• International Journal of Highway Engineering
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• v.15 no.6
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• pp.103-111
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• 2013

PURPOSES : Previous Speed Profile reflects the patterns of speeds in sections of tangents to curves in the roads. However these patterns are uniform of speeds and Acceleration/Deceleration. In oder to supplement these shortcomings. this study made a new profile which can contain factors of Acceleration/Deceleration through theories of Previous Speed Profiles. METHODS : For sakes, this study developed the speed prediction model of Rural Multi-Lane Highways and calculated Acceleration/Deceleration by appling a Polynomial model based on developed speed prediction model. Polynomial model is based on second by second. Acceleration/Deceleration Profile is developed with the various scenarios of road geometric conditions. RESULTS : The longer an ahead tangent length is, The higher an acceleration rate in curve occurs due to wide sight distance. However when there are big speed gaps between two curves, the longer tangent length alleviate acceleration rate. CONCLUSIONS : Acceleration/Deceleration Profile can overview th patterns of speeds and Accelerations/Decelerations in the various road geometric conditions. Also this result will help road designer have a proper guidance to exam a potential geometric conditions where may occur the acceleration/deceleration states.

• Journal of Industrial Technology
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• v.19
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• pp.179-187
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• 1999

The computer pattern sewing machine is an automatic sewing machine that is controlled by an input pattern. Even a novice can run this machine for various tasks fast and reliably such as sewing a button, a belt ring and an airbag, etc. The pattern processing software, which is the main software of this machine, is for editing and modifying pattern data by online teaching or off-line editing, setting up parameters, and calculate a moving distance of working area on the x-y axes. In this paper we propose an algorithm to generate pattern data for sewing by simplifying image data. The pattern data are composed of outline data like dot, line, circle, arc, curve, etc. We need converting this data into sewing data which involve sewing parameter, moving distance of working are an the x-y axes, thread, spindle speed.

• Journal of Korean Society of Transportation
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• v.20 no.1
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• pp.131-139
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• 2002

This study introduces a developed artificial neural networks(ANN) model as a more efficient and reliable prediction model in operating speed Prediction with the 85th percentile horizontal curve of two-way rural highway in the aspect of evaluating highway design consistency. On the assumption that the speed is decided by highway geometry features, total 30 survey sites were selected. Data include currie radius, curve length, intersection angle, sight distance, lane width, and lane of those sites and were used as input layer data of the ANN. The optimized model structure was drawn by number of unit of hidden layer, learning coefficient, momentum coefficient, and change in learning frequency in multi-layer a ANN model. To verify learning Performance of ANN, 30 survey sites were selected while data in obtained from the 20 cites were used as learning data and those from the remaining 10 sites were used as predictive data. As a result of statistical verification, the model D of 4 types of ANN was evaluated as the most similar model to the actual operating speed value: R2 was 85% and %RMSE was 0.0204.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.567-573
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• 2003

Korean High Speed Train (KHST) has been tested on high speed line in JungBu site since it was developed in 2002. The data acquisition system was developed to accomplish successfully this on-line test for proving the dynamic Performance of KHST. This system was consist of the personal computers based on National Instrument PXI modules and the test programs based on Labview 6i. This paper shows that this system is efficient to acquire the test data through the multi-channels connected the accelerometers which located in long distance places and flexible to change and add channels for data acquisition. The dynamic analysis of an on-line test is very complicate because the environmental conditions, as examples radius of curve, inclination of the track, tunnels, bridges, and so forth, and running conditions, as examples driving, braking, the number of working motors, and so forth, have an effect on the results. Therefor, the analysis method is important and this paper proposes the efficient procedure graphically, showing the proposed method simplify the accelerations of 5th bogie frame acquired during the on-line test for KHST.

• Membrane and Water Treatment
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• v.13 no.5
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• pp.219-225
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• 2022

5th Assessment Report of the Intergovernmental Panel on Climate Change Weather (AR5) predicts that recent severe hydrological events will affect the quality of water and increase water pollution. To analyze changes in water quality due to future climate change, input data (precipitation, average temperature, relative humidity, average wind speed, and solar radiation) were compiled into a representative concentration curve (RC), defined using 8.5. AR5 and future use are calculated based on land use. Semi-distributed emission model Calculate emissions for each target period. Meteorological factors affecting water quality (precipitation, temperature, and flow) were input into a multiple linear regression (MLR) model and an artificial neural network (ANN) to analyze the data. Extensive experimental studies of flow properties have been carried out. In addition, an Acoustic Doppler Velocity (ADV) device was used to monitor the flow of a large open channel connection in a wastewater treatment plant in Ho Chi Minh City. Observations were made along different streams at different locations and at different depths. Analysis of measurement data shows average speed profile, aspect ratio, vertical position Measure, and ratio the vertical to bottom distance for maximum speed and water depth. This result indicates that the transport effect of the compound was considered when preparing the hazard analysis.

