• Title/Summary/Keyword: Sight distance

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A Novel Visual Servoing Approach For Keeping Feature Points Within The Field-of-View (특징점이 Field of View를 벗어나지 않는 새로운 Visual Servoing 기법)

  • Park, Do-Hwan;Yeom, Joon-Hyung;Park, Noh-Yong;Ha, In-Joong
    • Proceedings of the KIEE Conference
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    • 2007.04a
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    • pp.322-324
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    • 2007
  • In this paper, an eye-in-hand visual servoing strategy for keeping feature points within the FOV(field-of-view) is proposed. We first specify the FOV constraint which must be satisfied to keep the feature points within the FOV. It is expressed as the inequality relationship between (i) the LOS(jine-of-sight) angles of the center of the feature points from the optical axis of the camera and (ii) the distance between the object and the camera. We then design a nonlinear feedback controller which decouples linearly the translational and rotational control loops. Finally, we show that appropriate choice of the controller gains assures to satisfy the FOV constraint. The main advantage of our approach over the previous ones is that the trajectory of the camera is smooth and circular-like. Furthermore, ours can be applied to the large camera displacement problem.

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Active Tactual Motion of Fingertips in FUUAI Evaluation Of Textile Fabrics

  • Lee, Su-Min;Kamijo, Masayoshi;Nishimatsu, Toyonori;Shimizu, Yoshio
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2002.05a
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    • pp.190-194
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    • 2002
  • Human uses sight, tactile sense to evaluate Total Hand Value(FUUAI) of textile fabrics. Tactile sense is important factor which decided the Total Hand Value of a textile fabric. When human feels the FUUAI, physical and physiological phenomena are occurred in finger. We first found out physical variable that is happened in fingertip when human is feeling the FUUAI. Such physical variable means characteristic of action tactual motion of finger such as moving range, tactile time, moved distance, speed of finger and applied force by finger. We study the relationship between action tactual motion and the ability in which the human distinguishes the textile fabric. As a result, we could know the characteristics of the tactual motion of fingertip to get high distinguishable ability. The characteristics were different in men and women respectively. In the case of man, touched time and moving range influenced to distinguish, and moving range, and the moving speed of finger influenced, in woman's case.

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A Study on Ku-band Antenna for Mounting on UAV (무인 항공기 탑재용 Ku대역 안테나에 관한 연구)

  • Park, Jin-Woo;Ryu, Ji-Ho
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.1
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    • pp.50-56
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    • 2014
  • In this paper, we proposed a Ku-band antenna that can be mounted on UAV. A proposed antenna structure has small size and light weight. It is considered long distance communication environment(LOS) and equipped UAV. Proposed antenna is designed $16{\times}2$ aperture coupled microstrip patch array antenna for high gain characteristics. In the measurement results, VSWR is less than 1.5 and the gain is over 21dBi in the bandwidth. Mechanical specifications of antenna assembly are ${\phi}250{\times}200mm$ of size and 3kg of weight.

양보차선의 설계이론

  • 최재성;최병국
    • Journal of Korean Society of Transportation
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    • v.7 no.2
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    • pp.5-15
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    • 1989
  • The Provision of a Passing lane is strongly recommended When adeguate Passing Sight distance cannot be acguired at a Section of two-lane highway. Passing lanes are usually installed at two-lane highways along the shoulder area to minimize the impact of slow-moving heavy vehicles. The design concepts and specific dimension associated with the Passing lane construction are investigated in This research. In addition a case study was made using the field study data. Currently the level of service at the case study area was analyzed to be "F" based on 1985 Highway Capacity Manual procedure. With the installation of passing lanes, the level of service was improved into "C". A computer Simulation program developed by Australian Road Research Boand was utilized to analyze the effect of passing lanes.

