• Title/Summary/Keyword: absolute model accuracy

Search Result 267, Processing Time 0.023 seconds

Pharmacodynamic Modeling of Vincristine in Lymphoma Patients (림프종 환자에서 회귀모형을 이용한 vincristine의 약물 용량 예측 인자 및 부작용 모델 연구)

  • Seo, Jeong-Won;Kim, Dong-Hyun;Yun, Jin-Sang;Kim, Seon-Hwa;Choi, Bo-Yoon;Oh, Jung-Mi;Kwon, Kwang-Il
    • Korean Journal of Clinical Pharmacy
    • /
    • v.21 no.2
    • /
    • pp.145-155
    • /
    • 2011
  • The objective of this study was to determine whether any pretreatment parameters were associated with pharmacological effect or toxicity parameters after vincristine administration and to describe a mathematical model, which explains the interpatient pharmacodynamic variability. The relationship between patient characteristics and vincristine dose and hematological toxicity were evaluated. 68 pediatric and adolescence patients and 107 adults with acute lymphoblastic leukemia were treated with vincristine $1.5mg/m^2/day$ IV and other anticancer drugs as scheduled. Complete blood counts and other blood test results were obtained. The input variables were age, gender, weight, lean body weight (LBW), height, body surface area, vincristine dose and total vincristine dose. The outcome measures were nadir values (white blood cells, absolute neutrophil counts, hemoglobin, and platelets); the absolute decrease, relative decrease, and survival fraction of blood cells. Polynomial regression analysis was carried out to determine the other significant covariates. The variability of $WBC_{nadir}$ was modeled with good precision and accuracy with a two-covariate model. This model should be validated and improved on with further clinical data. We believe that such pharmacodynamic modeling should be explored further to determine its performance and clinical relevance compared with modeling using pharmacokinetic parameter.

Development of Korean VTEC Polynomial Model Using GIM

  • Park, Jae-Young;Kim, Yeong-Guk;Park, Kwan-Dong
    • Journal of Positioning, Navigation, and Timing
    • /
    • v.11 no.4
    • /
    • pp.297-304
    • /
    • 2022
  • The models used for ionosphere error correction in positioning using Global Navigation Satellite System (GNSS) are representatively Klobuchar model and NeQuick model. Although these models can correct the ionosphere error in real time, the disadvantage is that the accuracy is only 50-60%. In this study, a method for polynomial modeling of Global Ionosphere Map (GIM) which provides Vertical Total Electron Content (VTEC) in grid type was studied. In consideration of Ionosphere Pierce Points (IPP) of satellites with a receivable elevation angle of 15 degrees or higher on the Korean Peninsula, the target area for model generation and provision was selected, and the VTEC at 88 GIM grid points was modeled as a polynomial. The developed VTEC polynomial model shows a data reduction rate of 72.7% compared to GIM regardless of the number of visible satellites, and a data reduction rate of more than 90% compared to the Slant Total Electron Content (STEC) polynomial model when there are more than 10 visible satellites. This VTEC polynomial model has a maximum absolute error of 2.4 Total Electron Content Unit (TECU) and a maximum relative error of 9.9% with the actual GIM. Therefore, it is expected that the amount of data can be drastically reduced by providing the predicted GIM or real-time grid type VTEC model as the parameters of the polynomial model.

Streamflow Forecast Model on Nakdong River Basin (낙동강유역 하천유량 예측모형 구축)

  • Lee, Byong-Ju;Bae, Deg-Hyo
    • Journal of Korea Water Resources Association
    • /
    • v.44 no.11
    • /
    • pp.853-861
    • /
    • 2011
  • The objective of this study is to assess Sejong University River Forecast (SURF) model which consists of a continuous rainfall-runoff model and measured streamflow assimilation using ensemble Kalman filter technique for streamflow forecast on Nakdong river basin. The study area is divided into 43 subbasins. The forecasted streamflows are evaluated at 12 measurement sites during flood season from 2006 to 2007. The forecasted ones are improved due to the impact of the measured streamflows assimilation. In effectiveness indices corresponding to 1~5 h forecast lead times, the accuracy of the forecasted streamflows with the assimilation approach is improved by 46.2~30.1% compared with that using only the rainfall-runoff model. The mean normalized absolute error of forecasted peak flow without and with data assimilation approach in entering 50% of the measured rainfall, respectively, the accuracy of the latter is improved about 40% than that of the former. From these results, SURF model is able to be used as a real-time river forecast model.

