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Characteristics of a Superposed Discharge Type Ozonizer(III) (중첩방전형 오존방생기의 특성(III))

  • Song, Hyun-Jig;Lee, Kwang-Sik;Lee, Dong-In;Kim, Gi-Chae;Lee, Dong-Heon;Kim, Geum-Young;Lee, Chun-Ha;Jeun, Young-Ju
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1815-1817
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    • 1998
  • In this paper, a superposed discharge type ozonizer(IESDO) has been designed and manufactured. IESDO is equipped with three electrodes(central, internal and external electrodes), and it is composed of two gaps. Ozone is generated by overlapping silent discharge, which is respectively came from two gaps. This paper describes the following characteristics : (1) The characteristics of discharge with variation of output voltage of AC H.V source, quantity of supplied gas and discharge voltage (2) the characteristics of ozone generation with variation of quantity of supplied gas, discharge power, operating number of IESDO.

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Estimation of excitation and reaction forces for offshore structures by neural networks

  • Elshafey, Ahmed A.;Haddara, M.R.;Marzouk, H.
    • Ocean Systems Engineering
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    • v.1 no.1
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    • pp.1-15
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    • 2011
  • Offshore structures are subjected to wind loads, wind generated wave excitations, and current forces. In this paper we focus on the wind generated wave excitations as the main source for the external forces on the structure. The main objective of the paper is to provide a tool for using deck acceleration measurements to predict the value of the force and moment acting on the offshore structure foundation. A change in these values can be used as an indicator of the health of the foundation. Two methods of analysis are used to determine the relationship between the force and moment acting on the foundation and deck acceleration. The first approach uses neural networks while the other uses a Fokker-Planck formulation. The Fokker-Plank approach was used to relate the variance of the excitation to the variance of the deck acceleration. The total virtual mass of the equivalent SDOF of the structure was also determined at different deck masses.

Building Competitive Advantages through Information Systems(IS) Outsourcing: A Resource-Based View(RBV) Approach (정보시스템 아웃소싱을 통한 경쟁력 제고: Resource-Based View(RBV) 접근)

  • Goo, Ja-Hyun
    • Asia pacific journal of information systems
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    • v.13 no.3
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    • pp.213-242
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    • 2003
  • This paper employs the lens of the resource-based view(RBV) to investigate how firms create competitive advantages through IS outsourcing arrangements. The RBV framework is used to explore how a firm adds value and reaps benefits from IS outsourcing arrangements. The primary finding is that in the process of value creation, the 'absorption' of the managerial and technical capabilities of external vendors is critical. When the client firm is able to absorb and integrate the IT capabilities of outsourcing vendors, these absorbed capabilities in turn become the source of IT competence and competitive advantages $vis-\grave{a}-vis$ the competition.

Upwind Finite Element Model for Suspended Sediment Transport

  • Noh, Joon-Woo
    • Journal of Wetlands Research
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    • v.5 no.1
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    • pp.67-78
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    • 2003
  • The unsteady 2D convection and diffusion equation is solved numerically for the real-time simulation of suspended load propagation. The streamlined upwind scheme efficiently reduces numerical oscillations due to the high Peclet number in the convection dominant flow. By using the mixed boundary condition to express the external source terms or externally induced suspended load as a function of time in the algorithm, the model is capable of handling not only continuous load cases but also non-continuous suspended load influx. The suspended load transport modelwas verified using a case study for which an analytical exact solution is available and was applied to the real-time simulation of a suspended load influx case on the Mississippi River. The model algorithm can provide a framework upon which water quality as well as contaminant transport models can be built.

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Charge Controlled Meminductor Emulator

  • Sah, Maheshwar Pd.;Budhathoki, Ram Kaji;Yang, Changju;Kim, Hyongsuk
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.6
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    • pp.750-754
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    • 2014
  • Emulations of memristor-family elements are very important, since their physical realizations are very difficult to achieve with recent technologies. Although some previous studies succeeded in designing memristor and memcapacitor emulators, no significant contribution towards meminductor emulator has been presented so far. The implementation of a meminductor emulator is very important, since real meminductors are not expected to appear in near future. We designed the first meminductor emulator whose inductance can be varied by an external current source without employing any memrisitve system. The principle of our architecture and its feasibility have been verified using SPICE simulation.

