Integrating the 1st Person View and the 3rd Person View Using a Connected VR-MR System for Pilot Training

Many virtual reality (VR)-based flight simulation programs provide pilots the enhanced reality from the 1st person-view to make themselves immersed in the cockpit. Using the VR simulations, pilots can take flight training in many challenging situations that are hard to create in real environments due to its natural entropy and safety concerns such as severe crosswind or engine fire. Mixed reality (MR) technology provides three-dimensional graphics so that users can effectively see all 360 degree-vertical and horizontal aspects of an object while they freely move around to see the graphics maintaining the consciousness of real space. Flight instructors may want to monitor the progress of an airplane itself above many regions from the 3rd person view as well as how the airplane’s pilot follows the desired flight procedures in the cockpit from the 1st person view. The investigators developed the prototype of a comprehensive pilot training system by connecting VR and MR that make both views available to evaluate a pilot’s flight performance from various aspects. Five flight instructors provided their feedbacks after trying the prototype system. They revealed that the prototype would provide a fast and accurate evaluation of pilot performance for novice pilots and insights to develop more economic and safer flight paths in a certain region. The function of evaluating two different perspectives for a single flight operation at the same time will provide an unprecedented advantage to the conventional training and monitoring environments that have been separated or the 2D base

Integrating the First Person View and the Third Person View Using a Connected VR-MR System for Pilot Training

Virtual reality (VR)-based flight simulator provides pilots the enhanced reality from the first-person view. Mixed reality (MR) technology generates effective 3D graphics. The users who wear the MR headset can walk around the 3D graphics to see all its 360 degrees of vertical and horizontal aspects maintaining the consciousness of real space. A VR flight simulator and an MR application were connected to create the capability of both first-person view and third-person view for a comprehensive pilot training system. This system provided users the capability to monitor the aircraft progress along the planned path from the third-person view as well as how the aircraft pilot follows the desired flight procedures in the cockpit from the first-person view. Six flight instructors provided their feedback after trying the prototype functions. The three flight instructors with more than 1,000 flight hours gave negative feedback whereas the three instructors with less than 1,000 flight hours were more open to the technologies. The effectiveness of MR-based real-time monitoring and post-debriefing system is yet to be clear. However, the test results included the potentials of the prototype for future improvement based on MR technology’s flexibility

Revisiting electromagnetic response of superconductors in mean-field approximation

In the standard mean-field treatment of superconductors, the electron-electron interactions are assumed to be written in terms of local density operators. However, more general interactions, such as pair-hopping interactions, may exist or may be generated in a low-energy effective Hamiltonian. In this work, we study the effect of correlated hopping interactions toward the electromagnetic response of superconductors. When only the Hamiltonian after the mean-field approximation is provided, one cannot unambiguously determine its electromagnetic response whenever such interactions are allowed. This work demonstrates that such interactions induce additional terms in the current operator, leading to modifications in the Meissner weight and optical conductivities that deviate from conventional expectations. These results underscore the need for caution when incorporating gauge fields into the BdG Hamiltonian.Comment: 6+7 pages, 3 figures; v2: discussions clarified, a new figure adde

Symmetry-Protected Solitons and Bulk-Boundary Correspondence in Generalized Jackiw-Rebbi Models

We investigate the roles of symmetry and bulk-boundary correspondence in characterizing topological edge states in generalized Jackiw-Rebbi (JR) models. We show that time-reversal ($T$), charge-conjugation ($C$), parity ($P$), and discrete internal field rotation ($Z_n$) symmetries protect and characterize the various types of edge states such as chiral and nonchiral solitons via bulk-boundary correspondence in the presence of the multiple vacua. As two representative models, we consider the JR model composed of a single fermion field having a complex mass and the generalized JR model with two massless but interacting fermion fields. The JR model shows nonchiral solitons with the $Z_2$ rotation symmetry, whereas it shows chiral solitons with the broken $Z_2$ rotation symmetry. In the generalized JR model, only nonchiral solitons can emerge with only $Z_2$ rotation symmetry, whereas both chiral and nonchiral solitons can exist with enhanced $Z_4$ rotation symmetry. Moreover, we find that the nonchiral solitons have $C, P$ symmetries while the chiral solitons do not, which can be explained by the symmetry-invariant lines connecting degenerate vacua. Finally, we find the symmetry correspondence between multiply-degenerate global vacua and solitons such that ${T}$, ${C}$, ${P}$ symmetries of a soliton inherit from global minima that are connected by the soliton, which provides a novel tool for the characterization of topological solitons

Design of Revising Proximity between Space and Time Cues on Flight Deck Displays to Support NextGen – The First Phase

The objective of this study is to develop and evaluate novel display formats to support RTA operations for near to midterm NextGen. Traditional cockpit displays separate space and time information in distant display sources in heterogeneous formats (graphics vs. text). This design composition may cause potential pilot errors when required time of arrival (RTA) obligations are imposed at every waypoint in NextGen. Pilots were randomly assigned to four different display conditions in a simulator – one traditional display with distant space and time cues, and three novel displays with close spatial proximity between the two cues. In the first phase of the experiment for this paper, pilots firstly participated in query tests answering space/time statuses during autopilot RTA flights. The novel displays did not degrade pilots’ situation awareness of space-time as an objective measure. For subjective measure, their situation awareness was significantly higher when the space and time cues were integrated into a single display with graphical temporal conformance indicators. The close spatial proximity between space and time cues and the support of graphical temporal conformance indicator showed a promise for improved RTA navigation

