• Title/Summary/Keyword: demand estimation

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A Comparative Study of Curriculum and Mathematics Learning Programme of Lower Grade Between Korea and New Zealand (한국과 뉴질랜드의 초등학교 저학년 교육과정 및 수학학습 프로그램의 비교와 분석)

  • 최창우
    • School Mathematics
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    • v.6 no.1
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    • pp.1-19
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    • 2004
  • Recently, we have been listening such a words, that is, the crisis of public education through the mass communication such as newspaper or broadcasting. This means that we didn't have an enough opportunity to think it over about good education programme which the education of school can be normalized or the design of curriculum in the current problems such as overcrowded class, teacher and poor finance which is not still solved. As we know, it is true that the older generation is familiar with the rote learning which was under the control of behaviorism for about three hundred years. Fortunately, The 7th curriculum which had made public by the ministry of education on 30 Dec. 1997 have changed so many things such as real life based or activity based and so on. But it still leaves something to be desired in reflecting the demand of teachers of field. Taking into account this real situation, I have wondered how they run curriculum and how math learning programme of lower grade is different with ours in New Zealand, etc and so I had tried to find some suggestive points through the comparison of curriculum and text between Korea and New Zealand. But, if we want to compare all the strands of curriculum between two countries, it is too global and so in this paper, we deal with only number and operations(number), measurement, figure(geometry), equation and patter(algebra), probability and statistics(statistics) which are dealt with more comparatively in the lower grade of primary school. Because the main purpose of this paper is a comparison and analysis of the curriculum and math learning program of the lower grade in the primary school between two countries and so we compare global characteristics of education system and curriculum between two countries, at first and then we dealt with the very core part of the content of New Zealand curriculum within the ranges of level 1, 2 and 3 and global characteristics of learning program simultaneously.

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Supply Chain-based Freight Distribution Channel Choice Model using Distribution Channel Analysis (유통경로분석을 통한 공급사슬기반의 화물유통경로선택모형 개발)

  • Go, Yeong-Seung;Park, Dong-Ju;Kim, Chan-Seong;Kim, Hyeon-Su;Park, Min-Cheol
    • Journal of Korean Society of Transportation
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    • v.28 no.6
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    • pp.133-146
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    • 2010
  • The objective of this study is to develop a supply chain-based freight distribution channel choice model considering shippers' logistics behaviors which will be used for freight demand estimation. For this purpose, this study utilized the distribution channel data of the petrochemical and automobile industries collected by KTDB center. The distribution channel choice models for these industries were developed by including transport mode, time, cost, and shipment size. It was found that the multinomial logit model with transport cost, time and shipment size is the best, and as shipment increases, bigger transport mode is preferred. Generally direct distribution channel with small truck was preferred over the one using distribution center and/or big truck.

DETERMINATION OF SUGARS AND ORGANIC ACIDS IN ORAGE JUICES USING NEAR INFRARED DIFFUSE REFLECTANCE SPECTROSCOPY

  • Tewari, Jagdish;Mehrotra, Ranajana;Gupta, Alka;Varma, S.P.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1522-1522
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    • 2001
  • Beverages based on fruit juices are among the most popular commercially available drinks. There is an ever-increasing demand for these juices in the market. Orange juice is one of the most common as well as most favorite flavor. The fruit processing industries have a tremendous responsibility of quality control. For quality evaluation estimation of various components of the juice is necessary. Sucrose, glucose, fructose, citric acid and malic acid are the prime components of orange juice. Little information is available on analysis of orange juice. However, conventional and general wet chemistry procedures are currently being used which are no longer desired by the industry owing to the time involved, labor input and harmful chemicals required for each analysis. Need to replace these techniques with new, highly specific and automated sophisticated techniques viz. HPLC and spectroscopy has been realized since long time. Potential of Near Infrared Spectroscopy in quantitative analysis of different components of food samples has also been well established. A rapid, non-destructive and accurate technique based on Near Infrared Spectroscopy for determination of sugars and organic acids in orange juice will be highly useful. The current study is an investigation into the potential of Near Infrared Diffuse Reflectance Spectroscopy for rapid quantitative analysis of sucrose, glucose, fructose citric acid and malic acid in orange juice. All the Near Infrared measurements were peformed on a dispersive NIR spectrophotometer (ELICO 153) in diffuse reflectance mode. The spectral region from 1100 to 2500nm has been explored. The calibration has been performed on synthetic samples that are mixtures of sucrose, glucose, fructose, citric acid and malic acid in different concentration ranges typically encountered real orange juice. These synthetic samples are therefore considered to be representatives of natural juices. All the Near Infrared spectra of synthetic samples were subjected to mathematical analysis using Partial Least Square (PLS) algorithm. After the validation, calibration was applied to commercially available real samples and freshly squeezed natural juice samples. The actual concentrations were compared with those predicted from calibration curve. A good correlation is obtained between actual and predicted values as indicated by correlation coefficient ($R^2$) value, which is close to unity, showing the feasibility of the technique.

