• Communications for Statistical Applications and Methods
• /
• v.28 no.6
• /
• pp.595-610
• /
• 2021

Recently a few articles have derived robust first-order rotatable and D-optimal designs for the lifetime response having distributions gamma, lognormal, Weibull, exponential assuming errors that are correlated with different correlation structures such as autocorrelated, intra-class, inter-class, tri-diagonal, compound symmetry. Practically, a first-order model is an adequate approximation to the true surface in a small region of the explanatory variables. A second-order model is always appropriate for an unknown region, or if there is any curvature in the system. The current article aims to extend the ideas of these articles for second-order models. Invariant (free of the above four distributions) robust (free of correlation parameter values) second-order rotatable designs have been derived for the intra-class and inter-class correlated error structures. Second-order rotatability conditions have been derived herein assuming the response follows non-normal distribution (any one of the above four distributions) and errors have a general correlated error structure. These conditions are further simplified under intra-class and inter-class correlated error structures, and second-order rotatable designs are developed under these two structures for the response having anyone of the above four distributions. It is derived herein that robust second-order rotatable designs depend on the respective error variance covariance structure but they are independent of the correlation parameter values, as well as the considered four response lifetime distributions.

• Journal of Broadcast Engineering
• /
• v.19 no.1
• /
• pp.109-117
• /
• 2014

This paper presents a superresolution restoration technique that can restore high-resolution images from differently blurred low resolution images rather than using the motion information between low-resolution images. In order to restore the super-resolution image the rotatable aperture mask lens system is proposed. The proposed technique does not need to estimate point spread function at each frame. In addition, it does not require image registration because there is no global translational motion between low resolution images. By using a rotatable rectangular aperture, two consecutive captured images provide sufficiently exclusive information for superresolution. Therefore, the proposed method can reduce the registration error between the low-resolution image as well as the calculation amount for superresolution restoration. The existing lens system of the camera can be extended to obtain a superresolution image by only adding an rotatable rectangular aperture mask. Finally, in order to verify the performance of the proposed system, experimental results are performed. By comparing with the existing superresolution methods, the proposed method showed the significant improvements in the sense of spatial resolution.

• The Korean Journal of Food And Nutrition
• /
• v.31 no.2
• /
• pp.301-307
• /
• 2018

In this study, a relatively effective process is used to sterilize Escherichia coli on the surface of micro-sized calcium citrate powder using nitrogen and argon as process gases in a low-temperature vacuum plasma treatment. The purpose of this study is to confirm and to introduce the effectiveness of homogeneous surface treatment for the sterilization of fine inorganic powder by the rotatable low-temperature RF plasma system designed by ourselves. The results of the test using 3M petrifilm showed that there were no remarkable spots in the case of the surface of plasma treated powder, whereas the untreated powder showed many blue spots, which indicating that the E. coli was alive. After 5 days, in the same samples, the blue spots were seen to be larger and darker than before, while the plasma-treated powder showed no changes. The results from FE-SEM analysis showed that the E. coli was damaged and/or destroyed by reactive species generated in the plasma space, resulting in the E. coli being sterilized. Furthermore, the sterilization effects according to the selected parameters ($N_2$ and Ar; flow rate 30 and 50 sccm) adapted in this study were mutually similar, regardless of such different process parameters, and this indicates that homogeneous treatment of powder surfaces could be more effective than conventional methods. Therefore, the plasma apparatus used in this study may be a practical method to use in a powerful sterilization process in powder-type food.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2011.06a
• /
• pp.261-262
• /
• 2011

Conventional automatic transmission system includes a hydrodynamic torque converter to transfer engine torque from an engine crank shaft to a rotatable input members, which are of complex design permitting them to serve several functions. These are clutches or brakes which couple the rotatable input member to member of a planetary gear set. The annulus gear for an automatic transmission is a monolithic gear having a set of gear teeth formed on an inner surface which is coupling with a set of planetary gear. In this study, the flow forming method is applied to the manufacturing of the annulus gear. This cold forming is proper method in order to manufacture dimensionally precise and round hollow components such as annulus gear. By pre-calculated amount of wall thickness reduction, the seamless tube of SAE1026 is compressed above its yield strength, plastically deformed and made to flow in several roll passes. According to this study, the desired geometry of the annulus gear can be achieved when the outer diameter and the thickness of the tube are properly decreased by compressed roll passes and the available material volume is easily forced to flow longitudinally over the shape of mandrel.

