27 research outputs found
Spinning scalar solitons in anti-de Sitter spacetime
No full textAbstractWe present spinning Q-balls and boson stars in four-dimensional anti-de Sitter spacetime. These are smooth, horizonless solutions for gravity coupled to a massive complex scalar field with a harmonic dependence on time and the azimuthal angle. Similar to the flat spacetime configurations, the angular momentum is quantized. We find that a class of solutions with a self-interaction potential has a limit corresponding to static solitons with axial symmetry only. An exact solution describing spherically symmetric Q-balls in a fixed AdS background is also discussed
EFEKTIFITAS PENGGUNAAN MEDIA AUDIO VISUAL TERHADAP MINAT DAN HASIL BELAJAR SISTEM PENGAPIAN
No full textABSTRACTThis study aims to determine the students' interest in learning TKR SMK Nasional Berbah Sleman ignition system subject, and to determine the effectiveness and effect of learning using audiovisual tools. This type of research is a quasi-experimental. The research was conducted at the Yogyakarta National Stock Exchange (SMK Nasional Berbah Sleman Yogyakarta) from November 2019 to December 2019. The total population was 70 students, and the sample was 35 students in category XI TKR A and 35 students in category XI TKR B. sample, used a questionnaire to measure interest in learning. The data analysis test was performed using the t-test, then a descriptive analysis was carried out. Previously, research data was tested through prerequisites, including normality test, homogeneity test, and balance test. The results showed that interest in using audiovisual media for learning ignition systems was more significant than interest in learning ignition systems without audiovisual media, and interest in using audiovisual media to study ignition systems was more effective than learning without audiovisual media. Keywords: effectiveness, tools, audio visual, SMK Keywords: audio visual, interest in learning, learning outcomesABSTRAKPenelitian ini bertujuan sejauah mana minat siswa belajar TKR SMK Nasional Berbah Sleman mata pelajaran sistem pengapian, dan untuk mengetahui keefektifan dan pengaruh pembelajaran memakai alat audiovisual. Jenis penelitian ini adalah eksperimen semu. Penelitian dilakukan di Bursa Efek Nasional Yogyakarta (SMK Nasional Berbah Sleman Yogyakarta) dari November 2019 hingga Desember 2019. Jumlah populasi adalah 70 siswa, dan sampelnya adalah 35 siswa pada kategori XI TKR A dan 35 siswa pada kategori XI TKR B. Hasilnya, dari segi sampel, digunakan angket untuk mengukur minat belajar. Uji analisis data dilakukan dengan menggunakan uji-t, kemudian dilakukan analisis deskriptif. Sebelumnya, data penelitian diuji melalui prasyarat, meliputi uji normalitas, uji homogenitas, dan uji keseimbangan. Hasil penelitian menunjukkan bahwa minat penggunaan media audiovisual untuk pembelajaran sistem pengapian lebih signifikan dibandingkan minat belajar sistem pengapian tanpa media audiovisual, dan minat penggunaan media audiovisual untuk mempelajari sistem pengapian lebih efektif daripada pembelajaran tanpa media audiovisual. Kata kunci: efektifitas, tools, audio visual, SM
Jigsaw learning model in increasing interest and learning of automotive electrical systems
No full textThe purpose of this study was to determine the increase in interest in learningvand learning outcomes Automotive subjects Jigsaw cooperative learning model. This research is a class act. The data collection technique using observation, tests and questionnaires. The validity of the instrument in this study using the content validity using expert judgment. Data were analyzed using quantitative analysis techniques. The results showed that the application of cooperative learning model Jigsaw on the subjects of automotive electrical systems can increase interest and student learning outcomes in class XI SMK (Taman Karya) Tamansiswa Jetis Yogyakarta. Increased student interest in the first cycle an average of 59.04 (low) increased to 73.96 (currently) in the second cycle and increased again to 76.80 (high) in the third cycle. It can be concluded that Jigsaw cooperative learning model can improve learning outcomes interest and automotive electrical systems in class XI student of SMK (Taman Karya) Tamansiswa Jetis Yogyakarta
Myers-Perry black holes with scalar hair and a mass gap: Unequal spins
