巻号一覧
44 巻 (1988 - 1989)
- 4 号 p. 253-
- 3 号 p. 175-
- 2 号 p. 91-
- 1 号 p. 1-
44 巻, 3 号
選択された号の論文の10件中1～10を表示しています
- |<
- <
- 1
- >
- >|
-
長谷場 徹也, 相原 研二, 松岡 秀樹, 伊藤 代次郎1988 年 44 巻 3 号 p. 175-180
発行日: 1988/12/10
公開日: 2010/02/25
ジャーナル フリーA low speed wind tunnel was designed and manufactured on the trial basis of air circulation caused by heat convection. The test section 7cm in length had a square cross section 14.5cm ×14.5cm. Under a range of flow speeds from 15 to 150cm·sec-1, the intensity of flow turbulence varied by less than 0.02 in the area of the section inwards 2cm from the inner wall of the duct.
In this area, flow speeds were found to be constant to within ±3 percent. A flow visualization showed a laminar flow in the section.
The boundary-layer transfer coefficients of water-vapor were evaluated for a flat leaf model 5cm in length in the flow direction and 10cm in the transverse width. The experimental coefficients were larger than those of the theoretical laminar forced-convective transfer at flow speeds below about 100cm·sec-1, above which the coefficients were in good agreement with the theory. An experimental equation representing the water-vapor transfer coefficient at low flow speeds was expressed as a function of the theoretical laminar forced-convection coefficient and Reynolds number in the situation of a certain value of Grashof number.抄録全体を表示PDF形式でダウンロード (699K) -
蔵田 憲次1988 年 44 巻 3 号 p. 181-186
発行日: 1988/12/10
公開日: 2010/02/25
ジャーナル フリーComputers have been applied to crop management in protected cultivation and have proved to be of great use. However, in the present computer systems, control algorithm is fixed and users can only change the setpoints of the controlled variables. Crop management is strongly influenced by the local conditions of climate, soil, etc. and well trained and eager growers manage their crops in the way which is suitable under the given local conditions and is obtained through the long period experience.
This study aims at developing a system which learns grower's managing methods (rules, hereafter) through measuring environmental factors, crop status, if possible, and grower's behavior.
After learning the grower's rules, the learned rules will be applied to the automatic management.
Thus, the grower will be released from the management labor without losing their own personal preference and principles in crop management. This system can also be applied to the rule aquisition and analysis of well trained growers. This report presents considerations on the characteristics of the growers' rules and the possibilities and problems of the simple learning algorism developed (K-algorithm, hereafter), which will be the framework of the system we aim at. Details of K-algorithm are given in another report (Kurata, 1988).
Considerations on the grower's rules revealed that there are many difficult aspects for the computer in learning, for examples, the problem of fuzziness associated with the human feelings, the problem of noise and how to find out a function which the grower's rule has but not directly measurable. All these points are omitted in the present study and left for the future study.
A simple simulation revealed that K-algorithm is very powerful in imitating the grower's behavior but the learned rules are somewhat longer than the assumed grower's rules, examples of which are listed Table 1. This redundant expression of the learned rule is due to some correlations among environmental factors, crops status and time. If we assume stochastic stationary state of these functions and their correlations, this brings about no problem in applying the learned rules to the automatic management.抄録全体を表示PDF形式でダウンロード (835K) -
權 在永, 高倉 直1988 年 44 巻 3 号 p. 187-194
発行日: 1988/12/10
公開日: 2010/02/25
ジャーナル フリーA numerical model is developed to predict the seasonal cooling load of a greenhouse with a refrigerator cooling system. It is necessary to estimate the running cost of a refrigerator. Recent studies showed the practical possibility of using refrigerator cooling systems in greenhouses, and as a result of this, intense interest has been shown towards it lately.
