A5102027037- Inertial Sensor and Navigation
- Planetary Science and Exploration
- Space Satellite Systems and Control
- Geophysics and Gravity Measurements
- GNSS positioning and interference
- Robotics and Sensor-Based Localization
- Spacecraft Dynamics and Control
- Pulsars and Gravitational Waves Research
- Advanced Frequency and Time Standards
- Spacecraft Design and Technology
- Organic Light-Emitting Diodes Research
- Robotic Path Planning Algorithms
- Magnetic Bearings and Levitation Dynamics
- Electric Motor Design and Analysis
- Organic Electronics and Photovoltaics
- Luminescence and Fluorescent Materials
- Blind Source Separation Techniques
- Geophysics and Sensor Technology
- Biofuel production and bioconversion
- Astro and Planetary Science
- Magnetic Properties and Applications
- Algal biology and biofuel production
- Biomimetic flight and propulsion mechanisms
- Advanced Wireless Communication Techniques
- Risk and Safety Analysis
Jet Propulsion Laboratory
2020-2025
Southern Taiwan University of Science and Technology
2022
University of California, Los Angeles
2017-2020
Tamkang University
2019-2020
National Taipei University of Technology
2015
NextGen Aeronautics (United States)
2014
National Cheng Kung University
2013
Fu Jen Catholic University
2013
Abstract Near‐infrared organic light‐emitting diodes (NIR OLEDs) enable many unique applications ranging from night‐vision displays and photodynamic therapies. However, the development of efficient NIR OLEDs with a low efficiency roll‐off is still challenging. Here, series new heteroleptic Pt(II) complexes ( 1 – 4 ) flanked by both pyridyl pyrimidinate functional azolate chelates are synthesized. The reduced ππ * energy gap chelate, strong intermolecular interaction high crystallinity in...
Abstract Pt(II) metal complexes are known to exhibit strong solid‐state aggregation and promising for realization of efficient emission in fabrication organic light emitting diodes (OLED) with nondoped emitter layer. Four pyrimidine–pyrazolate based chelates, together four isomeric complexes, namely: [Pt(pm2z) 2 ], [Pt(tpm2z) [Pt(pm4z) [Pt(tpm4z) isolated systematically investigated their structure–property relationships practical OLED applications. Detailed single molecular aggregated...
Localization of a mobile robot in the absence an absolute position sensor often relies on techniques such as visual or lidar-inertial odometry. While lidar has many advantages, most capable sensors use scanning mechanisms, leading to motion-distorted scans. Previous strategies used account for motion when performing state estimation and outlier rejection have drawbacks highly dynamic, resource-constrained robots spacecraft during descent landing. In this letter we develop novel probabilistic...
Three homoleptic Pt(II) metal complexes [Pt(imPz)2] (1), [Pt(imiz)2] (2), and [Pt(imMz)2] (3) were synthesized from the treatment of Pt(DMSO)2Cl2 functional imidazolyl pyrazole in refluxing tetrahydrofuran (THF). Alternatively, heteroleptic [Pt(imPz)(fppz)] (4), [Pt(imiz)(fppz)] (5), [Pt(imMz)(fppz)] (6) obtained a common intermediate [Pt(fppzH)Cl2] with corresponding chelate. 1, 2, 5 studied by single-crystal X-ray diffraction to reveal packing arrangement their crystal lattices, among...
Microalgal biofuels have been long considered as potentially clean and sustainable alternatives to conventional fossil fuels. In this study, several parameters, including light intensity, initial nitrogen concentration, starvation duration were investigated for their effects on biomass production carbohydrate accumulation of Chlorella vulgaris FSP-E by using two well-established modeling optimization methods, namely response surface methodology (RSM) artificial neural networks (ANN). RSM...
In this paper, autonomous pulsar-based spacecraft navigation is formulated in terms of a single nonlinear filter. The observability and the positioning accuracy traveling at known constant velocity are analyzed to build insights into general problem. A variation extended Kalman filter developed implemented track Poisson pulsar measurements collected by an orbiting spacecraft. This leverages multirate structure more efficiently process measurements. An alternative formulation using quadrature...
