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L-N-Benzylaspartic acid의 선택적 에스테르화 반응
이채호,김일광,박승화,이영행,정봉영 圓光大學校 基礎自然科學硏究所 1987 基礎科學硏究誌 Vol.6 No.1
Selective esterification and synthesis of L-N-benzylaspartic acid from L-aspartic acid are described. L-Aspartic acid was transformed into dibenzyl L-asparate p-toluenesulfonate, which was treated with sodium bicarbonate to afford dibenazyl L-asparate. Formation of Schiff base of dibenayl ester with benzaldehyde and subsequent hydrogenation-dehydrogenation of the Schiff base produced L-N-benaylaspartic acid. L-N-Benaylaspartic adcid was transformed into L-N-benzylaspartic anhydride hydrogen bromide, which was treated with methyl alcohol and benzyl alcohol to afford a-methyl and a-benzyl L-N-benzylaspartate and L-N-benaylaspartic acid was transformed into L-N-benaylaspartic acid copper(Ⅱ) salt, which was treated with N,N,N,N-tetramethylguanidine and benzyl bromide to afford β-benzylaspartate
성공적인 eCRM, CRM을 위한 유전자알고리즘의 혼합 초기화법을 이용한 데이터마이닝
강래구,김승언,정채영 朝鮮大學校 統計硏究所 2006 統計硏究所論文誌 Vol.8 No.1
고객관리가 기업의 성패를 좌우하는 중요한 화두로 떠오르면서 보다 쉽고 편리하게 고객의 다양한 Pattern을 발견하고 예측하기 위해 많은 기업들이 CRM과 eCRM을 빠르게 도입하고 있다. 과거엔 고객관리가 통계학자들이나 전문적인 통계패키지에 의해 관리되어 왔으나 IT 분야의 급격한 발달을 기반으로 통계적 과정을 자동화시킨 Data Mining 기법으로 점점 대체되고 있는 추세이다. 이러한 Data Mining이 대표적으로 이용되고 있는 분야가 CRM, eCRM이다. Genetic Algorithm을 이용하여 Data Mining을 적용함에 있어서 본 논문에서는 무작위 초기화법과 유도된 초기화법을 동시에 사용하는 새로운 집단 초기화 방법을 적용하여 A할인점의 2004년과 2005년도 우수고객을 예측하였고 실제 고객 데이터와의 비교를 통해 본 논문에서 제안한 새로운 집단 초기화 방법의 성능을 입증하였다.
Jung, Seung Chai,Yoon, Bye-Ri,Oh, Jin Sun,Choi, Seung Hong,Han, Moon Hee,Lee, Jang Yeol,Cho, Hye Rim,Rhee, Kyehan,Jho, Jae Young Ovid Technologies (Wolters Kluwer) - Lippincott Wi 2012 ASAIO journal Vol.58 No.5
<P>In this study, we propose a new method for the enhancement of intraarterial thrombolysis by use of an endovascular vibrating polymer actuator probe (VPAP), which is fabricated from an ionic polymer metal composite (IPMC) actuator. The endovascular VPAP was fabricated by combining 0.8 0.8 10 mm3 IPMC samples, 0.22 mm 50 cm copper wires, and 40 cm of Teflon tube. The purpose of this study was to evaluate the thrombolysis efficiency of an endovascular VPAP in a dog model. Both renal arteries of the enrolled dogs (n = 5) were used in the current study. A distal portion of the renal artery in a mongrel dog was occluded by a blood clot from autologous venous whole blood. Intraarterial thrombolysis was performed by use of a VPAP without the actuation force (control group), by a VPAP-only (VPAP-only group), or with a combination of recombinant tissue plasminogen activator (rtPA) and a VPAP (VPAP + rtPA group). The thrombolysis efficiency was evaluated by the modified Thrombolysis in Myocardial Infarction (TIMI) grading system based on the consensus between two radiologists. The grading scales were compared according to each intraarterial thrombolysis method. The VPAP + rtPA and VPAP-only groups showed a significantly higher thrombolysis efficiency than did the control group (p < 0.05). The VPAP-only group also showed a significantly higher thrombolysis efficiency than did the control group (p < 0.05). The VPAP+ rtPA group showed a significantly higher thrombolysis efficiency than did the VPAP-only group (p < 0.05). The use of an endovascular VPAP was a feasible and useful method for intraarterial thrombolysis, and it enhanced the thrombolysis efficiency when combined with the thrombolytic agent rtPA.</P>
열, 첨가제, 촉매에 의한 DPF내 포집된 입자상 물질 재생 모델링
정승채(Seung-chai Jung),윤웅섭(Woong-sup Yoon) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
DPF reduce particulate emission by physically trapping the particles and the collected PM has to be periodically or continuously removed from the filter by a regeneration process. One of the major issue for DPF system is developing a safe and effective regeneration strategy. In the present study, PM oxidation by heat, fuel additive and catalyzed filter was studied. One-dimensional mathematical models describing regeneration and filtration process were developed. These models can produce spatio-temporal evolution of filter temperature, pressure drop and mass of PM remained in the filter during regeneration. Models are calibrated by measured data and simulation results showed good agreement.
