• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.17 no.3
• /
• pp.178-187
• /
• 2005

A reliability analysis model f3r studying the influence of joint distribution of wave heights and periods on wave un-up is presented in this paper. From the definition of failure mode related to wave run-up, a reliability function may be formulated which can be considered uncertainties of water level. In particular, the reliability analysis model can be directly taken into account statistical properties and distributions of wave periods by considering wave period in the reliability function to be a random variable. Also, variations of wave height distribution conditioned to mean wave periods can be taken into account correctly. By comparison of results of additional reliability analysis using extreme distributions with those resulted from joint distribution of wave height and periods, it is found that probabilities of failure evaluated by the latter is larger than those by the former. Although the freeboard of sloped-breakwater structures can be determined by extreme distribution based on the long-term measurements, it may be necessary to investigate additionally into wave run-up by using the present reliability analysis model formulated to consider joint distribution of a single storm event. In addition, it may be found that the effect of spectral bandwidth parameter on reliability index may be little, but the effect of wave height distribution conditioned to mean wave periods is straightforward. Therefore, it may be confirmed that effects of wave periods on the probability of failure of wave run-up may be taken into account through the conditional distribution of wave heights. Finally, the probabilities of failure with respect to freeboard of sloped-breakwater structures can be estimated by which the rational determination of crest level of sloped-breakwater structures may be possible.

• Journal of Digital Convergence
• /
• v.12 no.4
• /
• pp.145-155
• /
• 2014

POSCO has been chosen as the most competitive steelmaker in the world, for the 4th year in a row. It's potentials and key success points lay at technology innovation as well as effective partnerships with suppliers and customers. Partnership with suppliers is based upon the effective supply chain management. While ERP system supports the standard business work flows, the biggest impact on business performance is created by exceptions and variability. A SCM Advanced Planning System reduces the amount of exceptional situations, helping to keep business in a standard mode of operation. A case summary on SCM Advanced Planning System of POSCO as well as its impact on firm performances is presented. As a supplement to this case study, we also investigate the employees' perceived level of SCM-related factors, including information sharing, collaboration, incentive system for suppliers and their impacts on SCM performances. As a conclusion, the practical implications of these findings are discussed.

• Journal of Convergence for Information Technology
• /
• v.10 no.9
• /
• pp.8-14
• /
• 2020

The objective of this research is to investigate how implementation of smart factory systems(SFS) effects management accounting(MA). The results based on data collected from 108 Korea small and medium enterprises(SME) confirmed that SFS implementation caused significant MA changes. Estimated regression models revealed that the most important SFS characteristic were the analytical capabilities since it positively influenced MA changes in four dimensions: internal reporting, budgeting, application of modern accounting techniques and MA employee's job. In the segment of budgeting, the quality of implementation of specialized bedgeting software had significant and positive influence. The only negative correlation founded was the one between the uncertainty of business environment and adoption of modern accounting techniques. Results from this study provide that SME should put special focus on implementation of business analytics modules in order to achieve comprehensive benefits in MA prctices.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.4
• /
• pp.887-896
• /
• 2015

This study estimates future AADT using historical AADT and socio-economic factors in isolated area. Multiple linear regression method by socio-economic factors are lower MAPE and higher R-square than using historical AADT. Analysis of socio-economic factors influence AADT in isolated typical areas, varied socio-economic factors influence on AADT. In isolated coastal areas, oil price influence on AADT. AADT forecasting model in isolated area is excellent when analysising $R^2$ and MAPE. It is assume that estimation of AADT in isolated area using multiple linear regression is accurate because of a little passed traffic volume and traffic volume fluctuation.

• Journal of Korea Water Resources Association
• /
• v.30 no.6
• /
• pp.691-698
• /
• 1997

The risk assessment model for dam and levee is applied to a river where two adjacent dams are located in the upstream of the watershed. "A" dam is proven to be safe with 200-year precipitation and unsafe with PMP condition, whereas "B" dam to be safe with 200-year precipitation and PMP condition. The computed risk considering the uncertainties of the runoff coefficient. initial water depth and relevant data of the dam and spillway turn out to be equivalent results in Monte-Carlo and AFOSM method. In levee risk model, this study addresses the uncertainty of water surface elevation by Manning's equation. Monte-Carlo simulation with the variations of Manning's roughness coefficient is calculated by assuming that it follows atriangular distribution. The model can be used for preparing flood risk maps, flood warning systems, and establishing nation's flood disaster protection plan.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.1541-1545
• /
• 2009

