• Journal of Veterinary Clinics
• /
• v.28 no.4
• /
• pp.422-426
• /
• 2011

For a national survey in which wide geographic region or an entire country is targeted, multi-stage sampling approach is widely used to overcome the problem of simple random sampling, to consider both herd- and animallevel factors associated with disease occurrence, and to adjust clustering effect of disease in the population in the calculation of sample size. The aim of this study was to establish sample size for estimating bovine tuberculosis (TB) in Korea using stratified two-stage sampling design. The sample size was determined by taking into account the possible clustering of TB-infected animals on individual herds to increase the reliability of survey results. In this study, the country was stratified into nine provinces (administrative unit) and herd, the primary sampling unit, was considered as a cluster. For all analyses, design effect of 2, between-cluster prevalence of 50% to yield maximum sample size, and mean herd size of 65 were assumed due to lack of information available. Using a two-stage sampling scheme, the number of cattle sampled per herd was 65 cattle, regardless of confidence level, prevalence, and mean herd size examined. Number of clusters to be sampled at a 95% level of confidence was estimated to be 296, 74, 33, 19, 12, and 9 for desired precision of 0.01, 0.02, 0.03, 0.04, 0.05, and 0.06, respectively. Therefore, the total sample size with a 95% confidence level was 172,872, 43,218, 19,224, 10,818, 6,930, and 4,806 for desired precision ranging from 0.01 to 0.06. The sample size was increased with desired precision and design effect. In a situation where the number of cattle sampled per herd is fixed ranging from 5 to 40 with a 5-head interval, total sample size with a 95% confidence level was estimated to be 6,480, 10,080, 13,770, 17,280, 20.925, 24,570, 28,350, and 31,680, respectively. The percent increase in total sample size resulting from the use of intra-cluster correlation coefficient of 0.3 was 22.2, 32.1, 36.3, 39.6, 41.9, 42.9, 42,2, and 44.3%, respectively in comparison to the use of coefficient of 0.2.

• Korean Journal of Veterinary Research
• /
• v.43 no.3
• /
• pp.435-438
• /
• 2003

The objective of this study was to investigate the residue depletion of cephaalexin in the flounder (Paralichthys olivaceus) after multiple oral administrations and to establish the appropriate withdrawal time for edible tissues. A highly sensitive and specific method for the determination of cephalexin in the serum of flounder by LC/MS was developed and validated. Mean recoveries from serum were 87.2% (ranged from 81.2% to 94.5%) for cepalexin. Recovery and precision met the criteria for the guideline of residual analysis of veterinary drugs by the National Veterinary Research and Quarantine Service (NVRQS) in Korea. The limit of detection and limit of quantitation of cephalexin were 10 ng/ml and 50 ng/ml, respectively. Residual levels of cephalexin in muscle samples were estimated with 95% tolerance limit and 95% confidence to fall below the MRL after a withdrawal time of 4 days and 5 days for the 40 and 160 mg/kg/day, respectively.

• Progress in Medical Physics
• /
• v.9 no.1
• /
• pp.29-35
• /
• 1998

There has been necessity of an air free ionization chamber using the gold-crystal-aluminium plates, henceforth called the crystal chamber. The crystal chamber formed of parallel plates is very small in size and has more response for absorbed dose of therapeutic radiation beams. The gold plate on the crystal facing the photon and electron beam acts as an intensifier of signals and crystal plate as an ionization medium respectively. Both the copper guard ring and the aluminum collecting electrode are connected to an electrometer. Using high energy photon (6, 15 MV) and electron (9, 12, 15, 18 MeV) beams, the responses of the crystal chamber are evaluated against a PTW Farmer-type chamber at a field size of 10${\times}$10cm$^2$ and 100 cm SSD. The responses of crystal chamber for therapeutic radiation electron and photon beams are greater in magnitude by several order than Farmer. The crystal chamber has good linearity without correction factor C$\_$t,p/ with respect to the signals, a reading reproduction with good accuracy and precision less than 0.5%, and has other useful functions in measuring radiation beams.

