• 전자공학회논문지 IE
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• v.49 no.1
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• pp.24-29
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• 2012

In this paper, we propose a progressive filter for impulse noise reduction. The proposed method uses non-linear filter and linear filter progressively. Non-linear filter reduces abrupt noise pattern. Also, linear filter adjusts filtering direction according to an edge in the image which is filtered by non-linear filter. Thus, our proposed method not only preserves edge, but also reduces noise in uniform region. Experimental results show that our proposed method has better quality than those by existing non-linear and linear progressive filtering methods.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.4
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• pp.43-49
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• 2004

The production parts have required multiple processes such as drawing, piercing, blanking and notching etc. are performed with a high production rates in progressive die. In order to prevent the defects of process result, the optimization of strip process layout design, die design, die making, and tryout etc. are needed. According to these factors of die development process, it has been required that the theory and practice of metal working process and its phenomena, die structure, machining conditions for die making, die materials, heat treatment of die components, processing know-how and so on. In this study, we designed and analyzed die components through the carrying out of upper relevant matters also simulated the strip process layout of multiple stage drawing by DEFORM. Especially the result of tryout and its analysis became to the feature of this study with a system of PDDC(Progressive Die design by computer).

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.618-623
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• 2000

In order to increase the porductivity of electrical parts, manufacturing processes using progressive dies have been widely used in the industry. Motor cores have been fabricated using progressive stacking die with the lamination procedure for better electro-magnetic property. for the proper design of a process, a prediction of the process is required to obtain many design parameters. In this work, rigid-plastic finite element analysis is carried out in order to simulate the lamination this work, rigid-plastic finite element analysis is carried out in order to simulate the lamination process of the motor core. The effects of the embossing depth and the amount of deviation are investigated and compared with experiments. The forming process can then be predicted successfully from the results of analyses, which enables to design appropriately the die and the process.

• Journal of Korean Neurosurgical Society
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• v.47 no.6
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• pp.477-479
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• 2010

A case of delayed progressive extradural pneumatocele after microvascular decompression (MVD) is presented. A 60-year-old male underwent MVD for hemifacial spasm; the mastoid air cell was opened and sealed with bone wax during surgery. One month after surgery, the patient complained of tinnitus, and progressive extradural pneumatoceles without cerebrospinal fluid (CSF) leakage was observed. Revision surgery was performed and the opened mastoid air cell was completely sealed with muscle patch and glue. The patient's symptoms were resolved, with no recurrence of pneumatoceles at 6 month follow up. Progressive extradural pneumatocele without CSF leakage after posterior fossa surgery is a very rare complication. Previous reports and surgical management of this rare complication are discussed.

• Communications for Statistical Applications and Methods
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• v.25 no.5
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• pp.569-575
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• 2018

Pareto distribution is important to analyze data in actuarial sciences, reliability, finance, and climatology. In general, unknown parameters of the Pareto distribution are estimated based on the maximum likelihood method that may yield inadequate inference results for small sample sizes and high percent censored data. In this paper, a new approach based on the regression framework is proposed to estimate unknown parameters of the Pareto distribution under the progressive Type-II censoring scheme. The proposed method provides a new regression type estimator that employs the spacings of exponential progressive Type-II censored samples. In addition, the provided estimator is a consistent estimator with superior performance compared to maximum likelihood estimators in terms of the mean squared error and bias. The validity of the proposed method is assessed through Monte Carlo simulations and real data analysis.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.289-292
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• 2007

To prevent the damage of glass lens molds and deterioration of glass lenses using in progressive GMP process, a thermal stress and a deformation of the glass lens molds at forming temperature should be considered in the design step. In this study, as a fundamental study to develop a multi cavity mold used in an aspheric glass lens molding, a heat transfer and a thermal stress analysis were carried out for the case of one cavity glass lens mold used in progressive GMP process. Finally, using analysis results, we estimated the thermal stress in a glass lens mold and predicted a modified height of guide ring that determines the forming height of a glass lens.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.295-300
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• 2001

The progressive die performs a series of fundamental sheet metal working, particularly this study regards to develop the center carrier feeding type die for thick sheet metal(SS41, 2.5mm) production that is a specific division. In order to prevent defect on the production, the analysis of production part, optimum design of strip process layout, die design and die making and tryout etc. are necessary. In this study, we designed and predicted a progressive die of multi stages by wide collected data base and computer aided method.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.66-69
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• 2000

In this paper, we propose a progressive transmission of a video using a 2$\times$2$\times$2 DCT First of all, the video data is transformed into multiresolution represented video data using a 2$\times$2$\times$2 DCT. Then. it is represented by a 3-D EZT(Embedded Zero Tree) coding fur the progressive transmission with a bit-rate scalability. The proposed progressive transmission algorithm needs much less computations and buffer memories than the higher-order convolution based wavelet filter. Also, since the 2$\times$2$\times$2 DCT requires independent local computations, parallel processing can be applied.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.5
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• pp.45-52
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• 2001

In order to increase the productivity of electrical parts, manufacturing processes using progressive dies have been widely used in the industry. Motor cores have been fabricated using progressive stacking die with the lamination procedure for better electro-magnetic property. For the proper design off process, a prediction of the process is required to obtain many design parameters. In this work, rigid-plastic finite element analysis is carried out in order to simulate the lamination process of the motor core. The effects of the embossing depth, the amount of deviation, and the number of stacked sheets are investigated and compared with experiments. The forming process can then be predicted successfully from the results of analyses, which enables an appropriate design to be made for the die and the process.

• Journal of the Korea Concrete Institute
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• v.11 no.3
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• pp.181-192
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• 1999

The progressive failure following strain localization in concrete can be analyzed effectively using finite element modeling of fracture process zone of concrete with a finite element embedded discontinuity. In this study, a finite element with embedded discontinuous line is utilized for the analysis of progressive failure in concrete. The finite element with embedded discontinuity is a kind of discrete crack element, but the difficulties in discrete crack approach such as remeshing or adding new nodes along with crack growth can be avoided. Using a discontinuous shape function for this element, the displacement discontinuity is embedded within an element and its constitutive equation is modeled from the modeling of fracture process zone. The element stiffness matrix is derived and its dual mapping technique for numerical integration is employed. Then, a finite element analysis program with employed algorithms is developed and failure analysis results using developed finite element program are verified through the comparison with experimental data and other analysis results.