地下大断面薄钢结构地震响应的试验研究及数值分析

为明确地下大断面薄钢结构的安全实用性,进行1/16大断面薄钢结构的系列模型振动试验、实际规模结构的现场试验和有限元分析。在把握作用于模型的地震动土压力及结构的应变状况的基础上,对施工过程中结构的响应特性及土压力的变化等进行研究。明确地下大断面薄钢结构的地震及施工时的安全性,为今后大断面薄钢结构的设计、施工提供依据。     

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.     

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.     

Numerical analysis of feedforward position control for non-pulley musculoskeletal system: a case study of muscular arrangements of a two-link planar system with six muscles

In a musculoskeletal system like a tendon-driven robot, redundant actuation is necessary because muscles (or mechanical parts such as tendons) can transmit tension only unidirectionally. This redundancy yields internal force among muscles, which has a particular field of potential energy. Using internal force as a feedforward input, a musculoskeletal system can achieve feedforward position control with no sensory feedback. This paper studies the feedforward position control coming from the redundancy for a non-pulley musculoskeletal system. Targeting a planar two-link system with six muscles as a case study, the motion convergence depending on the muscular arrangement is examined quasi-statically. The results point out that the convergence is extremely sensitive to the muscular arrangement, and adding small offsets for the muscular connected points can remarkably improve the positioning performance.     

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.     

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.     

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...