• 대한청각학회지
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• 제24권3호
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• pp.149-156
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• 2020

Background and Objectives: The gap prepulse inhibition of the acoustic startle response has been used to screen tinnitus in an animal model. Here, we examined changes in the auditory late response under various conditions of gap prepulse inhibition. Subjects and Methods: We recruited 19 healthy adults (5 males, 14 females) and their auditory late responses were recorded after various stimuli with or without gap prepulsing. The N1 and P2 responses were selected for analysis. The gap prepulse inhibition was estimated to determine the optimal auditory late response in the gap prepulse paradigm. Results: We found that the gap per se generated a response that was very similar to the response elicited by sound stimuli. This critically affected the gap associated with the maximal inhibition of the stimulus response. Among the various gap-stimulus intervals (GSIs) between the gap and principal stimulus, the GSI of 150 ms maximally inhibited the response. However, after zero padding was used to minimize artifacts after a P2 response to a gap stimulus, the differences among the GSIs disappeared. Conclusions: Overall, the data suggest that both the prepulse inhibition and the gap per se should be considered when using the gap prepulse paradigm to assess tinnitus in humans.

• 한국지진공학회논문집
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• 제12권6호
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• pp.35-45
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• 2008

구조물의 응답에 대한 잔류변위의 영향을 평가하기 위하여, 초기 잔류변형이 있는 상태에서 작용하는 설계지진에 대한 좌굴방지 가새골조(BRBF)와 특수 모멘트골조(SMRF)의 응답을 평가하였다. 초기 잔류변형은 구조물에 두 가지 방법으로 적용하였다. 첫 번째 방법은 첫 지진에 대하여 구조물이 정지 상태에 도달한 이후 같은 크기의 지진을 적용하는 것이다. 두 번째 방법은 소요 잔류층간 변형이 발생할 때까지 일방향으로 가력한 다음 지진하중을 적용하였다. 해석결과에 따르면 초기 잔류층간변위는 BRBF와 SMRF의 응답에 큰 영향을 주었다. SMRF 시스템보다 BRBF의 응답이 초기 잔류변형에 크게 의존하였다. 그러므로 지진발생 이후 보수비용을 최소화하기 위하여 잔류층간변위를 줄이는 것이 필요하다.

• Geomechanics and Engineering
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• 제22권5호
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• pp.415-431
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• 2020

In this study, dynamics responses of advanced composite plates resting variable elastic foundations via a quasi-3D theory are developed using an analytical approach. This higher shear deformation theory (HSDT) is included the shear deformation theory and effect stretching that has five unknowns, which is even inferior to normal deformation theories found literature and other theories. The quasi-three-dimensional (quasi-3D) theory accounts for a parabolic distribution of the transverse shear deformation and satisfies the zero traction boundary conditions on the surfaces of the advanced composite plate without needing shear correction factors. The plates assumed to be rest on two-parameter elastic foundations, the Winkler parameter is supposed to be constant but the Pasternak parameter varies along the long side of the plate with three distributions (linear, parabolic and sinusoidal). The material properties of the advanced composite plates gradually vary through the thickness according to two distribution models (power law and Mori-Tanaka). Governing differential equations and associated boundary conditions for dynamics responses of the advanced composite plates are derived using the Hamilton principle and are solved by using an analytical solution of Navier's technique. The present results and validations of our modal with literature are presented that permitted to demonstrate the accuracy of the present quasi-3D theory to predict the effect of variables elastic foundation on dynamics responses of advanced composite plates.

• Earthquakes and Structures
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• 제25권3호
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• pp.187-198
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• 2023

Model Predictive Control (MPC) is an advanced control approach that uses the current states of the system model to predict its future behavior. In this article, according to the seismic dynamics of structural systems, the Predictive Functional Control (PFC) method is used to solve the control problem. Although conventional PFC is an efficient control method, its performance may be impaired due to problems such as uncertainty in the structure of state sensors and process equations, as well as actuator saturation. Therefore, it requires the utilization of appropriate estimation algorithms in order to accurately evaluate responses and implement actuator saturation. Accordingly, an extended PFC is presented based on the H-ifinity (H∞) filter (HPFC) while considering simultaneously the saturation actuator. Accordingly, an extended PFC is presented based on the H-ifinity (H∞) filter (HPFC) while considering the saturation actuator. Thus, the structural responses are formulated by two estimation models using the H∞ filter. First, the H∞ filter estimates responses using a performance bound (𝜃). Second, the H∞ filter is converted into a Kalman filter in a special case by considering the 𝜃 equal to zero. Therefore, the scheme based on the Kalman filter (KPFC) is considered a comparative model. The proposed method is evaluated through numerical studies on a building equipped with an Active Tuned Mass Damper (ATMD) under near and far-field earthquakes. Finally, HPFC is compared with classical (CPFC) and comparative (KPFC) schemes. The results show that HPFC has an acceptable efficiency in boosting the accuracy of CPFC and KPFC approaches under earthquakes, as well as maintaining a descending trend in structural responses.

