• 한국도로학회논문집
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• 제14권6호
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• pp.131-138
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• 2012

PURPOSES : Two-lane highways have one lane in each direction, and lane changing and passing maneuvers take place in the opposing lane depending on the availability of passing sight distance. 2001 Korea Highway Capacity Manual (KHCM) is classified into two classes of two-lane highways (Type I, II), and average travel speed and time-delayed rate are used as measures of effectiveness (MOEs). However, since existing two-lane highways have both uninterrupted and interrupted traffic flow-system elements, a variety of free-flow speeds exhibits in two-lane highways. In addition, it is necessary to check if the linear-relationship between volumes and time-delayed rate is appropriate. Then, this study is to reestablish the relationship between average travel speed, time-delayed rate, and flow. METHODS : TWOPAS model was selected to conduct this study, and the free-flow speeds of passenger cars and the percentage of following vehicles observed in two-lane highways were applied to the model as the input. The revised relationships were developed from the computer simulation. RESULTS : In the revised average travel speed vs. flow relationship, the free-flow speed of 90km/h and 70km/h were added. It shows that the relationship between time delayed-rate and flow appeared to be appropriate with the log-function form and that there was no difference in time-delayed rate between the free flow speeds. In addition to revise the relationships, the speed prediction model and the time-delayed rate prediction model were also developed. CONCLUSIONS : The revised relationships between average travel speed, time-delayed rate, and flow would be useful in estimating the Level of Service(LOS) of a two-lane highway.

• 한국재료학회지
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• 제22권8호
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• pp.426-432
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• 2012

This study involves using nickel chloride solution as a raw material to produce nano-sized nickel oxide powder with average particle size below 50 nm by the spray pyrolysis reaction. The influence of the inflow speed of raw material solution on the properties of the produced powder is examined. When the inflow speed of the raw material solution is at 2 ml/min., the average particle size of the powder is 15~25 nm and the particle size distribution is relatively uniform. When the inflow speed of the solution increases to 10 ml/min., the average particle size of the powder increases to about 25 nm and the particle size distribution becomes much more uneven. When the inflow speed of the solution increases to 20 ml/min., the average particle size of the powder increases in comparison to the case in which the inflow speed of the solution was 10 ml/min. However, the particle size distribution is very uneven, showing various particle size distributions ranging from 10 nm to 70 nm. When the inflow speed of solution increases to 50 ml/min., the average particle size of the powder decreases in comparison to the case in which the inflow speed was 20 ml/min., and the particle size distribution shows more evenness. As the inflow speed of the solution increases from 2 ml/min. to 20 ml/min., the XRD peak intensities gradually increase, while the specific surface area decreases. When the inflow speed of solution increases to 50 ml/min., the XRD peak intensities rather decrease, while the specific surface area increases.

• 한국수학교육학회지시리즈A:수학교육
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• 제57권3호
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• pp.311-328
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• 2018

In school mathematics, the concept of an average is not a concept that is limited to a unit of statistics. In particular, high school students will learn about arithmetic mean and geometric mean in the process of learning absolute inequality. In calculus learning, the concept of average is involved when learning the concept of average speed. The arithmetic mean is the same as the procedure used when students mean the test scores. However, the procedure for obtaining the geometric mean differs from the procedure for the arithmetic mean. In addition, if the arithmetic mean and the geometric mean are the discrete quantity, then the mean rate of change or the average speed is different in that it considers continuous quantities. The average concept that students learn in school mathematics differs in the quantitative nature of procedures and objects. Nevertheless, it is not uncommon to find out how students construct various mathematical concepts into mathematical knowledge. This study focuses on this point and conducted the interviews of the students(three) in the second grade of high school. And the expression of students in the process of average concept formation in arithmetic mean, geometric mean, average speed. This study can be meaningful because it suggests practical examples to students about the assertion that various scholars should experience various properties possessed by the average. It is also meaningful that students are able to think about how to construct the mean conceptual properties inherent in terms such as geometric mean and mean speed in arithmetic mean concept through interview data.

