• 제목/요약/키워드: Link-structure

검색결과 875건 처리시간 0.028초

Emergence and Structure of Complex Mutualistic Networks

  • Lee, KyoungEun;Jung, Nam;Lee, Hyun Min;Maeng, Seung Eun;Lee, Jae Woo
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • 제3권3호
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    • pp.149-153
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    • 2022
  • The degree distribution of the plant-pollinator network was identified by analyzing the data in the ecosystem and reproduced by a model of the growing bipartite mutualistic networks. The degree distribution of pollinator shows power law or stretched exponential distribution, while plant usually shows stretched exponential distribution. In the growth model, the plant and the pollinator are selected with probability Pp and PA=1-Pp, respectively. The number of incoming links for the plant and the pollinator is lp and lA, respectively. The probability that the link of the plant selects the pollinator of the existing network given as $A_{k_i}=k^{{\lambda}_A}_i/{\sum}_i\;k^{{\lambda}_A}_i$, and the probability that the pollinator selects the plant is $P_{k_i}=k^{{\lambda}_p}_i/{\sum}_i\;k^{{\lambda}_p}_i$. When the nonlinear growth index is 𝛌X=1 (X=A or P), the degree distribution follows a power law, and if 0≤𝛌X<1, the degree distribution follows a stretched exponential distribution. The cumulative degree distributions of plants and pollinators of 14 empirical plant-pollinators included in Interaction Web Database were calculated. A set of parameters (PA,PP,lA,lP) that reproduces these cumulative degree distributions and a growth index 𝛌X (X=A or P) were obtained. We found that animal takes very heterogenous connections, whereas plant takes a more flexible connection network.

팜봇과 연동하는 작업기 자동체결 장치 개발 (Development of Automatic Module Changer for Farmbot)

  • 권준혁;이명호;조형호;홍형길;조용준;윤해룡;오장석;박희창;강민수
    • 한국기계가공학회지
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    • 제20권12호
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    • pp.30-35
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    • 2021
  • In this study, we developed an automatic module changer for agricultural implements for using in unmanned agricultural robots. An automatic module changer is attached by lowering from the top to bottom of the implements and fixing the four fastener bars attached to the implements in combination. The lift function was implemented using seesaw-type structures to keep the engagement point constant when the automatic module changer climbs and descends, and the switching function of the automatic module changer was implemented using the link device in the cam structure. We developed an algorithm to check the presence of attachment and opening/closing of the workpiece using limit switches and verified the performance through combination assessment and weight lift test to assess whether the combination was within the error range.

Identification of venular capillary remodelling: a possible link to the development of periodontitis?

  • Townsend, David
    • Journal of Periodontal and Implant Science
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    • 제52권1호
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    • pp.65-76
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    • 2022
  • Purpose: The present study measured changes in arteriolar and venular capillary flow and structure in the gingival tissues during the development of plaque-induced gingival inflammation by combining dynamic optical coherence tomography (OCT), laser perfusion, and capillaroscopic video imaging. Methods: Gingival inflammation was induced in 21 healthy volunteers over a 3-week period. Gingival blood flow and capillary morphology were measured by dynamic OCT, laser perfusion imaging, and capillaroscopy, including a baseline assessment of capillary glycocalyx thickness. Venular capillary flow was estimated by analysis of the perfusion images and mean blood velocity/acceleration in the capillaroscopic images. Readings were recorded at baseline and weekly over the 3 weeks of plaque accumulation and 2 weeks after brushing was resumed. Results: Perfusion imaging demonstrated a significant reduction of gingival blood flow after 1 and 2 weeks of plaque accumulation (P<0.05), but by 3 weeks of plaque accumulation there was a more mixed picture, with reduced flow in some participants and increased flow in others. Participants with reduced flux at 3 weeks also demonstrated venular-type flow as determined by perfusion images and evidence of the development of venular capillaries as assessed by the velocity/acceleration ratio in capillaroscopic images. After brushing resumed, these venular capillaries were broken down and replaced by arteriolar capillaries. Conclusions: After 3 weeks of plaque accumulation, there was wide variation in microvascular reactions between the participants. Reduced capillary flow was associated with the development of venular capillaries in some individuals. This is noteworthy, as an early increase in venous capillaries is a key vascular feature of cardiovascular disease, psoriasis, Sjögren syndrome, and rheumatoid arthritis-diseases with a significant association with the development of severe gingival inflammation, which leads to periodontitis. Future investigations of microvascular changes in gingival inflammation might benefit from accurate capillary flow velocity measurements to assess the development of venular capillaries.

