• 제목/요약/키워드: validation range

검색결과 734건 처리시간 0.029초

휴대용 근적외선 분광분석기를 이용한 비침투 혈당 측정 (Non-invasive Blood Glucose Measurement by a Portable Near Infrared (NIR) System)

  • 강나루;우영아;차봉수;이현철;김효진
    • 약학회지
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    • 제46권5호
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    • pp.331-336
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    • 2002
  • The purpose of this study is to develop a non-invasive blood glucose measurement method by a portable near infrared (NIR) system which was newly integrated by our lab. The portable NIR system includes a tungsten halogen lamp, a specialized reflectance fiber optic probe and a photo diode array type InGaAs detector; which was developed by a microchip technology based on the lithography. Reflectance NIR spectra of different parts of human body (finger tip, earlobe, and inner lip) were recorded by using a fiber optic probe. The spectra were collected over the spectral range 1100 ∼ 1740 nm. Partial least squares regression (PLSR) was applied for the calibration and validation for the determination of blood glucose. The calibration model from earlobe spectra presented better results, showing good correlation with a glucose oxidase method which is a mostly used standard method. This model predicted the glucose concentration for validation set with a SEP of 33 mg/dL. This study indicated the feasibility for non-invasive monitoring of blood glucose by a portable near infrared system.

천리안위성 운용 준비를 위한 위성시뮬레이터 활용효과 분석 (Utilization and Effect of Satellite Simulator for COMS Operation Preparation)

  • 이훈희;김방엽;박봉규;양군호;백명진;천용식
    • 항공우주기술
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    • 제9권1호
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    • pp.84-92
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    • 2010
  • 통신해양기상위성의 명칭인 천리안위성 발사를 앞두고 위성운용을 위한 지상시스템의 검증이 실제 위성과 위성시뮬레이터 등을 이용하여 수행되었다. 본 논문에서 특히 시뮬레이터가 적용된 지상시스템 시험 부분을 중점적으로 분석하여 시뮬레이터의 활용시간, 활용범위, 활용비중 등을 기술한다. 아울러 시스템 검증을 위한 시뮬레이터의 적용 경험을 바탕으로 시뮬레이터의 효과를 설명하고 한계점과 개선방향을 제시한다.

유전체 코호트 연구의 주요 통계학적 과제 (Statistical Issues in Genomic Cohort Studies)

  • 박소희
    • Journal of Preventive Medicine and Public Health
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    • 제40권2호
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    • pp.108-113
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    • 2007
  • When conducting large-scale cohort studies, numerous statistical issues arise from the range of study design, data collection, data analysis and interpretation. In genomic cohort studies, these statistical problems become more complicated, which need to be carefully dealt with. Rapid technical advances in genomic studies produce enormous amount of data to be analyzed and traditional statistical methods are no longer sufficient to handle these data. In this paper, we reviewed several important statistical issues that occur frequently in large-scale genomic cohort studies, including measurement error and its relevant correction methods, cost-efficient design strategy for main cohort and validation studies, inflated Type I error, gene-gene and gene-environment interaction and time-varying hazard ratios. It is very important to employ appropriate statistical methods in order to make the best use of valuable cohort data and produce valid and reliable study results.

The Potential of Centella asiatica (Linn.) Urban as an Anti-Microbial and Immunomodulator Agent: A Review

  • Harun, Nurul Hikmah;Septama, Abdi Wira;Ahmad, Wan Amir Nizam Wan;Suppian, Rapeah
    • Natural Product Sciences
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    • 제25권2호
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    • pp.92-102
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    • 2019
  • Centella asiatica (Linn.) Urban (Umbelliferae) which is also known as 'pegaga' is highly consumed and eaten raw as 'ulam' in Malaysia. C. asiatica is used in traditional medicines to treat various health conditions such as rheumatism, inflammation, syphilis, skin diseases and diarrhoea. Various reports exhibited that the crude extracts and isolated bioactive compounds of C. asiatica possessed a broad range of pharmacological activities such as anti-oxidant, anti-diabetic, anti-tumor, wound healing, anti-microbial, anti-inflammatory, immunomodulatory, hepatoprotective and memory enhancing properties. The pharmacological validation on anti-microbial and immunomodulatory of C. asiatica is very limited and several existence review papers related for this plant had not been focused for both activities. This review therefore attempts to combine the existing literature to offer immense scope for researchers engaged in validation of the traditional claims and bioactivities of this plant related with anti-microbial and immunomodulatory potential.