• Journal of Electrical Engineering and Technology
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• 제11권6호
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• pp.1548-1555
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• 2016

This paper presents an application of time series analysis in hourly wind speed simulation and forecast in Jeju Island, Korea. Autoregressive - moving average (ARMA) model, which is well in description of random data characteristics, is used to analyze historical wind speed data (from year of 2010 to 2012). The ARMA model requires stationary variables of data is satisfied by power law transformation and standardization. In this study, the autocorrelation analysis, Bayesian information criterion and general least squares algorithm is implemented to identify and estimate parameters of wind speed model. The ARMA (2,1) models, fitted to the wind speed data, simulate reference year and forecast hourly wind speed in Jeju Island.

• 한국분말재료학회지
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• 제11권6호
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• pp.493-502
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• 2004

In this study, nano-sized indium oxide powder with the average particle size below 100 nm is fab-ricated from the indium chloride solution by the spray pyrolysis process. The effects of the reaction temperature, the concentration of raw material solution and the inlet speed of solution on the properties of powder were studied. As the reaction temperature increased from 850 to $1000^{\circ}C$, the average particle size of produced powder increased from 30 to 100 nm, and microstructure became more solid, the particle size distribution was more irregular, the intensity of a XRD peak increased and specific surface area decreased. As the indium concentration of the raw material solution increased from 40 to 350 g/l, the average particle size of the powder gradually increased from 20 to 60 nm, yet the particle size distribution appeared more irregular, the intensity of a XRD peak increased and spe-cific surface area decreased. As the inlet speed of solution increased from 2 to 5 cc/min., the average particle size of the powder decreased and the particle size distribution became more homogeneous. In case of the inlet speed of 10 cc/min, the average particle size was larger and the particle size distribution was much irregular compared with the inlet speed of 5 cc/min. As the inlet speed of solution was 50 cc/min, the average particle size was smaller and microstructure of the powder was less solid compared with the inlet speed of 10 cc/min. The intensity of a XRD peak and the variation of specific area of the powder had the same tendency with the variation of the average par-ticle size.

• 한국컴퓨터정보학회논문지
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• 제28권1호
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• pp.137-142
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• 2023

본 연구에서는 초등학교 야구선수의 타격 속도와 균형 능력의 상관관계를 규명을 제안한다. 본 연구의 대상자는 40명이었다. 타격 속도는 zepp2baseball을 이용하여 측정하였고, 균형 능력은 biorescue를 이용하여 측정하였다. 균형능력의 측정은 눈 뜬 상태에서 이동 면적·눈 뜬 상태에서 이동거리·눈 뜬 상태에서 평균 이동속도·눈 감은 상태에서의 이동 면적·눈 감은 상태에서의 이동거리·눈 감은 상태에서의 평균 이동속도를 측정하였다. 타격 속도와 균형 능력 간의 상관관계를 분석하기 위해 피어슨 상관분석을 이용하였다. 타격 속도와 눈 감은 상태에서의 이동면적 사이에는 유의한 음의 상관관계가 있었습니다(r=-0.366, p<0.05). 타격 속도와 눈 감은 상태에서의 이동길이 사이에는 유의한 음의 상관관계가 있었다(r=-0.348, p<0.05). 타격 속도와 눈 감은 상태에서 평균 이동속도 사이에는 유의한 음의 상관관계가 있었다(r=-0.455, p<0.01). 그 중 눈 감은 상태에서 평균 이동속도가 가장 높은 상관관계를 보였다(p<0.01). 이러한 결과는 균형능력의 향상이 타격 속도에 긍정적인 영향을 미친다는 것을 시사한다.

• 한국방재학회 논문집
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• 제11권1호
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• pp.37-43
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• 2011

봄철은 강수량이 연평균의 13% 정도로 적어 건조한 계절이며, 영동지역에 대형 산불이 많이 발생했던 해는 풍속은 강하고 공중습도가 봄철 평균보다도 낮고 강수량도 상대적으로 적어 더욱 건조했다. 대형산불이 발생했던 날은 평균풍속, 최대풍속, 최대순간풍속이 5.9 m/s, 11.3 m/s, 20.9 m/s로 산불 발생일의 평균값보다 1.8 m/s, 3.0 m/s, 6.9 m/s 크게 나타나, 산불의 대형화와 기상요소는 밀접한 관계를 나타냈다.

