• International journal of advanced smart convergence
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• 제10권1호
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• pp.1-11
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• 2021

Document page segmentation is an important step in building a quality optical character recognition module. The study examined already existing work on the topic of page segmentation and focused on the development of a segmentation model that has greater functional significance for application in an organization, as well as broad capabilities for managing the quality of the model. The main problems of document segmentation were highlighted, which include a complex background of intersecting objects. As classes for detection, not only classic text, table and figure were selected, but also additional types, such as signature, logo and table without borders (or with partially missing borders). This made it possible to pose a non-trivial task of detecting non-standard document elements. The authors compared existing neural network architectures for object detection based on published research data. The most suitable architecture was RetinaNet. To ensure the possibility of quality control of the model, a method based on neural network modeling using the RetinaNet architecture is proposed. During the study, several models were built, the quality of which was assessed on the test sample using the Mean average Precision metric. The best result among the constructed algorithms was shown by a model that includes four neural networks: the focus of the first neural network on detecting tables and tables without borders, the second - seals and signatures, the third - pictures and logos, and the fourth - text. As a result of the analysis, it was revealed that the approach based on four neural networks showed the best results in accordance with the objectives of the study on the test sample in the context of most classes of detection. The method proposed in the article can be used to recognize other objects. A promising direction in which the analysis can be continued is the segmentation of tables; the areas of the table that differ in function will act as classes: heading, cell with a name, cell with data, empty cell.

• 한국콘텐츠학회논문지
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• 제21권8호
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• pp.258-270
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• 2021

이 연구는 치의학 교육을 위한 부정교합 진찰용 가상현실 시뮬레이션의 적용 효과를 검증하기 위한 것이다. 부정교합 진단을 위해서는 치아모형을 사실적인 수준으로 만들어야 하며 이렇게 개발된 치아모형을 손으로 쥐고 상세하게 관찰할 수 있어야 한다. 이 연구에서는 치의학 가상현실 시뮬레이션을 만들기 위한 4단계 모델링 절차를 적용했다. 또한 이렇게 개발된 가상현실 시뮬레이션이 학습자의 숙달수준에 따라서 어떻게 지각되는가를 확인하기 위해서 HMD를 착용하고 진단을 하도록 했다. 이 연구에는 치의학전문대학원 재학생 3학년(29명), 4학년(29명), 치의학 전공의(28명)이 참여했으며, 두 가지 증례에 대한 진단활동을 통해서 과제부하와 사용용이성을 측정했다. 과제부하에 대한 검증에서 3학년이 전공의보다 더 많은 정신적 요구량과 당혹감을 지각하고 있었다. 이 결과는 시뮬레이션을 사용할 때 숙달수준에 따라서 지각하는 과제부하가 달라지고 있음을 보여주는 것이다. 반면에 사용용이성(구강모형의 조작, 오류수정, 오류인식)에서 4학년이 전공의보다 더 높은 용이성 지각을 보여줬다. 이 연구를 통하여 전문 훈련용 가상현실 시뮬레이션의 개발을 위한 함의점을 논의하였다.

• 반도체디스플레이기술학회지
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• 제20권4호
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• pp.171-176
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• 2021

Die-to-wafer (D2W) hybrid bonding in the multilayer semiconductor manufacturing process is one of wafer direct bonding, and various studies are being conducted around the world. A noteworthy point in the current die-to-wafer process is that a lot of voids occur on the bonding surface of the die during bonding. In this study, as a suggested method for removing voids generated during the D2W hybrid bonding process, a flexible mechanism for implementing convex for die bonding to be applied to the bond head is proposed. In addition, modeling of flexible mechanisms, analysis/design/control/evaluation of static/dynamics properties are performed. The proposed system was controlled by capacitive sensor (lion precision, CPL 290), piezo actuator (P-888,91), and dSpace. This flexure mechanism implemented a working range of 200 ㎛, resolution(3σ) of 7.276nm, Inposition(3σ) of 3.503nm, settling time(2%) of 500.133ms by applying a reverse bridge type mechanism and leaf spring guide, and at the same time realized a maximum step difference of 6 ㎛ between die edge and center. The results of this study are applied to the D2W hybrid bonding process and are expected to bring about an effect of increasing semiconductor yield through void removal. In addition, it is expected that it can be utilized as a system that meets the convex variable amount required for each device by adjusting the elongation amount of the piezo actuator coupled to the flexible mechanism in a precise unit.

