learning media.
Multi-face Recognition for the Detection of Prisoners in Jail using a Modified Cascade Classifier and CNN
Authors: Diyasa G S M , Fauzi A , Idhom M , Setiawan A 
Published: March 2021

Abstract
Identifying the identity of a prisoner in a detention cell, through facial recognition automatically is a big, exciting problem and there are many different approaches to solve this problem because it must detect multiple faces (multi-face). Especially in uncontrolled real-life scenarios, faces will be seen from various sides and not always facing forward, which makes classification problems more difficult to solve. In this research, one method is combined deep neural networks that is Convolutional Neural Networks (CNN) and Haar Cascade Classifier as real-time facial recognition, which has proven to be very efficient in face classification. Methods are implemented with assistance library Open-CV for multi-face detection and 5MP CCTV camera devices. In preparing the architectural model Convolutional Neural Networks Do configuration parameter initialization to speed up the network training process. Test results on 51 test data using constructs Convolutional Neural Networks VGG16 models up to a depth of 16 layers of convolution layers with input from the extraction of the Haar Cascade Classifier resulting in facial recognition system performance reaching an accuracy rate of about 87%.
Single Phase Inverter with Power Monitoring using Arduino
Authors: Maghfiroh H , Affandy J T , Adriyanto F , Nizam M 
Published: March 2021

Abstract
The inverter is an electronic device which able to convert DC electricity into AC electricity. In the development of renewable energy resources, for example, solar power plants, inverters are needed. In this research, an inverter is made by real-time power monitoring. The inverter is made using unipolar PWM modulation and a full H bridge topology. PWM signals are generated from Arduino microcontrollers that will control MOSFET switching. Power monitoring is done by installing a DC voltage sensor and INA219 DC current sensor while on the output side using the PZEM 004t (v3) sensor and results will be displayed on the OLED. The experiment was successfully carried out by producing an approaching sine wave signal with a frequency of 50 Hz and 220 V AC voltage. The efficiency of the inverter is low because of loss from the transformer which has a no-load efficiency of 68.7%. When the 15W load has installed the efficiency of the inverter is 31.83% and when the 20W load has installed the efficiency of the inverter is 34.72%. Finally, when the smartphone’s charger is installed the total efficiency was 49.96%.
Monitoring of Hydrogen Fuel Cell Modeling with Boost Converter
Authors: Mubarok Husein , Santoso Tegar Hery 
Published: March 2021

Abstract
Energy plays a very important role in human life. Every year, the demand for energy needs continues to increase and the majority of energy generation uses fossil fuels. So we need an energy source that is environmentally friendly. One of the environmentally friendly energy sources is a fuel cell. Fuel cells can produce electrical energy at a lower cost than the electrical energy generated by conventional power grids. In making a fuel cell system, a modeling is needed so that the fuel cell system can work properly and in accordance with the desired specifications. One method for modeling a fuel cell system is to use MATLAB. The use of a DC-DC boost converter with a properly designed closed loop PID controller has a very important role in regulating the PWM of the DC-DC boost converter switch and plays a very important role in controlling power regulation. In this research, a modeling analysis of NEXATM 1.2 kW hydrogen fuel cell with a DC-DC boost converter controlled by a PID controller was carried out for a compact Power Conditioning Unit (PCU) design. The purpose of this research is to model and analyze the characteristics of the performance of the hydrogen fuel cell system and the performance of the PID controller in regulating the DC-DC boost converter output voltage on the hydrogen fuel cell. The results showed that the performance of the hydrogen fuel cell was influenced by the pressure of oxygen gas, hydrogen, and temperature. The greater the value of oxygen gas pressure, hydrogen gas pressure, and temperature on the fuel cell, the greater the voltage and current output of the fuel cell. The simulation results show the fuel cell output voltage is 47.89 V with an error percentage of 4.22%, and the fuel cell output current is 23.94 A with an error percentage of 0.25%, and the fuel cell output power is 1147 W with an error percentage of 4.12%. The performance of the PID controller with the DC-DC boost converter in regulating the fuel cell output voltage is very good. This is indicated by the results of the response curve for the fuel cell output current, namely the value of rise time (tr) of 4 seconds, delay time (td) of 0.2 seconds, peak time (tp) of 4 seconds, settling time (ts) of 4 seconds, and a maximum overshoot (Mp) of 0%. For output voltage, the value of rise time (tr) is 4 seconds, delay time (td) is 0.2 seconds, peak time (tp) is 4 seconds, settling time (ts) is 4 seconds, and maximum overshoot (Mp) is 0% with the parameter value Proportional (P) of 0.001, Integral (I) of 10, and Derivative (D) of 0.
Fractal Based Feature Extraction Method for Epileptic Seizure Detection in Long-Term EEG Recording
Authors: Humairani A , Atmojo B S , Wijayanto I , Hadiyoso S 
Published: March 2021

