• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.10a
• /
• pp.256-257
• /
• 2017

Pressure sensors are usually used in the measurement of drone altitude in an indoor environment since GPS (global positioning system) signal is not available. In this paper, we propose a new method which uses the Chebyshev filter to decrease a high frequency error in the measured values of the pressure sensor. Considering performance of a drone flight controller, the filter order is limited to the $3^{rd}$ order. We explain the transfer function of the $3^{rd}$ order Chebyshev filter.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.2
• /
• pp.138-147
• /
• 2009

In this paper, improved direct torque control(DTC) system for five-phase squirrel-cage induction motor(IM) is proposed. Due to the additional degrees of freedom, five-phase 1M drives present unique characteristics. Also five-phase motor drives possess many other advantages compared with the traditional three-phase motor drive system, such as reducing an amplitude of torque pulsation and increasing the reliability. The DTC method is advantageous when it is applied to the five-phase IM, because the five-phase inverter provides 32 space vectors in comparison to 8 space voltage vectors into the three-phase inverter. However, five-phase motor has structural drawback of 3rd space-harmonics current component, it is necessary to controlled 3rd harmonic current. So to control 3rd harmonic current and enhance dynamic characteristics of five-phase squirrel-cage IM drive, modified DTC method should be demanded. The characteristics and dynamic performance of traditional five-phase DTC are analyzed and new DTC for five-phase IM is presented. A more precise flux and torque control algorithm for the drives can be suggested and explained For presenting the superior performance of the proposed direct torque control, experimental results are presented using a 32-[bit] fixed point TMS320F2812 digital signal processor with 2.2[kW] induction motor.

• Journal of Families and Better Life
• /
• v.7 no.2
• /
• pp.1-13
• /
• 1989

The purpose of this stud is : (1) to figure out the amount of time being usually spent on the housework performed by the employed wives and (2) to find out factors influencing the total and the specified housework time. The major findings are the following : 1) A employed wife spends 374 minutes(6.2 hours) on the average a day on the housework. Compared with research results of the past, this shows little difference, and less 157 minutes than full time homeworker. Time connected with meals is 123minutes, clothing (68), management and marketing(64), family care(61), and housing care(58). 2) Family environment variables (the wife's education level, wife's employment status, income, young child's age and presence of employed housekeeper) significantly differentiates the housework time. In general, a wife with higher SES level spends less time for housework except family care. 3) Housework related variables (planning, preference, performance competency, and performance stand rd) significantly differentiate the specified houseworks. High planning, preference, and performance competency do not necessarily diminish the housework time except routine houseworks. High performance standard causes her to spend more time. 4) A wife' sex-role attitudes and a husbands attitudes perceived are more traditional, she spends more time.

• Journal of Korean Society for Quality Management
• /
• v.49 no.1
• /
• pp.1-15
• /
• 2021

Purpose: The purpose of this study was to propose a sensor fusion algorithm that integrates vehicle motion sensor(VMS) into the hybrid navigation system. Methods: How to evaluate the navigation performance was comparison test with the hybrid navigation system and the sensor fusion method. Results: The results of this study are as follows. It was found that the effects of the sensor fusion method and α value estimation were significant. Applying these greatly improves the navigation performance. Conclusion: For improving the reliability of navigation system, the sensor fusion method shows that the proposed method improves the navigation performance in a combat vehicle.

• Journal of Preventive Medicine and Public Health
• /
• v.38 no.2
• /
• pp.132-140
• /
• 2005

Objectives: To propose a risk-adjustment model from insurance claims data, and analyze the changes in cesarean section rates of healthcare organizations after adjusting for risk distribution. Methods: The study sample included delivery claims data from January to September, 2003. A risk-adjustment model was built using the 1st quarter data, and the 2nd and 3rd quarter data were used for a validation test. Patients' risk factors were adjusted using a logistic regression analysis. The c-statistic and Hosmer-Lemeshow test were used to evaluate the performance of the risk-adjustment model. Crude, predicted and risk-adjusted rates were calculated, and compared to analyze the effects of the adjustment. Results: Nine risk factors (malpresentation, eclampsia, malignancy, multiple pregnancies, problems in the placenta, previous Cesarean section, older mothers, bleeding and diabetes) were included in the final risk-adjustment model, and were found to have statistically significant effects on the mode of delivery. The c-statistic (0.78) and Hosmer-Lemeshow test ($x^2$=0.60, p=0.439) indicated a good model performance. After applying the 2nd and 3rd quarter data to the model, there were no differences in the c-statistic and Hosmer-Lemeshow $x^2$. Also, risk factor adjustment led to changes in the ranking of hospital Cesarean section rates, especially in tertiary and general hospitals. Conclusion: This study showed a model performance, using medical record abstracted data, was comparable to the results of previous studies. Insurance claims data can be used for identifying areas where risk factors should be adjusted. The changes in the ranking of hospital Cesarean section rates implied that crude rates can mislead people and therefore, the risk should be adjusted before the rates are released to the public. The proposed risk-adjustment model can be applied for the fair comparisons of the rates between hospitals.

