Digital Library[ Search Result ]
API-call Constraint Checking Considering Alarms and ISRs for IoT Device Control Software
http://doi.org/10.5626/JOK.2018.45.12.1269
The IoT operating system provides a set of API functions for applications along with a set of API-call constraints and all the applications are required to use API in accordance with these constraints. Improper use of API can result in breaking of system integrity and system failure. The prior study introduced a method for API-call constraint checking by converting the operating system and application into formal models and identifying API-call constraint violation scenarios through model checking. But, Alarms that should be considered for actual time or interrupts that can occur arbitrarily were left out of the scope of the verification. This study introduces the method for verifying API-call constraints considering the Alarms and ISRs. The actual time of an alarm is converted to the relative time of the formal model, and interrupts are defined to be generated anytime to activate an ISR in the verification model. Application of the verification method to 19 IoT applications led to the detection of a total of 34 API-call constraint violations, 15 of which were not detected due to lack of consideration of Alarms and/or ISRs.
Case Study for Collecting Policy Evaluation Factors upon Request when Creating XACML Policy
http://doi.org/10.5626/JOK.2018.45.9.975
As the Internet of Things environment continues to expand, access control issues continue to emerge. OneM2M, one of the standards of the IOT platform, allows access control using XACML. In the arena of access control, conflicts must be solved. Because of this, various solutions are being investigated in order to solve these problems. Currently, however, the policy editor must solve policy conflicts by themselves. So, the policy editor needs to be able to effectively collect information about policies and conditions that affect their policy evaluation decisions in order to resolve policy conflicts. In this paper, we analyze policy and express policy evaluation methods in terms of Truth Table. In addition, we present a tree-based policy evaluation factor collection method through a case study on a policy evaluation factor collection method according to requests using Truth Table.
RANSAC-based Time Synchronization over Wireless Networks
Junyoup Hwang, Daehyeon Wi, Jungjin Lee
http://doi.org/10.5626/JOK.2018.45.7.626
This paper describes a method to improve the quality of time synchronization for synchronous video streaming over a wireless network using a Simple Network Time Protocol (SNTP) with the RANdom SAmple Consensus (RANSAC) Algorithm. Time synchronization is mostly accomplished by using the NTP server. Speed and accuracy are important in synchronizing the video play module; however, NTP is limited because too much time is spent to operate the module. It also requires a complex structure and algorithms for customization. And SNTP, which is easy to implement, is also inappropriate for the wireless network because there is no filtering process for network failure. Our method refined those timestamps of SNTP using RANSAC, so that it achieves a stable synchronization, with 5 milliseconds of accuracy, which takes less than 5 seconds. This method enables high- quality time synchronization with a simple implementation for any kind of system, and will be useful for IoT devices.
CEP Rule Distribution Algorithm for In-network Processing in an IoT Network Environment
http://doi.org/10.5626/JOK.2018.45.7.722
As the number of IoT devices increases, data coming from devices are also increasing exponentially. The data generated from devices are stored and managed through a system structure using the database. However, to manage the surging data, the existing database is limited in terms of maintenance costs and in real time. Too overcome these limitations, Complex Event Processing (CEP), which processes data as much as possible within the network, has emerged, and data processing is being carried out using this strategy. In this paper, we propose a CEP Rule distribution algorithm which can reduce server burden and guarantee network performance through distribution of the CEP Rule in an IoT environment. To prove this, we perform a small experiment using open source, such as the OpenWSN and TelosB node, and verify the mitigation of server load and the performance of data processing according to the algorithm.
Activity Prediction from Sensor Data using Convolutional Neural Networks and an Efficient Compression Method
Woojeong Jin, Dongjin Choi, Youngjin Kim, U Kang
http://doi.org/10.5626/JOK.2018.45.6.564
The identification of the number of occupants and their activities using the IoT system in a building is an important task to improve the power efficiency and reduce the cost of using smart cooling/heating systems. In the actual building management system, it is possible to use equipment such as a camera to understand the current situation in the room, and to directly determine the number of occupants and their types of behavior. However, identifying the number of people and behavior types in this way is inefficient and requires a large amount of storage space for data. In this study, indoor sensor data were collected using an infrared Grid-Eye sensor and noise sensor. Based on this data, we also propose a deep learning model that captures the number of participants and behavior patterns and a deep learning model that considers the temporal characteristics of data. The proposed model identifies the number of people with an accuracy of about 95.3% and human activities with an accuracy of 90.9%. We also propose a method to reduce the storage space while minimizing the loss of accuracy using truncated SVD.
