Forecast of Growth and Development of Modal Fir Stands in the Lower Angara Region

The paper presents an assessment of the growth dynamics of the modal fir plantations in the Lower Angara region. At present, a vast area of fir forests in the Lower Angara region is characterised by a significant decrease in sustainability due to periodic forest fires, insect pests outbreaks and diseases, which lead to their natural degradation and death. However, the intensity of coniferous stand growth in certain forest site characteristics persists in the long term. Therefore, creating regression models of forest growth and development involving the identification of site conditions is very important both from a practical point of view and for environmental monitoring. The materials of the mass inventory of 3491 stands served as the initial data for studying the processes of fir plantations natural growth. The Hoerl Model function is suitable for the best approximation of stand growth since it is characterised by high levelling factor (from 0.970 to 0.987) and a small standard error (not exceeding 7%). As a result of the research, there have been constructed sketches of the growth rate tables for the modal Siberian fir stands of the third bonitet class of the forb and mossy groups of forest types.

Bootstrap Residual Ensemble Methods for Estimation of Standard Error of Parameter Logistic Regression To Hypercolesterolemia Patient Data In Health Laboratory Yogyakarta

Logistic regression is one of regression analysis to determine the relationship between response variable that have two possible values and some predictor variables. The method used to estimate logistic regression parameters is the maximum likelihood estimation (MLE) method. This method will produce a good estimate of the parameters if the estimation results have a small standard error.<br />In a research, the characteristics of good data must be representative of the population. If the samples taken in small size they will cause a large standard error value. Bootstrap is a resampling method that can be used to obtain a good estimate based on small data samples. Small data will be resampling so it can represent the population to obtain minimum standard error. Previous studies have discussed resampling bootstrap on residuals as much as b times. In this research we will be analyzed resampling bootstrap on the error added to the dependent variable and take the average parameter estimation ensemble logistic regression model resampling result. Next we calculate the standard value error logistic regression parameters bootstrap results.<br />This method is applied to the hypercholesterolemic patient status data in Health Laboratory Yogyakarta and after bootstrapping, the standard error produced is smaller than before the bootstrap resampling.<br />Keywords : logistic regression, standard error, bootstrap resampling, parameter estimation ensemble

Feasibility study of using a Microsoft Kinect for virtual coaching of wheelchair transfer techniques

The purpose of this study was to test the concurrent validity and test-retest reliability of the Kinect skeleton tracking algorithm for measurement of trunk, shoulder, and elbow joint angle measurement during a wheelchair transfer task. Eight wheelchair users were recruited for this study. Joint positions were recorded simultaneously by the Kinect and Vicon motion capture systems while subjects transferred from their wheelchairs to a level bench. Shoulder, elbow, and trunk angles recorded with the Kinect system followed a similar trajectory as the angles recorded with the Vicon system with correlation coefficients that are larger than 0.71 on both sides (leading arm and trailing arm). The root mean square errors (RMSEs) ranged from 5.18 to 22.46 for the shoulder, elbow, and trunk angles. The 95% limits of agreement (LOA) for the discrepancy between the two systems exceeded the clinical significant level of 5°. For the trunk, shoulder, and elbow angles, the Kinect had very good relative reliability for the measurement of sagittal, frontal and horizontal trunk angles, as indicated by the high intraclass correlation coefficient (ICC) values (>0.90). Small standard error of the measure (SEM) values, indicating good absolute reliability, were observed for all joints except for the leading arm’s shoulder joint. Relatively large minimal detectable changes (MDCs) were observed in all joint angles. The Kinect motion tracking has promising performance levels for some upper limb joints. However, more accurate measurement of the joint angles may be required. Therefore, understanding the limitations in precision and accuracy of Kinect is imperative before utilization of Kinect.

Near-Field Touch Interface Using Time-of-Flight Camera

[abstFig src='/00280005/20.jpg' width='300' text='Near-field touch interface system, NFTIS' ] The purpose of this study is to realize a near-field touch interface that is compact, flexible, and highly accurate. We applied a 3-dimensional image sensor (time-of-flight camera) to achieve the basic functions of conventional touch interfaces, such as clicking, dragging, and sliding, and we designed a complete projector-sensor system. Unlike conventional touch interfaces, such as those on tablet PCs, the system can sense the 3-dimensional positions of fingertips and 3-dimensional directions of fingers. Moreover, it does not require a real touch screen but instead utilizes a mobile projector for display. Nonetheless, the system is compact, with a working distance of as short as around 30 cm. Our methods solve the shadow and reflection problems of the time-of-flight camera and can provide robust detection results. Tests have shown that our approach has a high success rate (98.4%) on touch/hover detection and a small standard error (2.21 mm) on position detection on average for different participants, which is the best performance we have achieved. Some applications, such as the virtual keyboard and virtual joystick, are also realized based on the proposed projector-sensor system.

