• Korean Journal of Heritage: History & Science
• /
• v.52 no.1
• /
• pp.64-81
• /
• 2019

Jeju Island is located at a strategic position, making it an important waypoint on the sea routes of East Asia. As a result, the island suffered many foreign invasions throughout history. Especially, it is widely known that Japanese pirates frequently invaded the island as the island was located on their way as they were sailing to China. Therefore, they built various defensive structures across the island. Fortresses, where a small number of defenders may fend off an enemy, were built in multiple places on the island. This was a strategy for the island to defend itself, as it was almost impossible to get prompt support in an emergency from the mainland due to the long distance. Fortresses, or walled cities, were the center of politics, culture, and economy of many areas. Therefore, they are a valuable resource to study the history and geographical characteristics of a place. For this reason, studies on fortresses started quite early on. However, studies on such relics in Jeju Island began very late. The research on fortresses was launched during the Japanese occupation for most mainland areas. However, studies on the relics on Jeju Island began as late as the 1970s. This was because scholars did not understand the importance of the city walls and fortresses on Jeju Island, and there were no researchers who specialized in city walls or fortresses on the island, as well. As archeological research on Jeju Island began to gain momentum, the studies on city walls and fortresses saw progress; however, these studies are still of an elementary level. In this study, the author summarized the status of studies on the city walls and fortress relics in Jeju Island and their preservation/maintenance status by era. According to the findings of this study, there were two Corean-era city wall/fortress relics and thirteen from the Chosun era., The researcher analyzed and presented the status of studies and the current condition of the relics. The status of attached structures was also documented.Furthermore, a short review of the maintenance work performed so far was provided. Also, the researcher mentioned the problems that accompanied the maintenance process of these relics, along with suggestions for improvement that could be referred to in future restoration/maintenance projects.

• Journal of the Korean Society of Earth Science Education
• /
• v.12 no.1
• /
• pp.82-93
• /
• 2019

The purpose of this study is to analyze the results of satisfaction for learning eco-system on the teacher training program conducted at the IS-Geo (International School for Geoscience Resources) which is KIGAM (Korea Institute of Geoscience and Mineral Resources), and to determine the satisfaction and educational effects of the teacher training programs on elementary and secondary teachers. And then, to suggest improvement points in the future operation of the teacher training program at the IS-Geo. Therefore, we conducted questionnaire of satisfaction for learning eco-system based on the data collected by a survey of 98 elementary and secondary teachers who participated in the teacher training program at the IS-Geo, from July 2017 to August 2018. The research results are as follows. First, the results of satisfaction for learning eco-system showed high values of 4.58 or higher in both the elementary and secondary programs, and the teacher training program conducted by the IS-Geo had a positive effect on the training participants. Second, internal factors indicating learning motivation and learning development were elementary teacher training 4.70 and secondary teacher training 4.64, and it is necessary to develop training contents and programs by classifying them into majors other than the earth science department. Third, intermediate factors indicating contents of education and learning curriculum were 4.67 for an elementary teacher training program and 4.72 for secondary teacher training program. In addition, in order to operate the teacher training program according to the purpose of science and technology culture, it is necessary to develop a teaching-learning model and to improve the quality of teaching. Fourth, external factors indicating learner support and quality of instructors were 4.83 for an elementary teacher training program and 4.72 for a secondary teacher training program. In particular, it is necessary to develop teaching materials that can be used immediately in school classes and can generate interest.

• Korean Journal of Poultry Science
• /
• v.46 no.1
• /
• pp.25-30
• /
• 2019

This study was conducted to investigate basic data of development for appropriate management system in broiler. Data such as ages at marketing, livability, body weight, etc. were collected from a total of 53 broiler farms located in Chungnam, Chungbuk, Jeollanam, Jeollabuk, Gyeongbuk. 1. Average of ages at marketing were 32 days. Those of windowless house and open-type house were 31.96 and 32.03 days, respectively. The significant difference among four seasons was highly found (P<0.001). The longest ages at marketing were 32.86 days in winter. Average of livability was 96.25%. According to type of chick house, those of windowless house and open-type house were 95.93% and 96.59%, respectively. The livability according to season showed significant difference (P<0.05). The highest livability was 97.39% in autumn. However, the lowest livability was 95.36% in summer. 2. Average body weight at marketing was 1.62 kg. The significant difference was found in marketing weight by season (P<0.05). The heaviest body weight was 1.65 kg in winter, but the lowest weight was 1.60 kg in summer. Average of FCR was 1.62. the significant differences according to the season were highly found (P<0.01). Especially, the best FCR was 1.59 in autumn. Average cycles of marketing was 5.70. The significant differences according to farms size were found (P<0.05), cycles of small farms and big farms were 5.8 and 5.3, respectively. The ages at marketing were highly correlated with marketing weight (r=0.684) and feed conversion (r=0.439). The correlation between feed conversion and livability was highly negative (r=-0.614). According to the above result, livability and body weight at marketing were badly detected in summer. In conclusion, broiler farms should be controlled through properly environmental management system for improvement of performances.

