• Title/Summary/Keyword: industrial mathematics

검색결과 826건 처리시간 0.025초

A Study on the Modified RLS Algorithm Using Orthogonal Input Vectors (직교 입력 벡터를 이용하는 수정된 RLS 알고리즘에 관한 연구)

  • Ahn, Bong Man;Kim, Kwang Woong;Ahn, Hyun Gyu;Han, Byoung Sung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • 제32권1호
    • /
    • pp.13-19
    • /
    • 2019
  • This paper proposes an easy algorithm for finding tapped-delay-line (TDL) filter coefficients in an adaptive filter algorithm using orthogonal input signals. The proposed algorithm can be used to obtain the coefficients and errors of a TDL filter without using an inverse orthogonalization process for the orthogonal input signals. The form of the proposed algorithm in this paper has the advantages of being easy to use and similar to the familiar recursive least-squares (RLS) algorithm. In order to evaluate the proposed algorithm, system identification simulation of the $11^{th}$-order finite-impulse-response (FIR) filter was performed. It is shown that the convergence characteristics of the learning curve and the tracking ability of the coefficient vectors are similar to those of the conventional RLS analysis. Also, the derived equations and computer simulation results ensure that the proposed algorithm can be used in a similar manner to the Levinson-Durbin algorithm.

A statistical study of mathematical thinkings and problem-solving abilities for logical-type problems with reference to secondary talented students (중등영재학생들의 수학적 사고 선호도와 논리형 문제의 해결능력에 관한 통계적 검증 연구)

  • Pak, Hong-Kyung
    • Journal of Korea Society of Industrial Information Systems
    • /
    • 제14권4호
    • /
    • pp.198-204
    • /
    • 2009
  • It is one of important and interesting topics in mathematics education to study the process of the logical thinking and the intuitive thinking in mathematical problem-solving abilities from the viewpoint of mathematical thinking. The main purpose of the present paper is to investigate on this problem with reference to secondary talented students (students aged 16~17 years). In particular, we focus on the relationship between the preference of mathematical thinking and their problem-solving abilities for logical-type problems by applying logistic regression analysis.

Comparative analysis of model performance for predicting the customer of cafeteria using unstructured data

  • Seungsik Kim;Nami Gu;Jeongin Moon;Keunwook Kim;Yeongeun Hwang;Kyeongjun Lee
    • Communications for Statistical Applications and Methods
    • /
    • 제30권5호
    • /
    • pp.485-499
    • /
    • 2023
  • This study aimed to predict the number of meals served in a group cafeteria using machine learning methodology. Features of the menu were created through the Word2Vec methodology and clustering, and a stacking ensemble model was constructed using Random Forest, Gradient Boosting, and CatBoost as sub-models. Results showed that CatBoost had the best performance with the ensemble model showing an 8% improvement in performance. The study also found that the date variable had the greatest influence on the number of diners in a cafeteria, followed by menu characteristics and other variables. The implications of the study include the potential for machine learning methodology to improve predictive performance and reduce food waste, as well as the removal of subjective elements in menu classification. Limitations of the research include limited data cases and a weak model structure when new menus or foreign words are not included in the learning data. Future studies should aim to address these limitations.

Food and Meal Preference of Workers in the Chonnam Yeosu Industrial Area (전남 여수지역 산업체에 근무하는 근로자의 식품 및 음식의 기호도 조사)

