This paper proposes a rank-constrained beamforming design for multiple-input multiple-output (MIMO) cognitive radio(CR) network where single primary user (PU) coexists with multiple secondary users (SUs). The optimal beamforming is designed to minimize the total interference leakage of the cognitive links while aligning the CR interferences to the PU receiver(PU-Rx) into a reduced-dimensional subspace. The rank-constrained optimization problem can be further approximated as a convex problem, and be solved via iteratively choosing the transmitter precoder and receiver subspace. Numerical results show that the proposed design can provide considerable sum rate for both secondary and primary transmissions under the rank constraint on CR interferences.
Primiparous women usually experience various parenting problems after childbirth that have negative effects on the well-being of mothers and infants. Although e-Support technology could provide an innovative and easily accessible intervention approach, mobile-phone interventions remain limited for Chinese primiparous women. Therefore, a new mobile application (APP) called the “Internet-based Support Program” (“ISP”) was designed, incorporating the self-efficacy theory and the social-exchange theory for Chinese first-time mothers to improve their levels of maternal self-efficacy (MSE), social support, and satisfaction, as well as to reduce their postpartum depression symptoms. The research was conducted to develop and optimize the “ISP” APP for new mothers via a theory-, evidence-, and person-based approach. Five modules of “learning forum”, “communication forum”, “ask-the-expert forum”, “baby home forum”, and “reminder forum” were included in the APP to meet various parenting needs of first-time mothers; and its contents and functions were validated by the experts and primiparous women. The majority of participants gave positive feedback on the APP’s perceived ease of use and usefulness. The “ISP” APP was the first designed for Chinese primiparous women, and a multicenter randomized controlled trial (RCT) will be conducted to measure its effectiveness on parenting outcomes.
Aimed at the problems in the experiment teaching of Computer Network,this paper puts forward an idea that network simulation techniques should be applied in the experiment teaching.It also discusses the integration of theory and practice.Experiment results show that it can help students understand abstract concepts and theories,and can help build their research abilities.
Abstract Patients with atopic dermatitis experience increased nocturnal pruritus which leads to scratching and sleep disturbances that significantly contribute to poor quality of life. Objective measurements of nighttime scratching and sleep quantity can help assess the efficacy of an intervention. Wearable sensors can provide novel, objective measures of nighttime scratching and sleep; however, many current approaches were not designed for passive, unsupervised monitoring during daily life. In this work, we present the development and analytical validation of a method that sequentially processes epochs of sample-level accelerometer data from a wrist-worn device to provide continuous digital measures of nighttime scratching and sleep quantity. This approach uses heuristic and machine learning algorithms in a hierarchical paradigm by first determining when the patient intends to sleep, then detecting sleep–wake states along with scratching episodes, and lastly deriving objective measures of both sleep and scratch. Leveraging reference data collected in a sleep laboratory (NCT ID: NCT03490877), results show that sensor-derived measures of total sleep opportunity (TSO; time when patient intends to sleep) and total sleep time (TST) correlate well with reference polysomnography data (TSO: r = 0.72, p < 0.001; TST: r = 0.76, p < 0.001; N = 32). Log transformed sensor derived measures of total scratching duration achieve strong agreement with reference annotated video recordings ( r = 0.82, p < 0.001; N = 25). These results support the use of wearable sensors for objective, continuous measurement of nighttime scratching and sleep during daily life.
In recent years, remote sensing images(RSIs) have witnessed significant improvements in both quality and quantity. With the application of deep learning techniques, these RSIs can be more effectively utilized to harnessed to aid in environment monitoring and urban planning. Semantic segmentation, as a common task in RSIs processing, confronts numerous challenges, including inaccurate classification, fuzzy boundaries, and other problems. This paper proposes a novel semantic segmentation network known as the Edge Enhanced Global Contextual Information Guided Feature Fusion Network (Edge Enhanced GCIFFNet) to address these challenges. This network consists of an edge-enhanced part and a backbone network part. Firstly, in the encoding stage, the Recurrent Criss-Cross Attention (RCCA) block is employed, which incorporates spatial attention, mechanisms to capture global information. Secondly, in the decoding stage, a Channel Attention Residual Block (CARB) module is proposed to facilitate the fusion of high-level and low-level features. Moreover, we enhance the network's ability to extract edge information during training by sharing parameters between the backbone and employing a specialized loss function. The network proposed in this paper utilises both channel attention and spatial attention at different stages, effectively utilizing edge information. Finally, we conduct experiments using the Yinchuan dataset and the LoveDA dataset. The experimental results show that the proposed network demonstrates excellent performance on both datasets.
