There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Introduction to Electromagnetic Compatibility

Antenna Theory And Design

Before the emergence of ultra-wideband (UWB) radios, widely used wireless communications were based on sinusoidal carriers, and impulse technologies were employed only in specific applications (e.g. radar). In 2002, the Federal Communication Commission (FCC) allowed unlicensed operation between 3.1–10.6 GHz for UWB communication, using a wideband signal format with a low EIRP level (−41.3dBm/MHz). UWB communication systems then emerged as an alternative to narrowband systems and significant effort in this area has been invested at the regulatory, commercial, and research levels.

IEEE Transactions on Microwave Theory and Techniques and Antennas and Propagation Announce a Joint Special Issue on Ultra-Wideband (UWB) Technology

Today’s data center networks (DCNs) are expected to support large number of different bandwidth-hungry applications with increased amounts of data for purposes such as real-time search and data analysis. As a result, significant challenges are imposed to identify the cause of link congestion between any pair of switch ports that may severely damage the overall network performance. Generally, it is expected that the granularity of the flow monitoring to diagnose network congestion in DCNs needs to be down to the flow level on a physical port of a switch in real time with high estimation accuracy, low computational complexity, and good scalability. In this chapter, motivated by a comprehensive study of a real DCN trace, we propose two sketch-based algorithms, namely “α-CU” and “P(d)-CU,” which are based on the existing conservative update (CU) approach. The α-CU algorithm adds no extra implementation cost to the traditional CU, and also successfully trades off the achieved error with time complexity. The P(d)-CU algorithm fully considers the amount of skew for different types of network services to aggregate traffic statistics of each type of network traffic at an individual and horizontally partitioned sketch. We also introduce a way to produce the real-time moving average of the reported results. By theoretical analysis and sufficient experimental results on a real DCN trace, we extensively evaluate the proposed and existing algorithms on their error performance, recall, space cost, and time complexity.

Cloud Computing: Efficient Congestion Control in Data Center Networks

Injection of the voltage noise into the PDN is so difficult due to the impedance mismatching between the PDN and connector. This paper proposed a triangular-current generator that can inject an artificial current waveform into the PDN and estimate the PDN noise. A slope and amplitude of triangular waveform manually varies depending upon the PDN impedance. Rogowski coils are implemented inside the generator to measure the current waveform.

A slope and amplitude controllable triangular-current generator for the injection of a broad-band PDN noise

Near-field measurements are widely used to indicate the radiation from integrated circuits (IC). To minimize the number of field components measured in a near-field scan, it is necessary to calculate the electric field from magnetic field or vice versa. In this paper, a method based on plane wave spectrum theory is proposed to perform the H to E transformation, and a filtering technique is proposed to address the noise problem in the calculation. A simple active circuit in a 3-D full-wave simulation tool is used to validate this method. This method is useful to reduce the number of field components to be measured, resulting in faster near-field scanning.

Near-field H to E transformation using plane wave spectrum theory

This paper presents an approach to quantify channel performance using TWDP (transmitter waveform and dispersion penalty) with frequency-domain S-parameter data. TWDP is initially defined to characterize the performance of a transmitter in optical links. The same concept has been extended to quantify channel performance as well, especially in high-speed copper links. This paper focuses on channel characterization. Instead of using time-domain oscilloscope measurements as defined in the original approach, a new method is proposed by using the frequency-domain S-parameter data, obtained either from measurements or simulations. A parametric study on TWDP with respect to bit rate, number of samples per bit, rise/fall time, etc., is also presented with discussions.

Using TWDP to quantify channel performance with frequency-domain s-parameter data

The paper deals with the extraction, from the measurement, of the parameters needed to identify in time domain the hysteretic behavior of the coupling capacitance of through silicon via (TSV). The algorithm is developed in such a way that the equivalent capacitance model can be implemented into standard circuit simulators. Results showing the effect of the hysteresis on the crosstalk among TSV and IC active devices are shown and discussed.

Jun Fan

Papers

Cloud Computing: Efficient Congestion Control in Data Center Networks

A slope and amplitude controllable triangular-current generator for the injection of a broad-band PDN noise

Near-field H to E transformation using plane wave spectrum theory

Using TWDP to quantify channel performance with frequency-domain s-parameter data

Extraction of the parameters of the coupling capacitance hysteresis cycle for TSV transient modeling