Universitas Negeri Yogyakarta
  • Yogyakarta, Yogyakarta, Indonesia
Recent publications
A milling cutter with inserted blades is designed for each screw rotor since the geometry profile is unique, corresponding to its purposes and function. Correctness in cutter design, including the cutting-edge insert profile, is necessary to achieve a precise rotor profile; therefore, it is essential to introduce an enhanced cutter design. This study proposes a design of a disk-type milling cutter with special inserts. The insert cutting edge was generated on the axial plane considering the cutter curve curvature and then positioned onto the cutter body according to the modified coordinate system with a revolve angle. The analytical cutting result indicates that the simulated profile is relatively even along the gear tooth profile and the normal deviation is significantly tinier than the insert arrangement area. In addition, the cutter design applying special inserts acquires better results than standard inserts. Finally, the experimental result, including the rotor surface topography, confirms that the proposed cutter design is reliable and realistic in CNC screw rotor milling.
Double-enveloping worms (DEWs) are widely used in many applications, especially in space-saving and high-reduction ratio equipment. DEWs have a higher transmission efficiency and contact ratio than non-enveloping worms. In this study, a general method to manufacture enveloping worms using a whirl-machining process is proposed. The whirl-machining tool profile is provided from a straight-lined blade, which is tilted with an angle the same as the lead angle of the worm. The whirl-machining model is developed by a relative-motion coordinate system of a proposed CNC machining machine. The cutting simulations, surface topologies, and normal deviations for worms are demonstrated with different pitch radius of gear, lead angles, and cylindrical worms. In order to determine the practicability and accuracy of the developed model, six numerical examples are performed. A virtual cutting simulation was conducted on the worm using VERICUT. The results verify the benefits of the proposed method in DEW manufacturing.
The cosmological view of the Madurese up to the 19th century, both macrocosmic and microcosmic, perceived themselves as an integral part of nature, following natural laws even if they were meta-empirical in nature. This is a belief that is believed to originate and refer to the pre-Islamic Madurese belief model. In the view of the adherents of determinism, the actions and beliefs of humans and society are influenced by a variety of factors such as geographic, biological, psychological, sociological, economic, religious, environmental, customs, traditions and social norms, because of these different factors the moral of society is not same. The religiousness and social stratification of the Madurese community does not provide much of a cosmological-philosophical dimension regarding environmental preservation. Broadly speaking, the social stratification or stratification of the Madurese community consists of three layers, namely oreng kene or what is called oreng dume as the lowest level of society, ponggaba as the middle layer, and parijaji or priyayi as the top layer of society. Religion does not provide much of a cosmological-philosophical dimension in the religiosity of Madurese society. Based on this analytical descriptive research, it can be seen that their cosmological tradition up to the nineteenth century was very strongly influenced by Javanese cosmology which put forward the principle of harmony and harmony with nature and supernatural beings.
Pada era sekarang ini sangatlah mudah untuk mendapatan informasi. Informasi-informasi tersebut seolah-olah berseliweran disekitar kita. Kemudahan mendapat informasi secara realtime tersebut terwujud karena adanya internet. Internet tidak selalu memberikan dampak yang positif, namun terdapat pula dampak negatif, contohnya adalah kejahatan dunia maya (cybercrime). Tidak sedikit yang telah menjadi korban dari kejahatan dunia maya. Kejahatan dunia maya ini sangat berbahaya bagi kita, terlebih lagi bagi anak-anak yang belum cukup memiliki pengetahuan. Diperlukan pembekalan atau pendampingan mengenai kejahatan dunia maya agar generasi muda kita memiliki pengetahuan mengenai bahaya kejahatan dunia maya dan aman ketika berinternet. Model yang dipilih dalam pengabdian kepada masyarakat adalah model Participation Action Research (PAR). Hasil dari pengabdian menunjukan terjadi peningkatan pengetahuan mengenai Cybercrime sebesar 72,02%.
An insulin infusion pump is a device that functions to enter insulin into the body of diabetes mellitus patients. One of the problems often encountered in these devices is unstable insulin flow, causing user discomfort, irregular blood sugar, increased risk of hyperglycemia, changes in blood pressure, and bleeding in immature brains. The dimension of the angle of the syringe barrel affects the flow pattern and affects the stress on the barrel wall. The simulation of fluid velocity and fluid pressure on the syringe can be analyzed by computational fluid dynamics and stress analysis software. The input fluid velocity can be used to calculate the fluid flow rate, while the input fluid pressure is used to calculate the stress that occurs in the syringe. This study shows that the simulation changes in the angle of the syringe barrel will affect the flow rate. The increasing syringe barrel angle will decrease the flow rate of the outlet nozzle and pressure drop while the maximum stress increases.