• Korean Journal of Optics and Photonics
• /
• v.12 no.4
• /
• pp.305-311
• /
• 2001

The new and simple velocimetry model to be perpendicularly arranged with two optical systems with a projected and reduced rotatable line grating is so proposed as to withstand an external vibration. We measured successfully the various velocities (V_{chop}$) of a chopper by using the new velocimeter. As a result, when rotational angles of projected volume gratings in two optical systems are $\alpha=73^{\circ}$ and $\beta=73^{\circ}$, respectively, we measured successfully the chopper velocities within 1 % accuracy from $V_{chop}=43.52cm/s to 249.36cm/s$. In this new velocimetry, we can determine the confidence of .the system by comparing the z-component of velocity, to be measured in one optical system with $V_z$ to be measured in one optical system with $V_z^'$ to to be measured in another optical system, which should be same.e same.

• Journal of Broadcast Engineering
• /
• v.23 no.1
• /
• pp.146-153
• /
• 2018

This paper presents a superresolution demosaicing technique that can restore high-resolution color image from differently blurred low resolution images in Bayer domain. The proposed superresolution demosaicing algorithm uses an aperture mask wheel to get differently blurred low resolution images, so we just need to estimate point spread function at each frame. In addition, it does not require image registration because there is no translational motion between low resolution images. By using a rotatable aperture mask wheel, consecutive captured images provide sufficiently exclusive information for superresolution. Therefore, the proposed method can reduce the registration error between the low-resolution image as well as the calculation amount for superresolution restoration. The existing lens system of the camera can be extended to obtain a superresolution image by only adding an rotatable aperture mask wheels. Finally, in order to verify the performance of the proposed system, experimental results are performed. The proposed method showed the significant improvements in the sense of spatial and color resolution.

• Applied Biological Chemistry
• /
• v.36 no.4
• /
• pp.296-303
• /
• 1993

Response surface methodology was employed to investigate the conditions for separating water-soluble proteins from egg yolk using sodium alginate, propylene glycol alginate (PGA), sodium carboxymethylcellulose (CMC) and pectin which are approved as food additives. Effects of plysaccharide concentration and pH of the reaction system on protein and lipid contents in the supernatant were evaluated at respectively five and three levels of concentration and pH using rotatable hexagon design. Statistical analysis showed that pH of the system was a more important factor than polysaccharide concentration as it significantly affected all two responses. Separating conditions established by a graphical optimization technique were $0.23{\sim}0.25%$ of sodium alginate at $pH\;5.9{\sim}6.0$, $0.15{\sim}0.17%$ of PGA at $pH\;4.3{\sim}4.5$, $0.30{\sim}0.25%$ of CMC at pH 3.0, and $0.09{\sim}0.10%$ of pectin at $pH\;5.6{\sim}5.8%$.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.3
• /
• pp.661-669
• /
• 1995

This paper presents a design method of dynamic positioning control system in view ofpractical design concept for reliability and robust realization. This method adopts a design method of multivariable robust servo system. The practical experiments of the dynamic positioning control were carried out for a semi-submersible 2-lower hull type platform model with 4 rotatable thrusters in a small water tank. The results fo overall experiment show that the proposed position control method will be an efficient method to the better control performance of dynamic positioning system under serere environment and it is substentially practicable for the platform.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.5 no.2
• /
• pp.69-79
• /
• 1997

This paper deals with the measurement and analysis on the scavenging performance of the oppet-valve type two-stroke engine with different shroud system. The scavenging flow characteristics is investigated by flow visualization under steady condition, in which a dye is introduced into single-cycle method using the difference of specific gravity between two working fluids is used to evaluate the scavenging efficiency and the trapping efficiency. The 90° shroud system was found to be the highest efficiency system through both flow visualization and single-cycle test, as well as the shroud system to generally be efficient for reducing a short-circuiting flow during scavenging process in a two-stoke engine.

• Journal of Ocean Engineering and Technology
• /
• v.10 no.3
• /
• pp.153-161
• /
• 1996

This paper presents a design method of dynamic positioning control system for floating platform with rotatable and retractable thruster using $H_{\infty}$ control technique. The norm band of uncertainty is captured by multiplicative perturbation between nominal model and reduced order model. A controller robust to the uncertainty is designed applying $H_{\infty}$ synthesis. The control law satisfying robust stabillity and nominal performance condition is determined through the mixed sensitivity approach. The evaluation for the resultant controller obtained by $H_{\infty}$ synthesis is done through simulations of the closed loop system. The results of $H_{\infty}$ synthesis are compared to those of the traditional LQ synthesis method.