The Influence of Human Capital on GDP Dynamics: Modeling in the COVID-19 Conditions

  • Derii, Zhanna;Zosymenko, Tetiana;Shaposhnykov, Kostiantyn;Tochylina, Yuliia;Krylov, Denys;Papaika, Oleksandr
    • International Journal of Computer Science & Network Security
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    • 제22권3호
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    • pp.67-76
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    • 2022
  • COVID-19 struck labor markets around the world, exposing and exacerbating the gender inequalities within the human capital structure. The last, in its turn, jeopardizes the return of the national economies to the growth trajectory undermined by pandemic impact. The authors assume that COVID-19 disproportionately affected the employment rates of women and men, which led to increased gender inequality in the labor market, which, in turn, affected GDP growth rates in the EU. To prove this hypothesis two research questions are discovered: 1) whether there was a different correlation between the number of COVID-19 cases in the EU and indicators of the labor market for women and men; and 2) whether there was a link between the growth of gender inequality in the EU labor market and the GDP dynamics in these countries. The analysis of the correlation between the number of cases of COVID-19 and indicators of the labor market in the EU revealed faster growth of women's unemployment rates compared to men's ones as the COVID-19 incidence unfolded. Multiple linear regression and factor analysis have been used to investigate the influence of gender inequality in the labor market on GDP dynamics. Despite the methodological limitations, the proposed model is both a sound argument and an analytical basis in favor of gender-responsive economic recovery backed by the systematic and consistent gender equality policy of a government.

The effectiveness of position of coupled beam with respect to the floor level

  • Yasser Abdal Shafey, Gamal;Lamiaa K., Idriss
    • Coupled systems mechanics
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    • 제11권6호
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    • pp.557-586
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    • 2022
  • In spite of extensive testing of the individual shear wall and the coupling beam (CB), numerical and experimental researches on the seismic behavior of CSW are insufficient. As far as we know, no previous research has investigated the affectations of position of CB regarding to the slab level (SL). So, the investigation aims to enhance an overarching framework to examine the consequence of connection positions between CB and SL. And, three cases have been created. One is composed of the floor slab (FS) at the top of the CB (FSTCB); the second is created with the FS within the panel depth (FSWCB), and the third is employed with the FS at the bottom of the CB (FSLCB). And, FEA is used to demonstrate the consequences of various CB positions with regard to the SL. Furthermore, the main measurements of structure response that have been investigated are deformation, shear, and moment in a coupled beam. Additionally, wall elements are used to simulate CB. In addition, ABAQUS software was used to figure out the strain distribution, shear stress for four stories to further understand the implications of slab position cases on the coupled beam rigidity. Overall, the findings show that the position of the rigid linkage among the CB and the FS can affect the behavior of the structures under seismic loads. For all structural heights (4, 8, 12 stories), the straining actions in FSWCB and FSLCB were less than those in FSTCB. And, the increases in displacement time history response for FSWCB are around 16.1-81.8%, 31.4-34.7%, and 17.5% of FSTCB.

