Automatic Food Intake Assessment Using Camera Phones

Obesity is becoming an epidemic phenomenon in most developed countries. The fundamental cause of obesity and overweight is an energy imbalance between calories consumed and calories expended. It is essential to monitor everyday food intake for obesity prevention and management. Existing dietary assessment methods usually require manually recording and recall of food types and portions. Accuracy of the results largely relies on many uncertain factors such as user\u27s memory, food knowledge, and portion estimations. As a result, the accuracy is often compromised. Accurate and convenient dietary assessment methods are still blank and needed in both population and research societies. In this thesis, an automatic food intake assessment method using cameras, inertial measurement units (IMUs) on smart phones was developed to help people foster a healthy life style. With this method, users use their smart phones before and after a meal to capture images or videos around the meal. The smart phone will recognize food items and calculate the volume of the food consumed and provide the results to users. The technical objective is to explore the feasibility of image based food recognition and image based volume estimation. This thesis comprises five publications that address four specific goals of this work: (1) to develop a prototype system with existing methods to review the literature methods, find their drawbacks and explore the feasibility to develop novel methods; (2) based on the prototype system, to investigate new food classification methods to improve the recognition accuracy to a field application level; (3) to design indexing methods for large-scale image database to facilitate the development of new food image recognition and retrieval algorithms; (4) to develop novel convenient and accurate food volume estimation methods using only smart phones with cameras and IMUs. A prototype system was implemented to review existing methods. Image feature detector and descriptor were developed and a nearest neighbor classifier were implemented to classify food items. A reedit card marker method was introduced for metric scale 3D reconstruction and volume calculation. To increase recognition accuracy, novel multi-view food recognition algorithms were developed to recognize regular shape food items. To further increase the accuracy and make the algorithm applicable to arbitrary food items, new food features, new classifiers were designed. The efficiency of the algorithm was increased by means of developing novel image indexing method in large-scale image database. Finally, the volume calculation was enhanced through reducing the marker and introducing IMUs. Sensor fusion technique to combine measurements from cameras and IMUs were explored to infer the metric scale of the 3D model as well as reduce noises from these sensors

Atlas of Mineral Deposits Distribution in China (2020)

This open access book includes instruction of national mineral database 2020 and atlas of national mineral deposits distribution derived from national mineral database 2020. National mineral database 2020 is based on data from National Geological Archives China(NGAC). Moreover, it introduces the construction method and updates maintenance mechanism of the mineral deposits database and proposes the concept of updating data based on collected archives. The construction guideline on national mineral deposits database provides guiding framework for the future development on geological database

Effects of Impeller Diameter on High-Speed Rescue Pump

Impeller diameter is a crucial design parameter of high-speed rescue pumps because it affects the performance and inner flow characteristics of these pumps. In this study, a pump with an impeller diameter of 248 mm was modeled and its performance was tested. Numerical simulations were conducted under steady and unsteady states, in which the sizes of the impeller diameters were designated as 248 mm (original), 235.6 mm (5% trimmed), 223.2 mm (10% trimmed), and 210.8 mm (15% trimmed). ANSYS software was used to test the shear stress transport (SST k-ω) of the four models, and results agreed well with experimental data. Diameter size affected impeller characteristics in both steady and unsteady states. Subsequently, the differences in performance, hydraulic loss, pressure pulsation, and radial force of the impellers were evaluated. In the performance test, the head and efficiency of the pump decreased as impeller diameter was reduced. The result trends are in accordance with the trim law within the acceptable error range. In terms of hydraulic loss, the impeller and diffuser vane components presented opposite trends with flow rate increase. Finally, in terms of pressure pulsation and radial force, the amplitude diminished while periodicity improved as impeller diameter decreased

Response of fatal landslides to precipitation over the Chinese Loess Plateau under global warming

Rain-induced loess landslides are especially prevalent in the Chinese Loess Plateau (CLP). Some became fatal landslide disasters, leading to numerous casualties and significant socioeconomic losses. Extreme precipitation is the main cause of landslide occurrence. Therefore, in this study we discuss the correlation between seven extreme precipitation indices, single continuous precipitation events and fatal landslides in the CLP using Pearson correlation analysis. We also predict future precipitation under climate changes using five optimal CMIP6 models. During the period 2004–2016, fatal landslides in the CLP increased at a rate of 0.6 per year, with frequent landslide events occurring especially in the central and southwestern parts of the CLP. We find that SDII (simple daily intensity precipitation index) and R×5day (max 5-day precipitation amount) show spatial distribution that are consistent with fatal landslides. Extreme precipitation events were frequent after year 2000; and several extreme precipitation indices show an increasing trend with a higher magnitude since 2000 than before 2000. In particular, in 2013 when the number of fatal landslides was as high as 17, SDII, R95pTOT (extremely wet days), R25mm (very heavy precipitation days), and R×5day all showed abrupt increases. Single continuous precipitation events have profound effects on fatal landslides. We show that single continuous precipitation events with cumulative precipitation of 185–235 mm and duration of 6 days or longer have the highest correlation with fatal landslides. As the increasing occurrence of extreme rainfall events by the global warming, the CLP may face more fatal landslides in the future, especially in the high emission scenario of greenhouse gases (GHGs)

