• 한국지반공학회논문집
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• 제20권6호
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• pp.137-150
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• 2004

모래의 aging 현상은 점성토에 비하여 무시할 정도로 매우 작아서 최근까지 연구되지 않았다. 그러나 퇴적이나 교란 후 시간경과에 따라 관입저항치의 증가가 관찰되면서 현장시험을 중심으로 모래의 aging 효과에 대하여 활발한 조사가 이루어졌고, 최근에는 현장시험뿐만 아니라 실내시험에서도 여러 연구자들에 의해 모래의 aging 효과가 규명 되어지고 있다. 본 연구에서는 모래의 비배수 정적전단거동에 대한 aging 효과를 살펴보기 위해 낙동강 모래를 이용하여 상대밀도 $(D_r)$, 압밀응력비$(K_c)$ 그리고 압밀시간을 달리하여 비배수 정적삼축압축시험을 실시하였다. 그 결과 응력-변형률의 탄성구간내 탄성계수가 압밀시간 경과에 따라 증가하는 것으로 나타났으며, 또한 상전이점 강도$(S_{PT})$와 한계응력비점 강도$(S_{CSR})$도 압밀시간 경과에 따라 증가하였다. 그러나 간극수압비$(u/{p_c}')$는 압밀시간에 비례하게 감소하는 등 모래의 정적전단에서 나타나는 aging 효과를 관찰할 수 있었다.

• Geomechanics and Engineering
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• 제36권1호
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• pp.51-69
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• 2024

Currently, composite lining mountain tunnels in China are generally classified based on the [BQ] method for the surrounding rock grade. Increasingly, tunnel field construction is replicated indoors for scale down model tests. However, the development of analogous materials for model tests of composite lining tunnels with different surrounding rock grades is still unclear. In this study, typical Class III and V surrounding rock analogous materials and corresponding composite lining support materials were developed. The whole processes of excavation-support dynamics of the mountain tunnels were simulated. Data on the variation of deformations, contact pressures and strains on the surrounding rock were obtained. Finally, a comparative analysis between model tests and numerical simulations was performed to verify the rationality of analogous material development. The following useful conclusions were obtained by analyzing the data from the tests. The main analogous materials of Class III surrounding rock are barite powder, high-strength gypsum and quartz sand with fly ash, quartz sand, anhydrous ethanol and rosin for Class V surrounding rock. Analogous materials for rockbolts, steel arches are replaced by aluminum bar and iron bar respectively with both shotcrete and secondary lining corresponding to gypsum and water. In addition, load release rate of Class V surrounding rock should be less than Class III surrounding rock. The fenestration level had large influence on the load sharing ratio of the secondary lining, with a difference of more than 30%, while the influence of the support time was smaller. The Sharing ratios of secondary lining in Class III surrounding rock do not exceed 12%, while those of Class V surrounding rock exceed 40%. The overall difference between the results of model tests and numerical simulations is small, which verifies the feasibility of similar material development in this study.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1769-1773
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• 1996

The remaining life of generator stator winding has been the controversial issue amomg many experts in this area. The report from Japan claims that they can predict the remaining life of generator winding, while the North American has the negative opinion about it. This study aimed at verifying the validity of both Japanese criteria and North American argument on evaluation of generator winding insulation. Non destructive and destructive tests were performed on two hydro-generators. The test results showed that the trend analysis of stator winding insulation was the better option.

• 한국환경보건학회지
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• 제45권3호
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• pp.285-294
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• 2019

Objectives: For suitable risk management of the domestic aquatic environment, it is necessary to conduct toxicity tests using species native to Korea. In the present study, we performed toxicity ring tests using endemic freshwater arthropoda Neocaridina denticulata and evaluated its validity and reproducibility as an international standard test species. Methods: To evaluate the sensitivity levels of N. denticulata to hazardous chemicals, toxicity values for several chemicals were compared with other standard test species. Intra- and inter-laboratory acute toxicity tests were performed both within a single laboratory and among four laboratories respectively using 3,4-Dichloroaniline, which is generally used as a reference test substance in fish toxicity tests. In addition, intra- and inter-laboratory coefficient of variations (CVs) were calculated to evaluate reproducibility based on the estimated toxicity values. Results: The sensitivity of N. denticulata to several chemicals was found to be similar with D. manga, indicating that the species is valid as a test species. The CVs of the intra- and inter-laboratory tests were 22.946% with four qualified runs and 8.828% among the four laboratories, respectively. Conclusions: N. denticulata serves in an important role in the food chain of Korean aquatic ecosystems and also inhabits several other Asian countries. Since the validity and reproducibility of the species were confirmed as a toxicity test species in this study, further efforts are needed to establish N. denticulata as the international standard test species for the appropriate risk assessment of aquatic ecosystems at home and abroad.

