• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.5
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• pp.177-187
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• 2014

This paper proposes a fast subspace tracking methods, which is called GVFF FAPI, based on FAPI (Fast Approximated Power Iteration) method and GVFF RLS (Gradient-based Variable Forgetting Factor Recursive Lease Squares). Since the conventional FAPI uses a constant forgetting factor for estimating covariance matrix of source signals, it has difficulty in applying to non-stationary environments such as continuously changing DOAs of source signals. To overcome the drawback of conventioanl FAPI method, the GVFF FAPI uses the gradient-based variable forgetting factor derived from an improved means square error (MSE) analysis of RLS. In order to achieve the decreased subspace error in non-stationary environments, the GVFF-FAPI algorithm used an improved forgetting factor updating equation that can produce a fast decreasing forgetting factor when the gradient is positive and a slowly increasing forgetting factor when the gradient is negative. Our numerical simulations show that GVFF-FAPI algorithm offers lower subspace error and RMSE (Root Mean Square Error) of tracked DOAs of source signals than conventional FAPI based MUSIC (MUltiple SIgnal Classification).

• Korean Journal of Cognitive Science
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• v.34 no.1
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• pp.21-38
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• 2023

The present study was designed to investigate the effect of the difficulty level of retrieval practice and the association strength of categories and stimuli within categories on memory inhibition. Most of the studies have investigated whether inhibition was occurred by manipulating the degree of association strength, emotion value or physical characteristics of non-retrieval practice words within the retrieval practice category. Therefore, it was necessary to study how inhibition occurs according to the degree of difficulty of retrieval stimuli during retrieval practice. The difficulty of retrieval was manipulated into three levels: difficult condition, normal condition, and easy condition through the degree of presentation of consonants and vowels of words during retrieval learning. Additionally, the strength of association between categories and words within categories was manipulated. In previous studies, retrieval-induced forgetting occurred under conditions where the association strength between categories and words within the categories was strong. On the other hand, retrieval-induced forgetting did not occur under conditions where the association strength between categories and words within the categories was weak. The present study, if the inhibition process differs according to the difficulty of retrieval, the possibility of different results from previous studies was explored according to the difference in the strength of association with the category. As a result of the study, in the condition of strong association strength, retrieval-induced forgetting was observed under normal and difficult retrieval difficulty conditions. Whereas retrieval-induced forgetting was not observed under conditions of easy retrieval difficulty condition. In the condition of weak association strength, retrieval-induced forgetting tended to occur under difficult retrieval difficulty conditions. Whereas retrieval-induced forgetting was not observed under conditions of normal and easy retrieval difficulty condition. These results suggest that memory inhibition may appear differently depending on the difficulty of retrieval.

• Smart Structures and Systems
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• v.26 no.1
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• pp.63-75
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• 2020

Substructure pseudo-dynamic hybrid simulation (SPDHS) combining the advantages of physical experiments and numerical simulation has become an important testing method for evaluating the dynamic responses of structures. Various parameter identification methods have been proposed for online model updating. However, if there is large model gap between the assumed numerical models and the real models, the parameter identification methods will cause large prediction errors. This study presents an ANN (artificial neural network) method based on forgetting factor. During the SPDHS of model updating, a dynamic sample window is formed in each loading step with forgetting factor to keep balance between the new samples and historical ones. The effectiveness and anti-noise ability of this method are evaluated by numerical analysis of a six-story frame structure with BRBs (Buckling Restrained Brace). One BRB is simulated in OpenFresco as the experimental substructure, while the rest is modeled in MATLAB. The results show that ANN is able to present more hysteresis behaviors that do not exist in the initial assumed numerical models. It is demonstrated that the proposed method has good adaptability and prediction accuracy of restoring force even under different loading histories.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.11
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• pp.1134-1142
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• 2003

This paper presents a hardware implementation of the STS diversity system, utilizing FPGAs and introduces the function and the design method of each of the modules of the system. In order to improve the performance of the implemented STS system which is an open loop transmit diversity system under fading environment, the exact estimation of the communication channel is essential. Therefore, we propose the optimal forgetting factor to estimate pilot channel in this paper, It is shown in this paper that the pilot channel is estimated using the forgetting factor of 0.7 without increasing the integration range of the pilot channel even when the power of pilot channel is not sufficiently large in CDMA 2000 1x signal environment.

• The Journal of the Acoustical Society of Korea
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• v.38 no.3
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• pp.283-289
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• 2019

RLS (Recursive-least-squares) algorithm is known to have good convergence and excellent error level after convergence. However, there is a disadvantage that numerical instability is included in the algorithm due to inverse matrix calculation. In this paper, we propose an algorithm with no matrix inversion to avoid the instability aforementioned. The proposed algorithm still keeps the same convergence performance. In the proposed algorithm, we adopt an averaged gradient-based step size as a self-adjusted step size. In addition, a variable forgetting factor is introduced to provide superior performance for time-varying channel estimation. Through simulations, we compare performance with conventional RLS and show its equivalency. It also shows the merit of the variable forgetting factor in time-varying channels.