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A Study on the Causal Relationship Between Electricity Consumption and Output in Manufacturing Sectors of Korea (국내 제조업종별 전력소비와 경제산출간 인과관계 분석)

  • Park, Min Hyuk
    • KEPCO Journal on Electric Power and Energy
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    • v.3 no.1
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    • pp.65-72
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    • 2017
  • This study analyzed causal relationship between electricity consumption and economic output (GDP) for Korea from 2001 to 2014 employing the vector error-correction model estimation by manufacturing sector. The results of unit-roots tests show that all sectoral GDP and electricity consumptions were not stationary. And cointegration tests show that processed foods, Wood Pulp Paper, electricity apparatus, Precision Medical sectors had a linear combinations in the long run between electricity consumptions and economic growth. With respect to the direction of causality, manufacturing sector has a uni-directional running from economic output (GDP) to electricity consumption in short term. The results of study show that sectoral causal relation were different each other in short term and long term. These findings imply that electricity demand management policy focusing on efficiency improvement is necessary to minimize negative impacts on economic growth and to adopt suitable structural policies can induce energy conservation.

Analysis of Traffic Accident Severity for Korean Highway Using Structural Equations Model (구조방정식모형을 이용한 고속도로 교통사고 심각도 분석)

  • Lee, Ju-Yeon;Chung, Jin-Hyuk;Son, Bong-Soo
    • Journal of Korean Society of Transportation
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    • v.26 no.2
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    • pp.17-24
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    • 2008
  • Traffic accident forecasting model has been developed steadily to understand factors affecting traffic accidents and to reduce them. In Korea, the length of highways is over 3,000km, and it is within the top ten in the world. However, the number of accidents-per-one kilometer highway is higher than any other countries. The rapid increase of travel demand and transportation infrastructures since 1980's may influence on the high rates of traffic accident. Accident severity is one of the important indices as well as the rate of accident and factors such as road geometric conditions, driver characteristics and type of vehicles may be related to traffic accident severity. However, since all these factors are interacted complicatedly, the interactions are not easily identified. A structural equations model is adopted to capture the complex relationships among variables. In the model estimation, we use 2,880 accident data on highways in Korea. The SEM with several factors mentioned above as endogenous and exogenous variables shows that they have complex and strong relationships.

Utility Maximization, The Shapes of the Indifference Curve on the Characteristic Space and its Estimation: A Theoretical Approach (개인여객 효용의 극대화 및 운송특성공간상의 무차별곡선의 형태와 그 추정)

  • Kim, Jong-Seok
    • Journal of Korean Society of Transportation
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    • v.27 no.2
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    • pp.157-168
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    • 2009
  • The random utility theory and the multinomial logit model (including a more recent variant--the mixed multinomial logit) derived from it have constituted a back bone for theoretical and empirical analyses of various travel demand features including mode choice. In their empirical applications, however, it is customary to specify random utilities which are linear in modal attributes such as time and cost, and in socio-economic variables. The linearity helps easy derivation of important information such as value of travel time savings by calculating marginal rate of substitution between time and cost. In this paper the author focuses on the very linearity of the random utilities. Taking into account the fact that the mode chooser is also labour supplier, commodity consumer as well as leisure-seeker, the author sets up a maximization model of the traveller, which encompasses various economic activities of the traveller. The author derive from the model the indifference curve defined on the space of modal attributes, time and cost and investigate under what conditions the random utility of the traveller becomes linear. It turns out that there exist the conditions under which the random utility is really linear in modal attributes, but the property does not hold when the traveller has a corner solution on the space of modal attributes, or when the primary utility function of the traveller is directly affected by labour provided and/or the travel time itself. As a corollary of the analysis, a random utility is suggested, approximated up to the second order of the variables involved for empirical studies of the field.

Analysis of Elementary School Teachers' Perception on Field Application of STEAM Education (융합인재교육(STEAM)의 현장적용에 대한 초등 교사들의 인식조사)

  • Lim, Soo-min;Kim, Youngshin;Lee, Tae-sang
    • Journal of Science Education
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    • v.38 no.1
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    • pp.133-143
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    • 2014
  • The purpose of this study is to analyze elementary school teachers' perception on application of STEAM education. For this study, a survey was administered to 80 primary teachers. The result showed as follows: First, even though, elementary school teachers have known about the meaning and aims of the STEAM education in detail, they often took a neutral attitude toward the actual teaching method. In addition, they take a negative attitude toward having the gathering. Second, only a few elementary school teachers prepared and used the teaching materials related to the STEAM education in class and teach students the concept based on the STEAM education. Only a few elementary school teachers said that they used the developed modules. However, the demand, developing the modules, was extremely high. This result means that the easy and available modules should be developed to establish the STEAM education. Third, only a few elementary school teachers applied the subject, activity, and estimation related to the STEAM education in actual class. Forth, even though, after applying, there much be the positive affects, most elementary school teachers could not recognize the positive affects. At the same time, elementary school teachers suggested the curriculum should be reorganized for students to connect between the results of the STEAM education and the contents of the textbook, and the easy and available program should be developed and spread, also. The attitude of elementary school teachers toward the application of the STEAM education was normally negative. Therefore, it is needed to include more STEAM related contents in the science textbooks and to develop various STEAM education materials and circulate them as well as to establish adequate teaching and assessment methods for STEAM education.

