• Korean Journal of Poultry Science
• /
• v.48 no.4
• /
• pp.193-206
• /
• 2021

This study aimed to identify the growth performance of Korean indigenous chicken pure-line by sex and twelve strains conserved in Poultry Research Institute, National Institute of Animal Science, Rural Development Administration. The effect of sex and strain on body weight was significantly different in every period, with males being heavier in all periods than females. In the case of biweekly weight gain, the tendency to increase rapidly from birth to six weeks old, and to decrease in the period from twelve to fourteen weeks old was common across all sex and strains. Depending on sex and strain, there were significant differences in age and the number of peaks. Regardless of sex and strain, the determination coefficient and adjusted determination coefficient showed high goodness of fit (99.1~99.9%) to growth functions. However, for each model, the goodness-of-fit had variations by sex and strains. von Betalanffy function had the best fit to growth curves in all the female strains except strain D. On the other hand, Gompertz function had the best fit for all the male strains except strain C. Logistic function showed the lowest goodness-of-fit in all sex and strains. Mature weights were in the order of von bertalanffy, Gompertz, and Logistic models, while growth ratio and maturing rate followed the order of logistic, gompertz, and von bertalanffy functions. This information could be useful for Korean indigenous chicken management and designing crossbreeding tests and breeding programs.

• Journal of Christian Education in Korea
• /
• v.69
• /
• pp.9-44
• /
• 2022

The purpose of this study is to restore religious education at home. Currently, Korean church education is facing a crisis. First, there is a decrease in the number of children in the church due to the problem of the low fertility rate. Second, the number of young people leaving the church is increasing. As a result, Maneun Church and church schools are being reduced or closed. In order to solve this problem, it is necessary to change from church school-centered education to family-centered faith education. This is because the restoration of faith education is also connected with the restoration of the Korean church in crisis. As an alternative to overcome the current crisis of church education, it is necessary to return to the original form of religious education. In other words, we must return to the way God commanded religious education through parents at home. The most important thing is to overcome and recover from the absence of religious education at home. A Christian home becomes a place of education that fulfills the primary responsibility of religious education for children. God has given his parents the primary authority and responsibility for the religious education of their children. However, amid changes in society and home, the educational function of the home was entrusted to other educational institutions or specialized teachers. Parents of Christian families tend to delegate their children's religious education to church schools by neglecting their educational authority and responsibility. Therefore, the purpose of this study is to reinforce that parents should have a Christian view of faith education and become the main agents of their children's faith education. Parents have the authority, responsibility, and duty as teachers for religious education given by God. The educational authority and responsibility of parents originate from God. God has commanded his parents to bring up their children in faith. Therefore, for parents to become the main agents of their children's religious education, restoration is needed in Christian home education. Therefore, the task of restoring the Christian family as a place of effective Christian education and fulfilling the educational mission of faith that God has given to parents is, first, that parents and the church must recognize the importance of Christian home education anew. Second, parents must have the correct awareness and mission in the Christian view of children. The mission of parents in a Christian home is to teach, train, and admonish their children in the Lord so that they can live with Christian values. Third, the church should actively support home education and form a deep bond between church education and home education.

• Korean Journal of Poultry Science
• /
• v.49 no.4
• /
• pp.199-210
• /
• 2022

This study was conducted to investigate the effects of the type and number of enrichments on growth performance, blood characteristics, footpad dermatitis (FPD) incidence, and litter moisture in broilers. A total of 1,140 1-day-old male Ross 308 broilers were assigned to a 3 × 2 factorial arrangement based on the type of enrichment (cabbage, alfalfa block, and angle sawdust) and the number of enrichments (one or two per 38 broilers). The growth performance, blood characteristics, FPD incidence, and litter moisture of the broilers were evaluated. Body weight and feed conversion rate were significantly improved (P<0.05) in the alfalfa block and sawdust group compared to the cabbage group, but there was no interaction effect between the type and number of enrichments. The heterophil/lymphocyte ratio, a stress index, was significantly decreased (P<0.05) in the alfalfa block and sawdust groups compared with the cabbage group. The incidence of FPD was significantly decreased in the order of cabbage (3.78), alfalfa block (3.06), and sawdust (1.43) groups at 5 weeks of age. Moreover, there was a significant decrease in the incidence of FPD (P<0.05) in the one-enrichment group compared with the two-enrichment group. Litter moisture at 5 weeks of age was significantly reduced in the sawdust group compared to the cabbage and alfalfa groups, but there was no significant difference in the interaction between the type and number of enrichments. It was concluded that sawdust enrichment positively influenced both growth performance and the animal welfare of broilers. In addition, it is expected that sawdust can be used to regulate litter moisture.

