• Journal of Korean Society for Quality Management
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• 제28권3호
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• pp.18-30
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• 2000

Recent studies have shown that the $\bar{X}$ chart with variable sampling intervals(VSI) and the $\bar{X}$ chart with variable sample size(VSS) are much quicker than Shewhart $\bar{X}$ chart in detecting shiks in the process. Shewhart $\bar{X}$ chart has been beneficial to detect large shifts but it is hard to apply Shewhart $\bar{X}$ chart in detecting moderate shifts in the process mean. In this article the $\bar{X}$ chart using variable sample size(VSS) and variable sampling Intervals(VSI) has been proposed to supplement the weak point mentioned above. So the purpose of this paper is to consider finding the design parameters which minimize expected loss costs for unit process time and measure the performance of VSSI(variable sample size and sampling interval) $\bar{X}$ chart. It is important that assignable causes be detected to maintain the process controlled. This paper has been studied under the assumption that one cycle is from starting of the process to eliminating the assignable causes in the process. The other purpose of this article is to represent the expected loss costs in one cycle with three process parameters(sample size, sampling interval and control limits) function and find the three parameters.

• Journal of Acupuncture Research
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• 제25권2호
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• pp.139-149
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• 2008

Objectives : The 7-zone-diagnostic system is a diagnostic device to predetermine bodily locations by measuring the energy of body. This study was to investigate the relation between the different patterns of Zone 2, 6 of Factor AA in VEGA DFM 722(VEGA, Germany), 7-zone-diagnostic system and clinical parameters. The purpose of this study was relation Korean traditional medicine and western medicine with the data from 7-zone-diagnostic system and the clinical parameters. Methods : This study was carried out with the data from some clinical parameters. We made two groups according to the Factor AA patterns of VEGA DFM 722. The Factor AA pattern of Group A is that the red bar graph of zone 2 was higher than the normal range and the red bar graph of zone 6 was lower than the normal range. The Factor AA pattern of Group B was that the red bar graph of zone 2 was lower than the normal range and the red bar graph of zone 6 was higher than the normal range. After the data from clinical parameters to correspond with conditions of each group were selected, the data from clinical parameters between each gropus analyzed statistically. Results and Conclusions : The values of Direct Bilirubin, GOT, BUN and BUN/Creatinine ratio of Group A were higher than them of Group B. The values of Sodium and Tyroxine of Group A were lower than them of Group B. These results mean that Group A has low energy but has increading tendency. To conclude, it is thought that the red bar graph of zone 2 is higher, the group is the more increasing and the red bar graph of zone 6 is lower, the group has the lower energy.

• Journal of Korean Institute of Industrial Engineers
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• 제31권1호
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• pp.87-98
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• 2005

This research investigates economic-statistical characteristics of variable sampling size and interval (VSSI)$\bar{X}$charts under two assignable causes. A Markov chain approach is employed in order to calculate average run length (ARL) and average time to signal (ATS). Six transient states are derived by carefully defining the state. A steady state cost rate function is constructed based on Lorenzen and Vance(1986) model. The cost rate function is optimized with respect to six design parameters for designing the VSSI $\bar{X}$ charts. Computational experiments show that the VSSI $\bar{X}$ chart is superior to the Shewhart $\bar{X}$ chart in the economic-statistical sense, even under two assignable causes. A comparative study shows that the cost rate may increase up to almost 30% by overlooking the second cause. Critical input parameters are also derived from a sensitivity study and a few guideline graphs are provided for determining the design parameters.

• Journal of the Korea Institute of Military Science and Technology
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• 제21권4호
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• pp.413-421
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• 2018

The pyroshocks can cause failure of electronics devices and structures. Metal-metal impact methods are utilized to simulate mechanical pyroshock, and to adjust the knee frquency of the SRS(Shock Response Spectrum) through resonant structures. In this paper, the major parameters of pyroshock simulation device which affect the SRS were examined. Through the Hertzian contact law and the modal characteristics of the resonant bar, it was found that the SRS is affected by the length and mass of a bar and various impact conditions such as velocity and mass of impactor. The characteristics due to the geometric parameters of a resonant bar was analyzed by performing FEA and also the resonant bar was designed and fabricated. Through the pyroshock simulation test, the characteristics of SRS due to the variation of impact parameters were examined.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제66권2호
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• pp.453-458
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• 2017

R-Bar (Overhead Rigid Conductor system) has been lately used for the speed of over 200km/h in Europe, while it has been developed and used for the max. speed of 120km/h in Korea. Because R-Bar has advantages of reduction of tunnel cross sectional area and maintenance, its development for more high-speed is urgent in Korea having many mountain area. Therefore a sensitivity analysis of design parameters for the speed-up of R-Bar has performed in this study. For the analysis, we have developed a program for the prediction of dynamic characteristics between a pantograph and R-Bar. The program was evaluated with the actual test result and a current collection performance according to the parameters such as a distance between brackets, a stiffness of bracket and of R-Bar rail was predicted with the program.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권2호
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• pp.277-286
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• 2013

