With the development of hardware equipment and storage technology, people are facing more and more problems about how to protect and publish private datasets. Therefore, many perturbation methods are ...proposed to cover the confidential information containing in the datasets. However, these methods are usually applied to the whole datasets, which means extreme value would lead to bias. Therefore, this study surveys the TPEGADP, a data perturbation method, combining the topology potential and EGADP. According to the topology potential in different areas, we can calculate the density of k neighborhood, so that TPEGADP or calculating mean can be used to produce perturbated data, covering the information. What's more, the cluster features as well as statistics can be maintained. TPEGADP also shows a good result in the experiment compared with GADP and NeNDS, and also shows good stability in different clustering methods, including K-means, Birch and DBSCAN.
Water quality monitoring is of great importance in managing drinking water lakes or reservoirs. However, developing such an effective monitoring system used in evaluating water quality is difficult, ...due to spatial and temporal variation in water quality that are usually hard to interpret. Principle component analysis (PCA) and canonical correlation analysis (CCA) techniques were used in this study to determine the principle water parameters, and explore the relationship between the physical and chemical water parameters, respectively in Macau Main Storage Reservoir (MSR) that is experiencing algal bloom in recent years. Twenty-eight water parameters including physical and chemical parameters were monitored each month from Jan 2001 to Dec 2010. The results showed that using PCA, six of the water quality parameters were found less important in explaining the monthly variation of the water quality and thus excluded from the further CCA, while applying CCA, the first six canonical correlations were 0.998, 0.988, 0.937, 0.778, 0.606 and 0.453, indicating that electro-conductivity and chloride compounds were the dominant (highly scored) variables of the physical parameters and chemical parameters, respectively. These results are helpful in understanding the main physical and chemical parameters involved in MSR, thus improving the water quality monitoring system in drinking water reservoirs.
With the rapid development of various hardware equipment and saving technology, multiple data with different types are uploaded to saving space. There are some private data can not be ignored. For ...provider, in order to use and deliver these private data to the third party, data anonymization, such as K-anonymity 1 should be applied to cover the explicit information. For receiver, there are still some way to transform these “fake” data to a new data set which obtain the same statistical properties with the original one while not exactly the same in detailed records.
Under this condition, we want to show our work —— data perturbation and data reconstruction to deal with this problem. We use RGADP (Retrievable General Addictive Data Perturbation) 2 to produce data perturbation and EM algorithm to reconstruct data. And the results are
Perturbated data can be produced by original data, and it can be delivered, reversed or further reconstructed easily.
The reconstructed data still keeps the statistical properties as the original one.
Compared with conditional way, this method can be more flexible to adjust the privacy protection degree according to the length of bias interval.
We integrated these two process and report on the findings of our experimental evaluation.
A series of block copolymers functionalized with aromatic 1,3,4-oxadiazole and stilbene derivatives have been synthesized by the palladium catalyzed reaction between polystyrene-block-polyisoprene ...and different functional units. These polymers exhibited different emission properties in solution and in the solid state. In chloroform solution, they showed relatively narrow and featured emission bands while, in the solid state, the emission band was broadened and showed a significant red shift. These observations were attributed to the formation of aggregates between the luminophores. After some oxadiazole functionalized copolymers were annealed at elevated temperature, such aggregation was enhanced and there were further changes in the emission spectra. For the bifunctional copolymers, such a shift in the emission band was not significant because the presence of two different chemical species in the same block may prevent the same type of luminophores from aggregating together.
Within the user-centred design method, the effectiveness of the visual representation of concepts approach in eliciting user experiences and thoughts about products, systems and interfaces depends on ...the visualization skills of the user. However, the ability to visualize relies on the cognitive functions of the user, which are known to decline over the course of a lifetime. The study reported in this paper was aimed at exploring whether older people might encounter difficulties or fail to participate in concept design visualization. Vividness of visual imagery (VVI), object imagery preference (OI) and spatial imagery preference (SI) instruments were administered on thirty-one older participants. VVI was found to be the best predictor of participants' ease of visualization in concept design, followed by OI and then SI. The findings provide useful information for designers and facilitators when involving older people in the user-centred design method. It is recommended that a precursor assessment of the vividness with which older participants visualize images be conducted before the user-centred design process begins.
