How to Keep the Binary Compatibility of C++ Based Objects

This chapter proposes the binary compatibility object model for C++ (BiCOMC) to provide the binary compatibility of software components in order to share objects among C++ based executable files such as .exe, .dll, and .so. In addition, the proposed model provides the method overriding and overloading, multiple inheritance, and exception handling. This chapter illustrates how to use the proposed model via a simple example in the Windows and Linux environment. The proposed method is validated by application examples and comparisons with known object models such as C++, COM, and CCC in terms of the call time of a method during execution and the binary compatibility such as reusability due to interface version and the types of compilers. Also this chapter shows that BiCOMC-based components compiled with Microsoft Visual C++ and GCC can call each other and the interface version problems are resolved

Real-Time Robot Software Platform for Industrial Application

In this study, we present the requirements of a real-time robot software (SW) platform that can be used for industrial robots and examine whether various kinds of existing middleware satisfy them. Moreover, we propose a real-time robot SW platform that extends RTMIA to various industrial applications, which is implemented on Xenomai real-time operating system and Linux. The proposed SW platform utilizes the timer-interrupt based approach to keep strict period and the shared memory for convenient usage, on which the shared variable is designed and used. We verify the proposed platform by showing that the robot task and the Programmable Logic Controller (PLC) program are performing with interlocking each other on the presented platform

Preferred listening levels of mobile phone programs when considering subway interior noise

Today, people listen to music loud using personal listening devices. Although a majority of studies have reported that the high volume played on these listening devices produces a latent risk of hearing problems, there is a lack of studies on "double noise exposures" such as environmental noise plus recreational noise. The present study measures the preferred listening levels of a mobile phone program with subway interior noise for 74 normal-hearing participants in five age groups (ranging from 20s to 60s). The speakers presented the subway interior noise at 73.45 dB, while each subject listened to three application programs [Digital Multimedia Broadcasting (DMB), music, game] for 30 min using a tablet personal computer with an earphone. The participants′ earphone volume levels were analyzed using a sound level meter and a 2cc coupler. Overall, the results showed that those in their 20s listened to the three programs significantly louder with DMB set at significantly higher volume levels than for the other programs. Higher volume levels were needed for middle frequency compared to the lower and higher frequencies. We concluded that any potential risk of noise-induced hearing loss for mobile phone users should be communicated when users listen regularly, although the volume level was not high enough that the users felt uncomfortable. When considering individual listening habits on mobile phones, further study to predict total accumulated environmental noise is still needed

A New Cycle-Slip Detection Algorithm for Network RTK Using Optimal Dual-Frequency Carrier-Phase Combinations

International audienceMany strategies for treating dual-frequency cycle slip have been studied over the years; however, the conventional method using the Melbourne-Wübbena (MW) combination is vulnerable to pseudorange multipath effects. In this paper, we propose a new detection algorithm of dual-frequency cycle slip using only carrier-phase stationary observations for the network real-time kinematic (RTK) system which generates high-precision corrections for user. Two independent and complementary carrierphase combinations, called the ionospheric negative (IN) and ionospheric positive (IP) combinations in this paper, are employed for avoiding insensitive pairs. They can successfully detect all of the cycle slips since two L1/L2 combinations combine cycle slips with opposite signs for uniquely detecting insensitive pairs. We verified that the actual error distributions under severe ionospheric storm of these monitoring values can be sufficiently bounded by the normal Gaussian distribution from a theoretical analysis. Consequently, we demonstrated that the proposed method ensures high-integrity performance with a probability of missed detection of 7.5 × 10?9 .under a desired false-alarm probability of 10?5 . In addition, the IN and IP combination shows the best detection performance than the other linear combinations such as ionosphere-free, wide-lane, and narrow-lane. Through an algorithm verification test using actual data collected under a severe ionospheric storm, we confirmed that all artificially inserted cycle slips are successfully detected. In conclusion, the proposed method is confirmed to be effective for handling dual-frequency cycle slips for network RTK system

