• 한국의료질향상학회지
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• 제22권2호
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• pp.75-90
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• 2016

Objectives: This study measures the level of cognition of employee's patient safety culture and evaluates the current level through comparing the results to external levels. Ultimately it is performed to construct a strategic improvement plan through the basic database for patient's safety culture. Methods: A questionnaire survey of self reporting type was carried out using structured questionnaire of the patient's safety culture for employees currently employed in a hospital. Total responders was 1,129 and a response rate was 54.6%. The survey results were calculated with a percent positive response, and the current level was evaluated by comparing with the survey results of a hospital (2009 and 2014) and the survey result of The Agency for Healthcare Research and Quality(2014). Results: Sub-dimension of high percent positive response for each area were 'teamwork within hospital units' (80%), 'feedback & communication about error' (73%) and 'supervisor/manager expectations & actions promoting safety' (67%). Meanwhile, 'teamwork across hospital units' (31%), 'hospital management support for patient safety' (29%), 'staffing' (27%) and 'non-punitive response to error' (17%) were relatively low percent positive response. Compared to the survey results of AHRQ (2014) for each area, 'teamwork within hospital units' (80%), 'feedback & communication about error' (73%), 'frequency of event reporting' (66%) were at the top 50% percentile level and the remaining sub-dimensions showed a very low level in the lower 10% percentile area. Conclusion: In order to establish a system for patient safety culture within the hospital and evaluate the effect on this, it is necessary to periodically evaluate the patient's safety culture and establish regulations on hospital safety culture to comply with this.

• 산업경영시스템학회지
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• 제16권28호
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• pp.137-143
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• 1993

Generally there are three methods to derive an approximation formula: 1) approching standard normal distribution by appropriate changing variable 2) using standardization variable for expansion 3) deriving approximation formula by direct method. This paper present correction terms having the form of $C_{1/v^{n/2}}/{\;}+{\;}C_2{\;}(n=1,2)$ with respect to $x^2_{\alpha}(v)$ distribution (${\nu}{\;}{\leq}{\;}30$), which minimize the error by EDA method and least square method.

• Imaging Science in Dentistry
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• 제43권4호
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• pp.267-272
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• 2013

Purpose: Demirjian's dental maturity scores and curves have been widely used for human age determination. Several authors have reported considerable differences between the true and estimated age based on the Demirjian curves, which have been accounted for by ethnicity. The purpose of the current study was to assess the role of ethnicity-specific dental maturation curves in age estimation of Saudi children. Materials and Methods: A sample of 452 healthy Saudi children aged 4 to 14 years were aged based on the original French-Canadian Demirjian curves and several modified Demirjian curves specified for certain ethnic groups: Saudi, Kuwaiti, Polish, Dutch, Pakistani, and Belgian. One-way ANOVA and a post hoc Scheff$\acute{e}$'s test were used to assess the differences between chronological age and dental age estimated by the different curves (P<0.05). Results: The curves designed for Dutch, Polish, Saudi, and Belgian (5th percentile) populations had a significantly lower error in estimating age than the original French-Canadian and Belgian (50th percentile) curves. The optimal curve for males was the Saudi one, with a mean absolute difference between estimated age and chronological age of 8.6 months. For females, the optimal curve was the Polish one, with a mean absolute difference of 7.4 months. It was revealed that accurate age determination was not related to certain ethnicity-specific curves. Conclusion: We conclude that ethnicity might play a role in age determination, but not a principal one.

• 한국태양광발전학회지
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• 제4권2호
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• pp.45-53
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• 2018

Natural gas demand for power generation continued to increase until 2013 due to the expansion of large-scale LNG power plants after the black-out of 2011. However, natural gas demand for power generation has decreased sharply due to the increase of nuclear power and coal power generation. But demand for power generation has increased again as energy policies have changed, such as reducing nuclear power and coal power plants, and abnormal high temperatures and cold waves have occurred. If the gas pipeline pressure can be properly maintained by predicting these fluctuations, it can contribute to enhancement of operation efficiency by minimizing the operation time of facilities required for production and supply. In this study, we have developed a regression model with daily power demand and base power generation capacity as explanatory variables considering characteristics by day of week. The model was constructed using data from January 2013 to December 2016, and it was confirmed that the error rate was 4.12% and the error rate in the 90th percentile was below 8.85%.

