• Title/Summary/Keyword: Self-supervised Learning

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Wearable Sensor based Gait Pattern Analysis for detection of ON/OFF State in Parkinson's Disease

  • Aich, Satyabrata;Park, Jinse;Joo, Moon-il;Sim, Jong Seong;Kim, Hee-Cheol
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2019.05a
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    • pp.283-284
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    • 2019
  • In the last decades patient's suffering with Parkinson's disease is increasing at a rapid rate and as per prediction it will grow more rapidly as old age population is increasing at a rapid rate through out the world. As the performance of wearable sensor based approach reached to a new height as well as powerful machine learning technique provides more accurate result these combination has been widely used for assessment of various neurological diseases. ON state is the state where the effect of medicine is present and OFF state the effect of medicine is reduced or not present at all. Classification of ON/OFF state for the Parkinson's disease is important because the patients could injure them self due to freezing of gait and gait related problems in the OFF state. in this paper wearable sensor based approach has been used to collect the data in ON and OFF state and machine learning techniques are used to automate the classification based on the gait pattern. Supervised machine learning techniques able to provide 97.6% accuracy while classifying the ON/OFF state.

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Optimization of Structure-Adaptive Self-Organizing Map Using Genetic Algorithm (유전자 알고리즘을 사용한 구조적응 자기구성 지도의 최적화)

  • 김현돈;조성배
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.3
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    • pp.223-230
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    • 2001
  • Since self-organizing map (SOM) preserves the topology of ordering in input spaces and trains itself by unsupervised algorithm, it is Llsed in many areas. However, SOM has a shortcoming: structure cannot be easily detcrmined without many trials-and-errors. Structure-adaptive self-orgnizing map (SASOM) which can adapt its structure as well as its weights overcome the shortcoming of self-organizing map: SASOM makes use of structure adaptation capability to place the nodes of prototype vectors into the pattern space accurately so as to make the decision boundmies as close to the class boundaries as possible. In this scheme, the initialization of weights of newly adapted nodes is important. This paper proposes a method which optimizes SASOM with genetic algorithm (GA) to determines the weight vector of newly split node. The leanling algorithm is a hybrid of unsupervised learning method and supervised learning method using LVQ algorithm. This proposed method not only shows higher performance than SASOM in terms of recognition rate and variation, but also preserves the topological order of input patterns well. Experiments with 2D pattern space data and handwritten digit database show that the proposed method is promising.

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Key Frame Detection Using Contrastive Learning (대조적 학습을 활용한 주요 프레임 검출 방법)

  • Kyoungtae, Park;Wonjun, Kim;Ryong, Lee;Rae-young, Lee;Myung-Seok, Choi
    • Journal of Broadcast Engineering
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    • v.27 no.6
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    • pp.897-905
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    • 2022
  • Research for video key frame detection has been actively conducted in the fields of computer vision. Recently with the advances on deep learning techniques, performance of key frame detection has been improved, but the various type of video content and complicated background are still a problem for efficient learning. In this paper, we propose a novel method for key frame detection, witch utilizes contrastive learning and memory bank module. The proposed method trains the feature extracting network based on the difference between neighboring frames and frames from separate videos. Founded on the contrastive learning, the method saves and updates key frames in the memory bank, witch efficiently reduce redundancy from the video. Experimental results on video dataset show the effectiveness of the proposed method for key frame detection.

The Development and Implementation of Problem-Based Learning Module Based on Lung Cancer Case (폐암환자사례를 바탕으로 한 PBL 모듈의 개발과 적용)

  • Hwang, Seon-Young;Chang, Keum-Sung
    • The Journal of Korean Academic Society of Nursing Education
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    • v.6 no.2
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    • pp.390-405
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    • 2000
  • PBL is a process and an effective educational tool that empower the student to be an active participant and emphasize a clinical context for learning, developing skills in working with a group, and encouraging self-directed study. The purpose of this study was to develop the PBL module based on lung cancer case, and to evaluate after implementation. The data on lung cancer patients at C university hospital in K city were collected from interviews and nursing records in June, 1999. A PBL module was developed including situation scenarios, timetable and tutor guide. PBL course was conducted at C university for short term period (3 days) in August, 2000. Fourteen nursing students at C college were participated in this study and they were divided into two small groups. I explained them about the PBL course through a preparatory meeting. At a stage of implementation, two groups went through the same process consisting of seven steps with group meetings and self-directed study. Their performances of identifying, stating problems and presenting referred resources were evaluated and supervised by researcher. The PBL course was evaluated by them with questionnaire and essay. Most students responded positively about PBL course and preferred the tutors in a supportive attitude. However, 3 days for PBL course seemed not enough for maximal educational benefits, and many possible problems were discussed. It is necessary for nursing educators to accumulate lots of knowledge and skills regarding creating good working problems and implementing and evaluating diverse PBL tutorials to test the feasibility changing to PBL curriculum.

