• 대한임베디드공학회논문지
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• 제8권1호
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• pp.11-16
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• 2013

With the development and general use of a variety of Android/iOS-based smart phones and smart pads, the existing e-learning contents need to be changed in such a way that they can be carried out on different smart device platforms. This paper shows what changes are needed for that aim, and, in particular, for the compatibility of different platforms by designing and implementing Android/iOS-based smart learning contents in the form of a hybrid app. This paper will hopefully help you consider what elements are required to develop smart-learning contents on a variety of platforms for mobile devices.

• 대한기계학회논문집B
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• 제33권9호
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• pp.718-721
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• 2009

A new progressive advanced approach (Loop thermosyphon Thermoelectric Power generation System) is suggested to optimize heat recovery ability from vehicle exhaust gas. As an initial look at device feasibility, the present new TE system adopted the loop thermosyphon as a cooling heat exchanger. The TE system with loop thermosyphon was investigated in terms of working fluids, instability of system, amount of working fluid, and so on. Basically, the present experimental works have been focused on finding the optimum working condition of the system to improve thermoelectric power output and to obtain stable power generation to operate hybrid vehicles. The present experimental results with the loop thermosyphon TE module shows possibilities as an improved TE system for future thermoelectric hybrid vehicles.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 제17회 워크샵 및 추계학술대회
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• pp.537-540
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• 2005

A battery is the primary energy source device presently used in hybrid electric vehicle. It can store much energy, but cannot provide enough current without inefficient units. However, an ultracapcitor can provide much current, but cannot store much energy. It will have better fuel economy by combining the two energy sources in parallel. The purpose of this paper is making the simulator of the two HEV systems. The one has only battery, the other have battery and ultarcapacitor in parallel. To compare the fuel economy, dynamic programing was used for optimization and prius was used for HEV model.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.323-325
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• 2007

$TiO_{2}$ electrode electrospun directly onto the substrate was developed for energy conversion device. To enhance energy conversion efficiency of dye-sensitized solar cell, electrodes should have higher surface area to absorb more dyes and higher conductivity to reduce recombination of generated electrons. $TiO_{2}$ nanofibers with higher surface areas were fabricated by annealing electrospun $TiO_{2}/PVP$ nanofibers at $500^{\circ}C$ for 3 hrs in air. it was revealed that $TiO_{2}$ nanofiber electrodes is hybrid with MWNT showed higher conductivity than $TiO_{2}$ semiconductor electrode possibly due to band gap change.

• 대한기계학회논문집B
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• 제30권8호
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• pp.756-763
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• 2006

PEMFC has several technical problems such as water management, long term stability and performance degradation as. PEMFC has been studied not only to solve water management, but also to generate power in stable manner to system by using a hybrid system with auxiliary energy storage device. The purpose of this study is to couple PEMFC with supercapacitor to make a hybrid system and to design and test control strategies for stable power generation in case of changing output power. The polarization curve and dynamic behaviors while changing power were investigated to find out characteristics of PEMFC stack. A DC/DC converter was fabricated in order to increase fuel cell and supercapacitor voltage and to charge supercapacitor. We found that the operation strategy 2 was recommended to the system because of solving water management problem and increasing the dynamic behavior.

• Journal of Magnetics
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• 제17권4호
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• pp.261-264
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• 2012

Interfacial properties of 5 nm MgO(001)/7 nm Fe(001)/1.8 nm MgO(001)/t nm Cu-phthalocyanine (CuPc) hybrid multilayers with t = 0, 1, 7, and 10 were investigated by using x-ray photoemission spectroscopy (XPS). Rather sharp interfacial properties were observed in the CuPc films grown on an epitaxial MgO/Fe/MgO(001) trilayer than a MgO/Fe(001) bilayer. This work suggests a new way to improve device performance of organic spintronic devices by utilizing an artificially grown MgO(001) thin layer.

• Advances in Energy Research
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• 제4권1호
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• pp.47-68
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• 2016

A well designed hybrid power system (HPS) can deliver electrical energy in a cost effective way. In this paper, model for HPS consisting of photo voltaic (PV) module and wind mill as renewable energy sources (RES) and solar lead acid battery as storage device connected to unidirectional grid is developed for peak demand reduction. Life time energy cost of the system is evaluated. One year hourly site condition and load pattern are taken into account for analysing the HPS. The optimal HPS is determined for least life time energy cost subject to the constraints like state of charge of the battery bank, dump load, renewable energy (RE) generation etc. Optimal solutions are also found out individually for PV module and wind mill. These three systems are compared to find out the most feasible combination. The results show that the HPS can deliver energy in an acceptable cost with reduced peak consumption from the grid. The proposed optimization algorithm is suitable for determining optimal HPS for desired location and load with least energy cost.

• 전력전자학회논문지
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• 제18권2호
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• pp.199-204
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• 2013

Recently, the demand for fuel efficient electric vehicles (EVs) and hybrid electric vehicles (HEVs) has been growing globally. Due to the increased number of switching devices in the electrified vehicles, the probability of the semiconductor device failure is much higher than in other application areas. A sudden failure in one of the power switches and insufficient power management ability in the systems not only decreases system performance, but also leads to critical safety problems. In this paper, novel switch open circuit fault detection method is proposed, and the proposed approach is verified by experiments.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.171.1-171
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• 2001

This paper describes the design and implementation of a new type of a force reflective joystick. It has single degree of freedom that is actuated by motor and brake pair. The use of motor and brake allows various objects to be simulated without the stability problem and related safety issues involved with high torque motors only. The joystick performance is measured by its ability to simulate various test objects. Simple test objects are modeled as a benchmark test of the system´s performance and to evaluate different control approaches for hybrid motor/brake actuator. The force output joystick is capable of simulating forces in a variety of virtual environments. This device demonstrates the effectiveness of a hybrid motor/brake haptic actuator.

• 대한기계학회논문집A
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• 제24권3호
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• pp.653-660
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• 2000

The automatization by industrial robot of today is merely rely on to the simple position repeating works, but requirements of research and development to the force control which would adapt positively to various restriction or contacting works to environment. In this paper, a learning control algorithm using, neural networks is proposed for the position and force control by a direct-drive robot. The proposed controller is the feedback controller to which the learning function of neural network is added on to and has a character of improving controller's efficiency by learning. The effectiveness of the proposed algorithm is demonstrated by the experiment on the hybrid position and force control of a parallelogram link robot with a force sensor.