• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.373-379
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• 2019

Smart-farm has been spreading across Korea to improve the labor efficiency and productivity of greenhouse crops. Although notable improvements have been made in the monitoring technologies and environmental-controlling systems in greenhouses, only a few simple decision-support systems are available for predicting the optimum environmental conditions for crop growth. In this study, a tomato growth model (GreenTom), which was developed by Seoul National University in 1997, was calibrated and validated to examine if the model can be used as a decision-supporting system. The original GreenTom model was not able to simulate artificial defoliation, which resulted in overestimation of the leaf area index in the late growth. Thus, an algorithm for simulating the artificial defoliation was developed and added to the original model. The node development, leaf growth, stem growth, fruit growth, and leaf area index were generally well simulated by the modified model indicating that the model could be used effectively in the decision-making of smart greenhouse.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.6
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• pp.493-500
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• 2014

This paper presents findings from the assessment of the volcanic ash fragility for multi-hazard resisting vinyl greenhouse and livestock shed among the agricultural facilities. The volcanic ash fragility was evaluated by using a combination of the FOSM (first-order second-moment) method, available statistics of volcanic load, facility specifications, and building code. In this study, the evaluated volcanic ash fragilities represent the conditional probability of failure of the agricultural facilities over the full range of volcanic ash loads. For the evaluation, 6 types(ie., 2 single span, 2 tree crop, and 2 double span types) of multi-hazard resisting vinyl greenhouses and 3 types(ie., standard, coast, and mountain types) of livestock sheds are considered. All volcanic ash fragilities estimated in this study were fitted by using parameters of the GEV(generalized extreme value) distribution function, and the obtained parameters were complied into a database to be used in future. The volcanic ash fragilities obtained in this study are planning to be used to evaluate risk by volcanic ash when Mt. Baekdu erupts.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.311-316
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• 2015

This study was performed to ascertain the potential of egg plant for use as a trap plant to attract Bemisia tabaci adults compared to that of tomato. Choice tests were conducted to compare the preference of B. tabaci adults to horseweed, egg-plant, cucumber, and tomato. B. tabaci adults were found to be more sensitive to visual cues than to odor cues, and they preferred the egg-plant and cucumber to horseweed. The attraction rates of the egg-plant and cucumber to B. tabaci adults were 82.3% and 82.5% respectively, compared to that of tomato. Because egg-plants are easier to manage compared to cucumber, we excluded cucumber from subsequent experiment. The attraction rate of egg-plant to B. tabaci adults was >90% when the height of egg-plant was equal or more than that of the tomato plant.

• Korean journal of applied entomology
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• v.49 no.4
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• pp.429-432
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• 2010

A mite damage was observed in spinach (Spinacia oleracea L.) under organic culture greenhouses. The mite was identified as Tyrophagus similis Volgin, 1949. It was very difficult for the farmers to diagnose the mite damage because of its tiny size about 0.5 nm in length. And the symptom was not clear at the early growth stage of the spinach because the mite mainly attack the very young leaves. In this study, we first report the spinach damages by T. similis in Korea. Informations on the mite morphology and the spinach damage symptoms are provided for the diagnosis.

• Korean journal of applied entomology
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• v.56 no.4
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• pp.439-440
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• 2017

The obscure mealybug, Pseudococcus viburni Signoret (Hemiptera: Pseudococcidae) is a polyphagous cosmopolitan pest, damaging vineyards and fruit orchards. The species has long been quarantined in Korea and has never been recorded in the wild in Korea. In this study, to confirm the absence of P. viburni in Korea, we have searched for the species from the orchards. 533 sites of persimmon orchards, 144 sites of apple and other orchards, and 281 sites of nurseries and greenhouses were surveyed for the last three years (2015-2017). As a result, P. viburni occurs neither in the wild nor in nurseries in Korea.

• Spatial Information Research
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• v.19 no.1
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• pp.61-72
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• 2011

Greenhouses gas emission due to usage of fossil fuel has been known as one of the main causes of global warming. Fundamentally, greenhouse gas is a by-product of economic activity. Since majority of economic activity happens in an urban setting, a countermeasure in an urban setting is needed. Therefore, an analysis of relationship between carbon dioxide emission and urban form will be investigated for urban planning and management in the future. The purpose of this study is to analyze the relationship between carbon dioxide emission and urban spatial patterns, and suggesting an urban form with low carbon dioxide emission. In order to achieve this, first theoretical analysis was carried out on urban spatial patterns related to physical size, usage rate, and activity level. Secondly, Seoul's dam on electricity, natural gas, local heating, petroleum, and water usage and mapping a carbon dioxide emission map. Thirdly, relationship between carbon dioxide emission and urban spatial patterns are analyzed and urban spatial patterns that affects energy usage in urban setting was elucidated, and elicited implications on future directions on urban planning based on our analyses above.

