• 한국멀티미디어학회논문지
• /
• 제2권1호
• /
• pp.38-46
• /
• 1999

본 논문에서는 복원시 사용될 정의역을 최소화하는 정의역 최소화 기법올 이용한 프랙탈 영상 압축방볍을 제안한디 기존의 프랙탈 영상복원은 복원하고자 하는 영상의 전체 치역블럭에 대해 반복축소변환올 적용함 으로써, 복원시 많은 계산량이 요구되었다 이를 개선하기 위해 각 치역블릭마다 정의역으로 참조된 횟수를 이용하여, 반복변환이 필요한 영역과 필요하지 않은 영역으로 구분하는 방법이 제시된 바 있다. 반복변환이 펼요한 영역이 감소할수록 복원시 계산량은 감소한다. 제안한 방법은 반복변환이 필요한 영역이 최소가 되는 최소정의역을정의하고,부호화시 정의역이 최소가되도록부호화하는알고리듬이다.즉,정의역의 탐색영역 을 치역과 비슷한 영역으로 제한하여, 정의역이 더 많이 중복되거나 중첩되도록 하였다 그 결과 프랙탈 영상 복원시 화질이나 압축율에 거의 영향을 미치지 않고, 반복변환에 필요한 계산량이 감소함으로써 고속 복원이 가능하였다.

• Journal of international Conference on Electrical Machines and Systems
• /
• 제2권2호
• /
• pp.232-238
• /
• 2013

The vehicle system is a multi-domain system that requires many branches of science and engineering. Therefore the development of the vehicle system requires the use of design methodologies that utilize simulations, which have grown increasingly sophisticated in recent years. Our research group proposed a simulation modeling method based on the VHDL-AMS language. This paper describes how VHDL-AMS is used to model of vehicle fuel consumption simulation. The fuel consumption is shown using proposed simulation model on the Japanese 10-15 mode. We examine the influence of the vehicle system with electrical load and hill climb resistance in the vehicle running resistance.

• Smart Structures and Systems
• /
• 제16권3호
• /
• pp.401-414
• /
• 2015

A developed hybrid method for crack identification of beams is presented. Based on the Euler-Bernouli beam theory and concepts of fracture mechanics, governing equation of the cracked beams is reformulated. Finite element (FE) method as a powerful numerical tool is used to discritize the equation in space domain. After transferring the equations from time domain to frequency domain, frequencies and mode shapes of the beam are obtained. Efficiency of the governed equation for free vibration analysis of the beams is shown by comparing the results with those available in literature and via ANSYS software. The used equation yields to move the influence of cracks from the stiffness matrix to the mass matrix. For crack identification measured data are produced by applying random error to the calculated frequencies and mode shapes. An objective function is prepared as root mean square error between measured and calculated data. To minimize the function, hybrid genetic algorithms (GAs) and particle swarm optimization (PSO) technique is introduced. Efficiency, Robustness, applicability and usefulness of the mixed optimization numerical tool in conjunction with the finite element method for identification of cracks locations and depths are shown via solving different examples.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2007년도 정기 학술대회 논문집
• /
• pp.495-500
• /
• 2007

A Meshfree is a method used to establish algebraic equations of system for the whole problem domain without the use of a predefined mesh for the domain discretization. A point interpolation method is based on combining radial and polynomial basis functions. Involvement of radial basis functions overcomes possible singularity. Furthermore, the interpolation function passes through all scattered points in an influence domain and thus shape functions are of delta function property. This makes the implementation of essential boundary conditions much easier than the meshfree methods based on the moving least-squares approximation. This study aims to investigate a stress analysis of structural element between a meshfree method and the finite element method. Examples on cantilever type plate and stress concentration problems show that the accuracy and convergence rate of the meshfree methods are high.

• Smart Structures and Systems
• /
• 제31권2호
• /
• pp.171-181
• /
• 2023

Using the most up-to-date system identification methods in both time and frequency domains, the dynamic monitoring data from the reinforced concrete Egebaekvej Bridge near Holte, Denmark, is examined in this investigation. The bridge was erected in the 1960s and was still standing during test campaign before demolishing. The ARTeMIS Modal was adopted to derive the modal parameters from ambient vibration data. Several Operational Modal Analysis (OMA) approaches were applied, including Enhanced Frequency Domain Decomposition (EFDD), Curve-fit Frequency Domain Decomposition (CFDD), and Frequency Domain Decomposition (FDD). Afterward, Principal Component (SSI-PC), Unweighted Principal Component (SSI-UPC) Stochastic Subspace Identification methods were utilized. Danish engineering consulting company, COWI with the allowance of the bridge contractor BARSLUND, allow the researcher for this experimental test to demonstrate the impact of OMA applications.

