• Clinics in Shoulder and Elbow
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• 제25권2호
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• pp.145-153
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• 2022

Background: While online orthopedic resources are becoming an increasingly popular avenue for patient education, videos on YouTube are not subject to peer review. The purpose of this cross-sectional study was to evaluate the quality of YouTube videos for patient education in ulnar collateral ligament (UCL) injuries of the elbow. Methods: A search of keywords for UCL injury was conducted through the YouTube search engine. Each video was categorized by source and content. Video quality, reliability, and accuracy were assessed by two independent raters using five metrics: (1) Journal of American Medical Association (JAMA) benchmark criteria (range 0-4) for video reliability; (2) modified DISCERN score (range 1-5) for video reliability; (3) Global Quality Score (GQS; range 1-5) for video quality; (4) ulnar collateral ligament-specific score (UCL-SS; range 0-16), a novel score for comprehensiveness of health information presented; and (5) accuracy score (AS; range 1-3) for accuracy. Results: Video content was comprised predominantly of disease-specific information (52%) and surgical technique (33%). The most common video sources were physician (42%) and commercial (23%). The mean JAMA score, modified DISCERN score, GQS, UCL-SS, and AS were 1.8, 2.4, 1.9, 5.3, and 2.7 respectively. Conclusions: Overall, YouTube is not a reliable or high-quality source for patients seeking information regarding UCL injuries, especially with videos uploaded by non-physician sources. The multiplicity of low quality, low reliability, and irrelevant videos can create a cumbersome and even inaccurate learning experience for patients.

• 대한원격탐사학회지
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• 제34권6_2호
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• pp.1251-1260
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• 2018

항공영상으로 제작한 고품질의 해빙표면모델은 인공위성 기반 원격탐사 기술 개발을 위한 현장자료 뿐만 아니라 북극 해빙의 정밀한 형상학적 변동 특성 분석에도 효과적으로 사용될 수 있다. 그러나 해빙 표면의 부족한 텍스쳐 정보는 영상정합을 어렵게 만드는 요인으로 작용한다. 이에 본 논문에서는 고품질 해빙표면 모델 생성을 위한 일환으로 균질한 해빙 표면에 대한 정합비용함수들의 성능 비교 분석을 수행한다. 정합비용함수로는 영상 도메인의 SSD(sum of squared differences), NCC(normalized cross-correlation), ZNCC(zero-mean normalized cross-correlation), 주파수 도메인의 PC(phase correlation), OC(orientation correlation), GC(gradient correlation)를 분석하였다. 텍스쳐 정보량에 따른 정합 성능을 보다 명확하고 객관적으로 분석하기 위해 객체 공간 기반 정합 기법의 원리를 바탕으로 하는 새로운 평가 방법을 도입하였다. 실험결과는 해빙 표면과 같이 텍스쳐 정보가 희박한 지역에 대해서는 정합 지역에 따라 적합한 크기의 탐색창을 가변적으로 적용해야만 정합의 신뢰성 및 정확도 확보가 가능함을 보여주었다. 정합비용함수들 사이에서는 NCC와 ZNCC가 텍스쳐 정보 변화에 대해서 가장 우수한 성능을 나타냈다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2595-2618
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• 2018

In this paper, we investigate secure communication with the presence of multiple eavesdroppers (Eves) in a two-tier downlink dense heterogeneous network, wherein there is a macrocell base station (MBS) and multiple femtocell base stations (FBSs). Each base station (BS) has multiple users. And Eves attempt to wiretap a macrocell user (MU). To keep Eves ignorant of the confidential message, we propose a physical-layer security scheme based on cross-layer cooperation to exploit interference in the considered network. Under the constraints on the quality of service (QoS) of other legitimate users and transmit power, the secrecy rate of system can be maximized through jointly optimizing the beamforming vectors of MBS and cooperative FBSs. We explore the problem of maximizing secrecy rate in both non-colluding and colluding Eves scenarios, respectively. Firstly, in non-colluding Eves scenario, we approximate the original non-convex problem into a few semi-definite programs (SDPs) by employing the semi-definite relaxation (SDR) technique and conservative convex approximation under perfect channel state information (CSI) case. Furthermore, we extend the frame to imperfect CSI case and use the Lagrangian dual theory to cope with uncertain constraints on CSI. Secondly, in colluding Eves scenario, we transform the original problem into a two-tier optimization problem equivalently. Among them, the outer layer problem is a single variable optimization problem and can be solved by one-dimensional linear search. While the inner-layer optimization problem is transformed into a convex SDP problem with SDR technique and Charnes-Cooper transformation. In the perfect CSI case of both non-colluding and colluding Eves scenarios, we prove that the relaxation of SDR is tight and analyze the complexity of proposed algorithms. Finally, simulation results validate the effectiveness and robustness of proposed scheme.

