Insomnies of medical staff: theoretical aspects (literature review)

More and more medical staff is involved in work in a continuous mode, and therefore the study of their health problems becomes more and more relevant and practically significant. In the article, we summarized domestic and foreign data of the problem of sleep disorders in employees with shift work, gave modern approaches to the classification and diagnosis of insomnia. We have described the adverse physiological effects of the daily and night schedule on the body of medical staff. Analyzing the literary sources, we came to the conclusion that the state of health and the violation of circadian rhythms due to the shift work schedule are directly related. To date, there is no undisputed curative and preventive doctrine of insomnia. Scheduling nursing staff according to circadian rhythms, maximizing schedule stability and adhering to a healthy lifestyle can minimize most of the problems caused by shift work.

An Efficient Procedure for Inserting Buffers to Generate Robust Berth Plans in Container Terminals

Uncertainty is an inevitable aspect of seaside operations in container terminals. Operators therefore need to find robust plans that can resist the impact of uncertainties. Instead of solving a stochastic berth allocation problem, this paper proposes an efficient procedure for inserting buffers into baseline berth plans to strengthen the schedule stability. Such a method is highly versatile and compatible with various solutions to berth allocation problem with different objectives. Numerical results obtained by using simulation on a representative set of instances of the problem are reported; these indicate that the proposed procedure not only increases the flexibility of operations with minor loss of resource utilization but also addresses the impact of service priority. Hence, the contribution in this paper will provide a short path that bridges the gap between berth allocation problem in deterministic and stochastic circumstances.

THE ISSUES OF TRAIN SCHEDULE FULFILLMENT STABILITY IMPROVEMENT

Objective: At present the majority of railway lines experiences serious difficulties in handling of the increased flow of freight trains with considerable amount of passenger traffic. In view of this there is a necessity to improve the level of train schedule stability by creating certain time slacks in it, which make it possible to eliminate errors. Methods: The methods of simulation, computational theory and construction of a train schedule graph were applied. Results: The method of train routing was developed on the basis of simulation of schedule configuration. The characteristics of schedule configuration and conditions of its creation were presented. The influence of trainhandling capacity efficiency coefficient on the choice of a configured train routing diagram was studied, as well as one of the vital factors, causing degradation of train schedule fulfillment stability – disagreement in train traffic. It was shown that in case of selecting a configuration it was necessary to increase the headway between consecutive trains after a bunch of trains, and if train overtaking is inevitable – to use the time of extra removal. In order to eliminate the consequences of disagreement in train traffic, it was proposed to increase intervals not between all trains, but to compensate the disagreement after passage of a number of trains, the latter should be specified on an individual basis. The assessment of compensating interval efficiency was fulfilled by means of removal coefficient calculation for different conditions on three options. It was concluded that the compensating interval not only reduces disagreement impact, but also improves train-handling capacity. The example of train schedule stability improvement was considered on the basis of applying configurations at “Malaya Vishera – Bologoye” section on down trains within the period of time from 11.30 pm to 7.30 am. Practical importance: Application of configurations makes it possible to achieve higher implementable levels of speed and train-handling capacity, leads to the detection of time slacks and time buffers, which considerably increase train schedule stability and, consequently, the stability of its fulfillment.

Aviation Crew Recovery Experiences on Outstations

ACMI flight crews spend considerable time away from home on outstations. This study suggests that this long term stay carries its own considerations in regards to rest recovery with practical implications for Fatigue Risk Management as prescribed by ICAO. Four recovery experiences, Work Detachment, Control, Relaxation and Mastery, are identified and correlated with 28 crew behaviours on base. The results indicate improvement considerations for airline management organizing a long term contract with ACMI crews, in particular to increase schedule stability to improve the crew member’s sense of Control.

THE METHOD FOR IMPROVING STABILITY OF CONSTRUCTION PROJECT SCHEDULES THROUGH BUFFER ALLOCATION / STATYBOS VYKDYMO GRAFIKO STABILUMO UŽTIKRINIMAS PASKIRSTANT LAIKO REZERVUS

The actual completion time of construction projects is rarely in accordance with initial plans. This is due to unforeseen events that affect the project execution. In the paper, the authors propose a method of improving the construction schedule reliability. The method is based on the idea of buffers allocation, whose proper sizing helps to reduce negative effects of random conditions on the progress and efficiency of project activities. The authors adopt a proactive approach to the construction of robust schedules to cope with multiple disruptions during project execution, applicable to two processes starting policies (as soon as possible or no sooner than on a predefined date). The proposed method, based on simulation technique and mathematical programming, was illustrated by an example. The results obtained by means of the proposed method were compared, in terms of schedule stability, to those of the float factor heuristic and starting time criticality heuristicprocedures. The method allowed reducing cost of deviations from the planned activity start dates in random conditions. Santrauka Tikrasis statybos projektų baigimo laikas retai atitinka pradinius užsibrėžtus planus. Taip yra dėl nenumatytų atvejų, kurie daro įtaką galutiniam projekto baigimo laikui. Šiame straipsnyje autoriai pristato metodą, kuris pagerina statybos grafikų patikimuma. Jis grindžiamas laiko rezervo paskirstymo idėja, padedančia sumažinti neigiamus atsitiktinių trikdžių poveikius vykdant projektą. Autoriai pritaiko veiksmingą būdą, kuris leidžia išvengti daugelio sutrikimų vykdant projektą. Siūlomas metodas pagrįstas modeliavimu ir matematiniu programavimu, darbe pateiktas jo taikymo pavyzdys. Gauti rezultatai, taikant siūlomą metoda, buvo lyginami įvairiais požiūriais. Metodas leidžia sumažinti išlaidas, kai atsitiktinėmis sąlygomis nukrypstama nuo planuojamų terminų.