• 제목/요약/키워드: semi-continuous type

검색결과 51건 처리시간 0.029초

회분식 및 반연속식 특이적 카르복실화 반응에 의한 ${\beta}$-1,3-glucan의 기능성 향상 (Enhancement of ${\beta}$-1,3-Glucan Functionality by Batch and Semi-continuous Typed Specific Carboxylation)

  • 정석윤;김상우;이용환;이재환;장판식
    • 한국식품과학회지
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    • 제40권2호
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    • pp.146-151
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    • 2008
  • 불용성 ${\beta}$-1,3-glucan의 물에 대한 수용성과 젤 형성능을 향상시키기 위해 회분식 혹은 반연속식 반응과 촉매로서 NaBr 첨가 및 무첨가 조건을 연구하였다. NaBr 무첨가 반응의 경우 회분식 및 반연속식에서 NaBr 첨가반응에 비해 반응종결시간이 각각 100, 150%씩 늦어졌으나 물에 대한 용해도, 젤 형성능 등의 이화학적 성질은 NaBr 첨가 조건과 동일하게 향상 되었다. 반응시간의 차이는 나타나지만 회분식 반응에서 NaBr 첨가 여부에 관계없이 0.5 N NaOH 20 mL를 소비하여 ${\beta}$-1,3-glucan의 특이적 산화 전환의 이론적 수준인 100% 수율을 보였으나 회수된 산화물은 NaBr 무첨가 반응의 수율이 NaBr 첨가 반응보다 약 7-8% 낮았다. 높은 산화수율을 보인 ${\beta}$-1,3-glucan의 반연속식 공정 연구를 통해 산화반응물의 대량 생산이 가능하여 천연 소재, 기능성식품, 음료 및 주류 등의 산업에 널리 응용될 수 있을 것으로 기대된다. 특히 NaBr을 첨가하지 않고서도 특이적인 산화반응을 유도함으로써 안전성이 확보된 산화 ${\beta}$-1,3-glucan을 생산할 수 있음을 확인하였다.

리버스 무단 댐퍼용 연속가변밸브의 튜닝 파라미터에 관한 연구 (A Study on the Tuning Parameter of Continuous Variable Valve for Reverse Continuous Damper)

  • 윤영환;최명진;유송민
    • 한국자동차공학회논문집
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    • 제10권3호
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    • pp.192-200
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    • 2002
  • Semi-active suspension systems are greatly expected to be in the mainstream of future controlled suspensions for passenger cars. In this study, a continuous variable damper for a passenger car suspension is developed, which is controlled actively and exhibits high performance with light weight, low cost, and low energy consumption. To get fast response of the damper, reverse damping mechanism is adapted, and to get small pressure change rate after blow-off, a pilot controlled proportional valve is designed and analyzed. The reverse continuous variable damper is designed as a HS-SH damper that offers good body control with reduced transferred input force from tire, compared with any other type of suspension system. The damper structure is designed, so that rebound and compression damping force can be tuned independently, of which variable valve is placed externally. The rate of pressure change with respect to the flow rate after blow-off becomes smooth when the fixed orifice size increases, which means that the blow-off slope is controllable using the fixed orifice size. The damping force variance is wide and continuous, and is controlled by the spool opening, of which scheme is usually adapted in proportional valves. The reverse continuous variable damper developed in this study is expected to be utilized in the semi-active suspension systems in passenger cars after its performance and simplicity of the design is confirmed through real car test.

DEVELOPMENT OF A REVERSE CONTINUOUS VARIABLE DAMPER FOR SEMI-ACTIVE SUSPENSION

  • Yoon, Young-Hwan;Choi, Myung-Jin;Kim, Kyung-Hoon
    • International Journal of Automotive Technology
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    • 제3권1호
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    • pp.27-32
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    • 2002
  • Semi-active suspension systems are greatly expected to be in the mainstream of future controlled suspensions fur passenger cars. In this study, a continuous variable damper for a passenger car suspension is developed. It is controlled actively and exhibits high performance with light weight, low cost, and low energy consumption. To get fast response of the damper, reverse damping mechanism is adapted, and to get small pressure change rate after blow-off, a pilot controlled proportional valve is designed and analyzed. The reverse continuous variable damper is designed as a HS-SH damper which offers good body control with reduced transferred input force from tire, compared with any other type of suspension system. The damper structure is designed, so that rebound and compression damping force can be tuned independently, of which variable valve is placed externally. The rate of pressure change with respect to the flow rate after blow-offbecomes smooth when the fixed orifice size increases. Damping forces are measured with the change of the solenoid current at the different piston velocities to confirm the maximum hysteresis of 20N, linearity, and variance of damping farce. The damping farce variance is wide and continuous, and is controlled by the spoof opening, of which scheme is usually adapted in proportional valves. The reverse continuous variable damper developed in this study is expected to be utilized in the semi-active suspension systems in passenger cars after its performance and simplicity of the design is confirmed through real car test.

CONTINUITY OF HOMOMORPHISMS AND DERIVATIONS ON BANACH ALGEBRAS

  • Park, Sung-Wook
    • 대한수학회보
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    • 제30권1호
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    • pp.109-115
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    • 1993
  • In 1940 Eidelheit showed that every homomorphism of a Banach algebra onto the Banach algebra B(X) of all bounded linear operators on a Banach space X is continuous. At about the same time, Gelfand proved that every homomorphism of a commutative Banach algebra into a commutative semi-simple Banach algebra is continuous. In [7] Johnson proved that every homomorphism of a Banach algebra onto non-commutative semi-simple Banach algebra is continuous, and this is still the most important result of this type. In this paper we are concerned with continuity of derivations on commutative Banach algebras and of homomorphisms into commutative Banach algebras. Throughout this paper we suppose that A is a commutative Banach algebra. R will denote the redical of A.

