• 대한인간공학회지
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• 제24권2호
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• pp.85-91
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• 2005

To understand the basic relationship between 3D curved surface model and 2D pattern, simplified torso model was generated by commercial CAD program (IDEAS). 3D torso model was then divided into different blocks and unfolded into a flat pattern as in ordinary works of clothing item design. As results, 2D pattern development of different part of 3D torso model was attempted and analyzed mathematically. It was found that different height, radius and tangent slope of 3D blocks resulted in different 2D pattern. The relationships between the shape parameters of 3D torso blocks and those of 2D patterns were analyzed using regression equations. Direct way of drawing a 2D pattern of corresponding 3D torso block was also illustrated for the convenience of pattern making using conventional measurements of upper/ lower radii and height of 3D torso block.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2005년도 추계학술발표대회 개요집
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• pp.17-19
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• 2005

To achieve high productivity of assembly hull blocks, it is important to predict welding deformations accurately and to apply these data to the production planning. In the deformation analysis of hull block, simplified methods (elastic analysis) such as inherent method, equivalent loading method and local & global approach are usually used instead of thermal-elastic-plastic analysis because of calculating time and cost. To be much more practical, these simplified methods should consider gravity effect of plate and contact condition between the plate and the positioning jig. In this research, using finite element method, practical predicting method for the welding deformation of the curved hull blocks with considering welding sequence, gravity effect and contact condition is proposed.

• 한국정밀공학회지
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• 제31권4호
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• pp.335-342
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• 2014

This paper describes the forming conditions of smart-phone curved glass using the glass molding system with force applying system. The force applying system is composed of a body, a motor and gear, a rectilinear movement structure, a force sensor, a LVDT sensor (Linear Variable Differential Transformer), a up and down moving block, and so on. The glass molding system for characteristic test to find the forming conditions consists of the force applying system and a chamber, a metallic mold, a upper heater, a lower heater and so on. The characteristic test for forming conditions of smart-phone curved glass was carried out at forming temperature $620^{\circ}C$ and $650^{\circ}C$ using the glass molding system. As a result of the characteristic test, the forming conditions of curved glass could be found, and it is thought that the conditions can be used to apply to the system for producing in large quantities.

• 대한조선학회논문집
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• 제49권1호
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• pp.87-92
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• 2012

Alignment of the main plates during the tack welding is essential to block assembly since most of the curved blocks and outfitting parts are assembled on the jigs and fixtures. Tact welding of main plates is the initial process of the curved hull block assembly. Due to the heavy weight of the main plates it is difficult to locate the plate on the accurate position of the jig and fixtures before welding. The conventional masonry process requires much time and manual work in order to achieve the accurate alignment. This labour-intensive process results in relatively high errors and correction works. Due to their larger dimensions and heavier weights, these hull blocks are not ergonomically desirable and, therefore, various mechanical devices such as hydraulic balancers or hydraulic jigs are used for the plate alignment. In this study, the position-sensing scheme implemented by sensors is presented in order to align the main plates on the accurate position during the hull block assembly. Integrating the Infrared photo sensors and micro processor unit, a small scaled prototype of the position-sensing module is developed to determine the alignment of main plates.

• 대한기계학회논문집B
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• 제27권4호
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• pp.534-541
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• 2003

To investigate the combustion characteristics in a low-pollutant municipal waste incinerator, the generalized multi-block simulation code that can be applied to turbulent reacting flow with gaseous hydrocarbon fuel in a 3D complex geometry has been developed with nongray radiation effects. To deal with the complex geometry, structured multi-block method and the scheme which treats interfaces implicitly are adopted. The developed code is validated through various engineering problems such as curved duct flow, driven cavity flow, gray multi-block radiation, nongray radiation. and combustion in a incinerator.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.574-580
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• 2003

This research heightens use efficiency of existent train railroad equipment by maximum through communication based train control system, and because system that take advantage of new skill compares with safety of old signal system same or it that show that is high be. Examined MBS Embodiment method of most suitable by presenting calculation that find out location of train that this treatise runs free curved line department to embody MBS(Moving Block System) through communication

• Restorative Dentistry and Endodontics
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• 제13권1호
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• pp.161-171
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• 1988

