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Article Citation - Scopus: 1Determination of Metabolic Rate From Physical Measurements of Heart Rate, Mean Skin Temperature and Carbon Dioxide Variation(Sakarya University, 2022) Özbey, M.F.; Çeter, A.E.; Turhan, C.Thermal comfort depends on four environmental parameters such as air temperature, mean radiant temperature, air velocity and relative humidity and two personal parameters, including clothing insulation and metabolic rate. Environmental parameters can be measured via objective sensors. However, personal parameters can be merely estimated in most of the studies. Metabolic rate is one of the problematic personal parameters that affect the accuracy of thermal comfort models. International thermal comfort standards still use a conventional metabolic rate table which is tabulated according to different activity tasks. On the other hand, ISO 8996 underestimates metabolic rates, especially when the time of activity level is short and rest time is long. To this aim, this paper aims to determine metabolic rates from physical measurements of heart rate, mean skin temperature and carbon dioxide variation by means of nineteen sample activities. 21 male and 17 female subjects with different body mass indices, sex and age are used in the study. The occupants are subjected to different activity tasks while heart rate, skin temperature and carbon dioxide variation are measured via objective sensors. The results show that the metabolic rate can be estimated with a multivariable non-linear regression equation with high accuracy of 0.97. © 2022, Sakarya University. All rights reserved.Article A Practical Distributed Lightweight Multi-Hop Time Synchronization Algorithm for Linear Wireless Sensor Networks Implemented on a Pic Based System With Realistic Experimental Analysis(Sakarya University, 2020) Erpay, A.; Al Imran, M.A.; Kara, A.Time synchronization is fundamental in the distributed networked systems, especially in Wireless Sensor Networks where a global time is essential to make sense of the events like collection of data and scheduled sleep/wake-up of nodes. There exists numerous time synchronization algorithms and techniques in the literature. Nonetheless, these proposed methods lack realistic experimentation of the synchronization process which is vital from the realization point of view. This study aims to bridge that gap by presenting a distributed lightweight time synchronization protocol implemented on an inexpensive PIC platform. Furthermore, PIC-based systems hadn’t been investigated before and gives an idea of the simplicity of the algorithm. Experimental analysis was done to see the performance of the protocol. The core motivation of the experiments was to the study the impact of the environment (e.g. indoor, outdoors, temperature variations and interference) on the synchronization. Our findings show that temperature indeed impedes the synchronization accuracy. © 2020, Sakarya University. All rights reserved.
