• The Journal of the Korea Contents Association
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• v.17 no.9
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• pp.300-309
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• 2017

This paper examines the cyclical fluctuation of 'construction orders' and 'construction investment' using HP filter, Bandpass filter and Beveridge-Nelson decomposition methods. The main results are as follows. As a result of the analysis of the cyclical fluctuation of construction orders, it was analyzed that there were about 7 cyclical fluctuations from 1976 to the first quarter of 2017. Construction orders for cyclical fluctuations peaked in the second quarter of 2015 and turned to a downward trend. On the other hand, construction investment has experienced about 6 cycles of fluctuations during the same period, and it has been rising continuously since the bottom of 3Q12. This is consistent with the general theory that construction orders precede construction investments. In addition, the comparison of the construction orders, construction investment, and GDP amplitude shows that the GDP amplitude is the smallest and stable, and the construction orders have the greatest variation in amplitude. Therefore, construction orders should be adjusted by government policy depending on economic fluctuations.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.11a
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• pp.132-139
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• 2002

본 실험은 청각 사상관련전위(ERP)를 이용하여 다양한 성격 특질 모형들의 생물학적 근거와, 구조의 공통점과 차이점을 명확히 하기 위해서 설계되었다. 48명의 대학생 피험자들에게 4가지 성격 측정 검사(NEO-PI-R, EPQ-R, BIS/BAS 척도, IVE)를 시행하고, 이어 두 종류의 청각 자극 세트(50ms와 300ms)를 이용한 오드볼 과제를 통해 ERP를 측정하였다. 설문지 간의 상관과, 설문지와 ERP 내외생적 구성 요소 간의 상관, 그리고 그 상관의 두피 분포 양상을 통합적으로 고려하여 해석하였다. 각 성격 검사의 외향성 척도에 해당한다 할 수 있는 E, E, BAS-FUN은 양성 모두에서 높은 수준의 설문지 척도 간 정적 상관을 보였으나, 50ms 자극으로 유발된 P3 진폭은 E와 BAS-FUN에 대해서만 유의하게 높은 상관을 나타내었다. 이 결과는 Eysenck의 모델과 일견 일치하는 결과이지만, 그가 개발한 EPQ-R의 외향성 척도(E) 보다는 오히려 다른 척도들이 뇌파에 반영된 성격의 생물학적 기제를 측정하기 위한 적절한 도구일 수도 있음을 시사한다. 신경증적 경향성을 반영하는 N과 N 척도는 50ms 자극에 대한 여성 피험자의 N1, P2 진폭과 유의한 상관을 보였다. 그러나 이론적으로 두 척도에 등가적인 것으로 예상되었던 BIS 척도는 설문지 간 상관이나 ERP 요소와의 상관에서 모두 유의한 결과를 보이지 않았다. Eysenck가 성격의 세 번째 축(차원)으로 제시했던 P(정신병적 경향성) 역시 여성 피험자들에게서 두드러지는 설문지 간 상관을 보였으나, 300ms 자극에 대한 P2 진폭과의 정적인 상관은 양성을 합한 자료에서만 발견되었다. 여성의 상관 분포는 비록 통계적으로 유의한 수준에는 이르지 못하였으나, 양성 자료의 분포와 유사함이 확인되었다. 이 실험의 결과는 P3 진폭과 외향성 간의 부적인 상관 관계를 보고하였던 기존 연구들을 지지한다. 또한 본 실험에서 확인된 Eysenck 모델의 신경증적 경향성이나 정신병적 경향성이 ERP의 비교적 초기에 나타나는 외생적 구성 요소들(N1, P2)과의 상관 양상은, P3 요소에 집중하였던 기존 연구들이 외향성 이외의 차원으로 일관된 결과를 얻어내지 못했던 이유를 설명해줄 수 있을 것이다. 또한 성격 차원과 그것을 지표 하는 ERP 구성 요소 간의 관계를 해석할 때에 성별이나 유발 자극의 속성을 고려해야 함을 보여준다.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.6
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• pp.41-47
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• 2012

It is very important to predict the nonlinear behavior of combustion instability such as transition phenomena and limit cycle amplitude for fully understanding and controlling the instabilities. These nonlinear instability characteristics are highly dependent upon the flames' nonlinear dynamics in a gas turbine premixed combustor. In this study, nonlinear instability TA(Thermo-acoustic) models were introduced by applying the concept of flame describing function to the thermoacoustic analysis method. As a result of model development, for a given combustor length, the growth rate of instability was greatly affected by the change in amplitude, although the instability frequency was not. Further researches under various operating conditions and model validation on limit cycle amplitude are required.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1027-1034
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• 2017

In this paper, we propose a new function embedding method that can measure mathematical projections of probability amplitude, probability, average expectation and matrix elements of stationary-state unit matrix at all control operation points of quantum gates. The function embedding method in this paper is to embed orthogonal normalization condition of probability amplitude for each control operating point into a binary scalar operator by using Dirac symbol and Kronecker delta symbol. Such a function embedding method is a very effective means of controlling the arithmetic power function of a unitary gate in a unitary transformation which expresses a quantum gate function as a tensor product of a single quantum. We present the results of evolutionary operation and projective measurement when we apply the proposed function embedding method to the ternary 2-qutrit cNOT gate and compare it with the existing methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.10
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• pp.1867-1872
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• 2016

