Clustering Methods for Electricity Consumers: An Empirical Study in Hvaler-Norway

The development of Smart Grid in Norway in specific and Europe/US in general will shortly lead to the availability of massive amount of fine-grained spatio-temporal consumption data from domestic households. This enables the application of data mining techniques for traditional problems in power system. Clustering customers into appropriate groups is extremely useful for operators or retailers to address each group differently through dedicated tariffs or customer-tailored services. Currently, the task is done based on demographic data collected through questionnaire, which is error-prone. In this paper, we used three different clustering techniques (together with their variants) to automatically segment electricity consumers based on their consumption patterns. We also proposed a good way to extract consumption patterns for each consumer. The grouping results were assessed using four common internal validity indexes. We found that the combination of Self Organizing Map (SOM) and k-means algorithms produce the most insightful and useful grouping. We also discovered that grouping quality cannot be measured effectively by automatic indicators, which goes against common suggestions in literature.Comment: 12 pages, 3 figure

Papillary cystadenoma of the parotid gland: A case report.

BackgroundPapillary cystadenoma is a rare benign epithelial tumor of the salivary gland, which is characterized by papillary structures and oncocytic cells with rich eosinophilic cytoplasm. We found only one case of papillary cystadenoma in nearly 700 cases of salivary gland tumors. Our case was initially mistaken for a tumor of the right temporomandibular joint (TMJ) capsule rather than of parotid gland origin. Preoperative magnetic resonance imaging (MRI) and computed tomography (CT) should be carefully studied, which allows for appropriate preoperative counseling and operative planning.Case summaryHere, we report an unusual case of a 54-year-old woman with a parotid gland papillary cystadenoma (PGPC) that was misdiagnosed as a tumor of the right TMJ capsule. She was initially admitted to our hospital due to a mass anterior to her right ear inadvertently found 5 d ago. Preoperative CT and MRI revealed a well circumscribed tumor that was attached to the right TMJ capsule. The patient underwent a resection through an incision for TMJ, but evaluation of an intraoperative frozen section revealed a benign tumor of the parotid gland. Then we removed part of the parotid gland above the temporal facial trunk. The facial nerve was preserved. Postoperative histopathological findings revealed that the tumor was PGPC. No additional treatment was performed. There was no recurrence during a 20-mo follow-up period.ConclusionThe integrity of the interstitial space around the condyle in MRI or CT should be carefully evaluated for parotid gland or TMJ tumors

A Study of IEEE 802.15.4 Security Framework for Wireless Body Area Network

A Wireless Body Area Network (WBAN) is a collection of low-power and lightweight wireless sensor nodes that are used to monitor the human body functions and the surrounding environment. It supports a number of innovative and interesting applications, including ubiquitous healthcare and Consumer Electronics (CE) applications. Since WBAN nodes are used to collect sensitive (life-critical) information and may operate in hostile environments, they require strict security mechanisms to prevent malicious interaction with the system. In this paper, we first highlight major security requirements and Denial of Service (DoS) attacks in WBAN at Physical, Medium Access Control (MAC), Network, and Transport layers. Then we discuss the IEEE 802.15.4 security framework and identify the security vulnerabilities and major attacks in the context of WBAN. Different types of attacks on the Contention Access Period (CAP) and Contention Free Period (CFP) parts of the superframe are analyzed and discussed. It is observed that a smart attacker can successfully corrupt an increasing number of GTS slots in the CFP period and can considerably affect the Quality of Service (QoS) in WBAN (since most of the data is carried in CFP period). As we increase the number of smart attackers the corrupted GTS slots are eventually increased, which prevents the legitimate nodes to utilize the bandwidth efficiently. This means that the direct adaptation of IEEE 802.15.4 security framework for WBAN is not totally secure for certain WBAN applications. New solutions are required to integrate high level security in WBAN.Comment: 14 pages, 7 figures, 2 table

Perceived Usefulness and Perceived Ease of Use of New Technologies Described by Chinese Textile and Apparel Firm Owners and Managers

In order to assess the Textile and Apparel firms\u27 technology acceptance behavior, semi-structured in-depth interviews were conducted in this paper. A total of 13 firm owners/senior managers from 13 different Chinese Textile and Apparel firms were interviewed by the researchers. Two major themes of perceived usefulness and three themes of perceived ease of use were generated from this study, working as fundamental determinants of firms\u27 technology acceptance. The study findings highlight the need for new ways to measure perceived usefulness and perceived ease of use that could successfully assess Textile and Apparel firms\u27 determinants of new technology acceptance, which will further develop appropriate technology acceptance model at the firm level

Influence Characteristics of Electronic Payment Platform Service on User Behavior: Focusing on Chinese Users

In recent years, mobile payment has gained widespread popularity and has become the main payment method for many consumers in China. With the increase in user scale and usage frequency, the scale of mobile payment transactions will continue to grow in the future. This study aimed at investigating the impact of electronic payment platform service characteristics on customer usage intentions in a user-centered study in China. This study made use of SPSS 22.0 handles basic statistics, while the statistical tool Smart PLS 3.0 handles hypothesis testing. A survey of 70 people who used electronic payment platforms was conducted. Results of the study revealed that between electronic payment platform service characteristics, convenience, security, reliability, and reactivity. The impact on customer usage intention and usage behavior is as follows: characteristics, convenience, security, reliability, and reactivity of electronic payment platform services. The results of the survey showed that users\u27 attitudes towards usage and user behavior had a positive impact

