• Structural Engineering and Mechanics
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• 제5권1호
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• pp.69-83
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• 1997

A new efficient hybrid/mixed thin~moderately thick plate bending element with 6-node (HM6-14) is formulated based on the Reissner-Mindlin plate bending theory. The convergence of this element is proved by error estimate theories and verified by patch test respectively. Numerical studies on such an element as HM6-14 demonstrate that it has remarkable convergence, invariability to geometric distorted mesh situations, to axial rotations, and to node positions, and no "locking" phenomenon in thin plate limit. The present element is suitable to many kinds of shape and thin~moderately thick plate bending problems. Further, in comparison with original hybrid/mixed plate bending element HP4, the present element yields an improvement of solutions. Therefore, it is an efficient element and suitable for the development of adaptive multi-field finite element method (FEM).

• 한국전자통신학회논문지
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• 제6권6호
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• pp.855-864
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• 2011

본 논문은 IPMSM(Interior Permanent Magnet Synchronous Motor)의 고성능 운전을 위해 비선형 제어를 기반으로 하는 적응 백스텝핑 제어기를 제안한다. 먼저 각속도의 추종성능을 향상시키기 위해서 비선형 백스텝핑 제어기를 설계한다. 파라메타 변동의 영향을 고려하지 않고 설계된 제어기는 고성능 운전이 어렵다. 부하토크의 변동에 대해 실시간 적응할 수 있는 파라메타 추정기를 설계에 포함하여 고성능 운전이 가능하게 한다. 또한 전동기의 효율적인 전력소비를 위하여 최대토크를 얻기 위한 최소전류의 운전을 할 수 있도록 제어기를 설계하였다. 제안된 제어기로 2마력급의 IPMSM에 적용하여 각속도 레퍼런스에 대한 추종성능과 부하토크 변동에 대한 추정, 그리고 MTPA(Maximum Torque per Ampere) 운전을 시험하여 일정토크 운전영역에서 안정화된 강건한 제어기임을 시뮬레이션을 통해 확인할 수 있었다.

• Preventive Nutrition and Food Science
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• 제4권1호
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• pp.47-51
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• 1999

In order to evaluate the dietary regulation of cysteine sulfinic acid decarboxylase (EC 4.1.1.29) in cats, acitivity and protein content of CSAD were assessed in the liver and kidney of cats fed different levels of dietary protein, with and without taurine. Four groups of cats were fed one of the follow diets for 5 weeks ; 20% protein and taurine- free diet(LP0T) ; 20% protein and 0.15% taurine diet(LPNT) ; 60% protein and taurine-free diet(HP0T); and 60% protein and 0.15% taurine diet (HPNT). CSAD activity was determined in the liver and kidney of cats by measuring 14C2 released form [1-14C]-L cysteine sulfinic acid. CSAD protein was quantified using an immunochemical method. CSAD activity was extremely low in cat tissues, among which kidney showed the highest activity which was 0.118$\pm$0.050, and 0.377$\pm$0.056 nmol.min-1.mg soluble portein-1 iin animals fed LP0T and HP0T, respectively. Even though renal CSAD protein content was 18~55% of the hepatic CSAD protein content, renal CSAD acitivity was 1.3~6.5 times of the hepatic CSAD activity . Renal CSAD acitivities of cats fed 60% protein were about 1.6~3.2 times those of animals fed 2.% protein , and hepatic CSAD activity was not significantly affected by the dietary level of protein. Taurine depletion significantly elevated both hepatic and renal CSAD activities above the values for cats having normal taurine status most probably as an adaptive response.