• Child Health Nursing Research
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• 제5권1호
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• pp.48-58
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• 1999

The purpose of this study was to determine the most accurate technique measuring the apical pulse rate, using three counting duration 15, 30 and 60 seconds, and two methods start ‘0’ and start ‘1’. The instrument used in the study was the EKG monitor, stethoscope and stopwatch. Data was analyzed by utilizing SPSSWIN program. General characteristics of the subjects were analyzed by frequency, percentile, mean, SD. The subject of this research is made up of 46 children and 20 nurses. The children were infants, & under the age of 5. They were hospitalised in PICU & NICU in 2 tertiary hospitals in seoul from Jan. 1. 1998 to Sep. 10. 1998. The measurement of starting 1 & measurement of starting ‘0’ used the T-test to find out the measurement error. Apical pulse duration of 15, 30, 60 seconds were used to find out measurement error, the measurement error depend on experience of Nurse were analyzed by using ANOVA. The result of this study are as follows. 1. When comparing the starting poin of apical pulse 0&1, starting with 1 the measurement error is less, but not statiscally significant. 2. When counting the apical pulse by 15, 30,60 sec. ; 60 seconds counting duration was more accurate, but not statistically significant. 3. The mean of measure error ; Group under 100/min, is 10.33 ; from 100 re 119/min, is 8.30 ; from 120 to 139/min, is 4.76 ; from 140 to 159/min, is 6.09 ; above 160, is 17.83. The differences of these groups are statistically significant. When 60sec were counted, under 140/min the mean of measurement error is 3.4. Also when 30 seconds were counted from 140/min to 159/min the measurement error is 7.14, above 160/min the measurement error is 16.4. That measurement mean is the smallest than the other durations. During the 15 sec. count the measurement error was the largest of them all. 4. By the experience of the nurses, the apical pulse count measurement error was discovered. Under a year experience this measurement error was the largest(11.09), 1 year to under 3 years, the error is the smallest(4.86). 3 year to under 6 years the error is 8.33, 5 years above the error is 6.11 but this is not statistical significant. Under a year experience when counting 15, 30, 60 seconds the error is the largest. The group of the nurses from a year to under 3 years, the measurement error is the smallest of all the groups. The result of the study is to determine the technique measuring the apical pulse rate, Hargest (1974), starting point ‘0’ is not proved. When the pulse rate increases the 30 sec measurement rate is accurate. Under 140/min the 60 sec measurement rate is the most accurate. Depending on the nurses experiences, there is a variable difference to the apical pulse rate measurement. Especially new nurses training courses should enforce the children’s pulse rate count and the basic vital signs.

• 한국농공학회지
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• 제43권5호
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• pp.163-171
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• 2001

Reaeration phenomena, the physical process of absorption of oxygen from atmosphere, is one of the important parameters of dissolved oxygen simulation in streams. This study was aimed at predicting reaeration coefficients in rural small streams, examining the influence of drop structure on reaeration and the seasonal fluctuation of reaeration coefficients. Reaeration coefficients of five streams including four tributaries of Bokha watershed in Gyeonggi Ichon and Onyang stream in Chungnam Onyang were measured. Constant rate injection (CRI) method using propane and Rhodamine-WT as gas and dye tracer was adopted. Reaeration coefficients ranged between 6.16 and 29.16 reciprocal day, higher than those in USGS database. Prediction equation,$k_2=CV^{0.593}$, was regressed from the measured data at 95% confidence level, with an absolute error of 21.2% and a standard error of 4.0 reciprocal days. Reaeration coefficients of experimental reaches with drop structure showed percentile increases of 42.3 to 159.2 compared to those without it, an indication that drop structure plays an important role on stream reaeration. Taking into consideration the seasonal fluctuation of reaeration coefficients, the values measured during September and October were the highest, mainly due to the removal of aquatic plants. by intensive rainfall during summer.

• 응용통계연구
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• 제32권1호
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• pp.99-109
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• 2019

비선형 시계열인 확률계수 자기회귀(random coefficient autoregressive; RCA) 모형에 대하여 여러 가지 방법을 이용한 추정량의 신뢰구간 비교하였다. RCA 모형에 대하여 자료의 분포를 가정하지 않아도 되는 Quasi 스코어 추정량과 Huber, Tukey, Andrew, Hempal 4가지 유계함수를 이용한 M-Quasi 스코어 추정량을 제시하였다. 이러한 추정량에 대하여 표준 붓스트랩 방법, 백분위수 붓스트랩 방법, 스튜던트화 붓스트랩 방법, 하이브리드 붓스트랩 방법을 이용한 신뢰구간을 구하였다. 모의실험을 통하여 RCA 모형의 오차항의 분포가 정규분포, 오염정규분포, 이중지수분포를 따를 때 Quasi 스코어 추정량과 M-Quasi 스코어 추정량들의 근사적 신뢰구간과 네가지 붓스트랩 방법을 이용한 신뢰구간을 비교하였다.

