• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.1201-1211
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• 2015

WSN acts as an effective tool for tracking the large scale environments. In such environment, the battery life of the sensor networks is limited due to collection of the data, usage of sensing, computation and communication. To resolve this, a mobile robot is presented to identify the data present in the partitioned sensor networks and passed onto the sink. In novel data collection algorithm, the performance of the data collecting operation is reduced because mobile robot can be used only within the limited range. To enhance the data collection in a changing environment, Non Linear Error Identifier (NLEI) algorithm has been developed and presented in this paper to configure the robot by means of error models which are non-linear. Experimental evaluation has been conducted to estimate the performance of the proposed NLEI and it has been observed that the proposed NLEI algorithm increases the error correction rate upto 42% and efficiency upto 60%.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.603-605
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• 2003

Constructing a geo-spatial database of Graphic Information Systems(GIS) in various applications is suffering from the difficulty of data acquisition, which is labor-intensive and time consuming. In order to provide the spatial data rapidly and accurately, 4S-Van, a prototype mobile mapping system, has been developed. This paper presents a novel approach for an analysis for Mobile Mapping Systems. Furthermore, we discuss the accuracy of measurements using images acquired from the 4S-Van. The first part of this paper introduces accuracies of other mobile mapping systems. Then, we describe main features of the 4S-Van and our proposed method for an analysis accuracies, which can be applicable to other mobile mapping systems. The last part of paper concludes with a summary and our suggestions for implementation of mobile mapping system.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2023년도 춘계학술발표대회
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• pp.104-106
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• 2023

The mobile crowdsensing platform obtains sensing data from mobile users, and the involvement of the public increases the untrustworthy of collected data. In order to distinguish factual data from inaccurate data provided by untrustworthy users, the truth discovery method has been introduced for accurate data aggregation in mobile crowdsensing (MCS). To explore the application of truth discovery in mobile crowdsensing, we overview the general concepts of truth discovery algorithms. Finally, we summarize the main existing application prospects of truth discovery in mobile crowdsensing.

• International Journal of Internet, Broadcasting and Communication
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• 제12권3호
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• pp.32-38
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• 2020

The deployment of geographically distributed wireless sensors has greatly elevated the capability of monitoring structural health in social-overhead capital (SOC) public infrastructures. This paper deals with the utilization of a distributed mobility management (DMM) approach for the deployment of wireless sensing devices in a structural health monitoring system (SHM). Then, a wireless sensing mechanism utilizing low-energy adaptive clustering hierarchy (LEACH)-based clustering algorithm for smart sensors has been analyzed to support the seamless data transmission of structural health information which is essentially important to guarantee public safety. The clustering of smart sensors will be able to provide real-time monitoring of structural health and a filtering algorithm to boost the transmission of critical information over heterogeneous wireless and mobile networks.

• Journal of Information Processing Systems
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• 제14권2호
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• pp.286-308
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• 2018

The availability of powerful and sensor-enabled mobile and Internet-connected devices have enabled the advent of the ubiquitous sensor network (USN) paradigm. USN provides various types of solutions to the general public in multiple sectors, including environmental monitoring, entertainment, transportation, security, and healthcare. Here, we explore and compare the features of wireless sensor networks and USN. Based on our extensive study, we classify the security- and privacy-related challenges of USNs. We identify and discuss solutions available to address these challenges. Finally, we briefly discuss open challenges for designing more secure and privacy-preserving approaches in next-generation USNs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권3호
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• pp.1287-1300
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• 2018

Target-tracking algorithm based on ad hoc camera sensor networks (ACSNs) utilizes the distributed observation capability of nodes to achieve accurate target tracking. A compressed sensing-based multiple-target tracking algorithm (CSMTTA) for ACSNs is proposed in this work based on the study of camera node observation projection model and compressed sensing model. The proposed algorithm includes reconfiguration of observed signals and evaluation of target locations. It reconfigures observed signals by solving the convex optimization of L1-norm least and forecasts node group to evaluate a target location by the motion features of the target. Simulation results show that CSMTTA can recover the subtracted observation information accurately under the condition of sparse sampling to a high target-tracking accuracy and accomplish the distributed tracking task of multiple mobile targets.

