In spatially distributed systems such as smart buildings and intelligent transportation systems, control of spatio-temporal patterns is an important issue. In this paper, we consider a finite-horizon optimal spatio-temporal pattern control problem where the pattern is specified by a signal spatio-temporal logic formula over finite traces, which will be called an SSTLf formula. We give the syntax and Boolean semantics of SSTLf. Then, we show linear encodings of the temporal and spatial operators used in SSTLf and we convert the problem into a mixed integer programming problem. We illustrate the effectiveness of this proposed approach through an example of a heat system in a room.

The colors of objects in natural images are affected by the color of lighting, and accurately estimating an illuminant's color is indispensable in analyzing scenes lit by colored lightings. Recent lighting environments enhance colorfulness due to the spread of light-emitting diode (LED) lightings whose colors are flexibly controlled in a full visible spectrum. However, existing color estimations mainly focus on the single illuminant of normal color ranges. The estimation of multiple illuminants of unusual color settings, such as blue or red of high chroma, has not been studied yet. Therefore, new color estimations should be developed for multiple illuminants of various colors. In this article, we propose a color estimation for LED lightings using Color Line features, which regards the color distribution as a straight line in a local area. This local estimate is suitable for estimating various colors of multiple illuminants. The features are sampled at many small regions in an image and aggregated to estimate a few global colors using supervised learning with a convolutional neural network. We demonstrate the higher accuracy of our method over existing ones for such colorful lighting environments by producing the image dataset lit by multiple LED lightings in a full-color range.

When BJTs are irradiated by gamma rays, interface trapped charges and positive oxide trapped charges are formed by ionization at the Si-SiO2 interface and SiO2 regions, respectively. These trapped charges affect the movement of carriers depending on the type of BJT. This paper presents experimental results regarding operating characteristics of gamma irradiated pnp Si BJTs.

In recent years, High-Altitude Platform Station (HAPS) has become the most interesting topic for next generation mobile communication systems, because platforms such as Unmanned Aerial Vehicles (UAVs), balloons, airships can provide ultra-wide coverage, up to 200km in diameter, from altitudes of around 20 km. It also offers resiliency to damage caused by disasters and so ensures the stability and reliability of mobile communications. In order to further integrate HAPS with existing terrestrial mobile communication networks in providing mobile services to users, radio wave propagation models such as terrain, vegetation loss, human shielding loss, building entry loss, urban/suburban areas must be taken into consideration when designing HAPS-based cell configurations. This paper proposes a human body shielding propagation loss model that considers the basic signal attenuation by the human body at high elevation angles. It also analyzes the effect of changes in actual urban/suburban environments due to the arrival of multipath radio waves for HAPS communications in the frequency range of 0.7 to 3.3GHz. Measurements in actual urban/rural environments in Japan and actual stratospheric base station measurements in Kenya are carried out to confirm the validity of the proposed model. Since the measured results agree well with the results predicted by the proposed model, the model is good enough to provide estimates of human loss in various environments.

In this paper, we propose a non-orthogonal multiple access with adaptive resource allocation. The proposed non-orthogonal multiple access assigns multiple frequency resources for each device to send packets. Even if the number of devices is more than that of the available frequency resources, the proposed non-orthogonal access allows all the devices to transmit their packets simultaneously for high capacity massive machine-type communications (mMTC). Furthermore, this paper proposes adaptive resource allocation algorithms based on factor graphs that adaptively allocate the frequency resources to the devices for improvement of the transmission performances. This paper proposes two allocation algorithms for the proposed non-orthogonal multiple access. This paper shows that the proposed non-orthogonal multiple access achieves superior transmission performance when the number of the devices is 50% greater than the amount of the resource, i.e., the overloading ratio of 1.5, even without the adaptive resource allocation. The adaptive resource allocation enables the proposed non-orthogonal access to attain a gain of about 5dB at the BER of 10-4.