Abstract
One of the most common brain disorders is epilepsy. A person who has epilepsy is not able to have normal days like the others. It’s characterized by more than two unprovoked seizures. However, the faster detection and treatment of epileptic seizures, the quicker reduction of the disease abnormal level. Neurologists are still diagnosing, detecting, and testing a seizure manually by observing the Electroencephalogram (EEG) signals. This takes a very long time because of the irregularity of EEG signals. Hence, a Computer-Aided Diagnosis (CAD) is developed by many scientists to help neurologists in detecting seizures automatically. In this research, a CAD system was developed at CHB-MIT dataset. The EEG signals were processed at several stages through this system, namely pre-processing, decomposition, feature extraction, and classification. In pre-processing, the EEG signals were uniformed by selecting the most appropriate channels and filtered using Butterworth Bandpass Filter (BPF) to remove noise. The process continued to the decomposition and feature extraction stage using Empirical Mode Decomposition (EMD) and fractal dimension-based methods, i.e. Higuchi, Katz, and Sevcik, respectively. Then, the features were classified by Support Vector Machine (SVM). The proposed method achieved the highest accuracy at 94.72% on the Chb07 record. Meanwhile, the average accuracy was 81.2% for all records. The proposed study is expected to be applied for the detection of seizure onset in a real-time system.
Optimization of design parameters for SPPC longitudinal dynamics
Authors: Zhang L.H. , Tang J.Y. , Hong Y. , Chen Y.K. , Wang L.J. 
Published: March 2021

Abstract
As the second stage of the CEPC-SPPC project, SPPC (Super Proton-Proton Collider) aims at exploring new physics beyond the Standard Model. The key design goal for the SPPC accelerator complex is to reach 75 TeV in center of mass energy with a circumference of 100 km for the collider and an injector chain of four accelerators in cascade to support the collider. As an important part of the SPPC conceptual study, the longitudinal beam dynamics was studied systematically, which includes the dynamics in the collider and its complex injector chain. First, the bunch filling scheme of the SPPC complex was designed on the basis of various constraints such as the technical challenges of the kicker magnets, limited extraction energy per injection and so on. Next, the study on the longitudinal dynamics in the collider focused on the RF scheme to meet the requirements for luminosity and mitigate relevant instabilities. A higher harmonic RF system (800 MHz) together with the basic RF system (400 MHz) to form a dual-harmonic RF system was employed to mitigate collective instabilities and increase the luminosity by producing shorter bunches. In addition, the longitudinal matchings between the bunches in the different accelerator stages were studied, with special attention to the space charge effects and the beam loading effect in the two lower energy rings (p-RCS and MSS), which result in an optimization of the RF schemes. A set of self-consistent beam and RF parameters for the SPPC complex was obtained. The collider and the three proton synchrotrons of the injector chain have unprecedented features, thus this study demonstrates how a future proton-proton collider complex looks like.
Mathematical analysis and experimental testing of floating building platform prototypes made from expanded polystyrene system (Styrofoam) and lightweight concrete
Authors: Handayani Fitri , Adi Henny Pratiwi , Wahyudi Slamet Imam 
Published: March 2021

Abstract
Floating building is one of the solutions to anticipate residential areas against Tidal floods which have been occurring on the North Coast of Central Java. This floating building can adjust its buoyancy to the effect of rising sea level and land subsidence. This building can be applied in sea tidal flood areas and retention ponds in polder systems. The main materials used as the floating building platform are styrofoam and lightweight concrete. This study aims to determine the stability, capacity and buoyancy of the prototype platform using styrofoam and lightweight concrete. This study uses mathematical analysis methods and prototype testing with laboratory experiments. Based on the analysis result for the styrofoam material platform with dimensions of 2 × 2 × 0.62 m, a buoyancy force of 2.73 tons was obtained with the Safety Factor (SF) of 1.25. A lightweight concrete weight of 0.97 tons, the load that can be supported by the prototype is 1.2 tons. The prototype of the styrofoam material platform with a lightweight concrete cover has a stable condition with a value of m>0, namely the center of object weight (B0) is +0.74 meters and the metacentric value is +0.9 meters.
Did socioeconomic status influence psychological preparedness for potential disaster of resident around lapindo mud disaster
Authors: Palupi L S 
Published: March 2021

