• Journal of Preventive Medicine and Public Health
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• v.25 no.2 s.38
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• pp.141-147
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• 1992

This study was carried out not only to determine blood alcohol levels by time but also to examine the changes of working ability and reaction speed after ingestion of alcohol. Fifteen healthy students aged from 21 to 27 volunteered as subjects for this study, Liguor (Sojoo) in concentration of 25% ethyl alcohol was administrated with the amount of 1ml of ethyl alcohol per kg of body weight to the subjects. The concentration of alcohol in the blood were determined by the 'Alcohol Sensor 100' at 5, 30, 60 and 90 minutes after the administration of alcohol. Also, the choice reactiontest, the eye-hand coordination test and kraepelin test were examined at the same time after checking of alcohol concentration in the blood. The results of this study can be summarized as follows. 1. Mean blood alcohol level changes resulting from administration of 1ml of ethyl alcohol per kg of body weight were $0.16%(160{\pm}57mg/100ml,\;0.10%(100{\pm}42mg/100ml),\;0.08%(80{\pm}36mg/100ml)\;and\;0.03%(30{\pm}24mg/100ml)$ at the 3, 30, 60 and 90 minutes after the administration respectively The peak in the concentration of blood alcohol was 5 miniutes after the ingestion according to alcohol examination by the respiration. 2. As for choice reaction test, reaction times became prolonged as blood alcohol levels increased. The reaction time showed a significant changes when the blood alcohol concentration reached 0.08% or more after alcohol ingestion. 3. In eye and hand coordination test, the accuracy of the performance became decreased as blood alcohol levels increased. The difference of accuracy of the test was significantly shown when alcohol levels in the blood reached 0.08% or more after alcohol intake. 4. As for kraepelin test, the abilities of calculation also became lowered as blood alcohol levels increased. The abilities of calculation differed signigicantly from control group when alchool levels of 0.08% and more.

• International Journal of Highway Engineering
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• v.14 no.2
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• pp.63-72
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• 2012

Current analysis method drives an irrationality a road, signal operation and cause confusion of road such as weaving, bottleneck being not including main traffic flow in analysis subject. Therefore, this research develops analysis method of simple grade facilities to grasp target equipment relationship effect as virtue process to grasp effect of simple grade facilities in city and there is the purpose to apply optimum space of analysis intersection. In this paper, get at effect of simple grade facilities in urban area, as well as, develop new analysis method of simple grade facilities and adapt optimal interval of intersection point. New method of this paper reasonably estimated to optimal interval of the traffic flow(diverge area, merge area). As research result, analysis method to present in this research could clarify vague part of existing analysis method and presume reasonable result. Optimal interval of diverge and merge area with facilities was appeared more then 65m from the main line and more then 45m from the frontage road. Meaning of this paper as follow. First, the effect of simple grade facilities estimate. as consider optimal interval of simple grade facilities in urban can plan efficiently operation planning of road and signal in connection with nearby intersection. Second, new method then previous methods. planner of transportation easily access due to run parallel with existing method. Third, new method is contained through traffic volumes. the existing method did not reflect one. and this new method reduce error to the minimum. when analysis of intersection and link. Fourth, using the new method propose improvement plan with road operation and signal operation.

• Proceedings of the KOR-KST Conference
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• 1995.02a
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• pp.3-32
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• 1995

