• International Journal of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.1-8
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• 2020

This paper studied a method of estimating target information using a radar in wireless communication. Position information on the target can be estimated angle, distance and velocity. The velocity information can be estimated since the Doppler frequency is changed in the moving target. The signal incident on the receiving array antenna is multiplied by the delay time and the reference signal to represent the output signal. This output signal is estimated by applying FFT (Fast Fourier Transform) after calculating signal correlation through correlation integrator. Since the output signal must be calculated within the correlator, it should be processed with the Dwell time. The correlation signal of the correlation integrator outside this Dwell time is indicated by the velocity measurement error. The FFT is applied to the signal that has passed through the correlated integrator in order to estimate the distance of the signal. The Doppler resolution must be improved because the FFT estimates target information using the Doppler information. The Doppler resolution decreases with increasing the integration time. The velocity information estimation should have no spread of the velocity. As a result of the simulation, there was no spread of the target velocity in this study.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.10
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• pp.4759-4780
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• 2017

Full Dimension multiple input multiple output (FD-MIMO) architecture employs a planar array design at the Base Station (BS) to provide high order multi-user MIMO (MU-MIMO) via simultaneous data transmission to large number of users. With FD-MIMO, the BS can also adjust the beam direction in both elevation and azimuth direction to concentrate the energy on the user of interests while minimizing the interference leakage to co-scheduled users in the same cell or users in the neighboring cells. In a typical highly populated macrocell environment, modelling the elevation angular characteristics of three-dimensional (3D) channel is critical to understanding the performance limits of the FD-MIMO system. In this paper, we study the throughput performance of FD-MIMO system with varying elevation angular spread and inter-element spacing using a 3D spatial channel model. Our results show that for a typical urban scenario, horizontal beamforming with correlated antenna spacing achieves optimal performance but by restricting the spread of elevation angles of departure, elevation beamforming achieves high array gain with wide inter-element spacing. We also realize significant gains due to spatial array processing via modelling the elevation domain and varying the inter-element spacing for both the transmitter and receiver.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.853-871
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• 2012

The location based service is divided into GPS that uses the artificial satellite or base transceiver station in order to cover the wide area and RTLS(Real Time Location System) using the Zigbee, RFID, CSS(Chirp Spread Spectrum), UWB, Bluetooth and Wi-Fi equipment in the space(close range) limited like the building inside or park. Moreover it also repeats the technical development upon through the acceleration of the development of the wire and wireless infrastructure and determination technology, the development of the Internet, diversification of the contents, and etc. As a result, it is expected to develop around the determination technology, witch is common core technology element, contents technology, Internet and mobile communication technology, and etc. afterward. In this research, the direction we investigate was to find and analyze new technology and standardization trend of LBS in order to contribute to the related industry.

• Journal of Internet Computing and Services
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• v.21 no.5
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• pp.31-37
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• 2020

Last year's Goseong-Sokcho forest fires have highlighted the limitations of extinguishing work for night-time forest fire and the importance of quick identification for information on the spread of forest fire. However, it is not easy to find services that take into account the characteristics of forest fires, as most existing disaster-related mobile applications and research assume various disaster situations rather than just forest fire situations. Therefore, a system that can provide information quickly is needed, taking into account the characteristics of forest fires and the limitations of extinguishing work. In this paper, we propose evacuation route guidance services that bypass areas where fire has already spread, supplement existing methods of extinguishing work, and provide general information on forest fire situations in real time, by putting drones into forest fire situations. It has been implemented to automate image analysis using the Rekognition service of Amazon Web Service (AWS), and the results of fire detection and the T Map API guide the evacuation path. It is expected that the results of this paper will allow efficient and rapid rescue and extinguishing work to be carried out, and further reduce the damage of human life caused by forest fires.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.1-7
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• 2013

In the next generation of mobile communication systems, high data rates and high capacity will be possible if multiple antennas are used at new frequencies. This paper presents the correlations between channel parameter path loss (PL), delay spread (DS), angular spread (AS) and K-factor established based on channel measurements. To avoid interference from Korean DTV broadcasting, we measured the channel characteristics in urban/rural/suburban areas on Jeju Island using a channel sounder and $4{\times}4$ antennas. The correlations between channel parameter show that the wireless channel characteristics can be determined and effective communication system design can be produced for use in similar environments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.6
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• pp.2018-2043
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• 2022

