• Title/Summary/Keyword: Rate of Change

Search Result 9,359, Processing Time 0.046 seconds

Application of Greenhouse Climate Management Model for Educational Simulation Design (교육용 시뮬레이션 설계를 위한 온실 환경 제어 모델의 활용)

  • Yoon, Seungri;Kim, Dongpil;Hwang, Inha;Kim, Jin Hyun;Shin, Minju;Bang, Ji Wong;Jeong, Ho Jeong
    • Journal of Bio-Environment Control
    • /
    • v.31 no.4
    • /
    • pp.485-496
    • /
    • 2022
  • Modern agriculture is being transformed into smart agriculture to maximize production efficiency along with changes in the 4th industrial revolution. However, rural areas in Korea are facing challenges of aging, low fertility, and population outflow, making it difficult to transition to smart agriculture. Among ICT technologies, simulation allows users to observe or experience the results of their choices through imitation or reproduction of reality. The combination of the three-dimension (3D) model and the greenhouse simulator enable a 3D experience by virtual greenhouse for fruits and vegetable cultivation. At the same time, it is possible to visualize the greenhouse under various cultivation or climate conditions. The objective of this study is to apply the greenhouse climate management model for simulation development that can visually see the state of the greenhouse environment under various micrometeorological properties. The numerical solution with the mathematical model provided a dynamic change in the greenhouse environment for a particular greenhouse design. Light intensity, crop transpiration, heating load, ventilation rate, the optimal amount of CO2 enrichment, and daily light integral were calculated with the simulation. The results of this study are being built so that users can be linked through a web page, and software will be designed to reflect the characteristics of cladding materials and greenhouses, cultivation types, and the condition of environmental control facilities for customized environmental control. In addition, environmental information obtained from external meteorological data, as well as recommended standards and set points for each growth stage based on experiments and research, will be provided as optimal environmental factors. This simulation can help growers, students, and researchers to understand the ICT technologies and the changes in the greenhouse microclimate according to the growing conditions.

Active Seniors' Organizational and Functional Entrepreneurial Competencies: Discovering Unobserved Heterogeneous Relationships between Entrepreneurial Efficacy and Entrepreneurial Intention using PLS-POS (액티브 시니어의 조직적과 기능적 창업역량: PLS-POS를 이용한 창업 효능감과 창업의지의 이질성 관계 확인)

  • Shin, Hyang Sook;Bae, Jee-eun;Chao, Meiyu;Lee, Yong-Ki
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.17 no.2
    • /
    • pp.15-31
    • /
    • 2022
  • This study was conducted to suggest a start-up policy that includes start-up education and support for active seniors with various careers who try to change their careers before and after retirement. From this point of view, this study divided the factors affecting the entrepreneurial will of active seniors into entrepreneurship organizational and functional competency and identified the effect of these competencies on entrepreneurial efficacy and entrepreneurial intention. In the proposed model, start-up competency is divided into organizational competency (leadership, creativity problem-solving, communication, decision-making) and functional competency (management strategy, marketing, business plan). And this study examined the mediating role of entrepreneurial efficacy in the relationship between entrepreneurial competency factors and entrepreneurial intention. Meanwhile, PLS-POS analysis was performed to uncover the heterogeneity and pattern in the proposed structural model. The survey was conducted with the help of an online survey company from November 27 to December 15, 2020 for the active senior age group from 40 to under 65 years old. Data were collected from a total of 433 panelists and analyzed using SPSS 22.0 and SmartPLS 3.3.7 programs. The findings are as follows. First, the finding shows that the entrepreneurial organizational and functional competencies of active seniors had significant positive(+) effects on entrepreneurial efficacy. Second, the result shows that entrepreneurial organizational and functional competencies of active seniors had significant positive(+) effects on entrepreneurial intention. Third, the findings show that entrepreneurship efficacy had a significantly positive(+) effect on entrepreneurial intention. The findings of PLS-POS show that entrepreneurship education needs to be carried out by identifying the needs that require entrepreneurial organizational and functional competency when training for entrepreneurship competency. In summary, the findings of the current study are to determine what the competency factors are for the government (local government) to increase the policy direction necessary for establishing and implementing entrepreneurship education and training programs to develop policies to enhance the economic activity participation rate of active seniors.

