• Title/Summary/Keyword: complex variable

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Monitoring of Commercial Red Pepper Powders for Their Irradiation Status (물리적 확인시험법을 이용한 시판 유통 중인 고춧가루의 방사선 조사여부 판별 모니터링)

  • Jeong, Mi-Seon;Ahn, Jae-Jun;Akram, Kashif;Kim, Gui-Ran;Kim, Hyun-Ku;Kwon, Joong-Ho
    • Korean Journal of Food Science and Technology
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    • v.44 no.6
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    • pp.673-679
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    • 2012
  • Ten commercially available red pepper powders were investigated using photostimulated-luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) analyses to confirm their irradiation status. The application of PSL, TL, and ESR analyses was also confirmed by in-house irradiation. In PSL-based screening, all samples gave negative photon counts (<700 PCs). The PSL calibration dose (1 kGy) showed a low sensitivity of 4 samples, while the others provided reliable screening results. TL glow curves demonstrated maximum peaks after $250^{\circ}C$ for the 6 samples; however 4 samples gave complex TL glow curves with maximum peaks in the range of $185-260^{\circ}C$ (radiation-specific), which could be the effect of an irradiated component in low concentration as the TL ratios of all samples were <0.1. Radiation-specific ESR features were absent in the all commercial samples. Variable irradiation detection properties were found; where the TL analysis showed the possible presence of an irradiated component in 4 samples requiring further monitoring and investigation.

The Development and Implementation of Problem-Based Learning Package in Physical Therapy (물리치료학에서의 PBL 학습교재 개발 및 적용)

  • Hwang, Hyun-Sook;Chung, Jin-Woo;Lim, Jong-Soo
    • Journal of Korean Physical Therapy Science
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    • v.9 no.4
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    • pp.83-94
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    • 2002
  • Within physical therapy education, there has been increased attention to curricula and course that emphasize problem solving, clinical reasoning, and synthesis of information across traditional discipline-specific boundaries. This article describes the development implementation, and outcomes of a problem-based learning course in Physical therapy. The course was designed to help students to integrate the various elements of a physical therapy curriculum and to enhance their abilities to respond to an ever-changing health care environment. An evaluation of the course by the first 50 students who completed it revealed both strengths and weaknesses. Students responded that the course enhanced their professional behavior, including interpersonal communication skills, team work, and follow-through with professional responsibilities. The learning package was developed by the authors and implemented to a college students during three weeks of the first semester of 2001. Most studies which conducted PBL module development were short period or temporary PBL package application and evaluation rather than a whole semester's. While, this study carried on partial integrated PBL curriculum development and application with recomposing content of the two subjects to one subject Physical therapy which includes four PBL packages. This package was developed from a simple concept to complex and partial integrated PBL curriculum application systematically variable learning methods such as discussion, practice, lecture, video. There are 2 classes, each class has 25 students, in the college. Each class has 5 small groups consisting 5 students. Two tutors proceeded discussion charging each class also, they used multiple methods and materials like tutorials, self-directed learning, lecture, and video. The package is 5 grades and 5 hours per week and the rate of discussion, lecture is 4, 1 respectively. One of the most change is the increase of interaction between students and tutors. Whenever students need information and suggestion, they can visit tutors who provide reading materials and guide for the direction of self learning. Therefore, this study describes the PBL package development process and application during one semester recomposing contents of two subjects to Physical therapy concepts. Besides, it will contribute to active application of existing each subject to tutors who intend to convert as PBL methods. The study has significant meaning to show potentiality of partially integrated PBL application, using systematic PBL package development from two subjects contents. However, when students' need of yearning is over the extent of Introduction of Physical therapy and Rehabilitation medicine, tutors should set learning extent. So, there is limitation to attain completely integrated PBL education within one subject, therefore, it is high lighted to proceed development of integrated curriculum to maximize learning effects of PBL. It is exected that partial integrated PBL package development and application will distribute to prosper excellent physiotherapist in practice.

