• Title/Summary/Keyword: Accuracy control

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Development and Validation of HPLC Method for Pharmacokinetic Study of Promethazine in Human (염산프로메타진 체내동태 연구를 위한 혈청 중 프로메타진의 HPLC 정량법 개발 및 검증)

  • Cho, Hae-Young;Kang, Hyun-Ah;Lee, Hwa-Jeong;Choi, Hoo-Kyun;Lee, Yong-Bok
    • Journal of Pharmaceutical Investigation
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    • v.36 no.1
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    • pp.23-29
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    • 2006
  • A rapid, selective and sensitive reversed-phase HPLC method for the determination of promethazine in human serum was developed, validated, and applied to the pharmacokinetic study of promethazine. Promethazine and internal standard, chlorpromazine, were extracted from human serum by liquid-liquid extraction with n-hexane containing 0.8% isopropanol and analyzed on a Capcell Pak CN column with the mobile phase of acetonitrile-0.2 M potassium dihydrogen phosphate (42:58, v/v, adjusted to pH 6.0 with 1 M NaOH). Detection wavelength of 251 nm and flow rate of 0.9 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^{3}$ factorial design using a fixed promethazine concentration (10 ng/mL) with respect to its peak area and retention time. In addition, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of 1-40 ng/mL with correlation coefficients greater than 0.999. The lower limit of quantification using 1 mL of serum was 1 ng/mL, which was sensitive enough for pharmacokinetic studies. The overall accuracy of the quality control samples ranged from 96.15 to 105.40% for promethazine with overall precision (% C.V.) being 6.70-11.22%. The relative mean recovery of promethazine for human serum was 63.54%. Stability (freeze-thaw and short-term) studies showed that promethazine was stable during storage, or during the assay procedure in human serum. However, the storage at $-80^{\circ}C$ for 4 weeks showed that promethazine was not stable. Extracted serum sample and stock solution were not allowed to stand at ambient temperature for 12 hr prior to injection. The peak area and retention time of promethazine were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of promethazine in human serum samples for the pharmacokinetic studies of orally administered Himazin tablet (25 mg as promethazine hydrochloride) at three different laboratories, demonstrating the suitability of the method.

Multiple Period Forecasting of Motorway Traffic Volumes by Using Big Historical Data (대용량 이력자료를 활용한 다중시간대 고속도로 교통량 예측)

  • Chang, Hyun-ho;Yoon, Byoung-jo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.1
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    • pp.73-80
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    • 2018
  • In motorway traffic flow control, the conventional way based on real-time response has been changed into advanced way based on proactive response. Future traffic conditions over multiple time intervals are crucial input data for advanced motorway traffic flow control. It is necessary to overcome the uncertainty of the future state in order for forecasting multiple-period traffic volumes, as the number of uncertainty concurrently increase when the forecasting horizon expands. In this vein, multi-interval forecasting of traffic volumes requires a viable approach to conquer future uncertainties successfully. In this paper, a forecasting model is proposed which effectively addresses the uncertainties of future state based on the behaviors of temporal evolution of traffic volume states that intrinsically exits in the big past data. The model selects the past states from the big past data based on the state evolution of current traffic volumes, and then the selected past states are employed for estimating future states. The model was also designed to be suitable for data management systems in practice. Test results demonstrated that the model can effectively overcome the uncertainties over multiple time periods and can generate very reliable predictions in term of prediction accuracy. Hence, it is indicated that the model can be mounted and utilized on advanced data management systems.

Charaeteristics and Applications of the Established Testosterone Immunoassays (Testosterone 면역측정법의 정립 특성과 응용)

  • Lee, Chang-Joo;Lee, Joon-Yeoung;Yoon, Yong-Dal
    • Development and Reproduction
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    • v.5 no.1
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    • pp.59-71
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    • 2001
  • Since the first radioimmunoassay (RIA) was developed in 1970s, many conventional RIAs and non-isotopic immunoassays (NIA) had been developed in which the degree of precision, accuracy, specificity and practicability have progressively increased. Recently ultrasensitive assay method at femtogram to determine testosterone in serum, saliva and feces is required for the study of sexual dysfunctions in male and female, monitoring the psychological stress and conditions, aging process such as menopause and partial androgen deficiency in aging male, the hormonal changes of small experimental animals etc. This review discussed the recentd evelopments of steroid assay methods, based upon the testosterone assay results of authors far 20 years, and the problems associated the assay set-up, the characterizations and applications of the established procedures, and desifls of assay, reliablity criteria, and the practical aspects of assay set-up and application, based upon the data of the authors. The present study demonstrates the general problems methods to be consider in order to set up the highly sensitive assay methods and to increase the assay quality and the necessity of assay quality control program. To improve the assay quality of each laboratory and to compare the assay results in homeland, the national QC programs should be organized.

