• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.9
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• pp.953-960
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• 2012

An overhung mounted carrier with flexible pins is applied to the planetary gear train of a wind turbine gearbox to investigate the influence of the self-aligning effect by means of the deflection of the planet spindle and the flexible pin on the lifetime of the planet gear for a wind turbine gearbox. To analyze the load distribution of planet gears, both Euler theory and commercial software are employed. By applying an overhung mounted carrier with flexible pins in the wind turbine gearbox, we can improve the misalignment performance, face load factor, and service life of the planet gears. In particular, it was confirmed that a service life of more than 20 years could be realized for wind turbine gearboxes by applying a flexible pin to the overhung mounted carrier.

• KIISE Transactions on Computing Practices
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• v.21 no.4
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• pp.315-319
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• 2015

This paper addresses the design and implementation of an Android application for real-time precise motion control. To provide stable real-time performance, we implemented the application in two parts: Android service in the form of a daemon process, which periodically transfers a set of position commands for all motors through a real-time fieldbus, and Android UI application, which generates and delivers the set of position commands to the Android service. To support such a real-time motion control application, we use multi-core partitioning, which partitions the processor cores into a real-time partition to be used by the real-time motion control service and a non-real-time partition to be used by the Android application, and set up a shared buffer between them for communication. Our experiments show that we can obtain a motion control period of 2 ms with 99% task activation jitters less than ${\pm}55{\mu}s$ for a configuration where each of the four threads controls two motors in a group.

• The KIPS Transactions:PartA
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• v.9A no.2
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• pp.207-216
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• 2002

This paper present a design and implementation of a distributed audio, Video stream service framework based on CORBA for efficient processing and control of audio/video stream. We design software components which support processing, control and transmission of audio/video streams as distributed objects. For optimization of stream transmission performance, we separate the transmission path of control data and media data. Distributed objects are defined by IDL and implemented using JAVA. And device dependent facilities like media capturing, playing and communication channels are implemented using JMF (Java Media Framework) components. We show a connection establishment and control procedure of streams communication. And for evaluation, we implement a test system and experiment a system performance. Our experiments show that test system has somewhat longer connection latency time compared to TCP connection establishment, but has optimized media transmission time compared to CORBA IIOP. Also test system show acceptable service quality of media transmission.

• Journal of Information Processing Systems
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• v.6 no.1
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• pp.1-20
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• 2010

Due to the convergence of voice, data, and video, today's telecom operators are facing the complexity of service and network management to offer differentiated value-added services that meet customer expectations. Without the operations support of well-developed Business Support System/Operations Support System (BSS/OSS), it is difficult to timely and effectively provide competitive services upon customer request. In this paper, a suite of NGOSS-based Telecom OSS (TOSS) is developed for the support of fulfillment and assurance operations of telecom services and IT services. Four OSS groups, TOSS-P (intelligent service provisioning), TOSS-N (integrated large-scale network management), TOSS-T (trouble handling and resolution), and TOSS-Q (end-to-end service quality management), are organized and integrated following the standard telecom operation processes (i.e., eTOM). We use IPTV and IP-VPN operation scenarios to show how these OSS groups co-work to support daily business operations with the benefits of cost reduction and revenue acceleration.

• Fashion & Textile Research Journal
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• v.23 no.3
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• pp.358-369
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• 2021

This study aims to classify the dimensions of the sales information of secondhand clothing goods on the C2C secondhand trading platform and to systematically analyze the components of each dimension. To this end, the NVivo 12.0 qualitative data analysis software was used. The content analysis showed that the sales information of secondhand clothing goods was classified into four dimensions: detailed information of the sale goods, information specific to secondhand clothing goods, seller opinion information, and service information. The components of each dimension were as follows. The detailed information of the sale goods included size, sale price, item, design, brand name, material, color, wearing season, fit, gender, etc. The information specific to secondhand clothing goods included the number of times the item was worn, its purchase history, and product condition. Seller opinion information included product review, sales motivation, notes for the transaction, coordination proposal, and usage proposal. The service information included the transaction mode, exchange·return·refund, and promotion. The frequency analysis showed that the highest frequencies were sale goods(37.47%), information specific to secondhand clothing goods(24.63%), seller opinion information(20.54%), and service information(17.37%). This study will help C2C secondhand trading platform managers or sellers establish clear standards for presenting sales information and developing ideas toward constructing differentiated platform contents.