• Structural Engineering and Mechanics
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• 제65권1호
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• pp.121-128
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• 2018

Three structure-dependent integration methods with no numerical dissipation have been successfully developed for time integration. Although these three integration methods generally have the same numerical properties, such as unconditional stability, second-order accuracy, explicit formulation, no overshoot and no numerical damping, there still exist some different numerical properties. It is found that TLM can only have unconditional stability for linear elastic and stiffness softening systems for zero viscous damping while for nonzero viscous damping it only has unconditional stability for linear elastic systems. Whereas, both CEM and CRM can have unconditional stability for linear elastic and stiffness softening systems for both zero and nonzero viscous damping. However, the most significantly different property among the three integration methods is a weak instability. In fact, both CRM and TLM have a weak instability, which will lead to an adverse overshoot or even a numerical instability in the high frequency responses to nonzero initial conditions. Whereas, CEM possesses no such an adverse weak instability. As a result, the performance of CEM is much better than for CRM and TLM. Notice that a weak instability property of CRM and TLM might severely limit its practical applications.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.641-644
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• 2005

This study reveals some recent attempt in modeling empirically obtained B&K HATS (Head and Torso Simulator) HRTFs (Head Related Transfer Functions) to Isolate parameters that stimulate lateral and elevation perception. Localization using non-individual HRTFs often yields poor performance in synthesizing virtual sound sources when applied to a group of individuals due to differences in size and shape of head, pinnae, and torso. For realization of both effective and efficient virtual audio it is necessary to develop a method to tailor a given set of non-individual HRTFs to fit each listener without measuring his/her HRTF set. Pole-zero modeling is applied to fit HRIRs (Head Related Impulse Responses) and modeling criterions for determining suitable number of parameters are suggested for efficient modeling. Horizontal HRTFs are modeled as minimum-phase transfer functions with appropriate ITDs (Interaural Time Delay) obtained from RTF (Ray Tracing Formula) to better fit the size of listener's head for usage in simple virtualizer algorithms without complex regularization processes. Result of modeling HRTFs in the median plane is shown and parameters responsible for elevation perception are isolated which can be referred to in the future study of developing customizable HRTFs.

• Asia Marketing Journal
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• 제13권4호
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• pp.55-76
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• 2012

사람들이 돈을 지불하지 않고 무료로 얻을 수 있는 공짜제품을 과다하게 선호하는 현상을 '공짜효과'라 한다. 기존 연구들에 의하면 공짜제품에 주어지는 특별한 가치 때문에 이와 같은 효과가 발생한다. 본 연구는 공짜효과가 항상 나타나는 것이 아니라 심리적 변수에 의하여 조절될 수 있다는 것을 보이기 위하여 자아조절자원과 해석수준의 조절효과를 살펴보았다. 자아조절자원이 고갈되면 통제의 힘이 약해져서 가격에 대한 민감도가 감소할 뿐만 아니라 직관적이고 노력을 별로 기울이지 않는 정보처리과정을 통해 의사결정을 수행한다. 또한, 주어진 정보를 어떤 해석수준에서 처리하는가에 따라 선택이 달라진다. 고차원 해석수준에서 중심기능을 바탕으로 대안의 바람직성에 따라서 선택하는 반면, 저차원 해석수준에서 부가기능을 바탕으로 대안의 실행가능성에 초점을 두어 선택한다. 이와 같은 특성이 공짜효과의 크기에 미치는 영향을 살펴보는 것이 본 연구의 가장 중요한 목적이다. 자아조절자원과 해석수준에 의해서 공짜효과의 크기가 조절될 수 있다는 사실을 검증하기 위해 2개의 실험설계를 채용하였다. 두 실험 모두에서 기존연구에서 사용한 실험재(키세스와 페레로로쉐 초콜릿)를 이용했다. 실험 1은 자아조절자원 고갈 여부가 공짜효과에 미치는 영향을 검증했다. 자아조절자원 고갈과 비고갈 집단으로 나누어 공짜대안이 있는 선택과업과 그렇지 않은 과업에 할당했다. 자아조절자원이 고갈되지 않은 집단에서 공짜효과가 확실하지만, 자아조절자원이 고갈된 집단에서 공짜효과가 약해진다는 것을 밝혔다. 실험 2는 해석수준이 공짜효과에 미치는 영향을 검증했다. 실험 2는 '왜(why)'와 '어떻게(how)'를 이용해 해석수준을 조작했으며, 실험 1과 유사하게 공짜대안이 존재하는 의사결정과업과 존재하지 않는 과업에 할당한 뒤 공짜대안 선택에 미치는 영향을 확인하였다. 고차원 해석수준의 집단은 저차원 해석수준의 집단에 비하여 공짜제품 선택비율이 낮았다.

