Showing papers by "Ohio State University published in 1974"

A uniform geometrical theory of diffraction for an edge in a perfectly conducting surface

Abstract: A compact dyadic diffraction coefficient for electromagnetic waves obliquely incident on a curved edse formed by perfectly conducting curved ot plane surfaces is obtained. This diffraction coefficient remains valid in the transition regions adjacent to shadow and reflection boundaries, where the diffraction coefficients of Keller's original theory fail. Our method is based on Keller's method of the canonical problem, which in this case is the perfectly conducting wedge illuminated by plane, cylindrical, conical, and spherical waves. When the proper ray-fixed coordinate system is introduced, the dyadic diffraction coefficient for the wedge is found to be the sum of only two dyads, and it is shown that this is also true for the dyadic diffraction coefficients of higher order edges. One dyad contains the acoustic soft diffraction coefficient; the other dyad contains the acoustic hard diffraction coefficient. The expressions for the acoustic wedge diffraction coefficients contain Fresenel integrals, which ensure that the total field is continuous at shadow and reflection boundaries. The diffraction coefficients have the same form for the different types of edge illumination; only the arguments of the Fresnel integrals are different. Since diffraction is a local phenomenon, and locally the curved edge structure is wedge shaped, this result is readily extended to the curved wedge. It is interesting that even though the polarizations and the wavefront curvatures of the incident, reflected, and diffracted waves are markedly different, the total field calculated from this high-frequency solution for the curved wedge is continuous at shadow and reflection boundaries.

The measurement of interpersonal attraction

Abstract: The study reports a factor analytic investigation of the interpersonal attraction construct. Two‐hundred and fifteen subjects completed 30 Likert‐type, seven‐step scales concerning an acquaintance. Factor analysis indicated three dimensions of the interpersonal attraction construct which were labeled “task” “social” and “physical.” The results of this study and four replications suggest that the resulting 15‐item instrument can be expected to measure reliably three dimensions of interpersonal attraction.

A Characterization of Banach Spaces Containing l1

Abstract: It is proved that a Banach space contains a subspace isomorphic to l1 if (and only if) it has a bounded sequence with no weak-Cauchy subsequence. The proof yields that a sequence of subsets of a given set has a subsequence that is either convergent or Boolean independent.

The Male Reproductive System

Abstract: The male reproductive system consists of external reproductive organs, penis and scrotum, and internal reproductive organs: testes, a duct system, and accessory glands. The adult, paired testes produce both male sex hormones (androgens) and sperm cells (spermatogenesis). Androgens, primarily testosterone, are necessary for development and maintenance of male behavioral and physical manifestations and for spermatogenesis.

Detection of Hypokinesis by a Quantitative Analysis of Left Ventricular Cineangiograms

Abstract: A method for detecting left ventricular hypokinesis is proposed. It involves superimposition of left ventricular silhouettes traced from 30 degree right anterior oblique cineangiograms, correcting for thoracic cage motion, descent of the aortic valve and rotation of the apex. Normal values for the percent of systolic motion of seven endocardial segments have been established from measurements in 20 patients, permitting a statistical definition of hypokinesis. The use of this quantitative method has been compared with visual inspection of ventriculograms (qualitative method), resulting in differences in definition of hypokinetic segments by the two methods in 13 of 16 patients with coronary heart disease. When the quantitative method was used, only one hypokinetic segment was found which did not correspond to an obstructive coronary lesion while six such segments were defined using the qualitative method. In four patients segments thought to be hypokinetic (qualitative method) appeared to be akinetic (quan...

The role of combined chemotherapy in the treatment of rhabdomyosarcoma in children.

