• Journal of Sensor Science and Technology
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• v.22 no.3
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• pp.207-211
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• 2013

In this research, the pH sensor was developed using CNT nanosheet with Nafion coating for the advanced medical sensor such as a blood gas analyzer. The CNT nanosheet was formed by dielectrophoresis and water-meniscus between cantilever-type electrodes. Then, the process of the heat annealing and the Nafion coating was conducted for reducing contact resistance and giving proton selectivity respectively. We measured the response of the pH sensor as the electrolyte-gated CNT-nanosheet field effect transistor. The sensor showed a linear current ratio in a similar range of the normal blood pH. A calibration method for decreasing of the response variation among sensors has also been introduced. Coefficient of variance of the pH sensor was decreased by applying the calibration method. A linear relation between the calibrated response of the sensors and pH variance was also obtained. Finally, the pH sensor with a high resolution was fabricated and we verify the feasibility of the sensor by applying the calibration method.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.211-218
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• 2001

This paper introduces a method of constructing expert systems in an integrated environment for automatic software design. This integrated environment may be applicable from top-level system architecture design, data flow diagram design down to flow chart and coding. The system is integrated with three CASE tools, FSD (Functional Structure Diagram), DFD (Data Flow Diagram) and structured chart PAD (Problem Analysis Diagram), and respective expert systems with automatic design capability by reusing past design. The construction way of these expert systems is based on systematic acquisition of design knowledge stemmed from a systematic design work process of well-matured developers. The design knowledge is automatically acquired from respective documents and stored in the respective knowledge bases. By reusing it, a similar software system may be designed automatically. In order to develop these expert systems in a short period, these design knowledge is expressed by the unified frame structure, functions of th expert system units are partitioned mono-functions and then standardized components. As a result, the design cost of an expert system can be reduced to standard work procedures. Another feature of this paper is to introduce the integrated environment for automatic software design. This system features an essentially zero start-up cost for automatic design resulting in substantial saving of design man-hours in the resulting in substantial saving of design man-hours in the design life cycle, and the expected increase in software productivity after enough design experiences are accumulated.

• Environmental Engineering Research
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• v.20 no.3
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• pp.205-211
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• 2015

Reduced forms of iron, such as zero-valent ion (ZVI) and ferrous ion (Fe[II]), can activate dissolved oxygen in water into reactive oxidants capable of oxidative water treatment. The corrosion of ZVI (or the oxidation of (Fe[II]) forms a hydrogen peroxide ($H_2O_2$) intermediate and the subsequent Fenton reaction generates reactive oxidants such as hydroxyl radical ($^{\bullet}OH$) and ferryl ion (Fe[IV]). However, the production of reactive oxidants is limited by multiple factors that restrict the electron transfer from iron to oxygen or that lead the reaction of $H_2O_2$ to undesired pathways. Several efforts have been made to enhance the production of reactive oxidants by iron-induced oxygen activation, such as the use of iron-chelating agents, electron-shuttles, and surface modification on ZVI. This article reviews the chemistry of oxygen activation by ZVI and Fe(II) and its application in oxidative degradation of organic contaminants. Also discussed are the issues which require further investigation to better understand the chemistry and develop practical environmental technologies.

• Archives of design research
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• v.20
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• pp.211-217
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• 1997

Natural dyes don't pollute the environments in contrast to artifical dyes. The cloths dyed with natural material can be developed into insect-proof clothing and bedding. With natural tint, they can also produce natural images. The purpose of this paper is to show the way to develop the natural dye material easily available at cheap cost, to produce high value added products in terms of dyeing a wide range of colors by using this material, and to suggest the way for farmers to cultivate the onions in their idle land, thus gaining additidnal income. In the process of dyeing natural cloth with onion skin produced largely in Mooan, Chonnam, we were able to extract a wide spectrum of colours from yellow to pale brown and gray. Having reaped good results in the various endurance tests(of washing, friction, water, sweat, sunlight), this material is estimated to be highly worthy of industrialization.

• Environmental Engineering Research
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• v.25 no.2
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• pp.205-211
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• 2020

Chlorhexidine digluconate (CHD) in the aquatic environment causes irreversible change to microbes, making them resistant to biodegradation, which needs remediation other than biological process. Adsorption study was performed for the removal of CHD on fly ash (FA) as a function of pH and ionic strength. Experimental result has been validated by characterization using Scanning electron microscopy, Fourier Transform-Infrared Spectroscopy and Brunauer-Emmett-Teller. CHD adsorption with FA showed an increasing trend with an increase in pH. Variation in pH proved to be an influential parameter for the surface charge of adsorbent and the degree of ionization of the CHD molecules. The adsorption capacity of CHD decreased from 23.60 mg g-1 to 1.13 mg g-1, when ionic strength increased from to M. The adsorption isotherms were simulated well by the Freundlich isotherm model having R2 = 0.98. The Lagergren's model was incorporated to predict the system kinetics, while the mechanistic study was better explained by pseudo-second order for FA. On the basis of operational conditions and cost-effectiveness FA was found to be more economical as an adsorbent for the adsorption of CHD.

