Optimal cycle time in a multi-product single machine with unit load, and storage space considerations

1991 ◽  
Vol 16 (2) ◽  
pp. 197-208
Author(s):  
Abdolazim Houshyar
Keyword(s):  
Single Machine ◽  
Cycle Time ◽  
Storage Space ◽  
Unit Load ◽  
And Storage

scholarly journals A Two-Stage Offline-to-Online Multiobjective Optimization Strategy for Ship Integrated Energy System Economical/ Environmental Scheduling Problem

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Qing An ◽  
Jun Zhang ◽  
Xin Li ◽  
Xiaobing Mao ◽  
Yulong Feng ◽  
...  
Keyword(s):  
Multiobjective Optimization ◽  
Real World ◽  
Operation Time ◽  
Energy System ◽  
Scheduling Problem ◽  
Storage Space ◽  
Optimization Strategy ◽  
Two Stage ◽  
Integrated Energy System ◽  
And Storage

The economical/environmental scheduling problem (EESP) of the ship integrated energy system (SIES) has high computational complexity, which includes more than one optimization objective, various types of constraints, and frequently fluctuated load demand. Therefore, the intelligent scheduling strategies cannot be applied to the ship energy management system (SEMS) online, which has limited computing power and storage space. Aiming at realizing green computing on SEMS, in this paper a typical SIES-EESP optimization model is built, considering the form of decision vectors, the economical/environmental optimization objectives, and various types of real-world constraints of the SIES. Based on the complexity of SIES-EESPs, a two-stage offline-to-online multiobjective optimization strategy for SIES-EESP is proposed, which transfers part of the energy dispatch online computing task to the offline high-performance computer systems. The specific constraints handling methods are designed to reduce both continuous and discrete constraints violations of SIES-EESPs. Then, an establishment method of energy scheduling scheme-base is proposed. By using the big data offline, the economical/environmental scheduling solutions of a typical year can be obtained and stored with more computing resources and operation time on land. Thereafter, a short-term multiobjective offline-to-online optimization approach by SEMS is considered, with the application of multiobjective evolutionary algorithm (MOEA) and typical schemes corresponding to the actual SIES-EESPs. Simulation results show that the proposed strategy can obtain enough feasible Pareto solutions in a shorter time and get well-distributed Pareto sets with better convergence performance, which can well adapt to the features of real-world SIES-EESPs and save plenty of operation time and storage space for the SEMS.

scholarly journals Making Education Collections Safe to Touch: Safety Assessments and Data Maintenance

2018 ◽  
Vol 2 ◽  
pp. e28197
Author(s):  
Kelsey Falquero ◽  
Katherine Roberts ◽  
Jessica Nakano
Keyword(s):  
Natural History ◽  
Specimen Preparation ◽  
Museum Specimens ◽  
National Museum ◽  
Storage Space ◽  
Collections Management ◽  
Vertebrate Zoology ◽  
Education And Outreach ◽  
Safety Assessments ◽  
And Storage

Q?rius is an interactive learning venue at the Smithsonian National Museum of Natural History (NMNH) designed specifically for a teen audience. The space gives visitors a chance to interact with museum specimens, especially in the Collections Zone. The Q?rius collections are non-accessioned education collections, belonging to the Office of Education and Outreach (E&O). The collections include the Museum’s seven disciplines – Anthropology, Botany, Entomology, Invertebrate Zoology, Mineral Sciences, Paleobiology, and Vertebrate Zoology. Starting in 2013, collections staff began performing safety assessments on specimens before their rehousing and storage in the publicly accessible Collections Zone. Risks assessed include sharpness, ingestibility, radioactivity, and contaminants (such as arsenic, mercury, and lead, which were historically used in specimen preparation or for pest management). Specimen and object fragility was also assessed. The goal of these assessments was to minimize risks to our visitors and to our collections. The safety assessments allow collections staff to make housing recommendations that would ensure the safety of NMNH’s visitors and the preservation of E&O’s collections in a publicly accessible storage space. This practice now extends to other pre-existing learning venues that contain publicly accessible portions of the E&O Collection, further minimizing risks. Staff have started adding the data gathered by these safety assessments to our collections management system, to protect the data from loss and to make the information easily accessible to staff. This poster relates to a second poster, Establishing Legal Title for Non-Accessioned Collections.

Selecting and Allocating Cubes in Multi-Node OLAP Systems

2011 ◽  
pp. 99-131
Author(s):  
Jorge Loureiro ◽  
Orlando Belo
Keyword(s):  
Cost Estimation ◽  
Cost Model ◽  
Storage Space ◽  
Communication Costs ◽  
Estimation Algorithms ◽  
Parallel Tasks ◽  
Maintenance Time ◽  
Dimension Space ◽  
And Storage ◽  
Linear Cost

OLAP queries are characterized by short answering times. Materialized cube views, a pre-aggregation and storage of group-by values, are one of the possible answers to that condition. However, if all possible views were computed and stored, the amount of necessary materializing time and storage space would be huge. Selecting the most beneficial set, based on the profile of the queries and observing some constraints as materializing space and maintenance time, a problem denoted as cube views selection problem, is the condition for an effective OLAP system, with a variety of solutions for centralized approaches. When a distributed OLAP architecture is considered, the problem gets bigger, as we must deal with another dimension—space. Besides the problem of the selection of multidimensional structures, there’s now a node allocation one; both are a condition for performance. This chapter focuses on distributed OLAP systems, recently introduced, proposing evolutionary algorithms for the selection and allocation of the distributed OLAP Cube, using a distributed linear cost model. This model uses an extended aggregation lattice as framework to capture the distributed semantics, and introduces processing nodes’ power and real communication costs parameters, allowing the estimation of query and maintenance costs in time units. Moreover, as we have an OLAP environment, whit several nodes, we will have parallel processing and then, the evaluation of the fitness of evolutionary solutions is based on cost estimation algorithms that simulate the execution of parallel tasks, using time units as cost metric.

