Deep Clustering with Self-supervision using Pairwise Data Similarities

Deep clustering incorporates embedding into clustering to find a lower-dimensional space appropriate for clustering. Most of the existing methods try to group similar data points through simultaneously minimizing clustering and reconstruction losses, employing an autoencoder (AE). However, they all ignore the relevant useful information available within pairwise data relationships. In this paper we propose a novel deep clustering framework with self-supervision using pairwise data similarities (DCSS). The proposed method consists of two successive phases. First, we propose a novel AE-based approach that aims to aggregate similar data points near a common group center in the latent space of an AE. The AE's latent space is obtained by minimizing weighted reconstruction and centering losses of data points, where weights are defined based on similarity of data points and group centers. In the second phase, we map the AE's latent space, using a fully connected network MNet, onto a K-dimensional space used to derive the final data cluster assignments, where K is the number of clusters. MNet is trained to strengthen (weaken) similarity of similar (dissimilar) samples. Experimental results on multiple benchmark datasets demonstrate the effectiveness of DCSS for data clustering and as a general framework for boosting up state-of-the-art clustering methods.

Deep Clustering with Self-supervision using Pairwise Data Similarities

Deep clustering incorporates embedding into clustering to find a lower-dimensional space appropriate for clustering. Most of the existing methods try to group similar data points through simultaneously minimizing clustering and reconstruction losses, employing an autoencoder (AE). However, they all ignore the relevant useful information available within pairwise data relationships. In this paper we propose a novel deep clustering framework with self-supervision using pairwise data similarities (DCSS). The proposed method consists of two successive phases. First, we propose a novel AE-based approach that aims to aggregate similar data points near a common group center in the latent space of an AE. The AE's latent space is obtained by minimizing weighted reconstruction and centering losses of data points, where weights are defined based on similarity of data points and group centers. In the second phase, we map the AE's latent space, using a fully connected network MNet, onto a K-dimensional space used to derive the final data cluster assignments, where K is the number of clusters. MNet is trained to strengthen (weaken) similarity of similar (dissimilar) samples. Experimental results on multiple benchmark datasets demonstrate the effectiveness of DCSS for data clustering and as a general framework for boosting up state-of-the-art clustering methods.

Group-walking effect on bidirectional pedestrian flow in a corridor

Groups are commonly found in general crowds and their behaviors are distinguished from that of isolated pedestrians. Thus, in recent five years researchers have started to investigate pedestrian group movement. In this paper, we considered group walking effect and introduced group floor field to the traditional floor field model. Furthermore, two different methods of generating group floor field were put forward, i.e. group center generation (method 1 for short) and group leader generation (method 2 for short), and we applied the proposed group model to simulate bidirectional pedestrian flow in a corridor. No matter which method of generating group floor field is adopted, the simulation results show that group members walk slower than singles, and with the group size increasing the transition point from the free flow phase to the jamming has a decrease trend. In addition, it seems that method 2 of generating group floor field makes group more cohesive and stable at the same crowd density than method 1. Afterwards it is found that the crowd with large group size is more easily affected by asymmetric injection rate. At last, people’s walking preference is shortly discussed, and it is obtained that people’s walking preference is also good for group movement from the perspective of movement efficiency.

Popular Music, the Devil, and Aerobics

This chapter advances the argument of Sonic Overload by turning to the interactions between art and popular music in Schnittke’s Symphony No. 1, Requiem (1975), Concerto Grosso No. 1 (1977), Piano Concerto (1979), Symphony no. 3 (1976–81), and Faust Cantata (Seid nüchtern und wachet, 1983), as well as several of his film scores. It considers for the first time Schnittke’s ongoing negotiations between high and low across his entire career, giving careful scrutiny to his declaration in the late 1980s that “pop culture is a good disguise for any kind of devilry.” Schnittke’s change of heart, from embracing popular music—and specifically jazz and rock—from the late 1960s through the 1970s, to expressing grave concerns about its effects a decade later, mirrored the sentiments of many. In the turbulent final years of the Soviet Union, rock supplanted poetry as the conscience of the nation yet it still inspired deep anxiety among those embracing traditional Soviet conceptions of being “cultured.” Schnittke’s apprehensions about popular music in the 1980s stemmed from its growing presence in the fragmented late-Soviet soundscape and its growing prestige among newly influential tastemakers, chief among them younger intellectuals and other cultural figures. The elevation of pop music in the USSR (as in the West) expanded a growing generational divide. Schnittke’s own rejection of popular music seems to have been instigated in part by his son, Andrey, who in the early 1980s was a member of the noted Moscow rock group Center (Tsentr), a fact overlooked by previous scholars.

Prague, the Victorious May of 1945

The article deals with complex and controversial issues related to the uprising and liberation of Prague in May 1945. Interpretation of the events became acute and caused lively discussions in connection with the demolition of the monument to Marshal I. V. Konev on April 3, 2020 by the order of the local municipality. The Czech Republic is also discussing the idea of «perpetuating the role of other liberators» of the capital – soldiers of the ROA division, which for two days (May 6-7) provided assistance to the rebels. Using new documents from the Central archive of the Ministry of defense of the Russian Federation, the author draws a conclusion about the limited influence of the Vlasov units. They, indeed, brought confusion to the German ranks, but early in the morning of May 8, they themselves left Prague on a rapid march. After that, fighting and negotiations between the rebels and the German command continued. The article emphasizes that the main goal of the Soviet military operation from 6 to 11 May 1945 was the defeat of the German Army Group Center. The liberation of Prague was only part of a powerful offensive by three Soviet fronts. Heavy battles for Prague did not happen, but the entry of Soviet tanks into the Czech capital and the subsequent jubilation of local residents became a symbol of the end of the war in Europe. The author concludes that the demolition of monuments to Soviet soldiers and commanders is a manifestation of internal political struggle in the countries where it occurs, and the Czech Republic is only one of these examples.

