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Implementing the GEOSS water strategy: from observations to decisions

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International Journal of Digital Earth 2023年第1期16卷 1439-1468页

作者： Richard Lawford Sushel Unninayar George J.Huffman Wolfgang Grabs Angélica Gutiérrez Chu Ishida-Watanabe Toshio Koike Morgan State University BaltimoreUSA NASA Goddard Space Flight Center GreenbeltUSA International Water Affairs Federal Institute of HydrologyKoblenz National Oceanic and Atmospheric Administration Silver SpringUSA japan Aerospace exploration agency Tsukuba International Centre for Water Hazard and Risk Management Tsukuba

In 2014,The GEOSS Water Strategy–From Observations to Decisions was published and steps were taken to implement the Strategy’s *** Strategy highlighted priority areas where the application of Earth observations to water research and water management decisions would have significant scientific and societal *** article reviews the implementation of the Strategy’s recommendations over the past eight *** a review of the Strategy’s assessment of the needs for water observations and their applications,it then reviews actions taken in response to the Strategy’s recommendations in its four major themes:improved data acquisition for Essential Water Variables,research and product development,interoperability,and capacity *** highlights significant achievements in the implementation of the Strategy including some motivated by factors beyond this Strategy,reviews actions taken by participating agencies and programs for each of the main themes and summarizes the remaining challenges in achieving the Strategy’s full *** article not only is an update for the Water Community regarding the GEOSS Water Strategy,but it is also an example of how other communities could develop and promulgate a set of strategic recommendations,monitor progress,and carry out assessments of their effectiveness.

关键词： Earth observations water essential water variables research interoperability capacity development

Summary of Studies on Space Solar Power Systems of japan Aerospace exploration agency

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Summary of Studies on Space Solar Power Systems of Japan Aer...

Automatic Damage Detection and Monitoring of a Stitch Laminate System Using a Fiber Bragg Grating Strain Sensor

2004无线电科学国际会议

作者： Masahiro Mori Yuka Saito japan Aerospace exploration agency 2-1-1 Sengen Tsukuba Ibaraki 305-8505 Japan japan Aerospace exploration agency 2-1-1 Sengen Tsukuba Ibaraki 305-8505 Japan

japan Aerospace exploration agency (JAXA) has been conducting studies on Space Solar Power Systems (SSPS) using microwave and laser beams for years since FY1998 organizing a special committee and wor

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Open Journal of Composite Materials 2014年第1期4卷 47-60页

作者： Agus Trilaksono Naoyuki Watanabe Atsushi Kondo Hikaru Hoshi Yutaka Iwahori Composite Technology Centre Japan Aero- space Exploration Agency Tokyo Japan Department of Aerospace Engineering Tokyo Metropolitan University Tokyo Japan

There are numerous aspects and questions related to the use of composite materials for primary structures in aircraft where the structural integrity is the most important factor. This is especially true if the main concerns are that the material should have good reliability and durability for the primary structural application. Composite laminates are highly sensitive to out-of-plane failure due to their low inter laminar fracture toughness. An alternate method to increase the damage resistance is through three-dimensional fibrous reinforcement such as through-the-thickness stitching with a single fiber as the thread. Recent studies have shown that the stitching of standard laminates can enhance damage tolerance to levels obtainable with toughened resin systems. However, for next-generation aircraft, material improvement alone is not enough to assure or increase the safety and reliability of the structure. Continuous damage monitoring during operation will become an important issue in aircraft safety. Embed ding fiber Bragg grating (FBG) technology into the composite structure as strain sensors could potentially solve the above problem because the FBG can be used to detect and characterize the damage before it reaches a critical stage. The model used to represent this problem is a 6 × 6 Vectran stitched carbon/ epoxy laminate under tension loading, and the real-time monitoring using the FBG strain sensors is combined with acoustic emissions that were conducted during the test. A numerical laminate theory using a rebar element and first-ply failure criterion is performed to determine the preferred area on the specimen for the placement of the FBG before manufacturing and testing. Experiments are presented to determine the damage growth that was quantified with an ultrasonic (water immersion) c-scan. In this research, the FBG successfully detected and characterized the damage in the carbon/epoxy stitch laminate caused in tension loading cases. The FBG is enhanced with

