• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.5
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• pp.359-371
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• 2013

This paper is the first paper among two papers which constitute the paper about the rigid body dynamic analysis on the spent nuclear disposal canister under accidental drop and impact on to the ground. This paper performed the general theoretical study on the rigid body dynamic analysis. Through this study the impulsive force which is occurring in the spent nuclear fuel disposal canister under accidental drop and impact to the ground and required for the structural safety design of the canister is intended to be theoretically formulated. The main content of the theoretical study is about the equation of motion in the multibody dynamics. On the basis of this study the impulsive force which is occurring in the multibody in the case of collision between multibody is theoretically formulated. The application of this theoretically formulated impulsive force to computing the impulsive force occurring in the spent nuclear fuel disposal canister under accidental drop and impact to the ground is investigated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.3
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• pp.280-292
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• 1989

In this paper, the error rate equations of digitally modulated signals transmitted through the channel which is not only Gaussian/Impulsive noise but also multi-path fading have been derived. Using the derived equations for the error probabilities of ASK, QAM, CPSK, DPSK, FSK, and MSK signals, the error rate performances of digital modulation systems have been evaluated and represented in the graphs as the functions of CNR, Impulsive indes, the ratio of Gaussian noise power component to Impulsive noise power component, and fading figures. The results show that, in the deep fading environment, the error is occurred more frequency by Gaussian noise than Impulsive noise. And the comparison of various systems certifies that PSK is superior to the ohter systems in the deep fading or shallow fading environment.

• Journal of Digital Convergence
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• v.17 no.2
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• pp.113-125
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• 2019

Mobile social commerce is one of the fastest growing distribution channels in recent years. Therefore, it is important to understand customer's buying behavior in mobile social commerce in order to continuously grow in the competitive mobile social commerce market. To achieve the purpose of this study is to investigate how impulsive buying behaviors are applied in mobile shopping and how factors affect impulse purchasing in online shopping. In order to verify the hypothesis, we surveyed the customers who have experiences of using mobile social commerce and analyzed 280 valid data by Smart PLS 3.0. As a result, it was confirmed that consumers' innovation and purchasing experience influenced impulse purchase in mobile social commerce, and scarcity messages among information attributes affect impulse buying. Through this study, impulsive buying behavior which is a frequently analyzed variable in an online shopping context will be extended to the mobile shopping context. and it will provide practical implications for customer strategy establishment in mobile social commerce market.

• Korean Journal of Schizophrenia Research
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• v.24 no.1
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• pp.8-16
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• 2021

Objectives: Although the characteristics of different aggression subtypes provide important information in establishing treatment and prevention strategies in schizophrenia patients, limited information is available about the characteristics of the aggressive subtype in schizophrenia patients in South Korea. The present study was designed to compare the demographic and psychological characteristics across the impulsive and premeditated aggression subtypes in schizophrenia patients in South Korea who had committed a crime. Methods: We enrolled 116 schizophrenia spectrum disorder patients who were admitted to the National Forensic Psychiatric Hospital. Using the criminal and interview records, the study subjects were divided into 83 impulsive and 33 premeditated aggression groups. The subjects' demographic and psychological characteristics were summarized and compared across aggression subtypes. Results: Compared to the premeditated aggression group, the impulsive aggression group had a higher intelligent quotient and a lower rate of physical and sexual abuse experience. Conclusion: To our knowledge, this is the first study to describe the characteristics of aggression subtypes in schizophrenia patients in South Korea who had committed a crime. Our results suggest that different treatment and prevention strategies should be considered for each aggression subtype.

• 한국전산유체공학회:학술대회논문집
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• 2009.11a
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• pp.115-119
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• 2009

We numerically investigated propagation of various waves in the two-phase flows such as sound wave, shock wave, rarefaction wave, and contact discontinuity in terms of pressure, void fraction, velocity and density of the two phases. The waves have been generated by a hydrodynamic shock tube, a pair of symmetric impulsive expansion, impulsive pressure and impulsive void waves. The six compressible two-fluid two-phase conservation laws with interfacial friction terms have been solved in two fractional steps. The first PDE Operator is solved by the HLL scheme and the second Source Operator by the semi-implicit stiff ODE solver. In the HLL scheme, the fastest wave speeds were estimated by the analytic eigenvalues of an approximate Jacobian matrix. We have discussed how the interfacial friction terms affect the wave structures in the numerical solution.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.3
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• pp.169-176
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• 1998

A method for the dynamic analysis of multibody systems undertaking impulsive force is introduced in this paper. A partial velocity matrix based on Kane's method is introduced to reduce the number of equations to be solved. Only minimum number of equations of motion can be obtained by using the partial velocity matrix. This reduces the computational effort significantly to obtain the dynamic response of the system. At the very moment of the impulse, instead of using the numerical integrator to solve the equations of motion, the impulse and momentum principle is used to obtain the dynamic response. The impulse as wall as the reaction force acting on the kinematic joints can easily calculated too.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.8
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• pp.1638-1644
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• 2002

A novel locomotion using the pneumatic impulsive actuator was proposed for robotic colonoscope. This locomotion showed good moving performance in the environment of rigid pipe, however, the displacement per one impact(step displacement) is greatly reduced due to the low stiffness and high damping characteristics of the colon. Therefore, the modeling technique based on spring and damping system is studied to predict the step displacement and some parametric studies are carried out to investigate main parameters that influence the step displacement of locomotion. Based on simulation result, a new locomotion to control the resistance force is suggested and fabricated. Through the experiment on the colon, the usefulness of modeling technique is confirmed and successful improvement of moving characteristics is achieved.

• International Journal of Naval Architecture and Ocean Engineering
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• v.2 no.3
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• pp.119-126
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• 2010

The response of ship roll oscillation under random ice impulsive loads modeled by Poisson arrival process is very important in studying the safety of ships navigation in cold regions. Under both external and parametric random excitations the evolution of the probability density function of roll motion is evaluated using the path integral (PI) approach. The PI method relies on the Chapman-Kolmogorov equation, which governs the response transition probability density functions at two close intervals of time. Once the response probability density function at an early close time is specified, its value at later close time can be evaluated. The PI method is first demonstrated via simple dynamical models and then applied for ship roll dynamics under random impulsive white noise excitation.

• Bulletin of the Korean Mathematical Society
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• v.50 no.2
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• pp.499-506
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• 2013

The half-inverse spectral problem for an impulsive Sturm-Liouville operator consists in reconstruction of this operator from its spectrum and half of the potential. In this study, the spectrum of the impulsive Sturm-Liouville problem is given and by using the Hochstadt and Lieberman's method we show that if $q(x)$ is prescribed on (0, ${\frac{\pi}{2}}$), then only one spectrum is sufficient to determine $q(x)$ on the interval (0, ${\pi}$) for this problem.

• Bulletin of the Korean Mathematical Society
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• v.55 no.4
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• pp.1065-1092
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• 2018

This manuscript is involved with a category of second-order impulsive functional integro-differential equations with nonlocal conditions in Banach spaces. Sufficient conditions for existence and approximate controllability of mild solutions are acquired by making use of the theory of cosine family, Banach contraction principle and Leray-Schauder nonlinear alternative fixed point theorem. An illustration is additionally furnished to prove the attained principles.