24 research outputs found
Pitfalls in machine learningâbased assessment of tumorâinfiltrating lymphocytes in breast cancer: a report of the international immunoâoncology biomarker working group
The clinical significance of the tumor-immune interaction in breast cancer (BC) has been well established, and tumor-infiltrating lymphocytes (TILs) have emerged as a predictive and prognostic biomarker for patients with triple-negative (estrogen receptor, progesterone receptor, and HER2 negative) breast cancer (TNBC) and HER2-positive breast cancer. How computational assessment of TILs can complement manual TIL-assessment in trial- and daily practices is currently debated and still unclear. Recent efforts to use machine learning (ML) for the automated evaluation of TILs show promising results. We review state-of-the-art approaches and identify pitfalls and challenges by studying the root cause of ML discordances in comparison to manual TILs quantification. We categorize our findings into four main topics; (i) technical slide issues, (ii) ML and image analysis aspects, (iii) data challenges, and (iv) validation issues. The main reason for discordant assessments is the inclusion of false-positive areas or cells identified by performance on certain tissue patterns, or design choices in the computational implementation. To aid the adoption of ML in TILs assessment, we provide an in-depth discussion of ML and image analysis including validation issues that need to be considered before reliable computational reporting of TILs can be incorporated into the trial- and routine clinical management of patients with TNBC
Effect of blue filter on the SNR and data rate for indoor visible light communication system
\u3cp\u3eFor an indoor Visible Light Communication system with phosphorescent LEDs, we show a blue receive filter is particularly suitable for cool-white LEDs but less attractive for warm-white LEDs. Distance and sunlight also influence whether a blue filter should be used.\u3c/p\u3
High-capacity optical wireless communication using 2-dimensional IR beam steering
\u3cp\u3eBy remotely-controlled 2D steering of multiple infrared beams using wavelength tuning and a compact fully passive AWGR-based module, simultaneous communication at 20Gbit/s OOK per beam is shown. A total throughput capacity of 1.6Tbit/s can be achieved.\u3c/p\u3
LED power consumption in joint illumination and communication system
This paper addresses the power penalty in an illumination LED caused by visible light communication (VLC). This study models the extra power consumption of the LED by taking into account the convex relation between the dissipated electrical power versus the LED current on one hand and the concave relation between the output luminous flux versus the current on the other hand. The ratio of the output luminous flux to input electrical power, which is known the LED luminous efficacy, is analyzed considering various recombination mechanisms and their dependency on current and temperature. As examples, the rapid light fluctuations induced by Pulse Amplitude Modulation (PAM) and orthogonal frequency division multiplexing (OFDM) are analyzed for joint illumination and communication (JIC) systems. Due to the signal modulation, there is a decrease in the output light of LED. Nevertheless, the total power offered to LED is larger than without modulation and thus extra heating occurs. Moreover, particularly when burst transmission is used in communication networks, visible flicker may occur
PIC-assisted high-capacity dynamic indoor network utilizing optical wireless and 60-GHz radio-over-fiber techniques
\u3cp\u3eWe present a bidirectional dynamic indoor fiber infrastructure using a photonic integrated cross-connect chip for optical wireless downstream and 60GHz radio-over-fiber upstream transmission. We demonstrate 10Gb/s on-off-keying downstream multicasting and 33Gb/s discrete-multi-tone upstream communication.\u3c/p\u3
Mitigating LED nonlinearity to enhance visible light communications
\u3cp\u3eThis paper addresses the nonlinear memory effects in the response of typical illumination light emitting diodes (LEDs), in order to enhance the performance of visible light communication (VLC) systems. These LEDs have a limited bandwidth of only several MHz. To reflect the physical mechanisms in the quantum well, we describe the LED transient response by a nonlinear dynamic differential equation. Three different mechanisms of the nonlinearity are relevant in the double hetero-structure LEDs, which result in dynamic nonlinearities, that is, a mixture of nonlinearities and memory effects. Hitherto, generic pre-distorter and non-linear equalizers have been studied for the LEDs. Yet this paper shows that recombination rates of photon generation can be translated into an equivalent discrete-time circuit that can be inverted. This allows us to develop a new pre-distorter with a simpler and more efficient structure than previously studied and overly generic approaches. The novel pre-distorter along with a parameter estimation can effectively overcome LED nonlinearity for high-speed VLC with amplitude-based single carrier modulations, including ON-OFF keying and pulse amplitude modulation-4 systems, and with the multi-carrier orthogonal frequency-division multiplexing. We report experimentally obtained eye-diagrams, first to justify our choice for the LED model on which our nonlinear pre-distorter have been based, and second to verify the effectiveness in enhancing the VLC link performance to the extent predicted by our model.\u3c/p\u3
Bi-directional 35-Gbit/s 2D beam steered optical wireless downlink and 5-Gbit/s localized 60-GHz communication uplink for hybrid indoor wireless systems
We present a full-duplex dynamic indoor optical wireless system using 2D passive optical beam steering for downlink and 60-GHz communication for upstream transmission. We demonstrate 35-Gb/s NRZ-OOK downstream multicasting and 5-Gb/s NRZ-ASK upstream communication
Bi-directional 35-Gbit/s 2D beam steered optical wireless downlink and 5-Gbit/s localized 60-GHz communication uplink for hybrid indoor wireless systems
\u3cp\u3eWe present a full-duplex dynamic indoor optical wireless system using 2D passive optical beam steering for downlink and 60-GHz communication for upstream transmission. We demonstrate 35-Gb/s NRZ-OOK downstream multicasting and 5-Gb/s NRZ-ASK upstream communication.\u3c/p\u3
Reconfigurable six-section wavelength-tunable distributed bragg reflector laser
\u3cp\u3eA novel operation mode field reconfigurable DBR laser is designed, realized and investigated experimentally. With different controlling of the same hardware, a shared-cavity six-section DBR laser diode can be flexibly configured to operate as a continuous wave or a pulsed wave laser.\u3c/p\u3
Optical wireless data transfer enabled by a cascaded acceptance optical receiver fabricated in an InP membrane platform
Utilizing an InP membrane based cascaded acceptance optical receiver (CAO-Rx), we demonstrate 17.4Gbps optical wireless transmission in C-band. By separating light collection and opto-electrical conversion, CAO-Rx provides better optical efficiency and electrical bandwidth simultaneously