• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.4
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• pp.479-486
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• 1999

In this paper the system performance degradation resulting from nonlinear transmitter power amplifier which is essential to increase the efficiency is analyzed in a forward link CDMA system. The power amplifier is modeled by power series model which includes only odd-order terms. The effects of power amplifier's nonlinearity such as intersymbol interference, phase distortion on the RF system performance were visualized by examining the distorted time domain waveforms, signal vector constellation. And through the investigation of the power spectrum density of the transmitted signal, spectral regrowth or sideband regrowth which is result from amplitude distortion can be seen. All these characteristics result in BER performance degradation due to other user interferences and intersymbol interference. The analysis technique described here applies not only to power amplifier but also to any other nonlinear components such as mixers and switches. Also the effects of adjacent channel interference and supurious emission can be analysed between different systems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.10
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• pp.1036-1043
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• 2003

In this paper, novel lumped equivalent circuits for a conventional parallel directional coupler are proposed. This novel equivalent circuits only have self inductance and self capacitance, so we can design exact lumped equivalent circuit. The equivalent circuit and design formula for the presented lumped element coupler is derived based on the even- and odd-mode properties of a parallel-coupled line. By using the derived design formula, we have designed the 3 dB and 10 dB lumped element directional couplers at the center frequency of 100 MHz and 2 GHz, respectively a chip type directional coupler has been designed with multilayer configurations by employing commercial EM simulator. Designed chip-type directional couplers have a 3 dB-coupling value at the center frequency of 2 GHz and fabricated lumped directional coupler on fr4 organic substrate has a 3 dB, 10 dB-coupling values at the center frequency of 100 MHz. Excellent agreements between simulation results and measurement results on the designed directional couplers show the validity of this paper. Furthermore, in order to adapt to multi-layer process such as Low Temperature Cofired Ceramic (LTCC), chip-type lumped element couplers have been designed by using this method.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7507-7512
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• 2015

Background: In the low incoming country Bangladesh, breast cancer is second most common neoplasm and is increasing at an alarming rate among females. Lack of awareness and illiteracy are contributory factors for late presentation and therefore mortality. Purpose: To examine associations of different factors with breast cancer mortality and to raise awareness among the women of society in Bangladesh. Materials and Methods: This descriptive case-control study was conducted on 160 participants from April 2011 till July 2014. Through a valid questionnaire covering personal and family history, data were collected by face to face interview. For analyzing correlations among factors with breast cancer data, binary logistic regression, Pearson's ${\chi}^2$-value, odd ratios and p-value tests were conducted with SPSS version 20. Results: The mean age of the patients was 43.0 ($SD={\pm}11.12$). In ascending order the leading significant factors were hormone therapy (p<0.0000, OR=4.897), abortion (p<0.0001, OR=3.452), early start menarche (p<0.0002, OR=3.500), family history (p<0.0022, OR=3.235), and late menopause (p<0.0093, OR=3.674) with both ${\chi}^2$ test and logistic regression analyses. Non-significant factors were cancer experience, fatty food habits, marital status and taking alcohol. Conclusions: Regarding the investigation of this study, significant and insignificant factor's correlation visualization with breast cancer will be helpful to increase awareness among Bangladeshi women as well as all over the world.

• Biomedical Science Letters
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• v.7 no.3
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• pp.117-125
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• 2001

This study was performed in order to evaluate the risk factors for nosocomial urinary tract infection and the frequencies of organisms isolated, and to provide the epidemiologic and basic data of hospital acquired urinary tract infection in intensive care unit. A prospective analysis was performed with 1,235 urine samples following urinary bladder catheterization in 569 patients, who had no evidence of UTI at the time of catheter insertion, admitted to intensive care unit in Pusan P hospital between June 1997 and May 1998. To identify risk factors for UTI, clinical characteristics of infected patients were analyzed. We analyzed these data by percentage, chi-square and odd ratio. Obtained results were as follows: A total of 569 patients (male 341 and female 228) were an average age of 50.8 years and catheterization of 8.04 days. Incidence of UTI was 16.1% (199/1,235) and The risk factors of UTI were duration of catheterization over 7 days, no use of systemic antibiotics, summer and female, and During the first 7 days these risk factors were no use of systemic antibiotics, summer, place of first catheter insertion (ICU) and type of intensive care unit (NSICU). A total of 220 the isolated strains were Gram negative rod 83 (37.7%), yeast like fungi 74 (33.6%) and Gram positive cocci 63 (28.6%). The common organisms isolated were Enterococcus faecalis 23 (10.5%), Serratia marcescens 19 (8.6%), Pseudomonu spp.17 (7.7%), E. ooh 16 (7.3%), Staphylococcus epidemidis 11 (5.0%) mdklebsiellapneumoniae 8 (3.6%). Therefore, in these results 199 of 569 (35%) patients in ICU with indwelling urinary catheter developed UTI. The risk factors for UTI are prolonged duration of catheterization, no use of systemic antibiotics, summer, and female.

