• International Journal of Highway Engineering
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• v.14 no.2
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• pp.93-99
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• 2012

This study analyzes traffic data which are collected by VDS(Vehicle Detection System) to research the relationship between spacing distribution and vehicles' relative speed. The collected data are relative speed between preceding and following vehicles, passing time and speed. They are also classified by lane and direction. For the result of the analysis, in the same platoon, we figure out that mean of spacing is 40m, which can be a value to determine section A to D. To compare spacing according to time interval, this study splits time intervals to peak hour and non-peak hour by peak hour traffic volume. In conclusion, vehicles in peak hour are in car following because most drive similar speed as preceding vehicle and they have relatively small spacing. On the other hand, non-peak hour's spacing between vehicles is bigger than that of peak hour. This implies driver's behaviors that the less spacing, the more aggressive and want to reduce their travel time in peak hour, whereas most drive easily in non-peak hour and recreational trip purpose because of less time pressure.

• Journal of Environmental Science International
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• v.24 no.4
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• pp.393-401
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• 2015

Rainfall-runoff model of Jeju Oedo Stream was used to compute the optimal unit hydrograph by HEC-HMS model that reflecting on watershed characteristics. Each rainfall event was comparatively analyzed with the actual flow measurement using Clark, Snyder and SCS synthetic methods for derived unit hydrograph. Subsequently, the null hypothesis was established as p-value for peak flow and peak time of each unit hydrograph by one-way ANOVA(Analysis of variance) was larger than significance level of 0.05. There was no significant difference in peak flow and peak time between different methods of unit hydrograph. As a result of comparing error rate with actual flow measurement data, Clark synthetic unit graph best reflected in Oedo Stream as compared to other methods, and error rate of Clark unit hydrograph was 0.02~1.93% and error rate at peak time was 0~2.74%.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.20 no.2
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• pp.161-170
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• 2022

The effect of oxidation time on the characteristics and mechanical properties of spent nuclear fuel cladding was investigated using Raman spectroscopy, tube rupture test, and tensile test. As oxidation time increased, the Raman peak associated with the tetragonal zirconium oxide phase diminished and merged with the Raman peak associated with the monoclinic zirconium oxide phase near 333 cm^-1. Additionally, the other tetragonal zirconium oxide phase peak at 380 cm^-1 decreased after 100 d of oxidation, whereas the zirconium monoclinic oxide peak became the dominant peak. The oxidation time had no effect on the tube rupture pressure of the oxidized zirconium alloy tube. However, the yield and tensile stresses of the oxidized nuclear fuel cladding tube decreased after 100 d of oxidation. The results of the scanning electron microscopy and transmission electron microscopy were represented with the in-situ Raman analysis result for the oxide characteristics generated on the cladding of spent nuclear fuel.

• Physical Therapy Korea
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• v.20 no.3
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• pp.45-53
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• 2013

The purpose of this study was to examine the differentiation of proprioception, invertor and evertor muscle strength, and time to peak torque at a velocity of $300^{\circ}/sec$ of the ankle joint in people with or without functional ankle instability (FAI). Nineteen subjects with a history of ankle sprain participated. All subjects were divided into FAI group ($n_1=9$, Cumberland ankle instability tool (CAIT)${\leq}24$) and a control group ($n_2=10$) based on their CAIT scores. Isokinetic dynamometer was used to measure the sense of active joint position of the ankle at mid-range and end-range of an inversion motion and invertor as well as the evertor muscle strength and time to peak torque at $300^{\circ}/s$. The FAI group showed a statistically reduction in invertor and evertor muscle strength and time to peak torque when compared to the control group (p<.05). Muscle strength and time to peak torque of the invertor and evertor, as well as the sense of active joint position at end-range were also lower in the FAI group than in the control (p<.05). Correlations between CAIT score and position sense at end-range (r=-.577) and invertor muscle strength (r=.554) were statistically significant (p<.05). Individuals with FAI showed reduction in invertor and evertor muscle strength and recruitment time as well as in proprioception of the ankle joint. Thus, proprioception and invertor and evertor muscle strength of the ankle joint at fast angular velocity may be investigated when examining and planning care for individuals with FAI.

• Journal of the Korean Institute of Telematics and Electronics
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• v.17 no.4
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• pp.38-44
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• 1980

We present a high speed pitch estimation algorithm that is based on peak detection and average magnitude difference function (AMDF). A few pitch candidates are first estimated from the low-pass filtered (800 Hz) speech by a peak detection algorithm. AMDF values of the pitch candidatestare then calculated, and the pitch candidate that yields the minimum AMDF value is chosen as the desired pitch period. The new method requires far less computation time than other pitch estimation algorithms, while it yields fairly accurate results.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.17 no.1
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• pp.63-76
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• 2013

The aims of this study are to investigate a logisitic regression equation of the vacuous pulse and the replete pulse for efficacy evaluation of clip-type pulsimeter by using magnetic Hall device. To evaluate the efficacy of clip-type pulsimeter by using magnetic Hall device as sensing the minute movement of a radial artery, one research clinical trial have been performed. The number of subject was 120, the clinical data of patients did treated with a normal statistical method. The systolic peak amplitude, the reflective peak amplitude and time, and the notch peak amplitude and time are analyzed major efficacy parameters to discern the vacuous pulse and the replete pulse. The equations included of five parameters such as systolic peak amplitude, the reflective peak amplitude and time, and the notch peak amplitude and notch amplitude time for determination of the vacuous pulse and the replete pulse were deducted by statistical logistic regression method. It suggests that the logistic regression equations are possible to develop the oriental algorithm for pulse diagnosis.

