Synchronous Node Research Articles

The Design of High-Speed Synchronization Data Collection Node Machine for Multi-Chip CCD Measurement

The high-speed synchronous node machine is developed for collecting high-precision and synchronous data from multi-chip CCD to measure the dynamic object with large field coverage by Visual technology. Node machine contains core, A/D converter module and Ethernet communication module. The FPGA of 600,000 gates which have a built-in FLASH chip is used as the core, which provides work-frequency of 10MHz and drive pulse for multi-chip CCD. A/D converter module configures the differential amplifier and builds 3-way 30MHz 16-bit A / D converter. 10/100M Ethernet protocol stack controller and RJ45 interface are internally installed in Ethernet module. This module also uses CC2430 chip to perform fast wireless synchronization control. Paper emphasizes how to implement the key technologies of multi-chip CCD for synchronous and precision measurement, and test the node machine by 5-chip CCD image data synchronous collecting with large field of vision. The node machine runs smoothly and reliably .The performance results of test show that the speed of image data collecting reaches up to 1800 frames/s, the speed of data processing reaches up to 150M Bytes/s and the transporting speed reaches up to 50M Bytes/s. The time of synchronous control is within 2 us.

A File System Synchronous Algorithm Combining State Transfer and Operation Transfer

In order to realize real-time synchronization of nodes and reduce space overhead by log maintenance in an unstable network, this paper adopts a method that combines the operation transfer-based method and the state transfer-based method. Based on file system synchronization, we design a new synchronous algorithm consisting of the state transform and events merge. the new algorithm can merge file system changes in the millisecond level and realize fast update response. Besides, the new algorithm can accurately identify file update semantics, which can effectively decrease the number of updates operations.

Regional Variation in Thyroid Cancer Incidence in Belgium Is Associated With Variation in Thyroid Imaging and Thyroid Disease Management

Increased thyroid cancer incidence is at least partially attributed to increased detection and shows considerable regional variation. We investigated whether regional variation in cancer incidence was associated with variations in thyroid disease management. We conducted a retrospective population-based cohort study that involved linking data from the Belgian Health Insurance database and the Belgian Cancer Registry to compare thyroid-related procedures between regions with high and low cancer incidence. Primary outcome measures were rates of TSH testing, imaging, fine-needle aspiration cytology (FNAC), and thyroid surgery. Secondary study outcomes were proportions of subjects with thyrotoxicosis and nodular disease treated with surgery, of subjects treated with surgery preceded by FNAC or with synchronous lymph node dissection, and of thyroid cancer diagnosis after surgery. The rate of TSH testing was similar, but the rate of imaging was lower in the low incidence region. The rate of FNAC was similar, whereas the rate of surgery was lower in the low incidence region (34 [95% CI 33; 35 ] vs 80 [95% CI 79; 81 ] per 100,000 person years in the high incidence region; P < .05). In the low incidence region compared to the high incidence region, surgery represented a less chosen therapy for euthyroid nodular disease patients (47% [95% CI 46; 48] vs 69% [95% CI 68; 70]; P < .05), proportionally more surgery was preceded by FNAC, more cancer was diagnosed after total thyroidectomy, and thyroid cancer patients had more preoperative FNAC and synchronous lymph node dissection. Regional variation in thyroid cancer incidence, most marked for low-risk disease, is associated with different usage of thyroid imaging and surgery, supporting variable detection as a key determinant in geographic variation.

Podocalyxin-like protein expression in primary colorectal cancer and synchronous lymph node metastases

AimsPrevious studies have shown that membranous expression of podocalyxin-like protein (PODXL) is associated with poor prognosis in colorectal cancer (CRC). In this study, we compared PODXL expression in primary CRC and synchronous lymph node metastases. We further analyzed whether its expression changed in rectal tumours after neoadjuvant radiation therapy.Methods and resultsThe studied cohort consists of 73 consecutive patients from the South-Swedish Colorectal Cancer Biobank. Immunohistochemical PODXL expression was examined on full-face sections from all primary tumours and all 140 available lymph node metastases from 31 cases. Membranous PODXL expression was denoted in 18/73 (24,7%) primary tumours, with a high concordance between primary and metastatic lesions. While all negative primary tumours had negative metastases, some PODXL positive primaries had a varying proportion of positive and negative metastatic lymph nodes. PODXL expression was also found to be mainly unaltered in pre- and post-irradiation surgically resected tumour specimens in rectal cancer patients (n=16).ConclusionsThe findings in this study suggest that analysis of PODXL expression in the primary tumour is sufficient for its use as a prognostic and treatment predictive biomarker in CRC, also in patients with metastatic disease.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9014177329634352

