This paper identifies the adverse events occurring during the execution of water supply and sewerage systems construction. The basis for this paper is research conducted in 2010-2014 on the construction sites of water supply and sewerage systems located in the provinces of Lower Silesia and Opole. The research consisted of direct observations of construction sites and review of construction documentation. It showed that work stoppages on the examined construction sites were frequent. They were caused by violations of work discipline by the production employees, adverse weather conditions, and defects in the project documentation. The study demonstrated that in almost every case, these bad an adverse effect on the completion date and budget of the investment. The analyses show that in such important and expensive investments as water supply and sewerage systems, organizational structures in which a special role is assigned to middle-rank personnel should be adopted.
In recent years, the construct of work engagement as well as methods for its measurement have generated growing interest in the field of occupational psychology. In this study, we aim to contribute to the current work engagement literature by investigating the possible advantages of single-item measures of work engagement by analysing their psychometric feasibility. Testing the validity of a single-item measure tool within the framework of the Job Demands-Resources theory, we have found similar pattern of correlations of single-item measures of work engagement with exhaustion, disengagement, job resources and job demands as for the well-established multi-item measure the Utrecht Work Engagement Scale. The reliability of single-item measures tested with factor analysis and the attenuation formula was estimated to be in the range of between .60 and .70, the figure depending on the particulars of the estimation methods. Our findings provide an initial modicum of evidence that, if a research purpose requires it, or if the use of a multi-item measurement tool is overly restrictive or costly, then a single-item measure of work engagement could be effectively adopted.
The contributions of work-hardening of austenite and the presence of martensite on the hardening of an AISI 304L stainless steel were evaluated based on plastic deformation under different reductions in thickness at two rolling temperatures. The cold deformation temperatures of 300 K and 373 K were chosen to induce strain-hardening plus strain-induced martensitic transformation in the former and strain-hardening in the latter. This made it possible to elucidate the real effects of strengthening mechanisms of metastable austenitic stainless steels during mechanical working.
We talk to Prof. Jan Marcin Węsławski from the PAS Institute of Oceanology in Sopot about how scientists work with members of the public and the benefits it brings.
The paper concerns the two-machine non-preemptive flow shop scheduling problem with a total late work criterion
and a common due date (F2|dj = d|Y ). The late work performance measure estimates the quality of a solution with regard
to the duration of late parts of activities performed in the system, not taking into account the quantity of this delay. In the
paper, a few theorems are formulated and proven, describing features of an optimal solution for the problem mentioned, which is
NP-hard. These theorems can be used in exact exponential algorithms (as dominance relations reducing the number of solutions
enumerated explicitly), as well as in heuristic and metaheuristic methods (supporting the construction of sub-optimal schedules
of a good quality).
This study builds on an existing structural model developed to examine the influence of
leadership and organizational culture on innovation and satisfaction of engineers in Australian
public sectors (APS). The objective of this study is to increase the understanding of
innovation process with a focus on causal relationships among critical factors. To achieve this
objective, the study develops an assessment approach to help predict creativity and work
meaningfulness of engineers in the APS. Three quantitative analysis methods were sequentially
conducted in this study including correlation analysis, path analysis, and Bayesian
networks. A correlation analysis was conducted to pinpoint the strong association between
key factors studied. Subsequently, path analysis was employed to identify critical pathways
which were accordingly used as a structure to develop Bayesian networks. The findings of
the study revealed practical strategies for promoting (1) transformational leadership and (2)
innovative culture in public sector organizations since these two factors were found to be key
drivers for individual creativity and work meaningfulness of their engineers. This integrated
approach may be used as a decision support tool for managing the innovation process for
engineers in the public sectors.
In order to assess the challenges and needs of Austrian companies with respect to current
business and technological developments, a regular well-researched compilation of empirical
data of the Austrian manufacturing industry is necessary. Hence, a panel of 104 decisionmakers
(owners, CEOs, managing directors and plant managers) from leading Austrian
industrial companies was assembled in form of an “industry panel” to investigate current
issues of production work in Austria by means of a survey.
