• Journal of Institute of Control, Robotics and Systems
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• v.19 no.8
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• pp.676-681
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• 2013

For underwater vehicles, the use of sensors such as cameras and laser scanners is limited by the difference in environment compared to robots designed to work on dry land. In underwater environments, if use is made of sound signals, valuable information can be obtained. The most important application is the localization of underwater sound sources. The estimated location of a sound source can be used to control underwater robots or submarines. Thus, the purpose of this research is to estimate the source's direction and location in a noisy underwater environment. The direction of the sound source is obtained using two hydrophones. Furthermore, if we assume that the robot or sound source is moving, the location of the sound source is estimated using more than two estimated directions. The feasibility of the developed algorithm is examined by experiments in a water tank and in the ocean.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.12
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• pp.1173-1177
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• 2015

This paper deals with estimating the acid concentration of pickling process using the Volterra inputs. To estimate the acid concentration, the whole pickling process is represented by the grey box model consists of the white box dealing with known system and the black box dealing with unknown system. Because there is a possibility of nonlinear term in the unknown system, the Volterra series are used to estimate the acid concentration. For the white box modeling, the acid tank solution level and concentration equations are used, and for the black box modeling, the acid concentration is estimated using the Volterra Least Mean Squares (LMS) algorithm and Least Squares (LS) algorithm. The LMS algorithm has the advantage of the simple structure and the low computation, and the LS algorithm has the advantage of lowest error. The simulation results compared to the measured data are included.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.232-232
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• 2006

SiC single crystal Ingots were prepared onto different seed material using sublimation PVT techniques and then their crystal quality was systematically compared. In this study, the conventional SiC seed material and the new SiC seed material with an inserted SiC epitaxial layer on a seed surface were used as a seed for SiC bulk growth. The inserted epitaxial layer was grown by a sublimation epitaxy method called the CST with a low growth rate of $2{\mu}m/h$ N-type 2"-SIC single crystals exhibiting the polytype of 6H-SiC were successfully fabricated and carrier concentration levels of below $10^{17}/cm^3$ were determined from the absorption spectrum and Hall measurements. The slightly higher growth rate and carrier concentration were obtained in SiC single crystal Ingot grown on new SiC Seed materials with the inserted epitaxial layer on the seed surface, maintaining the high quality.

• International Journal of Costume and Fashion
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• v.10 no.2
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• pp.37-49
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• 2010

The Samguk-yusa(三國遺事) is one of the two classics of Korean ancient history together with the Samguk-sagi(三國史記); however there has not been any positive attempt to analyse clothing culture centering on the Samguk-yusa until now. Thereupon, this study aims to find the records related to fabrics, color and fashion appearing in the Samguk-yusa, and to analyse the fashion culture of the three kingdoms projected in the Samguk-yusa, referring to the Samguk-sagi and ancient Chinese reference books. According to the records in the book, the fabrics used for clothing of those days included Jikgeum-wimun(織錦爲紋), Geum(錦), Chaebaek(彩帛), Osaek-geumchae(五色錦彩), Geumbaek(錦帛), Geumsam(錦衫), Ma(麻), Neung(綾), Geum-su-neung-ra(錦繡綾羅), Poh(布), Daecho, Bira-geumjeom(緋羅金點), Gyeon(絹). Japchoe(雜綵), Robtyeom(羅緋染). Chimilpoh(緻密布), Gi(綺) and Whan(紈), and they had colors such as brown black(緇), black(黑), purple(紫), yellow(黃), blue(碧), clear white(素), white(白), five colors(五色). There is substantial amoung of report on Buddhism, and the terms used for Buddhist clothing included Beobeui(法衣), Nabeui(衲衣), Bangpoh(方袍), Gasa(袈裟) and Yueui(由衣). It is also ascertained that Gasa had a variety of Bira-geumjeom-gasa(緋羅點袈裟), Manap-gasa(摩納袈裟) and Geumra-gasa(金羅袈裟).

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.5
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• pp.305-312
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• 2016

Modern embedded systems are typically operated by the rechargeable batteries in our daily life. Since charge of batteries is considered as an time consuming task, there have been extensive efforts to manage the charge time from the perspective of materials, circuits, and systems. Estimation of battery charge time is one of the essential information to design the charge circuitry. A compact macro model for the constant-current and constant-voltage charge protocol was recently introduced, which gives us a quick estimation of charge time with similar shape to the famous Peukert's law for discharge time estimation. The CC-CV charging protocol is widely used for Lithium-based batteries and Lead-acid batteries. In this paper, we characterize the lead-acid battery by measurement to extract the model coefficients, which was not covered by the previous studies. By our proposed model, the key coefficient Kcc results in 1.18-1.31, which is little bit higher than that of Lithium batteries. The accuracy of our model is within the range of ${\pm}10%$ error, which is compatible with the other studies such as Peukert's law.

