• Title/Summary/Keyword: Research management

Search Result 46,777, Processing Time 0.075 seconds

Effects of Light Intensity and Electrical Conductivity Level on Photosynthesis, Growth and Functional Material Contents of Lactuca indica L. 'Sunhyang' in Hydroponics (수경재배에서 광도와 양액 농도가 베이비 산채 왕고들빼기 '선향' 광합성과 생육 및 기능성 물질 함량에 미치는 영향)

  • Kim, Jae Kyung;Jang, Dong Cheol;Kang, Ho Min;Nam, Ki Jung;Lee, Mun Haeng;Na, Jong Kuk;Choi, Ki Young
    • Journal of Bio-Environment Control
    • /
    • v.30 no.1
    • /
    • pp.1-9
    • /
    • 2021
  • This study was conducted to examine the changes of photosynthesis, growth, chlorophyll contents and functional material contents in light intensity and EC concentration of wild baby leaf vegetable, Indian lettuce (Lactuca indica L. cv. 'Sunhyang') in DFT hydroponics. The cultivation environment was 25±1℃ of temperature and 60±5% of relative humidity in growth system. At 14 days after sowing, combination effect of light intensity (Photosynthetic Photon Flux Density (PPFD 100, 250, 500 µmol·m-2·s-1) and EC level (EC 0.8, 1.4, 2.0 dS·m-1) of nutrient solution was determined at the baby leaf stage. The photosynthesis rate, stomatal conductance, transpiration rate and water use efficiency of Indian lettuce increased as the light intensity increased. The photosynthesis rate and water use efficiency were highest in PPFD 500-EC 1.4 and PPFD 500-EC 2.0 treatment. The chlorophyll content decreased as the light intensity increased, but chlorophyll a/b ratio increased. Leaf water content and specific leaf area decreased as light intensity increased and a negative correlation (p < 0.001) was recognized. Plant height was the longest in PPFD 100-EC 0.8 and leaf number, fresh weight and dry weight were the highest in PPFD 500-EC 2.0. Anthocyanin and total phenolic compounds were the highest in PPFD 500-EC 1.4 and 2.0 treatment, and antioxidant scavenging ability (DPPH) was high in PPFD 250 and 500 treatments. Considering the growth and functional material contents, the proper light intensity and EC level for hydroponic cultivation of Indian lettuce is PPFD 500-EC 2.0, and PPFD 100 and 250, which are low light conditions, EC 0.8 is suitable for growth.

A Proposal of Direction of Wind Ventilation Forest through Urban Condition Analysis - A Case Study of Pyeongtaek-si - (도시 여건 분석을 통한 바람길숲 조성방향 제시 - 평택시를 사례로 -)

  • SON, Jeong-Min;EUM, Jeong-Hee;SUNG, Uk-Je;BAEK, Jun-Beom;KIM, Ju-Eun;OH, Jeong-Hak
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.23 no.4
    • /
    • pp.101-119
    • /
    • 2020
  • Recently, as a plan to improve the particulate matter and thermal environment in the city, urban forests acting as wind ventilation corridor(wind ventilation forest) are promoted nationwide. This study analyzed the conditions for the creation of wind ventilation forest(vulnerable areas of the particulate matter and thermal environment, distribution of wind ventilation forest, characteristics of ventilation corridor) of in Pyeongtae-si, one of the target cities of wind ventilation forest project. Based on the results, the direction of developing on the wind ventilation forest in Pyeongtaek-si was suggested. As a result of deriving areas vulnerable to particulate matter and thermal environment, it was most vulnerable in urban areas in the eastern area of Pyeongtaek-si. Especially, emissions were high from industrial complexes and roads such as the Pyeongtaek-si thermal power plant, ports, and the national road no. 1. The wind ventilation forest in Pyeongtaek-si was distributed with small-scale windgenerating forests, wind-spreading forests, and wind-connection forests fragmented and disconnected. The characteristic of the overall wind ventilation corridor in Pyeongtaek-si is that the cold air generated from Mt.Mubong, etc., strongly flowed into Pyeongtaek-si and flowed in the northwest direction. Therefore, it is necessary to preserve and expand the wind-generating forests in Pyeongtaek-si in the long term, and it was important to create wind-spreading forests and wind-connection forests so that cold air could flow into the vulnerable area. In addition, in industrial complexes and roads where particulate matter is generated, planting techniques should be applied to prevent the spread of particulate matte to surrounding areas by creating wind-spreading forests considering the particulate matter blocking. This study can be used not only as the basis data for wind ventilation forest project in Pyeongtaek-si, but also as the basis data for urban forest creation and management.

