184 research outputs found

    User activities outliers detection; integration of statistical and computational intelligence techniques

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    In this paper, a hybrid technique for user activities outliers detection is introduced. The hybrid technique consists of a two-stage integration of Principal Component Analysis (PCA) and Fuzzy Rule-Based Systems (FRBS). In the first stage, the Hamming distance is used to measure the differences between different activities. PCA is then applied to the distance measures to find two indices of Hotelling's T2 and Squared Prediction Error. In the second stage of the process, the calculated indices are provided as inputs to the FRBSs to model them heuristically. The model is used to identify the outliers and classify them. The proposed system is tested in real home environments, equipped with appropriate sensory devices, to identify outliers in the activities of daily living of the user. Three case studies are reported to demonstrate the effectiveness of the proposed system. The proposed system successfully identifies the outliers in activities distinguishing between the normal and abnormal behavioural patterns

    Echo state network for occupancy prediction and pattern mining in intelligent environment

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    Pattern analysis and prediction of sensory data is becoming an increasing scientific challenge and a massive economical interest supports the need for better pattern mining techniques. The aim of this paper is to investigate efficient mining of useful information from a sensor network representing an ambient intelligence environment. The goal is to extract and predict behavioral patterns of a person in his/her daily activities by analyzing the time series data representing the behaviour of the occupant, generated using occupancy sensors. There are various techniques available for analysis and prediction of a continuous time series signal. However, the occupancy signal is represented by a binary time series where only discrete values of a signal are available. To build the prediction model, recurrent neural networks are investigated. They are proven to be useful tools to solve the difficulties of the temporal relationships of inputs between observations at different time steps, by maintaining internal states that have memory. In this paper, a special form of recurrent neural network, the so-called Echo State Network (ESN) is used in which discrete values of time series can be well processed. Then, a model developed based on ESN is compared with the most popular recurrent neural net-works; namely Back Propagation Through Time (BPTT) and Real Time Recurrent Learning (RTRL). The results showed that ESN provides better prediction results compared with BPTT and RTRL. Using ESN, large datasets are learnt in only few minutes or even seconds. It can be concluded that ESN are efficient and valuable tools in binary time series prediction. The results presented in this paper are based on simulated data generated from a simulator representing a person in a 1 bedroom flat

    Activity Recognition and Prediction in Real Homes

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    In this paper, we present work in progress on activity recognition and prediction in real homes using either binary sensor data or depth video data. We present our field trial and set-up for collecting and storing the data, our methods, and our current results. We compare the accuracy of predicting the next binary sensor event using probabilistic methods and Long Short-Term Memory (LSTM) networks, include the time information to improve prediction accuracy, as well as predict both the next sensor event and its mean time of occurrence using one LSTM model. We investigate transfer learning between apartments and show that it is possible to pre-train the model with data from other apartments and achieve good accuracy in a new apartment straight away. In addition, we present preliminary results from activity recognition using low-resolution depth video data from seven apartments, and classify four activities - no movement, standing up, sitting down, and TV interaction - by using a relatively simple processing method where we apply an Infinite Impulse Response (IIR) filter to extract movements from the frames prior to feeding them to a convolutional LSTM network for the classification.Comment: 12 pages, Symposium of the Norwegian AI Society NAIS 201

    Agility index evaluation using fuzzy logic in a supply chain management company

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    Agility is one of the coming challenges to the supply chain management companies. This paper presents a model to evaluate agility for supply chain management companies and answers the question that how agile a supply chain management company is. It shows a complete set of items in evaluating agility in SCM companies.The model surveys agility in responsiveness with indexes such as strategic planning, sensitivity to change and virtual enterprise; flexibility with indexes such as market flexibility, logistics flexibility,operations system flexibility and supply flexibility;competency with indexes such as integrative mechanism, shared culture, joint decision making, trust and communication; and finally quickness with indexes such as speed of new product introduction,delivery time and speed in operation.The results of S.G.S Co. show that it is in the middle range of agility. It also identifies weak factors within the organization which by improving them, the company can improve its agility index. Evaluation is done in fuzzy logic