• Wind and Structures
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• v.23 no.4
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• pp.275-300
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• 2016

Synchronous multi-pressure measurements were carried out with relatively long time duration for a double-layer reticulated shell roof model in the atmospheric boundary layer wind tunnel. Since the long roof is open at two ends for the storage of coal piles, three different testing cases were considered as the empty roof without coal piles (Case A), half coal piles inside (Case B) and full coal piles inside (Case C). Based on the wind tunnel test results, non-Gaussian time-dependent statistics of net wind pressure on the shell roof were quantified in terms of skewness and kurtosis. It was found that the direct statistical estimation of high-order moments and peak factors is quite sensitive to the duration of wind pressure time-history data. The maximum value of COVs (Coefficients of variations) of high-order moments is up to 1.05 for several measured pressure processes. The Mixture distribution models are proposed for better modeling the distribution of a parent pressure process. With the aid of mixture parent distribution models, the existing translated-peak-process (TPP) method has been revised and improved in the estimation of non-Gaussian peak factors. Finally, non-Gaussian peak factors of wind pressure, particularly for those observed hardening pressure process, were calculated by employing various state-of-the-art methods and compared to the direct statistical analysis of the measured long-duration wind pressure data. The estimated non-Gaussian peak factors for a hardening pressure process at the leading edge of the roof were varying from 3.6229, 3.3693 to 3.3416 corresponding to three different cases of A, B and C.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.4
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• pp.76-82
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• 2018

3D formed Electrical Discharge Machining (EDM) and hole EDM were conducted for die and mold manufacturing with electrodes which were made by mechanical machining and wire EDM. It is difficult to machine the hardened material after heat treatment and quenching with traditional machining. The only method of machining hardened material is die-sinking EDM. In this research, hole EDM was conducted for heat-treated cold-worked tool steel (SKD11) for use as a die material. The EDM surfaces were analyzed by pulse-on time and peak current of EDM current, according to the machining conditions of EDM. The EDM surface profiles were affected by the peak current. The contribution of each factor is peak current (91.63%) and pulse-on time (0.93%). The best surface roughness was obtained with a $130{\mu}s$ pulse-on time and a 14.2 A peak current. With uniform EDM processing, the surface deteriorated with increasing pulse-on time and peak current. The thickness of the solidified layer induced by EDM was increased as the peak current, crater shapes, and erupted shapes of EDM surfaces were increased. Therefore, microcracking gaps induced by surface tension were increased.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.5
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• pp.312-325
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• 2006

Integration applications, such as EAI, B2Bi, need stable massive data processing systems during overload state cause by service request congestion in a short period time. In this paper, we propose the PLC (Peak Load Control)-based Worker-Linker pattern, which can effectively and stably process massive I/O transactions in spite of overload state generated by service request congestion. This pattern uses the delay time algorithm for the PLC mechanism. In this paper, we also show the example of applying the pattern to business-business integration framework and the experimental result for proving the stability of performance. According to our experiment result, the proposed delay time algorithm can stably control the heavy overload after the saturation point and has an effect on the controlling peak load.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.1
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• pp.35-41
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• 2003

In this paper statistics on the radiation field waveforms produced by stepped leaders just prior to lightning return strokes were described. As a parameter of stepped leader pulse characteristics, the time interval between the final leader pulse and return stroke peak, the pause time between stepped leaders, the ratio of the final leader peak to the return stroke peak and the stepped leader pulse width at half maximum were examined. The average time intervals between the final leader pulse and return stroke peak were about 16.2 and 14.8$mutextrm{s}$ for the positive and negative polarities, respectively. When the stepped leader approaches closely to ground, the time interval between leader steps was decreased and the mean value was about 17$mutextrm{s}$, and the present results were in reasonable agreement with the data observed in Florida and Japan. The large fraction of the ratios of the final stepped leader pulse to the lightning return stroke peak were distributed over the range from 5 to 35% and in average the ratio of the final leader pulse to the return stroke peak was 17.4$\pm$11.9% for the positive and 18.5$\pm$9.4% for the negative electric field waveforms. In addition, the mean pulse widths at half maximum of the stepped leaders are 1.4Us with a standard deviation of 0.9 for the positive Polarity and 2.2us with a standard deviation of 1.2 for the negative polarity, respectively.