• Title/Summary/Keyword: Stop sign

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A study on the operation performance control of urban rail vehicle using an optimal control (최적제어를 이용한 도시철도 차량 주행제어 연구)

  • Tak Kil Hun;Kim Dong-Hwan;Kim Chi Tae
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.107-112
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    • 2005
  • When it comes to automatic operation control of urban rail vehicle, a PID control makes it run between stations within the fixed time and stop exactly at the stop sign on the platform, satisfying jerk limit. An optimal control is applied to automatic operation performance control to minimize energy consumption while the urban rail vehicle satisfies automatic operation condition on this paper. The control performance in terms of energy minimization along with the constraint on precision stops is compared between the optimal control and PID control.

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A Study on Image-Based Mobile Robot Driving on Ship Deck (선박 갑판에서 이미지 기반 이동로봇 주행에 관한 연구)

  • Seon-Deok Kim;Kyung-Min Park;Seung-Yeol Wang
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.7
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    • pp.1216-1221
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    • 2022
  • Ships tend to be larger to increase the efficiency of cargo transportation. Larger ships lead to increased travel time for ship workers, increased work intensity, and reduced work efficiency. Problems such as increased work intensity are reducing the influx of young people into labor, along with the phenomenon of avoidance of high intensity labor by the younger generation. In addition, the rapid aging of the population and decrease in the young labor force aggravate the labor shortage problem in the maritime industry. To overcome this, the maritime industry has recently introduced technologies such as an intelligent production design platform and a smart production operation management system, and a smart autonomous logistics system in one of these technologies. The smart autonomous logistics system is a technology that delivers various goods using intelligent mobile robots, and enables the robot to drive itself by using sensors such as lidar and camera. Therefore, in this paper, it was checked whether the mobile robot could autonomously drive to the stop sign by detecting the passage way of the ship deck. The autonomous driving was performed by detecting the passage way of the ship deck through the camera mounted on the mobile robot based on the data learned through Nvidia's End-to-end learning. The mobile robot was stopped by checking the stop sign using SSD MobileNetV2. The experiment was repeated five times in which the mobile robot autonomously drives to the stop sign without deviation from the ship deck passage way at a distance of about 70m. As a result of the experiment, it was confirmed that the mobile robot was driven without deviation from passage way. If the smart autonomous logistics system to which this result is applied is used in the marine industry, it is thought that the stability, reduction of labor force, and work efficiency will be improved when workers work.

Efficient stop criterion algorithm of the turbo code using the maximum sign change of the LLR (LLR 최대부호변화를 적용한 터보부호의 효율적인 반복중단 알고리즘)

  • Shim Byoung-Sup;Jeong Dae-Ho;Lim Soon-Ja;Kim Tae-Hyung;Kim Hwan-Yong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.5 s.347
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    • pp.121-127
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    • 2006
  • It is well known the fact that turbo codes has better performance as the number of iteration and the interleaver size increases in the AWGN channel environment. However, as the number of iteration and the interleaver size are increased, it is required much delay and computation for iterative decoding. Therefore, it is important to devise an efficient criterion to stop the iteration process and prevent unnecessary computations and decoding delay. In this paper, it proposes the efficient stop criterion algorithm for turbo codes using the maximum sign change of LLR. It is verifying that the proposal variable iterative decoding controller can be reduced the average iterative decoding number compared to conventional schemes with a negligible degradation of the error performance.

Development of Software for the Preventive Maintenance (설비 예방보전을 위한 소프트웨어 개발)

  • 이장원;김원중
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.21 no.46
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    • pp.229-240
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    • 1998
  • In these days, we are facing the needs of the times that the product have to be converted from quantity to quality. Most companys now pay more attention to maximize efficiency of facilities with introducing high priced equipments, those equipments are too automated and electronic that partial failure or short time stop leads to the stop of producing process in the whole factory. Consequently, effective maintenance management of production equipment becomes a only solution against problems. This thesis develops a preventive maintenance software that grasp a failure sign through daily inspection with management item, Machine-Capability index and estimate a trend, determine the time of preventive maintenance. The software is useful to the plant operator in analyzing information easily and controlling preventive maintenance operations efficiently.

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A Study on the Establishment of a Standard for Road Projection Lighting Devices for School Buses (어린이 통학버스의 로드 프로젝션 등화장치 표준 제정에 관한 연구)

  • Panju Shin;Jaecheol Kim;Hyun Kim
    • Journal of Auto-vehicle Safety Association
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    • v.15 no.3
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    • pp.43-52
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    • 2023
  • When a children's school bus stops on the road, the operator enables an amber flashing light (indicating stopping or slowing) or a red flashing light (indicating that children are getting on and off). Drivers of vehicles passing by the stopped school bus, as well as vehicles in adjacent lanes to the school bus must stop temporarily. However, many drivers are not aware of the laws and do not comply with them, so children are exposed to an increased risk of being hit, especially at night as the color recognition of the vehicle is significantly lower than during the day. In our experiments, messages and shapes using light were projected to the front and rear of a parked school bus, in addition to its red lights flashing.

