• International Journal of Safety
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• 제8권1호
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• pp.10-13
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• 2009

In this study, a framework for web-based information system in VDN environment for safety and health monitoring in subway stations is suggested. Since physical variables that describing safety and health need to be closely monitored in multiple locations in subway stations, concept of distributed monitoring network using wireless media needs to be implemented. Connecting remote wireless sensor network and device (LonWorks) networks to the IP network based on the concept of VDN can provide a powerful, integrated and distributed monitoring performance, making a web-based information system possible.

• 대한임베디드공학회논문지
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• 제3권3호
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• pp.158-166
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• 2008

These days, mobile embedded systems adopt flash memory capable of XIP feature since they can reduce memory usage, power consumption, and software load time. XIP provides direct access to ROM and flash memory for processors. However, using XIP incurs unnecessary degradation of applications' performance because direct access to ROM and flash memory shows more delay than that to main memory. In this paper, we propose a memory management framework, dynamic XIP, which can resolve the performance degradation of using XIP. Using a constrained RAM cache, dynamic XIP can dynamically change XIP region according to page access pattern to reduce performance degradation in execution time or energy consumption resulting from native XIP problem. The proposed framework consists of a page profiler gathering applications' memory access pattern using PMU and an XIP manager deciding that a page is accessed whether in main memory or in flash memory. The proposed framework is implemented and evaluated in Linux kernel. Our evaluation shows that our framework can reduce execution time at most 25% and energy consumption at most 22% compared with using XIP-only case adopted in general mobile embedded systems. Moreover, the evaluation shows that in execution time and energy consumption, our modified LRU algorithm with code page filters can reduce more than at most 90% and 80% respectively compared with applying just existing LRU algorithm to dynamic XIP.

• 대한임베디드공학회논문지
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• 제1권2호
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• pp.56-63
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• 2006

In this paper, we propose the integrated security management framework supporting the trust for the ubiquitous environments. The proposed framework provides the gathering and analysis of the security related information including the location of mobile device and then dynamically configures the security policy and adopts them. More specially, it supports the authentication and delegation service to support the trusted security management for the ubiquitous networks. This system also provides the visible management tools to give the convenient view for network administrator.

• ETRI Journal
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• 제39권2호
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• pp.202-212
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• 2017

With the advent of the Internet-of-Things paradigm, the amount of data production has grown exponentially and the user demand for responsive consumption of data has increased significantly. Herein, we present DART, a fast and lightweight stream processing framework for the IoT environment. Because the DART framework targets a geospatially distributed environment of heterogeneous devices, the framework provides (1) an end-user tool for device registration and application authoring, (2) automatic worker node monitoring and task allocations, and (3) runtime management of user applications with fault tolerance. To maximize performance, the DART framework adopts an actor model in which applications are segmented into microtasks and assigned to an actor following a single responsibility. To prove the feasibility of the proposed framework, we implemented the DART system. We also conducted experiments to show that the system can significantly reduce computing burdens and alleviate network load by utilizing the idle resources of intermediate edge devices.

• 한국컴퓨터정보학회논문지
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• 제20권2호
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• pp.71-77
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• 2015

본 논문은 무선 센서 네트워크를 이용하여 동적 애플리케이션 프레임워크 기반의 데이터 수집 및 모니터링 기법을 제안한다. 무선 측정 노드의 펨웨어 프로그램을 위한 애플리케이션 개발의 최적화를 통해서 다양한 센서들과의 통합 및 제어를 수행한다. 사용자 애플리케이션의 수집 데이터는 노드의 온보드 프로세서에서 무선으로 다운로드되고, 노드의 온도 초기값 설정을 사용자 애플리케이션으로부터 변경을 지시할 수 있으므로 측정 노드의 동적 샘플링이 가능하다. 따라서 노드의 동적 샘플링 제어를 통해서 기존의 유선 기반의 데이터 모니터링에 비해 센서의 소비전력을 감소시킬 수 있다.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.1-10
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• 2018

Wide-area monitoring of tree-related high impedance fault (THIF) efficiently contributes to increase reliability of large-scaled network, since the failure to early location of them may results in critical lines tripping and consequently large blackouts. In the first place, this wide-area monitoring of THIF requires managing the placement of sensors across large power grid network according to THIF detection objective. For this purpose, current paper presents a framework in which sensors are distributed according to a predetermined risk map. The proposed risk map determines the possibility of THIF occurrence on every branch in a power network, based on electrical conductivity of trees and their positions to power lines which extracted from spectral data. The obtained possibility value can be considered as a weight coefficient assigned to each branch in sensor placement problem. The next step after sensors deployment is to on-line monitor based on moving data window. In this on-line process, the received data window is evaluated for obtaining a correlation between low frequency and high frequency components of signal. If obtained correlation follows a specified pattern, received signal is considered as a THIF. Thereafter, if several faulted section candidates are found by deployed sensors, the most likely location is chosen from the list of candidates based on predetermined THIF risk map.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권7호
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• pp.112-120
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• 2015

Statistical trend analysis using the data from the National Groundwater Quality Monitoring Network (NGQMN) of Korea was conducted to establish a new groundwater quality management framework. Sen’s test, a non-parametric statistical method for trend analysis, was used to determine the linear trend of the groundwater quality data. The analysis was conducted at different confidence levels (i.e., at 70, 80, 90, 95, and 99% confidence levels) for three of groundwater quality parameters, i.e., nitrate-nitrogen, chloride, and pH, which have sufficient time series of the NGQMN data between 2007 and 2013. The results showed that different trends can be determined for different depths even for the same monitoring site and the numbers of wells having significant trends vary with different confidence levels. The wells with increasing or decreasing trends were far less than the wells with no trend. Chloride had more wells with increasing trend than other parameters. On the other hand, nitrate-nitrogen had the most wells with increasing trend and concentration exceeding 75% of the threshold values (TVs). Based on the methodology used for this study, we suggest including groundwater TVs and trend analysis to evaluate groundwater quality and to establish an advanced groundwater quality management framework.