Covariance Analysis of Real-Time Precise GPS Orbit Estimated from Double-Differenced Carrier Phase Observations

The covariance of real-time global positioning system (GPS) orbits has been drawing attention in various fields such as user integrity, navigation performance improvement, and fault detection. The international global navigation satellite system (GNSS) service (IGS) provides real-time orbit standard deviations without correlations between the axes. However, without correlation information, the provided covariance cannot assure the performance of the orbit product, which would, in turn, causes significant problems in fault detection and user integrity. Therefore, we studied real-time GPS orbit covariance characteristics along various coordinates to effectively provide conservative covariance. To this end, the covariance and precise orbits are estimated by means of an extended Kalman filter using double-differenced carrier phase observations of 61 IGS reference stations. Furthermore, we propose a new method for providing covariance to minimize loss of correlation. The method adopted by the IGS, which neglects correlation, requires 4.5 times the size of the covariance to bind orbit errors. By comparison, our proposed method reduces this size from 4.5 to 1.3 using only one additional parameter. In conclusion, the proposed method effectively provides covariance to users

A New Algorithm for High-Integrity Detection and Compensation of Dual-Frequency Cycle Slip under Severe Ionospheric Storm Conditions

Many strategies for treating dual-frequency cycle slip, which can seriously affect the performance of a carrier-phase-based positioning system, have been studied over the years. However, the legacy method using the Melbourne-Wübbena (MW) combination and ionosphere combination is vulnerable to pseudorange multipath effects and high ionospheric storms. In this paper, we propose a robust algorithm to detect and repair dual-frequency cycle slip for the network-based real-time kinematic (RTK) system which generates high-precision corrections for users. Two independent and complementary carrier-phase combinations, called the ionospheric negative and positive combinations in this paper, are employed for avoiding insensitive pairs. In addition, they are treated as second-order time differences to reduce the impact of ionospheric delay even under severe ionospheric storm. We verified that the actual error distributions of these monitoring values can be sufficiently bounded by the normal Gaussian distribution. Consequently, we demonstrated that the proposed method ensures high-integrity performance with a maximum probability of missed detection of 7.5 × 10−9 under a desired false-alarm probability of 10−5. Furthermore, we introduce a LAMBDA-based cycle slip compensation method, which has a failure rate of 1.4 × 10−8. Through an algorithm verification test using data collected under a severe ionospheric storm, we confirmed that artificially inserted cycle slips are successfully detected and compensated for. Thus, the proposed method is confirmed to be effective for handling dual-frequency cycle slips of the network RTK system

Ultrafast light emission at telecom wavelengths from a wafer-scale monolayer graphene enabled by Fabry-Perot interferences

Ultrafast light emission from monolayer graphene shows attractive potential for developing integrated light sources for next-generation graphene-based electronic-photonic integrated circuits. In particular, graphene light sources operating at the telecom wavelengths are highly desired for the implementation of graphene-based ultrahigh-speed optical communication. Currently, most of the studies on ultrafast light emission from graphene have been performed in the visible spectrum, while studies on ultrafast emission at the telecom wavelengths remain scarce. Here, we present experimental observations of strong ultrafast thermal emission at telecom wavelengths from wafer-scale monolayer graphene. Our results show that the emission spectra can be strongly modified by the presence of the cavity effect to produce an enhanced emission at telecom wavelengths. We corroborate our experimental results with simulations and show that by designing a suitable cavity thickness, one can easily tune the emission profile from visible to telecom wavelength regardless of the pump power. In addition, we demonstrate that the insertion of a monolayer of hexagonal boron nitride between graphene and the substrate helps improve the thermal stability of graphene, thereby providing more than five times enhancement of the ultrafast thermal emission. Our results provide a potential solution for stable on-chip nanoscale light sources with ultrahigh speed modulation.Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)National Research Foundation (NRF)Agency for Science, Technology and Research (AME IRG (A2083c0053)); National Research Foundation Singapore (NRF2018-NRF-ANR009 TIGER, NRF-CRP19-2017-01); Ministry of Education - Singapore (AcRF TIER 1 (RG 115/21), AcRF TIER 2 (MOE2018-T2-2-011 (S)))

