• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.7 s.110
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• pp.665-672
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• 2006

In this paper, we propose and fabricate the dual-band microstrip patch antenna with parasitic patch for S-DMB(Satellite-Digital Multimedia Broadcasting) and ITS (Intelligent Transport System) services. The measured - 10 dB bandwidth and the minimum return loss is 300 MHz and - 27 dB for S-DMB, 600 MHz and -17 dB for ITS, respectively. It is noticed that the measured and simulated results are agreed well. The S-DMB antenna has conical beam pattern in the vertical plane and has omni-directional beam pattern in the horizontal plane. The conical beam pattern has the maximum gain about 4.2 dBi when ${\theta}$ is $45^{\circ}$ at the center frequency of 2.6 GHz. The ITS antenna has directional beam pattern in the vertical plane that has maximum gain about 6.4 dBi when ${\theta}$ is $0^{\circ}$ at the center frequency of 5.8 GHz.

• Transactions on Electrical and Electronic Materials
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• v.16 no.3
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• pp.124-129
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• 2015

Organic electronics are the domain in which the components and circuits are made of organic materials. This new electronics help to realize electronic and optoelectronic devices on flexible substrates. In recent years, organic materials have replaced conventional semiconductors in many electronic components such as, organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs) and organic photovoltaic (OPVs). It is well known that organic light emitting diodes (OLEDs) have many advantages in comparison with inorganic light-emitting diodes LEDs. These advantages include the low price of manufacturing, large area of electroluminescent display, uniform emission and lower the requirement for power. The aim of this paper is to model polymer LEDs and OLEDs made with small molecules for studying the electrical and optical characteristics. The purpose of this modeling process is, to obtain information about the running of OLEDs, as well as, the injection and charge transport mechanisms. The first simulation structure used in this paper is a mono layer device; typically consisting of the poly (2-methoxy-5(2'-ethyl) hexoxy-phenylenevinylene) (MEH-PPV) polymer sandwiched between an anode with a high work function, usually an indium tin oxide (ITO) substrate, and a cathode with a relatively low work function, such as Al. Electrons will then be injected from the cathode and recombine with electron holes injected from the anode, emitting light. In the second structure, we replaced MEH-PPV by tris (8-hydroxyquinolinato) aluminum (Alq₃). This simulation uses, the Poole-Frenkel -like mobility model and the Langevin bimolecular recombination model as the transport and recombination mechanism. These models are enabled in ATLAS- SILVACO. To optimize OLED performance, we propose to change some parameters in this device, such as doping concentration, thickness and electrode materials.

• Journal of Broadcast Engineering
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• v.23 no.2
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• pp.261-273
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• 2018

As progress on image processing, computer vision and display technologies aroused market's interests on generation and consumption of various types of media, interests on UWV media are also increasing. In context of consumption of UWV media, to effectively manage load of servers and resources of end terminal devices and provide user-derived services, technology which enables users to select and consume interested regions of media seems to be needed. Here, this paper proposes a method for description and transmission of spatial relationships among media, which composes UWV, by expanding MPEG-CI and Layout signaling to enable users' selective consumption of UWV media.

• 한국ITS학회:학술대회논문집
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• 2008.11a
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• pp.585-589
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• 2008

• Journal of the Korean Ceramic Society
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• v.49 no.4
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• pp.397-397
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• 2012

• Proceedings of the Korean Vacuum Society Conference
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• 2009.02a
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• pp.235.1-235.1
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• 2009

• Journal of Korea Technology Innovation Society
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• v.1 no.1
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• pp.96-105
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• 1998

Electronic cash affects central bank in many areas, in particular regarding the issuance of money, supervision of cashless payments, supervision of the banking system and monetary policy. The effects of electronic cash on central bank policies, the security and integrity of the payment system, and naturally also on single sector such as company engaged in the transport of money and valuables, depend mainly on the extent to which the new payment methods can replace cash. The possible development of electronic cash merits special attention from central banks for at least three reasons. First, central banks are concerned that the introduction of the new payment instrument should have no adverse effect on public confidence in the payment system and payment media. Second, although the substitution of electronic cash for other forms of money should not theoretically hamper central bank's ability to control the money supply, it might, however, have practial implications, at least in the long run, which need to be carefully examined. Third, because electronic cash may be used for payments of very small value, they have the potential, more than any other cashless instrument, to take over the role of notes and coins in the economy and, therefore, have implications for central bank's activities and revenues.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1425-1427
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• 2008

디지털 사회에서는 정보 기술의 발전에 따른 다양한 디지털 컨텐츠들이 필요하고 수많은 디지털 컨텐츠들이 다양한 용도로 사용되고 있다. 그러나 불법복제로 인해 저작권자의 지적재산권을 침해받는 문제가 부각되면서 디지털 컨텐츠의 저작권을 보호하기 위한 많은 기술들이 개발되고 있다. 그 중 DRM은 가장 최적의 기술로 평가되고 있으며 이미 다양한 분야에서 사용되고 있다. DRM을 구성하는 기술 중에 인증기술은 불법복제를 방지하고 저작권을 보호하기 위한 핵심기술이다. 본 논문에서는 DRM의 기존 인증기술들이 가지고 있는 문제점을 해결하기 위하여 RFID기술을 이용하였다. 제안한 인증 기법은 RFID 태그에 저장된 디지털 컨텐츠의 인증 정보와 디지털 컨텐츠에 저장되어진 인증 정보를 주기적으로 비교하여 인증 여부를 결정한다. RFID 태그는 쉽게 복제될 수 없기 때문에 디지털 컨텐츠의 저작권을 효과적으로 보호할 수 있다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.5
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• pp.338-343
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• 2015

Dye sensitized solar cells (DSSCs), which is one of the contending renewable energy sources, have the problem of low efficiency. To improve the efficiency, the fast electron transport and long electron lifetime are required. In this study, one-dimensional sodium hexatitanate, which is expected to have an advantageous structure for electron transports, was synthesized and the feasibility of the material on DSSC was tested. Its physical properties were characterized by the SEM, XRD, and BET method. The dye adsorption and solar cell properties were also characterized. In addition to the expectation of fast electron transport, sodium hexatitanate showed longer electron lifetime: This means sodium hexatitanate can improve the DSSC efficiency. However, it showed low current and voltage because of the low surface area leading to the low amount of dye adsorbed. Therefore, it should be mixed with titanium oxide with high surface area for the optimal performance.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.675-679
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• 2004

The existing conjugated blue emitting material polymer which has been used for the two-wavelength method white-emission has good stability and low operating voltage as merits, but the imbalanced carrier transport has been indicated as problem area. We have introduced a novel blue emitting material having perylene moiety unit with hole transporting ability and blue emitting property and triazine moiety unit with electron transporting ability into the same host chain. We have synthesized N-[p-(perylen-3-y1)pheny1]methacry1 amide (PPMA) monomer and [N-(2,4-dipheny1-1,3,5-triazine)pheny1 methacry1 amide] (DTPM) monomer having blue light-emitting unit and electron transport unit, respectively by three steps. A novel non-conjugated blue emitting material Poly[N -[p­(perylene-3-y1) pheny1] methacry1 amide-co-N-[P-(4,6-dipheny1-1,3,5-triazine-2-y1]pheny1]methacry1 amide] (PPPMA-co-DTPM) copolymer having electron transporting unit was synthesized by the solution polymerization of PPMA and DTPM monomers with an AIBN initiator and showed high yield of $75{\%}$. It was very soluble in common organic solvents, and the fabrication of the thin film using a spin coating method was very simple. The PPPMA exhibited a good thermal stability.