• Journal of the Korean Society of Safety
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• v.33 no.4
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• pp.98-104
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• 2018

Macroscopic accident analyses have been conducted to incorporate transportation safety into long-term transportation planning. In macro-level accident prediction model, exposure variable(e.g. a settled population) have been used as fundamental explanatory variable under the concept that each trip will be subjected to a probable risk of accident. However, a settled population may be embedded error by exclusion of active population concept. The objective of this research study is to develop macro-level accident prediction model using floating population variable(concept of including a settled population and active population) collected from mobile phone data. The concept of accident prediction models is introduced utilizing exposure variable as explanatory variable in a generalized linear regression with assumption of a negative binomial error structure. The goodness of fit of model using floating population variable is compared with that of the each models using population and the number of household variables. Also, log transformation models are additionally developed to improve the goodness of fit. The results show that the log transformation model using floating population variable is useful for capturing the relationships between accident and exposure variable and generally perform better than the models using other existing exposure variables. The developed model using floating population variable can be used to guide transportation safety policy decision makers to allocate resources more efficiently for the regions(or zones) with higher risk and improve urban transportation safety in transportation planning step.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.3
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• pp.149-156
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• 2020

The study aims to investigate a close relation between macro and non-macro variables on stock performance of tourism companies in Korea. The sample used in this study includes monthly data from January 2001 to December 2018. The stock price index of the tourism companies as a dependent variable are obtained from Sejoong, HanaTour, and RedcapTour as three leading Korean tourism companies that have been listed on the Korea Stock Exchange. This study assesses the tourism stock performance using the quantile regression approach. This study also investigates whether global crisis events as the Iraq War and the global financial crisis as non-macro variables have a significant effect on the stock performance of tourism companies in Korea. The results show that the oil prices, exchange rate and industrial production have negative coefficients on stock prices of tourism companies, while the effects of tourist expenditure and consumer price index are positive and significant. We estimate the result of quantile regression that non-macro determinants have statistically a significant and negative effect on tourism stock performance because the global crisis could threaten traveler's safety and economy. Overall, empirical results suggest that the effects of macro and non-macro variables are statistically asymmetric and highly related to tourism stock performance.

• Magazine of the Korea Concrete Institute
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• v.11 no.1
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• pp.77-87
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• 1999

The conventional design of prestressed concrete box girder bridges has been based on the linear elastic analyses using simplified geometric models. To overcome the restriction involved in the simplifications, a macro element for the rational analysis of prestressed concrete box girder bridges with variable cross sections is incorporated in the present analysis. Through the adoption of nonlinear material models, the behaviour of prestressed box bridges up to ultimate loading stage can be examined. The time dependent material models included in the present macro element code enable to predict the long term behaviour of prestressed concrete box girder bridges. The proposed macro element code with the nonlinear material models and time dependent routines can be efficiently used for the realistic analysis of prestressed concrete box girder bridges with arbitrary shapes.

• Journal of Wetlands Research
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• v.7 no.4
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• pp.51-65
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• 2005

The insects and Benthic Macro-Invertebrates are very important for index of investigation. This reserch is executed a field investigation with a date analysis of the laboratory under such as above hypothesis and we have grasped the change of the creature according to the season through the executing of field investigation(We executed six times about the insects, seven times about the Benthic Macro-Inbertebrates each expending from Apr. to Oct. 2004). The result of summary in 2004 show that, we have grasped 12 orders 56 familys 116 species on 2001 and 10 orders 42 familys 78 species on 2002 through the investigation. Also we have grasped 13 orders 53 familys 114 species on 2003 and 12 orders 63 familys 121 speceies on 2004 through the investigation. In the case of enthic Macro-Invertebrates, we executed the analysis through the investigation result expending from 2003 to 2004 due to there is no literature investigation record from 2001 to 2002. We have grasped 8 orders 17 familys 24 species on 2003 and 7 orders 11 familys 24 species on Aug. 2004 through the investigation. We executed the analysis about an each condition due to it is difficult to compare the above result simply by the various variable at the investigation. We expect that it become the fundamental reference data to establish a efficient mode of life undo plan after grasped the inhabitation and movement route of creature inside the river through this reserch.

• Structural Engineering and Mechanics
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• v.51 no.3
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• pp.447-470
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• 2014

Numerical simulation of the non-linear behavior of (RC) structural walls subjected to severe earthquake ground motions requires a reliable modeling approach that includes important material characteristics and behavioral response features. The objective of this paper is to optimize a simplified method for the assessment of the seismic response and damage development analyses of an RC structural wall building using macro-element model. The first stage of this study investigates effectiveness and ability of the macro-element model in predicting the flexural nonlinear response of the specimen based on previous experimental test results conducted in UCLA. The sensitivity of the predicted wall responses to changes in model parameters is also assessed. The macro-element model is next used to examine the dynamic behavior of the structural wall building-all the way from elastic behavior to global instability, by applying an approximate Incremental Dynamic Analysis (IDA), based on Uncoupled Modal Response History Analysis (UMRHA), setting up nonlinear single degree of freedom systems. Finally, the identification of the global stiffness decrease as a function of a damage variable is carried out by means of this simplified methodology. Responses are compared at various locations on the structural wall by conducting static and dynamic pushover analyses for accurate estimation of seismic performance of the structure using macro-element model. Results obtained with the numerical model for rectangular wall cross sections compare favorably with experimental responses for flexural capacity, stiffness, and deformability. Overall, the model is qualified for safety assessment and design of earthquake resistant structures with structural walls.

