146 research outputs found
SIMULASI PENGATURAN KECEPATAN MOTOR INDUKSI 3 PHASA DENGAN DIRECT TORQUE CONTROL MENGGUNAKAN MATLAB
Induction motors are widely used in the industrial world because they have many advantages, including construction that is very simple and strong, cheap, has high efficiency, quite good power factor, and maintenance is easier. Besides the advantages of induction motors also have weaknesses, one of the disadvantages of an induction motor is not being able to maintain its speed constantly if there is a change in load. If there is a change in load, the speed of the induction motor will decrease. One method of regulating the speed of an induction motor developed in addition to vector control is the Direct Torque Control (DTC) method. The DTC control technique allows direct and separate flux and torque settings and can be done without using a speed sensor. The estimated rotor rotation, torque and flux is carried out by the DTC which is inputted with stator voltage and current. To achieve the desired flux and torque estimation is used as feedback on the control system. In this final assignment, the speed regulation of the induction motor will be simulated using the DTC method using Matlab. The results obtained through the simulation show the length of time to reach the reference speed for speeds of 500rpm and 1000 rpm is around 0.5 seconds. Keywords : Induction motor, Direct Torque Control, Matlab
Impact of the 2015 Godzilla El Niño event on the Indonesian rainfall
The impacts of El Niño events on the Indonesian rainfall have been documented by several earlier studies. This paper is aimed to extend the study on the El Niño impact by investigating the 2015 El Niño event, which was labelled as a “Godzilla El Niño” by NASA’s climatologist. The event is unique because of its strong intensity and it was preceded by weak 2014 El Niño. We analysed rainfall record of 87 stations for period 1981-2015 using percentile technique. The results show that during March 2015 – February 2016, the majority of stations recorded annual rainfall less than the 30th percentile, a dry condition. Based on analysis of three monthly running accumulation, we found 84%, 89% and 78% stations recording a dry condition during July-August-September (JAS), August-September-October (ASO) and September-October-November (SON), respectively. The largest impact was observed during October 2015 where 51% stations reported the rainfall below the 10th percentile, an extremely dry condition. Compared to 1997, the 2015 Godzilla El Niño event seems to have less impact on Indonesian rainfall even though the intensity of those two events is comparable. The number of stations experiencing dry and extremely dry condition was lower in 2015 than that in 1997, for all time scale we analysed. This may relate to the condition of sea surface temperature (SST) around Indonesia. We found that the Indonesian SST during June-November 2015 was warmer than that during 1997 indicating a more supporting condition for developing convective activity in 2015
Rainfall Changes over Java Island, Indonesia
Trends and patterns of extreme rainfall over Java Island, Indonesia were studied here for the period 1981-2010. The 9 low land and 10 mountainous gauges in respect to northern plain and southern mountainous area were selected after passing criteria such as gross error check, the restriction of at least 90% completed series, and homogeneity test. Some of recommended WMO/CLIVAR extreme indices were calculated annually and seasonally to express the frequency and its intensity. The total rainfall trend (PRCP), the frequency of heavy (R20mm) and very heavy (R50mm), and the simple daily intensity index (SDII) have been analyzed. The significance temporal trend was further assessed using the non-parametric Mann-Kendal test. The result showed that the extreme rainfall event over Java Island is depicted by an incoherent pattern which is spatially distributed across the island and is proportional between positive and negative trend with statistically not significant trend as a dominant changing. From annual extreme indices, it has been revealed that Banyuwangi, Malang, Tuban, Cilacap, and Jakarta Halim and Priok show a consistent increasing trend, while Jember, Probolinggo, Tegal, Semarang, Solo, Cirebon, Ciamis, and Serang show a consistent decreasing trend. Seasonal analyses exhibited a prominent negative trend during peak of dry season (JJA) with high coherency among nineteen stations and for some cases these decreases are followed by increasing SON rainfall indices which generate a hypothesis of a shifted rainfall from JJA to SON. Further analyses of seasonal indices have also detected some stations with a consistently increased DJF rainfall and decreased JJA rainfall e.g. Yogyakarta, Cilacap, Bogor, and Jakarta Priok which may lead a higher risk of hydro-meteorological hazard. Variability analyses on monthly rainfall series showed that the large scale phenomena such as ENSO may play an important role in the occurrence of extreme rainfall event. Keywords: rainfall, trend, pattern, Java Islan
