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type:Conference Paper, As the electron emission yield induced by electron and photon plays a key role in surface potential of spacecraft materials, the ground based degradations including 500 keV electron and 50 keV proton irradiation with 4 different fluences were conducted for the polyimide film separately. Based on the developed measuring systems, thecomparative measurements of total electron emission yield and photoelectron emission yield were carried out for the virgin and degraded polyimide samples respectively. The total electron emission yield and photoelectron emission yield tended to have different variation tendency after high energy electron and proton irradiation. The Monte-Carlo analysis software Casino and SRIM were used to analysis the distribution and stopping power of electron and proton respectively. According to the measurement results and analysis, the free radicals caused by irradiation was considered to be the main effect for polyimide films, which can primarily reveal the degradation mechanism of energetic electron and proton on the emission yield of polyimide., The 29th International Symposium on Space Technology and Science (29th ISTS), June 2-9, 2013, Nagoya, Aichi

type:Journal Article, In this paper, we propose the criteria of bias voltage from parasitic capacitance and demonstrate the criteria in an experiment with the present IGBT. The bias voltage criteria are theoretically predicted for the new generation IGBT based on the scaling principle. For safe switching, the required gate voltage bias is predicted to be −1.2V or less for the present IGBTs and −6V or less is required to completely cancel the gate noise voltage. From the IGBT design, the bias voltage of scaling IGBT requires −2V to completely cancel the gate noise voltage.

type:Conference Paper, The need of robotic clothing assistance in the field of assistive robotics is growing, as it is one of the most basic and essential assistance activities in daily life of elderly and disabled people. In this study we are investigating the applicability of using Dynamic Movement Primitives (DMP) as a task parameterization model for performing clothing assistance task. Robotic cloth manipulation task deals with putting a clothing article on both the arms. Robot trajectory varies significantly for various postures and also there can be various failure scenarios while doing cooperative manipulation with non-rigid and highly deformable clothing article. We have performed experiments on soft mannequin instead of human. Result shows that DMPs are able to generalize movement trajectory for modified posture., 3rd International Conference of Robotics Society of India (AIR '17: Advances in Robotics), June 28 - July 2, 2017, New Delhi, India

type:Conference Paper, Inverters used in motor-drive and grid-connected applications usually employ current sensors at the output terminal because they have to control the output current. Existing current sensors like the Hall sensor and the current transformer are a constraint to reduce the volume and cost of the inverter. This paper proposes an output-current measurement method of a PWM inverter using a tiny PCB sensor that is based on the so-called Rogowski coil and can be integrated into an IGBT module. The method utilizes the switching current of the lowside switch for reproducing the output current, which allows using the PCB sensor because the switching current consists of high-frequency components. The method uses a single PCB sensor per leg and takes the polarity of the output current into account. Experimental results using a half-bridge sinusoidal PWM inverter verify that the proposed method measures the output current including its fundamental frequency component, switching ripple one, and polarity., IEEE Energy Conversion Congress and Exposition (ECCE 2019), September 29-October 3, 2019, Baltimore, Maryland, USA

type:Preprint, The 31st IEEE International Symposium on Power Semiconductor Devices and ICs (ISPSD), May 19-23, 2019, Shanghai

type:Journal Article, Hafnium (Hf) has attracted considerable attention as a component of biomedical titanium (Ti) alloys with low Young's moduli and/or shape‐memory functionalities, because its cytotoxicity is as low as that of Ti. The drawback of metals is that their bone‐bonding ability is generally low. It is known that apatite formation in the body is a prerequisite for bone‐bonding. Although several chemical treatments have been proposed for preparing Ti for bone‐bonding, there have been no similar investigations for Hf. In the present study, NaOH‐ and heat‐treatments were applied to pure Hf and Ti‐Hf alloys and their bone‐bonding ability was assessed in vitro with the use of simulated body fluid (SBF). After NaOH‐ and heat‐treatments, anatase formed on alloys with low Hf content (20–40% (atom%) Hf); mixtures of sodium titanate and hafnium titanate formed on alloys with similar Ti and Hf content (60% Hf); and hafnium oxide formed on alloys with high Hf content (80% Hf and pure Hf). Precipitates of apatite were observed on all the metals in SBF, except for the alloy with 60% Hf. We speculated that the hafnium titanate formed on this alloy had a low apatite‐forming ability owing to its high negative surface charge, which inhibited P adsorption. The apatite‐forming abilities of the Ti‐Hf alloys strongly depended on their Hf content. The present results indicate that Hf‐based materials have good potential for bone‐bonding.

