Seong Ro Lee

Android based smart home system with control via Bluetooth and internet connectivity

Automation plays an important role in todays human life and peoples life is gradually changing with smart living due to modern technology development and Android Smartphone. This paper presents a low-cost Smart Living System, which uses Android based User Interface for control of home appliances. Connection to the smart living system can be made from the designed app via Bluetooth or internet connection. It also integrates home security and alert system.

Towards Internet of Things (IOTS): Integration of Wireless Sensor Network to Cloud Services for Data Collection and Sharing

Cloud computing provides great benefits for applications hosted on the Web that also have special computational and storage requirements. This paper proposes an extensible and flexible architecture for integrating Wireless Sensor Networks with the Cloud. We have used REST based Web services as an interoperable application layer that can be directly integrated into other application domains for remote monitoring such as e-health care services, smart homes, or even vehicular area networks (VAN). For proof of concept, we have implemented a REST based Web services on an IP based low power WSN test bed, which enables data access from anywhere. The alert feature has also been implemented to notify users via email or tweets for monitoring data when they exceed values and events of interest.

Received signal strength ratio based optical wireless indoor localization using light emitting diodes for illumination

We propose optical wireless indoor localization using light emitting diodes (LEDs). In the proposed method, four LED lamps for illumination are employed and strength ratio between received LED light signals is utilized for location estimation.

Relay Precoding for Non-Regenerative MIMO Relay Systems with Partial CSI Feedback

We consider a relay precoding problem in a non-regenerative multiple-input multiple-output (MIMO) relay system, where the relay has the perfect channel state information of the source-relay link and only the covariance information of the relay-destination link. The average capacity seen by the relay is maximized under a relay transmit power constraint. The relay precoding problem is transformed to its equivalent power allocation problem at the relay. The optimal power allocation solution is then derived by formulating the optimization problem via difference of convex (DC) functions programming. To reduce the computational complexity, we also propose a suboptimal scheme by modifying the naive Jensen method. Furthermore, we propose the maximum eigenmode relaying (MER) scheme, which allocates the relay transmit power only to the maximum eigenmode. A necessary and sufficient condition for the MER to be asymptotically optimal is derived in the high signal-to-noise ratio (SNR) regime of the source-relay link. The performance of the proposed schemes is investigated through extensive numerical simulations.

Integrating Wireless Sensor Network into Cloud services for real-time data collection

This paper presents an extensible and flexible architecture for integrating Wireless Sensor Networks with the Cloud. REST based Web services is used as an interoperable application layer that can be directly integrated into other application domains for remote monitoring such as e-health care services and smart environments. For proof of concept, we have set up a REST based Web services on an IP based low power WSN test bed, which enables data accessibility from anywhere. The alert feature has also been implemented to notify users via email or tweets for monitoring data when they exceed values and events of interest.

Red tides prediction system using fuzzy reasoning and the ensemble method

A red tide is a temporary natural phenomenon in which harmful algal blooms (HABs) can lead to fin fish and shellfish dying en masse. For example, HABs can damage sea farming on the coast of South Korea, and generally have a bad influence on the coastal environment and sea ecosystem. Prediction of red tide blooms, which consists of a categorical type and a numerical type, can minimize the mitigation cost of HAB disasters and the suffering caused by the damage from red tide events. The first type of prediction has high precision but it represents a simple binary result, and the second can predict how much harm an algal increase causes, but its prediction has lower accuracy than the results of the categorical type. To enhance the automatic forecast of red tide, this paper proposes a red tide prediction method that uses fuzzy reasoning and the ensemble method to obtain prediction results for the categorical and numerical types. The proposed method improves the precision of categorical prediction because the ensemble classifier is enhanced by optimal data of the proposed preprocessing. The method forecasts a numerical prediction, such as the increasing density of red tide algae, using the fuzzy reasoning by which the accuracy of numerical results is improved by the proposed post-processing. The experimental results demonstrate that the proposed method achieves a better red tide prediction performance than other single classifiers.

Review on Sensor Cloud and Its Integration with Arduino Based Sensor Network

The expansion of embedded ICT infrastructure has resulted in the deployment of a wide range of embedded systems in our environment which indicate the need for reusable, manageable and flexible Wireless Sensor Network. Integration of WSN infrastructure with Cloud simplifies the system operation and maintenance as well as the cost and capable of providing services to multiple end users. The integration offers benefits whereby common processing, computational and analytical tasks can be hosted on cloud service and freeing the devices from running heavy applications, hence reducing power consumption and maximizing the lifetime of power units as well as the network itself. The sensor clouds are therefore gaining popularity for providing an open, flexible and a reconfigurable platform for many monitoring and controlling applications. This paper looks at the benefits and basic features of Senor Cloud Services and how Ethernet enabled Arduino microcontroller based sensor network can be integrated to send sensor data to them by looking at three popular cloud services.

Indoor location awareness based on received signal strength ratio and time division multiplexing using light-emitting diode light

Abstract. We propose and demonstrate an indoor location awareness method for an autonomous robot vehicle using light-emitting diodes (LEDs). The location is estimated by measuring received signal strength ratio (RSSR), which is the relative ratio of optical powers detected between each LED and optical receiver. In this method, multiple LED lamps on the indoor ceiling are used, which can radiate light only during the individual time slot assigned to each of them. Using the RSSRs, circle or straight line equations are obtained and the crossing point among those equations determines the location of the object. In the experiment, four LED lamps are identified by time-division multiplexing with room dimensions of 1.0×1.0×1.3  m3, and the results show that the mean of the location error is 3.24 cm in the entire floor area.

Design and Analysis of Low-Complexity Multi-Antenna Relaying for OFDM-Based Relay Networks

A class of low-complexity multi-antenna relaying schemes is proposed for orthogonal frequency division multiplexing based one-way and two-way relay networks. In the proposed schemes, two single-antenna terminal nodes complete the data transfer in two time phases via a multi-antenna amplify-and-forward relay without channel state information, discrete Fourier transform (DFT), and inverse DFT. The relay signal processing consists of receive combining, power scaling, and transmit diversity, where instantaneous time domain power scaling is proposed for power scaling and power-based selection combining and cyclic delay combining are proposed for receive combining, to leverage the performance only with time domain operations. An approximation to the outage probability is also derived to predict the coded performance behavior under practical channel models. It is shown by evaluating the outage probability and coded bit error rate that the proposed schemes outperform the conventional schemes of comparable complexity.

Rate-aware three phase analog network coding with low-complexity multi-antenna relay processing

A low-complexity design of multi-antenna relay processing is proposed for two-way relay networks with asymmetric data flows. The proposed scheme adopts three-phase (3P) analog network coding (ANC) which allows orthogonal transmission of two communicating nodes to overcome some disadvantages of two-phase (2P) ANC protocols. For the 3P ANC, we propose antenna selection at the relay to exploit the diversity without channel estimation and rate-aware relay power allocation (RPA) to improve the outage performance under the asymmetric rate requirements. The results show that the proposed scheme without or with RPA outperforms the conventional two-phase ANC significantly in various relay locations. It is also shown that the suboptimal RPA proposed for practical implementation provides a performance close to that of the optimal RPA.