Frequency characteristics for a converter are necessary to design circuit and control parameters and they are utilized, for example, for stability analysis by the impedance method. This paper proposes an automatic formulation and analysis method, which are based on a general-purpose simulation algorithm for the frequency analysis of an averaged power converter, based on node-connection and model characteristic information of circuit and control elements. The general equation formulation method is extended to be able to include circuits controlled in αβ frame and characteristic expressions with αβ or dq frame. As the first application example, a three-phase grid-following inverter with a digital sinusoidal controller based on the complex vector theory in αβ frame is analyzed for the frequency characteristics of the output admittances. The characteristics are utilized for stability analysis by the impedance method and the inverter is assured to have passive characteristics and to be stable. As the second example, a three-phase inverter is analyzed for its αβ and dq impedances. The proposed method is investigated for the computed results and it is validated.

The aim of this study was to investigate the dynamic characteristics of proper sucking in infants. We measured the contact force between the tongue and artificial nipples in infants able to breastfeed directly from the mother’s nipple (Group A) and infants who are fed using bottles or tubes (Group B). In both groups, we observed that the measured output waveforms were periodic and that the force from the sensor installed at the base of the nipple (Fmax₂) was greater than that at the tip of the nipple (Fmax₁). However, a smaller ratio between the two measured forces (Fmax₂ / Fmax₁) was observed in Group B. Furthermore, the difference between the time when the output from the sensor at the tip of the nipple reached its maximum value and the time at which the output of the sensor at the base of the nipple reached its maximum value was smaller in Group B, with some subjects in this group showing values below or close to zero. A separation boundary line was estimated based on the measured values of force. By improving the accuracy of the classification formula, it may be used to assess sucking ability of infants.

In a large-scale system like building air-conditioning system, measured time-series data is observed from many kinds of sensors. It is difficult to detect the fault by the administrators because only the limited experts can diagnose the unusual system. If we can extract characteristic changes of measured time-series data, we can calculate the evaluation value and grasp the sign of target fault condition. This paper proposes the evaluation method of fault condition with decision rule of rough set in building air-conditioning system. First, the proposal method extracts outline of target measured time-series data, and build the data set with qualitative values, which indicate the state of target system. Next, this method constructs the decision rule of a rough set with existence probability by comparison between normal and fault conditions. Finally, this method calculates evaluation value every time, based on the existence probability of each decision rules. Through practical experiments, it is confirmed that the proposal method can evaluate fault conditions called hunting, which occurs in supply air temp, water volume, and air volume.

Proximity sensors that can be operated without contact are attracting attention as a countermeasure against infectious diseases. In this paper, the proximity sensing method using the variations in the antenna impedance is explained. Here, different descriptions are used for near and far regions. A prototype circuit is made to prove the phenomenon and performed measurements using it. The measurement results matched the expected ones. In the future, we will improve the performance with the aim of commercialization.

In this paper, a design method of CSD (Canonic Signed Digit) coefficient FIR (Finite Impulse Response) filters using parameter-free genetic algorithm (PfGA) is proposed. In GA (Genetic Algorithm), we have a large amounts of difficulties for settings many parameters involved in the GA before the design. Such a task often forces excessive effort to the filter designers. In addiion, the general GA requires many individuals for increasing the diversification ability of search. This fact causes a large amounts of computational time for design. In order to overcome those difficulties, PfGA was proposed, in which any GA parameters are not needed to set in advance. As a result, the task for the parameter verification is not required. However, a detail effectiveness of this strategy for CSD coefficient FIR filter design problem which has a complex structure is not known. In this paper, several design examples are shown to present the practical effectiveness. The outcomes of this paper may give a good opportunity to free a lots of difficulties from the filter designers.

This paper presents passivity-based cooperative dynamic control for human-rigid body networks. In the human-rigid body network, a human operator sends a command signal to and receives visual information from only a part of the robotic group. In this setting, the proposed dynamic control scheme achieves not only pose synchronization of all mobile robots but also convergence to the reference pose that the human operator specifies. First, we derive robot dynamics of an omni-directional mobile robot through the Newton-Euler equation. Second, we design a control input to the robots with dynamics and show the passivity property of the robot system. Next, we discuss convergence analysis of the closed-loop system through the Lyapunov stability theorem and the LaSalle's invariance principle. The main advantage of the proposed method is to guarantee convergence of not only the position but also the orientation to the reference ones in the human-rigid body network. Finally, we provide simulation results and experimental results using four ground vehicles and a tablet PC to illustrate the performance of the proposed control method.

