• Journal of the Ergonomics Society of Korea
• /
• v.18 no.3
• /
• pp.1-12
• /
• 1999

This study investigated human operator's perceptual and psychophysical responses to vibrotactile stimulation on various parts of the hand. Using a small vibrotactile display, the effects of three mechanical parameters consisting vibrotactile stimulations, i.e., vibration frequency, pulse-width modulation duty cycle, and number of contactors, on differential thresholds were examined at five different loci of the hand. It was observed that differential threshold varies with vibration frequency and number of active contactors. Differential sensitivity was the greatest at the vibration frequency of 120 Hz. The differential sensitivity was not found to be affected by loci on the hand. The area of stimulation on the hand was also found to be significant in that the sensitivity increased with the number of active contactors. It should be noted that the conclusions from this study generally correspond to those from the previous study on the absolute sensitivity. which means that tactile sensitivity to vibrotactile stimulations can be controlled with a systematic and consistent passion for emulating normal everyday contact on human hands in teleoperation and virtual reality applications.

• Korean Journal of Childcare and Education
• /
• v.16 no.5
• /
• pp.155-171
• /
• 2020

Objective: The purpose of this study is to analyze the structural relations between infant teachers' career, efficacy, sensitivity, and the development of their professionalism. Methods: Data were collected from 320 infant teachers working at day care centers in Gyeonggi-do and Seoul. The collected data were applied to SPSS 22.0 program. With the data, correlation analysis and structural equation model analysis were conducted. Results: Firstly, infant teachers' career didn't influence the development of their professionalism directly, but indirectly affected their efficacy and sensitivity. Secondly, the variables that directly affected the development of their professionalism were teacher efficacy and sensitivity. Thirdly, teacher efficacy and sensitivity had full mediation between their career and the development of professionalism. Conclusion/Implications: Infant teachers' career affected the development of their professionalism through teacher efficacy and sensitivity. Based on the result, a plan for developing infant teachers' professionalism was proposed, and suggestions of follow-up research were discussed.

• Journal of Information Display
• /
• v.13 no.1
• /
• pp.43-49
• /
• 2012

Depth sensitivity is considered one of the factors influencing 3D displays the most. In this paper, the perceptual 3D depth was quantitatively measured to compare the depth difference among the display devices. No difference was found in the typical display performance among the devices, but the subjective evaluation of the depth sensitivity where the disparity was varied showed that the organic light emitting diode (OLED) had the highest performance, mainly due to its almost 0% crosstalk, one of the features of OLED. Crosstalk is a form of image superposition that greatly affects the depth sensitivity. The experiment results showed that the quantitative depth sensitivity varies due to geometric factors such as disparity, viewing distance, and subjective sensitivity, depending on the display image characteristics, such as crosstalk and contrast.

• Fashion & Textile Research Journal
• /
• v.6 no.4
• /
• pp.427-432
• /
• 2004

We evaluate what kinds of differences are existed to the visual sensitivity of college students m Daegu and Daejeon. Evaluation used the produced basic pattern to change modeling element of figure, direction, proportion, and color. The results are as below. The circle is preferred to the figure sensitivity and the triangle in Daegu and triangle and quadrangle in Daejeon is disliked. The direction sensitivity shows the difference of preferences according to figure. The angle of $0^{\circ}$ and $90^{\circ}$ which could be felt stability is preferred in general. In proportion sensitivity, the basic figure 1:1 rectangular proportions are preferred. The color sensitivity I shows the differences of preference according to figure and there are difference to the area in the degree of aversion.

