• Journal of Chest Surgery
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• v.33 no.9
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• pp.729-733
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• 2000

Background: Recent trends suggest that minimally invasive cardiac surgery reduces postoperative morbidity and offers a cosmetic benefit. This study was performed to evaluate the CPB time, ACC time, OP time, ICU stay and postoperative hospital stay following a lower partial sternotomy and those of the median sternotomy. Material and Method: A group of 26 adult patients who underwent cardiac surgery through lower partial sternotomy from August 1997 to July 1999(A group) were compared to 45 adult patients who underwent cardiac surgery through median sternotomy from January 1996 to July 1997(B group). The mean ages(46.4$\pm$14.6 years, A group and 46.8$\pm$13.2 years, B group) were similar. Operations were performed with central cannula and antegrade/retrograde blood cardioplegia. Result: There was no death in each group. No differences were found in CPB time, ACC time, OP time, ICU stay and postoperative hospital stay. Postoperative complications were sternal splitting in a patient in group A and a patient with bleeding that required reoperation and a patient with delayed wound closure in group B. Conclusion: The lower partial sternotomy offered a cosmetic benefit, but does not significantly reduced the length of operative time and hospital stay. Minimally invasive cardiac surgery will be applied increasing because of the suggested advantage and choosing a proper operative technique will be helpful.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.2
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• pp.1-11
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• 2023

This study analyzed the impact of greenhouse cultivation area and groundwater level changes due to the water curtain cultivation in the greenhouse complexes. The groundwater observation data in the Miryang study area were used and classified into greenhouse and field cultivation areas to compare the groundwater impact of water curtain cultivation in the greenhouse complex. We identified the characteristics of the groundwater time series data by the terrain of the study area and selected the optimal model through time series analysis. We analyzed the time series data for each terrain's two representative groundwater observation wells. The Seasonal ARIMA model was chosen as the optimal model for riverside well, and for plain and mountain well, the ARIMA model and Seasonal ARIMA model were selected as the optimal model. A suitable prediction model is not limited to one model due to a change in a groundwater level fluctuation pattern caused by a surrounding environment change but may change over time. Therefore, it is necessary to periodically check and revise the optimal model rather than continuously applying one selected ARIMA model. Groundwater forecasting results through time series analysis can be used for sustainable groundwater resource management.

• Geomechanics and Engineering
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• v.34 no.1
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• pp.1-15
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• 2023

This study conducts uniaxial compression tests on intact and single crack-contained rocks to investigate the time-frequency domain characteristics of acoustic emission (AE) signals monitored during the deformation failure process. A processing approach, short-time Fourier transform (STFT), is performed to obtain the evolution characteristics of time-frequency domain of AE signals. The AE signal modes at different deformation stages of rocks are different. Five modes of AE signal are observed during the cracking process of rocks. The evolution characteristics of time-frequency domain of AE signals processed by STFT can be utilized to evaluate the damage process of rocks. The difference of time-frequency domain characteristics between intact and cracked rocks is comparatively analyzed. The distribution characteristics of frequency changing from a single band-shaped cluster to multiple band-shaped clusters can be regarded as an early warning information of damage and failure of rocks. Meanwhile, the attenuation of frequency enables the exploration of rock failure trends.

• Journal of the Korean Society of Safety
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• v.25 no.5
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• pp.33-38
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• 2010

Railway is one of popular transportation systems. Due to the safety and in time, the transportation by train is preferred to the others for a long time. However, accidents under railway construction get more serious problems than in case of the other system, because it is the largest mass transportation system. Especially, the railway construction is composed of different kinds of construction works such as civil, architect, electric and mechanic. It is closely/complicatedly connected with various workers, large machines and facilities, regulations etc. In this study the data on safety accidents are corrected during 6 years(2004~2009) and analyzed by time(year, month, week, day, a.m or p.m), place, field, type etc. Results shows that there exists remakable trends on accidents, so efficient treatments should be prepared considering this trend.

