• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.9
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• pp.873-882
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• 2013

The effective way of estimation and analysis of EMI(Electromagnetic Interference) in Wireless Power Transfer System operating at 13.56 MHz is proposed. In this paper methodology of driving magnetic field strength and electric loop current of two antennas which are in free space and on PEC plane using image theory and duality is proposed. Perfect electric conductor(PEC) is planar, infinite in extent, and perfectly conducting plane. And we will refer it as PEC plane. A equivalent circuit model is used to analyze. Using this theoretical analysis, we can derive maximum magnetic field strength of the far-field region numerically using measured data of near-field maximum magnetic field strength. The experimental results using commercial numerical simulation tool are in agreement with the theoretical results. Also, using the derivation of maximum magnetic field strength in the far-field region, we can easily estimate the maximum allowable power dissipation that meets EMI regulations.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.4
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• pp.473-477
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• 2015

In this paper, a commercial phosphorescent white light-emitting diode (WLED) visible light communication (VLC) system with an equalization circuit to achieve the high modulation bandwidth was designed and demonstrated. An analytical method to examine the performance of the equalizer was carried out using a general circuit-simulator, PSpice. The equalization circuit was composed of two passive filters with resisters and a capacitor and an active filter with an op-amp. Utilizing our post-equalization technology, the ~3.5 MHz bandwidth of phosphor WLED could be extended to ~25 MHz without using an optical blue-filter. In this VLC system with a single round-type WLED and a single PIN photo-diode, ASK data transmission up to 35 Mbps at a 1m free space distance was obtained. The resulting bit-error-rate was $7.6{\times}10^{-4}$, which is less than the forward error correction (FEC) limit of $3.8{\times}10^{-3}$.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.2
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• pp.213-219
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• 2013

Recently, with the rapid advancement in information and communication technology, indoor location-based services(LBSs) that require precise position tracking have been actively studied with outdoor-LBS using GPS. However, in case of a ship which consists of steel structure, it is difficult to measure a precise localization due to significant ranging error by the diffraction and refraction of radio waves. In order to reduce location measurement errors that occur in these indoor environments, this paper presents distance compensation algorithms that are suitable for a narrow passage such as ship corridors without any additional sensors by using UWB(Ultra-wide-band), which is robust to multi-path and has an error in the range of a few centimeters in free space. These improvement methods are that Pythagorean theory and adjacent node technique are used to solve the distance error due to the node deployment and distance variation analysis technique is applied to reduce the ranging errors which are significantly fluctuated in the corner section. The experimental results show that the number of nodes and the distance error are reduced to 66% and 57.41%, respectively, compared with conventional CSS(Chirp spread spectrum) method.

• Journal of the Korea Fashion and Costume Design Association
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• v.16 no.4
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• pp.15-25
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• 2014

The purpose of this study is to promote the artistic value and formative aesthetic of clothes in daily life through a proposal of inventive fashion design by utilizing Depaysement of Surrealism, which visualizes a more realistically and more specifically than fact in illogical and unfamiliar situation, Focused on details of Korean traditional costume silhouette. The method of this study, the literature and existing researches related to Depaysement were analyzed through theoretical review for establish the expressive techniques of Depaysement expressed in contemporary fashion. Conclusions from this study are as follows: first, the expressive techniques of Depaysement are derived that are 'change of scale', 'change of materials', 'combination of heterogeneous objects', 'arrangement of object in a strange space', 'overlapped object', 'paradoxical image', 'variable awareness of boundary.' Second, expressive techniques of Depaysement present a new methodology which can express an irrational thinking, which is not controled by reason such as unconsciousness, dream, and fantasy etc, in a way that is easier and more realistic rather than thinking centered on an art which is ruled by consciousness. Third, unique and free-form fashion design, which destroys a general idea, was could develop by using abundant materials and composing items borrowed various silhouette for expressive the techniques of Depaysement. Forth, Through this study, the concept of Korean fashion design, that was limited by the standard form when we approach Korean fashion design as identity of social culture, ideology of reflection and expression, object of commercial expression, was could think outside of the box.

