μ-Oxido-bis­[bis­(penta­fluoro­phenolato)(η5-penta­methyl­cyclo­penta­dien­yl)titanium(IV)]

The dinuclear title complex, [Ti2(C10H15)2(C6F5O)4O], features two TiIV atoms bridged by an O atom, which lies on an inversion centre. The TiIV atom is bonded to a η5-penta­methyl­cyclo­penta­dienyl ring, two penta­fluoro­phenolate anions and to the bridging O atom. The environment around the TiIV atom can be considered as a distorted tetra­hedron. The cyclo­penta­dienyl ring is disordered over two sets of sites [site occupancy = 0.824 (8) for the major component]

DSTEA: Improving Dialogue State Tracking via Entity Adaptive Pre-training

Dialogue State Tracking (DST) is critical for comprehensively interpreting user and system utterances, thereby forming the cornerstone of efficient dialogue systems. Despite past research efforts focused on enhancing DST performance through alterations to the model structure or integrating additional features like graph relations, they often require additional pre-training with external dialogue corpora. In this study, we propose DSTEA, improving Dialogue State Tracking via Entity Adaptive pre-training, which can enhance the encoder through by intensively training key entities in dialogue utterances. DSTEA identifies these pivotal entities from input dialogues utilizing four different methods: ontology information, named-entity recognition, the spaCy, and the flair library. Subsequently, it employs selective knowledge masking to train the model effectively. Remarkably, DSTEA only requires pre-training without the direct infusion of extra knowledge into the DST model. This approach resulted in substantial performance improvements of four robust DST models on MultiWOZ 2.0, 2.1, and 2.2, with joint goal accuracy witnessing an increase of up to 2.69% (from 52.41% to 55.10%). Further validation of DSTEA's efficacy was provided through comparative experiments considering various entity types and different entity adaptive pre-training configurations such as masking strategy and masking rate

Snake Robot with Driving Assistant Mechanism

Snake robots are composed of multiple links and joints and have a high degree of freedom. They can perform various motions and can overcome various terrains. Snake robots need additional driving algorithms and sensors that acquire terrain data in order to overcome rough terrains such as grasslands and slopes. In this study, we propose a driving assistant mechanism (DAM), which assists locomotion without additional driving algorithms and sensors. In this paper, we confirmed that the DAM prevents a roll down on a slope and increases the locomotion speed through dynamic simulation and experiments. It was possible to overcome grasslands and a 27 degrees slope without using additional driving controllers. In conclusion, we expect that a snake robot can conduct a wide range of missions well, such as exploring disaster sites and rough terrain, by using the proposed mechanism. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. T.1

Bis(μ-trimethyl­silanolato-κ2 O:O)bis­{[2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentyl­phenolato-κ2 N,O]zinc}

The binuclear title complex, [Zn2(C22H28N3O)2(C3H9OSi)2], has a crystallographic imposed centre of symmetry. The ZnII atom is coordinated by three O and one N atom from one 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentyl­phenolate ligand and two bridging trimethyl­silanolate anions in a distorted tetra­hedral geometry. The dihedral angle between the benzotriazole ring system and the benzene ring is 19.83 (5)°. The tert-pentyl groups are disordered over two orientations with refined site-occupancy ratios of 0.858 (4):0.142 (4) and 0.665 (6):0.335 (6)

Empirical Approaches for Improving Inertial Pedestrian Navigation: Approximating Gravitational Acceleration and Digitizing Heading Change Angles

Spatial mobility provides a rich context for human life, and the demand for indoor navigation and localization has increased. Pedestrian dead reckoning (PDR) is a viable solution thanks to its cost advantages and robustness to environmental changes. In this paper, we propose two generic ideas for improving inertial pedestrian navigation. One is about the estimation of gravitational acceleration and the other is about the estimation of heading change angles. Gravitational acceleration is dynamically extracted on the fly rather than assuming sensors to be fixed in a certain orientation. It can be used to estimate step lengths and heading change angles as a baseline. Also, heading change angles are digitized by combining the estimated gravitational acceleration with a simple threshold-based turn detection algorithm. Turns tend to occur across multiple steps and we separate turns from steps in walking. To demonstrate the effectiveness of the ideas a simple scheme, steps-and-a-turn (SnT), is designed for inertial pedestrian navigation. In experiments using a complete daily route, we show that the estimation of gravitational acceleration is consistent and robust, and that the digitization of heading change angles is highly effective in typical building environments: the positioning error is about 1.2% of the total length of the experimental path. Various state-of-the-art schemes served on top of pure inertial pedestrian navigation are expected to benefit by utilizing the proposed ideas as basic building blocks

Feature-First Add-On for Trajectory Simplification in Lifelog Applications

Lifelog is a record of one’s personal experiences in daily lives. User’s location is one of the most common information for logging a human’s life. By understanding one’s spatial mobility we can figure out other pieces of context such as businesses and activities. With GPS technology we can collect accurate spatial and temporal details of a movement. However, most GPS receivers generate a huge amount of data making it difficult to process and store such data. In this paper, we develop a generic add-on algorithm, feature-first trajectory simplification, to simplify trajectory data in lifelog applications. It is based on a simple sliding window mechanism counting occurrence of certain conditions. By automatically identifying feature points such as signal lost and found, stall, and turn, the proposed scheme provides rich context more than spatio-temporal information of a trajectory. In experiments with a case study of commuting in personal vehicles, we evaluate the effectiveness of the scheme. We find the proposed scheme significantly enhances existing simplification algorithms preserving much richer context of a trajectory

A Block-based 3D Map: a Crude Sketch of Steric Environment

A 3D map provides useful information for various services. Traditional 3D maps, however, consist of a raw image data and are not suitable for real-time applications. In this paper, we propose a block-based 3D map, which forms three dimensional spaces in a collection of cubic blocks. The block-based 3D map has two major parameters: an object ratio and a block size. The object ratio is defined as the rate of object pixels to air-filled pixels within a block and determines the type of a block. The block size determines actual length of the side of a cubic block and is a matter of resolution and focal distance of images. Experimental results show benefits of the block-based 3D map in reducing sensitivity to noise and in saving amounts of data to be processed. Block-based 3D maps would support a variety of new services by providing additional information to image data in intelligent real-time applications

2,8,9-Tris(2-methylpropyl)-2,5,8,9-tetraaza-1λ5-phosphatricyclo[3.3.3.01,5]undecan-5-ium chloride dihydrate

The asymmetric unit of the title hydrated salt, C18H40N4P+·Cl−·2H2O, consists of two ionic molecules and four water molecules. The molecular geometry around the pentacoordinate P atom is trigonal–bipyramidal, with a H atom and an apical N atom in axial positions and three N atoms with isobutyl substituents in equatorial positions. The Cl− ions and water molecules are connected via O—H...Cl hydrogen bonds, forming chains along [100]. The ethylene bridging groups are disordered with refined site-occupancy ratios of 0.578 (9):0.422 (9)

2-Benzhydryl-6-tert-butyl-4-methylphenol

The title compound, C24H26O, was prepared by the reaction between 2-tert-butyl-4-methylphenol and diphenylmethanol in the presence of sulfuric acid. Three benzene rings are attached directly to the central C—H group in a twisted propeller conformation with the local pseudo-C3 rotational axis coinciding with the C—H bond. There are three short C—H...O contacts in the molecule