type:Conference Paper, Methylation frequently occurs in cytosines of CpG sites to regulate gene expression. The identification of aberrant methylation of certain genes is important for cancer marker analysis. The aim of this study was to determine the methylation frequency in DNA samples of unknown length and/or concentration. Unmethylated cytosine is known to be converted to thymine following bisulfite treatment and subsequent PCR. For this reason, the AT content in DNA increases with an increasing number of methylation sites. In this study, the fluorescein-carrying bis-acridinyl peptide (FKA) molecule was used for the detection of methylation frequency. FKA contains fluorescein and two acridine moieties, which together allow for the determination of the AT content of double-stranded DNA fragments. Methylated and unmethylated human genomes were subjected to bisulfide treatment and subsequent PCR using primers specific for the CFTR, CDH4, DBC1, and NPY genes. The AT content in the resulting PCR products was estimated by FKA, and AT content estimations were found to be in good agreement with those determined by DNA sequencing. This newly developed method may be useful for determining methylation frequencies of many PCR products by measuring the fluorescence in samples excited at two different wavelengths., India-Japan Expert Group Meeting on Biomolecular Electronics & Organic Nanotechnology for Environment Preservation (IJEGMBE 2015), 23–26 December, 2015, Fukuoka, Japan, source:https://doi.org/10.1088/1742-6596/704/1/012015

type:Journal Article, With the coming of CubeSat standard, it has become very attractive venture or endeavor for many universities or schools as an easy approach in conducting research on space related science or education. The nucleus of CubeSat’s mission is the electrical power system which is critical to the spacecraft’s bus and payload. This paper details the testing and sizing of an electric double layer capacitor (EDLC) based CubeSat power system using direct energy transfer topology with utmost consideration for simplicity, ease to handle and durability attributes of EDLC.

type:Conference Paper, To protect the satellite from the accidents due to spacecraft charging, Kyushu Institute of Technology (Kyutech) is developing a device called ELFs-Charm, which stands for ELectron-emitting Film for Spacecraft CHARging Mitigation. ELFs-Charm was mounted on HORYU-II, which was launched to a Polar Earth Orbit in May 2012. From the orbital data, the emitter’s soundness and working principles were confirmed. As a next step, we are considering the practical operation for mitigation of spacecraft charging. The present emission level was not enough to increase the satellite potential. Theoretically, if the emitter can emit more electrons than the incoming electrons, it can increase the satellite potential during the sub-storm. We focus our efforts on improving two parameters. One is the potential difference of the emitter surface. Another one is the threshold voltage of electron emission. A potential difference of the emitter surface depends on the insulator charging capacity due to the secondary electron emissions with each energy gap between the satellite potential and the primary electron energy. The threshold voltage depends on the shape of emitter. We can improve the ELFs-charm emission performance by measurement of these two parameters in ONERA Space Environment vacuum chamber and Kyutech Space Environment chamber. In this paper, we describe the two parameters of several samples and how the performance was improved., The 31st International Symposium on Space Technology and Science (31st ISTS), June 3-9, 2017, Matsuyama, Japan

type:Journal Article, Molecular ions in the magnetosphere can be a tracer of fast ion outflows from the deep ionosphere. Statistical properties of molecular ions (O2+/NO+/N2+) in the ring current are investigated based on ion composition measurements (<180 keV/q) by medium‐energy particle experiments‐electron analyzer and low‐energy particle experiments‐ion mass analyzer instruments on board the Arase (Exploration of energization and Radiation in Geospace, ERG) satellite. The investigated period from late March to December 2017 includes 11 geomagnetic storms with the minimum Dst index less than −40 nT. The molecular ions are observed in the region of L = 2.5–6.6 and clearly identified at energies above ~12 keV during most magnetic storms. During quiet times, molecular ions are not observed. The average energy density ratio of the molecular ions to O+ is ~3%. The ratio tends to increase with the size of magnetic storms. Existence of molecular ions even during small magnetic storms suggests that the fast ion outflow from the deep ionosphere occurs frequently during geomagnetically active periods.

type:Journal Article, The recent demographic trend across developed nations shows a dramatic increase in the aging population, fallen fertility rates and a shortage of caregivers. Hence, the demand for service robots to assist with dressing which is an essential Activity of Daily Living (ADL) is increasing rapidly. Robotic Clothing Assistance is a challenging task since the robot has to deal with two demanding tasks simultaneously, (a) non-rigid and highly flexible cloth manipulation and (b) safe human–robot interaction while assisting humans whose posture may vary during the task. On the other hand, humans can deal with these tasks rather easily. In this paper, we propose a framework for robotic clothing assistance by imitation learning from a human demonstration to a compliant dual-arm robot. In this framework, we divide the dressing task into three phases, i.e. reaching phase, arm dressing phase, and body dressing phase. We model the arm dressing phase as a global trajectory modification using Dynamic Movement Primitives (DMP), while we model the body dressing phase toward a local trajectory modification applying Bayesian Gaussian Process Latent Variable Model (BGPLVM). We show that the proposed framework developed towards assisting the elderly is generalizable to various people and successfully performs a sleeveless shirt dressing task. We also present participants feedback on public demonstration at the International Robot Exhibition (iREX) 2017. To our knowledge, this is the first work performing a full dressing of a sleeveless shirt on a human subject with a humanoid robot., source:http://www.tandfonline.com/10.1080/01691864.2019.1636715