Underwater Localization with Time-Synchronization and Propagation Speed Uncertainties

Underwater acoustic localization (UWAL) is a key element in most underwater communication applications. The absence of GPS as well as the signal propagation environment makes UWAL similar to indoor localization. However, UWAL poses additional challenges. The propagation speed varies with depth, temperature, and salinity, anchor and unlocalized (UL) nodes cannot be assumed time-synchronized, and nodes are constantly moving due to ocean currents or self-motion. Taking these specific features of UWAL into account, in this paper, we describe a new sequential algorithm for joint time-synchronization and localization for underwater networks. The algorithm is based on packet exchanges between anchor and UL nodes, makes use of directional navigation systems employed in nodes to obtain accurate short-term motion estimates, and exploits the permanent motion of nodes. Our solution also allows self-evaluation of the localization accuracy. Using simulations, we compare our algorithm to two benchmark localization methods as well as to the Cramer-Rao bound (CBR). The results demonstrate that our algorithm achieves accurate localization using only two anchor nodes and outperforms the benchmark schemes when node synchronization and knowledge of propagation speed are not available. Moreover, we report results of a sea trial where we validated our algorithm in open sea.

Biomarker expression and St Gallen molecular subtype classification in primary tumours, synchronous lymph node metastases and asynchronous relapses in primary breast cancer patients with 10 years’ follow-up

Molecular profiles of asynchronous breast cancer metastases are of clinical relevance to individual patients' treatment, whereas the role of profiles in synchronous lymph node metastases is not defined. The present study aimed to assess individual biomarkers and molecular subtypes according to the St Gallen classification in primary breast tumours, synchronous lymph node metastases and asynchronous relapses and relate the results to 10-year breast cancer mortality (BCM). Tissue microarrays were constructed from archived tissue blocks of primary tumours (N=524), synchronous lymph node metastases (N=147) and asynchronous relapses (N=36). The samples were evaluated by two independent pathologists according to oestrogen receptor (ER), progesterone receptor (PR), Ki67 and human epidermal growth factor receptor 2 (HER2) by immunohistochemistry and in situ hybridisation. The expression of biomarkers and molecular subtypes in the primary tumour was compared with that in the synchronous lymph node metastases and relapses, and related to 10-year BCM. Discordances were found between primary tumours and relapses (ER: p=0.006, PR: p=0.04, Ki67: p=0.02, HER2: p=0.02, St Gallen subtypes: p=0.07) but not between primary tumours and metastatic lymph node. Prognostic information was gained by the molecular subtype classification in primary tumours and nodal metastases; triple negative subtype had the highest BCM compared with the luminal A subtype (primary tumours: HR 4.0; 95% CI 2.0-8.2, p<0.001, lymph node metastases: HR 3.5; 95% CI 1.3-9.7, p=0.02). When a shift in subtype inherence between primary tumour and metastatic lymph node was identified, the prognosis seemed to follow the subtype of the lymph node. Molecular profiles are not stable throughout tumour progression in breast cancer. Prognostic information for individual patients appears to be available from the analysis of biomarker expression in synchronous metastatic lymph nodes. The study supports biomarker analysis also in asynchronous relapses.

Melanoma Patients with Unknown Primary Site or Nodal Recurrence after Initial Diagnosis Have a Favourable Survival Compared to Those with Synchronous Lymph Node Metastasis and Primary Tumour

BackgroundA direct comparison of prognosis between patients with regional lymph node metastases (LNM) detected synchronously with the primary melanoma (primary LNM), patients who developed their first LNM subsequently (secondary LNM) and those with initial LNM in melanoma with unknown primary site (MUP) is missing thus far.Patients and MethodsSurvival of 498 patients was calculated from the time point of the first macroscopic LNM using Kaplan Meier and multivariate Cox hazard regression analysis.ResultsPatients with secondary LNM (HR = 0.67; p = 0.009) and those with initial LNM in MUP (HR = 0.45; p = 0.008) had a better prognosis compared to patients with primary LNM (median survival time 52 and 65 vs. 24 months, respectively). A high number of involved nodes, the presence of in-transit/satellite metastases and male gender had an additional independent unfavourable effect.ConclusionsSurvival of patients with LNM in MUP and with secondary LNM is similar and considerably more favourable compared to those with primary LNM. This difference needs to be considered during patient counselling and for stratification purposes in clinical trials. The assumption of an immune privilege of patients with MUP which is responsible for rejection of the primary melanoma, and results in a favourable prognosis is not supported by our data.

