• Advances in nano research
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• v.15 no.4
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• pp.367-384
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• 2023

Natural frequency behavior of graphene platelets reinforced composite (GPL-RC) joined truncated conical-cylindrical- conical shells resting on Winkler-type elastic foundation is presented in this paper for the first time. The rule of mixture and the modified Halpin-Tsai approach are applied to achieve the mechanical properties of the structure. Four different graphene platelets patterns are considered along the thickness of the structure such as GPLA, GPLO, GPLX, GPLUD. Finite element procedure according to Rayleigh-Ritz formulation has been used to solve 2D-axisymmetric elasticity equations. Application of 2D axisymmetric elasticity theory allows thickness stretching unlike simple shell theories, and this gives more accurate results, especially for thick shells. An efficient parametric investigation is also presented to show the effects of various geometric variables, three different boundary conditions, stiffness of elastic foundation, dispersion pattern and weight fraction of GPLs nanofillers on the natural frequencies of the joined shell. Results show that GPLO and BC3 provide the most rigidity that cause the most natural frequencies among different BCs and GPL patterns. Also, by increasing the weigh fraction of nanofillers, the natural frequencies will increase up to 200%.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.8
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• pp.331-337
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• 2001

The purpose of this study is to analyze the principal causes of vibration problem and find out the method of vibration reduction in a chip-mount system. The principal causes are investigated through measurements of vibration spectrum and model parameters. Modal parameters are obtained by using an experimental model test. Based on the model parameters from experiments. a model of finite element method is formulated. The model presents effective redesign of increasing the natural frequencies in order to reduce the vibration of a chip-mount system. Further, through computer simulation for the behavior of head to be main vibration source, the best acceleration pattern of head movement can be verified to achieve effective head-positioning and reduce the vibration due to head movement.

• Korean Journal of Human Ecology
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• v.18 no.5
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• pp.1103-1113
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• 2009

Now in the 21st century, all the industries in our world are rapidly changing, including fashion trends and customers' needs as well. Fashion textile planning is also developing towards the direction where it could satisfy the merged sensitivity and incentive of the customers through an idea. The purpose of this study is to accentuate the importance of fashion material planning in fitting conventional patterns and eco-benign fabric materials. Accordingly, this study is mainly focused on the reflection of fabric planning characteristics to show tradition containing comfort and naturalness. As mixing with established fabrics and blending with natural/functional fabrics, and conforming to the trend of the seasonal fabric, it has developed a new structure and pattern by changing the basic source of traditional patterns to a computer aided design system. Therefore, four different types of items were basically up-graded by fitting it in with traditional patterns.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.107.4-107
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• 2002

One of the most important functions of a biped robot is to walk naturally like human. For the human being, toe is very important joint in order to walk naturally. Thus, for a biped robot, the existence of toe joint much affects gait pattern generation and contributes to natural walking, which is similar to the human gait or faster walking like running. Since a conventional biped robot has the feet which consist of soles without toes, it seems difficult to walk naturally. For realizing the gait to be similar to human one, toes are necessary to the biped robot. In this paper, the effect of the toe joint for gait pattern generation is studied. In order to find the effect of toe joint, a biped r...

• ALGAE
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• v.25 no.2
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• pp.71-76
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• 2010

Centroceras gasparrinii is characterized by 1) straight spines, 2) an ovoid gland cell, 3) tetrasporangia with involucral branchlets, and 4) ovoid cortical cells on the first and second cortical initials. A similar Centroceras species with dichotomous habit, "Centroceras clavulatum", has been widely known as a common species of Korean marine flora. However, the species known as "C. clavulatum" in Korea is recognized as C. gasparrinii based on the molecular and morphological evidence. Newly generated sequences of rbcL gene reveal that all taxa of Centroceras from Korea having dichotomous branching pattern are C. gasparrinii. There is 0-0.07% sequence divergence among specimens of C. gasparrinii in Korea. "Centroceras clavulatum" is excluded from Korean flora and C. gasparrinii is included instead of "Centroceras clavulatum". C. gasparrinii also differs from C. distichum in Korea in that it has tetrasporangia with involucral branchlets and dichotomous branching pattern, while C. distichum has immersed tetrasporangia and an alternate branching pattern.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.321-329
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• 2002

Artificial neural network has been used for damage assessment by many researchers, but there are still some barriers that must be overcome to improve its accuracy and efficiency. The major problems with the conventional neural network are the necessity of many training patterns for neural network teaming process and ambiguity in the relationship of neural network structure to the convergence of solution. In this paper, the PNN is used as a pattern classifier to detect the damages of the railway bridge using dynamic response. The comparison between the mode shape and the natural frequency of structure as training pattern is investigated for approriate selection of the training pattern in the damage detection of railway bridge using the PNN.