IDENTIFYING PRECURSOR CONDITION FOR “PUTING BELIUNG” EVENT IN PANGKALPINANG
This paper discusses an effort to identify the precursor condition for “puting beliung” or tornado-like eventwhich was occured in Pangkalpinang town on January 9, 2008. The analyses has been done based on the dynamicpipe effect of tornado genesis theory. Several data obtained from surface observation as well as the advantage ofsatellite data image were used to identify signal of presence of puting beliung. The result indicates that the putingbeliung event was triggered by the presence of low level wind shear which was supported by favorable surfacecondition such as the existing of enough water vapor aloft indicated by high relative humidity, enough surfaceheating to initiate a rapid cooling of the atmosphere to produce deep convection, and there is an initiation of alocal anomaly surface wind speed to produce low level wind shear. Revealed surface precursor for puting beliungin Pangkalpinang are the rapid increasing the relative humidity one hour in advance, together with rapid drop intemperature and the presence of “horn-like” pressure anomaly
Analisa Mesin Pengering Makanan Food Dehidrator Menggunakan Sensor Thermostat Berbasis Hybrid
The process of drying food is done in the traditional way, by drying it in the hot sun, but the traditional drying method makes the food unhygienic. Several factors can influence the drying results of food ingredients, including temperature and drying time. Using optimal drying temperatures and times can reduce the level of damage caused by the drying process. This research aims to obtain an analysis of a food dehydrator drying machine using a hybrid-based thermostat sensor that can optimally condition the temperature and time factors in the drying process, the hyfood dehydrator machine system uses a dehumidification method, there is a heat recovery mechanism that recycles heat to open new air, thus saving 60-70% of fresh air preheating energy consumption. Hot air moving in the room dries the material. It is known that the test result data was analyzed by calculating the accuracy values, down to the relative distance values. The results of the comparison process are used as validation of the output values produced by the temperature measuring instrument. The measurement results of the Digital Thermostat Sensor are in accordance with the datasheet and have a high level of accuracy. So the Digital Thermostat Sensor measuring instrument can be used as a measurement tool. With an internal fan, thermostat, and time settings on this device, you only need to set the right heat according to the type of food you want to dry. The shelves in the cupboard consist of drying trays that can maximize the drying proces
PENGARUH PENERAPAN MODEL PEMBELAJARAN LEARNING CYCLE 5E TERHADAP HASIL BELAJAR SISWA PADA STANDAR KOMPETENSI MEMASANG INSTALASI PENERANGAN LISTRIK
Abstrak Latar belakang adanya penelitian ini adalah kurangnya keterampilan siswa pada standar kompetensi memasang instalasi penerangan listrik karena masih digunakannya model pembelajaran yang berpusat pada siswa. Pada model pembelajaran tersebut, siswa kurang dituntut untuk menguasai materi sehingga berpengaruh pada hasil belajar siswa. Pada penelitian eksperimen ini menggunakan dua kelas sebagai sampel, yaitu kelas XI TIPTL 2 sebagai kelas eksperimen yang dibelajarkan dengan model pembelajaran Learning Cycle 5E dan kelas XI TIPTL 3 sebagai kelas kontrol yang dibelajarkan dengan model pembelajaran langsung. Adapun tujuan dari penelitian ini adalah: (1) untuk mengetahui apakah ada perbedaan peningkatan hasil belajar antara siswa yang dibelajarkan menggunakan model pembelajaran Learning Cycle 5E dengan siswa yang dibelajarkan menggunakan model pembelajaran langsung; dan (2) untuk mengetahui apakah ada perbedaan hasil belajar antara siswa yang dibelajarkan menggunakan model pembelajaran Learning Cycle 5E dengan siswa yang dibelajarkan menggunakan model pembelajaran langsung. Penelitian menyimpulkan: (1) rata-rata nilai gain (peningkatan) siswa yang dibelajarkan dengan model pembelajaran Learning Cycle 5E lebih tinggi secara signifikan (0,77) dibanding siswa yang dibelajarkan dengan model pembelajaran langsung (0,68) pada standar kompetensi memasang instalasi penerangan listrik; (2) hasil belajar ranah kognitif siswa yang dibelajarkan dengan model pembelajaran Learning Cycle 5E lebih tinggi secara signifikan (83,54) dibanding siswa yang dibelajarkan dengan model pembelajaran langsung (77,70); (3) hasil belajar ranah afektif siswa yang dibelajarkan dengan model pembelajaran Learning Cycle 5E lebih tinggi secara signifikan (83,48) dibanding siswa yang dibelajarkan dengan model pembelajaran langsung (82,06); dan (4) hasil belajar ranah psikmotor siswa yang dibelajarkan