A User-Centered Concept Mining System for Query and Document Understanding at Tencent

Concepts embody the knowledge of the world and facilitate the cognitive processes of human beings. Mining concepts from web documents and constructing the corresponding taxonomy are core research problems in text understanding and support many downstream tasks such as query analysis, knowledge base construction, recommendation, and search. However, we argue that most prior studies extract formal and overly general concepts from Wikipedia or static web pages, which are not representing the user perspective. In this paper, we describe our experience of implementing and deploying ConcepT in Tencent QQ Browser. It discovers user-centered concepts at the right granularity conforming to user interests, by mining a large amount of user queries and interactive search click logs. The extracted concepts have the proper granularity, are consistent with user language styles and are dynamically updated. We further present our techniques to tag documents with user-centered concepts and to construct a topic-concept-instance taxonomy, which has helped to improve search as well as news feeds recommendation in Tencent QQ Browser. We performed extensive offline evaluation to demonstrate that our approach could extract concepts of higher quality compared to several other existing methods. Our system has been deployed in Tencent QQ Browser. Results from online A/B testing involving a large number of real users suggest that the Impression Efficiency of feeds users increased by 6.01% after incorporating the user-centered concepts into the recommendation framework of Tencent QQ Browser.Comment: Accepted by KDD 201

Green Mobile Networks: from self-sustainability to enhanced interaction with the Smart Grid

Nowadays, the staggering increase of the mobile traffic is leading to the deployment of denser and denser cellular access networks, hence Mobile Operators are facing huge operational cost due to power supply. Therefore, several research efforts are devoted to make mobile networks more energy efficient, with the twofold objective of reducing costs and improving sustainability. To this aim, Resource on Demand (RoD) strategies are often implemented in Mobile Networks to reduce the energy consumption, by dynamically adapting the available radio resources to the varying user demand. In addition, renewable energy sources are widely adopted to power base stations (BSs), making the mobile network more independent from the electric grid. At the same time, the Smart Grid (SG) paradigm is deeply changing the energy market, envisioning an active interaction between the grid and its customers. Demand Response (DR) policies are extensively deployed by the utility operator, with the purpose of coping with the mismatches between electricity demand and supply. The SG operator may enforce its users to shift their demand from high peak to low peak periods, by providing monetary incentives, in order to leverage the energy demand profiles. In this scenario, Mobile Operators can play a central role, since they can significantly contribute to DR objectives by dynamically modulating their demand in accordance with the SG requests, thus obtaining important electricity cost reductions. The contribution of this thesis consists in investigating various critical issues raised by the introduction of photovoltaic (PV) panels to power the BSs and to enhance the interaction with the Smart Grid, with the main objectives of making the mobile access network more independent from the grid and reducing the energy bill. When PV panels are employed to power mobile networks, simple and reliable Renewable Energy (RE) production models are needed to facilitate the system design and dimensioning, also in view of the intermittent nature of solar energy production. A simple stochastic model is hence proposed, where RE production is represented by a shape function multiplied by a random variable, characterized by a location dependent mean value and a variance. Our model results representative of RE production in locations with low intra-day weather variability. Simulations reveal also the relevance of RE production variability: for fixed mean production, higher values of the variance imply a reduced BS self-sufficiency, and larger PV panels are hence required. Moreover, properly designed models are required to accurately represent the complex operation of a mobile access network powered by renewable energy sources and equipped with some storage to harvest energy for future usage, where electric loads vary with the traffic demand, and some interaction with the Smart Grid can be envisioned. In this work various stochastic models based on discrete time Markov chains are designed, each featuring different characteristics, which depend on the various aspects of the system operation they aim to examine. We also analyze the effects of quantization of the parameters defined in these models, i.e. time, weather, and energy storage, when they are applied for power system dimensioning. Proper settings allowing to build an accurate model are derived for time granularity, discretization of the weather conditions, and energy storage quantization. Clearly, the introduction of RE to power mobile networks entails a proper system dimensioning, in order to balance the solar energy intermittent production, the traffic demand variability and the need for service continuity. This study investigates via simulation the RE system dimensioning in a mobile access network, trading off energy self-sufficiency targets and cost and feasibility constraints. In addition, to overcome the computational complexity and long computational time of simulation or optimization methods typically used to dimension the system, a simple analytical formula is derived, based on a Markovian model, for properly sizing a renewable system in a green mobile network, based on the local RE production average profile and variability, in order to guarantee the satisfaction of a target maximum value of the storage depletion probability. Furthermore, in a green mobile network scenario, Mobile Operators are encouraged to deploy strategies allowing to further increase the energy efficiency and reduce costs. This study aims at analyzing the impact of RoD strategies on energy saving and cost reduction in green mobile networks. Up to almost 40% of energy can be saved when RoD is applied under proper configuration settings, with a higher impact observed in traffic scenarios in which there is a better match between communication service demand and RE production. While a feasible PV panel and storage dimensioning can be achieved only with high costs and large powering systems, by slightly relaxing the constraint on self-sustainability it is possible to significantly reduce the size of the required PV panels, up to more than 40%, along with a reduction in the corresponding capital and operational expenditures. Finally, the introduction of RE in mobile networks contributes to give mobile operators the opportunity of becoming prominent stakeholders in the Smart Grid environment. In relation to the integration of the green network in a DR framework, this study proposes different energy management policies aiming at enhancing the interaction of the mobile network with the SG, both in terms of energy bill reduction and increased capability of providing ancillary services. Besides combining the possible presence of a local RE system with the application of RoD strategies, the proposed energy management strategies envision the implementation of WiFi offloading (WO) techniques in order to better react to the SG requests. Indeed, some of the mobile traffic can be migrated to neighbor Access Points (APs), in order to accomplish the requests of decreasing the consumption from the grid. The scenario is investigated either through a Markovian model or via simulation. Our results show that these energy management policies are highly effective in reducing the operational cost by up to more than 100% under proper setting of operational parameters, even providing positive revenues. In addition, WO alone results more effective than RoD in enhancing the capability to provide ancillary services even in absence of RE, raising the probability of accomplishing requests of increasing the grid consumption up to almost 75% in our scenario, twice the value obtained under RoD. Our results confirm that a good (in terms of energy bill reduction) energy management strategy does not operate by reducing the total grid consumption, but by timely increasing or decreasing the grid consumption when required by the SG. This work shows that the introduction of RE sources is an effective and feasible solution to power mobile networks, and it opens the way to new interesting scenarios, where Mobile Network Operators can profitably interact with the Smart Grid to obtain mutual benefits, although this definitely requires the integration of suitable energy management strategies into the communication infrastructure management

