NEC

About: NEC is a company organization based out in Tokyo, Japan. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 33269 authors who have published 57670 publications receiving 835952 citations. The organization is also known as: NEC Corporation & NEC Electronics Corporation.

Compensation of soliton broadening in nonlinear optical fibers with loss

Abstract: A novel optical fiber is proposed that supports the lowest-order soliton despite the presence of optical loss. Group-velocity dispersion of this fiber decreases with distance, in accord with soliton attenuation that is due to the inherent optical loss of the fiber.

A critical look at software capability evaluations

Abstract: The methods used by the Software Engineering Institute (SEI's) Software Capability Evaluation program (SCE) are assessed. The goal of the SCE program is to provide the US Defense Department with a method by which it can rank the overall capability of organizations to produce software in a timely, repeatable fashion. Because SEI assessments are a preparation for SCEs, the authors first describe the major steps in an SEI process assessment and highlight its strengths and weaknesses. The SCE grading methods are described, focusing on their statistical reliability. It is concluded that the system is so seriously and fundamentally flawed that it should be abandoned rather than modified or updated. SEI's overall process-improvement paradigm, that is, the set of goals and directions it is trying to impart to the industry through its assessment and evaluation programs, is examined. It is suggested that the assessment program needs some type of structured, preferably graphical, method for recording the details of an organization's existing processes. >

Multiple Rabi Splittings under Ultrastrong Vibrational Coupling.

Abstract: From the high vibrational dipolar strength offered by molecular liquids, we demonstrate that a molecular vibration can be ultrastrongly coupled to multiple IR cavity modes, with Rabi splittings reaching 24% of the vibration frequencies. As a proof of the ultrastrong coupling regime, our experimental data unambiguously reveal the contributions to the polaritonic dynamics coming from the antiresonant terms in the interaction energy and from the dipolar self-energy of the molecular vibrations themselves. In particular, we measure the opening of a genuine vibrational polaritonic band gap of ca. 60 meV. We also demonstrate that the multimode splitting effect defines a whole vibrational ladder of heavy polaritonic states perfectly resolved. These findings reveal the broad possibilities in the vibrational ultrastrong coupling regime which impact both the optical and the molecular properties of such coupled systems, in particular, in the context of mode-selective chemistry.

Enhanced spontaneous emission from GaAs quantum wells in monolithic microcavities

Abstract: Enhanced spontaneous emission has been observed with wavelength‐sized monolithic Fabry–Perot cavities containing GaAs quantum wells. With an on‐resonance cavity structure, the photoluminescence intensity increases in the cavity axis direction, and the spontaneous emission lifetime is experimentally found to decrease.

System-level performance analysis for designing on-chip communication architectures

Abstract: This paper presents a novel system-level performance analysis technique to support the design of custom communication architectures for system-on-chip integrated circuits. Our technique fills a gap in existing techniques for system-level performance analysis, which are either too slow to use in an iterative communication architecture design framework (e.g., simulation of the complete system) or are not accurate enough to drive the design of the communication architecture (e.g., techniques that perform a "static" analysis of the system performance). Our technique is based on a hybrid trace-based performance-analysis methodology in which an initial cosimulation of the system is performed with the communication described in an abstract manner (e.g., as events or abstract data transfers). An abstract set of traces are extracted from the initial cosimulation containing necessary and sufficient information about the computations and communications of the system components. The system designer then specifies a communication architecture by: 1) selecting a topology consisting of dedicated as well as shared communication channels (shared buses) interconnected by bridges; 2) mapping the abstract communications to paths in the communication architecture; and 3) customizing the protocol used for each channel. The traces extracted in the initial step are represented as a communication analysis graph (CAG) and an analysis of the CAG provides an estimate of the system performance as well as various statistics about the components and their communication. Experimental results indicate that our performance-analysis technique achieves accuracy comparable to complete system simulation (an average error of 1.88%) while being over two orders of magnitude faster.