• Title/Summary/Keyword: random points

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Electric Power Line Dips Measurement Using Drone-based Photogrammetric Techniques (드론 기반 사진측량기법을 활용한 고압 송전선의 처짐량 측정)

  • Kim, Yu Jong;Oh, Jae Hong;Lee, Chang No
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.6
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    • pp.453-460
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    • 2017
  • High voltage power transmission lines have been to keep the proper dip for maintenance. Powerline dips at a random point are conventionally measured by the direct or indirect observation but it is not only unsafe but labor-intensive. Therefore in this study we applied the photogrammetric technique to remotely measure the powerline dips. Since it is not easy to extract conjugate points from linear powerlines, we exploited the epipolar lines acrossing the powerlines for 3D mapping of the powerlines and dip measurements. The vertical mapping accuracy estimated at two field-surveyed power line points was 15~16cm that are within 5% of deflection at the points and less than 3% of the powerline dip.

Test Time Reduction for BIST by Parallel Divide-and-Conquer Method (분할 및 병렬 처리 방법에 의한 BIST의 테스트 시간 감소)

  • Choe, Byeong-Gu;Kim, Dong-Uk
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.49 no.6
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    • pp.322-329
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    • 2000
  • BIST(Built-in Self Test) has been considered as the most promising DFT(design-for-test) scheme for the present and future test strategy. The most serious problem in applying BIST(Built-in Self Test) into a large circuit is the excessive increase in test time. This paper is focused on this problem. We proposed a new BIST construction scheme which uses a parallel divide-and-conquer method. The circuit division is performed with respect to some internal nodes called test points. The test points are selected by considering the nodal connectivity of the circuit rather than the testability of each node. The test patterns are generated by only one linear feedback shift register(LFSR) and they are shared by all the divided circuits. Thus, the test for each divided circuit is performed in parallel. Test responses are collected from the test point as well as the primary outputs. Even though the divide-and-conquer scheme is used and test patterns are generated in one LFSR, the proposed scheme does not lose its pseudo-exhaustive property. We proposed a selection procedure to find the test points and it was implemented with C/C++ language. Several example circuits were applied to this procedure and the results showed that test time was reduced upto 1/2151 but the increase in the hardware overhead or the delay increase was not much high. Because the proposed scheme showed a tendency that the increasing rates in hardware overhead and delay overhead were less than that in test time reduction as the size of circuit increases, it is expected to be used efficiently for large circuits as VLSI and ULSI.

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Knowledge and Perceptions about Colorectal Cancer in Jordan

  • Taha, Hana;Jaghbeer, Madi Al;Shteiwi, Musa;AlKhaldi, Sireen;Berggren, Vanja
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8479-8486
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    • 2016
  • Background: Colorectal cancer (CRC) is the third most common cancer globally. In Jordan, it is the number one cancer among men and the second most common cancer among women, accounting for 15% and 9.4% respectively of all male and female diagnosed cancers. This study aimed to evaluate the knowledge and perceptions about colorectal cancer risk factors, signs and symptoms in Jordan and to provide useful data about the best modes of disseminating preventive messages about the disease. Materials and Methods: A stratified clustered random sampling technique was used to recruit 300 males and 300 females aged 30 to 65 years without a previous history of CRC from four governorates in Jordan. A semi-structured questionnaire and face to face interviews were employed. Descriptive and multivariate analysis was applied to assess knowledge and perceptions about CRC. Results: Both males and females perceived their CRC risk to be low. They had low knowledge scores about CRC with no significant gender association (P=0.47). From a maximum knowledge score of 18 points, the median scores of males and females were 4 points (SD=2.346, range 0-13) and 4 points (SD=2.329, range 0-11) respectively. Better knowledge scores were associated with governorate, higher educational level, older age, higher income, having a chronic disease, having a family history of CRC, previously knowing someone who had CRC and their doctor's knowledge about their family history of CRC. Conclusions: There is a low level of knowledge about CRC and underestimation of risk among the study participants. This underlines the need for public health interventions to create awareness about the illness. It also calls for further research to assess the knowledge and perceptions about CRC early detection examinations in Jordan.

