• Journal of Construction Engineering and Project Management
• /
• 제3권1호
• /
• pp.14-21
• /
• 2013

To analyze building energy consumption, the building description for building energy performance analysis (BEPA) is required. The required data input for subject building is a basic step in the BEPA process. Since building information modeling (BIM) is applied in the construction industry, the required data for BEPA can be gathered from a single international standard file format like IFCXML. However, in most BEPA processes, since the required data cannot be fully used from the IFCXML file, a building description for BEPA must be created again. This paper proposes IFCXML-based automatic data input approach for BEA. After the required data for BEPA has been defined, automatic data input for BEPA is developed by a prototype system. To evaluate the proposed system, a common BIM file from the BuildingSMART website is applied as a sample model. This system can increase the efficiency and reliability of the BEPA process, since the data input is automatically and efficiently improved by directly using the IFCXML file..

• 한국언어정보학회지:언어와정보
• /
• 제9권1호
• /
• pp.69-92
• /
• 2005

Pattern recognition in cognitive agents is based on (i) the uninterpreted input data (e.g. parameter values) provided by the agent's hardware devices and (ii) and interpreted patterns (e.g. templates) provided by the agent's memory. Computationally, the task consists in finding the memory data corresponding best to the input data, for any given input. Once the best fitting memory data have been found, the input is recognized by applying to it the interpretation which happens to be stored with the memorized pattern. This paper presents a fast converging procedure which starts from a few initially recognized items and then analyzes the remainder of the input by systematically checking for items shown by memory to have been related to the initial items in previous encounters. In this way, known patterns are tried first, and only when they have been exhausted, an elementary exploration of the input is commenced. Efficiency is improved further by choosing the candidate to be tested next according to frequency.

• 국제학술발표논문집
• /
• The 5th International Conference on Construction Engineering and Project Management
• /
• pp.173-180
• /
• 2013

To analyze building energy consumption, the building description for building energy performance analysis (BEPA) is required. The required data input for subject building is a basic step in the BEPA process. Since building information modeling (BIM) is applied in the construction industry, the required data for BEPA can be gathered from a single international standard file format like IFCXML. However, in most BEPA processes, since the required data cannot be fully used from the IFCXML file, a building description for BEPA must be created again. This paper proposes IFCXML-based automatic data input approach for BEA. After the required data for BEPA has been defined, automatic data input for BEPA is developed by a prototype system. To evaluate the proposed system, a common BIM file from the BuildingSMART website is applied as a sample model. This system can increase the efficiency and reliability of the BEPA process, since the data input is automatically and efficiently improved by directly using the IFCXML file.

• 전자공학회논문지SC
• /
• 제46권2호
• /
• pp.52-60
• /
• 2009

본 논문에서는 입력에 시간 지연이 존재하는 비선형 다중입출력(multi-input/multi-output (MIMO)) 시스템을 위한 디지털 제어기를 제안하였다. 다중 입력 시간 지연 비선형 시스템을 테일러의 추산 방법으로 이산화하고, 이 이산형 시스템을 일반적인 비선형 시스템으로 변환할 수 있다. 결과적으로, 일반 비선형 제어기를 이산형 시간 지연 시스템에 적용할 수 있다. 본 논문에서는 MAC 제어기를 설계하고 컴퓨터 시뮬레이션을 실시하여 제안된 방법의 성능을 검증하였다. 시뮬레이션의 결과 제안된 제어기는 비선형 다중입력 다중 시스템에 있어서 입력에 시간지연이 발생하더라도 시스템의 성능을 유지함을 확인할 수 있었다. 따라서 제안된 방법은 비선형 시간 지연 시스템의 제어에 유용함을 알 수 있다.

• Journal of Power Electronics
• /
• 제15권1호
• /
• pp.10-17
• /
• 2015

A quasi-constant on-time controlled buck front end in combined discontinuous conduction mode and boundary conduction mode is proposed to improve power factor (PF).When instantaneous AC input voltage is lower than the output bus voltage per period, the buck converter turns into buck-boost converter with the addition of a level comparator to compare input voltage and output voltage. The gate drive voltage is provided by an additional oscillator during distortion time to eliminate the cross-over distortion of the input current. This high PF comes from the avoidance of the input current distortion, thereby enabling energy to be delivered constantly. This paper presents a series analysis of controlling techniques and efficiency, PF, and total harmonic distortion. A comparison in terms of efficiency and PF between the proposed converter and a previous work is performed. The specifications of the converter include the following: input AC voltage is from 90V to 264V, output DC voltage is 80V, and output power is 94W.This converter can achieve PF of 98.74% and efficiency of 97.21% in 220V AC input voltage process.