Exploring value co-creation within buyer-seller relationship in mobile applications services : a model development

Mobile phones have become an indispensable part of consumers’ life where they access core and supporting services via mobile applications services (m-applications). The focus of the present study is to explore dyadic buyer-seller roles in m-applications services’ value creation taking mobile banking applications services (MB-applications) as a case study. While prior research on value co-creation in service dominant logic (S-d logic) serves as a foundation for this study, it does not provide adequate guidance on how buyer and seller co-create value in m-applications services.To address this shortcoming, semi-structured interviews were carried out with 12 banks’ officials in banks’ headquarters of Saudi Arabia. Also, six focus groups were conducted; three with MB-application services users and three with non-users which were held in Riyadh College of Technology (RCT). In addition, a content analysis of MB-applications services was conducted to support suppliers’ perspectives regarding value propositions (service offering). A conceptual framework is developed for managing co-creation to illustrate practical application of the framework.The findings pointed to six factors that shape shape service suppliers’ ability to offer and deliver value via MB-applications, namely; brand image building, bank’s business vision, customer culture-orientation, bank’s internal environment, information technology system and positioning strategy. These factors combine to establish a value proposition for banks’ customers in the MB-applications services domain.Customer’s value creation as value in-use during usage emerged in different usage situations. A value framework incorporating value consumptions (Sheth et al., 1991a) is proposed. It identifies the main value-adding elements in m-applications and the primary drivers for adopting m-applications. Findings revealed that bank managers attempted to support customers’ value creation, which was reflected in MB-application content. However, support was constrained by some insufficient assumptions about customers and the m-commerce architecture. Factors that impede MB-applications use include consumers’ banking habits, perceived risk (security and privacy); usability hindrance, marketing and promotion, technical problems, and socio-cultural barriers. Implications are drawn for service delivery value perception and mobile marketing theory, and recommendations are made to service suppliers and commercial banks to achieve sustained returns of investment from MB-applications services

