Comments, with reply, on `Power-handling capability of the rhombicwaveguide' by P.L. Overfelt and C.S. Kenney

The commenters congratulate the authors of the above-titled paper (see ibid., vol.38, no.7, p.934-941, 1990) and present some considerations regarding the solution of the Helmholtz equation as well as other wave-type equations in rhombic domains. The authors respond by discussing some relevant results they have obtained since their paper was written     

Author's reply to M. G. M. Hussain's `Corrections to`two-dimensional beamforming with nonsinusoidal signals'

The author states that the analytical derivations and the closed form expressions given in his article (see ibid., vol.EMC-29, no.4, p.303, 1987) are correct since they are based on correct expressions for the time delay and correct versions of equations containing typographical errors     

Comments, with reply on `Magnetotelluric exploration forhydrocarbons' by A.S. Orange

An oversimplification of the treatment of the incidence angle and of the source dependence of magnetotelluric surface impedance in a previous treatment of magnetotelluric exploration of hydrocarbons (see ibid., vol.77, no.2, p.287-317, 1989) is pointed out. The author of the original paper agrees with the comments and recognizes the paper's lack of rigor. He points out that the intent of the paper was to present a broad overview to a general audience and to focus on the utility and applications of the method     

Author's reply to `On the generalized multinomial distribution,optimal multinomial detectors, and generalized weighted partial decisiondetectors' by N.C. Beaulieu

Beaulieu (see ibid., vol.39, no.2, p.193, 1991) states that the equivalence between the generalized multinomial detectors and the generalized weighted partial decision detectors is obscured by E.K. Al-Hussaini (see ibid., vol.37, p.1099, 1989), who concluded that the former outperforms the latter. In reply, Al-Hussaini clarifies his results     

Author's reply to comments on “Propagation of EM pulsesexcited by electric dipole in a conducting medium”

It is not surprising that our paper attracted Dr. Wait's interest, since this subject is one of his many contributions. We mentioned that previous studies are “incomplete” because they report either magnetic fields or electric fields excited by a step-junction excitation that is only a special case (as reaffirmed by Dr. Wait). We presented both electric and magnetic fields excited by an impulsive excitation from which the EM field excited by any arbitrary excitation can be obtained by a convolution. This information was needed because we attempted to find the optimal excitation that can excite a maximum electric field. In our humble opinion, our solution is “exact” because we solved Maxwell's equation exactly within the assumption of frequency independent conductivity and permittivity. The adjective “complete” means that we have presented complete expressions for both the electric and magnetic fields. It is not our intention in using these adjectives to be immodest     

F.S.K. bursts for efficient clutter rejection

The clutter-rejection properties of compact f.s.k. bursts with amplitude modulation are investigated. A procedure for computer-aided design of such signals is given. The loss of clutter performance on constraining the individual pulse amplitudes to be equal is evaluated.     

Comments, with reply, on `On the hazard rate of the lognormaldistribution' by A.L. Sweet

In the above-named work (see ibid., vol.39, p.325-8, Aug 1990), A.L. Sweet calls attention to some incomplete or inaccurate representation of the hazard rate of lognormal distributions. His principal concern apparently is that these representations may lead modelers to overlook an important property of the lognormal distribution: its hazard rate increases and then decreases as a function of elapsed time. He also provides approximations for the location and value of the hazard rate maximum. The commenter observes that, as theoreticians are likely to have ready access to expanded tables of the normal distribution and unlikely to have need for the approximations, the Sweet paper was aimed at practitioners dealing with actual data. The commenter cautions such practitioners that some serious problems, unrelated to table availability or approximation accuracy, arise if σ_1n(T) is high or low. In his reply, Sweet remarks that the commenter is correct in assuming that Sweet's work was aimed at practitioners-specifically, at those being introduced to the lognormal distribution for the first time by reading about it in the books referenced in Sweet's article     

Comment, with reply, on `Hot-electron hardened Si-gate MOSFETutilizing F implantation' by Y. Nishioka, et al

For original paper see ibid., vol.10, p.141-3 (Apr. 1989). The commenters point out that the authors of the original paper were not, as they have claimed, the first to show the technique and benefits of implanting and diffusing fluorine. They raise a number of questions about their experimental method and interpretation of results. The authors reply that they did not make the claim attributed to them, and they defined their method and findings at length     

Comments with reply on `Evaluating fault trees (AND and OR gatesonly) with repeated events' by K.S. Brown

The commenter summarizes his own approach to fault tree analysis (see ibid., vol.R-36, no.2, p.250-54, 1987) and wonders why K.S. Brown (see ibid., vol.39, no.2, p.226-35, 1990), did not compare his own approach with the commenter's approach. He asks Brown to comment on the latter and raises a number of questions about Brown's paper. Brown, in reply, points out the limitations of the commenter's approach and responds to each of the points he raises     

L.S.A. microstrip phase-locked power amplifier

A distributed amplifier structure is described using the l.s.a. mode of operation in a microstrip transmission line where gallium arsenide replaces the dielectric. The amplifier gain against frequency is given, and various practical design criteria are discussed.     

Comments, with reply, on `Dual-gate operation and volume inversionin n-channel SOI MOSFETs' by S. Venkatesan et al

For original paper see ibid., vol.13, no.1, pp.44-6 (Jan. 1992). The commenter disagrees with the suggestion by S. Venkatesan, et al. that dual-channel volume inverted devices do not offer significant current-enhancement advantages, other than that expected from the second channel, over the conventional single-channel devices for silicon thicknesses in the 0.1-μm range. The commenter argues that this suggestion is in contradiction with previous demonstrations and with recent results that experimentally show the advantages of volume inversion. In replying, Venkatesan, et al., maintain that, while volume inversion could cause drain current enhancements in the near threshold region, it does not significantly affect the device characteristics in the strong inversion regime     

Comments, with reply, on `Passive equalization of semiconductordiode laser frequency modulation' by S.B. Alexander et al

Some flaws in a recent article by S.B. Alexander et al. (ibid., vol.7, no.1, p.11-23, Jan. 1989) on the theory of equalization of FM response of a laser diode using passive filters are noted. An error has occurred as a result of assuming a constant C as a positive instead of negative. When C is negative and large, the equalization network cannot be realized with passive networks. Also the simulated time waveform shown in the article for the optical frequency of an equalized laser does not show some spikes which are expected theoretically. The spikes occur as a result of an imperfect equalization provided by the proposed passive filters that were realized assuming C as positive. In replying the original author feels that the comments and observations result simply from attempting to extend the simple FM transfer-function model far beyond its limits while trying to introduce unnecessary theoretical rigor     

采用数字技术测量扬声器及其系统频响特性的低频响应补偿法

本文针对采用数字技术在非消声室环境中测量扬声器频响时低端很难测准的问题,介绍了关于扬声器单元,封闭式和倒相式等扬声器系统的低频响应补偿法。实验证明结果是令人满意的。