Laser technology plays fundamental roles in the modern optical experiments and applications. The performance of optical devices will be significantly affected by micro impurities and defects on the optical surfaces. Therefore, precisely positioning the optical impurities and defects is an important issue in optics. In this paper, we theoretically propose to adopt the deep learning neural networks in addressing this problem. Specifically, we generate the training data via simulating the dynamic process in which a probe optical pulse being scattered by a micro-impurity on an optical surface, and then the position information of the impurity carried by the reflection and the transmission signal can be efficiently learned by a deep convolutional neural network. One step further, we show that the deep neural network can make precise predictions on the generalization datasets generated through varying the size, refractive index, and geometry of the impurity, respectively. Additionally, we also compared the learning capability of two different networks architectures. This work provides new perspective for the impurity and defect detections in the field of precision optics.
The deficiency existing in the curriculum of computer network was discussed. In order to combine theory with practice, a method to develope the performance test experiment of computer network based on NS2 simulation was presented. An application example to the test throughput of IEEE802.11 DCF protocol was introduced. These experiments can help students to understand recondite concepts and theories, which is an efficient way to train research abilities of students.
To compare the clinical efficacy and safety between percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) in the treatment of osteoporotic vertebral compression fracture (OVCF) with intravertebral vacuum cleft (IVC).Between January 2010 and December 2013, 68 patients with single OVCF and IVC were treated, and the clinical data were retrospectively analyzed. Of 68 patients, 48 underwent PVP (PVP group) and 20 underwent PKP (PKP group). There was no significant difference in age, gender, disease duration, fracture level, bone mineral density (BMD), visual analogue scale (VAS), Oswestry disability index (ODI), and preoperative radiological parameters between 2 groups (P>0.05). The intraoperative incidence of cement leakage, cement volume, and operative time were compared between 2 groups; VAS score was used for evaluation of back pain and ODI for evaluation of dysfunction; the incidence of adjacent vertebral fracture was observed within 2 years. The vertebral height and kyphotic angle were measured on X-ray films; the rate of vertebral compression (CR), reduction rate (RR), progressive height loss (PHL), reduction angle (RA), and progressive angle (PA) were calculated.There was no significant difference in cement volume and the incidence of cement leakage between 2 groups (P>0.05). The operative time in PVP group was shorter than that in PKP group, showing significant difference (t=-8.821, P=0.000). The mean follow-up time was 2.4 years (range, 2.0-3.1 years). The VAS scores and ODI were significantly reduced at 1 day, 1 year, and 2 years after operation when compared with preoperative scores (P<0.05), but there was no significant difference between different time points after operation in 2 groups (P>0.05). Adjacent vertebral fracture occurred in 5 cases (10.4%) of PVP group and in 2 cases (10.0%) of PKP group, showing no significant difference (χ2=0.003, P=0.963). BMD was significantly