• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.2
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• pp.15-25
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• 2007

This paper aims at testing the applicability of RFID (radio frequency identification) based link travel time estimation algorithm in urban street settings in Jeju island Korea. For this, we developed algorithm and compared link travel times derived from the RFID probe based algorithm with those from (already available) GPS based link travel time estimation algorithm and with the actual link travel times from survey. RFID readers are composed of master reader and slave reader and the participating passenger cars were supposed to be equipped with RFID tag inside the vehicle. The data were sent to traffic information center and we used those data in comparison. The algorithm produced link travel times in a successful manner and the accuracy of those link travel times was about 88%. For the same link segments, the accuracy of GPS based link travel times was 93%. The t-test showed that both RFID and GPS based link travel times were not different in accuracy from statistical point of view. The applicability of RFID was tested successfully and the algorithm proposed seemed to be used in similar urban settings. Some limits and future research agenda have also been presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.47-54
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• 2014

Endurance of ship hull can be estimated by existing regulations and fatigue estimation methods. These can be applied to the hull materials that are recommended by ship regulations but can't be applied to new materials. In this study, structural force in the worst sailing condition is obtained by the acceleration measurement test of small polyethylene boat and the endurance of small polyethylene hull is estimated by rainflow cycle counting method and linear cumulative damage rule. Maximum Von-Mises stress on the polyethylene boat is 1.8MPa and much lower than the fatigue strength of at least 5.9MPa for the fatigue life of $1{\times}10^9$ cycles. Fatigue life of the polyethylene boat hull is estimated to be 6,229 years.

• Composites Research
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• v.18 no.6
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• pp.19-25
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• 2005

This paper has performed an experimental study on the hybrid composite carbody of Korean tilting railway vehicle. The hybrid composite carbody has the length of 23m and is comprised of a 40mm-thick aluminium honeycomb core and 2mm-thick woven fabric carbon/epoxy face sheet. In order to evaluate the structural behavior and safety of the hybrid composite carbody, the static load tests such as vertical load, end compressive load, torsional load and 3-point support load tests have been conducted. The test was performed under Japanese Industrial Standard (JIS) 17105 standard. from the tests, the maximum deflection was 12.3mm and the equivalent bending stiffness of the carbody was $0.81\times10^{14}\;kgf{\cdot}mm^2$. The maximum strain of the composite body was below $20\%$ of failure strain of the carbon/epoxy face sheet.

• International Journal of Highway Engineering
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• v.18 no.4
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• pp.1-8
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• 2016

PURPOSES : This study evaluates the reliability of the patterns of changes in the road surface temperature during winter using a statistical technique. In addition, a flexible road segmentation method is developed based on the collected road surface temperature data. METHODS : To collect and analyze the data, a thermal mapping system that could be attached to a survey vehicle along with various other sensors was employed. We first selected the test route based on the date and the weather and topographical conditions, since these factors affect the patterns of changes in the road surface temperature. Each route was surveyed a total of 10 times on a round-trip basis at the same times (5 AM to 6 AM). A correlation analysis was performed to identify whether the weather conditions reported for the survey dates were consistent with the actual conditions. In addition, we developed a method for dividing the road into sections based on the consecutive changes in the road surface temperature for use in future applications. Specifically, in this method, the road surface temperature data collected using the thermal mapping system was compared continuously with the average values for the various road sections, and the road was divided into sections based on the temperature. RESULTS : The results showed that the comparison of the reported and actual weather conditions and the standard deviation in the observed road surface temperatures could produce a good indicator of the reliability of the patterns of the changes in the road surface temperature. CONCLUSIONS : This research shows how road surface temperature data can be evaluated using a statistical technique. It also confirms that roads should be segmented based on the changes in the temperature and not using a uniform segmentation method.

• International Journal of Automotive Technology
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• v.8 no.6
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• pp.799-806
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• 2007

One method for improving the torque capacity of the CVT is to use a split-powered CVT(SPCVT) to reduce the power transmitted into a continuously variable unit(CVU). A variable bridge SPCVT with two planetary gear units(PGUs), which are composed of a sun gear, a ring gear, and carrier and planetary gears, can minimize the power to the CVU. However, a SPCVT with a conventional CVT should possess a dual mode, which would allow the conventional CVT to be used at high speeds and an additional gear train to be used at low speeds. The inner-spherical CVU(ISCVU) with an inner and outer spherical contact mechanism developed in this study can cover the range from low to high speeds. The rated power and the overall speed ratios were 100 kW and $0.09{\sim}0.36$, respectively. Power efficiency was numerically calculated to be over 90% over the speed ratio range of $0.1{\sim}0.29$. The maximum shear stress at the two contact areas of the rotor pairs, the minimum life and the overall size were estimated to be 700 MPa, 276 kh and $350{\times}350{\times}400mm^3$, respectively. This study shows that an ISCVU and a variable bridge type PGU can realize the SPCVT with a single mode for a vehicle.

• YAKHAK HOEJI
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• v.44 no.6
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• pp.558-565
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• 2000

SK-1080 is one of the newly developed orally active nonpeptide angiotensinII $AT_1-receptor$ antagonist that selectively acts at $AT_1$ receptor with high affinity. The cardiac effect on ischemia/reperfusion injury of SK-1080 was compared with those of losartan, a prototype of this class, in isolated rat hearts. Isolated perfused rat heart was pretreated with drug for 10 min and then subjected to global ischemia for 30 min followed by reperfusion with- or without drug for 30 min. The possible additive effect of SK-1080 on the platelet aggregation and coagulation in human blood was also studied. We investigated whether SK-1080 effects the platelet aggregation induced by ADP, a platelet agonist partially dependent on $thromboxaneA_2$. The clotting times in the prothrombin time (PT) and activated partial thromboplastin time (APTT) were also examined in human plasma in vitro as coagulation screening test. SK-1080 improved reperfusion function (LVDP, left ventricular developed pressure; PRP, rate-pressure product) in a dose-dependent manner. SK-1080 reduced ADP-induced platelet aggregation compared with vehicle but less than losartan, and did not affect clotting times.