type:Conference Paper, 2nd International Conference on Material Strength and Applied Mechanics, MSAM2019, 27–30 May 2019, Kiev, Ukraine

type:Conference Paper, This paper deals with optimum UHF sensor design and fabrication suitable for oil-filled transformer as well as the sensor characteristics and sensitivity check. As one promising UHF sensor, we make design of small loop antenna and fabricate it, investigating antenna characteristics and sensitivity in detecting PD in a model transformer., 18th International Symposium on High Voltage Engineering, ISH2013, August 25-30, 2013, Soul, Korea

type:Journal Article, After three H-II transfer vehicles (HTVs) had finished their mission to resupply the International Space Station (ISS), NASA requested data of the HTV's potential to evaluate the charging/discharging process that occurs when the HTV docks to the ISS. To measure these data, a new instrument was installed on the fourth HTV. This instrument allows us to measure the HTV-4 surface potential relative to the surrounding plasma, and is called advanced technology on-orbit test instrument for space environment-mini (ATOTIE-mini). The ATOTIE-mini observed the HTV's local potential in the orbit for more than one month. The measured potential during the HTV solo-flight phase varied between -30 and -60 V in sunlight and was about 0 V in eclipse conditions. The HTV's potential during the time when it was docked to the ISS followed the ISS's potential with an almost constant offset of about 10 V. The data measured by ATOTIE-mini are consistent with those measured by the floating potential measurement unit on the ISS, and thus are considered reliable. The HTV's potential level itself was acceptable for ISS. Note that the solar array panels can generate up to approximately 120 V, which is much larger than the absolute potential range in sunshine. We analyze the potential distribution on the HTV surface by a multi-utility spacecraft charging analysis tool, because ATOTIE-mini can only observe one point on the HTV surface. The analysis results are discussed with respect to the flight attitude.

type:Conference Paper, This paper investigates the gains and losses in terms of power, area, reliability, and speed when applying time redundancy fault tolerance techniques on single core designs compared to space redundancy fault tolerance techniques applied to multi-core designs. The system is developed on the virtex5 FPGA from Xilinx, it uses 65nm technology with a relatively moderate to high static power consumption. The system consists of two design alternatives. The first is a single core embedded processing system that applies time redundancy fault tolerance through execution repetition to perform self-check pointing through consensus. The second system is built from 3 soft IP core processors which perform a space redundancy approach through Triple-Modular-Redundancy (TMR) with feedback among the processors. The performance of both systems is evaluated in terms of the execution speed and latency due to fault tolerance techniques compared to the non-fault tolerant system., The 29th International Symposium on Space Technology and Science (29th ISTS), June 2-9, 2013, Nagoya, Aichi

type:Conference Paper, We monitored the current imbalance in a SiC-MOSFET chip under unclamped inductive switching condition by using our printed circuit board Rogowski coils. The current imbalance varied significantly from sample to sample. The SiC-MOSFET with a larger current imbalance was destroyed with lower avalanche current than other samples. It is assumed that the chip was destroyed due to partial temperature rise accompanying current concentration from current distribution and thermal simulation. The result shows that the current monitoring system is effective for analysis of avalanche robustness., 14th International Seminar on Power Semiconductors, August 29-31, 2018, Prague, Czech

type:Conference Paper, Emerging countries worldwide can benefit technologically, economically, and socially from domestic space-related activities. However, limited resources and lack of know-how prevent many non-space faring nations from initiating space projects, much less building sustainable space or satellite programs. New opportunities exist to overcome these barriers. The number of small satellites launched in the last three years has increased by an order of magnitude, and the market of satellites less than 50kg is projected to grow from $700M USD in 2014 to ∼$2B USD by 2019. This paper gives an overview of space-related activities in various emerging countries and categorizes countries in nine regions worldwide according to level of satellite activity., The 30th International Symposium on Space Technology and Science (30th ISTS), July 4-10, 2015, Kobe, Hyogo

type:Conference Paper, The high voltage generated by solar arrays can cause catastrophic damage such as that from short-circuit due to sustained arcs. Recently, many satellites suffered from sustained arc. The purpose of this paper is to develop the technique of mitigating the sustained arc. Three kinds of substrate were used to investigate the effect of substrate on sustained arc. The experiments were performed in vacuum chamber with an electron beam gun. The polyimide coupon had sustained arc in the condition of 60V and 2A. The ceramic coupon had also sustained arc in 60V and 2A. The coupon without substrate had no sustained arc up to 80V and 3A. We found that no sustained arc could occur without substrate between cells on this condition., The 25th International Symposium on Space Technology and Science (25th ISTS) June 4-11, 2006, Kanazawa City, Ishikawa, Japan