• 대한한방내과학회지
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• 제39권1호
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• pp.44-68
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• 2018

Objective: This study aimed to investigate the trend in the research on breast cancer using traditional Korean medicine (TKM) and establish the direction for further study. Methods: Breast cancer studies using Korean medicine were searched using the Oriental Medicine Advanced Searching Integrated System (OASIS). The search term was 'breast' and there was no restriction in year. The searched studies were analyzed according to the type of research. Results: 1. 83 studies were searched. The types and numbers of study were as follows: 42 were in vitro studies, 5 were in vivo studies, 12 were studies for review, and 27 were clinical research including case reports. 2. Various cell lines such as MCF-7, MDA-MB-231, SKBR3, and MCF-10A were used for in vitro studies. The studies reported a decrease in cell viability, induction of apoptosis, and change of expression in cancer-related genes. In vivo studies also reported induction of apoptosis, and anti-proliferative activity of herbal medicine against the cancer cells. 3. Among the clinical research, 8 were cross-sectional studies, 3 were controlled-trial, and 15 were case reports. The baseline characteristics of breast cancer patients were analyzed in the cross-sectional studies. Interventions such as pharmacopuncture, herbal medicine, massage, Qi gong, acupuncture, electroacupuncture and moxibustion were used in clinical research. 4. Research on the review of breast cancer covered various subjects as follows: herbal medicine, acupuncture, pattern identification of breast cancer in traditional Korean medicine, analysis of previous experimental studies, and clinical trials. Conclusion: We have found the applicability of TKM for treatment of breast cancer through this review. It is necessary to conduct further studies, such as well-designed clinical trials based on the results from experimental research.

• Safety and Health at Work
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• 제11권3호
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• pp.262-265
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• 2020

Coronavirus disease 2019 (Covid-19) poses an important occupational health risk to health workers (HWs) that has attracted global scrutiny. To date, several thousand HWs globally have been reported as infected with the severe acute respiratory syndrome coronavirus 2 virus that causes the disease. It is therefore a public health priority for policymakers to understand risk factors for this vulnerable group to avert occupational transmission. A rapid review was carried out on 20 April 2020 on Covid-19 risk factors among HWs in PubMed, Google Scholar, and EBSCOHost Web (Academic Search Complete, CINAHL Complete, MEDLINE with Full Text, CINAHL with Full Text, APA PsycInfo, Health Source-Consumer Edition, Health Source: Nursing/Academic Edition) and WHO Global Database. We also searched for preprints on the medRxiv database. We searched for reports, reviews, and primary observational studies (case control, case cross-over, cross-sectional, and cohort). The review included studies conducted among HWs with Covid-19 that reported risk factors irrespective of their sample size. Eleven studies met the inclusion criteria. Lack of personal protective equipment, exposure to infected patients, work overload, poor infection control, and preexisting medical conditions were identified as risk factors for Covid-19 among HWs. In the context of Covid-19, HWs face an unprecedented occupational risk of morbidity and mortality. There is need for rapid development of sustainable measures that protect HWs from the pandemic.

• 대한토목학회논문집
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• 제11권3호
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• pp.37-46
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• 1991

이 논문(論文)은 변단면(變斷面) 보의 자유진동(自由振動)을 해석한 연구(硏究)이다. 보의 기하학적(幾何學的) 형상(形狀)은 보의 단면(斷面)이 직선적으로 변하는 변단면(變斷面) 보(tapered beam)를 택하였으며 균일폭 변화높이의 구형단면(矩形斷面), 균일(均一)높이 변화폭(變化幅)의 구형단면(矩形斷面), 정방형단면(正方形斷面) 또는 원형단면(圓形斷面)의 3가지 단면형상(斷面形狀)을 고려하였다. 보의 동적(動的) 평형방정식(平衡方程式)을 이용하여 변단면(變斷面) 보의 자유진동(自由振動)을 지배하는 미분방정식(微分方程式)을 유도하고, 이를 수치해석 기법인 Runge-Kutta method와 행렬(行列)값 탐사법(探査法)을 이용하여 고유진동수(固有振動數)와 진동형(振動形)을 산출할 수 있는 수치해석 기법을 개발하였다. 또한 타(他) 문헌(文獻)의 결과와 본 연구의 결과를 비교하여 본 연구방법의 타당성을 입증하였다. 실제의 수치해석 예는 힌지-힌지, 힌지-고정, 고정-고정, 자유-고정의 4가지 단부조건(端部條件)에 대하여 수치해석하였다. 수치해석의 결과로 $C_i-d_b/d_a$의 관계를 도시(圖示)하였고, 단부조건(端部條件)과 단면형상(斷面形狀)이 무차원 고유진동수에 미치는 영향을 분석하였다.

