Force control and exponential stabilisation of one-link flexible arm

In this paper, we discuss a force control problem for a constrained one-link flexible arm. To solve the force control problem, we propose a simple boundary feedback controller that consists of the bending moment at the root of the flexible arm and its time derivative. The striking point is that information about the force and the rotational angle of the motor is not necessary for the implementation of the controller, and thus we do not need a force sensor or encoder in the construction of the controller. The exponential stability of the closed-loop system is then provided using the energy multiplier method. We describe several experiments carried out to investigate the performance of the proposed controller.     

Indonesian rainfall variability observation using TRMM multi-satellite data

It is important to understand the characteristics of Indonesian rainfall within the world’s climate system. The large rainfall in the Indonesian archipelago plays an essential role as a central atmospheric heat source of the Earth’s climate system throughout the year. Monthly rainfall satellite data, measured by the Tropical Rainfall Measuring Mission (TRMM) 3B43 over the course of 13 years, were employed to analyse monthly means, total means, maximum and minimum variability, standard deviation, and the trends analysis of Indonesian rainfall variability. The rainfall estimated from satellite data was then compared to the rain gauge data over the Indonesian region to determine the accuracy level. The results show that oceans, islands, monsoons, and topography clearly affect the spatial patterns of Indonesian rainfall. Most high-rainfall events in Indonesia peak during the December–January–February (DJF) season and the lowest rainfall events occur during the June–July–August (JJA) season. Those conditions are associated and generated with the northwest and southeast monsoon patterns. High fluctuations between maximum and minimum monthly rainfall data of over 400 mm month^?1 occur over Jawa (Java) Island, the Jawa Sea, and southern Sulawesi Island. A high annual and monthly rainfall typically occurs throughout Indonesia over island areas. The trend analysis shows an increasing trend in rainfall from 1998 to 2010 in Kalimantan, Jawa, Sumatra, and Papua. Decreasing rainfall trends occur along the west and south coast of Sumatra, eastern Jawa, southern Sulawesi, Maluku Islands, western Papua, and Bali Island.     

Development of Web Service for Japanese Text Triplification

Linked Open Data (LOD) is recently attracting attention as a vast amount of distributed knowledge base on the Web. Thus, semi-structured data such as tables and hierarchical data in several domains have been triplified to the LOD. Moreover, triplification of unstructured data such as text and sensor data is actively studied in the research area. We thus developed a Web API for extracting triples from natural sentences, which is useful for the promotion of the LOD. In this paper, we first describe the service specification, its technical background, and the evaluation of the current extraction accuracy, and then introduce several use cases of the service. Although this service adopts a novel combination of a method using ontology-based rules and a machine learning method using Conditional Random Field based on a probability distribution, the main contributions are in the practical aspect, that is, mashup of several natural language processing (NLP) techniques for the text triplification, and its deployment as a public Web API, so that non-experts of NLP can easily use it.     

Fabrication and evaluation of LED-embedded ribbons for highly flexible lighting applications in rooms

We have developed very flexible and lightweight LED-embedded ribbons in which LED-mounted printed circuit board (PCB) pieces are mounted and soldered to ribbons with the copper wires of power lines to apply them to the complicated three dimensional shapes of ceilings, walls, and furniture in rooms and provide higher levels of safety during earthquakes. Since it has been difficult to integrate LEDs in flexible ribbons and not only mount them on flat substrates but on bendable ribbons, we developed a new structure for LED-embedded ribbons and their fabrication process using a reel to reel mounting machine. A 2-cm wide ribbon with copper power lines on both sides was first constructed for the fabrication process of LED-mounted ribbons and then 5 × 20 mm LED mounted PCB pieces were mounted and soldered to the power lines of the ribbon. The ribbon was pulled under an optimal tension of 3.16 N to flatten the ribbon in the mounting process and the PCB pieces were pushed onto the ribbon with a rib height of 5 mm to strongly connect the pieces to the ribbon. The LED-embedded ribbon we constructed was 1.2 m long and very lightweight because it only weighed 7 g/m. The fabricated device had enough luminance of 96 lx for home and office lighting and could be installed on complicated surfaces such as adhering it to ceilings and the edges between ceilings and walls because our LED ribbon could be bent to a diameter of 5 mm. Our LED-embedded ribbon structure and assembly tool should provide new types of highly bendable and light-weight lighting for complicated three dimensional surfaces and safety during earthquakes.     