• Korean Journal of Applied Biomechanics
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• v.23 no.4
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• pp.319-326
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• 2013

The objective of this study is to help golfers to select adequate putters and to provide golfers basic scientific data for improving athletic performance by showing differences of kinematic variables according to the shape of putter head. In this research three right-handed male pro-golfer who are listed at KPGA were studied and three video camera (GR-HD1KR, JVC, Japan) were used and recording speed was 60 frame/sec during the research. In this study kinematic variables were calculated using Kwon3D XP program and analysed on the 4 events and 3 phases. This study showed the following results : (1) The swing of heel-toe putter showed longer time than that of face balanced putter, and there are statistical significant difference of kinematic variables of each objective (2) As of the trajectory of putter head, heel-toe putter showed more approximating curve trajectory than that of in-between, face balanced putter on the X-axis (3) heel-toe putter showed longer distance follow-through than that of other putters by statistically significant difference on the Y-axis (4) Heel-toe putter showed longer distance swing trajectory over the ground than that of other putters by statistically significant difference on the Z-axis.

• Journal of the Korean Institute of Navigation
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• v.18 no.4
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• pp.137-146
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• 1994

In this paper, a new algorithm to measure the ultrasonic travel time is proposed, which is fundamental to estimate distance depth and volume in several media. Pulse wave has been used to measure travel time of transmitted signal. However, due to the characteristic of transducer and propagation, the received signal is so distorted that it is difficult to measure travel time, which is propagation, the received signal is so distorted that it is difficult to measure travel time, which is to be time difference between transmitted and received signals. In this proposed method, transmitted and received signal are transformed respectively into norm phase newly designed by this paper and displayed on phase-time curve. And travel time is simply determined by the arithmetic numerical mean of time difference at the identical norm phase on the phase-time curves of transmitted and received signals. This method has several features; firstly, travel time is calculated analytically with high accuracy by least square error method, secondly, it is useful to compare the difference of signal magnitude for time information, thirdly, noise and discrete errors are relatively small, finally, the measurement accuracy is not influenced by D.C. bias. In particular, this method is useful and applicable to measuring very short distance and sound speed with high accuracy.

• The Journal of the Acoustical Society of Korea
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• v.37 no.1
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• pp.1-11
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• 2018

Sound propagation in shallow water changes from spherical spreading to cylindrical spreading, depending on boundary conditions, and this point is defined as a transition point of the sound propagation condition. Theoretically, the transition point can be estimated using the transmission loss as a function of source-receiver range. In this paper, the transmission loss curve in a Pekeris waveguide is predicted using a parabolic-equation based acoustic propagation model and using this transmission loss curve, the range from the source of the transition point is estimated, which is compared to the critical distance calculated using the sound speed ratio of water to sediment. In addition, the effects of the sound speed profile and source depth change on the transition point are investigated. Finally, the transition point is estimated using the transmission loss data measured during the period of the SAVEX15 (Shallow Water Acoustic Variability EXperiment 2015) conducted 65 km southwest of Jeju Island in May 2015, and it is compared to the ocean environmental parameters to understand the properties of sound propagation in the experimental area.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.2
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• pp.141-149
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• 1996

Lateral dispersion parameter(.sigma.$_{y}$) which is an important factor in atmospheric dispersion can be estimated byusing wind direction fluctuation(.sigma.$_{\theta}$). In this paper, we studied the characteristics of the .sigma.$_{\theta}$ in the Chunchon basin and calculated the .sig- ma.$_{y}$ by using the .sigma.$_{\theta}$. We could find some characteristics of the .sigma.$_{\theta}$ which showed small value, when the atmospheric condition was in weak unstable (C class) and neutral (D class). Moreover, when the atmospheric stability was neutral, there was no difference of .sigma.$_{\theta}$ with wind speed. On the other hand, .sigma.$_{\theta}$ showed large values at the strong unstable (A class) and strong stable (F class) condition with low wind speed. In this case, the .sigma.$_{\theta}$ increased as long as averaging time due to the long-period wind direction fluctuation by the terrain effect. In the result of calculation of .sigma.$_{y}$, it was smaller than that of pasquill-Gifford curve. Especially, when the atmospheric condition was in a neutral and stable, .sigma.$_{y}$ showed small increment as the downwind distance increased.creased.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.6
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• pp.52-63
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• 1997

Non-circular gear has a good velocity ratio in high speed and heavy load without any slip, moreover, it can transmit various motion, using simpler structure than link and cam, automation mechainism. In case of designing and manufacturing non-circular gear. I suggest one of references in applying non-circular gear to industrial plant, and suitable range of application by pressure angle curvature and angle ratio