• Journal of Korea Water Resources Association
• /
• v.55 no.11
• /
• pp.923-929
• /
• 2022

The Chuncheon Mullori area is an underprivileged area of water welfare where local water supply is not supplied, and it is supplying water to the villages with small water supply facilities using lateral flow and groundwater as water sources. This is an area with poor water supply conditions, such as relying on water trucks due to water shortages during the recent severe drought. Therefore, in order to solve the problem of water shortage during drought and to prepare for the increasing water demand, a sand dam was installed along the valley, and this facility has been operating since May 2022. In this study, repeated simulations were performed according to the hydraulic conductivity of the filler material and the storage coefficient value for the inflow condition for about two years from mid-March 2020 to mid-March 2022. For each case, the amount of discharge through the perforated drain pipe was calculated. Overall, as the hydraulic conductivity increased, the amount of discharge and its ratio increased. However, when the hydraulic conductivity of the second floor was relatively low, the amount of discharge increased and then decreased as the hydraulic conductivity of the third floor increased. This is considered to be due to the fact that the water level was kept low due to the rapid drainage compared to the net inflow into the third floor because the water permeability of the third floor and the drainage coefficient of the drain pipe were large. As a result of simulating the flow of the open channel in the upper part of the sand dam as a hypothetical groundwater layer with very high hydraulic conductivity, the decrease in discharge rate was slower than the increase in the hydraulic conductivity of the hypothetical layer, but it was clearly shown that the discharge volume decreased relatively as the hydraulic conductivity of the virtual layer increased.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.25 no.1
• /
• pp.120-132
• /
• 2022

Recently, the rapid increase in vacant houses in urban areas has caused various problems such as worsening urban landscape, causing safety accidents, crime accidents, and hygiene problems. According to the Statistics Korea Future Population Estimation results, the growth rate of Korean population and households is expected to continue to decrease, which is likely to lead to an increase in the occurrence of vacant houses. If the problem caused by the occurrence of vacant houses is neglected, it causes not only a physical decline such as a deterioration of the residential environment but also a social and economic decline. In order to solve this problem, it is necessary to grasp the spatial distribution characteristics of vacant houses at the local level considering the existence of regional characteristics and spatial influence. Therefore, in this study, in order to measure global spatial autocorrelation, the analysis was conducted centering on the old downtown area of Busan, where there are many vacant houses through Moran's I and Geographically Weighted Regression(GWR). In addition, the distribution of vacant houses in different spatial units in Eup_Myeon_Dong and Census was analyzed to evaluate the possibility of Modifiable Areal Unit Problem(MAUP), which differ in the results of spatial analysis as the spatial analysis units change. As a result of the analysis, the occurrence of vacant houses by Eup_Myeon_Dong in the old downtown area of Busan had spatial heterogeneity, and the spatial analysis results of vacant houses were different as the spatial analysis units were different. Accordingly, in order to understand the exact distribution characteristics of vacant house occurrence, spatial dimensions using the GWR model should be considered, and it is suggested that consideration of the MAUP is necessary.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.29 no.4
• /
• pp.366-375
• /
• 1984

