742 research outputs found

    The Mx/G/1 queue with queue length dependent service times

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    We deal with the MX/G/1 queue where service times depend on the queue length at the service initiation. By using Markov renewal theory, we derive the queue length distribution at departure epochs. We also obtain the transient queue length distribution at time t and its limiting distribution and the virtual waiting time distribution. The numerical results for transient mean queue length and queue length distributions are given.Bong Dae Choi, Yeong Cheol Kim, Yang Woo Shin, and Charles E. M. Pearc

    CerebraI Aneurysm Associated with AduIt PIoycystic Kidney Disease -Report of 2 Cases-

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    Two Cases of ruptured cerebral aneurysms associated with polycystic kidney diseases (PKD) are presented. Case 1 is a 60-year-old woman diagnosed as PKD after rupture of an anterior communicating artery aneurysm. Eleven days after successful aneurysmal clipping, she died of sudden massive intra-abdominal bleeding from kidney rupture. Case 2 is a 60-year-old man diagnosed as aneurysmal rupture 15 years after diagnosis of PKD. After anterior and posterior communicating artery aneurysms were clipped he recovered well. Since cerebral aneurysms is far more prevalent in patients with PKD than in the general population and aneurysm rupture is a leading cause of death, screening of the aneurysm by digital subtraction angiography or magnetic resonance angiography and prophylactic surgery of the aneurysm should be done

    Seismic evaluation of asymmetric wall systems using a modified three-dimensional capacity spectrum method

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    This paper proposes a modified three-dimensional capacity spectrum method to efficiently evaluate the seismic behavior of a building structure with asymmetric walls, where twisting is induced due to lateral loading. This method utilizes the demand surfaces and capacity curves that are created based on the inelastic earthquake response and seismic capacity of the asymmetric wall system, respectively. These two parameters are calculated from the displacement, torsional rotation angle and force coordinates of the structure under seismic loading. The seismic retrofit strategy of existing structures can be effectively determined by applying the proposed three-dimensional capacity spectrum method. In this procedure, a new performance point indicating the enhanced performance of the structure can be easily found by the modification of demand surfaces or capacity curves. The seismic evaluation and retrofitting strategies based on this approach are also discussed

    Association between lower urinary tract symptoms and cigarette smoking or alcohol drinking

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    Background: Although there have been several studies about the relationship between alcohol or smoking and lower urinary tracts symptoms (LUTS). This study aimed to investigate the association between alcohol or smoking and severity of LUTS in men, as alcohol intake and cigarette smoking is important modifiable lifestyle factors for LUTS. Methods: A cross-sectional analysis has been performed and a total of 86,707 participants in Korean Community Health Survey were included for final analysis. The adjusted odds ratio (OR) or coefficient with 95% confidence interval (CI) estimates were described to show the association between alcohol consumption or cigarette smoking and LUTS. Results: Among the total subjects, 77,398 (89.3%), 7,532 (8.7%), and 1,777 (2.0%) had mild, moderate, and severe symptoms, respectively, according to International Prostate Symptom Score (IPSS) grade. Those who drank alcohol at least once per month were significantly associated with decreased risk of having the worst IPSS grade (OR: 0.80, 95% CI: 0.68 to 0.93). Those who smoked in the past but currently quitted and those who were daily smokers showed significantly increased risk of having the worst IPSS grade (past smoker, OR: 1.26, 95% CI: 1.14 to 1.39; daily smoker, OR: 1.21, 95% CI: 1.10 to 1.34). For nocturia, daily smoking showed positive effect (OR: 0.79, 95% CI: 0.75 to 0.84) whereas heavy alcohol drinking showed negative effect (OR: 1.22, 95% CI: 1.14 to 1.32) Conclusions: Alcohol showed positive effect on LUTS except nocturia whereas cigarette smoking had negative effect on LUTS except nocturia. Daily smoking showed positive effect on nocturia whereas heavy alcohol drinking showed negative effect on nocturia

    Quantitative agreement of Dzyaloshinskii-Moriya interactions for domain-wall motion and spin-wave propagation

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    The magnetic exchange interaction is the one of the key factors governing the basic characteristics of magnetic systems. Unlike the symmetric nature of the Heisenberg exchange interaction, the interfacial Dzyaloshinskii-Moriya interaction (DMI) generates an antisymmetric exchange interaction which offers challenging opportunities in spintronics with intriguing antisymmetric phenomena. The role of the DMI, however, is still being debated, largely because distinct strengths of DMI have been measured for different magnetic objects, particularly chiral magnetic domain walls (DWs) and non-reciprocal spin waves (SWs). In this paper, we show that, after careful data analysis, both the DWs and SWs experience the same strength of DMI. This was confirmed by spin-torque efficiency measurement for the DWs, and Brillouin light scattering measurement for the SWs. This observation, therefore, indicates the unique role of the DMI on the magnetic DW and SW dynamics and also guarantees the compatibility of several DMI-measurement schemes recently proposed.Comment: 24 pages, 5 figure

    Analytical model of IEEE 802.15.4 non-beacon mode with download traffic by the piggyback method

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    Abstract. We analyze the MAC performance of the IEEE 802.15.4 LR-WPAN non-beacon mode with the piggyback method in non-saturated condition. Our approach is to model a stochastic behavior of one device as a discrete time Markov chain. We propose an analytical model describing the download behavior of a device using piggyback method. We obtain the performance measures such as throughput, packet delay, energy consumption and packet loss probability of a device. Numerical results and simulation results show that the piggyback method which removes a backoff procedure in the backoff method can reduce the delay, loss probability and energy consumption compared with backoff method. Our results can be used to find the optimal number of devices with some constraints on packet delay and packet loss probability

    Remote Bio-Sensing: Open Source Benchmark Framework for Fair Evaluation of rPPG

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    Remote Photoplethysmography (rPPG) is a technology that utilizes the light absorption properties of hemoglobin, captured via camera, to analyze and measure blood volume pulse (BVP). By analyzing the measured BVP, various physiological signals such as heart rate, stress levels, and blood pressure can be derived, enabling applications such as the early prediction of cardiovascular diseases. rPPG is a rapidly evolving field as it allows the measurement of vital signals using camera-equipped devices without the need for additional devices such as blood pressure monitors or pulse oximeters, and without the assistance of medical experts. Despite extensive efforts and advances in this field, serious challenges remain, including issues related to skin color, camera characteristics, ambient lighting, and other sources of noise, which degrade performance accuracy. We argue that fair and evaluable benchmarking is urgently required to overcome these challenges and make any meaningful progress from both academic and commercial perspectives. In most existing work, models are trained, tested, and validated only on limited datasets. Worse still, some studies lack available code or reproducibility, making it difficult to fairly evaluate and compare performance. Therefore, the purpose of this study is to provide a benchmarking framework to evaluate various rPPG techniques across a wide range of datasets for fair evaluation and comparison, including both conventional non-deep neural network (non-DNN) and deep neural network (DNN) methods. GitHub URL: https://github.com/remotebiosensing/rppg.Comment: 19 pages, 10 figure
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