• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.5
• /
• pp.980-987
• /
• 2009

A timing synchronization method is presented for IEEE 802.11a wireless OFDM system. First the signal detection is achieved by measuring the moving energy of the received OFDM signal in two consecutive windows. By measuring the correlation between the short training signal and received envelope signal, fine OFDM symbol synchronization can be acquired. The variance and average value of the correlation value is acquired. And the theoretical values are compared with computer simulation results.

• Proceedings of the IEEK Conference
• /
• 2009.05a
• /
• pp.9-11
• /
• 2009

It is well-known that the performance of turbo codes can be improved by allocating different energies per code symbol. In this paper, based on this observation, we propose a joint encoding and modulation scheme for quadrature amplitude modulated turbo code systems. In the proposed scheme, the amount of energy difference between the turbo coded symbols is optimized by optimizing the constellation of quadrature amplitude modulation(QAM). The proposed scheme offers better coding gain compared to the conventional combination of binary turbo code and QAM at the bit error rate of $10^{-5}$.

• The Research Journal of the Costume Culture
• /
• v.14 no.2
• /
• pp.177-191
• /
• 2006

The purpose of this study was to analyze the signification system between logo and brand concept systematically in sportswear brands. For this purpose, 37 apparel brands focused on sportswear brand were selected and the results of the study were following : First, the sportswear brands that symbolize a specific sports used a related supplies such as a golf ball or tennis ball, etc to express sports or concept that pursuit each brand. Second, the sportswear brands used the brand logo that represent or symbolize a specific animal, plant and natural world to express a strong spirit of sports and active energy. Third, the sportswear brands used the word mark or symbol that design a brand name in dynamic or speedy typeface to represent a speed and progressive spirit of sports. Fourth, the sportswear brands used the symbols that represent a concrete object, person such as a mast, shield, etc to emphasize the brand concept. Fifth, the sportswear brands used the symbols of a graphic or geometric style to represent the special quality of brand in type.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2012.06a
• /
• pp.129-129
• /
• 2012

Pumps are used widely in industry, the commercial sector and ships. A poorly selected pump or a pump that does not run at optimum design duty point is a classic symbol of wasted energy and money. It, therefore, becomes important to evaluate the efficiency of these pumps. This paper analyzes traditional technique and instrument to measure some parameters needed to calculate a pump efficiency. The pump efficiency measuring instrument (PEMI) was made and tested on real pump systems. It has been giver the accurate results compared with performance curve given by pump maker.

• Resources Recycling
• /
• v.4 no.4
• /
• pp.22-36
• /
• 1995

Waste tires are increased by increasing number of automobiles, which are the symbol of the mordern society. The waste tires create the environmental, visual hazard and landfill space problems. Recycling waste tires is the best way to solve the problems. The landfill space and the natural resources could by reserved by utilizing waste tires. The waste tires were utilized as whole tires, processed tires (crumb rubber) and energy. The plants for manufacturing crumb rubber also were investigated for their equipments and scales.

• Electronics and Telecommunications Trends
• /
• v.37 no.6
• /
• pp.74-83
• /
• 2022

Shannon and Weaver's semantic communication has been actively studied in recent years as a new communication method to provide intelligent mobile services without requiring more capacity, infrastructure, and energy, even with limited radio resources. Considered a breakthrough beyond the Shannon paradigm, semantic communication aims at successfully transmitting semantic information conveyed by a source rather than accurately receiving each symbol or bit, regardless of meaning. Thus, semantic communication can lead to knowledgeable systems that significantly reduce data traffic because the transmitter only transmits the necessary information related to a specific task. This study describes essential differences between existing and semantic communication, research trends related to semantic communication principles and theory, performance metrics of semantic communication, semantic communication system framework, and future research and development issues.