• Korean Journal of Pharmacognosy
• /
• v.40 no.3
• /
• pp.224-228
• /
• 2009

For the quality control of traditional herbal medicine, Galgeun tang, simultaneous determination of glycyrrhizin, paeoniflorin, puerarin, 6-gingerol was established by using a high performance liquid chromatographic (HPLC) method with diode array detector. To separate five four constituents, DIONEX $C_{18}$ column ($5{\mu}m$, $120{\AA}$, $4.6\;mm{\times}150\;mm$) was used with gradient elution system of water and methanol. Validation of the chromatography method was evaluated by linearity, recovery, and precision test. Calibration curve of standard components showed excellent linearity ($R^2$>0.9906). Limits of detection (LOD) and limits of quantification (LOQ) varied from 0.15 to $0.52{\mu}g$/ml and 0.27 to $0.80{\mu}mg$/ml, respectively. The relative standard deviations (RSDs) of data of the intra-day and inter-day experiments were less than 2.88% and 1.21%, respectively. The results of recovery test were ranged from 96.71 to 106.29% with RSD values 0.01-0.80%.

• Journal of Radiation Protection and Research
• /
• v.36 no.3
• /
• pp.107-118
• /
• 2011

Conventional (SRS) and fractionated (FSRS) stereotactic radiosurgery necessarily require stringent overall target point accuracy and precision. We determine three-dimensional intracranial target point deviations (TPDs) in a whole treatment procedure using magnetic resonance image (MRI)-based polymer-gel dosimetry, and suggest a technique for overall system tests. TPDs were measured using a custom-made head phantom and gel dosimetry. We calculated TPDs using a treatment planning system. Then, we compared TPDs using mid bi-plane and three-dimensional volume methods with spherical and elliptical targets to determine their inherent analysis errors; finally, we analyzed regional TPDs using the latter method. Average and maximum additive errors for ellipses were 0.62 and 0.69 mm, respectively. Total displacements were 0.92 ${\pm}$ 0.25 and 0.77 ${\pm}$ 0.15 mm for virtual SRS and FSRS, respectively. Average TPDtotal at peripheral regions was greater than that at central regions for both. Overall system accuracy was similar to that reported previously. Our technique could be used as an overall system accuracy test that considers the real radiation field shape.

• The Journal of Korean Society for Radiation Therapy
• /
• v.10 no.1
• /
• pp.30-44
• /
• 1998

Accurate delivery of doses using a high dose rate(HDR) brachytherapy, remote afterloading system(RALS) depends on knowing the strength of the radioactive source at the time of treatment, the precision and consistency of the timer, and the ability of the unit to position the source at the proper dwell location along the applicator. Periodic Quality Assurance(QA) on HDR machines is a part of the standard protocol of any user. The safety of the patient & staff, positional accuracy, temporal accuracy, and dose delivery accuracy are periodically(weekly, quarterly, monthly) estimated using HDR source(Ir-192), treatment planning devices, measurement devices, and overall treatment devices with regard to treatment delivery. The overall measurement results are estimated successfully and assessed its clinical significance. As a result, our HDR brachytherapy units has been very accurate until now. The QA program protocol permits routine clinical use and provides a high confidence level in the accurate operation of HDR units. Therefore, regular QA of HDR brachytherapy is essential for successful treatment.

• Archives of Plastic Surgery
• /
• v.37 no.4
• /
• pp.499-530
• /
• 2010

Purpose: Lateral osteotomy is an essential step in the correction of nasal bony asymmetry. Direct visualization allows accurate repositioning of the nasal bones compared to blind techniques, which require precision and manual dexterity. We propose direct visualization procedures in open corrective rhinoplasty. Methods: The technique was used on 16 patients. All patients underwent open rhinoplasty with a columellar incision. The marginal incisions were extended on either side to allow access to the piriform aperture. A double hook was used to caudally retract the lower lateral cartilages and the fibrous connections between the upper and lower lateral cartilages were released until the piriform aperture was visualized. Through the incision, lateral osteotomy was performed using a reciprocating saw at that time with direct visualization. Additional procedures including augmentation rhinoplasty, hump resection, septoplasty and tip plasty were performed simultaneously. Results: This method provided excellent exposure to the lateral nasal bones and allowed the lateral osteotomy to be carried out precisely using the reciprocating saw. Conclusion: This extended open rhinoplasty method is suitable for most individuals, allowing a wide surgical field.

