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Degradasi Mekanik Beton Mutu Tinggi Pasca Bakar

Hamdi, Fauzan ( Universitas Muhammadiyah Makassar ) , Zainuddin, Muh Amir ( Universitas Muhammadiyah Makassar ) , Gaffar, Farida ( Universitas Muhammadiyah Makassar )

Semesta Teknika Vol 21, No 2 (2018): NOVEMBER 2018
Publisher : Semesta Teknika

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Abstract

Research on the effect of temperature on concrete is still a hot topic. The effect of temperature was measured on its mechanical properties and analyzed using descriptive statistical analysis. The desire of researchers to know accurately the shape, description, and influence of temperature on concrete is something that still needs further research. The researchers began to research by making concrete test objects which were then burned directly in the furnace. After that, testing is done on the test object in the form of compressive strength. The research that was carried out was the remains of a burning building. But so far the assessment research has not yet found a strong starting point. Broadly speaking, the problem examined in this study is that researchers want to know the magnitude of high quality concrete mechanical degradation after being burned at a certain temperature and compared with high quality concrete that is not burned. These results are expected to provide a basis for the repetition of buildings that use high quality concrete that has been burned. The results of the mechanical degradation test reviewed were the average compressive strength of high quality concrete at a normal temperature of 53.46 MPa, a temperature of 100oC of 34.93 MPa, a temperature of 300oC of 29.76 MPa, a temperature of 600oC of 25.57 MPa.

Deteksi Kecacatan Permukaan Buah Manggis Menggunakan Metode Deep Learning dengan Konvolusi Multilayer

Azizah, Laila Marifatul ( Universitas Muhammadiyah Yogyakarta ) , Umayah, Sitti Fadillah ( Universitas Muhammadiyah Yogyakarta ) , Fajar, Febriyana ( Universitas Muhammadiyah Yogyakarta )

Semesta Teknika Vol 21, No 2 (2018): NOVEMBER 2018
Publisher : Semesta Teknika

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Abstract

Mangosteen is one of Indonesian potential export fruits. Nevertheless, mangosteens quality is compulsary. A good quality fruit surface is needed in export fruit. This is the reason of this research to detect the flaw in rind surface, particularly mangosteen. Some researcher has been done many type of image processing for fruit detection. However, there aren’t any research for mangosteen rind detection especially used Deep Learning. This research used CNN (Convolutional Neural Network) as deep learning method to detect mangosteen rind surface. Our research is to find configuration which was the best accurancy value. The rind detection calcuted between epoch and layer to obtain maximum accurancy value. This method achieved maximum value by parameter 4 layer and epoch value of 30. From our experiment, the test result for rind detection was 98% accurancy.

Simulasi CFD Aliran Stratified Air-Udara pada Pipa Horisontal

Sukamta, Sukamta ( Universitas Muhammadiyah Yogyakarta ) , Thoharudin, Thoharudin ( Universitas Muhammadiyah Yogyakarta ) , Nugroho, Dedy Melianto ( Universitas Muhammadiyah Yogyakarta )

Semesta Teknika Vol 21, No 2 (2018): NOVEMBER 2018
Publisher : Semesta Teknika

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Abstract

Two-phase flow can be found in industries, such as petroleum, electricity generation. In geothermal power plants, two-phase flow occurs from a mixture of water and steam which should be avoided in the piping system because it can cause equipment damage in the operating system. Therefore, an operator and engineer need a knowledge of flow patterns, phenomena and characteristics of the two-phase flow. One of the methods to predict the flow pattern is udsing the Computational Fluid Dynamic (CFD). This CFD simulation was modeled using Ansys Fluent 15.0 software to determine the changes of Stratified flow characteristics. The model used is Volume of Fluid (VOF). The fluid type is water and air. The variation of superficial water velocity JL of 0.025 m/s - 0.1 m/s while the superficial air velocity (JG) of 0.05 m/s - 1 m/s. The pipe used is an acrylic of 19 mm diameter and length of 1000 mm. The simulation results show that: (1). Stratified flow occurred for the low velocity of the liquid and gas phases. It was shown by the water and air are clearly separated. (2). Flow patterns are not stable, but it can change depending on the superficial velocity of gas and water. (3). The larger of JG causes the wave height because of Bernoulli’s effect so that it will make the stratified wavy or ripple flow pattern. (4). The frequency of stratified-wavy and ripple waves will tend to decrease when the JL increases, while the effect of JG is insignificant. Furthermore, it can be concluded that the speed of gas must be regulated so as not too large to the speed of water.