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Nonlinear Characteristics of Fuzzy Inference Systems by Means of Individual Input Space (개별 입력 공간에 의한 퍼지 추론 시스템의 비선형 특성)

  • Park, Keon-Jun;Lee, Dong-Yoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.11
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    • pp.5164-5171
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    • 2011
  • In fuzzy modeling for nonlinear process, typically using the given data, the fuzzy rules are formed by the input variables and the space division by selecting the input variable and dividing the input space for each input variables. The premise part of the fuzzy rule is identified by selection of the input variables, the number of space division and membership functions and the consequent part of the fuzzy rule is identified by polynomial functions in the form of simplified and linear inference. In general, formation of fuzzy rules for nonlinear processes using the given data have the problem that the number of fuzzy rules exponentially increases. To solve this problem complex nonlinear process can be modeled by separately forming the fuzzy rules by means of fuzzy division of each input space. Therefore, this paper utilizes individual input space to generate fuzzy rules. The premise parameters of the fuzzy rules are identified by Min-Max method using the minimum and maximum values of input data set and membership functions are used as a series of triangular, gaussian-like, trapezoid-type membership functions. And lastly, using the data which is widely used in nonlinear process we evaluate the performance and the system characteristics.

GIS-based Spatial Integration and Statistical Analysis using Multiple Geoscience Data Sets : A Case Study for Mineral Potential Mapping (다중 지구과학자료를 이용한 GIS 기반 공간통합과 통계량 분석 : 광물 부존 예상도 작성을 위한 사례 연구)

  • 이기원;박노욱;권병두;지광훈
    • Korean Journal of Remote Sensing
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    • v.15 no.2
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    • pp.91-105
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    • 1999
  • Spatial data integration using multiple geo-based data sets has been regarded as one of the primary GIS application issues. As for this issue, several integration schemes have been developed as the perspectives of mathematical geology or geo-mathematics. However, research-based approaches for statistical/quantitative assessments between integrated layer and input layers are not fully considered yet. Related to this niche point, in this study, spatial data integration using multiple geoscientific data sets by known integration algorithms was primarily performed. For spatial integration by using raster-based GIS functionality, geological, geochemical, geophysical data sets, DEM-driven data sets and remotely sensed imagery data sets from the Ogdong area were utilized for geological thematic mapping related by mineral potential mapping. In addition, statistical/quantitative information extraction with respective to relationships among used data sets and/or between each data set and integrated layer was carried out, with the scope of multiple data fusion and schematic statistical assessment methodology. As for the spatial integration scheme, certainty factor (CF) estimation and principal component analysis (PCA) were applied. However, this study was not aimed at direct comparison of both methodologies; whereas, for the statistical/quantitative assessment between integrated layer and input layers, some statistical methodologies based on contingency table were focused. Especially, for the bias reduction, jackknife technique was also applied in PCA-based spatial integration. Through the statistic analyses with respect to the integration information in this case study, new information for relationships of integrated layer and input layers was extracted. In addition, influence effects of input data sets with respect to integrated layer were assessed. This kind of approach provides a decision-making information in the viewpoint of GIS and is also exploratory data analysis in conjunction with GIS and geoscientific application, especially handing spatial integration or data fusion with complex variable data sets.

Case study of design and construction for cutter change in EPB TBM tunneling (EPB 쉴드 TBM 커터 교체 설계 및 시공 사례 분석)

  • Lee, Jae-won;Kang, Sung-wook;Jung, Jae-hoon;Kang, Han-byul;Shin, Young Jin
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.24 no.6
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    • pp.553-581
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    • 2022
  • Shortly after tunnel boring machine (TBM) was introduced in the tunneling industry, the use of TBM has surprisingly increased worldwide due to its performance together with the benefit of being safely and environmentally friendly. One of the main cost items in the TBM tunneling in rock and soil is changing damaged or worn cutters. It is because that the cutter change is a time-consuming and costly activity that can significantly reduce the TBM utilization and advance rate and has a major effect on the total time and cost of TBM tunneling projects. Therefore, the importance of accurately evaluating the cutter life can never be overemphasized. However, the prediction of cutter wear in soil, rock including mixed face is very complex and not yet fully clarified, subsequently keeping engineers busy around the world. Various prediction models for cutter wear have been developed and introduced, but these models almost usually produce highly variable results due to inherent uncertainties in the models. In this study, a case study of design and construction of disc cutter change is introduced and analyzed, rather than proposing a prediction model of cutter wear. As the disc cutter is strongly affected by the geological condition, TBM machine characteristic and operation, authors believe it is very hard to suggest a generalized prediction model given the uncertainties and limitations therefore it would be more practical to analyze a real case and provide a detailed discussion of the difference between prediction and result for the cutter change. By doing so, up-to-date idea about planning and execution of cutter change in practice can be promoted.