• Analyses & Alternatives
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• v.4 no.2
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• pp.163-202
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• 2020

This paper examines how Japanese society produced and reproduced a distinctively gendered history and memories of the experience of WWII and colonialism in the postwar era. We argue that these gendered narratives, which were embedded in postwar debates about the Peace Constitution and comfort women, have engendered contradictions and made the historical conflicts with neighboring countries challenging to resolve. On the one hand, this deepens conflict, but on the other, it also generates stability in East Asia. After Japan's defeat in WWII, the American Occupation government created the Peace Constitution, which permanently "renounces war as a sovereign right of the nation and the threat or use of force as means of settling international disputes." The removal of the state's monopoly on violence - the symbol of masculinity - resulted in Japan's feminization. This feminization led to collective forgetting of prewar imperialism and militarism in postwar Japan. While collectively forgetting the wartime history of comfort women within these feminized narratives, the conservative movement to revise the Peace Constitution attempted to recover Japan's masculinity for a new, autonomous role in international politics, as uncertainty in East Asia increased. Ironically, however, this effort strengthened Japan's femininity because it involved forgetting Japan's masculine role in the past. This forgetting has undermined efforts to achieve masculine independence, thus reinforcing dependence on the United States. Recurrent debates about the Peace Constitution and comfort women have influenced how Japanese political elites and intellectual society have constructed distinctive social institutions, imagined foreign relations, and framed contemporary problems, as indicated in their gendered restructuring of history.

• Journal of Distribution Science
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• v.22 no.6
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• pp.23-32
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• 2024

Purpose: Trade in small and medium businesses must improve innovation performance before and after the COVID-19 pandemic. The requirement for rapid innovation is being able to compete and survive post-pandemic. This research attempts to investigate the influence of organizational forgetting, knowledge management, and business agility in distributing innovation performance improvementsto SMEs in Tasikmalaya, Indonesia. Research design, data and methodology: In this research, a structural equation modeling approach with SmartPLS was applied. This research used 221 Tasikmalaya SMEs as samples. The findings of this study show that SMEs are still underrepresented in technological advancement. Results: Organizational forgetfulness does not have a significant impact on innovation performance, nor does it have an indirect impact through knowledge management. Business agility, on the other hand, has a significant indirect effect on innovation performance. Knowledge management does not have a significant and direct impact on innovation performance, but business agility has a significant impact. Conclusions: Efforts to enhance SMEs' trade must be willing to challenge the status quo or abandon knowledge that is no longer relevant to current developments to improve business agility and innovation. Technology-oriented SMEs can quickly become agile by implementing organizational forgetting. SME owners must be willing to adapt to technological advances to adopt organizational forgetfulness.

• Journal of the Korean association of regional geographers
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• v.10 no.4
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• pp.800-823
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• 2004

This paper aims at examining the ways in which foreign immigrant workers in South Korea have been "forgotten" and "marginalized" in the regulatory politics of globalization and how the politics of "forgetting" has influenced the formation of immigrant local communities in South Korea. More specifically, by focusing on the immigrant community in Wongok dong, Ansan, it explores the forming questions. First, under what conditions has Wongok' dong become one of the biggest communities for foreign workers in South Korea? Second, how has the growth of the Wongok-dong immigrant community been influenced by the politics of "exclusion", and "inclusion" taking place at various geographical scales? Based on this case study, this paper suggests that the practices of "exclusion" and "forgetting" should not be seen as an inevitable outcome of globalization; instead, they need to be seen as an outcome of political processes, in which the practices of "exclusion" and "inclusion" are intertwined with one another through interactions and negotiations among different interests and ideas that take place in the multi-scalar regulatory processes, which contribute to the (material and discursive) construction of globalization.

• The Journal of the Acoustical Society of Korea
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• v.20 no.1E
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• pp.7-13
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• 2001

In this paper we propose a new subspace tracking algorithm based on the PASTd (Projection Approximation Subspace Tracking with deflation). The algorithm is obtained via introducing the variable forgetting factor which adapts itself to the time-varying subspace environments. The tracking capability of the proposed algorithm is demonstrated by computer simulations in an abruptly changing DOA scenario. The estimation results of the variable forgetting factor PASTd(VFF-PASTd) outperform those of the PASTd in the nonstationary case as well as in the stationary case.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.173-176
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• 2000

시변 신호 추적 특성을 향상시키기 위하여, Gauss-Newton Variable Forgetting Factor RLS (GN-VFF-RLS) Algorithm을 제안한다. 최적화된 망각인자를 가정한 기존의 RLS 알고리듬과 비교하여, 제안된 방법은 특히 신호의 변화가 급격히 일어날 경우 주목할만한 추정 성능의 향상을 보여준다. 제안된 알고리듬의 시변 추정 특성을 신호 대 잡음비와 시변 정도에 대하여 모의 실험하고 기존의 추정 알고리듬들과 비교한다.