Abstract: Current therapy of rhabdomyosarcoma involves the use of several modalities of treatment: surgery, radiotherapy, and chemotherapy. The present controlled study was designed to evaluate the role of chemotherapy in the control of occult residual disease following surgery and radiotherapy. The results of this study support the adjunctive use of combined chemotherapy with actinomycin D and vincristine sulfate for 1 year in preventing growth of metastatic or recurrent disease when children are made grossly tumor free by surgery and radiotherapy. Twenty-four (85.7%) of 28 children in this category are disease free for periods greater than 2 years after initial treatment and a year of chemotherapy. Initial staging and the degree to which a patient can be made tumor free with primary definitive therapy are the most significant variables in prognosis. Vinblastine was not useful in the treatment of metastatic rhabdomyosarcoma.

On the Dynamic Stability of Biped Locomotion

Abstract: While biped locomotion involves very complicated dynamical processes, a good deal can be learned about stability and feedback control from an analysis of simplified mathematical models. This paper treats locomotion dynamics relative to planar motion under an assumption that leg mass can be ignored in comparison to body mass. Thus the hypothetical biped possesses one rotational degree of freedom and two translational degrees, leading to a sixth-order system of nonlinear differential equations. These equations are linearized and feedback control laws are then derived to produce the desired stable forward motion. The feedback laws proposed involve a combination of continuous and discrete concepts to produce both step length and step period control as well as control of body attitude and altitude. The applicability of the control laws to the nonlinear system in the presence of large disturbances is verified by computer simulation. Hopefully, the results presented are significant relative to control processes arising in lower extremity prostheses and orthoses as well as to the design of biped robots.

Identification of Three-Dimensional Objects Using Fourier Descriptors of the Boundary Curve

Abstract: The feasibility of a method for the identification of a three-dimensional object from information contained in the boundary of its silhouettes is demonstrated. A silhouette is characterized by parametric representation of its boundary curve in the complex plane. After normalization and transformation, a set of Fourier descriptors is derived for every silhouette. A minimum distance classifier uses the descriptors to identify the three-dimensional object and to estimate its position and attitude with respect to a known reference coordinate system. The method was tested for identification of four aircraft representing complex and nonconvex objects. Simulation results, quantitative and statistical, are presented.

Some properties of truncated turbulence signals in bounded shear flows

Abstract: Measurement results of turbulent shear flows are re-examined. Various statistical properties of the truncated streamwise and normal velocity components u and v and of their product uv have been determined in an attempt to characterize quantitatively the motions of the flow. Average values and probability density distributions both of the truncated and untruncated signals have been taken.

Socializing Functions of Primate Play

Abstract: The socializing functions of nonhuman primate play behavior are discussed. An evolutionary perspective of play behavior is presented to provide a concise view of its importance in primate phylogeny. Some of the major variables influencing play behavior's socializing functions, i.e., gender, age, group structure and population dynamics, and the econiche, are reviewed. It is concluded that the major socializing functions of play behavior include proper social development, setting the basis for the adult dominance hierarchy, social integration of individuals into the group structure, and learning the social communicatory matrix.

Morphine Anesthesia Blocks Cortisol and Growth Hormone Response to Surgical Stress in Humans

Abstract: Because of the increasing use of morphine anesthesia for open-heart surgery and the known ability of the drug to inhibit ACTH release, we have studied the effect of morphine anesthesia on plasma cortisol and growth hormone response to major surgery. In patients receiving 1 mg/kg morphine anesthesia the normal rise in plasma cortisol in response to major abdominal surgery was suppressed. This was also true in patients receiving 4 mg/kg morphine as anesthesia for open-heart surgery. In the latter group the normal rise in serum growth hormone was suppressed as well. This suppression of cortisol and growth hormone response during morphine anesthesia caused no clinically observable ill effect and could be reversed with ACTH.

Polypeptide influences on attention, memory and anxiety in man.

Abstract: The effects of two polypeptides, ACTH 1–24 and ACTH 4–10 on a variety of bioelectric and behavioral measures of attention, memory and anxiety in human subjects were examined within the context of a disjunctive reaction time paradigm. ACTH 1–24 had no effect on any of the measures involved; ACTH 4–10 , however, served to improve visual memory, decrease anxiety, reinstitute a previously habituated alpha blocking response in the occipital EEG, and generally influence the occipital EEG toward a pattern consistent with increased attention. The results were taken to suggest a direct polypeptide influence on CNS attentional mechanisms.