The purpose of this study was to examine the morphological changes of different simulated canals according to the preparation procedures. With the use of clear casting resin, simulated straight and curved canals were created so that canal preparation procedures could be directly visualized and compared. Thirty clear polyester casting resin blocks which contained four simulated canals divided into three groups; Group A($0^{\circ}$), Group B($15^{\circ}$), and Group C($30^{\circ}$). In each block, 3 canals were prepared different preparation techniques, which were conventional method, step-back method, and giromatic filing. But, one canal was not prepared as a control group. The results were as follows: 1. There was no difference on canal shape among three canal preparation methods in straight canals (Group A). 2. When conventional method and Giromatic filing were used in curved canals (Group B, C), elbow, zip and hour-glass shape were formed in apical third. 3. When conventional method and Giromatic filing were used in curved canals (Group B, C), tear-drop appearance developed at the site of the canal exit in curved canals. 4. In curved canals (Group B, C), file tend to straighten within the canal. 5. There was no difference on canal shape according to curved angle in step-back method (p > 0.1). But there was significant difference on canal shape according to curved angle in conventional method and Giromatic filing (p < 0.001). 6. Step-back method was significantly more effective than conventional method and Giromatic preparation in morphologic aspects of apical third of original canals.

• 한국기계가공학회지
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• 제13권4호
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• pp.50-55
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• 2014

Currently, flat cover glasses are widely applied to mobile devices. However, for a good design and for convenience of use, curved cover glasses are in demand. Thus, many companies are attempting to produce curved cover glasses using a shaving technique, but the production efficiency is very low. Therefore, a molding technique has been adopted to increase the efficiency of curved glass production systems. For a glass molding system, a uniform temperature distribution of the mold is crucial to produce high-quality curved cover glasses. Before setting the heating conditions of the molding system for a uniform temperature distribution by a thermal analysis, verification is required. Therefore, in this study, temperature measurements were conducted for a prototype molding system and the experimental results were compared with simulation computations. The temperatures of the heating block surface were in good agreement with the computational results for transient and steady conditions.

• Restorative Dentistry and Endodontics
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• 제41권1호
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• pp.1-5
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• 2016

Objectives: The purpose of this study was to assess the ability of ProTaper Gold (PTG, Dentsply Maillefer) in maintaining the original profile of root canal anatomy. For that, ProTaper Universal (PTU, Dentsply Maillefer) was used as reference techniques for comparison. Materials and Methods: Twenty simulated curved canals manufactured in clear resin blocks were randomly assigned to 2 groups (n = 10) according to the system used for canal instrumentation: PTU and PTG groups, upto F2 files (25/0.08). Color stereomicroscopic images from each block were taken exactly at the same position before and after instrumentation. All image processing and data analysis were performed with an open source program (FIJI). Evaluation of canal transportation was obtained for two independent canal regions: straight and curved levels. Student's t test was used with a cut-off for significance set at ${\alpha}=5%$. Results: Instrumentation systems significantly influenced canal transportation (p < 0.0001). A significant interaction between instrumentation system and root canal level (p < 0.0001) was found. PTU and PTG systems produced similar canal transportation at the straight part, while PTG system resulted in lower canal transportation than PTU system at the curved part. Canal transportation was higher at the curved canal portion (p < 0.0001). Conclusions: PTG system produced overall less canal transportation in the curved portion when compared to PTU system.

• 로봇학회논문지
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• 제6권2호
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• pp.141-146
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• 2011

In the TV manufacturing industry, a demand for chic design of TVs is increasing. As a reult of this trend in TV design, more curved surfaces in a TV cabinet are introduced, which enforces the use of fixers to combine a front cabinet with a TV main body. In this paper, we introduce a robot system for attaching various types of fixers to a TV cabinet. The developed system consists of three main blocks. The first one is the dispensing block, in which transferred cabinet is centered and UV adhesives are dispensed on the cabinet. The second one is the fixer attaching block, in which a cabinet is centered again and fixers are attached to pre-determined places on a cabinet by a robot with several end effectors. The last one is the UV hardening block, in which very strong ultraviolet rays are applied to the cabinet for attaching fixers tightly to the cabinet. The developed system is successfully adopted in a TV manufacturing process.