• The Journal of Korean Academy of Sensory Integration
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• v.7 no.1
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• pp.1-12
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• 2009

Objective : This study is to verify effect of a sensory integration (SI) intervention on sensory processing of children with sensory modulation disorder (SMD), and to explore how the SI intervention affect play, socialization, occupational performance and occupational satisfaction of those children. Method : Five children with developmental disabilities living in metropolitan were diagnosed as SMD by the Sensory History Interview (SHI) and Short Sensory Profile (SSP). The SMD children undergone the 48 sessions of 50 min intervention twice in a week for six months and took the Revised Knox Preschool Play Scale(RKPPS), Social maturity test, Canadian Occupational Performance Measure(COPM), and Japanese Sensory Inventory Revised(JSI-2) before- and after the intervention. The result data analyzed by the Wilcoxon matched-pair signed rank test. Results : All data of post-intervention differed significantly; RKPPS(Z=-2.023, p=.043), Social maturity test(Z=-2.023, p=.043); occupational performance(Z=-2.023, p=.043); satisfaction(Z=-2.032, p=.042); and tactile system of JSI-2(Z=-2.032, p=.042). Conclusions : The results advocate that sensory integration intervention is effective in improving tactile processing, play, socialization, occupational performance, and occupational satisfaction of child with SMD. It is found that sensory integration intervention improves not only one's occupational performance but also underlying components of the performance. In order to generalize this conclusion, further studies need to be done with more number of subjects and consideration of environmental factors. Striving for more reliable and valid methods of data collection is also suggested.

• The Mathematical Education
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• v.45 no.2 s.113
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• pp.145-154
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• 2006

The main purpose of this study is to investigate the effect of departures from normality and equal variance on the two-sample test when the variances are unknown. We have found that type I error brought about a little bit change which is ignorable in relation to kurtosis. But the change of type I error was mainly based on the skewness of the parent population. In introductory statistics classes where data analysis includes techniques for detecting skewness of two populations, we recommend the two-sample t-test when maximal skewness of two populations is smalter than the value 4 when the variances seem equal. Furthermore, our simulations reveal that the two-sample t-test appears somewhat more robust than that of z-test if the assumption of equal variance is satisfied. In the case of unequal variance, the two-sample t-test appears somewhat more robust provided the t-statistic using Satterthwaite's approximate degrees of freedom.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.2
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• pp.172-182
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• 2020

In order to offer specific information needed to assist in operation of a ship with same type rudder through evaluating the maneuverability of training ship A-Ra with flapped rudder, sea trials based full scale for turning test, zig-zag test with rudder angle 10° and 20°, and spiral test at service condition were carried out on starboard and port sides around Jeju Island according to the standards of maneuverability of IMO. As a result, the angular velocity of port turn was higher than that of starboard turn. Therefore, the size of turning circle was longer on the starboard side. In addition, variation of the transfer due to various factors was more stable than those of the others. In the Z-test results, the mean of 1st and 2nd overshoot angles were 9.8°, 6.3° and 15.3°, 9.2° respectively when the port and starboard was 10°; the 1st overshoot angle were 18°, 13.7° when using 20°. Her maneuverability index T' and K' can be easily determined by using a computer with the data obtained from Z-test where K' and T' are dimensionless constants representing turning ability and responsiveness to the helm, respectively. In the Z-test under flap rudder angle 10°, the obtained K' value covered the range of 2.37-2.87 and T' was 1.74-3.45. Under the flap rudder angle 20°, K' and T' value showed 1.43-1.63, 1.0-1.73, respectively. In the spiral test, the loop width was unstable at +0.3° and -0.5°-0.9° around the midship of flap rudder. As a result, course stability was comparatively good. From the sea trial results, training ship ARA met the present criterion in the standards of maneuverability of IMO.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.3
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• pp.54-61
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• 2004

This paper describes the development of a 6-axis robot's finger force/moment sensor, which measures forces $F_x$(x-direction force), $F_y$and $F_z$, and moments $M_x$ (x-direction moment), $M_y$ and $M_z$ simultaneously, for stable grasping of an unknown object. In order to safely grasp an unknown object using the robot's gripper, the force in the gripping direction and the force in the gravity direction should be measured, and the force control should be performed using the measured forces. Also, the moments $M_x$, $M_y$ and $M_z$ to accurately perceive the position of the object in the grippers should be detected. Thus, the robot's gripper should be composed of 6-axis robot's finger force/moment sensor that can measure forces $F_x$, $F_y$ and $F_z$, and moments $M_x$ $M_y$ and $M_z$ simultaneously. In this paper, the 6-axis robot's finger force/moment sensor for measuring forces $F_x$, $F_y$ and $F_z$, and moments $M_x$ $M_y$ and $M_z$ simultaneously was newly modeled using several parallel-plate beams, designed, and fabricated. The characteristic test of the fabricated sensor was performed, and the result shows that interference errors of the developed sensor are less than 3%. Also, Robot's gripper with the 6-axis robot's finger force/moment sensor for the characteristic test of force control was manufactured, and the characteristic test for grasping an unknown object using the sensors was performed using it. The fabricated gripper could grasp an unknown object stably. Thus, the developed 6-axis robot's finger force/moment sensor can be used for robot's gripper.