Study on Internal Layout of UK's Day Care Unit for Older People

2014 ◽  
Vol 507 ◽  
pp. 7-10
Author(s):  
Da Ke Wei ◽  
Hong Jin ◽  
Hong Yuan Mei
Keyword(s):  
Older People ◽  
Day Care ◽  
Public Spaces ◽  
Basic Type ◽  
Relative Location ◽  
Storage Space ◽  
Internal Circulation ◽  
Private And Public ◽  
The Relationship ◽  
And Storage

This study focuses on the internal layout of premises of UKs day care unit for older people, including possible combinations of rooms and spaces, access and circulation. All day units require a minimum of a dining/activity space, a kitchen, (a) toilet (s) and storage space, these rooms and spaces are combined into the basic type of premises. Depending on the aims of the unit, the number of places provided, and users' needs, many of the disadvantages associated with basic premises can be overcome if the premises have extra spaces. From the above analysis we can see that, in existing day unit premises, the number and type of rooms and spaces and how they are grouped together vary considerably, ranging from simple to complex arrangements. Also, the relationships between rooms and spaces in layouts for all day unit premises need to be pondered over, including distances between key rooms/spaces, the relative location of spaces in terms of their functions, the relationship between private and public spaces and the views within and between rooms, and from external windows. In addition, access and circulation of a day unit need to be considered carefully, including access to the day unit premises and the reception space and internal circulation.

Effects of phosphorus limitation and temperature on PHA production in activated sludge

2004 ◽  
Vol 50 (8) ◽  
pp. 135-143 ◽  
Author(s):  
S. Chinwetkitvanich ◽  
C.W. Randall ◽  
T. Panswad
Keyword(s):  
Activated Sludge ◽  
Nutrient Limitation ◽  
Growth Phase ◽  
Cycle Time ◽  
Phosphorus Limitation ◽  
Two Stage ◽  
Mixed Liquor ◽  
Pha Production ◽  
Effects Of Temperature ◽  
And Storage

The study was designed to investigate the effects of temperature and phosphorus limitation on polyhydroxyalkanoate (PHA) production and storage by activated sludge biomass. The two-stage operation approach, i.e. a growth phase followed by a nutrient limitation phase, was applied to induce PHA accumulation. The pre-selected temperatures of 10, 20 and 30°C were investigated under phosphorus limitation conditions using three four-litre fully aerobic SBR systems operated at an SRT of 10 days with cycle time and HRT of 6 and 10 hours. PHA production was greater in the 10°C system than in the 20°C and 30°C systems but there was little difference between the two higher temperatures. The maximum PHA fractions of the sludge were 52, 45 and 47%TSS for the three temperatures from low to high, and the maximum PHA concentrations in the mixed liquors were 1,491, 1,294 and 1,260 mg/l, respectively. However, it was observed that very low values of PHA yield per unit COD consumed were obtained, i.e., 0.05, 0.03 and 0.04 mgPHA/mgCODu, for the 10, 20 and 30°C reactors, respectively. This was because all three systems required several days to reach maximum PHA accumulation in their mixed liquor biomasses. It is probable the bacteria still had some stored poly-P in their cells upon initiation of the phosphorus limited influent, and PHA accumulation was delayed until the stored phosphorus was depleted. Also, PHA productivity was reduced by the large amounts of biomass lost from the systems because of sludge bulking.

scholarly journals Labour implementation and efficiency of the foodstuffs wholesales

2012 ◽  
Vol 48 (No. 8) ◽  
pp. 347-352
Author(s):  
M. Vicen ◽  
I. Ubrežiová
Keyword(s):  
Main Part ◽  
Slovak Republic ◽  
Labour Productivity ◽  
Storage Space ◽  
Main Factors ◽  
And Storage ◽  
Made In

The analysis is made in the set of the selected foodstuffs wholesales in the Slovak Republic and shows their differences from the viewpoint of the size (sale place 15 m2–1 300 m2 , storage space 106 m2–6 500 m2 ), number of workers (1–81) and yearly turnover (219 thousand SKK–2 748 thousand SKK). The main part of wholesales is operated by owners (83%) and a small part (17%) is on lease. From the viewpoint of location, the wholesales are situated in the centre of town (50%) and village (27%). The rest is located in the habitations and suburbs of town. The competitive wholesales (43%) are situated in the distance from 11 to 500 m. The highest labour productivity was obtained at the wholesale with location in the suburbs of town and the distance from competitive firms is about 500–1 000 m. Suitable results were achieved in the wholesales on lease with location in the suburbs of towns. The efficiency of wholesales was affected by the main factors, including the number of workers, size of sale place and storage space which determined up to the 92% of the volume of yearly turnover.

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