• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.110-123
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• 2019

Traffic data is the most basic element necessary for transportation planning and traffic system operation. Recently, a method of estimating traffic flow characteristics using distance to a leading vehicle measured by an ADAS camera has been attempted. This study investigated the feasibility of the ADAS vehicle reflecting the distance error of image-based vehicle identification technology as a means to estimate the traffic flow through the normalized root mean square error (NRMSE) based on the number of lanes, traffic demand, penetration rate of probe vehicle, and time-space estimation area by employing the microscopic simulation model, VISSIM. As a result, the estimate of low density traffic flow (i.e., LOS A, LOS B) is unreliable due to the limitation of the maximum identification distance of ADAS camera. Although the reliability of the estimates can be improved if multiple lanes, high traffic demands, and high penetration rates are implemented, artificially raising the penetration rates is unrealistic. Their reliability can be improved by extending the time dimension of the estimation area as well, but the most influential one is the driving behavior of the ADAS vehicle. In conclusion, although it is not possible to accurately estimate the traffic flow with the ADAS camera, its applicability will be expanded by improving its performance and functions.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.3
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• pp.292-303
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• 2002

This paper presents experimental results for early-age properties of concrete such as the setting time and strength, evaluated via the ultrasonic pulse velocity (UPV). Developing and using an automatically-recording monitoring system, the UPV's of mortar and concrete with various water to binder ratios (W/B) were measured during the first 24 hours. In addition, probe penetration and compression tests were conducted to measure the setting time and compressive strength, respectively. It was observed that the UPV's of mortar with high W/B remained constant during the first 6.5 hours and then abruptly began to increase at constant rates. On the other hand, the UPV of mortar with low W/B increased relatively slowly and gradually due to the setting retardation caused by the use of high range water reducing agent (HRWR). It was found that setting of concrete occurs when the UPV reaches a certain value. Moreover, it was concluded that the estimation formulas should incorporate the effects of W/B to more accurately estimate the early-age strength of concrete from the UPV.

• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.271-278
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• 1995

The relative distribution ratio of barbiturates between hyarocarbon interior and surface region of outer monolayer of synaptosomal plasma membrane vesicles (RSPMV) isolated from rat whole brain was determined by employing the fluorescent probe technique. The two fluorescent probes N- octadecylnaphthyl-2-amine-6-sulfonic acid (ONS) and 12-(9-anthroyloxy) stearic acid (AS) were utilized as probes for hydrocarbon interior and surface of outer monolayer of RSPMV. respectively. The Stern-Volmer equation for fluorescent quenching was modified to calculate the relative distribution ratio. The analysis of preferential quenching of these probes by barbiturates indicates that pentobarbital, hexobarbital, amobarbital and phenobarbital are predominantly distributed on the surface region. whereas thiopental sodium has an accessibility to the hydrocarbon interior of the outer monolayer of the RSPMV. From these results, it is strongly suggested that the more effective penetration into the hydrocarbon interior of the outer monolayer of the membrane lipid bilayer could result in higher general anesthetic activity.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.189-195
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• 1999

We have studied the vortex dynamics in YBa$_2Cu_3O_7$ single crystals with columnar defects using micro Hall-probe array. The Hall-probe array technique allowed a simultaneous measurement of the time and spatial dependence of the vortex density so that more detailed information on flux dynamics could be obtained. We found that field profiles inside sample were similar to the Bean's critical state model from the magnetic hysteresis measurement. Normalized relaxation rates were maximum near the center and decreased toward the edge if applied field H$_{app}$ is greater than the penetration field H. But applied magnetic field H$_{app}$ is less than H, relaxation rates were minimum near the center and increased toward edge. We found that glassy exponent ${\mu}$ has the value of ${\sim}$ 1 whose corresponding vortex motion is half-loop excitation. However, single vortex creep, ${\mu}$ ${\sim}$ 1/7, was also found at 30 K and H$_{app}$ ${\cong}$ H'. Calculation of activation energy, U, was possible from direct analysis of the local relaxation data using the basic diffusion equation. From these results, we found that U increases logarithmically with time and U around center was lower than that at the edge.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.5
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• pp.183-193
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• 2019

This study developed a shockwave detection and prediction of their extinction point method based on continuous wavelet transform using trajectory data from probe vehicles equipped with automotive sensors.. To analyze the effectiveness of the proposed method, this paper proposed two measures which are a distance error between the extinction points of the predictor and an time-location error of the extinction points. The proposed concept was proved using the micro simulation based experiment with three exogenous variables of traffic volume, lane-close duration, market penetration of probe vehicles. The analysis results show that the proposed method is capable of detecting the traffic shockwaves as well as predicting their extinction point, and also that the accuracy of the proposed method is highly dependent on the rate of the probe vehicles.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.3101-3101
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• 2001

Near Infrared spectroscopy (NIR) used on human skin measurement was explored in the past decade. Many publications in different journals and magazines discussed the feasibility of the NIR technique for cosmetic product property studies. Based upon the results of pioneers, we have pursued some work of the NIR instrument coupled with a probe module for skin measurement in vivo and vitro. In part I of this paper, the specific Near Infrared spectroscopy instrument stability, human subject conditions and other parameters, which could affect the measurements reproducibility are discussed. Second derivative NIR spectra and Principle Components Analysis (PCA) are utilised for data interpretation. In part II of this paper, the relationship of human skin moisture and ageing, the gender information and finally, the discovery of penetration depth of NIR incident light on skin are reported. A theoretical penetration depth calculation equation is proposed. In part III, the study results of a couple of commercial skin care products effect will be described. The skin lotions were applied on human skin (in vivo) in order to exam the NIR feasibility to monitor the changes of moisture level. The results are consistently positive. From our primary study, it can conclude that the NIR is potentially a very powerful instrument for skin condition diagnostics, either for cosmetic and/or for medication purposes.

