Review of Legal Aspects of Electrical Power Quality in Ship Systems in the Wake of the Novelisation and Implementation of IACS Rules and Requirement

This paper deals with new challenges regarding power quality in ship technology resulting from the novelisation and implementation of IACS (International Association of Classification Societies) rules and requirements. These rules, known as IACS E24 2016/2018, address harmonic distortion for ship electrical distribution systems, including harmonic filters. The reasons for the legislative changes based on a short overview of power quality-related accidents are discussed, after which a brief presentation of the updated IACS rules illustrated by a related DNV GL (Det Norske Veritas Germanischer Lloyd) case study is shown. A key part of this paper includes proposals concerning harmonics and interharmonics, distortion indices and transient disturbances. The aim of these proposals is to unify power quality indices and measurement procedures to maintain effective and comparable criteria for monitoring distortion and establish requirements for ship owners, designers, shipbuilders, classifiers, and crew members of marine objects.

Confocal biomicroscopic changes of the corneal layers following MyoRing implantation with corneal collagen crosslinking in keratoconus

Purpose. To study morphological changes in the cornea by confocal microscopy of simultaneous MyoRing implantation with corneal crosslinking in patients with keratoconus. Material and methods. The clinical study included 15 patients (16 eyes) with progressive keratoconus. All patients underwent a combination treatment: implantation of MyoRing intrastromal corneal rings (Dioptex GmBH, Linz, Austria) in combination with corneal crosslinking. The number of cells and quality indicators in each layer of the cornea were compared before and during 36 months after surgery. Results. Qualitative analysis of the cornea showed transient disturbances of the subepithelial nerve plexus, an increase in the reflectivity of stromal keratocytes, and moderate fibroplasia in the middle parts of the stroma in the area of the intrastromal pocket. During the follow-up period of 12 months or more after surgery, no significant changes in the corneal ultrastructure were detected in the dynamics. There was no significant decrease in endothelial cell density in the postoperative period. Conclusion. Analysis of morphological changes confirms the safety of a combination of simultaneous implantation of the MyoRing intrastromal ring and corneal crosslinking in stage II-III keratoconus by confocal microscopy and allows dynamic observation of changes in the corneal structure during intrastromal surgery. Key words: keratoconus, confocal microscopy, intrastromal corneal rings, MyoRing, corneal crosslinking.

An Adaptive Multi-Dimensional Vehicle Driving State Observer Based on Modified Sage–Husa UKF Algorithm

An accurate vehicle driving state observer is a necessary condition for a safe automotive electronic control system. Vehicle driving state observer is challenged by unknown measurement noise and transient disturbances caused by complex working conditions and sensor failure. For the classical adaptive unscented Kalman filter (AUKF) algorithm, transient disturbances will cause the failure of state estimation and affect the subsequent process. This paper proposes an AUKF based on a modified Sage–Husa filter and divergence calculation technique for multi-dimensional vehicle driving state observation. Based on the seven-degrees-of-freedom vehicle model and the Dugoff tire model, the proposed algorithm corrects the measurement noise by using modified Sage–Husa maximum posteriori. To reduce the influence of transient disturbance on the subsequent process, covariance matrix is updated after divergence is detected. The effectiveness of the algorithm is tested on the double lane change and Sine Wave road conditions. The robustness of the algorithm is tested under severe transient disturbance. The results demonstrate that the modified Sage–Husa UKF algorithm can accurately detect transient disturbance and effectively reduce the resulted accumulated error. Compared to classical AUKF, our algorithm significantly improves the accuracy and robustness of vehicle driving state estimation. The research in this paper provides a reference for multi-dimensional data processing under changeable vehicle driving states.