Proposal and evaluation of online medical services expansion mode for specialties: a patient perceived value perspective

There is a great imbalance and difference in the distribution of Chinese medical resources in urban and rural areas, as most medical resources are concentrated in urban areas. Against the backdrop of China’s promotion of "Internet + medical healthcare", medical institutions are encouraged to apply Internet and other information technologies to expand the space and content of medical services, but patients in remote places lack independent choice of consultation platform. Based on the theory of Maslow's hierarchy of needs, customer perception theory, Synergy theory, TAM and ACSIM, the model building of remote patients' perceived value satisfaction with online medical services for specialties is hypothesized. Take F hospital as the subject, The research provides an empirical research on the process rebuilding and redesigning specialized online health services based on the perceived value of remote patients. To obtain the perceived value needs of remote patients’ visits, this study carries out questionnaire survey to understand the main needs of remote patients visiting. The results show that: social contact and respect value need > safety and survival value need > self-value need > cost losses value. Meanwhile, the preliminary evaluation indicators of patients' perceived value are derived based on the results of the questionnaire. The research is mainly to verify the effect of the implementation of the Internet-based specialized medical partnership medical service access model for remote patients. The post-test questionnaire is designed to understand the overall level of remote patients’ perceived value of online medical services, including the level of perceived ease of use, the level of perceived usefulness, the level of perceived value, the level of satisfaction, and the level of synergy. Among them, the perceived usefulness scores the highest, It is found that the cost of the new model in terms of time, distance, expense, and energy has been significantly reduced. The research, through building the SEM model, tests the path relationships of relevant dimensions and mediating effect of the model of remote patients’ perceived value satisfaction with online medical services for specialties.Verifica-se um grande desequilíbrio na distribuição dos recursos médicos chineses nas áreas urbanas e rurais, visto que a maioria dos recursos médicos está concentrada nas áreas urbanas. No contexto da promoção chinesa de "Internet + saúde médica", as instituições médicas são incentivadas a recorrer à Internet e a outras tecnologias de informação para expandir o espaço e o conteúdo dos serviços médicos, mas os pacientes em lugares remotos não têm escolha independente da plataforma de consulta. Com base na teoria da hierarquia de necessidades de Maslow, teoria da perceção do cliente, teoria da sinergia, TAM e ACSIM, realizou-se a construção do modelo de satisfação do valor percebido de pacientes remotos, com serviços médicos online para especialidades. Considerou-se o hospital F como caso de estudo. A investigação fornece uma pesquisa empírica sobre o processo de reconstrução e redesenho de serviços de saúde online especializados, com base no valor percebido de pacientes remotos. Para obter as necessidades de valor percebido das visitas de pacientes remotos, neste estudo realizou-se uma pesquisa por questionário para entender as principais necessidades das visitas de pacientes remotos. Os resultados mostram que: contato social e respeito valor necessidade e > segurança e valor de sobrevivência necessidade > necessidade de valor próprio > valor de perdas de custo. Enquanto isso, os indicadores de avaliação preliminar do valor percebido dos pacientes são derivados com base nos resultados do questionário. O objetivo principal do presente trabalho é verificar o efeito da implementação do modelo de acesso a serviços médicos especializados, baseada na Internet para pacientes remotos. O questionário pós-teste foi projetado para compreender o nível geral de valor percebido de pacientes remotos de serviços médicos online, incluindo o nível de facilidade de uso percebida, o nível de utilidade percebida, o nível de valor percebido, o nível de satisfação e o nível de sinergia. Entre eles, a utilidade percebida pontua mais alto. Verifica-se que o custo do novo modelo em termos de tempo, distância, despesa e energia foi reduzido significativamente. Por meio da construção do modelo SEM, testaram-se as relações do caminho de dimensões relevantes, e o efeito mediador do modelo de satisfação de valor percebido de pacientes remotos, com serviços médicos online para especialidades

Meeting summary : Department of Health and Human Services, Board of Scientific Counselors, National Center for Health Statistics, Centers for Disease Control and Prevention, September 17-18, 2020

The Board of Scientific Counselors (BSC) convened via Zoom on September 17-18, 2020. The virtual meeting was open to the public (via Zoom).Publication date from document properties.bsc-meeting-summary-september-2020-508.pdf20201038

