Label optimal regret bounds for online local learning

We resolve an open question from (Christiano, 2014b) posed in COLT'14 regarding the optimal dependency of the regret achievable for online local learning on the size of the label set. In this framework the algorithm is shown a pair of items at each step, chosen from a set of $n$ items. The learner then predicts a label for each item, from a label set of size $L$ and receives a real valued payoff. This is a natural framework which captures many interesting scenarios such as collaborative filtering, online gambling, and online max cut among others. (Christiano, 2014a) designed an efficient online learning algorithm for this problem achieving a regret of $O(\sqrt{nL^3T})$, where $T$ is the number of rounds. Information theoretically, one can achieve a regret of $O(\sqrt{n \log L T})$. One of the main open questions left in this framework concerns closing the above gap. In this work, we provide a complete answer to the question above via two main results. We show, via a tighter analysis, that the semi-definite programming based algorithm of (Christiano, 2014a), in fact achieves a regret of $O(\sqrt{nLT})$. Second, we show a matching computational lower bound. Namely, we show that a polynomial time algorithm for online local learning with lower regret would imply a polynomial time algorithm for the planted clique problem which is widely believed to be hard. We prove a similar hardness result under a related conjecture concerning planted dense subgraphs that we put forth. Unlike planted clique, the planted dense subgraph problem does not have any known quasi-polynomial time algorithms. Computational lower bounds for online learning are relatively rare, and we hope that the ideas developed in this work will lead to lower bounds for other online learning scenarios as well.Comment: 13 pages; Changes from previous version: small changes to proofs of Theorems 1 & 2, a small rewrite of introduction as well (this version is the same as camera-ready copy in COLT '15

Photolytic Hazes in the Atmosphere of 51 Eri b

We use a 1D model to address photochemistry and possible haze formation in the irradiated warm Jupiter, 51 Eridani b. The intended focus was to be carbon, but sulfur photochemistry turns out to be important. The case for organic photochemical hazes is intriguing but falls short of being compelling. If organic hazes form, they are likeliest to do so if vertical mixing in 51 Eri b is weaker than in Jupiter, and they would be found below the altitudes where methane and water are photolyzed. The more novel result is that photochemistry turns H$_2$S into elemental sulfur, here treated as S$_8$. In the cooler models, S$_8$ is predicted to condense in optically thick clouds of solid sulfur particles, whilst in the warmer models S$_8$ remains a vapor along with several other sulfur allotropes that are both visually striking and potentially observable. For 51 Eri b, the division between models with and without condensed sulfur is at an effective temperature of 700 K, which is within error its actual effective temperature; the local temperature where sulfur condenses is between 280 and 320 K. The sulfur photochemistry we have discussed is quite general and ought to be found in a wide variety of worlds over a broad temperature range, both colder and hotter than the 650-750 K range studied here, and we show that products of sulfur photochemistry will be nearly as abundant on planets where the UV irradiation is orders of magnitude weaker than it is on 51 Eri b.Comment: 24 pages including 11 figures and a tabl

Analisis Aktor Sosial dalam Reportase Mencari Keadilan bagi Korban Kekerasan Seksual di Project Multatuli

