• Journal of Navigation and Port Research
• /
• v.28 no.10 s.96
• /
• pp.851-859
• /
• 2004

This paper describes a new method for the acquisition of deviation coefficients, B and C, using a single observed deviation at a fixed compass heading. At first it discusses some problems in the synthesis of two coefficients, B and C, from various observed deviation values in the four USS warships. Then, new theories and procedures for optimal coefficients, $\^{B}\;and\;\^{C},$ are dealt with and then the validity of the proposed method are evaluated. The result of findings indicates that the approximated coefficients, $\^{B}\;and\;\^{C},$ can give optimal approximation to an single observed deviation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.11a
• /
• pp.23-32
• /
• 2004

This paper describes a new estimation method for deviation coefficients, B and C. using only measured single deviation at a fixed compass bearing. At first, some problems in the deviation synthesis with only two coefficients, B and C, are discussed using observed deviation values measured in the four USS warships. Then, acquisition theories and procedures to obtain optimal coefficients, B and C, are expanded and then the efficiencies of the proposed prediction method are evaluated. As results from evaluations, it is shown that the approximated coefficients, B and C, can give optimal approximation to observed single deviation.

• Journal of the Korean Statistical Society
• /
• v.33 no.4
• /
• pp.381-399
• /
• 2004

Statistical process control (SPC) and engineering process control (EPC) are based on different strategies for process quality improvement. SPC re-duces process variability by detecting and eliminating special causes of process variation, while EPC reduces process variability by adjusting compensatory variables to keep the quality variable close to target. Recently there has been need for an integrated process control (IPC) procedure which combines the two strategies. This paper considers a scheme that simultaneously applies SPC and EPC techniques to reduce the variation of a process. The process model under consideration is an IMA(1,1) model with a step shift. The EPC part of the scheme adjusts the process, while the SPC part of the scheme detects the occurrence of a special cause. For adjusting the process repeated adjustment is applied according to the predicted deviation from target. For detecting special causes the exponentially weighted moving average control chart is applied to the observed deviations. It was assumed that the adjustment under the presence of a special cause may increase the process variability or change the system gain. Reasonable choices of parameters for the IPC procedure are considered in the context of the mean squared deviation as well as the average run length.

• Journal of Educational Research in Mathematics
• /
• v.24 no.3
• /
• pp.375-385
• /
• 2014

This study compares the confidence interval estimation of population mean with that of population ratio, and considers whether these two estimations ensures consistency. As a result, this study suggests the following acquisition method of consistency : dealing with population mean and population ratio in the same mode, substituting the observed or experimental value of sample standard deviation for standard deviation in population in setting a confidence interval of both population mean and population ratio, and distinguishing population ratio $\hat{P}$ from its observed vale $\hat{p}$.

• Journal of Biomedical Engineering Research
• /
• v.11 no.1
• /
• pp.13-18
• /
• 1990

Frequency responses of ambulatory electrocardiogram systems were measured. Phase shift was assessed by our improved Wagner's method. The characteristics of the systems were found much worse than that of ordinary ECG equipment both in gain and phase responses. The decay of -3dB in amplitude observed in 0.2Hz and the lead of 45 dog in phase was observed in 0.6Hz. In order to investigate which of these 2 responses play major role in generating false S -T deviation, mathe- matical filters were Composed in a computer and actual ECGs were fed. The false S-T deviation were found to be caused mostly by enormous lead in phase, and then, the compensation circuit to diminish the lead in phase was inserted in the commercial systemes. The compensated systems showed no false deviation in S-T segment.

• Current Optics and Photonics
• /
• v.3 no.3
• /
• pp.210-214
• /
• 2019

The allowable path-deviation time of aircraft in a free-space optical communication system has been estimated from various trajectories, using different values of aircraft speeds and turn rates. We assumed the existence of a link between the aircraft and a ground base station. First, the transmitter beam's divergence angle was calculated through two different approaches, one based on a simple optical-link equation, and the other based on an attenuation coefficient. From the calculations, the discrepancy between the two approaches was negligible when the link distance was approximately 110 km, and was under 5% when the link distance ranged from 80 to 140 km. Subsequently, the allowable path-deviation time of the aircraft within the tracking-error tolerance of the system was estimated, using different aircraft speeds, turn rates, and link distances. The results indicated that the allowable path-deviation time was primarily determined by the aircraft's speed and turn rate. For example, the allowable path-deviation time was estimated to be ~3.5 s for an aircraft speed of 166.68 km/h, a turn rate of $90^{\circ}/min$, and a link distance of 100 km. Furthermore, for a constant aircraft speed and turn rate, the path-deviation time was observed to be almost unchanged when the link distance ranged from 80 to 140 km.