Cross-shore sediment transport is very important factor in the design of coastal structures, and the beach profile is mainly affected by a number of parameters, such as wave height and period, beach slope, and the material properties of the bed. In this study cross-shore sediment movement was investigated using a physical model and various offshore bar geometric parameters were determined by the resultant erosion profile. The experiments on cross- shore sediment transport carried out in a laboratory wave channel for initial base slopes of 1/8, 1/10 and 1/15. Using the regular waves with different deep-water wave steepness generated by a pedal-type wave generator, the geometrical of sediment transport rate and considerable characteristics of beach profiles under storm conditions and bar parameters affecting on-off shore sediment transport are investigated for the beach materials with the medium diameter of $d_{50}$=0.25, 0.32, 0.45, 0.62 and 0.80 mm. Non-dimensional equations were obtained by using linear and non-linear regression methods through the experimental data and were compared with previously developed equations in the literature. The results have shown that the experimental data fitted well to the proposed equations with respect to the previously developed equations.

• Computers and Concrete
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• 제22권2호
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• pp.249-259
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• 2018

This paper presents Artificial Neural Network (ANN) models for evaluating bond strength of deformed, plain and cold formed bars in low strength concrete. The ANN models were implemented using the experimental database developed by conducting experiments in three different universities on total of 138 pullout and 108 splitting specimens under monotonic loading. The key parameters examined in the experiments are low strength concrete, bar development length, concrete cover, rebar type (deformed, cold-formed, plain) and diameter. These deficient parameters are typically found in non-engineered reinforced concrete structures of developing countries. To develop ANN bond model for each bar type, four inputs (the low strength concrete, development length, concrete cover and bar diameter) are used for training the neurons in the network. Multi-Layer-Perceptron was trained according to a back-propagation algorithm. The ANN bond model for deformed bar consists of a single hidden layer and the 9 neurons. For Tor bar and plain bars the ANN models consist of 5 and 6 neurons and a single hidden layer, respectively. The developed ANN models are capable of predicting bond strength for both pull and splitting bond failure modes. The developed ANN models have higher coefficient of determination in training, validation and testing with good prediction and generalization capacity. The comparison of experimental bond strength values with the outcomes of ANN models showed good agreement. Moreover, the ANN model predictions by varying different parameters are also presented for all bar types.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.109-112
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• 1995

This paper analyzes high efficiency anti-vibration boring bars which increase stability against chatter vibration in boring operations. Structural analysis and mathematical modeling with considering dynamic properties for three types of existing boring bars are performed to search for optimal design parameters. The purpose of this paper is to find out design parameters for high efficiency anti-vibration boring bar.

• Journal of the Korean Society for Precision Engineering
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• 제32권5호
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• pp.471-481
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• 2015

This paper presents the robot vision control schemes using Extended Kalman Filter (EKF) method for the slender bar placement in the appearance of obstacles during robot movement. The vision system model used for this study involves the six camera parameters($C_1{\sim}C_6$). In order to develop the robot vision control scheme, first, the six parameters are estimated. Then, based on the estimated parameters, the robot's joint angles are estimated for the slender bar placement. Especially, robot trajectory caused by obstacles is divided into three obstacle regions, which are beginning region, middle region and near target region. Finally, the effects of number of obstacles using the proposed robot's vision control schemes are investigated in each obstacle region by performing experiments of the slender bar placement.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제66권4호
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• pp.740-744
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• 2017

Overhead Line is divided by two systems which are OCS (Overhead Catenary Line) and R-Bar (Overhead Rigid Conductor system). R-Bar has an advantage of maintenance and economic aspect comparing with OCS. R-Bar in Korea has developed for the max. speed of 120km/h, but it is evaluated up to the max. speed of 250 km/h in Europe. There are lots of mountains and underground sections in korea, it is really necessary to develop the R-Bar for a high-speed line. In the study, design parameters for the max. speed of 250 km/h of R-Bar was proposed. A bracket space, stiffness, and especially an installation tolerance of contact wire height at a bracket were considered as a parameter, and a dynamic behavior between a contact wire and pantograph was predicted by evaluated FEM simulation tool. The installation tolerance and bracket space are more important for the high-speed system. The proposed parameters was decided very conservative. Because the aerodynamic characteristics of a pantograph in tunnel is more severe than an open route and the simulation tool is not considered the such kind of aerodynamic characteristics.