• Journal of KIISE:Computing Practices and Letters
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• v.16 no.7
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• pp.759-767
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• 2010

RT-eCos 3.0 is a micro-sized embedded real-time kernel that has been developed based on the open source eCos 3.0 to support the basic task model of the well-known distributed real-time object model, TMO(Time-Triggered Message-triggered Object). In this paper, the design and implementation techniques of the RMMC(Real-time Multicast & Memory replication Channel) that is a standard distributed IPC model of the TMO is described based on the RT-eCos 3.0. And the support technique of the global time for using the same time in a distributed environment using the RMMC is also described. The developed global time based RMMC supports highly abstracted distributed IPC environment in a wide area distributed computing environment with the RT-eCos 3.0.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.2
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• pp.37-45
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• 1999

CORBA IDL and RMI, the representative of distributed object model, support different approaches for distributed computing environments. CORBA approach does not support the application generated by RMI, even though it supports multiple programming languages. Object translation system between RMI to CORBA is designed and implemented for interoperability of distributed objects on the two different distributed programming environments. Suggested system is considered binding, inheritance, polymorphism, object passing, and callback which are key properties on the distributed objects. To validate the usefulness of the proposed system, we adopt a model for distrubuted objects and implement it as an application on the RMI environment. And, we translated it to an application on the CORBA environment. We observed the performance of translated application in the respect of inheritance, object passing, polymorphism across the machine boundary. Experiments showed that performance of distributed objects, those generated by translation system and those implemented on the CORBA environment, is equivalent.

• Journal of Internet Computing and Services
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• v.3 no.2
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• pp.79-85
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• 2002

In open communication architecture, application systems consist of objects distributed in lots of computing nodes. To reduce complexity of development. and management of distributed software, to manage efficiently distributed objects and to provide realtime service, the mechanisms for object group management and communication are needed in distributed environment. In this paper we compose object groups and provide reliable group communication mechanism based on CORBA which can adopt a new service without lots of changes on existing system. Group consist of some subgroups that subgroup manager manages for improving the efficiency of group management and message ordering is kept by using sequencer, Communication method among groups uses multicast based on paint to point communication as well as IP multicast and we provide high performance by using selective retransmission of message through message history, We analyze the performance of the proposed mechanism through simulation in distributed environment.

• Journal of the Korea Computer Industry Society
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• v.3 no.8
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• pp.1019-1026
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• 2002

The Distributed system environments are developing into a structure of the opening information communication network based on object-oriented concepts and distributed technologies. Such a reason is that it can not only decrease the complexity of distributed softwares, but also support object oriented application services to distributed environments without changes of its own communication network structure. In this paper, we designed object group model, that is, an extended middleware, we developed before. The distributed environment suggested consists of the CTS server and clients. As our results, we showed the interaction procedures between/among object groups and service procedures of distributed application in given distributed system.

• Journal of the Korean Professional Engineers Association
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• v.30 no.2
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• pp.79-86
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• 1997

As network has high speed and wide communication capability, users demand diverse and new software to satisfy their needs. To meet users needs, the softwares for multimedia or groupware or distributed virtual environments can communicate the widely distributed information fast and accurately. Even though the technology for this is under development, it is deficient to support the reliable computer communication. Distributed Object System aims, as the new paradigm of distributed system software development to overcome this problem, to obtain in distributed environment the easiness of development and management, expandability, reusability which object oriented technologies support by solving the complexity of communication processing through the object oriented methods. This paper aims to introduce distributed object system, its technological properties and the current status and trend of technology development related to its standardization. Additionally, with explaining the Replicated Shared Object System(RSOS) which is developed in our country as one of the distributed object systems, its future prospects and technical issues are discussed.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.11
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• pp.675-690
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• 2003