• The Journal of Fisheries Business Administration
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• v.14 no.1
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• pp.1-18
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• 1983

This study has examined the principle of rationalization as a guiding principle in fisheries management. Generally speaking, the guiding principle of business management is the principle of profitability which is oriented to the profit maximization, but it has been insisted by Dr, Mohri that the principle of profitability should be translated into the maximization of ratio of added value on gross capital, According to Dr. Durcker, added value (contributed value) can be used to analyze productivity only if the allocation of costs which together make up the figures is economically meaningful. Therefore, the rationalization of fisheries management can be measured as a result of economic allocation of costs, The analysis of economic allocation of costs divides into macro-allocation of costs and micro-allocation of costs. In fisheries management, the former makes use of the analysis of break-even point, and the latter analyzes the efficiency of individual cost respectively and the state of division of costs which allocate into above-the-line expenses of lay system and management's burden expenses. In macro-allocation of costs, it is advisable that fixed costs be converted into variable costs. This is characteristically possible in fisheries management, because wages belong to variable costs in fisheries management while they are regarde as fixed cost in the other industires. Because we could find that all costs would belong to above-the-line expenses, in micro-allocation analysis, the very costs which are directly related to fisherman's poduction activity should be classified into above-the-line expenses, and the other costs into management's burden expenses. This is a central problem in the rationalization of fisheries management.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.11b
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• pp.243-248
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• 1999

MPEG-4에서 오류강인성(Error Resilience)를 위한 한 방법으로 Resynchronization Markers(RM)을 사용한다. 한 프레임이 시작될 때 StartCode를 사용하여 동기를 맞추고 몇 개의MacroBlock을 encoding한 후 일정한 비트수(Threshold 값)가 지나면 재동기 마커 표시하여 재동기를 한다. 이렇게 하므로서 한 프레임 내에서 어떤 부분에 에러가 발생하더라도 그 에러가 속해있는 비디오패킷(재동기 마커와 재동기 마커사이의 Data)만을 버리거나 RVLC(ReversibleVariable Length Codes)를 사용하여 Data를 복원할 수 있다. 그러나 만약 재동기 마커에 에러가 발생하거나 에러의 전파로 인하여 재동기 마커를 인식 못한다면 두 개 이상의 패킷이 손실되거나RVLC를 사용한 데이터 복원을 할 수 없다. 본 논문에서는 이를 막기위해 디코딩 전에 Prescan을 통해서 재동기 마커의 위치를 탐지하고 에러가 생긴 재동기 마커를 복원하는 방법을 제안하였다. 그리고 bitrate에 따른 MB(MacroBlock)의 크기와 비디오 패킷 크기(재동기 마커와 재동기 마커간의 거리)를 분석하여 재동기 마커를 찾는 루틴에 적용하였다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.31-36
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• 1997

Thermal expansion of the ball screw in semi-closed loop type CNC Lathe directly affects the position precision along the travel axis. In this paper, the thermal displacement of the ball screw is estimated by using macro variables. The estimated displacements of the ball screw are managed by calculating the interval of pitch error rate in the NC. The thermal behaviour of the ball screw of the CNC Lathe, under the constant operating conditions, was measured to examine the effectiveness of this compensation method. The results showed that thermal displacement of the ball screw could be maintained its accuracy better than 6${\mu}{\textrm}{m}$ while applying this method.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.1
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• pp.45-51
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• 1999

Thermal expansion of the ball screw can directly affect the accuracy of positioning along the travel axis in the semi-closed loop type CNC Lathe. In this paper, use of MACRO variables can make the thermal displacement of the ball screw estimated. Also, the estimated displacements of the ball screw are controlled by calculating the interval of pitch error rate in the Numerical Control(NC). Under the constant operating conditions, the thermal expansion of the ball screw was measured to confirm the effectiveness of the compensation method in the CNC Lathe. By using this method the results show that the thermal displacement of the ball screw could be reduced to 20% compared with ordinary method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.181-186
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• 1993

Thermal expansion of ball screw in the semi-closed loop type CNC LATHE introduces positioning errors directly along the travelling the axis. In this paper the thermal displacements of the ball screw were estimated by using macro variable. The estimated displacements of the ball screw were given to the ball screw of the CNC LATHE under the constant driving conditions were measured to examine the effectiveness of the compensation method. The results showed that thermal displacements of the ball screw could be maintained less then 6 .mu.m positioning accaracy while using this compensation.