• Communications for Statistical Applications and Methods
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• 제20권4호
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• pp.283-290
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• 2013

Subjects can experience two types of recurrent events in a longitudinal study. In addition, there may exist intermittent dropouts that results in repeated observation gaps during which no recurrent events are observed. Therefore, theses periods are regarded as non-risk status. In this paper, we consider a special case where information on the observation gap is incomplete, that is, the termination time of observation gap is not available while the starting time is known. For a statistical inference, incomplete termination time is incorporated in terms of interval-censored data and estimated with two approaches. A shared frailty effect is also employed for the association between two recurrent events. An EM algorithm is applied to recover unknown termination times as well as frailty effect. We apply the suggested method to young drivers' convictions data with several suspensions.

• E2M - 전기 전자와 첨단 소재
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• 제8권5호
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• pp.551-557
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• 1995

For the observation of treeing, a visual measurement with an optical microscope has been used to explain breakdown mechanism in high-voltage systems. The conventional directed visual method of tree aging observation is difficult to measure in short time processing, and it is impossible to analyze on tree degradation area, progressed direction, tree pattern, etc. By using an image processing technique, the tree features which appear immediately after the tree initiation as well as changes in the configuration of the tree can be easily measured and observed than using the conventional visual methods. In this paper, we have developed a tree observating system by using image processing for tree growth, degradation area and other treeing progress. As an experimental result, it can be concluded that the image processing method is a more effective alternative than directed visual observation method. As a matter of fact, it is possible to record the image of tree propagation immediately after its first appearance and explain the characteristics of tree growth froth the computer processing image.

• Communications for Statistical Applications and Methods
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• 제4권2호
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• pp.465-471
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• 1997

This paper deals with the problems of obtaining some Bayesian and empirical Bayesian Predictive densities and prediction intervals of a future observation $X_{(\tau+\gamma)}$ in the Rayleigh distribution. Using an inverse gamma prior distribution, some prodictive densities and prodiction intervals are proposed and studied. Also the behaviors of the proposed results are examined via numerical examples.

• Communications for Statistical Applications and Methods
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• 제4권1호
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• pp.49-63
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• 1997

We consider the problem of classifying a p x 1 observation into one of two multivariate normal populations when the training smaples contain a block of missing observation. A new classification procedure is proposed which is a linear combination of two discriminant functions, one based on the complete samples and the other on the incomplete samples. The new discriminant function is easy to use.

• Communications for Statistical Applications and Methods
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• 제6권3호
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• pp.667-676
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• 1999

We investigate the effects of omission of initial observations in each individuals in the panel data regression model when the disturbances follow a serially correlated one way error components. We show that the first transformed observation can have a relative large hat matrix diagonal component and a large influence on parameter estimates when the correlation coefficient is large in absolute value.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.22.2-22
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• 2001

Recently, Reinforcement Learning (RL) methods in MDP have been extended and applied to the POMDP problems. Currently, hierarchical RL methods are widely studied. However, they have the drawback that the learning time and memories are exhausted only for keeping the hierarchical structure, though they aren´t necessary. On the other hand, our "Labeling Q-learning (LQ-learning) proposed previously, has no hierarchical structure, but adopts a characteristic internal memory mechanism. Namely, LQ-1earning agent percepts the state by pair of observation and its label, and the agent can distinguish states, which look as same, but obviously different, more exactly. So to speak, at each step t, we define a new type of perception of its environment ～ot = (ot, $\theta$t), where of is conventional observation, and $\theta$t is the label attached to the observation. Then the conventional ...

• The Journal of Korean Physical Therapy
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• 제32권2호
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• pp.65-69
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• 2020

Purpose: This study examined the effects of action-observation training using the Y-Balance on the balance ability of young adults. Methods: Thirty-four healthy adults were randomized into an action-observation group (n=17) or a control group (n=17). All subjects performed the Y-Balance test before and after watching the video. The action observation group watched a video of someone performing a Y-Balance test, and the control group watched a video of scenery unrelated to the training. The subjects were measured through a Y-Balance test for both the length of the legs extended in three directions and the Y-balance composite score. Results: A significant difference in the Y-balance composite score was observed between the two groups. A part of the direction of the extended leg in the action observation group was increased significantly (posteromedial direction of the right leg, posterolateral direction of the right leg, posteromedial direction of left leg) compared to the control group. Conclusion: These results suggest that action observation training only could help improve balance.

