• Steel and Composite Structures
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• v.42 no.2
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• pp.161-172
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• 2022

In this paper, four specimens of CFST column joints with endplates and long bolts are tested in the scenario of progressive collapse. Flush endplate and extended endplate are both adopted in this study. The experimental results show that increasing the thickness of the endplate could improve the behavior of the joint, but delay the mobilization of catenary action. The thickness of the endplate should not be relatively thick in comparison to the diameter of the bolts, otherwise catenary action would not be mobilized or work effectively. Effective bending deformation of the endplate could help the formation and development of catenary action in the joints. The performance of flexural action in the joint would affect the formation of catenary action in the joint. Extra middle-row bolts set at the endplates and structural components set below the bottom beam flange should be used to enhance the robustness of joints. A special weld access hole between beam and endplate should be adopted to mitigate the chain damage potential of welds. It is suggested that the structural components of joints should be independent of each other to enhance the robustness of joints. Based on the component method, a formula calculating the stiffness coefficient of preloaded long bolts was proposed whose results matched well with the experimental results.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.3
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• pp.157-162
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• 2023

Elongated styloid syndrome (ESS) can present with myriad symptoms that mimic common features of orofacial pain, such as temporomandibular joint disorders (TMJDs), often causing a challenge and delay in diagnosis. We report the case of a 52-year-old male with a three-year history of non-painful clicking during jaw movement initially diagnosed as TMJD-related internal derangement. The patient presented with a history of annoying jaw sounds for three years, described as a popping sound without bilateral clicking or crepitation. Tinnitus and progressive hearing loss were observed in the right ear, and a hearing aid was recommended by an otolaryngologist. The patient was initially diagnosed with TMJD and managed accordingly; nevertheless, his symptoms persisted. Imaging revealed prominent bilateral styloid process elongation that exceeded the recognized cut-off level of >30 mm for elongation. The patient was informed of his diagnosis and its treatment but opted only for further swallowing and auditory assessments of his ear and nose symptoms. Clinicians should consider including ESS as a differential diagnosis in patients presenting with non-specific chronic orofacial symptoms for timely diagnosis and favorable clinical outcomes.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.1
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• pp.38-42
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• 2002

Conditions are discussed for operating a dissymmetric human master-small (or micro) slave system in best (large position gain-small velocity gain) conditions allowing higher operator dexterity when real effects (joint compliance, link flexion delay and transmission distortion) are taken into account. It is shown that position PD feedback law advantage for ideal case no longer holds, and that more complicated feedback law depending on real effects has to be implemented with adapted transmission line. Drawback is slowdown of master slave interaction, suggesting to use more advanced predictive methods for the master and more intelligent control law for the slave.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.59-62
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• 2000

본 논문에서는 실측 데이터를 기준으로 9가지의 다양한 모델을 제안한 JTC(Joint Technical Committee) 모델을 전송 채널 모델로 채택하여 채널의 PDP(Power Delay Profile)의 불규칙성 따른 OFDM (Orthogonal Frequency Division Multiplexing) 통신 시스템의 성능을 분석하였다 전송 채널의 불규칙성은 Main profile의 길이, Peak 위치, Echo profile의 지연 시간, 그리고 Echo profile의 강도로 분류하여 각각에 따른 PDP를 설정하여 각 모델에 따른 OFDM 시스템의 성능 분석을 하였다.

• Journal of applied mathematics & informatics
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• v.28 no.1_2
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• pp.275-282
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• 2010

This paper analyzes a discrete-time bulk-service queue with probabilistic bulk size, where the service process is interrupted by a Markov chain. We study the joint probability generating function of system occupancy and the state of the Markov chain. We derive several performance measures of interest, including average system occupancy and delay distribution.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.284-289
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• 1995

This paper presents a haptic display of a cooperative work between the networked multiple users. Excluding the possibility of large timedelay among the users, it is presented the way of configuring individual haptic display systems including the computation of interaction forces, joint driving forces of haptic devices and simulation of the virtual objects. A haptic display system is developed consisting of two haptic display devices operated by two remote users and experimental results to show the validity of the proposed method are also presented.

• Journal of applied mathematics & informatics
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• v.22 no.1_2
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• pp.453-460
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• 2006

A discrete-time priority queueing system with place reservation discipline is studied, in which two different types of packets arrive according to batch geometric streams. It is assumed that there is a reserved place in the queue. Whenever a high-priority packet enters the queue, it will seize the reserved place and make a new reservation at the end of the queue. Low-priority arrivals take place at the end of the queue in the usual way. Using the probability generating function method, the joint distribution of system state and the delay distribution for each type are obtained.

• The Journal of the Acoustical Society of Korea
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• v.16 no.5
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• pp.96-104
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• 1997

In this paper, we proposed new methods for estimation of time delay and time-frequency delay in impulsive noise environment. The proposed methods are developed using the theory of ${\alpha}-stable$ distribution, including the fractional negative order moment(FNOM) and minimum dispersion(MD), which are formulated for the time delay estimation and the fractional negative order ambiguity function and complex minimum dispersion, which are difined for the joint estimation of time delay and frequency delay. Through simulation work, its performance was compared with various other algorithms. As a result, while the conventional approaches based on second-order statistics are only verified in Gaussian noise environent ($S{\alpha}S$ noise with ${\alpha}$=2) and also the recently proposed robust methods by Nikias[7] are verified only in limited impulse noise ($S{\alpha}S$ noise with the range of $1<{\alpha}{\le}2$), the methods proposed are able to estimate the time delay in Gaussian and any impulsive noise environments($S{\alpha}S$ noise with the range of $0<{\alpha}{\le}2$).

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1654-1659
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• 2003

In this paper, the performance evaluation of the JADE-MUSIC estimation based on the indoor channel is presented. By means of the JADE-MUSIC algorithm, DOA and time delay can be obtained simultaneously. In the JADE-MUSIC method, the channel impulse response is first estimated from the received samples and then this impulse response is employed to estimate DOAs and time delays of multipath waves. Moreover, according to the JADE-MUSIC characteristics, it can work in cases when the number of impinging waves is more than the number of antenna elements, unlike the traditional parametric subspace-based method, such a case is not true. Therefore, we employ the JADE-MUSIC algorithm applying for the real indoor environment where is rich of the multipath propagation waves and can imply that the number of waves is very possibly higher than that of the array element. The experiment is carried out in our laboratory considered to be the real indoor environment. The performance of the JADE-MUSIC algorithm is evaluated in terms of the comparison between the simulation and experiment results by using the simulated channel model and the real indoor channel model, respectively. It is clear that the joint angle and delay estimation using the simulated channel model are in good agreement with the estimation using the real indoor channel model. Therefore, we can say that the JADE-MUSIC algorithm accomplishes the high performance to jointly estimate the angle and delay of the arriving signal for the indoor environment.

• Journal of Korea Water Resources Association
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• v.43 no.10
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• pp.843-850
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• 2010

By employing multi-directional random waves, a parameter controlling the force acting on a long caisson breakwater is investigated in detail. Both JONSWAP (Joint North Sea Wave Project) and asymmetric directional spectra are adopted for frequency and directional spectra. It is found that the parameter decreases as the length of caisson and the angle of main direction of incident waves increase. Furthermore, the parameter is much similar to that of regular waves as the maximum spreading parameter $s_{max}$ increases. The parameter, however, decreases as asymmetry parameter ${\mu}$ increases when the main direction of incident waves is oblique to the breakwater.