• Journal of Digital Contents Society
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• v.3 no.1
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• pp.1-9
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• 2002

This paper is proposed to algorithm for measuring traffic information automatically, for example, volume count, speed and occupancy rate, from CCTV camera images installed on highway, add to function of image detectors which can be collected the traffic information. Recently the method of traffic informations are counted in lane one by one, but this manner is occurred critical errors by occlusion frequently in case of passing larger vehicles(bus, truck etc.) and is impossible to measure in the 8 lanes of highway. In this paper, installed the detection area include with all lanes, traffic informations are collected using tracking algorithm with passing vehicles individually in this detection area, thus possible to detect all of 8 lanes. The experiment have been conducted two different real road scenes for 20 minutes. For the experiments, the images are provided with CCTV camera which was installed at Kiheung Interchange upstream of Kyongbu highway, and video recording images at Chungkye Tunnel. For image processing, images captured by frame-grabber board 30 frames per second, $640{\times}480$ pixels resolution and 256 gray-levels to reduce the total amount of data to be interpreted.

• Journal of Oriental Neuropsychiatry
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• v.28 no.2
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• pp.123-136
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• 2017

Objectives: The objective of this study is to investigate the anti-amnesic effects of AR, Aucklandiae Radix, ground powder on scopolamine (Sco)-induced memory impairment in mice (C57BL/6) through its favorable acetylcholine (ACh) and acetylcholinesterase (AChE) activity, Choline acetyltransferase (ChAT) mRNA expression, and antioxidant effect. Methods: Six groups, a total of 20 intact or 100 Sco treated mice, were selected based on their body weights and were used in this study. Half of the mice in each group were used for the passive avoidance task test and the measurements of hippocampus ACh content, AChE activity and ChAT mRNA expression. The remaining half of the mice in each group were used for the Morris water maze test and cerebral antioxidant defense system measurement. Results: Marked decreases in step-through latency times in the passive avoidance task test and increases in escape latency times in the Morris water maze test were observed with decreases in the hippocampus ACh content and ChAT mRNA expression, and increases in the hippocampal AChE activities, as a result of Sco intraperitoneal treatment, in the present study. In addition, destruction of the cerebral cortex antioxidant defense systems was observed in Sco control mice as compared with intact vehicle control mice. However, 28 days of continuous oral pre-treatment with AR ground powder at doses of 400, 200 and 100 mg/kg markedly and dose-dependently inhibited the Sco treatment-related amnesia. Conclusions: The results prove that oral administration of AR ground powder reduces Sco-induced memory impairment. This is because it can preserve ACh, related to ChAT mRNA expression, cause AChE inhibition, and activate the cerebral antioxidant defense system.

• Journal of Oriental Neuropsychiatry
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• v.30 no.3
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• pp.221-235
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• 2019

Objectives: The purpose of this study was to confirm the anti-amnesic effects of Bunsimgieum (BSGE) through its favorable acetylcholine (ACh) and, acetylcholinesterase (AChE) activity, choline acetyltransferase (ChAT) mRNA expressions, and antioxidant effect on scopolamine (Sco)-induced memory impairment in C57BL/6 mice. Methods: Six groups, a total of 20 intact or 100 Sco-induced mice were used in this study, based on their body weight. Half of each group underwent passive avoidance tests and the measurement of hippocampus AChE activity, ACh content, and ChAT mRNA expression, The remaining half of each group underwent a Morris water-maze test and antioxidant defense system measurement as well. Results: Significant reductions in the step-through latency times from the passive avoidance test and reductions in the escape latency times from the Morris water-maze test were observed with increases of hippocampal AChE activities and, reductions in ACh contents and ChAT mRNA expression in hippocampus, as a result of Sco intraperitoneal treatment, in this study. Additionally, the increases in cerebral cortical MDA levels and, reductions in GSH contents, SOD activities, and CAT activities were demonstrated in the Sco control mice compared with the intact vehicle control mice, respectively. However, 28 days of consecutive oral pre-treatment of BSGE hot water extracts of 400, 200, and 100 mg/kg, respectively, markedly and dose-dependently inhibited Sco treatment-related amnesia. Conclusions: The results demonstrate that the oral administration of BSGE hot water extracts reduces Sco-induced memory impairment, through preserving ACh, related to ChAT mRNA expressions, causes AChE inhibition, and enhances the cerebral antioxidant defense system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2484-2490
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• 2012

This study reports on the development and performance verification of cell simulation boards of simulator and the embedded program for board control of the battery management system (BMS) of electric vehicle (EV) cars, which manages the next-generation automotive lithium-ion battery pack. Here, we have improved the speed of the simulator by using operational (OP) amplifier and transistors that were connected in series. In addition, using a digital analog converter (DAC) in each channel, we have improved the performance by channel-to-channel isolation (isolation) as compared to the traditional methods. Furthermore, by constructing a current-limiting protection circuit, one can be protected from disturbance and, by utilizing a precision shunt resistor for the current sensor, we have increased the precision of the current control. In order to verify the performance of the developed simulator, we have performed the experiment 10 times, with values ranging from 0.5 V to 5 V, and a voltage drop step of 0.5 V. Significance analysis of experimental data, and repeatability tests were performed, showing an average standard deviation of 0.001~0.004 V, indicating high repeatability and high statistical significance of the current method and system.