Most offline reinforcement learning (RL) methods suffer from the trade-off between improving the policy to surpass the behavior policy and constraining the policy to limit the deviation from the ...behavior policy as computing \(Q\)-values using out-of-distribution (OOD) actions will suffer from errors due to distributional shift. The recently proposed \textit{In-sample Learning} paradigm (i.e., IQL), which improves the policy by quantile regression using only data samples, shows great promise because it learns an optimal policy without querying the value function of any unseen actions. However, it remains unclear how this type of method handles the distributional shift in learning the value function. In this work, we make a key finding that the in-sample learning paradigm arises under the \textit{Implicit Value Regularization} (IVR) framework. This gives a deeper understanding of why the in-sample learning paradigm works, i.e., it applies implicit value regularization to the policy. Based on the IVR framework, we further propose two practical algorithms, Sparse \(Q\)-learning (SQL) and Exponential \(Q\)-learning (EQL), which adopt the same value regularization used in existing works, but in a complete in-sample manner. Compared with IQL, we find that our algorithms introduce sparsity in learning the value function, making them more robust in noisy data regimes. We also verify the effectiveness of SQL and EQL on D4RL benchmark datasets and show the benefits of in-sample learning by comparing them with CQL in small data regimes.
An atmospheric frontal system over the South China Sea (SCS) arising from the replenishment of the northeast monsoon is investigated by using multi-sensor satellite data, weather radar data, and a ...numerical model. The replenishment or freshening of the northeast monsoon results from the merging of two high pressure areas over the Chinese Continent. The near-sea surface wind field associated with this event was measured by the Advanced Scatterometer (ASCAT) onboard the European MetOp satellite and the Advanced Synthetic Aperture Radar (ASAR) onboard the European Envisat satellite. The high resolution ASAR image reveals that the frontal line separating this wind field from the synoptic-scale ambient wind field is as sharp as in the case of a cold air outbreak and contains embedded rain cells. Furthermore, it shows that this replenishment was associated with northeasterly winds with speeds of up to 13 ms -1 over the SCS at offshore distances larger than 60 km, but only with speeds of around 6 ms -1 near the coast. The comparison of the observational data with model results of the pre-operational version of the AIR (Atmospheric Integrated Rapid-cycle) forecast model of the Hong Kong Observatory shows that the AIR model can successfully simulate the time evolution of the frontal system and the wind field over the open ocean, but fails to simulate the wind field near the coast.
There is only limited experience of using the minimally invasive surgery (MIS) technique in resecting pediatric solid tumors. In this paper, we report our experience of using the MIS technique in the ...management of pediatric solid tumors.
A retrospective review was undertaken on all children who had undergone MIS for their solid tumors between 1995 and 2005.
Over a 10-year period, there were 38 patients who had undergone MIS for tumor resection. The mean age at the time of surgery was 7.5 years (range, 1 day to 15 years). There were 22 ovarian tumors, 4 sacrococcygeal tumors, 3 adrenal tumors, 3 retroperitoneal tumors, 1 kidney tumor, 1 liver mass, 1 intra-abdominal testicular tumor, and 3 intrathoracic masses. Thirty of 38 patients had undergone a successful resection using the MIS technique (78.9%). Eight patients required a conversion to the open procedure because of limited intraperitoneal space in 7 and excessive bleeding in 1. Of the 28 successfully MIS-resected intra-abdominal tumors, 18 required enlargement of the umbilical incision and 5 required an additional Pfannenstiel incision for tumor retrieval. Enlargement of the thoracic port site for specimen retrieval was required in the 2 successfully MIS-resected intrathoracic masses. The mean operation time was 171 minutes (range, 45-275). There was no postoperative complication encountered. On an average follow-up of 3.1 years, there was no recurrence observed, even in the 7 patients with malignant tumors, and all patients with successful MIS tumor excision had good cosmetic results.
With the advance of laparoscopic instruments and techniques, a variety of pediatric solid tumors can be resected safely by the MIS technique. This has the potential benefit of a more rapid postoperative recovery and better cosmetic results. The role of the MIS technique in resecting malignant tumors is uncertain, as the number of cases in the current series is too small to draw any conclusion.
With the development of artificial intelligence (AI) and the continuous improvement of medical informatization, health assessment and auxiliary diagnosis based on physiological time series has become ...a hot research topic. However, the direct use of raw time series data is inappropriate due to privacy protection regulations in medial scenarios. Therefore, we designed a privacy-preserved framework based on Visibility Graph (VG) transformation and Graph Neural Network (GNN) for physiological data multi-classification. In particular, we proposed a Time Labeled Visibility Graph (TLVG), which uses the idea of VG to protect privacy while retaining more information that is useful for classification. Experiments are conducted based on the ECG5000 electrocardiogram dataset of the UCR time series classification archive. The comparison with existing classic and transformation-based classifiers shows the effectiveness and stable performance of our proposed method, providing an alternative and reasonable way for diseases diagnosis decision supports. Furthermore, from this research, it is discovered that the time sequence of each node in VG is an important feature in time series classification tasks.