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Determination of geosmin and 2-MIB in Nakdong River using headspace solid phase microextraction and GC-MS (HS-SPME-GC/MS를 이용한 낙동강 수계 하천수 중 조류기원성 냄새물질 분석)

  • Lee, Injung;Lee, Kyoung-Lak;Lim, Tae-Hyo;Park, Jeong-Ja;Cheon, Seuk
    • Analytical Science and Technology
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    • v.26 no.5
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    • pp.326-332
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    • 2013
  • Geosmin and 2-methylisoborneol (2-MIB) are volatile organic compounds responsible for the majority of unpleasant taste and odor events in drinking water. Geosmin and 2-MIB are byproducts of blue-green algae (cyanobacteria) with musty and earthy odors. These compounds have odor threshold concentration at ng/L levels. It is needed to develop a sensitive method for determination of geosmin and 2-MIB to control the quality of drinking water. In this study, geosmin and 2-MIB in water samples were determined by gas chromatography-mass spectrometry (GC-MS) with headspace-solid phase microextraction (HS-SMPE). The detection limits of this method were 1.072 ng/L and 1.021 ng/L for geosmin and 2-MIB, respectively. Good accuracy and precision was also obtained by this method. Concentrations of the two compounds were measured in raw waters from Nakdong River in the cyanobacterial blooming season. Water bloom formed by cyanobacteria has been occurred currently in Nakdong River. It is needed to investigate the concentrations of geosmin and 2-MIB to control the quality of drinking water from Nakdong River. Both geosmin and 2-MIB were detected in raw waters from Nakdong River at concentrations ranging from 4 to 24 ng/L and 6 to 16 ng/L, respectively.

3D Digital Design Optimization Process Considering Constructability of Freeform Structure (비정형 구조물의 시공성을 고려한 3차원 디지털 설계 최적화 프로세스)

  • Ryu, Han-Guk
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.5
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    • pp.35-43
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    • 2013
  • Nowadays the widely used media in architecture include visualizations, animations and three-dimensional models. 3D digital methods using active CAM(Computer Aided Manufacturing) and CNC(Computerized Numerical Control) imaging have been developed for accurate shape and 3D measurements in freeform buildings. In contrast to a conventional building using auto CAD system and others, the proposed digital optimization method is based on a combination of 3D numerical data and parametric 3D model for design and construction. The objective of this paper is therefore to present digital optimization process for constructability of freeform building. The method can be useful in the effective implementation of an error-proofing process of freeform building during design and construction phase. 3D digital coordinate data can be used effectively to identify correct size of structural and finish members and installation location of each members in construction field. In addition, architects, engineers and contractors can evaluate design, materials, constructability and identify error-proofing opportunities. Other project participants can also include representatives from all levels of management, departments as well as workers and key subcontractors' personnel, if necessary. The 3D digital optimization process is therefore appropriate to serious variations in freeform shape. For future study, the developed digital optimization method is necessary to be carried out to verify the robustness and accuracy for constructability in construction field.

The long-term effect of Interactive Video Game on Cognitive Information Processing the elderly: P300 (장기간의 상호작용적 비디오 게임이 노인의 인지정보처리에 미치는 영향: P300)

  • Kim, Sung-Woon;Kim, Han-Cheol
    • Journal of Digital Convergence
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    • v.18 no.8
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    • pp.493-504
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    • 2020
  • The objectives of this study was to examine the effect of Interactive Video Game on cognitive information processing the elderly. Sixty elderly were attended in this study. Their ages ranged from 65 to 70, with a mean age of 67.60 years. The subjects were randomly assigned to one of three experimental conditions: (1) interactive video game group (n=20), (2) aerobic exercise group (n=20), (3) control group (n=20). The experimental design of this study was analyzed using two-way ANOVAs with repeated measures of groups and time. Cognitive function was assessed by neuroelectrical response, and ERP analysis. The results of the study showed that the interactive video game group and aerobic exercise group showed no significant statistical differences in the response time, response accuracy, amplitude and potential of the performance of the exercise in cognitive function and ERP analysis, but improved the interaction video game group and aerobic exercise (walking) group over the control group. It was concluded that long-term aerobic exercise like interactive video game is associated with attenuation of cognitive decline in the elderly.

Development of Models for Estimating Growth of Quinoa (Chenopodium quinoa Willd.) in a Closed-Type Plant Factory System (완전제어형 식물공장에서 퀴노아 (Chenopodium quinoa Willd.)의 생장을 예측하기 위한 모델 개발)

  • Austin, Jirapa;Cho, Young-Yeol
    • Journal of Bio-Environment Control
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    • v.27 no.4
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    • pp.326-331
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    • 2018
  • Crop growth models are useful tools for understanding and integrating knowledge about crop growth. Models for predicting plant height, net photosynthesis rate, and plant growth of quinoa (Chenopodium quinoa Willd.) as a leafy vegetable in a closed-type plant factory system were developed using empirical model equations such as linear, quadratic, non-rectangular hyperbola, and expolinear equations. Plant growth and yield were measured at 5-day intervals after transplanting. Photosynthesis and growth curve models were calculated. Linear and curve relationships were obtained between plant heights and days after transplanting (DAT), however, accuracy of the equation to estimate plant height was linear equation. A non-rectangular hyperbola model was chosen as the response function of net photosynthesis. The light compensation point, light saturation point, and respiration rate were 29, 813 and $3.4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. The shoot fresh weight showed a linear relationship with the shoot dry weight. The regression coefficient of the shoot dry weight was 0.75 ($R^2=0.921^{***}$). A non-linear regression was carried out to describe the increase in shoot dry weight of quinoa as a function of time using an expolinear equation. The crop growth rate and relative growth rate were $22.9g{\cdot}m^{-2}{\cdot}d^{-1}$ and $0.28g{\cdot}g^{-1}{\cdot}d^{-1}$, respectively. These models can accurately estimate plant height, net photosynthesis rate, shoot fresh weight, and shoot dry weight of quinoa.

