• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1079-1085
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• 2003

Modified atmosphere packaging was applied to oyster mushrooms (Pleurotus ostreatus) to study the effect of storage temperatures and packaging materialso. Whole mushrooms (200g) were package with polyethylene film $(PE,\;60{\mu}m\;thickness)$, ethylene vinyl acetate (EVA), or ceramic film (containing 5% zeolite) and stored at 0, 5, 10 and $20^{\circ}C$. Weight loss, color, firmness, gas composition $(O_2,\;CO_2)$ inside the film package and ethanol content in the tissue of MA packaged mushrooms were examined. Mushroom that were packed unwrapped in a conventional hardboard box (2 kg) lost marketability at a very early stage of storage due to weight loss, shrinkage, browning, and spore formation. During storage, film packaging prevented or retarded the deterioration of the mushrooms in the aspects of appearance, texture, and discoloration. Firmness slightly decreased with storage time. Total color difference was much higher in the control than in the film-packaged mushroom and rapidly increased at the early of storage. Correlation analysis showed a high correlation between total color difference and b values. These results were characterized by the reduced respiration rate resulting from elevated carbon dioxide and reduced oxygen levels in the package. At all storage temperatures, ethanol content in the tissue increased slightly at the early part of storage and rose considerably towards the end of the storage period. Ethanol content in the oyster mushrooms was higher in the stipe than in pileus tissues. The shelf life of the oyster mushrooms was about $8{\sim}11$ days at $0^{\circ}C$, about $4{\sim}6$ day at $5^{\circ}C$, about $2{\sim}3$ days at $10^{\circ}C$, and about $1{\sim}2$ days at $20^{\circ}C$.

• Animal Systematics, Evolution and Diversity
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• v.9 no.2
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• pp.151-170
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• 1993

Morphometric, band-pattern and electrophoretic analysis on Cobitis taenia complex were performed to investigate the morphological and genetic differentiation and to clarify their taxonomic status. Intermediate types of band-pattern (C and D type) were more frequently expressed than that of types of C. t. taenia(type A) and C. t. lutheri (type B). Sexual dimorphism of band-pattern was observed not only in C. t. taenia(type A) and C. t. lutheri(type B). Sexual dimorphism of band-pattern was observed not only in C. t. lutheri but also in C. t. taenia and C. t. striata as well. Discriminant function analysis based on 19 morphological characters shows no significant differences among C. taenia complex. The degree of genic variation of C. t. striata was higher ( =1.48, P=31.2%, HD=0.009) than those of C. t. striata was higher( =1.48, P=31.2%, HD=0.082 and HG=0.009) than those of C. t. lutheri ( =1.37, P=2.7%, HD=0.058 and HG=0.065). The average genetic similarities between C. t. lutheri and C. t. taenia-C. t. striata were S=0.62 and S=0.66 respectively and these values indicate that C. t. tanenia has evolved specific level of differentiation. C. t. striata and C. t. lutheri show subspecifc level of close genetic similarity (S=0.82). Based on the divergent time estimate (Nei, 1975) it is assumed that C. t. tanenia was branched off from the other subspecies about two million years before present (MYBP) and C. t. striata and C. t. lutheri were differentiated about 0.6 MYBP. The use of C. sinesis an the scientific name for the Korean C. t. taenia, proposed by Kim and Lee (1988) seems incorrect since they are quite different in the structure of lamina circularis (Vladycov, 1935), the external morphology and distribution (Cheng and Zheng, 1987) and the chromosome number(Yu et al., 1989). Kim and Lee(1988) also argued that C.t. striata and C. t. lutheri should be treated as distinct species but the present study and other reports (Kim and Lee, 1984; Kim and Yang, 1993) do not support it. We conclude that C. t. taenia is a good species and C. t. striata and C. t. lutheri are subspecific status. Their scientific names should be revised in the future.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.1
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• pp.51-62
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• 2020

