• IEMEK Journal of Embedded Systems and Applications
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• v.9 no.4
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• pp.245-251
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• 2014

Wireless Sensor Networks(WSNs) are applied to many monitoring applications. Present sensor nodes can perform many functions at the same time and contain complex software. During the lifetime of sensor nodes, they are required to reprogram their software because of their new functions, software, software bug fixes. The nodes are inaccessible physically or it is very difficult to upgrade their software by one by one. To upgrade the software of sensor nodes in WSNs remotely, this paper presents an energy efficient method by selecting an optimal relay node. The CHR(Cluster Head Relay) method is compared with SPIN and RANDOM method. Three methods are simulated in NS-2 with the same environmental parameters. Simulation results show that CHR shows faster update time and less power consumption compared with other two methods.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.947-953
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• 2006

ATC on-board equipment require realtime embedded software with high level of safety and reliability. To satisfy these requirements, many techniques are applied to the development of software during the lifecycle. In case of software modeling, object-oriented methodology is widening its niche replacing traditional structured methodology and modeling in UML using a CASE tool is a growing trend. In this paper, we modeled ATC on-board software in UML using Rhapsody, which is a modeling tool for realtime embedded software. We modeled the behavior of ATC on-board equipment based on state machine diagram and validated the model using the animation feature provided in the tool. According to our study, the CASE tool based on UML showed high level of applicability in modeling and verifying the software with complex behavioral characteristics.

• IEMEK Journal of Embedded Systems and Applications
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• v.7 no.1
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• pp.17-24
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• 2012

Recently automotive software has been more complex and needs to be reduced its development time. Software testing of its functionalities and performance should be conducted in an early development phase to reduce time to market and the development cost. Software functional testing can be performed through simulating the hardware, but it is not guaranteed that evaluation of real-time performance using simulation has enough accuracy. Real-time performance can be precisely evaluated with hardware-in-the-loop simulation, but it costs time and effort to set up hardware for testing. In this paper, we suggest a testing system that can evaluate functional requirements and real time properties with a general-purpose development board in the early development phase. In addition, we improve reusability of the testing system through modularized and layered architecture. With the proposed testing system we can contribute to building reliable testing system at low cost without difficulty.

• The KIPS Transactions:PartD
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• v.12D no.7 s.103
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• pp.931-936
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• 2005

There may be subtle errors in embedded software since its functionality is very complex. Thus formal verification for detecting them is very needed. Model checking is one of formal verification techniques, and SLAM is a well-known software model checking tool for verifying safety properties of embedded C program. In this paper, we develop a software model checker like SLAM for verifying embedded Java program Compared to SLAM, our tool allows to verify liveness properties as well as safety ones. As a result, we verify some desired properties in embedded Java program for controlling REGO robot.

• Journal of information and communication convergence engineering
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• v.11 no.2
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• pp.112-117
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• 2013

In order to reuse a register transfer level (RTL)-based IP block, it takes another architectural exploration in which the RTL will be put, and it also takes virtual platforms to develop the driver and applications software. Due to the increasing demands of new technology, the hardware and software complexity of organizing embedded systems is growing rapidly. Accordingly, the traditional design methodology cannot stand up forever to designing complex devices. In this paper, I introduce an electronic system level (ESL)-based approach to designing complex hardware with a derivative of SystemVerilog. I adopted the concept of reuse with higher levels of abstraction of the ESL language than traditional HDLs to design multiplication server farms. Using the concept of ESL, I successfully implemented server farms as well as a test bench in one simulation environment. It would have cost a number of Verilog/C simulations if I had followed the traditional way, which would have required much more time and effort.

• Journal of Information Processing Systems
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• v.17 no.1
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• pp.191-202
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• 2021

In an Internet of Things (IoT)-configured system, each device executes on-chip software. Recent IoT devices require fast execution time of complex services, such as analyzing a large amount of data, while maintaining low-power computation. As service complexity increases, the service requires high-performance computing and more space for embedded space. However, the low performance of IoT edge devices and their small memory size can hinder the complex and diverse operations of IoT services. In this paper, we propose a remote on-demand software code execution unit using the cloudification of on-chip code memory to accelerate the program execution of an IoT edge device with a low-performance processor. We propose a simulation approach to distribute remote code executed on the server side and on the edge side according to the program's computational and communicational needs. Our on-demand remote code execution unit simulation platform, which includes an instruction set simulator based on 16-bit ARM Thumb instruction set architecture, successfully emulates the architectural behavior of on-chip flash memory, enabling embedded devices to accelerate and execute software using remote execution code in the IoT environment.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.3
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• pp.159-167
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• 2017

