• NEWSLETTER 전기공업
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• no.91-28 s.41
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• pp.1-17
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• 1991

• Journal of Astronomy and Space Sciences
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• v.14 no.2
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• pp.355-366
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• 1997

This paper presents a comprehensive analytical approach for determining key maneuver parameters associated with the acquisition and maintenance of the ground track for a low-earth orbit. A livearized model relating changes in the drift rate of the ground track directly to changes in the orbital semi-major axis is also developed. The effect of terrestrial atmospheric drag on the semi-major axis is also explored, being quantified through an analytical expression for the decay rate as a function of density. The non-singular Lagrange planetary equations, further simplified for nearly circular orbits, provide the desired relationships between the corrective in-plane impulsive velocity increments and the corresponding effects on the orbit elements. The resulting solution strategy offers excellent insight into the dynamics affecting the timing, magnitude, and frequency of these maneuvers. Simulations are executed for the ground track acquisition and maintenance maneuver as a pre-flight planning and analysis.

• Imaging Science in Dentistry
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• v.42 no.4
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• pp.237-242
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• 2012

Purpose: The objectives of this study were to survey the radiographic exposure parameters, to measure the patient doses for intraoral dental radiography nationwide, and thus to establish the diagnostic reference levels (DRLs) in intraoral dental X-ray examination in Korea. Materials and Methods: One hundred two intraoral dental radiographic machines from all regions of South Korea were selected for this study. Radiographic exposure parameters, size of hospital, type of image receptor system, installation duration of machine, and type of dental X-ray machine were documented. Patient entrance doses (PED) and dose-area products (DAP) were measured three times at the end of the exit cone of the X-ray unit with a DAP meter (DIAMENTOR M4-KDK, PTW, Freiburg, Germany) for adult mandibular molar intraoral dental radiography, and corrections were made for room temperature and pressure. Measured PED and DAP were averaged and compared according to the size of hospital, type of image receptor system, installation duration, and type of dental X-ray machine. Results: The mean exposure parameters were 62.6 kVp, 7.9 mA, and 0.5 second for adult mandibular molar intraoral dental radiography. The mean patient dose was 2.11 mGy (PED) and 59.4 $mGycm^2$ (DAP) and the third quartile one 3.07 mGy (PED) and 87.4 $mGycm^2$ (DAP). Doses at university dental hospitals were lower than those at dental clinics (p<0.05). Doses of digital radiography (DR) type were lower than those of film-based type (p<0.05). Conclusion: We recommend 3.1 mGy (PED), 87.4 $mGycm^2$ (DAP) as the DRLs in adult mandibular molar intraoral dental radiography in Korea.

• Imaging Science in Dentistry
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• v.40 no.4
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• pp.165-169
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• 2010

Purpose : To survey the radiographic examination protocol for lateral cephalometric radiographic examinations and to measure their patient doses in Korea and to compare the dose according to the size of hospital, the type of image receptor system, and the installation duration. Materials and Methods : The radiographic examination protocols (kVp, mA, and exposure time) for lateral cephalometric radiography were surveyed with 61 cephalometric radiographic equipments and their patient dose-area product (DAP) measured with a DAP meter (DIAMENTOR M4-KDK, PTW, Freiburg, Germany) for 51 cephalometric radiographic equipments. The radiographic examination protocols and patient doses were compared according to the size of hospital (university dental hospital, dental hospital, and dental clinic), the type of image receptor system (film-based, DR and CR type) and the installation duration, respectively. SPSS 12.0.1 for Windows (SPSS Inc., Chicago, USA) was used for independent t-test and ANOVA test. Results : The average protocols were 77.0 kVp, 12.7 mA, 6.2 second for cephalometric radiography. The average patient dose (DAP) was $128.0mGy\;cm^2$ and 3rd quartile dose (DAP) $161.1mGy\;cm^2$ for cephalometric radiography for adult male. There was no statistically significant difference at average patient DAP according to the size of hospital, the type of image receptor system, and the installation duration, repectively. Conclusion : The average patient dose was $128.0mGy\;cm^2$ and the third quartile patient dose $161.1mGy\;cm^2$ for lateral cephalometric radiography for adult male in Korea.

