• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.269-275
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• 2018

In order to establish the criterion for analyzing outdoor weather conditions in the greenhouse heating and cooling system design, we analyzed heating and cooling design outdoor temperatures by the annual percentile method and compared with design outdoor temperatures by the existing seasonal percentile method. In the annual percentile method, 0.4%, 1% and 2% of the total 8,760 hours per year are presented as cooling design outdoor temperatures and 99.6% and 99% as heating design outdoor temperatures. When the annual percentile method was adopted, heating design outdoor temperatures increased by 6.7 to 9.6% compared with the seasonal percentile method, and cooling design outdoor temperatures decreased by 0.6 to 1.1%. The maximum heating load in the same greenhouse condition decreased by 3.0 to 3.6% when the annual percentile method was adopted, but the effect on the maximum cooling load was insignificant. Therefore, it is necessary to consider the change of heating design outdoor temperatures to the annual percentile method, but it is not necessary to change the cooling design outdoor temperatures since there is little difference between the two methods.

• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.35-42
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• 2005

Few studies have been carried out to find out the interaction of design speeds, operating speeds, and posted speeds though they have a complementary relationships. As an attempt to find the relationships, this study measured the speeds of the free flowing vehicles at four lane rural highways. In comparison of 95th percentile speeds and inferred design speeds determined from the road design manual with the geometric features of each sites, operating speeds were constantly higher than the inferred design speeds at the sites where the inferred design speed is under 110km/h. and the reverse situation was observed at the sites where the inferred design speed is over 130km/h. In the comparison of operating speeds and posted speeds. the range of the 85th percentile speeds at the sites where posted speeds is 80km/h was distributed from 95km/h to 110km/h. and the range was distributed from the 105km/h to the 120km/h at the sites where posted speeds is 90km/h. Multiple regression analysis was used to develop prediction equations for mean. 85th. and 95th percentile speeds at approach and curve midpoint locations. At the midpoint, only posted speeds influenced the mean, 85th. At the approach locations, the mean, 85th, 95th percentile speeds were influenced by posted speeds and length of the approach tangent.

• Clinical and Experimental Pediatrics
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• v.51 no.12
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• pp.1300-1309
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• 2008

Purpose :This study aimed to estimate age- and gender-specific cut points for metabolic syndrome (MS) components, including body mass index (BMI), blood pressure (BP), triglycerides, high-density lipoprotein (HDL) cholesterol, and glucose. Methods :Data from the 1998, 2001, and 2005 Korean NHANES (National Health and Nutrition Examination Survey) were analyzed (n=4164; 2,139 boys and 2,025 girls, aged 10-19 years). Height, weight, waist circumference (WC), BP, triglycerides, HDL cholesterol, and fasting glucose were measured. Results :BMI over $25kg/m^2$ represents the $85^{th}P$ (percentile) in 17-year-old boys and the $90^{th}P$ in 17-year-old girls. A level of WC higher than that of the cutoff points of Asian adults was found in the $90^{th}P$ of 17-year-old boys and girls. The $90^{th}P$ of boys aged 15 years old and the $95^{th}P$ of 13-year-old were included in the range of systolic BP over 130 mm Hg. Over the $75^{th}P$ of the group showed triglycerides greater than 110 mg/dL, (criterion of MS presented by NCEP-ATP III) and the $90^{th}P$ of the group showed triglycerides greater than 150 mg/dL by IDF. An HDL cholesterol level of 40 mg/dL represents the $25^{th}P$ in boys and the $10^{th}P$ in girls. A glucose level greater than 110 mg/dL represents the $95^{th}P$ and greater than 100 mg/dL represents the $90^{th}P$. Conclusion :Values of the $90^{th}P$ of MS components in late adolescent boys (WC, BP, and triglycerides) and girls (WC and triglycerides) were very high and in close proximity to the diagnostic criteria of adult MS.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.2
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• pp.43-51
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• 2011

Probabilistic seismic hazard analysis (PSHA), which can effectively apply inevitable uncertainties in seismic data, considers a number of seismotectonic models and attenuation equations. The calculated hazard by PSHA is generally a value dependent on peak ground acceleration (PGA) and expresses the value as an annual exceedance probability. To represent the uncertainty range of a hazard which has occurred using various seismic data, a hazard curve figure shows both a mean curve and percentile curves (15, 50, and 85). The percentile performs an important role in that it indicates the uncertainty range of the calculated hazard, could be calculated using various methods by the relation of the weight and hazard. This study using the weight accumulation method, the weighted hazard method, the maximum likelihood method, and the moment method, has calculated the percentile of the computed hazard by PSHA on the Shinuljin 1, 2 site. The calculated percentile using the weight accumulation method, the weighted hazard method, and the maximum likelihood method, have similar trends and represent the range of all computed hazards by PSHA. The calculated percentile using the moment method effectively showed the range of hazards at the source which includes a site. This study suggests the moment method as effective percentile calculation method considering the almost same mean hazard for the seismotectonic model and a source which includes a site.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.95-105
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• 2002

