• Journal of The Korean Society of Grassland and Forage Science
• /
• v.24 no.1
• /
• pp.61-70
• /
• 2004

Silage additives are needed to increase the quality of whole crop rice silage which seldom produce without the additives due to both high pH and butyric acid concentrations. Little information, however, is available about the silage fermentation of whole crop rice added with silage additives in Korea. This study was conducted to determine the optimum levels of silage additives by evaluating the effects of latic acid bacteria (LAB) and formic acid concentrations on the silage quality of whole crop rice harvested at different mature stages. Field study was established early in May until October 7th on a rice field at Yupori, Sinbuk-yeup, Chunchon, Kangwon-Do. "Ilpum" mutant rice was harvested at six different mature stages; booting stage (17 Aug.), milk-ripe stage (27 Aug.), dough stage (7 Sep.), yellow ripe stage (17 Sep.), dead ripe stage (27 Sep.) and full ripe stage (7 Oct.). Each sample was ensiled in three different ways; with 1) LAB (0.05, 0.1 and 0.2% of sample wt), 2) formic acids (0.2, 0.3 and 0.4% of sample wt.) and 3) no additive. The additive levels did not affect dry matter content, crude protein, fiber and total digestable neutriant concentrations at all stages. Addition of additives significantly decreased the silage pH and butyric acid concentrations which tended to be more decreased with higher levels of additives. Latic acid concentrations were higher with the use of additives, especially with LAB. The lower concentrations of ammonia-N were observed in additive treatments at all stages, but the concentrations of ammonia-N did not differ according to the additve levels after yellow ripe stage (0.69, 0.60 and 0.71% of DM in 0.05, 01 and 0.2% of LAB, respectively; 0.64 0.59 and 0.75% of DM in 0.2, 0.3 and 0.4% of formic acid, respectively). These results indicate that the optimum addition levels of LAB and formic acid are 0.5∼0.1% and 0.2∼0.3%, respectively, on which the high quality of rice whole crop silage was produced. produced.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.31 no.4
• /
• pp.361-370
• /
• 2011

This study was conducted to obtain basic a information on growth characteristics, productivity, and feed values of whole crop barleys with different awn types. The field experiments were conducted on land at Iksan, Jeollabuk-do province in Korea for one year. Six barleys with three different awn types, such as Youngyang (rough), Yuyeon (hood), Youho (hood), Iksan449 (hood), Iksan456 (hood), and Iksan448 (awnless), were used in this study. Barleys were harvested on five growth stages after (DAH); 20 days after heading (20 DAH), 25 DAH, 30 DAH, 35 DAH, and 40 DAH. Heading was earlier in Yuyeon (April 22), while was later in Iksan448 (April 29). The maximum dry matter and total digestible nutrients (TDN) yields, 11.8 and 8.1 ton per ha, respectively, was recorded in Ikan456 harvested at 35~40 DAH, followed by Youngyang, Yuyeon, Iksan448, Youho and the lowest in Iksan449. They were increased significantly with advancing crop maturity. Crude protein content was the highest in Iksan448 (10.9%) and the lowest in Youho (9.7%) and that was decreased significantly with late harvest. Total digestible nutrients (TDN) and relative feed value (RFV) were the highest in Iksan448 (73.0%, 183.8, respectively) and the lowest in Iksan456 (68.0%, 135.4, respectively) and they were increased significantly with late harvest. The mean RFV evaluated by awn types was the highest in Iksan448 (183.8) of awnless, the lowest in Youho (149.5) and Iksan456 (135.4), indicated the insufficiency of hooded type barleys as good fodder use. Therefore, in this study suggest that hooded barley should improve forage productivity as well as quality.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.16 no.3
• /
• pp.233-245
• /
• 2014