• The Korean Journal of Gastroenterology
• /
• v.72 no.6
• /
• pp.286-294
• /
• 2018

Background/Aims: The predictive factors of functional dyspepsia (FD) remain controversial. Therefore, we sought to investigate symptom responses in FD patients after Helicobacter pylori (H. pylori) eradication and used predictive factor analysis to identify significant factors of FD resolution at one-year after commencing eradication therapy. Methods: This prospective, multi-center clinical trial was performed on 65 FD patients that met Rome III criteria and had H. pylori infection. Symptom responses and factors that predicted poor response were determined by analysis one year after commencing H. pylori eradication therapy. Results: A total of 63 patients completed the one-year follow-up. When an eradication success group (n=60) and an eradication failure group (n=3) were compared with respect to FD response rate at one year, results were as follows; complete response 73.3% and 0.0%, satisfactory response 1.7% and 0.0%, partial response 10.0% and 33.3%, and refractory response 15.0% and 66.7%, respectively (p=0.013). Univariate analysis showed persistent H. pylori infection (p=0.021), female gender (p=0.025), and medication for FD during the study period (p=0.013) were associated with poor FD response at one year. However, age, smoking, alcohol consumption, and underlying disease were not found to affect response. Finally, multivariate analysis showed that female gender (OR, 4.70; 95% CI, 1.17-18.88) was the sole independent risk factor of poor FD response at one year after commencing H. pylori eradication therapy. Conclusions: Female gender was found to predict poor response in FD patients despite H. pylori eradication. Furthermore, successful H. pylori eradication appears to be associated with FD improvement, but the number of non-eradicated patients was too small to conclude.

• ANNALS OF ANIMAL RESOURCE SCIENCES
• /
• v.29 no.4
• /
• pp.150-157
• /
• 2018

The Zygote arrest 1 (ZAR1) gene is known to affect early embryonic development in various vertebrates. In this study, we performed the association analysis to check whether there is any significant relationship between semen kinematic characteristics and the ZAR1 gene. To determine semen kinematic characteristics, we measured motility (MOT), straight-line velocity (VSL), curvilinear velocity (VCL), average path velocity (VAP), linearity (LIN), straightness (STR), amplitude of lateral head displacement (ALH), and beat cross frequency (BCF) of spermatozoa in boars. In order to detect single nucleotide polymorphisms (SNPs), we extracted genomic DNA from multiple Duroc boars, and then subsequently used them in sequencing reactions. As a result, three SNPs were detected in the intronic region of ZAR1 gene (g.2435T>C in intron 2, g.2605G>A and g.4633A>C in intron 3 ). SNPs g.2435T>C and g.2605G>A were significantly associated with MOT (p<0.01) and VSL (p<0.05), and g.4633A

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.11
• /
• pp.116-125
• /
• 2018

This study was carried out physicochemical and sensory evaluation to compare the quality characteristics of pork loins from Yorkshire, Duroc, Pietrain, and Duroc ${\times}$ Pietrain (DP). A total of 79 pigs from Yorkshire(22), Duroc(22), Pietrain(17), and DP(18) was used for the experiment. After 24 hours of cooling, pork loins were gathered and vacuum-packed from left carcasses and then the physicochemical traits and sensory evaluation were conducted. The pH of the loins from breed Pietrain was lower than those of the other breeds (p<0.01). While the moisture content of loins was higher in Pietrain than in the other breeds (p<0.01). The fat content of loins was higher in Duroc and DP than in the other breeds and lower in Pietrain than in the other breeds (p<0.01). Pietrain loins had the lowest drip loss (p<0.01) and the highest water holding capacity (p<0.01). There were no significant differences in the cooking loss and shear force of the loins among 4 breeds (p>0.05). There was a significant difference in the CIE color L*, a* and b* values of the loins from 4 breeds (p<0.01). Sensory scores of the loins were ranked lower in Pietrain in overall. The results of this study indicate that meat quality could be altered according to the breeds.

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.4
• /
• pp.985-994
• /
• 2018

Bio-heavy oil for power generation is a product made by mixing animal fat, vegetable oil and fatty acid methyl ester or its residues and is being used as steam heavy fuel(B-C) for power generation in Korea. However, if the fuel supply system of the fuel pump, the flow pump, the injector, etc., which is transferred to the boiler of the generator due to the composition of the raw material of the bio-heavy oi, causes abrasive wear, it can cause serious damage. Therefore, this study evaluates the fuel characteristics and lubricity properties of various raw materials of bio-heavy oil for power generation, and suggests fuel composition of biofuel for power generation to reduce frictional wear of generator. The average value of lubricity (HFRR abrasion) for bio-heavy oil feedstocks for power generation is $137{\mu}m$, and it varies from $60{\mu}m$ to $214{\mu}m$ depending on the raw materials. The order of lubricity is Oleo pitch> BD pitch> CNSL> Animal fat> RBDPO> PAO> Dark oil> Food waste oil. The average lubricity for the five bio-heavy oil samples is $151{\mu}m$ and the distribution is $101{\mu}m$ to $185{\mu}m$. The order of lubricity is Fuel 1> Fuel 3> Fuel 4> Fuel 2> Fuel 5. Bio-heavy oil samples (average $151{\mu}m$) show lower lubricity than heavy oil C ($128{\mu}m$). It is believed that bio-heavy oil for power generation is composed of fatty acid material, which is lower in paraffin and aromatics content than heavy oil(B-C) and has a low viscosity and high acid value, resulting in inhibition of the formation of lubricating film by acidic component. Therefore, in order to reduce friction and abrasion, it is expected to increase the lubrication of fuel when it contains more than 60% Oleo pitch and BD pitch as raw materials of bio-heavy oil for power generation.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.38 no.4
• /
• pp.253-259
• /
• 2018

