In this paper, a hierarchical control approach with three layers is defined to control the crop growth based on climate and economic criteria for tomato greenhouse. Integrated greenhouse management consists of energy, climate, water-fertilizer, crop quality and pest-disease management. The main purpose of a modern greenhouse is to define the information flow, to control optimum material and ene...

“Soft Operation Research and Practice: The Contribution of the Founders Operations Research” explores two themes relating to 43 people whose profiles constitute Assad Gass book referred in article. First, it direct influence founders on development soft operations research (OR) alignment their work with characteristics OR. Second, how many key early developments OR stemmed from founders’ engage...

As we saw last week, the worldwide scientific community has reached consensus that global warming is inevitable if humans continue to dump "greenhouse gases" into the atmosphere at anything like present rates. Greenhouse gases include carbon dioxide, methane, nitrous oxide, chlorofluorocarbons (CFCs) and a few others. These gases act like the glass covering a greenhouse, letting sunlight in but...

abstract today, greenhouses are used for controlling different climacterics parameters, specially light and temperatures on agricultural productions. the most part of productions is vegetables production in traditional greenhouses (tg) and unfortunately productions quality and quantity in greenhouses is lower than modern (mg) ones. this experiment studies the effects of different climates of tw...

The objective of this work was to study the effect of shading screens, normally used during the day for cooling purposes, on the night-time climate of unheated greenhouses. For this purpose, f irst a number of experimental measurements were taken during cold nights to characterise the greenhouse climate both with and without an aluminised external screen. Secondly a Computational Fluid Dynamic ...

In a greenhouse system, a control is important to allow optimal growth conditions for crops. However, because testing the greenhouse for real conditions requires much time and money, the modeling-and-simulation approach is necessary to predict and improve the greenhouse environment. There is much research related to greenhouse control, there is a lack of research on applicable frameworks for re...

Using the discourse model for negotiation of meaning developed by Varonis and Gass (1985), this study investigates the quality of the negotiation of meaning by eTandem partners in a videoconferencing-supported multimodal environment, and the facilitating effects of such an environment on L2 acquisition. To achieve this, three case studies were chosen from the interaction between15 pairs of Mand...

Greenhouse is a building, which provides controlled climate conditions to the plants to keep them from external hard conditions. Greenhouse technology gives freedom to the farmer to select any crop type in any time during year. The quality and productivity of plants inside greenhouse is highly dependent on the management quality and a good management scheme is defined by the quality of the info...

The rate at which the global average surface temperature is increasing has slowed down since the end of the last century. This study investigates whether this warming hiatus results from a change in the well-known greenhouse effect. Using long-term, reliable, and consistent observational data from the Earth's surface and the top of the atmosphere (TOA), two monthly gridded atmospheric and surfa...