Perancangan dan Pembuatan Website Pengambilan Ide Skripsi Pada Prodi Teknik Informatika UMY

Kurnianti, Apriliya ( Universitas Muhammadiyah Yogyakarta ) , Setyawan, Haris ( Universitas Muhammadiyah Yogyakarta ) , Firdaus, Fathania Firwan ( Universitas Muhammadiyah Yogyakarta ) , Yuma, Safira Nira ( Universitas Muhammadiyah Yogyakarta )

Semesta Teknika Vol 21, No 2 (2018): NOVEMBER 2018
Publisher : Semesta Teknika

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Abstract

In the Kamus Besar Bahasa Indonesia (KBBI), Idea is a design arranged in mind. The thesis idea is a design that can come from thought of student and lecturer. In the Informatics Engineering Department at  Muhammadiyah University of Yogyakarta, thesis idea is often offered to student by several lecturers through social networking forums or instant messaging. Thesis ideas was offered through social networking forum or instant messaging can be covered by other content quickly, thus  the information was not delivered to students who need a thesis idea optimally . The effect was some students were still confused to get thesis ideas and lecturers who had thesis ideas did not know that there were still students whom needed the idea. To overcome this case, a website-based thesis idea taking system was built to help students to get information and to take thesis ideas which was given by lecturers. In building or repairing a website, Researcher used the waterfall method. Using this method, website development will be more organized. Website development used PHP programming language with CodeIgniter framework. Researcher Tested through three steps, i.e. user interface, functionality and validation testing.

Perkiraan Masa Tunggu Alumni Mendapatkan Pekerjaan Menggunakan Metode Prediksi Data Mining Dengan Algoritma Naive Bayes Classifier

Asroni, Asroni ( Universitas Muhammadiyah Yogyakarta ) , Ali, Nadiyah Maharty ( Universitas Muhammadiyah Yogyakarta ) , Riyadi, Slamet ( Universitas Muhammadiyah Yogyakarta )

Semesta Teknika Vol 21, No 2 (2018): NOVEMBER 2018
Publisher : Semesta Teknika

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Abstract

Student and Alumni data Universitas Muhammadiyah Yogyakarta is very common, and one of these is the alumni data obtained from work after the completion of undergraduate studies. Former students are given jobs caused or influenced by a range of factors. This research aims to have the grace period Classification or old alumni gain positions by triggering a process of data extraction and using the Bayes naïve classification algorithm. The algorithms used later succeeded in predicting sooner or later to get a job, the predictive results alumni can be used to make decisions to improve the quality of a university. Research on the support system using several parameters, i.e., gender, faculty, GPA, year of graduation, and job status. The data used are as much as 435, including seven years of 2011-2014 volume. The results of this study have the accuracy level of former students having the grace period come to 71% and of the calculated results of the predictions of the former students obtaining a job at Universitas Muhammadiyah Yogyakarta of the year 2011-2014 the Ensure that the work is carried out more quickly with the status of the slow to deliver the work

Pengaruh Mode Shape Frekuensi Alami terhadap Estimasi Gaya Tarik Batang Baja dengan Metode Vibrasi

Nugroho, Guntur ( Universitas Muhmmadiyah Yogyakarta )

Semesta Teknika Vol 21, No 2 (2018): NOVEMBER 2018
Publisher : Semesta Teknika

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Abstract

The vibration method has been widely applied to estimate the force on cable structures as well as beams. This method utilizes the natural frequency of structural elements in estimating tensile as well as compressive forces. On the cable element, a different natural frequency will appear according to the shape number. This study raises the suitability of force estimation by using the natural frequency of the first second and third modes. The steel specimen have cross section of width, thickness and length of 6 mm, 40 mm and 2000 mm respectively. The results of natural frequency, calculated by using analytic formulas (string, beam-string and stokey) has been compared with the natural frequency resulted by numerical modeling. The difference of  natural frequency of specimen calculated by using analytic formulas (strings, beam-strings, stokey), compared with the result of numerical modeling  has the smallest value in the first mode which is 3.75% at 5,000N load and 0.61% at 50,000N load.

Pemeriksaan Material pada Pembangunan Rumah Non-Engineered di Daerah Rawan Gempa Dusun Serut, Palbapang Kabupaten Bantul, Yogyakarta

Zulfiar, Muhammad Heri ( Universitas Muhammadiyah Yogyakarta )

Semesta Teknika Vol 21, No 2 (2018): NOVEMBER 2018
Publisher : Semesta Teknika

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Abstract

Bantul Regency is a region with high level of seismic activity in Indonesia. Buildings that have the highest risk of collapse to earthquake are non-engineered buildings or residential buildings built without planning or not according regulation. This study aims to know contruction practices and material examination on non-engineered buildings in earthquake prone areas in accordance with the Indonesian National Standard. The object research is the construction of non-engineered building in Serut Village, Palbapang, Bantul Regency. The testing of material construction materials include: concrete test, reinforcing steel test and bricks test. the material are tested on the laboratory of Universitas Muhammadiyah Yogyakarta.  The observations and measurements to the practices of construction consist of: concrete sloof with size 15 × 20 cm with the main reinforcement 4Ø12 and beugel reinforcement Ø6-150; column with size 10 × 15 cm with main reinforcement 4Ø10 and beugel reinforcement Ø6-150; the concrete mixture is made manually with a composition 1 cement: 3 sand: 2 gravel; Brick size 4.35 cm x 12.036 cm x 23.902 cm class criteria M-6 module. Laboratory material test results showed: steel reinforcement diameter Ø 10 mm obtained tensile strength (fy) 401.52 Mpa; Ø12 mm diameter obtained tensile strength (fy) 393,736 M.Pa; concrete have average compressive strength of 181 kg/cm2; brick test have average compressive strength of 20.03 kg/cm2. The conclusion of contruction practices on non-engineered buildings in earthquake prone areas are adequate on major earthquake, the quality of construction concrete and reinforcing steel are fulfilling the criteria and requirements of the Indonesian National Standard, but quality of material brick is not adequate standar. 