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An Indoor Localization Algorithm based on Improved Particle Filter and Directional Probabilistic Data Association for Wireless Sensor Network

  • Long Cheng;Jiayin Guan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.11
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    • pp.3145-3162
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    • 2023
  • As an important technology of the internetwork, wireless sensor network technique plays an important role in indoor localization. Non-line-of-sight (NLOS) problem has a large effect on indoor location accuracy. A location algorithm based on improved particle filter and directional probabilistic data association (IPF-DPDA) for WSN is proposed to solve NLOS issue in this paper. Firstly, the improved particle filter is proposed to reduce error of measuring distance. Then the hypothesis test is used to detect whether measurements are in LOS situations or NLOS situations for N different groups. When there are measurements in the validation gate, the corresponding association probabilities are applied to weight retained position estimate to gain final location estimation. We have improved the traditional data association and added directional information on the original basis. If the validation gate has no measured value, we make use of the Kalman prediction value to renew. Finally, simulation and experimental results show that compared with existing methods, the IPF-DPDA performance better.

Fading Effects and Antenna Diversity Tests of WAVE Communications (WAVE 통신의 페이딩 효과와 안테나 다이버시티 실험)

  • Choi, Hyun-Kyun;Oh, Hyun-Seo;Cho, Woong;Jang, Youn-Seon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39C no.10
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    • pp.967-973
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    • 2014
  • WAVE (Wireless Access in Vehicular Environments) communications is the core technology for C-ITS (Cooperative-Intelligent Transportation System) which communicates with the road infrastructure and other vehicles to exchange traffic information and service while driving. In this paper, to analyze the performance degradation according to the distance between WAVE communication terminals, we derived the formulas for the locations of down-fade and up-fade points by using the two-ray ground reflection model, and verified these theoretical results by comparing with those of RSSI (Receiver Signal Strength Indicator) measurements. In addition, to solve the problem of down-fade, we suggested the WAVE communication with the antenna diversity and experimentally confirmed the performance improvement in the highway LOS (Line Of Sight) environments.

Simulation to Evaluate CCTV Positioning in Use of Ray-Tracing Algorithm (Ray-Tracing 알고리즘을 이용한 CCTV배치 평가시뮬레이션)

  • Kim, Suk-Tae;Ahn, Sang-Ook
    • Korean Institute of Interior Design Journal
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    • v.22 no.6
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    • pp.40-48
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    • 2013
  • Utilization of CCTV in crime prevention for public safety is accepted as the most effective measure in terms of crime prevention and control. Also, it is frequently used as a device that shows evidence of an unexpected situation or record on public social relationship. However, it is rare to find a study that qualitatively accessed the monitoring performance of a certain space depending on the choice and positioning of CCTVs. Thus, this study suggested a technology that can quantitatively compare and assess the monitoring performance of CCTVs depending on view angle and effective sight range of cameras as well as the monitoring performance depending on positioning measures. For the analysis, the concept of 3-dimensional surveillance field in the form of a frustum was suggested while deriving 3-dimensional range of sight and quantitative monitoring performance by applying Isovist theory. For the analysis technology, space of analysis subject, point of view (camera), and target point (measurement node) were installed at a 3-dimensional space and in use of ray-tracing algorithm, the line segment that was visually connected between the point of view and target point was extracted and accumulated. For such verification, analysis application was constructed and then applied to four alternative models on view angle and distance as well as four alternatives on positioning in order to verify its efficacy. Through the experiment, it was possible to compare and assess visibility depending on alternatives while quantifying the results by understanding the shadow areas beyond the monitoring range.

Performance analysis of UWB receiver using PPM and BPSK modulation scheme in the LR-WPAN System (LR-WPAN 시스템에서 PPM+BPSK 변조 방식을 사용하는 UWB 송수신기의 성능 분석)

  • Lee, Kyoung-Tak;Lim, Dong-Guk;Sohn, Sung-Hwan;Kim, Jae-Moung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.5 no.2 s.10
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    • pp.19-28
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    • 2006
  • In the IEEE 802.15.4a system, they require simple, economical and low power consumption transmitter and receiver to transmit low rate data and to identify distance and location. To meet these requirements, LR-WPAN system use transmitter and receiver with simple modulation and demodulation scheme. In this paper, use PPM+BPSK modulation and windowing scheme to overcome multipath fading effect. Then we apply this channel estimation scheme to LR-WPAN system and compare performance depends on transmitter scheme. Proposed method using preamble to find channel characteristic out and we compensate distorted data with that information. Therefore we can detect signal easily at the demodulation part. Simulation result shows that performance evaluation is greater at the NLOS channel than LOS channel no matter what the receiver scheme.

