• Journal of the Korean Home Economics Association
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• v.36 no.8
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• pp.63-76
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• 1998

The purposes of this research were to find out general trends of the efficiency of the interspouse communication and the level of stress recognition, to estimate the differences of the efficiency of communication and the level of stress recognition according to socio-demographic, communication variables, and to analyze correlations between stress recognition and communication efficiency. The subjects of this study were 220 couples in Kwang-ju. The major results were as follow; 1) The level of wives' stress recognition was higher than husbands' and the level of interspouse communication efficiency was median. 2) Communication efficiency showed significant differences according to number of children, the duration of marriage in wives. The level of stress recognition showed significant differences according to the hours they spend in daily communication, the typeds of communication, the satisfaction of communication in both groups of husbands and wives. 3) Marital communication efficiency was negatively correlated with the level of stress recognition in couples.

• Journal of Family Resource Management and Policy Review
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• v.7 no.2
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• pp.25-44
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• 2003

The purpose of the present study was to suggest the efficient communication methods for improving the quality of marriage and life in the elderly couples. For this study we considered variables connected with the communication efficiency of elderly couples. We investigated 462 elderly men and women whose spouse is alive and Seoul and the National Capital region. The major findings of this study are summarized as follows. 1) The communication efficiency of elderly couples was over than middle level so we could find that they communicate efficiently. 2) The communication efficiency of elderly couples differs significantly according to sex, education level, economic condition, health status, family type, social activity, sociotropy Personality, self-esteem, internal-external controllability, marital intimacy, relative comparison in the level of living. 3) The communication efficiency of elderly couples was dependently affected by intimacy, economic status, relationship; this variables had 40% explanation for communication efficiency.

• Current Optics and Photonics
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• v.6 no.1
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• pp.23-31
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• 2022

Heterodyne efficiency is an indicator to evaluate the performance of space coherent laser communication systems. It is affected by signal light and local oscillator (LO) light amplitude, phase and polarization state. In this paper, based on the common heterodyne efficiency, a heterodyne efficiency model that can reflect polarization aberration of optical system is proposed. The heterodyne efficiency is analyzed when the signal light and the LO light are linearly polarized or circularly polarized. For a coherent communication optical system, when the incident signal light is right-circularly polarized light and the incident LO light is 45° linear polarized light. Based on the three-dimensional ray tracing theory and the heterodyne efficiency proposed in this paper, the change of polarization states and the distribution of heterodyne efficiency of the signal light and LO light influenced by the optical system's polarization aberration are analyzed. Analysis shows that the heterodyne efficiency model proposed in this paper can be used to evaluate coherent communication systems and reflect the influence of optical system polarization aberration.

• Proceedings of the Korea Database Society Conference
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• 2008.05a
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• pp.321-338
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• 2008

Information and communication industry, which shows rapid growth rate, is now leading the global economic growth, contributing a ripple effect on general business and economic structure. It is said that information and communication industry enables swift economic growth taking a role as a basic industry of information-oriented society. Especially, rapid technical innovation promotes mutual growth of other related industries and it is technology-intensive. The purpose of this research is to analyze the management efficiency of information and communication industry using DEA method, and finally suggest numerical value for inefficient organizations to improve their efficiency. CCR-I, BCC-I efficiency and RTS(Returns to scale) of 29 companies engaged in information and communication industry was evaluated. With the results, I suggested model companies for benchmarking in information and communication industry. To summarize, 7 companies were selected with CCR-I efficiency rate 1, and 12 companies with BCC-I efficiency rate 1. RTS was finalized with 8 IRS companies, 10 DRS companies, and 11 CRS companies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.4
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• pp.1392-1413
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• 2022

In order to meet the rapid development of the unmanned aerial vehicle (UAV) communication needs, cooperative spectrum sensing (CSS) helps to identify unused spectrum for the primary users (PU). However, multi-UAV mode (MUM) requires the large communication resource in a cognitive UAV network, resulting in a severe decline of spectrum efficiency (SE) and energy efficiency (EE) and increase of energy consumption (EC). On this account, we extend the traditional 2D spectrum space to 3D spectrum space for the UAV network scenario and enable UAVs to proceed with spectrum sensing behaviors in this paper, and propose a novel multi-slot mode (MSM), in which the sensing slot is divided into multiple mini-slots within a UAV. Then, the CSS process is developed into a composite hypothesis testing problem. Furthermore, to improve SE and EE and reduce EC, we use the sequential detection to make a global decision about the PU channel status. Based on this, we also consider a truncation scenario of the sequential detection under the sensing delay constraint, and further derive a closed-form performance expression, in terms of the CSS performance and cooperative efficiency. At last, the simulation results verify that the performance and cooperative efficiency of MSM outperforms that of the traditional MUM in a low EC.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.6
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• pp.777-788
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• 2014

This paper presents a wide output range, high power efficiency reconfigurable charge pump for driving touch panels with the high resistances. The charge pump is composed of 4-stages and its configuration automatically changes based on the required output voltage level. In order to keep the power efficiency over the wide output voltage range, internal blocks are automatically activated or deactivated by the clock driver in the reconfigurable charge pump minimizing the switching power loss due to the On and Off operations of MOSFET. In addition, the leakage current paths in each mode are blocked to compensate for the variation of power efficiency with respect to the wide output voltage range. This chip is fabricated using $0.18{\mu}m$ BCD process with high power MOSFET options, and the die area is $1870{\mu}m{\times}1430{\mu}m$. The power consumption of the charge pump itself is 79.13 mW when the output power is 415.45 mW at the high voltage mode, while it is 20.097 mW when the output power is 89.903 mW at the low voltage mode. The measured maximum power efficiency is 84.01 %, when the output voltage is from 7.43 V to 12.23 V.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2024-2034
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• 2016

