• Journal of Institute of Control, Robotics and Systems
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• v.17 no.4
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• pp.362-367
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• 2011

The collision-free path of a manipulator should be regenerated in the real time to achieve collision safety when obstacles or humans come into the workspace of the manipulator. A probabilistic roadmap (PRM) method, one of the popular path planning schemes for a manipulator, can find a collision-free path by connecting the start and goal poses through the roadmap constructed by drawing random nodes in the free configuration space. The path planning method based on the configuration space shows robust performance for static environments which can be converted into the off-line processing. However, since this method spends considerable time on converting dynamic obstacles into the configuration space, it is not appropriate for real-time generation of a collision-free path. On the other hand, the method based on the workspace can provide fast response even for dynamic environments because it does not need the conversion into the configuration space. In this paper, we propose an efficient real-time path planning by combining the PRM and the potential field methods to cope with static and dynamic environments. The PRM can generate a collision-free path and the potential field method can determine the configuration of the manipulator. A series of experiments show that the proposed path planning method can provide robust performance for various obstacles.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.854-857
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• 2001

Electron spin resonance (ESR) spectroscopy was used to detect free radicals in irradiated dried vegetables. Dried carrot, mushroom and green onion were irradiated with doses of 0, 1, 3, 5 and 7 kGy at room temperature using a Co-60 irradiator. Free radicals were detected in irradiated dried carrot, green onion and mushroom, while those were not detected in non-irradiated samples. Since concentration of free radicals linearly increased with applied doses (1~7 kGy), highly positive correlation coefficients ($R^2$=0.9747~0.9919) were obtained between irradiation doses and free radical concentrations right after irradiation. Although concentration of free radicals slowly decreased with storage time, the characteristic ESR signals of free radicals slowly decreased with storage time, the characteristic ESR signals of free radical in irradiated samples were observed even after 3 months of storage at room temperature.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.71-72
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• 2022

In the case of free-form buildings, it is difficult to reuse the form for panel production because the shape and size of the interior and exterior panels of the building are different. In general, it is a free-form concrete panel (FCP) production technology using the existing plywood formwork, and the form is produced in a different shape each time and is discarded after only one use. The production of these disposable forms requires enormous resources, including materials, labor and time. Hence, it is necessary to develop innovative forms that can be reused for sustainable FCP construction. In this study, a technology has been developed that combines 3D Plastering Technique (3DPT) to produce FCP. By applying this technology to free-form building projects, the time and cost required for FCP production can be reduced. However, specific studies on the production process for this technology have not been done yet. Therefore, the objective of this study is a basic study of free-form concrete panel production process using 3D plastering technique.

• Korean journal of food and cookery science
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• v.19 no.3
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• pp.271-279
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• 2003

This study was conducted to investigate the sensory and physicochemical properties of beef consomme made with different boiling times (1, 2, 3 and 4hrs). The sensory properties were evaluated with respect to both the acceptability (color, smell, mouth feel, taste, overall acceptability) and intensity characteristics (color, smell, clarify, taste). From the results, the 3hr treatment was most favored for color, smell, mouth feel, taste and overall acceptability, from the sensory evaluation tests. According to a quantitative descriptive analysis of the sensory evaluation for the product, the color, smell and taste gave higher scores with increases in the boiling time. As for the physicochemical characteristics, the pH was increased with increasing boiling time. The reducing sugars, turbidity and viscosity increased with increasing boiling time. The colorimetric lightness values (L) decreased, and redness (a), yellowness(b) and color difference values (ΔE) increased with increasing boiling time. There were 18 free amino acids identified; the alanine, glutamic acid, arginine and leucine contents were high in the free amino acids of the consomme made with different boiling times. There were 3 free sugars identified, glucose, fructose and sucrose. The free sugar contents increased with increasing boiling time. There were changes in the mineral contents of the consomme made with different boiling time; with high K, Na and P contents. The mineral contents increased with increasing, boiling time. The results showed the consomme made by boiling for 3hrs was superior in both its sensory and physicochemical qualities.

• Smart Structures and Systems
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• v.17 no.5
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• pp.753-771
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• 2016

This paper addresses the free and transient responses of a SDOF linear complex stiffness system by making use of the Hilbert transform and the convolution integral. Because the second-order differential equation of motion having the complex stiffness give rise to the conjugate complex eigen values, its time-domain analysis using the standard time integration scheme suffers from the numerical instability and divergence. In order to overcome this problem, the transient response of the linear complex stiffness system is obtained by the convolution integral of a green function which corresponds to the unit-impulse free vibration response of the complex system. The damped free vibration of the complex system is theoretically derived by making use of the state-space formulation and the Hilbert transform. The convolution integral is implemented by piecewise-linearly interpolating the external force and by superimposing the transient responses of discretized piecewise impulse forces. The numerical experiments are carried out to verify the proposed time-domain analysis method, and the correlation between the real and imaginary parts in the free and transient responses is also investigated.

