• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.155-161
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• 2023

In this paper, we present a WebRTC-based emergency video call system structure that builds a service system in a constant monitoring environment to increase the usability and stability of elevator emergency call devices. The proposed system provides a smooth call environment between the emergency call system in the elevator and maintenance managers in case of an emergency, performs rapid response processing to elevator emergency calls through monitoring of the target elevator, and handles any emergency calls that may occur in the physical space of the elevator. The purpose is to build an environment that can implement low-latency, real-time video call services of voice and video by overcoming the physical constraints required for video calls. To this end, we have established a service environment based on OpenAPI, which is currently used in various fields and its performance has been proven, and provides video calls and emergency situation dissemination through rapid messaging by providing low-latency call quality. The presented system structure will be able to provide a basis for expanding various functions and constructing a reliable service environment and intelligent model for the elevator system through combination with the elevator control panel and various devices.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.9-15
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• 2021

With the recent development of 5G and artificial intelligence technologies, it is interested in AIOT technology to collect, process, and analyze information in cloud edge environments. AIIoT technology is being applied to various smart environments, but research is needed to perform fast response processing through accurate analysis of collected information. In this paper, we propose a technique to minimize bandwidth and processing time by blocking the connection processing between AIOT information through fast processing and accurate analysis/forecasting of information collected in the smart environment. The proposed technique generates seeds for data indexes on AIOT devices by multipointing information collected by blockchain, and blocks them along with collection information to deliver them to the data center. At this time, we deploy Deep Neural Network (DNN) models between cloud and AIOT devices to reduce network overhead. Furthermore, server/data centers have improved the accuracy of inaccurate AIIoT information through the analysis and predicted results delivered to minimize latency. Furthermore, the proposed technique minimizes data latency by allowing it to be partitioned into a layered multilayer network because it groups it into blockchain by applying weights to AIOT information.

• Phonetics and Speech Sciences
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• v.12 no.2
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• pp.63-72
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• 2020

This study aims to develop a video-based smart utterance deep analyser (SUDA) application that analyzes semiautomatically the utterances that child and mother produce during interactions over time. SUDA runs on the platform of Android, iPhones, and tablet PCs, and allows video recording and uploading to server. In this device, user modes are divided into three modes: expert mode, general mode and manager mode. In the expert mode which is useful for speech and language evaluation, the subject's utterances are analyzed semi-automatically by measuring speech and language factors such as disfluency, morpheme, syllable, word, articulation rate and response time, etc. In the general mode, the outcome of utterance analysis is provided in a graph form, and the manger mode is accessed only to the administrator controlling the entire system, such as utterance analysis and video deletion. SUDA helps to reduce clinicians' and researchers' work burden by saving time for utterance analysis. It also helps parents to receive detailed information about speech and language development of their child easily. Further, this device will contribute to building a big longitudinal data enough to explore predictors of stuttering recovery and persistence.

• Journal of KIISE:Databases
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• v.30 no.5
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• pp.476-493
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• 2003

Data broadcast is an effective data transmission method from a data base server to numerous mobile clients due to the restrictions on mobile environment such as low wireless communication bandwidth and energy shortage of mobile devices. There are various broadcast methods based on clients' data access frequencies or semantic relationship of data. The broadcast schedule based only on the access frequencies does not consider semantic relations of data, so that when a client needs to access a series of semantically related data, the client has to listen to the wireless channel for a long time. On the other hand, the broadcast schedule based only on semantic relationship of data makes data access time longer when clients highly request specific data which are not semantically related but frequently accessed. In this paper, we present an efficient data broadcast method based on not only data access frequencies but also semantic relationship to improve mobile clients' query response time. The new hybrid broadcast method we propose creates a data broadcast schedule according to the data access frequencies and then the schedule is adjusted to reflect semantic relationship of data. We show our method is efficient by experimental performance analysis.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.4
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• pp.83-92
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• 2005

D-OCSP-KIS proposed by Koga and Sakurai not only reduces the number or OCSP Responder's certificate but also criers the certificate status validation about OCSP Responder to the client. Therefore, D-OCSP-KIS is an effective method that can reduce the communication cost, computational time and storage consumption in client, but it has some problems. In case an attacker accidentally acquires an OCSP Responder's session private key in a time period (e.g., one day), she can disguise as the OCSP Responder in the time period unless the OCSP Responder recognizes. She can offer the wrong response to the client using the hash value intercepted. And the server and user on I-commerce can have a serious confusion and damage. And the computation and releasing of hash chain can be a load to CA. Thus, we propose a method detecting immediately the exposure of an OCSP Responder's session private key and the abuse of hash value in D-OCSP-KIS.

