Replacing Discrete Demand with Continuous Demand

1995 ◽  
pp. 33-42 ◽  
Author(s):  
Zvi Drezner
Keyword(s):  
Continuous Demand

Multiple Boris solvers for particle-in-cell (PIC) simulation

2021 ◽  
Author(s):  
Seiji Zenitani ◽  
Tsunehiko Kato
Keyword(s):  
Plasma Physics ◽  
Particle Motion ◽  
Charged Particles ◽  
Single Step ◽  
Pic Simulation ◽  
Particle In Cell ◽  
Step Procedure ◽  
Cell Simulation ◽  
Continuous Demand

<div> <div> <div> <p> Particle-in-cell (PIC) simulation has long been used in theoretical plasma physics. In PIC simulation, the Boris solver is the de-facto standard for solving particle motion, and it has been used over a half century. Meanwhile, there is a continuous demand for better particle solvers. In this contribution, we introduce a family of Boris-type schemes for integrating the motion of charged particles. We call the new solvers the multiple Boris solvers. The new solvers essentially repeat the standard two-step procedure multiple times in the Lorentz-force part, and we derive a single-step form for arbitrary subcycle number <em>n</em>. The new solvers give <em>n<sup>2</sup></em> times smaller errors, allow larger timesteps, but they are computationally affordable for moderate <em>n</em>. The multiple Boris solvers also reduce a numerical error in long-term plasma motion in a relativistic magnetized flow.</p> </div> </div> </div><p>Reference:</p><ul><li>S. Zenitani & T. N. Kato, <em>Multiple Boris integrators for particle-in-cell simulation</em>, Comput. Phys. Commun. <strong>247</strong>, 106954, doi:10.1016/j.cpc.2019.106954 (2020)</li> </ul>

Process Management as a Means to Analyze the Effectiveness of a Company in Global Markets

2019 ◽  
pp. 263-286
Author(s):  
Lidia Sanchez-Ruiz ◽  
Beatriz Blanco ◽  
Carlos A. Perez-Labajos ◽  
Alberto Porras
Keyword(s):  
Process Management ◽  
The Other ◽  
Global Markets ◽  
Fixed Costs ◽  
Management Perspective ◽  
Demand Fluctuations ◽  
A Company ◽  
Continuous Demand ◽  
Low Activity

Companies need to ensure the effectiveness of all their processes. The case of the shipbuilding sector is exactly the same. From a management perspective, two important points should be highlighted. In order to face the continuous demand fluctuations, many shipyards, especially the smaller ones, have reduced their staff. This fact allows shipyards to be more flexible and to reduce their fixed costs in order to survive in low activity periods. On the other side, when there are peaks of workload, they outsource many activities. In fact, outsourcing has become one of the main and most important processes in shipyards. The level of outsourced activities is so high that shipyards are considered to be synthesis industries. Therefore, it is very important to ensure that the outsourcing process is correctly managed. Thus, the aim of this study is to show how process management can be used as a means to guarantee the effectiveness of a process. Specifically, the case of a small shipyard applying process management in its outsourcing process will be described.

The evolution of informal land use in a Nigerian market

2018 ◽  
Vol 47 (5) ◽  
pp. 745-758
Author(s):  
Adekunle Moruf Alabi ◽  
Mubarak Olatunji Lasisi ◽  
Maryam Abimbola Azeez
Keyword(s):  
Land Use ◽  
Informal Economy ◽  
Open Space ◽  
Human Interaction ◽  
Geographical Information ◽  
Economic Activities ◽  
Urban Markets ◽  
The Unemployed ◽  
The Impact ◽  
Continuous Demand

