• Proceedings of the KSR Conference
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• 2009.05b
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• pp.395-400
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• 2009

The HEMU-400X project starts at 2007. It is important first of all that describing correctly system requirement during configuration of system, design, manufacturing, installation and test verification so that the complicated high-speed electric multiple unit is to run safety and reliable and to achieve target performance and function properly. The system requirement assist the system designer to understand the performance and function of system in basic design. For this process, system engineer have to manage the system requirement. This paper proposes the management contents of system requirement such as change management, requirement traceability, etc, for HEMU-400X.

• Journal of Appropriate Technology
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• v.7 no.2
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• pp.172-187
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• 2021

In remote villages without access to modern IT technology, simple devices such as smartcards can be used to carry out business transactions. These devices typically store multiple business applications from multiple vendors. Although devices must prevent malicious or accidental security breaches among the applications, a secure communication channel between two applications from different vendors is often required. In this paper, first, we propose a method of establishing secure communication channels between applications in embedded operating systems that run on multi-applet smart cards. Second, we enforce the high assurance using an intransitive noninterference security policy. Thirdly, we formalize the method through the Z language and create the formal specification of the proposed secure system. Finally, we verify its correctness using Rushby's unwinding theorem.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.59-60
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• 2022

According to the recent issue regarding the shortage of concrete supply, it is common to appoint various concrete suppliers and allow mixed pouring according to the specification requirements. Moreover, if the concrete is mixed inevitably a strength and property test is carried out for verification. Therefore, in this research, multiple concrete suppliers were selected and each required raw material was collected for the test of all variable mixed design. Through the test, the property of the unhardened and hardened concrete was quantitatively evaluated.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.3
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• pp.437-445
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• 1999

This paper presents a simple modification technique of finite element model for dynamic analysis of linear/nonlinear structural system subjected to multiple support excitation. For the sake of verification of the proposed method, dynamic responses obtained by the present technique for a couple of linear and nonlinear structural systems were compared with those by a general-purpose structural analysis software which can deal with the multi-support analysis. The method presented in this paper is expected to be used for multiple support excitation analysis by means of a computer code without the capability of modeling the non-synchronous support motion.

• Journal of Mechanical Science and Technology
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• v.14 no.9
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• pp.956-967
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• 2000

In this paper, we explore the issues of force display in the cooperative virtual environment shared by multiple users distributed over the network with heterogeneous hardware platforms. The proposed method is to cope with the problem of small time delay and the difference of sampling rate in the distributed configuration. In the proposed approach the interaction forces of the participants are just treated as the independent sources of acceleration. Thus the action of a participant simply changes the acceleration of the virtual object and consequently the states of the virtual object will be updated. When the updated states are reported to all the participants, the information on the time of state changes is delivered, too. Employing the discrete state information updated by the other users, each user modifies his own virtual environment and pseudo-realtime simulation can be realized. Excluding the software interface and the communication technique, it is proposed the simulation method for the operation of respective users and the way of calculating the driving input to the display device. For experimental verification we construct a cooperative virtual environment shared by two remote users and outline the results of experiments.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.647-653
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• 2011

In vessels, various communication systems are now working with different vendor-specific ways, which are apt to cause the inter-operability problems. That, of course, leads to needs of standardization of communication network systems for vessels. The e-navigation system introduced by IMO also takes the standardization process as expected. In this paper, a 4S multiple media communication switching server for seamless communications among existing media for vessels is introduced, and the development of a information exchange software for the sever and its functionality verification results are presented as well.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.12
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• pp.2392-2402
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• 2011

In order to protect some important information communicated through an insecure network, a common hidden key must be used. One can produce the common hidden key using key agreement protocols; and this helps to have high security in modern data networks. Today, the designers of public key cryptography protocols try to set the public identity of a system's users (like their email addresses) as their public key. This not only makes a cryptographic protocol more efficient but also decreases its cost. These protocols are called "identity-based". In this article, an identity-based multiple key agreement scheme will be presented; this scheme uses the challenge-response method to do the verification. While the number of random values produced in our scheme is the same as other schemes, the number of keys generated in this scheme is much more than what many other key agreement schemes produce,. Therefore, we will have less computational complexities campered with other schems. In this paper, we consider the security of our scheme and consequently, we will show that it satisfies many security conditions such as strong security.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.5
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• pp.297-305
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• 2006

Trace-driven simulation is widely used for measuring the performance of a microprocessor in its initial design phase. However, since it requires much time and disk space, the statistical simulation has been studied as an alternative method. In this paper, statistical simulations are performed for a high performance superscalar microprocessor with a perceptron-based multiple branch predictor. For the verification, various hardware configurations are simulated using SPEC2000 benchmarks programs as input. As a result, we show that the statistical simulation is quite accurate and time saving for the evaluation of microprocessor architectures with multiple branch prediction.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.28-31
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• 2003

In the present work, a main purpose is to propose a fuzzy integral-based aggregation framework to complementarily combine partial information due to lack of completeness. Based on Choquet integral (CI) viewed as monotone expectation, we take into account complementary, non-interactive, and substitutive aggregations of different sources of defective information. A CI-based system representing upper, conventional, and lower expectations is designed far handling three aggregation attitudes towards uncertain information. In particular, based on Choquet integrals for belief measure, probability measure, and plausibility measure, CI$\_$bi/-, CI$\_$pr/ and CI$\_$pl/-aggregator are constructed, respectively. To illustrate a validity of proposed aggregation framework, multiple matching systems are developed by combining three simple individual template-matching systems and tested under various image variations. Finally, compared to individual matchers as well as other traditional multiple matchers in terms of an accuracy rate, it is shown that a proposed CI-aggregator system, {CI$\_$bl/-aggregator, CI$\_$pl/-aggregator, Cl$\_$pl/-aggregator}, is likely to offer a potential framework for either enhancing completeness or for resolving conflict or for reducing uncertainty of partial information.

• Journal of the Korean Society of Systems Engineering
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• v.7 no.2
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• pp.7-11
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• 2011

A high-speed railway system represents a typical example of large-scale multi-disciplinary system, consisting of subsystems such as rolling-stock, electrical hardware, electronics, control, information, communication, civil technology etc. The system design and acquisition data of the large-scale system must be the subject under strict configuration control and management. Systems engineering technology development project for Korea next generation High-speed Electric Multiple Unit (HEMU) system in progress is a national large system development project that is not only a large-size and complex but also multi-disciplinary in nature. Therefore, all stakeholders must understand and share the functional and performance requirements of HEMU throughout its life-cycle phases. Also in the test and evaluation phase, all systems requirements must be verified. In 2011, the prototype train manufacturing will be completed. It will do test run on the commercial line and all systems requirements are verified until 2012. For the system verification, the test and evaluation process have to be established before the test trial run. Using a systems engineering tool, the system design database(SDD) with requirements traceability and development process management in the course of the development have to be established. This paper represents the test and evaluation process development based on the SEMP(Systems Engineering Management Plan) developed in the design stage. The test and evaluation process is refined and updated in comparison to the design stage one. The test and evaluation process consists of procedure, test and evaluation method and schedule. So through this process, it is defined that each systems requirements is verified on which test and about what time.