• Journal of the Microelectronics and Packaging Society
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• v.7 no.1
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• pp.13-18
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• 2000

Low temperature co-fired ceramics on metal (LTCC-M) is efficient for embedding passive components with good tolerance in a module due to the dimensional stability in x and y directions by the constraint of metal core during the firing. In addition, the radiation noise can be reduced by metal core. In this paper, embedded passive components were introduced and a power amplifier module (PAM) fabricated by using the passive components was explained. The embedded passive components in test patters showed the tolerance of 10~20% and the good repeatability in tolerance of embedded passives was maintained in module fabrication. The shortened traces in multi chip modules (MCMs) make the signal delay time decreased and the embedded passives simplify the packaging processes owing to the less solder points, which enhance the electrical performance and increase the reliability of the modules. The LTCC-M technology is one of the promising candidates for RF application and is expected to expand its applications to power and high performance devices.

• Tunnel and Underground Space
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• v.24 no.1
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• pp.55-66
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• 2014

In this study, a joint survey system was developed to efficiently analyze geometrical characteristics of joint structures in rock mass using photogrammetric technique. The system includes both hardware and software. The hardware consists of a high resolution image camera for photographing image of a surface of rock body, a direction controlling system for adjusting the attitude of camera, and a digital compass for measuring the rotation angle of camera. The software was also developed in order to analyze the orientation, density, mean length of joints revealed on the images of rock surfaces. The software developed in this study was named as JointeXtractor. As applying this system into several field measurements, the orientation, density, mean length of joints could be quantitatively measured through analyzing the images of rock surfaces, in which the case of a difficult-to-access area was especially included for the test of the system.

• Pediatric Infection and Vaccine
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• v.12 no.1
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• pp.95-99
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• 2005

Pneumocystis carinii pneumonia is an infectious disease which is highly prevalent in the group of immunosuppressed patients, particularly with hematologic tumors as lymphomas and acquired immune deficiency syndrome(AIDS), severe malnutrition, organ transplantations, high dose corticosteroid therapy. Some cases of Pneumocystis carinii pneumonia in infants with primary immune deficiency were already reported. The authors present a case of Pneumocystis carinii pneumonia developed in an infant who suffered from 10 days of poor feeding and failure to thrive and not included in the risk groups listed above. He had bilateral interstitial infiltrations on the chest radiography, diagnosed as Pneumocystis carinii pneumonia after Gomori-methenamine silver staining of his sputum that was taken through tracheal intubation. He improved after administering Trimethoprim-sulfamethoxazole for 14 days.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.4 s.31
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• pp.61-68
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• 2004

In this paper, we suggest an automatic technique to obtain 3-D road information in complex urban areas using road pavement markings. This method is composed of following three main steps. The first step is extracting the pavement markings from aerial images, the second one is matching the same pavement markings in two aerial images, and the last one is obtaining the 3-D coordinates of those using EOP(exterior orientation parameters) of aerial images. Here, we focus on the first and second step because the last step can be performed by using the well hewn collinearity condition equation. We used geometric properties and spatial relationships of the pavement markings to extract the lane line markings on the images and extracted arrow lane markings additionally using template matching. And then, we obtained 3-D coordinates of the road using relational matching for the pavement markings. In order to evaluate the accuracy of extraction, we did a visual inspection and compared the result of this technique with those measured by digital photogrammetric system.

• Journal of the Korean Data and Information Science Society
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• v.26 no.2
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• pp.289-299
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• 2015

The objective of the present study is to develop statistical quantitative forecast model for PM10 concentration over Seoul. We used three types of data (weather observation data in Korea, the China's weather observation data collected by GTS, and air quality numerical model forecasts). To apply the daily forecast system, hourly data are converted to daily data and then lagging was performed. The potential predictors were selected based on correlation analysis and multicollinearity check. Model validation has been performed for checking model stability. We applied two models (multiple regression model and threshold regression model) separately. The two models were compared based on the scatter plot of forecasts and observations, time series plots, RMSE, skill scores. As a result, a threshold regression model performs better than multiple regression model in high PM10 concentration cases.

