• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.19 no.3
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• pp.253-270
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• 2015

Two major simultaneous attack strategies have been introduced, as one of cooperative attack of multiple missiles. One strategy is an undesignated time attack, in which the missiles communicate among themselves to synchronize the arrival times by reducing the mutual differences of times-to-go of multiple missiles during the homing. The other is a designated time attack, in which a common impact time is commanded to all members in advance, and thereafter each missile tries to home on the target on time independently. For this individual homing, Impact-Time-Control Guidance (ITCG) law is required. After introducing cooperative proportional navigation (CPN) for the first strategy, this article presents a new closed-form ITCG guidance solution for the second strategy. It is based on the linear formulation, employing base trajectories driven by PNG with various navigation constants. Nonlinear simulation of several engagement situations demonstrates the performance and feasibility of the proposed ITCG law.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10a
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• pp.433-435
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• 1999

The Synchronized Multimedia Integration Language (SMIL) is a recommendation from the W3C that makes authoring of TV-like multimedia presentations on the Web easier. It uses the eXtensible Markup Language (XML) to define a set of markup tags to synchronize the timing and positioning relationships between multimedia objects. We present the design and implementation of JAVA-based SMIL player, SSP(Sejong SMIL Player). SSP processes different types of media objects using multiple threads. Moreover, its cache engine detects the mediatype and allocates the proper cache memory for the corresponding media object.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.9
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• pp.1633-1637
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• 2008

A protocol is proposed to control the rate of each subcarrier in OFDM-based wireless network systems. The proposed protocol adds an OFDM symbol in CTS frame defined in IEEE 802.11 standard. A receiver determines the rate of its subcarrier after it receives the RTS frame. The determined rate is added to OFDM symbol in CTS frame. In order to synchronize the rate information between the sender and the receiver, error recovery process is proposed. The performance improvement of the proposed method is shown by numerical results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.12
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• pp.2226-2231
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• 2008

As the mobile devices and the wireless networks have high-performance capabilities, it is possible to synchronize the spatio-temporal data of a server with the spatio-temporal data of a mobile device which are collected at a field. However, since the server process the synchronization which the model device requests, the whole synchronizations of mass mobile devices take long time. In this paper, we propose the scheme to process concurrently the synchronizations of mobile devices to use multi-queue which does not conflict.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.6
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• pp.377-382
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• 2011

This paper describes the method of data synchronization among devices for personal cloud services. Existing data synchronization for mobile devices is based on a central server to mobile devices or a PC to a mobile device. However, the purpose of this paper is to share user data in heterogeneous environments, without depending on central server. This technology can be applied to synchronize personal data between a device and a personal cloud storage for personal cloud services. The ad hoc synchronization needs a sync agent service discovery module, a user authentication module, a network adapter, and an application data synchronization module. The method described in this paper is better than existing synchronization technology based on client-server in availability, performance, scalability quality attributes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.141-142
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• 2014

Recently, personal information issue has been increased. When personal information is taken, it is very important to prevent secondary damage. In this paper, I suggest new logging system using typing pattern that each user has different. So even if someone knows my password and tries to log in to my account, this system rejects it because the intruder has different typing pattern from mine. To justify my research, I develop algorithm extracting personal typing pattern and finding pattern to synchronize with the original user's pattern.

• International Journal of Computer Science & Network Security
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• v.21 no.6
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• pp.269-274
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• 2021

Businesses and manufacturing have benefited from the evolution of digital information technology. The introduction of e-commerce has changed the way companies are conducted, and the manufacturing industry is using emerging technologies to automate and synchronize production processes in order to increase productivity and profitability. The results of the study show that incorporating the internet into e-commerce has transformed the process, making it one of the most advanced and high users of digital technology. E-commerce has advanced by leaps and bounds, allowing products and services to flow electronically with minimal delays. Manufacturing has benefited from the implementation of IoT, which has increased the productivity of production processes and is gradually becoming a major beneficiary of modern computer technology.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.3
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• pp.292-299
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• 2022

In this paper, we proposed an automatic TOD synchronization and verification method for improving the performance of air-to-ground radio(hereafter SATURN) of legacy aircraft. In order to automatically synchronize TOD with SATURN radio, it is proposed to modify the GPS antenna installed in the existing aircraft according to the minimum operating performance standard. In addition, test methods and results are presented to verify the TOD information generation capability before and after the GPS antenna modifying. It is expected that the automatic TOD synchronization method proposed in this paper can be applied to the SATURN performance improvement design.

• Molecules and Cells
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• v.45 no.3
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• pp.101-108
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• 2022

Drosophila melanogaster lymph gland, the primary site of hematopoiesis, contains myeloid-like progenitor cells that differentiate into functional hemocytes in the circulation of pupae and adults. Fly hemocytes are dynamic and plastic, and they play diverse roles in the innate immune response and wound healing. Various hematopoietic regulators in the lymph gland ensure the developmental and functional balance between progenitors and mature blood cells. In addition, systemic factors, such as nutrient availability and sensory inputs, integrate environmental variabilities to synchronize the blood development in the lymph gland with larval growth, physiology, and immunity. This review examines the intrinsic and extrinsic factors determining the progenitor states during hemocyte development in the lymph gland and provides new insights for further studies that may extend the frontier of our collective knowledge on hematopoiesis and innate immunity.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.2
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• pp.292-300
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• 1987

This paper, realizes the design of the sequential controller of a reinforced warehousing-delivery and unmanned transportation system for automated warehouse system. The system is composed of ware housing delivery adn transportation system using two unmanned vehicles with hierachical structure. It is described by GRAFCET and realized by programmed logic with microprocessor. Being described by GRAFCET, the system is able to divide it into subsystems and to synchronize them. Defining the concept of program module, one can easily program the system with the microprocessor instruction language.