Recognition Distance Research Articles

Field Evaluation of Elongated Pavement Marking Signs

Research has shown that elongated pavement marking letters and arrows significantly improve recognition distance; however, the effect of elongated pavement marking signs, which are symbolized pavement markings that are elongated versions of signs, has not been evaluated. The goal was to evaluate the effectiveness of elongated pavement marking signs in conjunction with the post-mounted signs they complement. Results from a driving simulator evaluation indicate that recognition distance increases quadratically as elongation ratio (i.e., the ratio of height to width) increases. Considering the trade-off between cost and recognition distance, an elongation ratio of 5:1 was chosen for field evaluation of speed limit regulatory signs and curve warning signs. A before-and-after study was conducted at sites in Kansas, Missouri, and Wisconsin. Operating speeds of free-flow vehicles were used as the measure of effectiveness; speed data were collected upstream of, at, and downstream of the corresponding post-mounted sign. The speed limit sign was tested at four sites (at least one in each state) and was found to reduce operating speeds effectively at three of the four sites. A curve warning sign was tested at three sites (two in Kansas, one in Wisconsin), and operating speed reductions were observed at two of the sites. Field data results indicated that the evaluated regulatory and warning elongated pavement marking signs reduced vehicle speeds. This demonstrates they can be effective in reinforcing a warning or a regulatory message to drivers. Future research should evaluate durability and long-term effectiveness and should test other signs.

Reflective Tape Applied to Bicycle Frame and Conspicuity Enhancement at Night.

Four studies were conducted to assess bicyclist conspicuity enhancement at night by the application of reflective tape (ECE/ONU 104) to the bicycle rear frame and to pedal cranks. Previous studies have tested the benefits of reflective markings applied to bicyclist clothing. Reflective jackets however need to be available and worn while reflective markings enhance conspicuity without any active behavior by the bicyclist. In the first study, reflective tape was applied to the rear frame. Detection distance was compared in four conditions: control, rear red reflector, high visibility jacket, and reflective tape. In the second study, the same conditions were studied with night street lighting on and off. In the third study, detection and recognition distances were evaluated in rainy conditions. In the fourth study, visibility was assessed with the reflective tape applied to pedal cranks. In the first study, the application of reflective markings resulted in a detection distance of 168.28 m. In the second study, the detection distance with reflective markings was 229.74 m with public street light on and 256.41 m with public street light off. In rainy conditions, detection distance using the reflective markings was 146.47 m. Reflective tape applied to pedal cracks resulted in a detection distance of 168.60 m. Reflective tape applied to the rear bicycle frame can considerably increase bicyclist conspicuity and safety at night. Reflective tape is highly recommended to complement anterior and rear lights in bicycle riding at night.

The Influence of Driver Expectation when Recognizing Lighted Targets at Nighttime

Over the years, in a night time driving scenario, expectancy has been linked with faster night time recognition. This study tries to evaluate the ability of observers to identify illuminated objects on the road in the absence of an associative pattern. In this study 47 of 60 participants did not respond to a light source that was in the drivers’ travel lane ahead. Of those who did not respond to the light when directly ahead, 64% indicated that had seen it beforehand. When the light was 2 meters to the drivers’ right, 33% that saw the light failed to respond. All of the drivers who saw the light before striking it claimed that they thought it was off the road until too late. When the drivers did not know what the light source was, they could not decipher where the light was. However, once aware of the presence of the light the average recognition distance improved 192 meters (632 feet) with 100% recognition. These results fit well with the SEEV search model and an Information Theory approach to driver expectancy. Previous claims that the difference between expected and unexpected driver responses is a 2 to 1 ratio was not supported by this research.

Low-rank representation integrated with principal line distance for contactless palmprint recognition

Contactless palmprint recognition has recently begun to draw attention of researchers. Different from conventional palmprint images, contactless palmprint images are captured under free conditions and usually have significant variations on translations, rotations, illuminations and even backgrounds. Conventional powerful palmprint recognition methods are not very effective for the recognition of contactless palmprint. It is known that low-rank representation (LRR) is a promizing scheme for subspace clustering, owing to its success in exploring the multiple subspace structures of data. In this paper, we integrate LRR with the adaptive principal line distance for contactless palmprint recognition. The principal lines are the most distinctive features of the palmprint and can be correctly extracted in most cases; thereby, the principal line distances can be used to determine the neighbors of a palmprint image. With the principal line distance penalty, the proposed method effectively improves the clustering results of LRR by improving the weights of the affinities among nearby samples with small principal line distances. Therefore, the weighted affinity graph identified by the proposed method is more discriminative. Extensive experiments show that the proposed method can achieve higher accuracy than both the conventional powerful palmprint recognition methods and the subspace clustering-based methods in contactless palmprint recognition. Also, the proposed method shows promizing robustness to the noisy palmprint images. The effectiveness of the proposed method indicates that using LRR for contactless palmprint recognition is feasible.