• Journal of the Korea Society for Simulation
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• v.28 no.2
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• pp.119-129
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• 2019

Although line production systems with finite buffers have been studied over several decades, except for some special cases there are no explicit expressions for system performances such as waiting times(or response time) and blocking probability. Recently, a max-plus algebraic approach for buffer-sharing systems with constant processing times was introduced and it can lead to analytic expressions for (higher) moment and tail probability of stationary waiting. Theoretically this approach can be applied to general processing times, but it cannot give a proper way for computing performance measures. To this end, in this study we developed simulation models using @RISK software and the expressions derived from max-plus algebra, and computed and compared blocking probability, waiting time (or response time) with respect to two blocking policies: communication(BBS: Blocking Before Service) and production(BAS: Blocking After Service). Moreover, an optimization problem which determines the minimum shared-buffer capacity satisfying a predetermined QoS(quality of service) is also considered.

• KIPS Transactions on Software and Data Engineering
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• v.8 no.7
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• pp.303-310
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• 2019

In the current mobile environment that is indispensable to our everyday lives, various forms of new business models are created including personalized services such as Google's "Google NOW" and Apple's "Siri". These services would not have been possible without technologies on the effective integration of various services and models. The requirements for effective integration of services include, 1) the efficient data sharing among multiple services, 2) the data-driven asynchronous execution of services, and 3) the simple extensible interaction method for the services. In this paper, we propose a mobile service architecture that utilizes the blackboard architecture to satisfy the aforementioned requirements to enable effective integration of various services, sharing and management of data between services, and asynchronous execution of services.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.736-738
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• 2014

As part of real-time streaming service, which is one of the latest QoS technology has become the issue. But the current majority of streaming services are specific S/W I a separate setup program supports real-time streaming service a reality, will be stored until the end of the video, save for a video about editing and is not available. In this paper, a video about multi-threaded and distributed processing system applied to the Storm technique based on separate software or installation of programs without the H T M L 5-based Web content is produced by each device using a Web browser, real-time streaming system you want, no. This is a streaming service that provides users with real-time editing and the footage is stored as about and respond in real time between the server and the client and content sharing that need training and will be utilized in the field of multimedia streaming.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.2
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• pp.7-14
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• 2021

By changing the bulky monolithic services architecture to a microservices-based architecture, industries are managing the rising complexity of Autonomous Vehicles. However, the underlying communication mechanisms for the utilization and distribution of these microservices are incapable of fulfilling the requirements of the futuristic AV, because of the stringent latency requirements along with intermittent and short-lived connectivity issues. This paper proposes to tackle these challenges by employing the revolutionary information-centric networking (ICN) paradigm as an underlying communication architecture. This paper argues that a microservice approach to building autonomous vehicle systems should utilize ICN to achieve effective service utilization, efficient distribution, and uniform service discovery. This research claims that the vision of an information-centric microservices will help to focus on research that can fill in current communication gaps preventing more effective, and lightweight autonomous vehicle services and communication protocols.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.5
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• pp.1133-1143
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• 2012

Currently, Many Cyber Security Centers(CSC) are established and being operated in our country. But, in the absence of indicators to evaluate activities of the Managed Security Service(MSS), We can't identify the CSC's level of overall job performance. Therefore, we can't derive strengths and weaknesses from the CSC. From these reasons, The purpose of this research is to develop an objective indicator to evaluate activities of the MSS. I studied both international and domestic Information Security Management System(ISMS) as related standards(ISO/IEC 27001, G-ISMS). Moreover, I analysed the NIST Computer Security Incident Handing Guide and the Incident Management Capability Metrics(IMCM) of Carnegie Mellon Software Engineering Institute(SEI). The implications for this analysis and domestic hands-on experience are reflected in the research. So I developed 10 evaluation domains and 62 detail evaluation items. This research will contribute to our understanding the level of the CSC's job performance.