• Bulletin of the Korean Chemical Society
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• v.27 no.8
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• pp.1127-1132
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• 2006

A new salicylate-selective electrode based on the complex N,N'-1,4-butylene bis(3-methyl salicylidene iminato) copper(II) as the membrane carrier was developed. The electrode exhibits a good Nernstian slope of 59.1 ${\pm}$ 1.0 mV/decade and a linear range of $1.0\;{\times}\;10^{-6}$-1.0 M for salicylate. The limit of detection was $5.0\;{\times}\;10^{-7}$ M. It has a fast response time 10 s and can be used for more than three months. The selective coefficients were determined by the fixed interference method (FIM) and could be used in the pH range 4.5-10.5. It was employed as an indicator electrode for direct determination of salicylate in pharmaceutical samples.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.147-148
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• 2015

현재 발전기 스케줄링은 제한된 발전 자원, 에너지 수요 및 연료비용 증가, 그리고 불규칙적인 부하 등 최적리스케줄링에 있어 많은 문제들을 해결하기 위한 새로운 변화가 요구된다. 본 논문에서는 Multi-Terminal Voltage Source Converter High Voltage Direct Current (VSC-MTDC)와 Bettary Energy Storage System (BESS)가 결합된 Hybrid Integrated system (HIS)를 통해 발전기 리스케줄링을 위한 최적화 기법을 제안한다. 최적 발전기 리스케줄링을 위한 HIS 퍼포먼스를 위해 VSC station limit과 충 방전을 기반으로 하는 최적화 과정을 수행한다. 최적조류계산 문제는 VSC-MTDC 시스템과 BESS룰 고려하여 정식화되며, 충 방전 전략은 24시간 수요 정보를 사용하여 발전기 리스케줄링을 위한 하이브리드 통합 시스템의 최적알고리즘을 보여준다. 제안된 최적 리스케줄링 기법을 수정된 IEEE 14 모선에 적용하여 효율성을 입증하고자 한다.

• Architectural research
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• v.8 no.2
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• pp.27-36
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• 2006

Structural uncertainties are generally modeled using probabilistic approaches in order to quantify uncertainties in behaviors of structures. This uncertainty results from the uncertainties of structural parameters. Monte Carlo methods have been usually carried out for analyses of uncertainty problems where no analytical expression is available for the forward relationship between data and model parameters. In such cases any direct mathematical treatment is impossible, however the forward relation materializes itself as an algorithm allowing data to be calculated for any given model. This study addresses a new method which is utilized as a basis for the uncertainty estimates of structural responses. It applies double uniform random numbers (i.e. DURN technique) to conventional Monte Carlo algorithm. In DURN method, the scenarios of uncertainties are sequentially selected and executed in its simulation. Numerical examples demonstrate the beneficial effect that the technique can increase uncertainty degree of structural properties with maintaining structural stability and safety up to the limit point of a breakdown of structural systems.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.477-481
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• 2002

Grinding which is the final finishing step in the machining processes plays an important role fur precision manufacturing because it directly affect the product quality. Since the ground surface is affected by the states of grains and voids on the grinding wheel surface, the wheel should be dressed before the machined surface deteriorates over a quality limit. This paper describes a systematic approach to decide a proper dressing chance. A fabricated eddy current sensor and CCD camera are used to measure the loading on the working wheel surface and to visualize the wheel surface states respectively. The dressing chance can be properly decided through the relation between the variation of the thresholding image of the wheel and the machined surface roughness as the variation of the eddy current sensor output is greater than the detected value previously.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.589-593
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• 2005

It is well known that proper encapsulation is crucial for the lifetime of organic light emitting diode (OLED) displays. With the development of increasingly better barrier coatings and perimeter seals, it has now become very desirable to be able to precisely measure the rate of water vapor and oxygen permeation through barrier coatings and perimeter sealing. This paper demonstrates a new permeation measurement method that uses tritium-containing water (HTO) as a tracer material. The theoretical detection limit of this direct method is $2.4{\times}10^{-8}g/(m^2day)$.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.227-230
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• 2009

The aim of this study was to improve extrudability limit, eliminate welding line and obtain optimum thixoextrusion conditions for manufacturing tubes of 7075 Al wrought alloy. By thixoextrusion, it was possible to improve deformability, control isotropy with extrusion direction, eliminate welding line (seamless) and save cost due to low energy consumption compared with conventional extrusion processes. The welded part was not observed at the welding line area. The grains of thixoextruded tube were homogeneously distributed and equiaxed grains were observed. Therefore, thixoextrusion is the most effective variable for the control of the magnitude of the welding line.

• International Journal of Control, Automation, and Systems
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• v.2 no.4
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• pp.494-500
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• 2004

The wing rock phenomenon is a high angle of attack aerodynamic motion manifested by limit cycle roll oscillations. Experimental studies reveal that direct control and manipulation of leading edge vortices, through the use of 'blowing' techniques is effective in the suppression of wing rock. This paper presents the design of a robust controller for the experimental implementation of one such 'blowing' technique - recessed angle spanwise blowing (RASB), to achieve wing rock suppression over a range of operating conditions. The robust controller employs Takagi - Sugeno fuzzy system, which is fine-tuned by experimental simulations. Performance of the controller is assessed by real-time wind tunnel experiments with an 80 degree swept back delta wing. Robustness is demonstrated by the suppression of wing rock at a range of angles of attack and free stream velocities. Numerical simulation results are used to further substantiate the experimental findings.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.50 no.3
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• pp.109-116
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• 2001

In this paper, we adapted BLDC motor to PV water pumping systems to maintain high efficiency in the wide speed area. Also, to design confidence we adapted the vector control that drive the maximum torque at each speed limit. We designed optimal gain value of current, speed and pressure PI controller. Inverter gate pulse used Space Vector PWM to reduce torque pulsation of BLDC motor. According to, it was improve general matters of high water storage tank method by direct water supply pumping method.

• Management & Information Systems Review
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• v.11
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• pp.45-69
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• 2002

One of important technology that must improve compulsorily on information-oriented society stores, search and transmit cultural contents data of great quantity in heterogeneous environment. SAN appeared by solution to resolve the problem such as integration management of heterogeneous system data, effective practical use of storage, data transmission limit is happened from here. SAN is system that manage and shares data of large quantity efficiently attaching directly to high speed network such as Fiber Channel that storage system has been attached to server individually SAN became more complicated than existent storage environment although offer much advantage such as decrease of storage expense and flexibility of system configuration. This study argues management way could consider in such environment that understand complexity and component of networked storage system.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.1
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• pp.321-327
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• 1996

Experiments were performed on the laminar premixed flame stabilized in a porous medium to know whether the flame downstream of the combustor exists or not. In previous theoretical studies, a stable flame has been predicted in the downstream region of the combustor, but it has never been observed in experiments. In this study, a stable downstream flame could be obtained for the lower burning velocity through circumferential heating by a blue flame positioned outside the periphery of the specially devised combustor. The existence of the stable downstream flame was confirmed by a direct photography of soot line, and temperature measurements. The effect of combustor diameter to flame stability was also considered. As the diameter of the combustor increases, the lean flammability limit was extended.