• 한국과학예술포럼
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• 제20권
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• pp.307-314
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• 2015

Tele-Gesture is a tangible user interface(TUI) device that allows a user to physically point to a 3D object in real life and have their gestures play back by a robotic finger that can point to the same object, either at the same time, or at another point in time. To understand the extent of the gestures as new way of digital collaborative communication, collaboration situation and types were experimented as TUI implementations. The design prototype reveals that there is a rich non-verbal component of communication in the form of gesture-clusters and body movements that happen in an digital communication. This result of analysis can contribute to compile relevant contributions to the fields of communication, human behavior, and interaction with high technology through an interpretive social experience.

• 대한가정학회지
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• 제32권3호
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• pp.105-120
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• 1994

The purposes of this research are to find out general trends of mother-adolescent communication and family stress to estimate the differences of communication patterns and family stress according to sociodemographic and communication variables and to analyze communication variables influencing on family stress. The samples were selected from high school students and their mothers and 342 couples were used in final analysis. Barnes & Olson(1982)'s parent-adolescent communication scale(PACI) and McCubbin(1981)'s family stress scale(FILE) were used to measure mother-adolescent communication pattern and family stress. The data were analyzed by frequency, percentage, mean, Chi-square, F-test Duncan-test, multiple regression, Pearson's r, and Chronbach's α. The result are summerized as follows: 1) Mothers highly perceived mother-adolescent open communication pattern but adolescents highly revealed mother-adolescent close communication pattern. The general trends of family stress showed that adolescents stress is higher than mothers. 2) Communication patterns showed significant differences in mother's age, adolescent's sex and communication variables in mother's education and conversation variables. Generally when mothers and adolescents communicated insufficiently and were not satisfied with communication patterns family stress was increased. 3) Family stress was significantly different in communication patterns. Form the regression analysis it was found that communication patterns are crucial to family stress. Especially open communication pattern between mothers and adolescents was the most important among the communication patterns for family stress was reduced.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권5호
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• pp.2357-2380
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• 2019

In this paper, we investigate the impact of hardware impairments (HWIs) on the performance of a downlink massive MIMO system. We consider a single-cell system with maximum ratio transmission (MRT) as precoding scheme, and with all the HWIs characteristics such as phase noise, distortion noise, and amplified thermal noise. Based on the system model, we derive closed-form expressions for a typical user data rate under two scenarios: when a common local oscillator (CLO) is used at the base station and when separated oscillators (SLOs) are used. We also derive closed-form expressions for the downlink transmit power required for some desired per-user data rate under each scenario. Compared to the conventional system with ideal transceiver hardware, our results show that impairments of hardware make a finite upper limit on the user's downlink channel capacity; and as the number of base station antennas grows large, it is only the hardware impairments at the users that mainly limit the capacity. Our results also show that SLOs configuration provides higher data rate than CLO at the price of higher power consumption. An approach to minimize the effect of the hardware impairments on the system performance is also proposed in the paper. In our approach, we show that by reducing the cell size, the effect of accumulated phase noise during channel estimation time is minimized and hence the user capacity is increased, and the downlink transmit power is decreased.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권2호
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• pp.550-565
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• 2018

Cognitive radio technology is still the key technology of future mobile communication systems. Previous studies have focused on improving spectrum utilization and less energy consumption. In this paper, we propose an Overhead Reduced Scheme (ORS) for green cooperative spectrum sensing. Compared to traditional cooperative sensing scheme, ORS scheme divides the sensing time into three time slots and selects the best multi-mode user to report decisions. In consideration of reporting channel deviation, we derive closed-form expressions for detection probability and false alarm probability of ORS scheme based on Rayleigh fading channel. Simulation results show that ORS scheme can improve the perception accuracy while reducing the perceived delay and energy consumption in the process of perception, so as to realize the green communication.

• 한국정보과학회논문지:시스템및이론
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• 제30권7_8호
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• pp.359-369
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• 2003

본 논문에서는 웜홀 라우팅 방식을 사용한 2차원 토러스에서 다대다 개별적 통신에 대한 효율적인 알고리즘을 제시한다. 다대다 개별적 통신은 집합체 통신(Collective Communication)의 일종으로 행렬 전이, FFT, 흑은 분산 테이블 검색과 같은 많은 응용 분야에 적용이 되고 있다. 이에 대한 연구는 망의 크기가 2의 멱승 혹은 4의 배수인 경우에 대한 알고리즘이 제시가 되었지만 그 크기가 일반적인 경우에 대해서는 아직은 제안되고 있지 않고 있다. 본 논문에서는 먼저 망의 크기가 2의 배수인 경우에 대한 다대다 개별적 통신에 대한 Double-Hop-2D 알고리즘을 제안한 다음 이 알고리즘을 확장하여 임의의 노드 수에 적합한 2개의 알고리즘을 제안한다. Split-and-Merge 알고리즘은 전체망을 4개의 지역으로 분할하여 각 분할된 영역이 독립적으로 영역별로 다대다 개별적 통신을 수행한 후 그 결과를 다시 결합하는 단계로 구성되어 있다. Modified Double-Hop-2D 알고리즘은 기본이 되는 Double-Hop-2D 알고리즘에서 추가적인 작업을 수행함으로써 다대다 개별적 통신을 수행한다. 마지막으로 망의 크기가 일반적인 경우에 Modified Double-Hop-2D 알고리즘이 Split-and-Merge 알고리즘보다 성능이 우수함을 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권2호
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• pp.483-503
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• 2015