  • Han, Hyun-Mi;Choi, Il-Su;Jung, Bok-Mi
    • Korean Journal of Community Nutrition
    • /
    • 제14권4호
    • /
    • pp.392-405
    • /
    • 2009
  • This study was conducted to investigate food and meal preference of workers (435 male and 212 female) in the Chonnam Yeosu industrial area. The results of the survey were analyzed by principal components analysis. The results were obtained as follows: 19.3% of the subjects were twenties, 28.3% were thirties, 28.8% were forties and 23.7% were fifties. Females liked rice rolled in dried laver, rice cakes, janchi-noodle and breads, on the other hand males liked thick beef soup, loach soup, an eel stew and soju. The young liked instant noodles, fried chicken, sweet and sour pork, pork cutlet, pizza, hamburger, ham, sausage and fruit beverage, on the other hand the old liked a fish pot stew, loach soup, eel stew, fish boiled in soy with spices, panfried fish, sea slug, ascidian, bunder, green laver and boiled burdock-lotus root in soy. Females who are young liked hamburger and sweet and sour pork whereas males who are young liked instant noodles, pork cutlet, ham, sausage and fruit beverage. Aged females liked fish boiled in soy with spices, panfried fish, bunder, green laver, boiled burdock-lotus root in soy whereas aged males liked a fish pot stew, loach soup, eel stew, sea mussel and oysters. Boiled rice was located within the middle irrespective of age and sex, but noodles, wheat flour meal, fast foods and fruits were situated at the young female side. Aged males liked soup and pot stew. Young males liked meats and eggs whereas fish and shellfish and kimch were located at the aged people side. Aged females liked sea weeds and most people disliked vegetables but females liked some vegetables irrespective of age. Processed foods, salted foods, and alcohol were generally disliked foods by subjects but males liked those foods. Soybean curd was liked more males than females, and teas, except coffee, was liked by males. (Korean J Community Nutrition 14(4) : 392${\sim}$405, 2009)

Informal Quality Data Analysis via Sentimental analysis and Word2vec method (감성분석과 Word2vec을 이용한 비정형 품질 데이터 분석)

  • Lee, Chinuk;Yoo, Kook Hyun;Mun, Byeong Min;Bae, Suk Joo
    • Journal of Korean Society for Quality Management
    • /
    • 제45권1호
    • /
    • pp.117-128
    • /
    • 2017
  • Purpose: This study analyzes automobile quality review data to develop alternative analytical method of informal data. Existing methods to analyze informal data are based mainly on the frequency of informal data, however, this research tries to use correlation information of each informal data. Method: After sentimental analysis to acquire the user information for automobile products, three classification methods, that is, $na{\ddot{i}}ve$ Bayes, random forest, and support vector machine, were employed to accurately classify the informal user opinions with respect to automobile qualities. Additionally, Word2vec was applied to discover correlated information about informal data. Result: As applicative results of three classification methods, random forest method shows most effective results compared to the other classification methods. Word2vec method manages to discover closest relevant data with automobile components. Conclusion: The proposed method shows its effectiveness in terms of accuracy and sensitivity on the analysis of informal quality data, however, only two sentiments (positive or negative) can be categorized due to human errors. Further studies are required to derive more sentiments to accurately classify informal quality data. Word2vec method also shows comparative results to discover the relevance of components precisely.

The development of industrial secure L2 switch and introduction example for management and security improvement of supervisory control network in purification plant (정수장 감시제어망의 관리와 보안개선을 위한 산업용 보안 L2스위치 개발 및 적용사례)

  • Kim, Yunha;Yu, Chool;Oh, Eun;Kim, Chanmoon;Park, Ikdong;Kim, Yongseong;Choi, Hyunju
    • Journal of Korean Society of Water and Wastewater
    • /
    • 제33권5호
    • /
    • pp.329-339
    • /
    • 2019
  • Recently, the advancement of information and communication technology(ICT) is expanding the connectivity through Internet of Things(IoT), and the media of connection is also expanding from wire/cable transmission to broadband wireless communication, which has significantly improved mobility. This hyperconnectivity has become a key element of the fourth industrial revolution, whereas the supervisory control network of purification plants in korea is operated as a communication network separated from the outside, thereby lagging in terms of connectivity. This is considered the best way to ensure security, and thus there is hardly any consideration of establishing alternatives to operate an efficient and stable communication network. Moreover, security for management of a commercialized communication network and network management solution may be accompanied by immense costs, making it more difficult to make new attempts. Therefore, to improve the conditions for the current supervisory control network of purification plants, this study developed a industrial security L2 switch that supports modbus TCP(Transmission Control Protocol) communication and encryption function of the transmission section. As a result, the communication security performance improved significantly, and the cost for implementing the network management system using Historical Trend and information of HMI(Human Machine Interface) could be reduced by approximately KRW 200 million. The results of this study may be applied to systems for gas, electricity and social safety nets that are infrastructure communication networks that are similar to purification plants.

