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In this study, we propose a dual-stream UNet neural network architecture design named CPF-UNet, specifically designed for efficient semantic pixel-level segmentation tasks. This architecture cleverly extends the basic structure of the original UNet, mainly through the addition of a unique attention-guided branch in the encoder part, aiming to enhance the model’s ability to comprehensively capture and deeply fuse contextual information. The uniqueness of CPF-UNet lies in its dual-path mechanism, which differs from the dense connectivity strategy adopted in networks such as UNet++. The dual-path structure in this study can effectively integrate deep and shallow features without relying excessively on dense connections, achieving a balanced processing of image details and overall semantic information. Experiments have shown that CPF-UNet not only slightly surpasses the segmentation accuracy of UNet++, but also significantly reduces the number of model parameters, thereby improving inference efficiency. We conducted a detailed comparative analysis, evaluating the performance of CPF-UNet against existing UNet++ and other corresponding methods on the same benchmark. The results indicate that CPF-UNet achieves a more ideal balance between accuracy and parameter quantity, two key performance indicators.

In order to explore the gaps between decoder's interpretations and encoder's designing intentions with respect to the same multimodal discourses, thirty linguistic and thirty art graphic participants were chosen as decoders and encoders, respectively. The participants were required to interpret the same research data in terms of the best and the worst major colors, as well as the best and the worst synergetic patterns formed by major modes. It was found that the complete unanimity in terms of both color and spatial arrangements among the interpretations between participants only reached 43.3%. The unanimity in the interpretations from the perspective of color alone reached 46.7%. Moreover, the interpretations from the perspective of spatial arrangements present high unanimity, with a rate up to 70%. It is concluded that there are both differences and similarities between the interpretations made by encoders and decoders. The possible reasons underlying both differences and similarities are probed in the present study as well. [ABSTRACT FROM AUTHOR]

This paper demonstrates a high-performance optical-code-division-multiple-access (O-CDMA) network testbed using the spectral phase encoded time spreading (SPECTS) method. Through additional time and polarization multiplexing, a total of 32 10-Gb/s users are supported while sharing eight O-CDMA spreading codes. User detection is achieved with time gating and nonlinear thresholding to suppress the multiaccess interference of other users. Incorporation of forward error correction successfully reduces the performance loss imposed by coherent beat interference, resulting in error-free performance (BER<10-11), significant per-user power penalty reduction, and the elimination of a bit-error-rate noise floor. The testbed also applies bandwidth suppression within the encoders and decoders, yielding a 52% increase in spectral efficiency [ABSTRACT FROM PUBLISHER]

This paper describes a study of the performance of various configurations for placing multiple optical amplifiers in a typical coherent ultrashort light pulse code-division multiple access (CULP-CDMA) communication system using the additive noise model. For this study, a comprehensive performance analysis was developed that takes into account multiple-access noise, noise due to optical amplifiers, and thermal noise using the saddle-point approximation technique. Prior to obtaining the overall system performance, the input/output statistical models for different elements of the system such as encoders/decoders, star coupler, and optical amplifiers were obtained. Performance comparisons between an ideal and lossless quantum-limited case and a typical CULP-CDMA with various losses exhibit more than 30 dB more power requirement to obtain the same bit-error rate (BER). Considering the saturation effect of optical amplifiers, this paper discusses an algorithm for amplifiers' gain setting in various stages of the network in order to overcome the nonlinear effects on signal modulation in optical amplifiers. Finally, using this algorithm, various configurations of multiple optical amplifiers in CULP-CDMA are discussed and the rules for the required optimum number of amplifiers are shown with their corresponding optimum locations to be implemented along the CULP-CDMA system. [ABSTRACT FROM PUBLISHER]

Low-density parity-check (LDPC) codes are excellent candidates for optical network applications due to their inherent low complexity of both encoders and decoders. A cyclic or quasi-cyclic form of finite geometry LDPC codes simplifies the encoding procedure. In addition, the complexity of an iterative decoder for such codes, namely the min-sum algorithm, is lower than the complexity of a turbo or Reed-Solomon decoder. In fact, simple hard-decoding algorithms such as the bit-flipping algorithm perform very well on codes from projective planes. In this paper, the authors consider LDPC codes from affine planes, projective planes, oval designs, and unitals. The bit-error-rate (BER) performance of these codes is significantly better than that of any other known foward-error correction techniques for optical communications. A coding gain of 9-10 dB at a BER of 10-9, depending on the code rate, demonstrated here is the best result reported so far. In order to assess the performance of the proposed coding schemes, a very realistic simulation model is used that takes into account in a natural way all major impairments in long-haul optical transmission such as amplified spontaneous emission noise, pulse distortion due to fiber nonlinearities, chromatic dispersion, crosstalk effects, and intersymbol interference. This approach gives a much better estimate of the code's performance than the commonly used additive white Gaussian noise channel model. [ABSTRACT FROM PUBLISHER]

This paper extends a pulse propagation previously developed by Marcuse for the characterization of pulse transmission in single mode fibers to the case of pulsed optical code-division multiple-access (CDMA) systems that employ encoders and decoders based on ladder networks. The model accounts for important degradation factors such as fiber dispersion, source linewidth (coherence), chip time duration and phase and delay mismatch between the source encoder and the destination decoder. Although results are only presented for the autocorrelation signal, the model can be employed to analyze the impact of the above mentioned [ABSTRACT FROM PUBLISHER]

In this letter, we show, for the first time, that an integrated spectral optical code-division multiple-access (OCDMA) technique has a comparable performance with respect to coherent OCDMA techniques based on a crosstalk analysis. The code set is further studied on its resilience against imbalances in the 3-dB couplers of the en/decoders (E/Ds). The orthogonality remains acceptable for imbalance penalties up to 1 dB. The analysis done in the letter considers a cascade and a tree E/D which shows negligible differences in performance. [ABSTRACT FROM PUBLISHER]

This letter presents a high-capacity optical code-division multiple-access (O-CDMA) network testbed based on the spectral phase-encoded time-spreading technique. Two 10-Gb/s/user O-CDMA network architectures (time-slotted and time-slotted polarization multiplexed) are investigated. The first O-CDMA network testbed architecture utilizes eight encoders and a decoder to produce 16 users equally distributed in two time slots while the second architecture evenly distributes 32 users in two time slots and two polarizations. The 16-user testbed achieved error-free performance. The 32-user testbed obtained bit-error rates below 10-8 without using forward-error-correction techniques [ABSTRACT FROM PUBLISHER]

We propose bidirectional fiber-optic code division multiple access networks based on the multiwavelength optical code, and the feasibility of the network is demonstrated experimentally. Encoders/decoders are implemented with AWG routers and fiber delay lines, and incoherent light sources are used. Due to the loop-back configuration of the AWG router-based encoder/decoder, bidirectional transmission is possible in the proposed access network. Decoding of broad-spectrum encoded signals (Δf=1.6 THz, Δλ=12.8 nm at 1550 nm) after transmission over a 40-km fiber link was performed with dispersion compensation [ABSTRACT FROM PUBLISHER]

World demand for Ethernet chips spurs second-source agreement A growing shortage of Ethernet controllers and transceivers should by alleviated by a technology-exchange and second-source agreement between Fujitsu's Advanced Products Division […]