Under a specific roadway alignment condition by design-speed standards, safety of the roadway is determined by an actual operating speed of a driver. This research takes first lanes of four-lane(hi-direction) rural highways as target facility. It also takes the straight and curved lanes of the selected highways for in-depth study. This study used NC-97 to detect speeds of passenger cars whose speeds are not affected by front vehicles. This research analyzed properties of 85th percentile operating speed at upstream of horizontal and through curves under various alignment conditions. The results show that 53∼65 Percent of drivers drive faster than the posted speed-limit (80KPH) by 14∼20 KPH on average. It also shows that the 85th-percentile operating speeds are the lowest at the middle point of curve length when curve radius is smaller. However, they are lowest at 1/4 point of curve length when curve radius is greater. Along roadways where curve radius is small, difference between upstream speed and the speed along the curve is considerably large. On the other hand. the speed difference is setting smaller as the curve radius is increasing. According to the results, significant variables affecting the 85th percentile operating speeds are curve radius and the 85th-Percentile operating speeds of upstream curves.

• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.985-988
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• 2011

본 논문의 주목적은 확률변수의 백분위수를 이용하여 Mg-Al-Zn합금에 적합한 확률론적 피로균열전파모델을 평가하여 제시하는 것이다. 균열성장의 변동성을 묘사하기 위하여 실험적 피로균열전파모델에 확률변수를 도입한 확률론적 피로균열전파모델을 제안하였다. 제안된 모델을 평가하기 위하여 시편두께조건을 변화시키면서 피로균열전파실험을 수행하여 균열성장의 통계데이터를 확보하였다. 각 모델의 파라미터는 최우추정법으로 추정하였으며, 균열성장에 따른 확률변수의 백분위수를 이용하여 모델적합성을 평가하였다. 일반적으로 Mg-Al-Zn합금에 적합한 모델은 '확률론적 Paris-Erdogan모델'과 '확률론적 Walker모델'이었으며, 두꺼운 시편의 경우엔 '확률론적 Forman모델'가 적합함을 규명하였다.

• The Korean Journal of Applied Statistics
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• v.2 no.1
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• pp.48-53
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• 1989

In contrast to the customary approximations based on standard normal percentage points, direct approximations involve simple functions of parameters (such as degrees of freedom and tail area of the t distributions). This article used techniques of exploratory data analysis following Hoaglin to develop direct approximations for percentage points in the commonly used portions of upper tail of the t distribution with small to moderate numbers of degrees of freedom. These approximations are convenient to use and they compare favorably in accuracy with the popular approximations based on standard normal percentage points such as Peiser's. They can be used as an initial value generator in algorithms for getting more accurate percentage points.

• Proceedings of the Korean Statistical Society Conference
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• 2003.05a
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• pp.149-150
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• 2003

소표본 분할표 자료에서 적합도 검정통계량들의 카이제곱 근사 적용 가능에 대하여 많은 연구가 진행되었다. 소표본에서 세 가지 검정 통계량(피어슨 카이제곱 $X^{2}$, 일반화 가능도비 $G^{2}$, 그리고 역발산 I(2/3) 검정통계량)에 관하여 비교한 Rudas(1986)의 연구를 확장하여, 최근에 제안된 차이측도(BWHD(1/9), BWCS(1/3), NED(4/3) 검정통계량)를 포함시켜 비교 분석하였다. 독립모형의 이차원 분할표, 조건부 독립모형과 한 변수 독립 모형을 따르는 삼차원 분할표에 대한 모의실험을 통하여 생성된 90과 95 백분위수와 이에 대응하는 95% 신뢰구간을 살펴보고 실제 백분위수와 비교하였다. 그 결과 $X^{2}$, I(2/3), 그리고 BWHD(1/9) 검정통계량이 유사한 결과를 나타내었고 이 통계량들이 기존에 제안된 검정통계량들보다 적은 표본크기에서도 카이제곱 근사방법에 적용 가능함을 발견하였다.

• Journal of the Korean Data and Information Science Society
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• v.20 no.3
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• pp.485-492
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• 2009

In this paper, we studied process capability analysis for brake-pad manufacturing system and considered Weibull, normal and logistic distributions for density estimation of wear life of brake pads for a passenger car with a real data. These three distributions are seem to work well. Estimated percentiles of brake pads can be used to evaluate the design criteria and customers' need for brake pads.

• The Korean Journal of Applied Statistics
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• v.6 no.2
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• pp.435-442
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• 1993

For the generalized gamma distribution, exact inferences about quantiles need many computations involving complicated numerical integrations. This paper suggests approximate confidence intervals which are easily obtained by considering the alternative location-scale model. Also, these intervals are very accurate even for small sample size. Approximate confidence intervals about quantiles in the lognormal distribution are also considered. With type 2 censoring data, approximate confidence intervals can also be obtained directly by the suggested methods.