• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1167-1172
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• 2017

Desktop computers, which were the main means of Internet use and information activity, were pushed out by smart devices that emphasized mobility and simplicity. The recent information production and consumption activities are performed through smart devices, but there is no input device for smart devices that can fully replace traditional input devices such as full-size PC compatible keyboards. Because of the small size of the virtual keyboard that uses the touch screen of the smart device, typographical error occurs at a high rate. In this paper, we propose a variable virtual keyboard that minimizes the typographical errors of the conventional virtual keyboards. The proposed method minimizes the user 's input error by adjusting the size of each key of the virtual keyboard based on accumulated dataset of position and pressure of the user' s input error even though there is no difference in the key position arrangement of the conventional virtual keyboards.

• Journal of Advanced Navigation Technology
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• v.24 no.4
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• pp.314-321
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• 2020

Logic automated stimulus and response (LASAR) software is an automatic test program development tool for logic function test and fault detection of avionics components digital circuit cards. LASAR software needs to the information for the logic circuit function and input and output of the device. If there is no component information, normal component modeling is impossible. In this paper, component modeling is carried out through reverse design of programmable logic device (PLD) device without element information. The developed LASAR program identified failure detection rates through fault simulation results and single-seated fault insertion methods. Fault detection rates have risen by 3% to 91% for existing limited modeling and 94% for modeling through the reverse design. Also, the 22 case of stuck fault with the I/O pin of EP310 PLD were detected 100% to confirm the good performance.

• Journal of Advanced Navigation Technology
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• v.19 no.1
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• pp.66-73
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• 2015

In this paper, an architecture of a perpetual smart video device and its energy control model for the internet of things (IoT) are proposed. The smart video device consists of a processor, an image sensor, a video codec, and a network controller. In the proposed energy control model, energy consumed by image sensing, video encoding, and transmission and energy harvested by solar panels are defined as an input and an output of a battery, an energy buffer. Frame rate, quantization parameter, and operating frequency of processor are defined as the energy control parameters, and these parameters control the input and the output energy of the energy buffer, finally control the energy left in the battery. The proposed energy control model is validated by the energy consumption measurement of the smart phone based platform for various combinations of energy control parameters, and can be used for the design of perpetual smart video device.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.655-658
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• 2005

Due to reduced device sizes and threshold voltages, leakage current becomes an important issue in CMOS design. In a CMOS combinational logic circuit, the leakage current in the standby state depends on the state of the inputs and thus can be minimized by applying an optimal input when the circuit is idling. In this paper, we present a New Input Vector Control algorithm, called Leakage Minimization by Input vector Control (LMIC) for minimal leakage power. This algorithm finds the minimal leakage vector and reduces leakage current up to 22.% on the average, for TSMC 0.18um process parameters. Minimal leakage vectors are very useful in reducing leakage currents in standby mode of operation.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.6
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• pp.77-84
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• 1997

buck type converter doesn't appear when an input voltag eis lower than an output voltage. This is the main reason the buck converter has not been used for high power factor converters. In this paper, soft switching high power factor buck converter is proposed. This converter is composed of diode rectifier, input capacitor can be small enough to filter input current, buck converter with loss less snubber circuit. Converter is operated in discontinous conduction mode, turn on of the switching device is a zero current switching (ZCS) and high powr factor input is obtianed. In addition, zero voltage switching (ZVS) at trun off is achieved and switching loss is reduced using loss less snubber circuit. The capacitor used in the snubber circuit raised output voltage. Therefore, proposed converter has higher output voltage and higher efficiency than conventional buck type converter at same duty factor in discontinous conduction mode operation. High power factro, efficiency, soft switching operation of proposed converter is veified by simulation using Pspice and experimental results.