A Mobile Object Tracking Scheme by Wired/wireless Integrated Street Lights with RFID

Since a sophisticated location determination technology (LDT) is necessary for accurate positioning in urban area environments, numerous studies related to the LDT using the RFID (Radio Frequency IDentification) technology have been implemented for real‐time positioning and data transferring. However, there are still lots of unsolved questions especially regarding what to use as base stations and what are corresponding results under the intrinsic complexity of alignment and configuration of components used for the RFID positioning. This study proposes the street light fixtures as base stations where the RFID receivers will be embedded for the mobile tracking scheme. As street light fixtures are usually installed at a certain distance interval, they can be used as base stations for the RFID receiver installation. Using the principle of the single row triangle network, the RFID receiver organization is determined based on the experiments such as recognition distance measurement and tag position accuracy estimation at inside and outside of the single row triangle network. The results verify that the mobile tracking scheme which uses RFID-embedded street light fixtures, suggested and configured in this study, is effective for the real-time outdoor positioning.

Noise Robust Radar HRRP Target Recognition Based on Scatterer Matching Algorithm

Since the signal-to-noise ratio (SNR) directly relates to the distance between the target and the radar for a given noise power and radar power, the noise robustness of a recognition algorithm is very important to increase the recognition distance between the target and the radar in the real application. In this paper, a novel noise-robust recognition method for high-resolution range profile (HRRP) data is proposed to enhance its recognition performance under the test condition of low SNR. The target dominant scatterers are first extracted based on the scattering center model of complex HRRP data via the orthogonal matching pursuit algorithm. Then, a scatterer matching recognition algorithm based on Hausdorff distance is developed with the magnitudes and locations of extracted dominant scatterers used as the feature patterns. Here, the noise reduction is accomplished based on the sparse distribution property of dominant scattering centers in a target. Experimental results on the synthetic and measured HRRP data demonstrate that the proposed method can improve the recognition performance under the relatively low SNR condition for both orthogonal and superresolution representations of scattering center model.

Application of Radio Frequency Identification Positioning Technology in Valuables Monitoring

With the development of positioning services, an increasing number of people and companies pay attention to the management and protection of the precious goods which they possess, through the determination of its location to achieve the management purpose [1]. At present, the main positioning way is to use the global positioning system (GPS), but many of the valuable items are stored in the indoor, and it's hard to receive a satellite signal in the room, so it cannot be accurate positioning. As a new short distance wireless data recognition technology at present, Radio Frequency Identification (RFID) indoor positioning technology is very suitable for the indoor positioning. Because it has many characteristics: large amount of data storage, readable and writable, strong penetrating power, long recognition distance, fast read-write speed and the use of the characteristics of long service life and good adaptability to the environment, etc. Among the RFID indoor positioning technology of many positioning algorithms, the three sides positioning algorithm is commonly used, and more mature. At the same time, the storage space of most valuable items is simple, and the environmental factors have little influence on the signal interference. So it is feasible to use the three sides positioning algorithm of RFID positioning algorithms to locate the valuables in the indoor.

Sequential Analysis on the Intensity of Store Information to the Commercial Street - from the Viewpoint of Pedestrian Movement -

AbstrctStores along commercial streets display their information to the outside using their facades facing the street to attract pedestrians, who are potential customers. Pedestrians, who are visitors to the commercial area, are exploring stores to meet the purpose of their visit. During this process, pedestrians experience the city space. This paper proposes a methodology for the sequential analysis of a commercial street from the viewpoint of pedestrian movement based on business type, which might be the most important factor for the formation of the atmosphere of a certain street, and location relationships between the pedestrians and stores on a street. To construct a quantitative model, the distribution of stores was first divided into a certain unit considering the recognition distance of pedestrians. In a divided unit, the business type of each store was replaced with a different point source individually and stacked vertically according to the location inside the building. By calculating the sequential change in intensity of the point sources, a final analytical model was obtained as the standing point of pedestrian movement. For the case study, the developed model was applied to Jungang-ro and Myeongdong-gil in Myeongdong and verified that the difference in store influence on pedestrians depended on the width of the street or number of floors where the store was located.

