• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.6
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• pp.1281-1285
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• 2013

In this paper, we propose a method to extract the area of appendix from ultrasonographic image via computational vision. A series of image processing techniques such as Ends-in search stretching for enhancing the brightness contrast, block binarization, grassfire algorithm for extracting lower part of fascia, and fuzzy sigma binarization method to finalize the appendix area are used to achieve our goal. The strength of this paper is using fuzzy sigma binarization instead of other binarization technique to handle the sensitivity of extracting the target area from regio hypogastrica. The experiment verifies the efficacy of the proposed method successfully.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.1
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• pp.26-32
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• 2017

This paper presents a low power and high resolution incremental delta-sigma ADC that utilizes a passive integrator instead of an opamp-based active integrator. Opamp is a power-hungry block that involves tight design tradeoffs. To avoid the use of active integrator, the s-domain characteristic of an active integrator is first analyzed. Based on the analysis, an active integrator with low gain design is proposed as an alternative design method. To save power even more aggressively, a passive integrator with no static current is proposed. A 1st order single-bit incremental delta-sigma ADC using the proposed passive integrator is implemented in a 65nm CMOS process. Transistor-level simulation shows that the ADC consumes only 0.6uW under 1.2V supply while achieving SNDR of 71dB with 22kHz bandwidth. The estimated total power consumption including digital filter is 6.25uW, and resulting power efficiency is on a par with state-of-the-art A/D converters.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.6
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• pp.109-116
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• 2017

In this study, the optimization of the overall dimensions of an automobile bumper was investigated through CAE and experiment using the Six Sigma method and design of experiment (DOE) method, respectively. Injection pressure, injection speed, injection time, cooling time, holding time, injection temperature, and holding pressure were selected as the vital parameters affecting the overall width of product through analysis of trivial many using CAE. The optimal values were determined using the DOE method, and we analyzed the improvement by applying the optimal conditions to the production process. As a result, the mean value of the overall width was close to the target value, with a deviation of 0.05mm, and the processability and I-MR control were remarkably improved. Finally, the dimension pass rate of the product improved by 20%.

• Journal of the Korean Geotechnical Society
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• v.26 no.12
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• pp.71-79
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• 2010

The reliable evaluation of the coefficient of variation (COV) of soil properties is required for the determination of adequate design values and the application of a probabilistic method for the design of geotechnical structures. In this paper, the applicability of methods for estimating the standard deviation, such as the. Three-Sigma Rule and a statistical method, is evaluated by using site investigation data of the Songdo area. It is found that the Three-Sigma Rule provides similar results to those of a statistical method when using $N_{\sigma}$=6 for the property with small variability and $N_{\sigma}$=4.2~5.3 for the property with large variability. It is also observed that, for the undrained shear strength that has an increasing trend with depth, a $N_{\sigma}$ value of 4 is adequate for the evaluation of the variability by the Three-Sigma Rule. The COVs of soil properties determined in this paper could be used in the estimation of the confidence interval and characteristic values of soil properties.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.4
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• pp.314-322
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• 2006

Despite its brilliant success, Six Sigma has suffered from two shortcomings, namely, the lack of a systematic method to identify the right projects in the "Define" stage and to sustain the improvement in the "Control" stage. The integration of Six Sigma and Business Process Management(BPM) seems to be a promising way to overcome the shortcomings of Six Sigma. This paper first reviews the existing efforts on this issue, and then proposes a framework for an effective integration of Six Sigma and BPM. The framework consists of five phases - DEFINE, EXECUTE, MONITOR, ANALYZE, and IMPROVE(DEMAI). A detailed description on the procedural model is also presented.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.6
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• pp.492-498
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• 2009

