Hand Drawing Research Articles

Metodologías docentes basadas en interfases táctiles para la docencia del dibujo y los proyectos arquitectónicos

Resumen es: El objetivo de esta investigacion es plantear una nueva forma de docencia del dibujo a mano alzada en base a dispositivos tactiles, tablet-pc's, aplicada...

The algorithmic beauty of plant roots – an L-System model for dynamic root growth simulation

Understanding the impact of root architecture on plant resource efficiency is important, in particular, in the light of upcoming shortages of mineral fertilizers and changed environmental conditions. In the 1950s, a great number of root systems of European cultivated plants were excavated and studied by L. Kutschera (1960). Her work gave enormous insight into the variety of root system architectures and helped to realize the importance of belowground processes to plant productivity. We analysed the resulting hand drawings by using mathematical modelling and found root system parameters for a newly developed parametric L-System model. In this way we were able to first reproduce the illustrations, second computationally analyse root system traits and finally access the dynamic root architecture development.

Contribution of the primary motor cortex to motor imagery: A subthreshold TMS study

Motor imagery (MI) mostly activates the same brain regions as movement execution (ME) including the primary motor cortex (Brodmann area 4, BA4). However, whether BA4 is functionally relevant for MI remains controversial. The finding that MI tasks are impaired by BA4 virtual lesions induced by transcranial magnetic stimulation (TMS) supports this view, though previous studies do not permit to exclude that BA4 is also involved in other processes such as hand recognition. Additionally, previous works largely underestimated the possible negative consequences of TMS-induced muscle twitches on MI task performance. Here we investigated the role of BA4 in MI by interfering with the function of the left or right BA4 in healthy subjects performing a MI task in which they had to make laterality judgements on rotated hand drawings. We used a subthreshold repetitive TMS protocol and monitored electromyographic activity to exclude undesirable effects of hand muscle twitches. We found that BA4 virtual lesions selectively increased reaction times in laterality judgments on hand drawings, leaving unaffected a task of equal difficulty, involving judgments on letters. Interestingly, the effects of virtual lesions of left and right BA4 on MI task performance were the same irrespective of the laterality (left/right) of hand drawings. A second experiment allowed us to rule out the possibility that BA4 lesions affect visual or semantic processing of hand drawings. Altogether, these results indicate that BA4 contribution to MI tasks is specifically related to the mental simulation process and further emphasize the functional coupling between ME and MI.

Comparative analysis of two methods for wound bed area measurement

Wound bed area measurements are considered to be an essential part of the wound assessment process. Wound care professionals should be aware of the reliability and validity of the techniques they use. The purpose of this study was to assess whether wound care professionals are able to make as accurate and reproducible a measurement of the wound bed area using two methods for area measurement. Five wound care professionals independently assessed 2285 digital wound images for the wound bed area. Each image was measured in random order, three times, and in four angles by providing the rotated versions of each image (0°, 90°, 180° and 270°). Two techniques were compared: free hand drawing and closed polygon (CP) graph algorithm. Comparison of the two techniques showed differences that are, in our opinion, not acceptable in clinical practice when these techniques are used interchangeably and/or the measurements are carried out by different observers. Variations observed between wounds and observers seem related to the difference in perception of the wound bed margin. Our results indicate that repetition of CP graph area measurement results in the lowest difference in repetitive measurements. Study limitations are related to an incomplete consensus on definitions of wound, wound bed, wound edge and wound border. The development of an ontology related to wound images could aid to reduce these ambiguities.

The clock drawing test: A comparison between copy and free hand drawing

The clock drawing test: A comparison between copy and free hand drawing

Representational Craft and Production: Comparison of the Value of Hand Drawing and Digital Media in Architectural Academies and Practices

Representational Craft and Production: Comparison of the Value of Hand Drawing and Digital Media in Architectural Academies and Practices

A Case for Drawing

Architecture faculty continue, at times contentiously, to debate theroles that hand drawing and digital media should have in the practicesand education of architects. Some argue for the computer as the"new pencil,” while others maintain that the pencil is irreplaceable. A survey conducted by the authors suggests that the academy itself mayrest in a dichotomous position of committing more resources to digitalmedia than hand drawing while simultaneously indicating that both typesof media are valued about equally. Rather than reinforce an oppositionalrelationship between the hand and the computer, this paper aims toreveal current trends regarding the roles of hand and digital designmedia in the academy and to provide a review of the primary benefits ofhand drawing within an environment that is, seemingly, preoccupied withdigital media.Hand drawing provides unique contributions to and opportunities within the development of architectural thought and work. Maintainingsketching and precision hand drawing as fundamental activities of thearchitect extends the post-Renaissance tradition of architecture as a distinct design discipline directed to architectural ideas and relationships.Furthermore, hand drawing creates unique opportunities for imaginative transformation, for bodily engagement and accommodation, and for preconditioningthe qualities of a built work and therefore should remain asignificant component of the discipline.

