• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.21 no.2
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• pp.61-65
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• 2015

Agricultural products packaged for transportation are put in the various dangerous environments owing to the damage factors like vibration, shock, compression, climate etc. under the distribution process. On fruits packaging for transportation, especially, the shock and vibration is considered as the most important damage factors. A major cause of shock damage to fruits is drops during manual handling. Especially, the damages of fruits during the parcel delivery service are very serious. The parcel delivery services of fruits are increasing and contribute to increasing of farm house earning. Also, the freight vehicle is mostly used to transport the fruits. Shock and impact generated by the freight vehicle may give serious damage to fruits. The optimum packaging design of parcel delivery service of fruits during transportation is required to reduce the fruits damages. In order to design the packaging system for parcel delivery service of fruits considering the transportation environment, the comprehension of characteristics for vibration and shock generated by manual handling and acting on transportation vehicles under various road conditions and loading methods is required. This research was performed to analyze the shock characteristics, acceleration level and power spectral density (PSD) during the parcel delivery service of fruits. The overall level of recommended PSD profile in a specific transportation of parcel delivery service for fruits was $0.63G_{rms}$.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5D
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• pp.563-570
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• 2009

This study is aimed to analyze the overall effects of the additional delay caused by the vehicle in front of the queue, at the signal, to the total delay estimation. To estimate the average vehicle delay at the signalized intersection, as survey of the queue length at the intersection and traffic counts were conducted. As a result of this analysis, all of the three delay estimation methods turned out to be similar in that the estimation of the average delay for the test vehicle was less than 60 sec/vehicle. However, the average delay time for the vehicle in front of the queue only, was estimated at 60-70 sec/vehicle which is similar to the average delay of the test vehicle.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.970-973
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• 2008

For commercial vehicles with a manual transmission, the pneumatic and fluid pressure servo-device is widely used for transmitting large torque. However, the pneumatic and fluid pressure servo-device usually results in non-linear variation of foot-efforts, also such characteristics tend to increase physical fatigue of drivers who drive commercial vehicles for a long time. Thus, vehicle manufacturers consider the hysteresis loops in the Clutch Actuation System (CAS) design when a new vehicle model is being developed. In this study, we numerically simulate the hysteresis loops for predictable CAS design, and the experimental results confirm the simulation results.

• Journal of the Korean Society for Advanced Composite Structures
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• v.2 no.4
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• pp.11-18
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• 2011

In this study, the performance of a steel-FRP composite bridge safety barrier was evaluated through vehicle crash simulation. Surface veil, DB and Roving fibers were used for FRP. The MAT58 material model provided by LS-DYNA software was used to model FRP material. Spot weld option was used for modeling contact between steel and FRP beam. The structural strength performance, the passenger protection performance, and the vehicle behavior after crash were evaluated corresponding to the vehicle crash manual. As the result, A steel-FRP composite safety barrier was satisfied with the required performance.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.849-854
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• 2007

This paper describes design and tuning of a full-range Adaptive Cruise Control (ACC) with collision avoidance. The control scheme is designed to control the vehicle so that it would feel natural to the human driver and passengers during normal safe driving situations and to avoid rear-end collision in vehicle following situations. In this study, driving situations are determined using a non-dimensional warning index and time-to-collision (TTC). A confusion matrix method based on natural driving data sets was used to tune control parameters in the proposed ACC System. An ECU-Brake Hardware-in-the-loop Simulation (HiLS) was developed and used for an evaluation of ACC System. The ECU-Brake HiLS results for alternative driving situation are compared to manual driving data measured on actual traffic way. The ACC/CA control logic implemented in an ECU was tested using the ECU-Brake HiLS in a real vehicle environment.