Change Prediction of Forestland Area in South Korea using Multinomial Logistic Regression Model (다항 로지스틱 회귀모형을 이용한 우리나라 산지면적 변화 추정에 관한 연구)

  • KWAK, Doo-Ahn
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.23 no.4
    • /
    • pp.42-51
    • /
    • 2020
  • This study was performed to support the 6th forest basic planning by Korea Forest Service as predicting the change of forestland area by the transition of land use type in the future over 35 years in South Korea. It is very important to analyze upcoming forestland area change for future forest planning because forestland plays a basic role to predict forest resources change for afforestation, production and management in the future. Therefore, the transitional interaction between land use types in future of South Korea was predicted in this study using econometrical models based on past trend data of land use type and related variables. The econometrical model based on maximum discounted profits theory for land use type determination was used to estimate total quantitative change by forestland, agricultural land and urban area at national scale using explanatory variables such as forestry value added, agricultural income and population during over 46 years. In result, it was analyzed that forestland area would decrease continuously at approximately 29,000 ha by 2027 while urban area increases in South Korea. However, it was predicted that the forestland area would be started to increase gradually at 170,000 ha by 2050 because urban area was reduced according to population decrement from 2032 in South Korea. We could find out that the increment of forestland would be attributed to social problems such as urban hollowing and localities extinction phenomenon by steep decrement of population from 2032. The decrement and increment of forestland by unbalanced population immigration to major cities and migration to localities might cause many social and economic problems against national sustainable development, so that future strategies and policies for forestland should be established considering such future change trends of land use type for balanced development and reasonable forestland use and conservation.

Identification of Bird Community Characteristics by Habitat Environment of Jeongmaek Using Self-organizing Map - Case Stuty Area Geumnamhonam and Honam, Hannamgeumbuk and Geumbuk, Naknam Jeongmaek, South Korea - (자기조직화지도를 활용한 정맥의 서식지 환경에 따른 조류 군집 특성 파악 - 금남호남 및 호남정맥, 한남금북 및 금북정맥, 낙남정맥을 대상으로 -)

  • Hwang, Jong-Kyeong;Kang, Te-han;Han, Seung-Woo;Cho, Hae-Jin;Nam, Hyung-Kyu;Kim, Su-Jin;Lee, Joon-Woo
    • Korean Journal of Environment and Ecology
    • /
    • v.35 no.4
    • /
    • pp.377-386
    • /
    • 2021
  • This study was conducted to provide basic data for habitat management and preservation of Jeongmaek. A total of 18 priority research areas were selected with consideration to terrain and habitat environment, and 54 fixed plots were selected for three types of habits: development, valley, and forest road and ridge. The survey was conducted in each season (May, August, and October), excluding the winter season, from 2016 to 2018. The distribution analysis of birds observed in each habitat type using a self-organizing map (SOM) classified them into a total of four groups (MRPP, A=0.12, and p <0.005). The comparative analysis of the number of species, the number of individuals, and the species diversity index for each SOM group showed that they were all the highest in group III (Kruskal-Wallis, the number species: x2 = 13.436, P <0.005; the number of individuals: x2 = 8.229, P <0.05; the species diversity index: x2 = 17.115, P <0.005). Moreover, the analysis by applying the land cover map to the random forest model to examine the index species of each group and identify the characteristics of the habitat environment showed a difference in the ratio of the habitat environment and the indicator species among the four groups. The index species analysis identified a total of 18 bird species as the indicator species in three groups except for group II. When applying the random forest model and indicator species analysis to the results of classification into four groups using the SOM, the composition of the indicator species by the group showed a correlation with the habitat characteristics of each group. Moreover, the distribution patterns and densities of observed species were clearly distinguished according to the dominant habitat for each group. The results of the analysis that applied the SOM, indicator species, and random forest model together can derive useful results for the characterization of bird habitats according to the habitat environment.