In order to confirm the effect of climatic consumption index (C C I) on the number of spikelets and yield of rice, 3 levels of shading rates such as 0, 25, 50% of full light were treated during the tillering stage, reproductive growth stage and ripening period, respectively, in a phytotron controlled with day/ night temperature of 20/10$^{\circ}C$ and 30/20$^{\circ}C$, and field at Crop Experiment Station, Suwon, Korea. The results are as follows: 1. As solar radiation decreased during the reproductive growth stage in 30/20$^{\circ}C$ or field condition, the number of spikelets per panicle was decreased due to the decrease of the number of differentiated secondary rachis branches and spikelets as well as the increase of the number of degenerated secondary rachis branches and spikelets. 2. Our results showed slight negative correlation between C C I of the reproductive growth stage and number of panicles per square meter and number of differentiated secondary rachis branches. On the other hand, there was highly significant positive correlation between C C I of the reproductive growth stage and the number of degenerated secondary rachis branches and spikelets, and negative correlation in number of differentiated spikelets. 3. The shading during the reproductive growth stage did not affect on the percentage of ripened grains and 1000 grains weight of hulled rice, whereas those were decreased with shading during the ripened period. 4. Influence of shading in each growing stage on the yield was severe in the order of ripened period, reproductive growth stage, tillering stage. 5. Respiration rate in Jinheung was higher than that of Tongil at low temperature, but reversed above 30$^{\circ}C$. Respiratory coefficients (Q$\sub$10/) of Tongil and Jinheung were 2.74 and 1.96, respectively. Respiration/ photosynthesis ratio in Jinheung was higher than that of Tongil at low temperature, while higher in Tongil above 32$^{\circ}C$. 6. Transportation of $\^$14/C was restricted at 20/10$^{\circ}C$ in Tongil, however, there was no differences at 30/20$^{\circ}C$ in both Tongil and Jinheung. The influence of shading on the transportation of $\^$14/C did not affect at 20/10$^{\circ}C$, but it was hampered with shading at 30/20$^{\circ}C$ in both varieties.

• The Journal of Engineering Geology
• /
• v.33 no.1
• /
• pp.85-103
• /
• 2023

The in-situ remediation of a solidified stratum containing a large amount of fine-texture material like clay or organic matter in contaminated soil faces limitations such as increased remediation cost resulting from decreased purification efficiency. Even if the soil conditions are good, remediation generally requires a long time to complete because of non-uniform soil properties and low permeability. This study assessed the remediation effect and evaluated the field applicability of a methodology that combines pneumatic fracturing, vacuum extraction, and plasma blasting (the PPV method) to improve the limitations facing existing underground remediation methods. For comparison, underground remediation was performed over 80 days using the experimental PPV method and chemical oxidation (the control method). The control group showed no decrease in the degree of contamination due to the poor delivery of the soil remediation agent, whereas the PPV method clearly reduced the degree of contamination during the remediation period. Remediation effect, as assessed by the reduction of the highest TPH (Total Petroleum Hydrocarbons) concentration by distance from the injection well, was uncleared in the control group, whereas the PPV method showed a remediation effect of 62.6% within a 1 m radius of the injection well radius, 90.1% within 1.1~2.0 m, and 92.1% within 2.1~3.0 m. When evaluating the remediation efficiency by considering the average rate of TPH concentration reduction by distance from the injection well, the control group was not clear; in contrast, the PPV method showed 53.6% remediation effect within 1 m of the injection well, 82.4% within 1.1~2.0 m, and 68.7% within 2.1~3.0 m. Both ways of considering purification efficiency (based on changes in TPH maximum and average contamination concentration) found the PPV method to increase the remediation effect by 149.0~184.8% compared with the control group; its average increase in remediation effect was ~167%. The time taken to reduce contamination by 80% of the initial concentration was evaluated by deriving a correlation equation through analysis of the TPH concentration: the PPV method could reduce the purification time by 184.4% compared with chemical oxidation. However, the present evaluation of a single site cannot be equally applied to all strata, so additional research is necessary to explore more clearly the proposed method's effect.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.67 no.4
• /
• pp.234-241
• /
• 2022

