• Journal of the Korean Society of Radiology
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• v.10 no.5
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• pp.359-365
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• 2016

Fluoroscopy is performed when tissue or organ in the human body is examined, and it is used for diagnosis and procedure in back ailments. With regard to fluoroscopy equipment, distortion occurs on the peripheral part of fluoroscopic image rather than on its central part. This study measured distortion factors of vertical spacing ratio and distortion factor of diagonal spacing ratio before and after correction by applying a correction algorithm. According to measuring the vertical spacing ratio, post-correction standard deviation decreased by 0.04 in comparison with pre-correction one. Also measuring the diagonal spacing ratio, post-correction standard deviation decreased by 0.06 in comparison with pre-correction one. Consequently, the distortion of fluoroscopic image decreased after correction. A decrease in the distortion of image through the application of correction algorithm and the improvement of performance will be helpful in finding a correct position of lumbar puncture in nucleoplasty to treat lumbar disc herniation in the future.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.2
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• pp.189-196
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• 2001

Photoelasticity is one of the most widely used methods for whole field stress analysis. In photoelasticity, the difference and the directions of the principal stresses we given isochromatic and isoclinic fringe patterns. Conventionally, principal stress directions are measured manually by relating the polarizer and analyzer of a plane polariscope at the same time. This is known to be the Tardy compensation method. This measurement can be very tedious and time consuming in whole field analysis. It is not possible to separate isoclincs from photoelastic fringes by conventional photoelastic technique. In this study, photoelastic theory is represented by Jones matrices and 4-steps and 8-steps phase shifting methods are described A feasibility study using computer simulation is done to separate isoclincs and isochomatics from photoelastic fringes of a circular disk under diametrical compression. Fringe patterns of the disk are generated using stress optic law. The magnitudes of isoclincs and isochromatics obtained from 8-step phase shifting method are compared with those of theories. From computer simulation, it is verified to separate isoclincs and isochomatics from photoelastic fringes.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.1
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• pp.47-56
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• 2009

Rock bolts and shotcrete play a crucial role as a main support system in the underground space. Thus, the safety of the underground space may be affected by the defect of rock bolts. In order to evaluate the rock bolt integrity by using non-destructive technique, the transmission method of the guided ultrasonic waves, which are generated by using the piezo disk elements has been successfully performed. The energy generated by the piezo disk elements, however, is not enough for the rock bolts in the field. In addition, the piezo disk elements should be installed at the end of the steel bar during construction of the rock bolts. The purpose of this study is the devolvement of the reflection method, which may generate enough energy, and the application in the field rock bolts. Both laboratory and field tests are carried out. The guided ultrasonic waves with high energy are generated by the hammer impact with the center punch, and the AE sensor is used to measure the reflected guided waves. The received guided waves are analyzed by the wavelet transform. The peak value of the wavelet transform produces the energy velocity, which is used for the evaluation of the rock bolt integrity. The energy velocity increases with an increase in the defect ratio in both laboratory and field rock bolts. This study demonstrates that the hammer-impact reflection method may be a suitable method for the evaluation of the rock bolt in the field.

• Journal of Veterinary Clinics
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• v.32 no.2
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• pp.158-161
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• 2015

Bacterial dermatitis is common disease that is necessary to treat with antibiotics. In recent, antibiotic-resistant bacteria is being increased in worldwide. The purpose of the present study was to evaluate the prevalence of resistant genes in Staphylococcus (S.) pseudintermedius isolated from dogs, and to compare the resistant gene profile with the result of antibiotic disc diffusion test. A total of seven S. pseudintermedius was included in the study. Bacterial identification was performed by 16S ribosomal RNA gene sequence analysis. S. pseudintermedius isolates had more than one antibiotic resistant gene (mecA, blaZ and aac(6')/aph(2"). While all isolates were PCR positive to blaZ gene, only two isolates were resistant to amoxicillin/clavulanate. Among five isolates harboring gentamicin resistance, one isolate was negative to aac(6')/aph(2")-targeted PCR. Taken together, the results suggest that resistant gene-targeted PCR and disc diffusion test are complementary to detect antibiotic resistance.