increased at 1 year and 2 years after operation when compared with preoperative BMD (P<0.05), but no significant difference was found between 2 groups (t=0.463, P=0.642; t=0.465, P=0.646). The X-ray films showed that CR and kyphotic angle were significantly restored at immediate after operation in 2 groups (P<0.05); but vertebral height and kyphotic angle gradually aggravated with time, showing significant difference between at immediate and at 1 and 2 years after operation (P<0.05); there was no significant difference in CR and kyphotic angle between 2 groups at each time point (P>0.05). RR, RA, PHL, and PA showed no significant difference between 2 groups (P>0.05).There is similar clinical and radiological efficacy between PVP and PKP for treatment of OVCF with IVC. Re-collapse could happen after operation, so strict observation and follow-up are needed.比较经皮椎体成形术（percutaneous vertebroplasty,PVP）和经皮椎体后凸成形术（percutaneous kyphoplasty,PKP）治疗伴椎体内真空裂隙（intravertebral vacuum cleft,IVC）的骨质疏松椎体压缩骨折（osteoporotic vertebral compression fracture,OVCF）疗效。.回顾分析2010年1月－2013年12月，行PVP或PKP治疗并符合选择标准的68例伴IVC的OVCF患者临床资料。其中48例行PVP治疗（PVP组），20例行PKP治疗（PKP组）。两组患者性别、年龄、病程、损伤节段、骨密度以及术前背部疼痛视觉模拟评分（VAS）、Oswestry功能障碍指数（ODI）、影像学测量指标等一般资料比较，差异均无统计学意义（P＞0.05），具有可比性。比较两组术中骨水泥渗漏率、骨水泥注入量、手术时间，采用VAS评分评价背部疼痛程度，ODI评价功能障碍严重程度，2年内邻椎再骨折率。手术前后摄正侧位X线片，测量伤椎椎体高度及后凸角，并计算椎体压缩率（rate of vertebral compression,CR）、复位率（reduction rate,RR）、进展性高度丢失率（progressive height loss,PHL）、复位角度（reduction angle,RA）、进展性后凸角（progressive angle,PA）。.两组骨水泥注入量及骨水泥渗漏发生率比较，差异均无统计学意义（P＞0.05）；但PVP组手术时间较PKP组显著缩短（t=—8.821，P=0.000）。术后患者均获随访，随访时间2.0~3.1年，平均2.4年。两组术后1 d、1年及2年VAS评分、ODI均较术前显著降低（P＜0.05）；术后各时间点间比较，差异无统计学意义（P＞0.05）。术后2年内，PVP组5例（10.4%）、PKP组2例（10.0%）发生邻椎骨折，骨折发生率比较差异无统计学意义（χ2=0.003，P=0.963）。术后1、2年两组骨密度均较术前显著改善（P＜0.05），但两组间比较差异无统计学意义（t=0.463，P=0.642；t=0.465，P=0.646）。X线片测量显示，两组CR及后凸角均获得明显矫正，术后即刻两指标与术前比较差异有统计学意义（P＜0.05）；但术后1、2年时与术后即刻比较，差异有统计学意义（P＜0.05）；术后各时间点两组间CR及后凸角比较，差异均无统计学意义（P＞0.05）。两组RR、RA、PHL、PA比较，差异均无统计学意义（P＞0.05）。.PVP及PKP治疗伴IVC的OVCF可获得相似疗效，术后均可能发生再塌陷及后凸畸形，因此需注意随访观察。.
We examined whether human operators move their eyes earlier to a target before hands when the level of task difficulty increases. We hypothesized that participants would perform less proactive eye movements in the difficult task than in the easy one, as they would need to focus more on their current hand movements. Sixteen university students were recruited to perform the aiming and touching task reciprocally on three paired targets (circles) differing in sizes and distances, while had their eye movements tracked. The movement time, the early eye engagement time (EEET), and the number of eye adjustments were recorded. The EEET was defined as the time that a subject's eyes fix on a target to the moment that the tool reaches out for it. The movement time increased as the index of difficulty (ID) value increased, echoing with the Fitts' Law prediction. When aiming to a target with a higher ID, participants' EEET was longer comparing to when reaching for a target with a lower ID. Participants reduced the movement speed to give themselves a longer time in searching visually for the target information before moving their hands. In contrast to our hypothesis, results suggested a proportional relationship between the task difficulty and the early eye engagement time. Participants also performed an increasing number of eye adjustments over the course of moving from the easy to the hard target. Future research is needed to examine eye hand coordination under the regulation of Fitts' Law.
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