The correlation between triglyceride to HDL cholesterol ratio and metabolic syndrome, nutrition intake in Korean adults: Korean National Health and Nutrition Examination Survey 2016 (한국 성인에서 중성지방/고밀도지단백콜레스테롤 비와 대사증후군 및 영양소 섭취와의 연관성 : 2016년 국민건강영양조사 자료를 이용하여)

  • Kim, Youngjon;Han, A Lum
    • Journal of Nutrition and Health
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    • v.52 no.3
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    • pp.268-276
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    • 2019
  • Purpose: Metabolic syndrome causes diabetes and increases the risk of cardiovascular disease. This study examined the correlation between metabolic syndrome, nutrition intake, and triglyceride (TG)/high-density lipoprotein (HDL) cholesterol ratio. Methods: Using the data from the $7^{th}$ KNHANES (2016), this study was conducted on healthy adults aged 19 and older. The components and existence of metabolic syndrome and nutrition intake were independent variables and the TG/HDLcholesterol ratio was a dependent variable. A complex sample logistic progress test was used with age, sex, smoking, and drinking frequency corrected. Results: The TG/HDLcholesterol ratio of people with metabolic syndrome was as high as 1.314 on average, compared to people without metabolic syndrome (p < 0.0001). Among each component of metabolic syndrome, the TG/HDL cholesterol ratio had a significant association with fasting blood glucose, TG, HDL cholesterol, and waist circumference (p < 0.05). Only energy and carbohydrate intake were significantly related to the TG/HDLcholesterol ratio (p < 0.05). Conclusion: The TG/HDLcholesterol ratio is associated with each component of metabolic syndrome, but in particular, it is positively correlated with the presence of metabolic syndrome. Lower energy intakehad a positive correlation with the TG/HDLcholesterol ratio. These results show that metabolic syndrome can be predicted using the TG/HDLcholesterol ratio, and a diet strategy through nutrition and health education is necessary to prevent metabolic syndrome.

Development of Underwater Positioning System using Asynchronous Sensors Fusion for Underwater Construction Structures (비동기식 센서 융합을 이용한 수중 구조물 부착형 수중 위치 인식 시스템 개발)

  • Oh, Ji-Youn;Shin, Changjoo;Baek, Seungjae;Jang, In Sung;Jeong, Sang Ki;Seo, Jungmin;Lee, Hwajun;Choi, Jae Ho;Won, Sung Gyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.3
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    • pp.352-361
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    • 2021
  • An underwater positioning method that can be applied to structures for underwater construction is being developed at the Korea Institute of Ocean Science and Technology. The method uses an extended Kalman filter (EKF) based on an inertial navigation system for precise and continuous position estimation. The observation matrix was configured to be variable in order to apply asynchronous measured sensor data in the correction step of the EKF. A Doppler velocity logger (DVL) can acquire signals only when attached to the bottom of an underwater structure, and it is difficult to install and recover. Therefore, a complex sensor device for underwater structure attachment was developed without a DVL in consideration of an underwater construction environment, installation location, system operation convenience, etc.. Its performance was verified through a water tank test. The results are the measured underwater position using an ultra-short baseline, the estimated position using only a position vector, and the estimated position using position/velocity vectors. The results were compared and evaluated using the circular error probability (CEP). As a result, the CEP of the USBL alone was 0.02 m, the CEP of the position estimation with only the position vector corrected was 3.76 m, and the CEP of the position estimation with the position and velocity vectors corrected was 0.06 m. Through this research, it was confirmed that stable underwater positioning can be carried out using asynchronous sensors without a DVL.

Factors Associated with the Use of Medical Care at Hospitals among Outpatients with Hypertension: A Study of the Korea Health Panel Study Dataset (2010-2016) (우리나라 고혈압 환자의 병원급 의료기관 외래이용 관련 요인: 한국의료패널자료(2010-2016)를 이용하여)

