• Journal of Korea Multimedia Society
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• v.19 no.9
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• pp.1679-1689
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• 2016

Recently, due to the rapid development of multimedia technologies, as image data has been extensive and large-scaled, the problem of increasing the time needed to retrieve the desired image is gradually critical. Image retrieval system that allows users to quickly and accurately search for the desired image information has been researched for a long time. However, in the case of content-based image retrieval representative Color Histogram, Color Coherence Vectors (CCV), Scale Invariant Feature Transform (SIFT) used in sensitive to changes in brightness, rotation, there is a problem that can occur misrecognized division off the power. In this paper, in order to evaluate the video retrieval system proposed, no change in brightness, respectively 0°, 90°, 180°, 270° rotated brightness up based on the case of changing, when the brightness down the results were compared with the performance evaluation of the system is an average of about 2% to provide the difference in performance due to changes in brightness, color histogram is an average of about 12.5%, CCV is an average of about 12.25%, it appeared in the SIFT is an average of about 8.5%, Thus, the proposed system of the variation width of the smallest in average about 2%, was confirmed to be robust to changes in the brightness and rotation than the existing systems.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.2
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• pp.33-40
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• 2016

Due to the growth of social network systems (SNS), big data are realized and Hadoop was developed as a distributed platform for analyzing big data. Enterprises analyze data containing users' sensitive information by using Hadoop and utilize them for marketing. Therefore, researches on data encryption have been done to protect the leakage of sensitive data stored in Hadoop. However, the existing researches support only the AES encryption algorithm, the international standard of data encryption. Meanwhile, Korean government choose ARIA algorithm as a standard data encryption one. In this paper, we propose a HDFS data encryption scheme using ARIA algorithms on Hadoop. First, the proposed scheme provide a HDFS block splitting component which performs ARIA encryption and decryption under the distributed computing environment of Hadoop. Second, the proposed scheme also provide a variable-length data processing component which performs encryption and decryption by adding dummy data, in case when the last block of data does not contains 128 bit data. Finally, we show from performance analysis that our proposed scheme can be effectively used for both text string processing applications and science data analysis applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.669-671
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• 2010

IStorage is a technology, which can use resources of server PC by using Android Phone supporting wireless internet access. IStorage utilizes resources of server PC through WebDAV protocol. And with GUI interface, Users upload their resources to the server PC and They can perform various kinds of works like Opening, Searching, Deleting and Downloading files. Since it is possible for them to use resources of server PC as if they are originally stored in their mobile devices, there is no limit on using the functions such as watching movies, listening musics and opening document files in real time. We expect this study can to overcome the limitation of storage space and also be a useful technology in the smart phone market.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.5
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• pp.97-105
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• 2008

The micro capacitors are passive elements necessary to electronic circuits and wireless portable PAN(personal area network) and Mobile Communications device modules in the baseband circuits in combination with another passive and active devices. As capacitance is proportionally increased with dielectric constant and electrode areas, in addition, inversely decreased the thickness of the dielectric material, thus thin film capacitors are generally seen as a preferable means to achieve high performance and thin film capacitors are used in a variety of functional circuit devices. In this paper, propose dielectric material as AIN(Aluminium nitride) to make micro thin film capacitor, and this capacitor has the MIM(metal-insulator-metal) structure. AIN thin films are widespread applied because they had more excellent properties such as chemical stability, high thermal conductivity, electrical isolation and so on. In addition, AIN films show low frequency response for baseband signal ranges, I-V and C-V electrical characterization of a thin film micro capacitor. The above experimental test and estimated results demonstrate that the thin film capacitor has sufficient and efficient functional performance to be the baseband range frequency of general electronics circuit and passive device applications.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.4
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• pp.773-778
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• 2007

