• Journal of KIISE:Software and Applications
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• v.32 no.5
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• pp.449-460
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• 2005

This paper proposes a method to track persons robustly in illumination changes and partial occlusions in color video frames acquired from a fixed camera. To solve a problem of changing appearance by illumination change, a time-independent intrinsic image is used to remove noises in an frame and is adaptively updated frame-by-frame. We use a hierarchical human model including body color information in order to track persons in occlusion. The tracked human model is recorded into a persons' list for some duration after the corresponding person's exit and is recovered from the list after her reentering. The proposed method was experimented in several indoor and outdoor scenario. This demonstrated the potential effectiveness of an adaptive model-base method that corrected distorted person's color information by lighting changes, and succeeded tracking of persons which was overlapped in a frame.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.10B
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• pp.831-840
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• 2004

Providing quality of service (QoS) guarantees over wireless link requires thorough understanding and quantification of the interactions among the traffic source, the wireless channel, and the underlying error control mechanisms. In this paper, we account for such interactions in a network-layer model that we use to investigate the delay performance of a wireless channel. We consider a single ON/OFF traffic stream transported over a wireless link. The capacity of this link fluctuates according to a fluid version of Gilbert-Elliot's model. We derive the packet delay distribution via two different approaches: uniformization and Laplace transform. Numerical aspects of both approaches are compared. The delay distribution is further used to quantify the wireless effective bandwidth under a given delay guarantee. Numerical results and simulations are used to verify the adequacy of our analysis and to study the impact of error control and bandwidth allocation on the packet delay performance. Wireless networks, QoS, delay distribution, fluid analysis.

• Convergence Security Journal
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• v.17 no.1
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• pp.63-68
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• 2017

The Jasmine Revolution started from Tunisia in January 2011 has brought many changes into countries in North Africa and Middle East. We need to study the causes of the revolution. First, the kings and dictators in those countries oppressed the opposition parties and the media aiming for long-term seizure of power. The power concentrated on specific people produced illegalities and corruption. Secondly, most of the national income of those countries belonged to kings and dictators producing problems during the distribution of the income. Especially, with the decrease of oil price in 1990s and the increase of the price of daily necessities in 2000s people lost their credits on their governments. Lastly, the number of people in those countries using the Internet has increased by 4,863% from 2000 to 2010. The expansion of social network services such as Facebook and Twitter was one of factors that made the information control by those countries difficult. We should think about the possibility of sudden change in North Korea. It is necessary to compare and analyze the political, economic and social characteristics between those countries and North Korea. It shouldn't be just a simple comparison or analysis. It should provide basic data for objective and quantified index development in relation to sudden change in North Korea.

• Fire Science and Engineering
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• v.24 no.4
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• pp.1-11
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• 2010

This paper describes a design and implementation of an analog detector and a fire alarm system with recent technology on information and communication. A hierarchical architecture design from the detector to the main system enables to accommodate medium to large size buildings located nearby or far-away. And a software design from communication protocol to application program handles large amount of events efficiently to show information on a large LCD. A PC-based alarm system provides higher speed and larger capacity in a large LCD screen compared with foreign microprocessor-based small screen systems. Thus, very large buildings with several thousands of analog detectors can be easily covered in a single system. When an alarm occurs, a staff alarm scenario specially attempted only in the system is considered to play a major role to distinguish a real fire from unwanted alarms.

• The Transactions of the Korea Information Processing Society
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• v.7 no.1
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• pp.181-199
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• 2000

In this paper, we implemented and tested MPOA(MutiProtocol Over ATM) standardized in ATM Forum, which provides service for various layer 3 protocols as well as legacy LAN applications over ATM networks. The functions of MPCs(MPOA Clients) and MPSs(MPOA Servers) which are the components in MPOA systems are implemented. MPCs are located at the edge device and MPOA hosts and MPSs exist in routers. The implemented MPCs have the functions such as exchances of primitives between an LEC(LAN Emulation Client) and an MPC, management and maintenance of Egress/Ingress cache, default transmission through LECs and shortcut transmission. Assuming that routing, convergence and NHRP(Next Hop Resolution Protocol) functions exist in routers, the implemented MPSs have the functions such as exchanges of primitives between an LEC and an MPC, conversion and exchanges of frames between MPOA and NHRP, and management and maintenance of Egress/Ingress cache. All of the possible scenarios are made up to test whether they run correctly. The implemented system is tested by simulation according to the scenarios.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3B
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• pp.91-99
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• 2008

In this paper, we design the function of ULSLE(Upper Layer Shared LAN Emulation) to provide both the efficient LAN service and compatibility with 802.1D bridge in Hybrid two-stage AWG based WDM-PON. The ULSLE layer lies above MAC control layer in order to provide a mean to interface WDM-PON and 802.1D bridge. It also performs LAN emulation based on PON-Tag which is only used to decide both the transmission mode and the destination of frames transmitted from ONUs. That is, the PON-Tag is not used for downstream frames but destination address field in original frame instead. This decreases the processing overhead and complexity caused by PON-Tag at OLT and ONU. The verification of designed ULSLE is performed according to the specific scenarios based on transmission mode and destination using OPNET.

