• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.4 no.1
• /
• pp.10-17
• /
• 2001

Purpose: We measured anti-H. pylori IgG in Korean elementary school children living in Shinchon area of Seoul, Korea to evaluate the influence of environmental living standards on H. pylori infection. Methods: IgG antibodies to H. pylori were measured in plasma using a commercial ELISA kit (GAP IgG Helicobacter pylori, Bio-Rad Laboratories Inc., Hercules, CA, USA). Information on environmental status such as place of birth, parental income, type of housing, number of persons in the household, parents' occupation, family history of peptic ulcer disease and gastric cancer was obtained. Statistical analysis was done by Chi-square and logistic regression test using SPSS $7.0^{TM}$ for Windows. Results: Study subjects consisted of 571 children, and the age distribution ranged from 6.0 to 13.6 years with a mean of $9.6{\pm}1.8$ years. Male-to-female ratio was 1.1:1. The seropositive rates of H. pylori infection ranged from 10.4% in children aged 6 years to 30.9% in 12 year-old group, overall 16.8%. The prevalence of H. pylori infection progressively increased with age, but there was no significant difference in seropositive rates among children in different age groups (p=0.06). Seropositive rates of anti-H. pylori IgG on the basis of gender, place of birth, parental income, type of housing, parents' occupation, family history of peptic ulcer disease and gastric cancer showed no statistically significant difference. Interestingly, however, seropositive rate of anti-H. pylori IgG showed statistical significance in relation to number of persons in the household (p=0.003; Odds ratio 1.50 by logistic regression test). Conclusion: These results suggest that number of persons in the household is the most important factor among environmental living standards, and that risk of H. pylori infection increases by increment of 1.5 times as the number of persons in the household increases by one.

• Korean Journal of Veterinary Service
• /
• v.36 no.4
• /
• pp.263-272
• /
• 2013

Consistent information on the chemical composition and its seasonal variation of goat udder half milk is limited in Korea. The objective of this study was to analyze the seasonal variation of the chemical composition of goat milk to take establish various parameters into consideration on the pricing of the goat milk. Variations in chemical composition, somatic cell count (SCC) and bacterial count of 1,038 udder half milk samples from 650 heads raised in 7 farms of Jeonnam province were determined by season. Fat, protein, lactose, non-fat solids, milk urea nitrogen (MUN), pH, SCC and bacterial counts were also analyzed. The average composition of the milk was: fat $3.80{\pm}1.36%$, protein $3.23{\pm}0.80%$, lactose $4.39{\pm}0.54%$, total solids $12.18{\pm}1.80%$, non-fat solids $8.38{\pm}0.80%$, and milk urea nitrogen $28.44{\pm}5.00mg/dL$. The average pH was $6.81{\pm}0.24$. The average of SCC and bacterial counts were $2.54{\pm}4.60{\times}10^6cells/mL$ and $1.25{\pm}3.76{\times}10^5CFU/mL$, respectively. Chemical composition, pH, SCC and bacterial counts of dairy goat milk varied widely during the lactation period and by season. The fat concentration was the lowest in spring ($3.39{\pm}1.53%$) and the highest in autumn and winter ($3.98{\pm}1.30%$ and $3.98{\pm}1.48%$). Protein concentration was the lowest during summer ($2.92{\pm}0.48%$) and the highest in winter ($2.92{\pm}0.48%$). Lactose concentration was the lowest in autumn ($4.24{\pm}0.41%$) and the highest in spring ($4.58{\pm}0.35%$). The lowest total solid value was obtained in the spring season ($11.75{\pm}1.80%$) which was then increased in winter ($12.85{\pm}1.96%$). Non-fat solid concentration was the lowest in summer ($8.07{\pm}0.64%$) and the highest in autumn ($8.94{\pm}0.82%$). MUN concentration was the highest in summer ($8.07{\pm}0.64%$), and the pH concentration was the highest in spring at $6.93{\pm}0.27%$. Seasonal variation of SCC and bacterial count were the lowest in spring ($0.94{\pm}1.54{\times}10^6cells/mL$ and $0.22{\pm}0.61{\times}10^5CFU/mL$, respectively) and was the highest in winter ($3.95{\pm}7.14{\times}10^6cells/mL$ and $2.23{\pm}5.54{\times}10^4CFU/mL$, respectively).