Monitoring of Plant Community Structure Change for Four Years(2007~2010) after Riparian Ecological Restoration, Nakdonggang(River) (낙동강 수변 생태복원지 시공 후 4년간(2007~2010년) 식생구조 변화 모니터링)

  • Ki, Kyong-Seok;Kim, Jong-Yup
    • Korean Journal of Environment and Ecology
    • /
    • v.26 no.5
    • /
    • pp.707-718
    • /
    • 2012
  • This study was conducted to monitor 4 years of changes in the vegetation structure starting from 2007 when restoration began and propose vegetation management ideas for the riparian ecological restoration areas in the purchased land around Nakdonggang(River). The study was conducted in each of 15 locations ($208,342m^2$) in the riparian ecological restoration areas in November 2007, September 2008, October 2009 and September 2010. The analysis results of the changes in planting species and population showed that, in the case of trees, Acer pseudo-sieboldianum, Quercus acutissima, Acer ginnala, Quercus aliena, Quercus variabilis indicated relatively little changes in their numbers and Quercus dentata, Cornus walteri, Morus alba, Styrax obassia, Sorbus alnifolia var. macrophylla indicated a 100% withering rate. Most shrubs withered due to the oppressive pressure of herbs and climbing plants. The planting density decreased over 4 years on average 28 plants/$100m^2$ to 20 plants/$100m^2$ to 16 plants/$100m^2$. Shortly after the restoration, The the amount of growth was reduced by restoration stress. however as time goes on after the restoration tended to stabilize. The changes in the basal area showed a decrease from $507.1cm^2/100m^2$ in 2007 right after restoration to $301.8cm^2/100m^2$ in 2008 and afterwards showed an increasing trend by going to $324.9cm^2/100m^2$ in 2009 and $372.7cm^2/100m^2$ in 2010. To improve the planting structure of the riparian ecological restoration area, the selection of tree species that have been considered for soil moisture and the differentiation of suitable planting structures that have been considered for local conditions were needed.

Formaldehyde Monitoring of Hygiene Products in Domestic Market (국내 유통 위생용품 중 포름알데히드 잔류량 모니터링)

  • Na, Young-Ran;Kwon, Hyeon-Jeong;Cho, Hyun-Nho;Kim, Hyeon-Jin;Park, Yon-Koung;Park, Sung-Ah;Lee, Seong-Ju;Kang, Jung-Mi
    • Journal of Food Hygiene and Safety
    • /
    • v.35 no.3
    • /
    • pp.225-233
    • /
    • 2020
  • By the standards and specifications for hygiene products, three test methods for formaldehyde are specified for each item type of hygiene product. After derivatization using acetylacetone and 2,4-dinitrophenylhydrazine (2,4-DNPH), formaldehyde is analyzed by spectrophotometer and high-performance liquid chromatography (HPLC). Validation of the three test methods was performed on tissue, diaper lining and waterproof layer, and panty liner products. The results of linearity (R2), limit of detection (LOD), limit of quantification (LOQ), recovery rate (%) and reproducibility (%), showed that all three methods are suitable for analyzing formaldehyde in hygiene products. After derivatization with 2,4-DNPH and cetylacetone, formaldehyde was analyzed at 0, 3, 6, 9, 24 and 48 hours by HPLC. Formaldehyde derivatized with 2,4-DNPH showed no statistically significant change in formaldehyde peak area over time (P>0.05). But, acetylacetone-derivatizated formaldehyde showed a negative correlation coefficient (r) over time (P<0.01). We investigated the residual amounts of formaldehyde in 205 hygiene products distributed in Busan. Among 74 disposable diaper products tested, 73 had low concentrations of formaldehyde (0.13-29.87 mg/kg). Moreover, formaldehyde was not detected in any of 78 tissue, 27 disposable paper towel, 12 disposable dishcloth, 7 paper cup, one brand of paper straw and 6 disposable napkin products.

Climatic Characteristics of August and Summer of 2007 and Long Term Trend of August and Summer Climate (한반도의 2007년 8월과 2007년 여름의 기후특성 및 8월과 여름의 장기 기후변화)

  • Shin, Im Chul;Kim, Tae Ryong;Lee, Eun-Jung;Kim, Eun-Hee;Kim, Eun Suk;Park, Yeon Ok;Bae, Sun-Hee;Yi, Hi-Il
    • Atmosphere
    • /
    • v.17 no.4
    • /
    • pp.471-481
    • /
    • 2007
  • Temperature and precipitation, particularly August and summer, in the Korean peninsular are analyzed. The analyzed period is 1973-2007 for the Korean peninsular (that is, 60 meteorological station average). In addition, 100 year record (1908-2007) of temperature and precipitation in Seoul are also analyzed. Results indicate that the temperatures (mean, maximun, and minimum) of August and summer of 2007, both in Korean peninsular and Seoul, are higher than normal. The increasing rate of minimum temperature for the August and summer during the period from 1973 to 2007 shows greater than the mean and maximum temperature both in Korean peninsular and Seoul due to the global warming and urbanization. Number of tropical night days, defined by the days with above $25^{\circ}C$ in minimum temperature, shows increasing trend both in August and summer from 1973 to 2007 due to the combination effect of the global warming and urbanization. The amount of precipitation, both in August and summer, for Korean peninsular and Seoul shows increasing trend from 1973 to 2007, and 1908 to 2007, respectively. Amount of precipitation and rainy days, both August and summer, during 2000s show greater than those of the 1970s both in Korean peninsular and Seoul. Extreme rainy days (greater than 120mm/day, greater than 80mm/day, greater than 30mm in any 1-hour period and greater than 10mm in any 10-minute period) show increasing trend from 1973 to 2007 for both in August and in summer.