dengan model pembelajaran Learning Cycle 5E lebih tinggi secara signifikan (83,96) dibanding siswa yang dibelajarkan dengan model pembelajaran langsung (82,73). Penelitian menyarankan: (1) model pembelajaran Learning Cycle 5E dapat dijadikan alternatif dalam menciptakan suatu pembelajaran yang menarik; (2) model pembelajaran Learning Cycle 5E dapat digunakan sebagai inovasi, sehingga pendekatan ini dapat diterapkan pada mata diklat lain yang sesuai; (3) penelitian ini dapat digunakan untuk penelitian lanjutan dengan model pembelajaran yang lebih variasi dan lebih kompleks. Kata kunci: Model pembelajaran Learning Cycle 5E, penelitian eksperimen, dan hasil belajar. Abstract The reason of this research is the lack of students's skills in competency standard of installing electrical lighting installation because it’s still use the student-centered learning model. In the student-centered learning model, students are less required to understand the learning materials with active so it’s effect on student learning outcomes. This experimental research use two classes as samples, XI TIPTL 2 class as an experimental class that learned using the 5E Learning Cycle model and XI TIPTL 3 class as a control class that learned using direct instructional model. The purpose of this research is: (1) to determine whether there are differences in learning outcome among the students that learned using the 5E Learning Cycle model with students that learned using the direct instructional model; and (2) to determine whether there are differences in learning outcomes among the students that learned using the 5E Learning Cycle model with students that learned using the direct instructional model. The research concluded: (1) the average gain value of students that learned using the 5E Learning Cycle model (0,77) is higher of the students that learned using the direct instructional model (0,68) significantly; (2) the learning outcomes in cognitive domain of students that learned using the 5E Learning Cycle model (83,54) is higher of the students that learned using the direct instructional model (77,70) significantly; (3) the learning outcomes in affective domain of students that learned using the 5E Learning Cycle model (83,48) is higher of the students that learned using the direct instructional model (82,06) significantly; and (4) the learning outcomes in psychomotor domain of students that learned using the 5E Learning Cycle model (83,96) is higher of the students that learned using the direct instructional model (82,73) significantly. The research suggests: (1) the 5E Learning Cycle model can be used as an alternative to creating an exciting learning; (2) the 5E Learning Cycle model can be used as an innovation, so this approach can be applied to other appropriate training; (3) this research can be used for further research with a learning model that more and more complex variations. Keywords: the 5E Learning Cycle model, experimental research, and learning outcomes
STUDY ON APPLICATION OF PROBLEM-BASED LEARNING TO INCREASE STUDENT’S LEARNING OUTCOME AT DATABASE LESSON IN VOCATIONAL HIGH SCHOOL
Purpose of Study: In the process of learning in vocational high school, the common problem happens today is low student learning outcomes. Predictably it is caused by several things, one of them is the learning model that is not in accordance with the characteristics of the subjects. One of the learning models in accordance with the database subject and can improve student learning outcomes is a problem-based learning model.
The purpose of this research is to know about: (1) how far the utilization of learning model based on problem in database subject; (2) how the procedure of implementing the problem based learning model in the database lesson; and (3) how the influence of problem-based learning on student learning outcomes in database subjects.
Methodology: Based on the problem as described above, problems can be formulated as follows: (1) how far the use of learning models problem based learning in database subjects?; (2) how is the procedure of implementing the problem-based learning model in database subjects?; And (3) What is the effect of problem-based learning on student learning outcomes in database subjects?
Results: Based on the literature review, the following conclusions are obtained: (1) problem-based learning model can be utilized for database subjects because most of the subject material is practical; (2) the procedure of implementing the problem based learning model on the database subject is started from orient student on the database operation problem, organizing the students to learn to operate the database software, guiding individual and group investigation to completing database operation, developing and presenting the results then evaluate the problem solving process on the operation of database software; (3) problem-based learning model can improve learning outcomes in database subjects.