Architecture Studio Archive: A Case Study in the Comprehensive Digital Capture and Repository of Student Design Work as an Aid to Teaching, Research, and Accreditation

The ‘Architecture Studio Archive’ pilot sought to form a comprehensive digital archive of the diverse student work conducted in the first year of the Bachelor of Design in Architecture Degree at the University of Sydney. The design studio is the primary vehicle for teaching architectural design. It is a locus for creative activity, with students producing diverse works in analogue and digital media (sketches, final hand and CAD drawings, conceptual and scale models, and written work). Following assessment, they either take their work home or abandon it to potential damage in the studio. This project promised the retention of this material and the production of a powerful, searchable digital archive in the Sydney eScholarship Repository, using the open access digital management system DSpace for long-term storage and dissemination of the material. The intention was to establish procedures and protocols for digital archiving practices suited to creative work.

Precision of cephalometric analysisviafully and semiautomatic evaluation of digital lateral cephalographs

The aim of this study was to evaluate the precision of the cephalometric analysis using the orthodontic software Orthometric((R)) in two modes: fully automatic without any help by the user and semiautomatic with manual determination of all cephalometric landmarks. From 100 indirectly digitally produced cephalographs, 72 were chosen randomly. On each one of these, three methods were applied on 12 decision-relevant cephalometric angles according to Hasund/Segner: (1) hand drawing on a transparent sheet over the cephalographic film; (2) software semiautomatically with manual correction on the screen; and (3) fully automatically. The hand-based method (1) is well established as a quality standard and reference. The angle measurement results of this method were compared with those of the semiautomatic and the fully automatic method by calculation of the mean absolute differences. Additionally, five randomly chosen cephalographs were evaluated ten times using all three methods for statistical evaluation of reproducibility. At tenfold evaluation of five cephalographs, the standard deviations of the angles were between 0.05 degrees and 0.8 degrees . These results were similar using all three methods. All three methods had similar reproducibility. At evaluation of 72 cephalographs, the mean absolute angle differences between the hand-based (1) and semiautomatic (2) methods were below 2 degrees and so within the allowed tolerance limit, except for the nasolabial angle. In contrast to this, all mean absolute angle differences between the (1) hand-based and (3) fully automatic methods exceeded 2 degrees , and with this the tolerance limit allowed by literature. The fully automatic determination of the cephalometric landmarks has led to relevant errors up to now, so that it is mandatory to check all automatically set landmarks and to correct them if required. In the case of the semiautomatic method, all relevant angles can be determined with the same reliability as hand drawing.

Molecular Reproduction & Development: Volume 76, Issue 10

AbstractSnapshot from the life of Ernest Everett Just (1883–1941), circa 1920s. Montage includes images of Just in the laboratory at the Marine Biological Laboratory at Woods Hole, MA USA (©Alfred Huettner, with permission from the Marine Biological Laboratory Archives) with his autograph; the building housing the Howard University Colleges of Medicine, Dentistry, and Pharmacy at that time (courtesy of the Howard University College of Medicine); and hand drawings made by Just of Platynereis megalops fertilization (chronology) and the early zygote (background) (Just, 1915; J Morphology 26; 217–233). The reviews and essays in this issue's special section are in honor of Just's contribution to reproductive biology.

Proposal for a standard system for drawing structural diagrams of N‐ and O‐linked carbohydrates and related compounds

Symbolic diagrams are commonly used to depict N- and O-linked glycans but there is no general consensus as to how individual constituent monosaccharides or linkages are shown. This article proposes a system that avoids ambiguities inherent in most other systems and is appropriate for both hand drawing and computer applications. Constituent monosaccharides are depicted by shapes modified to show OAc, deoxy, etc. Linkage is indicated by the bond angle and anomericity by solid (beta) or dashed (alpha) lines.

