• Journal of the Korean Society of Tobacco Science
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• v.21 no.1
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• pp.36-48
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• 1999

Field test was conducted in Chungbuk province to evaluate the soil fertility using landscape and soil attributes by application of geographic information system(GIS) in 48 tobacco fields during 2 years(1996 ; 23 fields, 1997 ; 25 fields). The soil fertility factors and fertilizer effects were estimated by twenty five independent variables including 13 chemical properties and 12 GIS databases. Twenty five independent variables were classified by two groups, 15 quantitative indexes and 10 qualitative indexes and were analyzed by multiple linear regression (MLR) of SAS, REG and GLM models. The estimation model for evaluation of soil fertility and fertilizer effect was made by giving the estimate coefficient for each quantitative index and for each group of qualitative index significantly selected by MLR. Estimation for soil fertility factors and fertilizer effects by independent variables was better by MLR than single regression showing gradually improvement by adding chemical properties, quantitative indexes and qualitative indexes of GIS. Consequently, it is assumed that this approach by MLR with quantitative and qualitative indexes was available as an evaluation model of soil fertility and recommendation of optimum fertilization for tobacco field.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.7
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• pp.1618-1631
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• 1994

In this paper, in-process chatter detection methodology which utilizes nondimensional characteristic variables is introduced. To obtain nondimensional chatter detection indexes which are constant regardless of the cutting conditions during machining with the same tool and workpiece material, both the cutting forces and accelerations are measured and processed in time and frequency domain. The indexes are calculated from the present and past value of the acceleration and cutting force signals in time and frequency domain. The chatter is identified when these chatter detection indexes are bigger than the threshold which is decided by preliminary experiments. The experiment shows that these indexes works very well in-process chatter detection.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.5
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• pp.37-44
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• 2010

Impact noise is induced in a car when it is driven on a harsh road or over some bumps. This noise occurs with the very high level of sound, which affects passengers in some way or other. Although it is impossible to clearly remove such noise, it is necessary to research an improvement in sound quality for impact noise. A new sound metric for impact sound is presented. This metric is verified by comparison between mean subjective ratings and several sound metrics. In this paper, more objective attributes are considered, which the attributes are expressing the level and modulation of sound. Three sound metrics are employed to get impact sound indexes for each course by the method of multiple linear regressions. The indexes are verified by considering the correlation between the estimated values from the multiple linear regressions and the mean subjective ratings by evaluators. Also, the subjective ratings on the indexes are estimated for the case in which some parts of suspension system are changed. The estimated ratings represent more reasonable or acceptable ratings. Thus, such indexes can be used for modification of the parts of suspension system under considering a good sound quality.

• Health Policy and Management
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• v.20 no.3
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• pp.21-35
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• 2010

This study examined the changes in the service mix of Korean hospitals in 6 metropolitan cities between 2003 and 2005, and assessed whether the sample hospitals exhibit consistent trend or chance variation in multiple years. Three measures of hospital service mix, focusing on the specialization of services, were applied: information theory index, internal Herfindahl index, and number of distinct diagnosis-related groups (DRGs) treated. National Health Insurance claims were used to calculate the indexes. Specialization indexes were calculated in each year, and then examined to identify the pattern over time. Kappa analysis was applied to assess the agreements of specialization score between two years after hospitals were categorized into 4 groups with quartiles. Kappa score showed that the service mix of hospitals were changed during the study years. Specialization scores were increased given the market structure for three years. Hospitals which showed higher or lower specialization scores than the average of the scores consistently classified into the same group. Specialization indexes showed relatively consistent pattern over 3 years, and such consistencies were evident for hospitals regardless of the specialization status. Policy makers can identify the degree of specialization with the indexes, and it could provide a picture of how hospital services were mixed and changed over time.

• Journal of The Korean Association For Science Education
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• v.29 no.3
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• pp.277-290
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• 2009

In the era of the outcome-based education, multiple-choice test has been widely employed owing to its efficiency that enables educators to evaluate a quantity of students with much objectiveness. However, the prevalent test has not been reconsidered enough to overcome its apparent shortcomings: examiners' effort for developing plausible and faultless distracters defending from every falsification, and students' random guessing on key choices. For alleviating such defects, tiered test as an experimental format of multiple-choice tests has been suggested in science education. Since there has not accumulated much study on the implementation of tiered tests, our research aim is set to construct a framework suggesting statistical indexes for rationally discerning tiered units that develop an effective tiered test. Graded both by our tiered-scoring and by the conventional partial-scoring, the preliminary tiered test in secondary physics attests the improvement in its discrimination and difficulty distribution. The findings reveal that the two indexes discern effective tiered items: discrimination increase (Ct-p) and difficulty decrease (Dp-t). Based on the index information, 4 heterogeneous tier types are recommended in the content of secondary physics: directional manipulation, repeated calculation, diverse explanation, and plural variables.