Worldwide Hot Mix Asphalt Layer Application and Scrap Rubber and Bitumen Emulsion Studies on Railway Track-Bed

Setiawan, Dian M ( Program Studi Teknik Sipil, Fakultas Teknik, Universitas Muhammadiyah Yogyakarta )

Semesta Teknika Vol 21, No 2 (2018): NOVEMBER 2018
Publisher : Semesta Teknika

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Abstract

Researchers around the world have performed various studies on reinforcement of track-bed and mitigation of ballast deterioration. This paper objective is to conduct a literature review comprehensively to analyse and discuss the development of rubber, bitumen emulsion, and asphaltic layer usage on railway track-bed to study the proposed alternative of Indonesian unconventional rail track design concept. Various asphalt track-bed concept around the world have been reviewed (Germany, USA, Italia, Japanese, France, Spain, and Austria). Research on scrap rubber and bitumen emulsion in railway track-bed also examined in this paper. There are no researchers’ uses these three methods together in their study. In fact, each design has its benefits and limitations, so if these three methods are combined, then they will complete each other and will produce better output. The author suggests developing a new track structural components design that combined asphalt layer, scrap rubber, and bitumen emulsion. This new design expected to have capabilities to serve high-speed railway and existing railway track corridors more cost-effectively compare to the conventional tracks in consequence of their potential to have greater structural stability, considerably lower maintenance works, and more service-life. It can serve the train journey with higher speed and higher axle load.

Penerapan Algoritma C4.5 untuk Klasifikasi Jenis Pekerjaan Alumni di Universitas Muhammadiyah Yogyakarta

Asroni, Asroni ( Universitas Muhammadiyah Yogyakarta ) , Respati, Badrahini Masajeng ( Universitas Muhammadiyah Yogyakarta ) , Riyadi, Slamet ( Universitas Muhammadiyah Yogyakarta )

Semesta Teknika Vol 21, No 2 (2018): NOVEMBER 2018
Publisher : Semesta Teknika

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Abstract

The development of education in Indonesia has increased very rapidly. One of the things that have become a benchmark for success in the quality of education at the university is the kind of job getting graduates after graduation. This research aims to identify factors that have an impact on the type of job classification method based on the C 4.5 alumni algorithm. The methodology of this research begins with the study of literature, the identification of a process of data extraction, data selection, data collection, data processing, data testing, and DA conclusion. This research uses some features of the data on a few faculty members, the year of graduation, the annual completion rate, and the strength as a classification performance parameter. Graduates data used up to 259, and consisted of 3 faculties of Economics, medicine and engineering forces from 2001-2013 and graduated from 2011-2016. The research results that have been done is if it comes from the Faculty of Economics, in 2011 and 2012 the majority of work in the private sector has passed, if it comes from the Faculty of Medicine with the years 2011 and 2012 graduated with a cumulative labor rate of between 3 to 3.5 majority working in The private sector, 2012 with a GPA between 3 and 3.5 working in the Private Sector. Finally, the C4.5 algorithm is suitable for the classification of alumni work types.

Sistem Informasi Menajemen Aset (Studi Kasus: Desa Barepan)

Setyawan, Haris ( Universitas Muhammadiyah Yogyakarta ) , Asroni, Asroni ( Universitas MUhammadiyah Yogyakarta )

Semesta Teknika Vol 21, No 2 (2018): NOVEMBER 2018
Publisher : Semesta Teknika

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Abstract

Barepan Village is one of the villages in Cawas sub-district, Klaten, Central Java. In 2017 Barepan Village has owned a new building as a means of village administration and obtains assets that support the implementation of government such as computers, tables, chairs, and others. However, asset management is currently not going well and does not have a unique asset database to facilitate the management and tracking of its assets. This caused the difficulty of conducting asset track which made it difficult for asset managers to know the condition of the asset was right, damaged or lost. Therefore, an information system is needed which has the objective to be able to run the business process of asset management to be neat and structured so that asset managers can efficiently manage and track assets. The process of designing an Asset Management Information System using the waterfall model software development method begins with needs analysis, design, coding, testing, and maintenance. From the design stage, it was then created with Code Igniter in the form of a PHP framework with the MVC concept so that a website-based Information System with the MVC concept was produced. Verification and validation are then carried out to determine the suitability of the system design with the Asset Management Information System final results that have been made. Finally, an asset information system can be obtained that fits your needs and archives assets well.