• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.55-58
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• 2001

In this paper, we present the results of the design and fabrication of the VCO(Voltage controlled Oscillator) using RF circuit simulator GENESYS and electromagnetic field simulator EMpower Frequency range is fabricated VCO is 850 MHz ~ 950 MHz, which is used Colpitts Circuit. the fabricated VCO is consisted of resonator, oscillator and MSL(Microstrip Line) is used in LC tuning circuit.(operated by negative feedback) MSL(Microstrip Line), Varactor(Plastic package), low noise TR(SOT-23), chip inductor(1608), chip capacitor(1005), chip resistance(1005). 1005 type is used for sample fabrication of VCO. In the fabrication process, circuit pattern is screen printed on the alumina substrates of over 99.9% purity. Center frequency of the sample VCO is 850MHz at $V_T=1.5V$, while the simulated value was 1.0GHz at $V_T=1.5V$. Variable frequency range of the sample is 860~950MHz in contrast to the 1068~1100MHz of the simulated values.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.153-156
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• 2001

In this paper, we present the results of the design and fabrication of the VCO(Voltage controlled Oscillator) using RF circuit simulator GENESYS and electromagnetic field simulator EMpower Frequency range is fabricated VCO is 850 MHz ~ 950 MHz, which is used Colpitts Circuit. the fabricated VCO is consisted of resonator, oscillator and MSL(Microstrip Line) is used in LC tuning circuit.(operated by negative feedback) MSL(Microstrip Line), Varactor(Plastic package), low noise TR(SOT-23), chip inductor(1608), chip capacitor(1005), chip resistance(1005). 1005 type is used for sample fabrication of VCO. In the fabrication process, circuit pattern is screen printed on the alumina substrates of over 99.9% purity. Center frequency of the sample VCO is 850MHz at $V_T$=1.5V, while the simulated value was 1.0GHz at $V_T$=1.5V. Variable frequency range of the sample is 860~950MHz in contrast to the 1068~1100MHz of the simulated values.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.444-454
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• 2017

Stop-motion animation is highly valued for realistic imagery and its ability to captivate the five senses of the audience. Despite this, practical research in this area is limited to date. The long hours required to produce stop-motion animation and turn these into profits can be attributed for the lack of knowledge in this area. In production research, the matter is made worse as it is difficult to protect the intellectual property made through the collaborated efforts of students and teaching staff through each laborious stage of planning, broadcasting and making 2D models. Meanwhile as the animation industry finds the investigation of new production processes taxing, it has maintained its focus on pre-existing processes such as the use of pipeline. This paper aims to shed light on new production methods that can be used to improve the effectiveness of existing stop-motion production. In addition, by working with Taktoon Enterprises on its T.V series Galaxy Kids the paper will revise real world production methods including the traditional use of hand made models. Thus by investigating the use of graphic technology such as 3D printing the paper will be able to extend current business models. Research conducted in this paper is a necessary part of overcoming various contents production obstacles. Furthermore, it may help publicize issues faced in production leading to the discussion and sharing of new innovations.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.4
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• pp.631-646
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• 2020

The government is pursuing a policy to remove plug-ins for public and private websites to create a convenient Internet environment for users. In general, financial institution websites that provide financial services, such as banks and credit card companies, operate fraud detection system(FDS) to enhance the stability of electronic financial transactions. At this time, the installation software is used to collect and analyze the user's information. Therefore, there is a need for an alternative technology and policy that can collect user's information without installing software according to the no-plug-in policy. This paper introduces the device fingerprinting that can be used in the standard web environment and suggests a guideline to select from various techniques. We also propose a user authentication model using device fingerprints based on machine learning. In addition, we actually collected device fingerprints from Chrome and Explorer users to create a machine learning algorithm based Multi-class authentication model. As a result, the Chrome-based Authentication model showed about 85%~89% perfotmance, the Explorer-based Authentication model showed about 93%~97% performance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1521-1527
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• 2010

Since inkjet printing is being employed in production lines of electronics and display industries, the tack time for inspection of jetting failure has become very important because the throughput of the inkjet printing system can be extended to the maximum limit by adopting a shorter jetting inspection time. The most popular method for inspecting jetting failure involves the use of a linear stage, a high magnification lens, and a charge coupled devicecamera. However, this conventional approach requires approximately 60 s to complete the jetting inspection and might not be suitable for a high-speed reciprocating jetting inspection in endurance tests due to the unwanted mechanical vibration. In this study, a novel concept of an inkjet monitoring module is introduced, which has an overall inspection time of 18 s. For the shorter tack time of jetting inspection, the parameters affecting the tack time are discussed in this paper.

• 프린팅코리아
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• v.7 no.8
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• pp.98-99
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• 2008

