This study presents a method for mapping forest vertical structures using fused satellite data sets, including data from Global Ecosystem Dynamics Investigation (GEDI) mission, Sentinel-1 and -2, by a Random Forest classifier. The method aims to develop an effective yet simple way to map the foliage height diversity, plant area index, canopy height, and forest structure index, which is a composite index of these three metrics. They are mapped at 10 m spatial resolution, which can provide information about the distribution and functioning of different plant functional types and canopy layers in a forest. The approach was tested in an area around Mt. Washibetsu, Hokkaido, Japan, and demonstrated the feasibility of capturing forest vertical structures using satellite remote sensing, which has important implications for forest management and conservation.

As ageing populations continue to grow, there is an increasing demand for mobility aids such as wheelchairs. However, conventional wheelchair wheels are designed for level ground and are not suitable for travelling over rough terrain or steps. In addition, with the rapid development of mega-cities, more obstacles such as steps and Braille blocks have been introduced, making outdoor mobility even more challenging for wheelchair users. Although electric wheelchairs have been developed for use in various environments, they are costly and not accessible for all users. To address this issue, the authors focused on developing an affordable wheel that can be used in various driving environments, including flat ground, steps, and rough terrain. They designed a wheel that utilizes a slider-crank mechanism, which can be adjusted by the wheelchair user using a central disc. In this paper, the design of the wheel is presented, and its performance was evaluated through experiments involving step climbing and rough terrain simulations. The results showed a reduction in the force required to overcome steps, improved stability when navigating steps, and enhanced driving performance on rough terrain after deploying the new wheel.

GEDI Satellite laser mission will take 3D data globally from International Space Station. The sensor has an improved navigation system to position laser shooting areas accurately. However, the ground validation is still difficult due to the misalignment caused by poor reception of GPS signals under the thick forest. This study introduces a new way to get more accurate ground positioning of trees in tropical forest using 3D data matching technique between airborne and terrestrial data. Our study site is in tropical forest at Robson Creek, Australia. RMSE of XY directions was 0.5 m in and Z direction was 0.6 m, which was impossible to achieve efficiently from the traditional positioning by GPS under dense canopy. The 3D data taken by terrestrial laser is not only useful for capturing structure data for the validation of the waveform analysis of satellite laser but also helps to position accurate ground coordinates in tropical forest through this technique.

Surface electromyography is currently the sensing modality of choice for control of biosignal-driven prostheses and exoskeletons; however, the sensor's noisy and aggregate nature inhibits collection of distinguishable signal streams to robustly manipulate multiple device degrees of freedom (DoF). We here explore 2D B-mode ultrasound as an alternative source of muscle activation data (namely, muscle deformation) that can be more precisely localized, allowing for the theoretical collection of multiple naturally-varying signals that could be used to control high-DoF assistive devices. We here present a proof-of-concept study showing a) the observability of muscle deformation via ultrasound, and b) novel descriptions of the spatially-varying nature of the signal. These analyses are accomplished through the study of nine volumetric scans of the biceps brachii under varied elbow angle and loading conditions, collected and spatially localized using an ultrasound scanner and motion capture. We here establish the feasibility of measuring several force-associated deformation signals (including muscle cross-sectional area and thickness) via real-time ultrasound scanning and quantify the spatial variation of these signals. Additionally, we propose future applications for both our signal characterizations and the generated muscle volume data set, including better design of assistive device sensor locations and validation of existing muscle deformation models.

Continuous, easy-to-implement, accurate inference of intended joint angles is important for effectively controlling powered prosthetic devices that can improve the lives and capabilities of upper-limb amputees. Estimation of intended joint angles is difficult because conventional biosignals are not directly related to the intended angle motion. In previous work, we began to address this issue by confirming that both transra-dial amputees and intact subjects, the measured deformation of the muscle bulge on the skin surface change according to the intended wrist joint angle. This paper presents a continuous prosthesis wrist joint control method using this deformation signal. We here verify the effectiveness of the distribution of the muscle bulge for accurate and stable wrist joint angle control in real time. The wrist joint angles were calculated in real time from a muscle viscoelastic model using the previously determined algorithm. We compared the error between measured and estimated angles with a conventional method, the Voigt model, and the KelvinVoigt model. Experimental results obtained for three intact people over three trials of wrist movement tasks gave the accuracy and stability of 7.96±6.16°when using the Voigt model; this is a similar performance compared to related work using a surface electromyogram. A method for continuously controlling the wrist joint angle for a prosthesis using the distribution of the muscle bulge was thus successfully established.

