scholarly journals The Reliability of a System Involving Change Points

2020 ◽  
Vol 6 (1) ◽  
pp. 296-308
Author(s):  
Amos E. Gera
Keyword(s):  
Change Points ◽  
Auxiliary Functions ◽  
Start Up ◽  
Set Up ◽  
Recursive Relations

The reliability of a system having some change points is presented. The technique of calculation is based on a previously developed TFCF procedure for evaluating the reliability for i.i.d. component. It involves the use of some auxiliary functions to set up a set of recursive relations. The resultant equations are solved numerically. An extension to the more general TSCSTFCF procedure and its application to start-up demonstration tests is given. Also, in case of testing, the possibility of carrying out simultaneous tests on a set of units is considered.

Development of Reliable NARX Models of Gas Turbine Cold, Warm and Hot Start-Up

2017 ◽  
Author(s):  
Hilal Bahlawan ◽  
Mirko Morini ◽  
Michele Pinelli ◽  
Pier Ruggero Spina ◽  
Mauro Venturini
Keyword(s):  
Gas Turbine ◽  
Training Data ◽  
Series Data ◽  
Data Sets ◽  
Control Logic ◽  
Start Up ◽  
Hot Start ◽  
Narx Models ◽  
Set Up ◽  
Rapid Transients

This paper documents the set-up and validation of nonlinear autoregressive exogenous (NARX) models of a heavy-duty single-shaft gas turbine. The considered gas turbine is a General Electric PG 9351FA located in Italy. The data used for model training are time series data sets of several different maneuvers taken experimentally during the start-up procedure and refer to cold, warm and hot start-up. The trained NARX models are used to predict other experimental data sets and comparisons are made among the outputs of the models and the corresponding measured data. Therefore, this paper addresses the challenge of setting up robust and reliable NARX models, by means of a sound selection of training data sets and a sensitivity analysis on the number of neurons. Moreover, a new performance function for the training process is defined to weigh more the most rapid transients. The final aim of this paper is the set-up of a powerful, easy-to-build and very accurate simulation tool which can be used for both control logic tuning and gas turbine diagnostics, characterized by good generalization capability.

Rapid start-up of one-stage deammonification MBBR without addition of external inoculum

2016 ◽  
Vol 74 (11) ◽  
pp. 2541-2550 ◽  
Author(s):  
Linda Kanders ◽  
Daniel Ling ◽  
Emma Nehrenheim
Keyword(s):  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Anammox Bacteria ◽  
Operational Mode ◽  
Bacterial Populations ◽  
Reject Water ◽  
One Stage ◽  
Start Up ◽  
Laboratory Reactor ◽  
Set Up

In recent years, the anammox process has emerged as a useful method for robust and efficient nitrogen removal in wastewater treatment plants (WWTPs). This paper evaluates a one-stage deammonification (nitritation and anammox) start-up using carrier material without using anammox inoculum. A continuous laboratory-scale process was followed by full-scale operation with reject water from the digesters at Bekkelaget WWTP in Oslo, Norway. A third laboratory reactor was run in operational mode to verify the suitability of reject water from thermophilic digestion for the deammonification process. The two start-ups presented were run with indigenous bacterial populations, intermittent aeration and dilution, to favour growth of the anammox bacterial branches. Evaluation was done by chemical and fluorescence in situ hybridization analyses. The results demonstrate that anammox culture can be set up in a one-stage process only using indigenous anammox bacteria and that a full-scale start-up process can be completed in less than 120 days.

scholarly journals Consolidating the interactive analysis and Grid infrastructure at DESY

2020 ◽  
Vol 245 ◽  
pp. 07003
Author(s):  
Christoph Beyer ◽  
Thomas Finnern ◽  
Martin Flemming ◽  
Andreas Gellrich ◽  
Thomas Hartmann ◽  
...  
Keyword(s):  
Lessons Learned ◽  
Tier 2 ◽  
Interactive Analysis ◽  
Batch Systems ◽  
Batch System ◽  
Start Up ◽  
High Responsiveness ◽  
Primary Focus ◽  
Set Up ◽  
National Analysis

Within WLCG, the DESY site in Hamburg is one of the largest Tier-2 sites with about 18500 CPU cores for Grid workloads. Additionally, about 8000 CPU cores are available for interactive user analyses in the National Analysis Factory [NAF]. After migrating these two batch systems onto a common HTCondor based set-up during the previous four years, we recapitulate the lessons learned during the transition especially since both use cases differ in their workloads. For Grid jobs start-up latencies are negligible and the primary focus is on an optimal utilization of the resources. Complementary, users of the NAF expect a high responsiveness of the batch system as well as the storage for interactive analyses. In this document, we will also give an outlook to future developments and concepts for the DESY high-throughput computing. In the ongoing evolution of the HTC batch system, we are exploring how to integrate anonymous jobs with the batch system as back-end for Function-as-a-Service workflows as well as an option for dynamic expansions to remote computing resources.