type:Journal Article, This paper describes a method of multilevel–multigroup analysis based on a nonlinear multiway dimensionality reduction. To analyze a set of groups in terms of the probabilistic distribution of their constituent member data, the proposed method uses a hierarchical pair of tensor self-organizing maps (TSOMs), one for the member analysis and the other for the group analysis. This architecture enables more flexible analysis than ordinary parametric multilevel analysis, as it retains a high level of translatability supported by strong visualization. Furthermore, this architecture provides a consistent and seamless computation method for multilevel–multigroup analysis by integrating two different levels into a hierarchical tensor SOM network. The proposed method is applied to a dataset of football teams in a university league, and successfully visualizes the types of players that constitute each team as well as the differences or similarities between the teams., 23rd International Conference on Neural Information Processing, ICONIP 2016, October 16–21, 2016, Kyoto, Japan

type:Journal Article

type:Journal Article, With the development and spread of Internet of Things (IoT) technology, various kinds of data are now being generated from IoT devices, and the number of such data is expected to increase significantly in the future. Data that depends on geographical location and time is commonly referred to as spatio-temporal data (STD). Since the “locally produced and consumed” paradigm of STD use is effective for location-dependent applications, the authors have previously proposed using a STD retention system for high mobility vehicles equipped with high-capacity storage modules, high-performance computing resources, and short-range wireless communication equipment. In this system, each vehicle controls its data transmission probability based on the neighboring vehicle density in order to achieve not only high coverage but also reduction of the number of data transmissions. In this paper, we propose a data transmission control method for STD retention in low vehicle density environments. The results of simulations conducted in this study show that our proposed scheme can improve data retention performance while limiting the number of data transmissions to the lowest level possible., 11th International Conference on Intelligent Networking and Collaborative Systems(INCoS 2019), September 5-7, 2019, Oita, Japan

type:Conference Paper, This paper presents a complete design and implementation of a Single Event Upset (SEU) emulation system that can be used to inject faults in Static Random Access Memory (SRAM) based Field Programmable Gate Array (FPGA). The FPGA is used to implement an avionics system for a small satellite. The fault injector emulates the expected Single Event Upset (SEU) rate as it would be in the Low Earth Orbit (LEO) of the polar orbiting satellites at inclinations close to 98° deg., and altitude of about 670 km. The emulator injects faults in the configuration bit-stream of the FPGA without stopping its operation. It makes use of the partial reconfiguration feature of today’s FPGAs. This provides a facility to assess the design performance in space even if radiation testing will not be conducted before launching. Also, it simulates the expected upset rate and hence calculates the corresponding data failure rates for Triple Modular Redundancy (TMR) fault tolerant designs. The system was implemented using the Xilinx Virtex- LX50T FPGA. The FPGA suffered system failures during the fault injection test. It recovered about 50% of the failures. TMR simulation at an upset rate of 0.1 upsets (per bit per second) for a data size of 2048 bits showed that about 33% of the faults will be fully corrected., The 29th International Symposium on Space Technology and Science (29th ISTS), June 2-9, 2013, Nagoya, Aichi

type:Journal Article, source:http://www.springerlink.com/content/x14384183g3v3r68

type:Conference Paper, Transmission Control Protocol (TCP) with a loss-based congestion control is still dominantly used for reliable end-to-end data transfer over diverse types of network although it is ineffective when traversing lossy networks. We previously proposed an IP tunneling system across lossy networks using the TCP with Network Coding (TCP/NC tunnel) and showed its potential to significantly mitigate the goodput degradation of end-to-end TCP sessions without any change of enddevice’s communications protocol stack, but it was shown only in homogeneous conditions. On the other hand, reliable end-to-end data transfer in diverse and heterogeneous IoT environments in a cost-efficient manner is an emerging challenge. Therefore, in this paper, we investigate the characteristics of the TCP/NC tunnel on heterogeneous networks with/without network congestions, to assess the applicability of the TCP/NC tunnel-based intelligent gateway system to IoT environments where end-devices are connected to a gateway with different link bandwidths or connected to different gateways in terms of network topology. The simulation results suggest the TCP/NC tunnel can efficiently utilize the bottleneck bandwidth in such heterogeneous situations even with congestion and achieve a significantly high goodput of end-to-end TCP sessions in a wide range of link loss degree especially when the tunnel link bandwidth is sufficient., The 10th International Conference on Intelligent Networking and Collaborative Systems (INCoS-2018), September 5 - 7, 2018, Comenius University in Bratislava, Slovakia