Quantitative Analysis of Automotive Radar-based Perception Algorithm for Autonomous Driving (자율주행을 위한 레이더 기반 인지 알고리즘의 정량적 분석)

  • Lee, Hojoon;Chae, HeungSeok;Seo, Hotae;Yi, Kyongsu
    • Journal of Auto-vehicle Safety Association
    • /
    • v.10 no.2
    • /
    • pp.29-35
    • /
    • 2018
  • This paper presents a quantitative evaluation method and result of moving vehicle perception using automotive radar. It is also important to analyze the accuracy of the perception algorithm quantitatively as well as to accurately percept nearby moving vehicles for safe and efficient autonomous driving. In this study, accuracy of the automotive radar-based perception algorithm which is developed based on interacting multiple model (IMM) has been verified via vehicle tests on real roads. In order to obtain experimental data for quantitative evaluation, Long Range Radar (LRR) has been mounted on the front of the ego vehicle and Short Range Radar (SRR) has been mounted on the rear side of both sides. RT-range has been installed on the ego vehicle and the target vehicle to simultaneously collect reference data on the states of the two vehicles. The experimental data is acquired in various relative positions and velocity, and the accuracy of the algorithm has been analyzed according to relative position and velocity. Quantitative analysis is conducted on relative position, relative heading angle, absolute velocity, and yaw rate of each vehicle.

Development of a Portable Multi-sensor System for Geo-referenced Images and its Accuracy Evaluation (Geo-referenced 영상 획득을 위한 휴대용 멀티센서 시스템 구축 및 정확도 평가)

  • Lee, Ji-Hun;Choi, Kyoung-Ah;Lee, Im-Pyeong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.28 no.6
    • /
    • pp.637-643
    • /
    • 2010
  • In this study, we developed a Portable Multi-sensor System, which consists of a video camera, a GPS/MEMS IMU and a UMPC to acquire video images and position/attitude data. We performed image georeferencing based on the bundle adjustment without ground control points using the acquired data and then evaluated the effectiveness of our system through the accuracy verification. The experimental results showed that the RMSE of relative coordinates on the ground point coordinates obtained from our system was several centimeters. Our system can be efficiently utilized to obtain the 3D model of object and their relative coordinates. In future, we plan to improve the accuracy of absolute coordinates through the rigorous calibration of the system and camera.

Comparative analysis on digital models obtained by white light and blue LED optical scanners (백색광과 청색 LED 방식의 광학스캐너로 채득된 디지털 모형의 비교분석)

  • Choi, Seog-Soon;Kim, Jae-Hong;Kim, Ji-Hwan
    • Journal of Technologic Dentistry
    • /
    • v.36 no.1
    • /
    • pp.17-23
    • /
    • 2014
  • Purpose: The purpose of this study was to analyze and compare the relative accuracy of digitized stone models of lower full arch, using two different scanning system. Methods: Replica stone models(N=20) were produced from lower arch acrylic model. Twenty digital models were made with the white light and blue LED($Medit^{(R)}$, Korea) scanner. Two-dimensional distance between the landmarks were measured on the Delcam $CopyCAD^{(R)}$(Delcam plc, UK). Independent samples t-test was applied for comparison of the groups. All statistical analyses were performed using the SPSS software package(Statistical Package for Social Sciences for Windows, version 12.0). Results: The absolute disagreement between measurements made directly on the two different scanner-based dental digital models was 0.02~0.04mm, and was not statistically significant(P>0.05). Conclusion: The precision of the blue LED optical scanner was comparable with the digitization device, and relative accuracy was similar. However, there still is room for improvement and further standardization of dental CAD technologies.

SCARA robot calibration on off-line programming (오프라인 프로그래밍에서 스카라 로봇의 보정)

  • Jung, Sung-Woo;Son, Kwon;Lee, Min-Chul;Choi, Jae-Won
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1997.10a
    • /
    • pp.1832-1835
    • /
    • 1997
  • Off-line programming systems are widely spread in assembly lines of minute electronic products to huge offshore structures. Any OLP system has to be calibrated before the on-line robot tasks are performed because there are inherent differences between the CAD model on OLP and the real robot workspace. This paper uses simple geometric expressions to propose a calibration method applicable to an OLP for SCARA robots. A positioning task on the two-dimensional horizontal surface was used in the error analysis of a SCARA robot and the anaysis shows that the inaccuracy results from the two error sources non-zero offset angles of two rotational joints at the zero return and differences in link lengths. Pen marks on a sheet of plotting paper are used to determine the accurate data on the joint centers and link dimensions. The calculated offset angles and link lengths are fed back to the OLP for the calibration of the CAD model of the robot and task environments.