• Korean Journal of Childcare and Education
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• v.17 no.1
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• pp.19-37
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• 2021

Objective: This study aimed to explore the effect of the national preschool curriculum on children's development in Korea, focusing on teachers' daily practice. By comparing the effect of the teachers' curriculum practice to that of quantitatively measured free play, it tried to add practical implications beyond the statistical significance. Methods: Participants were 512 three-year-old children who participated in the Panel Study of Korean Children and their teachers. National curriculum practice and free play time at the age of three was put in the hierarchical linear regression models to discover children's developmental outcomes at the age of four, in domains of language, cognitive development, and social development. Results: Results demonstrated the significant positive influence of national curriculum practice on every domain of developmental outcomes. However, no facilitative influence of free play time was observed. Conclusion/Implications: The importance of teachers' practice of the national curriculum was emphasized. It was implied that the quantity of free play time itself did not assure the sound development of children. Policy implications were discussed regarding teacher practice and education.

• Communications for Statistical Applications and Methods
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• v.18 no.6
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• pp.697-705
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• 2011

This paper proposes an optimal replacement policy following the expiration of a free renewing replacement-non-renewing minimal repair warranty. To do so, the free renewing replacement-non-renewing minimal repair warranty is defined and then the maintenance model following the expiration of free renewing replacement-non-renewing minimal repair warranty from the user's point of view is studied. As the criteria to determine the optimality of the maintenance policy, we consider the expected cost rate per unit time from the user's perspective. We derive the expressions for the expected cycle length and the expected total cost to obtain the expected cost rate per unit time. Finally, the numerical examples are presented for illustrative purposes.

• Journal of Microbiology
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• v.42 no.2
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• pp.133-138
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• 2004

This study was aimed to determine the accumulation of free fatty acid by mesophilic lactic acid bac-teria (Lactococcus lactis subsp. lactis 1471, Lactococcus lactis subsp. cremoris 1000 and Lactobacillus casei 111) in cold-stored milk. According to the results, all cold-stored milks had higher acid degree val-ues than those of fresh milk. This phenomenon showed that a slight increase occurred in the accumulation of free fatty acids as a result of spontaneous lipolysis during cold storage. All lactic acid bacteria showed good performance in production of titratable acidity, which increased during fermentation of the milk (fresh and stored milks). Moreover, as the storage time was prolonged, more free fatty acid accumulation was obtained from the fermentation of the cold-stored milk by the investigated lactic acid bacteria. The control milk, which was without lactic acid bacteria, showed no change in the accumulation of free fatty acid during fermentation. From this result, it can be suggested that longer cold-storage time can induce higher free fatty acid accumulation in milk by lactic acid bacteria.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.12-13
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• 2013

Free-form building is increasing because of request that an order to raise the value and request of the local residents and the government trying to own iconic and beautiful buildings. In addition, the installation and production of free-form concrete segment are now available because of development of construction technology, such as the development of materials and equipment. However, the production of free-form concrete segment requires a lot of time and manpower than shaping. In particular, resources of the mold for the production of free-from segment will be invested excessively because mold can not be recycled. Thus, the problems of increased costs, construction periods and loss of productivity occur. To solve these problems, this study proposes a technique of making the mold of for variable within a short time. Technique proposed in this study can be recycled die and will realize fast and accurate free-form concrete segment.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.2
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• pp.15-27
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• 2022

The paper addresses the importance of redesigning strategies for resilient and sustainable regional economic development - by applying strategic approaches to free economic zones for the digital economy. The purpose of the paper is to provide a broad comparative perspective on developed versus developing country efforts to use free economic zone programs to enhance various economic and social objectives. First, the paper introduces the chronicle experiences of free economic zone programs in South Korea and mainland China - developed versus developing economies. The main results of the analysis indicate that (1) achieving the goals and objectives of free economic zones is challenging over time; (2) trying to upgrade the technical component, develop knowledge-based and eco-friendly new industries, or value-added to the economy through free economic zone policies is even challenging; and (3) incentives and other program-specific variables are highly context-specific and not structurally correlated with free economic zone performance. In addition, the paper shows that the initial conception of the role of free economic zones has undergone significant change as individual countries have tried to enhance the contributions and avoid damages from incorporating free economic zones into their development strategy respectively, over time.