Bats (Chiroptera) are divided into two suborders (Yinpterochiroptera and Yangochiroptera). More than 50% of species of bats use caves as their roosting sites. Thus, they play a crucial role in the cave ecosystem. For that reason, they also exist as keystone species in the karst area. Gunung Sewu is one of the karst areas in Indonesia that best exemplifies tropical karst. Furthermore, Gunung Sewu is still at risk of habitat loss despite being designated as a Geopark. This study aimed to understand the diversity of bats that live in caves in the karst region of Gunung Sewu, specifically in four caves near Ngobaran Beach between April and June 2020. A harp net and misnet placed at the cave’s entrance were used to capture bats for data collection. After they were captured, the bats were identified using Morphometry and the Shannon-Wiener index. Through another index, Margalef index, the bat diversity in the four cave habitats was expressed, with a discovery that there are many different species. Based on the Jaccard similarity index, bats were categorized again using cluster analysis and the unweighted pair-group method using arithmetic averages (UPGMA). A total of nine species across five families were identified. The diversity of existing species variety was also recognized by analyzing the composition of the four cavern inhabitants. The four cave ecosystems’ bat diversity was divided into three categories: moderate variety, low similarity, and high species diversity. Except for Cekelan 1 Cave and Gebyog Cave (P=0.015), other variations did not demonstrate a meaningful difference (P0.05). This demonstrates how different each ecosystem is. Therefore, they could be classified as potentially spoiled habitats, demanding additional conservation efforts.
Miskonsepsi diartikan sebagai suatu konsep awal yang dimiliki siswa yang tidak sesuai dengan penjelasan yang diterima umum akibat dari pengalaman yang dikonstruksi siswa. Miskonsepsi dapat juga disebut suatu konsep alternatif. Penelitian ini bertujuan untuk mengidentifikasi miskonsepsi calon guru kimia pada materi kesetimbangan kimia. Pengumpulan data dilakukan menggunakan soal berbentuk tes diagnostik two-tier, yang diujikan kepada 15 mahasiswa secara purposive sampling melalui metode survey. Hasil penelitian menunjukkan bahwa mahasiswa yang mengalami miskonsepsi sebanyak 13,85% pada materi kesetimbangan kimia yaitu pada konsep pendekatan kesetimbangan, aplikasi prinsip Le Chatelier, kekonstanan dari konstanta kesetimbangan, kesetimbangan heterogen, dan efek dari katalis.
Hoaxes about COVID-19 can spread to anyone, not least school students. Students need to be given knowledge about COVID-19 in.science learning. Therefore, the research aims to examine the integration of the COVID-19 context in science learning in schools, overview of its implementation and respons of junior high school science teachers. This research is descriptive research using qualitative methods. Data sources were obtained through literature study and interviews of science teacher in Yogyakarta, Indonesia. Qualitative data analysis is carried out using the Mile-Hiberman method. After the analysis, it was obtained that the context of COVID-19 can be incorporated into the material of respiratory system disorders class VIII junior high school Indonesia, especially concept on Pneumonia due to COVID-19, how the symptoms and ways of prevention. This integration can be learned through socio-scientific issues-based learning. Science teachers agree with this integration because students need to analyze for themselves what COVID-19 is how symptoms and ways of prevention, so that students can be aware of their own understanding impulses to respond to pandemics. It can be conclude that COVID-19 context can be integrated in science learning. Therefore, it takes a development of teaching materials related to integration COVID-19 in science learning.
Issues of global and local importance such as climate change, health (covid-19), tolerance, meeting the need for food and shelter, and development of artificial intelligence technology require critical perspectives across a wide range of disciplines including science, technology, engineering, and mathematics (STEM). One of the problems in implementing STEM is the "loss" of mathematics in the STEM learning. Mathematics teachers should make mathematics transparent and explicit in promoting STEM education. The focus of this research is how the teacher's efforts to design learning that strengthen M in/for STEM. The research method used is phenomenological research. Dialogue with 10 mathematics teachers who implement STEM is used as a method to examine how the implementation of STEM that can instill a strong understanding of mathematics. The results showed that the efforts made by mathematics teachers to strengthen mathematics in STEM education were 1) prioritizing mathematics content by pushing other disciplines into the background, 2) using an embedded approach in implementing STEM education with the aim of understanding mathematical concepts, 3) and using project or problem in STEM education more load mathematical concepts.