Nighttime correction of $CO_2$ flux is one of the most important and challenging tasks in eddy covariance measurements over a complex mountainous terrain. In this study, we have scrutinized the quality and the credibility of the $CO_2$ flux datasets which were produced by employing three different methods of nighttime correction, i.e., (1) friction velocity ($u^*$) correction, (2) light response curve (LRC) correction, and (3) advection-based van Gorsel (VG) correction. The whole year datasets used in our analysis were collected at the two KoFlux tower sites (i.e., GDK deciduous forest site at the upper hill and GCK coniferous forest site at the lower hill) located in the valley of Gwangneung National Arboretum in central Korea. The resultant magnitudes and patterns of ecosystem respiration ($R_E$), gross primary productivity (GPP), and net ecosystem exchange (NEE) of $CO_2$ showed marked differences among the datasets produced with three different correction methods, which were also site-specific. The examination from micrometeorological and ecological perspectives suggests that the major cause of some inconsistency seems to be associated with the advection of $CO_2$ along the sloping terrain and the inappropriate selection of the correction data that might have been already affected by advective flows. The comparison with the results from other studies indicated that the overall characteristics of the corrected $CO_2$ fluxes at GDK and GCK (except those with LRC correction) were well within the ranges reported in the literature for various ecosystems in East Asia in similar latitudes. However, our study also implies that there will be always a room for further improvement in the present datasets. Therefore, caution must be exercised for the data users in order to properly use the updated version of datasets through transparent, open and participatory communication with data producers.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.18 no.4
• /
• pp.357-365
• /
• 2016

The effects of elevated atmospheric $CO_2$ on photosynthesis and growth of Chinese cabbage (Brassica campestris subsp. napus var. pekinensis) were investigated to predict productivity in highland cropping in an environment where $CO_2$ levels are increasing. Vegetative growth, based on fresh weight of the aerial part, and leaf characteristics (number, area, length, and width) of Chinese cabbage grown for 5 weeks, increased significantly under elevated $CO_2$ ($800{\mu}mol{\cdot}mol^{-1}$) compared to ambient $CO_2$ ($400{\mu}mol{\cdot}mol^{-1}$). The photosynthetic rate (A), stomatal conductance ($g_s$), and water use efficiency (WUE) increased, although the transpiration rate (E) decreased, under elevated atmospheric $CO_2$. The photosynthetic light-response parameters, the maximum photosynthetic rate ($A_{max}$) and apparent quantum yield (${\varphi}$), were higher at elevated $CO_2$ than at ambient $CO_2$, while the light compensation point ($Q_{comp}$) was lower at elevated $CO_2$. In particular, the maximum photosynthetic rate ($A_{max}$) was higher at elevated $CO_2$ by 2.2-fold than at ambient $CO_2$. However, the photosynthetic $CO_2$-response parameters such as light respiration rate ($R_p$), maximum Rubisco carboxylation efficiency ($V_{cmax}$), and $CO_2$ compensation point (CCP) were less responsive to elevated $CO_2$ relative to the light-response parameters. The photochemical efficiency parameters ($F_v/F_m$, $F_v/F_o$) of PSII were not significantly affected by elevated $CO_2$, suggesting that elevated atmospheric $CO_2$ will not reduce the photosynthetic efficiency of Chinese cabbage in highland cropping. The optimal temperature for photosynthesis shifted significantly by about $2^{\circ}C$ under elevated $CO_2$. Above the optimal temperature, the photosynthetic rate (A) decreased and the dark respiration rate ($R_d$) increased as the temperature increased. These findings indicate that future increases in $CO_2$ will favor the growth of Chinese cabbage on highland cropping, and its productivity will increase due to the increase in photosynthetic affinity for light rather than $CO_2$.

• Journal of Korean Home Economics Education Association
• /
• v.20 no.4
• /
• pp.223-237
• /
• 2008

The purpose of this research was to provide the information needed for improving the contents in housing unit of middle school technology and home economic textbook. For this purpose, a survey questionnaire was developed to examine teachers' importance perception of 48 contents in housing unit. A direct survey and an e-mail survey were used to collect data from teachers, and a total number of 233 data were analyzed. Conclusions were summarized as following: 1. Among the 48 contents in housing unit, the average score of teachers' importance perception of the 18 contents on 'interior environment and equipments' was 3.94; the average score of teachers' importance perception of the 15 contents on 'living space plan and use' was 3.78; and the average score of teachers'importance perception of the 15 content on 'housing maintenance and repair' was 3.42. Therefore, the 15 contents on 'housing maintenance and repair' must be revised. 2. Teachers' importance perception of 25 contents, among the 48 contents in housing unit, were significantly differentiated by gender, age, teaching experience, scholastic attainment, subject in charge(technology, home economics, technology and home economics), school type(boys' middle school, girls' middle school, coeducation), and region(city, county). Therefore, the 25 contents, of which importance perception were influenced by teachers' characteristics, must be revised in order to maintain the consistent importance perception. Suggestions were that the team teaching of technology and home economic textbook was more recommendable; that the local situations must be considered in the contents of housing unit and; that the contents of housing unit must be segmented into a minimum unit for the accurate evaluation.

