• Korean Journal of Computational Design and Engineering
• /
• v.6 no.2
• /
• pp.78-88
• /
• 2001

In order to adopt feature-based parametric modeling, CAD/CAM applications must have a geometric constraint solver that can handle a large set of geometric configurations efficiently and robustly. In this paper, we describe a graph constructive approach to solving geometric constraint problems. Usually, a graph constructive approach is efficient, however it has its limitation in scope; it cannot handle ruler-and-compass non-constructible configurations and under-constrained problems. To overcome these limitations. we propose an algorithm that isolates ruler-and-compass non-constructible configurations from ruler-and-compass constructible configurations and applies numerical calculation methods to solve them separately. This separation can maximize the efficiency and robustness of a geometric constraint solver. Moreover, the solver can handle under-constrained problems by classifying under-constrained subgraphs to simplified cases by applying classification rules. Then, it decides the calculating sequence of geometric entities in each classified case and calculates geometric entities by adding appropriate assumptions or constraints. By extending the clustering types and defining several rules, the proposed approach can overcome limitations of previous graph constructive approaches which makes it possible to develop an efficient and robust geometric constraint solver.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.448-454
• /
• 2010

Currently a KTX train of 20-car formation is 388m long and carries 931 passengers including one captain and three crews which is quite a few to cover the lengthy service area and many customers. On the other hand, if a passenger wants to talk to an attendant, he has to wait for an attendant passing by his/her seat or walk to an intercom which is placed at every other car. Any of these choices is inconvenient. So, in this paper, we presented a system design for developing an audio/visual communication system for a passenger and an attendant. The system was analyzed and designed according to the Object-Oriented methodology with UML (Unified Modeling Language). Based on a problem statement, a Use-case Diagram, Sequence Diagrams, Class Diagram, State Charts, collaboration Diagram were generated. The design will be used in system implementation to a HEMU-400X test train and to be tested.

• Korean Journal of Computational Design and Engineering
• /
• v.5 no.3
• /
• pp.255-262
• /
• 2000

A computer-aided process planning (CAPP) system for rotationally symmetric deep drawing products has been developed. The application for non-axisymmetric components, however, has not been reported yet. Therefore, this study investigates process sequence design in deep drawing process and constructs an expert system of process planning for non-axisymmetric motor frame products with elliptical shape. The system developed consists of four modules. The first one is recognition of shape module to recognize the products. The second one is a 3-D modeling module to calculate surface area for non-axisymmetric products. The third one is a blank design module that creates an oval-shaped blank with the identical surface area. The forth one is a process planning module based on production rules that play the best important role in an expert system for manufacturing. The production rules are generated and upgraded by interviewing with field engineers. The constructed system using AutoLISP language under the AutoCAD environment is baled on the knowledge base system which is involved a lot of expert's technology. Results of this system will be provide effective aids to the designer and engineer in this field.

• BMB Reports
• /
• v.42 no.3
• /
• pp.172-177
• /
• 2009

Phosphoglucose isomerase (PGI) is involved in synthesizing extracellular polysaccharide (EPS). The gene encoding PGI in Sphingomonas chungbukensis DJ77 was cloned and expressed in E. coli, and the protein was characterized. The pgi gene from DJ77 is 1,503 nucleotides long with 62% GC content and the deduced amino acid sequence shows strong homology with PGIs from other sources. The molecular masses of PGI subunit and native form were estimated to be 50 kDa and 97 kDa, respectively. Four potentially important residues (H361, R245, E330 and K472) were identified by homology modeling. The mutations, H361A, R245A, E330A, R245K and E330D resulted in decrease in Vmax by hundreds fold, however no significant change in Km was observed. These data suggest that the three residues (H361, R245Aand E330) are likely located in the active site and the size as well as the spatial position of side chains of R245 and E330 are crucial for catalysis.

• Journal of Construction Engineering and Project Management
• /
• v.2 no.3
• /
• pp.1-7
• /
• 2012

The reconstruction of surfaces from unorganized point clouds can provide very useful information for construction managers. Although point clouds are generally created using 3D scanners, they can also be generated via the structure-from-motion technique using a sequence of images. Here we report a novel surface reconstruction technique for modeling and quantifying earthworks that can be used for preliminary planning, project updates and estimating of earthwork quantities, as well as embedded planning systems in construction equipment. The application of structure-from-motion techniques in earth works is examined and its advantages and limitations identified. Data from 23 earthwork excavation construction sites were collected and analyzed. 3D surface reconstructions during the construction phase were compared to the original land form. Similar experiments were conducted with piles of earth and the results analyzed to determine appropriate ranges of use for structure-from-motion surface reconstructions in earthwork applications. The technique was found to be most suited to pile of materials with volumes less than 2000 m3. Piles up to 10 m in height and with base areas up to $300m^2$ were also successfully reconstructed. These results should be of interest to contractors seeking to utilize new technology to optimize operational efficiency.

