• Journal of Industrial Technology
• /
• v.15
• /
• pp.63-70
• /
• 1995

This paper presents an impact control algorithm for reducing the potentially damaging effects by interation of redundant manipulators with their environments. In the proposed control algorithm, the redundancy is resolved at the torque level by locally minimizing joint torque, subject to the operational space dynamic formulation which maps the joint torque set into the operational forces. For a given pre-impact velocity of the manipulator, the proposed approach is on generating joint space trajectories throughout the motion near the contact which instantaneously minimize the impulsive force which is a scalar function of manipulator's configurations. The comparative evaluation of the proposed algorithm with a local torque optimization algorithm with a local torque optimization algorithm without reducing impact is performed by computer simulation. The simulation results illustrate the effectiveness of the algorithm in reducing both the effects of impact and large torque requirements.

• Proceedings of the KSR Conference
• /
• 2005.11a
• /
• pp.872-877
• /
• 2005

The train entry into a tunnel generates a strong compression wave in the tunnel. The high amplitude of compression wave causes high pressure gradients that are responsible for both the aural discomfort of passengers and the impulsive acoustical wave called the miro-pressure wave. This paper provides a numerical study on effects of hood for micro'-'pressure wave reduction. An axisymmetric numerical solver, considering the cross sectional area of Korean Tilting Train eXpress, is used for a transient flow field in the tunnel. Results show that the micro-pressure wave is able to be reduced by a hood. In this results, the maximum reduction of micro--pressure wave is shown at 2L(length), 1.35D(diameter) hood around $56\%$ against the non-hood case.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 1999.10a
• /
• pp.83-90
• /
• 1999

This paper presents a method of seismic analysis for a cylindrical liquid storage structure on horizontally layered half-space considering the effects of the interior fluid and exterior soil medium in the frequency domain. the horizontal and rocking motions of the structures are included in this study. The fluid motion is expressed in terms of analytical velocity potential function which can be obtained by solving the boundary value problem including the sloshing behavior of the fluid as well as deformed configuration of the structure. The effect of the fluid is included in the equation of motion as the impulsive added mass and a frequency-dependent convective added mass along the nodes on the wetted boundary with structure. The soil medium is presented using the 3-D axisymmetric finite elements and dynamic infinite elements. The present method can be applied to the structures embedded in ground as well as on ground since it models the soil medium directly as well as the structure. For the purpose of vertification dynamci characteristics of a tank on homogeneous half-space is analyzed. Comparison of the present results with those by others shows good agreement.

• Structural Engineering and Mechanics
• /
• v.19 no.2
• /
• pp.231-236
• /
• 2005

This study considers the buckling of orthotropic cylindrical thin shells with material nonhomogeneity in the thickness direction, under torsion, which is a power function of time. The dynamic stability and compatibility equations are obtained first. Applying Galerkin's method then applying Ritz type variational method to these equations and taking the large values of loading parameters into consideration, analytic solutions are obtained for critical parameter values. Using those results, the effects of the periodic and power variations of Young's moduli and density, ratio of Young's moduli variations, loading parameters variations and the power of time in the torsional load expression variations are studied via pertinent computations. It is concluded that all these factors contribute to appreciable effects on the critical parameters of the problem in question.

• Science of Emotion and Sensibility
• /
• v.20 no.1
• /
• pp.83-94
• /
• 2017

In this study, we figured out that music modes and item types could affect people's urged decision making through a k-value which results from a delay discounting's hyperbolic function. Generally, high k-value is related to impulsive decision making. Concretely, there was a significant interaction between items and music. For the luxury item, the k-value was higher while listening to major music than minor. However, for the non-luxury item condition the k-value difference was not significant between two pieces of music. Moreover, we expected mood could be manipulated after listening to the music and mediate a difference of tendency. We used first movement as an allegro and second as an andante of Mozart piano concerto No.5 D-major and No.20 D-minor for stimuli. As a result, mode and tempo's main effects were not significant. Nevertheless, there was a significant two-way interaction. To put it concretely, the k-value of major condition was marginally higher than minor condition on allegro. However, the k-value of major condition was significantly lower than minor condition on andante. Also, depressed degree difference was significant but it was not significant as a mediator. Set depressed degree as a predict variable and future time span as a mediator, further research found future time perception partially mediated the effect that depressed degree affects impulsivity.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.38 no.1
• /
• pp.87-96
• /
• 2014

E-shopping is traditional method to purchase products in a modern society. Fashion products are one of the most popular product categories sold and impulsively bought online. This study examined the causal relationship of shopping value, positive emotion, urge to buy impulsively, and e-impulse buying in the context of shopping for apparel products. A self-administered questionnaire developed from the literature was administered in class to 501 female college students in Busan. AMOS 21.0 estimated the structural equation model of e-impulse buying using a correlation matrix with a maximum likelihood. The analysis of the data supported most of the predictions. The results suggested that consumer shopping values (hedonic shopping value and utilitarian shopping value) had a positive effect on positive emotion; in addition, positive emotion urge to buy impulsively directly affected the e-impulse buying of apparel products. In the structural model, e-impulse buying of consumers can be predicted by the attitudinal component (e.g., shopping values), emotional factors (e.g., enthusiastic or proud), and the urge to buy impulsively felt by young consumers. There are implications that both positive emotion and impulsive buying are important predictors for the e-impulse buying of apparel products by consumers. Moreover, the urge to buy impulsively was an important mediator to determine the e-impulse buying of apparel products. This study provides insight to retailers and researchers to understand the structural relationship of consumer characteristics and the e-impulse buying of apparel products.

