• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.4
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• pp.217-224
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• 2020

In this study, a framework for optimizing the opening in an outrigger wall is proposed. To solve a constrained bounded optimization problem, an in-house finite element program and SQP algorithm in Python SciPy library are utilized. The openings of the outrigger wall are located according to the strut-tie behavior of the outrigger wall deep beam. A linear interpolation method is used to obtain differentiable continuous functions required for optimization, whereas a database is used for the efficiency of the optimization program. By comparing the result of the two-variable optimization through the moving path of the search algorithm, it is confirmed that the algorithm efficiently determines the optimized result. When the size of each opening is set to individual variables rather than the same width of all openings, the value of the objective function is minimized to obtain better optimization results. It was confirmed that the optimization time can be effectively reduced when using the database in the optimization process.

• Journal of the Korean Geosynthetics Society
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• v.17 no.2
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• pp.9-18
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• 2018

In this study, a field model experiment was performed to analyze the bahavior of slope during failure. It was analyzed through x-MR control chart method with inverse displacement and K-value. As a result, the portent was confirmed at 4 minutes before slope failure in Case 1. The change of the control limit line according to moving range was analyzed and it was effective to apply K = 3. Use of the inverse displacement and x-MR control chart method will be useful for the prediction of abnormal behavior through quick and objective judgment. Prediction of slope failure using control chart method can be used as basic data of slope measurement management standard, and it can contribute in reduction of life and property damage caused by slope disaster.

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.6
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• pp.451-462
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• 2011

The smoke control system plays the most important role in securing evacuation environment when a fire occurs in road tunnels. Smoke control methods in road tunnels are classified into two categories which are longitudinal ventilation system and transverse ventilation system. In this study it is intended to review the characteristics of smoke behavior by performing numerical analysis for calculating the optimal smoke exhaust air volume with scaled-model and simulation when a fire occurs in tunnels in which transverse ventilation is applied, and for obtaining the basic data required for the design of smoke exhaust systems by deriving optimal smoke exhaust operational conditions for various conditions. As a result of this study, when the critical velocity in the tunnel is 1.75 m/s and 2.5 m/s, the optimal smoke exhaust air volume has to be more than $173m^3/s$, $236m^3/s$ for the distance of the smoke moving which can limit the distance to 250 m. In addition, in case of uniform exhaust the generated smoke is effectively taken away if the two exhaust holes near the fire region are opened at the same time.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.2
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• pp.38-45
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• 1997

In this paper, the three-dimensional stress effect of thermal oxide is simulated. We developed a three-dimensional finite element numerical simulator including three-dimensional adaptive mesh generator that is able to refine and eliminate nearby moving boundary of oxide, and oxidation solver with stress model. To investigate the behavior of thermal oxidation the simulations of thermal oxidation for island and hole structures are carried out assuming silicon wafer of <100> direction, temperature of $1000^{\circ}C$, oxidation time of 60min, wet ambient, initial oxide thickness of $300\AA$, and nitride thickness of $2, 000\AA$. The main effect of deformation at the corner area of oxide is due to distribution of oxidant, but the deformation of oxide is affected by the stressin theoxide. In the island structure which is the structure mostly covered with nitride and a coner is opended to oxidation, oxidation is reduced at the coner by compressive stress. In the hole structure which is the structure mostly opedned to oxide and a coner is convered with nitride, however, oxidation is increased at the coner by tensile stress.

• Journal of computational fluids engineering
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• v.21 no.3
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• pp.15-23
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• 2016

In the present study, two phase flows around a projectile vertically launched from an underwater platform have been numerically investigated by using a three dimensional multi-phase RANS flow solver based on pseudo-compressibility and a homogeneous mixture model on unstructured meshes. The relative motion between the platform and projectile was described by six degrees of freedom equations of motion with Euler angles and a chimera technique. The propulsive power of the projectile was modeled as the fluid force acting on the lower surface of the body by the compressed air emitted from the underwater platform. Various flow conditions were considered to analyze the fluid-dynamics motion parameters of the projectile. The water level of platform and the current speed around the projectile were the main parametric variables. The numerical calculations were conducted up to 0.75sec in physical time scale. The dynamics tendency of the projectile was almost identical with respect to the water level variation due to the constant buoyancy term. The moving speed of the projectile along the vertical axis inside the platform decreased when the current speed increased. This is because the inflow from outside of the platform impeded development of the compressed air emitted from the floor surface of the launch platform. As a result, the fluid force acting on the lower surface of the projectile decreased, and injection time of the projectile from the platform was delayed.