• 한국통신학회논문지
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• 제32권1A호
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• pp.83-90
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• 2007

본 논문에서는 ISO/IEC 18000-6C 표준안을 만족하는 UHF대역 RFID 수신단(리더)의 지터(Jitter)처리와 글리치제거 알고리듬 및 설계방안을 제안하고 이를 이용한 리더를 구현하여 실제 TI(Texas instrument) Gen2 태그의 응답을 분석하였다. ISO/IEC 18000-6C표준안은 Reader에서 Tag로 데이터 전송 시 +/-1%의 오차와 Tag에서 Reader로 데이터 전송 시 최대 +/-22%의 오차를 허용하도록 정의하고 있다. 이러한 허용오차범위 내의 데이터에 대해 본 논문에서 제시한 회로는 기존의 PLL(DPLL, ADPLL)을 이용한 방식이 아닌 최대허용치(tolerance)와 허용치누적을 이용하여 일정치의 오차범위를 허용하며 디코딩 하도록 설계하였다. 또한 글리치와 지터제거 알고리듬의 기본원리를 동일하게 구성하여 글리치제거와 지터제거를 따로 구분하지 않고 하나의 기능으로 동작하게 한다. 주 클럭은 19.2MHz로 설정하였으며 LF는 국내 전파법에 맞도록 40kHz로 설정하였다 시뮬레이션결과 15%이하의 위상지터를 가진 입력데이터에 대해 판독에러율은 0이었으며 $15%{\sim}22%$ 위상지터를 가진 입력데이터에 대해서 는 0.000589였다. 그러나 동적LF생성회로를 사용한 결과 $15%{\sim}22%$ 위상변화를 가진 입력데이터에 대해 판독에러율은 0이었으며 표준안에 정의된 최대 +/-22%오차 범위내의 지터 발생에 대해서 판독에러율은 0이었다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권8호
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• pp.1074-1080
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• 2017

Objective: The growth, carcass and retail cut yield records on 1,428 Hanwoo steers obtained through progeny testing were analyzed in this study, and their heritability and genetic relationships among the traits were estimated using animal models. Methods: Two different models were compared in this study. Each model was fitted for different fixed class effects, date of slaughter for carcass traits and batch of progeny test live measurement traits, and a choice of covariates (carcass weight in Model 1 or backfat thickness in Model 2) for carcass traits. Results: The differences in body composition among individuals were deemed being unaffected by their age at slaughter, except for carcass weight and backfat thickness. Heritability estimates of body size measurements were 0.21 to 0.36. Heritability estimates of retail cut percentage were high (0.56 from Model 1 and 0.47 from Model 2). And the heritability estimates for loin muscle percentage were 0.36 from Model 1 and 0.42 from Model 2, which were high enough to consider direct selection on carcass cutability traits as effective. The genetic correlations between body size measurements and retail cut ratio (RCR) were close to zero. But, some negative genetic correlations were found with chest girths measured at yearling (Model 1) or at 24 months of age or with chest widths. Loin muscle ratio (LMR) was genetically negatively correlated with body weights or body size measurements, in general in Model 1. These relationships were low close to zero but positive in Model 2. Phenotypic correlation between cutability traits (RCR, LMR) and live body size measurements were moderate and negative in Model 1 while those in Model 2 were all close to zero. Conclusion: Therefore, the body weights or linear body measurements at an earlier age may not be the most desirable selection traits for exploitation of correlated responses to improve loin muscle or lean meat yield.

• 한국음향학회지
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• 제29권5호
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• pp.339-346
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• 2010

음향 간섭제거기는 머리전달함수 (head-related impulse response; HRIR)의 길이에 큰 영향을 받게 되어, 일반적으로 큰 차수의 필터를 필요로 한다. 간섭제거필터의 길이를 줄이기 위한 방법으로 주파수 워핑, 공통 극점과 영점 (common acoustical pole and zero; CAPZ) 모델링 등의 방법들이 제안되었는데, 본 논문에서는 이 두 가지 방법을 결합한 방법을 제안한다. 이를 위해, 주파수 워핑 영역에서 공통 극점과 영점 모델링을 통해 필터를 설계하며, 디워핑 과정을 통해 종래의 선형 영역에서 안정된 필터를 구현한다. 제안된 방법은 주파수 워핑을 통한 간섭제거 성능 향상과 공통 극점 모델링을 통한 필터 계수 감소를 함께 제공할 수 있다. 이러한 성능을 검증하기 위해 다양한 컴퓨터 모의 실험을 진행하였다.