Christian Koehler

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Reducing the large energy consumption of temperature regulation systems is a challenge for researchers and practitioners alike. In this paper, we explore and compare two common types of solutions: A manual systems that encourages reduced energy use, and an intelligent automatic control system. We deployed an eco-feedback system with the ability to remotely(More)
Smart devices are becoming increasingly commercially available. However, uptake of these devices has been slow and abandonment swift, which indicates that smart devices may not currently meet the needs of users. To advance an understanding of the ways users benefit from, are challenged by, and abandon smart devices, we asked a group of users to purchase(More)
Location prediction enables us to use a person's mobility history to realize various applications such as efficient temperature control, opportunistic meeting support, and automated receptionists. Indoor location prediction is a challenging problem, particularly due to a high density of possible locations and short transition distances between these(More)
Mobile phones allow us to reach people anywhere, at anytime. In addition to the benefits for end users, researchers and developers can also benefit from the powerful devices that participants carry on a daily basis. Collectively, mobile phones form a ubiquitous computer. Ubiquitous Mobile Instrumentation (UbiMI) workshop focuses on using mobile devices as(More)
GPGPUs (General Purpose Computation on Graphics Processing Unit) have become the most important invention in the last years in computer graphics and the vision domain. Despite improvement of the two main programming platforms, CUDA (Compute Unified Device Architecture) and OpenCL (Open Computing Language), GPGPU programming and development is still a(More)
Occupancy count in rooms is valuable for applications such as room utilization, opportunistic meeting support, and efficient heating-cooling operations. Few buildings, however, have the means of knowing occupancy beyond simple binary presence-absence. In this paper we present the <i>PerCCS</i> algorithm that explores the possibility of estimating person(More)
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