http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 여재구 (검색결과 6 건)
- 무료
- 기관 내 무료
- 유료
-
-
여재구,김정원 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0
The heterogeneous (Ru(OH)x@2D-graphene) catalyst was prepared by plain permeate method for the efficient oxidative synthesis of aldehydes from various alcohols at 100°C in the molecular oxygen environment.Catalysts with various metals as active species and solvents were tested in the oxidation reaction for the modification of conditions. The catalyst (Ru(OH)x/2D-graphene) exhibited good to excellent yield selectivity and conversion for various alcohol substrates. The (Ru(OH)x/2D-graphene) catalyst able to showed almost nearly the same catalytic performance after almost ten times recycling after the first reaction cycle.
-
Oxidation of Alcohols to Aldehydes or Ketones by Heterogeneous Ru(OH)x@2D-Graphene Catalyst in Air
여재구,김정원 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0
The heterogeneous (Ru(OH)x@2D-graphene) catalyst was prepared by plain permeate method for the efficient oxidative synthesis of aldehydes or ketones from alcohols at 100°C in the presence of molecular oxygen. Various kinds of catalysts and solvents were tested in the oxidation reaction for the adjustment of conditions. The as-prepared catalyst (Ru(OH)x/2D-graphene) exhibited good to excellent yield and selectivity for a large number of alcohol substrates. The (Ru(OH)x/2D-graphene) catalsyt was able to show almost the same catalytic performance after several times recycling as the first reaction cycle.
-
여재구,김정원 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1
The heterogeneous ruthenium 2-dimension graphene catalyst (Ru(OH)x/2D-G) was synthesized by plain permeate method for the functional oxidative transformation of alcohols to aldehydes or ketones at 100°C. The reaction conditions for alcohol oxidation were optimized by testing various solvent and catalysts. The synthesized catalyst (Ru(OH)x/2D-G) demonstrated excellent yield and selectivity for a wide range of alcohol substrates. The (Ru(OH)x/2D-G) was able to proceed not only first oxidation with high catalytic activity but also showed almost same catalytic performance after several times recycling.
-
여재구,박창이,구자용 한국자료분석학회 2011 Journal of the Korean Data Analysis Society Vol.13 No.6
신용평점표 작성시 각 특성변수들을 적은 수의 속성들로 나누고 각 속성에 적절한 가중치를 부여하게 된다. 이러한 과정을 성김화라 한다. 성김화의 목적은 1) 신용대출에 대한 결정을 고객에게 이해하기 쉽도록 설명하기 위함이며 2) 신용위험도와 특성변수간에 비선형적 관계를 허용함으로써 예측력을 향상시키기 위한 것이다. 통계적 관점에서 보면 성김화는 연속형 변수를 몇 개의 구간으로 이산화하거나 이산형 변수의 수준들을 소수의 수준 그룹으로 재그룹화 하는 것이다. 본 논문에서는 연속형 변수를 이산화 할 때 그 기준이 되는 절단값 선택에 대하여 연구한다. 문헌상의 절단값 선택법으로는 등구간법, 분위수법, 모의 담금질법, 스플라인 분류 기계 등이 있다. 스플라인 분류 기계에서는 최적의 절단값들을 자동적으로 선택하는 반면 나머지 방법들은 절단값의 개수를 입력값으로 요구한다. 본 연구에서는 속성의 개수를 입력으로 요구하는 방법들에 대해서는 확인오차법으로 최적의 속성수와 절단값들을 동시에 결정한다. 모의실험 및 실제 신용자료 분석 결과 스플라인 분류 기계가 예측력과 계산속도의 측면에서 전반적으로 우수함을 알 수 있었다. In constructing a credit scorecard, each characteristic variable is divided into a few attributes and weights are assigned to those attributes. Such a process is called coarse classification. The purposes of coarse classification are 1) to make a customer easily understand the decision on credit loan and 2) to improve a prediction by allowing a nonlinear relationship between the credit risk and a characteristic variable. From statistical perspective, coarse classification is to divide a continuous variable into a few intervals or regroup levels of a categorical variable into a small number of level groups. In this paper, we study the selection of cutpoints by which a continuous variable is discretized. In the literature, cutpoint selection methods such as equal spacing, quantile method, simulated annealing, and classification spline machine have been proposed. While classification spline machine automatically selects optimal cutpoints, the other methods requires the number of cutpoints as an input. We determine the optimal number of cutpoints by a cross-validation for those methods requiring the number of cutpoints as an input. Results from simulated and real credit data analysis indicate that overall performance of classification spline machine is good in terms of prediction and computing time.
-
Muhammad Asif Hussain,최은주,Adnan Maqbool,Muhammad Atif,Hassan Zeb,여재구,유정아,조영훈,Moses Noh,김정원 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.99 No.-
A facile eco-friendly heterogeneous catalytic system has been developed for amide synthesis that furtherutilized in pharmaceutical and organic chemistry. The Ru/MnO2 catalyst has shown outstanding andunprecedented activity for a wide range of aliphatic and benzylic nitriles in green solvent water at 60 C. The system has also exhibited a remarkable tolerance for selective hydration of heteroatom (e.g. nitrogen,oxygen and sulphur atoms) containing nitriles. Pharmaceutically important nicotinamides andpyrazinamide has been synthesized by hydration of the heteroatomic nitriles with appreciable yieldsand selectivities. Moreover, the Ru/MnO2 catalyst has employed water as a benign solvent, with morethan 30,000 TONs and reusabilityfive times after isolation from the reaction mixture by centrifugationand easy workup that established a path for green environmental and technologically acceptableprotocol.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
