• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.265-278
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• 1986

This study was attempted to improve the thermal efficiency of 6 kW water-cooled diesel engine on power tiller. The engine performance tests were conducted to find out the effect of cooling water capacity of 2700cc, 2800cc, 2900cc, 3000cc, 3100cc on power, brake specific fuel consumption (BSFC), torque, temperature of cooling water and lubricating oil and friction losses of the engine with D. C. dynamometer. The results obtained in the study are summarized as follows: 1. The performance of the engine tested was adequated to Korea Industrial Standard but actual economy power was 10% higher than the labeled rated power of the engine. The BSFC of the engine tested 297.8g/kW-h which is belong a little higher level than hreign products. The temperature of cooling water was $101^{\circ}C$ which is higher than SAE standard ($88^{\circ}C$) 2. The friction losses of engine tested was 3.656 kW at 2200 rpm of rated rpm (piston speed 6.97m/sec) and is higher than those of foreign products. 3. When the cooling water capacity was increased from 2700cc to 3100cc the power output of the engine was increased from 6.7 kW to 7.13 kW at the rate of 6.4% and also the torque of the engine was increased from 28.85 N.m to 30.76 N.m at the rate of 6.39%. 4. When the cooling water capacity was increased from 2700cc to 3100cc, the BSFC was decreased 6.9g/kW-h from 310.9g/kW-h to 304.1g/kW-h, and after one half hour operation with full load, the temperature of cooling water was decreased $13^{\circ}C$ from $101^{\circ}C$ to $88^{\circ}C$ and also the temperature of lubricant oil was decreased $6.4^{\circ}C$ from $76.7^{\circ}C$ to $70.4^{\circ}C$. 5. The mechanical efficiency was increased from 70.08% to 71.08% when the cooling water capacity was increased from 2700cc to 3100cc.

• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.198-209
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• 1986

This study was conducted to find optimum heating temperature and time as milk was heated over a wide range of temperature and time combinations at $70{\sim}100^{\circ}C$ into $5^{\circ}C$ interval for 10, 15 and 20 second. The results obtained were summarized follows: 1. The effects of heat treatment on the bacteria by $75^{\circ}C/20s$, $80^{\circ}C/10s$ and $100^{\circ}C/20s$ were 99.56%, 99.52% and 99.92% respectively. 2. Sterilized rate of milk which was added Bacillus subtilis by $75^{\circ}C/20s$, $80^{\circ}C/10s$ and $100^{\circ}C/20s$ were 99.23%, 99.25% and 99.85% respectively. 3. The pH value fell in accordance with the increasing of heating temperature. 4. Content of protein, fat and lactose was not changed by heat treatment. 5. The content of total nitrogen was not changed. The content of casein nitrogen and non - protein nitrogen increased, but non - casein nitrogen reduced, according to heat trea ted of milk. 6. According to the increasing of heating and time, filter - passing nitrogen reduced. 7. The artificial digestibility was increased when milk was heated from $70^{\circ}C$ to $100^{\circ}C$ into $5^{\circ}C$ interval at 10, 15 and 20 second.

• Korean Journal of Agricultural Science
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• v.1 no.1
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• pp.59-66
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• 1974

This paper describes how location influences on the development of dairy farming. It compares Chuncheon, which in the mountains, Daejeon, which is a transportation center and on flat ground, and Incheon, which is the gate to Seoul and an industrial city. The results analyzed are summarized as follows : 1. Incheon, due to her vast market, influenced strongly on the development of management. But shortage of roughage for feeds is the critical problem there. 2. Owing to the side job of raising chicks, which involves 92% of dairy farmers there, Chuncheon does not make smooth utilization of vast grass pasture. 3. In Daejeon's case, running orchards concurrently is the problem. 4. There exists no gap in wages between the region. The labor supply is most affluent in Incheon and there is competition with other forms of agriculture in the mountainous area. 5. The full-time employee tends to be skillful in accordance with his career. Family labor has been skillful, but the full-time employee is very fluid and shows varieties of skill. 6. Because of the obscurity of the distribution of labor with other jobs in Chuncheon and Daejeon, many unspecialized men serve. 7. The prices of milk are different in each region. The income of dairy farmers is strongly influenced by the low purchasing price of milk plants, and this is one of the important factors hindering the development of dairy farm ing in Chuncheon.

• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.121-134
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• 1976

There are many evidences that vaiious plant pathogenes were introduced with imported plants and agricultural productsrfrom foreign countries and caused heavy losses of domestic economic plants, ever since the early twentieth century when our country began to trade plants and agricultural products with foreign countries. There are many ways that foreign plant pathogenes have been introduced into our country, but the main route is considered to be imported plants and agricultural products contaminated with plant pathogenes. Plant quarantine which prevent effectively introduction of plant pathogenes from abroad was practiced for the first time in our country in 1912, and that is relatively earlier activity in the history of plant quarantine of the world. Several plant pathogenes have been introduced into our country even after plant quarantine had been practiced. Particularly for about 15 years, from the 2nd World War to 1961 when the law of Plant Protection was enacted and practical works of plant quarantine was reoperated, Korean agriculture was opened to various foreign plant pathogenes as a lapse period of plant quarantine in our country. Introduced plant pathogenes are, for the most part, from Japan because of depending upon Japan in the foreign trade of plants and agricultural products of our country. As present plant quarantine is required more exactness and rapidness, reasonable organization of quarantine system including more trained quarantine specialists, modernized facilities and introduction of improved quarantine techniques are necessary. Reasonable organization and improvement of plant quarantine system are important not only for protection of korean agriculture to plant pathogenes possible to be introduced from foreing countries, but also for increasing and stabilization of export of plants and agricultural product of our country.

• Journal of dental hygiene science
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• v.1 no.1
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• pp.28-38
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• 2001

The aim of this study was to analyze the dental caries of chilren's deciduous teeth in relation to their mothers' socioeconomic factors and their oral health beliefs to increase the effect on children's oral health. One hundred seventy four children and their mothers were selected for the study. The children were 5 and 6 years old in children house in Kun-san, Korea. Research was conducted by oral examination, their mothers' socioeconomic factors and dental health belief model. The finding of analysis can be summaried as follows; In regard to the caries in deciduous teeth status, the five-year-old boy children's dft index was 3.39 and that of the girls of the same age was 2.76. The dft index of the boys of six was 3.86 and that of the girls of the same age was 3.27. The five-year-old boy children had the highest df rate(81.8%), and their dt rate was more than their ft rate. But for the six-year-old girl children, ft rate was higher than dt rate. For the five years old, the boy children's ft rate was significantly higher than that of the girls(p<0.05). Concerning the caries in deciduous teeth states by socioeconomic factors, their oral health status was significantly different according to mother employment and householder age. The df rate of the preschoolers with working mothers(84.7%) was significantly higher than that of those with nonworking mothers(66.7%)(p<0.05). The dft index of the group whose households were over forty was highest with 4.07, followed by the children of the households aged 35 to 39 with 3.83, those of the households aged 25 to 29 with 3.33, and those of the households aged 30 to 34 with 2.15. The difference between the groups was significant(p<0.05). As to the difference of maternal dental health beliefs by maternal socioeconomic factors, households educational background and whether to live with parents or parents-in-law under the same roof made a significant difference to maternal oral health beliefs. The mothers whose households were college graduates or better-educated were stronger in oral health susceptibility and seriousness(p<0.01, p<0.05). The salience was recognized more by those who lived with parents or parents-in-law than by the others who didn't(p<0.05). The dft index of the preschoolers was related to maternal dental health beliefs. That was lower when their mothers perceived dental health benefit better.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.106-112
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• 2015