type:Conference Paper, We synthesized DyMn2O5 nanoparticles with the nanometer size using mesoporous silica as template of nanoparticles. The size effects of the DyMn2O5 nanoparticles were investigated through crystal structure analysis and magnetic measurement. The powder X-ray diffraction measurement revealed that the synthesized nanoparticles have orthorhombic structure with particle size of approximately 7 nm. The lattice constants for the nanoparticles deviated from those for the bulk crystal. The DyMn2O5 nanoparticles exhibited superparamagnetic behaviors. The evaluated Weiss temperature for the nanoparticles was positive value, whereas that for bulk crystal was negative one. The experimental results suggested that the distortion of crystallographic structure in the nanoparticles induced the changes in magnetic exchange interactions and magnetic frustration among manganese spins., 20th International Conference on Magnetism(ICM 2015), 5th to 10th July, 2015, Barcelona, Spain

type:Journal Article, Virtual inertia emulation could be regarded as an inevitable component of microgrids with renewable energy, enhancing microgrid inertia and damping properties. In applying this control technique, a phase-locked loop (PLL) is necessary to obtain the estimation of the system frequency data. However, the employment of PLL could cause larger frequency oscillation to the microgrid due to its dynamics. This issue would be exacerbated in a low-inertia microgrid driven by high renewable penetration, severely deteriorating the frequency stability. Thus, the effect of PLL with measurement delay is a critical issue in utilizing the virtual inertia control. To overcome such problem, this paper proposes a robust virtual inertia control for a low-inertia microgrid to minimize the undesirable frequency measurement effects, improving the microgrid frequency stability. The robust H ∞ control design using a linear fractional transformation (LFT) technique is used to develop the virtual inertia control loop, considering the dynamics of PLL with measurement delay and the uncertainties of system inertia and damping. The efficacy of the proposed H ∞ control method is compared to the conventional and optimum proportional-integral (PI)based inertia control. The results show that the H ∞ -based robust virtual inertia control is superior to both conventional virtual inertia control and optimum PI-based virtual inertia control against a wide range of microgrid operating conditions, disturbances, and parametric uncertainties.

type:Journal Article, In recent years, miniaturization and thinning of the power supply are attracted attentions. In this paper, we discuss the structure for the on-chip inductor and assembly technology suitable for 3D power SoC, which stacks GaN power device, passive devices, control circuit, and driver, based on wafer direct bonding technology and clarified the potential of the high frequency switching applications. We also propose the optimum structure and technology according to the switching frequency based on simulations., 2018 IEEE 68th Electronic Components and Technology Conference (ECTC), 29 May-1 June 2018, San Diego, CA, USA

type:Journal Article, As action recognition undergoes change as a field under influence of the recent deep learning trend, and while research in areas such as background subtraction, object segmentation and action classification is steadily progressing, experiments devoted to evaluate a combination of the aforementioned fields, be it from a speed or a performance perspective, are far and few between. In this paper, we propose a deep, unified framework targeted towards suspicious action recognition that takes advantage of recent discoveries, fully leverages the power of convolutional neural networks and strikes a balance between speed and accuracy not accounted for in most research. We carry out performance evaluation on the KTH dataset and attain a 95.4% accuracy in 200 ms computational time, which compares favorably to other state-of-the-art methods. We also apply our framework to a video surveillance dataset and obtain 91.9% accuracy for suspicious actions in 205 ms computational time., This work was presented in part at the 23rd International Symposium on Artificial Life and Robotics, Beppu, Oita, January 18–20, 2018., source:https://doi.org/10.1007/s10015-018-0518-y

type:Journal Article, Quorum sensing in Pseudomonas aeruginosa controls the production of costly public goods such as exoproteases. This cooperative behavior is susceptible to social cheating by mutants that do not invest in the exoprotease production but assimilate the amino acids and peptides derived by the hydrolysis of proteins in the extracellular media. In sequential cultures with protein as the sole carbon source, these social cheaters are readily selected and often reach equilibrium with the exoprotease producers. Nevertheless, an excess of cheaters causes the collapse of population growth. In this work, using the reference strain PA14 and a clinical isolate from a burn patient, we demonstrate that the initial amount of public goods (exoprotease) that comes with the inoculum in each sequential culture is essential for maintaining population growth and that eliminating the exoprotease in the inoculum leads to rapid population collapse. Therefore, our results suggest that sequential washes should be combined with public good inhibitors to more effectively combat P. aeruginosa infections., source:https://doi.org/10.3389/fmicb.2019.02322

type:Journal Article, Recently, sodium‐ion batteries have attracted great attention, owing to the rich resource and low cost. In the present work, a feather‐like MnO2 nanostructure was prepared directly on carbon paper by using a rapid and simple hydrothermal route for the first time. The formation mechanism was proposed by investigating the intermediate products during the reaction. When applied as an anode for a sodium‐ion battery, the feather‐like MnO2 nanostructure on carbon paper exhibited a high discharge capacity, good rate reversibility, and long‐term cycling stability. A high specific capacity of approximately 300 mAh g−1 could be obtained even after cycling 400 times with a current density of 0.1 A g−1. Furthermore, the Na+ storage mechanism of MnO2 on carbon paper in the sodium‐ion battery was also investigated in this work. Such high performance can be attributed to the porous structure of the substrate and high specific surface area of the feather‐like nanostructure., source:https://doi.org/10.1002/celc.201800830