Nowadays, COVID-19 infections are influencing our daily lives which have spread globally. The major symptoms' of COVID-19 are dry cough, sore throat, and fever which in turn to critical complications like multi organs failure, acute respiratory distress syndrome, etc. Therefore, to hinder the spread of COVID-19, a Computerized Doughty Predictor Framework (CDPF) is developed to yield benefits in monitoring the progression of disease from Chest CT images which will reduce the mortality rates significantly. The proposed framework CDPF employs Convolutional Neural Network (CNN) as a feature extractor to extract the features from CT images. Subsequently, the extracted features are fed into the Adaptive Dragonfly Algorithm (ADA) to extract the most significant features which will smoothly drive the diagnosing of the COVID and Non-COVID cases with the support of Doughty Learners (DL). This paper uses the publicly available SARS-CoV-2 and Github COVID CT dataset which contains 2482 and 812 CT images with two class labels COVID⁺ and COVI^-. The performance of CDPF is evaluated against existing state of art approaches, which shows the superiority of CDPF with the diagnosis accuracy of about 99.76%.

• The Journal of Information Systems
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• v.15 no.3
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• pp.131-157
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• 2006

A lack of trust in the technical and institutional environments surrounding the web can hinder e-commerce adoption, because Internet social cues are minimal and trust is difficult th establish. Web vendors must act purposefully to overcome consumer perceptions of uncertainty and risk by building trust-both in their own web sites and in the broader Internet environments. Trust makes consumers comfortable by sharing personal information making purchases, and acting on web vendor advice-behaviors essential to wide-spread adoption of e-commerce. Understanding the nature and antecedents of trust is, therefore, a major issue for both Internet researchers and practitioners. Prior research on e-commerce trust has used diverse, incomplete, and inconsistent definitions of trust therefore, making it difficult to compare results across studies. This study tried to and the empirical relationships among the trust-related factors on the usage of Internet shooing mall. The model includes five high-level constructs-disposition to trust institution-based trust trusting beliefs, trusting intention and environmental factors. The results showed that the disposition to trust and the environmental factors had a significant effect on the web site trust however, their effect was not consistent Moreover, the model suggested in this study need to be extended including with the more sociological factors and results in this study required to be verified with those extended model.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.10a
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• pp.125-128
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• 2000

The Internet banking service, through which customers process their banking-related works, was introduced in July 1997. The service has since spread quickly, and as of the end of June 2000, just one year after its introduction into Korea, its subscribers numbered 1.23 million people. This figure is ten times larger than the 120,000 subscribers recorded over the six months period up to the end of 1999. In addition, since the end of June 2000, subscriptions on average increase by more than 10,000 a day, and by the end of December 2000, it is expected to pass the 3 million mark. There has been no empirical study conducted on the invigorated Internet banking's status and its services. Therefore, this research is designed to conduct a survey on the Internet banking service status, to conduct actual transactions from the viewpoint of customers and then make a empirical evaluation of it. This will indicate directions for improvement and development of the domestic Internet banking service. We have evaluated ten areas of the Internet banking service including financial service, customers service, users'convenience, and system safety. As of the end of June 2000, 18 out of 20 commercial domestic banks are providing an Internet banking service, and we have conducted evaluations of all these banks. The evaluation is divided into ten categories with 100 points as a maximum score. These are then classified into six grades AAA, AA, A, BBB, BB and B. The outcome of this evaluation was featured in the major domestic journals, and the banks, acknowledging the value of the report, declared that they would adopt it as their criteria for evaluation.

• Journal of the Korea Society of Computer and Information
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• v.7 no.2
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• pp.46-52
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• 2002

Trend of wire internet has been transferred to wireless internet gradually due to the spread of mobile phone which made Possible Mobility and portability which wire internet could not afford. Not only front line of business part can access business information but also people can use government information for their daily life without limit of place. The frequent report of larceny and misuse of information has been issued to social sector that the need for IDS considering wire wireless internet. In this paper to design IDS to protect information first, searched wire internet intrusion type, intrusion detection method, and wireless intrusion type. In this paper, first, separate abnormal access at the point of system landing and detect intrusion attack with disguise through mobile wireless internet. Due to the intruder can access system normally with disguise, Circuit Patrol model has been suggested to monitor from intrusion attack.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.427-430
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• 2016

Internet of Things is one of the technologies that become a hot topic in recent years, is a technology that connects objects with wired or wireless network and share a information between objects. Gartner predicts that spread rapidly devices for end users, also increase revenue from enterprise equipment through the Annual 'Internet of Things' reports. By this trend, Internet of Things is becoming the platform of various kinds, the platform and the protocol for that have been developed a new technique. In this paper, we compared the performance of the communication protocol between devices in the Internet of Things, and propose a way to improve performance efficiency.