Pengukuran Luas Daun dengan Metode Simpson

Since leaf area has important role in photosynthesis and often used in plant growth analysis, it is important to use a method of leaf area measurement that are easy, cheap, accurate and widely applicable. In this research we use Simpson method to measure leaf area of mango, mustard, guava and banana and the result will be used to calculate the ratio of leaf area and long times wide of leaf. The result indicate that the ratio calculated in this method has smaller standard error than the gravimetric method conducted by previous researcher. Furthermore, the ratios of the leafs have small standard error.

Adjustment coefficients for planimetric analysis of the granulometry of coarse-grained sediments

Adjustment coefficients for planimetric analysis of the granulometry of coarse-grained sedimentsThe relationship between results from granulometric analyses of by sieving and by planimetry was investigated by numerical simulation of cubes filled with boulders, cobbles and pebbles. Cross-sections through the sediment were simulated and compared with photos of an actual outcrop wall. Volumes estimated on the basis of planimetric analysis using the cross-sections were compared with sieve analyses, thus allowing to determine adjustment coefficients. The coefficients for pebbles and cobbles have a small standard error, but are larger for boulders, which might be a consequence of too small areas formed by the cross-sections.

A SIMPLE, RELIABLE METHOD OF MEASURING GLOMERULAR FILTRATION RATE USING SINGLE, LOW DOSE SODIUM IOTHALAMATE I131

The renal clearances of sodium iothalamate I131 after a single intravenous dose of 10 µCi were compared with inulin clearances and endogenous creatinine clearances. In a total of 40 comparative studies made between the isotope and inulin clearances, correlation was excellent (r = .995) with a very small standard error (±5.9), suggesting that sodium iothalamate I131 clearance accurately measures glomerular filtration rate. In 43 comparative studies between endogenous creatinine and inulin clearances, correlation was good (r = .935) only when determined simultaneously, and even then the standard error was so great (± 18.7) that any individual creatinine clearance was of limited value. In performing the isotope clearance, adequate hydration is maintained orally. Ten microcuries of sodium iothalamate I131 are injected intravenously. After a 30 to 60 minute equilibration period, the bladder is emptied by voiding and a blood specimen obtained. A timed, voided urine is then collected and again a blood specimen obtained at the time of voiding. Both blood specimens and the urine are counted in a well-type scintillation counter with gamma spectrometer. The mean of the beginning and end-point plasma radioactivity is used in the clearance formula. This isotope method is recommended as the test of choice in measuring glomerular filtration rate.

A PRELIMINARY STUDY OF AERIAL VOLUME TABLE CONSTRUCTION FOR LODGEPOLE PINE IN WEST-CENTRAL ALBERTA

Some aspects of photo-measurement and aerial volume table construction for the pure lodgepole pine type are dealt with. Tables giving gross stand volume in cubic feet are shown with stand height as the independent variable. Crown closure was not significantly correlated with gross stand volume in this study; probably because only fully-stocked stands were surveyed.The 70-plot sample was divided into three strata composed of distinct parent materials. The data from stands on one stratum, the lacustrine deposits which are mapped as the Caroline Silt Loam soil series, were developed into a regression equation which differed from the composite equation (for all parent materials).This study indicated that trained photogrammetrists can consistently measure tree heights to 8-foot height classes with a uniformly small standard error. It also indicates that a larger sample may permit the development of different aerial volume tables for different parent materials or soil types.

A new Monte Carlo technique: antithetic variates

As we have stressed in a previous paper (9), the main concern in Monte Carlo work is to achieve without inordinate labour a respectably small standard error in the final result. Mere replication of the Monte Carlo results is unrewarding; for, to reduce a standard error by a factor k, the labour must be increased k2-fold, and this will be beyond the resources of even electronic computers when k = 1000, say. The remedy lies in a skilful choice of sampling technique and the substitution of analytical methods for random processes wherever possible. The efficiency of a Monte Carlo process may be taken as inversely proportional to the product of the sampling variance of the final estimate and the amount of labour expended in obtaining this estimate; and it is profitable to allow some increase in the labour if that produces an overwhelming decrease in the variance. For instance, in the last example quoted below (Table 2), we reduce the variance by a factor of four million at the expense of only multiplying the labour sixteenfold, thereby attaining a 250,000-fold gain of efficiency.