type:Journal Article, In this work, a simple interface engineering process for SnO2 electron selective layer (ESL) surface passivation employing a SnCl2 solution is introduced, which has successfully reduced the energy loss for a high open-circuit voltage (Voc) output and consequently improved the performance of all-inorganic CsPbIBr2 perovskite solar cells (PSCs). It was found that surface passivation can effectively suppress the recombination process at the interface between the perovskite and SnO2 due to higher recombination resistance. The shorter PL decay time is attributed to the excellent electron extraction from the perovskite film. After optimizing surface passivation, the power conversion efficiency (PCE) was enhanced from 4.73% to 7.00% and a high Voc of 1.31 V was achieved, which is one of the highest Voc values reported for inorganic Cs-based PSCs. More importantly, the passivated SnO2 based device retains 95.5% of its initial performance at 90 °C in air without encapsulation. This work provides a simple and efficient interface engineering method to improve the Voc and efficiency of all-inorganic PSCs., source:DOI:10.1039/C8TA09838G

type:Journal Article, In a wide industrial field, the bolt-nut joint is unitized as an important machine element although anti- loosening performance is always required. In this paper, the effect of slight pitch difference between bolt and nut is studied. The prevailing torque required for the nut rotation is analyzed before the nut touches the clamped body as well as the tightening torque after the nut touches the clamped body. The results show that a large pitch difference may provide large prevailing torque that causes an anti- loosening effect although a very large pitch difference may deteriorate the bolt tightening force even under a certain tightening torque. By taking into account the anti-loosening and clamping abilities, the most desirable pitch difference is proposed to improve anti-loosening.

type:Journal Article, Transient luminous events above thunderstorms such as sprites, halos, and elves require large electric fields in the lower ionosphere. Yet very few in situ measurements in this region have been successfully accomplished, since it is typically too low in altitude for rockets and satellites and too high for balloons. In this article, we present some rare examples of lightning‐driven electric field changes obtained at 75–130 km altitude during a sounding rocket flight from Wallops Island, Virginia, in 1995. We summarize these electric field changes and present a few detailed case studies. Our measurements are compared directly to a 2D numerical model of lightning‐driven electromagnetic fields in the middle and upper atmosphere. We find that the in situ electric field changes are smaller than predicted by the model, and the amplitudes of these fields are insufficient for elve production when extrapolated to a 100 kA peak current stroke. This disagreement could be due to lightning‐induced ionospheric conductivity enhancement, or it might be evidence of flaws in the electromagnetic pulse mechanism for elves.

type:Conference Paper, We detail the solution to the UCAmI Cup Challenge to recognizing on going activities at home from sensor measurements. We use binary sensors and proximity sensor measurements for the recognition. We use an hybrid strategy, combining a probabilistic model and a definition-based model. The former consists of a Hidden Markov Model using the result of a neural network as emission probabilities. It is trained with the labelled data provided by the Cup. The latter approach takes advantage of the descriptions provided for each of the activities which are expressed in logical statements based on the sensors states. We then combine the results with a weighted average. We compare the performance of each individual strategy and of the combined strategy., 12th International Conference on Ubiquitous Computing and Ambient Intelligence (UCAmI 2018), 4–7 December 2018, Punta Cana, Dominican Republic, source:https://doi.org/10.3390/proceedings2191266

type:Conference Paper, Recently, we have presented a method of ensemble prediction of chaotic time series. The method employs strong learners capable of making predictions with small error, where usual ensemble mean does not work well owing to the long term unpredictability of chaotic time series. Thus, we have developed a method to select a representative prediction from a set of plausible predictions by means of using LOOCV (leave-one-out cross-validation) measure to estimate predictable horizon. Although we have shown the effectiveness of the method, it sometimes fails to select the representative prediction with long predictable horizon. In order to cope with this problem, this paper presents a method to select multiple candidates of representative prediction by means of employing hierarchical K-means clustering with K = 2. From numerical experiments, we show the effectiveness of the method and an analysis of the property of LOOCV predictable horizon., The 2017 IEEE Symposium Series on Computational Intelligence (IEEE SSCI 2017), November 27 to December 1, 2017, Honolulu, Hawaii, USA