• Atmosphere
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• v.18 no.3
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• pp.199-206
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• 2008

This study employs a structural time series method in order to model and estimate stochastic trend of surface temperatures of the globe, Northern Hemisphere, and Northeast Asia ($20^{\circ}N{\sim}60^{\circ}N$, $100^{\circ}E{\sim}150^{\circ}E$). For this study the reanalysis data CRUTEM3 (CRU/Hadley Centre gridded land-surface air temperature Version 3) is used. The results show that in these three regions range from $0.268^{\circ}C$ to $0.336^{\circ}C$ in 1997, whereas these vary from $0.423^{\circ}C$ to $0.583^{\circ}C$ in 2007. The annual mean temperature over Northeast Asia has increased by $0.031^{\circ}C$ in 2007 compared to 1997. The climate change in surface temperatures over Northeast Asia is slightly higher than that over the Northern Hemisphere.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.118.1-118
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• 2002

Recent trends in internet access to the device network require that information be provided from anywhere in the enterprise. One then needs to integrate both device network protocol and data network protocol to realize Virtual Device Network (VDN). Interoperability between devices and equipments is essential to enhance the quality and the performance of VDN. LonWorks technology is incorporated as device network protocol for interoperability. VDN integrating both device network and data network has varying time delay. Inherent varying time delay of VDN can significantly degrade the reliability of Distributed Control System. This study investigates the transmission characteristics of VDN and s...

• Journal of Korean Society of Rural Planning
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• v.22 no.1
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• pp.49-56
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• 2016

Throughout the economic development era of Korea, migration occurred within a spatial hierarchy, with upward flows from rural areas to urban. The concept of step migration is a typical theory to explain these upward migration flows. Recent migration data and trends, however, indicate that migration-pattern regime shows strongly opposite-direction flows, with many of the major migration flowing downward on this national-spatial hierarchy, away from urban areas. In this study, we examine the most recent structure of migration flows up and down within the national-spatial hierarchy. We define seven tiers to tabulate origin-destination migration flows from population density of local administrative districts for the period 2001-2014, and then analyze the migration patterns between the tiers over time. The results show differentiated patterns of migration within the national-spatial hierarchy over time including specific states of migrants' life cycles.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.03a
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• pp.207-211
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• 1999

Nowadays human sensibility ergonomics is spotlighted as one of trends which we have pursued for improvement of humanity. Human sensibility ergonomics is a technique making human life more convenient by applying it to many kinds of products and design for environment by measuring and estimating human sensibility more qualitatively and quantitatively. The study of human sensibility can be discovered in oriental philosophy based on human being. Therefore there is an close relationship between human sensibility ergonomics and oriental philosophy. In this study, we research the sensibility factors of diagnostics by Sasang constitutional medicine, Five element properties and biorhythm by human sensibility ergonomics, and will apply the result of this study - the analyses of the difference among reaction time by using ANOVA after measuring the reaction time depending on one's individual temperament and condition- to job design.

• Journal of the Korean Dietetic Association
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• v.9 no.2
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• pp.149-158
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• 2003

This study investigated changes in the household expenditure for food outside home using the time-series family expenditure data during 1982-2002. Major findings were as following: first, expenditure for food outside home had been increasing, while over all level of the food expenditure had been decreasing; second, two thirds of the total amount of expenditure for food outside home were for regular meals; the proportion of food outside home which were paid to alcohols and other beverages have been decreasing since 1999; lastly, over the half of the total expenditure for food outside home had been spent on Korean food. Based on the results implications for consumer trends for food and food industry were provided.

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1133-1140
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• 2008

The goal of this paper is to analysis of the trend for stream quality in Gumi industrial complex with Winters' exponential smoothing method. It used the five different monthly time series data such as BOD, COD, TN, TP and EC from January 1998 to December 2006. The data of BOD, COD, TN, TP and EC are analyzed by time series method and forecasted the trends until December 2007. The stream qualities change for the better about BOD, COD, TN and TP, but the stream qualities resulted by EC is still serious.