This study was conducted to develop a method for depth assessment of embedded sources using gamma-spectrum ratio and for the evaluation of field applicability. To this end, Peak to Compton and Peak to valley ratio changes were evaluated according to ¹³⁷Cs, ⁶⁰Co, ¹⁵²Eu point source depth using HPGe detector and MCNP simulation. The effects of measurement distance of PTV and PTC methods were evaluated. Using the results, the source depth assessment equation using the PTC and PTV methods was derived based on the detection distance of 50 cm. In addition, the sensitivity of detection distance changes was assessed when using PTV and PTC methods, and error increased by 3 to 4 cm when detection distance decreased by 20 cm based on 50 cm. However, it was confirmed that if the detection distance was increased to 100 cm, the effects of detection distance were small. And PTV and PTC methods were compared with the two distance measurement method which evaluates the depth of source by the change of net peak counting rate according to the detection distance. As a result of source depth assessment, the PTV and PTC showed a maximum error of 1.87 cm and the two distance measurement method showed maximum error of 2.69 cm. The results of the experiment confirmed that the accuracy of the PTV and PTC methods was higher than two distance measurement. In addition, Sensitivity evaluation by horizontal position error of source has maximum error of less than 25.59 cm for the two distance measurement method. On the other hand, PTV and PTC method showed high accuracy with maximum error of less than 8.04 cm. In addition, the PTC method has lowest standard deviation for the same time measurement, which is expected to enable rapid measurement.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.251-261
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• 2003

To measure the GPS position accuracy and its distribution according to the length of the baseline, 30 minutes to 24 hours observations at the fixed location were conducted with two GPS receivers (Ll, 12 channels) on May 29 to June 2, 2002. The GPS data received at the reference station, the rover station and the ordinary times GPS observation station operated by the National Geography Institute in Korea were processed in kinematic and static post-processing methods with a post -processing software. The results obtained are summarized as follows: 1. The number of the satellite that could be observed continuously more than six hours was 16 and most of these satellites were positioned at east-west direction on May 31, 2002. The number of the satellite observed and the geometric dilution of precision (GDOP) determined by the average of every 10 minute for the day were 8 and 3.89, respectively. 2. Both the average GPS positions before and after post-processing were shifted (standalone: 1.17 m, post -processing: 0.43m) to the south and west. The twice distance root mean square (2drms) measured with standalone was 6.65m. The 2drms could be reduced to 33.8% (standard deviation 0=17.2) and 5.3% (0=2.2) of standalone by the kinematic and the static post-processing methods, respectively. 3. The relationship between the length of the baseline x (km) and the 2drms y (m) obtained by the static post-processing method was y=0.00l6x+0.006 $(R^2=0.87)$. In the case of the positioning with the static post-processing method using the GPS receiver, it was found that a positioning within 20cm 2drms was possible when the length of the baseline was less than 100km and the receiving time of the GPS is more than 30 minutes.

• Korean Journal of Environment and Ecology
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• v.34 no.2
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• pp.170-178
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• 2020

There are few landscape ecological analyses of Khingan fir (Abies nephrolepis) and other habitats of the sub-alpine zone in South Korea. In this study, we tried to quantitatively interpret and assess the habitat characteristics by analyzing 15 landscape indices according to the differences in tree layer coverage, in the Khingan fir habitat growing naturally in the sub-alpine zone of Seoraksan National Park. It was difficult to identify the tendency of landscape ecology to increase and decrease the tree layer coverage in the study site, which was the entire Khingan fir habitat in Seoraksan National Park. However, the Khingan fir habitat was found to be generally low in coverage, and population density as the tree layer coverage of less than 50 percent accounts for 85 percent of the total habitat. Moreover, the Khingan fir habitat in the 10 to 50 percent range was fragmented into a total of 286 patches, making it relatively less connected to the habitat. The total edge length and edge density, which could determine the edge effect of the main part according to the physical form, were the highest in the habitat of 26 to 50 percent coverage, indicating a relatively high impact from outside than habitats of other coverages. The shape with the tree layer coverage of between 10 and 50 percent was more complex even with patches of the same size, and it is believed that these characteristics make it more susceptible to habitat fragmentation and external confounding. We expect that the results of this study can be useful for time series analysis of spatial expansion or reduction of the Khingan fir habitat in Seoraksan National Park and provide the reference data for the morphological change and movement of patches and the connectivity and break-off between forests.

• Korean Journal of Heritage: History & Science
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• v.52 no.4
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• pp.170-183
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• 2019