In the area of digital signal processing, it is necessary to improve the quality of the speech signal after removing the background noise which exists in a various real environments. The important thing to consider when removing the background noise acoustically is that to solve the problem, depending on the information of the human auditory mechanism is mainly the amplitude spectrum of the speech signal. This paper introduces the characteristics of a frequency-weighted spectrum shaping filter for the extraction of the amplitude spectrum of the speech signal with the primary purpose. Therefore, this paper proposes an algorithm using the methods of a Wiener filter and the frequency-weighted spectrum shaping filter according to the acoustic model, after extracted the amplitude spectral information in the noisy speech signal. The spectral distortion (SD) output of the proposed algorithm is experimentally improved more than 5.28 dB compared to a conventional method.

• Composites Research
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• v.23 no.6
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• pp.39-46
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• 2010

Acoustic emission (AE) signals are detected during the polymerization shrinkage of composite resin restoration in artificial dental ring according to various interfacial treatment conditions. AE amplitudes and the number of AE hit events were compared through the non-parametric statistics of Mann-Whitney method and Kruskal-Wallis method. The AE amplitudes detected from the PMMA and human tooth ring specimens were not significantly different according to adhesive conditions. The stainless steel ring specimen, meanwhile, had a difference in AE amplitude (p<0.05). The quantity of hit events for the human molar dentin specimens of the good bonding state was much less than that for the steel ring specimen but more than that for the PMMA ring specimen. For the same substrate, the better the bonding state, the less the AE hit events (p<0.05). The degree of marginal disintegration measured by SEM was proportional to the amount of AE hit events detected.

• Journal of Korean Association for Spatial Structures
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• v.7 no.5
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• pp.57-65
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• 2007

After measuring wind induced response for a high-rise steel building, the damping ratio and natural frequency were analyzed in this paper. In order to examine amplitude dependence, random decrement method was used. Two methods were analyzed by comparing dynamic properties from random decrement method and half powered-band width method. In addition, through serviceability evaluation during strong wind, compatibility of two methods to Japanese guidelines for the evaluation of habitability to building vibration and national building code of Canada was considered. The amplitude dependence of the damping ratio by RD method was shown and the amplitude dependence of the natural frequency was relatively very small in an aspect of engineering sense. Moreover, the measured building was satisfied with serviceability and Japanese guideline is stricter than NBCC code.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.4
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• pp.112-118
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• 2013

The selection of appropriate ground motions and reasonable modification are becoming increasingly critical in reliable prediction on seismic performance of structures. A widely used amplitude scaling approach is not sufficient for robust structural evaluation considering a site specific seismic hazard because only one spectral value is matched to the design spectrum typically at the structural fundamental period. Hence alternative approaches for ground motion selection and modifications have been suggested. However, there is no means to evaluate such methodologies yet. In this study, it is focused to describe the main questions resided in the amplitude scaling approach and to propose a regression model for structural damage as point of comparison. Spectrum compatible approach whose resulting spectrum matches the design spectrum at the entire range of the structural period is considered as alternative to be compared to the amplitude scaling approach. The design spectrum is generated according to ASCE7-05.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4629-4635
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• 2012

This study was aimed at the relationship between peak EMG amplitude on low back muscles acting on L5/S1 and load center of gravity, trunk lateral bending while lifting an object. Musculoskeletal disorders including low back pain can occur even when handling heavy objects only once as well as when doing non-heavy materials repeatedly. 11 male subjects with average 23 age were required to lift a 15.8kg object symmetrically three times. Peak EMG amplitudes on 6 muscles related with L5/S1 were recorded and analyzed. The lifting conditions consisted of lifting symmetric load with no trunk lateral bending, asymmetric load with no trunk lateral bending, and asymmetric load with trunk lateral bending to the load center of gravity within an object. The results showed that peak EMG amplitude on back muscles contralateral to load center of gravity was observed greater in comparison with the symmetric load. Also, in case of lifting asymmetric load the posture with trunk lateral bending increased peak EMG amplitude on muscles contralateral to load center of gravity more than with no trunk lateral bending. This research can be used as one administrative intervention in order to reduce the low back pain incidence with suggesting workers that they keep the trunk not bending to load center of gravity if possible when lifting a heavy asymmetric object.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.5
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• pp.525-533
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• 2010

Direct time integration method such as Newmark method is numerically performed under the assumption that continuous load function such as constant amplitude load can be treated as a discontinuous load fuction. It is due that the load can be treated as a constant value at the given time period regardless of variation of load at the time increment interval. It means the numerical results should be accompanied by the error due to approximation of load fuction. In contrast, the load function is calculated by convolution integral for the given time interval at finite element equation based on Gurtin's variation equation. Therefore. precise numerical results can be obtained by Gurtin's method because of convolution integral for the continuous load fuction curve even at the variation of load function in the given time interval. In this study, we prove that Gurtin's method can be more suitable than Newmark method in the problem of constant amplitude loading, using the numerical results for the free end of the one-dimensional rod. This study also shows that Gurtin's method is more effective in constant amplitude loading than in constant loading. The accuracy and the validity are verified by comparison between the results of in-house FORTRAN code and ADINA, a commercial software supporting Newmark method.