• International Journal of Computer Science & Network Security
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• v.23 no.2
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• pp.140-146
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• 2023

With the rapid growth of new users and massive need for very high data rate in 5G communications system, different technologies have been developed and applied to enhance communication efficiency. One of those technologies is the MISO, MISO and MIMO which transmits and receives information with more reliability by using multiple antennas on transmitter or/and receiver side. This paper presents the latest trends in 5G telecommunications system based on software defined radio, A novel low-cost SIMO, MISO and MIMO using flexibility between USRP and Simulink is implemented tested and validated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5248-5255
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• 2014

Because of the rapid growth of smart phone market, the number of mobile applications has increased exponentially. As mobile applications are developing at a rapid rate, many of them are being developed without considering a systematic development process or quality factors, such as reusability, extensibility, etc.. As a result, they have many faults internally, they are being underrated in satisfaction or reliability from customers, and finally customers do not update or repeat the purchase. Therefore, a meta-model of development process for mobile applications was designed to improve the continuous usability of mobile applications as well as the satisfaction and reliability from users. Applying development process based on a meta-model to mobile application development is expected to improve development productivity and quality of mobile applications.

• The Research Journal of the Costume Culture
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• v.20 no.2
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• pp.195-207
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• 2012

In South Korea, the growth of online shopping malls that are overtaking traditional offline distributors in sales requires the latter to concentrate on developing a variety of contents amidst the ever-changing and competitive market environment. First of all, attention should be paid to information on fashion item materials. This study examined the current status of online shopping malls with a focus on their three different types-specialized malls, general malls, and open markets-and investigated consumers' hedonic shopping motives and influence on fashion materials in terms of purchasing behavior. In doing so, this study surveyed men and women in their 20s-30s residing in Seoul or its surrounding cities and used a total of 255 questionnaires for statistical analysis. The statistical software program SPSS 15.0 was used to conduct frequency analysis, factor analysis, reliability analysis, and multiple regression analysis. The study results showed that in general and specialized shopping malls, consumers granted greater reliability and importance to fashion materials when their interest in shopping or attention to fashion items/brands was high and when they wanted rare items. In open markets, the more interest consumers had in shopping and the more sensitive they were to fashion information, the more dependent they were on prices; in other words, prices were found to have a greater influence on their purchase decisions than the quality of fashion materials. The findings of this study would be useful to marketers and distributors who are trying to develop their marketing strategies based on fashion material information, according to the different types of online shopping malls.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.165-168
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• 1995

The recent rapid growth of air conditioning load has become a major reason of peak load increase in summer. In connection with this, we surveyed the load management projects of utilities world-wide and their detailed activities. This study is to develop a remote load control system using computer and radio communications. We finished the field-test of this system on August 1995 in Seoul area. During the field-test, the remote load control of air conditioners was proved to be well-timed. Two control modes, group control and all control, are available for the user to select. The transmission reliability of the load control signal was very good and the functions of system hardware as well as the software were excellent. So we confirmed the applicability of the load control system including the paper communication network. In this paper, detailed information on the system functions and experimental results are described.

• The KIPS Transactions:PartD
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• v.10D no.7
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• pp.1085-1092
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• 2003

The rapid growth of high speed multimedia services demands the large capacity of the server's storage that maintains the multimedia contents. Among the server's devices, the low I/O speed and physical or logical failure of storage device decrease the total performance of system. The continuous increase of multimedia contents require the flexibility of storage capacity. In order to solve the these problems, we propose the uses of software RAID and LVM techniques that provide the performance improvement and reliability of storage device and the flexibility of storage device respectively. In the LINUX 2.4 kernel, we implemented the reliable and flexible storage device and evaluated the performance of it.

• Smart Structures and Systems
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• v.12 no.2
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• pp.209-233
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• 2013

With an annual growth rate of about 30%, wind energy systems, such as wind turbines, represent one of the fastest growing renewable energy technologies. Continuous structural health monitoring of wind turbines can help improving structural reliability and facilitating optimal decisions with respect to maintenance and operation at minimum associated life-cycle costs. This paper presents an integrated monitoring system that is designed to support structural assessment and life-cycle management of wind turbines. The monitoring system systematically integrates a wide variety of hardware and software modules, including sensors and computer systems for automated data acquisition, data analysis and data archival, a multiagent-based system for self-diagnosis of sensor malfunctions, a model updating and damage detection framework for structural assessment, and a management module for monitoring the structural condition and the operational efficiency of the wind turbine. The monitoring system has been installed on a 500 kW wind turbine located in Germany. Since its initial deployment in 2009, the system automatically collects and processes structural, environmental, and operational wind turbine data. The results demonstrate the potential of the proposed approach not only to ensure continuous safety of the structures, but also to enable cost-efficient maintenance and operation of wind turbines.

