• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.180-187
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• 2003

In engineering design environment it is hard to link design data and systems because the types of them are disparate. Therefore, the importance of metadata has increased. Some researches have been executed to develop metadata. But they cannot interact with other metadata and are difficult to extend. The purpose of this paper is to develop a common document structure which represents the general information of mechanical part assembly using XML, and to use it as base documents in order to integrate design data and systems. It is composed of part, assembly and user documents. Part document represents the information of a part independently to part type. Assembly document represents the location of constituent part documents. User document represents user's information. Common documents can be used as a broker between design data and systems, and it can improve the interpretability and reusability of document. We applied the developed common document structure to 2-stage spur gear drive.

• Nuclear Engineering and Technology
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• v.49 no.4
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• pp.855-864
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• 2017

The control rod assembly controls reactor power by adjusting its position during normal operation and shuts down chain reactions by its free drop under scram conditions. Therefore, the drop performance of the control rod assembly is important for the safety of a nuclear reactor. In this study, the drop performance of the conceptually designed control rod assembly for the prototype generation IV sodium-cooled fast reactor that is being developed at the Korea Atomic Energy Research Institute as a next-generation nuclear reactor was experimentally investigated. For the performance test, the test facility and test procedure were established first, and several free drop performance tests of the control rod assembly under different flow rate conditions were then carried out. Moreover, performance tests under several types and magnitudes of seismic loading conditions were also conducted to investigate the effects of seismic loading on the drop performance of the control rod assembly. The drop time of the conceptually designed control rod assembly for 0% of the tentatively designed flow rate was measured to be 1.527 seconds, and this agrees well with the analytically calculated drop time. It was also observed that the effect of seismic loading on the drop time was not significant.

• IE interfaces
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• v.16 no.2
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• pp.240-247
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• 2003

Generally, the assembly system relied on conveyor lines is efficient for mass production. But it is not efficient when the product types are often varying and their lot sizes are small. Especially, it is much inefficient for the assembly lines for the electronic products whose types are varying very often. This paper suggests the design of U-shaped assembly lines to replace the existing conveyor systems. The assembly line for the mini-cassette production is dealt with as a case study. The proposed procedure was successfully applied for the design of U-shaped lines. The developed method resulted in the improvement of the productivity such as the decrease of the man power and the cycle time, and the increase of the line utility.

• Journal of the Korea Society for Simulation
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• v.12 no.2
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• pp.45-53
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• 2003

This paper presents a retargetable compiled assembly simulation technique for fast ASIP(application specific instruction processor) simulation. Development of ASIP which satisfies design requirements in various fields of applications such as telecommunication, wireless network, etc. needs formal design methodology and high-performance relevant software environments such as compiler and simulator In this paper, we employ the architecture description language(ADL) named ${HiXR}^2$ to automatically synthesize an instruction-level compiled assembly simulator. A compiled simulation has benefit of time efficiency to interpretive one because it performs instruction fetching and decoding at compile time. Especially, in case of assembly simulation, instruction decoding is usually a time-consuming job(string operation), so the compiled simulation of assembly simulation is more efficient than that of binary simulation. Performance improvement of the compiled assembly simulation based on ${HiXR}^2$ is exemplified with an ARM9 architecture and a CalmRISC32 architecture. As a result, the compiled simulation is about 150 times faster than interpretive one.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.151-159
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• 2003

This paper presents a new DFA methodology to estimate the standard assembly time and evaluate the assemblablity of a product. The assembly time is estimated with some decision and influencing factors of assembly using motion analysis. The assemblability is evaluated using weights of the decision and influencing factors and assembly difficulty scores, and the tables that include the time and score of assembly are suggested. Finally, a new DFA system supporting the DFA is implemented to help designers to analyze the product during the design process in concurrent engineering.

• Korean Journal of Computational Design and Engineering
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• v.8 no.3
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• pp.189-200
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• 2003

This paper introduces the development of a three-dimensional jig design system for automotive body welding assembly. Recently, three-dimensional CAD systems have been introduced in the jig design area, because they reduce errors in design process and the design result can be used readily for virtual manufacturing simulation. However, to facilitate three-dimensional jig design, it is essential to customize three-dimensional CAD system for this specific design area. To accomplish this object, we first standardized the parts and units in a jig assembly, and then built the standard part library. We also developed the dedicated 3D design capabilities of jig units and a jig base. By using this system, design can be performed more intuitively, and verification and simulation of design results can be done more easily. The proposed system has been implemented using the UG/Open API of the Unigraphics system.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.4
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• pp.30-41
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• 1993

Developed in this paper is a feature based modeling system for the design of welded plat construction(WPC) which is composed of flat or bended plates represented as reference plane with a constant thickness. First, the necessity and the characteristics of the modeing system for WPC as compared with the assembly of mechanical parts are investigated. Secondly, feature library for the assembly of WPC is shown which contains several types of features like joint feature, groove feature, material feature, and precision feature. Thirdly, the assembly procedures are presented which mainly consist of both the assembly transformation and the correct assembly checking. Fourthly, weld lines of the assembled WPC are defined so that those can be used in the process planning or the manufacturing stage. Finally, a prototype by a geometric modeling software Pro/Engineer, a graphic software GL(Graphic Library), and C language on a CAD workstation IRIS.

• Korean Journal of Computational Design and Engineering
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• v.10 no.2
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• pp.133-142
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• 2005

This paper proposes an object-oriented conceptual information model of mechanical assemblies, named open assembly model (OAM). The proposed assembly model primarily defines hierarchical relationships between parts and subassemblies. Together with the assembly hierarchy. the model also provides a way to represent tolerances, kinematic information, and parametric assembly constraints. Relational information such as mating conditions and degree of freedom between parts and subassemblies is captured via assembly features and relationships thereof. The information model is described using class diagrams of the Unified Modeling Language (UML), and instance diagrams are used to exemplify the proposed information model. The conceptual model presented in this paper is an integrated information model for assembly representation, which could supply necessary information for tolerance analysis and synthesis, kinematic simulation, and assembly simulation. Such a conceptual information model plays an important role for the exchange of information between modeling, analysis and planning systems. Hence, the proposed model could serve as a framework for developing data exchange standards of mechanical assemblies. The proposed model is demonstrated through a case study of a planetary gear assembly.

• Korean Journal of Computational Design and Engineering
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• v.13 no.3
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• pp.217-226
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• 2008

Web Services for CAD (WSC) aims at interoperation with CAD systems based on Web Services. This paper introduces one part of WSC which enables remote users to retrieve assembly model data using Web Services. However, retrieving assembly model data takes long time. To resolve this problem, this paper proposes using parallel Web Services. As assembly models comprise a set of part models, it is easy to separate the problem domain into smaller problems. In addition, Web Services inherently supports distributed computing. This characteristic makes the parallel processing of Web Services easy. Firstly, the implementation of WSC which retrieves assembly model data based parallel Web Services is shown. And then, for the comparison, the experiments on the retrieval of assembly model data based on single Web Services and parallel Web Services are shown.

• Journal of the Korean Society for Precision Engineering
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• v.3 no.1
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• pp.77-92
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• 1986

Wire harness assembly is one of the most labor intensive processes in manufa- tuing, but the process has not been fully automated yet. In this paper a variety of concepts for flexible automated assembly system are suggested to design a robot- based wire harness assembly cell. All concepts are featuring an automatic, fedkng of wires, terminating routing, inserting and bundling. Based upon possible assembly methods and procedures, six alternative systems are proposed and, finally, evaluated10 from the view point of system performance such as flexibility, reliability assembly time and equipment cost.