Manual Sketching Research Articles

External procedures in design problem solving by experienced engineering designers – methods and purposes

In the creative early phases of design problem solving, several kinds of external – especially manual – procedures of thinking (‘externalizations’) are applied. This was mainly shown in experimental settings for tasks of architects. We analysed the kinds and the reported purposes of externalising in the everyday work of experienced engineering designers. Three field studies with different samples of engineers (n = 55) show: the majority of experienced designers reported the application of simple low-cost externalising (especially manual sketching and impromptu-prototyping) in their everyday work mainly for memory relief, communication and generation of ideas. Different mental processes in the early phases of engineering design require different kinds of externalising to support them. Simple low-cost externalisations offer most perceived support for communication and sophisticated ones (e.g. manufactured prototypes) for the evaluation of solutions. The results based on retrospective memory reports of engineers are confirmed by self-records of an ongoing conceptual design process and the documented frequencies of different kinds of externalising.

Left ventricular myocardium segmentation on delayed phase of multi-detector row computed tomography

Advanced ischemic heart disease is usually accompanied by left ventricular (LV) myocardial volume loss and an abnormal enhancing pattern on delayed phase of multi-detector row computed tomography (MDCT). To assist radiologists and physicians in estimating the LV myocardial volume on delayed phase, this paper proposes an adaptive segmentation method for contouring the myocardial region in the delayed-phase MDCT and for computing the volume. The proposed method uses an anisotropic diffusion filter as a preprocessing procedure to enhance contrast and reduce specks in MDCT imaging. This work picks the middle of mid-ventricular level image slices as the lead slice. The proposed method develops two contouring modes to sketch the myocardium contour on the lead slice. By establishing the obtained contours as the initial contours, the region-growing method is employed to identify the contour of the myocardial region for each slice. The convex-hull finding algorithm is then used to refine the extracted contour. Finally, the width properties of the myocardial region and the morphological operators are used to obtain the entire LV myocardial volume. Twenty-seven healthy patients who had no symptoms of ischemic heart disease are examined to evaluate the performance of the proposed method. Compared with manual contours delineated by two experienced experts, the contouring results using computer simulation reveal that the proposed method reliably identifies contours similar to those obtained using manual sketching. The proposed method provides robust contouring for the LV myocardium on delayed-phase MDCT. The potential role of this technique may substantially reduce the time required to sketch manually a precise contour with high stability.

Left ventricular myocardium segmentation on arterial phase of multi-detector row computed tomography

Rationale and objectives Variation of left ventricular myocardial volumes correlates closely with ischemic heart diseases. In clinical practice, because physicians and radiologists rely much on myocardial contour to diagnose many different cardiac diseases, automatic segmentation of left ventricular myocardium and quantifying myocardium characteristics is clinically beneficial. This paper presents a hybrid segmentation method for left ventricular myocardium on arterial phase of multi-detector row computed tomography (MDCT) imaging. Materials and methods The proposed method utilizes an intensity transformation equation as a preprocessing procedure to enhance contrast and reduce noise in MDCT imaging. By setting the centroid of left ventricle (LV) as an initial seed, the conventional region growing method is employed to identify the endocardial contour of LV cavity for each slice. Then the level-set method (LSM) utilizes the extracted endocardial contour as initial contour to delineate the epicardium of LV. The two extracted contours are integrated to form the region of interest (ROI) of the LV. Finally, the ROIs from all slices are combined to obtain the volume of the whole LV myocardium. Results Twenty-two healthy patients who had no symptoms of ischemic heart disease are applied to evaluate the performance of the proposed method. Compared with manual contours delineated by two experienced experts, the contouring results from computer simulation reveal that the proposed method always identifies similar contours as that obtained by the manual sketching. Conclusion The proposed method provides a robust and fast automatic contouring for LV myocardium on arterial phase of MDCT. The potential role of this technique may save much of the time required to manually sketch a precise contour with high stability.

Impacts of VR 3D sketching on novice designers’ spatial cognition in collaborative conceptual architectural design

Conventional Computer Aided Design tools lack intuitivity for being used in conceptual architectural design process. This paper identifies the impact of using a haptic based VR 3D sketching interface for integrating novice designers’ cognitions and actions to improve design creativity. This study employs protocol analysis for comparing the collective cognitive and collaborative design protocols of three pairs of novice architectural designers in both 3D and manual sketching sessions. Results show that the simple and tangible haptic based design interface improved designers’ cognitive and collaborative activities. These improvements also increased their engagement with ‘problem-space’ and ’solution-space’ that led towards more artefact maturity. Research findings from this study can help the development of cutting-edge haptic-based collaborative virtual environments in architectural education and associated professions.

