• Title/Summary/Keyword: Learning history data model

검색결과 65건 처리시간 0.021초

적응 훈련 신경망을 이용한 플라즈마 식각 공정 수율 향상을 위한 공정 분석 및예측 시스템 개발 (Development of Process Analysis and Prediction Systeme to Improve Yield in Plasma Etching Process Using Adaptively Trained Neural Network)

  • 최문규;김훈모
    • 한국정밀공학회지
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    • 제16권11호
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    • pp.98-105
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    • 1999
  • As the IC(Integrated Circuit) has been densified and complicated, it is required to thorough process control to improve yield. Experts, for this purpose, focused on the process analysis automation, which is came from the strict data management in semiconductor manufacturing. In this paper, we presents the process analysis system that can analyze causes, for a output after processes. Also, the plasma etching process that highly affects yield among semiconductor process is modeled to predict a output before the process. To approach this problem, we use adaptively trained neural networks that exhibit superior accuracy over statistical techniques. And in comparison with methods in other paper, a method that history of trend for input data is considered is shown to offer advantage in both learning and prediction capability. This research regards CD(Critical Dimension) that is considerable in high integrated circuit as output variable of the prediction model.

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시계열 예측 모델을 활용한 암호화폐 투자 전략 개발 (Developing Cryptocurrency Trading Strategies with Time Series Forecasting Model)

  • 김현선;안재준
    • 산업경영시스템학회지
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    • 제46권4호
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    • pp.152-159
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    • 2023
  • This study endeavors to enrich investment prospects in cryptocurrency by establishing a rationale for investment decisions. The primary objective involves evaluating the predictability of four prominent cryptocurrencies - Bitcoin, Ethereum, Litecoin, and EOS - and scrutinizing the efficacy of trading strategies developed based on the prediction model. To identify the most effective prediction model for each cryptocurrency annually, we employed three methodologies - AutoRegressive Integrated Moving Average (ARIMA), Long Short-Term Memory (LSTM), and Prophet - representing traditional statistics and artificial intelligence. These methods were applied across diverse periods and time intervals. The result suggested that Prophet trained on the previous 28 days' price history at 15-minute intervals generally yielded the highest performance. The results were validated through a random selection of 100 days (20 target dates per year) spanning from January 1st, 2018, to December 31st, 2022. The trading strategies were formulated based on the optimal-performing prediction model, grounded in the simple principle of assigning greater weight to more predictable assets. When the forecasting model indicates an upward trend, it is recommended to acquire the cryptocurrency with the investment amount determined by its performance. Experimental results consistently demonstrated that the proposed trading strategy yields higher returns compared to an equal portfolio employing a buy-and-hold strategy. The cryptocurrency trading model introduced in this paper carries two significant implications. Firstly, it facilitates the evolution of cryptocurrencies from speculative assets to investment instruments. Secondly, it plays a crucial role in advancing deep learning-based investment strategies by providing sound evidence for portfolio allocation. This addresses the black box issue, a notable weakness in deep learning, offering increased transparency to the model.

기계학습 기반 지하매설물 속성 및 밀집도를 활용한 지반함몰 위험도 예측 모델 (Ground Subsidence Risk Grade Prediction Model Based on Machine Learning According to the Underground Facility Properties and Density)

  • 이성열;강재모;김진영
    • 한국지반환경공학회 논문집
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    • 제24권4호
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    • pp.23-29
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    • 2023
  • 지반함몰의 주요 발생원인은 지하매설물의 손상으로 알려져 있다. 지반함몰은 상·하수관의 손상으로 인한 물길 형성에 따른 지반 내 토립자의 이동으로 공동이 형성되어 상부지반이 붕괴되는 메커니즘을 보이고 있다. 따라서 지반함몰은 지하매설물의 밀집도가 높은 도심지를 중심으로 발생하고 있으며, 사고 발생 시 인명 및 경제적 피해를 야기하므로 사고에 대한 대비가 반드시 필요하다. 이에 따라 지반함몰 위험을 예측하기 위한 연구가 꾸준히 수행되고 있으며, 본 연구에서는 ○○시의 2개 구를 대상으로 지반함몰 위험도 예측 모델을 제시하고자 하였다. 대상 지역의 지하매설물 속성 데이터(활용년수, 관직경)와 지하매설물 밀집도, 지반함몰 이력 데이터를 활용하여 데이터셋을 구축하고 전처리를 수행한 뒤, 기계학습 모델에 적용하여 최적의 평가지표가 도출되는 모델을 선정하였으며, 선정된 모델의 신뢰도를 평가하고 모델에서 도출되는 지반함몰 위험도 예측 시 활용된 영향인자의 중요도를 제시하고자 하였다.