A parcel delivery method combining a vehicle and a drone is proposed. In a parcel delivery business where delivery time windows exist, the delivery order is determined by considering both keeping the delivery time windows restriction and shorting the total delivery time. Additionally, it is necessary to plan for the vehicle to visit a drone airfield and to load/reload the drone, so that the waiting time of both the vehicle and the drone is reduced. To solve this problem, firstly, an initial plan is greedily searched. Then, the initial plan is successively improved. Through simulation evaluation, it is confirmed that the proposed method can reduce delivery time compared to a method where only the delivery time windows are considered and where the vehicle visits the drone airfield on a priority basis.

This paper describes an optimization of user interface (UI) design for interactive systems by user acceptability evaluation. In our previous works, we defined the similarity among product functions and the similarity among operational methods in UIs as the criteria for evaluating the consistency of UIs. However, the similarities among product functions sometimes differ between designer results and user results. Different UI design solutions are derived for the same product function based on the different product function classifications. Therefore, developers need to decide which of these different UI design solutions to adopt. Our proposed user acceptability evaluation is structured with three simple questions based on the technology acceptance model (TAM) and measures the user’s mental change for the UI design solution. By measuring this mental change, it is possible to select a UI design solution that users are likely to find more rational. We applied the proposed method to the UI design of a digital camera, and the results suggested the properness and effectiveness of the method.

In this paper, we propose a method which can extract food regions from food images to improve extraction accuracy compared with a conventional method by decreasing misdetermination of the food regions as the background regions. The proposed method uses a convex hull based on the local extrema and their density to generate initial seeds for GrabCut, which can revise the food and background regions on the basis of color similarity and distribution. Our experiment demonstrated that the proposed method significantly increased the F-measure, which shows the comprehensive extraction accuracy, by 4.41% or more compared with the conventional method. The proposed method also increased the F-measure by 4.54% or more compared with SegNet based on deep convolutional neural network trained by 1017 food images available on the Internet. These results provided the fact that the proposed method was effective in the extraction accuracy compared with the existing methods which can be constructed by limited introduction cost.

In this research, we proposed a data cleansing method to support the management and utilization of access logs in the operation of websites. We focused on detecting and removing bots hidden in access logs. The method we propose discovers the hidden features of bots by extracting access logs using multiple methods. We propose a new method that combines the hidden features of bots with rule-based methods and traditional anomaly detection methods. The proposed method can automate the same degree of accuracy as manual bot discrimination. In addition, the proposed method improves the prediction accuracy of recommender systems.

At a business process, it has a work that to make a final data create step by step by some software. At the almost cases, these software use a unique input and output data (s) and format. In these days, a work to make the input and output data (s) and format by the operator become extremely hard, because kind of software and data size getting to grow.

It's not so hard a thing to make the input data (s) and format automatically. But there's no way to management that add and/or delete software, modification of software running sequence. Thus it's one of the factors of work confusion and constitutes a limiting factor of an automatic design system. This paper supplies a new matrix style programing language and software for the I/O stream expression between external software. Note that, data create functions are supplied by external software, thus these process aren't included in it.

For data-driven decision making, it is essential to build a data infrastructure that stores various data. Since various data are accumulated within organizations such as universities, companies, and local governments, integration of data in different contexts and cross-sectional analysis are issues. Knowledge graphs with a graphical structure that can flexibly change the schema are suitable for integrating heterogeneous data. In this study, we focused on a university campus as an example and proposed an ontology for various data such as lectures, buildings, purchasing, bicycle parking, and energy consumption. In particular, it has become easier to extract data across heterogeneous data collected within an organization by semantically linking dimensions with various expressions. Then, the collected unstructured data was accumulated as a knowledge graph based on the ontology, and the data infrastructure was constructed. In addition, we found several correlations through scenario-based experiment using this knowledge graph and showed the possibility that it could be applied to considering approach for university managemsent and improving the campus environment.