• Weed & Turfgrass Science
• /
• v.4 no.3
• /
• pp.159-175
• /
• 2015

Surveys of weed species on upland fields were conducted in Korea to investigate the occurrence of weed flora from April to May 2014 for winter crop fields and from July to August 2014 for summer crop fields. From the nation-wide survey, 375 weed species in 50 families were identified and classified to 162 annuals, 78 biennials and 135 perennials. Based on the occurrence ratio, the most weed species belonged to Compositae (73 species). 44 and 25 weed species belonged to Poaceae and Polygonaceae, respectively, and these 183 weed species in the most five families accounted for 49% of total weed occurrence. While 287 weed species in 45 families occurred in the winter crop fields, 339 weed species in 47 families occurred in summer crop fields. The most dominant weed species in Korean upland fields were Digitaria ciliaris, followed by Portulaca oleracea, Acalypha australis, Chenopodium album, Rorippa palustris etc. 129 weed species in 25 families were considered as exotic weeds. Based on the importance analysis, the highest value was C. album followed by Amaranthus lividus, Conyza canadensis etc. This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in upland fields of Korea.

• Journal of Mushroom
• /
• v.17 no.4
• /
• pp.211-217
• /
• 2019

Currently, cultivation of mushrooms using the Information and Communication Technology (ICT)-based smart farming technique is increasing rapidly. The main environmental factors for growth of mushrooms are temperature, humidity, carbon dioxide (CO₂), and light. Among all the mentioned factors, currently, only temperature has been maintained under automatic control. However, humidity and ventilation are controlled using a timer, based on technical experience.Therefore, in this study, a Pleurotus eryngii first-generation smart farm model was set up that can automatically control temperature, humidity, and ventilation. After installing the environmental control system and the monitoring device, the environmental condition of the mushroom cultivation room and the growth of the fruiting bodies were studied. The data thus obtained was compared to that obtained using the conventional cultivation method.In farm A, the temperature during the primordia formation stage was about 17℃, and was maintained at approximately 16℃ during the fruiting stage. The humidity was initially maintained at 95%, and the farm was not humidified after the primordia formation stage. There was no sensor for CO₂ management, and the system was ventilated as required by observing the shape of the pileus and the stipe. It was observed that, the concentration of CO₂ was between 700 and 2,500 ppm during the growth period. The average weight of the mushrooms produced in farm A was 125 g, and the quality was between that of the premium and the first grade.In farm B. The CO₂ sensor was in use for measurement purposes only; the system was ventilated as required by observing the shape of the pileus and the stipe. During the growth period, the CO₂ concentration was observed to be between 640 and 4,500 ppm. The average weight of the mushrooms produced in farm B was 102 g.These results indicate that the quality of the king oyster mushroom is determined by the environmental conditions, especially by the concentration of CO₂. Thus, the data obtained in this study can be used as an optimal smart farm model, where, by improving the environmental control method of farm A, better quality mushrooms were obtained.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.11 no.2
• /
• pp.72-78
• /
• 2009

The demand for rainfall data in gridded digital formats has increased in recent years due to the close linkage between hydrological models and decision support systems using the geographic information system. One of the most widely used tools for digital rainfall mapping is the PRISM (parameter-elevation regressions on independent slopes model) which uses point data (rain gauge stations), a digital elevation model (DEM), and other spatial datasets to generate repeatable estimates of monthly and annual precipitation. In the PRISM, rain gauge stations are assigned with weights that account for other climatically important factors besides elevation, and aspects and the topographic exposure are simulated by dividing the terrain into topographic facets. The size of facet or grid cell resolution is determined by the density of rain gauge stations and a $5{\times}5km$ grid cell is considered as the lowest limit under the situation in Korea. The PRISM algorithms using a 270m DEM for South Korea were implemented in a script language environment (Python) and relevant weights for each 270m grid cell were derived from the monthly data from 432 official rain gauge stations. Weighted monthly precipitation data from at least 5 nearby stations for each grid cell were regressed to the elevation and the selected linear regression equations with the 270m DEM were used to generate a digital precipitation map of South Korea at 270m resolution. Among 1.25 million grid cells, precipitation estimates at 166 cells, where the measurements were made by the Korea Water Corporation rain gauge network, were extracted and the monthly estimation errors were evaluated. An average of 10% reduction in the root mean square error (RMSE) was found for any months with more than 100mm monthly precipitation compared to the RMSE associated with the original 5km PRISM estimates. This modified PRISM may be used for rainfall mapping in rainy season (May to September) at much higher spatial resolution than the original PRISM without losing the data accuracy.