지역사회 치매 고위험군 선별 및 웹을 이용한 예방프로그램 개발 (Screening for High Risk Population of Dementia and Development of the Preventive Program Using Web)

  • 김정순;정인숙;김윤진;황선경;최병철
    • 대한간호학회지
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    • 제33권2호
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    • pp.236-245
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    • 2003
  • Purpose: This study was to develop a screening model for identifying a high risk group of dementia and to develop and evaluate the web-based prevention program. Method: It was conducted in 5 phases. 1) Data were collected from dementia patients and non-dementia patients in a community. 2) A screening model of the high risk population was constructed. 3) The validity test was performed and the model was confirmed. 4) Four weeks-prevention program was developed. 5) The program was administered, and evaluated the effects. Result: The model consisted of age, illiteracy, history of stroke and hypercholesterolemia. The program was designed with 12 sessions, group health education using web-based individual instruction program, and 12 sessions of low-intensity physical exercise program. After the completion, their self-efficacy, and health behaviors in experimental group were significantly improved over those in the control group. The perceived barrier in the treatment group is significantly decreased. Conclusion: The screening model developed is very simple and can be utilized in diverse community settings. And the web based prevention program will encourage individual learning and timely feedback, therefore it can facilitate their active participation and promote health management behaviors at home.

케이슨식 안벽 항만시설의 성능저하패턴 연구 (A Study on the Performance Degradation Pattern of Caisson-type Quay Wall Port Facilities)

  • 나용현;박미연;장신우
    • 한국재난정보학회 논문집
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    • 제18권1호
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    • pp.146-153
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    • 2022
  • 연구목적: 국내 항만시설의 경우 사용년수가 오래된 항만구조물은 선박의 대형화 및 사용빈도 증가, 기후변화에 따른 자연재해의 영향 등으로 안전과 기능적 측면에서 상당히 많은 문제가 있다. 항만시설의 유지관리 이력 데이터를 기반으로 시설 노후화 패턴을 예측 할 수 있는 근사모델 개발을 위하여 빅데이터 분석 방법을 연구하였다. 연구방법: 본 연구에서는 케이슨식 안벽에 유지관리 데이터 수집하여 빅데이터를 바탕으로 시설물의 노후화 패턴 및 성능저하를 확인하기 위한 예측모델을 도출하였다. 가우시안 프로세스(GP)과 선형보간(SLPT) 기법을 통하여 생성된 상태기반 노후도 패턴 예측모델을 제안하고 유효성 검토를 통해 빅데이터 적용에 적합한 모델을 비교하고 제안하였다. 연구결과: 제안된 기법을 검토한 결과 SLPT기법은 RMSE 및 는 0.9215와 0.0648로 SLPT기법의 예측모델이 보다 더 적합한 것으로 검토 되었다. 결론: 이러한 연구를 통해 빅데이터 기반 시설물 성능저하 예측 연구는 유지관리를 위환 의사결정에서 중요한 체계가 될 것으로 기대된다.

하브루타를 적용한 경전강독 수업 사례 연구 (A Case Study on the Havruta Method in the Reading the Chinese Classics)

  • 이해듬;김용진
    • 한국의사학회지
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    • 제36권2호
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    • pp.89-98
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    • 2023
  • Objectives: This study applied Havruta, a learner-centered educational method, and verified its effectiveness, to break from the existing mechanical memorization methods of scripture reading classes, which are basic subjects of East Asian medicine at East Asian medicine universities. Method: To this end, D University's scripture reading course was redesigned according to Havruta's teaching model, and Havruta classes were conducted according to the instructional design. Results: As a result of the class, students' Chinese translation ability improved, and they were able to concentrate on class (M=4.24). Through class, they acquired knowledge in the field (M=4.21) and their ability to communicate with others improved (M=4.21). M=4.25), it can be inferred and interpreted that the learner is engaged. Conclusion: The results of this study are examples of applying various teaching and learning methods required in the East Asian medicine evaluation and certification of East Asian medicine at East Asian medicine universities, and can be used as practical basic data that can be applied not only to scripture reading subjects but also to other subjects.