• 대한통합의학회지
• /
• 제10권3호
• /
• pp.209-219
• /
• 2022

Purpose : The purpose of this study was two-fold: to investigate the effects of uncertainty and depression on the quality of life (QoL) of elderly people with chronic diseases and to provide basic data on the physical, emotional, and psychological factors affecting their QoL in the field of physical therapy. Methods : A questionnaire covering uncertainty, depression, and QoL was distributed among 320 elderly people. Pearson's correlation analysis was performed to examine the correlation between uncertainty (ambiguity, complexity, inconsistency, and unpredictability), depression, and QoL (physical, psychological, social, and living environment domains) of the respondents; furthermore, multiple regression analysis was performed to identify the factors affecting the QoL of the respondents with a chronic disease. Results : The sub-factors of uncertainty and QoL-"complexity and social domain" (r=-.295, p<.001), "complexity and living environment domain" (r=-.302, p<.001), and "inconsistency and living environment domain" (r=-.360, p<.001)-showed a negative (-) correlation, as did depression and the sub-factors of QoL-"depression and physical domain" (r=-.782, p<.001), "depression and psychological domain" (r=-.876, p<.001), "depression and social domain" (r=-.668, p<.001), and "depression and living environment domain" (r=-.731, p<.001). The factors affecting QoL were complexity (𝛽=-.122, p<.001), inconsistency (𝛽=-.102, p=.002), unpredictability (𝛽=.112, p<.001), and depression (𝛽=-.850, p<.001). The relative influence of the independent variables was in the order of depression, complexity, unpredictability, and inconsistency, and the explanatory power was 77.1 % (F=215.853, p<.001). Conclusion : It is important to help the elderly with chronic diseases reduce the negative impact on their quality of life by helping them gain support from their families and medical professionals and by increasing their understanding through communication so that they can transition from negative emotions to positive emotions of opportunity.

• ETRI Journal
• /
• 제46권1호
• /
• pp.59-70
• /
• 2024

We introduce a high-performance named entity recognition (NER) model for written and spoken language. To overcome challenges related to labeled data scarcity and domain shifts, we use transfer learning to leverage our previously developed KorBERT as the base model. We also adopt a meta-pseudo-label method using a teacher/student framework with labeled and unlabeled data. Our model presents two modifications. First, the student model is updated with an average loss from both human- and pseudo-labeled data. Second, the influence of noisy pseudo-labeled data is mitigated by considering feedback scores and updating the teacher model only when below a threshold (0.0005). We achieve the target NER performance in the spoken language domain and improve that in the written language domain by proposing a straightforward rollback method that reverts to the best model based on scarce human-labeled data. Further improvement is achieved by adjusting the label vector weights in the named entity dictionary.

• 융합신호처리학회논문지
• /
• 제2권2호
• /
• pp.13-19
• /
• 2001

기존의 프랙탈 영상복원은 모든 치역 블럭에 대해 반복축소변환을 수행하므로 복원시 많은 계산량이 요구되었다. 이를 개선하기 위해 각 치역 블럭마다 반복축소변환이 필요한 영역과 필요하지 않은 영역으로 구분하는 방법이 제시된 바 있다. 반복축소변환이 필요 없는 영역을 데이타 의존영역이라 하고, 데이타 의존영역이 확장될수록 반복축소변환 영역은 줄어든다. 그래서 본 논문에서는 정의역 블록의 탐색 영역을 치역과 비슷한 영역으로 제한하여, 정의역 블럭이 더 많이 중복되도록 부호화하여 데이타 의존영역을 최대화 즉, 반복축소변환 영역을 최소화한다. 반복축소변환 영역이 최소가 되는 정의역을 정의역 최소화 기법으로 정의한다. 그래서 정의역 최소화 기법을 이용하여 프랙탈 영상 복원시 화질에 거의 영향을 미치지 않고, 반복축소변환에 필요한 계산량을 감소시켜 고속 복원이 가능하다.

• 융합보안논문지
• /
• 제22권4호
• /
• pp.169-178
• /
• 2022

도메인이 여러 개로 구성된 멀티 네트워크를 운영하는 조직에서는 단일 화면 상에 다수의 네트워크 토폴로지를 시각화하여 전체 노드들과 링크들을 감시할 수 있는 기능이 필요한데, 도메인간의 연결점이 없는 토폴로지를 단일 화면 상에 표시하는 것은 간단하지가 않다. 게다가, 다수의 네트워크 형상들을 단일 화면 상에 실제와 같은 물리적 모습으로 표시하는 것은 어렵기 때문에, 멀티 도메인 네트워크를 하나의 화면을 통해 관리하는데는 어려움이 있다. 본 연구에서는 멀티 도메인 환경에서 노드간의 최소 연결 정보만을 이용하여 토폴로지를 시각화하는 효율적인 방법을 제안한다. 이 방법은 네트워크를 구성하는 노드들의 중심성 지수를 활용하여 도메인별 중심 노드를 찾고, 자식 노드들과의 연결정보를 재귀적으로 탐색하여 토폴로지를 생성한다. 화면 상의 도메인별 토폴로지 표시 영역은 자식 노드들의 가중치의 합으로 계산 및 동적 분할되고, 가상의 Root 노드를 활용하여 3D 공간 상에 전체 노드들을 배치함으로써 멀티 도메인 토폴로지를 시각화한다. 이 방법은 노드간의 최소 연결 정보만을 이용하는 단순한 방법이지만, 멀티 도메인 네트워크의 물리적 형상을 유지하면서 하나의 화면에 표시할 수 있는 효율적인 토폴로지 시각화 방법이다.

• 패션비즈니스
• /
• 제6권2호
• /
• pp.110-123
• /
• 2002

This study investigated the influence of cultural and general trend of the times on fashion trends and the hybridization of these trends. The objectives of this study were to suggest new approach method of the fashion forecasting and to find out the cultural meanings and values of fashion. Key words that explains fashion trend from spring/summer of 1995 to fall/winter of 2002 were collected from professional fashion trend journals. These terms were analysed with domain analysis based on the semantic relationship. The frequency of their appearance in each season and the aspect of their appearance in each season were analysed. The hybrids of the fashion trends were analysed longitudinally and cross-sectionally as well by investigating the cover terms that were found as a result of domain analysis. The method used in this study can be applied to future study of fashion trend in that it offers an objective view of fashion trend and can allow researchers to study fashion trend in a concrete way.