Design of Revising Proximity between Space and Time Cues on Flight Deck Displays to Support NextGen – The Second Phase

The prior first phase of this study investigated the effectiveness of new design of flight deck display for required time of arrival operation of NextGen by collecting objective query response data during autopilot flights and subjective data about the perception between display condition and situation awareness level. To evaluate pilots’ mental workload during the operations when they interacted with novel flight deck display design, this second phase provided pilots with simulation flight tasks arriving at four successive waypoints on time in the same display conditions as the first phase and asked them to rate their mental workload ratings. The workload was significantly lower with the High Proximity condition - all space and time data were integrated into a single display and temporal conformance graphics were added removing the need of control display unit - than with the traditional display condition. This result strengthened the implications from the first phase: the close spatial proximity between space and time cues and the support of graphical temporal conformance indicator showed a promise for improved required time of arrival navigation

Long distance fiber Bragg grating strain sensor interrogation using a high speed Raman-based Fourier domain mode-locked fiber laser with recycled residual Raman pump

We propose a novel fiber Bragg grating (FBG) sensor interrogation using a Raman-based Fourier-domain mode locking (FDML) fiber laser for a high speed and long distance measurement. A residual Raman pump after the generation of the Raman-based FDML fiber laser is recycled for secondary signal amplification in a 2-m erbium-doped fiber (EDF) to further enhance the output power. The chromatic dispersion is precisely controlled to suppress the phase noise in the FDML laser cavity, resulting in the improvement of an R-number of 1.43 mm/dB. After recycling residual pump, we achieve the 40-km round trip transmission of the sensing probe signal with a high scan rate of 30.8 kHz. With 205-mW residual pump power, the bandwidth and the maximum gain are measured to be more than 50 nm, 10.3 dB at 1550 nm, respectively. The sensitivity of the proposed Raman-based FDML fiber laser to strain is also measured, which are 0.81 pm/μstrain in the spectral domain and 0.19 ns/μstrain in the time domain, respectively

Microporation is a valuable transfection method for efficient gene delivery into human umbilical cord blood-derived mesenchymal stem cells

<p>Abstract</p> <p>Background</p> <p>Mesenchymal stem cells (MSCs) are an attractive source of adult stem cells for therapeutic application in clinical study. Genetic modification of MSCs with beneficial genes makes them more effective for therapeutic use. However, it is difficult to transduce genes into MSCs by common transfection methods, especially nonviral methods. In this study, we applied microporation technology as a novel electroporation technique to introduce enhanced green fluorescent protein (EGFP) and brain-derived neurotropfic factor (BDNF) plasmid DNA into human umbilical cord blood-derived MSCs (hUCB-MSCs) with significant efficiency, and investigated the stem cell potentiality of engineered MSCs through their phenotypes, proliferative capacity, ability to differentiate into multiple lineages, and migration ability towards malignant glioma cells.</p> <p>Results</p> <p>Using microporation with EGFP as a reporter gene, hUCB-MSCs were transfected with higher efficiency (83%) and only minimal cell damage than when conventional liposome-based reagent (<20%) or established electroporation methods were used (30-40%). More importantly, microporation did not affect the immunophenotype of hUCB-MSCs, their proliferation activity, ability to differentiate into mesodermal and ectodermal lineages, or migration ability towards cancer cells. In addition, the BDNF gene could be successfully transfected into hUCB-MSCs, and BDNF expression remained fairly constant for the first 2 weeks <it>in vitro </it>and <it>in vivo</it>. Moreover, microporation of BDNF gene into hUCB-MSCs promoted their <it>in vitro </it>differentiation into neural cells.</p> <p>Conclusion</p> <p>Taken together, the present data demonstrates the value of microporation as an efficient means of transfection of MSCs without changing their multiple properties. Gene delivery by microporation may enhance the feasibility of transgenic stem cell therapy.</p

Recommendations Supporting Development of Flight Deck DataComm Text and Graphic Display Evaluation Guidance

In the Next Generation Air Transportation System (NexGen), voice communications will become less frequent, and most communication will occur via data communications -- uplink messages (UM) (to pilot) and downlink messages (DM) and requests (to ATC). Clearances may include simple one-element clearances such as CLIMB TO [altitude] or complex clearances created by concatenating messages to create flight trajectories that include ATC-authorized route segments, altitudes, and at least one required time of arrival (RTA). Due to the complexity of clearances, aircraft and flight deck equipment manufacturers may seek approval for new and modified flight deck displays to more clearly depict clearances to the flight crew, likely using text and graphics. This research evaluated text and hybrid text and graphic concepts to develop human factors (HF) recommendations for specialists who participate in certification of new and modified flight deck DataComm displays, and as a potential update to AC 20-140, Guidelines for Design Approval of Aircraft Data Link Communication Systems Supporting Air Traffic Services (ATS)