• The KIPS Transactions:PartC
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• v.12C no.5 s.101
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• pp.749-756
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• 2005

We developed the CNU nt emulator which is an development environment for WIPI applications, wireless Internet applications for cellular phones with the WIPI software platform. The CNU WIPI emulator provides stable memory management and ability of installing, executing, deleting or managing WIPI applications. WIPI WAM provides quick execution of applications and convenient debugging function. In this paper, we describe the design, implementation issues of the CNU WIPI emulator and show its correctness of executing and performance improvement over $25\%$ by comparing it with other WIPI emulators.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.2
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• pp.220-228
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• 2008

Toluene adsorption characteristics in the adsorption bed packed with activated carbon fiber (ACF) were studied. Experimental apparatus is composed of VOC generation equipment, adsorption bed, and analytical instrument. Breakthrough characteristics were investigated with length of the adsorption bed which consisted of 3 or 5 sheets of the ACF and flow rate when toluene concentration are 400 ppm and 800 ppm respectively. When mass transfer zone (MTZ) comes out of the adsorption bed, toluene concentration is increased sharply and reached plateau region by saturation. Experimental results are compared with semi-empirical gas adsorption model proposed by Yoon and Nelson. In order to investigate the movement of the MTZ with adsorption time in the adsorption bed packed with ACFs, weight increment of each ACF was measured with the location of ACF at each run. When the weight increment of ACF by toluene adsorption which located at the exit of the bed reaches about 20%, toluene started to be detected.

• Journal of the Korea Society for Simulation
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• v.25 no.2
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• pp.63-74
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• 2016

This research aims to perform the simulation of self-adaptive lighting control software, and to evaluate the performance of the implemented system. In this text, Self-adaptive software means what detects unexpected changes in surrounding environment by self-monitoring during its run-time, and satisfies demanded condition by adjusting its operation. This is a research about the lighting control system which is operating with the fundamental of self-adaptation concept in IoT(Internet of Things) environment. The system, which is proposed in this text, operates adaptation onto the request of a defined user as recognizing the changes of surrounding environment. This text introduces a relating simulation scenario, system architecture, architecture valuation basis,, and executed evaluation of performance by processing simulations.

• Journal of the Semiconductor & Display Technology
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• v.4 no.1 s.10
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• pp.61-64
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• 2005

This study presents a new algorithm to detect the facial feature in a color image entered from the mobile device with complex backgrounds and undefined distance between camera's location and the face. Since skin color model with Hough transformation spent approximately 90$\%$ of running time to extract the fitting ellipse for detection of the facial feature, we have changed the approach to the simple geometric vector operation, called a TS(Triangle-Square) transformation. As the experimental results, this gives benefit of reduced run time. We have similar ratio of face detection to other methods with fast speed enough to be used on real-time identification system in mobile environments.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.11
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• pp.572-580
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• 2007

Wireless sensor networks are sensing, computing and communication infrastructures that allow us to monitor, instrument, observe, and respond to phenomena in the harsh environment. Generally, the wireless sensor networks are composed of many deployed sensor nodes that were designed to be very cost-efficient in terms of production cost. For example, UC Berkeley's MICA motes have only 8-bit CPU, 4KB RAM, and 128KB FLASH memory space. Therefore, sensor operating systems that run on the sensor nodes should be able to operate efficiently in terms of the resource management. In this paper, we present a dynamic threads stack management scheme for space-constrained and multi-threaded sensor operating systems. In this scheme, the necessary stack space of each function is measured on compile-time. Then, the information is used to dynamically allocate and release each function's stack space on run-time. It was implemented in Nano-Qplus sensor operating system. Our experimental results show that the proposed scheme outperforms the existing fixed-size stack allocation mechanism.

• Journal of the Korea Society for Simulation
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• v.23 no.2
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• pp.57-64
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• 2014

This paper proposes a framework to construct the synthetic battlefield based aviation engagement simulation model for the distributed system. The proposed framework has the synthetic battlefield in the HLA (High Level Architecture)/RTI (Run-Time Infrastructure) based distributed system to reflect environmental effects into the aviation engagement simulation model. In an aviation engagement, the environment affects weapon systems such as detection and movement. Therefore, environmental effects are required to be reflected in the simulation. However, former researches are inadequate for complex operations of weapon systems that are requirements of the engagement simulation. Thus, the construction of the engagement simulation system of which reflects environmental effects based on environmental data is still difficult. The main objective of this paper is to propose a framework to solve the difficulty and constructs an example system based on the proposed framework.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.5
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• pp.901-909
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• 2021

Since mobile devices have limited computational resources, it tends to use the cloud to compute or store data. As real-time becomes more important due to 5G, many studies have been conducted on edge clouds that computes at locations closer to users than central clouds. The farther the user's physical distance from the edge cloud connected to base station is, the slower the network transmits. So applications should be migrated and re-run to nearby edge cloud for smooth service use. We run applications in docker containers, which is independent of the host operating system and has a relatively light images size compared to the virtual machine. Existing migration studies have been experimented by using network simulators. It uses fixed values, so it is different from the results in the real-world environment. In addition, the method of migrating images through shared storage was used, which poses a risk of packet content exposure. In this paper, Containers are migrated with Secure CoPy(SCP) method, a data encryption transmission, by establishing an edge computing environment in a real-world environment. It compares migration time with Network File System, one of the shared storage methods, and analyzes network packets to verify safety.

• Particle and aerosol research
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• v.10 no.2
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• pp.61-75
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• 2014

Five on-road measurements were made using a mobile laboratory (ML) to characterize spatial and temporal air pollutant distributions over roads around a day-care center in urban area on 30 August 2013. Fixed monitoring was also done near the day-care center using the ML during the periods between on-road measurements. On-road air pollution monitoring route was classified into seven sections and three zones to identify severe polluted roads among many roads having different traffic volumes and directions. Typical pollutants emitted from vehicles such as $NO_x$, black carbon, particle-bound polycyclic aromatic hydrocarbons, and submicron particles including nanoparticles were monitored using real-time instruments. Peak concentration episodes were frequently observed during the on-road measurements and most peaks were simultaneously monitored at four pollutants. Colored on-road air pollution map for each pollutant provides an insight on spatial air pollution distribution, showing heavily polluted roads and sections. Average on-road $NO_x$ concentration of each run was similar to that monitored at the nearest roadside air monitoring station.

• Journal of Navigation and Port Research
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• v.30 no.9
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• pp.741-748
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• 2006

Number of researches on efficient terminal operation system applying RFID(Radio Frequency Identification) are in progress. However, RFID has limitations on tracking and providing accurate positions of containers. In this paper, to enhance the performance of the integrated terminal operation system, an efficient loading management of yard is proposed by applying RFID based RTLS(Real Time Locating System) that provides real time accurate positions of containers. It was found that a group based sequence system is more efficient than the existing individual sequence number system in the container yard In the group based sequence system, the containers in the same group should have similar characteristics such as port of destination(POD), size, weight, etc. In order to run this system, we proposed the parameters to the unspecified N bytes of RFID tag which are specified in ISO 18000 7. And then, we developed an integrated operation system of container terminal using RFID. The proposed system reduces the ship turnaround time in ubiquitous port environments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.625-627
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• 2011

Smart phone users with an increase in the use of public transportation at this time due to promote the above social minute at a time and place anytime, anywhere without worrying improving concentration and peace of mind when the cost to run this study in order to complete an application at a time and place without giving the necessary content, improved concentration, and by running an application that gives peace of mind to develop.