In order to resolve problems with the phase error in QPSK demodulator of the digital satellite broadcasting systems, the demodulator requires carrier recovery loop which searches for the frequency and phase of the carrier. In this paper the complexity of implementation is reduced by the reduction into half of the number of the multiplier in Inter structure of the conventional carrier recovery loop, and as the drawback of NCO of the conventional carrier recovery loop wastes a amount of power for the structure of lookup table, We designed the structure of combinational logic without the lookup table. In the comparison with dynamic power of the proposed NCO, the power of NCO with the lookup table is $175{\mu}W$, NCO with the proposed structure is $24.65{\mu}W$. As the result, it is recognized that about one eight of loss power is reduced. In the simulation of carrier recovery loop designed QPSK demodulator, it is known that the carrier phase is compensated.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.4
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• pp.670-677
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• 2007

Virtual instruments are the mobile software designed to help users navigate, measure hidden environmental properties, or support various user interactions in a virtual environment. Over the past few years, we have developed several virtual instruments for educational virtual environments. However, the process of constructing virtual instruments is often difficult and time consuming because it requires the developers to understand not only the virtual reality systems but also mobile computing platforms. In this paper, we Int identify a few requirements for the development of virtual instruments. Then, we introduce the VIST (Virtual Instrument Scripting Toolkit), specifically designed for reducing the effort of designing virtual instruments. Finally, we will illustrate some applications of using VIST and then discuss the future research directions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.75-82
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• 2007

In advanced countries, a gas turbine engine is developed to use in aircraft, vessels, and target weapons. Our nation also passed the level of producing engine components and now, we are developing small-sized gas turbine engine. The most important point of the gas turbine engine, the engine control technique, is evaded by the advanced nations. This document contains the research about the development of the gas turbine engine simulator. The simulator presented in this document has a mathematical engine model based on a capacity data of the gas turbine engine to advance the engine simulator. Through this process, it eases the development of the gas turbine engine control algorithm and helps to check the engine controller function. In this simulator, the engine sensor signal conversion board is designed, so the engine model shows like a real sensor signal during the simulation. Also, this paper contrasts the actual engine test with the simulation results to verify the performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.1976-1979
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• 2008

Studies on binary adder have been variously developed. According to those studies of critical worst delay and mean delay time of asynchronous binary adders, carry select adders (CSA) based on hybrid structure showed 17% better performance than ripple carry adders (RCA) in 32 bit asynchronous processors, and 23% better than in 64 bit microprocessor implemented. In the complicated signal processing systems such as RSA, it is essential to optimize the performance of binary adders which play fundamental roles. The researches which have been studied so far were subject mostly to addition algorithms or adder structures. In this study, we analyzed and designed adders in an asp;ect of synthesis method. We divided the ways of implementing adders into groups, each of which was synthesized with different synthesis options. Also, we analyzed the variously implemented adders to evaluate the performance and area so that we can propose a different approach of designing optimal binary adders.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.8
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• pp.1415-1423
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• 2007

Total efficiency of transmitter system was improved by developing combinational 2-Way Isohybrid for GSM1900 base station in this paper. The size of product was decreased and the characteristics were stabilized. The isohybrid transmitter combiner of chip coupler type and hybrid coupler type were designed and fabricated. Insertion loss for chip coupler type isohybrid was $3.17\;dB{\sim}3.47\;dB$. On the other hand, insertion loss for hybrid coupler type was $3.17\;dB{\sim}3.42\;dB$. Isolations between ANT and port were $24.23\;dB{\sim}29.98\;dB$ in case of chip coupler type Isohybrid and were $26.28\;dB{\sim}36.91\;dB$ in case of hybrid coupler type, respectively.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.5
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• pp.305-311
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• 2019

In this study, we examined the proper spacing between the expansion joints according to the temperature load of the inter-modal terminal platform infrastructure to implement a new inter-modal automated freight transport system, which we intend to introduce in Korea. To review the proper expansion joint spacing of the terminal platforms, we set the maximum expansion joint spacing according to the regional temperature changes using the equation proposed by the Federal Construction Council (FCC) of the United States. Then, the maximum displacement value, which was calculated through the structural analysis program, and the limit of the horizontal displacement of the building structure were compared. The proper expansion joint spacing was selected as the slab length at which the maximum displacement of the structure, due to temperature changes, was below the horizontal displacement limit. Based on the application of maximum expansion joint spacing for each region calculated through the FCC's suggestion, the maximum displacement that could occur within the limit of the lateral displacement of the structure was determined.