• Journal of the Institute of Convergence Signal Processing
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• v.18 no.2
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• pp.55-61
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• 2017

In radio astronomy, high-capacity HDDs are being used to save huge amounts of HDDs in order to record the observational data. For VLBI observations, observational speeds increase and huge amounts of observational data must be stored as they expand to broadband. As the HDD is frequently used, the number of failures occurred, and then it takes a lot of time to recover it. In addition, if a failed HDD is continuously used, observational data loss occurs. And it costs a lot of money to buy a new HDD. In this study, we developed the integrity verification system of the Serial ATA HDD using FirmOS. The FirmOS is an OS that has been developed to function exclusively for specific purposes on a system having a general server board and CPU. The developed system performs the process of writing and reading specific patterns of data in a physical area of the SATA HDD based on a FirmOS. In addition, we introduced a method to investigate the integrity of HDD integrity by comparing it with the stored pattern data from the HDD controller. Using the developed system, it was easy to determine whether the disk pack used in VLBI observations has error or not, and it is very useful to improve the observation efficiency. This paper introduces the detail for the design, configuration, testing, etc. of the SATA HDD integrity verification system developed.

• The Journal of the Korea Contents Association
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• v.19 no.10
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• pp.198-205
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• 2019

The purpose of this study was to identify whether cutaneous sensory (CS) changes induced by mechanical intervention(MI) increases the trigger point threshold and muscle tone of the same spinal segment to neck disc patients. Thirty persons with Neck disc patients were recruited in this experiment. The subjects consisted of 10 men and 20 women. The mechanical stimulus group induced CS changes for 5 minutes using the Graston instrument and the control group received no action. The CS changes were estimated by using the Von Frey Filament, PPT changes were measured by using the pressure threshold meter and msucle tone changes were measured by using Myotone pro. CS threshold increased significantly when MI was applied (p<0.05). On the same spinal segment, increases in the right infraspinatus PPT and muscle tone was observed (p<0.05) and decreases in the right trapezius PPT was observed(p<0.05). However, the PPT and muscle tone changes in other muscles were not significantly different. Furthermore, the control group CS, PPT and muscle tone were not significantly different. As a result, CS changes induced by MI make to change PPT and muscle tone on the same spinal segment. Therefore, application of MI to the same spinal segment may be of clinical significance as a new rehabilitation method for increasing pain threshold, muscle tone and pain control in neck disc patients.

• Journal of The Korean Association of Information Education
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• v.16 no.4
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• pp.397-407
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• 2012

According to the fast supply of the SMART device, many people have a lot of interests about SMART education. The Korean government is showing a lot of effort towards the promotion of SMART education. In this study, I developed a behavioral assessments and QR code based mobile web application for school education. The developed system works seamlessly across all popular mobile device platforms and if you save the data after the assessment, this system will automatically create each person's mobile web page. Students and teachers can add comments to this page and can improve the accessibility for finding the address of this page to QR code. The developed system can contribute to the class members understanding the personality of each other and make communication run smoothly. As a result of application of developed system, it is expected to contribute to increasing the interaction between a students, parents and teachers because the developed system provides a service based to education consumer's TPO(Time, Place, Occasion).

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.2
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• pp.120-125
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• 2016

Purpose: The purpose of this study is to identify the effect of mesenchymal stem cell proliferation on recombinant human transforming growth factor-beta (rhTGF-${\beta}2$) / poly (D,L-lactide-co-glycolide) (PLGA) treated titanium discs by electrospray. Materials and methods: Anodized titanium surface coated with PLGA was used for a control group to compare anodized titanium surface coated with 125 ng/ml and 500 ng/ml rhTGF-${\beta}2$ as test groups. Atomic force microscope (AFM) test was utilized to determine the difference in coating surface roughness, and field-emission scanning electron microscopy (FE-SEM) was taken to visualize even distribution of coating particles on titanium discs. The mesenchymal stem cell proliferation was tested by using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl-tetrazolium bromide) assay on 1st, 4th, 7th days. Results: According to AFM results, there was no statistically significant difference in titanium discs treated with PLGA and with rhTGF-${\beta}2$/PLGA (P>.05). MTT assay test results showed that there was statistically significant difference in mesenchymal stem cell proliferation on test groups compared to control groups at 7th day, and cell viability on discs coated with rhTGF-${\beta}2$ was significantly higher than control groups (P<.05). Conclusion: Titanium surface coated with rhTGF-${\beta}2$/PLGA shows statistically significant higher cell proliferation and the titanium surface coated with the higher concentration of rhTGF-${\beta}2$ presents faster cell growth activity.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06b
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• pp.273-278
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• 2007