• Journal of Advanced Navigation Technology
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• v.25 no.5
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• pp.370-376
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• 2021

development of the aerospace industry is increasing the research of projectiles. In addition, many tests are under way and many failures occur accordingly. Projectiles should be able to minimize failures because they are more dangerous than other electronic equipment. Therefore, it is necessary to verify wiring before powering the projectile. Accordingly, the wiring status was verified by resistance measurements. However, the wiring test of the previous resistance measurement method cannot be accurately measured due to devices such as capacitors and inductors in the projectile circuit. In this paper, impedance is measured in the connection state of cables and projectiles using a TDR meter. The Z-Segmentation algorithm is used to set the reference value for the measured steady state impedance. The Z-Segmentation algorithm first finds the peak values of the impedance waveform using a Kalman filter and obtains the final impedance peak segment through segmentation. In this way, the wiring status is determined based on the reference value for the normal state of the wiring.

• Restorative Dentistry and Endodontics
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• v.34 no.2
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• pp.145-153
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• 2009

The purpose of this study was to evaluate the effect of instrument compliance on the polymerization shrinkage stress measurements of dental composites. The contraction strain and stress of composites during light curing were measured by a custom made stress-strain analyzer, which consisted of a displacement sensor, a cantilever load cell and a negative feedback mechanism. The instrument can measure the polymerization stress by two modes: with compliance mode in which the instrument compliance is allowed, or without compliance mode in which the instrument compliance is not allowed. A flowable (Filtek Flow: FF) and two universal hybrid (Z100: Z1 and Z250: Z2) composites were studied. A silane treated metal rod with a diameter of 3.0 mm was fixed at free end of the load cell, and other metal rod was fixed on the base plate. Composite of 1.0 mm thickness was placed between the two rods and light cured. The axial shrinkage strain and stress of the composite were recorded for 10 minutes during polymerization. and the tensile modulus of the materials was also determined with the instrument. The statistical analysis was conducted by ANOVA. paired t-test and Tukey's test (${\alpha}<0.05$). There were significant differences between the two measurement modes and among materials. With compliance mode, the contraction stress of FF was the highest: 3.11 (0.13). followed by Z1: 2.91 (0.10) and Z2: 1.94 (0.09) MPa. When the instrument compliance is not allowed, the contraction stress of Z1 was the highest: 17.08 (0.89), followed by FF: 10.11 (0.29) and Z2: 9.46 (1.63) MPa. The tensile modulus for Z1, Z2 and FF was 2.31 (0.18), 2.05 (0.20), 1.41 (0.11) GPa, respectively. With compliance mode. the measured stress correlated with the axial shrinkage strain of composite: while without compliance the elastic modulus of materials played a significant role in the stress measurement.

• Journal of the Korean Society for information Management
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• v.14 no.1
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• pp.183-206
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• 1997

The information Retrieval Protocol, Z39.50 is applied to the shared cataloging gateway. The history and functions of the Z39.50 are reviewed and the characteristics and the database update service of Z39.50 are taken into account in the notion of the shared cataloging. And for the test, one of the domestic on-line shared cataloging systems is adopted and newly remodelled using Z39.50 protocol. Two kinds of Z39.50 shared cataloging gateway models (th centralized shared cataloging gateway model and the distributed shared cataloging gateway model) are operated in Web server.

• Journal of Electrical Engineering and Technology
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• v.7 no.4
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• pp.558-563
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• 2012

In this paper, a novel planar type magnetic levitation system without other assistant devices is proposed and it can move with 6 degree of freedom (X, Y, Z, ${\theta}_X$, ${\theta}_Y$, ${\theta}_Z$) in wafer size as well as in nano scale positioning.The mover is composed with 2-D Halbach permanent magnet array and the stator is composed with $10{\times}10$ coil arrays.It was composed in laboratory and tested with short stroke (4 [mm]) and long stroke (160 [mm])movements. The errors of short movement test is [X, Y, Z, ${\theta}_X$, ${\theta}_Y$, ${\theta}_Z$]${\leq}$ [${\pm}200nm$, ${\pm}200nm$, ${\pm}250nm$, ${\pm}3urad$, ${\pm}2urad$, ${\pm}1urad$]The errors of long stroke movement test is [X, Y, Z, ${\theta}_X$, ${\theta}_Y$, ${\theta}_Z$]${\leq}$ [${\pm}200nm$, ${\pm}200nm$, ${\pm}250nm$, ${\pm}1.5urad$, ${\pm}2urad$, ${\pm}0.5urad$].

• Special Issue of the Society of Naval Architects of Korea
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• 2017.10a
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• pp.8-13
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• 2017

The rolled carbon steel plate has anisotropic property in Z-direction(thickness direction). This is induced by cooling rate difference of Z-direction and sulfur which make non-metallic inclusion(MnS) at center line of thickness direction. Z-directional mechanical properties of normal steel plate are not generally specified and it is defined for Z-Quality steel only through tensile test in Z-direction. If Z-quality steel is not applied for cruciform joint, the lamella tearing will be occurred by tensile stress after welding & during operation of the structure. In this research, one equation estimating Z-directional(orthogonal to plate) stress was developed to prevent lamella tearing by welding. This equation deals with plate thickness & joint configuration(eccentricity, angle and curvature). Analyses were done by strain boundary method using sectional FE modeling and FE 3D models are also used for some cases. Designers can predict the possibility of lamella tearing by adequately applying the result and can appropriately minimize the application of Z-quality steel by revising welding design to some extent.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.328-330
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• 2007

This paper deals with the estimation method on the initial pole position of a z-axis permanent magnet linear synchronous motor(PMLSM) without magnetic pole sensors such as Hall sensors. The proposed method takes account of the z-axis conditions such as the gravitational force and also the load conditions. The algorithm consists of two steps. The first step is to estimate the initial q-axis approximately by monitoring the movements at predefined different test q-axes. The second step is to estimate the real q-axis as accurately as possible based on the results at three different test q-axes. Experimental results on the z-axis PMLSM show good estimation characteristics of the proposed method.