Some remarks on weakly compactly generated banach spaces

Abstract: A simple example is given of a non WCG space whose dual is a WCG space with an unconditional basis. It is proved that ifX* is WCG andX is a subspace of a WCG space thenX itself is WCG.

On the uniqueness of the equilibrium state

Abstract: More generally, we consider the subshifts of F z. These are the closed subsets of F z that are invariant under S. We denote for such a subshift X by C(X) the set of continuous real-valued functions on X, and by d//(X) the set of shiftinvariant Borel probability measures on X. h(/z) will stand for the entropy of a tz E rig(X). (For the entropy and its properties see, e.g., [11].) We set for a subshift X,

The effect of the separation of ownership from control on accounting policy decisions

Abstract: T HE theories of managerial enterprise found in the economics literature are concerned with the behavior of management in large firms, where management has secured for itself a considerable degree of latitude in directing the affairs of the corporation. In their discussion of managerial enterprise, the economists carefully have maintained the distinction between firms which are controlled by their owners and firms which are controlled by managers. Some of these economists have argued that the maintenance of a relatively smooth income stream is in the best interest of the management of the latter group of firms.' The accounting profession, in granting to management the primary responsibility for financial reports, has provided management one means by which they may generate a relatively smooth income stream. The wide variety of reporting alternatives considered to be acceptable representations of the events of any particular period provides management with a range of possible profit figures for any one period. Michael Schiff [1966] was one of the first accountants to indicate an awareness of the implications that this variety of reporting alternatives had for the behavior of managers in manager firms. After observing the behavior of a firm listed on the New York Stock Exchange, Schiff expressed his belief that:

Microbial activation of prophenoloxidase from immune insect larvae

Abstract: INTEREST in the infection of insects by parasites has been generated by the pathogenic potential of the parasite to the insect itself, or to a vertebrate host to which the parasite may be transmitted. For example, because of the effects of malaria on man, the relationships between Plasmodia and various mosquito species have received much attention1,2. An important part of the host-parasite relationship is the defence system of the host. In insects, phenoloxidase (o-diphenol: O2 oxidoreductase, EC 1.10.3.1.) has been suggested to be at least partially responsible for insect immunity and parasite resistance3–5.

Myocardial lactate production in patients with angina-like chest pain and angiographically normal coronary arteries and left ventricle.

Abstract: Twenty-nine patients with angina-like chest pain and angiographically normal coronary arteries and left ventricle underwent rapid coronary sinus pacing with sampling of coronary sinus and arterial blood for lactate and recording of electrocardiograms and left ventricular pressures. In 25 patients immediate postpacing left ventricular cineangiograms were obtained. Two groups were defined: 9 patients who showed evidence of myocardial lactate production and 20 who did not. The degree of S-T segment depression with pacing provided the only means of separating lactate producers (> 2 mm) from nonproducers (

A streamlined metallic radome

Abstract: The results of research and development, fabrication, and measured transmission performance for a specific streamlined metallic radome are contained in this paper. The measured results presented demonstrate that high-quality radome transmission performance can be attained with a streamlined metallic radome. The conical metallic radome presented is 6 ft 4 in long and has a base diameter of 25.5 in. The specially designed resonant slotted surface of the metallic radome consists of 90 percent metal and, for frequencies within its operating band, the radome permits transmission with any signal polarization over a wide range of scan angles. At its 8.90 GHz resonant frequency the metallic radome introduces less than 0.5 dB signal loss and less than 2 mrad boresight error. This radome has been purposely designed for operation over a narrow frequency band. Over a 200 MHz band, measured insertion loss and boresight error values of 1 dB and 6 mrad, respectively, are attained.