Abstract
Lumpur Sidoarjo or known as LUSI is geologicall disaster that has been going on for 14 years since 2006. It is consider as the world’s largest mud volcano eruption. It bring tremendous impact to the livelihood of the resident live around the site. People live around the site mostly relied on the ponds as a living thus LUSI bring a devastated impact to the local communities. The condition has bring negative impact not only to their economic condition but also to their mental health. Study found that there are growing number of people live around the site that experience psychological problem. Psychological preparedness for disaster is one of the factors that could help people in coping with stress after disaster strike. Previous study has found that most of the resident live around the LUSI site has average level of psychological preparedness. Research on psychological preparedness found that one of the factor that associated with psychological preparedness is socioeconomic status. It is said that people with low socioeconomic would also have a low level psychological preparedness. However, the relationship between socioeconomic status and the psychological preparedness in resident around lapindo mud disaster (LUSI) was unclear. Therefore, this study aimed to investigate the relationship between socioeconomic status and the psychological preparedness for potential disaster among resident around lapindo mud disaster. The study was conducted in Sidoarjo. Survey research was applied using a Psychological Preparedness for Potential Disaster scale as a mean to identify the psychological preparedness of the Sidoarjo people.
Analysis of Work Accident Factors in the Shipyard
Authors: Zaman M B , Baheramsyah A , Ashari I 
Published: March 2021

Abstract
In the shipbuilding industry, the majority of ship accidents are caused by human error. other factors are caused by the work environment, company conditions, management policies and others. These data show that human factor has a major impact on accidents. Therefore, a proper prevention is required. The purpose of this research is to determine the relationship between individual characteristics and work accident factors as well as to determine the prevention of work accidents. The method used in this paper is bivariate method. Then, the analysis was conducted using the chi square approach. The result of this research showed that age has a relationship with knowledge of engineering and skill. It has meaning that older workers would most likely understand in engineering better than the younger ones. Work pressure also has a relationship with age. It has meaning that the workers with an age of <35 and >45 have more work pressure than those with an age of 35 - 45. Furthermore, tenure and education do not have a relationship with work accident factors. Thus, some efforts are needed to minimize work accidents, such as providing in-class training to new workers, doing on-job training or field training, providing assistance on every job, exchange of workers from one place to another, sharing sessions on static electricity to young workers, creating a comfortable work atmosphere, provide adequate facilities, provide training on stress management and decision making.
Evacuation Analysis of Ship Passenger Using Agent Based Modelling Simulation
Authors: Zaman M B , Siswantoro N , Zulfikar M 
Published: March 2021

Abstract
Ship accidents that occur in Indonesian have a high frequency. The ship accidents is dominated by fires of Ro-ro or passenger ships which cause material loss, water pollution and loss of human life. In this paper, an analysis of the ship evacuation system will be carried out. The Agent Based Modelling Simulation (ABMS) was using in this study. Initial data required are in the form of ship general arrangement, passenger walking speed, as well as the composition and distribution of passengers. The distribution of ship passengers in Indonesia for the category of women aged less than 30 years is 12%, women aged 30-50 years are 21%, women aged greater than 50 years are 5%, there are no female passengers with disabilities, while for the category of males aged less than 30 years as much as 19%, males with an age range of 30-50 years as much as 31%, males over 50 years old as much as 12%, and no male passengers were found. a man with a disability. The number of ship passengers is conditioned to exceed the passenger capacity, namely 880 passengers should be conditioned to become 1527 passengers. The evacuation simulation of ship passengers using an agent based modelling simulation is run based on the IMO MSC. 1 / Circ. 1533 using 4 cases during the day and night. In the case of a normal night it takes 38.24 minutes to evacuate all passengers, and in the case of a night the evacuation takes 36.45 minutes. In the normal day case it took 29.49 minutes and in the afternoon case the evacuation took 28.12 minutes.