• Journal of Korean Home Economics Education Association
• /
• v.20 no.1
• /
• pp.101-116
• /
• 2008

Most who were polled stated that they use the internet everyday. Also, it is undeniable that Internet has become one of the popular shopping markets with the spatial-convenience and time-saving it provides. With the growth of Internet and Internet shopping malls, effects on clothing purchasing of adolescents. The purpose of this study was to investigate the clothing shopping orientation and Internet clothing purchasing type of high school students. Subjects were 685(male 354, female 331) high school students located in Jeollabukdo province. In this statistical analysis, SPSS 11.5 for Windows Program. These data were analyzed by factor analysis, $x^2$ test, t-test, One-way Anova, Duncan' multiple range, Pearson's correlation coefficient. The results of this study were as follows. Six dimensions of clothing shopping orientation were derived by factor analysis: fashion hedonic shopping brand ostentation time convenience economic esthetics orientation. The clothing purchasing type in Internet had 3 factors(convenience active impulse buying economic pursuit). The groups were significantly different in regard to clothing shopping orientation, clothing purchasing type in Internet shopping mall according to demographic variables(gender, educational background of parents, a school record). Clothing shopping orientation variables had positive correlations except of hedonic shopping economic orientation with clothing purchasing type in Internet. As a conclusion, high school students' shopping orientation and purchasing type of apparel in Internet shopping mall constituted important characteristics which could affect directly Internet purchase behavior of adolescents. These results should be fundamental information for clothing and textile education in secondary school.

• Journal of the Korean earth science society
• /
• v.39 no.5
• /
• pp.419-435
• /
• 2018

The purpose of this study is to understand meteorological and climatological factors that have influence on the garlic product in Seosan and Taean, and to analyze the economic value according to the use of climatical information data for garlic farmers. The climatological characteristics and trends in this area are analyzed using the meteorological data at the Seosan local meteorological agency from 1984 to 2013, the national statistical data for the product of garlic from 1989 to 2013, and the scenario data for climate change (RCP 4.5 and 8.5) for the period from 2001 to 2100. The results are as follows. First, the condition of lower temperature for garlic growth in winter season is satisfied with the mean air temperature. The wind speed are lower and stronger in Seosan and Taean than other garlic area. The suitable condition for the growth of northern type of garlic shows the decreasing trend in the accumulated precipitation in May. However, the area of growing the northern type garlic in the future is likely diminished because mean air temperature, accumulated precipitation, and mean wind speed are strong in the harvest time of garlic. Second, the seedtime of the northern and southern type of garlic using climate change scenarios (RCP 4.5, 8.5) in Seosan and Taean is getting late as time passes. and the harvest time gets faster, which indicates s that the period of garlic cultivation becomes shorter from 50 days to around 90 in the next 100 years. Third, the beginning days of white rot and delia platura of garlic are estimated by applying to the meteorological algorithm using mean air temperature and soil humidity. Especially, the beginning day of white rot garlic is shown to be faster according to the scenarios of RCP 4.5 and RCP 8.5. Fourth, the product of garlic (kg/10a) shows a high correlation with the minimum air temperature of a wintering time, the mean wind speed of a wintering time, the accumulated precipitation of a corpulent time, and the mean relative humidity of corpulent time of garlic. On the other hand, the analysis of garlic product when using the meteorological information data in cultivating garlic in Seosan and Taean reveals that the economic value increases up to 9% in total.