Injection volume control of carboxy-gun using a solenoid valve (솔레노이드 밸브를 이용한 카복시 건의 주입량 제어)

  • Tak, Tae-Oh;Han, Nam-Gyu;Shin, Young-Kyu
    • Journal of Industrial Technology
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    • v.32 no.A
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    • pp.65-70
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    • 2012
  • Carboxy-guns are used for rapid and precise injection of $CO_2$ gas to the target skin area using external power source. In the design of carboxy-gun, the most important thing is how to precisely control injection volume of $CO_2$ gas. This paper deals with the control scheme of injection volume of carboxy-gun using solenoid valve. First the amount of volume that passes through the solenoid valve under on-off time ratio control is estimated based on the assumption of compressible gas flow. The flow rate of gas is experimentally measured under the varying pressure of the gas reservoir. Two results showed good correlation to each other, thus demonstrating the validity of the volume control strategy.

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Acid Fermentation Characteristic of Food Wastes According to the Organic Loading Rate (유기물부하에 따른 음식물찌꺼기의 산발효 특성)

  • Park, Jin-Sik;Ahn, Chul-Woo;Jang, Seong-Ho
    • Journal of Environmental Science International
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    • v.15 no.10
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    • pp.975-982
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    • 2006
  • This study has been conducted to optimum operating conditions for effective acid fermentation according to OLR(organic loading rate) in the mesophilic and thermophilic acid fermentation process. The results are summarized as follows. In order to obtain reasonable acid fermentation efficiency in performing acid fermentation of food wastes in thermophilic condition, organic loading rate was required below 20 gVS/L.d. As $SCOD_{Cr}/TKN,\;SCOD_{Cr}/T-P$ of thermophilic acid fermented food wastes In organic loading rate 20 gVS/L.d were 18.9, 73.4 respectively, it was possible to utilize as external carbon source for denitrification in sewage treatment plant after solid-liquid separation as well as co-digestion of fermented food wastes and sewage sludge.

[Invited Paper] Technology of Outdoor Readability Development in LCD Application

  • Choi, Hyun-Chul;Kang, In-Byung;Jung, In-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.10-13
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    • 2009
  • We have developed variety of LCD technologies for the out-door display, which improve out-door readability as well as reliability from external impacts. This improvement was made possible by new approach on LCD cell optical design and modification of LCD surface, which allows surrounding light to be transmitted to enhance the visibility and at the same time filtering out light, which are considered to be source of noise in terms of visibility. This technology enables users to maintain high display performance in both in-door & out-door environments moreover alternatively choosing in-door/out-door.

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Energization method of Superconducting Magnet System with Persistent Current Mode (영구전류모드를 가지는 초전도 마그네트 시스템의 여자방법)

  • Ye, Jung-Hee;Nah, Wan-Soo;Joo, Jin-Ho;Hong, Gye-Won
    • Proceedings of the KIEE Conference
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    • 1998.07a
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    • pp.305-307
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    • 1998
  • One of the merits of superconducting magnet system is that it has persistent current mode, in which the current can be constant without any external power supply. The problem is that when we energize the magnet we can not reach the target current with constant current source, in principle. It needs another energization methods, in which it can be energized with reasonable accuracy and time. This paper suggests two energization methods for a superconducting magnet with persistnet current mode and the comparisons of the two are made with respect to the accuracy and the time.

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Measurement of The Thermal Transfer Coefficient Predicting Efficiency of The Heat Pipe (히트파이프 성능예측 열전달계수 측정)

  • Lim, Soo-Jung;Moon, Jong-Min;Rhee, Gwang-Hoon
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2039-2042
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    • 2008
  • Recently, Electronic & Electrical Products have problems how to reduce heat in trend reducing size and increasing speed. heat pipes worked by latent heats can solve problems for effective and quiet electronic applications. Heat Pipes have to be suitably designed for the external conditions due to showing optimum performance. it has influence on efficiency of heat pipes to the exterior structure changed by length, bending angle, diameter. Designing heat pipes has depended on experience from trial and error. this method wasted too many resources, but can't guarantee efficiency. to prevent those wastes, this study aims at making the thermal transfer coefficient predicting efficiency. In this study, the thermal transfer coefficient has been made from experimental results that used variables - lengths between heat source and radiation, bending angles, diameters of heat pipes. variables become non-dimensional in modeling process for making the coefficient.

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