3-Points Average Pivot Quicksort (3-점 평균 피벗 퀵정렬)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.6
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    • pp.295-301
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    • 2014
  • In the absence of a sorting algorithm faster than O(n log n), Quicksort remains the best and fastest of its kind in practice. For given n data, Quicksort records running in O(n log n) at best and $O(n^2)$ at its worst. In this paper, I propose an algorithm by which 3-points average P=(L+M+H)/3 is set as a pivot for first array L=a[s], last array H=a[e], and middle array $M=a[{\lfloor}(s+e)/2{\rfloor}]$ in order to find the more fast than Quicksort. Test results prove that the proposed 3-points average pivot Quicksort has the time complexity of O(n log n) at its best, average, and worst cases. And the proposed algorithm can be reduce the $O(n^2)$ time of Quicksort to O(n log n).

The Influence of Dental Hygiene Student's Communication Ability and Conflict Management Types on Adaptation to College Life

  • Shin, Myong-Suk;Han, Ji-Hyoung;Hwang, Ji-Min
    • Journal of dental hygiene science
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    • v.21 no.1
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    • pp.19-27
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    • 2021
  • Background: The purpose of this study was to investigate the effects of dental hygiene students' communication ability and conflict management types on adaptation to college life improve adaptation to college life and to suggest strategies to play a role as a professional dental hygienist in clinical practice. Methods: The subjects of this study were selected by random sample extraction of dental hygiene students from two colleges in Gyeonggi and one Chungcheong area. The survey was conducted online for dental hygiene students from July 20 to October 31, 2020. In order to comply with research ethics, this study was investigated with the consent of the subjects. The sample was analyzed for the final 351. Results: Dental hygiene students' communication ability was 3.74 points, conflict management types was 3.01 points, and adaptation to college life was 3.30 points. In the type of conflict management according to the general characteristics, the problem-solving method, the avoidance method, the compromise method, and the concession method showed statistically significant differences in major satisfaction. Among the types of conflict management, the highest positive correlation (r=0.613) was shown in the relationship between the problem-solving method and the compromise method. Factors influencing the adaptation to college life were concentration, forced method, self-disclosure, conversational coherence, and social relaxation. Conclusion: This study is significant in that it derives sub-areas of communication ability and conflict management types that influence adaptation to college life. In the future, there is a need to improve the quality of dental hygienists by continuously conducting research on the types of conflict management targeting dental hygienists, and responding more proactively and actively to conflict situations in the clinical field.

A Hybrid Semantic-Geometric Approach for Clutter-Resistant Floorplan Generation from Building Point Clouds

  • Kim, Seongyong;Yajima, Yosuke;Park, Jisoo;Chen, Jingdao;Cho, Yong K.
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.792-799
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    • 2022
  • Building Information Modeling (BIM) technology is a key component of modern construction engineering and project management workflows. As-is BIM models that represent the spatial reality of a project site can offer crucial information to stakeholders for construction progress monitoring, error checking, and building maintenance purposes. Geometric methods for automatically converting raw scan data into BIM models (Scan-to-BIM) often fail to make use of higher-level semantic information in the data. Whereas, semantic segmentation methods only output labels at the point level without creating object level models that is necessary for BIM. To address these issues, this research proposes a hybrid semantic-geometric approach for clutter-resistant floorplan generation from laser-scanned building point clouds. The input point clouds are first pre-processed by normalizing the coordinate system and removing outliers. Then, a semantic segmentation network based on PointNet++ is used to label each point as ceiling, floor, wall, door, stair, and clutter. The clutter points are removed whereas the wall, door, and stair points are used for 2D floorplan generation. A region-growing segmentation algorithm paired with geometric reasoning rules is applied to group the points together into individual building elements. Finally, a 2-fold Random Sample Consensus (RANSAC) algorithm is applied to parameterize the building elements into 2D lines which are used to create the output floorplan. The proposed method is evaluated using the metrics of precision, recall, Intersection-over-Union (IOU), Betti error, and warping error.

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Process Optimization of the Contact Formation for High Efficiency Solar Cells Using Neural Networks and Genetic Algorithms (신경망과 유전알고리즘을 이용한 고효율 태양전지 접촉형성 공정 최적화)

  • Jung, Se-Won;Lee, Sung-Joon;Hong, Sang-Jeen;Han, Seung-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.11
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    • pp.2075-2082
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    • 2006
  • This paper presents modeling and optimization techniques for hish efficiency solar cell process on single-crystalline float zone (FZ) wafers. Among a sequence of multiple steps of fabrication, the followings are the most sensitive steps for the contact formation: 1) Emitter formation by diffusion; 2) Anti-reflection-coating (ARC) with silicon nitride using plasma-enhanced chemical vapor deposition (PECVD); 3) Screen-printing for front and back metalization; and 4) Contact formation by firing. In order to increase the performance of solar cells in terms of efficiency, the contact formation process is modeled and optimized using neural networks and genetic algorithms, respectively. This paper utilizes the design of experiments (DOE) in contact formation to reduce process time and fabrication costs. The experiments were designed by using central composite design which consists of 24 factorial design augmented by 8 axial points with three center points. After contact formation process, the efficiency of the fabricated solar cell is modeled using neural networks. Established efficiency model is then used for the analysis of the process characteristics and process optimization for more efficient solar cell fabrication.