Penelitian ini bertujuan untuk mengetahui bagaimana aktor-aktor sosial ditulis dalam reportase tentang perjuangan seorang Ibu dalam mencari keadilan bagi anak-anaknya yang diperkosa yang ditulis oleh Project Multatuli. Reportase tersebut mengundang perhatian publik yang dampaknya adalah dibukanya kembali kasus tersebut oleh kepolisian yang sebelumnya dihentikan pada 2019. Namun, terdapat salah satu pihak, yaitu pihak pelaku yang keberatan dengan isi reportase tersebut dan menggugat reportase tersebut ke Polisi sebagai pencemaran nama baik. Dalam penulisan jurnalistik secara umum, pihak-pihak yang dihadirkan dalam suatu reportase harus berimbang. Apakah prinsip tersebut juga penting dihadirkan pada reportase tentang perjuangan yang melibatkan korban kekerasan seksual?. Penelitian ini menggunakan paradigma kritis dengan metode penelitian kualitatif, menggunakan teori dan teknik analisis wacana kritis model Theo Van Leeuwen, yaitu pendekatan aktor sosial untuk mengetahui bagaimana sebuah kelompok atau pihak ditampilkan atau disembunyikan. Hasil penelitian menunujukan, Project Multatuli dalam reportasenya menghadirkan Ibu Lydia sebagai aktor sosial yang berjuang untuk mendapatkan keadilan untuk ketiga anaknya yang merupakan korban kekerasan seksual. Pihak-pihak pelaku juga dihadirkan dengan ditampilkan dengan ciri fisik, anak kalimat, dan kategori pekerjaan secara tidak begitu gamblang atau abstrak. Terdapat aktor sosial yang dihilangkan yaitu pihak kepolisian yang dalam reportase ini ditulis medukung pelaku. Kehadiran aktor sosial yaitu Ibu Lydia bertujuan untuk menunjukan perjuangannya dalam memperoleh keadilan untuk anak-anaknya. Sedangkan, pihak pelaku ditampilkan dengan tujuan menunjukan bahwa kasus kekerasan seksual ini juga berkaitan dengan adanya ketidakadilan, ketimpangan, dominasi, dan relasi kuasa. Penghilangan salah satu aktor sosial ini menunjukan bahwa Project Multatuli berusaha untuk memfokuskan reportase pada pihak korban dengan tujuan agar kasus kekerasan seksual tersebut dibuka kembali oleh kepolisian dengan penanganan yang baik. Penelitian ini menemukan bahwa Project Multatuli menerapkan jurnalisme sensitif gender dengan menjadikan Ibu Lydia sebagai objek dalam pemberitaan untuk bercerita. Dalam pemberitaan tentang kekerasan seksual tidak ada urgensi untuk menampilkan pihak pelaku dalam reportase tersebut selama memperhatikan kode etik dan pedoman dalam penulisan tentang kekerasan seksual di media. Kata kunci: Aktor sosial, Media alternatif, Project Multatuli, Kasus Pemerkosaan Luwu Timur. / This study aims to find out how social actors are written in the reportage about a mother's struggle in seeking justice for children written by Project Multatuli. The reportage attracted public attention that the police had reopened these cases, which were previously stopped in 2019. However, there was one party, namely the perpetrator who was the police with the contents of the report and sued the reportage as a good name. In journalistic writing in general, the parties presented in a report must be balanced. Are these principles also important to be presented in reporting on struggles involving victims of sexual violence? This study uses a critical paradigm with qualitative research methods, using theory and techniques of critical analysis model Theo Van Leeuwen, namely the approach of social actors to find out how a group or party is presented or. The results of the study show that Project Multatuli in its report presents Mrs. Lydia as a social actor who struggles to get justice for her three children who are victims of sexual violence. The actors are also presented with physical characteristics, clauses, and job categories that are not so obvious or abstract. There is a social actor that has been omitted, namely the police, which in this report it is written that the actors support it. The presence of a social actor, Mrs. Lydia, aims to show her struggle in obtaining justice for children. Meanwhile, the parties presented with the aim of showing that this sexual violence case is also related to injustice, treatment, and power relations. The disappearance of one of these social actors shows that Project Multatuli was handled to focus on the victim's report with the aim that the violent case was reopened by the police properly. This study finds that Project Multatuli applies gender sensitive journalism by making Mrs. Lydia the object of the news to tell stories. In reporting on sexual violence, there is no urgency to present the perpetrators in the report as long as they pay attention to the code of ethics and guidelines in writing about sexual violence in the media. Keywords: Social actor, Alternative media, Project Multatuli, East Luwu Rape Cas

Understanding the Atmosphere of 51 Eri b: Do Photochemical Hazes Cloud the Planets Spectrum?

The first young giant planet to be discovered by the Gemini Planet Imager was the (is) approximately 2MJ planet 51 Eri b. This approximately 20 Myr old young Jupiter is the first directly imaged planet to show unmistakable methane in H band. To constrain the planet's mass, atmospheric temperature, and composition, the GPI J and H band spectra as well as some limited photometric points were compared to the predictions of substellar atmosphere models. The best fitting models reported in the discovery paper (Macintosh et al. 2015) relied upon a combination of clear and cloudy atmospheric columns to reproduce the data. However for an object as cool as 700 K, the origin of the cloud coverage is somewhat puzzling, as the global silicate and iron clouds would be expected to have sunk well below the photosphere by this effective temperature. While strong vertical mixing in these low gravity atmospheres remains a plausible explanation, we have explored whether atmospheric photochemistry, driven by the UV flux from the primary star, may yield hazes that also influence the observed spectrum of the planet. To explore this possibility we have modeled the atmospheric photochemistry of 51 Eri b using two state-of-the-art photochemical models, both capable of predicting yields of complex hydrocarbons under various atmospheric conditions. In our presentation we will summarize the modeling approach employed to characterize 51 Eri b, explaining constraints on the planet's effective temperature, gravity, and atmospheric composition and also present results of our studies of atmospheric photochemistry. We will discuss whether photochemical hazes could indeed be responsible for the particulate opacity that apparently sculpts the spectrum of the planet