The Highway Capacity Manual specifies procedures for evaluating intersection performance in terms of delay per vehicle. What is lacking in the current methodology is a comparable quantitative procedure for ass~ssing the safety-based level of service provided to motorists. The objective of the research described herein was to develop a computational procedure for evaluating the safety-based level of service of signalized intersections based on the relative hazard of alternative intersection designs and signal timing plans. Conflict opportunity models were developed for those crossing, diverging, and stopping maneuvers which are associated with left-turn and rear-end accidents. Safety¬based level-of-service criteria were then developed based on the distribution of conflict opportunities computed from the developed models. A case study evaluation of the level of service analysis methodology revealed that the developed safety-based criteria were not as sensitive to changes in prevailing traffic, roadway, and signal timing conditions as the traditional delay-based measure. However, the methodology did permit a quantitative assessment of the trade-off between delay reduction and safety improvement. The Highway Capacity Manual (HCM) specifies procedures for evaluating intersection performance in terms of a wide variety of prevailing conditions such as traffic composition, intersection geometry, traffic volumes, and signal timing (1). At the present time, however, performance is only measured in terms of delay per vehicle. This is a parameter which is widely accepted as a meaningful and useful indicator of the efficiency with which an intersection is serving traffic needs. What is lacking in the current methodology is a comparable quantitative procedure for assessing the safety-based level of service provided to motorists. For example, it is well¬known that the change from permissive to protected left-turn phasing can reduce left-turn accident frequency. However, the HCM only permits a quantitative assessment of the impact of this alternative phasing arrangement on vehicle delay. It is left to the engineer or planner to subjectively judge the level of safety benefits, and to evaluate the trade-off between the efficiency and safety consequences of the alternative phasing plans. Numerous examples of other geometric design and signal timing improvements could also be given. At present, the principal methods available to the practitioner for evaluating the relative safety at signalized intersections are: a) the application of engineering judgement, b) accident analyses, and c) traffic conflicts analysis. Reliance on engineering judgement has obvious limitations, especially when placed in the context of the elaborate HCM procedures for calculating delay. Accident analyses generally require some type of before-after comparison, either for the case study intersection or for a large set of similar intersections. In e.ither situation, there are problems associated with compensating for regression-to-the-mean phenomena (2), as well as obtaining an adequate sample size. Research has also pointed to potential bias caused by the way in which exposure to accidents is measured (3, 4). Because of the problems associated with traditional accident analyses, some have promoted the use of tqe traffic conflicts technique (5). However, this procedure also has shortcomings in that it.requires extensive field data collection and trained observers to identify the different types of conflicts occurring in the field. The objective of the research described herein was to develop a computational procedure for evaluating the safety-based level of service of signalized intersections that would be compatible and consistent with that presently found in the HCM for evaluating efficiency-based level of service as measured by delay per vehicle (6). The intent was not to develop a new set of accident prediction models, but to design a methodology to quantitatively predict the relative hazard of alternative intersection designs and signal timing plans.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.2
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• pp.106-116
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• 2011

USN(Ubiquitous Sensor Network) environment permits us to access whatever information we want, whenever we want. The technologies to provide a basement to these environments premise an accurate location establishment. Especially, ITS(Intelligent Transportation Systems) is easily constructed by applying USN technology. Localization can be categorized as either Range-based or Range-free. Range-based is known to be not suitable for the localization based on sensor network, because of the irregularity of radio propagation and the additional device requirement. The other side, Range-free is much appropriated for the resource constrained sensor network because it can actively locate by means of the communication radio. But, generally the location accuracy of Range-free is low. Especially, it is very low in a low-density environment. So, these two methods have both merits and demerits. Therefore, it requires a new method to be able to improve tracking accuracy by combining the two methods. This paper proposes the tracking scheme based on range-hybrid, which can markedly enhance tracking accuracy by effectively using the information of surrounding nodes and the RSSI(Received Signal Strength Indication) that does not require additional hardware. Additionally, we present a method, which can improve the accuracy of vehicle tracking by adopting the prediction mechanism. Simulation results show that our method outperforms other methods in the transportation simulation environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.207-214
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• 2016

RFID technology is a technology perceiving information with the device called reader and tag which is now used in public transportation such as Hi-pass. In this paper, we design a system which tracks indoor location using this technology. GPS, the most frequently used location-tracking system, has a defect that its accuracy decreases when the device is indoor. In suggested experiment, we simulate signals according to the moving of located objects, then compare with the result of the experiment. Based on the extracted data, we inform data which is for the purpose of tracking system based on analysis of the route and errors. Simulations for the tracking were performed with relocation of real objects. In the real experiment, we arrange the readers around the room and move the tagged object that we like to know the location, then analyze the data from the equipment. This paper suggests the analyzed data for the future indoor tag tracking applications. We expect that the RFID based location positioning data will be used for other indoor positioning research and development.

• Science of Emotion and Sensibility
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• v.16 no.2
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• pp.195-206
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• 2013

The main causes of traffic accidents while driving a car is of the driver's visual distraction. In this study, the color sensitivity of the information projected on the windshield were evaluated for HUD (Head Up Display) system which helps the driver's eyes on the road while driving. The driving Information were projected $9^{\circ}$ downward from front sight $0^{\circ}$ under lab's fluorescent lights, LED floorlights and the TV had having 25 [lux] illumination when driving at night environment and 100,000 [lux] of daylight environment. Munsell color hue of the basic five colors (R, Y, G, B, P) and the color of traffic lights YR, W were the color of the seven characters, each character were outlined by White, Gray except for W. Total of 19 experimental stimuli was shown in the environment of day and night driving for asking visibility information of color, fatigue, preferences, and evaluate the degree of interference. The results came out that the bright Y and G color is visibility significantly for daylight. Second, with the outline of the text, the color of the outline works as a background for luminance contrast effects and affects visibility. Third, without the outline, the glass in front of the vehicle acts as the background and the luminance contrast of characters achieve greater brightness and visibility. The luminance contrast between the stimuli and background should be considered for increasing color visibility for driving information which is an important factor for HUD commercialization.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.131-143
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• 2014

