• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.279-283
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• 2012

In is paper, we design and implement the low power, high speed touch screen controller that calculates and outputs the coordinate of touch point on the touch screen of mobile devices. The system clock is 10HMz, the number of input channels is 21, standby current is $20{\mu}A$, dynamic range of input is 140pF~400pF and the response time is 0.1ms/frame. It contains the power management unit for low power, automatic impedance calibration unit in order to adapt to humidity, temperature and evaluation board, adjacent key and pattern interference suppression unit, serial interface unit of I2C and SPI. The function and performance is verified by using FPGA and $0.18{\mu}m$ CMOS standard process. The implemented touch screen is designed for using in the double layer ITO(Indium Thin Oxide) module with diamond pattern and single layer ITO module for cost-effective which are applied to mobile phone or smart remote controller.

• International Journal of Reliability and Applications
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• v.8 no.1
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• pp.83-94
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• 2007

In this paper, we consider a standby redundant structure with a function of switchover processing which may not be not perfect. The switchover processing is governed by a control module whose failure may cause the failure of the whole system. The parameters measuring such an effect of failure of the control module is included in our reliability model. We compute several reliability measures such as reliability function, failure rate, MTBF, mean residual life function, and the steady state availability. We also compare a single unit structure and the redundant structure with regard to those reliability measures. An example is given to illustrate our results.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.146-149
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• 2008

최근 대기전력저감기능을 갖는 PWM IC를 적용한 플라이백 컨버터는 대기전력 모드 시 Burst 스위칭 동작에 의해 소모 전력을 최소화 할 수 있지만 경 부하 및 대기전력모드 시 변압기를 통해 흐르는 큰 여자전류에 의해 여전히 낮은 효율특성을 가지는 문제점이 있었다. 본 논문에서는 경 부하 및 대기전력모드 동작 시 변압기에 흐르는 여자전류를 최소화함으로 효율을 개선한 회로를 제안하였으며 50인치 PDP TV PSU (Power Supply Unit)에 있어서 대기전력 및 보조전원으로 사용된 74W 플라이백 컨버터에 적용하여 비교 검토하여 보았다.

• Journal of the Korean Electrochemical Society
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• v.5 no.1
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• pp.27-29
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• 2002

We report a fuel cell power supply unit for mobile phone which operates at room temperature and ambient pressure using liquid methanol and air. The unit consists of a direct methanol fuel cell (DMFC) and a back-up battery connected parallely to the fuel cell. DMFC supplies half of the required power and the back-up battery supplies the other half during talk mode. In standby mode, DMFC covers $100\%$ of the required power and charges the back-up battery as well, Eight unit cells, each having $9 cm^2$ of active area, were connected in series in order to raise the output volotage to $2.5\~3.9V$, which is typical for most mobile phones.

• Journal of Power Electronics
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• v.15 no.5
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• pp.1348-1357
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• 2015

Under traditional unified power quality conditioner (UPQC) control, a UPQC series converter (SC) is mainly used to handle grid-side power quality problems while its parallel converter (PC) is mainly used to handle load-side power quality problems. The SC and PC are relatively independent. The SC is usually in standby mode and it only runs when the grid voltage abruptly changes. In this paper, novel UPQC coordinated control strategies are proposed which use the SC to share the reactive power compensation function of the PC especially without grid-side power quality problems. However, in some cases, there will be a circulating current between the SC and the PC, which will probably influence the compensation fashion, the compensation capacity, or the normal work of the UPQC. Through an active power circulation analysis, strategies with and without a circulating current are presented which fuses the reactive power allocation strategy of the SC and the PC, the composite control strategy of the SC and the compensation strategy of the DC storage unit. Both of the strategies effectively solve the SC long term idle problem, limit the influence of the circulating current, optimize all of the UPQC units and reduce the production cost. An analysis, along with simulation andexperimental results, is presented to verify the feasibility and effectiveness of the proposed control strategies.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.7
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• pp.935-941
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• 2012