• The Journal of Korean Physical Therapy
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• 제32권6호
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• pp.365-371
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• 2020

Objective: To investigate the action observation effects of functional electrical stimulation (FES) on the communication between motor cortex and muscle through corticomuscular coherence (CMC) analysis. Methods: Electroencephalogram (EEG) and electromyogram (EMG) of 27 healthy, nonathlete subjects were measured during action observation, FES, and action observation with FES, which lasted for 7sper session for 10 times. All trials were repeated for 30 times. Simultaneously measured EEG raw data and rectified EMG signals were used to calculate CMC. Only confidence limit values above 0.0306 were used for analysis. CMC was divided into three frequency domains, andthe grand average coherence and peak coherence were computed. Repeated ANOVA was performed to analyze the coherence value difference for each condition's frequency band. Results: CMC showed significant differences in peak coherence and average coherence between the conditions (p<0.05). Action observation application with FES in all frequency band showed the highest peak and average coherence value. Conclusions: The results of this study are assumed to be the combination of increased eccentric information transfer from the sensorymotor cortex by action observation and an increased in concentric sensory input from the peripheral by the FES, suggesting that these are reflecting the sensorimotor integration process.

• 연구윤리
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• 제2권2호
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• pp.5-10
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• 2021

Purpose: Ethical behaviors become more salient when researchers utilize face-to-face interviews and observation with vulnerable groups or communities, which may be unable to express their emotions during the sessions. The present research aims to investigate ethical behaviors while conducting research have resonance due to the deep nature of observation and interview data collection methods. Research design, data and methodology: The present research obtained non-numeric (Textual) data based on prior literature review to investigate Ethical Conducts in Qualitative Research. Non-numeric data differs from numeric data in how the data is collected, analyzed and presented. It is important to formulate written questions and adopt them what the method claims for the researcher to understand the studied phenomenon. Results: Our findings show that while conducting qualitative research, researchers must adhere to the following ethical conducts; upholding informed consent, confidentiality and privacy, adhering to beneficence's principle, practicing honesty and integrity. Each ethical conduct is discoursed in detail to realize more information on how it impacts the researcher and research participants. Conclusions: The current authors concludes that five ethical conducts are important for realizing extensive and rich information during qualitative research and may be exploited in implementing research policies for researchers utilizing observation and interviews methods of data collection.

• 한국초등과학교육학회지:초등과학교육
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• 제41권4호
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• pp.593-615
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• 2022

본 연구는 야외 식물 관찰 학습에서 초등학생의 관찰 능력과 과학 창의성의 관계를 알아보고, 관찰능력과 과학 창의성에 영향을 미치는 요인에 대해 알아보았다. 이를 위해 서울특별시 5학년 21명을 대상으로 야외 식물 관찰 학습을 시행했다. 관찰 과제를 통해 학생의 관찰 능력과 과학적 창의성을 평가하여 정량적 자료를 얻은 뒤, 식물 관찰에 대한 학생과의 면담을 통해 정성적 자료를 얻었다. 이외에도 연구자의 참여 관찰 기록, 학생의 활동 결과물 등 다양한 자료를 수집함으로써 연구의 타당성을 높이고자 했다. 본 연구의 주요 결과는 다음과 같다. 첫째, 초등학생을 관찰 능력과 과학 창의성 상·하 수준에 따라 HH(고관찰-고창의)형, HL(고관찰-저창의)형, LH(저관찰-고창의)형, LL(저관찰-저창의)형의 4개 집단으로 유형화한 결과 전체 학생 21명 중 HH형과 LL형에 속한 학생이 15명으로 관찰 능력이 높을수록 과학적 창의성이 높은 것으로 나타났다. 둘째, 관찰 능력과 과학 창의성은 정적인 상관관계를 보였으며. 특히 과학 창의성 요소 중 독창성과도 관찰 능력과 약한 정적 상관관계를 보였다. 셋째, 야외 식물 관찰 학습에서 초등학생의 관찰 능력에 영향을 미치는 요인은 평상시 식물 관찰 빈도와 식물 관찰 학습에 대한 흥미, 식물 관찰 학습에서의 협력이었다. 넷째, 야외 식물 관찰 학습에서 과학 창의성에 영향을 미치는 요인은 관찰 능력과 식물 관련 지식의 양임을 알 수 있었다. 이러한 분석을 바탕으로, 본 연구는 관찰 능력과 과학 창의성을 향상시키기 위한 교육적 방법에 대해 논의하였다.