• 지구물리와물리탐사
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• 제24권4호
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• pp.149-157
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• 2021

유도분극 탐사와 전기비저항 탐사는 자료획득이 유사하며, 대부분의 전기비저항 탐사 시스템에는 시간영역 유도분극 탐사 기능이 함께 탑재되어 있다. 또한 시간영역 유도분극 탐사 자료에는 전기비저항 자료가 내포되어 있다. 따라서 유도분극 탐사와 전기비저항 탐사와는 불가분의 관계가 있으며, 유도분극 자료의 역산도 전기비저항 탐사 자료의 역산에 근거한 2단계 역산법이 적용되고 있다. 그러나 유도분극 탐사는 효과적인 해석법의 부재로 인하여 전기비저항 탐사에 비하여 널리 적용되지 못하고 있다. 이 연구에서는 수치 모델링 및 역산실험을 통하여 시간영역 유도분극 자료의 역산해석에 사용되는 역 사상법의 문제점을 분석하였다. 또한 역 사상법 적용시 문제가 되는 역산잡음을 효과적으로 억제할 수 있는 수정된 역 사상법을 제시하였다. 마지막으로 수치자료에 대한 역산실험을 통하여 개발된 역 사상법의 효과를 검증하였다.

• 한국해양공학회지
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• 제36권5호
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• pp.340-352
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• 2022

This article presents a modeling method for the uncorrelated measurement error of the ultra-short baseline (USBL) acoustic positioning system for aiding navigation of underwater vehicles. The Mahalanobis distance (MD) and principal component analysis are applied to decorrelate the errors of USBL measurements, which are correlated in the x- and y-directions and vary according to the relative direction and distance between a reference station and the underwater vehicles. The proposed method can decouple the radial-direction error and angular direction error from each USBL measurement, where the former and latter are independent and dependent, respectively, of the distance between the reference station and the vehicle. With the decorrelation of the USBL errors along the trajectory of the vehicles in every time step, the proposed method can reduce the threshold of the outlier decision level. To demonstrate the effectiveness of the proposed method, simulation studies were performed with motion data obtained from a field experiment involving an autonomous underwater vehicle and USBL signals generated numerically by matching the specifications of a specific USBL with the data of a global positioning system. The simulations indicated that the navigation system is more robust in rejecting outliers of the USBL measurements than conventional ones. In addition, it was shown that the erroneous estimation of the navigation system after a long USBL blackout can converge to the true states using the MD of the USBL measurements. The navigation systems using the uncorrelated error model of the USBL, therefore, can effectively eliminate USBL outliers without loss of uncontaminated signals.

• 한국환경보건학회지
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• 제48권3호
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• pp.151-158
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• 2022

Background: Chemical emissions in the environment have rapidly increased with the accelerated industrialization taking place in recent decades. Residents of industrial complexes are concerned about the health risks posed by chemical exposure. Objectives: This study was performed to suggest modeling methods that take into account multimedia and multi-pathways in human exposure and risk assessment. Methods: The concentration of benzene emitted at industrial complexes in Daesan, South Korea and the exposure of local residents was estimated using the Caltox model. The amount of human exposure based on inhalation rate was stochastically predicted for various activity stages such as resting, normal walking, and fast walking. Results: The coefficient of determination (R²) for the CalTOX model efficiency was 0.9676 and the root-mean-square error (RMSE) was 0.0035, indicating good agreement between predictions and measurements. However, the efficiency index (EI) appeared to be a negative value at -1094.4997. This can be explained as the atmospheric concentration being calculated only from the emissions from industrial facilities in the study area. In the human exposure assessment, the higher the inhalation rate percentile value, the higher the inhalation rate and lifetime average daily dose (LADD) at each activity step. Conclusions: Prediction using the Caltox model might be appropriate for comparing with actual measurements. The LADD of females was higher ratio with an increase in inhalation rate than those of males. This finding would imply that females may be more susceptible to benzene as their inhalation rate increases.

• 한국컴퓨터정보학회논문지
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• 제14권12호
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• pp.139-145
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• 2009

본 논문에서는 관리자가시스템 운영과 감사 측면에서 침해사고에 대응하고 사고 발생 즉시 포렌식 데이터를 수집 분석 및 복구할 수 있는 포렌식 데이터의 실시간 수집 절차 모델을 제안한다. 제안한 모델은 기능 요소별로 구별된 7단계 절차를 가지며 추상적이고 관리적인 기존의 포렌식 절차와는 달리, 관리자가 시스템 운영과 감사 측면에서 침해사고에 대응하고, 사고 발생시 포렌식 데이터를 수집 분석 및 복구할수 있는 절차들이 포함되어 있다. 또한 즉각적인 대응이 어려운 경우 기존의 절차와 마찬가지로 종합적이고 조직적인 대응이 가능하도록 대응 전략 체계화 단계를 통한 포렌식 데이터 수집 단계로의 피드백 절차를 둔다.