• 대한임상검사과학회지
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• 제47권4호
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• pp.168-174
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• 2015

류마티스 관절염은 주로 관절의 활막 세포의 증식, 병리학적 면역 반응과 관절의 진행성 파괴를 특징으로 하는 만성 염증성 질환이다. 이 질환은 중요한 사회적 건강 문제로 대두된다. 이 논문을 통해 분자수준에서 변화와 류마티스 관절염의 진단 또는 질병의 진행에 대한 발병 기전을 새로운 관점에서 발병기전을 제공한다. 또한 조기 진단과 류마티스 관절염의 예후에 도움이 될 것으로 보인다. 새로운 혈청학적 및 면역학적 바이오마커에 초점을 맞추고 있다. 따라서 넓게 질병 진행의 위험 환자를 식별하는 혈청학적, 생체 면역학적 요인 등을 규명하고 적용시키는 것을 도출할 수 있다. 진단 검사 의학을 기반으로 하는 증거는 환자에게 최선의 결과를 제공할 수 있다. 마지막으로. 최근의 연구 데이터는 이 접근을 통해서 치료를 최적화하기 위해 조기 진단 및 치료에 도움이 되는 새로운 접근 방식으로 궁극적인 유용성을 정립하는데 도움이 될 것으로 사료된다.

• 대한임상검사과학회지
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• 제38권1호
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• pp.34-37
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• 2006

Beta-hemolytic streptococci (BHS) are frequently isolated pathogens in clinical microbiology laboratories. Among them, Group C, G and F streptococci infrequently cause respiratory infections, but they often invade other sites. Patients with underlying diseases are prone to be infected by the organisms and some of them can be fatal. Therefore, combination tests of serological and biochemical tests are needed to correct the identification of non-A, B streptococci because to various species belong to this species. The aim of this study was to investigate the isolation rates of strains and distribution of serogroup C, G and F streptococci at Wonju Hospital during the period of 2003-2004. 133 clinical isolates of group C, G and F streptococci were examined. Of them, 13 (9.8%) were group C, 41 (31.8%) were group F, 79 (59.4%) were group G. The prevalent isolation of the strains by serogroup were: group C, Streptococcus constellatus (38.5%); group F, Streptococcus anginosus (56.1%), Streptococcus constellatus (26.9%); group G, Streptococcus anginosus (54.4%), Streptococcus dysgalatiae subsp. equisimilis (26.5%). Overall, the most frequently isolated BHS was Streptococcus anginosus (51.2%).

• 한국동물위생학회지
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• 제35권2호
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• pp.99-104
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• 2012

Otitis externa (OE) is a frequent disease in the ear canals of dogs. To identify the pathogens causing OE in dogs and to determine their antimicrobial resistances, specimens were collected from animal hospitals in Daejeon. The isolates were examined by morphological and biochemical tests, 16S rRNA analysis and antimicrobial susceptibility tests. We analyzed correlation between the isolated pathogens and external factors of dogs such as breed, age, gender, ear mite, hair in ears and experience with antibiotic therapy. Thirty three strains of bacteria were isolated from 26 of the 68 heads of dogs with OE. The most isolated bacteria were Enterococcus faecalis (E. faecalis) followed by Staphylococcus aureus (Sta. aureus), Sta. pseudointermedius, E. faecium, E. avium and Streptococcus canis (Strep. canis) in order of frequency of occurrence. Isolation frequency of Enterococcus spp. and Staphylococcus spp. were 51.5% and 45.5%, respectively. E. faecalis and E. faecium isolates showed VanB phenotype, which is resistant to vancomycin but sensitive to teicoplanin were 58% and 25%, respectively. Nine isolates among total twelve isolates of E. faecalis were isolated from the dogs treated with antibiotics. There was no methicillin-resistant Sta. aureus (MRSA), but were MR-Sta. pseudointermedius (MRSP) (57.1%) and vancomycin-resistant (VR)-Sta. pseudointermedius (14.3%) (VRSP) showing VanB phenotype. However, vanA, vanB and vanC genes were not detected in VR isolates from the dogs. Taken together, VR-Enterococcus spp. (VRE) is one of the major pathogens in domestic animals, as well as community-and hospital-acquired infection.

