• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.42 no.1
• /
• pp.121-127
• /
• 2017

In the land mobile satellite (LMS) communication, a hybrid satellite-terrestrial relay networks (HSTRNs) using a maximal ratio combining (MRC) scheme are widely used to enhance the quality of signal from a satellite. In this paper, we derive equations for the TCP throughput and the spectral efficiency in the HSTRN and analyze results of the performance evaluation for TCP in various environments. In the simulation results, it is shown that increasing the number of terrestrial relays can enhance the TCP throughput and spectral efficiency thanks to the MRC scheme. However, the usage of the static number of terrestrial relays considering no channel states would cause the overhead. Furthermore, it has a limitation to enhance the network performance by only MRC scheme in HSTRN because the TCP performance is sensitive to the packet los rate. Therefore, we discuss the possible solutions that can additionally enhance the network performance and reduce the overhead.

• Current Photovoltaic Research
• /
• v.2 no.3
• /
• pp.95-102
• /
• 2014

Light trapping techniques can change the propagation direction of incident light and keep the light longer in the absorption layers of solar cells to enhance the power conversion efficiency. In thin film silicon (Si) solar cells, the thickness of absorption layer is generally not enough to absorb entire available photons because of short carrier life time, and light induced degradation effect, which can be compensated by the light trapping techniques. These techniques have been adopted as textured transparent conduction oxide (TCO) layers randomly or periodically textured, intermediate reflection layers of tandem and triple junction, and glass substrates etched by various patterning methods. We reviewed the light trapping techniques for thin film Si solar cells and mainly focused on the commercially available techniques applicable to textured TCO on patterned glass substrates. We described the characterization methods representing the light trapping effects, texturing of TCO and showed the results of multi-scale textured TCO on etched glass substrates. These methods can be used tandem and triple thin film Si solar cells to enhance photo-current and power conversion efficiency of long term stability.

• Proceedings of the Korean Information Science Society Conference
• /
• 2005.11a
• /
• pp.112-114
• /
• 2005

In today's hyper-competitive business environment, Radio Frequency Identification (RFID) technology is expected to enhance the operation efficiency of supplying chain management in both manufactures and retail industries. However, the widespread deployment of RFID tags may create new threats to user privacy, due to the powerful tracking capability of the tags. Many authentication protocols for RFID have been proposed. They are helpful preventing passersby being scanned to determine what articles they are carrying. However, most of them would not prevent the bigger physical tracking problem of RFID, especially when being tracked by the 'constellation' of products they carry. We proposed this RFID scheme to prevent these tracking problems.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.48 no.2
• /
• pp.14-20
• /
• 2011

In mobile ad hoc networks where the communication nodes are moving around, one may perform dynamic routing that can increase the total communication throughput of the network, by determining the ranks of pairs of nodes according to their communication throughput. The balanced Howell rotation is a tournament design scheme for bridge games. This paper explains that the balanced Howell rotation can be applied to enhance the overall communication throughput of mobile ad hoc networks, and proposes and proves the condition under which the balanced Howell rotations may exist.

• Journal of Engineering Education Research
• /
• v.15 no.5
• /
• pp.82-86
• /
• 2012

These days, the cruise tourist industry is one of the most dynamic and fastest growing components of the leisure industry in the world. Therefore, the cruise ship with ubiquitous technology is expected to enhance the operation efficiency of the ship. It can also provide valuable addition to the ship's service as well as high quality of life to crews and passengers. Since a large number of passengers are dwelling in cruise ship, all passengers are not easy to use ship's facilities, such as restaurants, fitness center, swimming pool and spa at anytime they want. In this paper, passenger service system in ship environment is tested in similar environment and under ship operation condition. We have proposed three applications of ubiquitous technology using Zigbee communication and LabView program.

• Nutrition Research and Practice
• /
• v.5 no.1
• /
• pp.73-79
• /
• 2011

In order to promote foodservice for the elderly, foodservice managers in Continuing Care Retirement Communities (CCRCs) must identify the main factors to enhance the satisfaction and behavioral intentions with food service. The purpose of this study was to investigate the relationships between relationship quality (consisting of trust, commitment, and satisfaction) and communication in the formation of elderly's behavioral intentions with food services at CCRCs. A survey was administered to residents in two CCRCs and a total of 327 residents participated. A tested structural equation model exhibited good model fit and explanatory power of the study construct. Satisfaction directly influenced word-of-mouth and service quality has an influence on commitment. Commitment was a significant determinant of behavioral intentions to eat more often in the dining room. Also, communication showed positive association with trust. The results provided strong evidence for the importance of satisfaction and communication as a consequence of relationship marketing efforts. Suggestions for future research to better understand the elderly' behavioral intention judgments were given.

• 한국정보통신설비학회:학술대회논문집
• /
• 2009.08a
• /
• pp.190-196
• /
• 2009

In this paper, performance of a turbo-coded OFDM system is analyzed and simulated in a power line communication channel. Since the power line communication system typically operates in a hostile environment, turbo code has been employed to enhance reliability of transmitted data. The performance is evaluated in terms of bit error probability. As turbo decoding algorithms, MAP (maximum a posteriori), Max-Log-MAP, and SOVA (soft decision Viterbi output) algorithms are chosen and their performances are compared. From simulation results, it is demonstrated that Max-Log-MAP algorithm is promising in terms of performance and complexity. It is shown that performance is substantially improved by increasing the number of iterations and interleaver length of a turbo encoder. The results in this paper can be applied to OFDM-based high-speed power line communication systems.

• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 2007.02a
• /
• pp.40-46
• /
• 2007

Established CRM system provides a powerful help for maintaining existing client, attracting new client, making profit from client or mobile communication industry. In the system structure of CRM eye, the mobile communication industry of CRM can be divided into three levels. : channel layer; operation layer, analysis layer. The data mining of CRM in mobile communication industry fall into six stages. Finally article gives some CRM's examples to illustrate how to gain client, enhance client's value, and how to maintain existing client.

• ETRI Journal
• /
• v.24 no.3
• /
• pp.255-258
• /
• 2002

We created a new design for an Nd-doped clad-pumped silica fiber laser to enhance the pump absorption and lasing efficiency for a butt-coupled, end-pumped scheme. Two concatenated adiabatic tapers formed within the laser cavity simultaneously removed higher order modes and were spliced to conventional single mode fibers. We theoretically analyzed mode propagation along the composite cavity and experimentally achieved continuous wave oscillation in the $LP_{01}$ mode at $1.06\;{\mu}m$ and a laser output power of over 820 mW with a slope efficiency of 27%.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.20 no.4
• /
• pp.463-470
• /
• 2014

Purpose: This study investigates the influence of education satisfaction, communication competence, and group cohesion on organizational socialization in nursing students. Method: The subjects were 175 third year nursing students. Data were collected from June 3 to 14, 2013 through a self-reporting questionnaire. Data analysis was performed by multiple regression using the SPSSWIN 21.0 program. Results: The organizational socialization score of nursing students averaged 3.79 points (5 Likert scale). Practice education satisfaction, communication competence and group cohesion of nursing students influenced organizational socialization ($R^2$ 52.5%, F=49.051, p<.001). Conclusion: For nursing students, practice education satisfaction, communication competence and group cohesion are significant variables for organizational socialization. Thus, in order to enhance the organizational socialization of nursing students, there is a need to develop a differentiated practicum curriculum that considers nursing student demands in collaboration with nursing faculty and administrators on the basis of education programs, including concepts of communication competence and group cohesion.