关键词： Carbon Fiber Stitch Laminate Damage Tolerance Structural Health Monitoring

Operating Characteristics of Multiple Evaporators and Multiple Condensers Loop Heat Pipe with Polytetrafluoroethylene Wicks

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Journal of Electronics Cooling and Thermal Control 2014年第1期4卷 22-32页

作者： Sho Okutani Hosei Nagano Shun Okazaki Hiroyuki Ogawa Hiroki Nagai Department of Aerospace Engineering Nagoya University Nagoya Japan Department of Aerospace Engineering Tohoku University Sendai Japan japan Aerospace exploration agency Sagamihara Japan

This paper presents fabrication and testing of a multiple-evaporator and multiple-condenser loop heat pipe (MLHP) with polytetrafluoroethylene (PTFE) porous media as wicks. The MLHP has two evaporators and two condensers in a loop heat pipe in order to adapt to various changes of thermal condition in spacecraft. The PTFE porous media was used as the primary wicks to reduce heat leak from evaporators to compensation chambers. The tests were conducted under an atmospheric condition. In the tests that heat loads are applied to both evaporators, the MLHP was stably operated as with a LHP with a single evaporator and a single condenser. The relation between the sink temperature and the thermal resistance was experimentally evaluated. In the test with the heat load to one evaporator, the heat transfer from the heated evaporator to the unheated evaporator was confirmed. In the heat load switching test, in which the heat load is switched from one evaporator to another evaporator repeatedly, the MLHP could be stably operated. The loop operation with the large temperature difference between the heat sinks was also tested. From this result, the stable operation of the MLHP in the various conditions was demonstrated. It was also found that a flow regulator which prevents the uncondensed vapor from the condensers is required at the inlet of the common liquid line when one condenser has higher temperature and cannot condense the vapor in it.

关键词： Loop Heat Pipe Multiple Evaporators Multiple Condensers Thermal Control Two-Phase Heat Transfer

Evaluating 3D position and velocity of subject in parabolic flight experiment by use of the binocular stereo vision measurement

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Chinese Optics Letters 2010年第6期8卷 601-605页

作者：金涛贾宏志侯文玫 Ryo Yamamoto Norihiro Nagai Yusaku Fujii Koichi Maru Naoya Ohta Kazuhito Shimada Shanghai Key Laboratory of Modern Optical System School of Optical-Electrical and Computer EngineeringUniversity of Shanghai for Science and Technology Department of Electronic Engineering Faculty of EngineeringGunma University Department of Computer Science Faculty of EngineeringGunma University Medical Operations Japan Aerospace Exploration Agency(JAXA)JAXA Houston OfficeHouston 77058USA

A practical method for evaluating the three-dimensional（3D） position and velocity of a moving object used in the parabolic flight experiment is developed by using the binocular stereo vision measurement theory. The camera calibration mathematic model without considering the lens distortion is *** direct linear transformation（DLT） algorithm is improved to accomplish the camera *** camera calibration result and optimization algorithm are used to calculate the object＇s world coordinate from image *** 3D position and the velocity of the moving object are *** standard uncertainty in estimating the velocity is 0.0024 m/s,which corresponds to 1%level of the velocity of the object in the *** results show that this method is very useful for the parabolic flight experiments.

关键词： Binoculars Calibration Cameras Experiments Linear transformations Measurement theory Three dimensional Uncertainty analysis Velocity

Achievements and Current Status of Space Science in japan

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Achievements and Current Status of Space Science in Japan

Investigation of the Mechanical Behavior of a Thin Composite Stiffened Skin with a Combined Joint

第六届中日微重力科学专题研讨会

作者： Takeo KOSUGI Institute of Space and Astronautical Science japan Space exploration agency SagamiharaKanagawa 229-8510 Japan

＜正＞1. History of ISAS In 1955 Professor Itokawa and colleagues of the University of Tokyo conducted small but important experiments with tiny "Pencil" rockets of 23 cm in length. This was japan’s first step toward the development of an indigenous sounding rocket for participation in the IGY activities from 1957 to 1958. Since then, several big steps were taken. The Institute of Space and Aeronautical Science was founded in the University of Tokyo in 1964. From the beginning, it was so designed as a national center for space science and an inter-university joint research facility, open to university-based space researchers in

