• Journal of KIISE:Software and Applications
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• v.32 no.8
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• pp.730-741
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• 2005

Layered Architecture is a kind of nodule decomposition techniques, which decomposes a program by generality This paper proposes a ]aver based method for recovering layered architecture from object-oriented program and checking conformance against architectural document. To specify the rules for layered style in object-oriented program, we define a partially ordered set on modules by module use relationship and module layer relationship by module override relationship. The meaning of module layer relationship is explained with an example from design patterns. Steps to recover layered architecture from program are described and a metamodel for the recovery is proposed. Architecture recovery is performed on source codes from open-source software project, and the implication of parts that do not conform to its architectural document is discussed. As a result of checking, it is pointed out that, although the parts are considered allowable exceptions of layered architecture, their modifications should be controlled carefully.

• Journal of KIISE:Software and Applications
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• v.35 no.11
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• pp.653-660
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• 2008

Recently, Service-oriented computing is the emerging computing paradigm. In this paradigm, we require the practical process model to support service oriented software development. The well-known development methods e.g., Unified Software Development Process, UML components have been proposed focused on component. So, these methods cannot support service-oriented computing concepts such as service definition, binding and composition concepts using Business Process Execution Language (BPEL). Also, a few proposed service-oriented approach, for example Service Oriented Unified process (SOUP), and Service Oriented Modeling and Architecture (SOMA) have appeared. However, these approaches do not explicitly represent detailed guideline, artifacts and approach. Therefore, in this paper we propose a practical and simple process model to support service oriented software development. Also, we explicitly represent process model and artifact using Software Process Engineering Metamodel (SPEM) which is proposed by OMG. By using our approach, it can enhance systematization and effectiveness for service-oriented software development.

• Transactions of Materials Processing
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• v.23 no.8
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• pp.501-506
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• 2014

Progressive shearing with blanking dies is commonly employed to produce large quantities of tiny sheet metal electronic parts. Sheet metal pins, which are narrow and long, that are sheared with a progressive die set are often twisted. The twist in the sheet metal pins, which usually occurs in the final shearing operation, generally decreases with increasing blank holding force. The blank holding forces in all shearing operations are not the same because of different shearing positions and areas. In the current study, the optimal layout of the springs in a progressive die set to minimize the twist of the sheet metal pin is proposed. In order to find the holding force acting on the tiny narrow blanks produced with the proposed springs during the shearing process, the equivalent area method is used in the structural analysis. The shearing of the sheet-metal pin was simulated to compute the twist angle associated with the blank holding force. The constraint condition satisfying the pre-set blank holding force from the previous shearing operations was imposed. A design of experiments (DOE) was numerically implemented by analyzing the progressive die structure and by simulating the shearing process. From the meta-model created from the experimental results and by using a quadratic response surface method (PQRSM), the optimal layout of the springs was determined. The twist of sheet metal pin associated with the optimal layout of the springs found in the current study was compared with that of an existing progressive die to obtain a minimal amount of twist.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.3
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• pp.432-439
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• 2003

Inconel 690 for nuclear steam generator tube has more Chromium than the conventionally used Inconel 600 in order to increase the corrosion resistance. To evaluate the tribological characteristics of Inconel 690 under fretting condition the fretting tests were carried out in air and elevated temperature water. Fretting tests of the cross-cylinder type were done under various vibrating amplitudes and applied normal loads in order to measure the friction forces and wear volumes. From the results of fretting wear tests. the wear of Inconel 690 can be predictable using the work rate model. The amounts of friction forces were proportional to relative movement between two fretting surfaces. The friction coefficients were decreased as increasing the normal loads and deceasing the vibrating amplitudes. Depending on fretting environment, distinctively different wear mechanisms and often drastically different wear rates can occur It was found that the fretting wearfactors in air and water at 2$0^{\circ}C$, 5$0^{\circ}C$, and 8$0^{\circ}C$ were 7.38 $\times$ $10^{-13}$$Pa^{-1}$, 2.12 $\times$$10^{-13}$$Pa^{-1}$, 3.34$\times$$10^{-13}$$Pa^{-1}$and 5.21$\times$$10^{-13}$$Pa^{-1}$, respectively flexibility to model response data with multiple local extreme. In this study, metamodeling techniques are adopted to carry out the shape optimization of a funnel of Cathode Ray Tube, which finds the shape minimizing the local maximum principal stress. Optimum designs using two metamodels are compared and proper metamodel is recommended based on this research.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.989-996
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• 2010