The model consisted mainly of three parts: the first part for the solar energy distribution in a greenhouse, the second part for the heat and vapour balances of a greenhouse, and the last part for the cooling system and control logic. The time step of the calculation was set to be a variable in a range up to several seconds. Hence, the heat and vapour balances were described mostly in differential equation forms. The dry bulb air temperature, the humidity ratio, the direct solar radiation at normal incidence, the scattered solar radiation at horizontal surface, the cloud amount and the wind velocity were the inputs as boundary conditions. The model was characterized by following points:
1) Both the seasonal cooling loads and heating loads could be calculated simultaneously.
2) The model was not only applicable to an even-span type greenhouse but to three-quarter type as well as greenhouse type plant factories.
3) Crops, cultivation beds, pots, screens and cooling or heating equipments could be presented in the greenhouse. It made it possible to analyze the loads in different conditions.
Suitability of the model was tested by comparing the simulated results with the observed results.
Data from the experiment of previous paper (Kozai et al., 1986), which had been carried mainly for measuring the nighttime cooling load of the greenhouse with a heat pump cooling system, were used as observed data. The fitness was generally good (Fig. 2). Yearly cooling loads and heating loads of different type greenhouses in different districts were calculated (Fig. 3, Fig. 4 and Table 3) as examples of using the model.抄録全体を表示PDF形式でダウンロード (960K) -
小森 友明, 関 平和1988 年 44 巻 3 号 p. 195-202
発行日: 1988/12/10
公開日: 2010/02/25
ジャーナル フリーHeating and thermal insulation characteristics of a falling hot water film on the roof or the screen sheet of a greenhouse may be analysed by evaluating the temperature profile of the thin water film. The temperature profile of the falling water film can be obtained by solving the conduction equation with several suitable boundary conditions, based on the concept of “Transfer and Rate of Processes”. The generalized analytical solution of the temperature profile of the water film was given by Eq. (15) and the average temperature at an arbitrary distance along the direction of water flow, ζ=ζ was given by Eq. (18).
From the calculated results of illustrative examples by the analytical solutions, the temperature of the water film at the water film-roof interface, ξ=1 could be approximated by the average temperature of the water film, an effective distance for heating the air in the greenhouse, ζR was determined from the relation between Φav(ζ) and the dimensionless temperature of the greenhouse ΦR and the most suitable thickness of the water film δ could be estimated by plotting Φav (1) against δ with a parameter ΦR, as shown in Fig. 6.
The relationship between Φav(1) and δ in Fig. 6 will be also applicable to estimate the suitable flow rate of water.
According to the calculated results, the water film performs broadly the task of thermal insulation at the water-roof interface. The corresponding amount of heat to the thermal insulation effect of the water film was given by Eq. (21), theoretically. Figs. 10, 11 and 12 show the over-all heat balance of the water film obtained by Eq. (21) and the amount of heat calculated from Eq. (21) is evaluated quantitatively by the rate of reduction of heating load for heating the greenhouse.
Therefore, the analytical solutions and procedures described here are useful for the calculation of actual heat requirement for heating a greenhouse, the design and operations of the practical water curtain system.抄録全体を表示PDF形式でダウンロード (832K) -
小野 祐幸, 金野 隆光, 奥野 隆, 浅野 聖子1988 年 44 巻 3 号 p. 203-208
発行日: 1988/12/10
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (738K) -
桜谷 哲夫, 大場 和彦1988 年 44 巻 3 号 p. 209-213
発行日: 1988/12/10
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (594K) -
1988 年 44 巻 3 号 p. 214
発行日: 1988/12/10
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (180K) -
細野 達夫, 廣部 明泰, 青木 正敏1988 年 44 巻 3 号 p. 215-218
発行日: 1988/12/10
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (526K) -
桜島近辺の場合山口 武則, 大政 謙次, 宝来 俊一, 藤井 國博1988 年 44 巻 3 号 p. 219-223
発行日: 1988/12/10
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (2540K) -
農業気象災害研究部会・中国・四国支部1988 年 44 巻 3 号 p. 225-228
発行日: 1988/12/10
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (596K)
- |<
- <
- 1
- >
- >|