Comparison of CAD and manual sketching tools for teaching architectural design

Communications for information synchronisation during the conceptual design phase usually require designers to employ more flexible and intuitive digital design tools. In developing such support tools, a case study research was initiated to first understand the current state of communication among novice design team members. The main purpose of the study is to understand the novice designers' collaboration culture when working on conceptual architectural design projects. The overall case study research involves 1) ethnography for data collection and 2) artefact and protocol analyses for data analysis. This paper presents the latter data analyses based on the earlier ethnography results about novice designers' conceptual design and technology design synthesis strategies. Data analyses on the characteristics of utilised external representation tools indicate that although conventional manual sketching is beneficial for providing rich intuitive design concepts, they have limitations when novice designers need to oversee complicated design problems. The study also found that although current conventional CAD tools are advantageous for detailed engineering design articulation, they do hinder novice designers' creativity due to their intuitive ideation limitation. Based on these results, this paper discusses the identified advantages and challenges of current design media and then proposes an alternative VR-based design interface for enhancing cognition and communication among designers during the conceptual design phase.

Automated Creativity: Digital Morphology and the Design Process

Literature shows that traditional creative methods may reinforce repetitive and habitual behavior resulting in ineffective environmental design solutions (Lawson, 1980; Lang, 1987; Laseau, 1989). Two case studies explored the use of an automated system called cyber–ideation (Gibson, 2000b) as a method to stimulate idea generation. This procedure employed individual and team involvement, recursive and linear exploration, and manual and digital processes. Analysis compared students’ production using traditional ideation processes with that resulting from cyber–ideation. Results from this case study found that: 1) digital creation was more linear when evaluated against traditional ideation output, 2) cyber–ideation had a positive impact on team dynamics, and 3) automated output possessed greater surface delineation when compared with subjects’ manual sketching.

Level Set Contouring for Breast Tumor in Sonography

The echogenicity, echotexture, shape, and contour of a lesion are revealed to be effective sonographic features for physicians to identify a tumor as either benign or malignant. Automatic contouring for breast tumors in sonography may assist physicians without relevant experience, in making correct diagnoses. This study develops an efficient method for automatically detecting contours of breast tumors in sonography. First, a sophisticated preprocessing filter reduces the noise, but preserves the shape and contrast of the breast tumor. An adaptive initial contouring method is then performed to obtain an approximate circular contour of the tumor. Finally, the deformation-based level set segmentation automatically extracts the precise contours of breast tumors from ultrasound (US) images. The proposed contouring method evaluates US images from 118 patients with breast tumors. The contouring results, obtained with computer simulation, reveal that the proposed method always identifies similar contours to those obtained with manual sketching. The proposed method provides robust and fast automatic contouring for breast US images. The potential role of this approach might save much of the time required to sketch a precise contour with very high stability.

Design devices: digital drawing and the pursuit of difference

We examine the uses of a prototypic device, in research and in design, for incorporating manual sketching into computer environments. We move from empirical and evolutionary conceptions of the role of such devices to the phenomenology of disclosure, attending to the revealing, generative, catalytic, metaphoric, signalling and provocative characteristics introduced by such devices. The discussion takes us through a series of steps that each amplifies the role of philosophical concepts of negation and difference in understanding the device.

Application of orthogonal neural network to craniomaxillary reconstruction

Traditionally, the orthopaedist, according to their past experience, reconstructs damaged area while the operation is in progress. This may prolong the operation and cause the wound to become infected. Most importantly it is difficult to precisely match the skeletal defect. A well-disciplined network of prediction re-fabricates the damaged area through automation. This research is based on the CT image file, which is the product of X-ray computed tomography (CT), and computes the skeletal positions around the damaged area through image processing and boundary detection. The skeletal positions are inputted into the orthogonal neural network and discipline the network so that it possesses the scattering characteristic of bone. The network then calculates skeletal positions in the damaged area and revises the former CT image file to rebuild a 3D model. Accordingly, in comparison with a manual sketch, the orthogonal neural network forecast is more geometrically precise. Moreover, the forecast satisfies the second order derivative, which is a continuous function, and the edge of the fabricated bone is therefore kept smoother.

Determination of Permeability Anisotropy in a Two-Way Permeameter

Abstract This paper describes the use of a new item of laboratory equipment, a two-way permeameter for determination of the degree of permeability anisotropy of compacted or undisturbed samples of soil. The test is performed on a single sample of soil. The relevant theoretical solutions for seepage flow through the permeameter have been provided, based on exact solutions and manual sketching of flow nets.

Mechanical drawing

We examine the uses of a prototypic device, in research and in design, for incorporating manual sketching into computer environments. We move from empirical and evolutionary conceptions of the role of such devices to the phenomenology of disclosure, attending to the revealing, generative, catalytic, metaphoric, signalling and provocative characteristics introduced by such devices. The discussion takes us through a series of steps that each amplifies the role of philosophical concepts of negation and difference in understanding the device.