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OSTROWSKI TYPE INEQUALITY FOR ABSOLUTELY CONTINUOUS FUNCTIONS ON SEGMENTS IN LINEAR SPACES

  • Kikianty, Eder;Dragomir, Sever S.;Cerone, Pietro
    • 대한수학회보
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    • 제45권4호
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    • pp.763-780
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    • 2008
  • An Ostrowski type inequality is developed for estimating the deviation of the integral mean of an absolutely continuous function, and the linear combination of its values at k + 1 partition points, on a segment of (real) linear spaces. Several particular cases are provided which recapture some earlier results, along with the results for trapezoidal type inequalities and the classical Ostrowski inequality. Some inequalities are obtained by applying these results for semi-inner products; and some of these inequalities are proven to be sharp.

PHRAGMEN-LINDELOF AND CONTINUOUS DEPENDENCE TYPE RESULTS IN GENERALIZED DISSIPATIVE HEAT CONDUCTION

  • Song, Jong-Chul;Yoon, Dall-Sun
    • 대한수학회지
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    • 제35권4호
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    • pp.945-960
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    • 1998
  • This paper is concerned with investigating the asymptotic behavior of end effects for a generalized heat conduction problem with an added dissipation term defined on a three-dimensional semi-infinite cylinder. With homogeneous Dirichlet conditions on the lateral surface of the cylinder it is shown that solutions either grow exponentially or decay exponentially in the distance from the finite end of the cylinder. In particular, to render decay estimate explicit, we pattern after the analysis of Payne and Song [13, 15]. The continuous dependence effect of perturbing the equations parameters is also investigated.

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연속 가변 댐퍼에 의한 반능동 현가장치의 고 자유도 제어기 (High Tunable Control Algorithm for Semi-active Suspension by a Normal Type CDC Damper)

  • 최주용
    • 제어로봇시스템학회논문지
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    • 제16권11호
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    • pp.1096-1103
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    • 2010
  • This paper proposes CDC (Continuous Damping Control) algorithm and verifies in multi-body dynamic vehicle. In order to distinguish a road profile on driving, waviness calculated by the filtered vertical-accelerations of sprung and unsprung masses is introduced. Sky-hook control is used at a low waviness road and constant damping level control is used at a high waviness road, where the hard damping level is determined by waviness, roll rate, acceleration, and deceleration. The damping levels of ride, anti-roll, anti-squat, and anti-dive modules are calculated by tuning parameters which is dependent upon vehicle velocity. Therefore this high tunable algorithm is useful to improve the ride and handling performance under various driving conditions. In the simulations, tire and dampers are modelled by SWIFT (Short Wavelength Intermediate Frequency Tire) model and 1st order delay model, and results are compared with conventional damper's.

Development of Practical Semi-active Suspension Control System

  • Takahashi, Hideaki;Zhang, Feifei;Mishima, Kiyoshi;Ito, Masanori
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.278-281
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    • 2003
  • The focus of this research is to realize the function which is equivalent to the active suspension system, with controlling semi-active suspension through the attenuation of power variable damper in lower cost and smaller energy. Actually some semi-active suspension systems have been adopted, but they are not sufficient in performance. The authors intended to develop more effective and practical system and applied the optimal control technique. The results of experiments with practical suspension system showed a degree of improvement of comfortableness.

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ON GENERALIZED VECTOR QUASI-VARIATIONAL TYPE INEQUALITIES

  • Cho, Y.J.;Salahuddin, Salahuddin;Ahmad, M.K.
    • East Asian mathematical journal
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    • 제26권1호
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    • pp.49-58
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    • 2010
  • In this paper, we consider and study a new class of generalized vector quasi-variational type inequalities and obtain some existence theorems for both under compact and noncompact assumptions in topological vector spaces without using monotonicity. For the noncompact case, we use the concept of escaping sequences.

KINETICS OF AUTOTROPHIC DENITRIFICATION FOR THE BIOFILM FORMED ON SULFUR PARTICLES : Evaluation of Molecular Technique on Monitoring Biomass Growth

  • Kim, Sung-Youn;Jang, Am;Kim, I-Tae;Kim, Kwang-Soo;Kim, In-S.
    • Environmental Engineering Research
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    • 제10권6호
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    • pp.283-293
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    • 2005
  • Characteristics of sulfur-based autotrophic denitrification in a semi-continuous type reactor and the kinetic parameters were studied. Enriched autotrophic denitrifying culture was used for the reactor operation. Biomass growth on sulfur particles and in the liquid medium was monitored using the DAPI staining method. From the result of ion concentration changes and the biomass growth, maximum specific growth rate, ${\mu}_{max}$, and the half velocity constant, $K_M$, were estimated as $0.61\;d^{-1}$ and 3.66 mg/L, respectively. Growth yield coefficient, Y values for electron acceptor and donor were found as 0.49 gVSS/g N and 0.16 gVSS/g S. The biomass showed specific denitrification rate, ranging 0.86-1.13 gN/g VSS-d. A half-order equation was found to best simulate the denitrification process in the packed bed reactor operated in the semi-continuous mode.