Fiber scutching refers to the process of extracting fibers from plants by separating or extracting fibers from the raw materials. As the definition of the term implies, the "Fiber Scutching" is performed on plants with advanced bast fiber as the primary material processing technique performed on plant materials. Some of the most popular phosphorus plants are ramie, hemp, flax, and the paper mulberry, which have a long history of cultivation and a wide range of distribution, making them very universal as a material supporting human life and culture. This study was described in Oju-yeonmunjangjeon-sango but was designed to re-examine the method of breaking dried stalks, which is currently unused in Korea, to examine the feasibility and characteristics of the technology. As a result of sampling and experimenting with hemp bast using the method recorded in the literature, hemp fiber was actually produced. The criteria for removing the shell from the hemp stem were the degree of discoloration and drying, and only when the stalk was completely discolored to yellow could segregation of the stalk from the shell be performed. The amount of sunlight and temperature were conditions that accelerated drying. However, if exposed for a long time, it is confirmed that hemp bast will be in a suitable condition to process, regardless of the amount of sunlight and temperature. 'Breaking of dried stalks', which utilizes the physical power of 'threshing with a flail' is considered a core process of the fiber scutching technique in 'Yukjin' in Hamgyeong-do. The bark and the core of the hemp were separated by tapping, the bast was thinly split, and the shell was peeled off, making it suitable for collecting with thread. The method of collecting the fibers by applying physical power causes downing on the fibers, which is to be generally avoided in the manufacture of bast fabric woven hemp or ramie. However, Hamgyeong-do's fiber scutching method seems to have applied this principle to the method of making fragile fabrics by using it in reverse. This method is distinct from the steaming or boiling of the stalks' in Andong, Korea, and it is similar to the Western method of spinning fabrics.

• Journal of dental hygiene science
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• v.4 no.3
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• pp.117-126
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• 2004

For a month of September, 2004, a questionnaire regarding dental hygiene was distributed to 165 workers of Ulsan area. A total of 125 questionnaire were analyzed: 102 collected of the distributed 165 pieces, and 23 questionnaires reported by patients of a dental clinic in Dong-gu, Woolsan. The result is as follows; (1) Labor workers of Ulsan have thought that they are in good dental health, 44.1% of respondents, following by those who they believe they are in moderate health and those who they think are in poor condition. 89.0% of total workers have experienced dental treatment. (2) Regarding the location of dental treatment, 85.0% of respondents have pointed out dental hospitals and clinics, while 3.9% have indicated that they had treatment from unlicensed dentists. Specifically, workers in their 40s over have ever experienced dental treatment by unlicensed dentists. Those who think they are in poor dental condition have tended to have more dental treatment by unlicensed dentists. (3) Regarding the reason that they put off the treatment, 59.1% of respondents have indicated that they have no time to have the treatment, following by economic burden and the lack of confidence in dentists. When they have tooth aches or the gum ache, 60% of respondents have suggested that they endure the ache or take a medicine to alleviate the pain, showing a lower understanding of early dental treatment. (4) Regarding the reason why they are unwilling to go to dentists, respondents have revealed the anxiety against pain, 50.4%, following by the difficulty of scheduling and unsatisfied services. (5) 47.2% of respondents have brushed their teeth 3 times everyday, following by those who have done it 2 times a day and those one a day. Regarding how to brush the teeth, most of respondents have brushed their teeth in the upper, lower, and the both side, 61.4%. The younger respondents and those who think they are in good dental health have tended to brush their teeth up and down. (6) Regarding the cause of the gum disease, 67.7% of respondents have thought that it is caused by poor dental hygiene, following by natural occurrence due to age, hereditary nature, and physical predisposition. (7) 67.7% of respondents have experienced dental scaling, while 32.3% of them have had no experience in it. 53.5% of workers have thought that scaling may not be recommended since they have the teeth scaled periodically once they had dental scaling, a higher rate than 46.5% who think scaling is good for the gum health.

• Korean journal of communication and information
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• v.22
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• pp.131-166
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• 2003

The opening of advertising market and introduction of the free competition doctrine make the competition harsher among advertising agencies. Advertising agencies do their best to execute their ad more efficiently and scientifically. But, it is the reality that broadcasting advertising industry in korea did not construct enough infrastructure to execute the systematic activities compared with that of advanced countries. So, we need to grasp the present conditions and draw a time-table to construct primarily necessary infrastructures. In case of hardware infrastructure in advertising industry, digitalization of broadcasting and convergence of broadcasting with telecommunication make it hurry to construct that. But as the ad agencies was in the situation to compete each other, they have a difficulty to construct common hardware infrastructure enthusiastically. Thus, it is necessary to build hardware infrastructure in advertising industry for policy. And the construction of that should be executed systematically not for the short term effects but for the long term objectives. Also, it is the most important to construct reliable Software infrastructure in advertising industry from all of ad agencies. In these days, ad agencies have a tendency not to believe the important information, like the data of ratings and advertising transaction information, in relation to the advertising activities. And they do not share and communicate about the information of the advertising industry trends, research trends, advertisement related information. So, it is also hurry to build the on-line and off-line database system. Finally, for the development of brainware infrastructure in advertising industry, it is the most necessary to activate the cooperation relation between university and advertising agencies. Universities need to invite experts in the advertising to teach the students practical knowledge and ad agencies to recruit students who want to develop their carrier in the advertising industries. In conclusion, advertising industry in korea to solve these tasks for the development of advertising industry infrastructure in the way of cooperation and harmony of each other rationally and efficiently.