Six sigma methode was applied for optimization of flow field design of a proton exchange membrane fuel cell (PEMFC). The optimization between number of channel and channel/rib width was suggested in this paper with six sigma method. With the help of six sigma design of experiment (DOE) the number of experiments may be reduced dramatically. The fuel cell channel design optimization with results of these experiments with a 100 $cm^2$ serpentine flow field indicates a optimization data for a given constant operating conditions.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.4
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• pp.291-297
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• 2006

Since the six sigma strategy was first introduced to Korean enterprises in 1997, it has been taken as an important business strategy to strengthen the competitiveness of major Korean companies under the global competitive environment. These major companies also demand their suppliers to implement six sigma. But small and medium sized companies have several barriers to overcome for successful implementation of six sigma. First, the financial status is not so sound to support initial expenses for launching six sigma. Second, physical and human resources are not sufficient for driving six sigma. And finally, the infrastructure is not well established to manage and support the six sigma program. In this paper, we suggest a method to overcome these barriers and propose a model for establishing six sigma in a small and medium sized company. We also provide some practical case studies.

• Journal of the Korea Safety Management & Science
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• v.7 no.5
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• pp.185-212
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• 2005

The ultimate objectives of the six sigma activities are to raise quality of products to the level where customers can be satisfied and to improve marketing efficiency through cost reduction. Recently, many businesses have been struggling to find out the most successful way to implement the six sigma to produce better results. This study is significant in a way that it provides readers with an actual evidence of efficiency and effectiveness of six sigma activities in marketing performance for the first time. The major data of this study can be divided into two categories ; First, secondary data research method was utilized to find out the effects of six sigma management on the quality and marketing performances, theoretically and empirically. Second, test of established hypotheses relevant to the effects of six sigma management on the quality and marketing performance based on the propositions drawn from existing literatures, and test hypotheses statistically. This study of six sigma looked into benefits in manufacturing industry in terms of improving quality, cutting cost and decreasing defection product-defect rate. In addition, the study has verified that how the quality performances can affect the marketing performances, such as enhancing corporate image, sales increase and customer satisfaction. The author believes that this study will help many businesses acquire best methods to increase sales and profits. And, business manager will be able to understand where to focus as they proceed with the six sigma project and improve corporate competitiveness.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.6
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• pp.155-161
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• 2009

Any classification process using SAR images presupposes the reduction of multiplicative speckle noise, since the variations caused by speckle make it extremely difficult to distinguish between neighboring classes within the feature space. This paper focus an argument of effective filter for preserving the weak boundaries by using the proposed method. To reduce speckle noise without blurring the edges of reconstructed image use wavelet-based sigma filter. As a result, the edge information of reconstructed image reduce blurring. Simulation results show that proposed method gives a better subjective quality than conventional methods for the speckle noise.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.543-552
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• 1994

A series of drained plane strain compression tests was performed on dried samples of dense Toyoura sand and Silver Leighton Buzzard sand prepared by air-pluviation method to find out the deformation and strength characteristics on the value of confining pressure ${\sigma}{_3}^{\prime}({\sigma}{_3}^{\prime}=0.05{\sim}4.0kgf/cm^2)$. The axial and lateral strains measured in this apparatus ranged from $10^{-6}$ up to the failure of the specimen. So the stress-strain characteristics would be investigated from very small to very large strain levels. It was found that the change of the angle of internal friction ${\phi}^{\prime}{_{max}}=arcsin\{({\sigma}{_1}^{\prime}-{\sigma}{_3}^{\prime})/({\sigma}{_1}^{\prime}+{\sigma}{_3}^{\prime})\}_{max}$ with the change of ${\sigma}{_3}^{\prime}$ is very small when ${\sigma}{_3}^{\prime}$ is lower than higher. Furthermore, the effect of confining pressure on stiffness of sands was evaluated. It was also found that for the range of shear strain ${\gamma}$ from $10^{-6}$ to those at peak, the Rowe's stress-dilatancy relation seems to be a good approximation for air-dried Toyoura sand and Silver Leighton Buzzard sand, irrespective of the change of ${\sigma}{_3}^{\prime}$.