• 대한임상검사과학회지
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• 제47권4호
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• pp.243-250
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• 2015

10% 질산으로 탈회과정을 거친 골수생검조직에서는 각종 병리검사가 불가능하거나 재현성이 극히 제한적이었다. 각 실험군의 고정액으로는 산을 포함한 고정액과 산 비포함 고정액으로 나누어 사용하고, 탈회액으로는 산성 탈회액과 알카리성 탈회액(EDTA계열)으로 나누어 사용하였으며, 단계별 시간을 각각 다르게 하여 실험하였다. 산이 포함된 고정액 및 탈회액을 사용하였을 경우 모든 병리검사가 불가능할 정도로 검체가 불량하였다. 그러나 EDTA 계열의 탈회액으로 처리한 검체들은 EBV ISH에서는 비특이적 반응이 없어졌으며 FISH, DNA, RNA 검사에서도 병리진단이나 각종 연구에 적합한 수준의 결과를 얻었다. 골수생검조직의 고정방법과 탈회방법을 개선함으로써 ISH, FISH, DNA 검사뿐만 아니라 RNA 연구도 가능하게 하며 각종 검사법의 민감도, 특이도 및 재현성을 확보할 수 있게 되었다. 골수생검조직을 이용한 각종 검사법의 안정화로 환자의 진단, 예후 예측 및 치료 방침결정에 기여 할 수 있을 것으로 생각된다.

• 대한핵의학회지
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• 제1권1호
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• pp.67-78
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• 1967

Over the past 6 years, from May 1960 to June 1966, 1,716 patients with various diseases of thyroid were examined and thyroid function tests with $^{131}I$ were done. Among them, 545 patients with hyperthyroidism were treated with $^{131}I$. A summary of the clinical data of the $^{131}I$-thyroid function tests and the therapeutic results of $^{131}I$ were presented and discussed. 1. The patients examined consisted of; 596 cases(34.7%) with toxic diffuse goiter, 412 cases(24.0%) with non-toxic nodular goiter, 278 cases(16.2%) with euthyroidism, 236 cases(13.8%) with non-toxic diffuse goiter, 89 cases(5.2%) with hypothyroidism, 53 cases(3.1%) with toxic nodular goiter, 32 cases(1.9%) with thyroiditis and 20 cases(1.2%) with dyshormonogenesis. 2. There were 218(12.7%) male patients and 1,498(87.3%) female patients, showing a ratio of 1:6.9. female predominantly. 3. The majority of patients(79.6%) were in the 3rd through 5th decades of their lives showing the peak in the 4th decades(35.9%). 4. The diagnostic values and normal ranges of $^{131}I$ uptake test, 48 hour serum activity, $T_3$ red blood cell uptake and $PB^{131}I$ conversion ratio were discussed. 5. An attention was given to dyshormonogenesis, a qualitative hypothyroidism, due to its characteristic findings of clinical and $^{131}I$ thyroid function tests, and its pathogenesis was briefly reviewed. 6. Among 545 patients with hyperthyroidism treated with $^{131}I$, 68.3% was cured after single. therapeutic dose and another 24.0% was cured after second dose. 7. The complications of $^{131}I$ therapy were discussed in some details and myxedema had developed. in 3.9% of our cases. No thyroid cancer was found after $^{131}I$ therapy.

• 대한임상검사과학회지
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• 제38권1호
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• pp.16-21
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• 2006

Parallel testing means ordering a number of tests at the same time so abnormalities in any of the tests can be found quickly and used in making the diagnosis. This is a good medical strategy to eliminate diseases and it is relatively inexpensive if all the tests are potential sources of information and performed on the same analyzer. In regression, the equation for the straight line is recast as y = bx + a. This change in terminology leads to confusion. Here a is the y-intercept or constant and b is the coefficient or slope of the line. A few more words of caution about regression - as in all of statistics there are certain assumptions: the x value is a true measure, both X and Y distributions are normal, and homoscedasticity, i.e., the variance of y is the same for each value of x. In this study the linearity classification made by different scientists were always in agreement. Typical examples of curves that were considered linear are presented in Fig. 1-5. Because these automated procedures values were usually within five percent of each other the curvature could be easily detected. The plot of the WBC, RBC, hemoglobin, hematocrit and platelet concentrations from approximately 74.4 to $0{\times}10^3/{\mu}L$ and $80.4-0{\times}10^3/{\mu}L$, $5.6-0{\times}10^6/{\mu}L$ and $6.1-0{\times}1106/{\mu}L$, 18.3-0 g/dL and 19.0-0 g/dL, 54.1-0% and 56.8-0% and 642.0 to $0.03{\times}10^3{\mu}L$ and $754.0-0{\times}10^3/{\mu}L$ on the ADVIA 2120 C Versus and A and B typical of an acceptable linear study as shown in Fig. 1-5. The grand mean of R2, intercept and slope is 0.99898, 0.99459 and 1.54626.