This paper analyzes the optimal user density and power allocation for Device-to-Device (D2D) communication underlaying cellular networks on multiple bands with the target of maximizing the D2D transmission capacity. The entire network is modeled by Poisson point process (PPP) which based on stochastic geometry. Then in order to ensure the outage probabilities of both cellular and D2D communication, a sum capacity optimization problem for D2D system on multiple bands is proposed. Using convex optimization, the optimal D2D density is obtained in closed-form when the D2D transmission power is determined. Next the optimal D2D transmission power is obtained in closed-form when the D2D density is fixed. Based on the former two conclusions, an iterative algorithm for the optimal D2D density and power allocation on multiple bands is proposed. Finally, the simulation results not only demonstrate the D2D performance, density and power on each band are constrained by cellular communication as well as the interference of the entire system, but also verifies the superiority of the proposed algorithm over sorting-based and removal algorithms.

• Asian Journal for Public Opinion Research
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• 제6권1호
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• pp.31-38
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• 2018

Leading up to the 2019 presidential election in Indonesia, campaigns have emerged through social media, particularly Twitter, using various hashtags, such as #2019GantiPresiden (2019 Change President) and #TetapJokowi (Always Jokowi). This paper tries to understand the presidential candidates' power map in forming opinions and influencing voter behavior by analyzing Twitter from August 6, 2018 to September 15, 2018, just before the beginning of the official campaign period, by searching for the keyword "pemilihan presiden RI Tahun 2019" (RI presidential election in 2019). According to our NodeXL's analysis, there were 1,650 active Twitter users talking about the 2019 presidential election. The 1,650 Twitter users have formed a communication network of 46,750 relationships formed from messages in the form of tweets, comments, and retweets. Our analysis found that those mentioning "pilihan presiden 2019" form large communication networks around four clusters: one for each of the two candidates (Jokowi and Prabowo) and two for opinion leaders who are undecided about the election (Gus Mus and Mas Piyu). GusMus is a religious leader, as an official of the PBNU Rais Syuriah (an Islamic organization) and has a large following both on and off Twitter. "MasPiyu" is an unidentified Twitter user; he only has a large following on Twitter, but does not have support offline.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권1호
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• pp.91-107
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• 2014

Device-to-device (D2D) communication is an excellent technology to improve the system capacity by sharing the spectrum resources of cellular networks. Multicast service is considered as an effective transmission mode for the future mobile social contact services. Therefore, multicast based on D2D technology can exactly improve the spectrum resource efficiency. How to apply D2D technology to support multicast service is a new issue. In this paper, a resource allocation scheme based on cognitive radio (CR) for D2D underlay multicast communication (CR-DUM) is proposed to improve system performance. In the cognitive cellular system, the D2D users as secondary users employing multicast service form a group and reuse the cellular resources to accomplish a multicast transmission. The proposed scheme includes two steps. First, a channel allocation rule aiming to reduce the interference from cellular networks to receivers in D2D multicast group is proposed. Next, to maximize the total system throughput under the condition of interference and noise impairment, we formulate an optimal transmission power allocation jointly for the cellular and D2D multicast communications. Based on the channel allocation, optimal power solution is in a closed form and achieved by searching from a finite set and the interference between cellular and D2D multicast communication is coordinated. The simulation results show that the proposed method can not only ensure the quality of services (QoS), but also improve the system throughput.

• 한국인쇄학회지
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• 제29권2호
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• pp.71-82
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• 2011

Electronic display markets has been developed. The cathode ray tube of brown form recently celebrated their 100th by first display. Also LCD of flat form recently celebrated their 25th by second display and it has advantage of small volume, lower consumption power. But FPD has problem that is property of brittle and noncarrying by glass substrate. Therefore the arrival of portable electronics devices has put an increasing premium on durable, lightweight and inexpensive display components. It is flexible display by third display. Also electronics field such as printed wiring board, RFID, membrane switch prefer flexible display. The conductive pattern can be used mostly in field of electronic displays and electronics. This manufacture of conductive pattern in present used is screen printing. The the conductive pattern. It has advantages of flexibility, high conductivity, drying in low temperature, good conductivity. screen printing has problem that is low productivity and use not flexible substrate because of high fire temperature. This study was developed novel method to form the conductive pattern. It has advantages of flexibility, high conductivity, drying in low temperature, good conductivity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권10호
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• pp.3342-3360
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• 2014

In this paper, the capacity and BER performance of downlink distributed antenna systems (DAS) with transmit antenna selection and multiple receive antennas are investigated in MIMO composite channel, where path loss, Rayleigh fading and lognormal shadowing are all considered. Based on the performance analysis, using the probability density function (PDF) of the effective SNR and numerical integrations, tightly-approximate closed-form expressions of ergodic capacity and average BER of DAS are derived, respectively. These expressions have more accuracy than the existing expressions, and can match the simulation well. Besides, the outage capacity of DAS is also analyzed, and a tightly-approximate closed-form expression of outage capacity probability is derived. Moreover, a practical iterative algorithm based on Newton's method for finding the outage capacity is proposed. To avoid iterative calculation, another approximate closed-form outage capacity is also derived by utilizing the Gaussian distribution approximation. With these theoretical expressions, the downlink capacity and BER performance of DAS can be effectively evaluated. Simulation results show that the theoretical analysis is valid, and consistent with the corresponding simulation.