Design and Implementation of Security System for Providing Secure Boot and Firmware Update in Low-end IoT Device
Kiyeong Lee, Byoungseon Kim, Jinsung Cho
http://doi.org/10.5626/JOK.2018.45.4.321
Low-end IoT devices are problematic due to the many limitations involved in applying IoT devices to various existing security solutions. This is because most security solutions are targeted at high-performance PC environments. These limitations are causing steadily increasing technical security vulnerabilities and various security threats to IoT devices. In this paper, we propose a secure boot and firmware update system that can be applied in a constrained environment. At the secure boot, the proposed system verifies the integrity of the firmware of the device. The secure firmware update performs reliability verification of the subject attempting to update. Finally, we analyze the security performance of the proposed system by simulating various threats that may occur in low-end IoT devices.
A Route Repair Scheme for Reducing DIO Poisoning Overhead in RPL-based IoT Networks
In the IoT network environments for LLNs(Low power and Lossy networks), IPv6 Routing Protocol for Low Power and Lossy networks(RPL) has been proposed by IETF(Internet Engineering Task Force). The goal of RPL is to create a directed acyclic graph, without loops. As recommended by the IETF standard, RPL route recovery mechanisms in the event of a failure of a node should avoid loop, loop detection, DIO Poisoning. In this process, route recovery time and control message might be increased in the sub-tree because of the repeated route search. In this paper, we suggested RPL route recovery method to solve the routing overhead problem in the sub-tree during a loss of a link in the RPL routing protocol based on IoT wireless networks. The proposed method improved local repair process by utilizing a route that could not be selected as the preferred existing parents. This reduced the traffic control packet, especially in the disconnected node’s sub tree. It also resulted in a quick recovery. Our simulation results showed that the proposed RPL local repair reduced the recovery time and the traffic of control packets of RPL. According to our experiment results, the proposed method improved the recovery performance of RPL.
Analysis of Research Trend and Performance Comparison on Message Authentication Code
Cryptographic technologies providing confidentiality and integrity such as encryption algorithms and message authentication codes (MACs) are necessary for preventing security threats in the Internet of Things (IoT) where various kinds of devices are interconnected. As a number of encryption schemes that have passed security verification are not necessarily suitable for low-power and low-performance IoT devices, various lightweight cryptographic schemes have been proposed. However, a study of lightweight MACs is not sufficient in comparison to that of lightweight block ciphers. Therefore, in this paper, we reviewed various kinds of MACs for their classification and analysis and then, we presented a new way for future MAC development. We also implemented major MAC algorithms and performed experiments to investigate their performance degradation on low-end micro-controllers.
Smart Fog : Advanced Fog Server-centric Things Abstraction Framework for Multi-service IoT System
Gyeonghwan Hong, Eunsoo Park, Sihoon Choi, Dongkun Shin
Recently, several research studies on things abstraction framework have been proposed in order to implement the multi-service Internet of Things (IoT) system, where various IoT services share the thing devices. Distributed things abstraction has an IoT service duplication problem, which aggravates power consumption of mobile devices and network traffic. On the other hand, cloud server-centric things abstraction cannot cover real-time interactions due to long network delay. Fog server-centric things abstraction has limits in insufficient IoT interfaces. In this paper, we propose Smart Fog which is a fog server-centric things abstraction framework to resolve the problems of the existing things abstraction frameworks. Smart Fog consists of software modules to operate the Smart Gateway and three interfaces. Smart Fog is implemented based on IoTivity framework and OIC standard. We construct a smart home prototype on an embedded board Odroid-XU3 using Smart Fog. We evaluate the network performance and energy efficiency of Smart Fog. The experimental results indicate that the Smart Fog shows short network latency, which can perform real-time interaction. The results also show that the proposed framework has reduction in the network traffic of 74% and power consumption of 21% in mobile device, compared to distributed things abstraction.
Systematic Development of Mobile IoT Device Power Management : Feature-based Variability Modeling and Asset Development
Hyesun Lee, Kang Bok Lee, Hyo-Chan Bang
Internet of Things (IoT) is an environment where various devices are connected to each other via a wired/wireless network and where the devices gather, process, exchange, and share information. Some of the most important types of IoT devices are mobile IoT devices such as smartphones. These devices provide various high-performance services to users but cannot be supplied with power all the time; therefore, power management appropriate to a given IoT environment is necessary. Power management of mobile IoT devices involves complex relationships between various entities such as application processors (APs), HW modules inside/outside AP, Operating System (OS), platforms, and applications; a method is therefore needed to systematically analyze and manage these relationships. In addition, variabilities related to power management such as various policies, operational environments, and algorithms need to be analyzed and applied to power management development. In this paper, engineering principles and a method based on them are presented in order to address these challenges and support systematic development of IoT device power management. Power management of connected helmet systems was used to validate the feasibility of the proposed method.
Search
Journal of KIISE
- ISSN : 2383-630X(Print)
- ISSN : 2383-6296(Electronic)
- KCI Accredited Journal
Editorial Office
- Tel. +82-2-588-9240
- Fax. +82-2-521-1352
- E-mail. chwoo@kiise.or.kr