• Journal of the Korean Statistical Society
• /
• v.33 no.3
• /
• pp.323-337
• /
• 2004

This article coined a general class of estimators for various measures in normal population when some' a priori' or guessed value of standard deviation a is available in addition to sample information. The class of estimators is primarily defined for a function of standard deviation. An unbiased estimator and the minimum mean squared error estimator are worked out and the suggested class of estimators is compared with these classical estimators. Numerical computations in terms of percent relative efficiency and absolute relative bias established the merits of the proposed class of estimators especially for small samples. Simulation study confirms the excellence of the proposed class of estimators. The beauty of this article lies in estimation of various measures like standard deviation, variance, Fisher information, precision of sample mean, process capability index $C_{p}$, fourth moment about mean, mean deviation about mean etc. as particular cases of the proposed class of estimators.

• Structural Engineering and Mechanics
• /
• v.68 no.3
• /
• pp.289-297
• /
• 2018

The real behavior of the RC structures constructed based on the assumed specifications of the used materials is matched with the designed ones when the assumed and the applied specifications in construction are the same. Despite in the construction phase of the reinforced concrete (RC) structures always it is tried to implement the same specifications of materials as given in the executive drawings, but considering the unpredicted/uncontrolled parameters that affect the specification of materials, always there is a deviation between the constructed and the designed materials' specifications. The objective of this paper is to submit a guideline for the evaluation of the strength and damage to the existing RC structures encountered deviation in materials' strengths. To achieve this goal, the lateral strength (plastic behaviors) and damage to twenty-five RC moment-resisting frames (MRFs) are studied by applying the inelastic analysis. In this study, a couple of concrete and reinforcement strengths' deviations are investigated. The obtained results indicate that in general, there is a semi-linear relationship between the deviation in the strength of reinforcement and the changes in the lateral strength values of the MRFs. The relative effect of the deviation in the strength of reinforcements is more than the relative effect of the deviation in the concrete strength on the damage rate. The obtained results could be a guideline for the engineers in the survey of the existing buildings encountered deviation in materials' strengths during their construction phase.

• Food Science and Preservation
• /
• v.9 no.2
• /
• pp.137-143
• /
• 2002

Temperature and humidity are the most important factors and should be effectively controlled for the cold storage of graius. Fuzzy logic can be easily implemented to the MIMO(Multi-Input Multi-Output) control systems. For the cold storage in grain bin, fuzzy logic was applied to an air conditioning system. The capacities of the grain bin and the air conditioner are 80 tons and 30㎾, respectively. Also, the target values of temperature and relative humidity in outlet duct of the air conditioner were 8$\^{C}$ and 75%, respectively. In order to control temperature and relative humidity of air, a damper in inlet duct was manipulated for temperature control and a heater was used for humidity control. Temperature deviation and change of temperature deviation were used as input parameters for the fuzzy system. Humidity was only considered as a load. The experimental results showed that the controlled temperature of exhausted air was maintained at 8$\pm$2$\^{C}$. Relative humidity of the air was also controlled at the target relative humidity of 50∼80%.

• Journal of Preventive Medicine and Public Health
• /
• v.20 no.2 s.22
• /
• pp.255-260
• /
• 1987

The digital dust indicator (Sibata P-5), one of the direct·reading instruments was evaluated for the respirable dust in the underground coal mine environments. As a reference, respirable dust was determined using three cyclones and/or impactors. All the tests were performed on aerosol in twenty underground coal mines. The coefficients of mass-relative concentration were $0.067{\pm}0.054$ (Mean$\pm$Standard deviation) (range: 0.006-0.172). The relationship between relative concentration and temperature was not significant statistically. Also, the relationship of relative concentration and relative humidity was not significant. Mass concentration and relative concentration were $5.31{\pm}5.22mg/m^3$ and $162{\pm}163$ CPM ($Mean{\pm}Standard$ deviation) respectively. The range of mass concentration was $1.22-22.69mg/m^3$; relative concentration 16-628 CPM. The relationship of mass concentration and relative concentration was not significant in these ranges.

• Progress in Medical Physics
• /
• v.33 no.4
• /
• pp.136-141
• /
• 2022

Purpose: This study aimed to develop a breath control training system for breath-hold technique and respiratory-gated radiation therapy wherein the patients can learn breath-hold techniques in their convenient environment. Methods: The breath control training system comprises a sensor device and software. The sensor device uses a loadcell sensor and an adjustable strap around the chest to acquire respiratory signals. The device connects via Bluetooth to a computer where the software is installed. The software visualizes the respiratory signal in near real-time with a graph. The developed system can signal patients through visual (software), auditory (buzzer), and tactile (vibrator) stimulation when breath-holding starts. A motion phantom was used to test the basic functions of the developed breath control training system. The relative standard deviation of the maxima of the emulated free breathing data was calculated. Moreover, a relative standard deviation of a breath-holding region was calculated for the simulated breath-holding data. Results: The average force of the maxima was 487.71 N, and the relative standard deviation was 4.8%, while the average force of the breath hold region was 398.5 N, and the relative standard deviation was 1.8%. The data acquired through the sensor was consistent with the motion created by the motion phantom. Conclusions: We have developed a breath control training system comprising a sensor device and software that allow patients to learn breath-hold techniques in their convenient environment.