HER2 in gastric cancer: a digital image analysis in pre-neoplastic, primary and metastatic lesions

The assessment of human epidermal growth factor receptor 2 (HER2) status in gastric cancer is crucial in selecting patients who may benefit from targeted therapy, yet heterogeneous expression could represent an important drawback for HER2 testing. We aimed to analyze (i) HER2 heterogeneity in primary gastric cancers, pre-neoplastic and metastatic lesions and (ii) HER2 prognostic role. We studied 292 surgically resected primary gastric carcinomas and constructed 21 tissue microarrays including tumor tissue cores, invasive front, paired lymph node metastasis, low- and high-grade dysplasia. Microarrays were immunohistochemically stained with HER2 antibody and digitally scanned. Novel digital analysis algorithms were developed to score HER2 expression. Fluorescence in situ hybridization was performed on equivocal cases. HER2-positive cases were 13% and heterogeneous HER2 expression was observed in 71% of positive samples. Analysis of HER2 status in tumor and tumor invasive front demonstrate concordance in 177 cases (88%). Comparison of HER2 expression in primary cancer and synchronous lymph node metastasis exhibited discordant status in 14% of cases. Dysplastic epithelium surrounding the tumor showed immunohistochemical score 2 or 3 in 19% of high-grade and in 9% of low-grade dysplastic samples. HER2 status was significantly associated with intestinal-type carcinomas (P=0.018) and prognosis since patients with primary HER2-positive tumor showed decreased overall survival (P=0.006). Intratumoral HER2 expression heterogeneity and variable lymph node metastases status strongly suggest evaluating more than one sample and, if available, metastatic foci for routinely HER2 testing.

OP102: Transoral robotic surgery in oropharyngeal cancer

In recent years, transoral robotic surgery (TORS) has been used for the removal of pharyngeal and laryngeal cancers with the objective to improve functional and aesthetic outcomes without worsening the survival. This prospective single-center cohort study described TORS in selected tumors of the tongue base in order to assess safety, efficacy and functional outcome of the procedure. From October 2010 to February 2012, TORS was performed in 13 consecutive patients affected by T1-T2 tumors of the base of the tongue. This procedure was applicable in all cases. The clinical stage demonstrated: 8 T1 tumors and 5 T2 tumors. Neck node metastases were clinically evident in 6 cases (7 N0, 1 N1, 4 N2b and 1 N2c). The final pathology report confirmed a malignancy in all cases (11 squamous cell carcinoma and 2 mucoepidermoid carcinoma). Negative-margin resections were obtained in all cases but in one with close margins. Synchronous lymph node neck dissections were performed in seven cases (six monolateral, one bilateral). Patients underwent temporary tracheostomies for a mean time of 6 days. Naso-gastric feeding tubes were positioned in 10/13 (76.9%) patients for a mean time of 7.5 days. The average time to carry out the TORS procedure was 95 min (set-up time 25 min; TORS 70 min). No deaths occurred. Surgical complications were observed in four cases (postoperative bleedings in three cases and intraoperative anaphilactic shock in one case). Median hospital stay was 9 days. All patients had good functional outcomes. Adjuvant treatment was indicated in 5/13 cases (35.4%). TORS represents a good tool for staging and treating neoplasm of the base of the tongue. The transoral removal is safe and can radically remove limited oropharyngeal tumors of the tongue base with good functional outcomes. The operating costs can be relatively high but are related to the number of procedures per year, however the advantages to patients seem to justify the procedure. TORS can represent the definitive treatment in selected T1–T2 cases of base of the tongue tumors without adverse features. and allow the possibility for the deintensification of adjuvant treatments.

Sa1456 Characteristics of Esphageal Achalasia in Patients Treated With Per-Oral Endoscopic Myotomy

