• 제목/요약/키워드: F-Measure

검색결과 1,401건 처리시간 0.028초

An Active Co-Training Algorithm for Biomedical Named-Entity Recognition

  • Munkhdalai, Tsendsuren;Li, Meijing;Yun, Unil;Namsrai, Oyun-Erdene;Ryu, Keun Ho
    • Journal of Information Processing Systems
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    • 제8권4호
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    • pp.575-588
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    • 2012
  • Exploiting unlabeled text data with a relatively small labeled corpus has been an active and challenging research topic in text mining, due to the recent growth of the amount of biomedical literature. Biomedical named-entity recognition is an essential prerequisite task before effective text mining of biomedical literature can begin. This paper proposes an Active Co-Training (ACT) algorithm for biomedical named-entity recognition. ACT is a semi-supervised learning method in which two classifiers based on two different feature sets iteratively learn from informative examples that have been queried from the unlabeled data. We design a new classification problem to measure the informativeness of an example in unlabeled data. In this classification problem, the examples are classified based on a joint view of a feature set to be informative/non-informative to both classifiers. To form the training data for the classification problem, we adopt a query-by-committee method. Therefore, in the ACT, both classifiers are considered to be one committee, which is used on the labeled data to give the informativeness label to each example. The ACT method outperforms the traditional co-training algorithm in terms of f-measure as well as the number of training iterations performed to build a good classification model. The proposed method tends to efficiently exploit a large amount of unlabeled data by selecting a small number of examples having not only useful information but also a comprehensive pattern.

이동형 방사선검사에서 영상의 왜곡과 선량에 관한 연구 (A Study on Distortion and Dose of Images in Mobile Radiography)

  • 송현석;임청환;정홍량;김종성;김영란;정성훈
    • 대한방사선기술학회지:방사선기술과학
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    • 제45권4호
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    • pp.305-312
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    • 2022
  • The proportion and testing of portable radiation tests, which are limited at the request of the doctor, are gradually increasing only for patients in emergency situations and difficulties in moving. However, as there are many limiting factors compared to fixed devices, this study intends to measure and analyze the distortion of images according to the angle of the detector and the change in dose according to the position of the subject. For distortion experiments using a mobile radiation generator used in Hospital A, the SID was tilted by 110 cm, 14"×17" wireless FPD detector to 0°, -5°, -10°, -15°, -20°, and -35° to measure the change in area. The dose according to the location of the detector was analyzed on average by measuring the central dose at 110 cm of the SID and measuring the dose of 9 locations three times each. The analysis result of distortion by location according to the angle of the detector showed a statistically significant difference (f=58.74, p<0.000). Therefore, it can be seen that the angle of the detector and the tube is closely related to the distortion of the image. The difference in dose by location of the detector increased with respect to the center - pole, and decreased with the + pole. Tests using mobile radiation generators will require careful efforts by clinicians to position patients in the center of the detector for accurate diagnosis, and efforts will be made to level the angle between the mobile radiation generators and the detector.

간호학생이 지각한 가족지지와 임상실습만족도와의 관계 (A Study on the Relationship between Perceived Family Support and Satisfaction of Clinical Practice by Nursing Students)

  • 구혜자
    • 한국간호교육학회지
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    • 제14권2호
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    • pp.205-215
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    • 2008
  • Purpose: This study was to identify the relationship between the degree of family support and the degree of satisfaction in clinical practice by nursing students. Method: This study was designed to measure the level of satisfaction according to the content, guidance, circumstance, hours, and the evaluation of clinical practice. Four hundred sixty-five nursing students from 4 nursing colleges, and 1 baccalaureate program in G area were randomly sampled. An instrument consisting of 64 questions, developed by the researcher and a nursing professor, was used to gather data from March 10 through 31, 2008. The data was analyzed by descriptive statistics, t-test, ANOVA, and Pearson Correlation, using the SPSS 14.0 program. Result: The results were summarized as follows : Family support of nursing students showed a significant difference by religion (t=2.104, p=0.036) and satisfaction of major (F=8.010, p<0.001). The satisfaction degree of clinical practice by nursing students showed a significant difference by university or college (t=2.636, p=0.012), residence type (t=2.098, p=0.036), and satisfaction of major (F=5.779, p=0.003). The relationship between generally perceived family support correlated with the degree of satisfaction in clinical practice of nursing students (r=.199, p<0.001). Conclusion: It was found that a higher degree of satisfaction in clinical practice depends on a higher degree of family support. Therefore, nursing faculty should plan interventions to inspire satisfaction level of clinical practice by family support.

