• The Magazine for Energy Service Companies
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• s.45
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• pp.15-15
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• 2007

• The Magazine for Energy Service Companies
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• s.48
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• pp.19-19
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• 2007

• Applied Microscopy
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• v.50
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• pp.3.1-3.1
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• 2020

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.533-535
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• 2017

MQTT provides three QoS levels on top of the TCP/IP layer to ensure message delivery reliability. However, in an environment where messages are concurrently transmitted and received in a node, messages are lost due to the delivery method for QoS level. In this paper, it construct an experimental environment in which MQTT generates concurrently messages, and confirm the message reliability according to QoS level. Therefore, we analyze the message reception ratio on the subscriber side by changing number of publisher and transmission cycle of message. Experimental results show that the message reception ratio of 1 and 2 except QoS level 0 decreases as the number of publisher increases or the message transmission cycle increases.

• Journal of Internet of Things and Convergence
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• v.10 no.2
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• pp.131-135
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• 2024

In the MQTT protocol, if the retained flag of a message published by a publisher is set, the message is stored in the broker as a retained message. When a new subscriber performs a subscribe, the broker immediately sends the retained message. This allows the new subscriber to perform updates on the current state via the retained message without waiting for new messages from the publisher. However, sending retained messages can become a traffic overhead if new messages are frequently published by the publisher. This situation could be considered an overhead when new subscribers frequently subscribe. Therefore, in this paper, we propose a retained message delivery scheme by considering the characteristics of the published messages. We model the delivery and waiting actions to new subscribers from the perspective of the broker using reinforcement learning, and determine the optimal policy through Q learning algorithm. Through performance analysis, we confirm that the proposed method shows improved performance compared to existing methods.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.29
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• pp.197-223
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• 2006

Uniform Computer Information Transactions Act (UCITA) is the first legislative attempt in the world that deals with transaction of digital information. This however gave rise to endless controversies and as of February 10, 2003, its life as the uniform law has expired. There are four kinds of relationships that UCITA regulates for the entities involved in information trading namely, 1) Relationship between licenser and licensee 2) The triangle relationship between dealers, end-user and publisher 3) Relationship between information right transferor and transferee 4) Relationship between financier, licenser and licensee. Amongst these, the most significant one is the triangle relationship amongst the publisher, commonly known as the licenser in the mass market, end-user and dealer. At the essence of the relationship is that the dealers is liable to refund the payment for the information regarding the end user if he/she does not agree with the publisher on the license of the common market. Looking at the relationship between license transferor and transferee, the transfer of license may be prohibited but the special contract must be conspicuously carried out. The relationship financier, licenser and licensee is unique to the United States and is rather unfamiliar to us. UCITA has been criticized for preferentially protecting the benefits of licensers especially when it comes to the specific regulations for the relationship. Therefore, it is not advisable to blindly accept UCITA regulations. However, UCITA does have components that we can utilize in formulating our own digital information trade regulations, save its proprietary nature as an American law and its preferential treatment for licensers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.11
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• pp.2535-2540
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• 2010

In traditional Publish/Subscribe system, the first procedure to deliver event from publisher to subscriber is that publisher publishes publisher's event to broker. Next step is that broker checks simple binary notion of matching : an event either matches a subscription or it does not. Lastly, broker delivers the event matched with subscriptions to the corresponding subscribers. In this system, information delivery has been accomplished in one way only. However, current some applications require two way delivery between subscriber and publisher. Therefore, we initiate an extended Publish/Subscribe system that supports two way delivery. Extended Publish/Subscribe system requires additional functions of delivering subscription to publisher and especially deciding top-n subscriptions using priority because broker might has a number of subscriptions. In this paper, we propose two priority retrieval techniques based on SIF using IS-List with deciding priority among subscriptions and defining SIF(Specific Interval First). The performance measurements show that RSO(resulting set sorting) technique results in better performance in index creation time and ITS&IS(insertion time sorting and inverse search using stack) technique results in better performance in search time.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.4
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• pp.362-369
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• 2018

In this paper, we propose a procedure to multiple SNS channels automatic streaming through multiple output channels including the output channel of an external streaming server. The multiple SNS channels automatic streaming server includes an output management module for controlling the transmission of video contents to RELAY module that establish two or more output channels. In this paper, we experimented by separate with HD and FHD video using RELAY module in multiple SNS channel automatic streaming. In stream modules using RELAY module of HD video, when the publisher client and the player client and the RELAY module are 1 channel, the occupancy rate of CPU is 0.6% and the occupancy rate of heap memory is 0.3%(20 Mbyte). When the publisher client and the player client and the RELAY module are 183 channels, the occupancy rate of CPU is 99.9% and the occupancy rate of heap memory is 45.8%(3.7Gbyte). Therefore, the paper is not limited to the size of the streaming server by extending the output channel from which the video is transmitted to the output channel of the external streaming server. And a process of allocating an output channel of an external streaming server to an output channel through which an video is transmitted can be easily performed, so that an efficient output channel management can be performed even when a plurality of videos are transmitted.

• Proceedings of the Safety Management and Science Conference
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• 2000.05a
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• pp.55-60
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• 2000

In recent dates, Internet advertising effects are expanded by the steep increment of the Internet users and the extension of the advertising market will be accelerated through Internet. This paper indicates the importance of Internet advertising and suggests the solution of a network advertising service. The system Is divided into an Advertise Server, an Advertiser and a Web Publisher. This study proposes both the collection and the analysis of traffic data in real time. Also, the banner advertising frames are smoothed for the impression using the solution for the banner exchange engine and are developed using various impression methods, that is, Fixed/variable Banner, Scheduling Banner, Multi-Impression Banner, and Frame Remote Control to increase the advertising effect. And then to increase the advertising effect web publisher, which is specialized in lottery site, is constructed using the network advertising service and various advertising technology.

• Journal of the Korea Safety Management & Science
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• v.2 no.2
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• pp.177-185
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• 2000

In recent dates, Internet advertising effects are expanded by the steep increment of the Internet users and the extension of the advertising market will be accelerated through Internet. This paper indicates the importance of Internet advertising and suggests the solution of a network advertising service. The system is divided into an Advertise Server, an Advertiser and a Web Publisher. This study proposes both the collection and the analysis of traffic data in real time. Also, the banner advertising frames are smoothed for the impression using the solution for the banner exchange engine and are developed using various impression methods, that is, Fixed/variable Banner, Scheduling Banner, Multi-Impression Banner, and Frame Remote Control to increase the advertising effect. And then to increase the advertising effect web publisher, which is specialized in lottery site, is constructed using the network advertising service and various advertising technology.