Horticultural Therapy Programs Enhancing Quality of Life and Reducing Depression and Burden for Caregivers of Elderly with Dementia

  • Kim, Yong Hyun;Park, Chul Soo;Bae, Hwa-Ok;Lim, Eun Ji;Kang, Kyung Heui;Lee, Euy Sun;Jo, Su Hyeon;Huh, Moo Ryong
    • Journal of People, Plants, and Environment
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    • v.23 no.3
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    • pp.305-320
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    • 2020
  • Background and objective: The problem that follows the increase of dementia patients is the burden of caregivers caring for dementia patients. The purpose of this study was to examine the effects of horticultural therapy programs improving the quality of life and reducing the depression and burden of caregivers of the elderly with dementia. Methods: In this study, 19 caregivers of the elderly with dementia were selected, and the experiment was conducted by dividing the control group (n=9) and the experimental group (n=10) by random distribution. The experimental group was given eight horticultural therapy programs twice a week for a total of 4 weeks. Subjects were assessed using the depression(CES-D), quality of Life (WHOQOL-BREF), and care burden scales. The evaluation results were verified at a 95% significance level using descriptive statistics, the Mann-Whitney U test, and Wilcoxon signed-rank test. Results: In the case of depression, the control group's score tended to increase, and the experimental group's score appeared to decrease, but it was not a statistically significant change. In the quality of life, the control group was not statistically significant, but scores decreased overall. On the other hand, in the experimental group, the general quality of life increased significantly from 11.60 to 14.20 points (p = .02), and the total quality of life increased to a marginally significant level from 61.59 points to 68.85 points (p = .059). In the post-test of the total care burden score, a marginally significant difference was found between the control group (94.44 points) and the experimental group (82.50 points; p = .079). Conclusion: This study confirmed the applicability to reduce the burden of caregiving and improve the deterioration of quality of life of the caregivers. In particular, the results will serve as an opportunity to confirm accessibility in a new way to support the caregiver of dementia patients by demonstrating the applicability of horticultural therapy at a time when problems such as the burden of supporting the caregiver are emerging as social problems.

RANSAC-based Or thogonal Vanishing Point Estimation in the Equirectangular Images

  • Oh, Seon Ho;Jung, Soon Ki
    • Journal of Korea Multimedia Society
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    • v.15 no.12
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    • pp.1430-1441
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    • 2012
  • In this paper, we present an algorithm that quickly and effectively estimates orthogonal vanishing points in equirectangular images of urban environment. Our algorithm is based on the RANSAC (RANdom SAmple Consensus) algorithm and on the characteristics of the line segment in the spherical panorama image of the $360^{\circ}$ longitude and $180^{\circ}$ latitude field of view. These characteristics can be used to reduce the geometric ambiguity in the line segment classification as well as to improve the robustness of vanishing point estimation. The proposed algorithm is validated experimentally on a wide set of images. The results show that our algorithm provides excellent levels of accuracy for the vanishing point estimation as well as line segment classification.

A Probabilistic Network for Facial Feature Verification

  • Choi, Kyoung-Ho;Yoo, Jae-Joon;Hwang, Tae-Hyun;Park, Jong-Hyun;Lee, Jong-Hoon
    • ETRI Journal
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    • v.25 no.2
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    • pp.140-143
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    • 2003
  • In this paper, we present a probabilistic approach to determining whether extracted facial features from a video sequence are appropriate for creating a 3D face model. In our approach, the distance between two feature points selected from the MPEG-4 facial object is defined as a random variable for each node of a probability network. To avoid generating an unnatural or non-realistic 3D face model, automatically extracted 2D facial features from a video sequence are fed into the proposed probabilistic network before a corresponding 3D face model is built. Simulation results show that the proposed probabilistic network can be used as a quality control agent to verify the correctness of extracted facial features.

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