• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1993.10a
• /
• pp.1186-1195
• /
• 1993

The Japanese type combine harvester has adopted rubber crawlers for the driving mechanism from first production . However, combine harvesters with movable track rollers in the rubber crawler system have been adopted recently for the purpose of stability at the time of climbing over the footpaths between rice fields, as the results of the machines becoming large. However, the dynamic characteristics of movable track rollers have not been clarified. For this reason, the design of movable track rollers depends on trial and errors. It is known that vibration characteristics of the vehicle with movable track rollers are different from the vibration characteristics of the vehicles with fixed track rollers even though the track roller arrangements are the same. Therefore, the theoretical analyses of movable track rollers must be hurried in order to formulate a reasonable track roller arrangement design. the authors have studied the vibration characteristics of the rubber crawler ve icle with fixed track rollers. in this study, the dynamic model of the vehicle with movable track roller sis compared with the dynamic model of the vehicle with fixed track rollers. Next, motions are simulated to analyze the movable track rollers by expanding the motion equation which were constructed for the dynamic model of the fixed track rollers.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.60-60
• /
• 2017

It is important to measure the gas exchange activity of the crops in canopy scale to understand the process of biomass production and yield formation. Thermal imaging of the canopy surface temperature is a powerful tool to detect the gas exchange activity of the crop canopy. The simultaneous measurement of the canopy temperature and the meteorological data enables us to calculate the canopy diffusive conductance ($g_c$) based on the heat flux model (Monteith et al. 1973, Horie et al. 2006). It is, however, difficult to realize the long-term and continuous monitoring of $g_c$ due to the occurrence of the calculation error caused by the fluctuation of the environmental condition. This is partly because the model assumption is too simple to describe the meteorological and aerodynamic conditions of the crop canopy in the field condition. Here we report the novel method of the direct measurement of the aerodynamic resistance ($r_a$) of the crop canopy, which enables us the stable and continuous measurement of the gas exchange capacity of the crop plants. The modified heat balance model shows the improved performance to quantify $g_c$ under the fluctuating meteorological condition in the field. The relationship between $g_c$ and biomass production of rice and soybean varieties is also discussed in the presentation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.10 no.1
• /
• pp.122-133
• /
• 1997

Purified diets containing 5 graded levels of threonine were fed to young, growing and finishing pigs to determine the threonine requirement for growth and maintenance. A model was developed to subdivide the threonine requirement for the maintenance from the requirement for growth. From this model, the threonine requirement for growth was 7.733, 10.968 and 11.235 g/kg live weight gain and the maintenance requirement was 0.118, 0.048 and 0.024 g per unit of metabolic body size at each stage of growth, respectively. In the young pigs, the threonine requirement for growth was 0.388 g/g N gain and the maintenance requirement was 0.122 g per unit of metabolic body size. The breakpoint of plasma threonine concentrations was 3.995, 7.933 and 7.738 g/d, respectively. Expected requirements obtained from these formulae were in general agreement with previous estimates. Based on the weight gain vs N gain equation, about 4.24% of the retained protein was comprised of threonine and compared to 3.81%, the mean threonine content of pig muscle CP.

• Asian-Australasian Journal of Animal Sciences
• /
• v.10 no.1
• /
• pp.86-97
• /
• 1997

Purified diets containing 5 graded levels of methionine + cystine were fed to young, growing and finishing pigs to determine the methionine + cystine requirement for growth and maintenance. A model was developed to subdivide the methionine + cystine requirement for maintenance from requirement for growth. From this model, the methionine + cystine requirement for growth was 8.633, 10.260 and 9.293 g/kg live weight gain and the maintenance requirement was 0.049, 0.016 and 0.019 g per unit of metabolic body size at each stage of growth, respectively. In the young pigs, the methionine + cystine requirement for growth was 0.491 g/g N gain and the maintenance requirement was 0.059 g per unit of metabolic body size. The breakpoint of plasma methionine + cystine concentrations was 3.888, 6.935 and 8.116 g/d, respectively. Expected requirements obtained from these formulae were in general agreement with previous estimates. Based on the weight gain vs N gain equation, about 4.44% of the retained protein was comprised of methionine + cystine and compared to 3.31%, the mean methionine + cystine content of pig muscle CP.

• Asian-Australasian Journal of Animal Sciences
• /
• v.10 no.1
• /
• pp.54-63
• /
• 1997

Purified diets containing 5 graded levels of lysine were fed to young and growing pigs to determine the lysine requirement for growth and maintenance. A model was developed to subdivide the lysine requirement for the maintenance from requirement for growth. From this model, the lysine requirement for growth was 18.018 and 19.431 g/kg live weight gain and the maintenance requirement was 0.115 and 0.033 g per unit of metabolic body size at each stage of growth, respectively. In the young pigs, the lysine requirement for growth was 0.950 g/g N gain and the maintenance requirement was 0.114 g per unit of metabolic body size. The breakpoint of plasma lysine concentrations was 8.695 and 13.464 g/d, respectively. Expected requirements obtained from these formulae were in general agreement with previous estimates. Based on weight gain vs N gain equation, about 7.92% of the retained protein was comprised of lysine as compared to 7.11%, the mean lysine content of pig muscle CP.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2000.11b
• /
• pp.287-294
• /
• 2000

