• Special Issue of the Society of Naval Architects of Korea
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• 2009.09a
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• pp.115-122
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• 2009

In shipbuilding process, automated marking systems are used to print steel part information on the steel plate. Especially, an automated marking system with a moving ink-head prints characters on each block, which divide the steel plate into a fixed size. Therefore it is necessary to split characters, because some characters can be extended into several blocks. Particularly the algorithm, which splits characters, must guarantee its printing quality in any direction since characters can be printed by any angle.

• Ceramist
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• v.23 no.1
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• pp.4-15
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• 2020

The recent advances and popularity of 3D printing technology have centered around building polymerbased 'plastic' materials, due to their low cost, simple and efficient processing, and mechanical toughness. For this reason, printable polymers are actively recruited to create 'ceramic resins' that allow more facile fabrication of ceramic materials that are difficult to print directly. Herein, a brief history and the current state of ceramic 3D printing technology aided by polymer is summarized. In addition, a new ceramic 3D printing technology using polymer-derived ceramics (PDC) is also introduced.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.961-964
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• 2007

본 논문에서는 FEM (Finite Element Method)을 이용한 압전세라믹의 특성해석을 통하여 잉크젯 프린트헤드를 설계, 제작하였다. 압전세라믹의 물질특성과 잉크유체 특성을 고려한 굽힘 모드방식의 구동원리와 이론정립을 하였다. 압전방정식은 압전구조에 의한 공진주파수로 압전 파라미터를 구할 수 있고, 실험을 통하여 이러한 측정값을 얻을 수 있었다. 제작된 압전세라믹 프린트헤드의 잉크드롭 실험결과 통하여 이에 대한 특성을 알 수 있었다. 이때 잉크유체의 음파와 압전 공진주파수 범위 내에서 압전세라믹 응력(변형)의 이득을 발생할 수 있음을 제작한 128노즐의 압전세라믹 잉크젯 프린트헤드로부터 알 수 있었다.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.862-866
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• 2002

This study was performed to analyze aroma pattern of Panax species (Korean Panax ginseng C.A. Meyer, Chinese Panax ginseng C.A. Meyer, Panax quinquefolium L, and Panax notoginseng F.H. Chen) by the PHGC (potable handheld gas chromatograph). Ratios of several peak areas in chromatogram of derivative parrtern were as follows. If ratio of Korean Panax ginseng was 1, Panax notoginseng was $0.030{\sim}0.674$, Chinese Panax ginseng was $0.005{\sim}0.212$ and panax quinquefolium was $0.241{\sim}0.871$. Ratios of peak area at $Rt_{20.02}$ were that if Korean panax ginseng was 1, Chinese Panax ginseng was 0.212, Panax quinquefolium was 0.343 and Panax notoginseng was 0.065. Ratios also of peak area at $Rt_{21.70}\;and\;Rt_{24.90}$ showed clear difference among aroma patterns of Panax specie cultivars. Flavor component at $Rt_{26.15}$ was not detected in Panax quinquefolium and Panax notoginseng but in Korean Panax ginseng and Chinese Panax ginseng. Ratios of peak area at $Rt_{26.15}$ were that if Korean Panax ginseng was 1, Chinese Panax ginseng was 0.185. And so habitat of Panax species cultivars was discriminated. Cultivar and habitat of dried panax species was remarkably distinguised by the chromatogram of frequency pattern, derivative pattern and visual pattern using olfactory images known as Vapor $print^{TM}$.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2563-2566
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• 2007

TFT LCD industries have endeavored to adopt the piezo Drop-On-Demand (DOD) inkjet printing technology to production lines of TFT LCD color filters and these efforts have significantly been based on experimental works. Because the degree of complexity in the piezo DOD inkjet printing technology results in too many combination of parameters, the matrix experimental method to investigate all possible sets of parameters becomes ineffective and hence the basic understanding of the piezo Drop-On-Demand inkjet print technology becomes important. In this study, one possible cause of the droplet volume variation across nozzles, which might cause visible swathe marks on an inkjet patterned TFT LCD color filter, is theoretically investiaged and new R&D directions are suggested.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.113-120
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• 2009