• 한국융합학회논문지
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• 제11권3호
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• pp.77-83
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• 2020

최근 지능형 예측감시 시스템이 등장하고 있다. 지능형 예측감시 시스템의 추론을 위해서는 현재 및 과거의 데이터가 필요하며, 이러한 데이터의 분석을 통하여 곧 발생할 상황에 대한 예측을 가능하게 한다. 그러나, 이러한 과정에서 영상 객체의 개인정보를 취급하게 될 소지가 높으므로, 개인정보보호를 위해서는 보안에 대한 고려가 필수적이다. 특히, 개인의 생활패턴, 주요 이동 경로 등에 대한 정보가 해킹을 통하여 공개적으로 노출된다면 프라이버시 측면에서 문제가 될 것이다. 기존의 영상감시 프레임워크는 개인정보보호 측면에서 한계점이 있으며, 특히 개인정보보호에 취약한 측면이 있다. 본 논문에서는 개인정보보호를 고려한 지능형 예측감시 시스템을 위한 보안 프레임워크를 제안하였다. 제안한 방법에서는 단말, 전송, 감시, 모니터링 계층으로 구분하여 단위별 세부 구성요소를 명시하였으며, 특히 객체 단위별 세부 접근제어와 비식별화를 지원하여 영상감시 과정에서의 능동형 개인정보보호가 가능하다. 또한, 데이터 전송시 보안 기능과 RBAC 제공을 통한 접근제어의 장점을 갖는다.

• Smart Structures and Systems
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• 제29권1호
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• pp.251-266
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• 2022

Structural Health Monitoring (SHM) of critical infrastructure comprises a major pillar of maintenance management, shielding public safety and economic sustainability. Although SHM is usually associated with data-driven metrics and thresholds, expert judgement is essential, especially in cases where erroneous predictions can bear casualties or substantial economic loss. Considering that visual inspections are time consuming and potentially subjective, artificial-intelligence tools may be leveraged in order to minimize the inspection effort and provide objective outcomes. In this context, timely detection of sensor malfunctioning is crucial in preventing inaccurate assessment and false alarms. The present work introduces a sensor-fault detection and interpretation framework, based on the well-established support-vector machine scheme for anomaly detection, combined with a coalitional game-theory approach. The proposed framework is implemented in two datasets, provided along the 1st International Project Competition for Structural Health Monitoring (IPC-SHM 2020), comprising acceleration and cable-load measurements from two real cable-stayed bridges. The results demonstrate good predictive performance and highlight the potential for seamless adaption of the algorithm to intrinsically different data domains. For the first time, the term "decision trajectories", originating from the field of cognitive sciences, is introduced and applied in the context of SHM. This provides an intuitive and comprehensive illustration of the impact of individual features, along with an elaboration on feature dependencies that drive individual model predictions. Overall, the proposed framework provides an easy-to-train, application-agnostic and interpretable anomaly detector, which can be integrated into the preprocessing part of various SHM and condition-monitoring applications, offering a first screening of the sensor health prior to further analysis.

• International Journal of Computer Science & Network Security
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• 제23권5호
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• pp.89-94
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• 2023

Cloud-based technology is used in different organizations around the world for various purposes. Using this technology, the service providers provide the service mainly SaaS, PaaS and while the cloud service consumer consumes the services by paying for the service they used or accessed by the principle of "pay per use". The customer of the services can get any services being at different places or locations using different machines or electronic devices. Under the conditions of being well organized and having all necessary infrastructures, the services can be accessed suitably. The identified problem in this study is that cloud providers control and monitor the system or tools by ignoring the calculation and consideration of various faults made from the cloud provider side during service delivery. There are currently problems with ignoring the consumer or client during the monitoring and mentoring system for cloud services consumed at the customer or client level by SLA provisions. The new framework was developed to address the above-mentioned problems. The framework was developed as a unified modeling language. Eight basic components are used to develop the framework. For this research, the researcher developed a prototype by using a selected cloud tool to simulate and java programming language to write a code as well as MySQL to store data during SLA. The researcher used different criteria to validate the developed framework i.e. to validate SLA that is concerned with a cloud service provider, validate what happened when the request from the client-side is less than what is specified in SLA and above what is specified in SLA as well as implementing the monitoring mechanism using the developed Monitoring component. The researcher observed that with the 1st and 3rd criteria the service level agreement was violated and this indicated that if the Service level agreement is monitored or managed only by cloud service prover, there is a violation of LSA. Therefore, the researcher recommended that the service level agreement be managed by both cloud service providers and service consumers in the cloud computing environment.