• 제목/요약/키워드: Functional reduction

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Thirty Six Years of Research on the Selective Reduction and Hydroboration

  • Cha, Jin-Soon
    • Bulletin of the Korean Chemical Society
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    • 제32권6호
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    • pp.1808-1846
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    • 2011
  • From 1975 to 2011, for thirty six years, the author and his collaborators have developed a variety of reducing and hydroborating agents, and applied them to organic synthesis, which involves the 1,2-reduction of ${\alpha}$,${\beta}$-unsaturated carbonyl compounds, stereoselective reduction of cycloalkanones, regioselective ring-opening of epoxides, partial reduction of carboxylic acid derivatives to aldehydes, regioselective addition to carbon-carbon multiple bonds, etc. by utilizing metal hydrides and the newly-devised the Meerwein-Ponndorf-Verley (MPV) type reagents. Such developments provide a new synthetic methodology making possible valuable selective reductions and hydroborations, not practical previously.

Selective Reduction of Orgainc Compounds with Al-Fluorodiisobutylalane

  • 차진순;박성진
    • 통합자연과학논문집
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    • 제2권3호
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    • pp.185-189
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    • 2009
  • The new MPV-type reagent, Al-fluorodiisobutylalane (DIBAF), has been prepared and their reducing characteristics in the reduction of selected organic compounds containing representative functional groups have been examined in order to find out a new reducing system with unique applicability in organic synthesis. In general, the reagent is extremely mild, showing only reactivity toward aldehydes, ketones, and epoxides. The reagent achives a clean 1,2-reduction of enals to the corresponding allylic alcohols in a 100% purity, but shows no reactivity toward enones. The reagent also shows an excellent regioselective cleavage of substituted epoxides. In addition, DIBAF produces the thermodynamically more stable alcohol epimer in high stereoselectivity in the reduction of cyclic ketones.

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Selective Reduction of Carbonyl Compounds with Dilsobutyldialkylaminoalanes

  • 차진순;권상용;권오운;김종미;송한철
    • Bulletin of the Korean Chemical Society
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    • 제17권10호
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    • pp.900-905
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    • 1996
  • Details are described of reaction of carbonyl compounds with diisobutyldialkylaminoalane (DIBAL-NR2; R=Et, i-Bu, Ph) in order to establish their reduction characteristics. The reagents were extremely mild and reduced only aldehydes and ketones effectively in ethyl ether at 25 ℃. The stereoselectivity in the reduction of representative cyclic ketones appeared not so high but quite different from that obtained by DIBAL-H itself. The reagents reduced α,β-unsaturated aldehydes and ketones to the corresponding allylic alcohols without any detectable 1,4-reduction products. DIBAL-NR2 also achieved the selective reduction of aldehydes or ketones in the presence of keto or other readily reducible functional group, however the chemoselectivity was less satisfactory than that achieved by diisobutylethoxyalane (DI-BAL-OEt).

요통환자의 도수교정 전.후의 기능적 다리길이 편차 비교 (A Comparison of Functional Leg Length Inequality Before and After Manipulation of patients with Low Back Pain)

  • 마상렬
    • 대한물리치료과학회지
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    • 제13권1호
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    • pp.21-27
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    • 2006
  • The purpose of this study was to identify the above mentioned therapy on the reduction of functional leg length inequality, by the manipulation(Thonpson technique). In 8 patients who have been chronically ill with low back pain and functional leg length inequality, for past 12 weeks, we analyzed and observed the progress of symptom and sign on pelvis(femur head line level, ilium length, ilium rotation), using by X-ray. The results after 12 week treatment, compared with before treatment, were as follows : 1. The improved in femur head line in the manipulation after 12 week treatment was very significant(p<.01) 2. The improved in ilium length in the manipulation after 12 week treatment was very significant(p<.01) 3. The improved in ilium rotation in the manipulation after 12 week treatment was significant(p<.05).

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기능적 전기자극에 대한 고찰 (The Review of Functional Electrical Stimulation)

  • 박규현;김선규;정현애;박래준
    • The Journal of Korean Physical Therapy
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    • 제13권2호
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    • pp.399-405
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    • 2001
  • Attainment of the goals of functional electrical stimulation(FES) applications such as strengthening of muscle, increasing muscular endurance, improvement in joint range of motion or the reduction of spasticity does not insure that patients will be able to produce voluntary muscle contraction sufficient to maintain posture or produce purposeful movements. In many patients who have sustained CNS damage, the control exerted by higher nervous system center over muscle contraction may impaired. In Searched patients, a variety of advanced therapeutic exercise techniques have been employed traditionally to facilitate the return of controlled functional muscular activity or maintain postural alignment until recovery from dysfunction occurs Among the most common clinical applications of FES for functional muscle contraction is as a substitute for static or dynamic orthotic devices

