Real-Time Cooling Power Attribution for Co-Located Data Center Rooms with Distinct Temperatures and Humidities

At present, a co-location data center often applies an identical and low temperature setpoint for its all server rooms. Although increasing the temperature setpoint is a rule-of-thumb approach to reducing the cooling energy usage, the tenants may have different mentalities and technical constraints in accepting higher temperature setpoints. Thus, supporting distinct temperature setpoints is desirable for a co-location data center in pursuing higher energy efficiency. This calls for a new cooling power attribution scheme to address the inter-room heat transfers that can be up to 9% of server load as shown in our real experiments. This article describes our approaches to estimating the inter-room heat transfers, using the estimates to rectify the metered power usages of the rooms’ air handling units, and fairly attributing the power usage of the shared cooling infrastructure (i.e., chiller and cooling tower) to server rooms by following the Shapley value principle. Extensive numeric experiments based on a widely accepted cooling system model are conducted to evaluate the effectiveness of the proposed cooling power attribution scheme. A case study suggests that the proposed scheme incentivizes rational tenants to adopt their highest acceptable temperature setpoints under a non-cooperative game setting. Further analysis considering distinct relative humidity setpoints shows that our proposed scheme also properly and inherently addresses the attribution of humidity control power.

Reducing the hydrodynamic force in the hydraulic distributor by modernizing the spool coupe parts

Due to a sharp change in the direction and velocity of the fluid flow in the hydraulic distributor, hydrodynamic forces arise. When positioning and holding the spool, the magnitude of the above forces determines the required control power. The aim of the article was to find an optimal constructive solution that would reduce the influence of hydrodynamic forces. In the article we have considered the theoretical foundations laid in the analytical solution of the problem of calculating the magnitude of the hydrodynamic force acting on the plunger of the spool. In addition, a numerical experiment was carried out using CAD Solidworks and the Flow Simulation application package and a comparison of the results obtained with the analytical solution of the problem. During the numerical experiment, it was found that by upgrading the spool sleeve, it is possible to reduce the value of the hydrodynamic force by 4.5 times, compared with the original design. At the same time, it was found that the modernization of the plunger does not further reduce the maximum hydrodynamic forces. The article highlights the economic benefits of reducing the required power to control the hydraulic distributor. The article may be of interest to both researchers whose research interests lie in the field of hydrodynamics, and manufacturers of hydraulics.

A new optimal control technique for solution of HIV infection model

In this paper, by means of the optimal control technique and power series technique,we introduce a new method, namely, the optimal control power series technique, bywhich one can obtain numerical solutions of the HIV infection model of CD4+T cells.The obtained approximate solution has shown good agreement with the experimentalresults and previous simulations using other methods.https://search.hthereadinghub.com/?uc=20180302&ad=appfocus1&source=d-lp0-bb9&uid=0d8983d2-5a26-4ec4-bba5-84ea234d1896&i_id=ebooks_100.7&page=newtab&

4th International Conference on Technology and Electrical Engineering (CITIE 2021)

Preface The curricular project of Technology in Electricity and Electrical Engineering by cycles of the Universidad Distrital Francisco José de Caldas (Colombia) celebrates every two years its international conference. Unlike previous editions, during 2021 the Universidad Distrital has its facilities closed, and with restricted access, as a preventive measure to avoid the spread of the SARS-CoV-2 virus. Probably in two years, for CITIE 2023, the conference will return to its usual physical space in Aduanilla de Paiba, our flagship library. However, for this fourth version of CITIE, we opted for a distance event, organized entirely by videoconference, an experiment that, although not a feature mastered by our community, was a success. The fourth International Conference on Technology and Electrical Engineering (CITIE 2021) was held on November 11-12, 2021. This event was attended by researchers from the electrical area with papers mainly focused on electronic instrumentation, control, power systems, and electromagnetic compatibility. From the talks and presentations, it was evident that our research community remains active and produces cutting-edge research despite the conditions of restriction and social unrest typical of our political and socio-economic circumstances, strongly affected by the COVID-19 pandemic. A total of 11 papers were submitted to CITIE 2021, of which 10 were approved by the jurors (conference committee members and international reviewers) in a double-blind evaluation process. The conference was held entirely online over two days, which included the test session, three 50-minute keynote speeches, and three author presentation sessions. The research papers were separated into three thematic sessions, Instrumentation and Control, Power Systems, and Electronic Compatibility. These papers were each given 20 minutes of presentation time, including five minutes for questions. The entire conference was broadcast live on the event’s YouTube channel, registering an average of 600 daily visits. I would like to take this opportunity to acknowledge the hard work of the entire CITIE 2021 committee. Their advice and support were fundamental to preparing for the conference. I would also like to thank the students of the Electrical Technology program who supported the videoconference platform and the live transmission. Likewise, a special thanks to the speakers and authors for considering CITIE 2021 as a means of dissemination of their researchers, and to the invited researchers, whose talks and discussions allowed to leave on the carpet countless ideas for further discussion and development of impact research. The three previous versions of CITIE allowed the development of activities such as business shows, workshops, and a degree of interaction that was not achieved in CITIE 2021. The face-to-face conferences allow a level of direct communication with authors and researchers that is difficult to replicate on a distance platform. Even so, CITIE continues to maintain its spirit of dissemination of research and innovation, as well as its function of identifying and promoting areas of research in the field of electrical energy. We are confident that this version of the event has provided a great experience for all attendees, increased interest in the research fields discussed, as well as renewed expectations for the CITIE 2023 meeting. Best regards Prof. Fredy Martínez, Ph.D CITIE 2021 Universidad Distrital Francisco José de Caldas List of Committees are available in this pdf.