• Journal of the Korea Society of Computer and Information
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• v.7 no.4
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• pp.211-219
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• 2002

The introduction of CRM alter production materials oriented into customer oriented, reengineering all process into customer's view and it means introduction of information system. This means introduction of information system which can support CRM strongly. This paper examines developmental transition of CRM marketing. proposes CRM approach and practical strategy. and CRM can embody Customer, Relationship. Management and System in many respects. It is desirable to build on CRM more serving than sell products in the Marketer's view point.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.04a
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• pp.211-216
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• 2009

Bidding systems in the domestic public construction work have been amended many times since the lowest-bidding system was implemented in 1951. However, this hasn't had much success. Competition in technical development among companies has declined as the contracts for buildings are given to company which submits the lowest price without considering traits of projects. In addition, as the construction market turns to the limitless competition system due to FTA(Free Trade Agreement), advanced techniques are needed to promote the national competitive power. Considering the needs of the times, Korean government announced that "Best Value Contract (Design-Bid-Build)" and "Bridging Contracts (Design-Build)" are included to 4 existing bidding systems in October 2007. Thus this study aims to suggest devised the evaluation criteria including major items for evaluating bidders, in order to establish and revitalize the best-value bid system successfully.

• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.4
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• pp.211-216
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• 2003

This work describes a 3 V 12b 100 MS/s CMOS digital-to-analog converter (DAC) for high-speed communication system applications. The proposed DAC is composed of a unit current-cell matrix for 8 MSBs and a binary-weighted array for 4 LSBs, trading-off linearity, power consumption, chip area, and glitch energy with this process. The low-glitch switch driving circuits are employed to improve linearity and dynamic performance. Current sources of the DAC are laid out separately from the current-cell switch matrix core block to reduce transient noise coupling. The prototype DAC is implemented in a 0.35 um n-well single-poly quad-metal CMOS technology and the measured DNL and INL are within ${\pm}0.75$ LSB and ${\pm}1.73$ LSB at 12b, respectively. The spurious-free dynamic range (SFDR) is 64 dB at 100 MS/s with a 10 MHz input sinewave. The DAC dissipates 91 mW at 3 V and occupies the active die area of $2.2{\;}mm{\;}{\times}{\;}2.0{\;}mm$

• Carbon letters
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• v.13 no.4
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• pp.205-211
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• 2012

Methanol as a carbon source in chemical vapor deposition (CVD) graphene has an advantage over methane and hydrogen in that we can avoid optimizing an etching reagent condition. Since methanol itself can easily decompose into hydrocarbon and water (an etching reagent) at high temperatures [1], the pressure and the temperature of methanol are the only parameters we have to handle. In this study, synthetic conditions for highly crystalline and large area graphene have been optimized by adjusting pressure and temperature; the effect of each parameter was analyzed systematically by Raman, scanning electron microscope, transmission electron microscope, atomic force microscope, four-point-probe measurement, and UV-Vis. Defect density of graphene, represented by D/G ratio in Raman, decreased with increasing temperature and decreasing pressure; it negatively affected electrical conductivity. From our process and various analyses, methanol CVD growth for graphene has been found to be a safe, cheap, easy, and simple method to produce high quality, large area, and continuous graphene films.

• Structural Engineering and Mechanics
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• v.65 no.2
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• pp.203-211
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• 2018

This paper introduces the development process of NCC(New Concrete Cutting) system and analyzes first verification test. Based on the first verification test results, some problems of NCC system have been newly modified. We carry out the second verification test. We tried to verify cutting performance and dust control efficiency of NCC system through the cutting test of concrete bridge piers. In particular, this verification test strives to solve the problem of concrete dust, which is the biggest problem of dry cutting method. The remaining dust problems in cutting section tried to solve through this verification test. This verification test of the NCC system shows that the dust problem of dry cutting method is closely controlled and solved. In conclusion, the proposed NCC method is superior to the dry cutting method in all aspects, including cutting performance, dust vacuum efficiency and cooling effect. The proposed NCC system is believed to be able to provide eco-friendly cutting technology to various industries, such as the removal of the SOC structures and the dismantling of nuclear plants, which have recently become a hot issue in the field of concrete cutting.