• 제목/요약/키워드: Final State

검색결과 869건 처리시간 0.026초

Analysis of Binodal Structures of Final State Distributions in Vibrational Predissociations of Triatomic van der Waals Molecules

  • 이천우
    • Bulletin of the Korean Chemical Society
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    • 제16권12호
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    • pp.1193-1203
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    • 1995
  • In this work, we focused on the setup of the tools for the analysis of the final rotational state distribution of photofragments in vibrational predissociations of triatomic van der Waals molecules A-B2. We found that reflection principle used for the direct photodissociation processes can also be applied to find out the final rotational state distributions for indirect photodissociation processes. The quantity which represents the strength of rovibrational coupling between the quasi-bound state and the final state is reflected into the mirror of the classical angular momentum function, instead of the initial state before light absorption used in the reflection principle of direct processes. The sign change in the first derivative of the interaction potential with respect to the bond distance of B2 is found to be the source of the binodal structures in the final rotational distributions of photofragments in the model system studied in this work. In MQDT analysis, short range eigenchannel basis functions were found to be localized in angle, in the previous work [Lee, C.W. Bull. Korean Chem. Soc. 1995, 16, 957.] and may be called angle functions. Angle functions enjoy simple geometrical structures which have simple functional relations with the final state distributions of photofragments. Two processes take place along the angle functions which resemble the quasi-bound state and dominate over other processes. Two such angle functions are found to be not only localized angularly but also localized either one of ends of B2 in motions along the bond of B2. These dominating photodissociation processes, however, cancel each other. This cancellation causes photodissociation to depend sensitively on the interaction potential at other angles than the dominant one. Part of potential surface where much larger torque exists can now play an important role in photodissociation. MQDT also enables us to see which processes play important roles after cancellation. This is done by examining the amounts of time delayed by asymptotic eigenchannels.

강소성 유한요소법을 이용한 냉간단조 공정의 최종단계 해석 (An Analysis of Cold Foging at Final State Using Rigid-Plastic FEM)

  • 최영;정성윤;김병민;최재찬
    • 소성∙가공
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    • 제8권1호
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    • pp.108-115
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    • 1999
  • In this paper, the analysis of cold forging in final state has been performed by using rigid-plastic FEM. For the analysis, the geometry and flow stress of the workpiece are required. One method to obtain the geometry is measurement of that made from experimet. To evaluate the flow stress, average effective strain is calculated from the load-stroke diagram by using energy method. The numerical test performed to show the validity of propose method. The analysis of PFIR, the precision forging of spurgear with inside relif, is performed.

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MOTION IN PARABOLIC CYLINDRICAL COORDINATES: APPLICATION TO J2 GRAVITY PERTURBED TRAJECTORIES

  • Sharaf, M.A.;Selim, H.H.;Saad, A.S.
    • 천문학회지
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    • 제39권4호
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    • pp.147-150
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    • 2006
  • In this paper, initial value problem for dynamical astronomy will be established using parabolic cylindrical coordinates. Computation algorithm is developed for the initial value problem of gravity perturbed trajectories. Applications of the algorithm for the problem of final state predication are illustrated by numerical examples of seven test orbits of different eccentricities. The numerical results are extremely accurate and efficient in predicating final state for gravity perturbed trajectories which is of extreme importance for scientific researches as well as for military purposes. Moreover, an additional efficiency of the algorithm is that, for each of the test orbits, the step size used for solving the differential equations of motion is larger than 70% of the step size used for obtaining its reference final state solution.

Crystallization and In-plane Alignment Behavior of Pb(Zr, Ti)$O_3$ Films

  • Hwang, Kyu-Seog;Kim, Byung-Hoon
    • The Korean Journal of Ceramics
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    • 제3권3호
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    • pp.191-194
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    • 1997
  • Epitaxial Pb(Zr, Ti)O3(PZT) thin films were prepared on MgO(100) substrates by dipping-pyrolysis (DP) process using metal naphthenates as starting materials, and effects of pyrolysis and final heat-treatment conditions on the film's orientation were investigated. Solid-state epitaxial growth of PZT proceeds at lower temperature around 650℃ from the precursor pyrolyzed at 350 and 500℃. The in-plane alignment of the PZT films depends not only on the final heat-treatment temperature but on the pyrolysis conditions; the films, pyrolyzed at a higher temperature for a short time, i.e., at 500℃ for 10 min, exhibited stronger orientation after the same final heat treatment at 650°∼750℃. The PZT films with the strongest orientation were prepared by pyrolysis under the above conditions followed by final heat treatment at 750℃.