Structure Prediction of Gasdermin a Receptor by Homology Modelling

  • Subathra Selvam
    • 통합자연과학논문집
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    • 제16권3호
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    • pp.97-102
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    • 2023
  • The gasdermins are a family of recently identified pore-forming effector proteins that cause membrane permeabilization and pyroptosis, a lytic pro-inflammatory type of cell death. A role in the regulation of cell proliferation and/or differentiation is suggested by the differentiation status-specific expression of gasdermin proteins in epithelial tissues. One of the GSDM protein is Gasdermin A (GSDMA), which decreased in stomach and esophageal cancers, suggesting a tumor suppressor role. GSDMA receptor antagonists have been researched as potential treatments for inflammatory diseases and baldness. GSDMA's significance in a wide range of disorders makes it an important therapeutic target. As a result, homology modelling of the GSDMA receptor was undertaken in the current study using the crystal structures of Mus musculus (GSDMA3), Human gasdermin D (GSDMD), and Murine gasdermin D (murine GSDMD). The best model was chosen based on the validation results after 20 models were developed utilising single template-based approaches. The generated structures can be used for further binding site and docking studies in the future.

LC-MS/MS를 이용한 인체시료 중 프탈레이트 대사체 동시분석법 확립 (Development and Validation of On-line Column Switching HPLC-MS/MS Method for 10 Phthalate Metabolites in Human Urine)

  • 홍순근;남혜선;정기경;강일현;김태성;조상은;정수희;이장우;김준철;고영림;강태석
    • 한국환경보건학회지
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    • 제36권6호
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    • pp.510-517
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    • 2010
  • Phthalates, such as di (2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) have been proved to be teratogenics and endocrine disruptors, metabolized rapidly and excreted in the urine. In this study, a simultaneous analytical method for 10 phthalate metabolites, MnBP, MiBP, MBzP, MCHP, MEHP, MEHHP, MEOHP, MnOP, MiNP and MiDP, in human urines, based on switching system with on-line pretreatment column using HPLC-MS/MS has been developed. This method was validated according to the guideline of bioanalytical method validation of National Institute of Toxicological Research. Limits of detection range between 0.2 and 0.9 ng/ml for 10 phthalate metabolites. The calibration curves showed linearity in the range 0.997~0.999, and the results of the intra- and inter-day validations were in the range from 0.4 to 14.7% RSD and from 0.3 to 9.4% RSD, respectively. Recoveries of phthalate metabolites varied from 87.0 to 116.1%. This analytical method showed high accuracy and stable precision for all metabolites, and seems to be suitable for biomonitoring of phthalates in human urine.

Validation of electromagnetic physics models and electron range in Geant4 Brachytherapy application

  • A. Albqoor ;E. Ababneh ;S. Okoor;I. Zahran
    • Nuclear Engineering and Technology
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    • 제55권1호
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    • pp.229-237
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    • 2023
  • The mechanics underlying photon and electron interactions was validated using our developed Brachytherapy computer code for high Dose Rate (HDR). By comparing the photon cross-section utilizing multiple physics libraries in the developed code, the results were benchmarked against experimental and theoretical findings. Klein-Nishina and experimental cross-section results were in good agreement with the Livermore library results. For two therapeutically relevant materials, the first scattered electron range was measured within 1 mm and 2 mm, which has significant implications for the interpretation of the kernel dose spikes observed in previous research.

각도 및 거리 유효성 검사를 적용한 블루투스 도래각 기반의 측위 방식 (Bluetooth AoA based Positioning Scheme using Angle and Distance Validation Test)

  • 송경희;백정훈
    • 방송공학회논문지
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    • 제26권6호
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    • pp.790-798
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    • 2021
  • 본 논문에서는 기존의 도래각을 활용한 블루투스 기반의 측위방식에 각도 및 거리 유효성 검사를 추가하여 측위의 정확도를 개선하는 방식을 제안한다. 기존의 측위방식은 비 가시거리 환경에서 유발되는 다중경로 현상 등에 의하여 측위 값에 오차가 발생하는 현상이 발생한다. 제안된 방식은 피 측위 장치의 이동속도를 고려하여 측정될 수 있는 최대 도래각과 최소 도래각을 도출한 후 측정된 도래각이 최대 도래각과 최소 도래각 범위를 초과하는지를 검사하는 각도 유효성 검사와 측정된 피 측위 장치의 위치 및 측위 장치와의 거리가 유효거리를 초과하는지 검사하는 거리 유효성 검사를 시행하여 측위의 정확성을 제고한다. 제안된 방식과 기존 방식과의 측위 성능을 분석하기 위하여 모의실험을 실시하고, 모의실험 결과를 통해 측위 오차가 증대되는 상황에서는 기존의 방식에 비하여 각도 및 거리 유효성 검사를 통해 측위 성능이 개선됨을 확인한다.