The Dynamics of CO2 Budget in Gwangneung Deciduous Old-growth Forest: Lessons from the 15 years of Monitoring (광릉 낙엽활엽수 노령림의 CO2 수지 역학: 15년 관측으로부터의 교훈)

  • Yang, Hyunyoung;Kang, Minseok;Kim, Joon;Ryu, Daun;Kim, Su-Jin;Chun, Jung-Hwa;Lim, Jong-Hwan;Park, Chan Woo;Yun, Soon Jin
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.23 no.4
    • /
    • pp.198-221
    • /
    • 2021
  • After large-scale reforestation in the 1960s and 1970s, forests in Korea have gradually been aging. Net ecosystem CO2 exchange of old-growth forests is theoretically near zero; however, it can be a CO2 sink or source depending on the intervention of disturbance or management. In this study, we report the CO2 budget dynamics of the Gwangneung deciduous old-growth forest (GDK) in Korea and examined the following two questions: (1) is the preserved GDK indeed CO2 neutral as theoretically known? and (2) can we explain the dynamics of CO2 budget by the common mechanisms reported in the literature? To answer, we analyzed the 15-year long CO2 flux data measured by eddy covariance technique along with other biometeorological data at the KoFlux GDK site from 2006 to 2020. The results showed that (1) GDK switched back-and-forth between sink and source of CO2 but averaged to be a week CO2 source (and turning to a moderate CO2 source for the recent five years) and (2) the interannual variability of solar radiation, growing season length, and leaf area index showed a positive correlation with that of gross primary production (GPP) (R2=0.32~0.45); whereas the interannual variability of both air and surface temperature was not significantly correlated with that of ecosystem respiration (RE). Furthermore, the machine learning-based model trained using the dataset of early monitoring period (first 10 years) failed to reproduce the observed interannual variations of GPP and RE for the recent five years. Biomass data analysis suggests that carbon emissions from coarse woody debris may have contributed partly to the conversion to a moderate CO2 source. To properly understand and interpret the long-term CO2 budget dynamics of GDK, new framework of analysis and modeling based on complex systems science is needed. Also, it is important to maintain the flux monitoring and data quality along with the monitoring of coarse woody debris and disturbances.

Research on the Legal Composition and Institutional Systems of The Dao Constitution: Focusing on The Constitution of the Republic of Korea (『도헌』의 법률적 구성과 제도적 장치 연구 - 대한민국헌법을 중심으로 -)

  • Kim, Young-jin
    • Journal of the Daesoon Academy of Sciences
    • /
    • v.40
    • /
    • pp.77-114
    • /
    • 2022
  • The purpose of this study is to analyze the ideological background, legal composition, and separation of powers contained within the institutional devices of The Dao Constitution based on the basic principles of the legal system, which would be embodied in The Constitution of the Republic of Korea. The ideological background of The Dao Constitution is that of the religion, Daesoon Jinrihoe. In Daesoon Jinrihoe, it is held that the Supreme God, Sangje, determined that Mutual Contention, the ruling pattern of the Former World, ran contrary to His divine will and this endangered the world as nature and humans had also fallen into Mutual Contention. As an act of divine intervention, Sangje established Mutual Beneficence so that nature and humanity could follow Mutual Beneficence as a paradigm shift culminating in a Great Opening of the universe. Sangje, the agent behind the paradigm shift, revealed His divine will that humans transform into mutually beneficent humans. Therefore, The Dao Constitution was written to be a set of fundamental norms based on the 'rights and obligations of the members of Daesoon Jinrihoe' to accept and implement the will of Sangje as it applies to each member's mission. The legal composition of The Dao Constitution consists of the body and supplementary provisions. The text consists of general rules, moral rights and obligations, origins, and institutional devices. Institutional devices include the Central Council, the Institute of Propagation and Edition, the Institute of Religious Services, Works, Financial Management, and the Institute of Audit and Inspection. The legal composition of The Dao Constitution is similar to that of the Constitution. The difference is that while the Constitution applies a 'principle of maximum rights and minimum obligations,' The Dao Constitution stipulates more obligations than rights in order to complete the mission of the members. The principle of separation of powers is applied to the institutional devices in The Dao Constitution. In The Dao Constitution, the organizational form of the central headquarters has been divided into a 'before and after' scheme surrounding the death of Dojeon. The organizational form of the central headquarters prior to Dojeon's death was similar to a Constitutional Monarchy. After the death of Dojeon, the central headquarters' organizational form became similar to a parliamentary cabinet system. The separation of powers at central headquarters is divided among a legislative power (the Central Council), an executive power (the Institute of Religious Services), and a judicial power (the Institute of Audit and Inspection). The separation of powers within the functions of the central government first occurs between the Central Council and its employees, then between the Central Council and the Institute of Auditing and Inspection, and also between the Legislative Government and the Institute of Religious Services. Furthermore, the principle of a vertical separation of powers exists between the central headquarters and the local organization.

