• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.113-116
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• 2005

In general, multiple mobile hosts (MH) access at a base station (BS) that terminates the wired link and relays data flow to the wireless link in wired and wireless heterogeneous network. In this network, the BS is tend to be a bottleneck and to degrade a network performance. Many studies have been done throughout several protocol layers. Especially on the transport layer, many techniques were studied to enhance TCP performance. But most of them are concerned to enhance TCP throughput and TCP fairness is hardly considered. In this paper, an algorithm for enhancing TCP fairness is proposed and its performance is verified by ns-2 simulation.

• The KIPS Transactions:PartC
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• v.12C no.3 s.99
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• pp.419-428
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• 2005

This paper divides domains into the intra, inter domain according to the mobile node's movement and .proposes the Fast RSVP algorithm on the HMIPv6. It is done to advance reservation using L2 beacon signal when MN is located to overlapped cell area. In case of intra-region handoff, the advance reservation is reserved at the nearest common router and In case of inter-region handoff, it is done to advance reservation through the other site MAP's QA(QoS Agent) to the AR and optimize CN's path. Because of using the bandwidth efficiently and switching the data path quickly, the proposal algorithm minimizes the service disruption by data routing.

• The KIPS Transactions:PartA
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• v.16A no.5
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• pp.369-380
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• 2009

SNMP (Simple Network Management Protocol) is a standard protocol for management of network devices, and it provides excellent features such as scalability, information management, authentication, encryption, and access control. However, SNMP has a structural weakness to fully support control functions for integrated management of digital convergence devices, and it has a limitation of message length in SNMP communication. In this paper, we present an extended SNMP scheme for integrated management of digital convergence devices with control functions. We modified the SNMP architecture by adding DDS (Device Driver Subsystem) to SNMP engine for controlling different devices and by defining CADM (Control Agent Driver Model), therefore we solved the ambiguity problem between 'set' and 'control' of SNMP. And the extended SNMP made it easy for SNMP applications to use various control functions. The extended SNMP can transport massive high-level information by adding three new SNMP commands which eliminate the limit of message length.

• The KIPS Transactions:PartA
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• v.9A no.1
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• pp.53-60
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• 2002

This paper describes a Gray Mode Graphic STN LCD drive circuit using USB interface. The drive circuit using USB interface can highly transfer image data created under PC t LCD. Hence, the LCD drive circuit doesn't use microprocessor for the convenience of users. The proposed LCD drive circuit part have been verified by simulation and by ALTERA EPF10K10TC144-3 FPGA implementation in VHDL. The USB interface part have been programmed in MS-Visual C++ 6.0. The validity and efficiency of the proposed LCD drive circuit have been verified by test board. After comparing this LCD drive circuit to specify it was verified that the developed LCD drive circuit showed good performances, such as convenience of users, low cost.

• Journal of the Korea Society of Computer and Information
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• v.19 no.11
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• pp.127-135
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• 2014

Interactive-typed devices and contents that have been often applied in the field of entertainment and game are the technology that allows you to maximize the enjoyment and participation of users through the interaction of each. In this paper, we designed an interactive-typed smartphone app that is based on the Android platform, implemented the wearable Bluetooth device to control via a interactive interface with a vibration sensor and three-axis acceleration sensor. We tested the functionality and 3-axis motion's operability by using smartphone app, interface interactive-typed device that has been developed, prove useful as a wearable Bluetooth device that has the convenience of the user. Further, it is shown that by implementing the optimized protocol of the sensor data transfer over Bluetooth, it is possible to reduce the malfunction of the content of the smart phone.

• Journal of Software Engineering Society
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• v.26 no.1
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• pp.1-16
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• 2013

Variable length information message is a communication protocol standard in order for computer network systems to provide efficient delivery of information. The variable length information messages were developed for varying and controlling details of information in accordance with message receiver's required information level or information access level. In the previous studies, data compressing techniques have been in use for information message optimization technologies in order to reduce physical sizes of information messages. In optimization technologies for information messages, accuracy of information is considered as the most important factor; therefore, only non-loss compression techniques are applied to the optimization technologies. However, the non-loss compression based information message optimization methods are not efficient in data compression, and these are limited to efficient delivery of information in wireless network environments that have constraint bandwidth. In this paper, we attempt to optimize information in the variable length information messages at message fields in order to reduce physical sizes of messages more efficiently. To demonstrate the efficiency of our approach, we conduct optimization experiments for variable length information messages.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.9
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• pp.1139-1145
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• 2019

In order to efficiently use defined satellite network resources, it is a priority to understand the performance and usage of the network. In this paper, in order to analyze the operational efficiency and stability of the system in the satellite communication system operated by K-water flood forecast and alarm network, FTP and ping testing and network traffic analysis methods of measuring download and upload speed between central and observational countries were introduced. As a result of measuring the transmission speed by the introduced test method, the effects of TCP accelerators have been improved by 120% upon download from the observational station. Through the performance test and traffic analysis of the satellite hydrologic observation system introduced, environmental improvement and improvement points of the satellite communication system were derived so that the operational efficiency and stability of the communication network could be expected.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.31-40
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• 2010

The evolution of internet have opened the world of IPTV. With internet protocol, IPTV broadcasts contents stream. The IP protocol doesn't provide secure service due to IP characteristics. So, it is important to provide both connect and secure service. Conditional Access System and/or Digital Right Management are being used to protect IPTV contents. However, there exist restrictions in the view of security. In this paper, we analyse existing security technologies for IPTV and propose a novel method to enforce security efficiently. In the proposed method, OTP is used for encryption/decryption contents and CAS controls key for encryption/decryption and the right of user. With this scheme, it reduces the load of the system and provides more security.

• Journal of Advanced Technology Convergence
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• v.2 no.1
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• pp.1-7
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• 2023

Recently, there have been increasing interests in researches to apply wireless communication technologies for smart farm. This paper introduces the problems in the smart farm for the outdoor culture and technical considerations to solve the problems. As candidate technologies, this paper selects LoRa, Sigfox, NB-IoT, and Wi-Fi and then determines that LoRa is a suitable technology based on the CAPEX, coverage, transmission rate, battery, and the price. To provide technical analysis, this paper introduces technologies related to the physical and medium access control (MAC) layers as well as the security. Specifically, this paper includes the modulation technology in the physical layer, Class (Class A, B, and C) based protocol operations in MAC layer, and security architecture based on the LoRa version.

• Smart Media Journal
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• v.12 no.10
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• pp.85-92
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• 2023

In December 2014, Livestock and Livestock Products Traceability Act was established, allowing consumers to receive livestock traceability information. While the Livestock Traceability System provides consumers with transparent and fair information about their food, it has brought increased workload and penalty burdens to stakeholders in the livestock industry. In this paper, we propose an IoT system for inventory management based on traceability numbers to enable sellers to conveniently provide livestock traceability information to consumers. We analyzed the protocol for managing data from electronic scales and conducted functional testing and verification on mobile devices. Furthermore, we implemented the design and system functionality, taking into account UI/UX on Android OS-based devices to synchronize and interconnect traceability and product information with electronic scales. We anticipate that the proposed approach will minimize user inconvenience and raise production efficiency in the existing market.