홍수 기간 중 부유잡목에 의한 수위상승 원인은 크게 상류부에서 이송되어진 유송잡물에 의한 교량 등의 수공구조물에 집적으로 인한 통수능 부족에 의하여 발생되는 수위상승과 하천내 수공 구조물의 부적절한 설계 및 시공으로 인한 수위상승으로 구분되어 진다. 현재 교량의 여유고 산정에 사용되는 홍수위는 통수능을 고려하지 않은, 하천정비계획에 사용되는 홍수위를 적용하고 있으며, 다만 통수능의 확보를 위하여 경간장에 대한 제한을 두고 있을 뿐이다. 중소하천에 위치하는 교량의 경우, 여유고 확보에 대한 기준을 적용함에 있어서 교량이 위치한 하천 단면에서의 통수능의 영향이 고려되어야 유수의 월류에 대한 위험성을 줄일 수 있다. 더욱이 하천설계기준(2005)에서는 고정 홍수량에 의한 여유고 산정치를 제안하고 있을 뿐이기 때문에, 하천설계기준에서 교량과 관련된 여유고도 하상변동과 만곡부에 의한 수위 상승, 유송잡물에 의한 통수능 영향, 계산오차 등을 고려하여 충분한 여유고를 확보하도록 보완할 필요가 있다. 본 연구에서는 부유잡목에 의한 수위상승 원인을 분석을 하고, 이에 따른 수리모형실험을 통하여 부유잡목의 높이/폭(H/B)변화에 의한 수위상승, 부유잡목의 형태별 수위상승, 교각사이 개도비에 따른 수위 상승량을 산정하여 기존의 여유고에 대한 추가적인 여유고를 확보하여 홍수시 통수능을 확보하고자 하였다. 부유잡목의 형태에 따른 수위상승량을 산정하기 위하여 개도비를 70%로 고정한 후, Fr수를 변화시켜 부유잡목의 높이/폭(H/B) 형태에 따라 산정한 결과, 부유잡목이 존재하지 않는 상태에 비하여 부유잡목에 의한 영향으로 인한 수위증가율이 Fr값이 클수록 더욱 크게 나타났으며, 부유잡목이 동일면적인 경우 폭(B)에 비하여 높이(H)가 커질수록 수위 상승이 크게 나타났다. 또한, Fr수 변화에 따른 최고수위 상승율을 구하였을 때, 상류조건에서 Fr < 0.5 인 경우는 기존 여유고에 대하여 최대 10%의 여유고를 추가 확보하며, 0.5 < Fr < 1 인 경우는 기존 여유고에 대하여 최대 20%의 여유고를 추가 확보하도록 설계하는 것이 바람직하다.

• Korean Journal of Construction Engineering and Management
• /
• v.11 no.5
• /
• pp.32-40
• /
• 2010

Recent periodical boom and burst of house price have made mortgage lending issues become the main public interest in Korean real estate market. However, because mortgage-lending issues had not been discussed until then, housing market forecasting associated with mortgage lending has been difficult while using an empirical approach. Thus, comprehensive and systematic approach is required as well as validity of mortgage lending policies should be evaluated. In this regard, this research conducts a sensitivity analysis to validate the proposed policies and estimates the effects of current policies on LTV and DTI ratios with a comparison of another policies scenario. A causal loop and sensitivity analysis using system dynamics confirmed that LTV and DTI regulation is strong clout to housing market. However, to prevent transfer of potential mortgage borrowers to nonmonetary institutions, regulations in loans of nonmonetary institutions should be practiced in accompaniment with regulations of primary lending agencies.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.14 no.5
• /
• pp.1115-1128
• /
• 1994

The condition of temperature gradients in asphaltic concrete (Ascon) pavement have been analyzed based on the data collected from 5 major sites in Korea. From this. considering heat transfer by insolation flux and air temperature within pavement slab. temperature variation on the surface of pavement was computed and numerical model using the theory of thermal conductivity was applied to estimate the temperature gradients in depth. To investigate the present condition of asphalt generally used in Korea. the asphalt property tests were applicated on 5 different AP-3 (AC 85~100), and AP-5 (AC 60~70) asphalts classified by penetration index. Uniaxial compression test and indirect tensile test were also carried out for varying temperature conditions to analyze the effect of temperature on the deformation characteristics of Ascon pavement by calculating the variation of static elastic modulus and layer coefficients.

• Journal of Korea Technology Innovation Society
• /
• v.14 no.spc
• /
• pp.1171-1186
• /
• 2011

Identifying Emerging Technology Trends is crucial for decision makers of nations and organizations in order to use limited resources, such as time, money, etc., efficiently. Many researchers have proposed emerging trend detection systems based on a popularity analysis of the document, but this still needs to be improved. In this paper, an emerging trend detection classifier is proposed which uses both academic and industrial data, SCOPUS and PATSTAT. Unlike most pre-vious research, our emerging technology trend classifi-er utilizes supervised, semi-automatic, machine learning techniques to improve the precision of the results. In addition, the citation information from among the SCOPUS data is analyzed to identify the early signals of emerging technology trends.

• Journal of Digital Convergence
• /
• v.11 no.11
• /
• pp.59-70
• /
• 2013

As people invest most of their asset in real estate, there is high interest in changing in housing and real estate prices in the future for a digital economy. Various variables are affecting the housing and real estate market. Among them, four variables : households, productive population, interest rate and index price are chosen and analyzed representatively. This study is aimed to build decision model of apartment prices in Seoul empirically. From the analysis result the stock index is the only variable which is significant statistically to apartments in Seoul. From this study, the households and productive population show the same direction as shown in the previous studies before but not significant statistically. Among the independent variables, the stock index is chosen as a major variable of determinant of Seoul apartment price. From the result of the research, prediction of stock market should be preceded to forecast the movement of housing and real estate market in the future.