Get PDFWe construct rotating boson stars and Myers-Perry black holes with scalar hair (MPBHsSH) as fully non-linear solutions of five dimensional Einstein gravity minimally coupled to a complex, massive scalar field. The MPBHsSH are, in general, regular on and outside the horizon, asymptotically flat, and possess angular momentum in a single rotation plane. They are supported by rotation and have no static limit. Such hairy BHs may be thought of as bound states of boson stars and singly spinning, vacuum MPBHs and inherit properties of both these building blocks. When the horizon area shrinks to zero, the solutions reduce to (in a single plane) rotating boson stars; but the extremal limit also yields a zero area horizon, as for singly spinning MPBHs. Similarly to the case of equal angular momenta, and in contrast to Kerr black holes with scalar hair, singly spinning MPBHsSH are disconnected from the vacuum black holes, due to a mass gap. We observe that for the general case, with two unequal angular momenta, the equilibrium condition for the existence of MPBHsSH is w = m(1)Omega(1)+m(2)Omega(2), where Omega(i) are the horizon angular velocities in the two independent rotation planes and w, m(i), i = 1, 2, are the scalar field's frequency and azimuthal harmonic indices
Pengaruh Konstanta Kosmologi Terhadap Model Standar Alam Semesta
Get PDFMetrik FLRW adalah sebuah metrik ruang-waktu yang digunakan un- tuk memodelkan alam semesta. Dalam membangun metrik ini, digunakan asumsi prinsip kosmologi, yaitu alam semesta isotropik dan homogen. Setelah itu, metrik FLRW dikerjakan pada Persamaan Medan Einstein dengan Konstanta Kosmologi, sehingga didapatkan dua solusi Friedmann. Solusi tersebut adalah solusi Friedmann jenis pertama dan solusi Friedmann jenis kedua. Pada tugas akhir ini, digunakan solusi Friedmann jenis pertama yang telah dimodifikasi agar sesuai dengan keadaan fisis alam semesta untuk memodelkan alam semesta. Dari model ini, dibandingkan antara model yang memiliki konstanta kosmologi dan tidak sehingga didapatkan pengaruh konstanta kosmologi terhadap model standar alam semesta
EFEKTIVITAS PENGUNAAN MODEL PEMBELAJARAN KOOPERATIF TIPE STUDENT TEAM ACHIEVEMENT DIVISION (STAD) TERHADAP HASIL BELAJAR PEKERJAAN DASAR OTOMOTIF (PDO)
No full textTujuan penelitian deskriptif  berikut ini adalah untuk mengetahui trend hasil pembelajaran PDO dengan menggunakan sub model student team performance dan model konvensional dalam pembelajaran, dan untuk mengetahui perbedaan hasil belajar PDO dengan menggunakan sub model student team performance dan model konvensional. Jenis penelitian ini adalah eksperimen semu. Metode pengumpulan data menggunakan tes dan dokumentasi. Instrumen penelitian adalah tes. Teknik analisis data menggunakan analisis deskriptif, pengujian hipotesis menggunakan uji-t, kemudian uji normalitas distribusi dan uji homogenitas varians. Hasil penelitian deskriptif menunjukkan bahwa hasil belajar PDO yang diajar dengan model Student Team Prestasi Divisi tergolong sangat tinggi dengan rata-rata 19.000, sedangkan model konvensional tergolong rata-rata tinggi dengan rata-rata 14.412. Sebaliknya terdapat perbedaan hasil belajar PDO, pembelajaran yang dilaksanakan dengan model parsial prestasi tim siswa dan model konvensional, dengan nilai thit = 3,926 dan p = 0,000 <0,05. Dengan menggunakan 19.000 model pembelajaran Jurusan Prestasi Beregu Mahasiswa dan 14.412 model pembelajaran konvensional untuk melihat rata-rata hasil belajar pekerjaan otomotif dasar, dibandingkan dengan model konvensional, model pembelajaran Jurusan Prestasi Beregu Mahasiswa memiliki pengaruh yang lebih besar terhadap hasil belajar pekerjaan otomotif dasar.Kata Kunci: efektifitas model belajar, hasil . The purpose of descriptive research was to determine the trend of PDO learning outcomes using the student team performance sub-model and the conventional model in learning, and to find out the differences in PDO learning outcomes using the student team performance sub-model and the conventional model. This type of research is a quasi-experimental. Methods of data collection using tests and documentation. The research instrument was a test. The data analysis technique used descriptive analysis, hypothesis testing using the t-test, then the distribution normality test and the variance homogeneity test. The results of the descriptive study show that the learning outcomes of the PDO taught by the Student Team Division Achievement model are classified as very high with an average of 19,000, while the conventional