• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.10
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• pp.3361-3377
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• 2014

Synchronous computing models provided by real-time synchrony protocols, such as TTA [1] and PALS [2], greatly simplify the design, implementation, and verification of real-time distributed systems. However, their application to real systems has been limited since their assumptions on underlying systems are hard to satisfy. In particular, most previous real-time synchrony protocols hypothesize the existence of underlying fault tolerant real-time networks. This, however, might not be true in most soft real-time applications. In this paper, we propose a practical approach to a synchrony protocol, called Quality-Aware PALS (qPALS), which provides the benefits of a synchronous computing model in environments where no fault-tolerant real-time network is available. qPALS supports two flexible global synchronization protocols: one tailored for the performance and the other for the correctness of synchronization. Hence, applications can make a negotiation flexibly between performance and correctness. In qPALS, the Quality-of-Service (QoS) on synchronization and consistency is specified in a probabilistic manner, and the specified QoS is supported under dynamic and unpredictable network environments via a control-theoretic approach. Our simulation results show that qPALS supports highly reliable synchronization for critical events while still supporting the efficiency and performance even when the underlying network is not stable.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3C
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• pp.233-240
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• 2012

Unlike traditional factory environment, in an industrial factory network applied wireless sensor network technologies, all procedures of discovery, identification and verification of devices should be performed in an automatic fashion. To address these challenges, we design a management system using the device registry server that we propose in this paper. In the phase of device discovery, the proposed system utilizes properties of routing protocol running in factories. Also, in the phase of identification and verification, the system uses unique and general information of a device stored within the device registration server. Such a way allows management system to reduce implementation complexity and to easily manage devices in a factory applied with a wireless network consisting of heterogeneous devices.

• The KIPS Transactions:PartC
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• v.13C no.2 s.105
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• pp.147-154
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• 2006

The certificate status validation mechanism is a critical component of a public key infrastructure based on certificate system. The most generally mechanisms used these days are the use of the certificate revocation list and the real-time certificate status protocol. But the certificate revocation list can not give the real-time certificate status because the certificate is being delivered periodically, and the real-time certificate status protocol method will generate a concentrated load to the server because the protocol in the central server will be accessed whenever a certification is necessary. It will also take a long time to validate the certificate because each trade has to send mass information through the network. This paper will present that real-time validation is guaranteed as the real-time certificate status protocol method and the traffic congestion in the network Is reduced in a way that the certification would be requested using the user information hash value and would be validated using the user information kept in the certification authorities and the service providers. Based on the this study, we suggest a real-time certificate status validation mechanism which can reduce the certificate status validation time using the signed user information hash value. And we confirm speed of certificate status verification faster than existing CRL(Certificate Revocation List) and OCSP(Online Certificate Status Protocol) method by test.

• Design Convergence Study
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• v.15 no.1
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• pp.37-48
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• 2016

Nowadays, CAD has became an essential tool for designers due to its easy edition and manipulation as well as the capability of communication between designers. Differences between design tool interfaces can cause gaps when visualize designer's ideas. This study is about the differences between various levels of metaphor interface language which is based on the theory of the Hutchins that high-level language interface can reduce the steps of process to visualize the idea of the designers than low-level language interface. This research is based on the assumption that high-level language interface will less interrupt the flow of the design thinking and make more various visual outcomes than the low-level language interface. We verified the hypothesis by analyzing differences of design thinking flow between user groups who used two different animation software. Hopefully, the verification of the hypothesis in this study can be able to guide the use pattern of the CAD tools.

• Journal of Internet Computing and Services
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• v.19 no.1
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• pp.19-26
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• 2018

Social issues for environmental pollution are continuously increasing globally. Especially, Users require services to measure environmental factors in indoor and outdoor and manage related data effectively and conveniently. According to this demand, sensors that can measure environmental factors in indoor and outdoor have been developed. However, since one sensor is composed of independent module, the interface of output data from each sensor is different. To solve the problem, we propose a customized protocol for low-power short-range wireless communication between smartphone using Bluetooth and All-in-One sensor device board and analyze the performance of the proposed customized protocol by developing program for performance verification of interface with user smartphone through Bluetooth. In addition, we implement a smartphone application using proposed protocol.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.5
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• pp.231-236
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• 2008

This paper proposes a cost-efficient and flexible FPGA-based logic circuit emulation platform. By improving the performance and adding more features, this new platform is an enhanced version of our LAPG. It consists of an FPGA-based hardware engine and software element to drive the emulation and monitor the results. It also provides an interactive verification environment which uses an efficient communication protocol through a bi-directional serial link between the host and the FPGA board. The experimental results show that this new approach saves $55%{\sim}99%$ of communication overhead compared with other methods. According to the test results, the new LAPG is more area efficient in complex circuits with many I/O ports.

