Abstract. This article is focused on the process of matching work items into an organized structure in order to semi-automatically identify work items and link them between BIModel and cost estimating software. Several sources are suggesting a computer aided cost estimation based on historical cost data, which is a desired method of cost estimation. However, it is only achievable, if cost data are collected in an organized way and if format of cost data is structured according with defined standards. Those standards can be internal standards of a company, or national, even international standards that clearly define the structure of work items. Since work items are generally named differently throughout various bills of quantities, it should be more suitable to mark and recognize work items by numbered codes that will be defined specifically for each and every work item. The question is, what level of detail of a particular work item should these numbered codes reflect. More specifically, should these numbered codes represent a general group of work items (such as concrete grade, steel grade, size of masonry), or should they represent a detailed representation of work items (such as diameter of reinforcement, type of plaster, etc.). It also states the possible benefits for various stakeholders (client, contractor, designer, architect) throughout the life cycle of a project. It is to support the good practice of BIM in AEC industry. A semi-automatic e-procurement process is presented on the basis of matching work items into an organized structure. This semi-automatic e-procurement process is presented from the main contractor's point of view, however, it also takes into consideration other project's stakeholders. The article takes into consideration two contractual relations, these are Design -Build contract and Design -Bid -Build contract.

The paper is focused on exploration of selected common data environment functions supporting procurement processes of subcontractors. As common data environments are becoming widespread within the construction industry, they must provide all project stakeholders with necessary functions to support their business processes. Generally speaking, common data environment is a digital space, where project stakeholders can share data and information between themselves. However, current common data environments can offer more functions than just a storage and a way of sharing data and information. They can provide their users with workflow and status management for setting up approval processes, mobile applications for monitoring construction site progress, as well as functions for managing BIM projects. That is why it should also be possible to manage procurement processes of subcontractors within existing common data environments. This paper's focus is to analyse selected common data environments and their available functions supporting procurement processes of subcontractors. Information presented in this paper was obtained from online sources, also questionnaires with predefined questions were sent to CDE representatives and videoconferences were conducted with CDE representatives. Main goal of this paper is to analyse, if selected common data environments have available functions for managing procurement processes of subcontractors. Identified functions are evaluated in accordance with current praxis of managing procurement processes of subcontractors for building construction projects, which also involve development of building projects in rural areas. The paper also describes strong and weak points of identified functions.

This paper is focused on current tender processes of subcontractors within construction industry in the Czech Republic. It identifies those tender processes as a vital part of general contractor's bid preparation for a client. Other processes related to working out general contractor's bid for a client are also presented, but not in detail. This paper is a continuation of a paper, which was published at a Construction Maeconomics Conference 2019. Therefore, it is based on obtained information from semi-structured qualitative interviews with general contractor's employees, who specialize in general contractor's bid preparation processes as well in tender processes of subcontractors. Their answers were analysed and synthesized back in a process map visualizing general contractor's bid preparation and tender processes. Process map is an attachment of this paper and text of this paper describes its parts in detail.

The PF 1000 plasma focus device with deuterium as filling gas is used for the study of hard X-rays and neutrons (originated from D-D fusion reactions). The time of generation and energy distribution of neutrons were determined using the time-of-flight method and MC simulations. The hard X-ray and neutron signals have usually two pulses: the first at the minimum of current derivative and the second 120 ÷ 170 ns later. An experimentally observed asymmetry of neutron pulses detected with scintillation detectors in axial z-direction downstream and upstream is explored by simple model in which each of both neutron pulses is decomposed into two components: the asymmetry one with energy above 2.45 MeV downstream and the symmetry one with the maximum of 2.45 MeV. In this article we describe in detail the shot No. 5566. The asymmetry component has energy downstream 2.55 ÷ 2.85 MeV (the first peak) or/and 2.70 ÷ 3.00 MeV (the second peak). The symmetric component in the energy range 2.2 ÷ 2.7 MeV is generated a few tens ns after the asymmetric one and it contains a lower part 25 ÷ 35 % of neutrons. In this presented shot the onset of neutrons was observed before the onset of hard X-rays. This fact declares the possibility of acceleration of a fraction of the fast energy deuterons before the fast electrons.PACS : 52.59.Hg

Testing of power electronic converters can advantageously be carried out in power-hardwarein-the-loop (P-HIL) environments that emulate the behavior of power grids, electric motors, etc. The interface between the model and the device under test requires a power amplifier whose bandwidth ultimately limits the accuracy of the emulation. Hence, there is a need for general-purpose AC power amplifiers with ultra-high power bandwidth. This paper first provides a comprehensive review of amplifier concepts proposed over the past decades, i.e., linear power amplifiers, switch-mode amplifiers, including advanced variants such as multilevel (parallel-interleaving) and multicell (series-interleaving) topologies, as well as hybrid approaches that, e.g., combine analog and switch-mode stages. Based on this review, the two key concepts (parallelinterleaving of bridge-legs and cascading of converter cells) that facilitate high efficiency and ultra-high power bandwidth are identified and discussed, covering also suitable isolated mains interfaces and control considerations. Finally, we present a three-phase amplifier system that uses six cascaded converter cells per phase to realize an effective switching frequency of 3.6 MHz. The prototype thus achieves a measured power bandwidth of 100 kHz at the nominal phase output voltage of 230 V rms, and an output power of up to 10 kW per phase.INDEX TERMS Power-hardware-in-the-loop (P-HIL), grid emulation, motor emulation, power amplifier topologies, switch-mode power amplifier, ultra-high-bandwidth power amplifier.