• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.11a
• /
• pp.65-66
• /
• 2023

This study is aimed to understand the effect of pyrolysis temperature on the biochar synthesis for shape stabilizing the Lauric acid (LA). Three different temperatures (350, 500, and 650 ℃) have been chosen with a soaking time of 1h for synthesizing biochars form sesame plants (SP). The structural characterizations indicate the formation of amorphous biochar at 350 ℃ whereas, a stain of graphene formation has been observed for the biochar synthesized at 500 ℃. Formation of a substantial amount of graphene has been found for the sample, synthesized at 650 ℃. Energy storage performances of the PCMs which are shape stabilized by these three biochars have been discussed in this paper.

• International Journal of Control, Automation, and Systems
• /
• v.4 no.4
• /
• pp.466-479
• /
• 2006

This paper addresses a formation navigation issue for a group of mobile robots passing through an environment with either static or moving obstacles meanwhile keeping a fixed formation shape. Based on Lyapunov function and graph theory, a NN formation control is proposed, which guarantees to maintain a formation if the formation pattern is $C^k,\;k\geq1$. In the process of navigation, the leader can generate a proper trajectory to lead formation and avoid moving obstacles according to the obtained information. An evolutionary computational technique using particle swarm optimization (PSO) is proposed for motion planning so that the formation is kept as $C^1$ function. The simulation results demonstrate that this algorithm is effective and the experimental studies validate the formation ability of the multiple mobile robots system.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.18 no.3
• /
• pp.165-181
• /
• 2016

This study looks into the Korean traditional costume formation and the thoughts of the Korean people that form the foundation of that Korean traditional costume formation. And the goal of this study is in linking the thoughts and formative characteristics reflected in the Korean traditional costume formation to the fractal geometry, in an attempt to reveal correlation between Korean traditional costume formation which have existed for thousands of years to contemporary science of the West. The fractal theory that appeared as the new paradigm of contemporary science displayed similarities with the traditional ideologies of Korea, and the fact that formation principles of fractal appear in the formation of Korean costume, formed based on the Korean ideologies, show magnanimous capacity of the traditional Korean culture. When we look at the concept of fractal, the word fractal refers to the structure in which the shape repeats, where small structure is similar to the whole structure in form in endlessly repeating structure. In other words, 'fractal' means a structure that geometrically untangles the concept of 'self-similarity' which possesses the same shape in parts and in whole, and its major characteristics include 'self-similarity', 'circularity' and 'repeatability'. Korean costumes were formed based on the Han-thoughts, with a structure that possesses parts within the whole and the whole within parts, in accordance with the self-similarity theory of 'fractal'. This study compared studied fractal phenomenon which appear in formation characteristics of Korean traditional costume, which were formed based on the Korean traditional ideology, in other words, Korean costume formation and formation principles of fractal geometry were compared studied.

• Korean Journal of Veterinary Research
• /
• v.41 no.3
• /
• pp.293-298
• /
• 2001

This study was conducted to observe the bone and cartilage formation of mouse fetuses. Mouse litters were sacrificed at pregnant 14th and 18th day and examined for gross skeletal formation using cartilage and bone staining. We identified well developed cartilage formation at the 14th pregnant day in mouse fetus. However mouse fetus at the 14th pregnant day did not show any part of bone formation. At 18th pregnant day, mouse fetus showed well developed body shape and bone and cartilage formation. This results will provide basic information for the evaluation of mouse malfromation and impairment of skeleton formation. Further study will be needed for exact explanation of bone formation from cartilage portion.

• Current Photovoltaic Research
• /
• v.8 no.1
• /
• pp.17-26
• /
• 2020

It is clear that monocrystalline Silicon (Si) ingots are the key raw material for semiconductors devices. In the present industries markets, most of monocrystalline Silicon (Si) ingots are made by Czochralski Process due to their advantages with low production cost and the big crystal diameters in comparison with other manufacturing process such as Float-Zone technique. However, the disadvantage of Czochralski Process is the presence of impurities such as oxygen or carbon from the quartz and graphite crucible which later will resulted in defects and then lowering the efficiency of Si wafer. The heat transfer plays an important role in the formation of Si ingots. However, the heat transfer generates convection in Si molten state which induces the defects in Si crystal. In this study, a crystal growth simulation software was used to optimize the Si crystal growth process. The furnace and system design were modified. The results showed the melt-crystal interface shape can affect the Si crystal growth rate and defect points. In this study, the defect points and desired interface shape were controlled by specific crystal growth rate condition.

• Journal of Ocean Engineering and Technology
• /
• v.28 no.4
• /
• pp.363-369
• /
• 2014

In this paper, a practical controller for a group of USVs is proposed in order to avoid matrix inversion problems in computation. Using nonlinear mapping, a formation composed of nonholonomic agents can be stabilized even when the formation is stationary. Since there is no matrix inversion in computing the control law, the computation complexity can be resolved. A controller for stabilizing the formation errors in the presence of model uncertainty is considered using the Lyapunov redesign method. The asymptotic stability of the formation errors is shown. It is also shown that the proposed controller can be applied to guide a formation to a different shape without modification.

• International Journal of Aeronautical and Space Sciences
• /
• v.10 no.1
• /
• pp.58-66
• /
• 2009

Formation controller for multiple spacecrafts is designed based on a decentralized approach. The objective of the proposed controller is to make each spacecraft fly to the desired waypoints, while keeping the formation shape of multiple spacecrafts. To design the decentralized formation controller, the output feedback linearization technique using error functions for goal convergence and formation keeping is utilized for spacecraft dynamics. The primary contribution of this paper is to proposed optimal controller for formation flying based on the decentralized approach. To design the optimal controller, eigenvalue assignment technique is used. To verify the effectiveness of the proposed controller, numerical simulations are performed for three-dimensional waypoint-passing missions of multiple spacecrafts.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.1565-1568
• /
• 1997

In this paper, a fuzzy based machine-cell formation algorithm for cellular manufacturing is presented. The fuzzy lovic is employed to express the degree of appropriateness when alternative machnies are specified to process a part shape. For machine grouping, the similarity coefficient based approach is used. The algorithm produces efficient machine cells and part families which maximize the similarity values.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10a
• /
• pp.111-111
• /
• 2003

In our experiments using a new apparatus, the drape formation process was found to consist of three stages, seeds generation, their development and the final stabilizing stages. A new parameter R evaluating the shape of the drape was defined in terms of the vertical projection of the drape. Both drape coefficient and R-parameter are expected to be useful for analyzing the formation process of the fabric drape quantitatively.

• The Bulletin of The Korean Astronomical Society
• /
• v.36 no.2
• /
• pp.51.1-51.1
• /
• 2011

We introduce new methods to measure distance in precision using large scale structure formation. The accuracy to determine geometrical factors is enhanced in comparison to the previous method known as BAO. We determine both D_A and H simultaneously as well as structure of growth of density fluctuations and peculiar velocities. Our method is independent of any given prior on large scale structure formation such as the shape of spectra.