Urban growth is one of the indicators that reflects human interaction with the environment and has a direct effect on land use change. Continuous demand for space in Nigeria’s urban markets to accommodate shops and other retail outlets used for informal economic activities is accompanied by a change of use. This study examined the impact of informal economic activities on change of use in Bola Ige International Market, Ibadan. The concept of informal economy and the bid rent theory provided the conceptual/theoretical framework for this study. Geographical Information System was used to capture the change of use between 2006 and 2016. Land used for informal economic activities increased from 39.45% in 2006 to 55.35% in 2016, signifying a 15.9% increase. This implies that other land uses have been illegally converted and encroached. Transportation land use decreased from 31.47% in 2006 to 30.28% in 2011 and to 28.73% in 2016. Land used for open space (including parking space, and open trading area) which was 26.7% in 2006 reduced to 20.24% and 11.05% in 2011 and 2016, respectively. Most of the green areas (62.1%) have been converted to informal trading spaces between 2006 and 2016. Illegal change of use was credited to harsh economic condition in the country, and the engagement of the unemployed and retirees in informal sector economic activities. It was suggested that urban managers in conjunction with informed activists, researchers and citizens need to formulate and implement planning regulations that will integrate informal economic activities.

Continuous Demand Chain Management

2011 ◽  
pp. 163-182 ◽  
Author(s):  
Merrill Warkentin ◽  
Akhilesh Bajaj
Keyword(s):  
Chain Structure ◽  
Third Party ◽  
Structured Interviews ◽  
Senior Managers ◽  
Chain Management ◽  
Demand Chain ◽  
New Business ◽  
Model C ◽  
Continuous Demand ◽  
Demand Chain Management

The demand side of supply chain management has drawn considerable research attention, with focus on disintermediation and syndication models. In this chapter, we evaluate new business models for establishing a continuous demand chain structure to streamline the logistics between the vendor and its direct consumers. The Continuous Demand Chain Management (CDCM) model of E-Commerce is one in which the physical products for sale are delivered directly to the customer without the use of a third party logistics provider, such as a common carrier, and in which the physical product may be continuously “pulled” from the seller. We present three submodels of CDCM. The CDCM Model A applies to business-to-consumer (B2C) online sellers of physical goods who own or control their own delivery vehicles, and may provide further services to extend the value proposition for the buyer. The online grocer is a typical example of businesses in this category. The CDCM Model B applies to business-to-business (B2B) sellers of physical goods, who also own a significant portion of their delivery fleet and deliver goods on demand to local distributors or business customers. Office supply E-Merchants provide an example of this model. The CDCM Model C applies to businesses that typically provide virtually instantaneous delivery of third party goods to consumers or businesses. Businesses in this category own or control their own delivery fleet and add value by delivering items within very short periods of time, usually one-hour delivery. In order to analyze these models, we conducted structured interviews with key senior managers of one representative business each in the CDCM Model A and Model B categories. We extensively surveyed recent literature on companies in the CDCM Model C category. We use the results of our study to analyze different aspects, such as revenue streams, cost structure, and operational peculiarities of businesses following the CDCM model and, finally, discuss the long-term viability of the sub models.

Coordination of elderly healthcare service supply chain with information asymmetry: Designs of option contracts under different demand distribution statuses

2020 ◽  
Vol 54 (5) ◽  
pp. 1291-1307
Author(s):  
Jun Zhao
Keyword(s):  
Supply Chain ◽  
Information Asymmetry ◽  
Information Sharing ◽  
Healthcare Service ◽  
Demand Distribution ◽  
Service Supply Chain ◽  
Option Contract ◽  
Demand Information ◽  
Continuous Demand ◽  
Elderly Healthcare

This paper studies the issue of demand information asymmetry in an elderly healthcare service (EHS) system represented by a two-echelon elderly healthcare service supply chain (EHSSC) comprising an elderly service integrator (ESI) and a service provider (ESP). The goal of the ESI is to decide on how much service capacity is required for placing orders to the ESP, who directly serves the customers. Considering discrete and continuous demand distribution statuses, a centralised model with symmetric demand information and decentralised models with asymmetric demand information are developed to analyse the optimal ordering decisions and discuss the influence of information asymmetry. Furthermore, option contracts are applied to help coordinate the supply chain under asymmetric demand information based on different demand distribution statuses. Optimal option contract menus are designed for the ESP to promote the information sharing. Results show that the option contract can coordinate the EHSSC with asymmetric demand information under both discrete and continuous demand distribution statuses. The exercise price will be higher under lower demand information than that under higher demand information and the transfer payment will be less under lower demand information than that under higher demand information. Moreover, although the ESI has demand information superiority and can make use of opportunistic behaviour to maximise its own profit, the ESP as the leader can design the option contract to incentive the ESI to achieve true information sharing, and even obtain nearly all of the channel profit.