HOW COMPETITIVE IS PHOTOVOLTAIC ELECTRICITY

Over the last decade prices for residential grid-connected PV systems have decreased by 50 to 80% depeding on the local market conditions. Electricity production from residential photovoltaic solar systems has shown that it can be cheaper as residential electricity prices in a growing number of countries, depending on the actual electricity price and the local solar radiation level. The article shows how the financing costs for a PV system and the actual electricity price determine the economics of a unsubsidised PV system.JRC.F.7-Renewable Energ

Cloud Computing cost and energy optimization through Federated Cloud SoS

2017 Fall.Includes bibliographical references.The two most significant differentiators amongst contemporary Cloud Computing service providers have increased green energy use and datacenter resource utilization. This work addresses these two issues from a system's architectural optimization viewpoint. The proposed approach herein, allows multiple cloud providers to utilize their individual computing resources in three ways by: (1) cutting the number of datacenters needed, (2) scheduling available datacenter grid energy via aggregators to reduce costs and power outages, and lastly by (3) utilizing, where appropriate, more renewable and carbon-free energy sources. Altogether our proposed approach creates an alternative paradigm for a Federated Cloud SoS approach. The proposed paradigm employs a novel control methodology that is tuned to obtain both financial and environmental advantages. It also supports dynamic expansion and contraction of computing capabilities for handling sudden variations in service demand as well as for maximizing usage of time varying green energy supplies. Herein we analyze the core SoS requirements, concept synthesis, and functional architecture with an eye on avoiding inadvertent cascading conditions. We suggest a physical architecture that diminishes unwanted outcomes while encouraging desirable results. Finally, in our approach, the constituent cloud services retain their independent ownership, objectives, funding, and sustainability means. This work analyzes the core SoS requirements, concept synthesis, and functional architecture. It suggests a physical structure that simulates the primary SoS emergent behavior to diminish unwanted outcomes while encouraging desirable results. The report will analyze optimal computing generation methods, optimal energy utilization for computing generation as well as a procedure for building optimal datacenters using a unique hardware computing system design based on the openCompute community as an illustrative collaboration platform. Finally, the research concludes with security features cloud federation requires to support to protect its constituents, its constituents tenants and itself from security risks

The effect of nonconformities encountered in the use of technology on the occurrence of collision, contact and grounding accidents

Technology and its innovative applications make life easier and reduce the workload on seafarers. Today's ship bridges have much more modern and integrated navigation systems than before, and the ship's handling and management have become much easier. However, nonconformities encountered in the use of technological devices may cause accidents. In this study, the effect of human factor related errors associated with the use of the bridge's electronic navigational devices on grounding and collision-contact accidents was investigated. Non-conformities obtained from 175 collision-contact and 115 grounding accident reports were qualitatively analysed by means of human factor analysis and a classification system. Afterwards, relationships between nonconformities and their probabilities were evaluated quantitatively via a Bayesian network method. As a result of the study, the accident network was revealed. This accident network summarizes how operating errors in the use of technological equipment cause accidents. Recommendations on the prevention of accidents caused by operating errors associated with the use of new technologies are finally given

Self-gifting and consumer perceived values : development and validation of a scale to measure consumer perceived values in self-gifting and applied to consumer satisfaction

