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We herein report a unique example of on-surface adaptive self-assembly. A pentagon-shaped macrocycle, cyclic [5]meta-phenyleneacetylene [5]CMPA, is trapped by the adaptive supramolecular network formed by an isosceles triangular molecule, alkoxy substituted dehydrobenzo[14]annulene [14]ISODBA at the liquid/graphite interface, leading to a highly ordered and large-area bicomponent self-assembled molecular network (SAMN), as revealed by scanning tunneling microscopy (STM).

The dianion and dication of tetramesityl-substituted tetracyclopentatetraphenylene, a circulene consisting of alternating five- and six-membered rings, have been generated by reduction with alkali metals and oxidation with antimony(V) halides, respectively. They are theoretically predicted to adopt double annulenoid structures called annulene-within-an-annulene models in which the outer and inner conjugation circuits are significantly decoupled. The theoretical structures were experimentally proven by X-ray crystallographic analyses and the electronic configurations were supported by MCD spectra. Based on the

Self-sorting of multiple building blocks for correctly positioning molecules through orthogonal recognition is a promising strategy for construction of a hierarchical self-assembled molecular network (SAMN) on a surface. Herein we report that a trigonal molecule, dehydrobenzo[12]annulene (DBA) derivative having three tetradecyloxy chains and three hydroxy groups in an alternating manner, forms hierarchical triangular clusters of different sizes ranging from 2.4 to 16.4 nm, consisting of 3 to 78 molecules, respectively, at the liquid/graphite interface. The key is the dynamic combination of three different conformational states, which is solvent and concentration dependent. The present knowledge extends design strategies for production of sophisticated hierarchical SAMNs using a single component at the liquid/solid interface., Self-sorting of multiple building blocks for correctly positioning molecules through orthogonal recognition is a promising strategy for construction of a hierarchical self-assembled molecular network (SAMN) on a surface.

This paper deals with map-construction problems for visual localization. Basically, the map is an aggregation of visual landmarks, and it is desirable that such landmarks exist densely and permanen...

Chiral structures created through the adsorption of molecules onto achiral surfaces play pivotal roles in many fields of science and engineering. Here, we present a systematic study of a novel chiral phenomenon on a surface in terms of organizational chirality, that is, meso-isomerism, through coverage-driven hierarchical polymorphic transitions of supramolecular assemblies of highly symmetric π-conjugated molecules. Four coverage-dependent phases of dehydrobenzo[12]annulene were uniformly fabricated on Ag(111), exhibiting unique chiral characteristics from the single-molecule level to two-dimensional supramolecular assemblies. All coverage-driven phase transitions stem from adsorption-induced pseudo-diastereomerism, and our observation of a lemniscate-type (∞) supramolecular configuration clearly reveals a drastic chiral phase transition from an enantiomeric chiral domain to a meso-isomeric achiral domain. These findings provide new insights into controlling two-dimensional chiral architectures on surfaces.

Scanning tunnelling microscope observations at the 1-phenyloctane/graphite interface reveal how chiral structural information at the molecular level is transferred and expressed structurally at the 2D supramolecular level for a porous system. The chirality of self-assembled molecular networks formed by chiral dehydrobenzo[12]annulene (cDBA) derivatives having three chiral chains and three achiral chains, alternatingly, is compared with those of cDBAs having six chiral chains reported previously. While for all cDBAs homochiral surfaces are formed, their handedness is not simply a reflection of the absolute configuration of the stereogenic centres. Both the number of stereogenic centres as well as the length of the achiral chains determine the supramolecular handedness, providing a deep insight into the supramolecular chirality induction mechanisms at play. Moreover, these cDBAs act to induce chirality in porous networks formed by achiral DBAs. ispartof: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION vol:58 issue:23 pages:7733-7738 ispartof: location:Germany status: published

Two isomers of 9,10-dihydro- as-indacenodithiophenes (DIDTs) and the corresponding diketones having an as-indacene core were synthesized. Their thermal, photophysical, and electrochemical properties were investigated, revealing that they depend on the direction of the fusion of the thiophene rings. For the DIDTs, the effect of the mode of ring fusion on the physical properties is discussed by comparison with the previously reported derivatives of DIDT isomers with an s-indacene core. The observed difference between the highest occupied molecular orbital (HOMO)/lowest unoccupied molecular orbital (LUMO) levels of the DIDT isomers is ascribed to the efficiency of π-conjugation, which depends on α- or β-linkage between the terminal thiophenes with the central benzene ring. In addition, the effect of the peripheral aromatic ring (thiophene or benzene) is elucidated by comparison with indeno[2,1- a]fluorene (DIF) bearing an as-indacene core. The HOMO levels of DIDTs are significantly raised compared to that of structurally related DIF because of electron-donating character of the thiophene rings. For the DIDT diketones, structural effect due to the proximate carbonyl groups is discussed by comparison with the isomers with remote carbonyl groups. In diketones bearing proximate carbonyl groups, the LUMO levels are destabilized owing to antibonding interaction between the carbonyl oxygen atoms, resulting in approach of the LUMO and LUMO+1 energy levels.

