• Journal of Advanced Navigation Technology
• /
• v.11 no.3
• /
• pp.259-265
• /
• 2007

Systematic components for implementing ubiquitous computing, for example, electronic devices, electric home appliances, and controllers, etc, are consist of not only circuits but also softwares expected to do some special system-controlling functions, and these softwares used to be called like as embedded software. Because embedded software is a core component controlling systems, the codes or control flows should be protected from being opened to the public or modified. Embedded software security can be divided into 2 parts: first is the unauthorized access to development site and embedded software, second is the unauthorized disclosure or modification. And this research is related to the first aspect of them.This paper proposes some security check requirements related to embedded software development site by analyzing the ALC_DVS.1 of the ISO/IEC 15408 and Base Practices (BPs) of the ISO/IEC 21827. By applying this research, we expect to protect unauthorized modification of embedded software indirectly.

• Journal of KIISE:Computing Practices and Letters
• /
• v.14 no.6
• /
• pp.589-593
• /
• 2008

These days, as a side effect of the growth of the mobile devices, malwares for the mobile devices also tend to increase and become more dangerous. Because embedded Linux is one of the advanced OSes on mobile devices, a solution to preventing malwares from infecting and destroying embedded Linux will be needed. We present a scheme using signature verification for embedded Linux that prevents executallle-Infecting malwares. The proposed scheme works under collaboration between mobile devices and a server. Malware detection is delegated to the server. In a mobile device, only integrity of all executables and dynamic libraries is checked at kernel level every time by kernel modules using LSM hooks just prior to loading of executables and dynamic libraries. All procedures in the mobile devices are performed only at kernel level. In experiments with a mobile embedded device, we confirmed that the scheme is able to prevent all executable-Infecting malwares while minimizing damage caused by execution of malwares or infected files, power consumption and performance overheads caused by malware check routines.

• Journal of KIISE:Computing Practices and Letters
• /
• v.14 no.6
• /
• pp.547-558
• /
• 2008

Embedded system is tightly coupled with heterogeneous layers such as application, as kernel, device driver, HAL and hardware. Embedded system is customized for the specific purpose and hardware. In addition, the product cycle is so fast that software and hardware, which are developed by several vendors, are integrated together under unstable status. Therefore, there are lots of possibilities of faults in all layers. Because embedded software developers test their codes integrated with faulty layers, they cannot confirm 'whether testing of every aspects was completed, their code was failed, or integrated software/hardware has some problems'. In this paper, we propose an embedded software interface test method and a test tool called Justitia for detecting faults and tracing causes in the interface among heterogeneous layers. The proposed technique is an automated method which improves debugging upto professional testing using an emulator for helping developer.

• Journal of KIISE:Computing Practices and Letters
• /
• v.13 no.3
• /
• pp.141-152
• /
• 2007

In this paper, we present a network-oriented lightweight real-time system, which is composed of an event-driven operating system called the Embedded Lightweight Operating System (ELOS) and a generic multi hop ad hoc routing protocol suite. In the ELOS, a conditional preemptive FCFS scheduling method with a guaranteed time slot is designed for efficient real-time processing. For more elaborate configurations, we reinforce fault tolerance by supplementing semi-auto configuration using wireless agent nodes. The developed hardware platform is also introduced, which is a scalable prototype constructed using off-the-shelf components. In addition, in order to evaluate the performance of the proposed system, we developed a ubiquitous network test-bed on which several experiments with respect to various environments are conducted. The results show that the ELOS is considerably favorable for tiny ubiquitous networked systems with real-time constraints.

• Journal of KIISE:Computing Practices and Letters
• /
• v.14 no.6
• /
• pp.594-598
• /
• 2008

In this paper we propose a fast booting technique based on Improved snapshot boot in embedded Linux, widely adopted in personal devices such as PDA and mobile phones. The existing Snapshot boot technique tries to create a snapshot image at the time of suspend, and later load the entire snapshot image into the system memory at the predefined location with the help of a bootloader at the time of resume. Since a bootloader has to copy the entire snapshot image into the predefined memory to resume the previous suspended computing state, a little bit long time is required to resume. Improved snapshot boot does not create a snapshot image consisting of whole memory pages at the time of suspend, thus resulting in smaller snapshot image than the existing snapshot boot. The remaining pages are in the swap area. The resulting smaller sized snapshot image enables much faster booting latency. Through the experiment, we can see the booting latency is reduced almost 30% with suspend image of 2982 pages. This result depends on the amount of swap-out pages.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.15 no.5
• /
• pp.227-234
• /
• 2020

In this paper, we propose wav-U-Net to improve speech enhancement in heavy noisy environments, and it has implemented three principal techniques. First, as input data, we use 128 modified Mel-scale filter banks which can reduce computational burden instead of 512 frequency bins. Mel-scale aims to mimic the non-linear human ear perception of sound by being more discriminative at lower frequencies and less discriminative at higher frequencies. Therefore, Mel-scale is the suitable feature considering both performance and computing power because our proposed network focuses on speech signals. Second, we add a simple ResNet as pre-processing that helps our proposed network make estimated speech signals clear and suppress high-frequency noises. Finally, the proposed U-Net model shows significant performance regardless of the kinds of noise. Especially, despite using a single channel, we confirmed that it can well deal with non-stationary noises whose frequency properties are dynamically changed, and it is possible to estimate speech signals from noisy speech signals even in extremely noisy environments where noises are much lauder than speech (less than SNR 0dB). The performance on our proposed wav-U-Net was improved by about 200% on SDR and 460% on NSDR compared to the conventional Jansson's wav-U-Net. Also, it was confirmed that the processing time of out wav-U-Net with 128 modified Mel-scale filter banks was about 2.7 times faster than the common wav-U-Net with 512 frequency bins as input values.