• Journal of the Korean Solar Energy Society
• /
• v.23 no.2
• /
• pp.21-34
• /
• 2003

This study aims to present the applicability of wind turbine generator system to urban buildings for the utilization of clean renewable energy. The results are as follows; According to the wind resource analysis, it has been found that small sized wind power system can be viable for buildings application due to the amplification of wind velocity around buildings or building clusters, in spite of low mean velocity of 2-3m/s in Seoul and Kyunggi urban areas. But planners must perform micrositing analysis around building so that wind turbine can be located at high velocity zones. The system must be designed to avoid obstacles preventing prevailing wind in buildings. It should be recognized that wind speeds are changing depending on the height and length from buildings. The wind power system can be used as a symbol of landmark which shows a sustainable architecture from the scenary Itself A case study for apartment building in urban showed that wind power systems can be applicable in two kinds of place, rooftops and ground levels. Especially, the wind power systems must be carefully positioned so that wind resources do not decrease when it is installed at ground levels. and according to life cycle cost analysis, adaption of new small win4 power systems to buildings were proved to produce a profit if it is considered the expense of environment improvement and the wind speed increasing according to rise of building height. This research will ultimately achieve green architecture that preserves nature and at the same time provides pleasant environment to humans, and will play a great role in establishing the environment-preserving sustainable architecture of the 21th century.

• Journal of Korea Multimedia Society
• /
• v.15 no.10
• /
• pp.1196-1204
• /
• 2012

In this paper, a series of algorithms are proposed for controlling different kinds of multimedia contents and realizing interact between human and computer by using single input device. Human gesture recognition based on NUI is presented firstly in my paper. Since the image information we get it from camera is not sensitive for further processing, we transform it to YCbCr color space, and then morphological processing algorithm is used to delete unuseful noise. Boundary Energy and depth information is extracted for hand detection. After we receive the image of hand detection, PCA algorithm is used to recognize hand posture, difference image and moment method are used to detect hand centroid and extract trajectory of hand movement. 8 direction codes are defined for quantifying gesture trajectory, so the symbol value will be affirmed. Furthermore, HMM algorithm is used for hand gesture recognition based on the symbol value. According to series of methods we presented, we can control multimedia contents by using human gesture recognition. Through large numbers of experiments, the algorithms we presented have satisfying performance, hand detection rate is up to 94.25%, gesture recognition rate exceed 92.6%, hand posture recognition rate can achieve 85.86%, and face detection rate is up to 89.58%. According to these experiment results, we can control many kinds of multimedia contents on computer effectively, such as video player, MP3, e-book and so on.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.12 no.1
• /
• pp.69-74
• /
• 2017

Due to the advantage of communication coverage extension and removement of shadowing area, relay can be applied in various wireless communication systems. In this paper, we analyze performance of downlink with dual-hop communication systems which use a relay in railway environments. We adopted asymmetric communication system which use coherent modulation scheme in base station-relay link and differential modulation scheme in relay-destination link. The performance of communication system is analyzed using symbol error rate, and performance comparison with the systems which adopts fully coherent scheme is studied. We also investigate the performance of system depending on relay distance and energy allocation.

• Journal of the Korean Home Economics Association
• /
• v.32 no.2
• /
• pp.193-206
• /
• 1994

Thinness has become a symbol for beauty acceptance and competence for women in our society especially for young college women. Relatively little is known about characteristics of women who are dissatisfied with their shape or weight and who are interested in performing weight control program. Four hundred college women in Seoul and Kyunggi-Do area were surveyed from November to December 1992 to investigate the relationship between the concern about weight control and various aspects of food related behaviors. The purpose of this research was to investigate the relationship between the weight concerns of college women and their aspects of several eating behaviors. Self-developed questionnaire was used after validity test. The results were as follows: 1) The average height weight and BMI value of subjects were 160$\pm$4.5cm 51.02kg and 19.86$\pm$4.5 respectively. 2) The 49% of subjects were highly concerned about weight control(high interest group) and 39% were moderate concerned(moderate interest group). 3) The average BMI and weight change per year were significantly higher in the high interest group than other groups. 4) The score of nutrition knowledge was also higher in the high interest group, 5) There were no significant differences among groups in the meal frequencies. and amount of nutrients intake. 6) The signs of eating trouble were found in subjects 59.0% of subjects felt feareness about weight gain after consumption of large amount of food. 7) The ratio of CPF was 64:14:22 and nutrient adquacy ratio(NAR) of energy was 0.94 NAR of Fe was 0.84 the other NAR of nutrient over 1.0.