• Restorative Dentistry and Endodontics
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• v.32 no.3
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• pp.180-190
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• 2007

The purpose of this study was to evaluate the abrasion resistance of surface penetrating sealant which was applied on a composite resin restoration and to provide proper time to reapply sealant on composite resin surface. Two hundred rectangular specimens, sized $8\times3\times2mm$, were made of Micronew (Bisco, Inc., Schaumburg, IL, U.S.A) and divided into two groups; F group (n = 10) was finished with coarse and medium grit of Sof-Lex discs and BisCoverwas applied B group (n = 190) after finishing with discs. B group was again subdivided into nineteen subgroups From B-1 group to B-18 group were subjected to toothbrush abrasion test using a distilled water-dentifrice slurry and toothbrush heads B-IM group was not subjected to toothbrush abrasion test. Average surface roughness (Ra) of each group was calculated using a surface roughness tester (Surfcorder MSE-1700: Kosaka Laboratory Ltd., Tokyo, Japan) . A representative specimen of each group was examined by FE-SEM (S-4700: Hitachi High Technologies Co., Tokyo, Japan). The data were analysed using cluster analysis, paired t-test, and repeated measure ANOVA. The results of this study were as follows; 1. Ra off group was $0.898{\pm}0.145{\mu}m$ and B-IM group was $0.289{\pm}0.142{\mu}m$. Ra became higher from B-1 group $(0.299{\pm}0.48{\mu}m$ to B-18 group $(0.642{\pm}0.313{\mu}m$. 2. Final cluster center of Ra was $0.361{\mu}m$ in cluster 1 $(B-IM\simB-7)$, $0.511{\mu}m$ in cluster 2 $(B-8\simB-14)$ and $0.624{\mu}m$ in cluster 3 ($(B-15\simB-18)$. There were significant difference among Ra of three clusters. 3 Ra of B-IM group was decreased 210.72% than Ra of F group. Ra of B-8 group and B-15 group was increased 35.49% and 51.35% respectively than Ra of B-IM group. 4. On FE-SEM, B-IM group showed the smoothest resin surface. B-8 group and B-15 group showed vertically shallow scratches , and wide and irregular vertical scratches on composite resin surface respectively. Within a limitation of this study, finished resin surface will be again smooth and glazy if BisCover would be reapplied within 8 to 14 months after applying to resin surface.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.2
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• pp.1-13
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• 2020

This study closely analyzed poems and paintings related to Beijing-Palgyeong, as well as ancient maps and ancient writings. Through the study, people who read this study can consider, Beijing-Palgyeong's the process of changing times, changing landscape perception, physical and symbolic landscape elements, structural analysis, national management relationships, and finally how it was localized as symbolic place. The view point of the Beijing-Palgyeong is distributed in four places, one outside and one inside the city. Outside of the capital city of Beijing-Palgyeong were concentrated in Seosan(西山) where the resting place of the emperor and the center of the landscape view of Beijing. The view point of Beijing-Palgyeong inside the capital city is located in two places in the royal palace's Imperial Garden and in two villages around the fortress. In other words, Beijing-Palgyeong was selected as a place closely related to the imperial family, emperor, and royal palace from the time of its initial creation. Since then, many scholars, including the emperor, have used it for national management through Won(元), Ming and Qing Dynasty, and it have become more and more characteristic of 'The capital city of eight scenic views'. The two places inside the capital city praised the Gods and Emperors in the same way. Outside the capital city, the two sites depict the comfortable lives of the people who are governed by the emperor and depicting the village landscape around the city. In the end, it can be seen that most of the Beijing-Palgyeong are related to imperial palaces and emperors. If you look at the physical landscape of Beijing-Palgyeong by element, it mainly contains the contents of national management and the emperor's eulogy. Qianlong Emperor established the Beijing-Palgyeong in 1751 through the construction of a monument. A four-character on the front of the monument, and inscribed with a seven-word written by the person on the back. It can be said that Qianlong Emperor's Beijing-Palgyeong were intended to show off the results of Manchurian rule through the material symbol of the monument. Beijing-Palgyeong have been transformed into a landmark, and modern people use it as an indicator of the Beijing-Palgyeong.