A Nomogram Using Imaging Features to Predict Ipsilateral Breast Tumor Recurrence After Breast-Conserving Surgery for Ductal Carcinoma In Situ

  • Bo Hwa Choi;Soohee Kang;Nariya Cho;Soo-Yeon Kim
    • Korean Journal of Radiology
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    • 제25권10호
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    • pp.876-886
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    • 2024
  • Objective: To develop a nomogram that integrates clinical-pathologic and imaging variables to predict ipsilateral breast tumor recurrence (IBTR) in women with ductal carcinoma in situ (DCIS) treated with breast-conserving surgery (BCS). Materials and Methods: This retrospective study included consecutive women with DCIS who underwent BCS at two hospitals. Patients who underwent BCS between 2003 and 2016 in one hospital and between 2005 and 2013 in another were classified into development and validation cohorts, respectively. Twelve clinical-pathologic variables (age, family history, initial presentation, nuclear grade, necrosis, margin width, number of excisions, DCIS size, estrogen receptor, progesterone receptor, radiation therapy, and endocrine therapy) and six mammography and ultrasound variables (breast density, detection modality, mammography and ultrasound patterns, morphology and distribution of calcifications) were analyzed. A nomogram for predicting 10-year IBTR probabilities was constructed using the variables associated with IBTR identified from the Cox proportional hazard regression analysis in the development cohort. The performance of the developed nomogram was evaluated in the external validation cohort using a calibration plot and 10-year area under the receiver operating characteristic curve (AUROC) and compared with the Memorial Sloan-Kettering Cancer Center (MSKCC) nomogram. Results: The development cohort included 702 women (median age [interquartile range], 50 [44-56] years), of whom 30 (4%) women experienced IBTR. The validation cohort included 182 women (48 [43-54] years), 18 (10%) of whom developed IBTR. A nomogram was constructed using three clinical-pathologic variables (age, margin, and use of adjuvant radiation therapy) and two mammographic variables (breast density and calcification morphology). The nomogram was appropriately calibrated and demonstrated a comparable 10-year AUROC to the MSKCC nomogram (0.73 vs. 0.66, P = 0.534) in the validation cohort. Conclusion: Our nomogram provided individualized risk estimates for women with DCIS treated with BCS, demonstrating a discriminative ability comparable to that of the MSKCC nomogram.

레이저 거리측정(SLR) 데이터를 사용한 GPS 기반 정밀궤도결정 시스템 결과의 검증 (Validation of GPS Based Precise Orbits Using SLR Observations)

  • 김영록;박은서;박상영;최규홍;황유라;김해연;이병선;김재훈
    • Journal of Astronomy and Space Sciences
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    • 제26권1호
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    • pp.89-98
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    • 2009
  • 이 연구에서는 SLR(Satellite Laser Ranging) NP (Normal Point) 데이터를 이용하는 인공위성 정밀궤도 결정 시스템 YLPODS(Yonsei Laser-ranging Precision Orbit Determination System)를 개발하였다. 먼저, 개발된 YLPODS의 성능 검증을 위해서 저궤도 위성인 TOPEX/POSEIDON과 CHAMP의 SLR NP 데이터를 사용한 궤도결정 시험을 수행하였다. JPL에서 배포하는 정밀궤도력을 참값으로 가정하고, 거리측정잔차(range residual)의 RMS(Root Mean Square) 및 결정된 궤도의 반경(radial), 진행(along-track), 교차(cross-track) 방향 오차를 확인하였다. 그리고 거리측정잔차 확인을 통해 검증된 YLPODS의 거리계산 정밀도와 SLR NP 데이터의 높은 거리측정 정밀도를 이용하여, 관측된 값(O)과 계산된 값(C)을 비교하는 방법으로 GPS(Global Positioning System) 데이터를 이용하는 GPS 기반 POD 시스템 결과의 정밀도 검증을 수행하였다. 검증을 위한 GPS 기반 POD 시스템 결과는 YGPODS(Yonsei GPS-based Precision Orbit Determination System)의 TOPEX/POSEIDON위성 POD 결과가 사용되었다. 관측된 값과 계산된 값의 비교(O-C)를 위해서 GPS 기반 POD 시스템 결과로부터 획득된 궤도 정보를 YLPODS의 초기 궤도로 사용하고, 첫 번째 반복 후 얻어진 거리측정잔차를 확인해 보았다. YLPODS의 궤도결정 수행 결과 TOPEX/POSE)DON과 CHAMP 위성 모두 거리측정잔차가 10cm 미만, 각 방향 오차가 1m 수준의 정밀도를 가지는 것을 확인하였다. GPS 기반 POD 시스템 결과에 대한 정밀도 검증 결과 TOPEX/POSEIDON위성의 경우 거리측정잔차가 10cm 미만으로 나오는 것을 확인하였다. YLPODS의 궤도결정 수행 결과에 비추어볼 때 GPS 기반 POD시스템 결과의 각 방향 궤도 정밀도가 1m 수준이 될 것을 예상해볼 수 있고, 실제로 JPL 정밀궤도력과 비교했을 때 1m 수준의 궤도 정밀도를 가지는 것을 확인할 수 있었다. 결과적으로 이 연구를 통해서 개발된 YLPODS는 향후 수행될 과학기술위성 2호와 다목적 실용위성 5호와 같은 SLR 데이터 획득이 가능한 위성의 SLR 기반 POD 및 GPS 기반 POD 결과 검증에 활용될 수 있을 것이다.