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The Saccades Distance Extraction Technique of Sight and the Spatial search Characteristics - Target Department Sports Store Space - (시선의 도약거리 추출 기법과 공간탐색 특성 - 백화점 스포츠 매장 공간을 대상으로 -)

  • Kim, Jong-Ha
    • Korean Institute of Interior Design Journal
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    • v.26 no.5
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    • pp.83-92
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    • 2017
  • This research is about the characteristics of the saccades that occurring in the process of observing the spatial. The size of the saccades is the visual activity for acquiring the information, and the search trace that left by the spatial visitor. Reviewed over the saccade through the analysis of observation process that appeared in the eye-tracking experiment of sports store from the department store, the saccade is defined as the sight movement in the process of finding a component to view in the spatial. If some spatial component induces saccade, and able to know which specific component acquired through the saccade, then the designer will have a clue which able to provide the spatial desired by the consumer. The results of analyzing the process in the deriving the spatial component and saccade characteristic from industrial space, can be summarised as follows. The first, the average fixed number of [IN].[OUT] zone appeared similarly, and it leads to knowing that the time used for attention with one frequency is about 0.3 seconds. Second, there were more saccades toward [$IN{\rightarrow}OUT$] (13 persons, 76.5%) than [$OUT{\rightarrow}IN$] (4 persons, 23.5%). The Los Angeles area has lots of interesting things to watch, so it able to thinks to begins with small saccade and then occur to bigger saccade activity to find new interests shortly after [OUT] saccade. Third, according to time range changes, keep eyes on the characteristics of saccade, [IN].[OUT] frequency has slightly decreased the changes of viewing time, but there was no significant change in an average number of observations. This means that the frequency and the number of observations are decreased together. Therefore, it can be seen that the amount of information to be acquired (frequency) is decreased (count) as the observation time elapses.

Verification of the Appropriateness of the Standard for Tunnel Luminance in the Threshold Zone Through a Full-scale Tunnel Driving Test (실 규모 터널 주행실험을 통한 터널 경계부 휘도 기준의 적정성 검증)

  • Park, Won Il;Cho, Won Bum;Jeong, Jun Hwa
    • International Journal of Highway Engineering
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    • v.17 no.6
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    • pp.105-115
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    • 2015
  • PURPOSES : This study aimed to evaluate the appropriateness of safety with the standard for threshold zone luminance as specified in the Recommendation for Lighting of Traffic Tunnel, which has been widely adopted worldwide. METHODS : A driving test of the subject in a full-scale road tunnel was conducted. The adaptation luminance and threshold zone luminance, which should be known for the driver to perceive an object within stopping sight distance, were obtained. These values were compared with the adaptation luminance and threshold zone luminance obtained by the existing reduced model test and tunnel lighting standard that has served as a guideline for the current threshold zone luminance standard. RESULTS : According to this study, threshold zone luminance should be increased to at least 1.8 times the value proposed in the existing studies and to twice the domestic tunnel lighting standard (KS C 3703: 2014). CONCLUSIONS : The threshold zone luminance proposed in this study differs largely from that obtained from indoor tests and from the current tunnel lighting standard used worldwide; this difference may be attributed to the fact that the indoor tests did not incorporate driving workload, non-uniformity of luminance distribution in terms of sight, and factors that reduce the visibility of the driver, such as the light reflected into the driver's eyes. Hence, it is necessary to further review the factors that reduce the visibility of drivers approaching tunnels in order to determine the rational tunnel threshold zone luminance.