Comparison of Growth Period and Local Climate for 'Hongro' Apple Orchards Located at Different Altitudes in Jangsu-Gun (장수군의 해발고도별 '홍로' 사과원의 미기상 및 생육기 비교)

  • Song, Ju-Hee;Seo, Byung Sun;Choi, Dong Geun;Choi, In Myung;Kang, In-Kyu;Guak, Sunghee
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.15 no.1
    • /
    • pp.1-8
    • /
    • 2013
  • This study was conducted to compare the local climate conditions and growth periods for the apple (Malus domestica 'Borkh') orchards at different altitudes (330, 500, and 670 m) in Jangsu-Gun, Korea. Observation data for the growth period show that the monthly mean air temperatures at the 'Hongro' apple orchard sites decrease with height at the rate of 1.0 to $3.0^{\circ}C$/100 m. The monthly minimum temperatures in April (blooming period for 'Hongro' apple) were 4.3, 2.9, and $0.4^{\circ}C$ at 330, 500, and 670 m, respectively. The monthly mean temperatures in September (i.e., the coloration and maturation period) were 20.6, 18.7, and $14.5^{\circ}C$, respectively. The annual precipitation range varied from 1,234 to 1,439 mm, which tended to increase with height. The heavy rainfall occurred in summer (June to August) and amounted to 827-933 mm. No significant differences in the duration of sunshine were observed amongst the orchards at three different altitudes. The earliest bud break was observed at the 330 m altitude (18 March 2009), which was 4 and 11 days earlier in comparison to those at 500 and 670 m, respectively. The time of full bloom at 330 m was 12 days ahead of that at 670 m. The optimal maturation of fruit (based on skin redness > 80%) was observed between 7 and 10 September at 330 m, 15 and 18 September at 500 m, and 21 and 23 September at 670 m.

Effect of 5 Week Long High-Fat Diet on Energy Metabolic Substrate Utilization and Energy Content Evaluation of Dietary Fat (5주간의 고지방식이 섭취시 흰쥐의 에너지 대사 기질 이용과 식이지방에너지 평가에 관한 연구)

  • Hwang, Hye-Jung;Kim, Ji-Su;Suh, Hea-Jung;Lim, Ki-Won
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.41 no.8
    • /
    • pp.1094-1099
    • /
    • 2012
  • This study investigated the effect of a long-term high-fat diet on energy metabolic substrate utilization in resting rats in order to revalue source fat energy efficiency during a high-fat diet and its effect on energy expenditure and body fat accumulation. Sprague-Dawley male rats at 4 weeks of age were bought from Orient Bio Con. The rats were divided into a control (CON) group and a high-fat diet (HF) group. Rats ate a high-fat diet (w/w 40%, kcal/kcal 64.9%) ad libitum for 5 weeks. Food intake and body weight were measured every day at 09:00 throughout the experimental period. Energy expenditure was measured using an animal energy metabolism chamber after 4 weeks. The final body weight did not change between the CON and HF groups, but caloric intake was significantly higher in the HF group than in the CON group (p<0.05). There was no difference between the groups in oxygen uptake, however carbon dioxide production was significantly higher in the HF group. Also, the respiratory exchange ratio was higher in the HF group. Carbohydrate oxidation was lower in the HF group than in the CON group, but fat oxidation in the HF group was greater. These results mean that energy substrate oxidation at rest is affected by diet composition, especially dietary fat content. Abdominal fat fad weights were significantly higher by 33% in the HF group than in the CON group even though the calorie intake in the HF group was higher by 6%. These results suggested that the dietary fat calorie value might have a higher Atwater value of 9 kcal/g, which mean that dietary fat calorie values could be reconsidered in body weight control scenarios such as which the obese or weight class athletes.

Quality Changes of Minimally Processed Sliced Deodeok (Codonopsis lanceolata) during Storage by Packaging Method (포장방법 차이에 따른 신선편이 슬라이스 더덕의 저장 중 품질 변화)