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A Structure-Adaptive Self-Organizing Map with Combination of Supervised and Unsupervised Learning Algorithms (비교사 학습과 교사 학습 알고리즘을 결합한 구조 적응형 자기구성 지도)

  • 김현돈;조성배
    • Proceedings of the Korean Information Science Society Conference
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    • 1999.10b
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    • pp.333-335
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    • 1999
  • 일반적으로 자기구성 지도에서는 구조가 초기에 결정되어 학습이 끝날때까지 변하기 않기 때문에 각 문제에 대한 구조를 반복된 실험을 통해서 최적화시켜야 한다. 그러나, 지도의 구조가 학습중에 적절하게 변경된다면, 해당 문제에 가장 알맞은 구조의 지도를 생성할 수 있을 것이다. 이 논문에서는 기존의 적응형 자기 구성 지도의 비교사 학습방법에 LVQ 알고리즘을 이용한 교사 학습방법을 결합한 구조 적응형 자기 구성 지도 모델을 제안한다. 이 방법은 일반적인 자기구성 지도 알고리즘보다 작은 수의 노드를 가지고 높은 성능을 보일 뿐만 아니라, 자기 구성 지도의 특성인 위상 보존도 잘 이루어진다. 오프라인 필기 숫자 데이터로 실험한 결과, 제안한 방법이 유용함을 알 수 있었다.

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The Model of Motion Selection Considered with Emotion (감정을 고려한 행동선택 모델)

  • 김병관;김성주;서재용;조현찬;전홍태
    • Proceedings of the IEEK Conference
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    • 2003.07d
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    • pp.1287-1290
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    • 2003
  • Generally, it is known that human beings have both emotion and rationality. Especially, emotion is so subjective that human beings might act in different way for the same environment according to their own emotion. Emotion also plays very important role in communication with someone else For an agent, even though it is designed to act delicately, when it is designed without internal emotion, it can not interact dynamically just like human beings. In this paper, we suggest an agent which action is effected by not only rationality but also emotion to make it interact with human beings dynamically. It is composed of supervised learning, SOM (Self-Organizing Map) and fuzzy decision.

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The Model with the Changing Internal Emotion

  • Ha, Sang-Hyoung;Kim, Seong-Hyun;Kim, Byeong-Kwoan;Kim, Seong-Joo;Jeon, Hong-Tae
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2003.09a
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    • pp.276-279
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    • 2003
  • Generally, it is known that human beings have both emotion and rationality. Especially, emotion is so subjective that human beings might act in different way for the same environment according to their own emotion. Emotion also plays very important role in communication with someone else. For an agent, even though it is designed to act delicately, when it is designed without internal emotion, it can not interact dynamically just like human beings. In this paper, we suggest an agent which action is effected by not only rationality but also emotion to make it interact with human beings dynamically. It is composed of supervised learning, SOM (Self-Organizing Map) and fuzzy decision.

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Human Posture Recognition: Methodology and Implementation

  • Htike, Kyaw Kyaw;Khalifa, Othman O.
    • Journal of Electrical Engineering and Technology
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    • v.10 no.4
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    • pp.1910-1914
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    • 2015
  • Human posture recognition is an attractive and challenging topic in computer vision due to its promising applications in the areas of personal health care, environmental awareness, human-computer-interaction and surveillance systems. Human posture recognition in video sequences consists of two stages: the first stage is training and evaluation and the second is deployment. In the first stage, the system is trained and evaluated using datasets of human postures to ‘teach’ the system to classify human postures for any future inputs. When the training and evaluation process is deemed satisfactory as measured by recognition rates, the trained system is then deployed to recognize human postures in any input video sequence. Different classifiers were used in the training such as Multilayer Perceptron Feedforward Neural networks, Self-Organizing Maps, Fuzzy C Means and K Means. Results show that supervised learning classifiers tend to perform better than unsupervised classifiers for the case of human posture recognition.

The Identifier Recognition from Shipping Container Image by Using The Enhanced Self-Organized Supervised Learning Algorithm (개선된 자가생성 지도학습 알고리즘을 이용한 컨테이너 식별자 연식)

  • 이혜현;김태경;김광백
    • Proceedings of the Korea Multimedia Society Conference
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    • 2002.11b
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    • pp.149-154
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    • 2002
  • 운송 컨테이너의 식별자를 추출하고 인식하는 것은 컨테이너 식별자들의 크기나 위치가 정형화되어 있지 않고 외부의 잡음으로 인하여 식별자의 형태가 훼손되어 있기 때문에 어렵다. 본 논문에서는 이러한 특성을 고려하여 컨테이너 영상에 대해 Canny 에지 추출 기법을 이용하여 컨테이너의 식별자 영역을 추출하고 추출된 컨테이너 식별자 영역에서 히스토그램 방법과 윤곽선 추적 알고리즘을 결합하여 개별 식별자를 추출한다. 추출된 컨테이너 개별 식별자 인식은 ART1을 수정하여 지도 학습 방법과 결합한 개선된 자가생성 지도학습 알고리즘을 제안하여 적용한다. 실험결과에서는 제안된 컨테이너 식별자 추출 및 인식 방법이 다양한 컨테이너 영상에 대해 효율적인 것을 보인다.

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Tool Wear Monitoring in Milling Operation Using ART2 Neural Network (ART2 신경회로망을 이용한 밀링공정의 공구마모 진단)

  • Yoon, Sun-Il;Ko, Tae-Jo;Kim, Hee-Sool
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.12
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    • pp.120-129
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    • 1995
  • This study introduces a tool wear monitoring technology in face milling operation comprised of an unsupervised neural network. The monitoring system employs two types of sensor signal such as cutting force and acceleration in sensory detection state. The RMS value and band frequency energy of the sensor signals are calculated for te input patterns of neural network. ART2 neural network, which is capable of self organizing without supervised learning, is used for clustering of tool wear states. The experimental results show that tool wear can be effectively detected under various cutting conditions without prior knowledge of cutting processes.

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