• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.794-807
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• 2021

The purpose of this study is to examine the effect of family poverty on the school adjustment of multi-cultural adolescents in Korea. For this purpose, the 7th data of Multi-cultural Adolescents Panel Study(MAPS) was used and the OLS multiple regression models ware applied. to the analyses. From the result of the OLS model analyses, we found out that family poverty affect significantly on the school adjustment of multi-cultural adolescents. Especially, family poverty has the significant negative(-) effects on academic achievement and friend relationships. These results of this study show that family poverty is an important factor influencing the school adjustment of multi-cultural adolescents. And they confirm that family poverty during period of the adolescent has an important meaning and influence on the aspect of school adjustment as to the multi-cultural adolescents. Implications of this study may be that policy attentions are necessary to not only multi-cultural characteristics but also family background such as poverty in oder to improve the school adjustment of the multi-cultural adolescents. In addition, results of this study suggest that more special support and interventions are requested to the multi-cultural adolescents from poverty families who are suffering dual difficulties such as multi-cultural problems and poverty problem.

• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.133-144
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• 2009

In Korea, the ITS project has been progressed to improve traffic mobility and safety. Further, it is to relieve traffic jam by supply real time travel information for drivers and to promote traffic convenience and safety. It is important that the traffic information is provided accurately. This study was conducted outlier elimination and missing data adjustment to improve accuracy of raw data. A method for raise reliability of travel time prediction information was presented. We developed Historical Profile model and adjustment formula to reflect quality of interrupted flow. We predicted travel time by developed Historical Profile model and adjustment formula and verified by comparison between developed model and existing model such as Neural Network model and Kalman Filter model. The results of comparative analysis clarified that developed model and Karlman Filter model similarity predicted in general situation but developed model was more accurate than other models in incident situation.

• Environmental and Resource Economics Review
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• v.22 no.2
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• pp.393-410
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• 2013

We employ a threshold vector error correction models (TVECM) to investigate the nonlinear dynamic adjustment of gasoline prices in Korea. We consider 10 regional gasoline markets including Seoul, Busan, Daegu, Incheon, Kwangju, Daejeon, Ulsan, Kangwon, Chungbuk, Jeonbuk and construct 9 price differences against Seoul. We use the bootstrap procedure suggested by Hansen (1999) and generalized by Lo and Zivot (2001) to show that three-regime TVECM is suitable for our analysis. Results indicate the gasoline price adjustment processes are nonlinear. Our estimation shows that Seoul-Daejeon, Seoul-Daegu and Seoul-Ulsan have bigger transaction costs than other market pairs and thus gasoline prices of these three regional markets are lower than that of Seoul. Gasoline prices of the other 6 regional markets are close to Seoul's price. One interesting finding is that the transaction costs are not proportional to geographical distances. This implies that transportation costs are not the main factor of the transaction costs. The transaction costs may depends on the competition intensity of gasoline markets in supply side.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.5
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• pp.445-458
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• 2012

The objective of GPS control surveying is ultimately to determine coordinate sets of control points within targeted accuracy through a series of observations and network adjustments. To this end, it is of equivalent importance for the accuracy of these coordinates to be realistically represented by using an appropriate method. The accuracy representation can be quantitively made by the variance-covariance matrices of the estimates, of which features are sensitive to the mathematical models used in the adjustment. This paper deals with impact of functional and stochastic modeling techniques into the accuracy representation of the GPS control surveying with a view of gaining background for its standardization. In order to achieve this goal, mathematical theory and procedure of the single-baseline based multi-session adjustment has been rigorously reviewed together with numerical analysis through processing real world data. Based on this study, it was possible to draw a conclusion that weighted-constrained adjustment with the empirical stochastic model was among the best scheme to more realistically describe both of the absolute and relative accuracies of the GPS surveying results.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.10a
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• pp.134-152
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• 1993

Many business forecasting problems are characterized by infrequent occurences, a large number of variables, presence of error, and great complexity. Because no forecasting models and tools are effective in handing these problems, managers often use the outcomes of past analogous cases to predict the outcome of the current one. They (1) observe significant attributes in describing a case, (2) identify the past cases similar in these attributes to the current case, and (3) predict the outcome of the current case based on those of the analogous cases identified through some mental simulation and adjustment. This process of forecasting can be termed forecasting-by-analogy. In spite of fairly frequent use of this forecasting process in practice, however, if has not been recognized as a primary forecasting tool, nor applied on a regular basis. In this paper, by automatizing this process using computer models, we develop a case-based forecasting system(CBFS), which identifies relevant cases and applies their outcomes to generate a forecast. We demonstrate the effectiveness of the CBFS in terms of its accuracy in predicting the outcome of the current problem based on the similar cases identified. We compare the forecasting accuracy of the CBFS with that of regression models developed by stepwise procedure under varied simulated problem conditions. The CBFS outperforms regression models in most comparisons. The CBFS could be used as an effective forecasting tool.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.2
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• pp.199-215
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• 1994

