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1

Architectural and structural and functional features of the organization of parallel-hierarchical memory

Timchenko Leonid, Kokriatskaia Natalia, Tverdomed Volodymyr, Yepifanova Iryna Yu., Didenko Yurii, Zhuk Dmytro, Kozyr Maksym, Shakhina Iryna

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2024

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T. 14, nr 1

46--52

EN

Parallel hierarchical memory (PI memory) is a new type of memory that is designed to improve the performance of parallel computing systems. PI memory is composed of two blocks: a mask RAM and a tail element RAM. The mask RAM stores the masks that are used to encode the information, while the tail element RAM stores the actual information. The address block of the PI memory is responsible for generating the physical addresses of the cells where the tail elements and their masks are stored. The address block also stores the field of addresses where the array was written and associates this field of addresses with the corresponding external address used to write the array. The proposed address block structure is able to efficiently generate the physical addresses of the cells where the tail elements and their masks are stored. The address block is also able to store the field of addresses where the array was written and associate this field of addresses with the corresponding external address used to write the array. The proposed address block structure has been implemented in a prototype PI memory. The prototype PI memory has been shown to be able to achieve significant performance improvements over traditional memory architectures. The paper will present a detailed description of the PI transformation algorithm, a description of the different modes of addressing organization that can be used in PI memory, an analysis of the efficiency of parallelhierarchical memory structures, and a discussion of the challenges and future research directions in the field of PI memory.

PL

Równoległa pamięć hierarchiczna (pamięć PI) jest nowym typem pamięci zaprojektowanym w celu poprawy wydajności równoległych systemów obliczeniowych. Pamięć PI składa się z dwóch bloków: maski RAM i ogon RAM. Maska RAM przechowuje maski używane do kodowania informacji, podczas gdy ogon RAM przechowuje rzeczywiste informacje. Blok adresowy pamięci PI jest odpowiedzialny za generowanie fizycznych adresów komórek, w których przechowywane są elementy końcowe i ich maski. Blok adresowy przechowuje również pole adresu, w którym tablica została zapisana i kojarzy to pole adresu z odpowiednim adresem zewnętrznym użytym do zapisu tablicy. Proponowana struktura bloku adresowego jest w stanie efektywnie generować fizyczne adresy komórek, w których przechowywane są elementy ogonowe i ich maski. Blok adresowy może również przechowywać pole adresu, w którym tablica została zapisana i powiązać to pole adresu z odpowiednim adresem zewnętrznym użytym do zapisu tablicy. Zaproponowana struktura bloku adresowego została zaimplementowana w prototypie pamięci PI. Wykazano, że prototyp pamięci PI jest w stanie znacznie poprawić wydajność w porównaniu z tradycyjnymi architekturami pamięci. W artykule zostanie przedstawiony szczegółowy opis algorytmu konwersji PI, opis różnych trybów adresowania, które mogą być używane w pamięci PI, analiza wydajności równoległo-hierarchicznych struktur pamięci oraz omówienie wyzwań i przyszłych kierunków badań w dziedzinie pamięci PI.

2

Non-limiting operation of the on-load tap changing transformer, and Its effect on voltage stability, with regards to the Nineveh electrical grid

Alkahdely Sinan Moayad A., Alsammak Ahmed Nasser B.

Przegląd Elektrotechniczny

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2023

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R. 99, nr 4

181--186

EN

The achievement of voltage stability is among the most prominent challenges faced by grid operators. In the past, generator excitation regulation was the only method available, for restoring the voltage to its rated values. However, rapid developments in the areas of power grids and power stations, has led to the need of a new technique, for controlling the voltage level, and maintaining the system in the voltage stability band. Onload tap changing (OLTC) is currently among the most widely employed methods, for improving the stability of the power system voltage. OLTC restores the voltage value, whether the disturbance occurs on its primary or secondary side. While a minor disturbance is easily overcome by OLTC, its capacity for restoring the voltage level, during a significant disturbance, is dependent on its ratings and setting values. The failure of the OLTC transformer, to restore the voltage value within a short period, may result in a collapse of the voltage system, when the transformer proceeds with reverse action. A simulation model in MATLAB Simulink shows the effect of OLTC on the Nineveh power grid.

PL

Osiągnięcie stabilności napięcia jest jednym z najważniejszych wyzwań, przed jakimi stają operatorzy sieci. W przeszłości regulacja wzbudzenia generatora była jedyną dostępną metodą przywracania napięcia do wartości znamionowych. Jednak szybki rozwój w obszarach sieci elektroenergetycznych i elektrowni spowodował konieczność opracowania nowej techniki kontroli poziomu napięcia i utrzymywania systemu w paśmie stabilności napięcia. Zmiana zaczepów pod obciążeniem (OLTC) jest obecnie jedną z najczęściej stosowanych metod poprawy stabilności napięcia systemu elektroenergetycznego. PPZ przywraca wartość napięcia, niezależnie od tego, czy zakłócenie występuje po stronie pierwotnej czy wtórnej. Podczas gdy małe zakłócenie jest łatwo przezwyciężane przez PPZ, jego zdolność do przywracania poziomu napięcia podczas znacznego zakłócenia zależy od jego wartości znamionowych i nastawczych. Awaria transformatora PPZ przywracająca w krótkim czasie wartość napięcia może skutkować załamaniem się układu napięciowego, gdy transformator działa odwrotnie.Model symulacyjny w MATLAB Simulink pokazuje wpływ PPZ na sieć energetyczną Niniwy.