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Journal of Mechanics Engineering and Automation 2013年第7期3卷 428-440页

作者： Agus Trilaksono Naoyuki Watanabe Hikaru Hoshi Atsushi Kondo Yutaka Iwahori Shinichi Takeda Department of Aerospace Engineering Tokyo Metropolitan University Tokyo 191-0065 Japan Composite Technology Centre Japan Aerospace Exploration Agency Tokyo 181-0015 Japan

Many joint models available to predict secondary bending moments in the structure have a stiffness mismatch, while this type of structure widely used in aircraft. To determine how to represent a structure with a stiffness mismatch in a combined joint （bonded/riveted）, a non-linear finite element analysis was performed. The detailed validation of this analysis identified the composite stiffened skin as the most suitable model in three dimensions. The use of this model for validating the secondary bending moment to calculate the behavior of the stiffener edge is straightforward and reliable. Experiments were performed to determine the distribution of the load in a combined joint under a tensile load that creates a secondary bending moment in a structure with a stiffness mismatch. The influence of related joint design considerations on the load transferred by the joint were examined through a finite element parameter analysis. The results are compared to determine best approach to predict the mechanical behavior at the edge of the stiffener. A close agreement between the finite element analysis and experimental results was obtained. Test observations using a C-scan compared well with the predictions of the onset of crack growth.

关键词： Carbon fiber delamination joints/joining cohesive elements secondary bending moment.

Vortex Dissipation Due to Airfoil-Vortex Interaction

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Journal of Mechanics Engineering and Automation 2014年第1期4卷 63-71页

作者： Masahiro Kanazaki Keitaroh Ohshio Masahiko Sugiura Department of Aerospace Engineering Graduate School of System Design Tokyo Metropolitan University japan Aerospace exploration agency Institute of Aeronautics

The influences due to several AVIs （airfoil-vortex interactions） are studied by using a two-dimensional CFD （computational fluid dynamics） method. The primary goal of this effort is to assess the variation of vortex center location and vortex circulation associated with sequential AVI toward an improvement of the hybrid method of CFD and prescribed wake model, which closely relates to predicting the BVI （blade-vortex interaction） noise radiated from a helicopter rotor. The representative of sequential AVI is performed by single vortex and two airfoils. Investigations with respect to vortex center location and vortex circulation after AVIs have been made by varying the miss-distance, which is the vertical distance between the airfoil leading edge and the vortex center. Correlations between miss-distance and vorticity field show that there exists complicated vortex wake flow with several vortices newly induced in 1st AVI. The pressure fluctuation amplitude clarifies that the intensity in 2nd AV1 is significantly low compared to the intensity in 1st AVI due to the influence of vortex dissipation. Simulations turned out to modify the vortex center location represented by the hybrid method using an offset value for a streamwise direction and to dissipate the vortex circulation for improving the accuracy of BVI noise prediction.

关键词： Helicopter noise airfoil-vortex interaction vortex dissipation computational fluid dynamics.

Damage Monitoring in Composite Stiffened Skin Using Fiber Bragg Grating under Tensile and Three-Point Loading

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Journal of Mechanics Engineering and Automation 2013年第4期3卷 227-237页

One of the problems associated with loading a fully composite structure with joints is that the loads are not linear through the neutral axis of the structure but are collinear; this induces additional moment and creates a load in the normal direction, which is typically a critical load because it can create delamination and can only be withstood if it is small. Another problem is that the structure is difficult to inspect using conventional methods because of limited accessibility. With fiber Bragg grating （FBG）, the problem can potentially be solved in structures with a stiffness mismatch. The model used to represent the problem above is a composite stiffened skin with two loading cases： tensile and three-point bending. Additionally, FBG is used to monitor and characterize the delamination caused by both loading cases. Finite element modeling （FEM） with traction versus separation theory is performed to determine the critical area on the specimen for placement of the FBG before manufacturing and testing. In this research, FBG can successfully monitor and characterize delamination caused by both loading cases in structures that have mismatched stiffnesses. Also, FBG can predict the delamination growth quantitatively. A spectrum graph of the FBG results can be used to replace a conventional mechanical graph for use in structural health monitoring.

关键词： Carbon fiber composite structural health monitoring delamination joints/joining smart structure