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Optimal Design of Water Distribution System considering the Uncertainties on the Demands and Roughness Coefficients (수요와 조도계수의 불확실성을 고려한 상수도관망의 최적설계)

  • Jung, Dong-Hwi;Chung, Gun-Hui;Kim, Joong-Hoon
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.1
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    • pp.73-80
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    • 2010
  • The optimal design of water distribution system have started with the least cost design of single objective function using fixed hydraulic variables, eg. fixed water demand and pipe roughness. However, more adequate design is accomplished with considering uncertainties laid on water distribution system such as uncertain future water demands, resulting in successful estimation of real network's behaviors. So, many researchers have suggested a variety of approaches to consider uncertainties in water distribution system using uncertainties quantification methods and the optimal design of multi-objective function is also studied. This paper suggests the new approach of a multi-objective optimization seeking the minimum cost and maximum robustness of the network based on two uncertain variables, nodal demands and pipe roughness uncertainties. Total design procedure consists of two folds: least cost design and final optimal design under uncertainties. The uncertainties of demands and roughness are considered with Latin Hypercube sampling technique with beta probability density functions and multi-objective genetic algorithms (MOGA) is used for the optimization process. The suggested approach is tested in a case study of real network named the New York Tunnels and the applicability of new approach is checked. As the computation time passes, we can check that initial populations, one solution of solutions of multi-objective genetic algorithm, spread to lower right section on the solution space and yield Pareto Optimum solutions building Pareto Front.

An Economic Review on the Short-run Storability of Field Citrus in Jeju (노지감귤 단기 저장가능성에 대한 경제적 효과 검토)

  • Ahn, Kyeong Ah;Moon, Tae Wan;Kim, Bae Sung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.8
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    • pp.392-402
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    • 2018
  • Citrus fruits can be classified as field citrus, greenhouse citrus, citrus produced by rain proof cultivation and late-harvested citrus such as Hallabong, Chunhaehyang, and Jinjihyang according to cultivation method or variety in Jeju province of Korea. The consumption of late-harvested citrus has been increasing steadily since 1990 because the sugar content of the fruits is ordinary higher than field citrus. The cultivation land of citrus produced by rain proof cultivation has been also enlarged continuously aided by Korean government support program and quality increasing effect of this cultivation method. However, the cultivation land of field citrus has been decreasing since 2010. In spite of such a decrease of cultivation land, recently the price of field citrus rather declined according to increasing of yield per 10a. For the estimation and forecast of the long-term supply-demand model in the field citrus, we constructed a partial balance model for the individual field citrus and estimated individual equation in each item's model by using the econometric method. As a result of the production storage scenario analysis, the cultivation area is expected to store 5%(14.49ha), 10%(14.97ha). 15%(15.50ha) of citrus production in 2027. This study reviews the structure of storage, and storability in Jeju field citrus and suggest several policy implications.

Duration to First Job of Korean Young Graduates: Before and After the Economic Crisis (청년층의 첫 일자리 진입 : 경제위기 전후의 비교)

  • Ahn, Joyup;Hong, Seo Yeon
    • Journal of Labour Economics
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    • v.25 no.1
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    • pp.47-74
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    • 2002
  • Since the Economic Crisis at the end of 1997, unemployment rate soared up to the record-high 8.6% (February 1999) and, for youth aged 15~29, it was 14.6% (27.8% for aged 15~19). In spite of economic recovery after the crisis, new participants in labor market at the school-to-work transition have faced with difficulties in finding their first jobs and, even further, the ratio of youth at out-of the labor force but not in school has remained at a higher level. It is important to calibrate the negative effects of nonemployment in the short-run as well as in the long-run, but there has been few study on the school-to-work transition in Korea. This study focus on the nonemployment duration to first job after formal education and comparison of its pattern before and after the crisis. A proportional hazard model, considering job prenaration before graduation (21.4% of the sample), with the semi-parametric baseline hazard is applied to the sample from the Korean Labor and Income Panel Survey(1998~2000) and its Youth Supplemental survey(2000). Interview of the Survey is conducted, by the Korea Labor Institute, to the same 5,000 household and 13,738 individual sample, guaranteeing nationwide representativeness. The Supplemental Survey consists of 3,302 young individuals aged 15 to 29 at the time of survey and 1,615 of them who are not in school and provide appropriate information is used for the analysis. The empirical results show that there exists negative duration dependence at the first three or for months at the transition period and no duration dependence since a turning point of the baseline hazard rate and that unemployment rate reflecting labor demand conditions has a positive effect on exiting the nonemployment state, which is inconsistent with a theoretical conclusion. Estimation with samples separated by the date of graduation before and after the crisis shows that the effect of unemployment rate on the hazard was negative for the pre-crisis sample but positive for the post-crisis sample.

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