  • Lee, Sumi;Park, Sohee;Kimm, Heejin;Lee, Yongjae;Chung, Woojin
    • Health Policy and Management
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    • v.30 no.4
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    • pp.479-492
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    • 2020
  • Background: As the prevalence of hypertension is increasing in Korea, the government is seeking policy actions to manage patients with hypertension more efficiently. In this paper, we aimed to identify factors associated with the use of medical care at hospitals among outpatients with hypertension. Methods: We analyzed a total of 15,040 cases of 3,877 outpatients with hypertension obtained from the Korea Medical Panel database from 2010 to 2016. The dependent variable was whether a patient with hypertension visited a hospital or not; and independent variables were the patient's various socio-demographic, health-related, and heath-status characteristics. We conducted a generalized linear mixed model analysis with logit link for all the cases and then conducted it stratified by gender. Results: As a result of a multivariable analysis, women were less likely than to visit at a hospital (odds ratio [OR], 0.44; 95% confidence interval [CI], 0.32-0.61) and people aged 65 years and older than those aged less than 65 years (OR, 0.71; 95% CI, 0.57-0.89). Residents in Busan, Ulsan, and Gyeongnam were more likely than those in than Seoul, Gyeonggi, Incheon, and Jeju to visit a hospital (OR, 1.40; 95% CI, 1.05-1.86). The likelihood of visiting a hospital was high in people belonging to a group of: the highest level of annual household income (OR, 1.73; 95% CI, 1.30-2.29); Medical care aid recipients (OR, 1.94; 95% CI, 1.34-2.83); people having three or more complex chronic diseases (OR, 1.59; 95% CI, 1.19-2.11); people having diabetes (OR, 1.81; 95% CI, 1.41-2.32); or people having ischemic heart disease or cerebrovascular disease (OR, 6.80; 95% CI, 5.28-8.76). Also, we found that factors associated with the use of medical care at hospitals among outpatients with hypertension differed between genders. Conclusion: A variety of factors seem to be associated with the use of medical care at hospitals among outpatients with hypertension. Future research needs to find a way to help patients with hypertension visit an appropriate medical institution between clinics and hospitals.

An Exploratory Research Trends Analysis in Journal of the Korea Contents Association using Topic Modeling (토픽 모델링을 활용한 한국콘텐츠학회 논문지 연구 동향 탐색)

  • Seok, Hye-Eun;Kim, Soo-Young;Lee, Yeon-Su;Cho, Hyun-Young;Lee, Soo-Kyoung;Kim, Kyoung-Hwa
    • The Journal of the Korea Contents Association
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    • v.21 no.12
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    • pp.95-106
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    • 2021
  • The purpose of this study is to derive major topics in content R&D and provide directions for academic development by exploring research trends over the past 20 years using topic modeling targeting 9,858 papers published in the Journal of the Korean Contents Association. To secure the reliability and validity of the extracted topics, not only the quantitative evaluation technique but also the qualitative technique were applied step-by-step and repeated until a corpus of the level agreed upon by the researchers was generated, and detailed analysis procedures were presented accordingly. As a result of the analysis, 8 core topics were extracted. This shows that the Korean Contents Association is publishing convergence and complex research papers in various fields without limiting to a specific academic field. Also, before 2012, the proportion of topics in the field of engineering and technology appeared relatively high, while after 2012, the proportion of topics in the field of social sciences appeared relatively high. Specifically, the topic of 'social welfare' showed a fourfold increase in the second half compared to the first half. Through topic-specific trend analysis, we focused on the turning point in time at which the inflection point of the trend line appeared, explored the external variables that affected the research trend of the topic, and identified the relationship between the topic and the external variable. It is hoped that the results of this study can provide implications for active discussions in domestic content-related R&D and industrial fields.

WQI Class Prediction of Sihwa Lake Using Machine Learning-Based Models (기계학습 기반 모델을 활용한 시화호의 수질평가지수 등급 예측)

  • KIM, SOO BIN;LEE, JAE SEONG;KIM, KYUNG TAE
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.27 no.2
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    • pp.71-86
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    • 2022
  • The water quality index (WQI) has been widely used to evaluate marine water quality. The WQI in Korea is categorized into five classes by marine environmental standards. But, the WQI calculation on huge datasets is a very complex and time-consuming process. In this regard, the current study proposed machine learning (ML) based models to predict WQI class by using water quality datasets. Sihwa Lake, one of specially-managed coastal zone, was selected as a modeling site. In this study, adaptive boosting (AdaBoost) and tree-based pipeline optimization (TPOT) algorithms were used to train models and each model performance was evaluated by metrics (accuracy, precision, F1, and Log loss) on classification. Before training, the feature importance and sensitivity analysis were conducted to find out the best input combination for each algorithm. The results proved that the bottom dissolved oxygen (DOBot) was the most important variable affecting model performance. Conversely, surface dissolved inorganic nitrogen (DINSur) and dissolved inorganic phosphorus (DIPSur) had weaker effects on the prediction of WQI class. In addition, the performance varied over features including stations, seasons, and WQI classes by comparing spatio-temporal and class sensitivities of each best model. In conclusion, the modeling results showed that the TPOT algorithm has better performance rather than the AdaBoost algorithm without considering feature selection. Moreover, the WQI class for unknown water quality datasets could be surely predicted using the TPOT model trained with satisfactory training datasets.