• Journal of Korean Academy of Nursing
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• v.28 no.1
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• pp.143-147
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• 1998

당뇨병환자의 자가혈당조절에 있어서의 기준이 되는 혈당측정에 있어서 하나의 지침을 제공하기 위해 본 연구는 말초혈관과 상완정맥에서의 혈액을 채취하여 이들 검사물들의 혈당치를 직접적으로 비교했다. 30명의 건강한 한국인 성인 남자(연령 : 평균=30세)로부터, 공복시의 혈액을 세가지의 서로 다른 방법들(우선 손가락 끝에 말초혈관을 울혈이 되도록 한 뒤에, 이후 같은 편의 팔의 상완정맥에서, 마지막으로 다시 처음 검채를 시행했던 바로 그 말초의 천자부위에서 혈액을 짜내는 방법으로.)로 각각의 대상에서 검채하였다. 검사물들의 혈당치는 간편측정용 혈당측정기(Glucocard, KDK Corp., Japan. 1995)로 측정한 결과 상완정맥에서 채취한 혈액의 혈당치(107.58$\pm$21.03mg/dl)가 말초에서 채취한 혈액(울혈 후 : 100.21$\pm$24.03mg/dl, .짜낸 경우 : 97.84$\pm$22.45mg/dl)들 보다 높았다(T=2.86. p=.0081 : T=3.084. p=.0055). 그러나 이 결과는 기타의 연구들에서의 결과와는 일치하지 않았다. 이러한 불일치는 자가혈당측정기가 인슐린 의존형 당뇨환자는 물론이고 비의존성 당뇨환자들의 자가관리에 결정적인 지침이 된다는 점을 고려할 때, 좀 더 통제된 상황에서 더욱 많은 사람을 대상으로 한 임상시험을 통해 자가 혈당측정치에 있어서 기계요인에 대한분석이 이루워질 필요를 시사하고 있다. 또한 동일한 부위에서 서로 다른 방법들(혈관을 울혈을 시킨 천자하여 얻은 경우와 천자 후 그 부위를 짜서 검사물을 얻는 방법)에 의해서 얻어진 혈액의 헐당치 측정 결과 간에 차이가 없는 것으로 나타나서(t=0.72, p=.4791), 일반적으로 혈당치의 측정 시 검채한 양이 부족할 때, 새로이 천자하여 검사를 시행하는 것을 원칙으로 인식하고 있으나 본 연구결과를 볼 때, 이러한 채혈의 방식에 의한 차이는 환자의 안녕의 차원에서 고려하여 필요하다면 간과될 수도 있음을 의미하고 있다.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.434-440
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• 2012

It has been suggested that probiotics could be useful for the prevention of symptomatic relapse in patients with inflammatory bowel disease (IBD). Interleukin (IL)-8 has been well recognized as one of the pro-inflammatory cytokines that could trigger inflammation and epithelial barrier dysfunction. In this study, the anti-inflammatory effects of probiotics were investigated using a human epithelial cell line (HT-29). Probiotics from infant feces and kimchi were tested for their cytotoxicity and effects on adhesion to epithelial cells. The present results show that seven strains could form 70 % adhesion on HT-29. The probiotics used in this study did not affect HT-29 cell viability. To screen anti-inflammatory lactic acid bacteria, HT-29 cells were pretreated with live and heat-killed probiotics, and lipopolysaccharide (LPS) ($1{\mu}g/mL$) was then added to stimulate the cells. The cell culture supernatant was then used to measure IL-8 secretion by ELISA, and the cell pellet was used to determine IL-8 and toll-like receptor (TLR-4) mRNA expression levels by RT-PCR. Some probiotics (KJP421, KDK411, SRK414, E4191, KY21, and KY210) exhibited anti-inflammatory effects through the repression of IL-8 secretion from HT-29 cells. In particular, Lactobacillus salivarius E4191, originating from Egyptian infant feces, not only decreased IL-8 mRNA expression, but also decreased TLR-4 expression. These results indicate that Lactobacillus salivarius E4191 may have a protective effect in intestinal epithelial cells.