• Journal of the Korean association of regional geographers
• /
• v.2 no.1
• /
• pp.25-38
• /
• 1996

As the proportion of women's participation in economic activities is rising, the increase of husband and wife both working and nuclear families makes children up-bringing a social problem. But many families have difficulties by the shortage of day nurseries which can solve it. As we can see in the research, the most urgent problem is the extension of nurseries in quantity. In Taegu, since it became a wide-area city, there are 473 nurseries. But in the respect of distribution, only less than 10% of Dongs have more than 7 nurseries and more than 90% of Dongs have less than 7 nurseries. Consequently nurseries are extremely insufficient. Moreover 29 Dongs don't have any nurseries at all and they take 18.6% of Dongs. The second problem is the unbalanced distribution of nurseries. West and north ward which are industrial complex and swarmed with low-income families, and Tal-sung county which is recently included in the wide-area city keenly need the establishment of nurseries. Besides, Bi-san 1 Dong and Non-gong which have only $1{\sim}2$ nurseries though they have high proportion of children and women who can be pregnant are also the areas which take precedence of nursery establishment. The third problem is that government support must be increased in the areas which have many small, petty and profit-making private nurseries so that good quality teachers can make breeding activities in nice facilities and environment. In materials which are obtained by the interviews with publich servants in charge of family welfare in some ward offices. Young and unexperienced persons who aquired certificate of qualification take day-nursery permits and run nurseries only a few months. and if the profits are insufficient, they sell the nurseries for premiums to third persons who are not qualified. Then the third managers only think of profits without thought of good quality childcare. As the result, the nurseries become asylums not nurseries. That is why the conditions of nursery establishment must be restricted to suitable scale and experienced persons. The fourth problem is that the nurseries in work places are extremely insufficient. The women who have jobs have many things to do before they go to work such as preparing meals and leaving children in the care of someone. Hence the childcare problem of working women must be solved. In nuclear families, childcare is the most serious problem for working women. The fifth one is the reduction of childcare expenses. Women must sacrifice themselves a lot to make social activities. To say nothing of physical and mental burden, they have to spend much of their salaries on childcare. And yet they don't take the benefit of good quality childcare. For the participation of women in public affairs, society must support the childcare problem to have then be devoted to their jobs without worries about their children. Therefore Taegu wide-area city must select west, north ward which are industrial complex and the low-income swarmed area before everything and establish many national, public and corporate nurseries which cost less expenses.

• Journal of Internet Computing and Services
• /
• v.14 no.5
• /
• pp.101-117
• /
• 2013

As the number of online game user has been rapidly increased thanks to the recent vitalization of online contents market, not only new business opportunity but also the opportunity to create high profits have been provided as well. However, the increase of the number of online game user and the rapid expansion of the market evoke a cutthroat completion among online game service providers, and also high barriers to entry to online game market have been erected. Thus, what kinds of efforts need for the business success and sales increase in online game market? In lots of researches regarding online contents business, the deepening of loyalty was considered as a critical factor for the business success. According to the study on user's behavior in online environment, users would experience the Flow while using online service, and then, if they were in state of the Flow, they would use the service constantly. High customer loyalty to online game means high will to use the online game too. The purpose of this research was i) to examine what factors enable users to be naturally immersed in online game while playing it, ii) to examine what properties of online game can make game more interesting and exciting, iii) to verify that such factors are critical in deepening customer loyalty, and iv) to suggest some essential factors to be fun and exciting games, on where the focus should be put, and the directionality for the development for sales expansion of online game developer or online game service provider. The research results are as below: First, the involvement and the perceived quality which were characteristics of brand appeared to be factors most affecting Flow. This shows that once game user get interested in online game that user has played frequently, even though new games are released, user will continuously flow the game not moving to new games, and also shows that users not only get more interested but also put more trust in games in the site to where users are frequently going than games in other sites, and consequently user can increasingly flow the game. Second, the compensation and graphics which are the characteristics of contents appeared to be factors affecting Flow. Proper compensation which is given to game users triggers fun and interests in game and makes them flow more and more. And graphics make users to feel game space as if real space and let them flow in game with more reality. Third, challenges, support, and the stability which are technical characteristics appeared to be factors affecting Flow. Challenges enable users to not only experience new virtual world but also solve various difficulties and obstacles. Once users feel fun and interests through this challenge, they can naturally flow games. In addition, the stability of network provides reliability in security and hacking. By doing so, it can induce users to flow more and more. Lastly, when aforementioned characteristics including contents characteristics, technical characteristics, and brand characteristics are organically combined each other, game users feel fun and total minutes are naturally increased, so that game users experience Flow, and consequently the customer loyalty will be deepened as well.

