1,505 research outputs found
Counting Simplices in Hypergraph Streams
No full textWe consider the problem of space-efficiently estimating the number of simplices in a hypergraph stream. This is the most natural hypergraph generalization of the highly-studied problem of estimating the number of triangles in a graph stream. Our input is a k-uniform hypergraph H with n vertices and m hyperedges, each hyperedge being a k-sized subset of vertices. A k-simplex in H is a subhypergraph on k+1 vertices X such that all k+1 possible hyperedges among X exist in H. The goal is to process the hyperedges of H, which arrive in an arbitrary order as a data stream, and compute a good estimate of T_k(H), the number of k-simplices in H.
We design a suite of algorithms for this problem. As with triangle-counting in graphs (which is the special case k = 2), sublinear space is achievable but only under a promise of the form T_k(H) ≥ T. Under such a promise, our algorithms use at most four passes and together imply a space bound of O(ε^{-2} log δ^{-1} polylog n ⋅ min{(m^{1+1/k})/T, m/(T^{2/(k+1)})}) for each fixed k ≥ 3, in order to guarantee an estimate within (1±ε)T_k(H) with probability ≥ 1-δ. We also give a simpler 1-pass algorithm that achieves O(ε^{-2} log δ^{-1} log n⋅ (m/T) (Δ_E + Δ_V^{1-1/k})) space, where Δ_E (respectively, Δ_V) denotes the maximum number of k-simplices that share a hyperedge (respectively, a vertex), which generalizes a previous result for the k = 2 case. We complement these algorithmic results with space lower bounds of the form Ω(ε^{-2}), Ω(m^{1+1/k}/T), Ω(m/T^{1-1/k}) and Ω(mΔ_V^{1/k}/T) for multi-pass algorithms and Ω(mΔ_E/T) for 1-pass algorithms, which show that some of the dependencies on parameters in our upper bounds are nearly tight. Our techniques extend and generalize several different ideas previously developed for triangle counting in graphs, using appropriate innovations to handle the more complicated combinatorics of hypergraphs
Pengaruh Tingkat Konsentrasi IAA dan Lama Perendamanan terhadap Pertumbuhan W.Ait)
No full textEfrizal." Pengaruh Tingkat Konsentrasi IAA dan Lama
(Jasminum
sambac
Perendamanan Terhadap Pertumbuhan W.Ait)", Haris, Setek Tanaman Melati Ibu Gembira Hj.T.Chairun nisa Sinuraya, sebagai anggota). sebagai ketua dan
(Dibawah
bimbingan
Tujuan penelitian tingkat konsentrasi ini untuk mengetahui pengaruh IAA dan lama perendaman terhadap pertumbuhan setek tanaman melati (Jasminum sambac W. Ait). Penelitian dilaksanakan di Fakultas Pertanian Laboratorium Dasar Agronomi, Universitas Sumatera Utara, dimulai sejak Juli hingga September 2001. Rancangan yang digunakan adalah Rancangan Acak Kelompok terdiri dari 2 faktor dan 3 ulangan.
