• International Journal of Precision Engineering and Manufacturing
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• v.5 no.3
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• pp.69-76
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• 2004

Polishing a die that has free-form surfaces is a time-consuming and tedious job, and requires a considerable amount of high-precision skill. In order to reduce the polishing time and cope with the shortage of skilled workers, an automatic polishing robot system was developed. The polishing robot system is composed of two subsystems, a three-axis machining center and a two-axis polishing head. The machining center is controlled by a FANUC controller, and the polishing head by DSP controller. The system has five degrees of freedom and is able to keep the polishing tool normal to the die surface during operation. To easily operate the developed polishing robot system, this study developed an integrated operating program in the Windows environment. The program consists of five modules: a polishing data generation module, a code separation module, a polishing module, a graphic simulator module, and a teaching module. Also, the automatic teaching system was developed to easily obtain teaching data and it consists of a three dimensional joystick and a proximity sensor. Also, to evaluate the performance of the integrated operating program and the polishing robot system, polishing experiments of a die of shadow mask were carried out.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.222-223
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• 2006

In this paper, we manufactured high flux LED module with Through Hole type. and we measured electrical, optical and thermal properties by driving type. LED module was composed with 8*8 arrangement form by using the glass epoxy PCB. Also, we measured the most suitable driving type with static voltage driving type and static current driving type. As a result, the LED Module of static voltage driving type showed high luminance characteristic than the static current driving type by suppling enough bias. However, the static current driving type showed more stable driving properties because of fast decreasing properties about brightness by increasing the surrounding temperature in the static voltage driving type. Also, due to Quantum confined Stark effect from piezoelectric field, the wavelength of bule peak shifted to long wavelength direction by increasing the surrounding temperature in the static voltage driving type.

• Journal of the Ergonomics Society of Korea
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• v.27 no.3
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• pp.43-52
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• 2008

Human errors are now considered as the most significant source of accidents or incidents in large-scale systems such as aircraft, vessels, railway, and nuclear power plants. As 61% of the train accidents in Korea railway involving collisions, derailments and fires were caused by human errors, there is a strong need for a systematic research that can help to prevent human errors. Although domestic railway operating companies use a variety of methods for analyzing human errors, there is much room for improvement. Especially, because most of them are based on written papers, there is a definite need for a well-developed computerized system supporting human error analyzing tasks. The purpose of this study is to propose a framework for a computerized human error analysis system focused on the railway industry on the basis of human error analysis mechanism. The proposed framework consists of human error analysis (HEA) module, similar accident tracking (SAT) module, cause factor recommendation (CFR) module, cause factor management (CFM) module, and statistics (ST) module.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.3
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• pp.41-47
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• 2008

This paper describes a wearable electro-stethoscope module for home-healthcare system. The module is consisted of a microphone, an instrumentation amplifier, a filter, a power amplifier etc. and is light and small. The phonogram signal from the module shows good performance. The test for the material and size of the sound collector of the chest piece is performed and the results is reflected on the prototype product. If the module is connected to wired or wireless communication network, so people can check their health without going hospital.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.12
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• pp.986-991
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• 2018

In this paper, an A/D conversion module was designed and fabricated to improve the dynamic range of wideband digital receivers. The A/D conversion module for expanding the dynamic range converts signals into a digital signal by branching the input signal into the normal path and the amplification path according to the input signal level. Test results of the fabricated module show that the normal path of the A/D conversion module converts an input level of -57 dBm to -12 dBm into a digital signal, and the amplification path converts an input level of -30 dBm to +12 dBm into a digital signal without distortion. This translates to an input dynamic range characteristic of 69 dB. Moreover, it is confirmed that the constant output characteristic is exhibited at an instantaneous bandwidth of 100 MHz.

• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.112-116
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• 2022

The demand for a rear reflective material is continuing according to the expansion of the bifacial soar module and the effect on the re-reflection of the ground using a back sheet that is not used due to the increase in the supply of the bifacial solar module was confirmed. For analysis, a bifacial solar module with an output of 445W was connected to a single inverter of 49.84kW, and analysis of each two inverters was carried out. In the analysis of the results, it was confirmed that the generation amount increased by 5.25% compared to the case where the back sheet reflective film was not installed and it was confirmed that the increase in the generation amount was the noon time when strong solar radiation was irradiated, not the time of sunrise and sunset.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.744-748
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• 2000

The characteristics of $CO_2$ exchange between plant and human modules, absorption rate of NO$_2$, and growth of lettuce were examined in an urban-type plant factory(UPF). With 150 lettuce plants, $CO_2$ concentrations of plant module were 600 ~ 700$\mu$mol mol$^{-1}$ at average leaf weight of 130g.plant$^{-1}$ and 900~1100$\mu$mol.mol$^{-1}$ at 75g.plant$^{-1}$ for one and two persons' stay in the human module, respectively. When the air of 0.13, 0.30 and 0.45 $\mu$molㆍmol$^{-1}$ NO$_2$ in a human module was circulated ON/OFF 10/20min between the human and plant modules, $NO_2$ decrement in the chamber during 10 min was 0.040, 0.109, and 0.149 $\mu$mol, respectively. The lettuces grown at 0.45 $\mu$molㆍmol$^{-1}$ $NO_2$ during experimental period showed no significant differences in growth factors such as leaf width, leaf length, leaf area and fresh weigh, and in the quality between treated and control.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.659-661
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• 2013

This paper, we study on multiple wireless network module support for the Android based set-top box. Limitation of mobile OS, Android based set-top box has limited choice of various wireless network modules, Atheros, Realtek, Ralink, etc. In this paper, for the request of Set-top box supplier and market demands, we research on reconfigure & change the Android network HAL(Hardware Abstract Layer) for Wi-Fi networking support and implementation about multiple Wi-Fi module support platform.

• The Transactions of the Korea Information Processing Society
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• v.4 no.1
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• pp.67-75
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• 1997

This paper presents a virtual-parallel multistage interconnection network (MIN) which provides multipath between processor and memory module. The proposed virtual-parallel MIN network which uses $m{\times}1$ mutiplexer at the input switching block, $1{\times}m$ demultiplexer at the output switching block and logN-1 switching stages has maximum $2{\times}m$ unique paths between processor and memory module. Because it has multi-redundance paths, a number of processors can connect a specific Also, this new virtual-parallel structured MIN network can reduce packet collision possibility at switching block and it has cost. It shown to improve a performance and to be a very simple structure in comparision with MBSF structured MIN.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.5
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• pp.523-528
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• 2012

A bendable electronic module is developed for a mobile application by using a low-cost roll-to-roll manufacturing process. In the module, a thin silicon chip is embedded in a polymer-based encapsulating adhesive between flexible copper clad polyimide layers. A set of tests are conducted for the purpose of qualification: thermal shock, high temperature storage, and autoclave tests. During the autoclave test, delamination occurs at many places within the module layers. To investigate the failure mechanism, moisture diffusion analysis is conducted for the interior of the module under the autoclave test condition. For the analysis, the hygroscopic characteristics of the encapsulating materials are experimentally determined. Analysis results indicate the moisture saturation process in the interior of the module under the autoclave test condition.