• Journal of Bio-Environment Control
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• v.9 no.2
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• pp.107-114
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• 2000

We constructed climagraphs for 16 regions of Korea by using the average monthly minimum air temperature, maximum air temperature and global radiation. We characterized the outside climate requirements corresponding to the climate requirements of crops in greenhouses. The climagraphs allow to decide the appropriate climate periods for greenhouse cultivation without heating and cooling equipment. These graphs may be used for analyzing climatic characteristic of a given area, selecting the suitable region and greenhouse and making a rational plan for greenhouse cropping in Korea. We found difficulty in deciding the beginning and end of greenhouse heating and cooling period due to insufficient references.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.6
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• pp.21-31
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• 2020

This study analyzed the spatio-temporal change pattern of greenhouse areas for Sangnam-myeon and Samrangjin-eup of Miryang-si in Gyeongnam, which is one of major greenhouse area. First, in order to overcome the lack of statistical data of the distribution of greenhouses, aerial and satellite images were interpreted from 1987 to 2018, and the spatial distribution of the greenhouse parcels which has continuously increased was mapped based on the digital cadastral map. Next, through the emerging hot spot tool in ArcGIS Desktop, the spatio-temporal change in transition from open-field to greenhouse cultivation was classified into 9 clusters. About 67.7% of the target area was categorized as a hot spot, and the pattern of New hot spot, which were recently converted to greenhouse parcels, covered about 34.1%. While, about 11.3% of parcels were expected to keep the existing open-field cultivation practice for a while. Overall, the greenhouse parcels have been densely developed along a river and were lately expanding even to the far neighbor. It implied that, in the future, the competition of water intake among farms would be more serious and the environmental responsibility in consideration of water quality as well as quantity would be getting strengthened due to increasing pollution loads and river intake.

• International Journal of Industrial Entomology and Biomaterials
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• v.20 no.2
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• pp.93-98
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• 2010

Bumblebees are widely used to pollinate various crops, especially tomato, in greenhouses and fields. An artificial hibernation is essential for year-round rearing of the bumblebee, which passes through one generation per year. Here, we investigated whether a chilling temperature and humidity affect artificial hibernation of the bumblebee queen Bombus terrestris. In chilling temperature regimes of $0^{\circ}C$, $2.5^{\circ}C$, $5^{\circ}C$, $7.5^{\circ}C$ or $12.5^{\circ}C$ under constant humidity >70%, the queens stored at $2.5^{\circ}C$ exhibited the highest rate of survival, which was 74.0% at one month, 67.0% at two months, 60.0% at three months, 46.0% at 4 months, 33.0% at 5 months, and 24.0% at 6 months. Rates of survival decreased at the following temperatures: $0^{\circ}C$, $5^{\circ}C$, $7.5^{\circ}C$ and $12.5^{\circ}C$. Colony developmental characteristics after diapause were 1.2- to 1.5-fold higher than those of queens stored at $5^{\circ}C$. In terms of chilling humidity, the queens hibernated at 70% under $2.5^{\circ}C$ exhibited the highest rate of survival, which was $93.3{\pm}3.4%$ at one month, $83.3{\pm}0.0%$ at two months, $76.7{\pm}0.0%$ at 3 months and $36.7{\pm}12.1%$ at 5 months. The rates of oviposition, colony foundation and progeny-queen production of queens hibernated at 70% were 80.8%, 30.8% and 30.8%, respectively. These values correspond to 1.7- to 3.3-fold increases in comparison to queens stored at 50% humidity. Therefore, $2.5^{\circ}C$ and 70% R.H. were the favorable chilling temperature and humidity conditions for diapause break of B. terrestris queens.

• Korean Journal of Organic Agriculture
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• v.25 no.1
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• pp.149-159
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• 2017

This study was conducted to develop an organic control method of tobacco whitefly (Bemisia tabaci) by using cooking oil and yolk mixture (COY). Mortality rate against B. tabaci nymph on paprika leaf was 94.5% by COY treatment and it was not significantly different from that by pyridaben treatment. Mortality rate against B. tabaci nymph on tomato leaf was 41.4% by COY treatment and it is lower than that by neem extract. But mortality rates of B. tabaci adult by COY and neem extract were no significant differences. Oviposition of B. tabaci were decrease respectively 75.8% and 52.7% by COY on paprika and tomato leaves. In paprika and tomato greenhouses, damaged by B. tabaci, COY was sprayed twice and resulted in respectively 100% and 38% control values.