A Channel Coding Perspective of Collaborative Filtering

We consider the problem of collaborative filtering from a channel coding perspective. We model the underlying rating matrix as a finite alphabet matrix with block constant structure. The observations are obtained from this underlying matrix through a discrete memoryless channel with a noisy part representing noisy user behavior and an erasure part representing missing data. Moreover, the clusters over which the underlying matrix is constant are {\it unknown}. We establish a sharp threshold result for this model: if the largest cluster size is smaller than $C_1 \log(mn)$ (where the rating matrix is of size $m \times n$), then the underlying matrix cannot be recovered with any estimator, but if the smallest cluster size is larger than $C_2 \log(mn)$, then we show a polynomial time estimator with diminishing probability of error. In the case of uniform cluster size, not only the order of the threshold, but also the constant is identified.Comment: 32 pages, 1 figure, Submitted to IEEE Transactions on Information Theor

Penerapan Perlindungan Hukum Hak Cipta terhadap Seni Batik Riau di Pekanbaru

Indonesia is an archipelago with a variety of art and culture is very rich, the overall wealth of the nation is a potential that needs to be protected. The wealth of art and culture is a source of intellectual property that are given legal protection through legislation. one of the art treasures are protected Indonesian Batik Art. Copyright law protection against Batik Art by Article 12, letter i of Law Number 19 Year 2002 on Copyright. This protection is given as batik art as an intellectual work is a work that has artistic value in the creation of images or motifs or color composition. Wealth of art and culture in every area there in this nation, in addition to useful for the formation of character and dignity of the nation, also can be used to grow the creative economy. Pekanbaru as the capital of Riau province has a variety of art that is steeped in Malay culture, is one of the artistic diversity in creating the famous batik art batik wither. Keywords: Protection, Law, Baik Ria

Pertumbuhan Bibit Generasi M-1 Tanaman Padi Gogo (Oryza Sativa L.) Varietas Lokal dengan Perlakuan Mutagen Ethyl Methane Sulfonate (Ems)

This study aimes of determine the effect of mutagen Ethyl Methane Sulfonate (EMS) on upland local rice (Oryza sativa L.) varieties at generation M-1. This research has been carried out at the Department of Agrotechnology Greenhouse, Faculty of Agriculture, University of Riau, in November to December 2013. The research used factorial Completely Randomized Design consisting of two factors, namely two local rice varieties and five concentrations of mutagens EMS and four replications. The mean deviation between treatments tested by Duncan New Multiple Range Test (DNMRT) at the level of 5%. Parameters observed were time of first tiller appeared, lamina length, midrib length, seedling height, number of leaves, number of tillers, number of life seedling, the number of variegate seedling. Results indicated that the mutagen EMS at a concentration of 1%, reduced the number of first seedling appear, decreasing plant height, number of tillers and total life seeds

Eastern Ghats tragedy: If the mines don’t get them… the dams will

“We hunt the leopard. I can show you how we track them too,” said the Konda Reddi tribal villager. We were at Villarthi village, in a remote forested stretch between the towns of Upper Sileru and Donkarayi in the northern Eastern Ghats of Andhra Pradesh’s Visakhapatnam district. Across the border lay Odisha. Historically this region supported a rich floral diversity, but in recent decades the Eastern Ghats have largely been ignored in favour of other hill regions across India. The rediscovery of the Indian golden gecko Calodactylodes aureus and the Jeypore ground gecko Geckoella jeyporensis, earlier presumed locally extinct has caused some resurgence of public interest, but not enough to make a significant difference. Several researchers have begun to study the faunal diversity of this incredible region, but the hazards confronting this landscape seem almost insurmountable

Efektivitas Pembelajaran Daring di Masa Pandemi COVID 19 Bagi Mahasiswa Universitas PGRI Yogyakarta

Wabah Corona membuat segala hal mengalami perubahan rutinitas, termasuk dalam hal pendidikan. Dulu pembelajaran di perguruan tinggi dilaksanakan secara tatap muka, akan tetapi sekarang pembelajaran harus dilaksanakan secara online. Tujuan penelitian ini adalah untuk mengetahui seberapa besar efektivitas pembelajaran secara daring dimasa pandemi covid 19 bagi mahasiswa Universitas PGRI Yogyakarta. Penelitian ini menggunakan model Kuantitatif dengan metode survei. Responden dari penelitian ini berjumlah 1.000 mahasiswa. Hasil penelitian ini menunjukan bahwa 79% mahasiswa menginginkan pembelajaran secara tatap muka, sedangkan hanya 1% saja mahasiswa yang menginginkan pembelajaran daring, sehingga dapat disimpulkan bahwa pembelajaran daring secara terus menerus selama masa pandemi ini sangat tidak efekti

Peningkatan Keaktifan Belajar Melalui Penerapan Model Picture And Picture Dalam Pembelajaran PPKn Di Sekolah Dasar

Keaktifan belajar siswa yang kurang terutama pada pembelajaran di Sekolah Dasar masih menjadi masalah yang sering terjadi. Diperlukan model pembelajaran interaktif yang harus digunakan oleh guru agar keaktifan belajar siswa semakin membaik. Tujuan penelitian ini adalah untuk mengetahui peningkatan keaktifan belajar pada pembelajaran Pendidikan Pancasila dan Kewarganegaraan di Sekolah Dasar Negeri 1 Kasihan Bantul Yogyakarta melalui penerapan model pembelajaran picture and Picture. Jenis penelitian ini adalah Penelitian Tindakan Kelas yang dilaksanakan sebanyak dua siklus. Penelitian ini diterapkan pada siswa kelas V yang berjumlah 30 orang dengan empat tahapan, yakni tahap perencanaan, tahap pelaksanaan, observasi, dan refleksi. Teknik pengumpulan data melalui observasi, wawancara, dan dokumentasi. Hasil penelitian menunjukan peningkatan keaktifan belajar siswa dalam pembelajaran Pendidikan Pancasila dan Kewarganegaraan melalui model Picture and Picture. Diperoleh data pada siklus I keaktifan belajar siswa masuk kategori sedang dan siklus II masuk kategori tinggi. Peningkatan keaktifan siswa juga tergambar melalui minat dan motivasi belajar, perhatian dan fokus pada materi ajar, presensi kehadiran siswa, dan partisipasi dalam tanya jawa

Variational deep learning of equilibrium transition path ensembles

We present a time dependent variational method to learn the mechanisms of equilibrium reactive processes and efficiently evaluate their rates within a transition path ensemble. This approach builds off variational path sampling methodology by approximating the time dependent commitment probability within a neural network ansatz. The reaction mechanisms inferred through this approach are elucidated by a novel decomposition of the rate in terms of the components of a stochastic path action conditioned on a transition. This decomposition affords an ability to resolve the typical contribution of each reactive mode and their couplings to the rare event. The associated rate evaluation is variational and systematically improvable through the development of a cumulant expansion. We demonstrate this method in both over- and under-damped stochastic equations of motion, in low-dimensional model systems and the isomerization of solvated alanine dipeptide. In all examples, we find that we can obtain quantitatively accurate estimates of the rates of the reactive events with minimal trajectory statistics, and gain unique insight into the transitions through the analysis of their commitment probability