Fator tingkat konsentrasi terdiri dari 4 taraf yaitu Ko (0 ppm). K (300 ppm), K₂ 1600 ppm), K (900 ppm), sedangkan faktor lama perendaman terdiri dari 3 taraf yaitu 1 (15 menit), L (30 menit), La (45 menit).79 HalamanSkripsi Sarjan
On the spatial and temporal coherence of wireless vehicular short range channels
No full textWe consider spatial and temporal coherence of the vehicle–to–vehicle (V2V) wireless communication channel with focus on a suburban residential highway. The dominant reflectors in such an environment are vehicles passing in the adjacent lane and houses
along the road. Instead of treating the reflectors as point targets, the V2V short range propagation environment requires partitioning of the illuminated reflector side into
sufficiently small tiles. The channel transfer function is obtained as a superposition of specular reflections from the tiles, the line–of–sight (LOS) component, and the ground reflection. The tile size is selected to ensure that the ratio of the tile area to the tile–to–receiver distance satisfies the far field conditions. The reflected power is described by the tile radar cross section (RCS). The bistatic physical optics RCS model is adapted to account for the tile’s orientation with respect to the ray geometry. We apply the superposition model to the numerical analysis of two general scenarios
for a 22MHz channel in the 2.4GHz band. The first scenario considers a single vehicle reflector passing in the lane adjacent to the V2V communication pair. Both the vector network analyzer (VNA) experiments and the tiling model analysis illustrate that repositioning of the reflector, the transmitter, or the receiver by a few centimeters results in change of the signal power by several decibels. The second scenario analysis characterizes the channel coherence statistics for the
suburban residential highway. We consider the V2V single lane LOS and non–LOS geometries, where in the latter the receiver is shadowed by a large vehicle. The reflectors are both houses and vehicles passing in the opposite direction. The measure of channel coherence is the normalized spatial covariance calculated by correlating transfer functions corresponding to feasible receiver position pairs and performing spatial smoothing. The area of feasible receiver positions is divided into contiguous squares
whose size ensures wide sense quasi–stationarity within the square. Irrespective of direction the correlation remains high and a typical sedan roof usually does not provide sufficient spacing to obtain average inter–antenna correlation lower than 0.5. The upper bound on coherence time extends over the transmission time of multiple packets for systems in the considered band, and does not allow for usable time diversity.Ph.D.Includes bibliographical referencesIncludes vitaby Haris Krem
Shapley meets Shapley
No full textThis paper concerns the analysis of the Shapley value in matching games. Matching games constitute a fundamental class of cooperative games which help understand and model auctions and assignments. In a matching game, the value of a coalition of vertices is the weight of the maximum size matching in the subgraph induced by the coalition. The Shapley value is one of the most important solution concepts in cooperative game theory. After establishing some general insights, we show that the Shapley value of matching games can be computed in polynomial time for some special cases: graphs with maximum degree two, and graphs that have a small modular decomposition into cliques or cocliques (complete k-partite graphs are a notable special case of this). The latter result extends to various other well-known classes of graph-based cooperative games. We continue by showing that computing the Shapley value of unweighted matching games is #P-complete in general. Finally, a fully polynomial-time randomized approximation scheme (FPRAS) is presented. This FPRAS can be considered the best positive result conceivable, in view of the #P-completeness result
Impact of financial leverage on sustainable growth, market performance, and profitability
No full textThe purpose of this study was to measure the impact of financial leverage on the performance of 424 Pakistani nonfinancial listed companies over the 2001–2017 period. Three measures of financial leverage, i.e., short-term debt (STDL), long-term debt (LTDL), and total debt (TLEVR), were applied to examine their impact on performance, i.e., sustainable growth (SGR), Tobin’s Q, return on assets (ROA), return on equity (ROE), and return on sales (ROS). Robust results obtained using the generalized method of moments (GMM) report a significant negative impact of financial leverage on performance. The results also confirm an inverted U-shaped relationship between financial leverage and performance, indicating that an increase in the financial leverage of Pakistani listed companies increases their performance up to a certain level, and after that, a further increase in financial leverage decreases their performance. The results further suggest that STDL is a main contributing source of debt that causes a higher risk of refinancing for companies and thus negatively affects performance. This study’s findings are useful for academics, management, policymakers, and regulators to understand the importance of financial leverage and to choose between STDL and LTDL to fund financial needs
PERUBAHAN SIFAT KIMIA TANAH ULTISOL PADA PEMBERIAN BEBERAPA DOSIS ABU BOILER
No full textRENALDI HARIS MAULANA (2024) PERUBAHAN SIFAT KIMIA TANAH ULTISOL PADA PEMBERIAN BEBERAPA DOSIS ABU BOILER
Ultisol merupakan tanah masam yang memiliki sebaran luas sehingga
berpotensi untuk pengembangan pertanian. Reaksi tanah yang masam dan
ketersediaan unsur hara yang rendah, menjadikan ultisol membutuhkan
penambahan amelioran sebelum praktik pemupukan. Salah satu amelioran yang
dapat digunakan adalah abu boiler. Tujuan penelitian ini adalah mengetahui
perubahan sifat kimia tanah ultisol akibat pemberian abu boiler. Penelitian ini
telah dilaksanakan di rumah kaca Fakultas Pertanian dan Peternakan, Universitas
Sultan Syarief Kasim Riau dan analisis tanah dilakukan di laboratorium Pengujian
Balai Penerapan Standar Instrumen Pertanian (BPSIP) Provinsi Riau. Penelitian
dilaksanakan pada bulan Maret hingga hingga Mei 2024. Unit percobaan yang
digunakan pada penelitian ini adalah tanah ultisol 5 kg yang di kombinasikan
dengan beberapa taraf dosis abu boiler yaitu 0 g, 250 g, 500 g, dan 750 g.
