• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.365-368
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• 2000

This paper describes image-rejection down conversion mixer for bluetooth application using 0.35u CMOS process. the proposed architecture is composed of LO phase shifter, mixer core, IF buffer, and IF phase shifter. IF phase shifter is designed using polyphase fillet. Simulation results show conversion gain = l0㏈, input 1㏈ compression point = -15.7㏈m. input third-order intercept point(IIP3) = -4.4㏈m, and image-rejection ratio = 37.8㏈, respectively, at 3V supply voltage, and 15.7㎃ current.

• Corrosion Science and Technology
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• v.7 no.3
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• pp.179-181
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• 2008

With nano-$SiO_2$ and sulphate acid, a kind of colloid electrolyte is synthesized by sol-gel method. It is placed outside the reference electrode as a layer of gel electrolyte so as to decrease the leaching of $Cu^{2+}$ and increase the life of the reference electrode. The performance of the gel electrode in simulating soil solution is measured as follows: the potential of the electrodes ranging from 60 mV to 80 mV (vs. SCE) with potential variation no more than $\pm10mV$, enough resistance to polarization. The $Cu^{2+}$ effusion rate of the reference electrode without gel electrolyte is 3 times that with colloid electrolyte, which means that gel electrolyte can extend the life of the reference electrode significantly.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.38 no.2
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• pp.38-49
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• 2001

This paper presents a new voltage down converter(VDC) using charge and discharge current adjustment circuitry that provides high frequency application. This VDC consist of a common driving circuit and compensation circuits: 2 sensors and each driving transistors for controlling gate current of driving transistor. These sensors are operated as adaptive biasing method with high speed and low power consumption. This circuit is designed with a $0.62{\mu}m$ N well CMOS technology. In H-spice simulation results, internal voltage is bounded ( IV, +0.6V) in proposed circuitry when load current rapidly increases and decreases during Gns between 0 and $200m{\Lambda}$. And the recovery time of internal voltage is about 7ns and 10ns when load current increases and decreases respectively. That is fast better than common driving circuit. Total power consumption is about 1.2mW.

• Current Applied Physics
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• v.18 no.11
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• pp.1415-1421
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• 2018

Unlike ordinary organic field-effect transistors (OFETs), saturation current is hardly to be found in vertical OFETs (VOFETs). Moreover, the fabrication process of patterned sourced for VOFETs is quite complex. In this current work, a simple solution processed VOFET with directly deposited intermediate silver source electrode has been demonstrated. The VOFET exhibits a high leakage current that induces an inversion polarity of its transistor behavior. Interestingly, a well-defined saturation current was observed in the linear scale of transfer characteristic. The VOFET operated with high-current density > $280mA/cm^2$ at $V_d=5V$. Overview potential of the fabricated device in display application is also presented. This preliminary work does open-up a new direction in VOFET fabrication and their application.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.3
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• pp.283-289
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• 2015

This paper provides a study on the application and proposals of safety culture, new public management and social amplification of risk framework via ship accidents in Korea. This document analyzes what are the concept of safety culture, new public management as well as social amplification and risk framework and describes how 3 issues act, harmonize, interrelate through M/V Sewol accident. Korean government is needed to apply social amplification of risk framework to the in order to promote the safety culture in the maritime administration. Hence, this paper proposes safety framework in order to prevent and resolve future unexpected accident especially for maritime field.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.56.1-56.1
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• 2010

A novel electrochemical potentiostatic method has been examined in order to enhance the hole concentration of p-type GaN thin films using KOH and HCl electrolyte. The hole concentration was increased more than 2 times by the electric voltge apply with the mobility of $10{\sim}12cm^2/V.s$. At optimum condition of 3V apply, hole concentration was enhanced more than reference sample from $1.7{\times}10^{-17}cm^{-3}$ to $4.1{\times}10^{-17}cm^{-3}$. Application of this activation method to blue-LED fabrication improved optical output from 18.4mW to 20.6mW, that is ~12% increase. SIMS analysis indicates that nearly 70% of hydrogen atoms could be removed by this method.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.387-388
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• 1996

The principles to attain improved accuracy in a new controller for large CCD and mosaics detectors with the application of 16- and 32-bit DSP are presented.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.7 s.361
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• pp.37-44
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• 2007

A low-voltage high-linear bipolar OTA and its application to IF bandpass filter for GSM cellular telephone are presented. The OTA consists of a low-voltage linear transconductor, a translinear current gain cell, and three current mirrors. The bandpass filter is composed of two cascaded identical second-order bandpass filters, which consist of a resistor, a capacitor, and a grounded simulated inductor realized with two OTA's and a grounded capacitor. SPICE simulations using an 8 GHz bipolar transistor-array parameter show that the OTA with a transconductance of 1 mS exhibits a linearity error of less than ${\pm}2%$ over an input voltage range of ${\pm}0.65\;V$ at supply voltages of ${\pm}2.0\;V$. Temperature coefficient of the transconductance is less than $-90ppm/^{\circ}C$. The bandpass filter has a center frequency of 85 MHz and Q-factor of 80. Temperature coefficient of the center frequency is less than $-182ppm/^{\circ}C$. The power dissipation of the filter is 128 mW.

• ETRI Journal
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• v.28 no.2
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• pp.175-181
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• 2006

A new CMOS voltage-controlled fully-differential transconductor is presented. The basic structure of the proposed transconductor is based on a four-MOS transistor cell operating in the triode or saturation region. It achieves a high linearity range of ${\pm}\;1\;V$ at a 1.5 V supply voltage. The proposed transconductor is used to realize a new fully-differential Gm-C low-pass filter with a minimum number of transconductors and grounded capacitors. PSpice simulation results for the transconductor circuit and its filter application indicating the linearity range and verifying the analytical results using $0.35\;{\mu}m$ technology are also given.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.141-142
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• 2009

The PEFP (Proton Engineering Frontier Project) is constructing a 100MeV proton Linac (Linear Accelerator). The 20 MeV 20 mA proton beam has been serviced for an application in the fields of material, biological, information technology and medical sciences. For a stable and efficient acceleration of a proton beam, the control requirements must be optimized by studying various control methods. We propose that the integrated control system for the Linac machine components must be based on a distribution control method to improve a centralized control system. Based on EPICS (Experimental Physics and Industrial Control System) real-time software, the VME (Versa Module European package format) IOC (Input Output Controller) was developed under cross development environment with a RISC (Reduced Instruction Set Computer) PowerPC system. In this paper, we describe the design and implementation of distributed control system using the VME-based EPICS middleware for various components of the large proton accelerator.