model is classified as high average with an average of 14,412. On the other hand, there are differences in the learning outcomes of PDO, learning which is carried out with the partial model of student team achievement and the conventional model, with a value of thit = 3.926 and p = 0.000 <0.05. By using 19,000 learning models of the Student Team Achievement Department and 14,412 conventional learning models to see the average learning outcomes of basic automotive work, compared to conventional models, the learning model of the Student Team Achievement Department has a greater influence on learning outcomes of basic automotive work.Keywords: the effectiveness of the learning model, out come
Pengembangan Pasar Tenun Serat PT Retota Sakti Kabupaten Pekalongan, Jawa Tengah
Get PDFPotential weaving industry nationally as one of the SMEs so far have not unearthed the maximum due to the development of production management systems. Therefor, PT Retota Sakti has prompted company management to enhance the creative abilities tenunnya always accompanied by the application of more precise marketing strategies that correspond with the development of competition situation that occurred in the weaving industry. The purpose of this study was (1) Identify and evaluate the position of Marketing PT Retota Way by internal and external factors, and (2) Develop appropriate marketing strategies in developing future business. Analyzed in a descriptive study to emphasize the aspect of marketing, covering demand products to meet market needs; offer, which gives an overview about the availability of products in the process of cultivation and the balance of factors between demand and supply prices. To examine the marketing strategies carried out by quantitative SWOT analysis. The results of factor identification strategy, there are five key factors of internal strengths and weaknesses of four key factors. While the external environment there are five key factors of opportunities and threats of five factors. IFE values 2.842 and 2.530 EFE value, and also the combination of these two values in the matrix IE indicates that the marketing strategy lies in the quadrant of five, namely the growth and stability, where the strategies that can run the market penetration, product development and market. QSP matrix analysis results obtained with the most attractive strategy to be implemented is to increase production capacity
Spinning black strings in five-dimensional Einstein–Gauss–Bonnet gravity
No full textAbstractWe construct generalizations of the D=5 Kerr black string by including higher curvature corrections to the gravity action in the form of the Gauss–Bonnet density. These uniform black strings satisfy a generalized Smarr relation and share the basic properties of the Einstein gravity solutions. However, they exist only up to a maximal value of the Gauss–Bonnet coupling constant, which depends on the solutionsʼ mass and angular momentum
Probing the universality of synchronised hair around rotating black holes with Q-clouds
Get PDFRecently, various families of black holes (BHs) with synchronised hair have been constructed. These are rotating BHs surrounded, as fully non-linear solutions of the appropriate Einstein-matter model, by a non-trivial bosonic field in synchronised rotation with the BH horizon. Some families bifurcate globally from a bald BH (e.g. the Kerr BH), whereas others bifurcate only locally from a bald BH (e.g. the D=5 Myers–Perry BH). It would be desirable to understand how generically synchronisation allows hairy BHs to bifurcate from bald ones. However, the construction and scanning of the domain of existence of the former families of BHs can be a difficult and time consuming (numerical) task. Here, we first provide a simple perturbative argument to understand the generality of the synchronisation condition. Then, we observe that the study of Q-clouds is a generic tool to establish the existence of BHs with synchronised hair bifurcating (globally or locally) from a given bald BH without having to solve the fully non-linear coupled system of Einstein-matter equations. As examples, we apply this tool to establish the existence of synchronised hair around D=6 Myers–Perry BHs, D=5 black rings and D=4 Kerr-AdS BHs, where D is the spacetime dimension. The black rings case provides an example of BHs with synchronised hair beyond spherical horizon topology, further establishing the generality of the mechanism
