Progressive Processing of Continuous Range Queries in Hierarchical Wireless Sensor Networks

In this paper, we study the problem of processing continuous range queries in a hierarchical wireless sensor network. Contrasted with the traditional approach of building networks in a "flat" structure using sensor devices of the same capability, the hierarchical approach deploys devices of higher capability in a higher tier, i.e., a tier closer to the server. While query processing in flat sensor networks has been widely studied, the study on query processing in hierarchical sensor networks has been inadequate. In wireless sensor networks, the main costs that should be considered are the energy for sending data and the storage for storing queries. There is a trade-off between these two costs. Based on this, we first propose a progressive processing method that effectively processes a large number of continuous range queries in hierarchical sensor networks. The proposed method uses the query merging technique proposed by Xiang et al. as the basis and additionally considers the trade-off between the two costs. More specifically, it works toward reducing the storage cost at lower-tier nodes by merging more queries, and toward reducing the energy cost at higher-tier nodes by merging fewer queries (thereby reducing "false alarms"). We then present how to build a hierarchical sensor network that is optimal with respect to the weighted sum of the two costs. It allows for a cost-based systematic control of the trade-off based on the relative importance between the storage and energy in a given network environment and application. Experimental results show that the proposed method achieves a near-optimal control between the storage and energy and reduces the cost by 0.989~84.995 times compared with the cost achieved using the flat (i.e., non-hierarchical) setup as in the work by Xiang et al.Comment: 41 pages, 20 figure

Predictive factors for breast cancer in patients diagnosed atypical ductal hyperplasia at core needle biopsy

<p>Abstract</p> <p>Background</p> <p>Percutaneous core needle biopsy (CNB) is considered to be the standard technique for histological diagnosis of breast lesions. But, it is less reliable for diagnosing atypical ductal hyperplasia (ADH). The purpose of the present study was to predict, based on clinical and radiological findings, which cases of ADH diagnosed by CNB would be more likely to be associated with a more advanced lesion on subsequent surgical excision.</p> <p>Methods</p> <p>Between February 2002 and December 2007, consecutive ultrasound-guided CNBs were performed on suspicious breast lesions at Seoul St. Mary's Hospital. A total of 69 CNBs led to a diagnosis of ADH, and 45 patients underwent follow-up surgical excision. We reviewed the medical records and analyses retrospectively.</p> <p>Results</p> <p>Sixty-nine patients were diagnosed with ADH at CNB. Of these patients, 45 underwent surgical excision and 10 (22.2%) were subsequently diagnosed with a malignancy (ductal carcinoma <it>in situ</it>, n = 8; invasive cancer, n = 2). Univariate analysis revealed age (≥ 50-years) at the time of core needle biopsy (p = 0.006), size (> 10 mm) on imaging (p = 0.033), and combined mass with microcalcification on sonography (p = 0.029) to be associated with underestimation. When those three factors were included in multivariate analysis, only age (p = 0.035, HR 6.201, 95% CI 1.135-33.891) was an independent predictor of malignancy.</p> <p>Conclusion</p> <p>Age (≥ 50) at the time of biopsy is an independent predictive factor for breast cancer at surgical excision in patients with diagnosed ADH at CNB. For patients diagnosed with ADH at CNB, only complete surgical excision is the suitable treatment option, because we could not find any combination of factors that can safely predict the absence of DCIS or invasive cancer in a case of ADH.</p

Xenon excimer emission from multicapillary discharges in direct current mode

Microdischarges in xenon have been generated in a pressure range of 400–1013 mbar with a fixed flow rate of 100 sccm. These microdischarges are obtained from three metallic capillary tubes in series for excimer emission. Total discharge voltage is thrice as large as that of a single capillary discharge tube at current levels of up to 12 mA. Total spectral irradiance of vacuum ultraviolet (VUV) emission also increases significantly compared to that of the single capillary discharge. Further, the irradiance of the VUV emission is strongly dependent on pressure as well as the discharge current

Comparative analysis of outcomes after multiport and single-port laparoscopic colectomy in emergency situations: Is single-port laparoscopic colectomy safe and feasible?

SummaryBackground/ObjectiveAlthough consensus has been reached on the superiority of laparoscopy for a majority of conditions underlying acute abdominal pain, the safety and feasibility of single-port laparoscopic colectomy (SPLC) in emergency situations have not been determined.MethodsA prospective electronic database of all emergency patients who underwent either multiport laparoscopic colectomy (MPLC) or SPLC between April 2006 and December 2014 was used to compare the surgical outcomes of these operative methods.ResultsDuring the study period, 31 MPLCs and 76 SPLCs were performed. These two operative methods resulted in similar operating times, transfusion amounts, lengths of stay, postoperative complications, attainment of lymph nodes, and proximal and distal cut margins. However, the SPLC group had a shorter time to first flatus (2.8±1.9 days vs. 3.8±1.5 days, p=0.005), earlier reinitiation of free oral fluids (3.2±2.1 days vs. 4.4±1.8 days, p=0.002), and lesser requirement of narcotic analgesics (2.5±3.9 times vs. 4.7±4.8 times, p=0.017).ConclusionSPLC could be a safe and effective alternative to MPLC, even in emergency situations when performed by surgeons who have overcome the learning curve associated with single-port laparoscopic techniques. The tendency toward earlier returns to bowel function and decreased incidence of postoperative analgesic use would be potential benefits of SPLC in emergency situations

Knowledge intensive service activities (KISAs) in Korea's innovation system

노트 : This is submitted to the Korea Development Institute as the Final Report of “Analysis on Knowledge-Intensive Service Activities in Korea’s Innovation System”, in fulfillment of the Contract between KDI and STEPI. This Research is Fully Sponsored by Strategic Research Partnership of Korea Development Institute