We propose a no-reference perceptual fog density and visibility prediction model in a single foggy scene based on natural scene statistics (NSS) and perceptual "fog aware" statistical features. Unlike previous studies, the proposed model predicts fog density without multiple foggy images, without salient objects in a scene including lane markings or traffic signs, without supplementary geographical information using an onboard camera, and without training on human-rated judgments. The proposed fog density and visibility predictor makes use of only measurable deviations from statistical regularities observed in natural foggy and fog-free images. Perceptual "fog aware" statistical features are derived from a corpus of natural foggy and fog-free images by using a spatial NSS model and observed fog characteristics including low contrast, faint color, and shifted luminance. The proposed model not only predicts perceptual fog density for the entire image but also provides local fog density for each patch size. To evaluate the performance of the proposed model against human judgments regarding fog visibility, we executed a human subjective study using a variety of 100 foggy images. Results show that the predicted fog density of the model correlates well with human judgments. The proposed model is a new fog density assessment work based on human visual perceptions. We hope that the proposed model will provide fertile ground for future research not only to enhance the visibility of foggy scenes but also to accurately evaluate the performance of defog algorithms.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.4
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• pp.45-54
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• 2020

This study investigated basic data on walking characteristics, including walking speed and cognitive-response for the elderly, and based on these, the time of walking signal was calculated. The on-site survey examined the actual pedestrian crossing speed using a stopwatch, and the age was divided into groups of ordinary people and the elderly. Analysis of the data showed that the average walking speed for the general public was 1.29 m/s, while the average walking speed for the elderly was 1.13 m/s, higher than that of the general public. In addition, the lower speed of the 15th percentile was analyzed to 1.01 m/s for the general population and 0.85 m/s for the elderly, showing a lower walking speed than the standard for the general area and 0.8 m/s for the protected area. However, for senior citizens who use walking sticks or wheelchairs, the speed of the lower 15th-percentile is 0.73 m/s, which is lower than the current standard of protected areas, according to the analysis.

• 전자공학회논문지 IE
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• v.46 no.4
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• pp.1-7
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• 2009

The final goal of ITS and ETC will be to improve the traffic efficiency and mobile safety without new road construction. DSRC system is emerging nowadays as a solution of them. China DSRC standard which was released in May 2007 has low bit rate, short message and simple MAC control. The DSRC system users want a long lifetime over 1 year with just one battery. In this paper, we propose the SoC of very low power consumption architecture. Several digital logic concept and analog power control logics were used for very low power consumption. The SoC operation mode and clock speed, operation voltage range, wakeup signal detector, analog comparator and Internal Voltage Regulator & External Power Switch were designed. We confirmed that the SoC power consumption is under 8.5mA@20Mhz, 0.9mA@1Mhz in active mode, and under 5uA in power down mode, by computer simulation. The design of SoC was finished on Aug. 2008, and fabricated on Nov. 2008 with $0.18{\mu}m$ CMOS process.

• Science of Emotion and Sensibility
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• v.9 no.2
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• pp.93-100
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• 2006

This paper aims at the development and clinical evaluation of the wireless gyro-mouse system. The wireless gyro-mouse system is a computer interface with gyro-sensor and wireless communication, for the patients with upper-extremity disabled from the traffic accident or stroke to use the computer software i.e. internet browser. In the development, we focused on, firstly, to make the system wireless for the patients to manipulate the mouse easily even on the bed or wheelchair, secondly, to insert the gyro-sensor into a headband for easy don-and-doff and aesthetic appearance, thirdly, to devise a click switch in case of $C5{\sim}C6$ patients and a head nodding detection in case of C4 patients for sending click message to computer operating system. We performed evaluation experiment for patients with upper-extremities disabled from spinal cord injury. The results show that the displacement error of the cursor position against the target position during linear (vertical/horizontal) movement manipulation decreased with trial number. The click rate per minute also increased with trial number. This indicates the developed wireless gyro-mouse system would be more useful to the patients with repetitive use.