• Journal of the Korean Applied Science and Technology
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• v.39 no.4
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• pp.580-587
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• 2022

In this study, the physiological activity effect of trichosanthis cucumeroidis radix extract on antioxidant activity, whitening, and anti-inflammatory activity was checked, and the possibility of its use as a functional material was checked. The purpose of this study was to confirm the antioxidant activity through DPPH radical scavenging activity of trichosanthis cucumeroidis radix extract, whitening activity effect through melanin production inhibition ability for melanin cell B16F10 melanoma cell, and anti-inflammatory activity effect through NO production inhibition ability for macrophage RAW 264.7 cell. As a result of the study, the concentration-dependent DPPH radical scavenging activity of the trichosanthis cucumeroidis radix extract was confirmed, and DPPH radical scavenging activity similar to that of the positive control Ascorbic acid was confirmed. It was confirmed that the melanin production inhibitory activity induced by 100 nM 𝛼-MSH and the NO production inhibitory ability induced by LPS 1 ㎍/mL were significantly suppressed. Accordingly, it is considered that the trichosanthis cucumeroidis radix extract may be used as a functional material having antioxidant, whitening, and anti-inflammatory effects.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.37 no.3
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• pp.163-171
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• 2024

Structural health monitoring for ships and offshore structures is important in various aspects. Ships and offshore structures are continuously exposed to various environmental conditions, such as waves, wind, and currents. In the event of an accident, immense economic losses, environmental pollution, and safety problems can occur, so it is necessary to detect structural damage or defects early. In this study, structural response data of multi-linked floating offshore structures under various wave load conditions was calculated by performing fluid-structure coupled analysis. Furthermore, the order reduction method with distortion base mode was applied to the structures for predicting the structural response by using the results of numerical analysis. The distortion base mode order reduction method can predict the structural response of a desired area with high accuracy, but prediction performance is affected by sensor arrangement. Optimization based on a genetic algorithm was performed to search for optimal sensor arrangement and improve the prediction performance of the distortion base mode-based reduced-order model. Consequently, a sensor arrangement that predicted the structural response with an error of about 84.0% less than the initial sensor arrangement was derived based on the root mean squared error, which is a prediction performance evaluation index. The computational cost was reduced by about 8 times compared to evaluating the prediction performance of reduced-order models for a total of 43,758 sensor arrangement combinations. and the expected performance was overturned to approximately 84.0% based on sensor placement, including the largest square root error.

• The Journal of the Acoustical Society of Korea
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• v.38 no.5
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• pp.549-557
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• 2019

The acoustical scattering characteristics of a target are influenced by the material properties and structural characteristics of the target, which are critical information for acoustic detection and identification of underwater target. In particular, for thin elastic target, unique scattered signals are generated around the target by the Lamb wave. In this paper, the results of scattered signal measurement of aluminum spherical shell in the water tank using the stepped frequency sweep sine signal are presented. In particular, the scattering of the water-filled aluminum spherical shell is compared with that of the air-filled one both theoretically and experimentally. The difference of the scattered signals are analyzed using the pseudo Wigner-Ville distribution in terms of average frequency, frequency distribution, and energy of the scattered signal. The result shows that all observed parameters increased when the aluminum sphere was water-filled, and it is well matched to the theoretical expectation.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.1
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• pp.1-8
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• 2022

To understand physical phenomena of ship maneuvering deeply, a numerical study based on computational fluid dynamics is required. A computational method that can simulate the interaction between the ship hull, propeller, and rudder will provide informative local flows during ship maneuvering tests. The analysis of local flows can be applied to improve a physical model of ship maneuvering that has been widely used in maneuvering simulations. In this study, the numerical program named as WAVIS that has been developed for ship resistance and propulsion problems is extended to simulate ship maneuvering by free-running tests. The six degree-of-freedom of ship motion is implemented based on Euler angles and the overset technique is applied to treat the moving grid of ship hull and rudder. The propulsion force due to a propeller is calculated by a panel method that is based on the lifting-surface theory. The newly extended code is applied to simulate turning and zig-zag tests of KCS and the comparison with the available experimental data has been made.

• Journal of KIISE
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• v.41 no.12
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• pp.1152-1159
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• 2014

In this paper, we presents a system to ensure the safety of residents through appropriate action or alarm in case the residents occurs an emergency situation and abnormal activity. We collect and analysis real-time data of living environment of the residents using video and sensor. The existing system have been determined by using only the sensor data it have several problems. Our system attach camera to solve the existing system problem. We use weighted difference image and motion vector. The existing system, it takes about 48 hours to determine that an abnormal activity occurs. However, our system takes less than 1 hour.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.270-281
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• 2017

In this paper, a vibratory disturbance to the rotor system generated by gyroscopic precession through helicopter rotor is examined. Also, active vibration reduction method is designed and simulated by designing feedback controller. For this purpose, structural analysis is carried out using EDISON's geometric exact beam program which can analyze the rotor with the cantilever condition. And the aeroelastic analysis is performed by coupling it with the simple aerodynamic model. In order to obtain the real-time structural response, the EDISON program analysis results were modeled by nonlinear equations and the Newton-Raphson method was used for the trim analysis.

• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.1
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• pp.27-36
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• 2000

One of the methods to improve the softness and comfortness of denture base is the use of soft denture liners. In this study, specimens were made by 2 kinds of acrylic based soft lining materials and 2 kinds of silicone based soft lining materials, and bonded to acrylic resin(Lucitone $199^{(R)}$). Then they were tested the differences of tensile bond strengths according to the materials, thickness, surface treatment and failure mode. 1. Tensile bond strength according to soft lining materials was increased in order of Coe-$soft^{(R)}$, $Mollosil^{(R)}$, $Trusoft^{(R)}$, Ufi-Gel $C^{(R)}$. The differences between groups were statistically significant at level of 0.05. 2. Tensile bond strength according to thickness of soft lining materials was increased in order of 3mm, 2mm, 1mm. The differences between groups were not statistically significant. 3. Tensile bond strength of treated surface showed higher bond strength than nontreated surface. The difference between groups was not statistically significant. 4. The failure mode of Coe-$soft^{(R)}$, $Trusoft^{(R)}$, $Mollosil^{(R)}$ were mainly cohesive failure, and that of Ufi-Gel $C^{(R)}$ were mainly adhesive failure.

• Fashion & Textile Research Journal
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• v.22 no.6
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• pp.705-715
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• 2020

The domestic fashion industry of the middle and late 20th century emphasized the importance of a standardized design process; however, the values of differentiated brand individuality have become increasingly important with the qualitative·quantitative growth of designer brands. Therefore, paying attention to designer individuality (or a differentiated element of a designer brand growing up in the domestic fashion industry) this study reestablished factors of the designer brand individuality. An in-depth interview was conducted with 13 designers and consumers for empirical analysis. In order to identify concepts of designer individuality based on the theory of the brand personality by Aaker along with precedent studies, the study devised a theoretical frame to explain a conceptual structure of designer brand individuality as well as reestablish its factors as the designer individuality, design and non-design factors through empirical research. Empirical research derived the designer individuality factors as an external designer image, designer taste, design philosophy and designer personality. Design factors were derived as concept, working process and method, style and formativeness. Non-design factors were also extracted as wearing experience, wearer image, lookbook image, fashion shows and exhibitions. It is meaningful that little empirical research has been conducted on domestic fashion designers who actually run designer brands and that this study helped understand designer brands through a new approach called designer individuality.

• Journal of the Korean Society for Library and Information Science
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• v.48 no.3
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• pp.335-351
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• 2014

This study proposes a customized SNS operational strategy for special libraries based on a case study on the Ocean Science Library (OSL) of South Korea. The study conducted an in-depth analysis on an organizational structure, manpower, contents, and promotion. The outcome of SNS operational strategy deducted from this study can be categorized into several items, including: (1) a selection of an appropriate SNS channel, which meets the objective of the operation; (2) a formal division of works for SNS operation; (3) a designation of full-time managers and an establishment of a task force team; (4) a specialization of contents according to specific subjects; (5) on/off-line promotions focused on events, which encourage participations; (6) an improvement of contents through regular log analyses; and (7) a promotion of library website access through SNS, and so on. This research also suggested the strategies for the development of SNS operation: strengthening of communication and cooperation among librarians; distribution of academic and research outcomes of the umbrella organization; enhancement of a role as a communication channel between librarians and users, and carry out a role as a 'social curator.'

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.5
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• pp.502-515
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• 2020

To identify the dynamic characteristics of the Auto-leveling system applied to the Tractor-Trailer type Transporter for mounting a large scale precision equipment, Dynamics Modeling & Simulation were performed using general Dynamics Analysis Program - RecurDyn(V9R2). The axial load data, transverse load data and pad trace data of leveling actuators were obtained from M&S. And they were analyzed and compared with each other by parameters, i.e. friction coefficients on the ground, landing ram speed of actuators, and direction & quantity of ground slope. It was observed that ground contact friction coefficients affected to transverse load and pad trace; the landing ram speed of actuators to both amplitude of axial & transverse load, and this phenomena was able to explain from the frequency analysis of the axial load data; the direction of ground slope to driving sequence of landing ram of actuators. But the dynamic behaviors on the two-directional slope were very different from them on the one-directional slope and more complex.