In order to allow for a longitudinal study, it is planned to survey the same group of people
every year; hence the instrument of an annual panel-survey was chosen. To date the panel
consists of 104 leaders from different Austrian or international companies with at least one
factory location in Austria. The panel was assembled first in 2018/2019 and the administered
survey contained 23 questions. The actual questions comprise topics that concern the current
economic situation and future expectations, operational issues with respect to delivery
time, product variability and demand fluctuations, as well as questions relating to innovation,
automation and the application of current technological developments (i.e. assistance
systems, machine learning, etc.) in manufacturing. This paper presents the survey results
and conclusions of the 2019 panel on production work in Austria.
In the article problems related to human labor and factors affecting the increasing use of
industrial robots are discussed. Since human factors affect the production processes stability,
robots are preferred to apply. The application of robots is characterized by higher performance
and reliability comparing to human labor. The problem is how to determine the real
difference in work efficiency between human operator and robot. The aim of the study is to
develop a method that allows clearly definition of productivity growth associated with the
replacement of human labor by industrial robots. Another aim of the paper is how to model
robotized and manual operated workstation in a computer simulation software. Analysis of
the productivity and reliability of the hydraulic press workstation operated by the human
operator or an industrial robot, are presented. Simulation models have been developed taking
into account the availability and reliability of the machine, operator and robot. We apply
OEE (Overall Equipment Effectiveness) indicator to present how availability and reliability
parameters influence over performance of the workstation, in the longer time. Simplified
financial analysis is presented considering different labor costs in EU countries.
This study included investigation of efficiency of the threshold used to classify symptoms as present, investigation of efficiency of the cut-off point used to identify potentially addicted to work individuals, investigation of magnitude of the problem of class overlap, and investigation of effects of dichotomization of polytomous items on the estimates of the latent trait level. The sample comprised 16,426 working Norwegians (Mage = 37.31; SD = 11.36) who filled out the Bergen Work Addiction Scale (BWAS). The results showed that the difficulty/third threshold parameters corresponding to the threshold used to classify symptoms as present were lower than 1.5 for the items corresponding to tolerance and conflict and higher than or equal to 1.5 for the items corresponding to salience, mood modification, relapse, withdrawal, and problems. The cut-off point used to identify individuals as potentially addicted to work identified 411 individuals (31.9% of all individuals classified by the polythetic approach as potentially addicted to work) whose estimates of the latent trait level were lower than 1.5 as potentially addicted to work. The problem of class overlap (being classified by the polythetic approach into different class despite almost the same level of the latent trait) affected 4,686 individuals (28.5% of the whole sample). The dichotomization of polytomous items had a substantial effect on the estimates of the latent trait level. The findings show that the polythetic approach is not efficient in identifying potentially addicted to work individuals and that the prevalence rates of work addiction based on the polythetic approach are not trustworthy.
Values define the directions of human activities and are related to people’s motivation to undertake specific activities and roles (Schwartz, 1994; Brown, 2002). Researchers and employers observe differences in motivation to work among representatives of different generations and genders (Twenge, Campbell, & Freeman, 2012; Gursoy & Karadag, 2013). In this research project, the authors asked what motivated contemporary employees, whether the intensity of their motives was different in different generations, what relationships there were between the dominant work motives and employees’ dominant values, and whether there were differences between women and men regarding work motives. To verify the hypotheses, they conducted a study with a sample of 307 professionally active people. They used their own Types of Work Motives Questionnaire designed for the purposes of the study and the Valued Living Questionnaire (VLQ; Wilson & Murrell, 2004). The obtained results indicate that younger employees choose the kind of work that gives them comfort and adequate pay. Regardless of age, however, social security support is the most important for all groups of respondents. For women, security and social security support are important at work. Moreover, the study has shown that there is a relationship between work values and work motives. For example people who appreciate values such as friendship and stability are motivated to work by good relationships and security, those who value recreation and stability are motivated by comfort and salary, those for whom respect and education are crucial are motivated by the possibility of development etc.
