• International Journal of Reliability and Applications
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• v.2 no.2
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• pp.107-115
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• 2001

This paper considers some reliability indices, such as availability, average availability, reliability and steady state availability, of a redundant system with the function of switchover processing. We also derive the confidence limits for steady state availability of such system. The system, which is considered in this paper, consists of an active unit, a standby unit and a switchover device. In addition, the switchover processing is controlled by a control module. The effect of failure of the control module is taken into account to develop our reliability model for the redundant structure. Numerical examples are presented to illustrate our results.

• Journal of Integrative Natural Science
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• v.2 no.4
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• pp.237-242
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• 2009

As semitransparent dye-sensitized solar cells (DSSCs) have advanced to large-scale applications from lab-level research, the large-scale performance has attracted much attention. Modules of DSSCs have been investigated to optimize the efficiency as a $TiO_2$ systhesis temperature and a surface treatment of $TiCl_4$ aqueous solution. Essentially, these semitransparent modules have an extended structure with lab-scale works with the exception of the dimensions and methods for the series connection. The $5cm{\times}6.5cm$ modules have shown an efficiency of about 6% without a scattering layer. While the fill factors of modules depend on the width of each $TiO_2$ unit cell, they are much less dependent on the lengths of the unit cells.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.1
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• pp.60-79
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• 2022

The U-Net architecture-based segmentation models attained remarkable performance in numerous medical image segmentation missions like skin lesion segmentation. Nevertheless, the resolution gradually decreases and the loss of spatial information increases with deeper network. The fusion of adjacent layers is not enough to make up for the lost spatial information, thus resulting in errors of segmentation boundary so as to decline the accuracy of segmentation. To tackle the issue, we propose a new deep learning-based segmentation model. In the decoding stage, the feature channels of each decoding unit are concatenated with all the feature channels of the upper coding unit. Which is done in order to ensure the segmentation effect by integrating spatial and semantic information, and promotes the robustness and generalization of our model by combining the atrous spatial pyramid pooling (ASPP) module and channel attention module (CAM). Extensive experiments on ISIC2016 and ISIC2017 common datasets proved that our model implements well and outperforms compared segmentation models for skin lesion segmentation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.507-509
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• 2022

In order to collect vehicle internal diagnostic data, it is necessary to collect diagnostic data of ECU (Electronic Control Unit) included in various automotive parts. Diagnostic communication can be used to collect diagnostic data of ECU. In this paper, the method of collecting diagnostic data according to ECU function through standard diagnostic communication and the diagnostic communication module were analyzed. Among the standard modules of AUTOSAR, a standard for automotive electronics used by many automobile manufacturers, the diagnostic communication module was studied, and the process of diagnostic data processing through ECU was studied.

• Journal of the Korea Institute of Building Construction
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• v.13 no.6
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• pp.609-618
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• 2013

The unit modular construction system is a building technique in which unit modules are manufactured at a factory and then assembled at the construction site. It has many benefits, including reduction of the construction period and improvement in quality. For this reason, it is utilized for various purposes in Japan and England. While it has been introduced in Korea, there have been few Korean studies conducted on the unit modular system. In particular, little research has been done on the method of safely fixating the unit modules to a truck. Therefore, this study reviewed the fixation methods of unit modules for transport, analyzed the problems, and designed a fixation device for unit modules. In addition, a device for the fixation of unit modules to a truck was developed, and a structural simulation was implemented for a safety test by considering the maximum stress generated during the transport of the unit modules fixed on a truck. When the device for the fixation of unit modules is manufactured based on the results of the structural simulation done in this study, it is expected to aid the development of a more practical fixation device for unit modules.

• Journal of Mechanical Science and Technology
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• v.20 no.12
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• pp.2087-2093
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• 2006

In this paper, auto focus actuator, which is used to move a lens module in the mobile phone having a camera module, is developed. Camera module containing auto focus actuator requires to minimize total size because of characteristics of the application area such as mobile phone, digital camera, and personal digital assistant. There are stepping motor, voice coil motor, and piezoelectric motor as auto focus actuator. In this paper, voice coil motor having new electromagnetic configuration is proposed. And actuator using proposed voice coil motor is developed by optimal design method using magnetic circuit analysis. The sectional area of the developed actuator is reduced to 32.4% compared with actuator using general electromagnetic configuration. From the performance test, the developed actuator has moving stroke of 0.64 mm for 2.1 volt, hysteresis of 40 $\mu$m, full stroke current of 54 mA, and unit step motion of 3 $\mu$m.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.3
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• pp.36-46
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• 1993

In CVT vehicle, the engine speed is completely decoupled from the vehicle speed within the range from maximum transmission ratio to minimum transmission ratio. This allows the engine to operate in optimal state(e.g. best fuel economy or maximum power mode.) In this study, the CVT control algorithm for optimal operation of engine is suggested. In order to implement the real time digital control of electro-hydraulic CVT system, a software called CVTCON has been developed. CVTCON also includes the CVT operation module, (2) system test module, (3) system control module and (4) data management module. By using the CVTCON and the electro-hydraulic CVT system, two modes of experiments were carried out: constant throttle opening mode and acceleration mode. From the experimental result, it was found that the algorithm suggested in this study showed optimal operation of the CVT system.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.8
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• pp.836-844
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• 1991

PLC(programmable logic controller) system is widely used for the control of factory. PLC system receives ladder diagram which is drawn by the user to implement hardware logic, converts the ladder diagram into sequence program which is executable in the PLC system, and executes the sequence program indefinitely unless user breaks. The sequence program processes the data of on/off signal, and endures 1 scan delay and missing of pulse-type signal shorter than a scan time. So, data dependency doesn't exist. By applying theis characteristics to multiprocessor architecture, we design parellel PLC functionally and evaluate performance upgrade. Parallel PLC consists of central processing module, N general processing unit, and a shared memory by master-slave type. Each module executes allocated sequence program by the control of central processing module. We can expect performance upgrade by parallel processing, and reliability by relocation of sequence program when error occurs in processing module.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.118-122
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• 2002

This paper is concerned with the design of the beam forming module that is a key unit of the active phased array antenna(APAA) system for mobile satellite communications. This module includes two blocks for main signal and tracking signal. Main signal block has the role of transmitting input signal from phased away antenna to tracking signal block. And, tracking signal block executes main roles, beam forming of tracking signal and electronic beam control. The several electrical performances of this module, phase characteristics and linear gain, etc., agreed with specifications needed for APAA, and for more clear verification of the performances, the satellite communication test of the APAA including the modules was accomplished in the outdoors.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.8
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• pp.1776-1784
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• 2003

In this paper, we propose the architecture of stream producer for MPEG­4 Video encoding. This module receives the quantized coefficient from DCT and Quantization module in macroblock unit and performs the VLC coding according to the encoding mode, and supports the error concealment mode of MPEG­4 and data partitioning mode. Using the VHDL, we designed the module using this architecture and performed the evaluations of this module by performing the post­-simulation.