• Genomics & Informatics
• /
• v.16 no.4
• /
• pp.28.1-28.6
• /
• 2018

Due to the increasing interest in synonymous codons, several codon bias-related terms were introduced. As one measure of them, the tRNA adaptation index (tAI) was invented about a decade ago. The tAI is a measure of translational efficiency for a gene and is calculated based on the abundance of intracellular tRNA and the binding strength between a codon and a tRNA. The index has been widely used in various fields of molecular evolution, genetics, and pharmacology. Afterwards, an improved version of the index, named specific tRNA adaptation index (stAI), was developed by adapting tRNA copy numbers in species. Although a subsequently developed webserver (stAIcalc) provided tools that calculated stAI values, it was not available to access pre-calculated values. In addition to about 100 species in stAIcalc, we calculated stAI values for whole coding sequences in 148 species. To enable easy access to this index, we constructed a novel web database, named STADIUM (Species-specific tRNA adaptive index compendium). STADIUM provides not only the stAI value of each gene but also statistics based on pathway-based classification. The database is expected to help researchers who have interests in codon optimality and the role of synonymous codons. STADIUM is freely available at http://stadium.pmrc.re.kr.

• Investigative Magnetic Resonance Imaging
• /
• v.25 no.3
• /
• pp.156-163
• /
• 2021

Recently, neuromelanin and nigrosome imaging techniques have been developed to evaluate the substantia nigra in Parkinson's disease. Previous studies have shown potential benefits of quantitative analysis of neuromelanin and nigrosome images in the substantia nigra, although visual assessments have been performed to evaluate structures in most studies. In this study, we investigate the potential of using deep learning based automatic region segmentation techniques for quantitative analysis of the substantia nigra. The deep convolutional neural network was trained to automatically segment substantia nigra regions on 3D nigrosome and neuromelanin sensitive MR images obtained from 30 subjects. With a 5-fold cross-validation, the mean calculated dice similarity coefficient between manual and deep learning was 0.70 ± 0.11. Although calculated dice similarity coefficients were relatively low due to empirically drawn margins, selected slices were overlapped for more than two slices of all subjects. Our results demonstrate that deep convolutional neural network-based method could provide reliable localization of substantia nigra regions on neuromelanin and nigrosome sensitive MR images.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2022.07a
• /
• pp.85-87
• /
• 2022

루푸스 신염을 정확히 진단하기 위해서는 신장의 침 생검을 통한 조직검사를 통해 사구체들을 찾아내고, 각각의 염증 정도를 분류해야 한다. 하지만 이에는 의료진의 많은 시간과 노력이 소요된다. 따라서 본 연구에서는 이러한 한계를 극복하기 위해 합성곱 신경망 (Convolutional neural network, CNN)에 기반한 검출 및 분할에 딥 러닝 접근법을 적용하는 YOLOv5 알고리즘을 통해 검체 이미지 내에서 사구체를 자동으로 검출해 내도록 하였다. 그리고 루푸스 신염 환자의 슬라이드 이미지에 대한 태깅 작업을 거쳐 학습을 위한 데이터와 테스트를 위한 데이터를 생성하여 학습 및 테스트에 활용하였다. 그 결과 고화질의 검체 이미지 내에서 대부분의 사구체를 0.9 이상의 높은 precision과 recall로 검출해 낼 수 있었다. 이를 통해 신장 내부의 사구체 검출을 자동화하고 추후 연구를 통해 사구체 염증 정도를 단계화 할 수 있는 발판을 마련하였다.