• Steel and Composite Structures
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• 제38권5호
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• pp.547-562
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• 2021

This paper aims to explore the mechanical behavior and moment-rotation model of blind bolted joints between concrete-filled double skin steel tubular columns and steel-concrete composite beams. For this type of joint, the inner tube and sandwiched concrete were additionally identified as basic components compared with CFST blind bolted joint. A modified moment-rotation model for this type of connection was developed, of which the compatibility condition and mechanical equilibrium were employed to determine the internal forces of basic components and neutral axis. Following this, load transfer mechanism among the inner tube, sandwiched concrete and outer tube was discussed to assert the action area of the components. Subsequently, assembly processes of basic coefficients in terms of their stiffness and resistances based on the component method by simplifying them as assemblages of springs in series or in parallel. Finally, an experimental investigation on four substructure joints with CFDST columns for validation purposes was carried out to capture the connection details. The predicted results derived from the mechanical models coincided well with the experimental results. It is demonstrated that the proposed mechanical model is capable of evaluating the complete moment-rotation relationships of blind bolted CFDST column composite connections.

• 한국태양에너지학회 논문집
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• 제36권4호
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• pp.1-9
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• 2016

The purpose of this study was to compare heat shading performance of various blind types in summer. 4 types of blinds were employed and the results are summarized as follows: 1) There were significant differences in indoor thermal environment and heat shading performance between different heat shading devices, and functional blinds demonstrated relatively superior heat shading performance. 2) Indoor long wave radiation influx measures were lowest for the coating roll blind (Blind B), followed by the coating venetian blind (Blind C), the venetian blind (Blind A), the roll blind, and not having any blinds at all. 3) Such examination results carry implications to reduce cooling load and enhance the indoor environment.

• Journal of the Optical Society of Korea
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• 제7권3호
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• pp.202-206
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• 2003

In this paper, minimum mean-squared-error(MMSE) and blind equalization schemes were employed to improve bit-error-rate(BER) and to reduce inter-symbol interference(ISI) generated during storage and retrieval processes of two-dimensional data in a digital holographic data storage system. We explained methods for designing and applying MMSE and blind equalization to improve BER in a digital holographic data storage system. From experimental evaluations, we compared the BER performances of MMSE and blind equalization and we showed that the BER performances of MMSE and blind equalization were improved significantly compared with those before equalization.

• 한국컴퓨터정보학회논문지
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• 제18권7호
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• pp.85-92
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• 2013

본 논문에서는G. Wang의 대리서명 방식과 Schnorr 은닉서명 방식을 이용하여 안전한 대리은닉서명방식을 제안한다. 대리은닉 서명은 대리서명과 은닉서명을 결합한 전자서명 방식이다. G. Wang은 두-참가자 Schnorr 서명방식에 기반한 안전성 증명 가능한 대리서명 방식을 제안하였다. 이 논문에서는, G. Wang의 대리서명 방식과 또한, 제안하는 대리 은닉 서명 방식을 이용하여 전자 투표를 위한 대리 에이전트를 고안한다. 그리고, 제안하는 서명 방식이 대리 서명과 은닉 서명의 안전성 요구사항을 모두 만족시키며 최적화된 효율적인 대리 은닉 서명 방식임을 보인다.

• Steel and Composite Structures
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• 제36권4호
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• pp.447-462
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• 2020

The paper aims to investigate the mechanical mechanism and seismic effect of stiffeners in blind bolt endplate connection to CFST column. A precise 3D finite element model with considering the cyclic properties of concrete and steel materials was established, and the efficiency was validated through monotonic and cyclic test data. The deforming pattern and the seismic performance of the unstiffened and stiffened blind bolt endplate connections were investigated. Then a parametric analysis was conducted to analyze the contribution of stiffeners and the joint working behaviors with endplate under cyclic load. The joint stiffness classifications were compared and a supplement stiffness classification method was proposed, and the energy dissipation ability of different class connections were compared and discussed. Results indicated that the main deformation pattern of unstiffened blind bolt endplate connections was the local bending of end plate. The vertical stiffeners can effectively alleviate the local bending deformation of end plate. And influence of stiffeners in thin endplate and thick endplate was different. Based on the stiffness of external diaphragm welded connection, a more detailed rigidity classification was proposed which included the pin, semi-rigid, quasi-rigid and rigid connection. Beam was the main energy dissipation source for rigid connection. For the semi-rigid and quasi-rigid connection, the extended endplate, stiffeners and steel beam would all participate in the energy dissipation.

• ETRI Journal
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• 제32권2호
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• pp.333-335
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• 2010

This letter proposes a non-coherent blind time-of-arrival (TOA) estimation scheme for impulse radio ultra-wideband systems. The TOA estimation is performed in two consecutive phases: the Rayleigh-quotient theorem-based coarse-signal acquisition (CSA) and the iterative-threshold-test-based fine time estimation (FTE). The proposed scheme serves in a blind manner without demanding any a priori knowledge of the channel and the noise. Analysis and simulations demonstrate that the proposed scheme significantly increases the signal detection probability in CSA and ameliorates the TOA estimation accuracy in FTE.