• Structural Engineering and Mechanics
• /
• v.7 no.1
• /
• pp.111-126
• /
• 1999

The work presented here focuses on the development of suitable discretised formulations, for large-displacement shape and non-shape design sensitivity analysis (DSA), which enable the straightforward incorporation of structural optimisation into established finite element analysis (FEA) codes. For the generalised displacement-based functional the design sensitivity vector has been expressed in terms of displacement sensitivity. The Total Lagrangian formulation is utilised for modelling of large deformation of truss structures. The variational formulation of the sensitivity analysis procedure is discretised by using "pseudo" - finite elements, Results are presented for the sensitivity analysis and optimisation of standard truss structures. For the purposes of this work, the analysis and optimisation procedures outlined below are incorporated into the FEA code ABAQUS.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.13 no.5
• /
• pp.500-510
• /
• 2013

In this paper, a high-sensitivity low power photodetector using double gate (DG) MOSFET is proposed for the first time using change in subthreshold current under illumination as the sensitivity parameter. An analytical model for optically controlled double gate (DG) MOSFET under illumination is developed to demonstrate that it can be used as high sensitivity photodetector and simulation results are used to validate the analytical results. Sensitivity of the device is compared with conventional bulk MOSFET and results show that DG MOSFET has higher sensitivity over bulk MOSFET due to much lower dark current obtained in DG MOSFET because of its effective gate control. Impact of the silicon film thickness and gate stack engineering is also studied on sensitivity.

• International Journal of Highway Engineering
• /
• v.14 no.5
• /
• pp.113-122
• /
• 2012

PURPOSES: The sensitivity of $CO_2$ emissions per vehicle by a various speeds is compared according to the type of roads. METHODS: The methodology of the study are as follows: First, the sensitivity of $CO_2$ emissions per vehicle are analyzed by averaged daily travel speeds. Second, the sensitivity of $CO_2$ emissions per vehicle are analyzed by averaged hourly travel speed. Third, the sensitivity of $CO_2$ emissions per vehicle are analyzed by sectional travel speeds. RESULTS: The sensitivity that on Saturday in a week, at peak times in a day and in close location from Seoul was higher than in other situations. CONCLUSIONS: From this study, we may conclude that $CO_2$ emissions per vehicle at low speeds are generally more sensitive.

• Journal of Welding and Joining
• /
• v.19 no.2
• /
• pp.228-234
• /
• 2001

A methodology is developed and used to evaluate the response sensitivity of the thermal systems to variations in their design parameters. Technique for computing the sensitivity of temperature distributions to changes in processing parameters needed to decide the more effective laser input parameters for laser surface hardening treatment is considered. In this study, a state equation governing the heat flow in laser surface treatment is analyzed using a three-dimensional finite element method and sensitivity data of the processing parameter obtained using a direct differentiation method is applied to the sensitivity analysis. The interesting processing parameters are taken as the laser scan velocity and laser beam radius ( $r_{ b}$), and the sensitivities of the temperature T versus v and $r_{b}$ are analyzed. These sensitivity results are obtained with another parameters fixed. To verify the numerical analysis results, hardened layer dimensions (width and depth) of the numerical analysis are compared with the experimental ones.nes.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.5 no.1
• /
• pp.38-48
• /
• 1997

A method for performing kinematic design sensitivity analysis of vehicle suspension systems is presented. For modeling of vehicle suspensions, the multibody dynamic formulation is adopted, where suspensions are assumed as combination of rigid bodies and ideal frictionless joints. In a relative joint coordinate setting, kinematic constraint equations are obtained by imposing cut-joints that transform closed-loop shape suspension systems into open-loop systems. By directly differentiating the constraint equations with respect to kinematic design variables, such as length of bodies, notion axis, etc., sensitivity equations are derived. By solving the sensitivity equations, sensitivity of static design factors that can be used for design improvement, can be obtained. The validity and usefulness of the method are demonstrated through an example where kinematic sensitivity analysis of a MacPherson strut suspension of performed.

• Journal of the Society of Naval Architects of Korea
• /
• v.43 no.2 s.146
• /
• pp.156-163
• /
• 2006

The accuracy of estimates of hydrodynamic coefficients can be increased by using sensitivity-maximizing inputs. In this study, sensitivity-maximizing actuator commands of a submersible, which are sequences of bang-bang type commands, were obtained using Genetic Algorithm (GA) optimization technique. By comparing the total sensitivity values, deduced actuator inputs were found to be superior to the other sea trials. Based on the sensitivity distribution of conventional sea trials and sensitivity distribution results through deduced input scenario a review of submersibles' manoeuvring equations of motion was conducted .