synchronous esophageal cancer, and 8 had a history of radiotherapy for pharyngeal cancer. Histologically, 127 lesions were carcinoma in situ, 50 showed invasion to the subepithelial layer, and 8 were finally diagnosed as high-grade intraepithelial neoplasia. Mean maximum tumor size was 20.2 mm (range 1-84 mm), lymphovascular involvement was observed in 5 patients, negative lateral margins were detected in 163 lesions (88%), and negative vertical margins were present in 183 lesions (99%). Treatment-related adverse events were observed in three cases: subcutaneous emphysema in two cases and aspiration pneumonia in one case. Cases improved with conservative medical management. There were no severe events or treatment-related deaths. Tracheostomy prior to ESD was performed in 6 patients, and extubation one day after ESD as a result of fear of laryngeal edema was performed in 41 patients. There were no remarkable events after extubation. Mean follow-up period was 920 days. Although local recurrence developed in one case at the primary site, it was treated by ESD. Synchronous lymph node metastasis was detected in one case and lymph node metastasis in the neck during follow-up developed in two cases. No other recurrent findings were detected in these three patients after cervical lymph node dissection. There were no deaths due to primary pharyngeal cancer, however, 8 patients died of other causes. The three-year-survival rate was 95.7%, and the five-year-survival rate was 84.3%. Conclusions: ESD for superficial pharyngeal cancer is a safe and feasible treatment option. No severe adverse events occurred and the average prognosis was extremely good.

Network time protocol performance evaluation in LAN environment

Network Time Protocol(NTP) is a simple,economic and efficient way to accomplish time and frequency synchronization of multiple nodes,while relevant study on the performance evaluation is hard to find in literature,which makes it a question whether to use NTP in application.Concerning this problem,the local network NTP performance and impact of system / network load were measured and analyzed on Windows platform.By comparing time value obtained from IRIG-B time code reader and GetLocalTime Windows API,frequency skew of computer clock signal was approximated.The skew value was close to the value calculated by NTP.

Detection System of Clone Attacks based on RSSI in Wireless Sensor Networks

Most of the existing node clone attack detection methods in wireless sensor networks depend on the accurate position information and the synchronization clock information of the network node. However, it is often very difficult to guarantee real-time node location information and synchronization clock information in actual network. Therefore, those detection schemes are either difficult to achieve or is with high cost and low availability. A new detection method based on distance measurement is proposed for detecting node clone attacks in wireless sensor networks, in which three detection rules are defined. It has provided that the design and implementation of the detection system. The system has low requirements for the hardware configuration of the node and is easy to implement; it can make real-time detection of clone node for network security. The analysis and the experiment show the system is secure and reliable.

Characterising and minimising sources of error in inertial body sensor networks

Body sensor network BSN applications depend on accurate and precise data from body-worn devices, but issues related to sensor variations, body mounting variations, integration drift and node-to-node synchronisation can dramatically impact the quality and reliability of collected data and, ultimately, application fidelity. Characterising and addressing these sources of error which are both static and dynamic e.g. sensors suffer from static manufacturing variability and dynamic environmental impacts - within the context of application requirements is therefore necessary for the viability of such applications. This work characterises and addresses errors related to node synchronisation, sensor and mounting calibration and integration drift on a case study application - knee joint angle as measured during walking by the TEMPO 3.1 inertial BSN platform. Using the Vicon® optical motion capture system to provide ground truth, synchronisation, calibration and drift error are quantied, and the efficacy of solutions for reducing such errors is evaluated.

Control System Design of DELTA Parallel Manipulator Based on Real-time Ethernet

To overcome the shortages of current DELTA parallel manipulator controllers in openness and expansibility,a control system design is proposed using motion control platform EtherMAC(Ethernet for Manufacture Automation Control),which is based on real-time Ethernet.In this method,synchronous real-time control is realized under standard Ethernet without special network adapter and hard real-time operation system by communication bus using slave node synchronization and clock correction technology.Furthermore,with the modular-structured slave node FPGA IP core and component-based layered software architecture,DELTA manipulator can be developed quickly to adapt to different sorting and packaging situations.According to controller response time under prototype working condition,this method is proved to meet the requirements of synchronous real-time control.

An efficient closed-form solution for joint synchronization and localization using TOA

This paper considers the joint node synchronization and localization problem, a key enabling aspect for wireless sensor networks. A new algorithm that can jointly estimate the clock bias and the position of an unknown sensor node is developed. The newly proposed method only involves the applications of closed-form weighted least squares (WLS) technique and therefore has lower computational complexity than conventional maximum likelihood (ML) estimators. More importantly, through theoretical performance analysis, the new algorithm is shown to be able to achieve the Cramér–Rao Lower Bound (CRLB) accuracy under the condition of high signal-to-noise ratio (SNR), a prominent advantage over other existing closed-form methods. Simulations demonstrate the good performance of the developed algorithm.

