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

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

This review focuses on inverter technologies for connecting photovoltaic (PV) modules to a single-phase grid. The inverters are categorized into four classifications: 1) the number of power processing stages in cascade; 2) the type of power decoupling between the PV module(s) and the single-phase grid; 3) whether they utilizes a transformer (either line or high frequency) or not; and 4) the type of grid-connected power stage. Various inverter topologies are presented, compared, and evaluated against demands, lifetime, component ratings, and cost. Finally, some of the topologies are pointed out as the best candidates for either single PV module or multiple PV module applications.

A review of single-phase grid-connected inverters for photovoltaic modules

https://robots.iopscience.iop.org/article/10.1088/1757-899X/705/1/012004/pdf

Point Cloud Data Segmentation Using RANSAC and Localization

A Communication-less adaptive protection scheme for Self-Healing distribution systems

This paper presents dc-dc converters based on multi switched capacitor cells for high boost. The essence in a grid connected micro-inverter is dc-dc converter; it is employed to boost the low PV voltage, which varies from 35-45 VDC in order to increase the bus voltage to be 380-400 VDC. Inverter utilizes this high bus voltage to match the grid voltage, which is 240 VAC at 60 Hz frequency. For conventional boost converter, this requires high boost ratio that is beyond its practical capability. Furthermore, the high duty ratio needed will result in high components stress that suppresses the overall efficiency of the converter. To overcome aforementioned problems, this paper suggests the integration of multiple switched-capacitor cells (SCs) with conventional boost and buck-boost converters to achieve high dc-link voltage. Results based on 100 W laboratory prototype are given to verify the theoretical analysis.

https://pureadmin.qub.ac.uk/ws/files/134910196/Voltage_Source_Multi_Switched_Capacitor_Boost_and_Buck_Boost_High_Gain_DC_DC_Converters_1_.pdf

Voltage Source Multi Switched Capacitor Boost and Buck-Boost High Gain DC-DC Converters

There is growing concern over power quality of ac supply systems. Power quality can be defined as the ability of utilities to provide electric power without interruption. Various power quality problems can be categorized as voltage sags, swells, harmonics, transients and unbalance are considered are the most common power quality problems in electrical distribution systems (Elandy etl., 2006). These types of disturbances can cause fails in the equipments, raising the possibility of an energy interruption.Voltage swells can be defined as a short duration increase in rms of main source with an increase in voltage ranging from 1.1 p.u up to 1.8 p.u. of nominal voltage source. There are various solutions to these problems

/pdf/performance-of-modification-of-a-three-phase-dynamic-voltage-4l7d368vfv.pdf

Performance of Modification of a Three Phase Dynamic Voltage Restorer (DVR) for Voltage Quality Improvement in Electrical Distribution System

Enhancing compensating capability is essential in a voltage-sag compensator. It involves two main aspects, first, sag detection technique and second, voltage sag compensator. Many detection techniques have been introduced to measure and to detect voltage sag, such as RMSValue Evaluation and Peak-Value Evaluation. Unfortunately, most of the techniques require a delay for sag to be detected then compensated, whereas immediate sag detection is vital to improvement of transient performance. Presented is a three-phase PWM-switched autotransformer voltage-sag compensator that is based on AC-AC converter and that uses the proposed three phase controller based on Phase Angle Analysis as the detection technique. The significant advantage of this detection technique is the detection time. It is capable of detecting and compensating voltage sag the moment sag occurs without delay. Its effectiveness and capability were verified via MATLAB/Simulink simulation.

/pdf/three-phase-control-for-pwm-switched-auto-transformer-8bnj6c92v0.pdf

Nasrudin Abd Rahim

Papers

Point Cloud Data Segmentation Using RANSAC and Localization

A Communication-less adaptive protection scheme for Self-Healing distribution systems

Voltage Source Multi Switched Capacitor Boost and Buck-Boost High Gain DC-DC Converters

Performance of Modification of a Three Phase Dynamic Voltage Restorer (DVR) for Voltage Quality Improvement in Electrical Distribution System

Three phase control for PWM switched auto transformer voltage sag compensator based on phase angle analysis