Comparative Analysis of the Keywords in Taekwondo News Articles by Year: Applying Topic Modeling Method (태권도 뉴스기사의 연도별 주제어 비교분석: 토픽모델링 적용)

  • Jeon, Minsoo;Lim, Hyosung
    • Journal of Digital Convergence
    • /
    • v.19 no.11
    • /
    • pp.575-583
    • /
    • 2021
  • This study aims to analyze Taekwondo trends according to news articles by year by applying topic modeling. In order to examine the Taekwondo trend through media reports, articles including news articles and Taekwondo specialized media articles were collected through Big Kinds of the Korea Press Foundation. The search period was divided into three sections: before 2000, 2001~2010, and 2011~2020. A total of 12,124 items were selected as research data. For topic analysis, pre-processing was performed, and topic analysis was performed using the LDA algorithm. In this case, python 3 was applied for all analysis. First, as a result of analyzing the topics of media articles by year, 'World' was the most common keyword before 2000. 'South and North Korea' was next common and 'Olympic' was the third commonest topic. From 2001 to 2010, 'World' was the most common topic, followed by 'Association' and 'World Taekwondo'. From 2011 to 2020, 'World', 'Demonstration', and 'Kukkiwon' was the most common topic in that order. Second, as a result of analyzing news articles before 2000 by topic modeling, topics were divided into two categories. Specifically, Topic 1 was selected as 'South-North Korea sports exchange' and Topic 2 was selected as 'Adoption of Olympic demonstration events'. Third, as a result of analyzing news articles from 2001 to 2010 by topic modeling, three topics were selected. Topic 1 was selected as 'Taekwondo Demonstration Performance and Corruption', Topic 2 was selected as 'Muju Taekwondo Park Creation', and Topic 3 was selected as 'World Taekwondo Festival'. Fourth, as a result of analyzing news articles from 2011 to 2020 by topic modeling, three topics were selected. Topic 1 was selected as 'Successful Hosting of the 2018 Pyeongchang Winter Olympics', Topic 2 was selected as 'North-South Korea Taekwondo Joint Demonstration Performance', and Topic 3 was selected as '2017 Muju World Taekwondo Championships'.

Analysis of Fire Occurrence Characteristics According to Ignition Heat Sources (발화열원에 따른 화재발생 특성 분석)

  • Lee, Kyung-Su;Kim, Tae-Hyeung;Lee, Jae-Ou
    • Journal of the Society of Disaster Information
    • /
    • v.18 no.2
    • /
    • pp.280-289
    • /
    • 2022
  • Purpose: In this study, the characteristics of fire occurrence according to ignition heat sources such as operating equipment, cigarette/lighter fire, and flame/fire were analyzed. Method: One-way ANOVA and cross-analysis were used to analyze the characteristics of fire occurrence by verifying the difference between the ignition environment, fire damage status and scale, and cause of ignition according to the ignition heat source. Result: The fire occurrence characteristics were analyzed through As a result of the analysis, it was found that fires caused by operating devices occurred more frequently on weekdays than other ignition heat sources, and the number of victims and the number of victims were the highest, so mobilization of firefighting power and property damage were the greatest. The initial ignition was generated by electric and electronic devices, and the combustion was expanded by the synthetic resin. For fires caused by cigarette and lighter fires, the most fires occurred on Saturdays and Sundays, and the mobilization of the police force was more characteristic than the mobilization of the firefighting force. In particular, it was found that the initial ignition and combustion expansion were caused by paper, wood, and hay. Fires caused by sparks and sparks occurred most frequently on Saturdays and Sundays, and initial ignition and combustion expansion were found to be caused by paper, wood, and hay. In particular, it showed the characteristic that it occurred in the place farthest from the fire station. The common characteristic of all ignition heat sources was that the fire occurred most frequently in the afternoon time, and the fire type was predominantly the building structure fire, and only the ignition point was burned the most. Conclusion: In order to prevent fire and minimize damage, it is necessary to analyze the tendency of fire occurrence and to prepare appropriate preparations according to the fire occurrence factors. In order to analyze the characteristics of fire occurrence using public data in the future, it is necessary to standardize disaster data and to open and activate data.