3

Organization Performance Composite Index Under Fuzziness: Application on Manufacturing Organization

El-Santty Mohamed Ibrahim, Zaher Hegazy Mohamed, Saeid Naglaa Ragaa

Production Engineering Archives

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2023

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Vol. 29, Iss. 1

14--22

EN

Measuring the organization's performance is essential for continuous improvement and operational excellence. Appropriate organizational measures include multiple dimensions. The relative importance of the multiple dimensions varies depending on the organization's context and the management team's visions. The vagueness and ambiguity in the management team's perspective toward the dimensions and associated sub-indicators show fuzzy property. This paper aims to synthesize the over-all organization performance in one aggregated index, engage the management team through index formulation, deal with ambiguity and vagueness in the management team perspective using fuzzy mathematics, and use the synthesized index in monitoring and controlling the organization's performance to achieve operational excellence. The proposed approach is implemented in manufacturing organizations to prove practicality. The implementation of the proposed method shows a positive im-pact on the organization's performance monitoring as the management team focused on one measure. Furthermore, it has engaged the management team in selecting and weighing the leading group and associated KPIs. The R programming and Minitab 19 are used in the collected data processing.

4

Layout design for efficiency improvement and cost reduction

Kovács G.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2019

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Vol. 67, nr 3

547--555

EN

In a reality of global competition, companies have to minimize production costs and increase productivity in order to boost com-petitiveness. Facility layout design is one of the most important and frequently used efficiency improvement methods for reducing operational costs in a significant manner. Facility layout design deals with optimum location of facilities (workstation, machine, etc.) on the shop floor and optimum material flow between these objects. In this article, the objectives and procedure of layout design along with the calculation method for layout optimization are all introduced. The study is practice-oriented because the described case study shows how the layout of an assembly plant can be modified to form an ideal re-layout. The research is novel and innovative because the facility layout design and 4 lean methods (takt-time design, line balance, cellular design and one-piece flow) are all combined in order to improve efficiency more significantly, reduce costs and improve more key performance indicators. From the case study it can be concluded that the layout redesign and lean methods resulted in significant reduction of the following seven indicators: amount of total workflow, material handling cost, total travel distance of goods, space used for assembly, number of workers, labor cost of workers and the number of Kanban stops.

5

Improvement of Operating Performance of a Cast-Iron Heat Exchanger by Application of a Copper Alloy Coating

Mróz M., Orłowicz A. W., Tupaj M., Jacek-Burek M., Radoń M., Kawiński M.

Archives of Foundry Engineering

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2019

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iss. 3

84--87

EN

The paper deals with possibility to improve operating performance of cast-iron heat exchangers by providing them with a copper alloy (CuTi2Cr) with the use of the flame spraying method. A test exchanger was cast of a gray cast iron with vermicular graphite in ferritic-pearlitic matrix obtained in production conditions at KAW-MET Iron Foundry with the wire method used to vermicularize the material. The test samples were two plates cast in sand molds, of which one was given a flame-sprayed CuTi2Cr coat on one side. The operating performance of such model cast-iron heat exchangers, with and without CuTi2Cr coating, was tested on a set-up for determining the heat flow rate (thermal power) transferred by the heat exchanger to environment. The obtained results indicate that the value of the heat flow rate characterizing the CuTi2Cr-coated cast-iron heat exchanger was by 10% higher compared to the flow rate of heat conveyed to environment by the heat exchanger without coating.

6

Continuously variable transmission leakage test results

Goszczak Jarosław, Radzymiński Bartosz, Mitukiewicz Grzegorz

Acta Innovations

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2019

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no. 31

5--13

EN

After a short introduction characterizing the general outline of the issue, this paper describes the test results of oil leakage measurements through CVT actuator seals. The research was done using Jatco company's CVT 7model, the popular gearbox for small passenger cars. Several curves of leakage values are given for both actuators, concerning different conditions such as rotational speed, oil temperature or pressure. In the summary several conclusions are formulated, based on presented test results. The determined maximal value of leakage is about 1 l/min. It emerged that the influence of centrifugal force is negligible. What is more, the observed phenomena are shortly described and projected for more detailed investigation.

7

Performance assessment and leakage analysis of feed water pre-heaters in natural gas-fired steam power plants

Shabani G. A. S., Ameri M., Akbari O., Seifi A.

Journal of Power Technologies

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2018

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Vol. 98, nr 4

352--364

EN

The performance of feed water pre-heaters (FWH) at a steam power plant with a capacity of 200 MW is evaluated in this paper. The main objective of this study is to investigate the behavior of these FWHs in various cases. The effect of leakage of condensates on the condenser was also studied in detail. To do this, each FWH was studied separately and also in groups (LP, HP and both groups). While some of the results are exclusive to the studied power plant, others can be generalized to similar power plants. The results show that although LPH-1 and LPH-2 have the lowest exergy efficiency, they have the greatest effect on the efficiency of the cycle. Whereas HPH-6 and LPH-4 have the highest heat exchange (31.3 and 21.73 MW), LPH-2 and LPH-1 deliver the greatest positive effect on energy efficiency (0.81% and 0.61/0%). Moreover, the results show the particular importance of preventing any leakage of heater condensate. In the event of leakage along the route to the condensate of heaters, the most negative effect will be due to the HP heaters: 20 kg/s leakage in the HPHs line will cause an increase in CO2 production p.a. of roughly 10150 metric tons. Furthermore, energy efficiency and power produced will fall by 0.374% and 5.1 MW. In terms of the impact of leakages on the cooling tower, the study showed that LPH-1 and LPH-2 have the greatest effect. The effects of LP and HP FWHs on the energy efficiency of the cycle were 2.53% and 0.82%.