• Journal of Broadcast Engineering
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• v.4 no.2
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• pp.134-143
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• 1999

In this paper, in order to implement the IDWT(inverse discrete wavelet transform) with relatively low complexity, we propose a VLSI architecture for odd-tap linear-phase IDWT filters. By considering the symmetric property of the linear phase filter, the input is added to the one located at symmetrical position of the filter before filtering. Then. we rearrange the delay line of the filter in a U-shaped fashion. requiring no global interconnection between the components. The proposed architecture for the IDWT filter consists of delay units. operator units, adder units. and postprocessor unit. Since each units are configured regularly and interconnected locally. the proposed architecture can accommodate arbitrary linear phase IDWTs by simply adding/removing the corresponding units. The M -level IDWT can be implemented by interconnecting the proposed architecture in a cascaded or semi-recursive form. It is expected that the proposed architecture for the IDWT can be effectively employed in the related area including MPEG-4, since the proposed architecture is less complex than the conventional architectures.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.5
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• pp.175-182
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• 2013

This paper proposes a readability enhancement filter for Patterned Retarder (PR) display. In general, when some texts in stereoscopic images are shown on PR display, their readability tends to be lowered. In order to overcome this problem, we present a readability enhancement algorithm which consists of readability filtering stage and post-processing stage for specific characters. First, each input stereo image is divided into an odd line image and an even line image. Then, they are independently up-scaled vertically by using Lanczos filter. Next, two up-scaled line images are averaged considering vertical phase difference. In post-processing stage, two specific characters which are normally difficult to read on PR display are detected, and they are filtered for additional readability enhancement. Here, this additional filtering is based on a specific brightness adjustment, and is applied only for two characters. The experiment results show that the proposed method achieves significant improvement in terms of readability in comparison with the previous scheme.

• The Transactions of the Korea Information Processing Society
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• v.7 no.1
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• pp.296-305
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• 2000

In this paper, we propose the method of embedding the encrypted digital watermark in quantization coefficient when we encode the image data in the process of JPEC. The proposed method is as following. After a DCT coefficient of each block is quantized, we arrange the quantization coefficient as on dimension with a zigzag scan and replace each block. By applying even-odd feature of frequency of the encrypted watermark to a quantization coefficient of some fixed domain of replaced each block and embedding it, we obtain the compressed image data by encoding after placing it in the order prior to replacement. The advantages of the proposed method here are as follows: We can embed many information keeping a secret as much as possible by using the algorithm of block replacement. We can control the amount of embedding of each use, as we embed the encrypted information by selecting some fixed domain of a quantization coefficient, we can fix the embedding data regardless of the image and the value of quantization. We verified the results by experiments and analyzed the efficiency of them in comparison with the former study.

• Journal of the Korean Magnetics Society
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• v.5 no.6
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• pp.968-973
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• 1995

In order to investigate the annealing effect for RF magnetron sputtered $Ni_{83}Fe_{17}$ thin films, we have studied the spin wave rehaviors by FMR after annealing the samples at $135^{\circ}C,\;225^{\circ}C$ in air and at $160^{\circ}C,\;220^{\circ}C,\;330^{\circ}C,\;390^{\circ}C\;and\;420^{\circ}C$ in argon gas for one hour respectively. In FMR spectra for the films annealed in argon gas and the assputtered film at perpendicular resonance, only odd numrer spin waves are observed. But even numrer spin waves are observed for the film annealed in air at $225^{\circ}C$ recause of the large difference retween both surface magnetic anisotropy. In the case of the sample annealed at $420^{\circ}C$ in argon gas, the spin waves are shifted toward high field, can due to the increase of saturation magnetization during annealing. The spacings retween the spin wave resonance fields are narrowed rapidly, this is thought that the magnetic homogeneity increased in the film after annealing at high temperature.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.8
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• pp.1095-1101
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• 2020

Vessels or aircraft should be loaded with containers or cargo to maintain weight balance in order to be stable when navigating the route. The container loading algorithm is known as the NP problem and several heuristic methods have been studied. Containers can be characterized by the uniform volume and weight, which makes it easier to find an optimal loading method. In this paper, we propose an algorithm for weight balance when the volume and weight of an object are uniform. It is assumed that the loading space has a special structure of m * n mesh (where m and n are both odd). In this case, we designed a greedy algorithm and proved that the algorithm is optimal in that it can always find a loading position that maintains a weight balance regardless of the number of objects. Our algorithm can be used in many engineering problems, such as loading algorithms and load balancing problems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.7
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• pp.2610-2630
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• 2021

The aim of this paper is to propose the alternative algorithm to finish the process in public key cryptography. In general, the proposed method can be selected to finish both of modular exponentiation and point multiplication. Although this method is not the best method in all cases, it may be the most efficient method when the condition responds well to this approach. Assuming that the binary system of the exponent or the multiplier is considered and it is divided into groups, the binary system is in excellent condition when the number of groups is small. Each group is generated from a number of 0 that is adjacent to each other. The main idea behind the proposed method is to convert the exponent or the multiplier as the subtraction between two integers. For these integers, it is impossible that the bit which is equal to 1 will be assigned in the same position. The experiment is split into two sections. The first section is an experiment to examine the modular exponentiation. The results demonstrate that the cost of completing the modular multiplication is decreased if the number of groups is very small. In tables 7 - 9, four modular multiplications are required when there is one group, although number of bits which are equal to 0 in each table is different. The second component is the experiment to examine the point multiplication process in Elliptic Curves Cryptography. The findings demonstrate that if the number of groups is small, the costs to compute point additions are low. In tables 10 - 12, assigning one group is appeared, number of point addition is one when the multiplier of a point is an even number. However, three-point additions are required when the multiplier is an odd number. As a result, the proposed method is an alternative way that should be used when the number of groups is minimal in order to save the costs.