대한인쇄정보기술협회와 월간 인쇄계가 주최한 제4회 국제인쇄기술컨퍼런스가 지난 7월 11일 서울 소피텔앰배서더호텔에서 인쇄 및 관련업계 관계자 300여명이 참석한 가운데 열렸다. 이날 컨퍼런스는 오성상 신구대학 교수의 진행으로 이어졌다. '드루파 2008을 통해 본 인쇄산업시장의 전망'을 주제로 열린 이번 컨퍼런스에서 김진배 대한 인쇄기술협회 회장은 인사말을 통해 "4회째를 맞은 국제인쇄기술컨퍼런스는 인쇄 각 분야 전문가들의 경험과 노하우를 공유하고 전 세계 인쇄산업의 최신 기술과 정보를 교류하는 기회의 장으로 인쇄기술의 발전에 기여해 왔다"며, "지금 인쇄산업은 미디어와의 융합을 통해 새로운 가치를 창조해내고 있어 이제 더 이상 인쇄가 고전적인 가치에만 머물러 있지 않다는 것을 의미 한다"고 말했다. 김 회장은 이어 "인쇄산업은 기존의 수준에만 머물러 있어서는 안 되며 전 세계적인 변화의 추세에 발맞춰 철저한 준비와 노력이 필요할 뿐 아니라 새로운 비전을 찾을 수 있도록 인쇄산업인 모두의 지혜를 모으는 데 힘을 쏟아야 할 것"이라고 말했다. 이어진 인사말에서 안정웅 월간인쇄계 발행인은 "이번 제4회 국제인쇄기술컨퍼런스는 각 인쇄분야에 있어 더욱 깊은 기술동향 정보를 제공할 것이며 드루파 이후 향후 4년 동안 인쇄산업을 이끌어 나갈 제품과 그 기술들을 만나보고 향방을 점쳐보는 기회가 될 것"이라고 말했다. 홍우동 대한인쇄문화협회 회장은 축사를 통해 "대내외적인 어려움에 직면해 있는 인쇄업계가 어려움을 극복하기 위해 인쇄인은 물론 기자재 공급업체와 언론계, 인쇄단체가 하나 된 마음으로 난관 극복을 위한 지혜를 발휘해야 할 때"라며 "올해부터 발효되고 있는 인쇄문화산업진흥법에 근거해 인쇄문화산업진흥위원회가 활동하는 한편으로 대한인쇄문화협회를 중심으로 정부와 국회가 머리를 맞대고 인쇄업계 발전을 위한 대책을 마련하고 있으며 특히 인쇄종주국으로써 세계적으로 빛나는 우리나라의 인쇄문화 유산과 세계인쇄 사료를 한 그릇에 담을 수 있는 가칭 '세계인쇄문화박물관'건립을 추진하고 있다"고 말했다.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.123-130
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• 2020

Prior to the introduction of automated systems such as jewelry CAD and CAM, the jewelry manufacturing industry had many originals made by hand. However, after the introduction of the automated system, original craftsmen with high technology have disappeared, and computer designers and 3D printing print engineers are taking their place. The introduction of automated systems such as CAD and CAM in the existing hand-made production line has resulted in diversification of designs and cutting-edge and specialization of jewelry manufacturing. In the domestic jewelry industry, the dependence of automation systems such as CAD and CAM in the manufacturing process continues to increase, and the situation is taking up more and more parts in the jewelry design curriculum of universities. From these results, the CAD/CAM automation system field in the jewelry manufacturing industry becomes an essential and important field in the future.

• Journal of the Korea Institute of Building Construction
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• v.17 no.1
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• pp.83-90
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• 2017

Recently, BIM has been actively adopted in construction projects and industries, and also integrated with Information and Communications Technology(ICT) such as cloud computing technology, sensor technology, 3D scanning and printing technology etc. However, it is very difficult to efficiently utilize BIM services, technologies and collaborate with each other because of differences of usage and requirements of technologies. Every participant in the same construction project has their own needs, requirements and details of the model in each phase. In order to enhance utilization BIM model, BIM services and technologies required in their project have to be clearly defined in the initial stage of the project. In order to support the owner to define the BIM level, BIM service level and application technologies are identified and guidelines how to define the level and technologies for their project purpose are suggested in this study.

• Journal of Platform Technology
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• v.8 no.1
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• pp.24-32
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• 2020

This paper designed and manufactured a chip mounter based on 3D printer technology that can be used for educational research or sample production to disseminate chip mounter, a core technology of SMT line. A stepper motor with open loop control is used for low cost drive design. The shortcomings of the motor's vibration and disassembly caused by the use of the step motor were compensated by the Micro-Step control method. In the chip mounter experiment, the gerber file was generated on the small chip mounter, printed at the actual size, and the solder cream was printed on the HASL-treated PCB in the same manner as the sample board fabrication. As a result of the experiment, unlike the 2012 micro components, parts such as SOIC and TQFP that require correction are twice as long as the component mounting time, but it can be confirmed that they are mounted relatively accurately. In addition, as a result of repeatedly measuring the error of the initial position 10 times, it was confirmed that a relatively small error of about 0.110mm occurs.

• Tribology and Lubricants
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• v.38 no.1
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• pp.27-31
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• 2022

Harmonic drives have attracted increasing attention with the development of materials, parts, and related equipment. Harmonic drives exhibit high deceleration, high accuracy, and light weight. The stiffness of flexible splines according to the radial load is studied using a commercial FEM program to design the structure of the flexible spline and finite element to improve the weight and price competitiveness of harmonic drives. In addition, several studies have measured and compared friction coefficients based on 3D printed tread patterns. However, owing to the characteristics of plastic materials, a decrease in stiffness in the radial direction is inevitable. To prevent a decrease in stiffness in the radial direction, we designed and manufactured flex splines with a wrinkle shape. Through structural analysis, the reaction force and stiffness in the radial direction were determined. In addition, the maximum angle of the mound was derived by theoretical calculations, and the performance of the harmonic drive was compared with the results obtained in the mound experiment. Structural analysis shows that the shape of wrinkles decreased the stress and reaction force and increased the safety factor in comparison with that of the circular shape. During performance verification through continuous experiments, the developed harmonic drive showed continuous performance similar to that of an actual tank model. It is expected that the flex spline with a compliant spring and wrinkle shape will prevent a decrease in the radial stiffness.