• International conference on construction engineering and project management
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• 2024.07a
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• pp.1316-1316
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• 2024

Greenhouses require various control systems to create an optimal environment, and from an architectural engineering perspective, the uniformity of the internal environment is crucial for crop growth. However, greenhouses are structurally exposed to external weather conditions, leading to a high probability of variations in temperature, humidity, CO2 levels, lighting, etc., across different zones within the greenhouse. Such non-uniformity can impact the growth rate, quality, and yield of crops, highlighting the necessity of maintaining a consistent environment within the greenhouse. To address this, experiments utilizing Computational Fluid Dynamics (CFD) simulations were conducted targeting greenhouses in Pocheon, South Korea, focusing on the central heating and cooling systems to propose an optimal design considering the uniformity of internal temperatures. Subsequently, validation was performed using measurements from temperature and humidity sensors within the greenhouses. The heating and cooling systems operate based on indoor temperatures, activating cooling when indoor temperatures exceed the set cooling temperature in summer and heating when temperatures fall below the set heating temperature in winter. A standard greenhouse model was set as case 1, and experiments were conducted by adjusting the position and spacing of the fabric ducts of the heating and cooling systems, resulting in six categorized cases. Variations in temperature and humidity distribution were observed among the cases, and quantitative analysis provided optimal positions and spacing for the fabric ducts. The results of this study can serve as foundational data for developing environmental control solutions for agricultural facilities.

• Journal of Korean Society for Quality Management
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• v.49 no.2
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• pp.213-231
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• 2021

Purpose: This study intends to provide decision-making information to improve efficiency by analyzing the management efficiency of smart greenhouse business entities and identifying factors that affect the efficiency based on input and output. Methods: The subjects of analysis were business entities for cultivating strawberries in smart greenhouses in Jeolla region (northern and southern Jeolla provinces), and the analysis focused on the management performance of the 2019-2020 crop period (year). Data Envelopment Analysis(DEA) was applied as an analysis method for efficiency analysis, Quantile Regression(QR) analysis was applied as a factor affecting the efficiency. Results: The reason for the efficiency gap between business entities was that there were many business entities that did not minimize the input cost at the current level of output, and the area where the variance among business entities was large was the fixed cost per 10a. In the results of the affecting factor analysis, it was found that the seed-seedlings cost, fertilizer cost, other material cost, and employment and labor cost had a negative (-) effect on the efficiency, and that the repair and maintenance cost had a positive (+) effect. Conclusion: Therefore, to achieve the efficiency of scale, it is necessary to reduce the input scale to an appropriate level. In the case of business entities with low efficiency by quartile, the seed-seedlings, fertilizer, and other material costs reduce expenditures, and repair maintenance costs can improve efficiency by increasing expenditures.

• Agribusiness and Information Management
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• v.7 no.2
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• pp.12-18
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• 2015

Since 2000s, proper utilization of IoT (Internet of Things) technology is a key factor for a firm to become more competitive, and this stream is not exceptional for the food and agriculture industry. Along with this stream, Korea government organization, for example MAFRA (Ministry of Agriculture, Food and Rural Affairs), elected to adopt IoT technology, such as USN and RFID technologies, in the food and agriculture industry. Based on the IoT technology, MAFARA launched six "IoT based farm" project in 2007. IoT based farm project includes IoT based greenhouse system project, and it shows drastic efficiency in terms of cost reduction. When it comes to the productivity, however, the effect of IoT based greenhouse system is still ambiguous. In this regard, this study conducted systems analysis and design for IoT based tomato greenhouse in order to help farmers' decision making related to the productivity by establishing standardized database structure and designing output form to analyze productivity indices. Proposed systems analysis and design can be utilized as a data analysis tools by farmers. Productivity data from the proposed systems is can be used by researchers to identify the relationship among environment, plant growth and productivity. Policy makers also can refer to the data and output forms to predict the quantity of fruit during certain period and to revise production guideline more precisely.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.2
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• pp.1-11
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• 2023

This study analyzed the impact of greenhouse cultivation area and groundwater level changes due to the water curtain cultivation in the greenhouse complexes. The groundwater observation data in the Miryang study area were used and classified into greenhouse and field cultivation areas to compare the groundwater impact of water curtain cultivation in the greenhouse complex. We identified the characteristics of the groundwater time series data by the terrain of the study area and selected the optimal model through time series analysis. We analyzed the time series data for each terrain's two representative groundwater observation wells. The Seasonal ARIMA model was chosen as the optimal model for riverside well, and for plain and mountain well, the ARIMA model and Seasonal ARIMA model were selected as the optimal model. A suitable prediction model is not limited to one model due to a change in a groundwater level fluctuation pattern caused by a surrounding environment change but may change over time. Therefore, it is necessary to periodically check and revise the optimal model rather than continuously applying one selected ARIMA model. Groundwater forecasting results through time series analysis can be used for sustainable groundwater resource management.

