• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2613-2620
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• 2014

In this paper, we consider a full duplexing (FD) wireless cellular network where a central base station (BS) works in the FD mode while the downlink (DL) and uplink (UL) users work in the time division duplexing (TDD) mode. Since this FD system induces the inter-user interference from UL user to DL user, the main challenge for maximizing the system performances is user scheduling that makes a pair of DL user and UL user to use the same radio resource simultaneously. We formulate an optimization problem for user pairing to maximize the cell capacity and propose a suboptimal user scheduling algorithm with low complexity. This scheduling algorithm is designed in a way where the DL user with a better signal quality has a higher priority to choose its UL user that causes less interference. Simulation results show that the FD system using the proposed user scheduling algorithm achieves the optimal performance and significantly outperforms the conventional TDD system in terms of the cell capacity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.3
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• pp.249-257
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• 2013

Recently, data traffic is significantly increased by high rate data service. As a result, radio spectrum is considered one of the most scarce and valuable resources for wireless communications. For the solution of this problem, cognitive radio(CR) has been proposed as an efficient means to opportunistic spectrum sharing between primary (licensed) users and cognitive radio users. In this paper, user selection scheme in CR networks is proposed for additional consideration of secondary system. The proposed user selection scheme mitigates interference to primary user by using orthogonal channel vectors while improves performance of secondary system. Simulation results show that the proposed scheme achieves 1.62bps/Hz higher average throughput of whole system than one of the existing scheme.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06b
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• pp.134-139
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• 1996

This paper discusses the user interface for content selection with a video-on-demand system. We suggest two modes for the selection process: active and passive. This paper analyses various video intensive user interfaces using logs of user operation to understand how users behave in each mode.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1997.11a
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• pp.140-145
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• 1997

A stuey to investigate the perception characteristics of color and brightness was conducted in a combined PC and TV monitor, The objective of this study is to suggest user's favorite color temperature in PC mode and user's favorite contrast in TV mode. Investigated factors were monitor coating(coatiog vs. non-coation)and screen brightness (30fL vs. 35fL)in first experiment and monitor coating and pucture movement(static vs. dynamic) in second experiment. The first experiment was conducted in TV mode. Twenty-three subjects (male 12, female 11) perticipated in this experiment. In first experiment, average color temperatures were about 8000K in all experimental conditions. In addition, there was significant difference between coating and non-coating screen at 0.1 level. In second experiment, average contrasts were obtained in all esperimental conditions. There was significant difference between coating and ndn-coating screen at 0.05 level, In addition, there was significant difference between static picture and dynamic picture at 0.1 level

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.7
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• pp.1364-1370
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• 2017

This paper proposes a method that automatically sets profile schedule context-based mobile phone by collecting the user's external situation based on the GPS sensor and accelerometer built into the smartphone and interacting with the data in the user's schedule to minimize the user's handset handling. However, real-time data collection in mobile phones causes energy shortage in the device due to battery consumption. In other words, a service control method is explained in a way that can efficiently handle resource consumption because accessing a measurement device such as GPS and other sensors may increase power consumption of the portable device. Therefore, effective data sharing for context awareness to reduce weekly schedules and smartphone mode has improved energy efficiency in sensing for data collection. The user can use the context more effectively by providing environmental adaptability for various situations such as the end user's local context and smartphone force control.

• Journal of IKEEE
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• v.24 no.1
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• pp.120-126
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• 2020

We present a user recognition method using human body impulse response signals. The body compositions vary from person to person depending on the portion of water, muscle, and fat. In the body communication study, the body has been interpreted circuit models using capacitance and resistances, and its characteristics are determined by the body compositions. Therefore, the individual body channel is unique and can be used for user recognition. In this paper, we applied pseudo impulse signals to the left hand and recorded received signals from the right hand. The empirical mode decomposition (EMD) method removed noise from the received signals and 10 peak values are extracted. We set the differences between peak amplitudes as a key feature to identify individuals. We collected data from 6 subjects and achieved accuracy of 97.71% for the user recognition application.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.343-353
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• 2021

The beauty industry of China POP-UP store service, has entered the peak development period. This paper takes China Estee Lauder POP-UP store as an example, based on the user experience of interactive marketing mode in Beauty POP-UP store under the new retailing model. The paper aims to establish a system interaction design process integrating online and offline to help enterprises complete the sustainable development of marketing services. To achieve this goal, this study uses questionnaires to investigate the key elements of user experience, customer journey map to determine the user pain points, and completes the design of the new system process. This process can provide designers with a new perspective through experimental verification, with high timeliness and practicability. It also promotes the collaborative optimisation and upgrading of physical retail and online retail and provides theoretical support and practical basis for other enterprises.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1046-1048
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• 2003

Recently, various researches in respect of the positioning technologies using satellites and the other sensors have made location-based services (LBS) more common and accurate. Consequently, concern about position information has been increasing. However, since these positioning systems only focus on user's position, it is difficult to know the user's attitude or detailed behaviors at the specific position. It is worthy to study on how to acquire such human attitude or behavior, because those information is useful to know the context of the user. In this paper, the sensor unit consisting of three dimensional accelerometer was attached to human body, and autonomously measured the perpendicular acceleration of ordinary human behaviors including activity modes such as walking, running, and transportation mode using transportation such as a train, a bus, and an elevator. Subsequently, using the classified measurement results, the method to identify the human activity modes was proposed.

• Journal of Multimedia Information System
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• v.7 no.1
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• pp.25-32
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• 2020

This paper proposes a mobile augmented reality mashup for cultural heritage sites such as natural monuments. Several benefits of mobile augmented reality solutions are ideal for preserving and protecting cultural heritage sites. By presenting mobile augmented reality mashup scenarios and mobile mashup framework, we introduce how user-generated multimedia contents can be added. We present two scenarios of Mashup Viewer and Mashup Maker. In Mashup Viewer mode, visitors can create new AR contents using mashup tools for memo, Twitter, images and statistical graphs. In Mashup Maker mode, other visitors also can view the user-generated multimedia AR contents using QR codes as access points. To show feasibility of our approach in mobile platforms, we compare several detection algorithms on PC and mobile platform and report on deployment of our approach in a natural monument museum. With our proposed mashup tools, visitors to the cultural heritage sites can enjoy default AR contents provided by the site administrators and also participate as active content producers and consumers.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.119.6-119
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• 2002

$\textbullet$ Introduction $\textbullet$ A Robotic Cane "RoJi" $\textbullet$ Shared Navigation Control $\textbullet$ Autonomous Control Mode $\textbullet$ User Control Mode $\textbullet$ Navigation $\textbullet$ Summary