• The Korean Journal of Community Living Science
• /
• v.24 no.3
• /
• pp.313-325
• /
• 2013

The purpose of this study is to investigate impulse buying and the searching for sources of information among males and females in their 20s by their utilization of sales promotion in an internet fashion shopping mall. The findings were as follows: First, there was a statistically significant difference in the use of sales promotion by age and gender. Second, two factors, such as a price-oriented utilization of sales promotion and a non price-oriented utilization of sales promotion were extracted from the analysis of sub factors of the utilization of sales promotion in an internet fashion shopping mall. Third, five factors, including affective impulse buying, provocative impulsive buying, situational impulse buying, reminder impulse buying, and pure impulsive buying, were extracted from the analysis of sub factors of impulse buying in an internet fashion shopping mall. Fourth, the utilization of sales promotions in an internet fashion shopping mall had statistically significant effects on the sub factors of impulse buying, provocative impulse buying, situational impulse buying, reminder impulse buying, and pure impulse buying. Fifth, the analysis of the correlation between the utilization of sales promotion and the searching for sources of information revealed that price-oriented utilization of sales promotion had a correlation with DM or text message, advice from friends or family, advice from a sales person, information from friends or colleagues, celebrity supporters on TV dramas or movies, and product commercials and information.

• Journal of Astronomy and Space Sciences
• /
• v.27 no.3
• /
• pp.195-204
• /
• 2010

The optimal Earth-Moon transfer trajectory considering spacecraft's visibility from the Daejeon ground station visibility at both the trans lunar injection (TLI) and lunar orbit insertion (LOI) maneuvers is designed. Both the TLI and LOI maneuvers are assumed to be impulsive thrust. As the successful execution of the TLI and LOI maneuvers are crucial factors among the various lunar mission parameters, it is necessary to design an optimal lunar transfer trajectory which guarantees the visibility from a specified ground station while executing these maneuvers. The optimal Earth-Moon transfer trajectory is simulated by modifying the Korean Lunar Mission Design Software using Impulsive high Thrust Engine (KLMDS-ITE) which is developed in previous studies. Four different mission scenarios are established and simulated to analyze the effects of the spacecraft's visibility considerations at the TLI and LOI maneuvers. As a result, it is found that the optimal Earth-Moon transfer trajectory, guaranteeing the spacecraft's visibility from Daejeon ground station at both the TLI and LOI maneuvers, can be designed with slight changes in total amount of delta-Vs. About 1% difference is observed with the optimal trajectory when none of the visibility condition is guaranteed, and about 0.04% with the visibility condition is only guaranteed at the time of TLI maneuver. The spacecraft's mass which can delivered to the Moon, when both visibility conditions are secured is shown to be about 534 kg with assumptions of KSLV-2's on-orbit mass about 2.6 tons. To minimize total mission delta-Vs, it is strongly recommended that visibility conditions at both the TLI and LOI maneuvers should be simultaneously implemented to the trajectory optimization algorithm.

• Journal of Digital Contents Society
• /
• v.8 no.4
• /
• pp.491-497
• /
• 2007

RPersonal area networking technology is becoming increasingly important in enabling useful wireless home applications. For example, Bluetooth and IEEE 802.11b standards are the most commonly deployed technologies for wireless home applications. However, because both standards share the same unlicensed ISM (Industrial, Scientific, Medical) radio spectrum, severe interference is inevitable and performance can be impaired significantly when heterogeneous devices using the two technologies come into close proximity. In this paper, we research Gaussian FSK Bluetooth system, which is an open specification technology for short-range wireless connectivity between electronic devices. In this paper, we analyzes the effects of co-channel interference on the performance of a Gaussian FSK Bluetooth system. Performance criteria used in the study are the signal to interference power ratio (SIR), interference index, and the bit error rate (BER) in the wireless channel. The effect of co-channel interference from various sources on the performance of a Gaussian FSK Bluetooth system is analyzed using an IGA(Impulsive Gaussian Approximation) method, and these quantities are plotted against Eb/No, $\rho$ and SIR for various channel conditions in figures.

• The Journal of the Korea Contents Association
• /
• v.21 no.1
• /
• pp.684-697
• /
• 2021

This study seeks to establish the structural relationship between the personal psychological risk factors of teenagers of depression, anxiety and impulsiveness and smartphone addiction (daily disability, virtual orientation, tolerance, withdrawal) and self-elasticity (vitality, optimism, curiosity, interpersonal relationships). Through this verification, the purpose of this study is to find out if the integrated model of smartphone addiction and self-elasticity and smartphone addiction among teenagers is reasonable, and to suggest ways to prevent and solve smartphone addiction among teenagers. In order to achieve this purpose, 356 teenagers in Seoul and the metropolitan area were surveyed for two months from August to September 2019 and the results were analyzed. The findings of this study are as follows. First, the "smartphone addiction factors" (depression, anxiety and impulsive) of adolescents have been shown to have negative effects on their self-elasticity (vitality, optimism, curiosity, interpersonal relationships). Second, the "smartphone addiction factors" (depression, anxiety and impulsive) of teenagers have been shown to have positive effects on the "smartphone addiction" (daily disability, virtual orientation, tolerance, withdrawal). Third, the youth's "self-elasticity (vitality, optimism, curiosity, interpersonal relationship)" was shown to have a negative impact on "smartphone addiction (daily disability, virtual orientation, tolerance, withdrawal)." The significance of this study is that it has examined personal psychological risk factors that affect smartphone addiction and suggested measures to prevent smartphone addiction among teenagers and solve related problems by micro-analyzing the effects on smartphone addiction by utilizing self-elasticity.