Calculation of the flexural rigidity value (EI) is indispensable for prescription of deflection characteristics of crop stalks in harvesting□Conventionally□EI has been determined by either average EI of the whole stalk or average EI of each stems divided into node through the calculation method of cantilever with homogeneous section□However□deflection characteristics of crop stalks caused by mechanical operation such as combine harvester were not exactly presumed by these conventional EI through the experiment by authors. Further, actual EI of a stalk changes in company with a change of moisture contents as time passes during the experiment. Finally, efficient calculation method for determining EI is needed in order to improve these problems. In this study, mechanical model based on actual structure of the crop stalk with variety sectional area was proposed. This mechanical model is calculated by the theory of cantilever with continuous stages. Therefore, improvement of both calculating accuracy on EI and efficiency of measuring system was tried. At first, this calculation method was applied to piano wire of which EI was recognized in advance. As a result, EI calculated from this new method coincided approximately with piano wire's EI. Next, applying to crop stalks as same as piano wire, relationship between loads acting on crop stalks and deflection values calculated by EI using this new calculation method was exactly presumed in comparison with conventional method. Further, measuring time of deflection test was greatly reduced. Finally, new calculation method of EI will be available for estimating mechanical characteristics of so many kinds of crop stalks in harvesting operation. Further, in this study, new deflection test using image-processing apparatus by computer will be introduced.

• Smart Media Journal
• /
• v.5 no.3
• /
• pp.17-24
• /
• 2016

Korean agriculture is currently experiencing difficulties as a cause of rural depopulation, aging of rural population, grain self-sufficiency rate decline, and deepening of climate change. It is necessary to ensure our country's agriculture industrial competitiveness in accordance with opening of FTA imports expanded. To ensure the underdeveloped competitive, Korean government defines the 3rd generation model from 1st generation model to extend the smart farms of Korean types. The agriculture smarting overcomes the growth limitations of agriculture, and efforts to develop 6th + ${\alpha}$ industry. In this paper, We define and verify the IoF(Internet of Farming)-Cloud based substantial services about 2rd generation model, and propose a greenhouse of IoF-Cloud testbed.

• Korean Journal of Agricultural Science
• /
• v.50 no.2
• /
• pp.307-307
• /
• 2023

• Structural Engineering and Mechanics
• /
• v.51 no.1
• /
• pp.15-37
• /
• 2014

In this study, the optimum silo dimensions for the barrel-type steel-concentrated silo with a conical outlet port usable in the hazelnut storage were investigated. Three different types of silo models as Model 1 (1635 tons), Model 2 (620 tons) and Model 3 (1124 tons) were used in the study. Varying wall thicknesses were used for Model 1 (10, 11, 12, 13, 14, 15 and 20 mm), Model 2 (10, 15 and 20 mm) and Model 3 (10, 15 and 20 mm) silos. For Model 1 silo has the most storage capacity here, to determine its optimum wall thickness, the wall thicknesses of 11, 12, 13 and 14 mm were used as different from the other models. Thus the stresses occurring in different lines with ANSYS finite element software were examined. In the study it was determined that the 10, 11 and 12 mm wall thicknesses of the Model 1 silo are not safe in terms of the stresses caused by the vertical pressure loads in the filling conditions. From the view of the filling and discharge conditions, other wall thicknesses and model silos were diagnosed to be secure. The optimum silo dimensions which won't cause any structural problems have been found out as the Model 1 silo with a 13 mm wall thickness when the filling capacity and the maximum von Mises stresses are taken into account. This barrel-type silo with conical outlet port sets forth the most convenient properties in hazelnut storing in terms of engineering.

• Korean Journal of Organic Agriculture
• /
• v.28 no.3
• /
• pp.289-313
• /
• 2020

This study was conducted to analyze the factors influencing participation intention in urban agriculture. The theoretical foundations of the study were Theory of Planned Behavior (TPB) and Pine and Gilmore's Experiencel Economy. The type of household composition was set as the moderating variable between these independent and dependent variables. In order to test the research model, hierarchical regression analysis was conducted on 439 effective respondents. The empirical analysis results are as follows. Educational experience factors, escapist experience factors, attitudes, subjective norm, and perceived behavioral control, which were set as independent variables to positive (+) influence participation intention in urban agriculture. In addition, the impact of their influence relationship was as follows : perceived behavioral control > attitudes > escapist experience factor > subjective norm > educational experience factor. On the other hand, as a result of analyzing the moderating effect according to the household composition, there was a significant difference in the effect of educational experiences, escapist experiences, and subjective norm on participation intention in urban agriculture. Significant results were not tested on the moderating effects between attitudes, perceived behavioral control, and participation intention in urban agriculture. Based on the results of this empirical analysis, academic and practical implications were presented.