무선전력 통신 네트워크에서 최적의 멀티홉 전송 방식 (An Optimal Multi-hop Transmission Scheme for Wireless Powered Communication Networks)

  • 최현호
    • 한국정보통신학회논문지
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    • 제26권11호
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    • pp.1679-1685
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    • 2022
  • 본 논문에서는 무선전력 통신 네트워크에서 소스에서 목적지 노드까지 종단간 데이터 전송률을 최대화하기 위한 최적의 멀티홉 전송 방식을 제안한다. 에너지 하베스팅을 하면서 멀티홉 전송을 위한 프레임 구조를 제시하고, 노드간 서로 다른 에너지 수확량과 링크 품질을 고려하여 종단간 전송률을 최대화하는 각 노드의 전송 시간을 수학적 분석을 통하여 도출한다. 아울러, 고려하는 무선전력기반 멀티홉 전송의 시스템 모델링을 통하여 최적화 문제를 도출하고, 이 최적화 문제가 convex 함을 보임으로써 전역 최적해가 존재함을 증명한다. 이를 통하여 최적화 문제를 계산 가능한 형태로 변형하여 손쉽게 최적해를 찾는다. 제안한 최적 멀티홉 전송 방식은 모든 링크의 전송률이 같아지도록 노드별 전송 시간을 최적으로 할당함으로써 종단간 전송률을 최대화한다.

Nanotechnology in early diagnosis of gastro intestinal cancer surgery through CNN and ANN-extreme gradient boosting

  • Y. Wenjing;T. Yuhan;Y. Zhiang;T. Shanhui;L. Shijun;M. Sharaf
    • Advances in nano research
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    • 제15권5호
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    • pp.451-466
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    • 2023
  • Gastrointestinal cancer (GC) is a prevalent malignant tumor of the digestive system that poses a severe health risk to humans. Due to the specific organ structure of the gastrointestinal system, both endoscopic and MRI diagnoses of GIC have limited sensitivity. The primary factors influencing curative efficacy in GIC patients are drug inefficacy and high recurrence rates in surgical and pharmacological therapy. Due to its unique optical features, good biocompatibility, surface effects, and small size effects, nanotechnology is a developing and advanced area of study for the detection and treatment of cancer. Because of its deep location and complex surgery, diagnosing and treating gastrointestinal cancer is very difficult. The early diagnosis and urgent treatment of gastrointestinal illness are enabled by nanotechnology. As diagnostic and therapeutic tools, nanoparticles directly target tumor cells, allowing their detection and removal. XGBoost was used as a classification method known for achieving numerous winning solutions in data analysis competitions, to capture nonlinear relations among many input variables and outcomes using the boosting approach to machine learning. The research sample included 300 GC patients, comprising 190 males (72.2% of the sample) and 110 women (27.8%). Using convolutional neural networks (CNN) and artificial neural networks (ANN)-EXtreme Gradient Boosting (XGBoost), the patients mean± SD age was 50.42 ± 13.06. High-risk behaviors (P = 0.070), age at diagnosis (P = 0.037), distant metastasis (P = 0.004), and tumor stage (P = 0.015) were shown to have a statistically significant link with GC patient survival. AUC was 0.92, sensitivity was 81.5%, specificity was 90.5%, and accuracy was 84.7 when analyzing stomach picture.

심층 주제, 지역, 장르를 모두 분류할 수 있는 다면적 뉴스 기사 자동 분류 모델 연구 (Research on Multi-facted News Article Classification Models Classifying Subjects, Geographies and Genres)

  • 이효진;최성필
    • 한국문헌정보학회지
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    • 제58권3호
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    • pp.65-89
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    • 2024
  • 본 연구는 한국어 사전학습 모델을 활용하여 뉴스 기사를 주제, 장르, 지역별로 각각 분류하는 모델을 구축하였다. 이를 위해 국내 언론사의 분류체계를 참고하여 새로운 뉴스 기사 분류체계를 설계하였다. 주제 및 장르 분류 모델은 대분류와 중분류 모델을 연결한 계층적 구조의 분류 모델로 구현하여 카테고리 통합 모델의 성능과 비교하였다. 평가 결과, 계층적 구조의 분류 모델은 모호하거나 중복된 카테고리에서 카테고리 통합 모델보다 더 명확한 분류를 수행할 수 있다는 이점이 있었다. 뉴스 기사의 지역적 분류를 위해서는 18개의 카테고리에 대하여 분류를 수행하는 모델을 구축하였으며 지역 관련 뉴스 기사의 경우, 지역적 특성이 본문에 명확히 드러나 높은 성능을 기록할 수 있었다. 본 연구는 주제, 장르, 지역의 다각적인 측면에서 뉴스 기사를 효과적으로 분류할 수 있음을 보여주었으며, 이를 통해 사용자 요구에 부합하는 다차원적 뉴스 기사 분류 서비스의 가능성을 제시한 점에서 의의가 있다.