• 한국농공학회지
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• 제26권2호
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• pp.69-84
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• 1984

This study was carried out to investigate the time distribution of single storms and to establish the model of storm patterns in korea. Rainfall recording charts collected from 42 metheorological stations covering the Korean peninsula were analyzed. A single storm was defined as a rain period seperated from preceding and succeeding rainfall by 6 hours and more. Among the defined single storms, 1199 storms exceeding total rainfall of 80 mm were qualified for the study. Storm patterns were cklassified by quartile classification method and the relationship between cummulative percent of rainfalls and cummulative storm time was established for each quartile storm group. Time distribution models for each stations were prepared through the various analytical and inferential procedures. Obtained results are summarized as follows: 1. The percentile frequency of quartile storms for the first to the fourth quartile were 22.0%, 26.5%, 28.9% and 22.6%, respectively. The large variation of percentile frequency was show between the same quartile storms. The advanced type storm pattern was predominant in the west coastal type storm patterns predominantly when compared to the single storms with small total rainfalls. 3. The single storms with long storm durations tended to show delayed type storm patterns predominantly when compared to the single storms with short storm durations. 4. The percentile time distribution of quartile storms for 42 rin gaging stations was estimated. Large variations were observed between the percentiles of time distributions of different stations. 5. No significant differences were generally found between the time distribution of rainfalls with greater total rainfall and with less total rainfall. This fact suggests that the size of the total rainfall of single storms was not the main factor affecting the time distribution of heavy storms. 6. Also, no significant difference were found between the time distribution of rainfalls with long duration and with short duration. The fact indicates that the storm duration was no the main factor affecting the time distribution of heavy storms. 7. In Korea, among all single storms, 39.0% show 80 to 100mm of total rainfall which stands for the mode of the frequency distribution of total rainfalls. The median value of rainfalls for all single storms from the 42 stations was 108mm. The shape of the frequency distribution of total rainfalls showed right skewed features. No significant differences were shown in the shape of distribution histograms for total rainfall of quartile storms. The mode of rainfalls for the advanced type quartile storms was 80~100mm and their frequencies were 39~43% for respective quartiles. For the delayed type quartile storms, the mode was 80~100mm and their frequencies were 36!38%. 8. In Korea, 29% of all single storms show 720 to 1080 minutes of storm durations which was the highest frequency in the frequency distribution of storm durations. The median of the storm duration for all single storms form 42 stations was 1026 minutes. The shape of the frequency distribution was right skewed feature. For the advanced type storms, the higher frequency of occurrence was shown by the single storms with short durations, whereas for the delayed type quartile storms, the higher frequency was shown gy the long duration single storms. 9. The total rainfall of single storms was positively correlated to storm durations in all the stations throughout the nation. This fact was also true for most of the quartile storms. 10. The third order polynomial regression models were established for estimating the time distribution of quartile storms at different stations. The model test by relative error method resulted good agreements between estimated and observed values with the relative error of less than 0.10 in average.

• 한국시뮬레이션학회논문지
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• 제29권2호
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• pp.83-93
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• 2020

BMORE(Bivariate measure of risk and error) 도표는 본래 확률적 시뮬레이션에서의 이변량 성과 데이터와, 그와 관계된 표본 평균, 중앙값, 이상점, 특정 백분위 내의 결과 데이터의 범위 등과 같은 통계량들을 시각화하기 위해 설계되었으며, 정적인 정보들만 제공하는 것에 비해 사용자들이 시뮬레이션 결과 데이터에 담긴 가변성을 더욱 직관적으로 쉽게 이해할 수 있도록 돕는다. 본 연구에서는 BMORE 도표를 단순히 한 시스템의 가변성을 시각화하기 위한 것이 아닌, 특정 확률적 제약 아래 대상 시스템들의 실행 가능성을 타진하고, 통계적 배경 아래 여러 시스템들의 성과 비교를 행하며, 매개변수들의 민감도 분석을 실시하기 위한 의사결정 도구로써 활용할 수 있음을 보이고 이를 위한 여러 방안을 제안한다. 그 활용 예시를 보이고자 본 연구에서는 간단한 재고 관리 문제를 차용하였으나, 제시된 방안들 자체는 이변량 성과 척도를 가지는 시뮬레이션/실험 데이터를 근거로하여 여러 시스템들을 비교하는 문제라면 어디든 사용될 수 있음을 밝혀둔다.

• 한국안전학회지
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• 제32권1호
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• pp.21-26
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• 2017

An IoT-based particulate matter (PM2.5) sensing device (PSD) is developed. The PSD consists of a PM2.5 sensor, signal processing circuit, and wi-fi enabled-microprocessor along with temperature and humidity sensors. The PSD estimates PM2.5 density by measuring light scattered by PM2.5. To gauge performance of the PSD, PM2.5 density of open air was measured with the PSD and compared with that of the collocated-government-certified measuring station. Measurements were taken at a sampling frequency of 100 Hz and moving-averaged to remove measurement noise. When compared to the result of the measuring station, average percentile error of PM2.5 density from the PSD is found to be 31%. A correlation coefficient is found to be 0.72 which indicates a strong correlation. Instantaneous variation, however, may far exceed average errors, leading to a conclusion that the PSD is more suitable for estimating average trend of PM2.5 density variations than estimating instantaneous PM2.5 density.