This paper describes a study of conventional electrical rig and simulated application of Flywheel Energy Storage system on the power system of the offshore plants with dynamic positioning system with the following aims: improve fuel consumption on engines, prevent blackout and mitigate voltage sags due to pulsed load and fault. Fuel consumption has been analyzed for the generators of the typical drilling rigs compared with the power plant with Flywheel Storage Unit which has an important aid in avoiding power interruption during DP (Dynamic Positioning) operation. The FES (Fly wheel Energy storage System) releases energy very quickly and efficiently to ensure continuity of the power supply to essential consumers such as auxiliary machinery and thrusters upon main power failure. It will run until the standby diesel generator can start and supply the electric power to the facilities to keep the vessel in correct position under DP operation. The proposed backup method to utilize the quick and large energy storage Flywheel system can be optimized in any power system design on offshore plant.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.401-407
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• 2016

For high fuel economy, many kinds of unit in vehicle have been developed. In steering system, as a result, HPS(Hydraulic Power Steering) system has been replaced as EHPS and EPS system. But the structures of these systems are totally different, and that causes the uncertainty of fuel economy evaluation. Therefore we undertake to research to find results and tendency of fuel economy and energy in steering system. For accurate evaluation, we modeled different types of steering systems on same vehicle model. The simulation came into action on various driving cycle. The driving condition is designed to show standby power of pump. Results show differences of fuel efficiency and energy consumption.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.46-48
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• 2015

본 논문은 외부 전원에 연결되었지만 본래의 용도(예: 셋톱박스인 경우 방송서비스 제공)로 사용되지 않는 대기상태에서도 기존 셋톱박스처럼 업데이트를 수행하면서도 기존의 셋톱박스에 비해 전력소모를 줄일 수 있는, 대기상태의 셋톱박스를 제어하는 방안을 제안한다. 본 논문의 제어방안은 셋톱박스로 전달되는 CPU 활성화 메시지를 이용하거나 메시지의 프로토콜의 일부만 분석하는 방법을 이용하여 셋톱박스 업데이트 필요 유무를 판별하는 방안으로 이는 낮은 CPU(Central Processing Unit) 연산 량만 필요로 하여 셋톱박스 전력소모 저감에 적합하다. 본 논문의 제어방안은 기존의 사업자 측면에서 대기상태 셋톱박스의 업데이트 편의성을 유지시키면서도 국가적 차원의 전력소모 저감에 기여를 할 것이다.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.1
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• pp.62-65
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• 2019

Wireless power transfer systems require an algorithm to determine the presence of the target object for mitigating standby power and safety issues. Although many schemes that sense various external objects have been actively proposed for inductive power transfer systems, not many studies on capacitive power transfer systems have been conducted compared with those on inductive power transfer systems. This study proposes a target object detection algorithm by monitoring the capacitance in transmitter-side electrodes without additional pressure sensors or distance sensors. The proposed algorithm determines the presence of a target object by monitoring the change in capacitance in transmitter-side electrodes using the step pulse of the microcontroller unit. The algorithm is verified by two step processes. First, the performance in capacitance measurement is compared with that of an LCR meter. Then, the verification is conducted in a 5-W capacitive power transfer hardware. Experimental result shows that the interelectrode capacitance increases by 6 times when the target object is fully aligned. Thus, the proposed scheme can successfully detect the presence of the target object.

• Korean Institute of Interior Design Journal
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• v.20 no.6
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• pp.262-271
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• 2011

The purpose of this study was to classify types of family visitors' behaviors more concretely, which could be useful in planning of exhibition spaces in a science museum, with given priority to their behaviors according to interaction between them, and to understand characteristics of the behaviors. With this view, the scope of this study was restricted to subjects, who were family visitors of Gwacheon National Science Museum, consisting of parents and their one elementary school child per family unit. For understanding their behaviors, itinerary tracking and observation method of behavior were conducted. Moreover, for understanding substantial types and characteristics of family visitors' behaviors, multivariate analysis was applied. Accordingly, the results of the study are as follows. First, as a result of factor analysis, two main factors were derived. In other words, they were 'Durability of viewing' as the first and 'Interactivity between family members' as the second, which were shown valid in classification of the types of their behaviors. Second, according to the factors derived, the types of their behaviors were classified into in-depth cooperative viewing, selective independent viewing, interest concentration child-led viewing and consideration parent-led viewing. They were shown valid in topological localization and classification, as a result of analysis of the main factors. Third, in view of common characteristics of the types, it is judged that active orientation prior to regular viewing could encourage visitors coming to the museum for the first time to feel more friendly to unfamiliar exhibition environments, during the initial seek time, and to reduce visual supersaturation. Fourth, it is judged that distributed arrangement of exhibits, which result in continuous standby, could avoid confused visitor circulation by the estimated time required for viewing.