Implications/Applications: Problem Based Learning model, if applied to database subjects, can improve learning outcomes in database subjects
PENGEMBANGAN MODUL PEMBELAJARAN PRAKTIK INSTALASI PENERANGAN LISTRIK DI SMK NEGERI 5 SURABAYA
ABSTRAK Modul merupakan salah satu bahan ajar yang dapat digunakan oleh siswa, dengan atau tanpa bantuan guru. Karena itu, modul perlu dikembangkan agar dapat berfungsi secara optimal sebagai panduan belajar bagi para siswa. Tujuan dari penelitian ini adalah untuk mengembangkan modul pembelajaran praktik instalasi penerangan listrik. Modul yang dikembangkan berpusat pada KD (1) 3.1; (2) 3.2; (3) 3.3; (4); 4.1; (5) 4.2; dan (6) 4.3. Metode yang digunakan dalam penelitian ini adalah metode Research & Development (R&D). Tahap-tahap dalam penelitian ini meliputi: (1) potensi dan masalah, (2) pengumpulan data, (3) desain produk (4) validasi produk; (5) revisi produk; (6) ujicoba produk; (7) revisi produk; dan (8) analisis dan pelaporan. Desain penelitian yang digunakan adalah Pretest Posttest Control Design. Berdasarkan aspek validitas, hasil pengembangan modul pembelajaran praktik instalasi penerangan listrik adalah sebagai berikut: (1) modul pembelajaran 1 memperoleh skor sebesar 85,86% dan dikategorikan valid; (2) modul pembelajaran 2 memperoleh skor sebesar 87,75% dan dikategorikan valid; dan (3) modul pembelajaran 3 memperoleh skor sebesar 86,31% dan dikategorikan sangat valid. Aktivitas belajar bagi siswa yang mengunakan modul pembelajaran praktik instalasi listrik penerangan, lebih tinggi secara signifikan dibanding siswa yang belajar dengan menggunakan LKS. Hasil belajar (ranah kognitif, afektif dan psikomotor) bagi siswa yang belajar dengan menggunakan modul instalasi listrik penerangan, lebih tinggi secara sangat signifikan dibanding siswa yang belajar dengan menggunakan LKS dengan nilai signifikansi sebesar 0,001. Kata kunci: aktivitas siswa, hasil belajar ranah kognitif, afektif dan psikomotor ABSTRACT Modules are one of the teaching materials that can be used by students, with or without the help of the teacher. Therefore, the module needs to be developed so that it can function optimally as a learning guide for students. The purpose of this study is to develop a practical learning module for electric lighting installations. The module developed is centered on KD (1) 3.1; (2) 3.2; (3) 3.3; (4); 4.1; (5) 4.2; and (6) 4.3. The method used in this study is the Research & Development (R & D) method. The stages in this study include: (1) potential and problems, (2) data collection, (3) product design (4) product validation; (5) product revisions; (6) product trials; (7) product revisions; and (8) analysis and reporting. The research design used was Pretest Posttest Control Design. Based on the aspect of validity, the results of the development of the electrical lighting installation practice learning module are as follows: (1) learning module 1 obtains a score of 85.86% and is categorized as valid; (2) learning module 2 obtains a score of 87.75% and is categorized as valid; and (3) learning module 3 obtains a score of 86.31% and is categorized as very valid. Learning activities for students who use lighting electrical installation practice learning modules are significantly higher than students who learn by using Student Worksheets. Learning outcomes (cognitive, affective and psychomotor domains) for students who study using lighting electrical installation modules are significantly higher than students who learn by using Student Worksheets with a significance value of 0.001. Keywords: student activities, cognitive, affective and psychomotor domains of learning outcome
DESAIN GENERATOR OZONE DENGAN TEKNOLOGI PLASMA DBD (Die-lectric Barrier Discharge)
Industrial sterilization is a very important problem. Ozone is a powerful oxidizer that can function for sterilization and is environmentally friendly. Plasma DBD (Dielectric Barrier Discharge) is one of the effective technologies to obtain ozone. The ozone generator currently uses a lot of manual control operations. Manual control uses a mechanical system in the form of a potentiometer to calibrate the frequency and output of the ozone generator output, so that digitization and automation are needed to operate to replace human labor. The design of the digital ozone control generator is done using an AVR microcontroller. Programming used in this research is basic language (BASCOM), then uses a DAC (Digital to Analog Converter) system which is the output of a Microcontroller with a Weighted Binnary Resistor. The output of the microcontroller is frequency and 8 bit digital with a decimal parameter of 200. The result of automation is that the timer works for 2 hours. The greater frequency the ozone produced. At a frequency of 1500Hz the power produced is 308.58 watts with an ozone concentration of 59 ppm. Efficiency using a switching system> 90%. Keywords: Plasma, AVR Microcontroller, Ozone
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