• Journal of Biosystems Engineering
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• v.27 no.5
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• pp.409-416
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• 2002

This study was conducted to develop a vehicle, leading or following a worker at a certain distance to assist laborious transporting works in greenhouses. A prototype vehicle, which consisted of the rear driving, the front steering and the console units, was designed and tested in the ideal indoor conditions. Results of this study were summarized as following: 1. The driving unit was designed to travel at the speed ranges of 0.3∼0.8 m/sec depending on the operating modes with a maximum payload of 100 kg. 2. The console unit consisted of a main-board including a 80C196KC microprocessor and peripheral devices, a power-board and safety interlock. Worker-leading, and following modes were available in automatic and manual modes. 3. Steering was achieved by turning the steering motor against the sensed direction. Proper steering angles for correcting travel direction were determined as 5 and 9 degrees when sensing cultivation beds and plants, respectively.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.6
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• pp.775-780
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• 2008

In this paper, unmanned driving of robotic vehicle using magnetic marker is proposed. One of the most important component of autonomous vehicle is to detect the position of a magnetic marker on the road. In order to calculate the precise position of a magnet embedded on the road, the relation of magnetic field and a sensor is analyzed, and a new position sensing system using arrayed magnetic sensor is proposed. Also, the steering control system using a stepping motor is developed for driving by automatic mode as well as manual mode. For the verification of usability, the developed robotic vehicle is tested on magnetic road.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4A
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• pp.197-206
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• 2012

It is found the first case of broad interpretation of the crash analysis in MASH (Manual for Assessing Safety Hardware, AASHTO, 2009) which is the guideline of roadside safety features in United States. They introduced the procedure of calculating 1,500 kg sedan safety index from the 2,270 kg pick-up truck crash test for crash cushion. First, following MASH's method, calculate 0.9 ton vehicle crash data and safety index using 1.3 ton vehicle crash test data and compare with actual 0.9 ton vehicle crash test data. results show that actual test data and the data calculated by MASH's method have great difference. Second, analyse the cause and develop new method. Proposed method can estimate not only the lighter vehicle (0.9 ton) crash data from the heavier vehicle (1.3 ton) crash test but also heavier vehicle (1.3 ton) data from lighter vehicle (0.9 ton) test. This method is superior to MASH's method and has stronger theoretical foundation. This paper proves the efficiency and the accuracy of new broad interpretation method using crash test data and investigates the principle.

• Journal of Drive and Control
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• v.10 no.2
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• pp.30-36
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• 2013

Tractor is a farm vehicle that is designed to provide a high tractive effort at low speed. It is used for versatile agricultural tasks such as hauling a trailer, tillage, mowing and construction work. Most older tractors use a manual transmission. However, as the intensity of work increases, tractors equipped with automatic transmission become popular due to the work convenience. In order to give the operator a large degree of control in field work, 24 gears with automatic 8-speed and manual 3-speed are arranged in transmission. This paper deals with the gear train that is designed for 8-speed automatic transmission by the engagement of multi-disk clutches. The gear ratio for each speed as well as power transmission mechanism is analyzed through velocity analysis. In addition, constraints of mesh gear ratio are derived by investigating the power flow path in velocity diagram for the given 8-speed gear ratio.

• Korean Security Journal
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• no.32
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• pp.205-225
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• 2012

This study is to present an improvement of facility security through the evaluation of facility security operation level. To fulfill the purpose of the study, a survey of some facilities was conducted and the result was analyzed as follows; First, although security personnels were deployed in the facilities, the level of security personnel operation was relatively low. Second, job education training level was relatively proper, that is relevant to the result that show the level of service mind and the working mind of security personnel were proper, also relevant to the relatively good work shift system. Third, although situation room was operated well, the level of restricted area set-up and access control of visitor were low, and the level of article inspection and vehicle access control were very low. Forth, the level of security manual application that include detailed security method and procedure was proper. But accident prevention and response manual application was lower than security manual application, that show preparation for fire and negligent-accident is passive. For the improvement of facility security, the high level part and low level part in the survey result could be merged. For example, we could specify factors that show low level in the survey such as security personnel operation, access control of visitor and vehicle, article inspection, accident prevention and response in the security manual and promote education circumstance that show high level.