• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1093-1095
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• 2003

MSC(Multi-Spectral Camera) system is a remote sensing instrument to obtain high resolution ground image. MSC system includes main control unit, called SBC(Single Board Computer). SBC controls all the sub-units of MSC system and communicates with spacecraft bus. The software developed for SBC should be reliable and autonomous to support various kinds of imaging missions. It is being developed using VxWorks real-time operating system to manage all tasks for all units efficiently. In this paper, the characteristics of the embedded software on the MSC system will be presented. It covers the hardware related characteristics like the BSP(Board Support Package), device driver and code patch mechanism.

• Journal of the Korea Society for Simulation
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• v.1 no.1
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• pp.87-102
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• 1992

This paper presents the development of event-driven system level simulation tool SMPLE(Smpl Extende, an extention fo smpl) and its application to the performance analysis of multiprocessor computer systems. Because of its data structure, it is very difficult to change, expand or add new functions to simulation language smpl implemented by MacDougall. In SMPLE, we change data structure with structure and pointer, add new functions, and enable dynamic memory management. Using new data structure, facilities, and functions added in SMPLE, we simulate job processing of a shared bus multiprocessor system with autonomous hierarchical I/O subsystem. We set system performance contribution of subsystems and units. The impact of disk I/O on system performance is evaluated under vairous conditions of number of processors, processing power, memory access time and disk seek time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.5669-5684
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• 2018

The new mobile edge network architecture has been required for an increasing amount of traffic, quality requirements, advanced driver assistance system for autonomous driving and new cloud computing demands on highway. This article proposes a hierarchical cloud computing architecture to enhance performance by using adaptive data load distribution for buses that play the role of edge computing server. A vehicular dynamic cloud is based on wireless architecture including Wireless Local Area Network and Long Term Evolution Advanced communication is used for data transmission between moving buses and cars. The main advantages of the proposed architecture include both a reduction of data loading for top layer cloud server and effective data distribution on traffic jam highway where moving vehicles require video on demand (VOD) services from server. Through the description of real environment based on NS-2 network simulation, we conducted experiments to validate the proposed new architecture. Moreover, we show the feasibility and effectiveness for the connected car media service on highway.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.3
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• pp.647-662
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• 2015

This study analyzes the factors that influence the number of public transportation passengers. By comparing the major TOD planning elements such as mixed-use level, job-housing proximity level, comparison of the density and pure density in the 66-autonomous city townships through a comparison such as TOD plan element achievements and indicators are chosen. A model is derived by correlation analysis and regression analysis of the parameters. The result of the regression analysis of the station influence area (SIA) in Incheon, the parameters that effect the number of passengers of public transportation are the number of employees, population, number of bus stops in the SIA, and the distance between the bus stop and the subway entrance. Therefore, as the number of employees and the resident population increase, the volume of traffic increases. Also, the number of public transportation users increases when there are more bus stops and when the distance between the bus stop and the subway entrance is short. This study shows that subways and SIA has achieved many parts of the TOD in Incheon, because the SIA around 29 subways and 11 Seoul-Incheon trail stations already included important TOD planning elements.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.5
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• pp.222-233
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• 2024

In recent years, there has been a trend towards seeking an integrated solution to social problems (fine dust, carbon emissions, etc.) through technological advancements in the utilization of automotive big data, the diversification of traffic environment improvement policies, and technological innovations. This study compares the differences in bus travel patterns between various types of buses in time and space by using digital odometer data, and draws implications by analyzing fuel consumption and greenhouse gas GHG emissions. As a result of the study, the acceleration dispersion value for diesel buses was higher than for CNG buses. The units of GHG emissions buses on weekdays in the metropolitan area of Gyeonggi-do were about 16% higher than on weekends compared to non-metropolitan areas due to differences in driving patterns. The methodology and results of this study are expected to be utilized in various fields, such as setting standard bus driving modes for autonomous buses, improving the economic efficiency of DRT buses, and in developing patterns to drive buses more economically.

• Journal of Auto-vehicle Safety Association
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• v.13 no.3
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• pp.78-85
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• 2021

Recently a traffic accident of heavy duty vehicles under the mandatory installation of ADAS (Advanced Driver Assistance System) is often reported in the media. Heavy duty vehicle accidents are normally occurring a high number of passenger's injury. According to report of Insurance Institute for Highway Safety, FCW (Forward Collision Warning) and AEB (Automatic Emergency Braking) were associated with a statistically significant 12% reduction in the rate of police-reportable crashes per vehicle miles traveled, and a significant 41% reduction in the rear-end crash rate of large trucks. Also many countries around the world, including Korea, are studying the effects of ADAS installation on accident reduction. Traffic accident statistics of passenger vehicle for business purpose in TMACS (Traffic safety information Management Complex System in Korea) tends to remarkably reduce the number of deaths due to the accident (2017(211), 2018(170), 2019(139)), but the number of traffic accidents (2017(8,939), 2018(9,181), 2019(10,095)) increases. In this paper, it is introduced a traffic accident case that could lead to high injury traffic accidents by being equipped with AEB in a bus. AEB reduces accidents and damage in general but malfunction of AEB could occur severe accident. Therefore, proper education is required to use AEB system, simply instead of focusing on developing and installing AEB to prevent traffic accidents. Traffic accident of AEB equipped vehicle may arise a new dispute between a driver's fault and vehicle defect. It is highly recommended to regulate an advanced event data recorder system.