고객의 특성 정보를 활용한 화장품 추천시스템 개발 (Beauty Product Recommendation System using Customer Attributes Information)

  • 김효중;신우식;신동훈;김희웅;김화경
    • 경영정보학연구
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    • 제23권4호
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    • pp.69-86
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    • 2021
  • 인공지능 기술이 발달함에 따라 빅데이터를 활용한 개인화 추천시스템에 대한 관심이 증가하고 있다. 특히 뷰티 제품의 경우 개인의 취향과 더불어 피부 특성 및 민감도에 따라 제품 선호도가 명확히 구분되므로 축적된 고객 데이터를 활용하여 고객 맞춤형 추천서비스를 제공하는 것이 필요하다. 따라서 본 연구에서는 딥러닝 기법을 활용하여 제품 검색 기록과 개인 사용자의 피부 타입과 고민 등의 콘텍스트 정보를 함께 반영한 심층 신경망 기반의 추천시스템 모델을 제시하고자 한다. 본 연구에서는 실제 화장품 검색 플렛폼의 데이터를 활용하여 성능 평가를 실시하였다. 본 연구의 실험 결과, 고객의 콘텍스트 정보를 포함한 모델이 제품 검색 기록만을 활용한 기존의 협업 필터링 모델들 보다 우수한 성능을 보임을 확인하였다.

보다 정확한 동적 상황인식 추천을 위해 정확 및 오류 패턴을 활용하여 순차적 매칭 성능이 개선된 상황 예측 방법 (Context Prediction Using Right and Wrong Patterns to Improve Sequential Matching Performance for More Accurate Dynamic Context-Aware Recommendation)

  • 권오병
    • Asia pacific journal of information systems
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    • 제19권3호
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    • pp.51-67
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    • 2009
  • Developing an agile recommender system for nomadic users has been regarded as a promising application in mobile and ubiquitous settings. To increase the quality of personalized recommendation in terms of accuracy and elapsed time, estimating future context of the user in a correct way is highly crucial. Traditionally, time series analysis and Makovian process have been adopted for such forecasting. However, these methods are not adequate in predicting context data, only because most of context data are represented as nominal scale. To resolve these limitations, the alignment-prediction algorithm has been suggested for context prediction, especially for future context from the low-level context. Recently, an ontological approach has been proposed for guided context prediction without context history. However, due to variety of context information, acquiring sufficient context prediction knowledge a priori is not easy in most of service domains. Hence, the purpose of this paper is to propose a novel context prediction methodology, which does not require a priori knowledge, and to increase accuracy and decrease elapsed time for service response. To do so, we have newly developed pattern-based context prediction approach. First of ail, a set of individual rules is derived from each context attribute using context history. Then a pattern consisted of results from reasoning individual rules, is developed for pattern learning. If at least one context property matches, say R, then regard the pattern as right. If the pattern is new, add right pattern, set the value of mismatched properties = 0, freq = 1 and w(R, 1). Otherwise, increase the frequency of the matched right pattern by 1 and then set w(R,freq). After finishing training, if the frequency is greater than a threshold value, then save the right pattern in knowledge base. On the other hand, if at least one context property matches, say W, then regard the pattern as wrong. If the pattern is new, modify the result into wrong answer, add right pattern, and set frequency to 1 and w(W, 1). Or, increase the matched wrong pattern's frequency by 1 and then set w(W, freq). After finishing training, if the frequency value is greater than a threshold level, then save the wrong pattern on the knowledge basis. Then, context prediction is performed with combinatorial rules as follows: first, identify current context. Second, find matched patterns from right patterns. If there is no pattern matched, then find a matching pattern from wrong patterns. If a matching pattern is not found, then choose one context property whose predictability is higher than that of any other properties. To show the feasibility of the methodology proposed in this paper, we collected actual context history from the travelers who had visited the largest amusement park in Korea. As a result, 400 context records were collected in 2009. Then we randomly selected 70% of the records as training data. The rest were selected as testing data. To examine the performance of the methodology, prediction accuracy and elapsed time were chosen as measures. We compared the performance with case-based reasoning and voting methods. Through a simulation test, we conclude that our methodology is clearly better than CBR and voting methods in terms of accuracy and elapsed time. This shows that the methodology is relatively valid and scalable. As a second round of the experiment, we compared a full model to a partial model. A full model indicates that right and wrong patterns are used for reasoning the future context. On the other hand, a partial model means that the reasoning is performed only with right patterns, which is generally adopted in the legacy alignment-prediction method. It turned out that a full model is better than a partial model in terms of the accuracy while partial model is better when considering elapsed time. As a last experiment, we took into our consideration potential privacy problems that might arise among the users. To mediate such concern, we excluded such context properties as date of tour and user profiles such as gender and age. The outcome shows that preserving privacy is endurable. Contributions of this paper are as follows: First, academically, we have improved sequential matching methods to predict accuracy and service time by considering individual rules of each context property and learning from wrong patterns. Second, the proposed method is found to be quite effective for privacy preserving applications, which are frequently required by B2C context-aware services; the privacy preserving system applying the proposed method successfully can also decrease elapsed time. Hence, the method is very practical in establishing privacy preserving context-aware services. Our future research issues taking into account some limitations in this paper can be summarized as follows. First, user acceptance or usability will be tested with actual users in order to prove the value of the prototype system. Second, we will apply the proposed method to more general application domains as this paper focused on tourism in amusement park.