The construction site and its elements create circumstances that are conducive to the formation of risks to work safety during the execution of works. Analysis indicates the critical importance of these factors in the set of characteristics that describe the causes of accidents in the construction industry. This paper attempts to analyse the characteristics of the construction site to indicate their importance in defining the circumstances of an accident at work. The research was carried out on the basis of data from the register kept by the District Labour Inspectorate in Krakow, Poland. Main substantive tasks include isolating patterns of accidents on site and identifying those of the analysed characteristics that are important in defining these patterns. In terms of methodology, the paper presents a method of analysing data resources by using means of conceptual grouping in the form of cluster analysis.
Lean mixture burning leads to a decrease in the temperature of the combustion process and it is one of the methods of limiting nitric oxide emissions. It also increases engine efficiency. An effective method to correct lean mixture combustion can be a two-stage system of stratified mixture combustion in an engine with a prechamber. This article presents the results of laboratory research on an SI engine (spark ignition) with a two-stage combustion system with a cylinder powered by gasoline and a prechamber powered by propane-butane gas LPG (liquefied petroleum gas). The results were compared to the results of research on a conventional engine with a one-stage combustion process. The test engine fuel mixture stratification method, with a two-stage combustion system in the engine with a prechamber, allowed to burn a lean mixture with an average excess air factor equal to 2.0 and thus led to lower emissions of nitrogen oxides in the exhaust of the engine. The test engine with a conventional, single-stage combustion process allowed to properly burn air-fuel mixtures of excess air factors λ not exceeding 1.5. If the value λ > 1.5, the non-repeatability factor COVLi increases, and the engine efficiency decreases, which makes it virtually impossible for the engine to operate. The engine with a two-stage combustion process, working with λ = 2.0, the Qin/Qtot = 2.5%, reduced the NOx content in the exhaust gases to a level of about 1.14 g/kWh. This value is significantly lower than the value obtained in a conventional engine, which worked at λ = 1.3 with comparable non-repeatability of successive cycles (about 3%) and a similar indicated efficiency (about 34%), was characterised by the emissions of NOx in the exhaust equal to 26.26 g/kWh.
Tekst podejmuje problem roli i znaczenia koncepcji granic między pracą i życiem (Border i Boundary Theory) w relacji do koncepcji równowagi między pracą a życiem (Work-Life Balance). Pierwsza część artykułu to krytyczny przegląd badań oraz podejść do problematyki WLB w kontekście zachodnim i na rodzimym gruncie. Autorki wskazują na wielość koncepcji służących badaniu i wyjaśnianiu równowagi praca–życie oraz na ich główne ograniczenia. W drugiej części tekstu przedstawiono teoretyczny zarys koncepcji obszarów granicznych z perspektywy teorii granic praca–życie, wskazując na główne cechy granic, ich umiejscowienie oraz style i taktyki zarządzania nimi. Opisano także model służący do badania dynamiki domen praca–życie z uwzględnieniem perspektywy indywidualnej oraz organizacyjnej.
This paper describes the results of a study that examined if psychological entitlement and hedonic well-being mediated relationships between counterproductive work behaviors (CWB) and grandiose narcissism. More specifically, the mediation effects of both types of narcissism on CWB via psychological entitlement and hedonistic subjective well-being (SWB) were examined. This study is based on self-reported, cross-sectional study on 119 working adults. Agentic and communal narcissism were positively related to CWB in parallel way, while simultaneously and indirectly decreasing CWB levels via higher SWB. Current paper is the first attempt to include agentic-communal narcissism model to explain the levels of CWB. The theoretical and practical implications of presented findings are discussed here in terms of the agency-communion model of narcissism and the “mixed blessing” effects of grandiose narcissism on subjective well-being.