Problems of Current Classification of Building Materials in the Context of Solution of Structure Fire Safety

2014 ◽  
Vol 1057 ◽  
pp. 204-211
Author(s):  
Róbert Leško ◽  
Martin Lopušniak
Keyword(s):  
Fire Safety ◽  
Building Materials ◽  
Point Of View ◽  
Building Structures ◽  
Innovative Solutions ◽  
Energy Economy ◽  
Negative Impacts ◽  
Continuous Demand ◽  
New Procedures

Fire safety, as one of six basic requirements for structures in Slovakia, does not reflect the increase of innovative solutions during last years in the field of building industry. At the present time, energy economy of structures sets the character of structures forming the heat exchange envelope of the building. Continuous demand for the application of ecological materials increases requirements for optimizing the existing or creating new procedures in the solution of fire safety of structures. The existing classification of building structures appears, from the point of view of fire safety, as insufficient one. Comparative analysis of different structural compositions of external cladding is the method that demonstrates in this paper unsuitability of criteria set. The development of new procedures can make more effective and can optimize requirements without any negative impacts on resulting fire safety of the structure.

scholarly journals Sweet Cherry Byproducts Processed by Green Extraction Techniques as a Source of Bioactive Compounds with Antiaging Properties

Antioxidants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 418 ◽  
Author(s):  
Luz Agulló-Chazarra ◽  
Isabel Borrás-Linares ◽  
Jesús Lozano-Sánchez ◽  
Antonio Segura-Carretero ◽  
Vicente Micol ◽  
...  
Keyword(s):  
Supercritical Co2 ◽  
High Performance ◽  
Food Industry ◽  
Sweet Cherry ◽  
Subcritical Water ◽  
Extraction Techniques ◽  
Green Extraction ◽  
Flight Mass Spectrometry ◽  
Cosmetic Industry ◽  
Continuous Demand

In the cosmetic industry, there is a continuous demand for new and innovative ingredients for product development. In the context of continual renovation, both cosmetic companies and customers are particularly interested in compounds derived from natural sources due to their multiple benefits. In this study, novel and green-extractive techniques (pressurized solvent, supercritical CO2, and subcritical water extractions) were used to obtain three new extracts from sweet cherry stems, a byproduct generated by the food industry. The extracts were characterized by high-performance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS), and 57 compounds, mainly flavonoids but also organic and phenolic acids, fatty acids, and terpenes, were identified. After analytical characterization, a multistep screening approach, including antioxidant, enzymatic, and photoprotective cellular studies, was used to select the best extract according to its benefits of interest to the cosmetics industry. The extract obtained with supercritical CO2 presented the best characteristics, including a wide antioxidant capacity, especially against lipid peroxyl and •OH free radicals, as well as relevant photoprotective action and antiaging properties, making it a potential new ingredient for consideration in the development of new cosmetics.

Computing optimal (s, S) policies in inventory models with continuous demands

1985 ◽  
Vol 17 (02) ◽  
pp. 424-442 ◽  
Author(s):  
A. Federgruen ◽  
P. Zipkin
Keyword(s):  
Markov Decision Process ◽  
Decision Process ◽  
Inventory Models ◽  
Cost Criterion ◽  
Continuous State Space ◽  
Continuous State ◽  
Phase Type ◽  
Phase Type Distributions ◽  
Markov Decision ◽  
Continuous Demand

Special algorithms have been developed to compute an optimal (s, S) policy for an inventory model with discrete demand and under standard assumptions (stationary data, a well-behaved one-period cost function, full backlogging and the average cost criterion). We present here an iterative algorithm for continuous demand distributions which avoids any form of prior discretization. The method can be viewed as a modified form of policy iteration applied to a Markov decision process with continuous state space. For phase-type distributions, the calculations can be done in closed form.

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