French Curve Research Articles

Improvement of graphic training of first year students of design specialties

The work considers issues of improvement of geometric and graphic training of students of the first year of architectural specialties. The low graphic culture of applicants entering design specialties is due to many factors, among them the lack of creative examination on drawing when entering these specialties in higher education institutions. The work shows that in order to improve the profile competence of future artists already from the first year it is necessary to improve their graphic culture, creating in the course of discipline "Project graphics" professionally oriented graphic tasks. First of all, it concerns the study of the topic "Line Curves." The results of many years of experience in the Department of Descriptive Geometry and Engineering Graphics at KNUCA and the analysis of Student’s drawings works made it possible to draw conclusions about the need to study the tasks of construction circular curves and manual draw smooth curves of varying radii using patterns (a French curve). Second-order curves should lines (quadric), also be used in the professional activities of future designers. They can be used to base the geometry and create geometric models of curved planar contours of different geometric entitiesAnalysis of graphic training of students of the first year of creative specialties showed the need for immediate improvement of their graphic culture. Graphic competence requires further training and improvement of the specifics of professional training of bachelor's degrees. The development and use of special graphic assignments, which will be oriented to further professional activities of future specialists, will allow setting up students to solve professional design issues.

Ease of Use Experimentation of Isometric Template

The objective of this research was to find out whether using a specially developed isometric template helps students to reduce time and efforts while drawing isometric drawings. The standard method of comparison of performance of two groups has been used to achieve the objective. An Isometric template specially designed was given to a group of 15 students. The time measurement has been done on group using stopwatch performed by volunteers. It has been found that the group using the template shown average reduction in time of about 3.39 min. This time reduction is very much of importance at the time of examination. There has been no such kind of effort has been carried out for the objective stated above. The application of this tool may be useful for the students of technical education such as ITI, Diploma, and Engineering etc. The template can be improved by adding various other features like circles of various diameters, French curve, a roller etc. such that it can be useful for other drawing concepts.

Deconstructing helicoplacoids: reinterpreting the most enigmatic Cambrian echinoderms

AbstractHelicoplacoids, the most enigmatic group of Early Cambrian echinoderms, have a spirally plated, inverted pear‐ to spindle‐shaped theca with numerous interambulacral pleats and a long triradiate ambulacrum. They occur in western Laurentia along with the earliest edrioasteroids and epispire‐bearing eocrinoids(?), but unlike these other groups, helicoplacoids do not show pentameral symmetry around a centrally located, upward‐facing mouth. It is uncertain where the major body openings were located in helicoplacoids, where new plates were added during thecal growth, and whether helicoplacoids were primitive, pre‐pentameral, stem‐group echinoderms or derived, relatively specialized forms that had lost several ambulacra.We made highly modified, side‐layout, plating diagrams of different helicoplacoid species by cutting the theca apart half‐way between the spiraling ambulacra, leaving four to six interambulacral pleats on each side. This deconstructed thecal strip resulted in an elongate sigmoid‐shaped plating diagram with a long central single or paired ambulacrum that is interpreted as three ambulacral branches (A down, C and D up) around a central mouth on the side of the theca. The unrolled plating diagram resembles an elongate French curve drawing template with nearly parallel sides, a large or small sigmoidal top (where the theca is rounded and the interambulacral pleats converge), and an open deviated bottom, where the interambulacral pleats turn down to a truncated conical base. The two upward‐extending ambulacra are only one to two interambulacral pleats apart, which only slightly increases the plating strip width. New interambulacral plates are added at the summit and base, and interambulacral pleats rarely branch elsewhere. New floor and cover plates are added at the top and bottom distal ambulacral tips. If this plating model is correct, the anus (which has still not been identified) should be located near the thecal summit where the C and D ambulacra end, and all imperforate extraxial plating has apparently been lost from the theca.If upright, spirally pleated helicoplacoids with three ambulacra were derived from attached, domal or pyrgate, pentameral edrioasteroids, numerous changes must have occurred in the thecal shape, number of ambulacra, and interambulacral areas. These changes either occurred gradually in a sequence, or a single major change (spiralled body form?) caused all the others to rapidly follow. Copyright © 2005 John Wiley & Sons, Ltd.