The 60-Minute MVP

2019 ◽  
Vol 3 (4) ◽  
pp. 371-386
Author(s):  
Doan Winkel ◽  
Justin Wilcox ◽  
Atul Teckchandani
Keyword(s):  
Hypothesis Testing ◽  
Iterative Process ◽  
Technical Expertise ◽  
Start Up ◽  
Starting Point ◽  
The Creation ◽  
Mind Set ◽  
Set Up ◽  
Critical Aspects

The 60-minute minimum viable product (MVP) exercise teaches critical aspects of the entrepreneurial mind-set and lean start-up methodology, namely, the iterative process of hypothesis testing through the creation of MVPs. In 60 minutes, with no prior technical expertise, students will work in teams to design a landing page, create a teaser video, and set up a way to gather information from prospective customers. The resulting low-fidelity MVP can subsequently be shared with prospective customers to gauge interest and be used as a starting point for the hypothesis testing process used in the lean start-up methodology. This is an immersive exercise that activates students, builds confidence, and teaches important entrepreneurial principles.

Study of the Pressure Distribution between the Piston Rings in Reciprocating Compressors

2011 ◽  
Vol 383-390 ◽  
pp. 6048-6052
Author(s):  
Dian Bo Xin ◽  
Jian Mei Feng ◽  
Yan Jing Xu ◽  
Xue Yuan Peng
Keyword(s):  
Pressure Distribution ◽  
Piston Ring ◽  
Dynamic Pressure ◽  
Threshold Value ◽  
Piston Rings ◽  
Premature Failure ◽  
Root Cause ◽  
Pressure Distributions ◽  
Start Up ◽  
Set Up

Piston ring is one of the most important sealing components that can be easily damaged in reciprocating compressors. The severe non-uniformity of the pressure distribution was suggested to be the essential reason for the premature failure of the piston rings. Therefore, a test rig was set up to measure the pressure distributions as well as the build-up of the dynamic pressure difference, which could reveal the root cause for the non-uniformity of the pressure distributions. The results showed that the build-ups of the pressure differences between different rings were not simultaneous; there existed a threshold pressure, and the latter ring could work only when the pressure before the former ring reached to the threshold value. The pressure distributions were also investigated at the start-up and shut-down of the compressor, which further validated the cause of the premature failure of the first ring.

AXIAL-FLOW BLOOD PUMP ACCELERATION CONTROL METHOD BASED ON A START-UP PROCESS DYNAMIC MODEL

2017 ◽  
Vol 41 (5) ◽  
pp. 691-705
Author(s):  
Xu Yan ◽  
Pang Youxia ◽  
Cheng Lizhi ◽  
Liang Liang
Keyword(s):  
Dynamic Model ◽  
Control Method ◽  
Axial Flow ◽  
Test System ◽  
Blood Pump ◽  
Theoretical Simulation ◽  
Process Dynamic ◽  
Axial Flow Blood Pump ◽  
Start Up ◽  
Set Up

The principle of a large gap magnetic drive system was used to achieve control of an axial-flow blood pump. A dynamic model of the start-up process of the axial-flow blood pump was established. It was analyzed and simulated. An acceleration control method for the blood pump was proposed based on the start-up process dynamic model. A corresponding parameter measurement test system was set up, and experimental data were compared with the results of the theoretical simulation. Results indicated that the experimental values obtained for the blood pump outlet pressure and flow rate changed similarly with the values obtained using theoretical simulation. These changes occurred simultaneously with the change in speed of the blood pump over time, and the driving control target value was reached within 4 seconds.

scholarly journals Numerical study of two-dimensional moist symmetric instability

2008 ◽  
Vol 17 ◽  
pp. 1-4 ◽  
Author(s):  
M. Fantini ◽  
P. Malguzzi
Keyword(s):  
Numerical Study ◽  
Finite Amplitude ◽  
Two Dimensional ◽  
Initial State ◽  
Linear Mode ◽  
Equivalent Potential ◽  
Start Up ◽  
Set Up ◽  
Symmetric Instability ◽  
Amplitude Evolution

Abstract. The 2-D version of the non-hydrostatic fully compressible model MOLOCH developed at ISAC-CNR was used in idealized set-up to study the start-up and finite amplitude evolution of symmetric instability. The unstable basic state was designed by numerical integration of the equation which defines saturated equivalent potential vorticity qe*. We present the structure and growth rates of the linear modes both for a supersaturated initial state ("super"-linear mode) and for a saturated one ("pseudo"-linear mode) and the modifications induced on the base state by their finite amplitude evolution.