• Journal of Korea Multimedia Society
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• v.8 no.6
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• pp.729-734
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• 2005

In order to access XML data stored in object databases, an efficient index scheme is inevitable. There have been several index schemes that can be used to efficiently retrieve XML data stored In object databases, but they are all the single path indexes that support indexing along a single schema path. Henee, if a query contains an extended path which is denoted by wild character ('*'), a query processor has to examine multiple index objects, resulting in poor performance and inconsistent index management. In this paper, we propose MPI (Multi-Path Index) scheme as a new index scheme that provides the functionality of multiple path indexes more efficiently, while it uses only one index structure. The proposed scheme is easy to manage since it considers the extended path as a logically single schema path. It is also practical since it can be implemented by little modification of the B -tree index structure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.137-142
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• 2009

Impact noise is induced in a car when it is driven on a harsh road or over some bumps. This noise occurs with the very high level of sound, which affects passengers in some way or other. Although it is impossible to clearly remove such noise. It is necessary to research an improvement in sound quality for impact noise. A new sound metric for impact sound is presented in the previous work. This metric is verified by comparison between mean subjective ratings and several sound metrics. In this paper, more objective attributes are considered, which are the attributes expressing the level and modulation of sound. Three sound metrics are employed to get impact sound indexes for each course by the method of multiple linear regressions. The indexes are verified by considering the correlation between the estimated values from the multiple linear regressions and the mean subjective ratings by evaluators. Also, the subjective ratings on the indexes are estimated for the case in which some parts of suspension system are changed. The estimated ratings represent more reasonable or acceptable ratings. Thus, such indexes can be used for modification of the parts of suspension system under considering a good sound quality.

• Nutrition Research and Practice
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• v.4 no.2
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• pp.155-162
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• 2010

Epidemiological evidence of the effects of dietary sodium, calcium, and potassium, and anthropometric indexes on blood pressure is still inconsistent. To investigate the relationship between dietary factors or anthropometric indexes and hypertension risk, we examined the association of systolic and diastolic blood pressure (SBP and DBP) with sodium, calcium, and potassium intakes and anthropometric indexes in 19~49-year-olds using data from Korean National Health and Nutrition Examination Survey (KNHANES) III. Total of 2,761 young and middle aged adults (574 aged 19~29 years and 2,187 aged 30~49 years) were selected from KNHANES III. General information, nutritional status, and anthropometric data were compared between two age groups (19~29 years old and 30~49 years old). The relevance of blood pressure and risk factors such as age, sex, body mass index (BMI), weight, waist circumference, and the intakes of sodium, potassium, and calcium was determined by multiple regression analysis. Multiple regression models showed that waist circumference, weight, and BMI were positively associated with SBP and DBP in both age groups. Sodium and potassium intakes were not associated with either SBP or DBP. Among 30~49-year-olds, calcium was inversely associated with both SBP and DBP (P = 0.012 and 0.010, respectively). Our findings suggest that encouraging calcium consumption and weight control may play an important role in the primary prevention and management of hypertension in early adulthood.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2011.04a
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• pp.247-250
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• 2011

The purpose of this study suggests the emotion of residents as indexes in Korean housing environment for providing a fundamental guideline for precise dwelling social science and indicating the view for understanding of residents in korean housing culture in korea. So this paper explores the role of residents emotion indexes in housing environment and community. For this study, survey and depth-interview methods were used for data collection. The subjects were 514 housewives living in apartments. The statistical methods for data analysis were frequency, mean, multiple linear regression and logistic regression analysis using the SPSS 18.0 program The major findings are as follows: 1)Pride of neighborhood, pride of apartment complex and sense of superiority were important factors for residental satisfaction. 2)Conspicuous image of neighbors and active contact with neighbors were import factors for their neighborship in the apartment complex. The results develop the housing environment evaluation indexes in community through the contextual understanding of space emotion society.

• Journal of KIISE:Databases
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• v.33 no.2
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• pp.201-213
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• 2006

A time-series database is a set of time-series data sequences, each of which is a list of changing values of the object in a given period of time. Subsequence matching is an operation that searches for such data subsequences whose changing patterns are similar to a query sequence from a time-series database. This paper addresses a performance issue of time-series subsequence matching. First, we quantitatively examine the performance degradation caused by the window size effect, and then show that the performance of subsequence matching with a single index is not satisfactory in real applications. We argue that index interpolation is fairly useful to resolve this problem. The index interpolation performs subsequence matching by selecting the most appropriate one from multiple indexes built on windows of their inherent sizes. For index interpolation, we first decide the sites of windows for multiple indexes to be built. In this paper, we solve the problem of selecting optimal window sizes in the perspective of physical database design. For this, given a set of query sequences to be peformed in a target time-series database and a set of window sizes for building multiple indexes, we devise a formula that estimates the cost of all the subsequence matchings. Based on this formula, we propose an algorithm that determines the optimal window sizes for maximizing the performance of entire subsequence matchings. We formally Prove the optimality as well as the effectiveness of the algorithm. Finally, we perform a series of extensive experiments with a real-life stock data set and a large volume of a synthetic data set. The results reveal that the proposed approach improves the previous one by 1.5 to 7.8 times.