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Repeatability and Reproducibility in Effective Porosity Measurements of Rock Samples (암석시험편 유효공극률 측정의 반복성과 재현성)

  • Lee, Tae Jong;Lee, Sang Kyu
    • Geophysics and Geophysical Exploration
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    • v.15 no.4
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    • pp.209-218
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    • 2012
  • Repeatability and reproducibility in solid weight and effective porosity measurements have been discussed using 8 core samples with different diameters, lengths, rock types, and effective porosities. Further, the effect of temperature on the effective porosity measurement has been discussed as well. Effective porosity of each sample has been measured 7 times with vacuum saturation method with vacuum pressure of 1 torr and vacuum time of 80 minutes. Firstly, effective porosity of each sample is measured one by one, so that it can provide a reference value. Then for reproducibility check, effective porosity measurements with vacuum saturation of 2, 4, and 8 samples simultaneously have been performed. And finally, repeated measurements for 3 times for each sample are made for repeatability check. Average deviation from the reference set in solid weight showed 0.00 $g/cm^3$, which means perfect repeatability and reproducibility. For effective porosity, average deviations are less than 0.07% and 0.05% in repeatability and reproducibility test sets, respectively, which are in good agreement too. Most of porosities measured in reproducibility test lies within the deviation range in repeatability test sets. Thus, simultaneous vacuum saturation of several samples has little impact on the effective porosity measurement when high vacuum pressure of 1 torr is used. Air temperature can cause errors on submerged weight read and even effective porosity, because it is closely related to the temperature, density, and buoyancy of water. Consequently, for accurate measurement of effective porosity in a laboratory, efforts for maintaining air or water temperature constant during the experiment, or a temperature correction from other information are needed.

Application of Predictive Microbiology for Microbiological Shelf Life Estimation of Fresh-cut Salad with Short-term Temperature Abuse (PMP 모델을 활용한 시판 Salad의 Short-term Temperature Abuse 시 미생물학적 유통기한 예측에의 적용성 검토)

  • Lim, Jeong-Ho;Park, Kee-Jea;Jeong, Jin-Woong;Kim, Hyun-Soo;Hwang, Tae-Young
    • Food Science and Preservation
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    • v.19 no.5
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    • pp.633-638
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    • 2012
  • The aim of this study was to investigate the growth of aerobic bacteria in fresh-cut salad during short-term temperature abuse ($4{\sim}30^{\circ}C$temperature for 1, 2, and 3 h) for 72 h and to develop predictive models for the growth of total viable cells (TVC) based on Predictive food microbiology (PFM). The tool that was used, Pathogen Modeling program (PMP 7.0), predicts the growth of Aeromonas hydrophila (broth Culture, aerobic) at pH 5.6, NaCl 2.5%, and sodium nitrite 150 ppm for 72 h. Linear models through linear regression analysis; DMFit program were created based on the results obtained at 5, 10, 20, and $30^{\circ}C$ for 72 h ($r^2$ >0.9). Secondary models for the growth rate and lag time, as a function of storage temperature, were developed using the polynomial model. The initial contamination level of fresh-cut salad was 5.6 log CFU/mL of TVC during 72 h storage, and the growth rate of TVC was shown to be 0.020~1.083 CFU/mL/h ($r^2$ >0.9). Also, the growth tendency of TVC was similar to that of PMP (grow rate: 0.017~0.235 CFU/mL/h; $r^2=0.994{\sim}1.000$). The predicted shelf life with PMP was 24.1~626.5 h, and the estimated shelf life of the fresh-cut salads with short-term temperature abuse was 15.6~31.1 h. The predicted shelf life was more than two times the observed one. This result indicates a 'fail safe' model. It can be taken to a ludicrous extreme by adopting a model that always predicts that a pathogenic microorganism will grow even under conditions so strict as to be actually impossible.

The Influence of Auxiliary Goods and Tooth Brushing for the Reduction of Oral Malodor (잇솔질과 구취감소보조용품제가 구취감소효과에 미치는 영향)

