• 한국수학교육학회지시리즈A:수학교육
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• 제63권3호
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• pp.393-409
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• 2024

분수와 소수가 나타내는 크기에 대한 이해를 돕기 위해, 수의 크기를 공간상에 직관적으로 표시하는 수직선 모델이 널리 활용된다. 본 연구에서는 수직선 추정 과제를 활용하여 초등학교 6학년 학생들의 분수와 소수에 대한 이해도 및 문제 해결 전략을 살펴보고, 다양한 전략 사용의 유연성이 분수와 소수의 표상의 정확성, 연산 능력, 수학 학업성취도의 개인차와 연관성이 있는지를 분석하였다. 분석 결과, 학생들은 자연수에 비해 분수와 소수의 수직선 표상 정확성이 상대적으로 낮았으며, 특별히 분수의 경우 분모가 짝수인 분수보다 홀수인 분수에서, 소수의 경우 소수 세 자리 수 보다 소수 두 자리 수에서 수직선 표상의 정확성이 더 낮게 나타났다. 전략 사용의 측면에서 학생들은 분수를 수직선에 표상할 때 기준점 참고 전략, 분할 전략, 어림 전략 순으로 많이 사용하였으며, 소수를 표상할 때에는 기준점 참고 전략, 반올림 전략, 자연수 변환 전략 순으로 많이 사용하였다. 마지막으로 분수를 표상할 때 사용하는 전략이 다양할수록 분수의 표상 정확성과 수학 학업성취 점수가 높게 나타났다. 이러한 결과를 토대로 분수의 다양한 개념과 자연수 대비 소수의 자릿값 및 0의 개념에 대한 세심한 지도의 필요성을 제언하였다. 또한 분수와 소수에 대한 이해를 돕기 위한 방안으로, 수직선 모델 활용과 함께 표상 전략을 병행해서 지도하는 방법에 대해 논의하였다.

• 대한기계학회논문집
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• 제17권2호
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• pp.393-406
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• 1993

In resistance spot welding process, size of molten nuggest have been utilized to assess the integrity of the weld quality. However real-time monitoring of the nugget size is an extremely difficult problem. This paper describes the design of an artificial neural networks(ANN) estimator to predict the nugget size for on-line use of weld quality monitoring. The main task of the ANN estimator is to realize the mapping characteristics from the sampled dynamic resistance signal to the actual negget size through training. The structure of the ANN estimator including the number of hidden layers and nodes in a layer is determined by an estimation error analysis. A series of welding experiments are performed to assess the performance of the ANN estimator. The results are quite promissing in that real-time estimation of the invisible nugget size can be achieved by analyzing the dynamic resistance signal without any conventional destructive testing of welds.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1258-1258
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• 2001

Estimation of sugar and reducing sugar content in molasses is very important task in sugar refineries. Conventional methods of determination of sugar content in molasses samples are highly time consuming and employ hazardous chemicals. Due to the physical properties of molasses, probability of error in conventional analytical techniques is high. These methods have proven to be inefficient for a process control in any sugar industry. Hence development of a rapid, inexpensive, physical and also accurate method for sugar determination in molasses will be highly useful. Near Infrared spectroscopy is being widely used worldwide as an analytical technique in food industry. The technique offers the advantage of being non-destructive and rapid. The present paper highlights the potential of near infrared reflectance spectroscopy as a rapid and automated analytical technique for determination of sugar and reducing sugar content in molasses. A number of molasses samples were collected during and after the sugar season from Havana Sugar Industry, Havana. The samples were chosen so as to obtain a wide range of concentration of sugar and reducing sugars. This was done in order to achieve a good calibration curve with widely spread data points. These samples were scanned in the region of 1100 - 2500 nm in diffuse reflectance mode. An indigenous ELICO NIR spectrophotometer, modified according to the requirements of sugar industry was used for this purpose. Each sample was also analyzed simultaneously by standard chemical methods. Chemical values were taken as reference for near infrared analysis. In order to obtain the most accurate calibration for the set of samples, various mathematical treatments were employed. Partial Least Square method was found to be most suitable for the analysis. A comparison is made between the actual values (chemical values) and the predicted values (NIR values). The actual values agree very well with the predicted values showing the accuracy of the technique. The validity of the technique is checked by predicting the concentration of sugar in unknown molasses samples using the calibration curve. The present investigation assesses the feasibility of the technique for on-line monitoring of sugars present in molasses in sugar industries.

• 유통과학연구
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• 제15권6호
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• pp.77-96
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• 2017

Purpose - This study aims to develop correspondence strategies to the environment change in domestic retail store types. Recently, new types of retails have emerged in retail industries. Therefore, trade area platform has developed focusing on the speed of data, no longer trade area from district border. Besides, 'trade area smart' brings about change in retail types with the development of giga internet. Thus, context shopping is changing the way of consumers' purchase pattern through data capture, technology capability, and algorithm development. For these reasons, the sales estimation model has been shown to be flawed using the notion of former scale and time, and it is necessary to construct a new model. Research design, data, and methodology - This study focuses on measuring retail change in large multi-shopping mall for the outlook for retail industry and competition for trade area with the theoretical background understanding of retail store types and overall domestic retail conditions. The competition among retail store types are strong, whereas the borders among them are fading. There is a greater need to analyze on a new model because sales expectation can be hard to get with business area competition. For comprehensive research, therefore, the research method based on the statistical analysis was excluded, and field survey and literature investigation method were used to identify problems and propose an alternative. In research material, research fidelity has improved with complementing research data related with retail specialists' as well as department stores. Results - This study analyzed trade area survival and its pattern through sales estimation and empirical studies on trade areas. The sales estimation, based on Huff model system, counts the number of households shopping absorption expectation from trade areas. Based on the results, this paper estimated sales scale, and then deducted modified probability model. Conclusions - In times of retail store chain destruction and off-line store reorganization, modified Huff model has problems in estimating sales. Transformation probability model, supplemented by the existing problems, was analyzed to be more effective in competitiveness business condition. This study offers a viable alternative to figure out related trade areas' sale estimation by reconstructing new-modified probability model. As a result, the future task is to enlarge the borders from IT infrastructure with data and evidence based business into DT infrastructure.