• 한국전문물리치료학회지
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• 제30권2호
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• pp.120-127
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• 2023

Background: In general, measurement qualities of cross-culturally adapted quality of life (QOL) measures are altered in many aspects, although versions of them are well-validated measures. The latent trait and measurement qualities of the QOL measures for cancer-related samples should be considered when developing cross-culturally adapted measures. Objects: To investigate the latent trait of the translated into Korean World Health Organization Quality of Life-BREF (WHOQOL-BREF) administered to different cancer survivors who had palliative rehabilitation care service (PRCS). Methods: A cross-sectional study with 139 cancer survivors who had an experience of cancer survivorship with PRCS were conducted with a two-step analytic procedure including exploratory factor analysis (EFA) to confirm the latent trait and Rasch rating scale modeling to investigate the measurement qualities of the cross-culturally adapted WHOQOL-BREF measure. Results: While the original WHOQOL-BREF measure constitutes a 4-latent trait, the EFA reveals that 24 items constitute six substantial factors. The item loadings are predominantly spread over factors 1 through 4 in a mixed manner of the latent traits, while the loadings of 'physical health' and 'environmental health' latent traits show similarity to what the original measure intended to assess. The latent trait of the cross-culturally adapted WHOQOL-BREF measure administered to different cancer survivors is likely to reveal more dimensions than the original WHOQOL-BREF measure. Person reliability (i.e., analogous to Cronbach's alpha) and separation are measured with 0.92 and 3.48, respectively. All items except the one item (medical treatment item) fit the Rasch rating model. Conclusion: Findings suggest that the latent trait and the measurement qualities of the cross-culturally adapted WHOQOL-BREF measure should be taken into consideration when applying versions of it to various populations.

• 해양환경안전학회지
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• 제29권3호
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• pp.281-287
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• 2023

Establishing a ship's passage plan is an essential step before it starts to sail. The research related to the automatic generation of ship passage plans is attracting attention because of the development of maritime autonomous surface ships. In coastal water navigation, the land, islands, and navigation rules need to be considered. From the path planning algorithm's perspective, a ship's passage planning is a global path-planning problem. Because conventional global path-planning methods such as Dijkstra and A^* are time-consuming owing to the processes such as environmental modeling, it is difficult to modify a ship's passage plan during a voyage. Therefore, the D^* algorithm was used to address these problems. The starting point was near Busan New Port, and the destination was Ulsan Port. The navigable area was designated based on a combination of the ship trajectory data and grid in the target area. The initial path plan generated using the D^* algorithm was analyzed with 33 waypoints and a total distance of 113.946 km. The final path plan was simplified using the Douglas-Peucker algorithm. It was analyzed with a total distance of 110.156 km and 10 waypoints. This is approximately 3.05% less than the total distance of the initial passage plan of the ship. This study demonstrated the feasibility of automatically generating a path plan in coastal navigation for maritime autonomous surface ships using the D^* algorithm. Using the shortest distance-based path planning algorithm, the ship's fuel consumption and sailing time can be minimized.

• 지적과 국토정보
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• 제53권1호
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• pp.21-36
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• 2023

전 세계적으로 가장 널리 사용되고 있는 교통수요모형은 전통적 4단계 교통수요모델이다. 하지만, 기존 분석방법은 시공간적으로 다양한 분석에 제약을 가지고 있으며, 이러한 한계를 극복하기 위해 최근 활동기반 모형 및 시스템이 활발히 연구 개발되고 있다. 이에 본 연구에서는 빅데이터를 활용한 활동기반 통행자분석시스템 ABATA(Activity-Based Traveler Analyzer) 기술개발을 소개한다. 이 시스템은 시간별 총인구 추정, 활동 프로파일 생성, 시간별 활동 인구 추정, 공간 활동 인구 추정 및 출발지·목적지 추정 등의 구성요소를 포함한다. 제안된 시스템을 실증하기 위해 사례연구로 세종시 5-1 블록스마트시티를 대상으로 토지이용변화에 따른 배기가스 배출영향을 평가하였다. 그 결과 업무시설 분산계획 시나리오의 토지이용이 업무시설 집중계획 시나리오보다 이동 거리가 길어 배출량이 더 많이 발생하는 것으로 나타났다. 제안된 ABATA 시스템은 활동 인구 및 통행 수요에 대한 인구, 활동 일정 및 미래 토지이용의 변화 영향을 시뮬레이션하기 위한 유용한 도구를 제공할 것으로 기대된다.