• Current Optics and Photonics
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• 제7권2호
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• pp.200-206
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• 2023

Near-infrared (NIR) sensing technology using CMOS image sensors is used in many applications, including automobiles, biological inspection, surveillance, and mobile devices. An intuitive way to improve NIR sensitivity is to thicken the light absorption layer (silicon). However, thickened silicon lacks NIR sensitivity and has other disadvantages, such as diminished optical performance (e.g. crosstalk) and difficulty in processing. In this paper, a pixel structure for NIR sensing using a stacked CMOS image sensor is introduced. There are two photodetection layers, a conventional layer and a bottom photodiode, in the stacked CMOS image sensor. The bottom photodiode is used as the NIR absorption layer. Therefore, the suggested pixel structure does not change the thickness of the conventional photodiode. To verify the suggested pixel structure, sensitivity was simulated using an optical simulator. As a result, the sensitivity was improved by a maximum of 130% and 160% at wavelengths of 850 nm and 940 nm, respectively, with a pixel size of 1.2 ㎛. Therefore, the proposed pixel structure is useful for NIR sensing without thickening the silicon.

• 한국통신학회논문지
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• 제34권4B호
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• pp.338-348
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• 2009

최근 들어 무선 센서망은 저렴한 가격과 망 구성의 용이함 덕분에 많은 관심을 끌고 있다. 특히, 사람들이 직접 센서를 설치할 수 없는 재난 지역이나 위험 지역에 공중에서 센서를 뿌리는 것만으로도 망을 구성할 수 있다는 것은 상당히 중요한 장점이다. 하지만, 공중에서 센서를 흩뿌려 망을 설치하는 경우 센서들이 최적의 장소에 설치될 수가 없는데, 이는 최적의 위치에 설치된 센서망에 비해 더 많은 에너지의 사용, 그에 따른 수명의 단축 등 상당한 성능 저하를 감수해야 한다. 게다가 센서들이 계획적으로 설치된 망과는 달리 임의로 설치된 경우에는 센서들의 감지 영역에 포함되지 못하는 부분들이 생길 수 있다. 이 논문에서는 감지 영역을 벗어난 지역으로 이동 가능한 센서들을 움직여 전체 망의 감지 능력을 향상시키는 센서 재배치 방법을 제안한다. 실험 결과, 이 논문의 제안 방법이 기존 방법들에 비해 넓은 감지 능력과 센서망의 수명 향상을 가져오는 것으로 확인되었다.

• Smart Structures and Systems
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• 제29권1호
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• pp.141-151
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• 2022

In recent years, the industry and research communities have focused on developing autonomous crack inspection approaches, which mainly include image acquisition and crack detection. In these approaches, mobile devices such as cameras, drones or smartphones are utilized as sensing platforms to acquire structural images, and the deep learning (DL)-based methods are being developed as important crack detection approaches. However, the process of image acquisition and collection is time-consuming, which delays the inspection. Also, the present mobile devices such as smartphones can be not only a sensing platform but also a computing platform that can be embedded with deep neural networks (DNNs) to conduct on-site crack detection. Due to the limited computing resources of mobile devices, the size of the DNNs should be reduced to improve the computational efficiency. In this study, an architecture called pruned crack recognition network (PCR-Net) was developed for the detection of structural cracks. A dataset containing 11000 images was established based on the raw images from bridge inspections. A pruning method was introduced to reduce the size of the base architecture for the optimization of the model size. Comparative studies were conducted with image processing techniques (IPTs) and other DNNs for the evaluation of the performance of the proposed PCR-Net. Furthermore, a modularly designed framework that integrated the PCR-Net was developed to realize a DL-based crack detection application for smartphones. Finally, on-site crack detection experiments were carried out to validate the performance of the developed system of smartphone-based detection of structural cracks.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.184-184
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• 2000

The new-type measuring modules for unmanned remote supervisory system using mobile communication network have been designed in this study. Measuring modules consist of temperature measuring module, humidity measuring module and human body sensing module. And we will design a main part to collect and process informations of each modules, evaluate reliability of combined total system.