• Analytical Science and Technology
• /
• v.11 no.6
• /
• pp.436-439
• /
• 1998

Ginseng saponins were analysed using reversed-phase high performance liquid chromatography with several columns. The optimum conditions were as following : reverse phase column; Novapak $C_{18}$ ODS column ($3.9mm{\times}150mm$, $5{\mu}m$), acetonitrile/water binary mobile phase gradient controller system, solvent flow rate; 1.5 mL/min, and UV (203 nm) detector. The complete separation of ginsenoside $Rb_1$, $Rb_2$, Rc, Rd, Re, Rf and $Rg_1$ was achieved within 50 min. The regression coefficients of the calibration curves for seven ginsenosides were 0.98~0.99.

• Journal of the Korea Society for Simulation
• /
• v.26 no.1
• /
• pp.13-19
• /
• 2017

6-DOF flight simulation program is most generally used M&S tool in domestic missile development procedure. The 6-DOF M&S method, however, cannot validate the performance of a imaging seeker-adopted missile in various conditions. A M&S tool for the analysis of the integrated-flight simulation is required since the tracking performance of the imaging seeker is highly dependent on the missile maneuvering, which introduces the displacement and rotation of the target in the seeker imagery. Through the development of the $3^{rd}$ generation anti-tank missile, Raybolt, the integrated-flight M&S tool was developed and applied to the missile configuration design. It integrates synthetic image generation S/W, imaging tracker, and flight simulation program and computes the main system performance criteria, hit probability by Monte-Carlo Simulation. In this paper, the issues in the $3^{rd}$ generation anti-tank missile configuration and the integrated-flight M&S method and results are described.

• Journal of Satellite, Information and Communications
• /
• v.9 no.2
• /
• pp.28-32
• /
• 2014

In this paper, we analyzed the performance of cyclostationary signal detection scheme for LTE system. We applied the cyclostationary signal detection scheme to the cognitive radio(CR) technology, which improves the usage efficiency of spectrums and shares frequencies, and we detected the signal in the long term evolution(LTE) band. LTE system has been designated as the standard to improve the maximum data rate and provide the low latency in the 3rd generation partnership project(3GPP). In this paper, we generated the LTE signals based on the orthogonal frequency division multiple access(OFDMA) and analyzed the performance of signal detection in accordance with the segment and threshold of the generated signals. Gaussian channel was used in the simulation and we discussed the future studies to apply the CR to the LTE system.

• Journal of Animal Science and Technology
• /
• v.66 no.1
• /
• pp.103-114
• /
• 2024

This study was done to investigate the effects of the incorporation of Achyranthes japonica extracts (AJE) in diet on the production parameters of growing pigs. Exp 1: Total, 105 crossbred pigs (average body weight: 24.47 ± 2.46 kg) were used in a 6-week feeding trial. Pigs (seven replicates, five pigs per pen) were allotted randomly to three treatments. Dietary treatments: CON (basal diet); basal diet with 0.025% AJE, and basal diet + 0.050% AJE). Growth performance, nutrient digestibility, fecal microbial count, and fecal noxious gas were assessed in this study. Average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G:F) were not affected by the addition of up to 0.05% AJE. In the case of apparent total tract digestibility (ATTD), dry matter (DM), nitrogen (N), and digestible energy (DE) were not changed in 3rd and 6th weeks of the feeding trial through the addition of AJE up to 0.05% in the growing pig diet. In microbial count, Lactobacillus and Escherichia coli count at 3rd and 6th week was similar in all the treatment diets. The inclusion of AJE at levels up to 0.05% in growing pig diet had no effect on the production of NH3, H2S, acetic acid, and CO₂ in the feces. After ending the Exp 1, a total of nine pigs were divided into three treatment groups. Treatment diets were included, TRT1, basal diet + powder quercetin 30 g; TRT2, basal diet + powder quercetin 150 g; TRT3, basal diet + powder quercetin 300g. Rate of absorption in blood was increased with the higher dose of quercetin. The results suggested incorporation of AJE up to 0.05% has no significant effect on ADG, ADFI, and G:F, as well as DM, N, and DE digestibility, fecal microbial count, and fecal noxious gas emission in growing pigs, even though no negative effect was found.

• Industrial Engineering and Management Systems
• /
• v.7 no.3
• /
• pp.214-227
• /
• 2008

Today's dynamic competitiveness requires an organization to improve its performance measurement and management. Quality Management Systems (QMS) abound, the main ones being: ISO series, Malcolm Baldridge National Quality Award (MBNQA), European Forum for Quality Management (EFQM), Six Sigma Business Scorecard and the Balanced Scorecard. Based on the literature, the IPMMM (Integrated Performance Measurement and Management Model) identified 7 key synthesized factors: leadership, strategy management and policy, customer and market, learning and growth, partnership and resources, internal processes and business results that are employed to investigate the key performance indicators of a car assembler using the Delphi methodology. In the 2 rounds of Delphi panels consisting of 20 senior management personnel, the $1^{st}$ round of 198 indicators in the IPMMM yielded 90 indicators. The $2^{nd}$ round yielded 43 performance indicators with 18 rated as critical based on the % assigned in the $1^{st}$ and $2^{nd}$ priority rating of "very important factor" and "key performance indicator" that must be ranked high on both of the priorities. The very critical indicators appeared to be: defect percentage and first time capability (tie in $1^{st}$ place) and revenue, goal setting, customer satisfaction index, on-time delivery, brand image, return on investment, Claim Occurrence Ratio, and debt being ranked from $3^{rd}$ to $10^{th}$. It can be surmised that an organization can identify and develop an appropriate set of performance indicators through the Delphi methodology and implement and manage them based on the Balanced Scorecard.