• Journal of Advanced Navigation Technology
• /
• v.12 no.1
• /
• pp.34-45
• /
• 2008

Broadcast encryption schemes are applied to transmit digital informations of multimedia, software, Pay-TV etc. in public network. User acquires message or session key to use key that broadcaster transmits, broadcaster need process that generation and distribution key in these process. Also, user secession new when join efficient key renewal need. In this paper, introduce about efficient key generation and distribution, key renewal method. The temporary conference environment base structure against an each mobile device wild gap. Without the transmission possible, it follows infrequent location change and with the quality where the key information change flow. Thus, in this paper, in order to apply to the embedded computing environment and the key generation and the efficient key renewal are done when the mobile device is used of the specify space it proposes.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.18 no.4
• /
• pp.159-164
• /
• 2023

Solar energy harvesting IoT devices prioritize maximizing the utilization of collected energy due to the periodic recharging nature of solar energy, rather than minimizing energy consumption. Meanwhile, research on edge AI, which performs machine learning near the data source instead of the cloud, is actively conducted for reasons such as data confidentiality and privacy, response time, and cost. One such research area involves performing various audio AI applications using audio data collected from multiple IoT devices in an IoT edge computing environment. However, in most studies, IoT devices only perform sensing data transmission to the edge server, and all processes, including data preprocessing, are performed on the edge server. In this case, it not only leads to overload issues on the edge server but also causes network congestion by transmitting unnecessary data for learning. On the other way, if data preprocessing is delegated to each IoT device to address this issue, it leads to another problem of increased blackout time due to energy shortages in the devices. In this paper, we aim to alleviate the problem of increased blackout time in devices while mitigating issues in server-centric edge AI environments by determining where the data preprocessed based on the energy state of each IoT device. In the proposed method, IoT devices only perform the preprocessing process, which includes sound discrimination and noise removal, and transmit to the server if there is more energy available than the energy threshold required for the basic operation of the device.

• Proceedings of the Korean Information Science Society Conference
• /
• 2005.11a
• /
• pp.904-906
• /
• 2005

소프트웨어 개발의 생산성을 높이고 신뢰성 있는 프로그램을 개발하기 위하여 테스트 자동화에 대한 연구가 활발히 진행되고 있다. 임베디드 소프트웨어는 일반 소프트웨어 개발 환경과는 달리 호스트-타겟(host-target) 구조의 교차 개발환경에서 개발이 이루어지고 있다. 본 논문은 임베디드 소프트웨어의 개발 환경에 맞추어 제한된 자원의 특성을 고려한 원격 단위 테스팅 도구를 제안한다. 제안하는 원격 단위 테스팅 도구는 XML 테스트 스크립트를 기반으로 대상 소스 언어에 맞는 테스트 드라이버를 생성하여 테스트 대상과 함께 테스트 작업 용구(Test harness)를 생성한다. 이러게 생성된 테스트 작업 용구는 이더넷(ethernet)을 통해 타겟(target)으로 전송되어 테스트를 수행한 후, 테스트 결과 로그를 호스트로 전송한다. 호스트에서는 로그를 수집하여 XML형태의 파일로 제공하여 다양한 형태의 리포트 뷰(View)를 가능하게 한다. 본 논문의 원격 단위 테스팅 도구는 임베디드 소프트웨어 개발 단계에서 반복적인 단위 테스팅의 절차를 간소화 하여 보다 효율적이고 신뢰성 있는 임베디드 소프트웨어 개발의 기회를 제공 할 것으로 기대된다.

• Proceedings of the CALSEC Conference
• /
• 2005.11a
• /
• pp.78-84
• /
• 2005

As the research activities related to 'Ubiquitous Computing' whose concept was introduced by Mark Weiser are growing, RFID(Radio Frequency Identification) technology has recently gained attention as a technology to advance the ubiquitous computing and a lot of related researches are also in progress. Research works done so far are mainly linked to the situation that the research outputs apply to meet the requirements for asset tracking and data sharing with partners over supply chain by using fixed RFID readers. However, it is essential that users have access to real-time information about the tagged objects and services whenever and wherever they want in the era of ubiquitous computing, so mobile devices-including PDA, smart phone, cellular phone, etc - which are equipped with an RFID reader can be regarded as an essential terminal for users living in ubiquitous computing environment. As far as the application with mobile devices are concerned, there are many considerations due to their limited capabilities of data processing, battery consumption and so on. In this paper, we review the generic RFID network model and introduce the revised RFID network model in consideration of incorporation with mobile devices equipped with an RFID reader. Also, we derive the requirements for software embedded within an RFID- enabled mobile terminal and then discuss essential components for implementation. Moreover, we develop the applications for asset management at museum by using mobile RFID network model.