Compatibility design of retrofit T5 LED tube: Passive and active methods

LED lamps becomemore and more economically attractive in the lighting market, primarily thanks to their great energy saving, long lifetime and ever decreasing cost compared with the conventional lighting solutions, such as incandescent or fluorescent ones. A traditional fluorescent lighting system consists of a fluorescent lamp(s) and a magnetic/electronic ballast. A direct replacement of a fluorescent lamp by a LED lamp with the same formfactor and pin connection avoids any rewiring or removal of the ballast, which is known as the retrofit concept. The retrofit LED lamps further guarantee a minimal total cost of ownership.This work investigates the compatibility issues between the T5 Retrofit LED lamps and the legacy electronic ballasts. The compatibility design focuses on the following points: 1. The LED lamps should generate stable light output at the specified lumen level; 2. The lifetime and reliability of the LED lamps and ballasts fulfill the given specifications; 3. The driver design should fit into the T5tubes.Two methods to ensure the compatibility have been studied, a passivemethod and an active method. The passive method utilizes inductance and capacitance to increase the load impedance seen by the ballasts so as to reduce the ballast output current and control the ballast thermal issues. Four structures with inductance and capacitance haven been analyzed by means of mathematical analysis and simulations. The active method realizes the LED current control that is absent in the passive method. Efforts are conducted to reduce the size of the two proposed active circuits. After the simulation analysis of each designs, a demonstration board has been built for experimental verification.Combining the passive methods with the active ones, four possible solutions that satisfy the design requirements are found. The comparisons between these solutions and the design suggestions are given in the last chapter

A 3D Object model for wireless camera networks with network constraints

A new general 3D object model is required in the literature of smart camera networks to facilitate future research. This paper presents a novel hierarchical and structural 3D model description which is well-suited for both events detection and real-time free view-point surveillance. With this 3D model, sparse points are used to reconstruct objects. In addition, the state of the model is easy to track and estimate, which can be used to reduce time and computation when reconstructing the model. Further, data flow in the network is reduced to the level where smart cameras can afford. Concrete data structure of the model is described in this paper and its reconstruction method, fusion method are provided. Finally, experiment results show its feasibility, efficiency and effectiveness. © 2009 IEEE

DietCam: Regular shape food recognition with a camera phone

The purpose of this paper is to develop an automatic camera phone based multi-view food classifier as part of a food intake assessment system. Food intake assessment is important for obesity management, which has shown significant impacts in public healthcare. Conventional dietary record based food intake assessment methods exhibit insufficient popularity due to their low accuracy and high dependence on human interactions. Image based food recognition appears recently. But it is still under development and far away from field applications. This paper presents DietCam, a camera phone based application to evaluate food intakes automatically from multiple perspectives. Food recognition from images is afflicted currently with a low recognition accuracy caused by the uncertainties of food appearances. The deformable nature of food items together with the complex background environment makes the problem even harder. DietCam separates every food item through evaluating the best perspective and recognize each of them from multiple images with a probabilistic method. The recognition accuracy is increased through an enhanced joint distribution from every viewpoint. A prototype of DietCam has been implemented on iPhone. In the field experiments, it shows an accuracy of 84% for regular shape food items. © 2011 IEEE

DietCam: Automatic dietary assessment with mobile camera phones

Obesity has become a severe health problem in developed countries, and a healthy food intake has been recognized as the key factor for obesity prevention. This paper presents a mobile phone based system, DietCam, to help assess food intakes with few human interventions. DietCam only requires users to take three images or a short video around the meal, then it will do the rest. The experiments of DietCam in real restaurants verify the possibility of food recognition with vision techniques. © 2010 Elsevier B.V. All rights reserved

A collaboration-based hybrid vehicular sensor network architecture

An intelligent transportation system aims to make roads safer and less congested. Compared to traditional sensor networks, this recently emerged sensor network is not restricted by the power supply and the storage space. These sensors are equipped with GPS devices and large amount flash memory cards. Under such environment, an effective and efficient architecture for data collection and data exchange is more important. This paper is concerned with such an system framework consisting of static road side sensors and mobile vehicular sensors. Road side sensors are distributed according to the road segmentation for collecting data from mobile vehicular sensors passing by. While mobile sensors on vehicles monitor the road condition and send this information to road side sensors and to mobile neighbors when they are close enough. This paper presents a detailed data collection, storage and exchange mechanism for vehicular sensor networks and addresses the congestion problem raised by multiple mobile sensor users when accessing to a single road side sensor at the same time. The simulation results show our system can reduce 42% traffic jams and save the drivers for upto 36.6% total time. © 2008 IEEE