고주파 신호주입을 이용한 센서리스 구동용 고출력밀도 매입형 영구자석 동기전동기의 설계
채승희(Seung-Hee Chai),이병화(Byeong-Hwa Lee),홍정표(Jung-Pyo Hong),설승기(Seung-Ki Sul),이근호(Geun-Ho Lee) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5
This paper estimates inductance profile well adapted to position sensorless control method based on the high frequency signal injection and proposes a direction to design for sensorless control in interior permanent magnet synchronous motor(IPMSM) having a high density output power. In sensorless control, controller calculates the position of rotor at smallest d-axis inductance from high frequency injection. In order to satisfy this characteristic, this paper designs a motor having a large magnetic loading and a small electric loading. Inductance is calculated by the FEM using frozen permeability method and voltage equations of d-q axis are used to analyze characteristics of IPMSM such as torque, output power, current angle and efficiency.
디젤 배기 내 NO<SUB>x</SUB> 저감을 위한 NH₃-SCR 과정의 모델링 및 해석
정승채(Seung-chai Jung),윤웅섭(Woong-sup Yoon) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
A mathematical modeling of NOx reduction in NH₃-SCR process is attempted. The model is deterministic in finding an reduction extent and hires one-dimensional equations for mass balance in the monolith channel, species balance on the catalyst surface and rate expressions of Langmuir-Hinshelwood type reaction scheme which deals NO and NO₂ reactions with NH₃ in the presence of vanadium catalyst. Present modeling was validated extensively with experimental data in terms of NOx reduction efficiency. Sensitivity of NOx reduction against oxygen and water concentrations was examined and the prediction yielded highly accurate solutions over a wide range of NO₂/NOx ratios from 0 to 1 in a temperature range of 200℃-550℃. Also examined is the effect of NH₃/NO ratio on NOx reduction. The NOx reduction depends heavily on NO₂/NOx ratio at temperatures lower than 300℃. NO reduction efficiency is significantly augmented with increasing in NH₃/NO ratio at higher temperatures, but is a very weak function of NH₃/NO ratio at lower temperatures.
NH₃-SCR 방법에 의한 디젤 배기 내 De-NO<SUB>x</SUB> 과정에서의 DOC에 의한 영향과 거감 성능 변화 해석
정승채(Seung-chai Jung),윤웅섭(Woong-sup Yoon) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
A positive influence of oxidation precatalyst on the NOx reduction by NH₃-SCR was analytically investigated. Physicochemical processes in regard to NOx reduction by NH₃-SCR and NO-NO₂ conversion by the oxidation catalyst are formulated with proper models for individual physics. A unified model is correctly validated with experimental data in terms of NOx reduction efficiency for SCR and NO-NO₂ conversion efficiency for DOC. The model equipped with rate expressions of Langmuir-Hinshelwood type reaction scheme is deterministic and finds a conversion extent directly. A series of numerical experiments were carried out and parametric analysis of the NOx reduction was conducted. NOx reduction is expedited in proportion to DOC volume at lower temperatures, whereas deactivated with increasing DOC volume when the space velocity is lower at intermediate temperature regime. At intermediate temperatures, NOx conversion is proportionally increasing with the space velocity. NOx conversion is a weak function of the space velocity and DOC volume at higher exhaust temperatures. In DOC-SCR system, the NOx reduction efficiency is gradually increasing with NH₃/NOx ratios.
정승채(Seung-chai Jung),윤웅섭(Woong-sup Yoon) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Diesel oxidation catalyst (DOC) is a widely used device to reduce harmful species of exhaust gas with less engine back pressure. A one-dimensional model simulating the oxidation of CO, HC and NO was developed to predict the state of gaseous emission exiting a DOC. The model formulation is based on the constraint of conservation of mass, species and energy inside DOC. Kinetics of CO, HC and NO were modeled assuming global reaction using inhibition factor. Steady-state experimental data covering a wide range of operating conditions calibrates the model parameters. The results showed good agreement with the experimental data in a test window of 200℃~500℃ for temperature and 0.1㎥/s~0.7㎥/s for volumetric flowrate.
정승채(Seung-chai Jung),박종선(Jong-sun Park),윤웅섭(Woong-sup Yoon) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_1
Prediction of diesel particulate filtration necessitates appropriate models for pressure drop and particulate matter (PM) collection, and the models are not frequently deterministic, thus must be closed with certain parameters of much smaller scales typically determined experimentally. Included are soot cake permeability, soot cake density, soot density in filter wall, and percolation constant. Aiming at elucidating these essential parameters, the present study attempts the enhancement of DPF filtration model with non-linear description of soot cake regression, The model is properly validated with single channel DPF measurements. Effects of these parameters on the pressure drop, a direct measure of filtration quality, are estimates in a parametric manner and discussed in terms of filtration velocity. Conclusively, the extent of percolation constant is controlling pressure drops, and soot density in the filter wall is relatively important in deep-bed filtration regime. Filtration quality of the deep-bed mode is relatively less sensitive to particle size than soot cake regime.