• Archives of design research
• /
• v.9
• /
• pp.901-906
• /
• 1994

Recently, symbol marks have been developing in many ways with different characteristics, which results in the generation of symbol marks design by space perception cue. We examined and discussed the examples which space perception cue is expressed in symbol marks based on Coren's theory regarding space perception cue.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.7C
• /
• pp.467-474
• /
• 2011

The performance of pilot-symbol-assisted channel estimation widely used for OFDM systems is degraded due to the small number of pilot symbols used for higher transmission efficiency. In this paper, we propose a pilot symbol based channel estimation using cross-correlation to improve the estimation performance of the OFDM system with small number of pilot symbols. The proposed technique detects a data symbol using the channel estimated by the pilot symbol and estimates the channel using the estimated data symbol and the pilot symbol. It is shown by computer simulations that the proposed technique outperforms the conventional pilot symbol assisted estimation technique.

• Journal of the Korean Society of Radiology
• /
• v.17 no.1
• /
• pp.99-106
• /
• 2023

This study measured the signal intensity (SI) of the hippocampus in relation to memory via fMRI analysis of 3 types of radiology symbols, 3 types of nuclear medicine symbols, and 3 types of oncology symbols among the most commonly employed medical symbols in hospitals. The following are the conclusions of the study. result of analyzing the SI values for symbol 1, symbol 2, and symbol 3 of the radiology, nuclear medicine, and oncology departments, symbol 3 had the highest SI value (1.72 ± 0.56) in radiology, symbol 2 had the highest SI value (1.69 ± 0.64) in nuclear medicine, and symbol 2 had the highest SI value (1.64 ± 0.63) in oncology. The overall mean of radiology, nuclear medicine, and oncology symbols was 1.62 ± 0.60 for nuclear medicine, 1.61 ± 0.59 for oncology, and 1.49 ± 0.49 for radiology. According to the overall SI measurement results, symbol 3 in radiology, symbol 2 in nuclear medicine, and symbol 2 in oncology were confirmed to have high SI values. If symbols with high SI values are used in a hospital, it is believed to be beneficial for navigating in any hospital.

• The Journal of the Korea Contents Association
• /
• v.7 no.1
• /
• pp.207-214
• /
• 2007

Symbol mark started with expressing the symbolic form through the long history of human beings, in order to transmit self or group's life and thoughts, and since the Industrial Revolution, symbol mark has beer used for the business activities of enterprise, along with the acquirement of term 'CI'. The symbol mark design of A.E.G, designed by Peter Behrens in 1907 is the onset of symbol mark in the CI concept, and the concept of CI and symbol mark was introduced to our nation in the early of 1970s. Since then, until now, CI has reflected the phase of the times as a key factor of CI, while repeating numerous changes, and recently, it is a state that the expression methods of symbol mark have been varied with the popularization of trend, appealing to emotion in the whole society and culture. Accordingly, this thesis examines the corporate symbol mark through the portfolio of representative CI specializes companies from the introduction period of CI to the present, and analyze the features of the time in order to present the basis of the direction of symbol mark design for the creation of future corporate images.

• Proceedings of the Acoustical Society of Korea Conference
• /
• autumn
• /
• pp.157-160
• /
• 1999

고속 무선통신에 적합한 OFDM 신호를 복조하기 위해서는 빠르고 정확한 심볼의 시작점을 찾는 것이 중요하다. 본 논문에서는 고속 무선 LAN에서 사용되는 Orthogonal Frequency Division Multiplexing (OFDM)시스템에서 훈련신호를 효율적으로 사용해서 심볼 동기를 검출하는 알고리즘을 제안한다. 제안된 알고리즘은 직교성이 뛰어난 PN 코드를 훈련신호로 사용하여 OFDM 심볼의 대략적 프레임 동기는 훈련 신호의 실수 부분을 최소오차 방식을 적용하고 정밀한 심볼동기는 주기가 짧은 PN 코드를 결합시켜 하나의 심볼을 만든 후 상관관계를 적용하여 검출하였다. 그 결과 제안된 알고리즘이 계산량을 현저하게 줄이면서 심볼 동기는 정확하게 검출함을 확인하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2010.07a
• /
• pp.112-115
• /
• 2010