검사점 및 복구 도구(Checkpointing & Recovery Facility)를 이용하여 임베디드 시스템에서 결함 허용(Fault Tolerance) 기법을 적용할 경우 쓰기 작업의 오버헤드로 인해 실용성이 크게 떨어지게 된다. 실시간 운영체제와 함께 어떠한 한계 상황에서 결함 허용 및 복구 도구가 오히려 시스템의 성능을 저하시키는 요인으로 작용하게 되면 이는 결국 쓸모없는 도구가 되어 사용되지 않을 것이다. 따라서 프로세스의 복구를 위해 저장하는 프로세스 이미지의 기록에 소요되는 시간을 크게 낮추어야만 비로소 검사점 도구가 그 진가를 발휘하게 될 수 있다. 본 논문에서는 NVSRAM(Non Volatile SRAM)을 검사점 및 복구 도구의 저장 장치로 활용함으로써 기존의 검사점 도구에서 성능을 저하시키는 주원인이었던 검사점 기록의 오버헤드를 개선하기 위한 연구를 수행하였다. 검사점 기록 시간을 줄이기 위한 방법으로 주 메모리에 저장된 프로세스의 복구와 관련된 데이터를 SRAM 특성을 갖는 비휘발성 저장 장치인 NVSRAM에 저장하여 디스크 접근에 소요되는 시간을 최소화시킴으로써 임베디드 시스템에서 실용적으로 사용 가능한 검사점 도구를 구현하였고, 이러한 연구의 결과를 검증하기 위해 기존 시스템에서 저장 장치로 사용되던 플래시 메모리, 주 메모리, 원격 메모리를 사용하는 경우의 성능과 NVSRAM을 활용할 때의 성능을 비교해 보았다. 본 연구에서 제안하는 결함 허용 도구는 실제 시스템에 적용하여 효과적인 성능을 발휘할 수 있을 것이며, 차세대 메모리를 이용한 결함 허용 도구의 연구에 기여를 할 수 있을 것으로 기대된다.ate첨가배지(添加培地)에서 가장 저조(低調)하였다. vitamin중(中)에서는 niacin과 thiamine첨가배지(添加培地)에서 근소(僅少)한 증가(增加)를 나타내었다.소시켜 항이뇨 및 Na 배설 감소를 초래하는 작용과, 둘째는 신경 경로를 통하지 않고, 아마도 humoral factor를 통하여 신세뇨관에서 Na 재흡수를 억제하는 작용이 복합적으로 나타내는 것을 알 수 있었다.으로 초래되는 복합적인 기전으로 추정되었다., 소형과와 기형과는 S-3에서 많이 나왔다. 이상 연구결과에서 입도분포가 1.2-5mm인 것이 바람직한 것으로 나타났다.omopolysaccharides로 확인되었다. EPS 생성량이 가장 좋은 Leu. kimchii GJ2의 평균 분자량은 360,606 Da이었으며, 나머지 두 균주에 대해서는 생성 EPS 형태와 점도의 차이로 미루어 보아 생성 EPS의 분자구조와 분자량이 서로 다른 것으로 판단하였다.TEX>개로 통계학적으로 유의한 차이가 없었다. Heat shock protein-70 (HSP70)과 neuronal nitric oxide synthase (nNOS)에 대한 면역조직화학검사에서 실험군 Cs2군의 신경세포가 대조군 12군에 비해 HSP70과 nNOS의 과발현을 보였으며, 이는 통계학적으로 유의한 차이를 보였다(p<0.05). nNOS와 HSP70의 발현은 강한 연관성을 보였고(상관계수 0.91, p=0.000), nNOS를 발현하는 세포가 동시에 HSP70도 발현함을 확인할 수 있었다. 결론: 우리는 cyclosporin A가 토끼의 25분간의 척수허혈에 대해 척수보호 효과가 있었으며 이는 HSP70의

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.4
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• pp.79-86
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• 1999

Electronic Speckle Pattern Interferometry(ESPI) is a powerful tool to measure the vibration mode shape and resonance frequency for modal analysis. As for ESPI this method is very suited for full-field measurement of objects in industrial areas because the interferograms are recorded with a video camera and evaluated in real-time with a computer. In this study We performed experiments at the same constraint conditions as disk brake of the practical vehicle as far as possible and obtained the resonance frequencies and vibration mode shapes by using time-averaged ESPI at once. Finally to assure the expetimental results by time-averaged ESPI we also compare those with results obtained by Laser Doppler Vibrometer and obtained good agreement.