• Computers and Concrete
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• 제21권4호
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• pp.407-417
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• 2018

Concrete which is a composite material is one of the most important construction materials. Compressive strength is a commonly used parameter for the assessment of concrete quality. Accurate prediction of concrete compressive strength is an important issue. In this study, we utilized an experimental procedure for the assessment of concrete quality. Firstly, the concrete mix was prepared according to C 20 type concrete, and slump of fresh concrete was about 20 cm. After the placement of fresh concrete to formworks, compaction was achieved using a vibrating screed. After 28 day period, a total of 100 core samples having 75 mm diameter were extracted. On the core samples pulse velocity determination tests and compressive strength tests were performed. Besides, Windsor probe penetration tests and Schmidt hammer tests were also performed. After setting up the data set, twelve artificial intelligence (AI) models compared for predicting the concrete compressive strength. These models can be divided into three categories (i) Functions (i.e., Linear Regression, Simple Linear Regression, Multilayer Perceptron, Support Vector Regression), (ii) Lazy-Learning Algorithms (i.e., IBk Linear NN Search, KStar, Locally Weighted Learning) (iii) Tree-Based Learning Algorithms (i.e., Decision Stump, Model Trees Regression, Random Forest, Random Tree, Reduced Error Pruning Tree). Four evaluation processes, four validation implements (i.e., 10-fold cross validation, 5-fold cross validation, 10% split sample validation & 20% split sample validation) are used to examine the performance of predictive models. This study shows that machine learning regression techniques are promising tools for predicting compressive strength of concrete.

• 한국발생생물학회지:발생과생식
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• 제6권1호
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• pp.7-16
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• 2002

점액질이 풍부한 꼼치 조직에서 NIH 3T3 세포주를 이용하여 subtracted cDNA 라이브러리를 얻어 200례의 클론을 제작하였다. 이 클른 중에서 비반복성 유전자를 선택하고, RNA in situ hybridization을 실행하여 꼼치 조직에서 특이하게 발현되는 곰신 클론(C90-171)을 선택하였다. 이 클론은 사람의 타액선 조직에서도 특이하게 발현되는 유전자로서 이를 확인하기 위하여 C90-171(곰신) 항체를 제작하였다. 꼼치의 cDNA 라이브러리에서 곰신의 항체를 통하여 스크리닝한 결과 PRP(proline-rich protein)와 가장 많이 교차반응하며, 면역조직화학적 염색으로 PRP와 유사한 양성반응으로 나타나 PRP와 유사한 기능을 하는 단백질로 사료된다. 또한 타액 내에서의 꼼치 단백질의 분해에 대한 실험결과 거의 분해가 일어나지 않는 것으로 보아, 곰신은 꼼치의 몸통을 보호하는 유전물질일 뿐만 아니라, PRP와 유사하게 조직을 보호하는 안정된 새로운 기능성 단백질로 사료된다.

• 한국통신학회논문지
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• 제34권9A호
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• pp.656-663
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• 2009

3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) 시스템의 하양링크에서는 초기 동기화 및 셀 탐색 과정을 수행하기 위해 PSS (primary synchronization signal) 와 SSS (secondary synchronization signal) 시퀀스를 사용한다. 단말기는 PSS를 이용하여 슬롯 타이밍과 주파수 동기, 그리고 셀 ID를 획득한 후 SSS를 검출해야 하는데, 3GPP LTE에서 지원되는 2 종류의 CP (Cyclie Prefix) 길이로 인해 2번의 FFT를 수행하여 SSS reference 신호와의 cross-correlation을 이용해 무선 프라밍 타이밍과 셀 그룹 ID를 획득한다. 본 논문에서는 단말기의 셀 탐색기에서 SSS 검출 시 복잡도를 최소화하기 위해 extended CP로 전송한 경우 CP 길이를 선 결정하여 FFT와 cross-correlation의 계산 복잡도를 최대 50%까지 감소시키는 알고리즘을 제안한다. 컴퓨터 모의실험을 통해 매우 작은 성능 열화를 가지면서, 복잡도는 크게 감소하는 결과를 확인할 수 있었다.

• 디지털콘텐츠학회 논문지
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• 제17권1호
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• pp.33-41
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• 2016

디지털 사이니지의 다양한 미디어 크리에이티브의 현황과 양태를 분석하여 수용자와 효율적으로 상호작용할 수 있는 실제적인 방안을 모색하였다. 이를 위해 디지털 사이니지의 다양한 사례들을 미디어 융합 관점에서 파악하는 한편, 디지털 사이니지의 주요 크리에이티브 속성으로서 상호작용성을 근거로 각각의 융합 사례가 시사하는 전략적 의미를 파악하였다. 선행연구와 네이버 검색서비스를 바탕으로, 수집된 자료를 (1)유튜브, SNS, 바이럴 영상 결합, (2)QR코드 등 재현적 기술 결합, (3)브랜드 어플리케이션(앱) 결합, (4)오프라인과 온라인 결합, (5)사이니지와 행동 요소 결합 등의 결합 유형으로 분류하고 대표적인 해당 사례를 선별하여 내용 분석을 실시하였다. 분석 결과를 토대로 감성적 바이럴 마케팅, 브랜디드 엔터테인먼트 형태 등에 기반한 미디어 크리에이티브 등 수용자와 효율적인 상호작용을 할 수 있는 전략적 방안을 제언하였다.