Forest disaster monitoring requires frequent data observation of remotely sensed data. It is getting more common to use open satellite image archives to monitor land use change from multi-temporal data. In this study, multi-temporal DSM created by UAV-SfM is used to identify forest gap. ALOS 2 full polarization data is compared with the finer scale height difference detected by multi-temporal UAV based DSMs. Advantage of UAV based observation is to identify forest gap area efficiently in wide area and collect more samples to compare wide coverage of the satellite radar backscatter to understand backscatter characteristics. As a result, HH and HV polarization has detection power of forest gap size.

Center for Environmental Remote Sensing, Chiba University develops L Band circularly polarized synthetic aperture radar (SAR) sensor for microsatellite (150 kg class). This paper explains the project, specification, antenna deployment, RF system, and experiment of circularly polarized SAR in anechoic chamber. In the future, this sensor will be employed to monitor global land deformation.

A novel joint angle estimation method is proposed using a new bio-signal for an amputee subject. We used the muscle bulge movement on the forearm skin surface as a new bio-signal for estimating the extent of motion in a previous study. We found that it is feasible to estimate the intended wrist joint angle using the distribution of the muscle bulge for intact subjects. Thus, in the present paper, we validate the feasibility of our method for an amputee. In applying our method to an amputee subject, we improved our distance sensor device so that it can accommodate the position of the muscle, which is variable for an amputee subject. In addition, we improved the algorithm that estimates the wrist joint angle using linear multiple regression for calculating the relationship between the intended wrist joint angle and the distribution of the muscle bulge. As a result, we found that the distribution of the muscle bulge changes for the amputee as for intact subjects. The movement of the position of the muscle bulge on the forearm skin corresponded to the extent of the intended wrist joint angle. According to the result of the estimation of the wrist joint angle, the root-mean-square error of the estimated angle with respect to the measured angle for the amputee was slightly larger than the error for intact subjects. Nevertheless, the root-mean-square error for the amputee was smaller than that when employing the previous method for intact subjects. Finally, it is feasible to use the muscle bulge movement on the forearm skin to estimate the intended wrist joint angle for the upper limb amputee.

Field tree measurement to collect ground truth data is labor intensive. To make it efficient to collect the field data in a large scale, Unmanned Aerial Vehicle is introduced in this study. An automated photogrammetric technique called Structure from Motion (SfM) is used to create 3D data out of photos collected by UAV. Tree structure created by SfM is compared with the 3D data obtained by several Terrestrial Laser Scanners to see the difference in vertical forest structure. Canopy structure is mainly captured by UAV-SfM and there is more point density around tree canopy than 3D data obtained by airborne laser. The point density of UAV around tree canopy is equivalent to that of TLS data, but tree trunk underneath the canopy cannot be reconstructed well, because the trunk is obscured by tree canopy and it is not visible on photos.

Various remote sensing technologies are utilized to monitor tropical forest for REDD project. In developing countries, the accuracy of field measurement does not satisfy the quality required for the validation of satellite remotely sensed data. Therefore, we introduce the most portable laser sensor, SICK LMS511, to measure trees in the field of tropical forest and the semi-automatic process to derive tree parameters from the 3D point cloud is established to provide accurate forest inventory data. From the accuracy assessment of the portable laser system provided 3.61 cm of root mean square error (RMSE) of stem diameter and 0.50 m of RMSE of tree height measurement. The portable terrestrial laser sensor can be the standard technique to create forest inventory data for the field validation of satellite remote sensing.

Forest monitoring for environmental policy requires accurate and efficient ground-truthing techniques in the field. In this paper, a portable terrestrial laser scanner (TLS) is utilized to estimate leaf area index (LAI) of mixed forest stands in Christchurch, New Zealand. Our method converted laser XYZ coordinates to orthographic coordinates to create fish-eye images, from which LAI was estimated. The results were highly correlated with LAI estimates from three traditional techniques: radiation obtained by AccuPAR (R2= 0.81), Landsat TM (R2= 0.79), and fish-eye lens photography (R2= 0.91). This novel technique is a simple and efficient way to collect and analyze LAI and provides good ground truth data for satellite remote sensing.