Forecasting Leaf Mold and Gray Leaf Spot Incidence in Tomato and Fungicide Spray Scheduling (토마토 재배에서 점무늬병 및 잎곰팡이병 발생 예측 및 방제력 연구)

  • Lee, Mun Haeng
    • Journal of Bio-Environment Control
    • /
    • v.31 no.4
    • /
    • pp.376-383
    • /
    • 2022
  • The current study, which consisted of two independent studies (laboratory and greenhouse), was carried out to project the hypothesis fungi-spray scheduling for leaf mold and gray leaf spot in tomato, as well as to evaluate the effect of temperature and leaf wet duration on the effectiveness of different fungicides against these diseases. In the first experiment, tomato leaves were infected with 1 × 104 conidia·mL-1 and put in a dew chamber for 0 to 18 hours at 10 to 25℃ (Fulvia fulva) and 10 to 30℃ (Stemphylium lycopersici). In farm study, tomato plants were treated for 240 hours with diluted (1,000 times) 30% trimidazole, 50% polyoxin B, and 40% iminoctadine tris (Belkut) for protection of leaf mold, and 10% etridiazole + 55% thiophanate-methyl (Gajiran), and 15% tribasic copper sulfate (Sebinna) for protection of gray leaf spot. In laboratory test, leaf condensation on the leaves of tomato plants were emerged after 9 hrs. of incubation. In conclusion, the incidence degree of leaf mold and gray leaf spot disease on tomato plants shows that it is very closely related to formation of leaf condensation, therefore the incidence of leaf mold was greater at 20 and 15℃, while 25 and 20℃ enhanced the incidence of gray leaf spot. The incidence of leaf mold and gray leaf spot developed 20 days after inoculation, and the latency period was estimated to be 14-15 days. Trihumin fungicide had the maximum effectiveness up to 168 hours of fungicides at 12 hours of wet duration in leaf mold, whereas Gajiran fungicide had the highest control (93%) against gray leaf spot up to 144 hours. All the chemicals showed an around 30-50% decrease in effectiveness after 240 hours of treatment. The model predictions in present study could be help in timely, effective and ecofriendly management of leaf mold disease in tomato.

Effect of Sterilization Conditions on Microbial Reduction in Cleaning Tools (살균 조건이 세척 도구 중 미생물 저감화에 미치는 영향)

  • Im, Ji-Yu;Kim, Chae-Young;Kim, Eun-yeong;Kim, Min-jin;Kim, Jung-Beom
    • Journal of Food Hygiene and Safety
    • /
    • v.37 no.5
    • /
    • pp.310-316
    • /
    • 2022
  • In this study, we compared the microbial reduction effects of drying, hot water, and microwave sterilization in scourers and dishcloths to suggest a most suitable sterilization method. Three scourer types (silver, copper, and mesh) were used, and three dishcloth types (silver, bamboo, and cotton) were used. Drying time dependent reduction in Escherichia coli was high in silver and copper scourers, but minimal bacterial reduction was obtained against Bacillus cereus in all scourers and dishcloths. In scourers, E. coli was not detected after ≥30 s of hot water sterilization at 77℃, and B. cereus was not detected after ≥60 s of hot water sterilization at 100℃. In dishcloths, E. coli was not detected after hot water sterilization at 77℃ for ≥30 s, but B. cereus was detected after hot water sterilization at 100℃ for ≥60 s. In scourers, E. coli was not detected after microwave sterilization at 700 W for 3 min, but B. cereus was detected. In dishcloths, E. coli was not detected after microwave sterilization with 700 W for ≥1 min, but B. cereus was detected in the cotton dishcloth even after sterilization for 3 min. In conclusion, the use of antimicrobial scourers (silver and copper) and dishcloths (silver and bamboo) are not sufficient to reduce the microbial contamination. The guideline provided by the Ministry of Food and Drug Safety suggesting dishcloth sterilization via hot water at 100℃ for 30 s was also found to be insufficient. Based on our research, we suggest that the most effective methods of microbial management are submerging scourers in hot water at 100℃ for ≥1 min, and sterilizing dishcloths for ≥3 min using a 700 W microwave.