Cross Layer Adaptation of Check Intervals in Low Power Listening MAC Protocols for Lifetime Improvement in Wireless Sensor Networks

Preamble sampling-based MAC protocols designed for Wireless Sensor Networks (WSN) are aimed at prolonging the lifetime of the nodes by scheduling their times of activity. This scheduling exploits node synchronization to find the right trade-off between energy consumption and delay. In this paper we consider the problem of node synchronization in preamble sampling protocols. We propose Cross Layer Adaptation of Check intervals (CLAC), a novel protocol intended to reduce the energy consumption of the nodes without significantly increasing the delay. Our protocol modifies the scheduling of the nodes based on estimating the delay experienced by a packet that travels along a multi-hop path. CLAC uses routing and MAC layer information to compute a delay that matches the packet arrival time. We have implemented CLAC on top of well-known routing and MAC protocols for WSN, and we have evaluated our implementation using the Avrora simulator. The simulation results confirm that CLAC improves the network lifetime at no additional packet loss and without affecting the end-to-end delay.

The Design of High-Speed Synchronization Data Collection Node Machine for Multi-Chip CCD Measurement

The high-speed synchronous node machine is developed for collecting high-precision and synchronous data from multi-chip CCD to measure the dynamic object with large field coverage by Visual technology. Node machine contains core, A/D converter module and Ethernet communication module. The FPGA of 600,000 gates which have a built-in FLASH chip is used as the core, which provides work-frequency of 10MHz and drive pulse for multi-chip CCD. A/D converter module configures the differential amplifier and builds 3-way 30MHz 16-bit A / D converter. 10/100M Ethernet protocol stack controller and RJ45 interface are internally installed in Ethernet module. This module also uses CC2430 chip to perform fast wireless synchronization control. Paper emphasizes how to implement the key technologies of multi-chip CCD for synchronous and precision measurement, and test the node machine by 5-chip CCD image data synchronous collecting with large field of vision. The node machine runs smoothly and reliably .The performance results of test show that the speed of image data collecting reaches up to 1800 frames/s, the speed of data processing reaches up to 150M Bytes/s and the transporting speed reaches up to 50M Bytes/s. The time of synchronous control is within 2 us.

A Clock Soft Synchronization Method Based on CAN Bus and Synchronization Error Analysis

Based on information pipeline technology, a clock soft synchronization method used in distributed measurement and control system is proposed. Using a separate information pipeline, the synchronization information is broadcasted to nodes in the distributed measurement and control system by synchronization node every message transaction cycle time, and all nodes automatically synchronize the local clock after receiving it. We analyze the theoretical synchronization error and verify this clock soft synchronization method in CAN bus. The theory analysis and experimental results indicate that the synchronization error mainly consists of propagation delay error, drift error and CAN loop delay error, and it increases linearly with the increasing of transmission distance.

Head and neck soft tissue sarcomas: Unique lack of significance of synchronous node metastases

Regional lymph node metastasis (RLNM) has been identified as a poor prognostic indicator for patients with soft tissue sarcomas (STS) of the extremities and trunk. However, the effect of RLNM on survival in patients with STS of the head and neck (HN) has not previously been explored. Our objective was to analyze RLNM as a prognostic indicator in HN-STS, and to compare this cohort to patients with STS of non-head and neck regions (NHN-STS). STS patients were identified using the Surveillance, Epidemiology, and End Results database. Only patients without concurrent distant metastasis who underwent surgery and pathologic node staging were included. Patients were categorized based on tumor location: (1) HN-STS and (2) NHN-STS. Clinicopathologic data and disease-specific survival (DSS) were compared between node-negative and node-positive patients in each group. We identified 183 cases of node-positive STS (25 HN-STS, 158 NHN-STS). In the HN-STS group, pN1 status was not associated with any of the clinicopathologic factors that we analyzed. DSS was similar among pN0 and pN1 patients with HN-STS (P = 0.59); however, in the NHN-STS group, node-positivity was significantly associated with disease-specific mortality (P < 0.001). Synchronous RLNM may not affect DSS in patients HN-STS. Node-positive patients with HN-STS appear to be unique from those with NHN-STS.

Global State Synchronization in Networks of Cyclic Feedback Systems

This technical note studies global asymptotic state synchronization in networks of identical systems. Conditions on the coupling strength required for the synchronization of nodes having a cyclic feedback structure are deduced using incremental dissipativity theory. The method takes advantage of the incremental passivity properties of the constituent subsystems of the network nodes to reformulate the synchronization problem as one of achieving incremental passivity by coupling. The method can be used in the framework of contraction theory to constructively build a contracting metric for the incremental system. The result is illustrated for a network of biochemical oscillators.