By using a novel protocol to spatially confine molecules in well-defined small 2D areas, the so-called nanocorrals, we show using scanning tunneling microscopy (STM) how this kind of confinement affects self-assembled molecular network (SAMN) formation at a liquid-solid interface. The 2D lateral confinement, imposed by the size of the nanocorrals, has a clear impact on the phase selectivity of a molecule that can form both low-density and high-density SAMNs, the high-density phase being promoted by the confinement. ispartof: CHEMICAL COMMUNICATIONS vol:55 issue:15 pages:2226-2229 ispartof: location:England status: published

Many types of human activity recognition (HAR) techniques have been developed based on machine learning (ML) using diverse sensors in our daily life, such as cameras, microphones, and acceleration sensors on smartphones and wearable devices. For this background, there are many pre-trained ML models of HAR available on the Internet. In addition, there are cases where multiple ML models are utilized in combination for HAR. Although combining multiple ML models can be expected to improve classification accuracy, it requires additional training to combine them, such as stacking. This paper proposes a method to integrate published and trained HAR ML models without additional training by utilizing word embedding, e.g., Glove and Word2vec. Word embedding enables to obtain plausible results by arithmetic operations on the labels output by multiple ML models. Utilizing the proposed integration method, a HAR system is developed, which implements publicly-available ML models. Evaluations using Glove are performed, and their results confirm the proposed method is able to improve classification accuracy compared to using each ML model alone.

Recently, various Internet of things (IoT) devices have become widely used in our daily lives and made houses and cities easier to live in. This paper proposes a machine learning scheme to take advantage of IoT devices. The proposed scheme realizes cooperation between devices to improve their performance, rather than learning independently. However, it is difficult to share local data directly because those data may contain private information, such as a picture with a user's face or lifelog data. Therefore, this paper provides a way of preserving privacy in interconnected IoT devices by sharing only learners from each device without sharing the original data directly. The proposed algorithm shares decision trees locally learned at each device and utilizes a random forest as a way of combining them together.

We have seen rapid growth of Internet of Things (IoT) paradigm. Challenges of IoT include the need to obtain comprehensive environmental information using multiple and different types of sensors as well as the need to reduce the amount of bandwidth used by a large number of sensors. Especially when image sensors are used, a significant amount of bandwidth is used for sending images. In addition, the use of IoT devices need not be limited to experts who are good at handling sensors. For example, there is the home IoT system which is expected to be used at home by several users. Thus, it is necessary to have an interface which is easy to handle, even for people who are not good at handling data and sensors. To solve these problems, we use Resource Description Framework (RDF) used in the Semantic Web field as metadata of sensor data for comprehensive environmental information acquisition. Then, by linking with an existing RDF search system called QAnswer, which uses natural language, we create a system that enables sensor data search using natural language. Thus, we design an intelligent system which enables users to interact with sensors using natural language. By combining an RDF database and a server which controls the flow of messages, we then investigate the trade-off between the response time to a user’s request and the amount of bandwidth usage by messages. Our results show that in a sensor network using RDF, it is possible to reduce the amount of communication traffic by optimally transferring RDF and sensor data only on arrival of a request and this can be done without much increase in the communication latency.

Telemedicine using information technology (IT) and communication networks is becoming common. Often, the medical doctor and the patient can discuss the problem by video teleconference and, if necessary, the patient's physiological data can be sent to the doctor. As part of this trend, we believe that brain waves can be used for telemedicine in the future. We expect that the diagnosis of remote patients will be realized by transferring electroencephalogram (EEG) data to a server or cloud. However, if EEG data are sent as they are, the data size will be significantly large. Thus, the compression of EEG data is desirable. Furthermore, should not affect the accuracy of diagnosis if data compression is performed. In this study, the relationship between the selected EEG signal features and the accuracy is investigated.

Stereocontrolled multilayer growth of supramolecular porous networks at the interface between graphite and a solution was investigated. For this study, we designed a chiral dehydrobenzo[12]annulene (DBA) building block bearing alkoxy chains substituted at the 2 position with hydroxy groups, which enable van der Waals stabilization in a layer and potential hydrogen-bonding interactions between the layers. Bias voltage-dependent scanning tunneling microscopy (STM) experiments revealed the diastereospecificity of the bilayer with respect to both the intrinsic chirality of the building blocks and the supramolecular chirality of the self-assembled networks. Top and bottom layers within the same crystalline domain were composed of the same enantiomers but displayed opposite supramolecular chiralities.

