• International Journal of Computer Science & Network Security
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• 제22권4호
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• pp.237-244
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• 2022

Eco-driving of vehicles today presents an advantage that aims to reduce energy consumption and limit CO2 emissions. The application for this option is possible to older vehicles. In this paper, we propose an efficient implementation for IoT (Internet of Things) system for controlling vehicle components that affect the quality of driving (acceleration, braking, clutch, gear change) via Smartphone using Wi-Fi and BLE as communication protocol. The user can see in real-time data from sensors that control driver action on vehicle driving systems such as acceleration, braking, and vehicle shifting through a web interface. Thanks to this communication, the user can control his driving quality and, hence, eco-driving can be achieved

• 한국대기환경학회지
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• 제29권6호
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• pp.734-744
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• 2013

In this study, the telematics device was installed on the car (OBD-II) to collect the information on the operation conditions from each sample vehicle. Based on the information the domestic driving pattern was analysed and the ratio of cold start length was estimated. As a result of analysis for driving pattern, we found a difference in the frequency of driving on the hourly or seasonal basis. Then, the driving pattern of the rush hours, weekdays, and weekends could be derived. Also, from the study, an average of 2.22 times per day occurred in a single trip and average driving distance for the trip was 15.72 km. In addition, the proportion of cold start length was analyzed to be 16.11%. The seasonal cold start length has big difference from season to season (Winter 26.63%, Summer 8.22%, Intermediate 12.65%). There was an inverse relationship between the outside temperature and ratio of cold start length. In order to improve the accuracy of the cold emission estimation, it is necessary to apply domestic ratio of cold start length that driving pattern and temperature in Korea is reflected.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.431-436
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• 2002

Train driving should be satisfied to run fixed distance within given time, and it is desirable to minimize energy consumption. Minimizing energy consumption depends on the train operation modes by driver or automatic operation. In this article, an optimal operation to minimize energy consumption by changing modes of train operation by a driver is investigated. First, powering model, braking model and consumed energy calculation model are introduced by using Matlab software. The accuracy of the model established by simulation is compared with the real experimental data, which is obtained from an authorized institution. Second, several simulations under a variety of operations in the ideal track are executed, and then the optimal pattern of train driving is found.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.159-162
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• 2007

Comparative study on a low cost sustaining driver with single and dual path energy recovery circuits for plasma display panels (PDPs) is shown in this paper. The cost of PDPs has been still high and about half of the cost has been occupied by driving circuit. A simple sustaining driver is proposed to reduce the cost and size of driving circuit. The proposed driver has small number of devices and reactive components and there are two methods for charging and discharging PDPs such as single and dual path energy recovery circuits. A comparative research on two-types of energy recovery path is practiced to evaluate performance. As a result, the dual energy recovery path circuit has low power consumption, low surge current and high performance. To verify those results, experiment will be shown with 42-inch HD panel.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.334-341
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• 2002

Nowadays, owing to the development of analysis techniques for PDA test, we can evaluate the serious damage of pile during driving in site. In this study, we checked the damage of pile by pulling it out after evaluation of the pile damage during driving by PDA testing. After that, almost damaged pile was checked and the outline depth of damage could be verified. To increase the quality of driven pile, we have to increase the number of PDA testing for drivability analysis with checking the damage especially for preliminary pile driving and dynamic load test for checking the bearing capacity and consider the application of driving by energy monitoring.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권4호
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• pp.173-178
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• 2003

The rotational force of ultrasonic motors is able to get from the frictional force of elliptical vibration by contact between rotor and stator. Generally, ultrasonic motors are suitable for driving at resonant frequencies of about 20∼80［KHz］. The driving characteristics of ring type ultrasonic motors are the object of this study. A two-phase driving signal is delivered to the tested ultrasonic motor, which has a $90^0$ phase difference respectively with both sine and cosine voltage waveforms. The driving frequency is almost equal to the mechanical resonant frequency for the proper operation, and the driving signal is supplied by the two-phase parallel resonant inverter. The validity of the proposed driving method is verified by experimental results with stable operation.