日比谷公園開園時における二・三の施設の石材加工・利用技術

This study examined into the technology of working and utilization of stone for some facilities, (1) entrance gateposts, (2) roadway curbstones and (3) pond bank stones in the beginning Hibiya Park (1903, Tokyo) by field survey and literature research. (1) The gateposts of Hibiya Park's 6 entrances were similar to gateposts of western-style building's exterior, and those were made by Japanese stonemasonry. The stones of gateposts were reused andesite or granite stones of the walls with outer castle gates of Edo castle. (2) The Hibiya park's western-style roadway set granite curbstones and concrete gutter. And the pedestrian way side in the park was set cobblestone curbstones and gutter. The cobblestones were local gardening material in Edo. (3) The bank of Shinji-ike-pond (Shinji means Chinese character 'Kokoro') : Japanese-style pond laid cobblestones randomly like the ponds of gardens in Edo. The bank of Kumogata-ike-pond (Kumogata means 'French curve') : western-style pond laid single sized cobblestones for artificial shape. Then, technology of working and utilization of stone for some facilities in the beginning Hibiya park were based on western style architecture and civil engineering, and exploited Japanese technique - skills and materials of Edo.

A simple method for ohmic loss in conductors with cross-section dimensions on the order of skin depth

The high-frequency skin-depth approximation for ohmic loss calculations is not valid if the conductor thickness decreases and approaches the skin depth. This is the situation in many monolithic microwave integrated circuits (MMICs). The two asymptotes of loss, at dc and at high frequency of the above, are, in fact, known. This letter constructs a single synthetic asymptote that joins the two original asymptotes, and gives good loss values at intermediate frequencies where the above skin depth occurs, not unlike a French curve fitting. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 20: 302–304, 1999.

ISLAND FLAPS INCLUDING THE BEZIER TYPE IN THE TREATMENT OF MALIGNANT MELANOMA

Despite the trend in current surgical practice in the treatment on melanoma to produce smaller excisional defects, any technique which can introduce a surgical closure that does not require split skin grafting must be of benefit. This paper introduces and illustrates a range of island flap techniques that employ no skin grafting for the treatment of malignant melanoma defects. The new cutaneous island flap described, termed the Bezier or the French Curve, employs a double V-Y appositional closure method, thus giving a more refined reconstructive result that fits into the line of the body curves aesthetically. The design of the Bezier flap is almost identical in size and shape to the excisional defect, with a facial or muscular base for vascular support. Appropriate guidelines that determine the design and application of this island flap technique are listed. They are illustrated both diagrammatically and clinically. Other flaps illustrated include fasciocutaneous island flaps and myocutaneous island flaps that use a single V-Y flap appositional closure technique. All these flaps were designed with special reference to the dermatomes, which act as an aid memoire upon which the flaps are marked.

A New Approach to the Hyperbolic Curve (includes associated papers 18728 and 18942 )

An efficient and timesaving approach to hyperbolic-decline-curve analysis has been developed that has made it possible to determine the hyperbolic b exponents characterized by thousands of wells. After extensive use of the technique, the authors concluded that the range of the b exponent previously prescribed by Arps is too narrow.

Data-reduction methods for immunoradiometric assays of thyrotropin compared.

In an attempt to optimize curve fitting for immunoradiometric assays, we investigated eight data-reduction methods with two commercially available assays of thyrotropin. In four of these methods linear data-reduction models are used: logit-log programs of Iso-Data, Micromedic, and Hewlitt-Packard, and probit-log of Hewlitt-Packard. The other four were nonlinear data-reduction models: Iso-Data's "French curve" (modified spline), four-parameter logistic function, and point-to-point methods, as well as a nonlinear least squares method. In using the eight data-reduction methods on data from analyses of 78 patients' samples, we found clinically relevant differences between models. In fact, differences found by changing data-reduction models were greater than the difference between the two commercial kits.

Technique of making fish illustration 23

Preparation of the specimen far drawing: The specimen was secured in the appropriate position in a petri dish and held with three thin pins inserted horizontally into the pfasticine. The first pin pressed the base of the caudaf fin; the second, the middle of the subject at the front of the second dorsal and anal fin; the third. an area just behind the eye. The pressure of these pins was sufficient to immobilize such a small subject without causing damage to delicate spines and rays. All fins were left in their natural state. The subject was positioned while submerged in ethyl alcohol to minimize problems associated with handling small delicate specimens. Sketching: Small pieces of tracing tissue and a technical pencil with 2H lead were used for drawing the initial image. A Wild MS stereomicroscope with camera lucida served as the viewing tool. During the preparation of the initial sketch special attention was given to the surface of the body of the subject and all scarred tissue was carefully checked for scales. Each area was probed with a specially prepared teasing needle. The teasing needle was a dentist’s tool used for cleaning teeth with an L-shaped tip. The tip was narrowed with a sharpening stone to a width of less than 0.5 mm with the original hook forming the very tip of the tool. With this L-shaped, narrowed hook each suspected portion of scarred tissue was probed by lifting portions of the tissue until it hecame certain that the subject had only two remaining intact scales. The fins were drawn separately. Firstly the position. spacing and the length of each component was noted. Later using these data a more refined version was drawn using a French Curve and a 0.3 mm Pentef technical pencil. The second generation sketches were affixed to the surface of the tracing tissue with the image of the body of the subject drawn, and the whole image was retraced. Coloration patterns as weft as tonal changes of the coloration were noted with outlines and the respective values were marked L (light). VL (very light). D (dark), D-t L (dark to light), directly onto the final sketch. The final sketch was drawn on tracing tissue and when completed a number of copies of the sketch was printed using blueprint equipment. Some of the copies were printed on sepia paper to facilitate reproduction of more copies if needed. The blueprint copies were given to the scientist for correction of the sketch and for records. Rendering: A Koh-i-noor technical pen with 00 and 000 nibs was used for the final rendering. The black and white drawing was executed on tracing tissue with the 00 nib used for the outline of the body and spines and rays, and the 000 nib for all tonal areas. The teeth were rendered black for clarity of reproduction. The illustration was prepared for production in the usual way by dry mounting to Crescent Hot Press 1 ply iffustration board with Seal Removable Dry Mounting tissue. A sheet of tracing tissue was affixed over the image for protection of the surface. Comment: Before thefinished illusirufio?t was dry mounted, a copy of the image was obtained using the blueprinting nzethod.7. The copy was reproduced in sepia for possible future printings. Although the hnckground was printed in tone, thut image serves

