Arterial Embolic Infarction After COVID-19 Vaccination Associated With Antiplatelet Factor 4 Antibody

박관영,정동영,하상희,김범준 대한신경과학회 2022 Journal of Clinical Neurology Vol.18 No.2

리만 좌표하강 알고리즘을 이용한 조각 측지선 적합

박관영,신재경,구자용 한국자료분석학회 2022 한국자료분석학회 학술대회자료집 Vol.2022 No.7

Adaptive log-density estimation

박관영,구자용 한국통계학회 2020 Journal of the Korean Statistical Society Vol.49 No.2

This study examines an adaptive log-density estimation method with an ℓ1-type penalty. The proposed estimator is guaranteed to be a valid density in the sense that it is positive and integrates to one. The smoothness of the estimator is controlled in a data-adaptive way via ℓ1 penalization. The advantages of the penalized log-density estimator are discussedwith an emphasis onwavelet estimators. Theoretical properties of the estimator are studied when the quality of fit is measured by theKullback–Leibler divergence (relative entropy). A nonasymptotic oracle inequality is obtained assuming a near orthogonality condition on the given dictionary. Based on the oracle inequality, selection consistency and minimax adaptivity are proved under some regularity conditions. The proposed method is implemented with a coordinate descent algorithm. Numerical illustrations based on the periodized Meyer wavelets are performed to demonstrate the finite sample performance of the proposed estimator.

새로운 메타물질 Single-Layer를 이용한 2.4GHz 대역을 위한 고 이득 메타물질 패치 안테나

박관영,양승인 대한전자공학회 2013 전자공학회논문지 Vol.50 No.6

In this paper, a high gain patch antenna using a single layer metamaterial superstrate with a near-to-zero refractive index (n) is proposed. Simulations for an ordinary patch antenna and our proposed metamaterial patch antenna were conducted. Our proposed metamaterial patch antenna was implemented and measured. The gain of our proposed metamaterial patch antenna is 6.77dB higher than that of an ordinary patch antenna. 이 논문에서는 ‘0’에 가까운 굴절률을 갖는 단일층 메타물질 커버를 이용한 고 이득 패치 안테나를 제안하였다. 보통의 패치안테나와 제안된 메타물질 패치 안테나를 전산모의를 통해 비교하였고, 제안된 메타물질 패치 안테나를 제작 및 측정하였다. 제안된 메타물질 패치 안테나는 보통의 패치 안테나에 비해 6.77dB 만큼 더 높은 이득을 가진다.

장애인복지관련 서비스기관 간 네트워크 특성에 관한 연구

박관영,이동영 한국장애인복지학회 2017 한국장애인복지학 Vol.- No.36

This study is based on the assumption that it is necessary to build a comprehensive integrated service system for the integrated needs for the disabled to realize their independent living and social integration in the community. The purpose of the study is to identify the realistic problems based on the characteristics of the service linkage (network) between the organizations providing related services with legal bases and to provide a basis for drawing the effective implication for the effective service integration. For this, the study investigated the welfare services center for the disabled using the structured questionnaires in Wonju, Gangwondo. The study focused on information sharing, service request, consultation, coordination and material and human resource exchange, and conducted the network analysis about characteristics, centrality and cohesion. As a result of the analysis, the linkage and density among the nodes showed the highest in information sharing and the lowest in the human resource exchange of the resource exchanges. The highest level of connectivity was the coordination which was 50.0%. The lowest level of resource exchange was the material one which was 43.478%. As a result of the centrality analysis, the influence of the connection centrality was the weakest which was 11.5-44.0%. The one of the proximity centrality was slower compared with other institutions, which was 3.9-22.8%. And the one of the betweenness centrality was very low at the connectivity and control of the whole network, which was 4.3%-9.1%. In other words, the network situation was very poor overall, such as the centrality between the organizations for the welfare center for the handicapped, and the level of collaboration was very low with the one of the sharing. Based on the clarification of the roles among the related organizations including granting of the central organization function, the study suggested that it is necessary to improve the cohesiveness through the systematization of case management for each type and actual structuring of regular working council within the period. It also suggested that it should promote the activation policy to improve the basic linkage and density through the improvement of the evaluation of the integrated services by cooperation. 본 연구는 장애인의 지역사회 내 원활한 자립생활과 사회통합을 구현하기 위해 통합적 욕구에 적합한 통합적 서비스 체계구축이 필수적 요소로 인식함을 전제로, 법적 근거를 갖고 관련 서비스를 제공하는 해당 기관 간 서비스 연계(네트워크)를 실증적으로 분석함으로써 그 특성에 기반 한 현실적 문제를 확인하고, 효과적 서비스 통합을 위한 실효성 높은 함의를 도출하는데 단초를 제공하고자 하였다. 이를 위해 본 연구는 강원도 원주지역 내 장애인복지 관련 서비스 기관 23곳 전체를 대상으로 구조화된 설문조사를 통해 정보공유, 서비스 의뢰, 협의 및 조정, 물적 및 인적 자원교류 등의 내용에 초점을 맞춰 네트워크 기본 특성과 중심성에 대한 네트워크 분석(network analysis)을 시행하였다. 분석결과, 기관(node) 간 연계와 밀도는 정보공유가 상대적으로 가장 높았고, 자원교류 중 인적자원교류가 가장 낮은 것으로 나타났으며, 연결성은 협의 및 조정이 50.0%로 가장 높고, 자원교류 중 물적 자원교류가 43.478%로 가장 낮았다. 다음으로 중심성 분석결과 연결 중심성 11.5-44.0%로 연결된 노드가 적어 영향력이 약하며, 근접 중심성은 3.9-22.8%로 타 기관에 대한 영향력의 신속성이 떨어지며, 매개 중심성은 4.3-9.1%로 네트워크 전체의 연결과 통제력에 대한 영향력이 매우 낮은 것으로 나타났다. 즉 장애인복지관련 기관 간 중심성 등 네트워크 실태는 전반적으로 매우 열악한 상황이고, 낮은 수준의 공유 외 실질적 협력은 매우 부족한 것으로 나타난 것이다. 이에 중심조직 기능부여를 포함한 관련 기관 간 역할의 명확화를 바탕으로, 서비스 유형별 사례관리의 체계화 및 기관 내 상시적 실무협의체의 실제적 구조화 등을 통해 실질적 응집성을 높이고, 기관협력에 의한 통합서비스의 평가반영 향상을 통해 기본적 연계와 밀도 등을 향상시키는 활성화 정책도 동시에 추진해야할 것임을 제언하였다.

