• Title/Summary/Keyword: Structural Synthesis

Search Result 793, Processing Time 0.034 seconds

SCHEDULING TECHNIQUE FOR CONTROL STEP (스케듈링 기법 연구)

  • JeongYoungSong;NamWooBack
    • Journal of the Korean Geophysical Society
    • /
    • v.4 no.3
    • /
    • pp.163-173
    • /
    • 2001
  • This paper deals with scheduling problems which are the most important subtask in High-Level Synthesis. Especially, we have concentrated our attentions on the data-path scheduling which can get the structural informaion trom the behavioral algorithm as a first step in synthesis procedure. Suggest Forward scheduling methode is executed the ASAP and ALAP scheduling to use the fifth - order elliptic wave filter of a standard benchmark moedl, and then it is drawing up T.N matrix table by the number resource and control-step, using the table extract of the simple than down-limit value of the control-step for the number of given resource th use this table. All of existing list scheduling techniques determine the priority function first, and then do the operation scheduling, But, the suggested forward scheduling technique does the schedule first, and determines the priority functions if needed in scheduling process.

  • PDF

SYNTHESIS OF CARBON NITRIDE THIN FILMS BY PLASMA PROCESSING

  • Takai, Osamu;Taki, Yusuke;Kitagawa, Toshihisa
    • Journal of the Korean institute of surface engineering
    • /
    • v.29 no.5
    • /
    • pp.363-370
    • /
    • 1996
  • Carbon nitride is one of the new carbon materials which show interesting properties. After the theoretical calculation by LIu and Cohen, many researchers are trying to prepare $\beta$-$C_3N_4$ which may be harder than diamond. Many carbon nitride films synthesized till now by various methods are amorphous and the N/C ratios in the films are usually below 0.5. First we review shortly the synthesis of carbon nitride thin films by plasma, ion and laser processing. Second we report on the preparation of amorphous carbon nitride thin films by shielded arc ion plating and the structural and mechanical properties of the films.

  • PDF

Scheduling Technique for Control Step (제어구간에 의한 스케듈링 기법)

  • Song, Jeong-Young;Back, Nam-Woo
    • The Journal of Engineering Research
    • /
    • v.4 no.1
    • /
    • pp.35-45
    • /
    • 2002
  • This paper deals with the scheduling problems which are the most important subtask in High-Level Synthesis. Especially, we have concentrated our attentions on the data-path scheduling which can get the structural informations from the behavioral algorithm as a first step in synthesis procedure. Suggest Forward scheduling methode is executed the ASAP and ALAP scheduling to use the fifth – order elliptic wave filter of a standard benchmark model, and then it is drawing up T.N matrix table by the number of resource and control-step, using the table extract of the simple than down-limit value of the control-step for the number of given resource to use this table. All of existing list scheduling techniques determine the priority functions first, and then do the operation scheduling, But, the suggested forward scheduling technique does the schedule first, and determines the priority functions if needed in scheduling process.

  • PDF

Observations on Fragmentation Pathway of Farinomalein and its Isomers by Structural Investigation Using LC-MS/MS

  • Firke, Narayan P.;Markandeya, Anil G.;Deshmukh, Rajendra S. Konde;Pingale, Shirish S.
    • Mass Spectrometry Letters
    • /
    • v.9 no.1
    • /
    • pp.37-40
    • /
    • 2018
  • Farinomalein is a maleimide-bearing compound well known for its anti-fungal activity. In the present study, synthesis of farinomalein is achieved via Stobbe condensation followed by Haval-Argade contrathermodynamic rearrangement. Kinetically driven Stobbe condensation followed by condensation with beta-alanine reveals formation of two isomers of farinomalein. This article describes application of LC-MS/MS in structure elucidation of farinomalein 1 and its isomers 2 and 3 encountered in its synthesis. The proposed distinct fragmentation pathway is supported by rational organic reaction mechanism. These fragmentation pathways are significant for analytical method development of farinomalein in near future. The structures of farinomalein 1 and its isomers 2 and 3 have been assigned undisputedly.

The pH Effect on the Preparation of MFI Type Ferrisilicate Zeolites

  • 염영훈;남상성;김성보;이규완
    • Bulletin of the Korean Chemical Society
    • /
    • v.20 no.7
    • /
    • pp.781-785
    • /
    • 1999
  • Ferrisilicates with MFI type structure were hydrothermally synthesized. The structural environments of iron in the ferrisilicates were characterized by XRD, SEM, IR, EPR, and ammonia-TPD. It has been shown that pH of the final gel mixture during the synthesis affects the crystal size, morphology, chemical composition and catalyticactivity. The results of the lattice parameters, IR, and EPR indicate the existence of a framework iron and the content of framework iron depends on pH of the synthesis gel. Finally, the catalytic activity of these zeolites was examined for the cyclohexane oxidation to cyclohexanol and cyclohexanone in the liquid phase. The conversion of this reaction was increased with increasing iron content of the framework lattice positions.