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Global seismic damage assessment of high-rise hybrid structures

  • Lu, Xilin;Huang, Zhihua;Zhou, Ying
    • Computers and Concrete
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    • 제8권3호
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    • pp.311-325
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    • 2011
  • Nowadays, many engineers believe that hybrid structures with reinforced concrete central core walls and perimeter steel frames offer an economical method to develop the strength and stiffness required for seismic design. As a result, a variety of such structures have recently been applied in actual construction. However, the performance-based seismic design of such structures has not been investigated systematically. In the performance-based seismic design, quantifying the seismic damage of complete structures by damage indices is one of the fundamental issues. Four damage states and the final softening index at each state for high-rise hybrid structures are suggested firstly in this paper. Based on nonlinear dynamic analysis, the relation of the maximum inter-story drift, the main structural characteristics, and the final softening index is obtained. At the same time, the relation between the maximum inter-story drift and the maximum roof displacement over the height is also acquired. A double-variable index accounting for maximum deformation and cumulative energy is put forward based on the pushover analysis. Finally, a case study is conducted on a high-rise hybrid structure model tested on shaking table before to verify the suggested quantities of damage indices.

신경회로망을 이용한 모터의 시간최적 제어 (Time-optimal control for motors via neural networks)

  • 최원수;윤중선
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.1169-1172
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    • 1996
  • A time-optimal control law for quick, strongly nonlinear systems has been developed and demonstrated. This procedure involves the utilization of neural networks as state feedback controllers that learn the time-optimal control actions by means of an iterative minimization of both the final time and the final state error for the known and unknown systems with constrained inputs and/or states. The nature of neural networks as a parallel processor would circumvent the problem of "curse of dimensionality". The control law has been demonstrated for a velocity input type motor identified by a genetic algorithm called GENOCOP.

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신경회로망을 이용한 시간최적 제어 (Time optimal Control via Neural Networks)

  • 윤중선
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 춘계학술대회 논문집
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    • pp.372-377
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    • 1996
  • A time-optimal control law for quick, strongly nonlinear systems like revolute robots has been developed and demonstrated. This procedure involves the utilization of neural networks as state feedback controllers that learn the time-optimal control actions by means of an iterative minimization of both the final time and the final state error for the known and unknown systems with constrained inputs and/or states. The nature of neural networks as a parallel processor would circumvent the problem of "curse of dimensionality".ity".uot;.

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감압조형시 흑연첨가 및 주입온도가 피복상태에 미치는 영향 (The Effect of Graphite Addition and Pouring Temperature on the Coating State in Vaccum Process)

  • 조성준
    • 한국세라믹학회지
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    • 제34권5호
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    • pp.544-551
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    • 1997
  • We tried to improve the coating capability of the coating material using an additive(hexagonal cystalline graphite) of 2%, 3%, 4% and 6% under various pouring temperature for the easy isolation of sand and coating material from the final product. As a result in case of using a 2% and 3% additive generally no burning state has been occurred under the low pouring temperature, but it has been gradually increased with the pouring temperature. On the other hand in case of using a 4% and 6% additive there has been no burning state through out the whole pouring temperature. From this result we could see that the best state of the final product without sand and coating material could generally be obtained if 4% and/or 6% of the crystalline graphite and the pouring temperature of 140$0^{\circ}C$$\pm$5$^{\circ}C$ would be used.

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비점성 평면 정체 유동 응고 문제에 대한 점근적 해석 (An Asymptotic Analysis on the Inviscid Plane Stagnation-flow Solidification Problem)

  • 유주식;엄용균
    • 대한기계학회논문집B
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    • 제24권6호
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    • pp.792-801
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    • 2000
  • The problem of phase change from liquid to solid in the inviscid plane-stagnation flow is theoretically investigated. The solution at the initial stage of freezing is obtained by expanding it in powers of time, and the final equilibrium state is determined from the steady-state governing equations. The transient solution is dependent on the three dimensionless parameters, but the equilibrium state is determined by one parameter of (temperature ratio/conductivity ratio). The effect of the fluid flow on the growth rate of the solid in the pure conduction problem can be clearly seen from the solution of the initial stage and the final equilibrium state. The characteristics of the transient heat transfer at the surface of the solid and the liquid side of the solid-liquid interface for all the dimensionless parameters are elucidated.

비점성 정체 유동 응고 문제에 대한 이론적 해석 (A theoretical analysis on the inviscid stagnation-flow solidification problem)

  • 유주식
    • 설비공학논문집
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    • 제12권1호
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    • pp.1-11
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    • 2000
  • This study investigates the problem of phase change from liquid to solid in the inviscid stagnation flow. The solution of dimensionless governing equations is determined by the three dimensionless parameters of (temperature ratio/conductivity ratio), Stefan number, and diffusi-vity ratio. The solution at the initial stage of freezing is obtained by expanding it in powers of time, and the final equilibrium state is determined from the steady-state governing equations. The equilibrium state is dependent on (temperature ratio/conductivity ratio), but is independent of Stefan number and diffusivity ratio. The effect of fluid flow on the pure conduction problem can be clearly seen from the solution of the initial stage and the final equilibrium state, and the characteristics of the solidification process for all the dimensionless parameters are elucidated.

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