주관절 굴곡 각도가 어깨주위 근육의 활동전위에 미치는 영향: 편측 상지 고유수용성 신경근 촉진법 중심으로 (Electromyographic Activity of Shoulder Muscles by Elbow Flexion Angle: During Unilateral Upper Extremity Proprioceptive Neuromuscular Facilitation Patterns)

  • 송태승;유상원;김완수
    • 한국전문물리치료학회지
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    • 제7권2호
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    • pp.88-95
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    • 2000
  • Thirty normal adults were tested to measure the electrical activity of the anterior (AD), middle (MD), and posterior portion (PD) of the deltoid muscle and sternal portion of the pectoralis major muscle (PM) during the performance of four upper extremity PNF diagonal patterns with elbow flexion angle in $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$. The PNF patterns in which these muscles function optimally have been theoretically advanced by Kabat and further described by Knott and Voss. They theorize that the MD should be most active with shoulder flexion, abduction, and external rotation (D2F); the PD with shoulder extension, abduction, and internal rotation (D1E); the AD with shoulder flexion, adduction, and external rotation (D1F); and the PM with shoulder extension, adduction and internal rotation (D2E). The patterns were performed through range of motion, with an isometric contraction performed in the shortened range. When the EMG activity of AD, MD, PD and PM in its optimal patterns was measured, it does not have significant difference among fixed elbow flexion angle $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$ (p>.05). In addition, suggestions were made for study of patients who exhibit imbalance of muscle strength and have muscle weakness.

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Medical Exercise Therapy가 만성 뇌졸중 환자의 보행능력 및 족관절 근활성도에 미치는 영향 (Effects of Medical Exercise Therapy on Walking Ability and Ankle Muscles Activation after Chronic Stroke)

  • 조영환;박종항;김경윤;남기원
    • 대한물리의학회지
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    • 제6권3호
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    • pp.311-321
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    • 2011
  • Purpose : The purpose of this study was to determine effect of Medical Exercise therapy on walking ability and ankle muscles activation after stroke. Method : Participants were randomly divided into either MET training group(n=12) and control group(n=12). All of participants had been receving a traditional rehabilitation program, 5 days a week. MET training group have additionally undergone for six weeks, 3 days a week, the MET program. But control group was not received any additional program except the traditional rehabilitation program. The 10 mWT, F8WT and 2 MWT to measure walking ability were carried out twice before and after training. Muscular activity of the ankle was estimated by analyzing the RMS of action potential for EMG in terms of tibialis anterior muscle(TA), soleus(SO), gastrocnemius medial head(GM), gastrocnemius lateral head(GL). Rresults : At the walking ability, MET training group demonstrated a significant improvememt in the score of the 10 mWT(p<0.001), 2 MWT(p<0.05), but F8WT was not significant improvement(p>0.05). At the ankle muscle activation, MET training group demonstrated a significant improvememt in the RMS of the TA(p<0.01) and SO(p<0.05) but GM(p>0.05) and GL(p>0.05) were not significant improvement. Conclusion : From these results of this study, MET training for 6 weeks has an effect on improvement of walking ability and ankle muscles activation after stroke.