A High Sensitivity Analog Front-end Circuit for Semi-Passive HF RFID Tag Applied to Implantable Devices

A high sensitivity analog front-end is presented for semi-passive HF RFID tag for implantable devices. The design is compatible with the ISO/IEC 14443 Type-A. A rectifier with high power conversion efficiency is presented to provide stable rectified voltage. Novel tag system architecture with wake-up circuit is proposed to improve the sensitivity. Other Key circuits are studied and designed to make the system work effectively. Simulation results show that the AFE has realized much longer recognition distance than passive tags. Its sensitivity is $-$ 5.7 dBm and can work properly when the magnetic field is 0.3A/m. The AFE was fabricated with HHNEC 0.13 $\mu{\rm m}$ 1P4M CMOS technology with an area of $416 \mu{\rm m}\times 472 \mu{\rm m}$ . The AFE is also measured with FPGA based digital baseband. Measurement results show that the proposed AFE can support the 100% ASK demodulation and a modulation depth of 16.4%. The AFE can also accommodate a data rates from 106 Kbps to 848 Kbps are supported. Its power consumption is as low as 129.6 $\mu{\rm W}$ . This chip meets the demands of a semi-passive HF RFID tag and has great potential for implantable devices.

Effects of Different Levels of Refractive Blur on Nighttime Pedestrian Visibility.

The aim of this study was to systematically investigate the effect of different levels of refractive blur and driver age on nighttime pedestrian recognition and determine whether clothing that has been shown to improve pedestrian conspicuity is robust to the effects of blur. Nighttime pedestrian recognition was measured for 24 visually normal participants (12 younger mean = 24.9 ± 4.5 years and 12 older adults mean = 77.6 ± 5.7 years) for three levels of binocular blur (+0.50 diopter [D], +1.00 D, +2.00 D) compared with baseline (optimal refractive correction). Pedestrians walked in place on a closed road circuit and wore one of three clothing conditions: everyday clothing, a retro-reflective vest, and retro-reflective tape positioned on the extremities in a configuration that conveyed biological motion (known as "biomotion"); the order of conditions was randomized among participants. Pedestrian recognition distances were recorded for each blur and pedestrian clothing combination while participants drove an instrumented vehicle around a closed road course. The recognition distances for pedestrians were significantly reduced (P < 0.05) by all levels of blur compared with baseline. Pedestrians wearing biomotion clothing were recognized at significantly longer distances than for the other clothing configurations in all blur conditions. However, these effects were smaller for the older adults, who had much shorter recognition distances for all conditions tested. In summary, even small amounts of blur had a significant detrimental effect on nighttime pedestrian recognition. Biomotion retro-reflective clothing was effective, even under moderately degraded visibility conditions, for both young and older drivers.

Fabrication of a planar spiral antenna using direct writing technology

Radio frequency identification (RFID) is a non-contact automatic identification technology that allows transmission of information and power via radio frequency signals. It has advantages including a short recognition distance, favorable efficiency, and reliable security. Planar antennas are an important aspect of RFID tags, and are usually manufactured by winding, screen-printing, and etching methods. These production processes typically involve thermal/mechanical stresses, chemical corrosion and other manufacturing processes which restrict the choice of substrate. On the other hand, direct writing technology provides a number of advantages, including no restrictions on the substrate, reduced costs, and simplified manufacturing processes. Because of these advantages, we propose a fabrication process for a spiral antenna using direct writing technology of a conductive material. The direct writing system was developed using a dispensing system and a 3-axis stage system. Consequently, a planar spiral antenna for an NFC tag was fabricated. The inductance of the fabricated spiral antenna was in good agreement with the designed value.