Efficient avalanche photodiodes with a WSe₂/MoS₂ heterostructure via two-photon absorption

Two-dimensional (2D) materials-based photodetectors in the infrared range hold the key to enabling a wide range of optoelectronics applications including infrared imaging and optical communications. While there exist 2D materials with a narrow bandgap sensitive to infrared photons, a two-photon absorption (TPA) process can also enable infrared photodetection in well-established 2D materials with large bandgaps such as WSe2 and MoS2. However, most of the TPA photodetectors suffer from low responsivity, preventing this method from being widely adopted for infrared photodetection. Herein, we experimentally demonstrate 2D materials-based TPA avalanche photodiodes achieving an ultrahigh responsivity. The WSe2/MoS2 heterostructure absorbs infrared photons with an energy smaller than the material bandgaps via a low-efficiency TPA process. The significant avalanche effect with a gain of ∼1300 improves the responsivity, resulting in the record-high responsivity of 88 μA/W. We believe that this work paves the way toward building practical and high-efficiency 2D materials-based infrared photodetectors.Ministry of Education (MOE)National Research Foundation (NRF)This work is supported by the Ministry of Education, Singapore, under Grant AcRF TIER 1 (RG 115/21)). This work is also supported by the Ministry of Education, Singapore, under Grant AcRF TIER 2 (MOE2018-T2-2-011 (S)). This work is also supported by the National Research Foundation of Singapore (Competitive Research Program (NRF-CRP19-2017-01)). This work is also supported by the National Research Foundation of Singapore (NRF-ANR Joint Grant (NRF2018-NRF-ANR009 TIGER)). This work is also supported by an iGrant of Singapore (A*STAR AME IRG (A2083c0053)). The authors acknowledge Donghoon Lee and Seok Woo Lee at Nanyang Technological University for the usage of the O2 plasma equipment

A two-dimensional mid-infrared optoelectronic retina enabling simultaneous perception and encoding

Infrared machine vision system for object perception and recognition is becoming increasingly important in the Internet of Things era. However, the current system suffers from bulkiness and inefficiency as compared to the human retina with the intelligent and compact neural architecture. Here, we present a retina-inspired mid-infrared (MIR) optoelectronic device based on a two-dimensional (2D) heterostructure for simultaneous data perception and encoding. A single device can perceive the illumination intensity of a MIR stimulus signal, while encoding the intensity into a spike train based on a rate encoding algorithm for subsequent neuromorphic computing with the assistanceofanall-opticalexcitationmechanism, a stochastic near-infrared (NIR) sampling terminal. The device features wide dynamic working range, high encoding precision, and flexible adaption ability to the MIR intensity. Moreover, an inference accuracy more than 96% toMIR MNIST data set encoded by the device is achieved using a trained spiking neural network (SNN).Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)National Medical Research Council (NMRC)National Research Foundation (NRF)Published versionThis work was supported by the Singapore Ministry of Education (MOE-T2EP50120-0009 (Q.J.W.)), Agency for Science, Technology and Research (A*STAR) (A18A7b0058 (Q.J.W.) and A2090b0144 (Q.J.W.)), National Medical Research Council (NMRC) (021528- 00001 (Q.J.W.)), and National Research Foundation Singapore (NRF-CRP22-2019-0007 (Q.J.W.)), National Key Research and Development Program of China (2022YFB2802803 (N.C.)), the Natural Science Foundation of China Project (61925104 (N.C.), 62031011 (N.C.)) and Major Key Project of PCL (N.C.), and F.H. acknowledges the support from the China Scholarship Council