• Journal of Internet Computing and Services
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• v.18 no.3
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• pp.37-48
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• 2017

Touch interface has been introduced as one of the most common input devices that are widely used in the Smart Device. Recently Force-Touch interface, a new approach of input method, having the power recognition mechanism, has been appeared in Smart industries. Force-Touching determining multiple things (the geographical and pressure values of touching point) in one touching act allows users to provide more than one input methods in a limited environments. Force-Touching Device is required different user communicational interaction than other common Smart devices because it is possible to recognize various inputs in the one act. It means that Force-Touching is only able to understand and to use the pressure sensitive values, not other Smart input methods. So, we built Force-Touch-Cover that makes typical Smart-Device to have Force-Touching interfaces. We analysis the accuracy of the Force-Touching-Cover's sensor and also assessment the changes in pressure values depending on the pressure position. Via this Paper, We propose the implement of user-oriented Force-Touching interface that is based on users' feedback as our conclusion.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.8
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• pp.41-51
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• 1997

The device simulator (BANDIS) which can analyze efficiently the electrical characteristics of the semiconductor devices under the three dimensional stationary conditions on the IBM PC was developed. Poisson, electon and hole continuity equations are discretized y te galerkin method using a tetrahedron as af finite element. The frontal solver which has exquisite data structures and advanced input/output functions is dused for the matrix solver which needs the highest cost in the three dimensional device simulation. The discretization method of the continuity equations used in BANDIS are compared with that of the scharfetter-gummel method used in the commercial three-dimensional device. To verify an accuracy and the efficiency of the discretization method, the simulation results of the PN junction diode and the BJT from BANDIS are compared with those of the commercial three-dimensiional device simulator such as DAVINCI. The maximum relative error within 2% and the average number of iterations needed for the convergence is decreased by more than 20%. The total simulation time of the BJT with 25542 nodes is decreased to about 60% compared with that of DAVINCI.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.3
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• pp.15-23
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• 2009

In ubiquitous environments, invisible devices and software are connected to one another to provide convenient services to users. In this environments, users want to get a variety of customized services by using only an individual mobile device which has limitations such as tiny display screens, limited input, and less powerful processors. Therefore, The device sharing for solving these limitation problems and its efficient processing is one of the new research topics. This paper proposes a device recommender system which searches and recommends devices for composing user requested services. The device recommender system infers devices based on environmental context of a user. However, customized devices for each user are different because of a variety of user preference even if users want to get the same service in the same space, Therefore the paper considers the user preference for device recommendation. Our device recommender system is implemented and tested on the real mobile object developed for device sharing in ubiquitous environments. Therefore we can expect that the system will be adaptable in real device sharing environments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.3
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• pp.558-567
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• 2003

Most digital signal processors provide 4 external interrupt input channels. But these are not sufficient for external interrupts of motor controls. Customized programmable interrupt controller, 8259, has 8 interrupt channels. Therefore, in the case of more external interrupt channels are needed, designers must expand by cascading the 8259. And this, 8259 device, have some inconvenience of interfacing the microprocessor in motor controls. In this paper, the expanded interrupt controller with 14 sufficient interrupt input channels for motor controls is designed using VHDL on the purpose of interfacing the microprocessor to the interrupt controller more compatibly and increasing the device utilization of FPGA/CPLD designed another peripherals. The interrupt controller model and each function blocks is proposed and illustrated. Simulation result are presented to estimate the designed interrupt controller.

• Journal of Computing Science and Engineering
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• v.10 no.1
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• pp.32-38
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• 2016

Navigating a large 3D virtual environment using a generic haptic device can be challenging since the haptic device is usually bounded by its own physical workspace. On the other hand, mouse interaction easily handles the situation with a clutching mechanism-simply lifting the mouse and repositioning its location in the physical space. Since the haptic device is used for both input and output at the same time, in many cases, its freedom needs to be limited in order to accommodate such a situation. In this paper, we propose a new mechanism called Z-Clutching for 3D navigation of a virtual environment by using only the haptic device without any interruption or sacrifice in the given degrees of freedom of the device's handle. We define the clutching state which is set by pulling the haptic handle back into space. It acts similarly to lifting the mouse off the desk. In this way, the user naturally feels the haptic feedback based on the depth (z-direction), while manipulating the haptic device and moving the view as desired. We conducted a user study to evaluate the proposed interaction technique, and the results are promising in terms of the usefulness of the proposed mechanism.