Case-based context ontology construction using fuzzy set theory for personalized service in a smart home environment

To provide context-based personalized services utilizing smart appliances in a smart home environment, we propose a framework for PersonAlized Service disCovery Using FuZZY-based CBR and Context Ontology (PASCUZZY). Basically, the PASCUZZY framework is implemented on case-based context ontology. To generate and manage the case instances on the case-based context ontology, we adopt the fuzzy set theory to transpose numerical-type context data sensed from the surrounding environment. The context is transposed to linguistic-type context instances on the context ontology. In addition, to formalize and manage the context and services as multi-attributed data, the context ontology was developed reflecting the structure of cases borrowed from case-based reasoning. Furthermore, we propose adaptation methods to adjust the generic fuzzy membership functions depending on the inhabitants’ context. It is performed by modifying the values of the membership number and/or modifying the numbers of the linguistic terms that are based on the inhabitants’ context to affect the membership numbers. The adapted membership functions return the personalized degree of memberships depending on the specialized context of a specific fuzzy variable. Inevitably, the number of cases on the case-based context ontology will be increased from time to time. We apply Ward’s method not only to reduce the search effort via a hierarchical clustering on the case-based context ontology but also to find the most similar service as a solution to the new context. To verify the superiority of the PASCUZZY framework, we perform two kinds of evaluations. First, we evaluate the effectiveness of the adaptation of the fuzzy membership functions. Second, we verify the effectiveness of the application of a clustering method to the case instances of the case-based context ontology to identify the most similar service. Results of the experiment verified the effectiveness and superiority of the PASCUZZY framework.     

Binary blends of nylons with ethylene vinyl alcohol copolymers: Morphological,thermal, rheological,and mechanical behavior

Binary blends of ethylene vinyl alcohol copolymers, containing 62 (EVOH-62) and 71 (EVOH-71) mole percent vinyl alcohols, with nylons (nylon-6, nylon-6/12, and nylon-12) have been prepared from melt mixing in a twin screw compounding machine. Morphological, thermal, rheological, and mechanical properties were determined. EVOH-62/nylon-6 and EVOH-71/nylon-6 blends showed homogeneous phase morphologies in the nylon-6-rich region, and fine phase separations (c.a. 2 × 10^?7 m) in the EVOH-rich region. Melting point depression, positive deviations in viscosity and flexural modulus, and negative deviation in impact strength from the simple additive rule were generally observed. And the results were possibly interpreted in terms of compatibility and increased nylon/EVOH interactions over the nylon/nylon interactions. On the contrary, clean phase separations in large domains were observed from EVOH-71/nylon-6/12 and EVOH-71 /nylon-12 blends. Fibrillation was also obtained from EVOH rich blends. Probably due to the incompatible nature of these blends, yield at low rate of shear and a mechanical property drop were also observed.     

Direct equivalence between geometric conditions and algebraic conditions for discrete-time nonlinear observer

Unlike the continuous-time case, algebraic necessary and sufficient conditions for a single output discrete-time system to be state equivalent to a nonlinear observer canonical form have been found and are easier to verify for those who are not accustomed to differential geometry. The geometric conditions look very different from the algebraic conditions. In this paper, we show direct equivalence of the geometric conditions and the algebraic conditions in order to enhance the understanding of the geometric conditions.     

互联电力系统未知机理低频振荡分析

近年来,我国互联电力系统多次发生低频振荡。针对南方互联电网"5.13"功率振荡,首先采用特征值分析法详细分析南方互联电网低频振荡特性,得出主要振荡模式以及发电机组参与因子和模态分布图。其次利用仿真软件PSS/E,对强相关机组的切机、三相短路故障以及原动机周期扰动分别进行时域仿真,并与实际振荡曲线进行对比。结果表明,南方电网此次功率振荡不是因为强相关机组电气侧故障,采用负阻尼机理也不能很好地解释,其产生原因可能是发电机组受原动机周期扰动有关。     

Fluidized bed combustion of high ash anthracite: Analysis of combustion efficiency and particle size distribution

Fluidized bed combustion of high ash anthracite (HAA) was experimentally studied. The combustor consists of 0.25 m ID bed, and auxiliary equipments for coal feeding, ash removal, lemperature control, etc. Experimental results elucidate main cause of fuel loss to be elutriation of fines (i.e., flyash) containing unburned carbon. However, detailed balances of particle size distribution show majority of carbon in flyash comes from fines contained in the feed instead of attrition of coarse particles. The latter is the main source of flyash for conventional coal. The difference is due to much smaller attrition rate of HAA; feed HAA particles do not shrink much in size by combustion and attrition.     

