• Korean Journal of Optics and Photonics
• /
• v.11 no.4
• /
• pp.294-298
• /
• 2000

The output characteristics of intracavity frequency doubling of laser-diode end-pumped Nd:S-VAP laser were investigated. Nd:S-VAP is suitable for a microchip laser medium, which has a low threshold property because of a very high value of the stimulated emission cross-section and lifetime product. The threshold energy measured was 81 J.ll. The second harmonic output energy measured was $126\mu\textrm{J}$at a pump energy of $2\mu\textrm{J}$. We described for intracavity frequency doubling by using theoretical calculations. Q-switched second harmonic energy measured was $15\mu\textrm{J}$per pulse with a pulse-width of 26 ns. at a pump energy of 2 mJ and an $M^2$ of 1.47 represented a good beam quality. ality.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.6
• /
• pp.1115-1122
• /
• 2003

In this paper we fabricated microchip antenna operating in bluetooth frequency bands(2.402∼2.480GHz). The antenna has a size of about 54mm${\times}419mm${\times}40.8mm, giving a total bluetooth PCB for support and chip of about 11mm${\times}44mm${\times}41.6mm. Bandwidth of the designed and fabricated chip antenna for bruetooth is 10.71 % at the resonated frequency of 2.45GHz and the resonant frequency and bandwidth versus change of any arbitrary feed point is observed. also, E-plane and H-plane in the Measured radiation pattern characteristic of chip antenna is compared and analyzed.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.2
• /
• pp.137-146
• /
• 2016

An increase in EGR rate can reduce NOx emissions. On the other hand, an excessive EGR rate is a major cause of incomplete combustion. Precise position control of the EGR valve that is optimized for the operating conditions of the engine should be supported to meet the strict emission regulations. Accordingly, this study performed mathematical modeling and control theory for characteristic analysis of an EGR valve motor. Because it is a step for controlling the position of the EGR valve motor using the Microchip development tool, this study analyzed the characteristics of the motor for each opening and closing section according to the input value of the duty ratio of PWM (Pulse Width Modulation).

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.13 no.3
• /
• pp.11-17
• /
• 2017

The aerial support air sculptures currently exhibited in indoor spaces are similar to simple ad balloons, using multiple rope strands. Users now want more advanced unfixed sculptures, and hope these will develop into buoyant sculptures that can maintain the attitudes that users want on their own. This study investigated an attitude control system for unfixed levitation sculptures that can levitate with no rope and continuously maintain a certain attitude at a height specified by the user. To facilitate levitation, the exterior part of the sculpture was made of lightweight fibers, and the interior part was filled with helium gas. The controller was composed of a microprocessor of the dsPIC30F line from microchip, gyro, acceleration, and earth magnetic field sensors, and a highly efficient brushless DC (BLDC) electric motor. The attitude and position control system requires scheduling considering the trajectories of the sculpture and the control system, because the roles of the overall components are more important than those of a single controller. Furthermore, the system was designed like a fusion system that is expanded and controlled as a total controller, because it is interconnected with various sensors. The attitude control system of buoyant sculptures was implemented in this study, such that it can actively cope with the position, direction, stopping, and time aspects. The system performance was then evaluated.

• Proceedings of the KOSOMBE Conference
• /
• v.1998 no.11
• /
• pp.127-128
• /
• 1998

It is necessary to maintain constant intravenous (IV) infusion rate. While infusion pump is able to control infusion rate with great accuracy, its rather large size and weight make it difficult for patients to move around. The most commonly used infusion device is gravity IV infusion set with its administration chamber being clamped according to the observed drip rate. In this case it may be easier and more accurate to maintain IV rate to given value if we automate the drip-counting process and tube-clamping work by electronic devices. We calculated volume infusion rate of specific fluid using optical drip rate meter which we had developed. To regulate fluid flow rate, we equipped the rate meter which we had developed with a miniaturized clamping apparatus using DC motor. Also, we Implemented drip detection and clamp control algorithm with PIC16C73 $\mu$-controller (Microchip). This system provides user interface through LCD display and key buttons.

• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2006.06a
• /
• pp.105-108
• /
• 2006

무선인지(RFID)시스템은 많은 산업 분야에 적용되고 있다. 대표적인 예로써 RFID 시스템을 이용한 출입 관제시스템을 들 수 있으며, 이런 경우 기존의 건물에 이 시스템을 설치하려고 하면 출입문을 개조하여야 한다. 하지만 무선 통신을 이용하면, 리더기에서 호스트 컴퓨터로의 접근이 용이해지므로 출입문 개조에 있어서도 한결 수월해진다. 이 때 필요한 것이 무선 디지털 데이터 통신 기술과 원격지에서 Tag의 ID를 모니터링을 위한 TCP/IP를 이용한 Ethernet 통신이다. 본 논문에서는 이러한 시스템의 개발방법에 대해 설명하였으며 RFID 리더기는 125KHz를 사용 주파수로 하고, Tag 칩은 Microchip사의 MCRF 250을 사용하였다. 그리고 무선 데이터 통신을 위해서 CC1020칩을 사용하였으며 이 칩의 장점은 간단히 레지스터를 설정으로 송신 상태 혹은 수신 상태로 변환이 가능하고 또한 주파수 설정도 가능하다는 것이다. 마지막으로 Ethernet 통신을 위해서는 W3100A칩을 이용하였으며, Ethernet 통신에 있어 OS가 차지하는 부분으로 하드웨어를 통해 구현하였다. 실험을 위해 하드웨어를 구성하고 각 모듈별 동작을 분석하고. 각 부분의 파형을 확인하였다. DB에 해당하는 Application을 통해 Tag ID DATA를 확인하였다.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.51 no.7
• /
• pp.328-334
• /
• 2002

The DNA chips are devices associating the specific recognition properties of two DNA single strands through hybridization process with the performances of the microtechnology. In the literature, the "Gene chip" or "DNA chip" terminology is employed in a wide way and includes macroarrays and microarrays. Standard definitions are not yet clearly exposed. Generally, the difference between macro and microarray concerns the number of active areas and their size, Macroarrays correspond to devices containing some tens spots of 500$\mu$m or larger in diameter. microarrays concern devices containing thousnads spots of size less than 500$\mu$m. The key technical parameters for evaluating microarray-manufacturing technologies include microarray density and design, biochemical composition and versatility, repreducibility, throughput, quality, cost and ease of prototyping. Here we report, a new method in which minute particles are arranged in a random fashion on a chip pattern using random fluidic self-assembly (RFSA) method by hydrophobic interaction. We intend to improve the stability of the particles at the time of arrangement by establishing a wall on the chip pattern, besides distinction of an individual particle is enabled by giving a tag structure. This study demonstrates the fabrication of a chip pattern, immobilization of DNA to the particles and arrangement of the minute particle groups on the chip pattern by hydrophobic interaction.ophobic interaction.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.30 no.10 s.253
• /
• pp.1261-1268
• /
• 2006

This paper reports low-cost microreactor $(10{\mu}{\ell})$ biochip for the DNA PCR (polymerase chain reaction). The microbiochip $(20mm{\times}28mm)$ is a hybrid type which is composed of PDMS (polydimethylsiloxane) layer with serpentine micochannel $(360{\mu}m{\times}100{\mu}m)$ chamber and glass substrate integrated with microheater and thermal microsensor. Undesirable bubble is usually created during sample loading to PMDS-based microchip because of hydrophobic chip surface. Created bubbles interrupt stable biochemical reaction. We designed improved microreactor chamber using microfluidic simulation. The designed reactor has a coner-rounded serpentine channel architecture, which enables stable injection into hydrophobic surface using micropipette only. Reactor temperature needed to PCR reaction is controlled within ${\pm}0.5^{\circ}C$ by PID controller of LabVIEW software. It is experimentally confirmed that SRY gene PCR by the fabricated microreactor chip is performed for less than 54 min.

• Journal of Satellite, Information and Communications
• /
• v.9 no.2
• /
• pp.12-17
• /
• 2014

In this paper, modified EDNMOS device with DPS (double polarity source) structure are suggested to realize stable and robust ESD (electrostatic discharge) protection performance of high voltage operating microchip. This DPS structure inserts the P+ diffusion layer on N+ source side, which in intended to block lateral extension of the electron rich region from N+ source side. Based on our simulation results, the inserted P+ diffusion layer effectively prevents the formation of deep electron channeling induced by high electron injection. As a result, our proposed DPS_EDNMOS devices could overcome the double snapback effect of conventional Std_EDNMOS device.

• Proceedings of the KIEE Conference
• /
• 2007.11a
• /
• pp.146-147
• /
• 2007

We present full 3-D simulation of dielectrophoretic (DEP) deflection of particle trajectory in micro channel and compare the simulation results with experimental results. In simulation, the particle 3-D movements along x, y and z-axis are simulated precisely, and the streamlines of particles movements and the change of particle height are investigated experimentally. Therefore, the deflection performance is investigated on the designed and fabricated deflection microchip.