This paper presents a DC-DC buck converter with a Phase-Locked Loop (PLL) that can compensates for power efficiency degradation over a wide input range. Its switching frequency is kept at 2 MHz and the delay difference between the High side driver and the Low side driver can be minimized with respect to Process, Voltage and Temperature (PVT) variations by adopting the PLL. The operation mode of the proposed DC-DC buck converter is automatically changed to Pulse Width Modulation (PWM) or PWM frequency modes according to the load condition (heavy load or light load) while supporting a maximum load current of up to 1.2 A. The PWM frequency mode is used to extend the CCM region under the light load condition for the PWM operation. As a result, high efficiency can be achieved under the light load condition by the PWM frequency mode and the delay compensation with the PLL. The proposed DC-DC buck converter is fabricated with a $0.18{\mu}m$ BCD process, and the die area is $3.96mm^2$. It is implemented to have over a 90 % efficiency at an output voltage of 5 V when the input range is between 8 V and 20 V. As a result, the variation in the power efficiency is less than 1 % and the maximum efficiency of the proposed DC-DC buck converter with the PLL is 95.4 %.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.8
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• pp.3766-3788
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• 2017

A blockchain is an underlying technology and basic infrastructure of the Bitcoin system. At present, blockchains and their applications are developing rapidly. However, the basic research of blockchain technology is still in the early stages. The efficiency and reliability of blockchain communication is one of the research problems that urgently need to be studied and addressed. Existing algorithms may be less feasible for blockchain-based communication because they only consider a single communication factor (node communication capability or node trust degree) and only focus on a single communication performance parameter(communication time or communication reliability). In this paper, to shorten the validation time of blockchain transactions and improve the reliability of blockchain-based communication, we first establish a multi-link concurrent communication model based on trust degree, and then we propose a novel integrated factor communication tree algorithm (IFT). This algorithm comprehensively considers the node communication link number and the node trust degree and selects several nodes with powerful communication capacity and high trust as the communication sources to improve the concurrency and communication efficiency. Simulation results indicate that the IFT algorithm outperforms existing algorithms. A blockchain communication routing scheme based on the IFT algorithm can increase communication efficiency by ensuring communication reliability.

• Journal of Families and Better Life
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• v.9 no.2
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• pp.155-170
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• 1991

The purpose of the study was to investigate the effects of demographic-socialogical variables.(ie. educational level, duration of marriage, mate selection type, monthly income, number of children and the frequencies of family's jonit-leisure-activity) and efficiency of the interspous communication on marital satisfaction over the family life cycle. The subject were 278 husbands and wives living in Seoul area who had the eldest child attending at elementary school, middle school , high school and university , respectively. The families were categorized to Duvall's family life cycle. Before the main study was conducted from SEP. 27 to OCT. 8. 1990. a pre-test was conducted on 52 subjects form SEP. 20 to SEP.23.1990. The values of Chronbach's α were obtained on the efficiency of the interspouse communication (α =0.885) and marital satisfaction (α=0.939). Data analysis was by Chronbach's α, ANOVA. Pearson's Product Moment Correlation. Path Analysis and Multiple Regression Analysis. The results were as follows; 1) Marital Satisfaction was positively related (1) to demographic-socialogical variables; educational level , monthly income, the frequencies of family's joint-leisure-activity (2) the efficiency of the interspouse communication. 2) Efficiency of the interspouse communication was positively related to the frequencies o family's joint-leisure-activity. 3) The relative importance of independent variables on marital satisfaction over the family life cycle was found to be varied in each stage of life cycle. (1) As for the group who had elementary-school-aged children; efficiency of the interspouse communication (β=0.717.p<.001), joint-leisure-activity frequency (β =0.303.p<.001), monthly income(β=0.202.p<.001), mate selection type(β=0.180.p<.05), (2) As for the group who had middle-school-aged children; efficiency of the interspouse communication (β=0.702.p<.001), (3)As for the group who had high school-aged children; efficiency of the interspouse communication (β=0.488.p<.001), joint-leisure-activity frequency (β=0.368.p<.001), (4)the group who had university-aged children; efficiency of the interspouse communication.(β=0.729.p<.001), monthly income (β=0.164.p<.01). The regression model showed that 55 percent of the marital satisfaction could be account for by demographic-socialogical variables and efficiency of the interspouse communication (R2=0.551)

• Journal of Communications and Networks
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• v.18 no.3
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• pp.320-326
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• 2016

In existing literature on multiple-input multiple-output (MIMO) relaying communication systems, antenna selection is often implemented by maximizing the channel capacity or the output single-to-noise ratio (SNR). In this paper, we propose an energy-efficient low-complexity antenna selection scheme for MIMO relaying communication systems. The proposed algorithm is based on beamforming and maximizing the Frobenius norm to jointly optimize the transmit power, number of active antennas, and antenna subsets at the source, relaying and destination. We maximize the energy efficiency between the link of source to relay and the link of relay to destination to obtain the maximum energy efficiency of the system, subject to the SNR constraint. Compared to existing antenna selection methods forMIMO relaying communication systems, simulation results demonstrate that the proposed method can save more power in term of energy efficiency, while having lower computational complexity.