Study on Developing Assessment Guideline for Safety and Performance of Electric Moxibustion Apparatus (전기식 온구기에 대한 안전성 및 성능 평가 가이드라인 개발 연구)

  • Yi, Seung-Ho;Kang, Jung-Won;Nam, Dong-Woo;Kim, Eun-Jung;Lee, Hye-Jung;Kim, Kap-Sung;Lee, Jae-Dong
    • Journal of Acupuncture Research
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    • v.27 no.1
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    • pp.75-86
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    • 2010
  • Objectives : We developed and proposed a guideline for safety and performance assessment of electric moxibustion apparatus (class II medical device). Methods : We drafted the guideline for safety and performance assessment of electric moxibustion apparatus by referring the existing standards, guidelines and measurement data from commercially available products. Temperature characteristics such as maximum temperature and ramp time, and physical characteristics such as weight, noise and diameter were measured. User friendliness was also evaluated for commercial devices. Results : This guideline only can be applied to the electric moxibustion apparatus where moxa is being heated by electricity for medical proposes. Maximum temperature of higher than $50^{\circ}C$ can be achieved mostly. Ramp rate of temperature seems to be reliable. Control of temperature is needed to be improved. Moxa and its derivative products seem to be regulated for reliable temperature performance for clinical application. Requirements for design and development of electric moxibustion apparatus are suggested : temperature indicator, temperature control and its accuracy, safety measure, surge protection, user friendliness and instruction for use (IFU). Design recommendation of the reduction of noise level and energy loss are suggested for better products. Conclusions : We proposed a guideline for safety and performance assessment of electric moxibustion apparatus to improve the quality of relating products and aid their commercialization by aiming higher industrial competitiveness of the medical device sectors in Korea. Discussion with related institutes such as industry, academy and government is further required. Public hearings also need to be held prior to the establishment of a final guideline and standard.

THE CHANGES OF SERUM C-REACTIVE PROTEIN IN THE HEAD AND NECK INFECTION (두경부 감염 환자에서 혈청 내 C-Reactive Protein의 변화)

  • Lee, Ju-Hyun;Kim, Chin-Soo;Lee, Sang-Han;Kim, Chul-Hwan
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.29 no.1
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    • pp.5-13
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    • 2003
  • The purpose of this study is to determine the value of serum concentration of C-reactive protein(CRP) in comparison with ESR and leukocyte as the tools for diagnosis and follow-up study of infection. For this study, thirty-one patients with head and neck infection and thirty-two patients performed the orthognathic surgery were selected for experimental and control groups each other. we analyzed the blood sample daily to measure CRP, ESR and leukocytosis. The results of this study are as the following : 1. Serum C-Reactive Protein levels in the experimental group were higher than control group and the pattern of CRP changes continued to decline in both groups(P<0.001). 2. ESR changes in both groups were scattered without any special pattern. 3. Correlation between CRP and Leukocyte was higher than others(r=0.664, P<0.01). 4. In the Receiver Operating Characteristic(ROC) Curve of experimental group, rapid increase of CRP curve and Area under the curve(AUC) value, 0.774, indicate the high accuracy of estimation. 5. In experimental group, sensitivity of CRP, ESR, and Leukocytosis on recovery day were 83%, 17% and 71%. Based on the results of this study, we could conclude that determination of CRP is more useful method to diagnosis and follow-up study of infection than other commonly used variables in oral and maxillofacial region.

Welfare Interface using Multiple Facial Features Tracking (다중 얼굴 특징 추적을 이용한 복지형 인터페이스)

  • Ju, Jin-Sun;Shin, Yun-Hee;Kim, Eun-Yi
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.1
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    • pp.75-83
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    • 2008
  • We propose a welfare interface using multiple fecial features tracking, which can efficiently implement various mouse operations. The proposed system consist of five modules: face detection, eye detection, mouth detection, facial feature tracking, and mouse control. The facial region is first obtained using skin-color model and connected-component analysis(CCs). Thereafter the eye regions are localized using neutral network(NN)-based texture classifier that discriminates the facial region into eye class and non-eye class, and then mouth region is localized using edge detector. Once eye and mouth regions are localized they are continuously and correctly tracking by mean-shift algorithm and template matching, respectively. Based on the tracking results, mouse operations such as movement or click are implemented. To assess the validity of the proposed system, it was applied to the interface system for web browser and was tested on a group of 25 users. The results show that our system have the accuracy of 99% and process more than 21 frame/sec on PC for the $320{\times}240$ size input image, as such it can supply a user-friendly and convenient access to a computer in real-time operation.