• Journal of radiological science and technology
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• v.33 no.3
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• pp.245-252
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• 2010

This study analyzed speed of sound, impedance, attenuation coefficient in accordance with acoustic characteristic standard of body soft tissue corresponding with Annex DD of IEC standard 60601-2-37(2007) which is about tissue mimicking materials (TMM) synthesized by polyurethane as a main material and new type of n-type scatter materials. This study reached the following conclusion after analyzing and evaluating image characteristic with SONOACE 9900 c PRIME (MEDESON Co.) and brightness, maximum penetration with convex probe (2.5~5.0 MHz). When n-type scatter materials are increasingly synthesised 0~8% with prepolymer as a main material and polyol mixture as a catalyst, 1. The more scatter materials are increased, the more sound speed of TMM becomes closely similar to soft tissue. 2. The more scatter materials are decreased, the more acoustic impedance becomes closely similar to soft tissue. 3. The more scatter materials are increased, the more attenuation coefficient is increased. 4. The more scatter materials are increased, the more average brightness of images is increased, but there is threshold. 5. The maximum penetration becomes closely similar to soft tissue at the 6% TMM as a scatter material.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.957-964
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• 2023

This study focused on hand sanitizer as a medium that can replace ultrasonic gel, which is vulnerable to contamination by bacteria that reside on the hand. Hand sanitizer produces a strong sterilization effect from germs resident on the hands through different sterilization principles depending on the ingredients. Select products of gel type, cream type, and foam type, except for liquid type with low viscosity, and ultrasonically apply one 62% ethanol gel type and one cream type, one benzalkonium chloride 0.066% cream type and one foam type, respectively. Using ATS-539 as a medium, image evaluation was performed on the axial and lateral resolution and penetration depth, and the presence or absence of an air layer between the probe and the phantom. As a result, in the evaluation of the axial and lateral resolution and the depth of penetration, all four experimental groups met the evaluation criteria. However, in the case of the foam type, although it was suitable for the evaluation criteria of resolution and penetration depth, dark shadows appeared on both sides except for the center of observation during image evaluation. Through this experiment, it was possible to confirm the possibility that the remaining three types of hand sanitizers except the foam type could replace the ultrasonic gel.

• Food Science of Animal Resources
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• v.40 no.4
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• pp.551-562
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• 2020

Beef fat was replaced with cold press pumpkin seed oil (PSO; 0%, 5%, 15%, and 20%) in the production of bologna-type sausages. A value of pH, water-holding capacity (WHC), jelly-fat separation, emulsion stability and viscosity values were determined in meat batters. Thiobarbituric acid reactive substances (TBARS), color, and textural characteristics (TPA, shear test, penetration test) were determined in end-product at 1, 7, 14, 21, and 28 days of storage at 4℃. The pH values were varied between 6.06 and 6.08. With the increase in the level of PSO in meat batters, there was a significant increase in WHC, jelly-fat separation and viscosity values (p<0.05) while a significant decrease in emulsion stability (p<0.05). TBARS values of sausages were found to be significantly higher than in the control group (p<0.05), and this trend continued during storage. Increasing of PSO level were caused a significant increase in L* and b* values while a decrease in a* value (p<0.05). Hardness, adhesiveness and chewiness values were significantly reduced whereas cohesiveness and resilience values increased (p<0.05). Maximum shear force and work of shear was significantly decreased as the level of PSO increased (p<0.05). Hardness, work of penetration and the resistance during the withdrawal of the probe values (penetration tests) increased significantly with the increase in the level of PSO (p<0.05). These results indicate that PSO has potential to be use as a replacement of animal-based fats in the production of bologna-type sausages.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09c
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• pp.24-30
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• 2010

The void ratio and elastic moduli are design parameters used in geotechnical engineering to understand soil behavior. Elastic and electromagnetic waves have been used to evaluate the various soil characteristics due to high resolution. The objective of this study is to evaluate the void ratio and elastic moduli based on elastic wave velocities and electrical resistivity. The Field Velocity Resistivity Probe (FVRP) is developed to obtain the elastic and electromagnetic wave profiles of soil during penetration. The Piezoelectric Disk Elements (PDE) and Bender Elements (BE) are used as transducers for measuring the elastic wave velocities such as compressional and shear wave velocities. The Electrical Resistivity Probe (ERP) is also installed for capturing the electrical resistivity profile. The application test is carried out on the southern coast of the Korean peninsula. The field tests are performed at a depth of 6~20 m, at 10 cm intervals for measuring elastic wave velocities and at 0.5cm intervals for measuring electrical resistivity. The elastic moduli such as constraint and shear moduli are calculated by using measured elastic wave velocities. The void ratios are also evaluated based on the elastic wave velocities and the electrical resistivity. Furthermore, the converted void ratios by using FVRP are compared with the volumetric void ratio obtained by a standard consolidation test. The comparison shows that the void ratios based on the FVPR match the volume based void ratio well. This study suggests that the FVRP may be a useful device to effectively determine the elastic moduli and void ratio in the field.