• Journal for History of Mathematics
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• v.28 no.2
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• pp.65-72
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• 2015

The Joseon dynasty (1392-1910) is basically an agricultural country and therefore, the main source of her national revenue is the farmland tax. Thus the farmland tax system becomes the most important state affair. The 4th king Sejong establishes an office for a new law of the tax in 1443 and adopts the farmland tax system in 1444 which is legalized in Gyeongguk Daejeon (1469), the complete code of law of the dynasty. The law was amended in the 19th king Sukjong era. Jo Tae-gu mentioned the new system in his book Juseo Gwan-gyeon (1718) which is also included in Sok Daejeon (1744). Investigating the mathematical structures of the two systems, we show that the systems involve various aspects of mathematics and that the systems are the most precise applications of mathematics in the Joseon dynasty.

• Journal of architectural history
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• v.19 no.3
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• pp.71-87
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• 2010

Sewon was a new type of private academy established by a class landed Confucian scholars known as sarim. During Joseon dynasty, sewon had dual functions as a shrine and a place of learning. The site plan of seowon appeared mainly two types of site plan according to the indications of the age and school. This paper was done to analyze the site plan and construction history of Simgok seowon with historical materials and excavation investigation result. Simgok seowon is dedicated to Jo Gwang-jo(1482~1519). This private Confucian academy was founded in 1605 as a small shrine, which was destroyed in 1636. Thereafter, when the shrine received a royal warrant naming as Simgok seowon in 1650, the new site for the seowon was chosen, which is currently located in Gyeonggi-do Yongin-si Sanghyeon-ri 203. Since then, buildings of Simgok seowon was constructed and repaired couple of times. Through the investigation, it was found that the site plan of Simgok seowon was originally a type of 'jeonjaehudang', that is, dormitory building between the lecture hall and the outer gate, or dormitory building is in front and lecture hall is in behind.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.198.2-198.2
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• 2014

We investigated change of the electronic structure, chemical states and elements ratio in graphene film by using photoelectron spectroscopy (PES). The graphene electrode has attracted considerable interest due to its possible applications in flexible organic light emitting diodes (F-OLEDs). However, to use the graphene for OLEDs, sufficient increase of work function is required, that is related with hole injection barrier. Plasma treatment is one of the most widely used method in OLEDs to increase the work function of the anode such as indium tin oxide (ITO). In this work, we used the plasma treatment, which is generated by various gas types such as O2, and Ar to increase the work function of the graphene film. From these results, we discuss the relation among the change of work function, plasma power, plasma treatment time and gas types.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.1
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• pp.68-75
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• 1998

The Intelligent Cruise Control system, ICC, is a driver assisting system for controlling relative speed and distance between two vehicles in the same lane. The ICC may be considered as an extension of a traditional cruise control, not only keeping a fixed speed of the vehicle, but correcting the speed also to that of a slower one ahead. This paper presents a real-time self-tuning fuzzy control algorithm to develop ICC. The self-tuning fuzzy control law is adopted to reduce the effects of nonlinearities of the vehicle and various road environments. In the self-tuning algorithm an interior penalty method is applied to preserve the inherent order of membership functions and is modified as an on-line algorithm for real time application. Via simulations, the performance of the suggested control algorithm is compared with a PID and a fuzzy control without self-tuning. The suggested control algorithm is implemented on PRV III and the results of the test driving on a local road are given.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.5
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• pp.646-653
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• 1998

Because there is a great concern' today about the damaging effect of chronic exposure to sunlight the use of sunscreen providing the photoprotection effect against ultraviolet (UV) was widely increased. As a result of common use of level of photosynthetic Vit. D3 in human skin decreased these days. In our experiment the animals covered with fabrics with 50% (fabric B) and 100% (fabric A) protection rate against ultraviolet B (UVB) were used to measure serum 25(OH)D3, ALP, total clacium and phosphorus. Vitamin D deficiency diet group had no effect on concentration of serum phosphorus. But the concentrations of serum 25(OH)D9 and total calcium were more decreased in vitamin D deficiency diet rats than in normal diet rats. Alkaline phosphatase activity in sunlight irradiated groups covered with 50% (fabric B) and 100% (fabric A) WB protection fabrics was more significantly decreased than vitamin D deficiency diet group. In conclusion, sunlight irradiateted groups were compared to effective to protect born disease due to the Vit. D deficeincy group.