Self-gifting has become a popular consumption practice. Self-gifts can take various forms, such as products, services, or experiences, and provide special meanings in certain contexts. Consumers’ desire for the psycho-social functions of self-gifting can be fulfilled by the values embodied in a self-gift. Consumer perceived values (CPVs) have been frequently detected in self-gifting behavior. These CPVs influence consumer choice behavior in various consumption circumstances and for different product/service types. Despite the important role of CPVs in self-gifting, a valid measurement of self-gifting behavior informed by CPVs is lacking in the literature. Furthermore, existing studies have focused on antecedents of self-gifting behavior, paying little attention to consumer satisfaction at the post-purchase stage. Given the research gaps, the purpose of this dissertation was two-fold: (1) to develop a self-gifting scale from the CPV perspective and (2) to test the developed scale to examine whether CPVs in self-gifting influence consumer satisfaction. A conceptual framework was developed based on the literature on self-gifting behavior, CPVs, the theoretical framework of Expectancy Disconfirmation Theory (EDT), and the concept of consumer satisfaction. To address the first part of the purpose, Churchill’s (1979) paradigm was adopted. Based on the paradigm, scale item generation, scale purification, and scale validation steps were conducted by examining how CPVs influence self-gifting behavior. The exploratory investigation included an extensive literature review and in-depth interviews conducted to define the dimensions of CPVs in self-gifting, which resulted in an initial pool of items across nine dimensions. Content validity of the items was confirmed through expert reviews and a pilot test. Survey data were then collected and subjected to EFA, Item Analysis, and CFA for scale purification and scale validation. This series of testing resulted in a new scale of CPVs in self-gifting (CPVS-G) with satisfactory reliability and validity. The final CPVS-G scale was comprised eight CPVs and 47 items: 4 items for satisfying quality (SQ), 7 items for social connection and social identity (SI), 7 items for sustainability (ST), 7 items for new knowledge (NK), 6 items for work/life balance (WL), 6 items for security through resale (RS), 6 items for new experiences (EX), and 4 items for mood diversion (MD). To address the second part of the purpose, the CPVS-G scale was then used to test the hypotheses using Structural Equation Modeling (SEM). The survey data were collected from Amazon Mturk and yielded 355 valid responses. A two-step approach (i.e., measurement and structural models) was adopted to test the proposed hypotheses. The results of the hypotheses testing indicated significant relationships between satisfying quality (SQ), work/life balance (WL), security through resale (RS), and mood diversion (MD) and consumer satisfaction (SF). The relationships between social connection and social identity (SI), sustainability (ST), gaining new knowledge (NK), and gaining new experiences (EX) and consumer satisfaction (SF) were nonsignificant. This dissertation provides several important contributions. First, the primary contribution of this study is the development of a reliable and valid scale to test CPVs in self-gifting. The resulting CPVS-G scale developed in this study expands upon the existing shopping motivation self-gifting scales. The CPVS-G scale can assist the implementation of targeted marketing by investigating the primary values relative to self-gifting. Second, in addition to the previously defined CPVs, this dissertation discovered new CPVs (i.e., security through resale, work/life balance, and sustainability) that reflect the diversification of self-gifting as a growing consumption phenomenon. Third, the results provide evidence of the theoretical and managerial significance of the relationships between CPVs in self-gifting and consumer satisfaction. The current study found that satisfying quality (SQ), work/life balance (WL), security through resale (RS), and mood diversion (MD) were significantly related to consumer satisfaction. Fourth, this dissertation offers theoretical insight into the Expectancy Disconfirmation Theory (EDT) and particularly within value-oriented self-gifting. Consumer post-purchase satisfaction was found to be determined by comparing expectations with outcomes of CPVs relative to the self-gifts purchased. Lastly, the CPVS-G scale exhibited excellent reliability and construct validity across the entire analyses. Therefore, it can be used in studies on self-gifting across categories of products, services, and experiences in various disciplines and industries, including fashion, tourism, hospitality, consumer needs, and entertainment, to name a few

Quality of spatial information for municipal infrastructure management

Management of municipal infrastructure involves many processes such as planning, construction, operation, and maintenance of various assets. Municipal infrastructure management systems require gathering and combining a large amount of data from different sources. These data consist of spatial and non-spatial data for describing the process information about each facility. In recent years, Geographic Information Systems (GIS) are widely used in municipal infrastructure management to spatially locate the elements of roads, sewers and water networks. However, the data used in these systems are collected from different sources using different methods with little information about the quality of the data. Problems regarding spatial data quality can affect all fields that use geographic data. Furthermore, the aging of municipal infrastructure assets combined with limited maintenance budgets presents unprecedented challenges to municipalities and public work agencies. A new integrated Municipal Infrastructure Management System (MIMS) is required to perform better quality performance for optimizing maintenance, repair and replacement activities. In this research, first a literature review is conducted about the existing MIMS software solutions, various spatial technologies are introduced, and data standards and quality concepts are discussed. Then, a new framework for MIMS spatial data quality assurance process is proposed. This framework is developed to cover all aspects of data quality and several practical methods for achieving spatial data quality assurance. One case study with four implementations is used to demonstrate the applications of the proposed approach