In this paper, we present the virtual dancing studio for distributed virtual environment. In this system, geographically distributed user shares the virtual dancing hall and interacts with each other. The participating object can be a graphical avatar or a live video stream. It allows the coexistence of graphic objects and real images in the shared virtual space. One of the main technical challenges in developing the distributed virtual environment is to handle excessive network traffic. In an effort to effectively reduce the network traffic, we propose a scheme to adjust the QoS of each object with respect to the distance from the observer in the virtual space. The server maintains the QoS vector for each client's shared space and controls the packet traffic to individual clients based on its QoS vectors. We develop a proto-type virtual dancing environment. Java based development enables the client to be platform independent. The result of experiment shows that the adoption of hierarchical QoS management significantly reduces the overall network traffic.

• The Transactions of the Korea Information Processing Society
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• v.5 no.1
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• pp.63-72
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• 1998

Diversity in hardware and software is increasing ever and our networked computing environment is becoming more diverse. The development of software becomes expensive works because of a collection of diverse computers, storing various data type in different places, working together by incompatabilities of operating system and various databases and protocols. CORBA is a standard for distributed computing environment and for system integration of heterogeneous distributed environment. CORBA provides many technical benefits for effective system integration and seamless infrastructure for distributed communication environment of heterogeneous systems. In this paper, we proposed a system integraton model based on CORBA for distributed object environment, softwarc reuse and the intcrconnecion of WWW. The model is composed of factory server, trading server, convcrsion scrvcr and applicaton scrvcr. Thc proposed model can easy application development and system integration. And we implcmcntcd thc gateway for cooperation with WWW. As a proof of the proposed model, we show how the distance learning system designed using the services provided by the proposed model.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.1
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• pp.101-107
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• 2011

The background noises and distortions by channel are major factors that disturb the practical use of speech recognition. Usually, noise reduce the performance of speech recognition system DSR(Distributed Speech Recognition) based speech recognition also bas difficulty of improving performance for this reason. Therefore, to improve DSR-based speech recognition under noisy environment, this paper proposes a method which detects accurate speech region to extract accurate features. The proposed method distinguish speech and noise by using entropy and detection of spectral energy of speech. The speech detection by the spectral energy of speech shows good performance under relatively high SNR(SNR 15dB). But when the noise environment varies, the threshold between speech and noise also varies, and speech detection performance reduces under low SNR(SNR 0dB) environment. The proposed method uses the spectral entropy and harmonics of speech for better speech detection. Also, the performance of AFE is increased by precise speech detections. According to the result of experiment, the proposed method shows better recognition performance under noise environment.

• Journal of the Korea Society for Simulation
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• v.24 no.4
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• pp.69-76
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• 2015

Modern warfare, which adopt an intensive technique of applied sciences, is difficult to predict, and has a high complexity. Thus, it is necessary to build a battle-field environment and simulation-based analysis. Various organizations are participated to build battlefield model for defense M&S according to a scale and format. On the basis of this trend, approaching from various systems is needed to reconfigure battlefield modeling for distributed system. This paper proposes building design for battlefield simulation environment with a sample of one-to-one single unit engagement model. The proposed method can expect to utilize an example of distributed environment for various participants that are involved in battlefield modeling and simulation.

• Journal of the Korea Society of Computer and Information
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• v.26 no.12
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• pp.69-75
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• 2021

Recently, deep learning, which is the most used in the field of artificial intelligence, has a structure that is gradually becoming larger and more complex. As the deep learning model grows, a large amount of data is required to learn it, but there are cases in which it is difficult to integrate and learn the data because the data is distributed among several owners and security issues. In that situation we conducted parallel learning for each users that own data and then studied how to integrate it. For this, distributed learning was performed for each owner assuming the security situation as V-environment and H-environment, and the results of distributed learning were integrated using Average, Max, and AbsMax. As a result of applying this to the mnist-fashion data, it was confirmed that there was no significant difference from the results obtained by integrating the data in the V-environment in terms of accuracy. In the H-environment, although there was a difference, meaningful results were obtained.