    Agility index evaluation using fuzzy logic in a supply chain management company

    Get PDF
    Agility is one of the coming challenges to the supply chain management companies. This paper presents a model to evaluate agility for supply chain management companies and answers the question that how agile a supply chain management company is. It shows a complete set of items in evaluating agility in SCM companies.The model surveys agility in responsiveness with indexes such as strategic planning, sensitivity to change and virtual enterprise; flexibility with indexes such as market flexibility, logistics flexibility,operations system flexibility and supply flexibility;competency with indexes such as integrative mechanism, shared culture, joint decision making, trust and communication; and finally quickness with indexes such as speed of new product introduction,delivery time and speed in operation.The results of S.G.S Co. show that it is in the middle range of agility. It also identifies weak factors within the organization which by improving them, the company can improve its agility index. Evaluation is done in fuzzy logic

    Gamma irradiation effects on physical properties of squash seeds

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    In order to study the effects of gamma radiation on some physical properties of squash (Cucurbit pepo. L) seed, five irradiation doses (25, 50, 75, 100 and 200 GY) have been used.  Some physical properties, including dimensional properties (length, width, thickness, geometric mean diameter, sphericity, volume, surface area, projected area, flakiness ratio and elongation ratio), mass, 1,000 seeds mass, bulk density, true density and porosity of gamma irradiated squash seeds were measured.  Statistical indices including maximum, minimum, average, variance, skewness and kurtosis, for dimensional properties and mass of the seeds were calculated.  Results revealed a significant raise in hollow seeds number by increasing gamma irradiation dose from 5% for 25 GY to nearly 100% for 100 and 200 GY.  On the other hand, length, width, thickness, mass of single seed, 1,000 seeds mass and porosity showed an increase followed by a decrease with the increasing gamma irradiation dose.  With the increasing gamma irradiation dose, true and bulk densities were found to decrease from 338.41   kg m-3 to 214.01 kg m-3 and 420.16 kg m-3 to 256.12 kg m-3, respectively.  In 100 and 200 GY all seeds were hollow and very small, therefore dimensions and mass of these seeds were not measured. Keywords: gravimetric properties, dimensional properties, squash seeds, irradiation, gamma ra

    Effects of storage duration and conditions on mechanical properties of Viola cucumber fruit under compression loading

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    In this research, the effects of storage duration and storage conditions on mechanical properties of cucumber fruit (Viola variety) were evaluated at different positions of the fruit length.  The cucumber fruit mechanical properties determined in this study were firmness, apparent modulus of elasticity, failure stress, failure strain and failure energy.  The mechanical properties determined under compression loading using puncture and uni-axial compression tests.  The results showed that the storage duration, storage conditions and fruit test position had significant (P<0.01) effect on the mechanical properties of Viola cucumber fruit.  The samples firmness, modulus of elasticity, failure stress and failure energy reduced about 49%, 39%, 38% and 33%, respectively during shelf life.  The failure strain of samples increased 18% during storage time.  Changing the mechanical properties of the cucumber fruit at room conditions was faster than refrigerator conditions.  The mechanical properties were differed along the length of cucumber fruits so that near the stem region of cucumber fruit had the maximum value of firmness, modulus of elasticity, failure stress and failure energy.  The sample failure strain had the minimum value at near the stem region of cucumber fruit.  Among the mechanical parameters that were evaluated in this research work, the firmness can be considered as the most appropriate parameter to evaluate textural properties of Viola cucumber fruit due to significant effect of independent parameters on it and ease of usage

    Ternary genetic algorithm for load dynamic balancing in low voltage three-phase 400 V networks

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    In three-phase low voltage networks, the random behavior of single-phase loads and also their placement in different parts of single-phase feeders, leads to load imbalance in these networks. Unbalanced load causes losses and voltage drop in three-phase feeders. In this paper, using a different proposed approach based on genetic algorithm, N loads are spread over the grid phases so that the minimum current difference between the phases is formed and the ground current approaches zero. The proposed method is compared with the random load distribution method and the results are analyzed. Among the most important results obtained, we can point out the difference in the calculation time of the two methods by reaching an optimal value, and the calculation speed of the proposed method is significantly better. The proposed method can be an effective tool for dividing the load on different phases of the network in order to prevent imbalance
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