  • Oh, Hye-Seaung
    • Journal of dental hygiene science
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    • v.7 no.3
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    • pp.129-133
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    • 2007
  • This study was carried out to see the effect of dental auxiliary product groups being used in case of not being able to brush teeth. This study was executed for 70 students in the Dept. of Dental Hygiene of S Health College, and it was divided into the group which used brushing teeth, the one which used only dental auxiliary products, the one which did onion juice gargle, etc, and measured the effect on the reduction of oral malodor. The experimental results of the study were as below. 1) After onion juice gargle, in the experimental group A which brushed teeth, it showed lasting decrease of oral malodor until 20min since the experiment, and after 30min, the degree of oral malodor started to increase again. 2) After onion juice gargle, the result of the experimental group B which took only supplementary products such as garglin, chewing gum, intaking green tea with roasted rice & brushing a tongue and so on, was as follows. First, in case of experimental group BG which used garglin, until 30 min has passed since the experiment, it showed the lasting reduction of oral malodor as the same trend with the experimental group BG. Second, in chewing gum (experimental group BC), intaking green tea with roasted rice (experimental group BT), and brushing a tongue (experimental group BO), continuous reduction of oral malodor was shown until 10minutes has passed since the experiment, but, after 20minutes, we could see the degree of oral malodor started to increase again. 3) After onion juice gargle, in the experimental group C which only the degree of oral malodor was measured with the passage of time, neither brushing teeth nor using auxiliary goods, until 30min since the experiment, it showed the similar trend of the reduction of oral malodor with other experimental groups, but, it showed high degree of oral malodor, as compared with other experimental groups A and B.

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A Study of the Department of Dental Hygiene and Dental Laboratory Technology Student's Demand for the Credit Bank System (학점은행제(치위생과, 치기공과)를 이용한 학사학위 취득에 관한 요구도 조사)

  • Yu, Ji-Su
    • Journal of dental hygiene science
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    • v.7 no.3
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    • pp.153-159
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    • 2007
  • To investigate requirements for the process of credit bank system in life-long education institutions attached to colleges, this research was conducted with seniors at the departments of dental hygiene and dental laboratory technology, in the health line of the specific College from March 26 to April 15, 2007, followed by analysis using an SPSS/WIN 12.0 program, obtaining the following results. 1. 89.7% of the respondents had a plan to take a bachelor's degree and 56.1% of whom had such a plan for the purpose of personal development (p<0.05). 2. 73.5% of the respondents preferred the credit bank system in a lifelong education institution attached to a college to take a bachelor's degree. 3. 34.8% presented the greatest advantage of taking a bachelor's degree through the credit bank system that they could take a degree in a short period of time while 33.8% presented the most serious disadvantage that they might low social recognition. 4. As for requirements for the process of operating the credit bank system, 80.3% regarded required subjects for the major as appropriate basic ones. 79.9% regarded it as proper that filling more than 20 credits made it possible to take a degree. 5. As directions for improving the system, it was found that the students was thinking that strict academic record management is needed, and the degrees from the system must be recognized equally to those in regular colleges, social awareness in those degrees should be enhanced, and also credits assigned to cultural subjects should be reduced, and the limitation in the number of credits being able to be obtained in one center should be removed.

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A Habitat Characteristic of Population of Khingan Fir(Abies Nephrolepis) in Seoraksan National Park Using Landscape Indices (경관지수를 활용한 설악산국립공원 아고산대 분비나무개체군의 서식지 특성)

  • Lee, Ho-young;Park, Hong-chul;Lee, Na-yeon;Lee, Ho
    • 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.

Sm-Nd mineral ages of charnockites and ilmenite-bearing anorthositic rocks of Jirisan area and their genetic relationship (지리산 지역 차노카이트와 함티탄철석 회장암질암의 Sm-Nd 광물연대 및 성인적 관계)

  • 박계헌;김동연;송용선
    • The Journal of the Petrological Society of Korea
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    • v.10 no.1
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    • pp.27-35
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    • 2001
  • The charnockite of Jirisan area occurs within the Precambrian high grade metamorphic terrane associated with anorthosite body as many foreign examples. Sm-Nd ages were determined from whole rock-garnet pairs, which turned out $1827\pm$32($2\sigma$) Ma for the massive charnockite and $1820\pm$22(2$\sigma$) Ma for the foliated charnockite with $$\varepsilon$_{Nd}(T)$ of $-5.5\pm$0.2 and $-6.0\pm$0.5 respectively. $^{87}Sr/^{86}Sr$ initial ratios calculated with the these ages are 0.71319 and 0.71532 respectively. The fact that massive and foliated charnockites show identical age, identical Nd isotopic initial ratio, and similar Sr isotopic initial ratios suggest that they were generated at the same time from the same material even through their present textures are different. Initial ratios of Nd and Sr of the charnockites are quite distinct from the mantle values indicating the influence of continental crust. Sm-Nd age determined from the titanium bearing anorthositic rocks intruding the anorthosite body, using mineral separates of garnet, plagioclase, and mafic fraction, is $1792\pm$90(2$\sigma$) Ma with $$\varepsilon$_{Nd}(T)=-3.9$\pm$0.2$. The ^${87}Sr/^{86}Sr$ initial ratios calculated with this age are 0.70616~0.70619. The charnockites and the anorthositic rocks occurring in contact each other also reveal the same age within the error, which suggest a genetic relationship between them. However, chemical compositions of the charnockites and Hadong-Sancheong anorthosites cannot be explained by igneous differentiation. Their differences in Nd and Sr initial isotopic ratios indicate different source materials. Therefore, temporal association between them suggests the possibility of the anorthosite acting as a thermal source for the generation of the charnockite as other studies.