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Synthesis of Epoxy Functional Siloxane and its Effect on Thermal Stress

  • Hyun, Dae-Sup;Jeong, Noh-Hee
    • 한국응용과학기술학회지
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    • 제26권4호
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    • pp.379-384
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    • 2009
  • Epoxy resin based encapsulants are widely used in semiconductor packaging applications. Epoxy resin based encapsulants are often subject to crack or delamination during the reliability test due to the thermal stress caused by high modulus nature of epoxy resins. Epoxy functional siloxanes are often added into epoxy resin to reduce the modulus so that the thermal stress can be reduced. Epoxy functional siloxanes, additives for reduced modulus, were synthesized and added into the curable epoxy resins. The modulus and the coefficient of thermal expansion (CTE) were also measured to investigate the thermal stress and to see whether the epoxy functional siloxane adversely affects the CTE or not. As a result, around 26% to 72% of thermal stress reduction was observed with no adverse effect on CTE.

기능성 성분을 가진 식품의 인체 건강 유용성에 대한 연구 (Study on Health Benefits in Human Body of Food with Functional Ingredients)

  • 한명규
    • 한국식품영양학회지
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    • 제16권3호
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    • pp.224-231
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    • 2003
  • The development of food science in the near future probably depends on the advance in functional food science. Actually, a number of substances and products with potential for disease risk reduction rather than simply for health maintenance have been investigated for their body-modulating functions. Some of them have been applied in practice to the industrialization of functional foods in terms of foods for health uses. Health is becoming a more important aspect of food. Consumers increasingly see the link between food and health, thus generating growing levels of consumer interest in more actively managing their diets and, by implication, their health. there is demand from consumers and strong manufacturer push towards the development of food as medicine. Pharmaceutical companies are currently focused on the medical aspects of food as medicine, but it is expected that there will be an increase in the rate of active ingredients for lifestyle application.

Illumination correction via improved grey wolf optimizer for regularized random vector functional link network

  • Xiaochun Zhang;Zhiyu Zhou
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제17권3호
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    • pp.816-839
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    • 2023
  • In a random vector functional link (RVFL) network, shortcomings such as local optimal stagnation and decreased convergence performance cause a reduction in the accuracy of illumination correction by only inputting the weights and biases of hidden neurons. In this study, we proposed an improved regularized random vector functional link (RRVFL) network algorithm with an optimized grey wolf optimizer (GWO). Herein, we first proposed the moth-flame optimization (MFO) algorithm to provide a set of excellent initial populations to improve the convergence rate of GWO. Thereafter, the MFO-GWO algorithm simultaneously optimized the input feature, input weight, hidden node and bias of RRVFL, thereby avoiding local optimal stagnation. Finally, the MFO-GWO-RRVFL algorithm was applied to ameliorate the performance of illumination correction of various test images. The experimental results revealed that the MFO-GWO-RRVFL algorithm was stable, compatible, and exhibited a fast convergence rate.

전통주택 안대청의 기능적 상관성에 관한 연구 (A Study on functional interrelationship of An- Daecheong in Traditional residence)

  • 여미나;윤재웅
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 1996년도 학술발표대회논문집
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    • pp.67-72
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    • 1996
  • The Purpose of this study is to examine the characteristics of the space composition of Korean traditional residence by analysing the meaning and function of traditional residence's An-Daecheong of late Chosun dynasty, as well as its interrelationship with other spaces. It can be analysed. then that such factors as the weak economic ablility of the current agricultural society and reduction of the number of family member have made the function of the An-Daecheong weak, and that such factors as westernization of life style and modernization of residence facilities have reduced the functional interrelationship of the An-Daecheong. An-Madang and Kitchen.

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비선형 미분방정식으로 표현되는 비선형 시스템의 해석을 위한 볼테리 시리즈의 응용 (Application of Volterra Functional Series to the Analysis of Nonlinear Systems Represented by Nonlinear Differential Equations)

  • Sung, Dan-Keun
    • 대한전자공학회논문지
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    • 제25권3호
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    • pp.315-321
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    • 1988
  • The input-output relation for nonlinear systems can e explicitly represented by the volterra functional series and it is characterized by the Volterra kernels. A block diagram reduction method is proposed to determine the Volterra kernels for nonlinear differential equations and is compared with the direct substitution techniques. The former method can significantly reduce the computational complexity. A degree of nonlinearity is defined and analyzed for the analysis of nonlinear systems.

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