Estimating the costs in lost power of alternative Snake‐Columbia Basin management policies

This work, in part, describes a 51 dam, 56 time period long‐range simulation model of the hydropower system in the Snake‐Columbia basin, including projects on those two rivers and on major tributaries thereof. The model is then applied to study a series of alternative basin management scenarios, and the consequences in lost power of these scenarios are evaluated economically. With 56 time periods and 51 projects (some having as many as five data sets), computational efficiency in a restricted computing environment is important. Efficiency in this model was achieved via use of ‘French Curve’ cubic spline data fits, together with fast pointers to carefully defined data structures. In addition, care was taken to couch the model in a setting making it accessible to use by nonprogramers, in a quasiconversational mode. Some technical detail on the implementation of the model is included in the paper. Mention is also made of another model developed during this effort, called PASO (Peaking Alternatives System Operation), a heuristic look ahead model now operational and available to interested users. Discussion of the validation procedures for both models is involved. The ‘firm power’ capability of the hydropower system in the Pacific Northwest is that maximal (monthly or biweekly) energy production which the system could produce during a 44½‐month ‘critical period’ of extremely low historical flows. In years of higher, more normal flows, the hydropower system can generate power substantially in excess of the firm capability. This ‘secondary’ power ebbs and flows annually as a function of many things, and it therefore seemed most relevant to focus studies of alternative basin management schemes on firm power production. Accordingly, the work assumed the historical flows of the period July 1, 1928‐June 30, 1932, a period of time including the critical period. The model and flow data was applied to the series of alternative basin management schemes, each selected for its environmental and/or political interest. The impact of each management scheme was then evaluated in terms of lost or foregone power against a ‘base regulation’ in which the objective was to generate as much power as possible over the critical period. Lost power was conservatively evaluated at 35 mills per lost kilowatt‐hour for baseload, with much higher costs possible for lost peaking.

A Completely Automatic French Curve: Fitting Spline Functions by Cross Validation

A Completely Automatic French Curve: Fitting Spline Functions by Cross Validation

A completely automatic french curve: fitting spline functions by cross validation

The cross validation mean square error technique is used to determine the correct degree of smoothing, in fitting smoothing solines to discrete, noisy observations from some unknown smooth function. Monte Cario results snow amazing success in estimating the true smooth function as well as its derivative.

Prediction of CO<inf>2</inf>laser signatures

Based on previous work, a method is presented to predict the signature of a CO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> laser, i.e., the output power as a function of the cavity length. For that purpose the normalized laser intensity curve versus cavity length is determined for a single line. The calculation is based on a homogeneously broadened line (Lorentzian shape) and takes into account the line dispersion. The curve is a parabola and its shape is assumed as being the same for all lines considered. From calculated positions of line centers and small-signal-gain data the signature can be drawn with the help of a parabolic French curve. The transition from one line to the next is assumed to occur at crossings of the normalized intensity curves. The theory agrees well with the experiment.

Summation of cycle ratios using french's curve

Summation of cycle ratios using french's curve

A French Word-Frequency Distribution Curve

By reference to Zipf's 'standard curve of distribution',' we can conveniently describe the frequency distribution of words in any language. When the wordfrequency curve for a given language is found to deviate markedly from the standard curve, then a consideration of such deviation may, as Zipf suggested, 'shed welcome light on significant factors in the structure of the language.'2 By analysis of two vocabulary studies of French, I have found a French wordfrequency curve which does in fact show definite peculiarities as compared with the standard. This paper is primarily to present that French curve for the consideration of linguists, and secondarily to suggest some approaches to ultimate interpretation of its significance.