• Journal of KIISE:Information Networking
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• v.30 no.4
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• pp.559-571
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• 2003

ENUM(tElephon NUmbering Mapping) is protocol that brings convergence between PSTN Networks and IP Networks using a unique worldwide E.164 telephone number as an identifier between different communication infrastructure. The mechanism provides a bridge between two completely different environments with E.164 number; IP based application services used in PSTN networks, and PSTN based application services used in IP networks. We propose a new way to organize and handle ENUM Tier 2 name servers to improve performance at the name resolution process in ENUM based application service. We build an ENUM based network model when NAPTR(Naming Authority PoinTeR) resource record is registered and managed by area code at the initial registration step. ENUM promises convenience and flexibility to both PSTN and IP users, yet there is no evidence how much patience is required when users decide to use ENUM instead of non-ENUM based applications. We have estimated ENUM response time, and proved how to improve performance up to 3 times when resources are managed by the proposed mechanism. The proposition of this thesis favorably influences users and helps to establish the policy for Tier 2 name server management.

• Journal of Korea Spatial Information System Society
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• v.1 no.2 s.2
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• pp.21-31
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• 1999

In accordance with the completion of the spatial database building works in the central and/or local government authorities as well as the rapid popularization of various information services through internet, it is heavily required to provide spatial information services through World Wide Web. To provide a qualified spatial information service, it is crucial to have a Web-based GIS (Geographic Information Service) service system equipped with the publicity, the convenient accessibility, and the easy-to-use user interface. In this paper, we introduce a new component system for Web-based spatial information services based on the OpenGIS Simple Feature specification for OLE/COM[3] and OLE DB specification[4]. The important functionality of a Web-based spatial information service system includes its accessibility of various existing GIS server system and huge databases in addition to the resolution of response-time delay problems caused by transmitting a large amount of digital maps via internet[6]. To cope with these problems, our component system has been designed to access heterogeneous databases in transparent manner and to support vector-based and/or image-based image production techniques for shortening transmission time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.7
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• pp.573-586
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• 2013

Recently, the research, utilizing bio and environment sensors in agricultural and cattle industries, are drawing attention among the various IT convergence technologies. Among such research IT convergence techniques which aim to improve the quality of cattle industry management are necessary in particular. Real-time monitoring of the cattles health condition, identification of the cause of the diseases and timely response to such epidemic based on IT convergence techniques are among them. In order to achieve the better management of cattle industry, we propose a cattles management system which based on various bio environment sensors and wireless network technologies. The system consists of wireless environmental sensor data acquisition nodes, sensor data processing nodes, the gateway and the server. The proposed system is able to actively monitor the cattle field, to respond quickly in the case of massive cattle diseases and to control the environment of the cattle fields. We believe the proposed system will demonstrate the successful application of IT technologies to an applied field such as farming industries because of real-time crisis management capability in case of epidemic and optimal management of cattle industry.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.2
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• pp.158-170
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• 2008

In response to the changing demands of ever competitive market, SK Telecom has built a new marketing system that can support dynamic marketing campaigns and, at the same time, scale up to the large volumes of data and transactions for the next decade. The system which employs Unix-based client-server (using Web browser interfaces) architecture will replace the current mainframe-based COIS system. The project, named NGM (Next Generation Marketing ), is unprecedentedly large in scale. However, both managerial and technical problems led the project into a crisis. The application framework that depended on a software solution from a major global vendor could not support the dynamic functionalities required for the new system. In March 2005, SK telecom declared the suspension of the NGM project. The second phase of the project started in May 2005 following a comprehensive replanning. It was decided that no single existing solution could cope with the complexity of the new system and hence the new system would be custom-built. As such. a number of technical challenges emerged. In this paper, we report on the three key dimensions of technical challenges - middleware and application framework, database architecture and tuning, and system performance. The processes and approaches, adopted in building NGM system, may be viewed as "best practices" in the telecom industry. The completed NGM system, now called "U.key System," successfully came into operation on the ninth of October, 2006. This new infrastructure is expected to give birth to a series of innovative, fruitful, and customer-oriented applications in the near future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.18-25
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• 2020

With the development of water internet technology, data communication between objects is expanding. Research related to data communication technology between vehicles that incorporates related technologies into vehicles has been actively conducted. For data communication between mobile terminals, data stability, reliability, and real-time performance must be guaranteed. The 5 GHz Wi-Fi band, which is advantageous in bandwidth, communications speed, and wireless saturation of the wireless network, was selected as the data communications network between vehicles. This study analyzes how to design and implement a 5 GHz Wi-Fi network in a vehicle network. Considering the characteristics of the mobile communication terminal device, a continuous variable communications structure is proposed to enable high-speed data switching. We simplify the access point access procedure to reduce the latency between wireless terminals. By limiting the Transmission Control Protocol Internet Protocol (TCP/IP)-based Dynamic Host Configuration Protocol (DHCP) server function and implementing it in a broadcast transmission protocol method, communication delay between terminal devices is improved. Compared to the general commercial Wi-Fi communication method, the connection operation and response speed have been improved by five seconds or more. Utilizing this method can be applied to various types of event data communication between vehicles. It can also be extended to wireless data-based intelligent road networks and systems for autonomous driving.