Many business forecasting problems are characterized by infrequent occurrences, a large number of variables, presence of error, and great complexity. Because no forecasting models and tools are effective in handing these problems, managers often use the outcomes of past analogous cases to predict the outcome of the current one. They (1) observe significant attributes in describing a case, (2) identify the past cases similar in these attributes to the current case, and (3) predict the outcome of the current case based on those of the analogous cases identified through some mental simulation and adjustment. This process of forecasting can be termed forecasting-by-analogy. In spite of fairly frequent use of this forecasting process in practice, however, it has not been recognized as a primary forecasting tool, nor applied on a regular basis. In this paper, by automatizing this process using computer models, we develop a case-based forecasting system (CBFS), which identifies relevant cases and applies their coutcomes to generate a forecast. We demonstrate the effectiveness of the CBFS in terms of its accuracy in predicting the outcome of the current problem based on the similar cases identified. We compare the forecasting accuracy of the CBFS with that of regression models developed by stepwise procedure under varied simulated problem conditions. The CBFS outperforms regression models in most comparisons. The CBFS could be used as an effective forecasting tool.

• Korean Journal of Construction Engineering and Management
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• v.7 no.2 s.30
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• pp.171-180
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• 2006

Change is inevitable and is a reality of construction projects. Most construction contracts include change clauses and allowing contractors an equitable adjustment to the contract price and duration caused by change. However, the actions of a contractor can cause a loss of productivity and furthermore can result in disruption of the whole project because of a cumulative or ripple effect. Because of its complicated nature, it becomes a complex issue to determine the cumulative impact (ripple effect) caused by single or multiple change orders. Furthermore, owners and contractors do not always agree on the adjusted contract price for the cumulative impact of the changes. A number of studies have attempted to quantify the impact of change orders on project costs and schedule. Many of these attempted to develop regression models to quantify the loss. However, regression analysis has shortcomings in dealing with many qualitative or noisy input data. This study develops ANN models to classify and quantify the labor productivity losses that are caused by the cumulative impact of change orders. The results show that ANN models give significantly improved performance compared to traditional statistical models.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.3
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• pp.246-251
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• 2014

In case of prosthesis fabrication by CAD/CAM, location, area and contour of occlusal contacts can be adjusted so more functional occlusion can be acquired. Also, errors in a manufacturing process is reduced compared to cast metal prostheses and porcelain fused metal prostheses fabricated by conventional methods such as casting and porcelain build up. Therefore, prostheses by CAD/CAM show superior occlusion accuracy. Recently, virtual articulator function has been introduced to CAD/CAM system, which reproduces mandibular movement against maxilla. Thus, it is possible to consider occlusal interference in anterior/lateral movement as well as closing movement. There have been many studies on the marginal and internal fit of prostheses using zirconia but the occlusal fit of zirconia crown fabricated by CAD/CAM has not been researched as much. In this case report, 7 zirconia crowns were designed and fabricated by CAD/CAM for total 5 patients. The models of zirconia crowns before and after occlusal adjustment during intraoral try-in were scanned for occlusal contacts, which were compared to evaluate accuracy of prostheses and understand patterns of occlusal adjustment. Most of the occlusal adjustments were done on functional cusps and slopes of zirconia crown, and the magnitude of occlusal adjustment ranged from $15{\mu}m$ to $60{\mu}m$. In the zirconia crown fabricated with CAD/CAM systems, the occlusal adjustment is a necessary procedure, so additional procedures will be needed for compensating reduced mechanical properties.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.15-19
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• 2003

The Total Least Squares (TLS) method is introduced in comparison with the conventional Least Squares (LS) method. The principles and mathematical models for both methods are summarized and the comparison results from their applications to a simple geometric example, fitting a straight line to a set of 2D points are presented. As conceptually reasoned, the results clearly indicate that LS is more susceptible of producing wrong parameters with worse precision rather than TLS. For many applications in surveying, can adjustment computation and parameter estimation based on TLS provide better results.

• Journal of the Korean Home Economics Association
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• v.38 no.9
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• pp.19-32
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• 2000

The purpose of this study was to discuss previous studies and theories on family business. This study were to examine the dominant trends in the precious research, and to introduce several conceptual frameworks and models, such as family business theory, family resource management theory, theory of household adjustment and adaptation, and family business viability model. This study will be helpful in understanding of the relationship between family and business, and the work-family interface, and in developing policies and programs that assist family business and enhance the well-being for family members who are involved in family business.