A new barley (Hordeum vulgare L.) cultivar 'Mihan' having ruminant-palatable semi-smooth awn and good silage quality was developed at National Institute of Crop Science(NICS), RDA in 2016. This cultivar was derived from a cross of the 'SB00T2064' and 'Suwon385' in 2001. And its promising line showed high yielding through the preliminary yield trials(PYT) and advanced yield trials (AYT) in Iksan from 2012 to 2013. It was designated as the 'Iksan487'. 'Iksan487' was conducted to regional yield trials (RYT) in one upland field and five paddy fields around Korea for three years from 2014 to 2016. And it was released as the name of 'Mihan'. It has growth habit of IV, erect plant type, green leaf and semi-smooth awn. Its heading date was April 23 in the paddy field and maturing date was May 24. Plant height of 'Mihan' was 96cm. Mihan's spikes per $m^2$ was 665. It has better winter hardiness and resistance to BaYMV (Barley Yellow Mosaic Virus) than that of barley cultivar 'Youngyang'. The average dry matter of 'Mihan' was about $10.9ton\;ha^{-1}$ in paddy field. And average feed quality of 'Mihan' was 10.3% of crude protein content, 26.1% of ADF (Acid Detergent Fiber), 46.9 % of NDF (Neutral Detergent Fiber) and 68.2% of TDN (Total Digestible Nutrients). 'Mihan' had grade I of silage quality. This cultivar would be suitable for the area above the daily minimum average temperature of $-8^{\circ}C$ in January in Korean peninsula.

• Journal of Environmental Impact Assessment
• /
• v.27 no.6
• /
• pp.658-673
• /
• 2018

Social conflicts with extremely low frequency magnetic field(ELF-MF) exposures are expected to exacerbate due to continued increase in electric power demand and construction of high voltage transmission lines(HVTL). However, in current environmental impact assessment(EIA) act, specific guidelines have not been included concretely about EIA of ELF-MF. Therefore, this study conducted a standardization study on EIA method through case analysis, field measurement, and expert consultation of the EIA for the ELF-MF near HVTL which is the main cause of exposures. The status of the EIA of the ELF-MF and the problem to be improved are derived and the EIA method which can solve it is suggested. The main contents of the study is that the physical characteristics of the ELF-MF affected by distance and powerload should be considered at all stages of EIA(survey of the current situation - Prediction of the impacts - preparation of mitigation plan ? post EIA planning). Based on this study, we also suggested the 'Measurement method for extremely low frequency magnetic field on transmission line' and 'Table for extremely low frequency magnetic field measurement record on transmission line'. The results of this study can be applied to the EIA that minimizes the damage and conflict to the construction of transmission line and derives rational measures at the present time when the human hazard to long term exposure of the ELF-MF is unclear.

• Journal of Environmental Impact Assessment
• /
• v.27 no.6
• /
• pp.695-703
• /
• 2018

This study was conducted to suggest a sustainable farming practice forresource recycling in vegetable gardens of North Korea. In North Korea, farmers are allowed to own private vegetable gardens less than $100m^2$. However, usage of fertilizers in private vegetable gardens is very limited due to economic sanctions by UN security council. If North and South Korea initiated the cooperative action in the near future, agricultural sector would be the highest priority cooperation area. Considering the current North Korean situation in agriculture, we would like to suggest a method for producing organic fertilizer manure. For raw materials for producing manure, we selected corn byproduct, which is the most abundant material, and rabbits' feces, which are easily obtained from individual private farms in North Korea. As we cannot get corn byproducts and rabbits' feces from North Korea, we prepared samples of corn byproducts and rabbits; feces from many places in South Korea. After statistical analysis of variance, there was no significant difference in the T-N contents of corn byproducts from Gyeonggi, Gangwon, Chungnam, Chungbuk, Jeollabuk and Gyeongsangnam-dos, which indicates that the fertilizing quality of corn byproducts does not vary significantly in the spatial scale of South. Korea. In this sense, if we use corn samples from Gyeonggi province, they would not be very different from those of North Korean regions. Physicochemical properties of rabbits' feces were different between those eating feed grains and those eating plants only. Hence, we used rabbits' feces of the rabbits from Yeonchun area, which were fed by plants only. Using three different mixing ratios of corn byproducts and rabbits' feces, composting was conducted for 60 days. The mixing ratio of 1:1 produced the manure with % T-N of 1.98% and OM/N ratio of 31.7 after 30 days of composting, which is comparable to the quality of commercial manure.