Wheat (Triticum aestivum L.) is a major staple foods and is in increasing demand in the world. The elevated temperature caused by changes in climate and environmental conditions is a major factor affecting wheat development and grain quality. The optimal temperature range for winter wheat is between 15 and 25℃, and it is necessary to study the physiological characteristic of wheat according to elevated temperatures. This study presents the effect of elevated temperature on the yield and quality of two Korean bread wheat (Baekkang and Jokyoung) in temperature gradient tunnels (TGT). Two bread wheat cultivars were grown in TGT at four different temperature conditions: T0 (control, near ambient temperature), T1 (T0+1℃), T2 (T0+2℃), (T0+2℃), T3 (T0+3℃). The period from sowing to heading stage accelerated and the number of grains per spike and grain yield reduced under T3 condition compared with those under T0 condition. Grain filling rate and grain maturity also accelerated with elevated temperature (T3). The increase in temperature led to the increase in protein contents, whereas decreased the total starch contents. These results are consistent with the decreased expression of starch synthesis genes and increased gliadin synthesis or gluten metabolism genes during the late grain filling stage. Taken together, our results suggest that the increase in temperature (T3) led to the decrease in grain yield by regulating the number of grains/spike, whereas increased the protein content by regulating the expression of starch and gliadin-related genes or gluten metabolism process genes expression. In addition, our results provide a useful physiological information on the response of wheat to heat stress.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.50 no.3
• /
• pp.360-372
• /
• 2023

The aim of this study was to identify the current state of pediatric dentists, evaluate the adequacy of pediatric dentist supply and demand, and find out the perception of all pediatric dentists on the current state of pediatric dentists and policy establishment. An Online survey was conducted among pediatric dentists. The questionnaire was subdivided into 'general characteristics', 'number of dental treatments and working days per year', 'proportion of covered services', 'perceptions of supply and demand of pediatric dentists'. Through the Korean Academy of Pediatric Dentistry, the Health Insurance Review and Assessment Services, the National Health Insurance Service (NHIS), and the Korean Statistical Information Service, the current state of pediatric dentists, the number of claims for covered services, and the decrease in births per year were investigated. Dental clinics claiming to be pediatric dentistry reached half of all medical institutions, but only 3.78% of pediatric dentists actually worked. 61.36% of all pediatric dentists were concentrated in the metropolitan area, showing a national imbalance. Although the population of children and adolescents have continuously decreased over the past 20 years, the number of NHIS-covered services has shown a continuous increase. Over the past 10 years, the optimal supply of pediatric dentists has been maintained at around 4,000. According to the analysis, 92.15% of pediatric dentists thought that it was necessary to prepare policies and support measures at the government level. This study is expected to be used as basic data for establishing a demand estimation method for pediatric dentistry specialists in the future.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.4 no.1
• /
• pp.110-118
• /
• 2002

This study was conducted to investigate the physiology of optimal reproductive age in Hanwoo for protection to decrease of reproductivity and improvement of production of offspring. Thirty two cows were devided into 4 groups of treatments : T1(12 months of age and 0.5kg daily gain), T2(12 months of age and 0.8kg daily gain), T3(15 months of age and 0.5kg daily gain) and T4(18 months of age and 0.5kg daily gain). The days of the first heat of treated cows were 263.3±6.4 days and average weight was 181.1±11.3kg. The conception rates of first insemination were 25%(T1) and 75%(T4), and the number of insemination of T3 and T4(both 1.5) was lower than those of T1 and T2(2.3 and 2.4), respectively. With regard to estrus return after the first parturition, T1, T2, T3 and T4 showed 66.2,76.7, 62.4 and 68.5 days, respectively, indicating the average days of estrus return was 65.7. Plasma progesterone(P4) concentration was nearly the same during the observation periods of treated cows and P4 began to be detected after 12months. Only 5(15.6%) out of 32cows showed normal estrus cycle and ovulation before 12 months. During the peri-parturition period, P4 concentration was rapidly decreased and there was no detection of P4 from parturition to 40 days after milking. P4 would be released again on 45 day after parturition. The results imply that the optimal reproductive age of Hanwoo heifers would be around at the 14 months of age, 110cm height and 265kg weight.