• 한국도로학회논문집
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• 제15권4호
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• pp.147-154
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• 2013

PURPOSES: To analyze the specific factors of drivers behaviors that amount of cause the greenhouse gas emissions per vehicle. METHODS: Drivers behaviors at intersections are analyzed on the conditions of acceleration and deceleration. RESULTS : First, it is resulted greenhouse gas emissions per vehicle is produced more at intersections than at the main lines of highway. Second, it is resulted that the average speed, the average acceleration rate and the maximum speed are three major factors to produce greenhouse gas per vehicle in acceleration sections. Third, it is resulted that rapid deceleration 20m before entering intersections is the major factor to produce greenhouse gas per vehicle in deceleration sections. CONCLUSIONS: At intersections, sudden acceleration and deceleration is not good for greenhouse gas emissions. Thus, and the average speed, the average acceleration rate and the maximum speed are the chosen as factors to be controlled for drivers' behavior to reduce vehicles' greenhouse gas at intersections.

• 수산해양기술연구
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• 제35권3호
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• pp.301-311
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• 1999

The investigation to evaluate the possible effects of fish behaviour on acoustic target strength was carried out during the 1997 and 1998 hydroacoustic-demersal trawl surveys in the southern waters of Korea.The swimming speed and the target strength of individual, acoustically resolved fished swimming through the sound beam were measured using the split-beam tracking method on board R/V Kaya.The results obtained can be summarized as follows:1. The alongship and athwartship angles between -3dB poionts of a hull mounted 38 kHz split beam tranducer used in these surveys was >$3.76^{\circ}\;and\;6.74^{\circ}$ respectively, and the equal energy contour obtained from the measured beam pattern showed approximately the circular pattern. 2. The swimming speed measured off the south coast of Sorido in 23 January 1997 ranged 0.10 to 0.80 m/s with the average swimming spped of 0.36 m/s, and the target strength ranged -64.8 to -31.7 dB with the average target strength of -52.7 dB. The most dominant species sampled in this survey area were Japanese scaled sardine, Sardinella zunasi and Konoshiro gizzard shad, Konosirus punctatus, respectively.3. The swimming speed measured off the east coast of Kojedo in 24 March 1997 ranged 0.10 to 1.10 m/s with the average swimming speed of 0.40 m/s, and the target strength ranged -64.8 to -51.5 dB with the average target strength of -59.2 dB. The most dominant species sampled in this survey area were Swordtip squid, Photololigo edulis, Konoshiro gizzard shad and Japanese flying squid, Toddarodes pacificus, respectively and the swimming activity of these species seems to be controlled at speeds between 0.20 and 0.60 m/s. 4. The swimming speed measured the south coast of Kojedo in 25 March 1997 ranged 0.10 to 1.40 m/s with the average swimming speed of 0.51 m/s and the target strength ranged -64.3 to -47.7 dB with the average target strength of -55.1 dB. The most dominant species sampled in this survey area were Swordtip squid, Blotchy sillage, Sillago maculata and japanese scaled sardine, respectively and the swimming activity of these species seems to be controlled at speeds between 0.20 and 0.70 m/s.5. The swimming speed measured during morning twilight in the southeastern water of Cheju Island in 11 July 1998 ranged 0.20 to 1.0 m/s with the average swimming speed of 0.53 m/s, and the target strength ranged -65.0 to -47.0 dB with the average target strength of -57.1 dB. The most dominant species sampled in this survey area were Swordtip squid, Black scraper, Thamnaconus modesutus and japanese flying squid, respectively and the tile angle ranged$ +28^{\circ}\;to\;+2^{\circ}$ with the average tilt angle of -8.1$^{\circ}$ showing the downward migration.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.591-595
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• 1998

This paper proposes a new concept of optimal shortest path algorithm which reduce average vehicle wating time and improve average vehicle speed, Electro sensitive traffic system can extend the traffic cycle when three are many vehicles on the road or it can reduce the traffic cycle when there are small vehicles on the road. But electro sensitive traffic light system doesn't control that kind of function when the average vehicle speed is 10km -20km. Therefore, in this paper to reduce vehicle waiting time we developed design of traffic cycle software tool that can arrive destinination as soon as possible using optimal shortest pass algorithm. Computer simulation result proved 10%-32% reducing average vehicle wating time and average vehicle speed which can select shortest route using built in G.P.S. vehicle is better than not being able to select shortest route function.