• Journal of Satellite, Information and Communications
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• v.1 no.2
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• pp.95-100
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• 2006

The COMS(Communication, Ocean and Meteorological Satellite) EPS(Electrical Power Subsystem) is derived from an enhanced Eurostar 3000 version. Eurostar 3000 EpS is fully autonomous operation in nominal conditions or in the event of a failure and provides a high level of reconfigure capability. This paper introduces the COMS EPS preliminary design result. COMS EPS consists of a battery, a solar arrat wing, a PSR(Power Supply Regulator), a PRU(Pyrotechnic Unit), a SDAM(Solar Array Drive Mechanism) and relay and fuse brackets. COMS EPS can offer a bus power capability of 3 kW. The solar array is made of a deployable wing with two panels. One type fo solar cells is selected ad GaAs/Ge triple junction cells. Li-ion battery is base lined with ten series cell module of five cells in parallel. PSR associated to battery and solar array wing generates a power bus fully regulated at 50 V. Power bus os centralized protection and distribution by relay and fuse brackets. PRU provides power for firing actuarors devices. The solar array wing is rotated by the SADM under control of the attitude orbit control subsystem. The control and monitoring of the EPS, especially of the battery, is performed by the PSR in combination with the on-board software.

• Journal of Sensor Science and Technology
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• v.7 no.2
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• pp.124-130
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• 1998

High-speed 3D vision systems are essential for autonomous robot or vehicle control applications. In our study, a stereo vision process has been developed. It consists of three steps : extraction of edges in right and left images, matching corresponding edges and calculation of the 3D map. This process is implemented in a VME 150/40 Imaging Technology vision system. It is a modular system composed by a display, an acquisition, a four Mbytes image frame memory, and three computational cards. Programmable accelerator computational modules are running at 40 MHz and are based on TMS320C31 DSP with a $64{\times}32$ bit instruction cache and two $1024{\times}32$ bit internal RAMs. Each is equipped with 512 Kbytes static RAM, 4 Mbytes image memory, 1 Mbytes flash EEPROM and a serial port. Data transfers and communications between modules are provided by three 8 bit global video bus, and three local configurable pipeline 8 bit video bus. The VME bus is dedicated to system management. Tasks between DSPs are distributed as follows: two DSPs are used to edges detection, one for the right image and the other for the left one. The last processor computes the matching process and the 3D calculation. With $512{\times}512$ pixels images, this sensor generates dense 3D maps at a rate of about 1 Hz depending of the scene complexity. Results can surely be improved by using a special suited multiprocessors cards.

• Smart Media Journal
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• v.12 no.11
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• pp.57-66
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• 2023

In this paper, we present a study on an AI-based system utilizing the CCTV system within city buses to predict the intentions of boarding and alighting passengers, with the aim of preventing accidents. The proposed system employs the YOLOv7 Pose model to detect passengers, while utilizing an LSTM model to predict intentions of tracked passengers. The system can be installed on the bus's CCTV terminals, allowing for real-time visual confirmation of passengers' intentions throughout driving. It also provides alerts to the driver, mitigating potential accidents during passenger transitions. Test results show accuracy rates of 0.81 for analyzing boarding intentions and 0.79 for predicting alighting intentions onboard. To ensure real-time performance, we verified that a minimum of 5 frames per second analysis is achievable in a GPU environment. his algorithm enhance the safety of passenger transitions during bus operations. In the future, with improved hardware specifications and abundant data collection, the system's expansion into various safety-related metrics is promising. This algorithm is anticipated to play a pivotal role in ensuring safety when autonomous driving becomes commercialized. Additionally, its applicability could extend to other modes of public transportation, such as subways and all forms of mass transit, contributing to the overall safety of public transportation systems.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.5 no.3 s.11
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• pp.1-12
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• 2006

Nowdays ITS is being installed in each local autonomous entity, and BIS installation and operation is prior to other ITS sub systems for the public service. The methods of positioning md wireless communication in BIS are DSRC+DSRC, GPS+wireless communication, Beacon+Beacon, which are chosen and operated as the local features. Before this study, the before and after survey of BIS' quality have only been done without performance evaluation of BIS. So the method of BIS' evaluation have been established including performance test in this paper. And the evaluation of some BIS' reliability and efficiency have been done using the reliability of arriving data and the wireless communication response rates after choosing typical BIS' sub system.