• Journal of the Korea Safety Management & Science
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• v.21 no.4
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• pp.81-89
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• 2019

Need to make efforts to reduce greenhouse gas emissions in order to slow global warming is globally recognized and also appealing to the United Nations. The main cause of greenhouse gases is carbon dioxide, and the nation has 23.9 percent of its total emissions in the transportation sector. It was also reported that 61.56 percent of living waste is being recycled, suggesting that environmentally friendly logistics activities should proceed with efforts on goods and services at each stage of distribution. In this study, we conducted a survey of green logistics activities that were environmentally friendly by businesses, divided into management, water/delivery and packaging waste, and identified the status and level of each business sector. As a result, data was collected from 36 manufacturing companies, 28 distribution businesses, and 40 logistics businesses, all of which were 104 companies, and based on the analysis results, a measure for environmentally friendly logistics activities was proposed.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.317-325
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• 2015

This paper attempts to present a review about simulation of different greenhouse parameters and energy supplying techniques by using building energy simulation, to find out the optimal solution for keeping greenhouse microclimate favorable for the crop production. The objectives of conducting this study were, to describe the various energy systems and techniques used for the greenhouse energy management and efficiency analysis of these technologies by using building energy simulation. We describe different models to understand the behavior of the energy saving technologies with respect to the resources available and different outside climatic conditions. We identified main features of the building energy simulation software, that enable users, to simulate hybrid agricultural building projects by using user defined parameters. At the end of the paper we draw some important concluding remarks on the basis of reviewing all the investigators contributions for the developments of simulation model of agricultural greenhouse energy management, using a building energy simulation software specifically TRNSYS. In conclusion, this paper provides information that TRNSYS have great potential for agricultural buildings energy simulation along with the renewable energy resources and energy saving techniques. This review paper provides aid to greenhouse researcher and energy planner for the future studies of greenhouses energy planning.

• Coupled systems mechanics
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• v.12 no.6
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• pp.531-537
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• 2023

Municipal solid waste landfills are unpredictable bioreactors which in cases of mishandling and bad supervision presents numerous risks. The key to municipal waste landfills is to approach them from the point of prevention of the possible consequences, which means using methods of organized waste disposal, and also utilizing landfill gas, as an unavoidable consequence with disposal of municipal solid waste with a high share of biodegradable organic matter. This paper presents an overview about problems of solid municipal waste management, type and composition of waste, and an overview of waste management condition. Further, the problem of landfill and landfill gasses is described with the calculation models of landfill production, as well as the use of the SWM GHG Calculator and LandGEM software on a specific example of gas production for the central zone at Sarajevo landfill "Smiljevici". Main focus of this thesis is the analysis of potentials of greenhouse gas emission reduction measures from the waste management. Overview of the best available techniques in waste management is presented as well as the methodology used for calculations. Scenarios of greenhouse gas emission reduction in waste management were defined so that emissions were calculated using the appropriate model. In the final section of the paper, its description of the problem of collection and utilization the landfill gas at the sanitary landfill "Smiljevici", and implementation of the system for landfill gas collection and solution suggestion for the gasification and exploitation of gas. Energy, environmental and economic benefits can be accomplished by utilizing municipal solid waste as fuel in industry and energy and moreover by utilizing energy generation from landfill gas, which this thesis emphasizes.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.5
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• pp.37-42
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• 2015

In order to provide fundamental data for the creation of environmental design criteria for horticultural facilities, we developed a method to easily calculate the seasonal heating load applying heating degree-hour while taking into account heating load reductions due to solar radiation in the daytime, and reviewed through greenhouse heating experiments. Heating experiments and measuring meteorological environments were carried out in three greenhouses located at Buyeo, Cheonan, and Buan, and we derived reduction factors of seasonal heating load according to hours of sunshine. Daily mean hours of sunshine during the experiment period in each of the greenhouse was 4.0 to 8.3 hours, and the reduction factor of seasonal heating load was 0.64 to 0.85, has been shown to decrease linearly with the increase in hours of sunshine. A method to estimate the seasonal heating load for greenhouses was developed using the reduction factor of seasonal heating load derived from the greenhouse heating experiment, including the adjustment factor of seasonal heating load according to hours of sunshine. The developed method was validated through heating experiments in a greenhouse located at Cheonan. Greenhouse seasonal heating loads calculated by the method developed in this study were analyzed to show the estimate error of 1.2 to 5.0%. It showed that the accuracy increased 2.3 times more than when using the heating load reduction factor of 0.75 applied uniformly in previous studies. Thus, the calculation method of seasonal heating load for greenhouses considering hours of sunshine developed in this study could be utilized for energy estimation, management planning, and economic evaluation in greenhouse design.

• Korean Journal of Environmental Biology
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• v.39 no.1
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• pp.39-45
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• 2021

To establish the environmentally friendly biological control of two-spotted spider mites (TSSM), Tetranychus urticae, in exported strawberry greenhouses, the TSSM density reduction efficiency of chemical and biological control measures was compared in commercial, exported strawberry greenhouses. In the biological control greenhouse, only Phytoseiulus persimilis, a natural enemy of TSSM, was released, and the chemical control greenhouse was only sprayed with commercial chemical pesticides. The density of each developmental stage of TSSM was higher in the chemical control greenhouse than in the biological control greenhouse. The management costs were lower for the biological control greenhouse than the chemical control greenhouse. These results suggest that it is possible to effectively control TSSM using P. pesrsimilis in exported strawberry greenhouses.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2005.11a
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• pp.47-53
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• 2005