High resolution active remote sensing data are getting more accessible. ALOS PALSAR radar data can provide 10 to 30 m resolution data. With those resolutions, land use changes can be detected and monitored well. The land use map of multi-temporal data is made by radar images, but seasonal change caused by deciduousness should be separately identified from the human activities. In this study, airborne lidar is used as ground truth data to estimate canopy volume and the estimated volume is compared with the change on the backscattering coefficients of multi-temporal radar images. The process used in this study is useful to monitor the small change detection with high resolution radar data given by ALOS 2 satellite launch near the future.

ALOS PALSAR uses L band which is related with volume scattering. The volume scattering is the reflection comes from the surface and the inside of canopy. Forest management activities can be monitored using PALSAR L-band for Reducing Emissions from Deforestation and Forest Degradation (REDD). But it is still unknown how the biomass changed by the thinning (forest management) influences the backscattering coefficients. In this study, the change of stem volume (biomass) was computed and mapped using multi-temporal airborne lidar data in wide area. The stem volume using field measured tree parameters were interpolated and mapped by the airborne lidar data and the mapped biomass was used as the ground truth for radar image to see the polarization change caused by the thinning. The polarization axis of HV/HH backscattering coefficients is shifted in 9.8 degrees. This axis change is a useful indicator for the end member analysis using HV/HH polarization.

It is often argued that rapidly increasing video content along with the penetration of high-speed access is leading to explosive growth in the Internet traffic. Contrary to this popular claim, technically solid reports show only modest traffic growth worldwide. This paper sheds light on the causes of the apparently slow growth trends by analyzing commercial residential traffic in Japan where the fiber access rate is much higher than other countries. We first report that Japanese residential traffic also has modest growth rates using aggregated measurements from six ISPs. Then, we investigate residential per-customer traffic in one ISP by comparing traffic in 2005 and 2008, before and after the advent of YouTube and other similar services. Although at first glance a small segment of peer-to-peer users still dictate the overall volume, they are slightly decreasing in population and volume share. Meanwhile, the rest of the users are steadily moving towards rich media content with increased diversity. Surely, a huge amount of online data and abundant headroom in access capacity can conceivably lead to a massive traffic growth at some point in the future. The observed trends, however, suggest that video content is unlikely to disastrously overflow the Internet, at least not anytime soon.

It has been reported worldwide that peer-to-peer traffic is taking up a significant portion of backbone networks. In particular, it is prominent in Japan because of the high penetration rate of fiber-based broadband access. In this paper, we first report aggregated traffic measurements collected over 21 months from seven ISPs covering 42% of the Japanese backbone traffic. The backbone is dominated by symmetric residential traffic which increased 37%in 2005. We further investigate residential per-customer trafficc in one of the ISPs by comparing DSL and fiber users, heavy-hitters and normal users, and geographic traffic matrices. The results reveal that a small segment of users dictate the overall behavior; 4% of heavy-hitters account for 75% of the inbound volume, and the fiber users account for 86%of the inbound volume. About 63%of the total residential volume is user-to-user traffic. The dominant applications exhibit poor locality and communicate with a wide range and number of peers. The distribution of heavy-hitters is heavy-tailed without a clear boundary between heavy-hitters and normal users, which suggests that users start playing with peer-to-peer applications, become heavy-hitters, and eventually shift from DSL to fiber. We provide conclusive empirical evidence from a large and diverse set of commercial backbone data that the emergence of new attractive applications has drastically affected traffic usage and capacity engineering requirements.

A rapid, stable decoupled algorithm for solving semiconductor hydrodynamic equations is proposed. First, the Newton iterations to solve each set of equations are omitted. This causes no change in obtained solutions nor in the block convergence. Second, in place of the exact Jacobian matrix, a reduced Jacobian matrix is constructed and used to solve the energy balance equation. This reduced-Jacobian-matrix method is applied to two different hydrodynamic formulations and shown to be very effective, in both formulations, in accelerating the block convergence speed of the decoupled algorithm. The method provides an efficient version of the decoupled algorithm, which is very simple and applicable to a large variety of hydrodynamic formulations.>

WIDE (Widely Integrated Distributed Environment) is a research project aimed at achieving a transparent distributed environment over heterogeneous distributed computing elements with the consideration of various types of connections for internetworking. The target environment of the research is computing environment in the academic and research communities especially in Japan.