• Journal of Korea Water Resources Association
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• v.37 no.10
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• pp.789-798
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• 2004

Conjunctive use of surface and ground water is emerging as an alternative to resolve water shortage problems caused by drought or overpopulation. The region whose water supply depends on a single source has high risk of emergency situations, and may need to consider conjunctive use to overcome its weakness. Conjunctive use also can be a realistic and effective solution when additional or new water resources are to be developed. This paper presents a new methodology for managing surface and ground water resources with the aim of supplying water in a sustainable way. The developed method encompasses procedures to assess site suitability for conjunctive use, to devise water supply scenarios based on drought analysis, and to quantify the amount of water attained. It is believed that the systematic and objective features of the developed method enable it to be a useful supportive tool for water management planning and decision-making.

• Advanced Industrial SCIence
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• v.2 no.3
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• pp.8-14
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• 2023

The majority of IoT devices already employ AIoT, however there are still numerous issues that need to be resolved before AI applications can be deployed. In order to more effectively distribute IoT edge resources, this paper propose a machine learning-based approach to managing IoT edge resources. The suggested method constantly improves the allocation of IoT resources by identifying IoT edge resource trends using machine learning. IoT resources that have been optimized make use of machine learning convolution to reliably sustain IoT edge resources that are always changing. By storing each machine learning-based IoT edge resource as a hash value alongside the resource of the previous pattern, the suggested approach effectively verifies the resource as an attack pattern in a distributed AIoT context. Experimental results evaluate energy efficiency in three different test scenarios to verify the integrity of IoT Edge resources to see if they work well in complex environments with heterogeneous computational hardware.

• Journal of KIISE:Software and Applications
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• v.33 no.9
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• pp.751-775
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• 2006

In this paper, we suggested an avatar control technique using the high-level behavior. We separated behaviors into three levels according to level of abstraction and defined layered scripts. Layered scripts provide the user with the control over the avatar behaviors at the abstract level and the reusability of scripts. As the 3D environment gets complicated, the number of required avatar behaviors increases accordingly and thus controlling the avatar-object behaviors gets even more challenging. To solve this problem, we embed avatar behaviors into each environment object, which informs how the avatar can interact with the object. Even with a large number of environment objects, our system can manage avatar-object interactions in an object-oriented manner Finally, we suggest an easy-to-use user interface technique that allows the user to control avatars based on context menus. Using the avatar behavior information that is embedded into the object, the system can analyze the object state and filter the behaviors. As a result, context menu shows the behaviors that the avatar can do. In this paper, we made the virtual presentation environment and applied our model to the system. In this paper, we suggested the technique that we controling an the avatar control technique using the high-level behavior. We separated behaviors into three levels byaccording to level of abstract levelion and defined multi-levellayered script. Multi-leveILayered script offers that the user can control avatar behavior at the abstract level and reuses script easily. We suggested object models for avatar-object interaction. Because, TtThe 3D environment is getting more complicated very quickly, so that the numberss of avatar behaviors are getting more variableincreased. Therefore, controlling avatar-object behavior is getting complex and difficultWe need tough processing for handling avatar-object interaction. To solve this problem, we suggested object models that embedded avatar behaviors into object for avatar-object interaction. insert embedded ail avatar behaviors into object. Even though the numbers of objects areis large bigger, it can manage avatar-object interactions by very efficientlyobject-oriented manner. Finally Wewe suggested context menu for ease ordering. User can control avatar throughusing not avatar but the object-oriented interfaces. To do this, Oobject model is suggested by analyzeing object state and filtering the behavior, behavior and context menu shows the behaviors that avatar can do. The user doesn't care about the object or avatar state through the related object.

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.526-535
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• 2021

Spatial sampling design plays an important role in GIS-based modeling studies because it increases modeling efficiency while reducing the cost of sampling. In the field of agricultural systems, research demand for high-resolution spatial databased modeling to predict and evaluate climate change impacts is growing rapidly. Accordingly, the need and importance of spatial sampling design are increasing. The purpose of this study was to design spatial sampling of paddy fields (11,386 grids with 1 km spatial resolution) in Korea for use in agricultural spatial modeling. A stratified random sampling design was developed and applied in 2030s, 2050s, and 2080s under two RCP scenarios of 4.5 and 8.5. Twenty-five weather and four soil characteristics were used as stratification variables. Stratification and sample allocation were optimized to ensure minimum sample size under given precision constraints for 16 target variables such as crop yield, greenhouse gas emission, and pest distribution. Precision and accuracy of the sampling were evaluated through sampling simulations based on coefficient of variation (CV) and relative bias, respectively. As a result, the paddy field could be optimized in the range of 5 to 21 strata and 46 to 69 samples. Evaluation results showed that target variables were within precision constraints (CV<0.05 except for crop yield) with low bias values (below 3%). These results can contribute to reducing sampling cost and computation time while having high predictive power. It is expected to be widely used as a representative sample grid in various agriculture spatial modeling studies.