본 논문은 그림 1과 같은 네트워크 환경에서 두 송신단이 LT code를 오류정정 부호로 사용할 때, 두 송신단이 생성하는 인코딩 심볼과 수신단이 수신하는 인코딩 심볼들의 degree distribution의 관계에 대해 다룬다. LT code를 복호하기 위해 belief propagation 방법을 사용했을 때, 수신단이 받은 인코딩 심볼들의 degree distribution은 robust soliton distribution(RSD)을 따를 때, overhead 대비 가장 높은 확률로 복호에 성공한다. 하지만 그림 1과 같은 네트워크 환경에서, 두 송신단 모두 RSD에 따라 인코딩 심볼을 생성하여 송신하면, 수신단에서 수신한 심볼은 RSD를 따르지 않는다. 본 논문은 한 송신단($S_1$) 이 생성하는 인코딩 심볼의 degree distribution을 알 때, 수신단에서의 인코딩 심볼의 분포가 근사적으로 RSD를 따르도록 하는 또 다른 송신단($S_2$)에서의 degree distribution을 구하는 방법을 제시한다.

• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.1033-1036
• /
• 1998

본 논문은 FLEX 디코더에서 필요한 심볼 클럭을 생성하기 위한 심볼 동기 알고리즘을 제안하고, 제안한 알고리즘을 기본으로 한 심볼을 동기회로의 설계에 관한 것이다. 제안한 알고리즘은 조-만 게이트 동기 (ELGS:Early-Late Gate Synchronization)기법을 이용하고 있다. VHDL(VHSIC Hardware Description Language)로 설계된 심볼 동기회로는 Synopsys 툴을 이용하여 기능레벨의 시뮬레이션을 수행하였고, Altera MAX+plus II를 이용하여 타이밍 분석을 수행하였다. 실험 결과로부터 Source unit와 FLEX 디스코더와의 시스템 동기가 정확히 이루어짐을 확인하였다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.12
• /
• pp.2805-2812
• /
• 2015

For the purpose of estimation of time variant frequency selective transmission channels, reference symbols are usually employed. The bit error performance of LTE OFDM systems is analyzed in the case of LTE standard reference symbol arrangement. Results show that LTE OFDM system with this LTE reference symbol arrangement is robust against Doppler time variant fading. However, the performance of that system is degraded due to channel estimation error in frequency domain. An equidistant arrangement with a diamond shape structure of reference symbols, however having 4 subcarriers distance in frequency domain, is suggested for the optimal channel estimation.

• Journal of Korea Multimedia Society
• /
• v.13 no.2
• /
• pp.161-170
• /
• 2010

ELF, an abbreviation for Executable and Linkable Format, is the basic file format for shared libraries and executable files used in the Linux system, whereas 'Linker' copies the symbol information of static shared libraries into the symbol table in the target file generated by way of static linking. At this time, the symbol table keeps various pieces of debugging-related information including function names provided by the shared libraries, and it can be deleted to avoid debugging for security reasons by utilizing the fact that it does not directly affect the program execution. This paper proposes a method for restoring the symbol information of static shared libraries from the ELF object file in which the symbol table is deleted, and confirms that the symbol information is restored by conducting practical experiments.

• Journal of Advanced Navigation Technology
• /
• v.15 no.6
• /
• pp.1042-1046
• /
• 2011

In this paper, we analyze the STO (Symbol Timing Offset) problem in conventional ZP-OFDM (Zero Padding-Orthogonal Frequency Division Multiplexing) systems and propose a robust ZP-OFDM system with bi-directional overlap-add scheme to overcome the problem. The proposed ZP-OFDM system is able to preserve the orthogonality between subcarriers and reduce the interference from other ZP-OFDM symbols due to the BOA scheme, which exploits both ZP intervals of the previous and the current ZP-OFDM symbols, even though serious STOs result from inaccurate symbol timing synchronization. Simulation results verify that the proposed ZP-OFDM system is superior to the conventional ZP-OFDM system.