• Korean Journal of Construction Engineering and Management
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• v.23 no.1
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• pp.37-45
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• 2022

It is very important to measure the displacement of a structure to evaluate the safety of the structure. This study shows a methodology to measure the displacement to determine the stability of a structure when it is damaged by loads. The methodology used Moiré's phenomenon and was verified through experiments. The experiments utilized pipes to simulate the pipe supports in the construction site and measured the vertical displacement of the Moiré interference patterns according to the horizontal displacement of the pipes. Experiments confirmed that the linear relationship between horizontal displacement of pipes and vertical displacement of Moiré patterns and derive a relational expression. In conclusion, the methodology presented in this work allows us to simultaneously measure a number of vertical members' displacements regardless of distance and determine the safety of the structure.

• Journal of KIISE:Software and Applications
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• v.26 no.5
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• pp.692-701
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• 1999

수퍼스칼라(superscalar)나 VLIW 와 같은 명령어 수준 병렬화(ILP) 프로세서의 성능을 극대화하는 과감한 명령어 스케쥴링은 소프트웨어 파이프라이닝과같은 스케쥴링 과정을 거치면서 일반적인 복사 명령어 제거 기법으로 없앨 수 없는 서로 간섭하는 복사 명령을 많이 만들어내는데 루프 내부에 생성된 이러한 복사명령은 적절한 루프 펼침을 수행하여 간섭관계를 없앰으로서 제거할 수 있다. 본 논문에서는 이와 같이 루프 펼침이 수행된 루프 내부의 복사명령을 제거하는 기법으로 그래프 컬러링 상에 구현한 낙관적 융합기법을 제안한다. 그래프 컬러링에서의 융합기법은 간선의 개수가 많은 노드를 만들어 낼수 있으므로 채색성에 부정적인 영향을 주는 것으로 알려져 왔으나 본 기법에서는 융합되는 노드에 동시에 간섭하는 노드의 간선의 수가 줄어드는 긍정적인 영향을 최대한 이용하여 채색성을 높이고 융합된 노드에 대한 실제 버림(spill)이 일어나는 경우 유효 범위 분절(live range splitting)을 통하여 버림의 부담을 최대한 줄이도록 하였으며 이를 VLIW 스케쥴링 된 SPEC 정수벤치마크 루프내부의 복사 명령 제거에 적용한 결과 제거 가능한 복사 명령의 99%를 제거하면서도 버림명령은 다른 융합 기법과 비교하여 가장 적게 발생하는 우수한 결과를 얻을수 있었다.

• Journal of Advanced Navigation Technology
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• v.5 no.2
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• pp.111-122
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• 2001

In this paper, we study the performance of eigencanceller which use a eigenvector and eigenvalue in order to update a weighter vector. Eigencanceller can suppress directional interferences and noise effectively while maintaining specified beam pattern constraints. The constraints and optimal weight vector of eigencanceller vary by using interference and noise or desired signal, interference signal and noise as array input signal. From the analysis results in the steady state, We show that weight vectors in each case are simplified the form of projection equation that belongs to desired subspace orthogonal to interference subspace and eigencanceller has the better performance than RLS method through mathematical analysis and simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6A
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• pp.631-639
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• 2004

In this paper, we presented a new interference suppression method based on code grouping and groupwise decorrelation for multirate DS-CDMA downlink. The code grouping is accomplished according to the correlation property between the mother code and the child codes in OVSF code tree. Using groupwise decorrelation, the proposed receiver has relatively low computational complexity and does not require any information about interference users, such as code, data, and amplitude. From the simulation results in multipath channels, the proposed receiver is to provide significant performance enhancement.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.2
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• pp.222-227
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• 2012

In this paper, we analyze the total performance according to duty cycle of interfering transmitter in hetero systems. We analyze this criteria as a parameter for co-use when hetero systems share the same frequency channels. In order to make an analysis of relationship between duty cycle and performances of two systems. We take into consideration on the case that WiBro is an victim receiver and WLAN is a interfering transmitter. Analyzed coexistence results may be widely applied into the technique developed to get the coexisting condition for wireless devices using many communication protocols in same frequency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.8
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• pp.693-700
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• 2016