Controlled covalent functionalization of graphitic surfaces with molecular scale precision is crucial for tailored modulation of the chemical and physical properties of carbon materials. We herein present that porous self-assembled molecular networks (SAMNs) act as nanometer scale template for the covalent electrochemical functionalization of graphite using an aryldiazonium salt. Hexagonally aligned achiral grafted species with lateral periodicity of 2.3, 2.7, and 3.0 nm were achieved utilizing SAMNs having different pore-to-pore distances. The unit cell vectors of the grafted pattern match those of the SAMN. After the covalent grafting, the template SAMNs can be removed by simple washing with a common organic solvent. We briefly discuss the mechanism of the observed pattern transfer. The unit cell vectors of the grafted pattern align along nonsymmetry axes of graphite, leading to mirror image grafted domains, in accordance with the domain-specific chirality of the template. In the case in which a homochiral building block is used for SAMN formation, one of the 2D mirror image grafted patterns is canceled. This is the first example of a nearly crystalline one-sided or supratopic covalent chemical functionalization. In addition, the positional control imposed by the SAMN renders the functionalized surface (homo)chiral reaching a novel level of control for the functionalization of carbon surfaces, including surface-supported graphene. ispartof: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY vol:142 issue:16 pages:7699-7708 ispartof: location:United States status: published

ispartof: CHEMNANOMAT vol:6 issue:4 pages:550-559 status: published

The covalent functionalization of carbon-based materials through aryldiazonium chemistry has emerged as a powerful tool for physicochemical property modification. However, the characterization tech...

Amazing aromaticity: ChemPlusChem is pleased to present its special issue on novel aromatic compounds, guest-edited by Nazario Martin and Yoshito Tobe. This project was initiated following the 2015 ISNA-16 meeting held in Madrid and the issue features top-quality contributions covering synthesis, properties and applications of acenes, annulenes, azulenes, fullerenes, oligo(thiophene)s, and porphyrin/phthalocyanines.

Thermal comfort is a personal assessment of one's satisfaction with the surroundings. Yet, most thermal comfort delivery mechanisms preclude physiological and psychological precursors to thermal comfort. Accordingly, many people feel either cold or hot in an environment that is supposedly thermally comfortable to most people. To address this issue, this paper proposes to use people's heart rate variability (HRV) as an alternative indicator of thermal comfort. Since HRV is linked to homeostasis, we hypothesize that it could be used to predict people's thermal comfort status. To test our hypothesis, we analyzed statistical, spectral, and nonlinear HRV indices of 17 human subjects doing light office work in a cold, a neutral, and a hot environment. The resulting HRV indices were used as inputs to machine learning classification algorithms. We observed that HRV is distinctively altered depending on the thermal environment and that it is possible to steadfastly predict each subject's thermal environment (cold, neutral, and hot) with up to a 93.7% prediction accuracy. The result of this study implies that it could be possible to design automatic real-time thermal comfort controllers based on people's HRV.

© 2018 American Chemical Society. Chemical and structural defects in otherwise pristine materials can result in either an improved or degraded material performance. Unfortunately, little is known about the role of these defects in complex hierarchical processes, such as self-assembly. Here, the influence of defective surfaces on physisorbed self-assembly occurring at liquid/solid interfaces is investigated. Covalently bound defects on graphite surfaces are generated by electrochemically activating diazonium cations. After creating the defective substrates, a solution containing self-assembling molecules was deposited on the surface. Subsequent scanning probe investigations expose how the chemisorbed molecular units can either be incorporated within a porous hexagonal network, or generate local perturbations in the form of partial or full desorption of the physisorbed molecules. Overall, the chemisorbed molecules alter the local energy landscape for self-assembly to isolate new molecular packing arrangements. With a single-molecule perspective, this work outlines how chemical defects contribute to the formation of metastable assemblies and their evolutionary pathways toward higher-symmetry networks. ispartof: JOURNAL OF PHYSICAL CHEMISTRY C vol:122 issue:42 pages:24046-24054 status: published

The development of smartphones and other portable devices has expanded new ways of communication and collaboration both in private and business settings where there are used e.g. for sharing files and other information. However, this communication is not always secure and can be intercepted by a third party in the vicinity. This paper proposes an intelligent communication control mechanism where the shared information is accessible only within a physically limited space. Normally, existing communication methods based on radio waves (Wi-Fi or Bluetooth) are accessible to anyone within a specific range; thus, they are susceptible to breach and communication eavesdrop beyond walls. Our proposed method is based on an association scheme whereby the sending smartphone can restrict the communication range by controlling an acoustic wave’s magnitude and frequency. Thus, unlike radio waves, it is possible to send the signal to devices located in a specific range, where the client devices exist, after recognizing the distance and angle between devices. Our experiments by sharing signals among smartphones indicate that it is possible to unidirectionally control the sharing range while sharply reducing any possibility to eavesdrop on the communication.