  • Choi, Duck-Joo;Lee, Yun-Jung;Kim, Youn-Kyeong;Kim, Mun-Ho;Choi, So-Rye;Park, In-Seon;Cha, Hwan-Soo;Youn, Aye-Ree
    • Food Science and Preservation
    • /
    • v.19 no.5
    • /
    • pp.626-632
    • /
    • 2012
  • In this study, the changes that occurred in the quality of minimally processed sliced Deodeok (Codonopsis lanceolata) in relation to the packing method during storage at $7^{\circ}C$ were investigated. The storage tests were conducted for seven days using PE sealing, but PP sealing and vacuum packaging preserved the Deodeok for 14 days. On the seventh day, the vinyl-packaged Deodeok showed a remarkable fall in quality with 4.5 °Brix, but the PP-sealed and vacuum-packaged Deodeok showed slight falls with 6.4 and $6.8^{\circ}Brix$, respectively. The PE- and PP-sealed Deodeok did not show significant differences in texture and moisture content for two days, and the moisture content was highest in the vacuum-packaged Deodeok during storage. In relation to the total viable cell and the coliform count, the vacuum-packaged Deodeok showed the lowest rate of increment during storage, followed by the others. Thus, the bubble-washed and vacuum-packaged minimally processed sliced Deodeok was found to have the best quality.

The Psychophysiologic Response in Korean Patients with Generalized Anxiety Disorder (범불안장애환자의 정신생리적 반응)

  • Chung, Sang-Keun;Hwang, Ik-Keun
    • Sleep Medicine and Psychophysiology
    • /
    • v.4 no.1
    • /
    • pp.107-119
    • /
    • 1997
  • Objectives: The psychophysiologic response pattern between healthy subjects and patients with generalized anxiety disorder, and the relationship among anxiety rating scales and those patterns in patients were examined. Methods: Twenty-three patients with generalized anxiety disorder(AD) and 23 healthy subjects were evaluated by Hamilton Rating Scale for Anxiety(HRSA) and State-Trait Anxiety Inventory before baseline stressful tasks. Subjective Units of Distress were evaluated just before baseline period, immediately after stressful tasks, at the end of the entire procedure, and psychophysiologic measures, i.e., skin temperature(ST), electromyographic activity(EMG), heart rate(HR), electrodermal response(EDR) during baseline & rest and during two psychologically stressful tasks (mental arithmetic, TM; talk about a stressful event, TT) were also evaluated. Results: 1) AD group showed significantly higher EMG level during rest after stressful tasks and higher HR level during all period except TM compared to control group. 2) AD group showed lower change in the startle response(SR) of ST, in the SR & the recovery response(RR) of EMG during TM, and in the RR of EDR immediately after TM than control group. AD group showed that the RR of EDR was significantly lower than the SR during stressful tasks. 3) We found that there was significantly negative correlation between state anxiety and the RR of EDR after TT in AD group. We also found that there were significantly positive correlations between HRSA score and the SRs of EDR during stressful tasks, and between state anxiety and the SR of EDR during TT. Conclusion: Our results suggest that patients with generalized anxiety disorder show higher autonomic arousal than healthy subjects and decreased physiologic flexibility or reduced autonomic flexibility.

  • PDF

A Study on Status Analysis for Advancement iNto Agricultural Sector in Central Asia (중앙아시아 농업분야 진출을 위한 현황분석 - 우즈베키스탄, 카자흐스탄, 키르기즈스탄 중심으로 -)

  • Park, Dong-Jin;Jo, Sung-Ju;Park, Jeong-Woon;Sa, Soo-Jin;Hong, Jung-Sik;Lee, Dong-Jin
    • Journal of the Korean Society of International Agriculture
    • /
    • v.30 no.4
    • /
    • pp.328-338
    • /
    • 2018
  • Central Asia (Uzbekistan, Kazakhstan, Kyrgyzstan) is a hot and arid continental climate, with most areas (68%) consisting of barren vegetation, desert, and meadows. The main agricultural areas for crop production include irrigated farmland, non-irrigated farmland, grassland, prairie and mountain. We are experiencing climate change with recent climate variability increasing. Agriculture is one of major economic sectors and provides a means of livings for the rural population of Central Asia, especially the poor. In the past two decades, Central Asia has experienced a high population growth rate, with Kazakhstan at 16.8%, Uzbekistan at 34.5% and Kyrgyzstan at 28.4%. As a major industry, Kazakhstan has the largest share of exports of agricultural products followed by petroleum, mineral resources, steel, and chemicals. Uzbekistan is the fifth largest cotton exporter as well as the sixth largest cotton producer in the world. Kyrgyzstan exports ores, stones, cultured pearls, and minerals. These three countries are rich in mineral resources, agricultural products, and energy resources. However, not only do they have difficulties in economic development due to the weakness of logistics and industrial infrastructure, but they also have imperceptible cooperation and investment among countries due to insufficient research and development. Through this study, we will investigate national outlook, economic indicators, major agricultural products, import and export status, and agricultural technology cooperation status, and study how Korean agricultural industry advances into these countries through SWOT analysis. Through this, we hope to contribute to the basic data of Central Asian studies and cooperation and investment in agriculture in each country. In addition, in order to increase cooperative exchange and investment in these countries, we will prepare a Central Asia logistics hub for the rapidly changing interKorean railroad era.