• Journal of the Korean Solar Energy Society
• /
• v.36 no.5
• /
• pp.31-50
• /
• 2016

To develope a greenhouse fog cooling system to control the temperature and relative humidity simultaneously to the target value, a theoretical analysis and experiments were done. The control process includes the measuring of environmental variables, setting and coding of the water and heat balance equations to maintain the target temperature and relative humidity in greenhouse, calculating of the open level of the greenhouse roof window that governs the natural ventilation and spray water quantity, and operating of the motor to open/close the roof window and pump to spray for water. The study results were shown to be very good because the average air temperature in the greenhouse was kept to be about $28.2^{\circ}C$ with the standard deviation of about $0.37^{\circ}C$ compared to the target temperature of $28^{\circ}C$ and the average relative humidity was about 75.2% compared to the target relative humidity was 75% during the experiments. The average outside relative humidity was about 41.0% and the average outside temperature was $27.2^{\circ}C$ with the standard deviation of about $0.54^{\circ}C$. The average solar intensity in the greenhouse was 712.9 W. The wind velocity of outside greenhouse was 0.558 m/s with the standard deviation of 0.46 m/s.

• Journal of Environmental Science International
• /
• v.9 no.4
• /
• pp.295-302
• /
• 2000

This study was conducted to investigate the characteristics of surface ozone concentration and occurrence of high ozone concentration using hourly ozone, nitrogen dioxide and meteorological data for 1997~1998 in Pusan coastal area. Monthly mean ozone concentration was the highest at Dongsamdong in Spring(35.4ppb), at Kwangbokdong in Fall(25.1ppb) and the lowest Dongsamdong(22.2ppb) and Kwangbokdong(16.0ppb) in Winter. Relative standard deviation indicating clearness of observation site was 0.42 at Dongsamdong and 0.49 at Kwangbokdong that is similar to urban area. The diurnal variation of ozone concentration of Dongsamdong and Kwangbokdong showed maximum at 1500~1600LST and minimum 0700~0800LST that typical pattern of ozone concentration. In ozone episode period(Sept. 10~15, 1998), diurnal change of ozone concentration was very high, and ozone concentration was related to meteorological parameters such as temperature, relative humidity, wind speed, cloud amount and radiation on a horizontal surface. During the episode days peak ozone concentrations are much higher than the normal values, wind speeds are always lower, and solar radiation is high with the exception of the September episode.

• Journal of Environmental Impact Assessment
• /
• v.8 no.2
• /
• pp.21-29
• /
• 1999

This study was conducted to investigate the characteristics of surface ozone concentration and occurrence of high ozone concentration using hourly ozone and meteorological data of 1997~1998 in Pusan coastal area. Monthly mean ozone concentration was highest in Spring(35.4ppb) and lowest in Winter(22.2ppb). Relative standard deviation indicating clearness of observation site was 0.42 that is similar to urban area. The diurnal variation of ozone concentration of Dongsamdong showed maximum at 15~16LST and minimum 07~08LST that typical pattern of ozone concentration. In ozone episode period(May 18~23, 1998), diurnal change of ozone concentration was very high, and ozone concentration was related to meteorological parameters such as temperature, relative humidity, wind speed, cloud amount and radiation on a horizontal surface.

• The Journal of Advanced Prosthodontics
• /
• v.13 no.4
• /
• pp.205-215
• /
• 2021

PURPOSE. The purpose of this study was to compare the accuracy of three intraoral scanner (IOS) systems with three different dental arch widths. MATERIALS AND METHODS. Three dental models with different intermolar widths (small, medium, and large) were attached to metal bars of different lengths (30, 40, and 50 mm). The bars were measured with a coordinate measuring machine and used as references. Three IOSs were compared: TRIOS 3 (TRI), True Definition (TD), and Dental Wings (DW). The relative length and angular deviation of both ends of the metal bars from the scan data set (n = 15) were calculated and analyzed. RESULTS. Comparing among scanners in terms of trueness, the relative length deviation of DW in the small (1.28%) and medium (1.08%) arches were significantly higher than TRI (0.46% and 0.48%) and TD (0.33% and 0.18%). The angular deviation of DW in the small (1.75°) and medium (1.83°) arches were also significantly greater than TRI (0.63° and 0.40°) and TD (0.55° and 0.89°). Comparing within scanner, the large arch of DW showed better accuracy than other arch sizes (P < .05). On the other hand, the larger arch of TD presented a greater tendency of angular deviation in terms of trueness. No significant differences were found in terms of trueness between the arch widths of TRI group. CONCLUSION. The different widths of the dental arches can affect the accuracy of some intraoral scanners in full arch scan.

• Journal of the Korean Statistical Society
• /
• v.24 no.1
• /
• pp.127-139
• /
• 1995

This paper is concerned with the asymptotic properties of the least absolute deviation estimators for nonlinear regression models. The simple and practical sufficient conditions for the strong consistency and the asymptotic normality of the least absolute deviation estimators are given. It is confirmed that the extension of these properties to wide class of regression functions can be established by imposing some condition on the input values. A confidence region based on the least absolute deviation estimators is proposed and some desirable asymptotic properties including the asymptotic relative efficiency also discussed for various error distributions. Some examples are given to illustrate the application of main results.