Segmentation and accuracy in copying and drawing: Experts and beginners

As part of an ongoing investigation into real-world copying and drawing, I recorded the eye–hand drawing strategies of 16 subjects with drawing experiences ranging from expert to novice while they copied a line drawing of a standing nude. The experts produced accurate copies whereas all the beginners produced marked inaccuracies of overall scaling, proportion and shape. Analysis of eye and hand movements showed that the experts alone segmented the original drawing into simple line sections that were copied one at a time using a direct eye–hand strategy not requiring intermediary encoding to visual memory. The results suggest that segmentation into simple lines defines the task-specific process of accurate copying, and that this process is restricted to experts, i.e. acquired through training and practice. Additional preliminary tests also suggest that a similar process may apply to drawing a model from life.

Neues Konzept einer computergestützten Dokumentation von Netzhautbefunden bei Frühgeborenenretinopathie

Pathological findings and clinical course of retinopathy of prematurity (ROP) are often documented with hand drawings. The use of software-based standardised symbols for ROP staging leads to improved documentation quality. We developed graphical symbols for all ROP stages as well as plus disease. All of the symbols were integrated into a java-based application as a particular ROP category of a complete symbol library for retinal changes. The symbols can be placed on a schematic retina with a mouse click. Using anchors each symbol can be individually adapted to the specific finding (size, position, shape). The use of standardised symbols in a software package allows the computer-aided manufacturing of graphically high-quality documentation in affordable time. The distinct assignment of all symbols to the ROP stages prevents misinterpretation and sketchy, illegible hand drawings. The digital documentation of pathological changes of ROP provides an easy, economic and standardised method to record retinal findings.

Double Dissociation between Motor and Visual Imagery in the Posterior Parietal Cortex

Because motor imagery (MI) and visual imagery (VI) are influenced differently by factors such as biomechanical constraints or stimulus size, it is conceivable that they rely on separate processes, possibly involving distinct cortical networks, a view corroborated by neuroimaging and neuropsychological studies. In the posterior parietal cortex, it has been suggested that the superior parietal lobule (SPL) underlies VI, whereas MI relies on the supramarginalis gyrus (SMG). However, because several brain imaging studies have also shown an overlap of activations in SPL and SMG during VI or MI, the question arises as to which extent these 2 subregions really contribute to distinct imagery processes. To address this issue, we used repetitive transcranial magnetic stimulation to induce virtual lesions of either SMG or SPL in subjects performing a MI (hand drawing rotation) or a VI (letter rotation) task. Whatever hemisphere was stimulated, SMG lesions selectively altered MI, whereas SPL lesions only affected VI, demonstrating a double dissociation between MI and VI. Because these deficits were not influenced by the angular distance of the stimuli, we suggest that SMG and SPL are involved in the reenactment of the motor and visual representations, respectively, and not in mental rotation processes per se.

アイデアを具現化する際の手描きの重要性に関する一考察

設計におけるアイデアは手描き（スケッチ）によって創出されるといっても過言ではない．この考え方を仮に肯定するならば，設計者に要求される能力とは，思考しながら線を引ける能力である．定規や二次元・三次元CAD などポインティングデバイスを介して線を引いている時，手描きに比べ，人の頭脳が働いていないことは感覚的にわかる．考えながら線を引く作業を大局的に捉えれば，工業的な判断力と思考力を培う助けとなる． 一方，三次元CAD の利便性も顕著なことは事実であり，利用しない理由は見つからない．そこで，三次元CAD を設計ツールとして，アイデアを具現化する際の手描きの重要性について考察した． 本論では，１）CAD の有用性とほころび，２）手描きの利便性，３）図面としての手描きの文化，４）直感的な線と色が創りだす独創性，５）教育における基礎とツールの連関について述べる．

Robust and Accurate Visual Echo Cancelation in a Full-duplex Projector-Camera System

In this paper we study the problem of "visual echo" in a full-duplex projector-camera system for telecollaboration applications. Visual echo is defined as the appearance of projected contents observed by the camera. It can potentially saturate the projected contents, similar to audio echo in telephone conversation. Our approach to visual echo cancellation includes an offline calibration procedure that records the geometric and photometric transfer between the projector and the camera in a look-up table. During run-time, projected contents in the captured video are identified using the calibration information and suppressed, therefore achieving the goal of cancelling visual echo. Our approach can accurately handle full-color images under arbitrary reflectance of display surfaces and photometric response of the projector or camera. It is robust to geometric registration errors and quantization effects and is therefore particularly effective for high-frequency contents such as texts and hand drawings. We demonstrate the effectiveness of our approach with a variety of real images in a full-duplex projector-camera system.

