• Journal of radiological science and technology
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• v.44 no.4
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• pp.375-380
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• 2021

This study aim was quantitative assessment of MTFs of spectrum of the square wave chart images and Coltman chart images for 0°, 1.7°, 2.2°, 2.9°, 4.1° by using chart method. In general device was AccuRay-650 (DK Medical System, Korea) used, indirect flat panel detector(FPD) Aero (Konica, Japan) used and MATLAB R2019a (MathWorks, USA) used. The result of comparison for each angle of MTF the edge image was highest quantitatively value for MTF finding of showed the best value of 0.1 based on the frequency of 3.5 mm^-1, value of 0.1 based on the square wave was frequency of 3.0 mm^-1 and value of 0.1 based on the Coltman transform was frequency of 2.4 mm^-1. In this study it was significant that the methodology of the international Electro-technical Commission was applied mutandis by using the Fujita method within 2~3°.

• Journal of the Korean Society of Clothing and Textiles
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• v.16 no.3 s.43
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• pp.271-284
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• 1992

The purpose of this study is to clarify the change of important clothing evaluative criteria according to the clothing buying process and to bulid the flow chart of clothing buying process and clothing evaluative criteria. The study is carried out in two ways, they are, literature study and empirical survey. The results are as following; 1. the change of the important clothing evaluative criteria according to the clothing buying process is found out. 2. The clothing buying process is that problem recognition -1 decision of clothing wearing situation $\rightarrow$ search and evaluation of genaral Clothing information $\rightarrow$ decision of price limit $\rightarrow$ (search and evaluation of brand information 1 narrowing of brand range) $\rightarrow$ search and evaluation of store information $\rightarrow$ decision of store $\rightarrow$ search and evaluation of clothings in the store $\rightarrow$ narrowing of determinant clothing range $\rightarrow$ trial, trial evaluation and decision $\rightarrow$ buy-ing (or reject) $\rightarrow$ result evaluation. 3. The flow chart is built by the clothing buying process and the clothing evaluative criteria

• Journal of Korean Society for Quality Management
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• v.44 no.1
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• pp.167-180
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• 2016

Purpose: The problem for the traditional control chart is that it is unable to monitor the very small fraction of nonconforming and the underlying distribution is the normal distribution. $Z_p$ control chart is useful where it controls the vert small fraction on nonconforming. In this study, we will design the $Z_p$ control chart in order to use under non-normal process. Methods: $Z_p$ is calculated not by failure rate based on attribute data but using variable data. Control limit for non-normal $Z_p$ control chart is designed based on ${\alpha}$-risk calculated by cumulative distribution function of Burr distribution. ${\beta}$-risk, which is for performance evaluation, obtains in the Burr distribution's cumulative distribution function and control limit. Results: The control limit for non-normal $Z_p$ control chart is designed based on Burr distribution. The sensitivity can be checked through ARL table and OC curve. Conclusion: Non-normal $Z_p$ control chart is able to control not only the very small fraction of nonconforming, but it is also useful when $Z_p$ distribution is non-normal distribution.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.365-370
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• 2002

In this study, according to MARMA(1,0) model which was suggested by Seppala, in case of existing autocorrelation in X control chart and EWMA control chart, the standard method and the non-parametric bootstrap method were compared and analysed using the bootstrap method which use the resampling prediction residual.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1844-1845
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• 2007

A CUSUM control chart was used to monitor semiconductor plasma equipment. The performance of plasma monitoring was evaluated with various combinations of design variables involved in CUCUM control chart. Experimental data collected by using a real-time matching monitoring system include electrical positions of impedance and phase positions, and reflected power. The evaluation revealed that by determining specific design variables plasma states could be more strictly monitored.

• Korean Management Science Review
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• v.27 no.1
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• pp.91-105
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• 2010

We proposed and stratified a selection standard model on Open Source Functional Board which could be found in Web. So we could grasp the weight about Performance Evaluation from the viewpoints of planners, developers, and web disigner professional of views. We suggested applying diverse measurement types in case of item which could chart Evaluation Standards on chosen sample boards. In case of item which couldn't do that, we compared and analyzed it by using selective type of 9 point scaling method on professionalists in every sample board. As a result of weight on upper estimate section of evaluation model chart, the order of importance was convenience(0.334), performance(0.333), function(0.240) and design(0.093) respectively. It indicates that there is more weight on performance and convenience which are hard to be structurally modified than designs and functions that are directly shown to the users. Also, it was evident that opposite results came out when using 9-point scale survey and measurement with objective data such as function and performance. The reason is because the surveyed subject can have his or her own subjectivity and bias unlike objective data. However, objectivity of the administrator is also an important factor thus both two perspectives have to be all considered when selecting the bulletin board.