The financial protection effect of Ghana National Health Insurance Scheme: evidence from a study in two rural districts

<p>Abstract</p> <p>Background</p> <p>One of the key functions of health insurance is to provide financial protection against high costs of health care, yet evidence of such protection from developing countries has been inconsistent. The current study uses the case of Ghana to contribute to the evidence pool about insurance's financial protection effects. It evaluates the impact of the country's National Health Insurance Scheme on households' out-of-pocket spending and catastrophic health expenditure.</p> <p>Methods</p> <p>We use data from a household survey conducted in two rural districts, Nkoranza and Offinso, in 2007, two years after the initiation of the Ghana National Health Insurance Scheme. To address the skewness of health expenditure data, the absolute amount of out-of-pocket spending is estimated using a two-part model. We also conduct a probit estimate of the likelihood of catastrophic health expenditures, defined at different thresholds relative to household income and non-food consumption expenditure. The analysis controls for chronic and self-assessed health conditions, which typically drive adverse selection in insurance.</p> <p>Results</p> <p>At the time of the survey, insurance coverage was 35 percent. Although the benefit package of insurance is generous, insured people still incurred out-of-pocket payment for care from informal sources and for uncovered drugs and tests at health facilities. Nevertheless, they paid significantly less than the uninsured. Insurance has been shown to have a protective effect against the financial burden of health care, reducing significantly the likelihood of incurring catastrophic payment. The effect is particularly remarkable among the poorest quintile of the sample.</p> <p>Conclusions</p> <p>Findings from this study confirm the positive financial protection effect of health insurance in Ghana. The effect is stronger among the poor group than among general population. The results are encouraging for many low income countries who are considering a similar policy to expand social health insurance. Ghana's experience also shows that instituting insurance by itself is not adequate to remove fully the out-of-pocket payment for health. Further works are needed to address the supply side's incentives and quality of care, so that the insured can enjoy the full benefits of insurance.</p

Spin-statistics relation and the Abelian braiding phase for anyons in fractional quantum Hall effect

Quasihole excitations in fractional quantum Hall (FQH) systems exhibit fractional statistics and fractional spin, but how the spin-statistics relation emerges from many-body physics remains poorly understood. Here we prove a spin-statistics relation using only FQH wave functions, on both the sphere and disk geometry. In particular, the proof on the disk generalizes to all quasiholes in realistic systems, which have a finite size and could be deformed into arbitrary shapes. Different components of the quasihole spins are linked to different conformal Hilbert spaces (CHS), which are nullspaces of model Hamiltonians that host the respective FQH ground states and quasihole states. Understanding how the intrinsic spin of the quasiholes is linked to different CHS is crucial for the generalized spin-statistics relation that takes into account the effect of metric deformation. In terms of the experimental relevance, this enables us to study the effect of deformation and disorder that introduces an additional source of Berry curvature, an aspect of anyon braiding that has been largely neglected in previous literature.Comment: 5 pages, 4 figures, comments very welcom

GOMCL: a t GOMCL: a toolkit t oolkit to cluster o cluster, evaluate, and extr aluate, and extract non-r act non-redundant edundant associations of Gene Ontology-based functions

Background Functional enrichment of genes and pathways based on Gene Ontology (GO) has been widely used to describe the results of various -omics analyses. GO terms statistically overrepresented within a set of a large number of genes are typically used to describe the main functional attributes of the gene set. However, these lists of overrepresented GO terms are often too large and contains redundant overlapping GO terms hindering informative functional interpretations. Results We developed GOMCL to reduce redundancy and summarize lists of GO terms effectively and informatively. This lightweight python toolkit efficiently identifies clusters within a list of GO terms using the Markov Clustering (MCL) algorithm, based on the overlap of gene members between GO terms. GOMCL facilitates biological interpretation of a large number of GO terms by condensing them into GO clusters representing non-overlapping functional themes. It enables visualizing GO clusters as a heatmap, networks based on either overlap of members or hierarchy among GO terms, and tables with depth and cluster information for each GO term. Each GO cluster generated by GOMCL can be evaluated and further divided into non-overlapping sub-clusters using the GOMCL-sub module. The outputs from both GOMCL and GOMCL-sub can be imported to Cytoscape for additional visualization effects. Conclusions GOMCL is a convenient toolkit to cluster, evaluate, and extract non-redundant associations of Gene Ontology-based functions. GOMCL helps researchers to reduce time spent on manual curation of large lists of GO terms, minimize biases introduced by redundant GO terms in data interpretation, and batch processing of multiple GO enrichment datasets. A user guide, a test dataset, and the source code of GOMCL are available at and

Single-filament Composite MgB2/SUS Ribbons by Powder-In-Tube Process

We report the successful fabrication of single-filament composite MgB2/SUS ribbons, as an ultra-robust conductor type, employing the powder-in-tube (PIT) process, by swaging and cold rolling only. The remarkable transport critical current (Ic) of the non-sintered MgB2/SUS ribbon has observed, as an unexpected result. Transport critical currents Ic ~ 316 A at T = 4.2 K and Ic ~ 82 A at T = 20 K were observed at self-field, for the non-sintered composite MgB2/SUS ribbon. In addition, the persistent current density Jp values, that were estimated by Bean formula, were more than ~ 7 &#61620; 105 A/cm2 at T = 5 K, and ~ 1.2 &#61620; 105 A/cm2 at T = 30 K, for the sintered composite MgB2/SUS ribbon, at H = 0 G.Comment: 10 pages, 4 figure