• Korean Journal of Ecology and Environment
• /
• v.38 no.1 s.110
• /
• pp.83-94
• /
• 2005

The objective of the study was to elucidate early life history of Rhinogobius brunneus, based on laboratory observations and field works, along with its courtship and spawning behaviors. The male and female fish matured were sampled for the lab experiments from Gap-Stream, which is one of the tributaries of Geum-River, Korea. The spawning behaviors and courtship of matured adults had a typical pattern; matured males of Rhinogobius brunneus built up spawning nests and had their own territory before the spawning, and the behavior then triggered the egg spawning of female with active courtship. The females attached elliptic egg mass as a single layer, on the stones below the spawning nest. After the spawning, the egg mass was guarded by males only until the hatching. The size of egg fertilized, measured by microscope was about 1.5${\pm}$0.1mm in length and 0.7${\pm}$0.1 mm in the egg's width. According to the lab experiments conducted under four temperature regime, the lapsed time for the hatching was shortened as temperatures increased in the treatments. On the contrary to the hatching time, the average length of newly hatched larvae showed a reverse relation with water temperature. The larvae, considered a final stage of the early life history was about 3.6 mm in total length for water temperature of $18^{\circ}C$, whereas they were between 3.1 mm and 3.2 mm for over $25^{\circ}C$. This indicates that higher water temperature may decrease the growth rate in the early life history. These results may provide valuable information for the population conservation and ecosystem protection under accelerated water pollution and habitat degradations in Korea.

• Journal of Animal Environmental Science
• /
• v.17 no.1
• /
• pp.39-48
• /
• 2011

The present survey was conducted to provide basic information on automatic milking system (AMS) in relation to purchase motive, milk yield and quality, customer satisfaction, difficulties of operation and customer suggestions, etc. Purchase motives of AMS were insufficient labor (44%), planning of dairy experience farm (25%), better performance of high yield cows (19%) and others (6%), respectively. Average cow performance after using AMS was 30.9l/d for milk yield, 3.9% for milk fat, 9,100/ml for bacterial counts. Sixty-eight percentage of respondents were very positive in response to AMS use for their successors but 18% were negative. The AMS operators were owner (44%), successor (44%), wife (6%) and company worker (6%), respectively. The most difficulty (31%) in using AMS was operating the system and complicated program manual. The rate of response to system error and breakdown was 25%. The reasons for culling cow after using AMS were mastitis (28%), reproduction failure (19%), incorrect teat placement (12%), metabolic disease (7%) and others (14%), respectively. Fifty-six percentages of the respondents made AMS maintenance contract and 44% did not. Average annual cost of the maintenance contract was 6,580,000 won. Average score for AMS satisfaction measurement (1 to 5 range) was 3.2 with decrease of labor cost 3.7, company A/S 3.6, increase of milk yield 3.2 and decrease of somatic cell count 2.8, respectively. Suggestions for the higher efficiency in using AMS were selecting cows with correct udder shape and teat placement, proper environment, capital and land, and attitude for continuous observation. Systematic consulting was highly required for AMS companies followed by low cost for AMS setup and systematization of A/S.

• Journal of Animal Environmental Science
• /
• v.15 no.1
• /
• pp.1-8
• /
• 2009

This study was conducted to analyze the effects of sow breeding environment on the reproduction in the first litter in a large-sized hog farm, located in Dangjin-gun, Chungnam from July 1st, 2007 to June 30th, 2008 and provide basic information to improve the sow productivity in a family farming sows. The results obtained were as follows; 1. The gestation periods were proved to be similar without significant differences between indoor and outdoor breeding grounds, The average of farrowing rate was 91.91%, and 92.54% farrowing rate of out-door ground breeding sows was slightly greater than 91.57% of group-housed sows, but there was no significance between two groups. 2. The average of total litter size and the number of born alive per litter were 9.81 and 9.02, respectively. The number of total number was 0.98 and the number of born alive per litter was 1.18 in the outdoor-ground breeding sows, which was significantly greater than group-housed sows(p<0.001). 3. The number(rate) of piglets stillborn was 0.22(2.10%) from the outdoor-ground breeding sows was significantly greater, compared with 0.33(3.53%) from group-housed sows(p<0.01). The number of piglets culled was 0.23(2.27%) and 0.26(2.77%), in the out-door ground breeding sows and in group-housed sows, respectively and it was not significantly similar between two groups. And, the number of mummies was 0.21(2.1%) and 0.28(2.29%), in the out-door ground breeding sows and in group-housed sows, respectively, which showed no significance. 4. The weaning number in the playground breeding sows was 9.48 and it was significantly greater than that in the group-housed sows(p<0.001). The average of weaned age was observed to be 22.91 days. The weaned age in the out-door ground breeding sows was 22.39 days, and it was significantly smaller than that in group-housed sows(p<0.001). The breeding rate for the weaning of pigs was satisfactory as 96.82%, but there was no significant difference between two groups.