포대/대대 별 재구성 가능한 전술작전화면 프레임워크 개발 (Development of Reconfigurable Tactical Operation Display Framework by Battery and Battalion)

  • 이상태;이승영;위성혁;조규태
    • 정보과학회 논문지
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    • 제44권5호
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    • pp.476-485
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    • 2017
  • 미래 대공 유도무기체계 전술작전센터는 미래 공중위협, 전술정보, 통합전장 환경 생성 및 관리, 교전통제 및 지휘통제 알고리즘 연구를 위한 환경을 제공한다. 통합전장상황 생성 및 처리, 전술작전 자동화 처리 핵심 기능요소에 대한 개발을 위해서는 다역할(포대/대대) 전술작전 통제 및 재구성 설계가 가능한 소프트웨어가 필요하다. 따라서 기능 별 알고리즘 소프트웨어, 전술작전화면 소프트웨어, 장비들 간 연동을 위한 링크 소프트웨어를 데이터 중심 설계를 통해 재구성 가능하도록 개발하였다. 본 논문에서는 포대/대대 별 전술작전 운용화면에 재구성이 가능한 전술작전화면 프레임워크를 소개한다. 전술작전화면 프레임워크는 포대/대대 및 임무별 다역할 전술작전화면을 재구성 가능한 구조를 위해 공통데이터 모델설계와 MVC패턴을 이용한 화면구성도구를 개발하였다. 화면구성도구를 이용하여 화면 개발을 위한 전술작전화면 프레임워크를 제공한다. 전술작전화면 프레임워크를 이용하게 된다면 공통기반의 구조를 통해 화면 설계를 재사용 할 수 있다. 또한 쉽고 빠르게 재구성이 가능한 화면을 개발할 수 있을 것이다.

Glucitol Fatty Acid Polyesters의 조성 및 구조확인 (Composition and Structure Confirmation of Glucitol Fatty Acid Polyesters)

  • 정하열;윤희남;공운영;김정한
    • 한국식품과학회지
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    • 제25권2호
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    • pp.148-153
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    • 1993
  • 최근 sucrose polyesters(SPE)와 더불어 유지대체 물질로서의 사용이 검토되고 있는 glucitol fatty acid polyesters(GPE)를 합성한 후, 화학적 구조 및 상대적 에스테르 분포에 따른 치환도를 조사하였다. 본 연구에서 합성한 GPE는 순상 HPLC에 의해 단일 에스테르 그룹으로 분리되었으며, 분리된 에스테르 그룹의 치환도는 6으로서 GPE 전체가 glucitol fatty acid hexaester임을 알 수 있었다. GPE의 IR 스펙트럼에서 $1747\;cm^{-1}$에 나타나는 흡수대는 GPE 분자내에 glucitol과 지방산을 연결하고 있는 에스테르 결합이 존재함을 보여주었다. GPE는 H-NMR 스펙트럼에서는 glucitol의 hydroxyl proton의 시그널이 존재하지 않음을 볼 때 glucitol의 모든 수산기가 지방산과의 에스테르 결합에 참여하고 있음을 알 수 있었다. 또한 GPE의 H-NHR 스펙트럼을 정량적으로 해석한 결과는 수산기가(hydroxyl value) 측정에 의해 결정된 GPE의 치환도와 일치하였다. 이상의 결과를 종합하여 볼 때 본 연구에서 합성한 GPE는 glucitol fatty acid hexaester임이 확인되었고 향후 유지대체물질로서 사용되어질 가능성을 지닌 것으로 생각되었다.

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