• Journal of Korean Clinical Health Science
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• v.5 no.4
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• pp.1015-1020
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• 2017

Purpose. Walking depends on the speed and type of shoe to be worn, and the degree of impact varies with the muscle used. In addition, the speed can be changed by moving objects and using objects when walking. This study analyzed the change of walking speed by applying various factors influencing walking. Methods. A total of 60 patients who had not undergone musculoskeletal diseases during the last 1 year were included. Shoe type was divided into slippers and shoe heels. Behavioral types were divided into bagging, books, and cell phone use. The walking speed was measured by the general walking, the middle walking, and the fast walking. The time was measured using a 10M linear distance test. The collected data were analyzed with SPSS program for independent samples t-test, one-way ANOVA. Results. There was a statistically significant difference according to the type of shoes when walking. Walking speed was slow in shoe heel. In addition, There was statistically significant difference according to type of behavior task at walking. Walking speed was slow in task type using mobile phone during walking. Conclusions. The walking speed were appeared difference in each type of shoe heel, using mobile phone.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.3
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• pp.276-280
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• 2008

Many dissemination protocols on the mobility support in wireless sensor networks have been designed based on the assumption that the movement trace of sinks, such as soldiers and fire fighters, is random. However, the mobility of the sinks in many applications, for example, the movement trace of a soldier on operation in a battle field, can be determined in advance. In this paper, we propose a Predictable Mobility-based Data Dissemination protocol that enables data to directly route from source nodes to moving sinks by taking into consideration predictable movement behavior of the sinks. We also show the superiority of the predictable mobility-based data dissemination protocol through the performance comparison with the random mobility-based data dissemination protocols.

• Biomolecules & Therapeutics
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• v.16 no.4
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• pp.343-350
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• 2008

Oroxylin A is a flavonoid isolated from Scutellaria baicalensis, which is one of the most important medicinal herbs in traditional Korean medicine. In this study, we investigated the psychopharmacological activities of oroxylin A using the open field, rota-rod, balanced wire and plus-maze tests in Spontaneously Hypertensive Rats (SHR) and Wistar Kyoto Rats (WKY). Oroxylin A reduced hyperactivity in SHR (ADHD animal model) although it tended to increase locomotor activity in WKY. Methylphenidate did not reduce hyperactivity. Oroxylin A alleviated impulsive behaviors such as rearing, the percentage of moving time to the central area and the tendency to move into an unstable condition (open area in elevated plus-maze). Methylphenidate also reduced the percentage of staying time in the central area and the tendency to move into an unstable condition. Both oroxylin A and methylphenidate enhanced motor attention in SHR and WKY. Oroxylin A antagonized the muscimol ($GABA_A$ receptor agonist)-induced $Cl^-$current and its action was similar to that of bicuculline ($GABA_A$ receptor antagonist). The effects of oroxylin A may be caused by the antagonism at the $GABA_A$ receptor. Thus, oroxylin A may be a candidate of drug for treatment of ADHD.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.141.1-141.1
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• 2011

New CCD BVR light curves of BD And are presented. Our light curves with nearly equal depths for both primary and secondary eclipses show well-defined photometric waves outside eclipse for all of BVR bandpasses. The orbital period is greatly revised as $0.^d92580519$ which is twice longer than that known previously. Sixteen timings from our observations and thirteen ones from the SuperWASP measurements were calculated. All available timings over 76 years, including ours, were analyzed to figure out the dynamical behavior of the system. It was found that the recent CCD O-C residuals varied in a cyclical way with a period of $9.^y18$ and a semi-amplitude of $0.^d0046$. The secondary period of $9.^y18$ is the most shortest one among those which have been ever found in the short period RS CVn binary stars. The periodic variation most likely arises from the light-travel time effect due to a low-mass ($m_3{\sim}0.88\;M_{\odot}$) tertiary companion moving in an orbit with an large eccentricity ($e_3$=0.70) and a low inclination ($i_3{\sim}28^{\circ}$). The Applegate mechanism could not operate properly in both components because the model parameters require too much large luminosity changes of ${\Delta}L/L_{p,s}$ > 10. The new light curves were synthesized using the 2003 version of Wilson-Divinney code. It was found useful to model two huge spots on the surface of the hotter star and a third-light in order to minimize the residuals from the observations. Astronomical basic parameters were deduced from our photometric solution.

• The Research Journal of the Costume Culture
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• v.26 no.3
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• pp.313-326
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• 2018

Over the past few years, companies have started moving into specific niches in plus-size fashion. The purpose of this study was to verify the marketability of young plus-size clothes in the USA. Data were collected from female consumers aged from 20 to 39 who have experience of purchasing plus-size items. A total of 282 responses were used for statistical analysis. The research result is as follows. First, the obesity stress is affected more by the subjective obesity level than by the objective obesity level and by how people recognize their body types. Second, from an analysis of the factors affecting the shopping orientation of plus-size consumers, style consciousness, pursuing reasonable, emphasizing comfort, and body consciousness are found to be important factors. Third, even if responders are aware of their exact body size, they actively look for the correct size. Fourth, fit evaluation of plus-size products is based on the factors of size fit and movement fit. The respondents were unsatisfied with chest and arm measurements, which deviate widely by body type for tops. Fifth, the overall dissatisfaction with the plus-size market is attributed to the fact that the product assortment range from which to select styles is narrow, and trend reflection is low. Sixth, the respondents tended to avoid fabrics that make their body type more obvious, textures that give the impression of a larger body size, or stiff textures. These results show that the psychological and physical characteristics of obese consumers should be considered to develop products for the young plus-size market.