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

An overview of the self-organizing map algorithm, on which the papers in this issue are based, is presented in this article.

The Self-Organizing Map

With construction of new large-scale water storage projects on the wane in the U.S. and other developed countries, attention must focus on improving the operational effectiveness and efficiency of existing reservoir systems for maximizing the beneficial uses of these projects. Optimal coordination of the many facets of reservoir systems requires the assistance of computer modeling tools to provide information for rational management and operational decisions. The purpose of this review is to assess the state-of-the-art in optimization of reservoir system management and operations and consider future directions for additional research and application. Optimization methods designed to prevail over the high-dimensional, dynamic, nonlinear, and stochastic characteristics of reservoir systems are scrutinized, as well as extensions into multiobjective optimization. Application of heuristic programming methods using evolutionary and genetic algorithms are described, along with application of neural networks and fuzzy rule-based systems for inferring reservoir system operating rules.

Optimal Operation of Multireservoir Systems: State-of-the-Art Review

This paper forms the second part of the series on application of artificial neural networks (ANNs) in hydrology. The role of ANNs in various branches of hydrology has been examined here. It is foun...

Artificial Neural Networks in Hydrology. II: Hydrologic Applications

This paper proposes an efficient methodology to optimally determine the best location and optimum size for Distributed Generators (DG), in a distribution network, while minimizing energy losses and improving voltage profile. The proposed methodology has been designed to consider variable demand and variable DG production scenarios, offering a set of optimum values for DG active power output and power factor. The optimization here presented uses the Genetic Algorithm (GA), and the OpenDSS power flow solver feature. The method has been tested on the IEEE 37 node test system comparing voltage profile and energy losses in three scenarios. Additional tests on the IEEE 123 node, 34 node and 13 node has been performed to compare the method proposed with results found in the literature.

Optimal location and size for various renewable distributed generators in distribution networks

The majority of the kinematics analysis carried out on the human body are usually available only for use in the sagittal plane. Limited studies were interested in this analysis in all three planes (sagittal, transverse, and frontal) where motions of all joints occur. The aim of this paper is to develop a new optimal kinematic analysis of human lower limbs in threedimensional space for a rehabilitation end. The proposed approach is focused on optimizing the manipulability and the human performance of the human leg, as being a physiologically constrained three-link arm. The obtained forward kinematic model leads to define the feasible workspace of the human leg in the considered configuration. Using an effective optimization-based human performance measure that incorporates a new objective function of musculoskeletal discomfort, the optimal inverse kinematic (IK) model is obtained.

Optimal 3D kinematic analysis for human lower limb rehabilitation

Due to demand increasing, most of power networks operate close to their stability limits. The high demand and the reduction of non-renewable energy sources impose the insertion of renewable energy sources. Their non-supervised insertion can cause voltage instability. In order to avoid this instability, a coordinated secondary voltage control system (CSVC) should be implemented. This paper describes the proposed procedure of CSVC system implementation. It is composed by three steps. The first step is the power network partitioning based on Self Organizing Map algorithm, the second one is the pilot buses selection based on the reduced Jacobian matrix and on voltage security performance index, and the third one is the CSVC system implementation based on the hybrid control approach using generators and shunt elements. These three steps are described in details in this paper. This procedure is used to maintain the voltage stability of large network. In this paper its efficiency is validated for small network also. Therefore it is implemented on the IEEE 39 bus system.

Voltage stability based on the implementation of a coordinate secondary voltage control system

This chapter presents a finite-time consensus problem of higher-order nonlinear multi-agent systems (MAS) in the presence of bounded disturbances. The nominal control is designed by homogeneous finite-time technique to track the desired target trajectories. The chattering is mitigated by designing an integral sliding surface using adaptive super twisting algorithm (STA). The design parameters of super twisting controller are estimated adaptively without knowing the bounds a priori. The finite time convergence of the consensus protocol for the higher-order MAS is presented using Lyapunov analysis. Simulation results shows the effectiveness of the proposed homogeneous adaptive sliding mode control for the MAS.

Maarouf Saad

Papers

Optimal location and size for various renewable distributed generators in distribution networks

Optimal 3D kinematic analysis for human lower limb rehabilitation

Voltage stability based on the implementation of a coordinate secondary voltage control system

An Adaptive Finite-Time Consensus Control for Higher-Order Nonlinear Multi-agent Systems

Group coordination control of multiple mobile robots with communication delay