Synthesis of Water-Soluble Methoxyethoxy-Aminoarlyoxy Cosubstituted Polyphosphazenes as Carrier Molecules for Bioactive Agents

  • Gwon, Seok Gi
    • Bulletin of the Korean Chemical Society
    • /
    • v.21 no.10
    • /
    • pp.1039-1040
    • /
    • 2000
  • The water-soluble poly(methoxyethoxy-aminoarlyoxy phosphazene) has been synthesized and investigated as a polymeric carrier molecule for the covalent attachment of bioactive agents. The synthetic procedures were developed first through the use of cyclic trimeric model systems. These model systems were utilized for the synthesis of polymeric analogues containing bioactive side groups. The sodium salts of 2-methoxyethanol and 4-acetamidophenol were allowed to react with $(NPCl_2)_3$ or $(NPCl_2)n$ or to yield derivatives of type $[NP-(OCl_2CH_2CH_2OCH_3){\chi}(OArNHCOCH_3)y]_3or$ n. The 4-acetamido groups were then hydrolyzed to 4-amino-phenoxy units with potassium tert-butoxide. Coupling reactions between amino group and N-acetylglycine was accomplished with the use of dicyclohexylcarbodiimide. Their properties and structural characterization are discussed.

Synthesis of Water-Soluble Aminoaryloxy-Methylamino Cosubstituted Polyphosphazenes as Carrier Species for Biologically Active Agents

  • Gwon, Seok Gi
    • Bulletin of the Korean Chemical Society
    • /
    • v.22 no.11
    • /
    • pp.1243-1247
    • /
    • 2001
  • The water-soluble poly(aminoaryloxy-methylamino phosphazene) has been synthesized and investigated as a polymeric carrier species for the covalent attachment of biologically active agents. The cyclic trimeric model systems were utilized for the synthesis of polymeric analogues containing bioactive side groups. The sodium salt of 4-acetamidophenol was first allowed to react with (NPCl2)3 or (NPCl2)n and was then treated with excess methylamine to yield derivatives of type [NP(NHCH3)x(OArNHCOCH3)y]3 or [NP(NHCH3)x(OArNHCOCH3)y]n. The 4-acetamido groups were then hydrolyzed to 4-aminophenoxy units with potassium tert-butoxide. Coupling reactions between amino group and N-acetylglycine was accomplished with the use of dicyclohexylcarbodiimide. Their properties and structural characterization are discussed.

Total Synthesis of Bacillariolide III

  • Suh, Young-Ger;Seo, Seung-Yong;Paek, Seung-Mann;Jung, Jae-Kyung;Han, Young-Taek;Kim, Seok-Ho
    • Proceedings of the PSK Conference
    • /
    • 2003.10b
    • /
    • pp.65.3-66
    • /
    • 2003
  • Bacillariolide III was isolated from the culture medium of the marine diatom, Pseudonitzschia multi series, a causative organism of amnesic shellfish poisoning by Shimizu et al. This extracellular metabolite features bicyclic system of hydroxycyclopentane and (Z)-pentenoic acid-bearing lactone ring. Bacillariolide I is known to possess significant inhibitory activity against phospholipase A$_2$, but the biological function of bacillariolide III is still under investigation. The unique structural feature as well as the promising biological activity led us to the total synthesis of bacillariolide III. (omitted)

  • PDF

Design and Synthesis of Chromenone derivatives as Potential Antioxidants

  • Kang, Hae-Eun;Lee, Kum-Ho;Lee, Dae-Hee;Cho , Jung-Sook;Lee, Hee-Soon
    • Proceedings of the PSK Conference
    • /
    • 2002.10a
    • /
    • pp.351.3-353
    • /
    • 2002
  • Oxygen radicals are produced in many pathophysiologic states whether the event is a causal factor of illness or is a result of their progression. Oxygen radicals including superoxide anions. hydrogen peroxide are thought to be involved in a number of type of acute. and chronic pathologic condition in the brain and neural tissue. So the antioxidants have recently received much attention as therapeutic agent for the treatment of neurodegenerative disease. In this study. we describe synthesis of a series of chromenone derivatives as antioxidant agents. The target compounds are designed to include the structural frature of caffeic acid. flavoniod. and focopherol known as antioxidants.

  • PDF

Control of Flexible Link using Mixed $H_2$/H$\infty$ and $\mu$-Synthesis Method

  • Y.W. Choe;Lee, H.K.;J.I. Bae
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2001.10a
    • /
    • pp.95.3-95
    • /
    • 2001
  • This paper investigates the simultaneous use of mixed H2/H_inf and mu-synthesis design methodology to design a robust controller for flexible link. We adopt four steps to design control system as follows: Step 1 : Generally, there are differences between the nominal and real model, so we consider the plant as a combination of parametric model uncertainty and unstructured uncertainty represents real structural uncertainties associated with the damping ratios of the flexible modes retained in the nominal model without payload. denotes the uncertainty which is due to the payload added at the tip. Step 2 : We adopt the mixed H2/H_inf theory to design a feedback controller K(s) by using the model uncertainty ...

  • PDF