• Smart Media Journal
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• v.9 no.3
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• pp.116-121
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• 2020

Digital Information Display and KIOSK have a problem that initial introduction cost and maintenance cost due to the development cost of dedicated contents and installation cost are high due to the characteristics of the product. In order to solve these problems, We designed and implemented of voice transmission system using Open Source Hardware and Event based Non-Blocking I/O Algorithm.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.888-891
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• 2002

Banyan network is a popular and basic structure of the multistage ATM switches. This paper presents a novel approach to resolve the internal blocking of the banyan network by using Non-Blocking Permutation Generator (NBPG). The NBPG performs two functions, i.e., the first is to extract the conflict cells from the incoming cells and the second is to re-assign new input port addresses to the conflict cells. As a result, NBPG generates non-blocking I/O permutations. To estimate the performance of NBPG, we provide several simulation results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.343-350
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• 2010

In the existing design of web server architecture, data encryption technique is used to keep the reliability, stability, and safety of web service. But the use of data encryption technique wastes the work of cpu while decreasing throughput of web server and increasing average response time so that it shows negative effect on the capacity of web application server. Also, the latest web applications require security and safety for the safe internet communication. Therefore, this paper suggests the improved web server which uses thread pool and Non-blocking I/O adding new web service modules to the existing web server for the safe web service, provides reliability and safety to show the safe web service capacity. And we compare and evaluate the safety and capacity through experiment on the existing traditional Tomcat based web server and the proposed system to evaluate the safety and capacity of the proposed web server system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.11C
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• pp.1124-1131
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• 2002

The banyan network is a popular and basic structure of the multi-stage ATM switches. This paper presents a novel approach to resolve the internal blocking of the banyan network by using a Non-Blocking Permutation Generator (NBPG). The NBPG performs two functions, i.e., the first is to extract the conflict cells from the incoming cells and Ole second is to re-assign new input port addresses to the conflict cells. As a result, NBPG generates non-blocking I/O permutations. To estimate the performance of the NBPG, we provide the results of several simulations.

• International journal of advanced smart convergence
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• v.8 no.1
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• pp.9-17
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• 2019

In this article, we present a performance enhancement scheme for mobile applications by adopting persistent memory. The proposed scheme supports the deadline guarantee of real-time applications like a video player, and also provides reasonable performances for non-real-time applications. To do so, we analyze the program execution path of mobile software platforms and find two sources of unpredictable time delays that make the deadline-guarantee of real-time applications difficult. The first is the irregular activation of garbage collection in flash storage and the second is the blocking and time-slice based scheduling used in mobile platforms. We resolve these two issues by adopting high performance persistent memory as the storage of real-time applications. By maintaining real-time applications and their data in persistent memory, I/O latency can become predictable because persistent memory does not need garbage collection. Also, we present a new scheduler that exclusively allocates a processor core to a real-time application. Although processor cycles can be wasted while a real-time application performs I/O, we depict that the processor utilization is not degraded significantly due to the acceleration of I/O by adopting persistent memory. Simulation experiments show that the proposed scheme improves the deadline misses of real-time applications by 90% in comparison with the legacy I/O scheme used in mobile systems.

• Journal of Advanced Navigation Technology
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• v.20 no.1
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• pp.79-85
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• 2016

Network traffic is increased rapidly, due to mobile and social network, such as smartphones and facebook, in recent web environment. In this paper, we improved web response time of existing system using direct buffer of NIO and DMA. This solved the disadvantage of JAVA, such as CPU performance reduction due to the blocking of I/O, garbage collection of buffer. Key values circulated many data due to priority change put on a hash map operated easily and apply a priority modification algorithm. Large response data is separated and stored at a fast direct buffer and improved performance. This paper showed that the proposed method using NIO was much improved performance, in many test situations of cache hit and cache miss.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.2037-2042
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• 2013

A TCO-less palladium (Pd) catalytic layer on the glass substrate was assessed as the counter electrode (CE) in a dye sensitized solar cell (DSSC) to confirm the stability of Pd with the $I^-/I_3{^-}$electrolyte on the DSSC performance. A 90nm-thick Pd film was deposited by a thermal evaporator. Finally, DSSC devices of $0.45cm^2$ with glass/FTO/blocking layer/$TiO_2$/dye/electrolyte(10 mM LiI + 1 mM $I_2$ + 0.1 M $LiClO_4$ in acetonitrile solution)/Pd/glass structure was prepared. We investigated the microstructure and photovoltaic property at 1 and 12 hours after the sample preparation. The optical microscopy, field emission scanning electron microscopy (FESEM), cyclic voltammetry measurement (C-V), and current voltage (I-V) were employed to measure the microstructure and photovoltaic property evolution. Microstructure analysis showed that the corrosion by reaction between the Pd layer and the electrolyte occurred as time went by, which led the decrease of the catalytic activity and the efficiency. I-V result revealed that the energy conversion efficiency after 1 and 12 hours was 0.34% and 0.15%, respectively. Our results implied that we might employ the other non-$I^-/I_3{^-}$electrolyte or the other catalytic metal layers to guarantee the long term stability of the DSSC devices.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.3
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• pp.268-275
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• 2003

In this paper, the capacity of VSG-CDMA system supporting multi-media service in the reverse link is analyzed by considering the two models according to the power control and user distribution. In analysis model I, assuming perfect power control and uniform distribution of users, the equation of blocking probability is calculated and the maximum number of voice and data user is derived in accordance with 1 % blocking probability. In analysis model II, it is analyzed by assuming power control error and non-uniform distribution of users. The result of analysis model I means the upper bound of system capacity in the 5 MHz wideband VSG-CDMA system, and the result of analysis model II shows the lower bound of system capacity. Also, the improved plan of performance for VSG-CDMA system is suggested by the analyzed result according to data activity and the value of $E_b/N_o$ in model II.

• Spatial Information Research
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• v.21 no.3
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• pp.45-53
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• 2013

Web GIS, based on the latest web-technology, has evolved to provide efficient and accurate spatial information to users. Furthermore, Web GIS Server has improved the performance constantly to respond user web requests and to offer spatial information service. This research aims to create a designed and implemented Web GIS Server that is named as Nodemap which uses the emergent technology, Node.js, which has been issued for an event-oriented, non-blocking I/O model framework for coding JavaScript on the server development. Basically, NodeMap is Web GIS Server that supports OGC implementation specification. It is designed to process GIS data by using DBMS, which supports spatial index and standard spatial query function. And NodeMap uses Node-Canvas module supported HTML5 canvas to render spatial information on tile map. Lastly, NodeMap uses Express module based connect module framework. NodaMap performance demonstration confirmed a possibility of applying Node.js as a (next/future) Web GIS Server development technology through the benchmarking. Having completed its quality test of NodeMap, this study has shown the compatibility and potential for Node.js as a Web GIS server development technology, and has shown the bright future of internet GIS service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10B
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• pp.1867-1875
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• 1999

This paper presents a very unique and analytic method for scheduling messages routed through a non-blocking switch. The laxities of schedulable messages are decomposed and the laxity table is rearranged so that the packets to be scheduled in the next time instance are placed in the diagonal of the traffic matrix. And the modified MLF-SDR algorithm is performed on the table. We present some examples and simulation results which show that the success rate is very high, even when the size of which is large.