• Korean Journal of Computational Design and Engineering
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• v.12 no.5
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• pp.366-375
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• 2007

Although the STEP modularization is the major development methodology for STEP Application Protocol, there have been few studies on the STEP Modularization in Korea. The necessity of STEP Modularization research has been raised continuously. In addition, the importance became larger and larger because most of newly developing APs, including AP241, are developed using modularization approach. The object of this study is to investigate the basic structure and contents of AEC facilities related Application Modules using STEP Modularization. This study examines 1) the technical analysis regarding STEP Modularization, 2) application modules development regarding civil engineering elements of AP241; Aec_faciliteis_classification", "Aec_civil_item", and "Aec_civil_componet", 3) the developed application modules verification, and 4) the implementation methodology suggestion for application modules and modular AP.

• The Transactions of the Korea Information Processing Society
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• v.3 no.6
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• pp.1522-1533
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• 1996

This paper presents a programming environment for the edition and verification of specification language SDL. It is implemented in the Concerto software factory, which has been as a support for the development of real size software. Concerto is a software factory designed for application development in the fields of computer communication protocols or real time system. It offers various kinds of tools to produce software, organize this production and automate it. Concerto allows a smooth integration of various formalism such as the C and $C^{++}$, languages, structured documentation, HOOD methodology (Hierarchical Object Orient Design). In this paper, as an important tools in the process of communication protocol software development, we describe fist describe the principles of this environment, then we illustrate its application by means of a simple example, the Inres protocol. Moreover, we study how hypertext mechanism of Concert to create logical links between a protocol and its asscoiated service.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.2
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• pp.43-52
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• 2019

The recent technological developments of smart devices, multiple services are provided to enhance the users' quality of life including smart city, smart energy, smart car, smart healthcare, smart home, and so on. Academia and industries try to provide the users with convenient services upon seamless technological research and developments. Also, whenever and wherever a variety of services can be used without any limitation on the place and time upon connecting with different types of devices. However, security weaknesses due to integrations of multiple technological elements have been detected resulting in the leakage of user information, account hacking, and privacy leakage, threats to people's lives by device operation have been raised. In this paper, safer communication framework is suggested by device control and user authentication in the mobile network environment. After implementations of registration and authentication processes by users and devices, safe communication protocol is designed based on this. Also, renewal process is designed according to the safe control of the device. In the performance evaluation, safety was analyzed on the attack of protocol change weakness occurred in the existing system, service halt, data leakage, illegal operation control of message, and so on, which confirmed the enhanced speed approximately by 8% and 23% in the communication and verification parts, respectively, compared to the existing system.

• Journal of Digital Convergence
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• v.13 no.5
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• pp.213-218
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• 2015

In parallel with evolving information communication technology, M2M(Machine-to-Machine) industry has implemented multi-functional and high-performance systems, and made great strides with IoT(Internet of Things) and IoE(Internet of Everything). Authentication, confidentiality, anonymity, non-repudiation, data reliability, connectionless and traceability are prerequisites for communication security. Yet, the wireless transmission section in M2M communication is exposed to intruders' attacks. Any security issues attributable to M2M wireless communication protocols may lead to serious concerns including system faults, information leakage and privacy challenges. Therefore, mutual authentication and security are key components of protocol design. Recently, secure communication protocols have been regarded as highly important and explored as such. The present paper draws on hash function, random numbers, secret keys and session keys to design a secure communication protocol. Also, this paper tests the proposed protocol with a formal verification tool, Casper/FDR, to demonstrate its security against a range of intruders' attacks. In brief, the proposed protocol meets the security requirements, addressing the challenges without any problems.