스마트 헬스를 위한 마이닝 기반의 정신 건강과 혈압 관리 서비스 (Mining based Mental Health and Blood Pressure Management Service for Smart Health)

  • 정은진;김주창;정호일;유현;정경용
    • 한국융합학회논문지
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    • 제8권1호
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    • pp.13-18
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    • 2017
  • 유비쿼터스 스마트 헬스케어에서 융합기술 급격히 발달하고, 이동식 모바일 장치가 보급됨에 따라 사용자는 스마트 헬스 플랫폼을 통해 의료 정보를 손쉽게 얻을 수 있게 되었다. 이러한 급격한 산업화, 웰니스 케어, 고령화 사회, 정보화 사회, 질병양상 및 생활습관의 변화, 의약분업 실시 등에 따라, 사용자 중심의 건강관리 및 건강증진 콘텐츠가 제공되고 있다. 이에 본 논문에서는 스마트 헬스를 위한 마이닝 기반의 정신 건강과 혈압 관리 서비스를 제안한다. 제안하는 방법은 마이닝 기반의 스마트 헬스 플랫폼에서 정신 건강관리 서비스와 혈압관리 서비스를 만성질환자를 위해 제공한다. 사용자는 PHR 기반의 스마트 헬스 플랫폼에서 시간과 장소에 구애 받지 않고 최적화된 건강관리 서비스를 제공받는다. 제안한 마이닝 기반의 정신 건강과 혈압 관리 서비스의 성능평가 결과, F-검증에서 우수한 성능을 보인다.

도시거주 중년기 성인의 노화에 대한 기대와 신체활동과의 관련성: Pender의 건강증진모델을 기반으로 (Relationship between Expectations Regarding Aging and Physical Activity among Middle Aged Adults in Urban Areas: Based on the Pender's Health Promotion Model)

  • 조성혜;최문기;이주희;조혜원
    • 대한간호학회지
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    • 제45권1호
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    • pp.14-24
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    • 2015
  • Purpose: The purpose of this study was to measure the level of expectations regarding aging (ERA) and identify relationship between ERA and physical activity of middle aged adults. Methods: Participants were middle aged adults who resided in the community in three cities in Korea. Data were collected using questionnaires that contained items on individual characteristic, International Physical Activity Questionnaires (IPAQ), and behavior-specific cognitive factors including ERA-12. Hierarchical multiple regression was conducted to examine whether ERA would predict physical activity by controlling other factors. Results: The mean age of the participants was $51.1{\pm}6.9$ years. The mean score for ERA (possible range=0 to 100) was $40.04{\pm}14.31$. More than half of the participants (62.6%) were not engaged in health promoting physical activity. Gender, employment status and exercise confidence were associated with level of physical activity (F=7.14, p<.001, $R^2=.36$). After controlling for individual factors and behavior-specific cognitive factors, ERA was independently related to physical activity (F=7.19, p<.001, $R^2=.38$). Conclusion: The results demonstrate that individuals' belief about aging has effects on physical activity in Korean middle aged adults. Thus, nursing interventions which focused on ERA could help enhance physical activity in middle aged adults.

비음수 텐서 분해 및 은닉 마코프 모델을 이용한 다음향 환경에서의 이중 채널 음향 사건 검출 (Dual-Channel Acoustic Event Detection in Multisource Environments Using Nonnegative Tensor Factorization and Hidden Markov Model)

  • 전광명;김홍국
    • 전자공학회논문지
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    • 제54권1호
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    • pp.121-128
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    • 2017
  • 본 논문에서는 다음향(multisource) 환경에서의 음향 사건 검출 정확도를 높이기 위해 비음수 텐서 분해(nonnegative tensor factorization, NTF)와 은닉 마코프 모델(hidden Markov model, HMM)을 이용한 이중 채널 음향 사건 검출 방법을 제안한다. 제안된 방법은 먼저 이중 채널 입력 신호들에 NTF 기법을 적용하여 얻은 각 음향 사건 별 채널 이득을 활용하여 다수의 음향 사건들을 검출한다. 그러고 나서, 채널 이득에 의해 검출된 음향 사건의 발생 여부를 검증하기 위하여 채널 이득을 우도 가중치로 활용하는 HMM 기반의 우도비 검증을 수행한다. 제안된 방법의 검출 정확도를 평가하기 위하여 다양한 잡음과 사건간 중첩 밀도를 고려하는 다중 사건 발생 환경에 대한 F-measure를 측정하였고, 기존의 혼합 가우시안 모델 및 비음수 행렬 분해 기반의 음향 사건 검출 방법들과 비교하였다. 실험 결과, 제안된 방법이 기존 방법들에 비하여 모든 실험 조건에서 높은 정확도를 보였다.