• 예술인문사회 융합 멀티미디어 논문지
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• 제9권5호
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• pp.865-872
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• 2019

본 논문은 한국교통대학교 태양광 자작 자동차 동아리 늘해랑에서 WSC(World Solar Challenge)에 참가하기 위해 제작한 Solar Car 구동시스템에 대하여 서술한다. WSC는 세계 최대의 태양광 자동차 경주 대회로 별도의 자동차 규정을 가지고 있어 태양전지 면적이나 배터리 용량등에 제약을 두기 때문에, 제한된 규정내에서 최대 에너지 효율을 가지도록 구동시스템을 설계하는 것이 가장 중요한 기술적인 팩터이다. Solar car의 구동시스템은 태양광 에너지를 전기 에너지로 변환해주기 위한 solar array, 변환된 전기에너지를 최대 출력으로 추적하기 위한 MPPT(Maximum Power Point Tracker) controller, 생산된 전기에너지를 저장하기 위한 battery, 전기에너지를 역학에너지로 변환하여 차량 구동을 위한 BLDC(Brushless DC) motor, BLDC motor를 제어하기 위한 motor controller 등으로 구성되어 있다. 본 연구에서는 최적 구동 시스템을 위해 태양전지 에너지 변환 시스템과 배터리, 모터로 구성된 전기 구동시스템 설계에 대한 내용을 포함하고 있다.

• Geomechanics and Engineering
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• 제9권3호
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• pp.345-360
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• 2015

Wave equation analysis programs (WEAP) such as GRLWEAP and TNOWave were primarily developed for pre-driving analysis. They can also be used for post-driving measurement applications with some refinements. In the case of pre-driving analysis, the programs are used for the purpose of selecting the right equipment for a given ground condition and controlling stresses during pile driving processes. Recently, the program is increasingly used for the post-driving measurement application, where an assessment based on a variety of input parameters such as hammer, driving system and dynamic behaviour of soil is carried out. The process of this type of analysis is quite simple and it is performed by matching accurately known parameters, such as from CAPWAP analysis, to the parameters used in GRLWEAP analysis. The parameters that are refined in the typical analysis are pile stresses, hammer energy, capacity, damping and quakes. Matching of these known quantities by adjusting hammer, cushion and soil parameters in the wave equation program results in blow counts or sets and stresses for other hammer energies and capacities and cushion configuration. The result of this analysis is output on a Bearing Graph that establishes a relationship between ultimate capacity and net set per blow. A further application of this refinement method can be applied to the assessment of dynamic formulae, which are extensively used in pile capacity calculation during pile driving process. In this paper, WEAP analysis is carried out to establish the relationship between the ultimate capacities and sets using the various parameters and using this relationship to recalibrate the dynamic formula. The results of this analysis presented show that some of the shortcoming of the dynamic formula can be overcome and the results can be improved by the introduction of a correction factor.

• 터널과지하공간
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• 제32권3호
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• pp.231-242
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• 2022

본 연구에서는 지하광산에서 로봇의 위치를 추정하고, 여러 경유지를 거쳐 주행한 후 원위치로 복귀하는 ROS (Robot Operating System) 기반의 자율주행 로봇을 개발하였다. 자율주행 로봇은 SLAM (Simultaneous Localization And Mapping) 기술을 활용하여 주행 경로에 대한 전역 지도를 사전에 생성한다. 이후, 라이다 센서를 통해 측정되는 벽면의 형태와 전역 지도를 매칭하고 AMCL (Adaptive Monte Carlo Localization) 기법을 통해 데이터들을 융합하여 로봇의 위치를 보정한다. 또한, 라이다 센서를 통해 전방 주행환경을 인지하고, 장애물을 회피한다. 개발된 자율주행 로봇을 활용하여 지하광산 현장을 모사한 실내 실험장을 대상으로 주행 실험을 수행하였다. 그 결과, 자율주행 로봇은 다중 지점의 경유지에 대해 순차적으로 주행하고 장애물을 회피하며 안정적으로 복귀하는 것을 확인할 수 있었다.

• 에너지공학
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• 제25권3호
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• pp.51-58
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• 2016

MLCC는 각종 전자제품의 핵심부품이며 이러한 MLCC 부품을 제작하기 위해 교반기가 사용되어진다. 과거에는 접촉식 교반기가 많이 사용되었으나 현재는 여러 장점으로 인해 비접촉식 교반기의 사용이 증가 추세에 있다. 이와 같은 비접촉식 중에서 특히 대용량 비접촉식 교반기의 경우, 구동기어의 기능이 중요하다. 따라서 본 연구에서는 대용량 비접촉식 교반기 구동기어의 최적설계를 통한 제작비용 절감을 위해 기존 모델에서 과도한 설계 변경 없이 구동기어의 형상최적화 연구를 수행하였다. 그 결과, 강건 설계된 기존 모델과 비교하여 형상최적화 된 수정모델의 안전율이 약 3.0 ~ 3.5 배 감소한 것으로부터 제작비용 절감 가능성을 확인하였다.