Penelitian disusun dengan Rancangan Acak Lengkap. Parameter yang diamati pH
tanah ultisol, kandungan C-Organik, kandungan N-Total, kandungan P-Tersedia,
dan kandungan K-Total. Hasil penelitian menunjukkan bahwa penambahan abu
boiler pada tanah ultisol nyata meningkatkan pH tanah, P-tersedia, C-Organik, dan
K-total, namun tidak nyata mempengaruhi nilai N-total tanah ultisol.
Kata kunci: abu boiler, sifat kimia tanah, ultiso
Student attendance system using facial recognition based on deep learning / Syahila Aina Haris and Zulfikri Paidi
No full textThe learning process depends on student attendance. There are many ways to track student attendance, and one of them is using their signatures. The procedure has a number of drawbacks, such as taking a long time to complete attendance, attendance papers are lost, the administration must manually enter each student’s attendance information into the computer and there is also a possibility of attendance fraud among students. In order to overcome this problem, this paper suggested a web-based face recognition student attendance system as a solution to this problem. In this suggested system, K-NN is used to categorize student faces, deep metric learning is used to build facial embedding, and Convolutional Neural Network (CNN) is used to detect faces in photos. The development of this system is also assisted by several other software. As a result, the computer can identify faces. This algorithm can identify the faces of students who appear in class, and their attendance will be recorded automatically into the system. As a consequence, tracking attendance information is made easier for student administration
Pemanfaatan K Means Clustering dalam Pengelompokan Judul Skripsi
No full textThesis is a term used in Indonesia to describe scientific writing. Thesis is in the form of a written explanation of the results of undergraduate research that discusses phenomena in certain fields of science using applicable rules. In this case study, data mining analysis was carried out using the K Means clustering method. The criteria used to classify thesis titles with K-Means are rpm, name, title, supervisor. The increasing number of students and variations in thesis titles cause difficulties in grouping thesis data. This study aims to classify the thesis data of students of the informatics engineering study program IIB Darmajaya. Grouping is done using an algorithm. K-Means Clustering. The process of calculating the K-Means clustering algorithm uses a simple application built using the PHP programming language and MySQL database.Skripsi merupakan istilah yang digunakan di Indonesia untuk menggambarkan karya tulis ilmiah. Skripsi berupa penjelasan tertulis hasil penelitian sarjana yang membahas fenomena dalam bidang ilmu tertentu dengan menggunakan kaidah-kaidah yang berlaku. Dalam studi kasus ini, analisis data mining dilakukan dengan menggunakan metode clustering K Means. Kriteria yang digunakan untuk mengelompokkan judul skripsi dengan K-Means adalah rpm, nama, judul, dosen pembimbing. Semakin bertambahnya jumlah mahasiswa dan variasi judul skripsi menyebabkan kesulitan dalam pengelompokan data skripsi. Penelitian ini bertujuan untuk mengelompokkan data skripsi mahasiswa program studi teknik informatika IIB Darmajaya. Pengelompokan dilakukan dengan menggunakan algoritma. K-Means Clustering. Proses perhitungan algoritma clustering K-Means menggunakan aplikasi sederhana yang dibangun dengan menggunakan bahasa pemrograman PHP dan database MySQL
Computational complexity of -stable matchings
No full textWe study deviations by a group of agents in the three main types of matching
markets: the house allocation, the marriage, and the roommates models. For a
given instance, we call a matching -stable if no other matching exists that
is more beneficial to at least out of the agents. The concept
generalizes the recently studied majority stability. We prove that whereas the
verification of -stability for a given matching is polynomial-time solvable
in all three models, the complexity of deciding whether a -stable matching
exists depends on and is characteristic to each model.Comment: SAGT 202
- …