Logical matrices are binary matrices often used to represent relations. In the map folding problem, each folded state corresponds to a unique partial order on the set of squares and thus could be described with a logical matrix. The logical matrix representation is powerful than graphs or other common representations considering its association with category theory and homology theory and its generalizability to solve other computational problems. On the application level, such representations allow us to recognize map folding intuitively. For example, we can give a precise mathematical description of a folding process using logical matrices so as to solve problems like how to represent the up-and-down relations between all the layers according to their adjacency in a flat-folded state, how to check self-penetration, and how to deduce a folding process from a given order of squares that is supposed to represent a folded state of the map in a mathematical and natural manner. In this paper, we give solutions to these problems and analyze their computational complexity.

In this study, AM-PM compensation of the cross-coupled capacitance neutralization technique is discussed. Cgd neutralization leads to AM-PM compensation of a power amplifier with negligible change of AM-AM characteristics. AM-PM compensation was confirmed via circuit analysis and measurements. The formulation analysis showed that AM-PM compensation can be derived via gm variation against input power with capacitance neutralization. A differential power amplifier with capacitance neutralization was fabricated with GaN high-electron-mobility transistors. The AM-PM characteristic of the fabricated differential power amplifier was measured at 17.7 GHz. It showed AM-PM reduction of 22° at compared to a single-phase power amplifier without capacitance neutralization at output power of 35 dBm.

The purpose of graph embedding is to learn a lower-dimensional embedding function for graph data. Existing methods usually rely on maximum likelihood estimation (MLE), and often learn an embedding function through conditional mean estimation (CME). However, MLE is well-known to be vulnerable to the contamination of outliers. Furthermore, CME might restrict the applicability of the graph embedding methods to a limited range of graph data. To cope with these problems, this paper proposes a novel method for graph embedding called the robust ratio graph embedding (RRGE). RRGE is based on the ratio estimation between the conditional and marginal probability distributions of link weights given data vectors, and would be applicable to a wider-range of graph data than CME-based methods. Moreover, to achieve outlier-robust estimation, the ratio is estimated with the γ-cross entropy, which is a robust alternative to the standard cross entropy. Numerical experiments on artificial data show that RRGE is robust against outliers and performs well even when CME-based methods do not work at all. Finally, the performance of the proposed method is demonstrated on realworld datasets using neural networks.

Regional Short Message Communication (RSMC) service of BeiDou Navigation Satellite System (BDS) has been widely used in various fields. BDS-3 officially started to provide service in 2020, and the performance of RSMC service was greatly improved, which offers an opportunity for large-scale applications of RSMC in consumer electronic products. Due to the complex application scenarios, the low-cost and low-power of RSMC terminals, a better coding scheme is needed to improve performance. In this paper, we propose a new polar encoding scheme with low code rate and variable code length, which adopts Polarization Weight (PW) to generate the reliability sequence of Polar codes and use a Nested Rate Adaptation Sequence (NRAS) to realize rate adaption for the BDS-3 RSMC. The performance of encoding gain and decoding complexity is analyzed by simulation and experiments. The results validate the effective of this scheme. Compared with Turbo codes, the proposed polar codes scheme achieves about 0.5dB gain with about 50% decoding complexity when the information length including CRC is 128 and code rate is 1/2. The proposed polar codes scheme provides a good reference for further applications in BDS.

Unique spatial eigenmodes for the spherical coordinate system are shown to be successfully synthesized by properly allocated combinations of current distributions along θ' and φ' on a spherical conformal array. The allocation ratios are analytically found in a closed form with a matrix that relates the expansion coefficients of the current to its radiated field. The coefficients are obtained by general Fourier expansion of the current and the mode expansion of the field, respectively. The validity of the obtained formulas is numerically confirmed, and important effects of the sphere radius and the degrees of the currents on the radiated fields are numerically explained. The formulas are used to design six current distributions that synthesize six unique eigenmodes. The accuracy of the synthesized fields is quantitatively investigated, and the accuracy is shown to be remarkably improved by more than 27dB with two additional kinds of current distributions.