Nonparametric matrix regression function estimation over symmetric positive definite matrices

박관영,김광래,Kim Peter T.,구자용,박창이,Zhu Hongtu 한국통계학회 2021 Journal of the Korean Statistical Society Vol.50 No.3

Symmetric positive definite matrix data commonly appear in computer vision and medical imaging, such as diffusion tensor imaging. The aim of this paper is to develop a nonparametric estimation method for a symmetric positive definite matrix regression function given covariates. By obtaining a suitable parametrization based on the Cholesky decomposition, we make it possible to apply univariate smoothing methods to the matrix regression problem. The parametrization also guarantees that the proposed estimator is symmetric positive definite over the entire domain. We adopt the Wishart log-likelihood and a smoothing technique using the basis methodology to define our estimator. The rate of convergence of the proposed estimator is obtained under some regularity conditions. Simulations are performed to investigate the finite sample properties of our proposed method using natural splines. Moreover, we present the results of an analysis of real diffusion tensor imaging data where the estimated fractional anisotropy is provided using 3 × 3 symmetric positive definite matrices measured at consecutive positions along a fiber tract in the brain of subjects.

기상재해와 대책

박관영,Park, Gwan-Yeong 한국기술사회 2008 技術士 Vol.41 No.4

The extreme weather events have increased around the world this century. One of the main reasons of frequent occurrence is the change of atmospheric circulation by El nino. also Korea Peninsular is not exception. The 97 % of death toll and 89 % of property loss of total are related with extreme-weather events for the last 10 years. for example the heavy rainfall (1998-4999) and Typhoon Rusa and Mamie. In spite of the percent of death toll by extreme-weather disaster is increasing and the total population is growing. but the number of death toll from natural disasters is decreasing. It shows that the loss of property and life can be minimize by preparing the proper disaster prevention measures. There are several preparations to reduce the damage by extreme-weather events: Public facilities have overall check up, to recognize the weather alert, the awareness of the escape route and the art of measures

새로운 메타물질 Single-Layer를 이용한 2.4㎓ 대역을 위한 고 이득 메타물질 패치 안테나

박관영(Kwan-Young Park),양승인(Seung-In Yang) 대한전자공학회 2013 전자공학회논문지 Vol.50 No.3

이 논문에서는 ‘0’에 가까운 굴절률을 갖는 단일층 메타물질 커버를 이용한 고 이득 패치 안테나를 제안하였다. 보통의 패치 안테나와 제안된 메타물질 패치 안테나를 전산모의를 통해 비교하였고, 제안된 메타물질 패치 안테나를 제작 및 측정하였다. 제안된 메타물질 패치 안테나는 보통의 패치 안테나에 비해 6.77㏈ 만큼 더 높은 이득을 가진다. In this paper, a high gain patch antenna using a single layer metamaterial superstrate with a near-to-zero refractive index (n) is proposed. Simulations for an ordinary patch antenna and our proposed metamaterial patch antenna were conducted. Our proposed metamaterial patch antenna was implemented and measured. The gain of our proposed metamaterial patch antenna is 6.77㏈ higher than that of an ordinary patch antenna.

모체 thyroxine 투여가 태아알코올효과를 가진 흰쥐 대뇌겉질 및 해마에서 NPY함유 신경세포의 생후 발달에 미치는 영향

김복 · 박상기 · 박영란 · 김종중 · 문정석 · 김주수 · 문영민 · 현영식 · 천관영 · 정윤영 조선대학교 의학연구원 2005 The Medical Journal of Chosun University Vol.30 No.2

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세라믹-세라믹 관절면의 무시멘트 인공고관절 전치환술의 5년이상추시결과

김진학,이송김경태,최대정차상규,박관영 대한고관절학회 2005 Hip and Pelvis Vol.17 No.3