• Proceedings of the KAIS Fall Conference
• /
• 2005.05a
• /
• pp.155-158
• /
• 2005

소규모 독립형 태양광 발전시스템은 최근 대체에너지에 대한 관심이 증가되면서 다양한 형태의 응용제품이 만들어지고 있다. 그러나 설계방법이 체계화되지 않아 태양전지 및 배터리가 필요이상으로 크게 설계되거나 반대로 너무 작게 설계되어 동작이 불안정해지고 잦은 고장의 원인이 되고 있다. 따라서 본 논문에서는 소규모 독립형 태양광발전 시스템의 설계를 위해 태양전지 및 배터리의 용량산정방법과, 부하특성을 고려하여 안정적인 시스템을 설계하기 위한 방안을 제시하고자 한다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.846-849
• /
• 2009

In this study, we manufactured polymer-LED using light emitting copolymer as the active layer. After cathode layer deposition, we did post-annealing at $150^{\circ}C$ during 10 min in $N_2$ glove box. Then, we confirmed that the efficiency of the device was significantly enhanced by post annealing process. Its value was increased from 0.18(cd/A) to 1.32(cd/A), approximately 7 times. This phenomenon is a result of improved stability between polymer and metal cathode for injection of electrons as the contact density increases.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.265-268
• /
• 2009

The discharge condition of Plasma display panel(PDP) changes as the display time increases. Imaginary part of permittivity of dielectric material which is related to dielectric loss has been often neglected because of relatively small value compare to that of the real part. The thermal characteristics of PDPs with two different dielectrics has been studied and compared.

• Proceedings of the KAIS Fall Conference
• /
• 2004.11a
• /
• pp.145-147
• /
• 2004

LED(light emitting diode)는 처리속도, 전력소모, 수명 등에서 큰 장점이 있기 때문에 첨단조명의 광원으로 각광받고 있다. LED는 전원의 변동에 따라 광출력이 변동되므로 일정한 전압, 전류를 유지하는 기술이 필요하다. 따라서 본 논문에서는 LED 조명의 안정된 동작을 위한 전원장치로서 일정한 전압과 전류를 유지해주는 PWM(pulse width modulation) 궤환제어 방식의 부스트 컨버터를 제안하였다.

• Proceedings of the KAIS Fall Conference
• /
• 2004.06a
• /
• pp.172-175
• /
• 2004

This paper analyzes the effects of Ge profiles shape of SiGe heterojunction bipolar transistors (HBT's) for high frequency application. Device simulations using ATLAS/BLAZE for the SiGe HBT with trapezoidal or triangular Ge profile are carried out to optimize the device performance. An HBT with $15\%$ triangular Ge profile shows higher cut-off frequency and DC current gain than that with $19\%$ trapezoidal Ge profile. The cut-off frequency and DC gain are increased from 42GHz to 84GHz and from 200 to 600, respectively. The SiGe HBT has been fabricated using a production CVD reactor.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1125-1128
• /
• 2007

The laminating technique for developing flexible liquid crystal display was demonstrated by using a thin UV curable polymer film and a plastic substrate with patterned polymer wall structure. We adopted the rigid wall structure to provide a solid mechanical support for the stable molecular alignment of liquid crystals (LCs) in the device. The cover film was prepared to have an ability of aligning LC molecules by patterning a micro-groove structure using the soft-lithographic process. These two substrates can be assembled tightly by the laminating and one-step UV irradiation process because of the adhesive nature of the used UV curable polymers. Proposed method can be used to fabricate the flexible LC display with simplicity and also be applicable for a cost-effective roll-to-roll process.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.743-746
• /
• 2006

We have demonstrated a transflective liquid crystal display (LCD) with a single cell gap in a patterned vertically aligned mode. In our configuration, the different electrode structure in a transmissive and a reflective part was suggested to compensate an optical path difference of each region. As the result, the similar electro-optic characteristic of each region was obtained which results in an enhanced performance of the device. Moreover, suggested technique can be highly effective to realize the practical transflective LCD due to the simple fabrication process.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.850-853
• /
• 2005

This paper presents issues of display hardware architecture, relating to memory, display driver IC architecture, and chip-to-chip interface. To achieve a low power and low cost mobile phone, not only the display architecture must be carefully selected, but also the driver-ICs optimized to accommodate the different modes of operation found in typical handheld devices. The technique of forming a photo sensor in each pixel using TFT and display module architecture are developed to add multi functions in display such as fingerprint recognition, image scanning, and integrated touch screen. Detailed architectures of IC partitioning, high-speed serial interface, D/A converter, and multi functions such as fingerprint recognition and image scanning using photo sensors are important to a power optimized system.

• Journal of Advanced Navigation Technology
• /
• v.14 no.3
• /
• pp.452-458
• /
• 2010

In case of an embedded system with computing resource restrictions such as system power and cpu, the overhead due to displaying data on the computer screen may have a significant influence on the system performance. This paper describes an initialization method for LCD-driving components such as an ARM Core, an LCD controller, and an SPI(serial peripheral interface). It also introduces a pixel display function and a panel display method using virtual screen for reducing the display overhead for an LN2440SBC system with an ARM9-based S3C2440A microprocessor. A virtual screen is a large space of computer memories allocated much larger than those needed for one-time display of an image. Displaying a specific region of a virtual screen is done by assigning it as a view-port region. Such a display is useful in an embedded system when concurrently running tasks produce and display their respective results on the screen; it is especially so when the execution result of each task is partially modified, instead of being totally modified, on its turn and displayed. If the tasks running on such a system divide and make efficient use of the region of the virtual screen, the display overhead can be minimized. For the performance comparison with and without using the virtual screen, two different images are displayed in turn and the amount of time consumed for their display is measured. The result shows that the display time of the former is about 5 times faster than that of the latter.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.41 no.1
• /
• pp.27-37
• /
• 2004

The detection of foreground objects in a projection display using color information can be hard due to changing lighting conditions and complex backgrounds. Accordingly, the current paper proposes a foreground object detection method using color information that is obtained from the input image to the Projector and an image captured by a camera above the projection display. After pixel correspondences between the two images are found by calibrating the geometry distortion and color distortion, the natural color variations are estimated for the projection display. Then, any pixel that has another variation not resulting from natural geometry or color distortion is considered a part of foreground objects, because a foreground object in a projection display changes the values of pixels. As shown by experimental results, the proposed foreground detection method is applicable to an interactive projection display system such as the DigitalDesk