In this paper, it is represented that equations for design of linear interferometer antenna when the 3 dB beamwidth is only region of interest. Using the equations, relationships between angle measurement ambiguity and element antenna spacings are described. And then, operating frequency, angle measurement accuracy, beamwidth, correct measurement probability are calculated for five antennas interferometer to measure azimuth and elevation angle. The interferometer antenna was designed and fabricated using the calculated parameters. The angle measurement accuracy were $0.01^{\circ}$ and $0.016^{\circ}$ for azimuth and elevation axes with 99 % probability of doing measurements correctly which means that ambiguous solution did not occur more than 1 % of the time. These results validated the equations and design procedures.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.179-184
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• 2011

In this paper, we analyze the sharing parameters in order to co-use of different communication systems in adjacent channels. We analyze the performance result according to various density of interfering transmitter and transmitter output in hetero systems. In order to get the relationship with between density of interfering transmitter and transmitter output, we consider the case that WiBro is an interfering transmitter an WLAN is a victim receiver. When the center frequency of WLAN is 687MHz and interferer density is 50/$km^2$, required guard band is 10MHz. Analyzed coexistence results may be widely applied into the technique developed to get the coexisting condition for wireless devices using many communication protocols in same frequency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.5
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• pp.694-704
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• 2001

In this work, We evaluate the performance of eigencanceller which can suppress directional interferences and noise effectively while maintaining specified beam pattern constraints. The constraints and optimal weight vector of eigencanceller vary by using interference and noise or desired signal, interference and noise as array input signal. From the analysis results in the steady state, We show that weight vectors in each case are simplified the form of projection equation that belongs to desired subspace orthogonal to interference subspace and eigencanceller has the better performance than DMI method through mathematical analysis and simulation.

• Journal of the korean Society of Automotive Engineers
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• v.2 no.1
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• pp.5-8
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• 1980

스트레인 게이지를 사용하여 회전체의 스트레인을 측정할 경우, 회전체 내에 브리지를 구성하여 브리지의 4점의 입출력단을 슬립 링을 매개로 정지 쪽으로 끌어내어 측정하는 것이 일반적으로 상용되고 있는 방법이다. 이 방법에 의하면 1측정점에 대하여 4소자의 슬립 링을 필요로 하기 때문에 다수점의 스트레인 측정은 곤란하다. 그래서 브리지를 셰브론 브리지식으로 구성하면 슬립링수를 대폭 줄일 수 있다. 그러나 이 방법은 다음의 이유로 인하여 측정 정밀도가 저하하는 결점이 있다. (1) 종래의 동응력 측정기는 입력 임피이던스가 작기 때문에 각 채널간에서 간섭을 일으킨다. (2) 채널간의 간섭은 공통브리지 저항값의 크기에 따라서도 영향을 받는다. 이 저항값이 작을수록 간섭량은 감소되기 때문에 이것을 작게 하면 브리지의 합성저항이 작아 지고, 브리지전원공급용 슬립 링의 접촉저항의 영향이 커진다. 그래서 셰브론 브리지식으로 슬립 링을 감소시키는 동시에 위에 말한 결점을 없앤 새로운 다점응력 측정기를 개발했다. 이 스트 레인측정기는 종래의 동스트레인 측정기와 다른 중요한 점은 다음의 두가지이다. (1) 증폭기의 입력임피이던스(impedance)를 크게 (약 50k.ohm.)하는 동시에 공통브리지의 저항을 작게 (약 10.ohm.)하고, 각 채널간의 간섭을 없앴다. (2) 브리지전원공급용 슬립 링의 접촉저항에는 관계없이 브리지에는 항상 일정한 전압이 공급 되게 했다. 본 보고에서는 (1)에 대한 검토는 생략하고, 주로 (2)에 대하여 기술한다.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.4
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• pp.285-290
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• 2007

A wavelength-demodulation algorithm for FBG sensor is proposed by using a double-pass Mach-Zehnder interferometer. Zero-crossing points of double-passed interference signal are used to trigger the accurate $90^{\circ}C$ phase difference positions in the sensor signal, which is an essential condition in the subsequent arctangent and phase unwrapping signal processing. With the proposed method, we could efficiently measure various measurands, such as dynamic-, static-strain, and temperature, and ${\sim}8pm$ of wavelength resolution was obtained.