• Journal of Yeungnam Medical Science
• /
• v.34 no.2
• /
• pp.290-292
• /
• 2017

Various changes in ocular position are possible during general anesthesia as opposed to the awakening state. However, unexpected ocular deviation under general anesthesia is a disconcerting event as it can lead to difficult complications intraoperatively. To date, sudden fixed upward ocular deviation has been rarely reported previously. This phenomenon was observed in an 8-year-old boy during strabismus surgery. Suddenly fixed upward ocular deviation occurred when the speculum was inserted into the right eye. When the eyeball was pulled down, using forceps, there was some resistance, such as contracture of superior rectus. The eyeball sprang back into the upward position when the forceps was released. These changes could hamper the good exposition of the surgical field, leading to significant intraoperative difficulties and complications. Surgeons should be aware of this possibility, despite general anesthesia; if it occurs, proceed with the surgery as planned preoperatively, and both ophthalmic and anesthetic interventions should be used to solve this problem.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2011.05a
• /
• pp.252-252
• /
• 2011

Rainfall-runoff models are calibrated and validated by using a same data set such as observations. The past climate change effects the present rainfall pattern and also will effect on the future. To predict rainfall-runoff more preciously we have to consider the climate change pattern in the past, present and the future time. Thus, in this study, the climate change represents changes in mean precipitation and standard deviation in different patterns. In some river basins, there is no enough length of data for the analysis. Therefore, we have to generate the synthetic data using proper distribution for calculation of precipitation based on the observed data. In this study, Kajiyama model is used to analyze the runoff in the dry and the wet period, separately. Mean and standard deviation are used for generating precipitation from the gamma distribution. Twenty hypothetical scenarios are considered to show the climate change conditions. The mean precipitation are changed by -20%, -10%, 0%, +10% and +20% for the data generation with keeping the standard deviation constant in the wet and the dry period respectively. Similarly, the standard deviations of precipitation are changed by -20%, -10%, 0%, +10% and +20% keeping the mean value of precipitation constant for the wet and the dry period sequentially. In the wet period, when the standard deviation value varies then the mean NSE ratio is more fluctuate rather than the dry period. On the other hand, the mean NSE ratio in some extent is more fluctuate in the wet period and sometimes in the dry period, if the mean value of precipitation varies while keeping the standard deviation constant.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.19 no.3
• /
• pp.93-101
• /
• 2017

The distribution of inter-annual variation in temperature would help evaluate the likelihood of a climatic risk and assess suitable zones of crops under climate change. In this study, we evaluated two methods to estimate the standard deviation of temperature in the areas where weather information is limited. We calculated the monthly standard deviation of temperature by collecting temperature at 0600 and 1500 local standard time from 10 automated weather stations (AWS). These weather stations were installed in the range of 8 to 1,073m above sea level within a mountainous catchment for 2011-2015. The observed values were compared with estimates, which were calculated using a geospatial correction scheme to derive the site-specific temperature. Those estimates explained 88 and 86% of the temperature variations at 0600 and 1500 LST, respectively. However, it often underestimated the temperatures. In the spring and fall, it tended to had different variance (e.g., increasing or decreasing pattern) from lower to higher elevation with the observed values. A regression analysis was also conducted to quantify the relationship between the standard deviation in temperature and the topography. The regression equation explained a relatively large variation of the monthly standard deviation when lapse-rate corrected temperature, basic topographical variables (e.g., slope, and aspect) and topographical variables related to temperature (e.g., thermal belt, cold air drainage, and brightness index) were used. The coefficient of determination for the regression analysis ranged between 0.46 and 0.98. It was expected that the regression model could account for 70% of the spatial variation of the standard deviation when the monthly standard deviation was predicted by using the minimum-maximum effective range of topographical variables for the area.

• 한국연소학회:학술대회논문집
• /
• 2000.12a
• /
• pp.47-58
• /
• 2000

The relationship among the flame radiation, NOx emissions, residence time, and global strain rate are examined for turbulent non-premixed jet flames with wide variations in coaxial air conditions. Measurements of NOx emission, flame geometry and flame radiation were made to explain the NOx emission scaling based on global parameters such as flame residence time, global strain rate, and radiant fraction. The overall 1/2-power scaling is observed in coaxial air flames, irrespective of coaxial air conditions, but the degree of deviation from the l/2-slope curve in each case differs from one another. From the comparison between the results of pure hydrogen flames and those of helium diluted hydrogen flames, it is observed that flame radiation plays a significant role in pure hydrogen flames with coaxial air and the deviation from 1/2-power scaling may be explained in two reasons: the difference in the flame radiation and the difference in jet similarity in coaxial air flames. From the radiation measurements, more detailed explanations on these deviations were suggested.