Activation and Functionalization of C–C σ-Bonds of Alkylidene Cyclopropanes at Main Group Centers

Aluminum(I) and magnesium(I) compounds are reported for the C–C s-bond activation of strained alkylidene cyclopropanes. These reactions result in the formal addition of the C–C s-bond to main group center either at a single site (Al) or across a metal–metal bond (Mg–Mg). Mechanistic studies suggest that rather than occurring by a concerted oxidative addition, these reactions involve stepwise processes in which substrate binding to the main group metal acts as a precursor to a- or b-alkyl migration steps that break the C–C s-bond. This mechanistic understanding is used to develop the magnesium-catalyzed hydrosilylation of the C–C s-bonds of alkylidene cyclopropanes.

Activation and Functionalization of C–C σ-Bonds of Alkylidene Cyclopropanes at Main Group Centers

Aluminum(I) and magnesium(I) compounds are reported for the C–C s-bond activation of strained alkylidene cyclopropanes. These reactions result in the formal addition of the C–C s-bond to main group center either at a single site (Al) or across a metal–metal bond (Mg–Mg). Mechanistic studies suggest that rather than occurring by a concerted oxidative addition, these reactions involve stepwise processes in which substrate binding to the main group metal acts as a precursor to a- or b-alkyl migration steps that break the C–C s-bond. This mechanistic understanding is used to develop the magnesium-catalyzed hydrosilylation of the C–C s-bonds of alkylidene cyclopropanes.

Activation and Functionalization of C–C σ-Bonds of Alkylidene Cyclopropanes at Main Group Centers

Aluminum(I) and magnesium(I) compounds are reported for the C–C s-bond activation of strained alkylidene cyclopropanes. These reactions result in the formal addition of the C–C s-bond to main group center either at a single site (Al) or across a metal–metal bond (Mg–Mg). Mechanistic studies suggest that rather than occurring by a concerted oxidative addition, these reactions involve stepwise processes in which substrate binding to the main group metal acts as a precursor to a- or b-alkyl migration steps that break the C–C s-bond. This mechanistic understanding is used to develop the magnesium-catalyzed hydrosilylation of the C–C s-bonds of alkylidene cyclopropanes.

KAJIAN METODE FUZZY K-RATAAN DAN FUZZY K-MEDOIDS (STUDI KASUS: PENGELOMPOKAN DESA DI KABUPATEN SORONG TAHUN 2016 BERDASARKAN STATUS KETERTINGGALAN)

The developments research in the cluster analysis using the fuzzy method. The fuzzy method allocates to each group with membership value located at interval [0, 1], showing the magnitude of the possibility of an object being a member into a particular group. Outlier in data very important known before grouping, because affect the final result. Grouping by using the mean value as the center of the group will be more sensitive than using the median value, so this research applies fuzzy c-means and fuzzy c-medoid method to the grouping of villages in Sorong Regency Year 2016 based on the underdevelopment status and examine the goodness of both methods. There are 23.2% of villages that do not change when done grouping with both methods. Overall average distance of group center object and varians in the resulting group the two methods are the same, the varins between groups of fuzzy c-means is greater than the fuzzy c-medoid method.

Rationale for Small Glenoid Baseplate: Position of Central Cage within Glenoid Vault (Exactech® Equinoxe® Reverse System)

Background: Glenoid baseplate location is important to good clinical outcomes of reverse total shoulder arthroplasty (RTSA). The glenoid vault is the determining factor for glenoid baseplate location, but, to date, there are no reports on the effect of central cage location within the glenoid vault on RTSA outcomes when using the Exactech^® Equinoxe^® Reverse System. The purpose of this study was to determine the appropriate cage location in relation to the glenoid vault and monitor for vault and/or cortex penetration by the cage.Methods: Data were retrospectively collected from the Samsung Medical Center (SMC) and Seoul National University Bundang Hospital (SNUBH). Patients who underwent RTSA between November 2016 and February 2018 were enrolled. Glenoid vault depth, central cage location within the vault were examined. Inferior glenoid rim?center distance, inferior glenoid rim?cage distance, and center?cage center distances were collected.Results: Twenty-two patients were enrolled. Three SNUBH patients had inappropriate central cage fixation (33.3%) versus 4 SMC patients (30.8%). All cage exposures were superior and posterior to the glenoid vault. Mean center?cage distance was 5.0 mm in the SNUBH group and 5.21 mm in the SMC group. Center?prosthesis distance was significantly longer in the inappropriate fixation group than in the appropriate fixation group (<i>p</i><0.024).Conclusions: To ensure appropriate glenoid baseplate fixation within the glenoid vault, especially in a small glenoid, the surgeon should place the cage lower than usually targeted, and it should overhang the inferior glenoid rim.