• 항공우주시스템공학회지
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• 제9권1호
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• pp.12-18
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• 2015

The inter-conversion between different control laws in flight has a lot of risk. The SWM(Switching Mechanism) including logic and stand-by mode is designed to analyze the transient response of aircraft during inter-conversion between different control laws, based on the in-house software for non-real-time and real-time simulation. The SWM applies the fader logic of TFS(Transient Free Switch) to minimize the transient response of an aircraft during the inter-conversion, and applies the reset '0' type of the stand-by mode to prevent surface saturation due to integrator effect in the disengaged flight control law. The transition time is also important to minimize the objectionable transient response in the inter-conversion, as well as the transition control law design. This paper addresses the results of non-real-time simulation for the characteristics of transient response to different transition time to select the adequate transient time, and the real-time pilot evaluation, using SSWM(Software Switching Mechanism) and HSWM(Hardware Switching Mechanism), which is met for Level 1 flying qualities and assures safety of flight.

• 한국식품영양학회지
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• 제6권3호
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• pp.158-168
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• 1993

For the conversion of WAD to NADP, Immobilized Brevibacterium ammoniagenes cells with NAD kinase was coupled with ATP-generating system by acetate kinase. The membrane permeability of B. ammoniagenes was improved by toluene treatment of cells. The toluene treated B. ammoniagenes cells were immobilized for stable enzyme activity. Partially purified acetate kinase was used in the reaction system. The optimum conditions for the efficient conversion of UAD to WADP by energy-coupled system were investigated. B. ammoniagenes cells treated with toluene for the Improvement of membrane permeability showed 4.5 fold improved permeability in the conversion of NAD to NADP compared with Intact cells. 3% k-carrageenan as the immobilization matrix of B. ammoniagenes showed the best efficiency for the conversion of NAD to NADP The optimum conditions for the WAR to WARP conversion reaction coupled nth ATP-generating system were 10mM acetylphosphate, 5mM ADP 200mM inorganic phosphate, 10mM MgCl2, 250mg/ml Immobilized cells, 49.3mUnit/ml acetate kinase, pH 7.5 and 37$^{\circ}C$. Under the optimum conditions, 72% of 5mM(340mg/ml ) NAD was converted to UADP In 12 hours.

• 드라이브 ㆍ 컨트롤
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• 제10권1호
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• pp.21-28
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• 2013

Wind energy has been more and more important and contributive in the energy utilization of the world. This paper proposed a novel method for Wind Energy Conversion System (WECS), in which a secondary control hydrostatic transmission (SC-HST) with two hydraulic accumulators, were employed for wind energy conversion system. This approach can absorb the excessive power of turbine, keep the generator from over-speed and maintain the speed of generator in low speed of turbine. A PID controller was designed for speed control to track a predefined speed. The simulation results indicated that the speed of the generator was ensured with the relative error less than 2%; and the efficiency of the proposed system was 70.4%.

• 대한음성학회지:말소리
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• 제68권
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• pp.65-74
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• 2008

A statistical parametric speech synthesis system based on the hidden Markov models (HMMs) has grown in popularity over the last few years, because it needs less memory and low computation complexity and is suitable for the embedded system in comparison with a corpus-based unit concatenation text-to-speech (TTS) system. It also has the advantage that voice characteristics of the synthetic speech can be modified easily by transforming HMM parameters appropriately. In this paper, we present experimental results of voice characteristics conversion using the HMM-based Korean speech synthesis system. The results have shown that conversion of voice characteristics could be achieved using a few sentences uttered by a target speaker. Synthetic speech generated from adapted models with only ten sentences was very close to that from the speaker dependent models trained using 646 sentences.

• Journal of Electrical Engineering and Technology
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• 제2권3호
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• pp.366-372
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• 2007

Joining thin aluminum alloy is difficult using most welding techniques. Many of the problems are associated with bum-through by the high heat input. Common welding techniques are TIG (Tungsten Inert Gas), MIG (Metal Inert Gas), and PULSE-MIG welding. The method provides more control of the heat balance in the welding arc by taking advantage of the different arc characteristics obtained with each of the two polarities. In this paper, we proposed a new welding method by control DSP 320C32, and the characteristic and experiment result-voltage, current, welding bead, and penetrations by this method are presented.

• International Journal of Automotive Technology
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• 제8권3호
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• pp.283-288
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• 2007

This paper presents the static characteristics of a urea-SCR system. The static characterization of the urea-SCR system was generated by sweeping urea flow rates at common engine torque/speed operating points. Several experiments were performed using engine operating points at different raw NOx emission levels, space velocities, and SCR catalyst temperatures. The recorded NOx emissions from the engine exhaust outlet and engine tailpipe are then compared. The urea-SCR static system results indicated that a $50{\sim}60%$ NOx conversion is achievable at most engine operating points using the stoichiometric $NH_3/NOx$ ratio, and a high 98% NOx conversion is possible by exceeding the stoichiometric $NH_3/NOx$ ratio. The effect of the pre-oxidation catalyst volume was also investigated and found to have a profound impact on experimental results, particularly the static NOx conversion.

• 산업기술연구
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• 제22권B호
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• pp.133-139
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• 2002

In precision instrumentation system, an A/D conversion of signal conditioning has been always suffered from some problems ; offset and drift voltage with environmental situation. This paper suggests a method of reducing the offset voltage and the drift error from the A/D conversion hardware using analog signal switching technique with specific operational amplifier circuits. Also, we have designed a hardware active filter and a software digital filter with Auto Zero Tracking algorithm for better dignal process of the our proposed weighing system. Software technique was performed to obtain the stable data from A/D converter. As a result of our experimental works, the proposed system is expected to be used in the industrial field where a high precision measurement is required.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.301-304
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• 2002

This paper has been studied an A/D conversion system for precision weighing signal process In weighing system. A/D conversion has some problem.; offset drift voltage with environment situation and nonzero value of initial output voltage. The Offset voltage in analog circuit produces a drift of an output voltage before A/D conversion stage. This paper suggested the method of reducing the offset voltage by switching analog chopping circuit and making the initial output close to zero to enhance the swing range by D/A converter. Also, we have designed active filter and digital filter with Auto Zero Tracking algorithm for better signal process of the weighing system.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 추계학술대회 논문집
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• pp.39-40
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• 2016

Power conversion system comes with a twenty-year warranty commonly. Life test requires a long time. The life of power conversion system that especially sensitive to temperature can be expected within a short time by using Arrhenius technique with worst stress condition than actual working condition. This paper researches reliability analysis and environment test of power conversion system.

• 한국컴퓨터정보학회논문지
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• 제17권10호
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• pp.129-136
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• 2012

본 논문에서는 논문 메타 데이터 특성 분석 연구를 토대로 데이터 변환 방법들을 고안하고 스키마 매핑 및 변환시스템을 구현한다. 빅 데이터 분석을 위해서는 다양한 시스템의 데이터베이스에 축적된 데이터를 공통의 형식으로 변환하는데, 현재의 데이터 변환 시스템들은 구문 의존적 문제와 사용의 불편함을 가지고 있다. 본 논문에서 구현된 시스템은 논문 메타데이터 분야에 특화된 시스템으로, 사용하기 쉬운 스키마 매핑 인터페이스를 가지고 있으며 다양한 논문 데이터 구문을 변환할 수 있다. 또한 시스템에 등록되지 않은 새로운 스키마를 가진 데이터가 입력되더라도 시스템의 재 컴파일이 필요 없다. 본 시스템은 사용성 평가를 통하여 시스템 사용성 평균 점수로 89.25점을 받았다.