• 감성과학
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• 제14권4호
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• pp.537-544
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• 2011

시각장애우와 청각장애우에서 상실된 감각기능을 대체할 목적으로 촉각제시장치를 이용할 경우 효과적으로 촉각을 제시하기 위하여 대조군, 시각장애군, 청각장애군, 합병증성 시각장애군에서 신체 부위에 따른 촉각인 지능을 컴퍼스와 JVP dome을 이용하여 각각 두점식별력과 격자해상능을 측정하였다. 컴퍼스를 이용한 두점식별력은 대조군에서 손가락이 가장 높은 민감도를 보였으나 남녀의 차이는 보이지 않았다. 시각장애군과 청각 장애군은 대조군과 비교하여 손가락에서는 차이를 보이지 않았으나 팔과 다리 부위에서는 낮은 민감도를 보였다. JVP dome을 이용한 격자해상능은 대조군에서 다섯 손가락 모두에서 상호간의 차이를 보이지 않았으며, 또한 남녀의 차이도 보이지 않았다. 시각장애군은 대조군과 비교하여 다섯 손가락 모두에서 높은 민감도를 보였으며, 청각장애군은 대조군과 차이를 보이지 않았다. 그러나 합병증성 시각장애군은 대조군 및 시각장애군과 비교하여 두점식별력 및 격자해상능에서 모두 낮은 민감도를 보였다. 이상의 연구결과는 촉각제시장치를 이용할 경우 자극 부위와 방법을 고려해야 하며, 감각상실의 원인 질환에 따라 촉각인지능에 차이가 있음을 시사한다.

• ETRI Journal
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• 제26권2호
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• pp.101-111
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• 2004

This paper presents a near-optimum blind decision feedback equalizer (DFE) for the receivers of Advanced Television Systems Committee (ATSC) digital television. By adopting a modified trellis decoder (MTD) with a trace- back depth of 1 for the decision device in the DFE, we obtain a hardware-efficient, blind DFE approaching the performance of an optimum DFE which has no error propagation. In the MTD, the absolute distance is used rather than the squared Euclidean distance for the computation of the branch metrics. This results in a reduction of the computational complexity over the original trellis decoding scheme. Compared to the conventional slicer, the MTD shows an outstanding performance improvement in decision error probability and is comparable to the original trellis decoder using the Euclidean distance. Reducing error propagation by use of the MTD in the DFE leads to the improvement of convergence performance in terms of convergence speed and residual error. Simulation results show that the proposed blind DFE performs much better than the blind DFE with the slicer, and the difference is prominent at the trellis decoder following the blind DFE.

• 대한물리의학회지
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• 제17권3호
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• pp.31-40
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• 2022

PURPOSE: This study was conducted to investigate the effects of postural control training using a visual blind board, on head control, trunk control, and the sitting abilities of children with moderate-to-severe cerebral palsy. METHODS: Ten children with moderate to severe cerebral palsy participated in this study. Postural control training with a visual blind board was given for 40 minutes per session, 3 times a week for 4 weeks (12 sessions). Before and after the intervention, head control, trunk control, and sitting abilities were quantified using the head control scale, Korean version-trunk control measurement scale, and the sitting part of the Korean version-gross motor function measure-88, respectively. RESULTS: Postural control with the visual blind board significantly improved the head control ability of children with moderate to severe cerebral palsy (p = .015). Their trunk control abilities also showed significant improvement after the intervention (p = .016). However, their sitting ability did not show a significant change. CONCLUSION: These results showed that postural control training using a visual blind board is effective in improving the head and trunk control abilities of children with cerebral palsy. Further studies with suitable sample sizes and control groups are needed to reach a conclusion about the use of postural control training with visual blind boards for improvement of postural control of children with moderate to severe cerebral palsy.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.225-228
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• 2005

According to a popularization of the Internet and digital lifestyle, digital watermarks have been proposed for protection of copyrighted multimedia content. In blind watermark detection, which an original image is not provided, robustness against geometric distortion and compression remains challenging. In this paper, we propose a new perceptual blind discrete wavelet transform - discrete Fourier transform (DWT-DFT) composite watermarking scheme that is robust against both general linear transform and JPEG compression. This algorithm constructs an image-dependent watermark in the most significant DWT coefficients, which is determined by using a hierarchical tree structure. Strength of watermark is determined from a just-noticeable difference (JND) profile of a perceptual model. Furthermore, a desired template is inserted into DFT domain of the watermarked image. In new manner, a cross-ratio of four collinear points is used for detecting the template. Experimental results have showed that the proposed scheme is robust against general linear distortion, JPEG compression and various general kinds of attacks in the Stirmark 3.1 watermark evaluation tool.