• Fisheries and Aquatic Sciences
• /
• v.10 no.1
• /
• pp.16-23
• /
• 2007

Myostatin (GDF8) is a growth factor that limits muscle tissue growth and development in vertebrates. We isolated a myostatin-like gene (Py-MSTN) from the marine invertebrate, the scallop Patinopecten yessoensis. Py-MSTN was highly expressed in the adductor muscle and in the gill unexpectedly. Amino acid analysis showed that Py-MSTN has 49% amino acid sequence identity and 64% similarity to human myostatin (Hs-MSTN), and 42% identity and 61% similarity to myoglianin, the only invertebrate homolog. These results indicated that Py-MSTN may be functionally similar to the vertebrate MSTN than the invertebrate homolog. Phylogenetic analysis suggested that Py-MSTN is an ancestral form of vertebrate MSTN and GDF11 and does not belong to other $TGF-{\beta}$ family members. Molecular modeling showed that Py-MSTN exhibits a similar tertiary structure to mammalian BMP7, a member of $TGF-{\beta}$ family. In addition, the amino acid residues which contact extracellular domain of the receptor were relavively conserved. Given these results, we propose that Py-MSTN is a functionally active member of the $TGF-{\beta}$ family and is involved In muscle growth and regulation.

• Korean Journal of Computational Design and Engineering
• /
• v.2 no.2
• /
• pp.103-110
• /
• 1997

In the development of large complex assembly, most design changes are from the following reasons.: 1) insufficient consideration of assembling sequence of downstream process. 2) interference and fit-up of related parts. 3) initial design changes which are not completely resolved. In order to reduce the first reason of above, the assembly-centric modeling methodology was proposed in the part (1) of the thesis. In this part (2), a Digital Mock-Up system, which is a tool to build a virtual mock-up in design stage, has been developed in order to prevent the other two reasons. The system can build a virtual assembly in various ways as followings.: 1) assembling parts which are located in user defined envelope. 2) assembling parts with the specified disciplines. 3) assembling parts that are selected in the part list. It can also make an assembly by the combination of above methods. In addition to that, it has the functions to read/write the virtual assembly and to explode parts of the assembly in desired direction. With the virtual assembly, engineers can design interference free parts without making physical mock-up. The system has been implemented with Oracle database management system in CATIA environment.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.2
• /
• pp.207-210
• /
• 2007

To identify structural or functional common subunit(s) in the CP1 (editing) domains of class Ia tRNA synthetases, five available structures were compared and analyzed. Through the sequence alignments and structural overlapping of the CP1 domains, three conserved regions were identified near the amino acid binding site in the editing domain. Structural overlapping of the three subunits clearly showed the existence of three common structural subunits in all of the five editing RS structures. Based on the established experimental results and our modeling results, it is proposed that subunits 1 and 3 accommodate the incoming amino acid binding, while subunit 2 contributes to the interactions with the adenosine ring of the A76 to stabilize the overall tRNA binding. Since these subunits are critical for the editing reaction, we expect that these key structures should be conserved through the most class Ia editing RSs.

• Journal of Digital Contents Society
• /
• v.14 no.1
• /
• pp.117-124
• /
• 2013

This paper suggests the robust method of extraction for moving objects in illumination variation by using image sequence from an immovable camera. The most difficult part of the implication is the effect by illumination and noise. The object area is hardly estimated when the dusky area occurs in illumination variation by time change. This thesis describes the extraction of moving objects employed by Gaussian mixture model which is noise robust measure. Also, the report suggests the elimination method of illumination part in input image by the representative illumination image which is defined to minimize the illumination influence.

• Composites Research
• /
• v.29 no.1
• /
• pp.33-39
• /
• 2016

In this study, geometric modeling and finite element analysis of 3-dimensional plain weave composite unit cell consisting of 3 interlaced fiber tows and resin pocket were performed to predict effective properties. First, tow properties were obtained from micro-mechanics finite element unit cell analysis, which were then used in the meso-mechanics analysis. The effective properties were obtained from a series of unit cell analyses simulating uniaxial tensile and shear tests. Analysis results were compared to the analysis and experimental results in the literature. Various crimp angles were considered and the effect on the effective properties was investigated. Initial failure strengths and failure sequence were also examined.