Time-specific encryption from forward-secure encryption: generic and direct constructions

Paterson and Quaglia (SCN 2010) proposed the concept of time-specific encryption (TSE) and its efficient constructions. TSE is a type of public-key encryption with an additional functionality where an encryptor can specify a suitable time interval, meaning that the ciphertexts may only be decrypted within this time interval. In this work, we propose a new methodology for designing efficient TSE schemes by using forward-secure encryption (FSE), and based on this methodology, we present a specific TSE scheme using Boneh–Boyen–Goh FSE, and a generic construction from any FSE. Our proposed TSE schemes are practical in all aspects with regard to computational costs and data sizes. The sizes of the ciphertext and the public parameter in our schemes are significantly smaller than those in previous schemes in an asymptotic sense.     

Computational wave optics library for C++: CWO++ library

Diffraction calculations, such as the angular spectrum method and Fresnel diffractions, are used for calculating scalar light propagation. The calculations are used in wide-ranging optics fields: for example, Computer Generated Holograms (CGHs), digital holography, diffractive optical elements, microscopy, image encryption and decryption, three-dimensional analysis for optical devices and so on. However, increasing demands made by large-scale diffraction calculations have rendered the computational power of recent computers insufficient. We have already developed a numerical library for diffraction calculations using a Graphic Processing Unit (GPU), which was named the GWO library. However, this GWO library is not user-friendly, since it is based on C language and was also run only on a GPU. In this paper, we develop a new C++ class library for diffraction and CGH calculations, which is referred to as a CWO++ library, running on a CPU and GPU. We also describe the structure, performance, and usage examples of the CWO++ library.Program summaryProgram title: CWO++Catalogue identifier: AELL_v1_0Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AELL_v1_0.htmlProgram obtainable from: CPC Program Library, Queen?s University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 109 809No. of bytes in distributed program, including test data, etc.: 4 181 911Distribution format: tar.gzProgramming language: C++Computer: General computers and general computers with NVIDIA GPUsOperating system: Windows XP, Vista, 7Has the code been vectorized or parallelized?: Yes. 1 core processor used in CPU and many cores in GPU.RAM: 256 M bytesClassification: 18External routines: CImg, FFTWNature of problem: The CWO++ library provides diffraction calculations which are useful for Computer Generated Holograms (CGHs), digital holography, diffractive optical elements, microscopy, image encryption and decryption and three-dimensional analysis for optical devices.Solution method: FFT-based diffraction calculations, computer generated holograms by direct integration.Running time: The sample runs provided take approximately 5 minutes for the C++ version and 5 seconds for the C++ with GPUs version.     

High‐Speed Organic Single‐Crystal Transistor Responding to Very High Frequency Band

Although high carrier mobility organic field‐effect transistors (OFETs) are required for high‐speed device applications, improving the carrier mobility alone does not lead to high‐speed operation. Because the cut‐off frequency is determined predominantly by the total resistance and parasitic capacitance of a transistor, it is necessary to miniaturize OFETs while reducing these factors. Depositing a dopant layer only at the metal/semiconductor interface is an effective technique to reduce the contact resistance. However, fine‐patterning techniques for a dopant layer are still challenging especially for a top‐contact solution‐processed OFET geometry because organic semiconductors are vulnerable to chemical damage by solvents. In this work, high‐resolution, damage‐free patterning of a dopant layer is developed to fabricate short‐channel OFETs with a dopant interlayer inserted at the contacts. The fabricated OFETs exhibit high mobility exceeding 10 cm² V^?1 s^?1 together with a reasonably low contact resistance, allowing for high frequency operation at 38 MHz. In addition, a diode‐connected OFET shows a rectifying capability of up to 78 MHz at an applied voltage of 5 V. This shows that an OFET can respond to the very high frequency band, which is beneficial for long‐distance wireless communication.     

Development of training environment for deep learning with medical images on supercomputer system based on asynchronous parallel Bayesian optimization

The Journal of Supercomputing - Recently, deep learning has been exploited in the field of medical image analysis. However, the training of deep learning models with medical images is...     

Human-centered image classification via a neural network considering visual and biological features

Multimedia Tools and Applications - In this paper, we propose a human-centered image classification via a neural network considering visual and biological features. The proposed method has two...     

Head direction estimation from low resolution images with scene adaptation

This paper presents an appearance-based method for estimating head direction that automatically adapts to individual scenes. Appearance-based estimation methods usually require a ground-truth dataset taken from a scene that is similar to test video sequences. However, it is almost impossible to acquire many manually labeled head images for each scene. We introduce an approach that automatically aggregates labeled head images by inferring head direction labels from walking direction. Furthermore, in order to deal with large variations that occur in head appearance even within the same scene, we introduce an approach that segments a scene into multiple regions according to the similarity of head appearances. Experimental results demonstrate that our proposed method achieved higher accuracy in head direction estimation than conventional approaches that use a scene-independent generic dataset.