• Journal of Integrative Natural Science
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• v.1 no.1
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• pp.32-35
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• 2008

We fabricated surface pattern on a light guide panel (LGP) using $CO_2$ laser to improve the luminescence performance of inner-scatterer LGP, which is made of PMMA sample with exploiting Q-switched $2^{nd}$ harmonic Nd:YAG laser engraving system, and the effect of surface pattern in the brightness distribution of LGP was analysed. To prove the feasibility of proposed method in the enhancement of LGP performance, we designed three different surface patterns on the inner-scatterer LGP. The experimental results has proved the potential in the application of surface pattern to increasing the brightness of inner-scatterer LGP.

• Korean Journal of Microbiology
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• v.22 no.2
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• pp.97-101
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• 1984

To investigate the biodegradation pattern of rice straw, mainly composed of cellulose, hemicellulose and lignin components, by the isolate stran Bacillus subtilis $DO_4$, the change of cell population was observed on CMC (carboxymethyl cellulose), larch wood xylan and lignosulfonate as a carbon source respectively. Also, the transition pattern of enzyme activities of cellulase and xylanase and lignin contents was measured on rice straw and mixed substrate according to growth. The results in these experiments revealed that xylanase activity was first appeared and cellulase activity in the next, while lignin component was almost not changed through the culture period.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.1
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• pp.103-111
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• 2010

The study was conducted to examine the possible psychological difference in visual preference for natural landscape depending on the residence characteristic of the visitors, with the aim to use as the reference when creating space for natural landscape. Visitors were classified into three groups, namely, urban, suburban, and rural residents, and their preferred type of landscape was surveyed. The result showed that regardless of their residence the highest preference was to the place with superior natural landscape features, and among such features the common preference was toward the landscapes with horizons and those with animals. Urban and suburban residents showed similar preference pattern, and there was artistically significant difference with rural residents. In this respect, the difference in preference for natural landscapes could be induced between urban and rural residents. Rural residents had similar preference with urban residents in that they both preferred the place with superior natural landscape features, but differed in that the former had significantly higher preference toward the landscapes that have mixed artificial elements. From the above research, the following conclusions can be inferred:for regions that need to create natural landscapes, differentiated visual landscape plans and strategies need to be established taking into account, inter alia, the natural richness of the neighborhood natural environment; for regions that need to conserve and manage natural environment and landscapes, the measures to adjust the natural landscape management plans need to be established taking into account the neighborhood environment of the protected areas and the number of visitors to the region.

• Journal of the Ergonomics Society of Korea
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• v.35 no.6
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• pp.581-594
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• 2016

Objective: The purpose of this study is to develop an all- in-one collar shirt with excellent appearance which is well suited to the body shape of the male adults. Background: As men's casual wear has recently become more casual and the number of cool biz wearing in the summer has increased, a variety of shirt colors have been preferred in addition to shirt collar. However, studies on the design and pattern development of men's casual shirt collars are very rare. So we have identified the necessity of various development and research of men's shirts. Method: We collected 8 all-in-one collar patterns for shirts from professional pattern books and men's shirt brands. Also, based on anthropometric data from the 6th Size Korea, we selected 5 subjects with measurements similar to the average adult men, manufactured shirts based on them and conducted a wearing test by 5 experts. Results: After selecting shirts with good fit and appearance, we developed a prototype of all-in-one collar. As for front appearance evaluation, E1 pattern had the most outstanding shape and size, and C1 pattern had the most natural creases and front adjustment curves. As for side appearance evaluation, C1 had the highest overall scores, and E1 pattern on outer line. As for back appearance evaluation, C1 pattern had the highest score. Conclusion: We suggested new all-in-one collar and shirt patterns. In addition, the prototype of the all-in-one collar shirt design was presented by reflecting results of the wearing test and preference survey. Application: The shirt's design and patterns could be manufactured using the developed patterns. It will fit well with the body shape of adult males and will be highly satisfied by them.