A Characteristic Analysis for Quality Competitiveness Excellent Company (품질경쟁력 우수기업의 특성분석)

  • Park, Dong Joon;Yun, Yeboon;Kang, In Seon;Yoo, Eun Jae;Kim, Ho Gyun;Yoon, Min
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • 제42권3호
    • /
    • pp.95-108
    • /
    • 2019
  • Quality management has become an pervasive philosophy in most sectors of business. Specific movements such as statistical quality control, quality circle, total quality management, and quality management system have become embedded in business organizations. Only the companies with competitive edge can survive in the competition in global market. KSA(Korean Standards Association) established in 1962 has launched all kinds of quality education, quality standard certification service for business, and KNQA(Korean National Quality Award) system. This article considers quality competitiveness excellent company award among KNQA. We performed a statistical analysis of audit data for quality competitiveness excellent company for three years, from 2015 to 2017. By using ANOVA and two sample t-tests, the average scores of 13 evaluation fields were significantly different depending on company size and type. We proposed ways to improve the current hall of fame system. We discovered that the average scores of 13 evaluation fields in the audit data according to years and hall of fame status were not significantly different. We also showed linear relationships among 13 evaluation fields by correlation analysis and obtained an estimated linear regression equation : Business Performance, which is a comprehensive index, as a dependent variable was significantly related to Customer Focus and Product Liability as regressor variables among 13 evaluation fields by regression analysis.

Spline Surface Approximation for Computing Pit Excavation Volume with the Free Boundary Conditions

  • Jaechil Yoo;Lee, Seung-Hoon;Mun, Du-Yeoul
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
    • /
    • 한국측량학회 2002년도 창립 20주년기념 국제학술대회
    • /
    • pp.229-238
    • /
    • 2002
  • The calculation of earthwork plays a major role in plan or design of many civil engineering projects, and thus it has become very important to improve the accuracy of earthwork calculation. In this paper, we propose an algorithm of finding a cubic spline surface with the free boundary conditions, which interpolates the given three dimensional data, by using B-spline and an accurate method to estimate pit-excavation volume. The proposed method should be of interest to surveyors especially concerned with accuracy of volume computations. We present some computational results showing that our proposed method provides good accuracy.

  • PDF

Critical thrust force and feed rate determination in drilling of GFRP laminate with backup plate

  • Heidary, Hossein;Mehrpouya, Mohammad A.;Saghafi, Hamed;Minak, Giangiacomo
    • Structural Engineering and Mechanics
    • /
    • 제73권6호
    • /
    • pp.631-640
    • /
    • 2020
  • Using backup plate is one of the most commonly used methods to decrease drilling-induced delamination of composite laminates. It has been shown that, the size of the delamination zone is related to the vertical element of cutting force named as thrust force. Also, direct control of thrust force is not a routine task, because, it depends on both drilling parameters and mechanical properties of the composite laminate. In this research, critical feed rate and thrust force are predicted analytically for delamination initiation in drilling of composite laminates with backup plate. Three common theories, linear elastic fracture mechanics, classical laminated plate and mechanics of oblique cutting, are used to model the problem. Based on the proposed analytical model, the effect of drill radius, chisel edge size, and backup plate size on the critical thrust force and feed rate are investigated. Experimental tests were carried out to prove analytical model.

THE EIGENVALUE ESTIMATE ON A COMPACT RIEMANNIAN MANIFOLD

  • Kim, Bang-Ok;Kim, Kwon-Wook
    • Bulletin of the Korean Mathematical Society
    • /
    • 제32권1호
    • /
    • pp.19-23
    • /
    • 1995
  • We will estimate the lower bound of the first nonzero Neumann and Dirichlet eigenvalue of Laplacian equation on compact Riemannian manifold M with boundary. In case that the boundary of M has positive second fundamental form elements, Ly-Yau[3] gave the lower bound of the first nonzero neumann eigenvalue $\eta_1$. In case that the second fundamental form elements of $\partial$M is bounded below by negative constant, Roger Chen[4] investigated the lower bound of $\eta_1$. In [1], [2], we obtained the lower bound of the first nonzero Neumann eigenvalue is estimated under the condtion that the second fundamental form elements of boundary is bounded below by zero. Moreover, I realize that "the interior rolling $\varepsilon$ - ball condition" is not necessary when the first Dirichlet eigenvalue was estimated in [1].ed in [1].

  • PDF