We proposed a new method for evaluating the deterioration of messenger wires by using terahertz waves. We use terahertz time-domain spectroscopy to measure several twisted wire samples with different levels of deterioration. We find that each twisted wire sample had a different distribution of reflection intensity which was due to the wires' twist structure. We show that it is possible to assess the degradation from the straight lines present in the reflection intensity distribution image. Furthermore, it was confirmed that our method can be applied to wire covered with resin.

This letter focuses on the cross-corpus speech emotion recognition (SER) task, in which the training and testing speech signals in cross-corpus SER belong to different speech corpora. Existing algorithms are incapable of effectively extracting common sentiment information between different corpora to facilitate knowledge transfer. To address this challenging problem, a novel convolutional auto-encoder and adversarial domain adaptation (CAEADA) framework for cross-corpus SER is proposed. The framework first constructs a one-dimensional convolutional auto-encoder (1D-CAE) for feature processing, which can explore the correlation among adjacent one-dimensional statistic features and the feature representation can be enhanced by the architecture based on encoder-decoder-style. Subsequently the adversarial domain adaptation (ADA) module alleviates the feature distributions discrepancy between the source and target domains by confusing domain discriminator, and specifically employs maximum mean discrepancy (MMD) to better accomplish feature transformation. To evaluate the proposed CAEADA, extensive experiments were conducted on EmoDB, eNTERFACE, and CASIA speech corpora, and the results show that the proposed method outperformed other approaches.

A sub-Terahertz band is envisioned to play a great role in 6G to achieve extreme high data-rate communication. In addition to very wide band transmission, we need spatial multiplexing using a hybrid MIMO system. A recently presented paper, however, reveals that the number of observed multipath components in a sub-Terahertz band is very few in indoor environments. A channel with few multipath components is called sparse. The number of layers (streams), i.e. multiplexing gain in a MIMO system does not exceed the number of multipaths. The sparsity may restrict the spatial multiplexing gain of sub-Terahertz systems, and the poor multiplexing gain may limit the data rate of communication systems. This paper describes fundamental considerations on sub-Terahertz MIMO spatial multiplexing in indoor environments. We examined how we should steer analog beams to multipath components to achieve higher channel capacity. Furthermore, for different beam allocation schemes, we investigated eigenvalue distributions of a channel Gram matrix, power allocation to each layer, and correlations between analog beams. Through simulation results, we have revealed that the analog beams should be steered to all the multipath components to lower correlations and to achieve higher channel capacity.

The characteristics of antenna array, like sensor location, gain and phase response are rarely perfectly known in realistic situations. Location errors usually have a serious impact on the DOA (direction of arrival) estimation. In this paper, a novel array location calibration method of MUSIC (multiple signal classification) algorithm based on the virtual interpolated array is proposed. First, the paper introduces the antenna array positioning scheme. Then, the self-calibration algorithm of FIR-Winner filter based on virtual interpolation array is derived, and its application restriction are also analyzed. Finally, by simulating the different location errors of antenna array, the effectiveness of the proposed method is validated.

In this letter, we give a new construction of a family of sequences of period pk-1 with low correlation value by using additive and multiplicative characters over Galois rings. The new constructed sequence family has family size (M-1)(pk-1)rpkr(e-1) and alphabet size Mpe. Based on the characters sum over Galois rings, an upper bound on the correlation of this sequence family is presented.

In this research, the effect of Ar/N2-plasma sputtering gas pressure on the LaBxNy tunnel and block layer was investigated for pentacene-based floating-gate memory with an amorphous rubrene (α-rubrene) passivation layer. The influence of α-rubrene passivation layer for memory characteristic was examined. The pentacene-based metal/insulator/metal/insulator/semiconductor (MIMIS) diode and organic field-effect transistor (OFET) were fabricated utilizing N-doped LaB6 metal layer and LaBxNy insulator with α-rubrene passivation layer at annealing temperature of 200°C. In the case of MIMIS diode, the leakage current density and the equivalent oxide thickness (EOT) were decreased from 1.2×10-2 A/cm2 to 1.1×10-7 A/cm2 and 3.5 nm to 3.1 nm, respectively, by decreasing the sputtering gas pressure from 0.47 Pa to 0.19 Pa. In the case of floating-gate type OFET with α-rubrene passivation layer, the larger memory window of 0.68 V was obtained with saturation mobility of 2.2×10-2 cm2/(V·s) and subthreshold swing of 199 mV/dec compared to the device without α-rubrene passivation layer.