• International Journal of Reliability and Applications
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• v.9 no.1
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• pp.17-30
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• 2008

Analysis of measurement systems is important to determine if the measurement process is adequate to measure the part-to-part variability in the process. Control chart techniques provide an effective, and easy-to-use method for performing this analysis. However, application with the real data for the evaluation procedure for multiple measurement systems have not been demonstrated. This research will provide a methodology for the evaluation of part-to-part variation and variation of different measurement systems step by step followed by number of case studies for each methodologies provided.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.638-647
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• 2007

In this study, we present the evaluation chart for assessing the applicability of $CO_2$ flooding method to oil reservoirs. The evaluation chart consists of four categories as source availability, miscibility, applicability and injecting method of miscible flooding. The applicability of reservoir and oil in the chart has basic items of the properties such as oil gravity, viscosity, oil saturation, reservoir temperature and permeability, and these are quantitatively graded. Meanwhile, for additional items of $CO_2$ purity, reservoir thickness and formation dip, they are graded as "highmediumlow". In the case of evaluating the injection method of either continuous injection or WAG ($CO_2$), the qualitative decision will be made according to formation dip, vertical permeability, reservoir thickness, etc. The recommended score in the chart was assigned by utilizing 51 oil producing fields which $CO_2$ flooding is successfully being applied. The evaluation chart developed in this work has been applied to the Captain oil producing field located in Scotland as well as to the Onado oil field of Venezuela, which Korean oil companies have participated in. For the Captain field, the reservoir quality in terms of permeability and porosity is considered to be very excellent to flow the oil. The oil in captain field contains heavier component of $C_{21+}$ as 54%. Therefore, this heavy oil could be immiscibly displaced, hence the evaluating result with the basis of immiscible criteria shows that $CO_2$ immiscible flooding in this field could be properly applied. In the case of Onado oil producing field, since the estimated minimum miscibility pressure is lower than the reservoir pressure, it was assessed that the Onado field would be efficiently conducted for $CO_2$ miscible flooding.

• Journal of radiological science and technology
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• v.39 no.2
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• pp.193-198
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• 2016

In clinical computed tomography (CT), regular quality assurance (QA) has been required. This study is to evaluate the MTF for analyzing the spatial resolution using AAPM phantom in CT exam. The dual source somatom definition flash (siemens healthcare, forchheim, Germany), the brilliance 64 (philips medical system Netherlands) and aquilion 64 (toshiba medical system, Japan) were used in this study. The quantitative evaluation was performed using the image J (wayne rasband national institutes of health, USA) and chart method which is measurement of modulation transfer function (MTF). In MTF evaluation, the spatial frequencies corresponding to the 50% MTF for the CT systems were 0.58, 0.28, and $0.59mm^{-1}$, respectively and the 10% MTF for the CT systems were 1.63, 0.89, and $1.21mm^{-1}$, respectively. This study could evaluate the characteristic of spatial resolution of MTF using chart method, suggesting the quantitative evaluation method using the data.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.6
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• pp.1105-1123
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• 2018

The main risk factors of tunnel excavation through urban areas are ground settlement and surface sink which caused by ground conditions, excavation method, groundwater condition, excavation length, support method, etc. In the process of ground settlement assessment, the numerical analysis should be conducted considering the displacement and stress due to tunnel excavation. Therefore a technique that can simplify such process and easily evaluate the influence of tunnel excavation is needed. This study focused on the tunnelling-induced ground settlement which is main consideration of underground safety impact assessment. The parametric numerical analyses were performed considering such parameters as ground conditions, tunnel depth, and lateral distance from tunnel center line, etc. A simplified ground settlement evaluation chart was suggested by analyzing tendency of ground subsidence, lateral influence area and character by depth. The applicability of the suggested settlement evaluation chart was verified by comparative numerical analysis of settlement characteristics.