• 대한전자공학회논문지TC
• /
• 제41권11호
• /
• pp.87-91
• /
• 2004

모바일 단말기는 터치패드 방식의 문자 입력을 한다. 따라서 사용자에게 긴 입력을 요구할 때 불편한 환경을 제공한다. 따라서 이미지의 특정 지점을 마우스로 선택함으로 문자입력을 대신하여 인증을 함으로써 편리한 환경을 제공한다. 보안을 제공하기 위하여 초기 이미지에 따른 이미지의 배열 정보 및 입력된 값을 해시코드화 하여 인증 및 키교환이 안전하게 이루어진다. HASH와 SEED 암호화 알고리즘을 적용하여 효율적이고, 전송 메시지의 무결성을 보장하며 내부 참여자에 의한 정보 유출이 있더라도 안전한 전자지불 프로토콜 시스템을 설계 및 구현하였다.

• Journal of Communications and Networks
• /
• 제9권1호
• /
• pp.18-27
• /
• 2007

The conventional normalized least mean square (NLMS) algorithm is the most widely used for adaptive identification within a non-stationary input context. The convergence of the NLMS algorithm is independent of environmental changes. However, its steady state performance is impaired during input sequences with low dynamics. In this paper, we propose a new NLMS algorithm which is, in the steady state, insensitive to the time variations of the input dynamics. The square soot (SR)-NLMS algorithm is based on a normalization of the LMS adaptive filter input by the Euclidean norm of the tap-input. The tap-input power of the SR-NLMS adaptive filter is then equal to one even during sequences with low dynamics. Therefore, the amplification of the observation noise power by the tap-input power is cancelled in the misadjustment time evolution. The harmful effect of the low dynamics input sequences, on the steady state performance of the LMS adaptive filter are then reduced. In addition, the square root normalized input is more stationary than the base input. Therefore, the robustness of LMS adaptive filter with respect to the input non stationarity is enhanced. A performance analysis of the first- and the second-order statistic behavior of the proposed SR-NLMS adaptive filter is carried out. In particular, an analytical expression of the step size ensuring stability and mean convergence is derived. In addition, the results of an experimental study demonstrating the good performance of the SR-NLMS algorithm are given. A comparison of these results with those obtained from a standard NLMS algorithm, is performed. It is shown that, within a non-stationary input context, the SR-NLMS algorithm exhibits better performance than the NLMS algorithm.

• Structural Engineering and Mechanics
• /
• 제20권3호
• /
• pp.347-362
• /
• 2005

The input energy to a base-isolated (BI) building during an earthquake is considered and formulated in the frequency domain. The frequency-domain approach for input energy computation has some notable advantages over the conventional time-domain approach. Sensitivities of the input energy to the BI building are derived with respect to uncertain parameters in the base-isolation system. It is demonstrated that the input energy can be of a compact form via the frequency integration of the product between the input component (Fourier amplitude spectrum of acceleration) and the structural model component (so-called energy transfer function). With the help of this compact form, it is shown that the formulation of earthquake input energy in the frequency domain is essential for deriving the sensitivities of the input energy to the BI building with respect to uncertain parameters. The sensitivity expressions provide us with information on the most unfavorable combination of the uncertain parameters which leads to the maximum energy input.

• 한국통신학회논문지
• /
• 제21권5호
• /
• pp.1240-1255
• /
• 1996

This paper suggests power optimization technique in multi-level SCPC system as a method for efficient utilization of limited satellite power. The power optimization is realized by optimal assignment of satellite input carrier powers considering interference and noise generated in up-link and down-link. The Fletcher-Powell algorithm searching minimum(or maximum) point using gradient information is used to detemine the optimal input carrier powers. To apply Flectcher-Powell algorithm mathematical descriptions and their partial derivatives to interference and nose are presented. Because a target, which should be optimized, is satellite input carrier power, amplitude of each carrier group will be assumed to be an independent variable. The performance criterion for optimal power assignmentis classified into 4 categories with respect to CNR of destination receiver earth station to meet the requirement for various satellite link environment. Simulation results for two-level, four-level and six-level SCPC system are presented.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2008년도 하계종합학술대회
• /
• pp.161-162
• /
• 2008

In this paper we design an irregular low-density parity-check (LDPC) code for a multi-input multi-output (MIMO) system. The considered MIMO system is minimum mean square error soft-interference cancellation (MMSE-SIC) detector. The MMSE-SIC detector and the LDPC decoder exchange soft information and consist a turbo iterative detection and decoding receiver. Extrinsic information transfer (EXIT) charts are used to obtain the edge degree distribution of the irregular LDPC code which is optimized for the input-output transfer chart of the MMSE-SIC detector. It is shown that the performance of the designed LDPC code is much better than that of conventional LDPC code optimized for the AWGN channel.