• The Journal of Korean Institute of Communications and Information Sciences
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• 제30권6A호
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• pp.465-473
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• 2005

In this paper, the reduction scheme of Interchannel Interference(ICI) caused by the phase noise in Orthogonal Frequency Division Multiplexing(OFDM) systems for archiving high data rates is proposed. The performance of conventional common phase error(CPE) compensation method is degraded by the phase noise with wide 3dB bandwidth in OFDM systems width a higher-order constellation. After estimating dominant ICI coefficients using pilot subcarriers and data subcarriers adjacent to pilot subcarriers, the proposed scheme compensates OFDM signals distorted by the phase noise using estimated coefficients in the time or frequency domain. Also, in order to determine the length of dominant ICI coefficients effectively, the estimation method of the 3dB bandwidth of the phase noise is proposed. The proposed phase noise reduction method is shown to improve the Bit Error Ratio(BER) performance compared with the conventional CPE compensation.

• Journal of Navigation and Port Research
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• 제31권8호
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• pp.671-674
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• 2007

In this paper, the EM wave absorber was designed and fabricated for ETC system, because ETC system has some problems including signal error and system-to-system interference. We fabricated some samples in different composition ratio of MnZn-ferrite, Carbon and CPE, confirmed that optimum composition ratio of Mn2n-ferrite, Carbon, CPE was 40 : 15 : 45 wt%. Complex relative permittivity and complex relative permeability was calculated by the measured data. And absorption abilities were simulated according to different thickness of the EM wave absorbers using complex relative permittivity and permeability. The EM wave absorber was fabricated based on simulated data Simulated and measured values agree well. As a result, the developed EM wave absorber has a thickness of 3.38 mm and absorption ability over 20 dB at 5.8 GHz.

• Journal of Navigation and Port Research
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• 제32권5호
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• pp.349-353
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• 2008

In this paper, the EM wave absorber was designed and fabricated for preventing Reader Interference of RFID communication system in UHF band We fabricated several samples in different composition ratios of Amorphous and CPE(Chlorinated Polyethylene). Absorption abilities were simulated in accordance with different thicknesses of the prepared absorbers and changed complex relative permittivity and permeability due to composition ratio. The mixing ratio of Amorphous and CPE was searched as 80 : 20 wt.% by experiments and simulation. Then the EM wave absorber was fabricated and tested using the simulated data. As a result, the developed EM wave absorber has a thickness of 4 mm and absorption ability was over 20 dB in frequency range of $860\;MHz{\sim}960\;MHz$. Therefore, it was confirmed that the developed absorber can be used for suppressing RFID reader interference in UHF band.

• Journal of the Institute of Electronics Engineers of Korea TC
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• 제43권9호
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• pp.1-5
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• 2006

In this paper, the EM wave absorber was designed and fabricated for the collision-avoidance radar as a basic sensor of ITS(Intelligence Transport System), because radar system has some problems including false image and system-to-system interference. We fabricated some samples in different composition ratio of Carbon and CPE, and defined that optimum composition ratio of Carbon and CPE was 20:80 wt%. The complex relative permittivity was calculated by the measured data. And absorption abilities were simulated according to different thickness of the EM wave absorbers using the complex relative permittivity. The EM wave absorber was manufactured based on the simulated design. Simulated and measured results agree very well. As a result, the developed EM wave absorber with the thickness of 2 mm has absorption ability over 20 dB in frequency range of $76{\sim}77$ GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제19권2호
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• pp.244-249
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• 2008

In this paper, we designed and fabricated the EM wave absorber consists of Sendust and Mn-Zn ferrite for suppressing EM wave noise from PCB in ISM(Industrial, Scientific and Medical) band of 2.4 GHz. We fabricated several samples in different ratios of Sendust to Mn-Zn ferrite with CPE(Chlorinated Ploy-ethylene) as binder and confirmed that optimum composition ratio of absorbing materials was Sendust. Mn-Zn ferrite : CPE=70:5:20 wt.%. The absorbing abilities were simulated according to different thickness of EM wave absorber as the function of material constants calculated by measured data. Measured absorption ability was analyzed and compared with simulated result. The simulated result agree well with the measured ones. As a result, the developed EM wave absorber with thickness of 0.85 mm has absorption ability of 5.4 dB at 2.4 GHz and over 3 dB in frequency rage of 1.4$\sim$4.1 GHz.

• Journal of electromagnetic engineering and science
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• 제8권3호
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• pp.110-113
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• 2008

In this paper, we designed and fabricated an electromagnetic(EM) wave absorber for automotive radar in cars using $TiO_2$ as a dielectric material and chlorinated polyethylene(CPE) as a binder. First of all, we confirmed that the optimum composition ratio of $TiO_2$ was about 70 wt.%. The complex relative permittivity of a sample containing $TiO_2$: CPE=70:30 wt.% was calculated from S-parameter. The EM wave absorption abilities were simulated for the EM wave absorbers of different thickness using the calculated relative permittivity, and the EM wave absorber was manufactured based on the simulated design. A comparison of simulated and measured results is in good agreement. Measurement shows that a 1.85 mm thick absorber has absorption ability higher than 20 dB in the frequency range of $76{\sim}77$ GHz for automotive radars.