type:Journal Article, Lignocellulosic degradation products from superheated steam (SHS) pretreatment of oil palm mesocarp fiber (OPMF) at 190°C to 240°C for 1 hour were recovered as a condensate. Compositional analysis of the condensate was carried out and subsequently its potential application as an antifungal agent was investigated. GCMS analysis revealed a total of 62 compounds in the condensate sample from SHS pretreatment at 240°C, which were identified and classified into ten different groups of aromatic phenolics, furans, pyrans, dioxoles; and open chains ketones, esters, alcohols, aldehydes, alkenes and alkanes. The presence of carboxylic acids was identified by HPLC and the condensate contained acetic, formic, levulinic and succinic acids at concentrations of 1671 mg L−1, 12 320 mg L−1, 831 mg L−1 and 435 mg L−1, respectively. Complete suppression of Ganoderma boninense UPM13 mycelial growth was observed in the agar dilution test, while spore germination of Aspergillus fumigatus UPM2 and Trichoderma asperellum UPM1 was completely inhibited in the spore germination test. The growth suppression of G. boninense, a fungal causing basal stem rot (BSR) disease in oil palm plantation shows the condensate potential benefit to combat the disease., source:DOI:10.1039/C6RA13292H

type:Journal Article, Background: The prevalence of non-communicable diseases is increasing throughout the world, including developing countries. / Objective: The intent was to conduct a study of a preventive medical service in a developing country, combining eHealth checkups and teleconsultation as well as assess stratification rules and the short-term effects of intervention. / Methods: We developed an eHealth system that comprises a set of sensor devices in an attaché case, a data transmission system linked to a mobile network, and a data management application. We provided eHealth checkups for the populations of five villages and the employees of five factories/offices in Bangladesh. Individual health condition was automatically categorized into four grades based on international diagnostic standards: green (healthy), yellow (caution), orange (affected), and red (emergent). We provided teleconsultation for orange- and red-grade subjects and we provided teleprescription for these subjects as required. / Results: The first checkup was provided to 16,741 subjects. After one year, 2361 subjects participated in the second checkup and the systolic blood pressure of these subjects was significantly decreased from an average of 121 mmHg to an average of 116 mmHg (P<.001). Based on these results, we propose a cost-effective method using a machine learning technique (random forest method) using the medical interview, subject profiles, and checkup results as predictor to avoid costly measurements of blood sugar, to ensure sustainability of the program in developing countries. / Conclusions: The results of this study demonstrate the benefits of an eHealth checkup and teleconsultation program as an effective health care system in developing countries.

type:Conference Paper, This paper presents a method for grading fruits and vegetables by means of using RGB-D (RGB and depth) images and convolutional neural network (CNN). Here, we focus on grading according to the size of objects. First, the method transforms positions of pixels in RGB image so that the center of the object in 3D space is placed at the position equidistant from the focal point by means of using the corresponding depth image. Then, with the transformed RGB images involving equidistant objects, the method uses CNN for learning to classify the objects or fruits and vegetables in the images for grading according to the size, where the CNN is structured for achieving both size sensitivity for grading and shift invariance for reducing position error involved in images. By means of numerical experiments, we show the effectiveness and the analysis of the present method., The 2017 IEEE Symposium Series on Computational Intelligence (IEEE SSCI 2017), November 27 to December 1, 2017, Honolulu, Hawaii, USA

type:Conference Paper, The 12th International Symposium on Particle Image Velocimetery, 2017, June 18–22, Busan, Korea

type:Conference Paper, The 14th World Congress on Medical and Health Informatics(Medinfo2013), 20-23 August, 2013,Copenhagen, Denmark

type:Conference Paper, The 12th International Symposium on Particle Image Velocimetery, 2017, June 18–22, Busan, Korea

type:Conference Paper

type:Journal Article, Nanocrystalline titanium dioxide (TiO2) thin film was successfully prepared by simple electrodeposition method from alkaline aqueous solution containing potassium titanium oxalate and hydroxylamine. Surface characterization of the electrodeposited films indicates the formation of crystalline TiO2. The dye solar cell constructed from dye-modified electrodeposited TiO2 film achieved an overall light-to-electricity conversion efficiency of 2.1 % under 1 sun illumination, indicating its high potential as a photoelectrode material for the DSCs.

type:Journal Article, We performed a feasibility study of Small angle X-ray scattering imaging under the condition of X-ray bright field imaging by Laue crystal diffraction optics of X-ray dark-field imaging that works as an angular analysis. Collagen in chicken tibia containing abundant soft fibrous tissue was chosen as a specimen. In traditional Small angle X-ray scattering optical system, we can derive the structure information of sample by calculating q value which is available from a scattering pattern. Thus it is usually necessary to conduct a 2D scan in order to obtain scattering image. In this paper it is described by a method by which not only small angle X-ray scattering imaging is available directly but also bright-field imaging and dark-field imaging can be obtained at the same time. As the first step, the feasibility of the imaging method should be confirmed by taking pictures of the samples with known periodic length. The preliminary test showed that the collgan’s lattice spacing d is 65.1 nm that was also taken photos by scanning electron microscopy. By rotating Laue angular analyzer by 112 arcseconds small angle X-ray scattering image appeared in bright-field., source:DOI: 10.4236/ojmi.2018.83007

