• Title/Summary/Keyword: LAH

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Stabilization Performance Test Technique for LAH Turret Driving System (소형무장헬기 회전형 포탑시스템의 안정화추적 성능 시험기법)

  • Nam, Byounguk;Lee, Hojung;Jo, Sihun;Cho, Sunghun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.6
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    • pp.786-792
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    • 2014
  • In this paper, we propose a novel method which can be applied to test and verify the stabilization-tracking performance of Gun/Turret Driving System(GTDS) for Light Armed Helicopter(LAH). In real system, GTDS is connected to TADS/SMC and drived to aim at the target with 20mm gun. But each equipment is separately developed during exploratory development stage, so GTDS cannot be tested under real system state. We suggest new configuration of test system for evaluating the stabilization-tacking performance, in which TADS and SMC are replaced by vision acquisition unit and processing unit, respectively.

A q-ANALOGUE OF THE GENERALIZED FACTORIAL NUMBERS

  • Song, Seok-Zun;Cheon, Gi-Sang;Jun, Young-Bae;Beasley, Leroy B.
    • Journal of the Korean Mathematical Society
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    • v.47 no.3
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    • pp.645-657
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    • 2010
  • In this paper, more generalized q-factorial coefficients are examined by a natural extension of the q-factorial on a sequence of any numbers. This immediately leads to the notions of the extended q-Stirling numbers of both kinds and the extended q-Lah numbers. All results described in this paper may be reduced to well-known results when we set q = 1 or use special sequences.

ON p, q-DIFFERENCE OPERATOR

  • Corcino, Roberto B.;Montero, Charles B.
    • Journal of the Korean Mathematical Society
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    • v.49 no.3
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    • pp.537-547
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    • 2012
  • In this paper, we define a $p$, $q$-difference operator and obtain an explicit formula which is used to express the $p$, $q$-analogue of the unified generalization of Stirling numbers and its exponential generating function in terms of the $p$, $q$-difference operator. Explicit formulas for the non-central $q$-Stirling numbers of the second kind and non-central $q$-Lah numbers are derived using the new $q$-analogue of Newton's interpolation formula. Moreover, a $p$, $q$-analogue of Newton's interpolation formula is established.

Selective Reduction by Lithium Bis- or Tris(dialkylamino)aluminum Hydrides. Ⅶ. Reaction of Lithium Tris(dihexylamino)aluminum Hydride with Selected Organic Compounds Containing Representative Functional Groups$^1$

  • Cha, Jin-Soon;Kwon, Oh-Oun;Lee, Jae-Cheol
    • Bulletin of the Korean Chemical Society
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    • v.14 no.6
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    • pp.743-749
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    • 1993
  • The approximate rates and stoichiometry of the reaction of excess lithium tris(dihexylamino)aluminum hydride(LTDHA) with selected organic compounds containing representative functional groups under the standardized conditions (tetrahydrofuran, 0$^{\circ}$C) were studied in order to define the reducing characteristics of the reagent for selective reductions. The reducing ability of LTDHA was also compared with those of the parent lithium aluminum hydride(LAH), lithium tris(diethylamino)aluminum hydride(LTDEA), and lithium tris(dibutylamino)aluminum hydride(LTDBA). In general, the reactivity toward organic functionalities is in order of $LAH{\gg}LTDEA{\geq}LTDBA>LTDHA$. LTDHA shows a unique reducing characteristics. Thus, the reagent reduces aldehydes, ketones, esters, epoxides, and tertiary amides readily. Anthraquinone is cleanly reduced to 9,10-dihydro-9,10-anthracenediol without hydrogen evolution, whereas p-benzoquinone in inert to LTDHA. In addition to that, disulfides are also readily reduced to thiols without hydrogen evolution. However, carboxylic acids, anhydrides, nitriles, and primary amides are reduced slowly. Especially, this reagent reduces aromatic nitriles to the corresponding aldehydes in good yields.

Comparative studies of the mechanochemically treatment of $La_{2}O_{3}-Al(OH)_{3}$ (메카노케미컬 공정에 의한 $La_{2}O_{3}-Al_{2}O_{3}$$La_{2}O_{3}-Al(OH)_{3}$의 비교연구)

  • 조정호;최상수;김강언;정수태
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.701-704
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    • 2001
  • The dielectric and sintering properties of LaAlO$_3$ceramics synthesised with La$_2$O$_3$-Al$_2$O$_3$(LAO) and La$_2$O$_3$-Al(OH)$_3$(LAH) were investigated. In case of LAH samples, a single phase of LaAlO$_3$powders was formed at 100$0^{\circ}C$, density of the ceramics sintered at 140$0^{\circ}C$ was 6.41g/㎤, and the dielectric constant and loss were 22.4 and 0.003, respectively. In case of LAO samples, a single phase of LaAlO$_3$powders was formed at 130$0^{\circ}C$, density of the ceramics sintered at 150$0^{\circ}C$ was 6.35g/㎤, and the dielectric constant and loss were 22.16 and 0.009, respectively.

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Selective Reduction by Lithium Bis- or Tris(dialkylamino)aluminum Hydrides. VIII. Reaction of Lithium Tripiperidinoaluminum Hydride in Tetrahydrofuran with Selected Organic Compounds Containing Representative Functional Groups

  • 차진순;이재철;주영철
    • Bulletin of the Korean Chemical Society
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    • v.18 no.8
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    • pp.890-895
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    • 1997
  • The approximate rates and stoichiometry of the reaction of excess lithium tripiperidinoaluminum hydride (LTPDA), an alicyclic aminoaluminum hydride, with selected organic compounds containing representative functional groups under the standardized conditions (tetrahydrofuran, 25°) were examined in order to define the reducing characteristics of the reagent for selective reductions. The reducing ability of LTPDA was also compared with those of the parent lithium aluminum hydride (LAH) and lithium tris(diethylamino)aluminum hydride (LTDEA), a representative aliphatic aminoaluminum hydride. In general, the reactivity of LTPDA toward organic functionalities is weaker than LTDEA and much weaker than LAH. LTPDA shows a unique reducing characteristics. Thus, benzyl alcohol, phenol and thiols evolve a quantitative amount of hydrogen rapidly. The rate of hydrogen evolution of primary, secondary and tertiary alcohols is distinctive. LTPDA reduces aldehydes, ketones, esters, acid chlorides and epoxides readily to the corresponding alcohols. Quinones, such as p-benzoquinone and anthraquinone, are reduced to the corresponding diols without hydrogen evolution. Tertiary amides and nitriles are also reduced readily to the corresponding amines. The reagent reduces nitro compounds and azobenzene to the amine stages. Disulfides are reduced to thiols, and sulfoxides and sulfones are converted to sulfides. Additionally, the reagent appears to be a good partial reducing agent to convert primary carboxamides into the corresponding aldehydes.