This paper outlines a method using finite-element analysis (FEA) to model the magnetization process of small brushless surface-magnet three-phase motor with isotropic ferrite magnets and concentrated windings. is aimed at allowing in situ machine winding. Radial nominal manufactured pattern; however, leads variation pattern, performance examined open-circuit simulations. The properties magnet material (a 5 type) are order simulate magnetization. Bulk Hs-sat levels for type indicate that...
The SPLICE project is continuing NASA's efforts to develop precision landing GN&C technologies for future lander missions. One of those the next generation Hazard Detection (HD) System, which consists a new HD Lidar and Algorithms. System modular system that will be adapted meet specific mission needs in future. This paper presents design approach, nominal concept operations first prototype being designed, expected performance system.
Future lander missions will travel to ambitious, scientifically interesting locations near rough and dangerous terrain. They need operate with limited prior information about the terrain, under varying lighting conditions. Landing safely precisely in face of these challenges is difficult for existing vision-based landing systems, which require detailed orbital reconnaissance, a priori hazard maps, impose time-of-day restrictions on ensure similar conditions descent imagery. Advanced 3D...
This paper evaluates the performance of surface-mounted permanent-magnet (PM) machines with anisotropic rare-earth magnets magnetized using its own stator windings. The in this process (often called in-situ magnetization) are after complete assembly. For manufacture PM process, part magnet may suffer from weaker magnetization due to magnetizing flux pattern, particular on two sides magnets. machine can thus be affected and needs evaluated. current required sufficiently magnetize should...
NAVIGATION is a quarterly journal published by the Institute of Navigation. The publishes original, peer-reviewed articles on all aspects positioning, navigation, and timing. also selected technical notes survey articles, as well papers exceptional quality drawn from Institute's conference proceedings.
Human-scale missions to Mars will likely require multiple landers delivered precisely designated locations. The current NASA human reference architecture assumes delivery of three 25 t payloads from a 1- or 5-Sol orbit the surface with landing precision 50 m ensure logistics are located near habitat. While initial navigation estimates improve on-orbit ground tracking, errors increase during post-deorbit coast. Likewise, atmospheric variability and forecasting uncertainty means that entry...
To meet NASA’s challenge to return humans the Moon in 2024 and establish a sustainable presence 2028 requires advances autonomous spacecraft navigation. The Safe Precise Landing Integrated Capabilities Evolution (SPLICE) project, which leverages previous work at NASA develop multi-mission precision landing hazard avoidance technologies, is using multi-faceted approach achieve advanced requirements. In addition increasing technology readiness level of key sensors developing high performance...
This paper discusses the observability analysis, estimation algorithm, numerical simulation, and experimental verification of a pulsar-based positioning system. system relies on unscented Kalman filter several open source pulsar timing software libraries to estimate observatory position in an Earth-fixed coordinate Monte Carlo analysis was used numerically verify implementation. Pulsar time-of-arrival data obtained from L-band measurements were for verification. The result this research...
NASA has established goals of returning humans to Moon by 2024 with a sustained presence 2028, which will require technological advances in spacecraft navigation enable precision landing. The ability assess the performance these new and existing technologies is critical identifying areas risk reduction investment. To that end, Safe Precise Landing Integrated Capabilities Evolution (SPLICE) project demonstrated detailed six degree-of-freedom integrated simulation framework can provide...
Pulsars are natural space navigation beacons. They provide and timing information from multiple directions at all times. Pulsar has been demonstrated using data collected large X-ray telescopes. However, in order to make this technique practical for spacecraft, the photon receiver be miniaturized. As a result, estimation algorithm overcome challenges associated with low signal-to-noise ratio measurements position uncertainty greater than pulsar wavelength. In article, we utilize Bayesian...
The fusion of LiDAR and inertial measurements during spacecraft descent landing can be used to estimate a lander's navigation state map the terrain below. Together, these data products enable safe precise on celestial bodies for which priori orbital reconnaissance is insufficient hazard detection avoidance. Unlike camera images in visual relative navigation, scans are insensitive changes illumination; as result, technique land poorly lit areas, or at times day when lighting conditions...