The COVID-19 Pandemic has resulted the change in every sector of life. Education institutions transform their learning methods from face-to-face learning to online-based distance learning to keep the learning process running during the pandemic era. The purpose of this study is to obtain the description and analysis results regarding learning profile and evaluation system used in the lecture at Biology Education Study Program during the Pandemic. This survey study was conducted in August 2020 until August 2021, even semester of 2019/2020, odd semester of 2019/2020, even semester of 2020/2021, and odd semester of 2021/2022. The population of this study was the students of Biology Education of UMM and the students of private universities in Malang City. Purposive sampling was employed for sample selection. The instruments used were survey and questionnaire forms. The data was analyzed descriptively and quantitatively. The results of the study show that online learning is apparently not optimal in Biology Education and other private universities in Malang due to limitations in discussions, assignments, and assessments. Therefore, it is necessary to conduct training session, planning, and implementation of innovative online learning to optimize learning process. To make the learning process more accurate and effective, evaluations are also needed.
The problem of sexual violence is in the spotlight of various groups because it has a multidimensional impact. Various efforts have been made to guarantee and protect the rights of victims. One of these efforts is the presence of Law Number 12 of 2022 concerning the Crime of Sexual Violence. This study aims to analyze the substance of the law and its compatibility with Sharia principles. This type of research is qualitative with a juridical-philosophical approach with the Jasser Auda’s perspective on Maqāṣid Sharia. The content analysis (content-analysis) is used to examine the content of the law in depth and its suitability with the theory. This study concludes that the concept of sexual violence contained in Law 12 of 2022 is in accordance with Maqāṣid Sharia, mainly in six respects, namely ḥifẓ al-dīn (the preservation of religion), ḥifẓ al-nafs (the preservation of the soul), ḥifẓ al’aql (the preservation of mind), ḥifẓ al-nasl (the preservation of offspring), ḥifẓ al-māl (the preservation of property), and ḥifẓ al-‘irḍ (the preservation of honor). This is based on the basic principles of Maqāsid Sharia which emphasizes morality, openness, development, humanity, and human rights.
Authentic context is a physical environment reflecting the knowledge application in the real world. In this study, we developed a tablet-based application, Ubiquitous Fraction (U-Fraction), to help fractions learning with authentic contextual support. Three topics were designed to learn fractions concept, fractions simplification, and fractions addition/subtraction. The learning achievement was evaluated by three variables: understanding fraction and fraction representation to evaluate fractions concept and fractions simplification, and problem solving to evaluate the three topics. This study used two groups of experimental research. The experimental group (EG) learned fractions using U-Fraction in authentic contexts, while the control group (CG) learned fractions using the traditional teaching method and paper-based assignment. The results showed that EG significantly outperformed CG. Furthermore, it was found that learning behaviors of EG had significant correlation among quantity of assignment, annotations of assignment, and post-test. Two assessment mechanisms, peer and teacher assessments using scaffoldings based on multiple representations (i.e., linguistic, logic mathematics, and visual representation), were employed to help assessment and improve the assessment results. It was found that the scaffoldings can help both peer and teacher assessments, which significantly correlated with post-test. Therefore, multiple representations and scaffoldings were helpful to improve students’ learning and peer assessment. Students also perceived positively toward using U-Fraction in terms of usefulness, ease of use, ease of learning, and satisfaction of the usability questionnaire. These imply that fraction learning should be designed in a way that students can apply their knowledge in authentic contexts by taking pictures and making multiple representations.
A robust design of a disk-type milling cutter involving multiple inserted blades is required in screw rotor milling since it significantly influences the machining precision. Hence, it is essential to discover a prediction model for rapidly simulating rotor profiles and cutting marks to evaluate the cutter design to enhance the cost-time savings in cutter manufacturing. This study proposes an insert-cutting trajectory (ICT) method that is resolved by considering the cutting-edge form of each insert type and cutting conditions. In addition, the ICT method’s accuracy is determined according to the number of points on the insert cutting-edge length and the number of grids on the tooth profile length. The result confirms that the rotor profile and the surface cutting marks were successfully generated by applying both disk-type milling cutters with standard and special inserts. The profile results indicate that the special insert can achieve smoother than the round-standard insert. The ICT method relied on the screw rotor milling with distinction cutting conditions utilizing the special inserts. Finally, an experimental result verified that the ICT method is reliable and practicable.