• Transactions on Electrical and Electronic Materials
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• v.3 no.1
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• pp.30-37
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• 2002

A focusing grating coupler (FGC) was not fabricated by the 'Continuous Path Control'writing strategy but by an electron-beam lithography system of more general exposure mode, which matches not only the address grid with the grating period but also an integer multiple of the address grid resolution (5 nm). To more simplify the fabrication, we are able to reduce a process step without large decrease of pattern quality by excluding a conducting material or layer such as metal (Al, Cr, Au), which are deposited on top or bottom of an e-beam resist to prevent charge build-up during e-beam exposure. A grating pitch period and an aperture feature size of the FGC designed and fabricated by e-beam lithography and reactive ion etching were ranged over 384.3 nm to 448.2 nm, and 0.5 $\times$ 0.5 mm$^2$area, respectively. This fabrication method presented will reduce processing time and improve the grating quality by means of a consideration of the address grid resolution, grating direction, pitch size and shapes when exposing. Here our investigations concentrate on the design and efficient fabrication results of the FGC for coupling from slab waveguide to a spot in free space.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.1
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• pp.9-14
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• 2014

The path loss data was re-calculated according to the distance between the base station and a mobile station in the mobile telecommunications network. In this paper, the averaged path loss data was plotted with the conventional path loss models(free space, plane earth, Hata model ${\ldots}$). The standard deviations for the 2 Km, 1 Km, 0.5 Km-interval averaged path loss were 2.29 dB, 3.39 dB, 4.75 dB, respectively. Additionally, the derivative values for the 2 Km, 1 Km, 0.5 Km-interval averaged path loss were evaluated to find the positions with more than 1 times or 2times of the standard deviation. The situations with the sharply fluctuated path loss were calculated to 5 positions in the 2 Km interval, to 7 positions in the 1 Km interval, to 19 positions in the 0.5 Km interval, respectively. And, the exact distances between the base station and a mobile station were found with the sharply fluctuated path loss.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.4
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• pp.2221-2221
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• 2002

The first laboratory culture of host-parasite system of Prorocentrum minimum- Amoebophrya sp. was established by single cell isolation method. Here, we report the life cycle stages of the parasitic dinoflagellate. Amoebophrya sp. of the red tide dinoflagellate P. minimum as observed by light and epifluorescence microscopy. Infections developed inside the nucleus of P. minimum. The trophont developed to occupy almost all the intracellular space of the host at its late stage. The fully developed trophont finally ruptured through the host cell. “Vermiform stage”, the free-swimming extracellular lift cycle stage is followed by another stage for the sudden release of many individual dinospores. Our laboratory strain of the host-parasite system for P. minimum, a causative species fur the huge red tides in spring and summer in Korean coastal waters, could be a useful living material for the in situ biological control of harmful algal blooms.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.7 no.4
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• pp.221-225
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• 2002

The first laboratory culture of host-parasite system of Prorocentrum minimum- Amoebophrya sp. was established by single cell isolation method. Here, we report the life cycle stages of the parasitic dinoflagellate. Amoebophrya sp. of the red tide dinoflagellate P. minimum as observed by light and epifluorescence microscopy. Infections developed inside the nucleus of P. minimum. The trophont developed to occupy almost all the intracellular space of the host at its late stage. The fully developed trophont finally ruptured through the host cell. “Vermiform stage”, the free-swimming extracellular lift cycle stage is followed by another stage for the sudden release of many individual dinospores. Our laboratory strain of the host-parasite system for P. minimum, a causative species fur the huge red tides in spring and summer in Korean coastal waters, could be a useful living material for the in situ biological control of harmful algal blooms.

• Journal of Advanced Navigation Technology
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• v.19 no.2
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• pp.168-174
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• 2015

Wireless communication system for firefighters has an important role as the last communication method between the commander and the firefighters in disaster sites like fire. But the operation of Gyeongnam wireless communication system is installed, and maintained and controlled without criteria for the selection of a transmitting station and the analysis of propagation environment because of the lack of budget and the absence of professional personnel. To improve the performance of the radio station, this paper theoretically calculated free space loss of UHF 400 MHz band used by all firefighters in Gyeongnam and diffractions caused by single and multiple obstacles and computed the error after comparing the results of the actual measurement to those of simulation with FRAS operated by KFL. In the results, Deygout model was the most consistent with the actual measurement for 400MHz band in Kimhae site.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.6
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• pp.1104-1114
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• 2007

Digital video compression technique has played an important role that enables efficient transmission and storage of multimedia data where bandwidth and storage space are limited. The new video coding standard, H.264/AVC, developed by Joint Video Team(JVT) significantly outperforms previous standards in compression performance. Especially, variable length code(VLC) plays a crucial pun in video and image compression applications. H.264/AVC standard adopted Context-based Adaptive Variable Length Coding(CAVLC) as the entropy coding method. CAVLC of H.264/AVC requires a large number of the memory accesses. This is a serious problem for applications such as DMB and video phone service because of the considerable amount of power that is consumed in accessing the memory. In order to overcome this problem in this paper, we propose a variable length technique that implements memory-free coeff_token, level, and run_before decoding based on arithmetic operations and using only 70% of the required memory at total_zero variable length decoding.