• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.110-114
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• 2003

In this paper, a new self-oscillated type high voltage charger controller circuit is proposed, which has variable constant current source characteristics to improve charge characteristic of charger roller. The proposed control method enables high quality printing characteristics regardless of the circumstance change such as ambient temperature or humidity by changing the current reference signal. To verify the proposed control method various experiments are performed.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.338-341
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• 1997

The current consumption and the heat produced in the printhead of thermal printer are mainly governed by total printing dots and printing time for each line. Simple algorithm is proposed to optimize the performance of a thermal printhead, which use variable division according to bit-mapped data of its 1 line. And, for protecting the thermal printhead from exceeding heat, I control the heat energy of each microheater(dots) on the thermal printhead through changes in the applied pulse width.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.2
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• pp.105-111
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• 2004

In this paper, a new self-oscillated type high voltage power supply for the OPC(Organic Photo Conductor) charge is proposed, which has variable constant current source characteristics to improve the charge characteristic of the OPC roller. The proposed control method enables high quality printing characteristics regardless of the circumstance change such as ambient temperature or humidity by changing the current reference signal. To verify the proposed control method various experiments are performed.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.635-638
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• 2002

In this paper, the connection device of RS232C and TCP/IP implementation using ARM processor and LINUX is proposed. Data interaction flash memory the multiple serial ports are transferred to ARM processor and the data are processed and formed into data packet for transfer via internet protocol. Packet flash memory Internet is decoded to extract the serial port data. The serial ports supports RS232C asynchronous protocol communication and control program is developed in GNU-C and installed in the on-board memory for packet conversion and control. The research result can be applied to terminal server, printer server and multiple serial ports equipments.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.219-220
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• 2015

본 논문에서는 높은 성능의 속도 제어 특성을 만족하기 위해 위치 기반의 반복제어기를 이용한 속도 제어기를 설계 하여, 레이저 프린터의 OPC 드럼의 속도제어에 적용 하였다. 레이저 프린터 OPC 드럼의 외란은 드럼의 위치에 종속적으로 나타난다. 따라서 위치 기반 반복제어기는 기존의 반복제어기 보다 기준 속도 변동에 강인하며, 레이저 프린터의 다양한 인쇄 속도에 적용 가능하다. 실험 결과, 위치기반 반복 제어기가 기존의 반복제어기 보다 기준 속도 변동에 강인하며 다양한 인쇄 속도에서도 적용 가능함을 보여주었다.

• The Transactions of the Korea Information Processing Society
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• v.3 no.1
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• pp.1-8
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• 1996

A conveyor system in corrugated manufacturing industry may be in charge of carriage/storage, and may control logistics flow and production activities of products in a manufacturing process which consists of corrugators, conveyors, and printer-slotter systems. It identifies problems that the conveyor system in this case study is overloaded and often operated manually. This research is to evaluate e the conveyor system though simulation model of technological evaluation beyond d eco-nomic and qualitative one. The rate of operation and the load of the conveyor system are used as parameters in the simulation. This paper suggests a direction to a new conveyor system implementation the basis of the results that are derived by new alternatives based on current model. The best alternative is supposed to be the number of conveyors and the operation times of the printer-slotter that may be increased at the same time.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.231-237
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• 2017

This paper presents an implementation of a smart flowerpot which can adjust humidity and illumination automatically after monitoring the temperature, humidity, and illumination. We made a container of the flowerpot with a 3D printer and embedded a NodeMCU micro controller in it. We attached a temperature sensor, a humidity sensor, an illumination sensor, and a water pump to the NodeMCU. We developed a control program that adjusts humidity and illumination and ran it on the NodeMCU. Also we developed an Android application and set up an MQTT server. Using the MQTT server, the NodeMCU and the Android application can exchange messages which keep sensor values and commands. Using the Android application. the user can send the proper temperature, humidity, and illumination to the smart flowerpot and monitor the sensor values.

• Journal of Technologic Dentistry
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• v.43 no.3
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• pp.77-83
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• 2021

Purpose: The purpose of this in vitro study was to measure and compare the thickness-dependent color dimensions of digital light processing (DLP) three-dimensional (3D) printer and conventional interim restorative resin. Methods: Specimens (N=60) were fabricated using either subtractive manufacturing (S group) or DLP 3D printing (D group) material. All milled and 3D-printed specimens were allocated into three different groups (n=10) according to different thicknesses as follows: 1.0, 1.5, and 2.0 mm. Color measurements in the CIELab coordinates were made using a spectrophotometer under room light conditions (1,003 lux). The color differences (𝚫E^*) between the specimen and control target data were calculated. Data were analyzed using the oneway analysis of variance (ANOVA). Post hoc comparisons were conducted using Tukey's honestly significant difference method (α=0.05 for all tests). Results: The 𝚫L^*, 𝚫a^*, 𝚫b^*, and 𝚫E^* values of interim restorative resin produced by DLP 3D printing were obtained in terms of the specimen's thickness increased compared with the increases by subtractive manufacturing. When the thickness was similar, the color difference between subtractive manufacturing and DLP 3D printing was ≥5.5, which is a value required by the dentist for remanufacturing. Conclusion: Color was influenced by the thickness of the interim restorative resin produced by DLP 3D printing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.12
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• pp.1645-1652
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• 2018

A drone which was developed first for military purpose has been expanded to various civil areas, with its technological development. Of the drones developed for such diverse purposes, a drone for photography has a camera installed and is actively applied to a variety of image contents making, beyond filming and broadcasting. A drone for photography makes it possible to shoot present and dynamic images which were hard to be photographed with conventional photography technology. This study made a view finder which helps a drone operator to control a drone and directly view an object to shoot with the drone camera. The view finder for drones is a type of glasses. It was developed in the way of printing out the data modelled with 3D MAX in a 3D printer and installing a ultra-small LCD monitor. The view finder for drones makes it possible to fly a drone safely and achieve accurate framing of an object to shoot.

• Journal of Technologic Dentistry
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• v.42 no.4
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• pp.355-361
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• 2020

Purpose: In this study, we added two kinds of photoinitiators (CQ and TPO) to prepare two kinds of denture base resins (Bis-GMA series and UDMA series) for three-dimensional (3D) printing to compare and analyze their mechanical and biological properties and to find the optimal composition. Methods: Control specimens were made using the mold made of polyvinyl siloxane of the same size. Light curing was performed twice for 20 seconds on both the upper and lower surfaces with LED (light emitting diode) light-curing unit (n=10). Experimental 3D printing dental resins were prepared, to which two photoinitiators were added. Digital light processing type 3D printer (EMBER, Autodesk, CA, USA) was used for 3D printing. The specimen size was 64 mm×10 mm×3.3 mm according to ISO 20795-1. The final specimens were tested for flexural strength and flexural modulus, and MTT test was performed. Furthermore, one-way analysis of variance was performed, and the post-test was analyzed by Duncan's test at α=0.05. Results: The flexural strength of both Bis-GMA+CQ (97.12±6.47 MPa) and UDMA+TPO (97.40±3.75 MPa) was significantly higher (p<0.05) in the experimental group. The flexural modulus in the experimental group of UDMA+TPO (2.56±0.06 GPa) was the highest (p<0.05). MTT test revealed that all the experimental groups showed more than 70% cell activity. Conclusion: The composition of UDMA+TPO showed excellent results in flexural strength, flexural modulus, and biocompatibility.