Drivers' judgments of the effect of headlight glare on their ability to see pedestrians at night

IntroductionSeveral studies have concluded that pedestrians typically overestimate their own conspicuity to approaching drivers at night. The present experiments extended this research by exploring the accuracy of drivers' judgments of pedestrian conspicuity while facing varying degrees of headlight glare. MethodIn Experiment 1, participants on an open road estimated their ability to see a roadside pedestrian in each of two clothing configurations and with each of three different glare intensities present. In Experiment 2, participants responded to a roadside pedestrian under the same open road conditions; the participants were naïve with regard to both the position of the pedestrian and to the clothing and glare manipulations. ResultsConsistent with earlier research, estimates of response distance were, on the average, over three times greater than actual recognition distance. The extent to which participants overestimated conspicuity was greater when the pedestrian wore a retroreflective vest, and participants incorrectly judged that headlight glare would not degrade drivers' ability to see a pedestrian wearing a retroreflective vest. Conclusions and Practical ApplicationsThese results confirm that road users' understanding of issues involving drivers' night vision is limited. These misunderstandings may result in road users behaving in ways that increase the risk of nighttime collisions with pedestrians.

UHF RFID Reader Design

UHF radio frequency identification system with write speeds, large storage capacity , recognition distance and simultaneously read multiple tags , etc. , has been more widely used in logistics. Introduced in line with ISO 18000-6 standard UHF RFID tag main characteristics, structure, working principle and write methods, proposed the corresponding reader solutions, focusing on the reader hardware design and software program flow. The application results show that the reader read and write speed (single tag 64bit / 6ms), recognition rate, recognition distance (≥ 4m).

NFC 통신거리 확장을 위한 페라이트 시트의 설계

Abstract In this paper, a ferrite sheet at the back of the smartphone by type, pattern, stars, the thickness of the recognition distance by attaching the NFC optimum ferrite sheet simulation was designed. Characterized by patterns rather than the Full-type I-type communication distance of about 1 ~ 2mm more extended. Ferrite sheet metal by applying the NFC antenna is effective in improving the characteristics were confirmed. In the case of the pattern C, the permeability is 140, a thickness of 0.1mm, Full-type ferrite sheet when applied to NFC communication distance than normal electromagnetic absorber is increased from 45 to 59 was confirmed that. Key Words : NFC, RFID, Ferrite Sheet, Absorber sheet, Communication distance Received 1 June 2014, Revised 30 July 2014Accepted 20 August 2014Corresponding Author: Yang-Jae Park(Gachon University) Email: pakryj@gachon.ac.krⒸ The Society of Digital Policy & Management. All rights reserved. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is ISSN: 1738-1916 properly cited.

Classification of hyperspectral remote sensing imagery by k-nearest-neighbor simplex based on adaptive C-mutual proportion standard deviation metric

The k-nearest-neighbor simplex (kNNS) based on an adaptive C-mutual proportion standard deviation metric for classification of hyperspectral remote sensing imagery was proposed. By analyzing spectral characteristics on the samples of the same and different classes, a C-mutual proportion standard deviation metric is put forward which innovates a novel metric on distance and similarity measures for pattern recognition. Combined with the adaptive adjusting algorithm, this metric is used for the classification of hyperspectral remote sensing imagery. The traditional kNNS classification algorithm is improved by this metric and the adaptive adjusting algorithm, and its classification accuracy is enhanced. Three experiments with different types of hyperspectral imagery are conducted to evaluate the performance of the proposed algorithm in comparison to the other five classification algorithms. The experimental results demonstrate that the proposed algorithm is superior to other algorithms on overall accuracy and kappa coefficient.

Modeling driver distance recognition and speed perception at night for freeway speed limit selection in china

Developing a proper speed limit for freeway is critical for roadway safety. Due to the difference in visibility between day and night, it is necessary to have different speed limits for the two time periods on freeways with changing geometric features. Aiming to reduce the number of crashes caused by speeding at night on freeways, an exploratory study was conducted on the maximum speed limit at night. In order to investigate the potential relationship between drivers' distance recognition and driving speed and between speed perception and driving speed under different geometric design features, an experiment was carried out on a 22-km-long freeway segment on Chang-song freeway in China. Based on round-trips made by 10 drivers during day and night on this segment, drivers' recognition distance (distance between a sign and the location where the sign was clearly recognized the first time) and estimated speed were recorded. The data analysis results show that driver recognition distance at night decreases by about 7% compared with recognition distance at daytime. The accuracy of driver speed perception at nighttime is only 29%, whereas it is 67% at daytime. With the collected data, several multivariate non-linear regression models were established to capture the relationship among the variables of recognition distance, estimated speed at night, driving speed, and highway alignment indexes. Then the modeling results were used to develop the speed limit model by physical equations. A case study is introduced at the end of the paper Keywords Freeway, traffic safety, nighttime, recognition distance, estimated speed, maximum speed limit. Language: en

Seeing pedestrians at night: effect of driver age and visual abilities.