• Journal of Korea Multimedia Society
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• v.24 no.8
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• pp.1101-1113
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• 2021

The rapid growth of sense-and-respond applications and the emerging cloud computing model present a new challenge: providing publish/subscribe middleware as a scalable and elastic cloud service. The publish/subscribe interaction model is a promising solution for scalable data dissemination over wide-area networks. In addition, there have been some work on the publish/subscribe messaging paradigm that guarantees reliability and availability in the face of node and link failures. These publish/subscribe systems are commonly used in information-centric networks and edge-fog-cloud infrastructures for IoT. The IoT has an edge-fog cloud infrastructure to efficiently process massive amounts of sensing data collected from the surrounding environment. In this paper. we propose a quorum-based hierarchical fault-tolerant publish/subscribe systems (QHFPS) to enable reliable delivery of messages in the presence of link and node failures. The QHFPS efficiently distributes IoT messages to the publish/subscribe brokers in fog overlay layers on the basis of proposing extended stepped grid (xS-grid) quorum for providing tolerance when faced with node failures and network partitions. We evaluate the performance of QHFPS in three aspects: number of transmitted Pub/Sub messages, average subscription delay, and subscritpion delivery rate with an analytical model.

• Structural Engineering and Mechanics
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• v.47 no.5
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• pp.643-660
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• 2013

In the present work, the capacity ratings of steel truss bridges have been carried out incorporating dynamic effect of moving vehicles and its accumulating effect as fatigue. Further, corrosion in the steel members has been taken into account to examine the rating factor. Dynamic effect has been considered in the rating procedure making use of impact factors obtained from simulation studies as well as from codal guidelines. A steel truss bridge has been considered to illustrate the approach. Two levels of capacity ratings- the upper load level capacity rating (called operating rating) and the lower load level capacity rating (called inventory rating) were found out using Load and Resistance Factor Design (LRFD) method and a proposal has been made which incorporates fatigue in the rating formula. Random nature of corrosion on the steel member has been taken into account in the rating by considering reduced member strength. Partial safety factor for each truss member has been obtained from the fatigue reliability index considering random variables on the fatigue parameters, traffic growth rate and accumulated number of stress cycle using appropriate probability density function. The bridge has been modeled using Finite Element software. Regressions of rating factor versus vehicle gross weight have been obtained. Results show that rating factor decreases when the impact factor other than those in the codal provisions are considered. The consideration of fatigue and member corrosion gives a lower value of rating factor compared to those when both the effects are ignored. In addition to this, the study reveals that rating factor decreases when the vehicle gross weight is increased.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.2
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• pp.37-42
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• 2008

Defects of corrugated board were limiting factors to the corrugated industry's growth. On-line detecting systems of defects are beneficial to increase profits of the corrugated board companies by reducing base paper consumption, increasing process reliability, and increasing productivity. By replacing naked eye inspection of defects to a defects detecting system, continuous inspection without fatigue may guarantee final products quality. The system was developed, which was consisted of line scan CCD camera, lens, illuminating parts, high speed image processor, software, various input parts, and output parts. First installation location of the system was at before fluting process after base paper unwinding, and surface of liner board was inspected by the system. Second installation location was after fluting process and combining process for liner board. Production loss includes ragged appearance of edge, irregular flute shape, wrong combination of flute, score cracking, defects in base paper, and flute cracking. The production loss was analyzed before and after the system installation at a commercial domestic mill. The production loss ratio was defined as a production loss weight per total production weight. The production loss ratio before the installation was decreased a lot from 1.28%(during 3 months before installation) to 0.76%(during 12 months after the first installation) and to 0.25%(during 6 months after the second installation).

• Korean Journal of Construction Engineering and Management
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• v.10 no.3
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• pp.139-147
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• 2009

Accurate construction cost estimation in the initial stage of building project plays a key role for project success and for mitigation of disputes. Total construction cost(TCC) estimation of apartment projects in Vietnam has become more important because those projects increasingly rise in quantity with the urbanization and population growth. This paper presents the application of artificial neural networks(ANNs) in estimating TCC of apartment projects. Ninety-one questionnaires were collected to identify input variables. Fourteen data sets of completed apartment projects were obtained and processed for training and generalizing the neural network(NN). MATLAB software was used to train the NN. A program was constructed using Visual C++ in order to apply the neural network to realistic projects. The results suggest that this model is reasonable in predicting TCCs for apartment projects and reinforce the reliability of using neural networks to cost models. Although the proposed model is not validated in a rigorous way, the ANN-based model may be useful for both practitioners and researchers. It facilitates systematic predictions in early phases of construction projects. Practitioners are more proactive in estimating construction costs and making consistent decisions in initial phases of apartment projects. Researchers should benefit from exploring insights into its implementation in the real world. The findings are useful not only to researchers and practitioners in the Vietnam Construction Industry(VCI) but also to participants in other developing countries in South East Asia. Since Korea has emerged as the first largest foreign investor in Vietnam, the results of this study may be also useful to participants in Korea.