지능적인 홈을 위한 상황인식 미들웨어에 대한 연구 (A Research on a Context-Awareness Middleware for Intelligent Homes)

  • 최종화;최순용;신동규;신동일
    • 정보처리학회논문지A
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    • 제11A권7호
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    • pp.529-536
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    • 2004
  • 무선네트워크와 각종 감지 센서로 통합된 스마트 홈은 우리의 삶의 일부분으로 자리 잡을 것이다. 이 논문은 사용자의 선호도에 근거하여 자동적인 흠 서비스를 제공하는 상황인식 미들웨어에 대하여 설명한다. 상황인식 미들웨어는 사용자의 선호도에 대한 학습과 예측 알고리즘을 수행하기 위하여 6가지의 기본 데이터를 이용하고 제시되는 6가지의 기본 데이터는 맥박, 체온, 얼굴표정, 실내온도, 시간, 사용자 위치이다. 6개의 데이터는 컨텍스트 모델을 구성하고 컨텍스트 매니저 모듈에 의해 기본 데이터로 사용된다. 사용자에 의해서 선택되어진 컨텐츠에 대한 정보를 유지하는 로그매니저가 제시되고 사용자에게 적절한 홈서비스를 제공하기 위해 신경망에 근거한 학습 및 예측 알고리즘을 제시한다. 실험결과는 개인의 선호도 패턴이 연구된 컨텍스트 모델에 의해서 효과적으로 예측되고 평가되는 것을 보여준다.

차륜 및 차축베어링 고장진단을 위한 빅데이터 기반 머신러닝 기법 연구 (A Study of Big data-based Machine Learning Techniques for Wheel and Bearing Fault Diagnosis)

  • 정훈;박문성
    • 한국산학기술학회논문지
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    • 제19권1호
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    • pp.75-84
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    • 2018
  • 본 철도 유지보수 산업의 효율화를 위해서는 핵심부품의 적시 관리를 통한 부품 가동률 향상 및 철도 운행의 안정성 향상이 필요하다. 또한 유지보수 시스템 고속화에 따른 신뢰성 향상과 핵심부품의 유지보수 비용 절감의 두 가지 측면을 모두 만족시키기 위해, 부품 이력관리와 대규모 빅데이터의 자동화된 분석 기술을 활용한 부품 상태 진단 기술 수요가 증가하고 있다. 이 논문에서는 철도차량의 차상 및 지상 장치로부터 발생되는 실시간 빅데이터 수집, 처리, 분석을 위해서 빅데이터 플랫폼 기반의 철도차량 부품의 상태 데이터 관리시스템을 개발하였으며, 이 시스템의 활용으로 철도차량의 부품 상태정보 및 시스템 리소스에 대한 실시간 모니터링이 가능하다. 또한 빅데이터 플랫폼으로부터 수집된 상태 데이터를 기반으로 분산/병렬처리 및 자동화된 부품 고장진단이 가능한 머신러닝 기법을 제안하였다. 실험결과, 분산/병렬처리 기술이 적용된 알고리즘의 실행시간 단축을 아마존 웹서비스의 가상 인스턴스 생성 시스템을 통해 증명하였으며, random forest 머신러닝 기법을 활용한 고장 진단 모델의 베어링 및 차륜 부품에 대한 상태 예측 정확도가 83%임을 확인하였다.