• Fibers and Polymers
• /
• v.7 no.4
• /
• pp.424-431
• /
• 2006

Roll drafting, a mechanical operation attenuating fiber bundles to an appropriate thickness, is an important operation unit for manufacturing staple yams. It influences not only the linear density regularity of the slivers or staple yams that are produced, but also the quality of the textile product and the efficiency of the thereafter processes. In this research, the dynamic states of the fiber bundle in the roll drafting zone were analyzed by simulation, based on the mathematical model that describes the dynamic behavior of the flowing bundle. The state variables are the linear density and velocity of the fiber bundles and we simulated the dynamics states of the bundle flow, e.g., the profiles of the linear density and velocity in the draft zone for various values of the model parameters and boundary conditions, including the initial conditions to obtain their influence on the dynamic state. Results showed that the mean velocity profile of the fiber bundle was strongly influenced by draft ratio and process speed, while the input sliver linear density has hardly affected the process dynamics. Velocity variance of individual fibers that could be supposed to be a disturbing factor in drafting was also influenced by the process speed. But the major disturbance occurred due to the velocity slope discontinuity at the front roll, which was strongly influenced by the process speed. Thickness of input sliver didn't play any important role in the process dynamics.

• Korean Journal of Computational Design and Engineering
• /
• v.1 no.2
• /
• pp.97-106
• /
• 1996

Existing CAD systems do not provide advanced functions for automatic checking design and drafting errors in mechanical drawings. If the knowledge of checking in mechanical ddrsfting can be implemented into computers, CAD systems could automatically check for design and drafting errors. This paper describes a method for systematic checking of dimension errors. such as deficiency and/or redundancy of dimension input-errors in dimension figures and symbols, etc. The logic for finding dimensional errors is written by using a proccedural language. A geometric model and a topological-graph model are used in this method. Checking for deficiency and redundancy of dimensions is based upon graph Theory.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10a
• /
• pp.114-114
• /
• 2003

Fiber bundles output from a draft operation have linear density irregularity. This study is dealing with modeling the dynamics of fiber bundle during roll drafting based on continuity, momentum balance, and a constitutive assumption. The simulation results from this model are compared with experimental results and analyzed by applying the concept of the Describing Function(DF). It can be confirmed that the simulation results agree well with experiments in a steady state, if the model parameters are good adjusted.

• Journal of Korean Home Economics Education Association
• /
• v.5 no.1
• /
• pp.45-59
• /
• 1993

The aims of this study are to develop CAI programs for bodice and sleeve pattern drafting for the 3rd grade students in a middle school and to compare the students’achievement degree in using traditional teaching method with that in using CAI programs. On the basis of results above the direction and possibility of using computers in education home economics is another aim. For this study, after the programs are developed, which is on the model of middle school text book, one hundred girl students of 2nd grade of middle school in Songpa Gu, Seoul, who have never given Bodice and Sleep Pattern Drafting lesson are chosen. The students are divided into two groups: one is called comparison group, which is taught by traditional method, the other, experimental group, which is taught by CAI programs. To evalute the learning achivement degree, evaluation test, effectiveness of learning and interest degree test and time test are given. Questionaire investigation about CAI program is given to experimental group. The results of this study are as follows: 1. CAI programs on pattern drafting are developed and can be used in the class. 2. In the tests of achievement degree, of effectiveness, and of interest the experimental group gets higher scores than the comparison group. 3. In the time test about how many students can draft the pattern in a given time, in every step more students in experimental group finished drafting than the comparison group. 4. The students showed interest in CAI programs and played an active part in the using computers. Therefore, using CAI programs in the class of pattern drafting saved the teachers lots of difficulties and enables individual learning improving the effectiveness of learning. I hope the studies of CAI will be established in other field as well as Home Economics, especially clothing part, and computers will be used lively

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.1643-1646
• /
• 2003

Drawing is a mechanical operation that attenuates thick material to an appropriate thickness for the next processing or end usage. When the input material has the form of a bundle or bundles made of very thin and long shaped wire or fibers, this attenuation operation is called "bundle drawing" or "drafting" Drafting is being used widely in manufacturing staple yarns. which is indispensable for the textile industry. However, the bundle processed by this operation undertake more or less defects in the evenness of linear density. Such irregularities cause many problems not only for the product quality but also for the efficiency of the next successive processes. Since long there have been many researches tying to find out factors affecting the irregularity of linear desity, to obtain optimal drafting conditions, to develop efficient measuring and analysis methods of linear density of bundle, etc., but there exists yet no fundamental equation describing the dynamic behavior of the flowing bundle during processing. In this research a mathematical model for the dynamic behavior of the bundle fluid is to be set up on the basis of general physical lows representing physical variables, i.e. linear density and velocity as the dynamic state of bundle. The conservation of mass and momentum balance was applied to the fluid field of bundle. while the movement of′ individual material was taken into account. The constitutive model relating the surface force and the deformation of bundle was introduced by considering a representative prodedure that stands for the bundle movement. Then a fundamental equations system could be simplified considering a steady state of the process. On the basis of the simplified model, the simulation was performed and the results could be confirmed by the experiments under various conditions.