• Journal of Korean Society for Quality Management
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• v.48 no.1
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• pp.171-186
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• 2020

Purpose: The purpose of this study is conducting of predictive models that considered multicollinearity of independent variables in order to carry out more efficient and reliable predictions about differential pressure in seawater reverse osmosis. Methods: The main variables of each RO system are extracted through factor analysis. Common variables are derived through comparison of RO system # 1 and RO system # 2. In order to carry out the prediction modeling about the differential pressure, which is the target variable, we constructed the prediction model reflecting the regression analysis, the artificial neural network, and the support vector machine in R package, and figured out the superiority of the model by comparing RMSE. Results: The number of factors extracted from factor analysis of RO system #1 and RO system #2 is same. And the value of variability(% Var) increased as step proceeds according to the analysis procedure. As a result of deriving the average RMSE of the models, the overall prediction of the SVM was superior to the other models. Conclusion: This study is meaningful in that it has been conducting a demonstration study of considering the multicollinearity of independent variables. Before establishing a predictive model for a target variable, it would be more accurate predictive model if the relevant variables are derived and reflected.

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.317-325
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• 2008

As a result of recent research, it is reported that the periodic replacements criterion of rails is able to extend as grinding rail surface and using the continuous welded rail (CWR). This study evaluated correlation between conditions of track and load capacity of rail by analysing the dynamic response of track while the metro train is running. Also, it was converted the measured stress waveform into stress frequency histogram by the rain-flow counting methods, and then accumulated fatigue damage ratio and remaining service life of laid rail were calculated so as the apply the equivalence of stress to S-N curve of a new welded rail. Finally, this study suggests a revision of the periodic replacements criterion of CWR, which was based on accumulated passing tonnage, classified by the types and conditions of track system.

• Journal of Digital Convergence
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• v.13 no.3
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• pp.75-84
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• 2015

As the service industry has been getting increased attention as the core for the national economic growth, in order to promote growth and development of the industry, in-depth research on the workers in the industry has been timely called for. Therefore current study aims to explore the effect of leadership style on organizational citizenship behavior(ie OCB) for increased productivity of workers in the service industry, and the role of multi-dimensional justice in the relationship between them. The findings suggest that transformational and transactional leadership both have positive effect on OCB, implying that application of leadership style that is appropriate to the context may be more important, Also, mediation test of multi-dimensional justice resulted partial mediation effect except for the procedural justice in the relationship between transformational leadership and OCB.

• PNF and Movement
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• v.8 no.2
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• pp.47-55
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• 2010

Purpose : The purpose of present study was to determine effects of a task-oriented circuit training(TOCT) for lower limb on walking ability after stroke. Methods : Twenty one chronic stroke patients participated. Participants were randomly divided into either TOCT group or control group(11 experimental, 10 control). All of participants were in-patients at local rehabilitation centre and had been receiving a traditional rehabilitation program, five days a week. TOCT group have additionally undergone for four weeks, three days a week, the TOCT program but control group was not received any additional program except the traditional rehabilitation program. The 10 m walking test (10MWT), the 2 min walking test (2MWT), the step test (ST) and the figure-8 walking test (F8WT) to measure a walking ability were carried out twice before and after training. Results : After participation in the program, subjects of TOCT demonstrated a significant improvement in the scores of the 10MWT, 2MWT, the ST, the F8WT. The control group had no change on the any tests. After the training, the results to improve significantly in TOCT group compared to post-test of control group were the time of 10MWT and the time and the step of curved walking of F8WT. Conclusion : The present study suggests that the TOCT program may become a useful strategy for enhancing walking ability in the rehabilitation of stroke patients.

• Fire Science and Engineering
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• v.28 no.2
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• pp.69-75
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• 2014

This study derives the factors which affect the occurrence of arson from statistical data (population, economic, and social factors) by multiple regression analysis. Multiple regression analysis applies to 4 forms of functions, linear functions, semi-log functions, inverse log functions, and dual log functions. Also analysis respectively functions by using the stepwise progress which considered selection and deletion of the independent variable factors by each steps. In order to solve a problem of multiple regression analysis, autocorrelation and multicollinearity, Variance Inflation Factor (VIF) and the Durbin-Watson coefficient were considered. Through the analysis, the optimal model was determined by adjusted Rsquared which means statistical significance used determination, Adjusted R-squared of linear function is scored 0.935 (93.5%), the highest of the 4 forms of function, and so linear function is the optimal model in this study. Then interpretation to the optimal model is conducted. As a result of the analysis, the factors affecting the arson were resulted in lines, the incidence of crime (0.829), the general divorce rate (0.151), the financial autonomy rate (0.149), and the consumer price index (0.099).