This service aims to increase students' knowledge and skills in operating WhatsApp Business as one of the most useful applications to be used as a business and digital marketing tool. Training and mentoring were used in this service. Sang Timur Yogyakarta High School was the service's partner. The evaluation instrument for this activity was interviews, which were analyzed descriptively. The results of this service showed that students had an understanding and skills in using WhatsApp Business, how to sell online correctly, and how to trade and reply to a good chat on WhatsApp Business. Moreover, the service indicated that they understood how to use WhatsApp Business and knew the benefits and advantages of selling online. They also could learn how to do business through WhatsApp Business and understand how to do business better and more accessible. The results were achieved in implementing mentoring, where several participants installed WhatsApp Business for businesses that matched their interests.
Introduction Previous studies showed that the Nordic hamstring exercise (NHE) effectively prevents primary hamstring injury. However, no study investigated the secondary preventing effect of the NHE on hamstring reinjury. The primary purpose of this study is to investigate the effectiveness of the NHE for preventing hamstring reinjury after return to play (RTP) following a hamstring injury in football players. The secondary purpose is to determine the effect of the NHE on sprint and jump performance.Methods and analysis This is an international multicentre, prospective, parallel-group randomised controlled trial study. Subjects include male or female football players aged 18–40 years and within 1 week of RTP following a hamstring injury will be randomised into Nordics or a control group. Subjects in both groups continue their regular football training, but the Nordics group will perform an additional NHE programme. An online questionnaire will be sent to the subjects in both groups once per week within the first 10 weeks, then continued at months 6, 9 and 12. In a (performance) substudy, we will evaluate the effect of the NHE on sprint and vertical jump performance at three time points (at the beginning of the study, after 10 weeks and 12 months of follow-up).The primary outcomes are the incidence of hamstring reinjury within 2 and 12 months. The secondary outcomes are sprint and jump performance, adherence to the programme, duration of reinjury and reinjury burden.Ethics and dissemination This study is approved by the medical ethics committee of Amsterdam University Medical Center (UMC) in the Netherlands (METC 2021_117), Faculty of Medicine Universitas Gadjah Mada in Indonesia (KE/FK/1248/EC/2021), Norwegian School of Sport Sciences in Norway (number 216–2 70 122) and Denmark (ethical submission in process). The study’s findings will be disseminated in scientific peer-reviewed journals and presented at international conferences.Trial registration number NL9711.
Background We reported for the first time the preparation of carbon nanodots/cajuput oil (C-dots/CJO) composites for potential antibacterial applications. Method The C-dots were synthesized from CJO distillation wastes via the low carbonization method. Then, the C-dots were mixed with CJO to obtain C-dots/CJO composites. The characteristics of the C-dots were determined using UV-Vis, PL, TRPL, FTIR, and HRTEM, whereas the C-dots/CJO composites were characterized using UV-Vis and FTIR. Result Antibacterial properties were investigated for samples of C-dots, CJO, and C-dots/CJO with no-light, white light, and UV/violet light treatments. The C-dots produced cyan luminescence with a decay lifetime of 6.54 ns. Based on the antibacterial tests, the C-dots/CJO composites have DIZ higher than the pure C-dots Conclusion The C-dots/CJO composites reached the highest DIZ of 3.6 nm under white light, which was attributed to the photodynamic effect and photodisinfection of the C-dots and CJO, respectively. Hence, the C-dots/CJO composites can be potential antibacterial agents against E. coli bacteria
One of the abilities that students in learning must possess is the ability to think creatively. Assessment of learning outcomes should measure students’ creative thinking skills, but it is often ignored. This research was made to analyze students’ creative thinking skills using a modern test theory approach. The test assessment approach used is Graded Response Models (GRM). GRM is following the characteristics of the essay test with the test response in the form of Linkert data. The research subjects consisted of 60 physics students who took courses in electrical circuits. The test scores are made differently on the answer indicators, with a scale of 1 to 5. The scale shows the level of student’s creative thinking abilities. The results of the analysis show that the lower the creative thinking ability of students, the greater the chance to get a score of 1. Likewise, to get a score of 5, the greater the students’ creative thinking ability, the more excellent the opportunity to get a score of 5. The four questions used have the same discriminating power of 1.059 and have increased the level of difficulty in each score on each question.