• Journal of Fashion Business
• /
• v.8 no.4
• /
• pp.22-32
• /
• 2004

The purpose of this research is to know the pattern of Hanbok Jegory with measuring Jegory and studying manufacturing method of the Jegory used currently. It is a purpose to find constitutional problem caused by the character of the bending somatotype and, to study the standard model of the Jegory for bending somatotyped women in old age, by comparison of this fitness for bending-somatotyped women in old age. The results obtained are as follows; 1. The kinds of measurements considered in manufacturing process are Hwajang Length, Bust girth, and the skirt length. The length of Jegory and width of Neck are also considered. 2. Manufacturers consider somatotype the most important thing when they make Jegory for women in old age. Front length, Back length and Width of the Jegory are considered secondly important. 3. The results of the comparison show that the Standard Hanbok drafting method is not suitable for drafting Jegory for bending somatotyped women in old age. 4. The suitability test for the model designed by the above methods shows that it fits in bending somatotyped women in old age better than standard drafting method. The results show the superiority of the above methods especially in the breast width, the Godae length, and the adaptedness to the body.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 2000.04a
• /
• pp.261-266
• /
• 2000

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.25 no.5
• /
• pp.433-438
• /
• 2012

This paper is the second paper among two papers which constitute the paper about the structural design of a dental implant. This paper completed the test drafting for the structural model of the new dental implant whose structural performance was confirmed and verified through the comparative structural analysis carried out in the first paper. This paper finished the structural design of a dental implant by manufacturing the dental implant using CNC machines and so forth on the basis of the completed draft and finally by evaluating the machining condition of the dental implant. The drafting work was performed using MDT(Mechanical Desk Top). The manufacturing work was carried out using CNC machines, general purpose milling machine, and Wire EDM. The manufactured surface condition of the dental implant was evaluated and confirmed finally using an electron microscope. As a result of evaluation, a testing dental implant with very good condition was designed and manufactured.

• Journal of Fashion Business
• /
• v.26 no.3
• /
• pp.116-137
• /
• 2022

The purpose of this study was to develop jacket patterns that could fit well for women in their 20s with turtle neck syndrome body shape and to present a pattern drafting method. As a research method, an educational pattern was chosen through a preliminary experiment. Fit problems of the educational pattern were derived by wearing it on a virtual model with a turtle neck syndrome body type for each neck angle. Based on the three types of experimental patterns developed by supplementing these problems, a development pattern drafting method was developed for each neck angle. Three development patterns were compared and evaluated with the educational pattern using 3D virtual fitting. Fit problems of the educational pattern included: 1) insufficient ease amounts for hip, hem, bicep, elbow, and sleeve hem circumference; 2) horizontal items could not be leveled due to insufficient back length; 3) the shoulder line went backwards; and 4) the front center line did not form a vertical line. To solve these problems, an experimental pattern was developed by increasing the insufficient ease amount, increasing the insufficient back length, and correcting the position of the shoulder line. Measurements that differed in the pattern drafting method of the three types of development patterns by neck angle were positions of back center line and back neck point, front length, and front neck width. Through appearance evaluation of the development pattern and educational pattern by neck angle, the development pattern was highly evaluated, indicating that problems of the educational pattern were improved.

• Korean Journal of Computational Design and Engineering
• /
• v.11 no.6
• /
• pp.393-402
• /
• 2006

The purpose of this study is to develop mechanisms of nD model-based design by the combination of 2D drawing standards and 3D building models from the current 2D and text-based design. The aim of this study can be archived by defining the 2D model extension definitions for the IFC model development and harmonizing existing 2D standards. The paper examines 1) 3D Representation of Building Element and Building Services element, and 2D Model extension of IFC2X.2, 2) Basic development of additional 2D element that should be added to IFC model, and 3) mapping method between current 2D standard and IFC2.X2. Following this approach, the interoperability problem between 3D model and 2D drawing can be solved and finally an extended data model could be developed.