• ETRI Journal
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• 제33권5호
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• pp.814-817
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• 2011

In this letter, the distributions of direct current (DC) coefficients for P-frames in H.264/AVC are analyzed, and the distortion model of the Gaussian source under the quantization of the dead-zone plus-uniform threshold quantization with uniform reconstruction quantizer is derived. Experimental results show that the DC coefficients of P-frames are best approximated by the Laplacian distribution and the Gaussian distribution at small quantization step sizes and at large quantization step sizes, respectively.

• 한국초전도ㆍ저온공학회논문지
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• 제2권1호
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• pp.31-34
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• 2000

this paper deals with the initial magnetic field decay for a large scale superconducting magnet e.g. NMR/MRI magnet. The high resolution image can not be obained during the periods of the initial field decay. It is known that all superconducting materials have the property of diamagnetism. This diamagnetism is usually explained with the concept of screening current. We assumed that the existence of the screening currebt. we assumed that the existence of the screening current makes the current distribution in the superconducting wire non-uniform. And the initial magnetic field decay is caused steady current state in the view of its pattern. The initial magnetic field decay is caused by the change of the current distribution between the energizing state and persistent current mode. in this paper the theoretical analysis for the current distributions has been introduced for each state. The experiments have been carried out to verify transport currents in order to veperiments, it small at the higher transport current.

• 한국초전도ㆍ저온공학회논문지
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• 제10권1호
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• pp.32-36
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• 2008

An HTS conductor with parallel HTS tapes is essential for a large power HTS device to flow a large current. One of the most important factor for this conductor is a current distribution. Non-uniform current distribution in parallel tapes makes the critical current of the conductor low and the AC losses high. In this paper we proposed a non-contact method which measured each current in parallel tapes by using an array of Hall sensors. A matrix can be derived from this array for calibration. The current distributions of 4 and 6 parallel tapes were measured.

• 한국전기전자재료학회논문지
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• 제19권3호
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• pp.273-279
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• 2006

High-$T_c$ superconducting (HTSC) power cable is one of the interesting parts in power application using HTSC wire. However, its stacked structure makes the current distribution between conducting layers non-uniform due to difference between self inductances of conducting layers and mutual inductances between two conducting layers, which results in lower current transmission capacity of HTSC power cable. In this paper, the transport current distribution between conducting layers was investigated through the numerical analysis for the equivalent circuit of HTSC power cable with a shield layer, and compared with the case of without a shield layer. The transport current distribution due to the increase of the contact resistance in each layer was improved. However, its magnetization loss increased as the contact resistance increased. It was confirmed from the analysis that the shield layer was contributed to the improvement of the current distribution between conducting layers if the winding direction and the pitch length were properly chosen.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.109-112
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• 2003

Small impedances in the superconducting parallel circuits cause unequal distribution of the currents in the circuits. This results in quenches or losses in some superconducting parts and decrease of total transport current. This paper presents the fabrication and test results of a superconducting multi- interphase transformers (SIPT) for equal current distribution in superconducting parallel circuits. The secondary loop configuration with air core SIPT seems to be the most efficient one for the SFCL. Test results show that the SIPT can effectively make the current distribution uniform in Parallel circuits that have unequal resistances.

• International Journal of Ocean System Engineering
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• 제3권2호
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• pp.90-94
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• 2013

This study represents the recent laboratory results from cathodic protection (CP) system with the use of sacrificial anodes at different environmental conditions (temperature of $10^{\circ}C$ and $40^{\circ}C$). Specimens were slab type with a dimension of $500mm{\times}50mm{\times}100mm$, and concrete cover thickness were 25mm. Zinc mesh and/or bulk type anodes were installed at the center of specimen to confirm the distance that CP system has influences on the specimen to distribute uniform CP current to rebar. Two different kinds of temperature condition were applied to verify the effect of temperature. Experiments were conducted for 60 days, and the distribution of potential and current that supplied from anode to rebar was measured. From the results, CP potential was varied with time, and temperature played an important role in CP potential variations. Current was also changed with time, and current distribution could be improved by installing additional bulk type anode.

• 한국의류학회지
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• 제28권11호
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• pp.1524-1535
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• 2004

The purpose of this study was to develop middle school girl's' school uniform sizing system according to their body types. The data collected with anthropometric measurements from 390 middle school girls aged 12-15 years old was analyzed using t-test, ANOVA, factor analysis and cluster analysis. A new sizing system was developed in accordance with each of the 2 body-type clusters. The analysis of two-way distribution of 'height-bust girth' and 'height-waist girth' was conducted for the girls of the first grade, which is the time when they purchase their school uniforms. The interval of sizing system was defined in consideration with the most efficient distribution of the body sizes utilizing Loss Function. This study also provided Reference-Sizes and Growth-Allowance Measures for each sizing system to help pattern drafting and clothing construction of the uniform manufacturers. The cover ratio of sizing system proposed by this study was higher when compared with that of the National Agency for Technology and Quality and uniform manufacturing companies, Thus, the result of this study is expected to make up the current sizing system of the school uniform.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.760-761
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• 2001

We have studied quench characteristics for current limiting elements of YBCO films in applied fields of 0 - 130 mT. The films were deposited on sapphire substrates and covered by gold top layer. The current limiting element consists of 2 mm wide YBCO stripes connected in series. The electric field - current density (E-J) measurements showed that the presence of applied magnetic fields induces uniform quench distribution for the stripes, otherwise non-uniform quenches were observed. We suggest that suppressing the critical current by increased fields due to fault current effectively forced the stripes of higher Jc(0) to quench, resulting in equalizing quench times.

• Journal of Electrical Engineering and Technology
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• 제11권4호
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• pp.961-968
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• 2016

The non-uniform distribution of contamination on insulator surface has appreciable effects on flashover voltage, and corresponding researches are valuable for the better selection of outdoor insulation. In this paper, two typical types of porcelain and glass insulators which are widely used in ac lines were taken as the research subjects, and their corrections of AC flashover voltage under non-uniform pollution were studied. Besides, their flashover characteristics under different ratio (T/B) of top to bottom surface salt deposit density (SDD) were investigated, including the analysis of flashover voltage, surface pollution layer conductivity and critical leakage current. Test results gave the modified formulas for predicting flashover voltage of the two samples, which can be directly applied in the transmission line design. Also, the analysis delivered that, the basic reason why the flashover voltage increases with the decrease of T/B, is due to the decrease of equivalent surface conductivity of the whole surface and the decrease of critical leakage current. This research will be of certain value in providing references for outdoor insulation selection, as well as in proposing more information for revealing pollution flashover mechanism.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권9호
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• pp.2017-2036
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• 2012

Based on the current solutions to the problem of energy hole, this paper proposed a nonuniform node distribution clustering algorithm, NNDC. Firstly, we divide the network into rings, and then have an analysis and calculation on nodes' energy consumption in each ring of the network when clustering algorithm is applied to collect data. We also put forward a scheme of nonuniform node distribution on the basis of the proportion of nodes' energy consumption in each ring, and change nodes' active/hibernating states under density control mechanism when network coverage is guaranteed. Simulation shows NNDC algorithm can satisfyingly balance nodes' energy consumption and effectively avoid the problem of energy hole.