This study was conducted to provide with baseline data with the purpose of increasing the values of medical services. Self-administered questionnaire survey was conducted on 236 patients at a dental clinic follow-up visit in dentist clinic Gyeongnam area from June 2013 to August 2013. All statistical analyses were performed using SPSS. The motivation visiting the dental clinic is that the first one is introduction from the family and friends, the second is accessibility, the third is conspicuity and the last one is awareness of the dentist. The main variables in the process of treatment are service system, kindness, satisfaction of service, efficient of re-call system. The relief of discomfort at revisit show the highest score in the process of implant treatment and intention of revisit hereafter do in the prostheses process. In the correlation between main variables, service system and relief of discomfort at revisit (r=0.440, p<0.001), kindness and satisfaction of medical service (r=0.675, p<0.001), revisit hereafter and satisfaction of service (r=0.387, p<0.001) and efficiency of re-call system and revisit showed the highest correlation. The influence on satisfaction of dental service show meaningful level in kindness (p<0.001) and efficiency of re-call system (p<0.05). The intention of revisit is affected meaningfully by relief of uncomfort (p<0.05), service system (p<0.05), kindness (p<0.01) and efficiency of re-call system (p<0.01). In summary, the personal network of patients is most important variable at intention for revisit of dental clinic. As satisfaction of kindness and efficiency of re-call system is higher, satisfaction of medical service and intention for revisit are shown higher. Therefore further research for improvement of satisfaction for medical service and of intention of revisit at the dental clinic should be carried out.

• Korean Journal of Poultry Science
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• v.39 no.3
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• pp.167-175
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• 2012

This study was undertaken to assess dietary CP and ME concentrations for optimum growth performance and carcass characteristics of Korean Native male ducks. In a $3{\times}3$ factorial arrangement, 1-d-old Korean Native male ducks were completely randomized design to experimental diets with 3,000, 2,900, and 2,800 kcal of ME/kg of diet; each contained 23, 22, and 21% CP, respectively, from 0 to 3 wk of age. From 4 to 8 wk of age, experimental diets had 3,100, 3,000, and 2,900 kcal of ME/kg of diet, and each contained 19, 18, and 17% CP, respectively. Each dietary treatment was replicated 4 times, and feed and water were provided ad libitum. Body weight, feed intake and uniformity were measured at 3 wk and 8 wk, and carcass characteristics were evaluated at 8 wk. As CP increased from 21 to 23 %, the body weight, BW gain and feed conversion ratios (FCR) linearly improved (P<0.01) during 0 to 3 wk of age. From 4 to 8 wk of age, the body weight, feed intake, BW gain, FCR and uniformity were not different (P>0.05). Carcass ratios of birds fed 3,000 kcal of ME/kg diets from 3 to 8 wk of age were quadratically increased significantly (P<0.01). As ME and CP increased, respectively, relative weight of liver weight per 100 g of BW was linearly decreased (P<0.01). Relative weights of left breast, thigh and drumstick weight per 100 of BW were not different (P>0.05). Also, breast meat color, pH, cooking loss and shear force were not different (P>0.05). Thus, diets with 2,800 kcal of ME/kg and 23% CP or with 2,900 kcal of ME/kg and 17% CP at 0 to 3 wk and 4 to 8 wk, respectively, were used more efficiently. However, diets with 3,000 kcal of ME/kg at 4 to 8 wk in carcass rate was quadratically increased.