Ascophyllum nodosum and its symbionts: XI. The epiphyte Vertebrata lanosa performs better photosynthetically when attached to Ascophyllum than when alone

  • Garbary, David J.;Miller, Anthony G.;Scrosati, Ricardo A.
    • ALGAE
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    • 제29권4호
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    • pp.321-331
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    • 2014
  • Vertebrata lanosa is an abundant and obligate red algal epiphyte of Ascophyllum nodosum that forms part of a complex and highly integrated symbiotic system that includes the ascomycete, Mycophycias ascophylli. As part of ongoing studies to resolve interactions among species in the symbiosis, we used pulse amplitude modulation fluorimetry of chlorophyll a fluorescence, from photosystem II (PSII), to measure the maximum quantum yield ($F_v/F_m$) of PSII [$QY(II)_{max}$] and relative photosynthetic electron transport rates (rETR), as a function of light intensity, in order to evaluate the photosynthetic capacity of the two algal symbionts in the field and in the laboratory under different treatments. Our primary question was 'Is the ecological integration of these species reflected in a corresponding physiological integration involving photosynthetic process?' In the laboratory we measured changes in $QY(II)_{max}$ in thalli of V. lanosa and A. nodosum over one week periods when maintained together in either attached or detached treatments or when maintained separated from each other. While the $QY(II)_{max}$ of PSII of A. nodosum remained high and showed no significant variation among treatments, V. lanosa showed decreasing performance in the following conditions: V. lanosa attached to A. nodosum, V. lanosa in the same culture, but not attached to A. nodosum, and V. lanosa alone. These results are consistent with observations in which rETR was reduced in V. lanosa maintained alone versus attached to A. nodosum. Values for $QY(II)_{max}$ in V. lanosa measured in the field in fully submerged thalli were similar to those measured in the laboratory when V. lanosa was attached to it obligate host A. nodosum. Our results provide evidence of a physiological association of the epiphyte and its host that reflects the known ecology.

SUNSHINE, EARTHSHINE AND CLIMATE CHANGE I. ORIGIN OF, AND LIMITS ON SOLAR VARIABILITY

  • GOODE PHILIP R.;DZIEMBOWSKI W. A.
    • 천문학회지
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    • 제36권spc1호
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    • pp.75-81
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    • 2003
  • Changes in the earth's climate depend on changes in the net sunlight reaching us. The net depends on the sun's output and earth's reflectance, or albedo. Here we develop the limits on the changes in the sun's output in historical times based on the physics of the origin of solar cycle changes. Many have suggested that the sun's output could have been $0.5\%$ less during the Maunder minimum, whereas the variation over the solar cycle is only about $0.1\%$. The frequencies of solar oscillations (f- and p-modes) evolve through the solar cycle, and provide the most exact measure of the cycle-dependent changes in the sun. But precisely what are they probing? The changes in the sun's output, structure and oscillation frequencies are driven by some combination of changes in the magnetic field, thermal structure and velocity field. It has been unclear what is the precise combination of the three. One way or another, this thorny issue rests on an understanding of the response of the solar structure to increased magnetic field, but this is complicated. Thus, we do not understand the origin of the sun's irradiance increase with increasing magnetic activity. Until recently, it seemed that an unphysically large magnetic field change was required to account for the frequency evolution during the cycle. However, the problem seems to have been solved (Dziembowski, Goode & Schou 2001) using f-mode data on size variations of the sun. From this and the work of Dziembowski & Goode (2003), we suggest that in historical times the sun couldn't be much dimmer than it is at activity minimum.