Tunica Adventitia of the Aorta is an Active Vascular Compartment

The tunica adventitia has previously been regarded as a passive connective tissue covering that offers only nutritive and physical support to the arterial wall. Recently, however, emphasis has been given to its role in atherosclerosis. Although the normal structure may bear the anatomical basis of these functions, microscopic anatomy of the tunica adventitia in normal arteries is seldom reported. These data are important in understanding disease process and potential areas of intervention. The goat is a suitable model for studying cardiovascular disease and the aorta is frequently afflicted by atherosclerosis. This study, therefore, aimed at describing the structure of tunica adventitia of normal aorta in goat. Materials for the study were obtained from abdominal aorta of 6 healthy young adult male goats (capra hircus) age range 12 – 24 months. Fresh specimens from euthanized animals were fixed in 3% phosphate buffered glutaraldehyde, post fixed in 1% phosphate buffered osmium tetroxide then embedded in durcupan. Ultrathin sections were stained with uranyl acetate counterstained with lead citrate and examined with electron microscope. Some specimens were processed routinely for paraffin embedding and sectioning. They were stained with Mason’s Trichrome and Weigert elastic/Van Gieson stains. The tunica adventitia was fibroelastic with numerous capillaries, arterioles and multiple cell types. The cells were active fibroblasts, phagocytic, perivascular and endothelial cells embedded in the fibrous stroma. These findings suggest that the tunica adventitia of the goat aorta is a metabolically active vascular compartment. These features namely microvasculature and multiple cell populations probably enable it to maintain structural and functional integrity and appropriately respond to vascular injury.Keywords: Tunica Adventitia, cells, Capillaries, Arterioles, Atherosclerosi

Reappraisal of the structure of arterial Tunica adventitia and its involvement in atherosclerosis

Tunica adventitia was previously considered an inert fibrous layer only involved in nutritional and physical support of the arterial wall. Recent studies reveal that it is an important dynamic layer actively involved in the regulation of vascular structure, function, response to injury and disease processes especially atherosclerosis. Many anatomical studies on arteries, however, still make only peripheral reference to it, without elucidating its detailed structure. Knowledge of the latter is important in understanding pathobiology and interventional approaches to atherosclerosis. This review, therefore, aims at consolidating contemporary literature on the structure and clinical significance of the arterial tunica adventitia. Google literature search was done using the key words tunica adventitia combined with: artery, aorta, cells, cell types, collagen, elastic fibres, vasa vasora, lymphatics, nerves, atherosclerosis. There is overwhelming evidence that the tunica adventitia comprises multiple types of collagen and elastic fibres arranged in various directions, a wide variety of cells including fibroblasts, smooth muscle, pericytes,  myofibroblasts, leukocytes, mononuclear phagocytic, defence, mesenchymal stem and mast cells; vasa vasora including  microvasculature, lymphatics and neural elements. The exact cellular, fibre composition and orientation vary between various arteries and regions of the same vessel. Its components are involved in the initiation, progression and complications of  atherosclerosis. In conclusion, the tunica adventitia is an active dynamic layer which, besides mechanical and nutritive  functions; has metabolic, regulatory and defence roles that are critical in arterial homeostasis and  atherosclerosis. Vascular studies should always include detailed analysis of the biology of the tunica adventitia.Key words: Tunica adventitia, cells, fibres, vessels, nerves, atherosclerosi

PENGARUH PROFITABILITAS DAN KOMPENSASI RUGI FISKAL TERHADAP PENGHINDARAN PAJAK PADA PERUSAHAAN INDUSTRI BARANG KONSUMSI YANG TERDAFTAR DI BEI PERIODE 2019-2021

ABSTRAK Tujuan penulisan penelitian untuk mengetahui pengaruh apa yang diberikan oleh variabel profitabilitas dan kompensasi rugi fiskal terhadap penghindaran pajak. Populasi yang digunakan pada penelitian ini adalah perusahaan industri barang konsumsi yang terdaftar pada Bursa Efek Indonesia tahun 2019-2021. Menggunakan purposive sampling sebagai kriteria pengumpulan data, dengan total 18 perusahaan yang berisi 51 data. Menggunakan regresi linear dalam melakukan pengujian data menggunakan SPSS 26. Hasil yang ditunjukkan adalah profitabilitas menunjukkan hasil yang tidak signifiakan terhadap tax avoidance, dan kompensasi rugi fiskal menunjukkan hasil yang signifikan terhadap tax avoidance.   Kata Kunci : Penghindaran Pajak, Kompensasi Rugi Fiskal dan Profitabilita