• Journal of Gastric Cancer
• /
• v.7 no.3
• /
• pp.152-159
• /
• 2007

Purpose: Recently, the use of laparoscopic assisted gastrectomy for early gastric cancer has been on the increase and the procedure has been quickly adopted by clincians. However, there are few reports regarding the safety and risk of this type of surgery. The aim of this study is to evaluate the morbidity and to verify the safety of laparoscopic assisted gastrectomy for early gastric cancer. Materials and Methods: A total of 376 patients that had undergone laparoscopic assisted gastrectomy for early gastric cancer between April 2004 and December 2006 were reviewed retrospectively. The clinicopathological characteristics, operative complications, and factors related to complications were evaluated. Results: The overall operative morbidity and mortality rates were 10.6% and 0%, intraoperative morbidity was 1.1% (4 of 376 patients) and post operative morbidity was 9.6% (36 of 376 patients). Most complications required no surgery except for an intestinal obstruction in two cases. Multivariate analysis of risk factors related to operative morbidity determined that age was an independent factor associated with morbidity (P=0.021). Conclusion: The complication rate of laparoscopic assisted gastrectomy is low and most complications can be managed by conservative methods rather than with surgery. There were no specific predicting factors for complications except old age. Laparoscopy is a technically feasible and acceptable surgical modality for early gastric cancer.

• KEPCO Journal on Electric Power and Energy
• /
• v.6 no.3
• /
• pp.305-313
• /
• 2020

The use of cable tunnels for electric power transmission as well as their construction in difficult conditions such as in subsea terrains and large overburden areas has increased. So, in order to efficiently operate the small diameter shield TBM (Tunnel Boring Machine), the estimation of advance rate and development of a design model is necessary. However, due to limited scope of survey and face mapping, it is very difficult to match the rock mass characteristics and TBM operational data in order to achieve their mutual relationships and to develop an advance rate model. Also, the working mechanism of previously utilized linear cutting machine is slightly different than the real excavation mechanism owing to the penetration of a number of disc cutters taking place at the same time in the rock mass in conjunction with rotation of the cutterhead. So, in order to suggest the advance rate and machine design models for small diameter TBMs, an EPB (Earth Pressure Balance) shield TBM having 3.54 m diameter cutterhead was manufactured and 19 cases of full-scale tunneling tests were performed each in 87.5 ㎥ volume of artificial rock mass. The relationships between advance rate and machine data were effectively analyzed by performing the tests in homogeneous rock mass with 70 MPa uniaxial compressive strength according to the TBM operational parameters such as thrust force and RPM of cutterhead. The utilization of the recorded penetration depth and torque values in the development of models is more accurate and realistic since they were derived through real excavation mechanism. The relationships between normal force on single disc cutter and penetration depth as well as between normal force and rolling force were suggested in this study. The prediction of advance rate and design of TBM can be performed in rock mass having 70 MPa strength using these relationships. An effort was made to improve the application of the developed model by applying the FPI (Field Penetration Index) concept which can overcome the limitation of 100% RQD (Rock Quality Designation) in artificial rock mass.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.48 no.4
• /
• pp.29-40
• /
• 2020

This study quantitatively and qualitatively analyzes the physical environment for health promotion in urban parks by indicators that were selected in consideration of overseas cases and previous studies. To evenly distribute the areas to be evaluated by region, Seodaemun Independence Park, Hongneung Park, Gocheok Park, Sillim Park, Cheongdam Park, Gaepo Park, and Sungin Park were selected among the old neighborhood parks already established in Seoul. The evaluation indicators consist of quantitative indicators (12 factors classified into the three categories of the surrounding environment, the park characteristics, and the park facilities) and qualitative indicators (14 factors classified according to the five categories of accessibility, safety, convenience, activities, and amenities). These indicators were selected after conducting advisory meetings with experts in the field. The physical environment perception factors were evaluated by experts and investigators by field inspections and were rated on a three-point scale (high, medium, low). According to the results of the analysis, first, not only were exercise facilities and trails, but also various factors which support health activities, such as rest areas, leisure spots, and cultural facilities, as well as accessibility, cleanliness, and drinking water facilities are important indicators for health promotion. Second, even if the requirements are met for quantitative factors, several inconveniences hinder the actual implementation or use in the qualitative evaluation. Thus, both quantitative and qualitative evaluations must be simultaneously performed for the proper judging of the physical environment of a park. Third, upon conducting a qualitative evaluation of the physical environmental factors, score differences depended on the evaluated categories in each park. These differences show that indirect indicators, such as accessibility, safety, and facility convenience are insufficiently equipped compared to direct indicators, such as activity, which includes exercise facilities and fitness centers for health promotion. As the utilization rate of parks is increasing due to COVID-19, more efforts should be made to improve park services in the post-corona era. To promote such services, it is necessary to regularly evaluate parks based on both quantitative and qualitative indicators and to contemplate services not only through direct factors but also indirect factors and security measures.