In this work, reduced graphene oxide-coated zinc borotellurite doped with erbium oxide nanoparticles denoted as ZBTEr (NPs)-rGO was studied as an approach to enhance the optical properties of glass materials. Herein, a melt-quenched technique was used to prepare the ZBTEr (NPs) glasses. A simple and inexpensive spray-coated technique was employed to deposit the rGO onto the glass surfaces directly. The morphological studies of ZBTEr (NPs)-rGO glass surfaces were investigated by scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HR-TEM) meanwhile, the structural investigation of ZBTEr (NPs) glasses was revealed by X-ray diffraction (XRD) and Raman analysis. The morphological analysis revealed the residual oxygen groups functionalized on ZBTEr (NPs)-rGO glass surfaces meanwhile, TEM images confirmed the presence of Er (NPs) in the glassy matrix. The glass samples showed the existence of structural disorder and amorphous nature. The absorption spectra presented the transition bands that existed from ⁴I15/2 ground state level to excited state levels of ²H9/2, ⁴F5/2, ⁴F7/2, ²H11/2, ⁴S3/2, ⁴F9/2, ⁴I11/2, and ⁴I9/2, respectively. Judd–Ofelt analysis was performed to obtain the intensity parameters (Ωλ), radiative transition (A), branching ratios (βR), and radiative lifetimes (tr). The radiative parameter and branching ratio values suggested the higher stimulated emission radiative at ²H11/2 → ⁴I15/2 transition for present glass The luminescence spectra exhibited two emission peaks centred at 539 nm and 558 nm which were assigned to ²H11/2 → ⁴I15/2 and ⁴S3/2 → ⁴I15/2 transitions, respectively. The optical results for ZBTEr (NPs)-rGO and ZBTEr (NPs)-uncoated were compared to determine the differences between coated and uncoated glasses. These results highlight the significant effect of rGO deposited onto tellurite-based glass and thus, this work proposed the potential coating materials for improving current fiber optics.
Green marketing is a marketing concept that carries the green concept, considering the environment in terms of green products, green prices, green places, and green promotional activities carried out. This service activity was carried out in Sawahan Hamlet, Pandowoharjo village, Sleman district, with the target participants being KWT Karya Manunggal members. This activity aims to increase participants' understanding and apply green marketing from environmentally friendly vegetables produced by KWT activities. Implementing FGD activities is face-to-face, accompanied by questions and answers, and assistance until the product is ready to be marketed. The participants enthusiastically followed the service activities, and KWT Karya Manunggal succeeded in having a logo used as a brand in marketing products. In addition, the team succeeded in obtaining the copyright for environmentally friendly vegetable packaging from DJKI under the Ministry of Law and Human Rights. To expand the market, social media is used to reach a broader range of consumers by presenting images of dancing products, thereby reducing physical contact with consumers.
Both the management and participants commit administrative violations in the general election. Often, they are not aware that they are breaking regulations. Since the fall of the New Order Era, administrative frauds in the general election are handled by administrative courts through administrative legal proceedings. Administrative violations bring about disadvantages to participants and raise administrative disputes between the two parties. The present article analyses the process of the settlement of administrative disputes in the 2019 general election in Indonesia and the roles of the administrative courts in the process. Data on the examples of cases and causes of disputes are obtained empirically in court verdicts by the High Court of the Republic of Indonesia that have legal standing. The analysis adopts the inductive logic method. This article concludes that the process of the settling of administrative disputes of the general election in Indonesia, as in various other democratic countries, takes the involvement of administrative dispute resolution bodies (ADR). ADR must be completed first before bringing dispute cases to the administrative court. The settlement of the disputes is done by the Constitution Court of the Republic of Indonesia and is regulated by State Law of the Republic of Indonesia Number 7 Year 2017 about the general election.
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8,955 members
Setyabudi Indartono
  • Department of Management
Anti Prodjosantoso
  • Department of Chemistry Education
Hari Sutrisno
  • Department of Chemistry Education
Herman Dwi Surjono
  • Information Technology Education
Mohammad Khairudin
  • Department of Electrical Engineering Education
Jl Colombo No.1 Yogyakarta, 55281, Yogyakarta, Yogyakarta, Indonesia
Head of institution
Prof. Dr. Sumaryanto, M.Kes.,AIFO.