There are continuous and strong demands for the DC-DC converter to reduce the size of passive components and increase the system power density. Advances in CMOS processes and GaN FETs enabled the switching frequency of DC-DC converters to be beyond 10MHz. The advancements of 3-D integrated magnetics will further reduce the footprint. In this paper, the overview of beyond-10MHz DC-DC converters will be provided first, and our recent achievements are introduced focusing on 3D-integration of Fe-based metal composite magnetic core inductor, and GaN FET control designs.

Inter-channel correlation is one of the redundancy which need to be eliminated in video coding. In the latest video coding standard H.266/VVC, the DM (Direct Mode) and CCLM (Cross-component Linear Model) modes have been introduced to reduce the similarity between luminance and chroma. However, inter-channel correlation is still observed. In this paper, a new inter-channel prediction algorithm is proposed, which utilizes coloring principle to predict chroma pixels. From the coloring perspective, for most natural content video frames, the three components Y, U and V always demonstrate similar coloring pattern. Therefore, the U and V components can be predicted using the coloring pattern of the Y component. In the proposed algorithm, correlation coefficients are obtained in a lightweight way to describe the coloring relationship between current pixel and reference pixel in Y component, and used to predict chroma pixels. The optimal position for the reference samples is also designed. Base on the selected position of the reference samples, two new chroma prediction modes are defined. Experiment results show that, compared with VTM 12.1, the proposed algorithm has an average of -0.92% and -0.96% BD-rate improvement for U and V components, for All Intra (AI) configurations. At the same time, the increased encoding time and decoding time can be ignored.

High-Altitude Platform Station (HAPS) provides communication services from an altitude of 20km via a stratospheric platform such as a balloon, solar-powered airship, or other aircraft, and is attracting much attention as a new mobile communication platform for ultra-wide coverage areas and disaster-resilient networks. HAPS can provide mobile communication services directly to the existing smartphones commonly used in terrestrial mobile communication networks such as Fourth Generation Long Term Evolution (4G LTE), and in the near future, Fifth Generation New Radio (5G NR). In order to design efficient HAPS-based cell configurations, we need a radio wave propagation model that takes into consideration factors such as terrain, vegetation, urban areas, suburban areas, and building entry loss. In this paper, we propose a new vegetation loss model for Recommendation ITU-R P.833-9 that can take transmission frequency and seasonal characteristics into consideration. It is based on measurements and analyses of the vegetation loss of deciduous trees in different seasons in Japan. Also, we carried out actual stratospheric measurements in the 700MHz band in Kenya to extend the lower frequency limit. Because the measured results show good agreement with the results predicted by the new vegetation loss model, the model is sufficiently valid in various areas including actual HAPS usage.

Geometric partitioning mode (GPM) is a new inter prediction tool adopted in versatile video coding (VVC), which is the latest video coding of international standard developed by joint video expert team in 2020. Different from the regular inter prediction performed on rectangular blocks, GPM separates a coding block into two regions by the pre-defined 64 types of straight lines, generates inter predicted samples for each separated region, and then blends them to obtain the final inter predicted samples. With this feature, GPM improves the prediction accuracy at the boundary between the foreground and background with different motions. However, GPM has room to further improve the prediction accuracy if the final predicted samples can be generated using not only inter prediction but also intra prediction. In this paper, we propose a GPM with inter and intra prediction to achieve further enhanced compression capability beyond VVC. To maximize the coding performance of the proposed method, we also propose the restriction of the applicable intra prediction mode number and the prohibition of applying the intra prediction to both GPM-separated regions. The experimental results show that the proposed method improves the coding performance gain by the conventional GPM method of VVC by 1.3 times, and provides an additional coding performance gain of 1% bitrate savings in one of the coding structures for low-latency video transmission where the conventional GPM method cannot be utilized.