  • PDF

Accuracy Improvement of the ICP DEM Matching (ICP DEM 매칭방법의 정확도 개선)

  • Lee, Hyoseong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.33 no.5
    • /
    • pp.443-451
    • /
    • 2015
  • In photogrammetry, GCPs (Ground Control Points) have traditionally been used to determine EOPs (Exterior Orientation Parameters) and to produce DEM (Digital Elevation Model). The existing DEM can be used as GCPs, where the observer’s approach is a difficult area, because it is very restrictive to survey in the field. For this, DEM matching should be performed. This study proposed the fusion method using ICP (Iterative Closest Point) and RT (proposed method by Rosenholm and Torlegard, 1988) in order to improve accuracy of the DEM matching. The proposed method was compared to the ICP method to evaluate its usefulness. Pseudo reference DEM with resolution 10m, and modified DEM (random-numbers are added from 0 to 2 at height; scale is 0.9; translation is 100 meters in 3-D axes; rotation is from 10° to 50° from the reference DEM) were used in the experiment. The results proposed accuracy was highest in the matching and absolute orientation. In the case of ICP, according to rotation of the modified DEM being increased, absolute orientation error is increased, while the proposed method generally showed consistent results without increasing the error. The proposed method would be applied to matching when the DEM is modified up to 30° rotation, compared to the reference DEM, based on the results of experiments. In addition when we use Drone, this method can be utilized to identify EOPs or detect 3-D surface deformation from the existing DEM of the inaccessible area.

Prediction of 305 Days Milk Production from Early Records in Dairy Cattle Using an Empirical Bayes Method

  • Pereira, J.A.C.;Suzuki, M.;Hagiya, K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.14 no.11
    • /
    • pp.1511-1515
    • /
    • 2001
  • A prediction of 305 d milk production from early records using an empirical Bayes method (EBM) was performed. The EBM was compared with the best predicted estimation (BPE), test interval method (TIM), and the linearized Wood's model (LWM). Daily milk yields were obtained from 606 first lactation Japanese Holstein cows in three herds. From each file of 305 daily records, 10 random test day records with an interval of approximately one month were taken. The accuracies of these methods were compared using the absolute difference (AD) and the standard deviation (SD) of the differences between the actual and the estimated 305 d milk production. The results showed that in the early stage of the lactation, EBM was superior in obtaining the prediction with high accuracy. When all the herds were analyzed jointly, the AD during the first 5 test day records were on average 373, 590, 917 and 1,042 kg for EBM, BPE, TIM, and LWM, respectively. Corresponding SD for EBM, BPE, TIM, and LWM were on average 488, 733, 747 and 1,605 kg. When the herds were analyzed separately, the EBM predictions retained high accuracy. When more information on the actual lactation was added to the prediction, TIM and LWM gradually achieved better accuracies. Finally, in the last period of the lactation, the accuracy of both of the methods exceeded EBM and BPM. The AD for the last 2 samples analyzing all the herds jointly were on average 141, 142, 164, and 214 kg for LWM, TIM, EBM, and BPE, respectively. In the current practices of collecting monthly records, early prediction of future milk production may be more accurate using EBM. Alternatively, if enough information of the actual lactation is accumulated, TIM may obtain better accuracy in the latter stage of lactation.

Modeling of Winter Time Apartment Heating Load in District Heating System Using Reduced LS-SVM (Reduced LS-SVM을 이용한 지역난방 동절기 공동주택 난방부하의 모델링)

  • Park, Young Chil
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.27 no.6
    • /
    • pp.283-292
    • /
    • 2015
  • A model of apartment heating load in a district heating system could be useful in the management and utilization of energy resources, since it could predict energy usage and so could assist in the efficient use of energy resources. The heating load in a district heating system varies in a highly nonlinear manner and is subject to many different factors, such as heating area, number of people living in that complex, and ambient temperature. Thus there are few published papers with accurate models of heating load, especially in domestic literature. This work is concerned with the modeling of apartment heating load in a district heating system in winter, using the reduced least square support vector machine (LS-SVM), and with the purpose of using the model to predict heating energy usage in domestic city area. We collected 23,856 pieces of data on heating energy usage over a 12-week period in winter, from 12 heat exchangers in five apartments. Half of the collected data were used to construct the heating load model, and the other half were used to test the model's accuracy. The model was able to predict the heating energy usage pattern rather accurately. It could also estimate the usage of heating energy within of mean absolute percentage error. This implies that the model prediction accuracy needs to be improved further, but it still could be considered as an acceptable model if we consider the nonlinearity and uncertainty of apartment heating energy usage in a district heating system.