• Journal of Software Assessment and Valuation
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• 제15권1호
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• pp.37-42
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• 2019

Many similarity analysis methods, one of the dispute resolution methods for computer programs, have been studied. This paper is about quantitative similarity analysis of MIB (Management Information Base) file. Quantitative similarity means that the source codes of two computers are analyzed and the results are compared with a certain standard. The source code to analyze is a program that provides network device management functions such as configuration management, fault management, and performance management using SNMP protocol for WiMAX CPE devices. Here, WiMAX refers to the IEEE 802.16 wireless network standard protocol and can be classified into fixed WiMAX and mobile WiMAX. WiMAX CPE is a wireless Internet terminal that is fixedly used in a customer's home or office. In this paper, we analyze the similarity between MIB file of company A and company B. We will analyze whether the MIB file leaked from the damaged company is not just a list to describe the product specifications, but whether the property value can be recognized.

• Journal of Navigation and Port Research
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• 제35권9호
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• pp.717-720
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• 2011

In this paper, we designed and fabricated the Electromagnetic(EM) wave absorber for an Electronic Toll Collection(ETC or Hi-pass) system by using Amorphous metal powder and CPE. The material properties and the absorption properties of the samples containing 50 wt.%, 60 wt.%, 70 wt.%, and 80 wt.% of Amorphous. Moreover, the EM wave absorption abilities were simulated for the different thicknesses of the EM absorbers by adopting the measured permittivity and permeability, and then the EM wave absorber was fabricated based on the simulated design values. As a result, the EM wave absorber with the composition of Amorphous metal powder : CPE = 50 : 50 wt.% with the thickness of 2.6 mm has excellent absorption ability more than 40 dB at 5.8 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제20권6호
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• pp.562-569
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• 2009

Recently, Hi-pass system(non-stop electric toll collection) using DSRC is working. However, it has various problems such as system errors by EM wave interference or multi-path reflection. The EM wave absorber is able to solve these problems. In this paper, we designed and fabricated EM wave absorber using amorphous substance. As a result EM wave absorber with composition of amorphous metal powder:CPE=45:55 wt.% has the thickness of 2.65 mm and absorption ability was higher than 40 dB at 5.8 GHz.

• Korean Journal of Veterinary Research
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• 제34권3호
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• pp.537-547
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• 1994

Ninety seven cases of histopathologically diagnosed spontaneous canine parvovirus enteritis(CPE) were studied gross pathologically, histopathologically, immunohistochemically, to investigate histopathological types of small intestinal lesions, and antigen distributions in each pattern related to the infected age. And also, reliability of histopathological method in diagnosis of CPE was inspected with immunohistochemistry. The results were as follows : 1. Age-related occurring ratio in histopathologically diagnosed CPE was 53.6% in 4-8 weeks, 26.8% in 9-15 weeks, 8.25 in 16-19 weeks and 11.3% in 20-45 weeks of the clog age. 2. In histopathologic classification based on patterns of villi/crypts lesions of small intestine(jejunum), the ratio of A type (initial phase of necrosis of crypt epithelia, desquamated epithelial cells in the dilated lumen of the crypt) was 20.6%; the ratio of B type(middle phase of atrophy and fission of the villi, collapse of the mucosa, loss of normal crypt structure) was 62.9%, and C type(regenerative phase of the crypt architecture) was 16.5%. 3. The ratio of A, B, C type in 4-8 weeks old, respectively, was 23.5%, 61.5%, 15.4%; in 9-15 weeks old was 19.2%, 65.4%, 15.3% in 16-19 weeks old was 25.0%, 75.0%, 0.0%; and in 20-45 weeks old was 9.0%, 54.5%, 36.4%. 4. The antigen distribution in the nuclei of the crypt epithelial cells was higher than of the cytoplasm and numerous desquamated epithelial cells in dialated crypts in A type; The antigen cytoplasm and numerous desquamated epithelial cells in dialated crypts in A type; The antigen distribution in the nuclei of the collapsed crypt epithelial cells was not higher than that of the cytoplasm, crypts were lined by and filled with released viral antigens from the destructed epithelial cells in B type; and its distribution was also higher than in the epithelial cells adjacent to the tips of the villi, but it was not reacted in the regenerative crypt epithelial cells in C type. 5. Immunohistochemically detected antigen ratio in the small intestine of histopathologically diagnosed CPE was 94.6%, and this result indicates that histopathological diagnosis is very reliable method in diagnosis of CPE.