The scope of this work focuses on the aspects of quality and safety assurance of the iron cast manufacturing processes. Special attention
was given to the processes of quality control and after-machining of iron casts manufactured on automatic foundry lines. Due to low level
of automation and huge work intensity at this stage of the process, a model area was established which underwent reorganization
in accordance with the assumptions of the World Class Manufacturing (WCM). An analysis of work intensity was carried out and the costs
were divided in order to identify operations with no value added, particularly at individual manufacturing departments. Also an analysis
of ergonomics at work stations was carried out to eliminate activities that are uncomfortable and dangerous to the workers' health. Several
solutions were proposed in terms of rationalization of work organization at iron cast after-machining work stations. The proposed solutions
were assessed with the use of multi-criteria assessment tools and then the best variant was selected based on the assumed optimization
criteria. The summary of the obtained results reflects benefits from implementation of the proposed solutions.
The paper presents methods of determining the location of cost buffers and corresponding contingency costs in the CPM schedule based on its work breakdown structure. Application of correctly located cost buffers with appropriately established reserve costs is justified by the common overrunning of scheduled costs in construction projects. Interpolated cost buffers (CB) as separate tasks have been combined with relevant summary tasks by the starttostart (SS) relationship, whereas the time of their execution has been dynamically connected with the time of accomplishment of particular summary tasks using the “paste connection” option. Besides cost buffers linked with the group of tasks assigned to summary tasks, a definition of the cost buffer for the entire project (PCB) has been proposed, i.e. as one initial task of the entire project. Contingency costs corresponding to these buffers, depending on the data that the planner has at his disposal, can be determined using different methods, but always depend on the costs of all tasks protected by each buffer. The paper presents an exemplary schedule for a facility and the method of determining locations and cost for buffers CB and PCB, as well as their influence on the course of the curve illustrating the budgeted cost of work scheduled (BCWS). The proposed solution has been adjusted and presented with consideration of the possibilities created by the scheduling software MS Project, though its general assumptions may be implemented with application of other similar specialist tools.
Having increasingly tightened geological and mining conditions in which the extraction of copper ore deposits in Poland is conducted, ensuring effective and safe mining is presently becoming a key task and a significant challenge for mine operators, mainly in the field of ground support systems being the equivalent for the new geological/mining conditions. As one may expect, these conditions shall be characterized by higher values of the primary stress tensor elements as well as the lower deformability and higher strength of the rock mass surrounding the copper ore body. T his means that in the near future, the rock bursts problem will become one of the most important issues deciding on the economy and safety within the newly developed mining areas. T herefore developing a novel effective ductile ground support systems which could be able to control the rock mass movement in squeezing and burst-prone rock conditions is recommended. T his type of requirement may fulfil only ductile or, in other words, the kinetic energy-absorbing systems, which permit slowing down a movement of violently ejected rock blocks. T his paper’s objective is to present the idea of the development of a new type of an effective and low cost ductile resin anchored rockbolt system with smooth and of the square cross-section steel rod is formed in coil shape of different pitch. T he developed bolt prototypes have been tested underground in the G-11 section of the Rudna mine. Results of the pull-out tests, involving different bolts’ shapes and different sliding materials set on the rockbolts’ rods, have proved those bolts’ efficiency as an element of the ductile support system.
One of the most important business areas of the company is the management of working capital. Energy companies that produce electricity and heat are the main consumers of steam coal, so their decision concerning stock levels is a major determinant of supply schedules. These decisions depend on legal and technical requirements as well as economic aspects. The seasonality of coal consumption jointly with pre-purchase costs and storage costs has a straight impact on delivery scheduling in a parabolic way. There is a divergence in expectations regarding delivery schedules among the coal market participants (energy, mining, transport companies). The purpose of this article is to present the concept of pricing of steam coal and transport service on the Polish market, assuming the use of price incentives, resulting in delivery scheduling during the year. The article presents selected theoretical content in the field of coal logistics and working capital management in the company, the expectations of the steam coal market participant regarding delivery schedules have been identified. The proposed concept of pricing steam coal and transport service should be discussed further in scientific and expert work.