type:Journal Article, Genetic algorithm is applied to find the optimum gas mixture ratio as gas insulating medium substituting pure SF/sub 6/. Genetic algorithm is very useful to find the optimum solution from vast searching possibilities. Testing each gas mixture by experiment requires a long time. The present method is very efficient to preselect the candidates of gas mixtures before more thorough but time-consuming investigation via experiment is carried out. The gas mixture ratio is coded as a series of bits simulating a genetic sequence of a life form. Two-term Boltzmann equation is used to calculate the effective ionization coefficient of each gas mixture that is used to evaluate the degree of adaptation of each individual representing one set of mixture ratios. Two types of degree of adaptation are used to evaluate each individual, the effective ionization coefficient at the critical ratio of the electric field to the gas density of SF/sub 6/ of 359.3/spl times/10/sup 21/Vm/sup 2/, and the global warming potential. Based on the degree of adaptation, better individuals can be selected as parents of the next generation, leaving their genes to future generations. After some generations, the group of individuals converges into the optimum with the best degree of adaptation.

type:Journal Article, Flashover voltage estimation has been carried out conventionally with the up-and-down method by Dixon and Mood. Recently, Hirose and Kato proposed a new version of the method to change the way of analyzing data. Although the method has better properties than the conventional one, it requires solving maximum likelihood equations. In this paper we reduce the troublesome task (e.g. implementation and the selection of a proper initial value) attendant on the requirement by using the expectation-maximization (EM) algorithm that gives a useful iterative formula to solve the equations. The iterative formula almost always can give the solutions of the likelihood equations because of its excellent global convergence of the EM algorithm

type:Journal Article, Glass beads of 43 m were coated in a vibro-fluidized bed by atomizing a fine silica powder together with polyvinyl alcohol aqueous solution. The coating efficiency and weight fraction of the agglomerated particles were measured under various experimental conditions, and their dependencies on the frequency and the direction of vibration were investigated. The coating efficiency and the degree of the agglomeration among core particles correlated well with an index R. The index R was introduced to evaluate quantitatively the drying conditions in a fluidized bed. Application of vertical vibration on the fluidized bed lowered the coating efficiency somewhat, while it prevented agglomeration. From the experimental results it was confirmed that coating with high quality and high efficiency, where few agglomerates were produced and silica powder was utilized efficiently, was possible in a vibro-fluidized bed with adequate vibration frequency and orientation of the vibration vector., source:http://www.informaworld.com/smpp/content~content=a713628017~db=all~order=page

type:Journal Article, The phonon Boltzmann equation is solved numerically in order to study the phonon thermal conductivity of micro/nanostructured thin films with open holes in a host material. We focused on the size effect of embedded pores and film thickness on the decrease in thermal conductivity of the film. Simulations have revealed that the temperature profiles in the micro/nanostructured materials are very different from those in their bulk counterparts, due to the ballistic nature of the microscale phonon transport. These simulations clearly demonstrate that the conventional Fourier heat conduction equation cannot be applied to study heat conduction in solids at microscale. The effective thermal conductivity of thin films with micro/nanoholes is calculated from the applied temperature difference and the heat flux. In the present paper, the effective thermal conductivity is shown as a function of the size of the micro/nanoholes and the film thickness. For example, when the size of the hole becomes approximately 1/20th the phonon mean free path in a film, the thickness is 1/10th the mean free path of phonons and the effective thermal conductivity decreases to as low as 6% of the bulk value. The distribution of holes also affects the reduction in the effective thermal conductivity. Thin films embedded with staggered-hole arrays have slightly lower effective thermal conductivities than films with aligned-hole arrays. The cross-sectional area in the thermal transport direction is a significant parameter with respect to the reduction of thermal conductivity. The results of the present study may prove useful in the development of artificial micro/nanostructured materials, including thermoelectrics and low-k dielectrics., source:DOI:10.1109/TCAPT.2006.875905

type:Journal Article, The question, whether the high-quality nucleon-nucleon potentials can successfully describe the three-nucleon system, and to what extent three-nucleon forces (3NFs) play a role, has become very important in nuclear few-body physics. One kinematic region where effects because of 3NFs show up is in the minimum of the differential cross section of elastic nucleon-deuteron scattering. Another observable, which could give an indication about the contribution of the spin to 3NFs, is the vector analyzing power. To investigate the importance of 3NFs systematically over a broad range of intermediate energies, both observables of elastic proton-deuteron scattering have been measured at proton bombarding energies of 108, 120, 135, 150, 170, and 190 MeV, covering an angular range in the center-of-mass system between 30° and 170°. The results show unambiguously the shortcomings of calculations employing only two-body forces and the necessity of the inclusion of 3NFs. They also show the limitations of the results of the present day models for few-nucleon systems at backward angles, especially at higher beam energies. New calculations based on chiral perturbation theory are also presented and compared with the data at the lowest energy., source:http://link.aps.org/abstract/PRC/v71/e064004, source:http://www.aps.org