To quantify the effects of driver age on night-time pedestrian conspicuity, and to determine whether individual differences in visual performance can predict drivers' ability to recognise pedestrians at night. Participants were 32 visually normal drivers (20 younger: M=24.4years±6.4years; 12 older: M=72.0years±5.0years). Visual performance was measured in a laboratory-based testing session including visual acuity, contrast sensitivity, motion sensitivity and the useful field of view. Night-time pedestrian recognition distances were recorded while participants drove an instrumented vehicle along a closed road course at night; to increase the workload of drivers, auditory and visual distracter tasks were presented for some of the laps. Pedestrians walked in place, sideways to the oncoming vehicles, and wore either a standard high visibility reflective vest or reflective tape positioned on the movable joints (biological motion). Driver age and pedestrian clothing significantly (p<0.05) affected the distance at which the drivers first responded to the pedestrians. Older drivers recognised pedestrians at approximately half the distance of the younger drivers and pedestrians were recognised more often and at longer distances when they wore a biological motion reflective clothing configuration than when they wore a reflective vest. Motion sensitivity was an independent predictor of pedestrian recognition distance, even when controlling for driver age. The night-time pedestrian recognition capacity of older drivers was significantly worse than that of younger drivers. The distance at which drivers first recognised pedestrians at night was best predicted by a test of motion sensitivity.

Differential Effects of Refractive Blur on Day and Nighttime Driving Performance

To investigate the effect of different levels of refractive blur on real-world driving performance measured under day and nighttime conditions. Participants included 12 visually normal, young adults (mean age = 25.8 ± 5.2 years) who drove an instrumented research vehicle around a 4 km closed road circuit with three different levels of binocular spherical refractive blur (+0.50 diopter sphere [DS], +1.00 DS, +2.00 DS) compared with a baseline condition. The subjects wore optimal spherocylinder correction and the additional blur lenses were mounted in modified full-field goggles; the order of testing of the blur conditions was randomized. Driving performance was assessed in two different sessions under day and nighttime conditions and included measures of road signs recognized, hazard detection and avoidance, gap detection, lane-keeping, sign recognition distance, speed, and time to complete the course. Refractive blur and time of day had significant effects on driving performance (P < 0.05), where increasing blur and nighttime driving reduced performance on all driving tasks except gap judgment and lane keeping. There was also a significant interaction between blur and time of day (P < 0.05), such that the effects of blur were exacerbated under nighttime driving conditions; performance differences were evident even for +0.50 DS blur relative to baseline for some measures. The effects of blur were greatest under nighttime conditions, even for levels of binocular refractive blur as low as +0.50 DS. These results emphasize the importance of accurate and up-to-date refractive correction of even low levels of refractive error when driving at night.

Non-Contact Gesture Recognition Using the Electric Field Disturbance for Smart Device Application

A non-contact gesture recognition algorithm for smart device application using electronic disturbance is proposed in this paper. Our method secures an enough recognition distance for real smart TV application. Input patterns of the non-contact electrometer EPIC (Electric Potential Integrated Circuit) sensors are projected into two dimensional movements in a preconditioning process. Change of surrounding electronic field caused by moving hands has been observed mainly around band of 10Hz. Butterworth IIR filter, and Kalman filter are used to minimize the signal noises. Our proposed recognition process using PCA, K-Mean, and adaptive DTW algorithms can successfully identify five different gestures with more than 90% correct classification rate.

Artificial magnetic conductor loaded long‐range passive RFID tag antenna mountable on metallic objects

A passive radio frequency identification (RFID) tag antenna providing a long recognition distance is proposed, which is mountable on various types of platforms including metallic and highly dielectric objects. To increase the reading distance, the antenna is installed in a recessed metallic cavity. To reduce further the height of the antenna, an artificial magnetic conductor is placed on the bottom face of the cavity. Consequently, the tag antenna not only can be miniaturised, but also can provide long reading distances on any type of platform objects. The measured maximum reading distance and the minimum sensitivity are 12.2 m and −17 dBm, under a reader transmitting 30 dBm with a 6 dBi antenna. Good agreement between the prediction and experimental results verifies that the approach is fairly effective and useful to substantially increase the reading distance.