• Korean Journal of Poultry Science
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• v.34 no.4
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• pp.259-269
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• 2007

This study was compared the effect of shelf-life and DHA accumulation in chicken meat from broilers fed experimental diets for two weeks($21{\sim}35$ days) of growers. Two hundred-ten male Ross broilers, 1 day of age, were randomly allocated to seven treatment groups. Experimental diets were assigned to each of the seven groups: control diet containing tallow, T1 with 1.00% fish oil, T2 with 2.00% fish oil, T3 with 2.00% fish oil, 200 ppm vitamin E and 200 ppm vitamin C, T4 with 2.00% fish oil and 200 ppm vitamin C, T5 with 2.00% fish oil and 200 ppm vitamin E, and T6 with 3.00% fish oil. The levels of DHA in chicken meat was the highest in T6, and T1 in breast muscle and thigh muscle with skin was higher than that of $T2{\sim}T5,\;T2{\sim}T5$ in raw chicken meat and wing with skin was about two-fold higher than that of T1. The contents of DHA in chicken meat according to storage days were significantly reduced to 42.30%, 49.38% and 48.51% in T1, T2 and T6, respectively, and this decrease was higher than that of T3, T4 and T5 (p<0.05). Particularly, the rate of reduction of DHA was the lowest in the T3 and T5, which were the lowest in TBARS(thiobarbituric acid reactive substances). TBARS increased in the order of T6, T2 and T1, but reduced in the order of T3, T5 and T4 according to storage days, and there was a significant difference among the treatment groups (p<0.05).

• Korean Journal of Poultry Science
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• v.34 no.4
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• pp.237-243
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• 2007

The objective of this experiment was to investigate the feeding influence of Prunus memu by-products (PMB) on productivity, blood composition, meat quality and intestinal microflora in semi-broiler chicks. Four hundred one day old chicks(Hanhyup 3) were raised in the floor pen with five treatments(0, 0.5, 1.0 2.0 3.0%) of four replicate for ten weeks. Basal diets contained 3,000, 3,100, 3,100, 3,200 kcal/kg ME and 22, 21, 19, 17% CP, respectively. There were no different performance for the first two weeks, but showed significantly different weight gain, feed intake in PMB 2.0, 3.0% addition treatments compared with control from three to five weeks of age. Weight gain of birds fed 2.0% PMB was significantly higher from nine to 10 weeks of age than control(P<0.05). Total weight gain tended to increase in PMB 1.0, 2.0, 3.0% addition treatments. Feed intake also showed increase in PMB 2.0, 3.0% addition treatments, but there were no different feed conversion. Total protein, albumin, cholesterol, neutral fat, glucose was significantly decreased in PMB 0.5% addition treatments compared with control. There were no different physico-chemical characteristics in breast meat. The number of yeast was significantly improved in PMB 3.0% compared with control(P<0.05), but found no difference in number of E. coli between control and PMB treatments. ND titer of birds fed PMB was not statistically different, but tended to decrease as dietary PMB increased. As the result of this experiment, PMB would be available as a feed additives in semi-broiler chicks.

• Korean Journal of Poultry Science
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• v.34 no.4
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• pp.271-278
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• 2007

The present study was conducted to investigate the effects of dietary supplementation of fermented wild-ginseng culture by-product on egg production, egg quality and blood characteristics in laying hens. A total of 216 ISA Brown laying hens, 55 wk of age, were used in the 6-wk feeding trial. Experimental diets were consisted of basal diet (CON), 2.5% fermented wild-ginseng culture by-product replaced lupin in basal diet (WG1) and 5.0% fermented wild-ginseng culture by-product replaced lupin in basal diet (WG2). Birds were randomly allotted to 18 replicate pens. There were 6 replicates per treatment, and 12 laying hens per replicate. Through the 6-wk feeding trial, egg production was significantly increased in WG1 and WG2 treatments compared to CON (P<0.05). Egg weight was significantly higher in WG2 than CON (P<0.05). WG1 resulted higher yolk color than CON (P<0.05). Albumen height and Haugh unit were significantly improve in WG1 compared to WG2 (P<0.05). Red blood cell was significantly lower in WG2 than CON (P<0.05). LDL-cholesterol was significantly decreased in CON compared to WG2 (P<0.05). In conclusion, fermented wild-ginseng culture by-product could improve egg production and egg weight in laying hens.