Using Hand Drawn Images to Determine Warning Symbol Design Parameters within Interactive Evolutionary Computation Software

The purpose of this pilot study was to explore the feasibility of using hand drawn images to identify symbol components for incorporation into warning symbol design software. This software will use an interactive evolutionary computation (IEC) algorithm to generate and evolve symbols mathematically described by a set of numerical parameters. Therefore, participants (N = 100) ages 19–43 (x = 23.2) were recruited to determine these symbol design parameters. Participants were invited to hand draw warning symbols for three referents: fall from elevation, hearing protection, and hazardous atmosphere. A panel of design engineers determined 27 attributes were present in the fall from elevation, 19 in the hearing protection, and 25 in the hazardous atmosphere images. A direct clustering algorithm was used to determine which attributes, or symbol parameters, were most commonly present or conspicuously absent among the clustered image families. For the fall from elevation, hearing protection and hazardous atmosphere referents, the clustering algorithm identified six, four and four symbol parameters, respectively, primarily responsible for distinguishing one drawn symbol from another. Thus, these parameters will be included as evolvable genes in the IEC software.

Five new myxosporean species (Myxozoa: Myxosporea) infecting the Nile tilapia Oreochromis niloticus in Bahr Shebin, Nile Tributary, Nile Delta, Egypt

Five new myxosporean species belonging to three different genera were described from the Nile tilapia Oreochromis niloticus in Bahr Shebin, Nile Tributary, Nile Delta, Egypt. These species are: Zschokkella nilei sp. n., Ortholinea africanus sp. n., Triangula egyptica sp. n., Myxobolus fomenai sp. n., and Myxobolus branchiophilus sp. n. Morphometry, light microscopy, and hand drawing of mature spores and plasmodia were presented for each species.

Three-dimensional arm movements at constant equi-affine speed

It has long been acknowledged that planar hand drawing movements conform to a relationship between movement speed and shape, such that movement speed is inversely proportional to the curvature to the power of one-third. Previous literature has detailed potential explanations for the power law's existence as well as systematic deviations from it. However, the case of speed–shape relations for three-dimensional (3D) drawing movements has remained largely unstudied. In this paper we first derive a generalization of the planar power law to 3D movements, which is based on the principle that this power law implies motion at constant equi-affine speed. This generalization results in a 3D power law where speed is inversely related to the one-third power of the curvature multiplied by the one-sixth power of the torsion. Next, we present data from human 3D scribbling movements, and compare the obtained speed–shape relation to that predicted by the 3D power law. Our results indicate that the introduction of the torsion term into the 3D power law accounts for significantly more of the variance in speed–shape relations of the movement data and that the obtained exponents are very close to the predicted values.

Effect of postural instability on drawing errors in children: A synchronized kinematic analysis of hand drawing and body motion

To investigate the role that postural stability plays in fine motor control, we assessed kinematics of the head, shoulder, elbow, and the pen during an accuracy drawing task in 24 children. Twelve children were classified into an accurate drawing (AD) group and 12 children into an inaccurate drawing (ID) group based on a manual dexterity task from the movement assessment battery for children [Henderson, S. E., & Sugden, D. A. (1992). Movement assessment battery for children. London: Psychological Corporation.]. Their parents completed a questionnaire to assess children’s inattention, hyperactivity, and impulsivity. An electromagnetic tracking system was used to monitor 3-D kinematic data of the body parts, while 2-D kinematic data of pen movement was simultaneously collected from a computer digitizer tablet. If a sudden body motion (1cm/s) occurred within a time window from one second prior to the onset of the drawing error to the end of the error, we considered that the error coincided with the extraneous body movement. For each drawing trial, the coincidence rate was computed as (number of coincidences)/(number of errors). The ID group had a significantly higher coincidence rate of head and shoulder movements compared with elbow movements, whereas coincidence rates did not differ between the three body parts in the AD group. Parental ratings of children’s behavioral ratings of inattention, hyperactivity, and impulsivity were not correlated with the coincidence rates. The results indicated that inaccurate drawing was a result of postural instability rather than fidgeting caused by inattention or hyperactivity/impulsivity.