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The Influence of Admixture of Lignosulfonic Acid Type on the Strength of Mortar (Lignosulfonic Acid계(系) 감수제(減水劑)가 모르터의 강도(强度)에 미치는 영향(影響))

  • Kim, Han Young;Kim, Seong Wan
    • Korean Journal of Agricultural Science
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    • v.12 no.1
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    • pp.75-85
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    • 1985
  • This study is intended to find out the influence of Lignosulfonic Acid Type Admixture on compressive, tensile, flexural strength and dispersing action of mortar, and fixation of by-product of pulp industry. 1. The more Pozzolith-84 is added, the larger flow value is. The admixture of lignosulfonic acid type adhere to cement particles and the surface potential of particles is generated. On account of the repulsion among the cement particles, they are dispersed and the mortar get workable, so the production cost of precast product is curtailed and the amount of cement is reduced in a certain workability of mortar. 2. The strength of mortar is greater than plain mortar when P/C added is 0.2 and 0.4%. As time passed the potential energy is reduced and the distance of particles which lignosulfonic acid adhered to get near according as the amount of adhesion is increased. The setting and hardening reaction of morter is occurred in close state, so the strength of mortar is increased a little. The strength of mortar is less than plain mortar when amount P/C added is 0.8%. Pozzolith-84 is mainly composed of lignosulfonic acid and lignin does not influence the hardening of mortar, therefore the remained $SO_3$, $SO_3H$ are the reason of decrease of strength. 3. There is high significance between specific gravity and compressive strength. The larger specific gravity is, the more compressive strength is increased. There is high significance between 7 day's strength and 28 day's strength. The larger compressive strength is, the more tensile and flexural strength are increased. 4. Since Pozzolith-84 is a by-product of pulp industry, by using the Pozzolith-84 admixture the concreate quality is improved. The water pollusion is reduced according to fix by-products in concrete structure.

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A Study on the Improvement of Capital Gains Tax Act through the Analysis of the Precedents of the cases of the lawsuit - Focusing on the transfer of inherited and donated property - (행정소송판례 검토를 통한 양도소득세법 개선방안 - 상속·증여받은 자산의 양도를 중심으로 -)

  • Yu, Soon-Mi;Kim, Hye-Ri
    • Management & Information Systems Review
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    • v.38 no.4
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    • pp.61-78
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    • 2019
  • When calculating gains from transfers of assets inherited or donated, the value recognized at the market price as of the date of inheritance or acquisition is recognized as the actual transaction value at the time of acquisition. However, Precedents for the appeal for review by the NTS, the request for adjudgment by the Tax Tribunal(TT) and the request of examination by the Board of Audit and Inspection of Korea(BAI) and the cases of the lawsuit have not shown a consistent results on how much such a the actual transaction value will be measured. This study investigates the operating state of the current tax appeal system using the statistical data of the TT, NTS, and BAI and cases of the lawsuit from 2008 to 2017, and suggests the Improvement of Capital Gains Tax Act on the transfer of inherited and donated property. As a result, total number of requested cases has diminished because cases of the pre-assessment review and the reconsideration appeal by the NTS have decreased steadily over the past decade, while the cases of the lawsuit and the administrative trials(the request for adjudgment by the TT, the appeal for review by the NTS, and the request of examination by the BAI) have been steadily increasing. Also This study found that more than 40% of the complainants proceeded with the cases of the lawsuit proceedings in disagreement with the disposition of tax dissatisfaction under the administrative trials. In addition, Even though the retrospective appraisal price is not recognized as the market price due to the strict interpretation of the tax regulations, it can be seen that it is interpreted as a more expanded concept in the application of the market price than the government office or the tax judge. Therefore, according to the precedents of the cases lawsuit, it is necessary to establish a regulation on the recognition of retroactive appraisal value.