Software safety is a key issue in embedded system of automotive and aviation industries. Various software testing approaches have been proposed to achieve software safety like ISO26262 Part 6 in automotive environment. In spite of one of the classic and basic approaches, stack memory is hard to estimating exactly because of uncertainty of target code generated by compiler and complex nested interrupt. In this paper, we propose an approach of analyzing the maximum stack usage statically from target binary code rather than the source code that also allows nested interrupts for determining the exact stack memory size. In our approach, determining maximum stack usage is divided into three steps: data extraction from ELF file, construction of call graph, and consideration of nested interrupt configurations for determining required stack size from the ISR (Interrupt Service Routine). Experimental results of the estimation of the maximum stack usage shows proposed approach is helpful for optimizing stack memory size and checking the stability of the program in the embedded system that especially supports nested interrupts.

• Journal of Internet Computing and Services
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• v.9 no.5
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• pp.59-72
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• 2008

Computing systems in the modern era are expanding rapidly to include mobile-based businesses that make us of the various convergence distributed business process. This has lead to growing interest in the field of mobile embedded software development methodology, which has in turn lead to the proliferation of the embedded mobility. The use of CBD (Component Based Development) provides reusability, maintainability and portability, all of which are very important and focus issues to the business process. It also comes with the inherent productivity, quality and reliability of CBD. To make efficient use of CBD, though, clarified interface definitions for component integration are necessary. These definitions should be made up of collaborative hierarchical and horizontal architecture layers. Successful definitions should apply an effective framework made up of the architecture and process. In this paper, we describe an interface specification for small grained mobile embedded components(MEC) for the mobile embedded domain to meet maximum user requirements. We build and deploy the reconfigurable design patterns and components (in business domain categories) to make a component hierarchy and business logics for mobile embedded software. Proposed components specification plays a major role in development of the software for handling inconsistency in existing specification. It also includes plenty of specification information, using semantics and modeling based mechanisms to support business processes. We propose a development model of mobile embedded software using CBD for very complex and dynamic mobile business. We can apply it in a plug and play manner to develop the software. We verify that our framework supports very good productivity, quality and maintainability to meet the user's requirements in mobile business.

• IEMEK Journal of Embedded Systems and Applications
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• v.5 no.3
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• pp.128-135
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• 2010

Recently complexity of embedded software cause to be used real-time operating system (RTOS) to implement various functions in the embedded system. And also, according to requirement of complex functions in embedded systems, the number as well as complexity of tasks get increased continuously. In case that many tasks collaborated in a microprocessor, context switching time between tasks is a overhead waisting a CPU resource. Therefore the time of task context switching is an important factor that affects performance of RTOS. In this paper, we concentrate on the improvement of task context switch for reducing overhead and achieving fast response time in RTOS. To achieve these goal, we suggest multiple register files and task context switching algorithm. By reducing the context switch overhead, we try to ease scheduling and assure fast response times in multitasking environment. As a result, the context switch overhead decreased by 8~16% depend on the number of register files, and some task set which are not schedulable with single register file are schedulable due to that decrease with multiple register files.

• Journal of KIISE:Software and Applications
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• v.35 no.1
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• pp.50-58
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• 2008

Most of Korean sentences are complex sentences which consisted of main clause and embedded clause. These complex sentences have more than one predicate and this causes various syntactic ambiguities in syntactic analysis. These ambiguities are caused by phrase attachment problems which are occurred by the modifying scope of embedded clause. To resolve it, we decide the scope of embedded clause in the sentence and consider this clause as a unit of syntactic category. In this paper, we use sentence patterns information(SPI) and syntactic properties of Korean to decide a scope of embedded clause. First, we split the complex sentence into embedded clause and main clause by the method that embedded clause must have maximal arguments. This work is done by the SPI of the predicate in the embedded clause. And then, the role of this embedded clause is converted into a noun phrases or adverbial phrases in the main clause by the properties of Korean syntax. By this method, the structure of complex sentence is exchanged into a clause. And some phrases attachment problem, which is mainly caused by the modifying scope, is resolved easily. In this paper, we call this method clausal segmentation for embedded clause. By empirical results of parsing 1000 sentences, we found that our method decreases 88.32% of syntactic ambiguities compared to the method that doesn't use SPI and split the sentence with basic clauses.