The Derivation of a New Blind Equalization Algorithm

  • Kim, Young-Kyun;Kim, Sung-Jo;Kim, Min-Taig
    • ETRI Journal
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    • v.18 no.2
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    • pp.53-60
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    • 1996
  • Blind equalization is a technique for adaptive equalization of a communication channel without the aid of training sequences. This paper proposes a new blind equalization algorithm. The advantage of the new algorithm is that it has the lower residual error than the GA (proposed by Godard) and Sign_GA (proposed by Weerackody et al.). The superior performance of the proposed algorithm is illustrated for the 16-QAM signal constellation. A Rummler channel model is assumed as a transmission medium. The performance of the proposed algorithm is compared to the GA, Sign_GA and Stop & Go Algorithm (SGA). The simulation results demonstrate that an improvement in performance is achieved with the proposed equalization algorithm.

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Guidelines for installing Traffic Signals at Diamond Interchanges (다이아몬드 입체교차에서의 신호등 설치기준)

  • ;Carroll J. Messer
    • Journal of Korean Society of Transportation
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    • v.4 no.2
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    • pp.75-92
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    • 1986
  • The paper contains the data collection methods and procedures employed in the study to evaluate the operational effects of stop sign and signal control at diamond interchanges. An assessment of traffic control alternatives is described in terms of operational effects of queues and travel speed. Guidelines for installing signal control at diamond interchanges are provided in terms of internal volume, left turn proportion within internal volume, and the sum of internal and external volume. The specific traffic volume guidelines were developed based on a combination of these variables affecting operational performance.

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A Study on the Safety Vest by Sports and Leisure Population Distribution -Focusing on Motorcycle Vest- (스포츠 레저 인구 확산에 따른 안전 상의에 관한 연구 -모터사이클 상의를 중심으로-)

  • Lee, Hyunyoung
    • Journal of Fashion Business
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    • v.22 no.5
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    • pp.125-136
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    • 2018
  • This study intended to develop a motorcycle safe vest that can be prepared against accidents by mounting a smart module (with built-in sensor) on the safe vest in order to emphasize safety among functional aspects of the motorcycle clothing. The research method investigated professional books, prior research, and Internet data to examine the characteristics of motorcycle wear and the theoretical examination of smart wear, and analyzed the functional characteristics of the design by reviewing smart jacket and vest design cases for motorcycles currently on the market. As a results of study an interface device sensor, which contains a sensor with IMU(Intertial Measurement Unit) and CPU(Central Processing Unit), was inserted into a motorcycle top in order to draw attention to the safety of motorcycle riders. The IMU sensor attached to the vest detected the tilting motion of the rider to either left or right side to obtain data on left or right direction, sudden stop, and so forth and displayed left or right turn signal and sudden stop sign on the backplate (back) through the LED module. As for charging the device to operate LEDs, a generator, which is designed to convert the heat energy in the exhaust into electric energy, was used to efficiently self-produce the power required to operate LEDs of the top while riding.

Assessment of the Drivers Sensibility due to the Changes on Speed and Driving Mode of a Vehicle in a Dynamic Simulator (동적 시뮬레이터에서 속도와 운전 형태 변화에 따른 운전자의 감성 평가)

  • 정순철;민병찬;신미경;김철중
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.24 no.65
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    • pp.51-63
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    • 2001
  • The present experiment investigated the possibility of evaluating of the human sensibility contingent on the speed and modes of driving using the responses from the autonomic nervous system, subjective assessments, Simulator Sickness (55) in dynamic simulator. The three conditions of the speed of driving were 40 $\pm$ 10 km/h, 100$\pm$10 km/h, 160 $\pm$ 10 km/h, and the participant was instructed to drive the car for three minutes on the elliptical track. It is programed in such a way that the modes of driving can be changed smoothly using road DB in Dynamic Simulator, and for signifying the change of the condition the road signs were used. The instruction was given to the participant to drive the car on the fixed speed of 20 km/h for 30 seconds, then to drive the car on sudden-start mode of driving from the 20 km/h to 160 km/h within 10 seconds. For the sudden-stop mode of driving, it was instructed that stop the car from the speed of 160km/h to 20km/h within 10 seconds when the subject see the road sign, then drive the car at the fixed speed of 20 km/h for 30 seconds. The results of the subjcetive assessment showed that the level of pleasantness and the tension was increased, and physiological response showed that the level of activity of the autonomic responses were also increased as the speed of the car increased. Also, for results on the driving modes showed that the level of pleasantness was highest for the sudden-stop, next highest was sudden-start, and the lowest was 20 km/h fixed speed condition for the subjective assessment, and tile order of the level of activation of the autonomic nervous system showed the same results as above. From the results of the present study it was concluded that the presentation and evaluation of the stimulus for the human sensitivity is possible in dynamic simulator.

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A Study on the Proper Position of Guide Sign for Bikeway in Korea (자전거 도로의 안내표지 설치 위치에 관한 연구)

  • Jeong, Gyu-Su;Lee, Yeong-In
    • Journal of Korean Society of Transportation
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    • v.28 no.6
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    • pp.99-108
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    • 2010
  • Due to the recent emergence of global warming concerns, the UN has made the issue of climate change its top priority. Accordingly, Korea has announced a new national master plan titled, 'Participation in global efforts in climate change through -Low Carbon, Green Growth-'. As part of the plan, the constructions of bicycle path networks are being pushed forward. Although the building of bicycle paths and infrastructure is being implemented, little consideration has been given for bicycle path signage. This essay is the study of methodology in the installation of signs on bicycle paths. The research includes a theoretical study of the standard and installation position of signs with consideration of the geometry of bicycles as well issues such as the distance required for the bicyclist to recognize and understand the road sign and to take actions like stopping, In addition, experimental verification of the test results has been carried out. Also, the test on height of signs by changing the installation heights according to a bicyclist's forward vision angle has been conducted.