scholarly journals Expanding Outreach via Colorado Master Gardener Clinics

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 784B-784
Author(s):  
Carol A. O'Meara* ◽  
Kerrie B. Badertscher
Keyword(s):  
Cultural Practices ◽  
Staff Time ◽  
Master Gardener ◽  
Volunteer Retention ◽  
The Public ◽  
Boulder County ◽  
Green Industry ◽  
Start Up ◽  
Set Up ◽  
Plant Clinics

Data supports the success of Colorado Master Gardener sm (MG) of Boulder County outreach beyond the Cooperative Extension office at outlying clinic sites. Initially unique in Colorado, MG plant clinics at area nurseries and garden centers has gained acceptance in other counties of Colorado. Exploration of benefits and investments for programs interested in expanding outreach to the public are discussed to provide a blueprint for clinics start-up. MG clinics are set up to provide answers to questions from the public on Friday through Sundays from April through mid-July. This schedule, coupled with the Monday through Friday MG desk hours, provides seven day per week access to the public during the busiest part of the growing season. Clinics are conveniently located in all county communities at Green Industry locations. Participating businesses consider the clinics a benefit worth investing IN and justification of sites is uniform. Additional single-day clinics have spun off as an addition to fixed clinic schedule. High requirement of staff time, increased sample load and resource investment is offset by the benefits of increased visibility of program in the community leading to increased recruitment of volunteers. Knowledge gained by the public has brought about measurable positive changes in pesticide use and responsible cultural practices. Volunteer retention is favorably affected with increased flexibility of scheduling opportunities and communications. Information on setting up clinic sites, what the sites receive, staff time and services requirements, and refinements as a result of clinic survey will be given.

scholarly journals Onshore Test Method for a 3 Unit 60 MW Gas Turbine-Generator Power Module

1985 ◽  
Author(s):  
Johannes Herdlevaer ◽  
Gordon Hugh Black
Keyword(s):  
Test Method ◽  
Test Facility ◽  
Test Results ◽  
Power Module ◽  
Test Program ◽  
The North ◽  
Start Up ◽  
The North Sea ◽  
Increasing Demand ◽  
Set Up

There has been an increasing demand for onshore testing of equipment destined for offshore operation. The justification for this requirement can be summarized as follows: 1. High cost of offshore commissioning where even minor faults detected, constitutes potentially serious problems. 2. Consequenses of delay of platform start-up are enormous. 3. Skilled experienced personel and diagnostic equipment is available onshore, and rectification of new units will benefit from the existence of previous experience. 4. Spare and renewal parts availability. This paper describes the method for string testing of a 3 unit 60 mw utility gasturbine-generator power module built for the gullfaks A platform in the Norwegian sector of the north sea. It describes the test facility and test equipment set up and also the test program which was followed. At the time of writing the paper the test program was barely initiated, and for that reason the test results will be presented in the form of an addendum to this paper during the meeting.

Sanctioning Mechanisms in Virtual Communities

2011 ◽  
pp. 409-413
Author(s):  
Elisa Bertino ◽  
Anna Cinzia Squicciarini ◽  
Elena Ferrari
Keyword(s):  
Resource Sharing ◽  
Virtual Communities ◽  
Virtual Community ◽  
Regulatory System ◽  
Personal Data ◽  
Automated System ◽  
Start Up ◽  
Set Up ◽  
Computational Resources ◽  
Access Policies

A virtual community is a composition of heterogeneous and independently designed subsystems, sharing services, resources, information, and knowledge to achieve a common goal. The concept of virtual community is very general and open to a number of interpretations (Ao & Misky, 2003; Sadighi & Sergot, 2002). Members belonging to a virtual community, indeed, may be represented by human beings, if the virtual community is a collection of people sharing common interests and ideas, or roles, programs or software/hardware modules, if the community is an automated system for sharing computing resources (Welch & Foster, 2002). The resource shared among a community may be computational resources as well as documents, information, or data. Whichever is the community-specific goal and features, assuming a community composed by interacting entities, several open issues need to be addressed, for instance, how to manage access policies to coordinate resource sharing, how to establish a community, how to oblige member communities to respect community policies, and so on. In the real world, to set up an organization it is necessary to perform some fundamental steps. First, the founder members have to draft a constitution, specifying the object and purpose of the organization, the rules, the kind of services and information provided. The constitution may be directly released to members or officially published in a registry’s Office. Furthermore, constitution must establish rules and responsibilities that each member has to follow. To join the community, a subject commonly has to apply for membership. The application consists of a procedure, where the applicant communicates his/her personal data, subscribes to the regulation of the community, and informs whether he/she has something to share, and which are the conditions under which he/she will release his/her services. Similarly, in order to start up a virtual community, it is necessary to define participant roles and resources to be shared, as well as a regulatory system composed of community laws and/or local laws defined by single members.

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