A Study on the Copy of Tripitaka Koreana at Otani University in Kyoto, Japan (일본 오타니대학(大谷大學) 소장 고려대장경 인경본 연구)

  • Jeong, Eunwoo;Shin, Eunjae
    • Korean Journal of Heritage: History & Science
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    • v.52 no.4
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    • pp.38-55
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    • 2019
  • At Otani University in Kyoto, Japan, there is a rubbed copy of Tripitaka Koreana, presumably printed in 1381. According to the postscript of the copy, written by Saek Lee himself, the rubbed copy was made at Haeinsa temple in 1381 and was kept at Sinluksa temple in Yeuju. The copy was delivered as a gift to Japan in 1414 and now is kept at the Library of Otani University. Although an approximate summary of the content of the copy was reported in the early 2000s after a basic survey, details of the copy, including the concrete format and packaging paper, are not known yet. In this paper a detailed survey of the copy is conducted on the 109 pages. The copy is divided into two parts: the wrapping and the inner pages. The wrapping paper is divided into yellow and brown colors depending on the material of the paper. The yellow colorwrapping paper was possibly made in 1381 at the time of the rubbed printing, and the brown wrapping paper was repaired after being moved to Japan. Using funds collected in February 1380, the copy of Gyeong(經), Yul(律), and Ron(論) chapters was printed in April 1381. Binding of the copy was completed in September, and the wrapping paper with the title in gold was made in October 1380. The box for keeping Buddhist scriptures was manufactured in November 1380. The copy was moved to Sinluksa temple in April 1382 and delivered to Japan in 1414. At Otani University, the copy is stored in separate rectangular boxes 32.1×25.3cm in size with a height of 23.6cm. The rectangular plate on the four sides is red in external color but black colorinside. The box for keeping Buddhist scriptures was probably made in 1381, but a partial repair was made later. Because of the difficulty of executing a detailed survey of the box for Buddhist scriptures, it is hard to find out its nation and period of production. We look forward to studying the copy as well as the box for Buddhist scriptures in future.

A Study on the Change of Materials and Fabrication Techniques of Stone Figures in Royal Tombs of the Joseon Period - Focusing on Shindobi, Pyo-Seok, and Sang-Seok - (조선시대 왕릉 석물의 재료와 제작 방법 변화에 관한 연구 - 신도비와 표석, 상석을 중심으로 -)

  • Cha, Moonsung
    • Korean Journal of Heritage: History & Science
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    • v.52 no.4
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    • pp.56-77
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    • 2019
  • Bi-Seok is a treasure trove of funeral rites and an important cultural asset that can shed light on the historical and social history of calligraphy, but research of the topic is still insignificant. In particular, research on the production method of Bi-Seok remains an unproven field. The production of Bi-Seok can be roughly divided into ma-jeong (refining stone), sculpture, and the Buk-chil (process of engraving letters) process. This article reveals some facts: First, performing ma-jeong to the Sang-Seok, Honyu-Seok, Bi-seok, which are known to be God's things. This process is needed because of the change in the perception of the Honyu-Seok due to the settlement and propagation of Confucian ceremonial rituals in the times of hardship in 1592 and 1636. As the crafting process of ma-jeong did not remain concrete, it was only possible to examine the manufacturing process of Bi-Seok through its materials and tools. Second, the rapid proliferation of Oh-Seok and Sa-jeo-chwi-yong (purchase of things made by private citizens) in the Yeongjo era has great importance in social and cultural history. When the Gang-Hwa-Seok of the commodity were exhausted, the Oh-Seok that was used by Sadebu (upper civil class) were used in the tomb of Jangneung, which made Oh-Seok popular among people. In particular, the use of Oh-Seok and the Ma-Jeong process could minimize chemical and physical damage. Third, the writing method of the Bi-seok is Buk-chil. After Buk-Chil of Song Si-Yeol was used on King Hyojong's tomb, the Buk-Chil process ( printing the letters on the back of the stone and rubbing them to make letters) became the most popular method in Korea and among other East Asian countries, and the fact that it was institutionalized to this scale was quite impressive. Buk-Chil became more sophisticated by using red ink rather than black ink due to the black color that results from Oh-Seok. Fourth, the writing method changes in the late Joseon Dynasty. Until the time of Yeongjo's regime, when inscribing, the depth of the angle was based on the thickness of the stroke, thus representing the shade. This technique, of course, did not occur at every Pyo-Seok or Shindobi, but was maintained by outstanding artisans belonging to government agencies. Therefore, in order to manufacture Bi-Seok, Suk-seok, YeonJeong, Ma-jeong, Jeong-Gan, ChodoSeoIp, Jung-Cho, Ip-gak, Gyo-Jeong, and Jang-Hwang, a process was needed to make one final product. Although all of these methods serve the same purpose of paying respects and propagandizing the great work of deceased persons, through this analysis, it was possible to see the whole process of Pyo-Seok based upon the division of techniques and the collaboration of the craftsmen.