• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2000년도 춘계종합학술대회
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• pp.217-221
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• 2000

본 논문에서는, PLL 주파수 합성기의 VCO로부터의 위상잡음이 64QAM 시스템 성능에 미치는 영향을 분석한다. 오실레이터에서 발생하는 위상잡음을 실제와 유사하게 예측하기 위해 오실레이터 의 입력 임펄스 전류가 소신호 일때를 가정하여 LTV(선형 시변) 모델을 고려하였으며 64QAM 시스템에서 위상잡음이 복조부에서 검출과정을 거칠 때 위상잡음이 없는 AWGN 환경에서의 BER과 비교하여 어느 정도의 시스템 성능 저하를 야기하는지에 대해 분석한다

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1433-1437
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• 2007

This paper describes the detection algorithm which can distinguish series arcing signal from voltage harmonics or noises produced by the operation of non-linear loads. A high pass filter with the cutoff frequency of 3 kHz is designed and it can attenuate power frequency signal to 80 dB. Series arcing phenomena is simulated to an incandescent lamp controlled by a dimmer. From the experimental results, it is confirmed that the amplitude of the filter output voltage varies at random during series arcing but the signal generated by non-linear loads appears on a regular basis. We proposed a series arcing detection algorithm using the chaotic nature of voltage signal.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.712-717
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• 2004

Recently, the concern for the environmental noise has increased due to the growing of the living standard. The environmental noise regulations based on the equivalent noise level are widely used. However, the noise level, which Is based mainly on the magnitude with A-weighting, the important characteristics of noises in frequency and time domains and the impulsive nature cannot be assessed properly. These can have substantial effects on how human respond to noise. Therefore, the noise evaluation methodology based on the sound quality rather than the equivalent noise level can be more suitable to represent human response to the environmental noise. This paper describes the study on environmental noise quality analysis for various noises. A cluster analysis was carried out and the noises were classified into several clusters using the values of sound quality metrics. The classification was confirmed by comparing time and frequency characteristics of the noises. And then the result of Jury testing was analysis.

• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 2002년도 한국해안해양공학발표논문집 Proceedings of Coastal and Ocean Engineering in Korea
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• pp.14-23
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• 2002

Wave breaking and breaking wave-induced hydrodynamics are very important subjects in the field of coastal and ocean hydrodynamics and engineering. In the coastal zone, a submerged breakwater has been increasingly popular, since it is one of nature-matching structures with multi- functions such as (1) wave energy dissipation by wave breaking and friction, (2) oxygen supply to sea by wave breaking and breaking wave, (3) water purification by entrained air bubbles, (4) keeping. good seascape. and (5) good habitat for sea livings. Recently, the breaking wave-induced high frequency pressure over a submerged breakwater is said to have a function of gathering sea livings around the structure, which has encouraged the construction of the submerged breakwater in coastal zone. (omitted)

• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.998-1007
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• 2018

The advent of Wireless Sensor Networks (WSN) has led to their use in numerous applications. Sensors are autonomous in nature and are constrained by limited resources. Designing an autonomous topology with criteria for economic and energy conservation is considered a major goal in WSN. The proposed honey-hive clustering consumes minimum energy and resources with minimal transmission delay compared to the existing approaches. The honey-hive approach consists of two phases. The first phase is an Intra-Cluster Min-Max Discrepancy (ICMMD) analysis, which is based on the local honey-hive data gathering technique and the second phase is Inter-Cluster Frequency Matching (ICFM), which is based on the global optimal data aggregation. The proposed data aggregation mechanism increases the optimal connectivity range of the sensor node to a considerable degree for inter-cluster and intra-cluster coverage with an improved optimal energy conservation.

• ETRI Journal
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• 제34권2호
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• pp.260-263
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• 2012

In this letter, we propose a moving-target tracking algorithm based on a particle filter that uses the time difference of arrival (TDOA)/frequency difference of arrival (FDOA) measurements acquired by distributed sensors. It is shown that the performance of the proposed algorithm, based on the particle filter, outperforms the one based on the extended Kalman filter. The use of both the TDOA and FDOA measurements is shown to be effective in the moving-target tracking. It is proven that the particle filter deals with the nonlinear nature of the movingtarget tracking problem successfully.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.103-108
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• 2004

In this study, examined heavy-weight floor impact sound to structure that have slab thickness of 4 form at a standard laboratory through noise and vibration measured. The results show that the nature Natural frequency increased according to change of thickness of each slab by finite element analysis, and acceleration value decreased. Results of measurements of noise and vibration at a standard laboratory, the slab 210, 240mm structures was construed result such as finite element analysis but the slab 150, 180mm structures is construed that influence in vibration acceleration level because edge condition has condition that contact to ground. Therefore, in modelling process for analysis, is thought that need that condition analyzes examining element influencing about structure that contact to ground.

• Steel and Composite Structures
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• 제6권3호
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• pp.221-236
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• 2006

The objective of this work is to describe the main steps involved in the derivation of a GBT (Generalised Beam Theory) formulation to analyse the vibration behaviour of loaded cold-formed steel members and also to illustrate the application and capabilities of this formulation. In particular, the paper presents and discusses the results of a detailed investigation about the local and global free vibration behaviour of lipped channel simply supported columns. After reporting some relevant earlier GBT-based results dealing with the buckling and vibration behaviours of columns and load-free members, the paper addresses mostly issues concerning the variation of the column fundamental frequency and vibration mode nature/shape with its length and axial compression level. For validation purposes, some GBT-based results are also compared with values obtained by means of 4-node shell finite element analyses performed in the code ABAQUS.

• Smart Structures and Systems
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• 제13권2호
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• pp.173-176
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• 2014

This special issue focuses on Smart Tuned Mass Dampers (STMD) that are either active or smart or semi-active in nature. Active tuned mass dampers or active mass dampers have found wide acceptance and have been implemented in many tall buildings and long span bridges. Recently researchers have developed a new class of smart tuned mass dampers using either variable stiffness and/or variable damping to effect the change in instantaneous frequency and damping. Since tuning plays a central role in STMDs it is of great current interest thus the topic of this special issue. Discussions of recent active and smart TMD implementations in tall buildings and bridges are also included.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.865-872
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• 2000

Helocobacter phylori is the major cause of gastritis, peptic ulcer, and a principal risk factor for gastric cancer. As the firs step towards a vaccine against H. pylori infection, Hy.pylori urease was expressed and purified as a recombinant apoenzyme (rUrease) in E. coli. In order to develop an effective immunization protocol using rUrease, the host immune responses were evaluated after the oral immunization of mice with rUrease preparations plus cholera toxin relative to various conditions, such as the physical nature of the antigen, the frequency of the booster immunization, the dose of the antigen, and the route of administration. The protective efficacy was assessed using a quantitative culture following an H. pylori SS1 challenge. It was demonstrated that rUrease, due to its particulated nature, was more superior than the UreB subunit as a vaccine antigen. The oral immunization of rUrease elicited significant systemic and secretory antibody responses, and activated predominantly Th2-type cellular responses. The bacterial colonization was significantly reduced (~100-fold) in those mice immunized with three or four weekly oran doses of rUrease plus cholera toxin (p<0.05), when compared to the non-immunized/challenged controls. The protection correlated well with the elicited secretory IgA level against rUrease, and these secretory antibody responses were highly dependent on the frequency of the booster immunization, yet unaffected by the dose of the antigen (25-200$\mu\textrm{g}$). These results demonstrate the remarkable potential of rUrease as a vaccine antigen, thereby strengthening the possibility of developing an H. pylori vaccine for humans.