换热管直径对换热器(火用)效率影响的探讨

本文通过换热管直径对换热器(火用)效率影响的分析,提出了换热器设计及改造时,减小(火用)损失的一条途径.     

Development of an index based on fish,macroinvertebrates, phytoplankton,and physicochemical properties to assess urban aquatic ecosystems in Jinan,China

Because of the rapid growth in urbanization over recent decades, urban aquatic ecosystems have been subjected to unprecedented threats and challenges. In this study, we visited 48 sites, of which 14 were reservoir sites, in water bodies in Jinan, China, on six occasions in May, August, and October of 2014 and 2015. We sampled fish, macroinvertebrates, and phytoplankton assemblages and physicochemical factors at each site. We used the richness and diversity of fish, macroinvertebrates, and phytoplankton to evaluate the condition of the aquatic ecosystems of the river sites. We also evaluated the water quality of the reservoir sites using the physicochemical factors of the State Environmental Protection Administration of China. We classified the results into five levels—excellent, good, moderate, poor, and bad—with the comprehensive evaluation index (CEI). More than 40% of the sampling sites were in either poor or bad condition. Nearly half of the excellent or good sites were in the south of Jinan. The CEI was significantly different between the reference and impaired sites; it was significantly and positively correlated with the qualitative habitat evaluation index and was significantly and negatively correlated with conductivity, total alkalinity, and ammonia nitrogen.     

Nitrogen removal using recycled polystyrene bottles as biofilm media

The performance of an attached growth wastewater treatment process was investigated in an effort to improve nitrogen removal efficiency. Recycled Yakult (lactic acid fermentation drink) bottles made of polystyrene were used as a biofilm media. The use of Yakult bottles as a biofilm media has been attempted by numerous researchers in Japan for the removal of solids and organics. However, these studies focused only on the removal of solids and organics. This study extended their application to the removal of nitrogen for domestic sewage treatment. Yakult media was placed in a reactor with 70% apparent reactor volume in a conventional A/O process. The bottom of the Yakult media was removed, and randomly filled Yakult media were effectively able to reduce the flow in tanks, resulting in an increase in the contact time between pollutants and microorganisms. With higher HRT, the nitrogen removal efficiency was increased by up to 83% with 12 hr of HRT. Nitrification appeared to be the limiting factor of nitrogen removal at an HRT that is less than 12 hr, indicating that the Yakult process requires more retention time to achieve nitrification compared to other biofilm processes. The removal efficiencies of organics and solids were high regardless of the change of operational parameters. This article is based on a presentation in “The 7th Korea-China Workshop On Advanced Materials” organized by the Korea-China Advanced Materials Cooperation Center and the China-Korea Advanced Materials Cooperation Center, held at Ramada Plaza Jeju Hotel, Jeju Island, Korea on August 24–27, 2003.     

Thermodynamic reassessment of the Cd−Zn system

The Cd−Zn system has been thermodynamically reassessed with the CALPHAD method by combining more recent experimental data, in particular the activities of zinc in the liquid phase. A good agreement is obtained between the calculated and experimental thermodynamic parameters as well asphase boundaries.     

How purchase intention consummates purchase behaviour: the stochastic nature of product valuation in electronic commerce

This study challenges the conventional assumption that online customers with high purchase intention routinely move to the purchase stage. To this end, the process of how online customers form purchase intention and behaviour is examined. On the basis of product value distribution (PVD), we propose that the hypothetically expected product value (i.e. PVD average) determines purchase intention, whereas the actual probability of attaining the expected product value (i.e. PVD variance) moderates purchase behaviour. This proposal indicates that the expected product value has significance only when repeated purchase is assumed given that most consumers do not repeatedly purchase the same product in reality. Thus, the actual probability of attaining the expected product value more critically affects customer behaviour than does its expected value. The effectiveness of the research model is verified by conducting a survey on 300 online mall shoppers in Korea. The results confirm model effectiveness.