Statistical regression and/or interpolation models have been used for data analysis and response prediction using the results of the physical experiments and/or computer simulations in structural engineering fields. These models have been employed during the last decade to develop a variety of design methodologies. However, these models only handled responses with respect to space variables such as size and shape of structures and cannot handle time-variant dynamic responses, i.e. response varying with time. In this research, statistical space-time metamodels based on multiple response approach that can handle responses with respect to both space variables and a time variable are proposed. Regression and interpolation models such as the response surface model (RSM) and kriging model were developed for handling time-variant dynamic responses of structural engineering. We evaluate the accuracies of the responses predicted by the two statistical space-time metamodels by comparing them with the responses obtained by the physical experiments and/or computer simulations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.5
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• pp.575-582
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• 2011

A cleaning blade is an attachment installed in the toner cartridge of a laser printer for removing the residual toner from an organic photo-conductive drum. There have been many studies on the performance and life of the rubber blade. We focus on optimally designing the blade shape parameters to minimize the maximum stress of the blade while satisfying design constraints on the cleaning performance and part interference. The blade is optimally designed using a design of experiments, meta-models and an optimization algorithm implemented in PIAnO (process integration, automation, and optimization), a commercial PIDO (process integration and design optimization) tool. We integrate the CAE tools necessary for the structural analysis of the cleaning blade, automate the analysis procedure, and optimize the solution using PIAnO. We decreased the maximum stress by 32.6% in comparison with that of the initial design.

• Journal of the Korea Society for Simulation
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• v.16 no.2
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• pp.45-54
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• 2007

In this article, we propose a different modeling approach, which aims at the simulation optimization so as to meet the design specification. Generally, Multi objective optimization problem is formulated by dependent factors as objective functions and independent factors as constraints. However, this paper presents the critical(dependent) factors as objective function and design(independent) factors as constraints for the selection of design factors directly. The objective function is normalized far the generalization of design factors while the constraints are composed of the simulation-based regression metamodels fer the critical factors and design factor's domain. Then the effective and fast solution procedure based on the pareto optimal solution set is proposed. This paper provides a comprehensive framework for the system design using the simulation and metamodels. Therefore, the method developed for this research can be adopted for other enhancements in different but comparable situations.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.6
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• pp.648-653
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• 2012

Cavity pressure, an important factor in injection molding process, should be minimized to enhance injection molding quality. In this study, we decided the locations of valve gates to minimize the maximum cavity pressure. To solve this problem, we integrated MAPS-3D (Mold Analysis and Plastic Solution-3Dimension), a commercial injection molding analysis CAE tool, using the file parsing method of PIAnO (Process Integration, Automation and Optimization) as a commercial process integration and design optimization tool. In order to reduce the computational time for obtaining the optimal design solution, we performed an approximate optimization using a meta-model that replaced expensive computer simulations. To generate the meta-model, computer simulations were performed at the design points selected using the optimal Latin hypercube design as an experimental design. Then, we used micro genetic algorithm equipped in PIAnO to obtain the optimal design solution. Using the proposed design approach, the maximum cavity pressure was reduced by 17.3% compared to the initial one, which clearly showed the validity of the proposed design approach.

• Journal of Internet Computing and Services
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• v.12 no.6
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• pp.161-170
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• 2011

Despite some practical confusion over the variations in the diagram which may be drawn differently depending upon the CASE, the statechart of UML has been widely used to show the dynamic behaviour of the systems. Prior research has employed either simple switch-case statement or the state design pattern to generate source code from the statechart, which may result in varying source codes. This paper made an attempt to formally define the statechart and generate source codes from it. Firstly we cleaned up the XMI which was generated from different CASEs. This XMI has been translated to the EHA to identify automata contained in it. Then the elements of the statechart metamodel were mapped to the java programs. We also verified the quality of source codes by measuring functionality and maintainability. The case employed in this study was the air conditioner. The reason was that the case includes various states and transitions of interest. It was found that XMI was well extracted by removing some legacy codes in the CASE and the source codes were then successfully generated with the concurrency and hierarchy of the statechart. Further research is required to validate it practical significance with a larger case.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5248-5255
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• 2014

Because of the rapid growth of smart phone market, the number of mobile applications has increased exponentially. As mobile applications are developing at a rapid rate, many of them are being developed without considering a systematic development process or quality factors, such as reusability, extensibility, etc.. As a result, they have many faults internally, they are being underrated in satisfaction or reliability from customers, and finally customers do not update or repeat the purchase. Therefore, a meta-model of development process for mobile applications was designed to improve the continuous usability of mobile applications as well as the satisfaction and reliability from users. Applying development process based on a meta-model to mobile application development is expected to improve development productivity and quality of mobile applications.