Through the automatic sensing of the environment, USN technology can give the best services. In this work, we have developed an active RFID system and examined its performance. By implementing it into water quality sensors, we constructed a system that can detect diverse indoor/outdoor environment and provide information about the pollution level obtained from the temperature and PH sensors. Our RF system had an internal Print-on-PCB antenna for the miniaturization of the tag. We used a RF transceiver CC2510 chipset of TI company to realize the active RFID function. By using RSSI constants obtained, we performed the evaluation of real time location accuracy with a software written in Labview. Among 10 arbitrary locations, we obtained average measurement errors of 1.69 m in x axis and 1.66 m in y axis. This technology can be applied to logistics, environmental monitoring, prevention of missing children and various applications.

• Journal of Drive and Control
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• v.16 no.3
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• pp.51-58
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• 2019

The objective of this study was to investigate a simulation technology for the AM field based on ANSYS Inc.. The introduction of metal 3D printing AM process, and the examining of the present status of AM process simulation software, and the AM process simulation processor were done in the previous study (part 1). This present study (part 2) examined the use of the AM process simulation processor, presented in Part 1, through direct execution of Topology Optimization, Ansys Workbench, Additive Print and Additive Science. Topology Optimization can optimize additive geometry to reduce mass while maintaining strength for AM products. This can reduce the amount of material required for additive and significantly reduce additive build time. Ansys Workbench and Additive Print simulate the build process in the AM process and optimize various process variables (printing parameters and supporter composition), which will enable the AM to predict the problems that may occur during the build process, and can also be used to predict and correct deformations in geometry. Additive Science can simulate the material to find the material characteristic before the AM process simulation or build-up. This can be done by combining specimen preparation, measurement, and simulation for material measurements to find the exact material characteristics. This study will enable the understanding of the general process of AM simulation more easily. Furthermore, it will be of great help to a reader who wants to experience and appreciate AM simulation for the first time.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.7 s.184
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• pp.168-176
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• 2006

Nowadays, Three dimensional printing (3DP) technique that is one of solid freeform fabrication (SFF) technology has been notable issue, and has been applied by various fields. The SFF system can fabricate three dimensional objects of solid freeform with high speed and low cost using ink jet printing technology. In this research, a SFF system to analyze 3DP process technology is developed. We applied sliding mode control with sliding perturbation observer (SMCSPO) algorithm and minimized position error to the developed SFF system. We analyzed and optimized process variables such as jetted volume, layer thickness, powder bed and so on experimentally. Also. the dimensional error of a developed SFF system is evaluated. Finally, the feasibility of application to bio manufacturing is presented through successful fabrication of teeth and cranium model.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.09a
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• pp.165-172
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• 2003

Wafer-level packaging technology has become established with increase of demands for miniaturizing and realizing lightweight electronic devices evolution. This packaging technology enables the smallest footprint of packaged chip. Various structures and processes has been proposed and manufactured currently, and products taking advantages of wafer-level package come onto the market. The package enables mounting semiconductor chip on print circuit board as is a case with conventional die-level CSP's with BGA solder bumps. Bumping technology is also advancing in both lead-free solder alternative and wafer-level processing such as stencil printing using solder paste. It is known lead-free solder bump formation by stencil printing process tend to form voids in the re-flowed bump. From the result of FEM analysis, it has been found that the strain in solder joints with voids are not always larger than those of without voids. In this paper, characteristics of wafer-level package and effect of void in solder bump on its reliability will be discussed.

• Journal of Institute of Convergence Technology
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• v.7 no.2
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• pp.21-23
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• 2017

Smart Factories could be regarded as a result of the integration of various key technologies of the fourth industrial revolutions. In smart factory, the IoT (Internet of things) is applied to capture the data generated by the production facility, store and analyze data generated in real time using Big Data technology. In addition, 3D printers are used to print expensive and complex parts, industrial robots supply materials and parts to the production site, store finished products in warehouses. In this paper, we introduced the definition of smart factory and change of job market. Also, we summarize several national policies to support enhancing transformation process of smart factory.