'Stolen from Its People and Wrenched from Its Roots'? A Study of the Crown's 1867 Acquisition of the Rongowhakaata Meeting House Te Hau ki Turanga

<p>Te Hau ki Tūranga is the oldest meeting house in existence. It was built in the early 1840s at Orakaiapu Pā, just south of Gisborne, by Ngāti Kaipoho (a hapū/subtribe of Rongowhakaata) chief Raharuhi Rukupō. In the nineteenth century whare whakairo (carved houses) were significant symbols of chiefly and tribal mana (prestige, control, power). They were ‗carved histories‘, physical embodiments of tribal history and whakapapa (genealogy) representing a link between the living and the dead. In 1867 Native Minister J C Richmond acquired the whare on behalf of the government to augment the collections of the Colonial Museum in Wellington. Over the almost 150 years since the whare arrived in Wellington, the acquisition of Te Hau ki Tūranga has been the subject of three government inquiries and numerous Rongowhakaata requests for its return. It has also been dismantled and re–erected three times and housed in three different museum buildings. At the close of the twentieth century Rongowhakaata submitted a claim to the Waitangi Tribunal for the ‗theft‘ of Te Hau ki Tūranga. Their claim also expressed concerns about the care and management of the whare in the hands of the Museum of New Zealand Te Papa Tongarewa and its predecessors. This thesis tells the story of Te Hau ki Tūranga from 1867 until the present. It asks: was the whare ‗stolen from its people and wrenched from its roots‘? as Rongowhakaata claim and places the story of Te Hau ki Tūranga in its historical context. It aims to understand the motives and agendas of the characters involved and reach a conclusion as to what most likely happened in 1867. This thesis also breaks new ground by examining the politics surrounding the whare as a museum exhibit and a Treaty of Waitangi claim. Overall this study provides a valuable insight into the history of Crown–Māori relations. It reveals why deep–seated grievances still exist among Māori today and demonstrates the value of the Treaty settlement process as an opportunity for Māori to tell their stories and gain redress for injustices that occurred in the past, but are still being felt in the present.</p>

'Stolen from Its People and Wrenched from Its Roots'? A Study of the Crown's 1867 Acquisition of the Rongowhakaata Meeting House Te Hau ki Turanga

<p>Te Hau ki Tūranga is the oldest meeting house in existence. It was built in the early 1840s at Orakaiapu Pā, just south of Gisborne, by Ngāti Kaipoho (a hapū/subtribe of Rongowhakaata) chief Raharuhi Rukupō. In the nineteenth century whare whakairo (carved houses) were significant symbols of chiefly and tribal mana (prestige, control, power). They were ‗carved histories‘, physical embodiments of tribal history and whakapapa (genealogy) representing a link between the living and the dead. In 1867 Native Minister J C Richmond acquired the whare on behalf of the government to augment the collections of the Colonial Museum in Wellington. Over the almost 150 years since the whare arrived in Wellington, the acquisition of Te Hau ki Tūranga has been the subject of three government inquiries and numerous Rongowhakaata requests for its return. It has also been dismantled and re–erected three times and housed in three different museum buildings. At the close of the twentieth century Rongowhakaata submitted a claim to the Waitangi Tribunal for the ‗theft‘ of Te Hau ki Tūranga. Their claim also expressed concerns about the care and management of the whare in the hands of the Museum of New Zealand Te Papa Tongarewa and its predecessors. This thesis tells the story of Te Hau ki Tūranga from 1867 until the present. It asks: was the whare ‗stolen from its people and wrenched from its roots‘? as Rongowhakaata claim and places the story of Te Hau ki Tūranga in its historical context. It aims to understand the motives and agendas of the characters involved and reach a conclusion as to what most likely happened in 1867. This thesis also breaks new ground by examining the politics surrounding the whare as a museum exhibit and a Treaty of Waitangi claim. Overall this study provides a valuable insight into the history of Crown–Māori relations. It reveals why deep–seated grievances still exist among Māori today and demonstrates the value of the Treaty settlement process as an opportunity for Māori to tell their stories and gain redress for injustices that occurred in the past, but are still being felt in the present.</p>

A new design of control & power management strategies of hybrid ac-dc microgrids toward high power quality

The micro grid idea provides for the lack of several reversing switches to unitary AC-DC grid that enables connection and charges (loads) to the electrical systems with changeable regenerative AC and CC sources. Safe operation and gadget safety involve digital integration with utilities/grid through power converters. Enhanced client reliability, decreased input losses, local voltages are supported, and waste heat efficiency increased, voltage drop or interruptible supply of electricity can be customized to satisfy their unique customer demands. Work at present Analyses the performance in grid tie mode of hybrid AC/DC systems. Here are PV systems, PV systems, For the construction of microgrids wind turbine generators and batteries are employed. Convert procedures for the correct coordination of AC sub-grids to DC subs-grids have also been established for converters. MATLAB/SIMULINK environment results are generated.

RNA Identification Technique and RST Control of a Hybrid Indirect Matrix Converter with a Flying Capacitor Three Level Inverter in Power Active Filtering Application

The present paper deals with RST controller using implementation of neural architectures to control power electronics systems dedicated to power quality improvement in a distribution grid. We present a technique for designing a robust RST controller, The computation of the controller is used to enhance the control a Hybrid Indirect Matrix Converter with a flying capacitor three level inverter (HIMC) coupled to the power grid (PG) by an RL filter, the synthesizing of this RST controller is formulated through open and close loop. Artificial neuronal network (ANN) identification technique is used to define/extract this disturbance. Simulation results by MATLAB, Simscap/sim power system code shows the effectiveness of the proposed method.