• 월간 기계설비
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• s.267
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• pp.78-79
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• 2012

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.540-545
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• 2008

The purpose of this study is to suggest problems and improving plan of process of calculating escalation rate of the Historical Cost by price fluctuation. In order to implement this research, we analyzed problems by calculating the rate of price fluctuation with Historical Cost and measurement applying method making on-site with historical cost data were included as samples and suggested improving plan to the adjustment of contract cost. The results of research according to this are same as followings:1) Of all construction details, it is more appropriate to calculate price fluctuation by applying measurement method to the contents of historical cost unit. 2) To avoid confusion in calculating method, it was indicated that amendment in part should be achieved in order to calculate by measuring the part of calculating escalation rate of Historical Cost at related law and regulation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.667-676
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• 2014

This study has conducted case studies in order to suggest alternatives to the historical data-based estimate system. Price fluctuation calculation methods based on historial cost indexes, standard estimate and construction cost indexes were applied to 9 road construction sites in Jeju for an analysis. As a result, in 5 construction sites (about 56% of 9 sites), the index control rate calculated based upon historical data-based estimate system was higher than that calculated based upon standard estimate and construction cost indexes. Thus the establishment of the requirements for the adjustment of contract price due to price fluctuation delays, which leads to a significant difference in price fluctuation amount. And, in an analysis of construction cost indexes, the indexes for road construction were used for calculating index control rate which ranges from 2.0 to 9.4 percent, indicating the time of construction amount and price fluctuation application has a significant influence on index control rate.

• Korean Journal of Construction Engineering and Management
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• v.5 no.6 s.22
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• pp.203-211
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• 2004

This study is the results to survey on the problems and improvable Policies for current escalation system in construction contracts, through a Delphi survey to experts. From the survey results, it is desirable to decide the fluctuation rate of construction cost, which is the requirement of escalation clause, on the basis of inflation rate or construction cost index. The desirable price fluctuation rate is proposed as a $3\%$ level. However, it is difficult for construction companies to cope with the sudden increase of material price in advance, arising from short-term shock factors such as exchange rate and international raw material's price. Accordingly escalation system for specified materials, as an exceptional mode, should be introduced. As a method to calculate the fluctuation rate, ARCA(adjustment rate for the categories of articles) is more desirable than ARI(adjustment rate for an index), because the ARCA can be more reflected the characteristics of each construction work.To rationalize the ARI method, it is needed to announce the wage index, material index and machinery expense index via detailed classification by construction types. Also, it is desirable to prescribe the bidding date as a starting date of the price change, rather than contact signing date. considering the price change can happen since the biddiilg stage.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.37-38
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• 2022

농산물의 산지 가격이나 도매가격이 등락하면, 즉시 또는 일정한 시차 이후에 소비자가격도 등락한다. 본 논문에서는 선형회귀모델을 통해 쌀 가격을 예측하고 쌀 가격에 영향을 미치는 날씨의 시기를 찾아보고자 한다. 이에 따라 KAMIS, 기상자료개방포털, KOSIS에서 수집한 날씨, 생산량, 그리고 소비자물가 등락률 데이터를 이용하여 쌀 가격 예측을 수행하고, 날씨 데이터와 쌀 가격 데이터의 날짜 간격을 두어 날씨가 쌀 가격에 영향을 미치는 시기를 알아보았다. 모델 평가 결과, 2개월 간격을 두고 예측한 RMSE가 164.135로 가장 큰 영향을 미쳤다. 본 연구를 기반으로 향후 다른 농산물의 가격 예측도 가능할 것이며 농산물에 영향을 미치는 변수의 시기도 예측할 수 있을 것으로 기대한다.

• Korean Journal of Construction Engineering and Management
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• v.13 no.1
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• pp.67-76
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• 2012

There are index adjustment method and item adjustment method in estimation methods for price fluctuation rate of public constructions. A relevant regulation has put item adjustment method as a principle, but in most construction, contract sum adjustment has been made by index adjustment method. Hence, this study, by figuring out width and causes of the gap between index adjustment method and item adjustment method through direct comparative analysis, solved inequality caused by difference between them and suggested a rational way against irrationality of each method. For building operations of public housing construction, a detailed fluctuation rate by index adjustment method and item adjustment method of construction cost elements of the same construction, that is, direct material cost, direct labor cost and historical construction cost was estimated to analyze difference between two adjustments and establish its cause. Across the analysis, it was found that fluctuation rate by item adjustment method was estimated lower than that by index adjustment method and difference between methods for estimating fluctuation rate of quotation unit price and application of index unrelated to construction type and construction nature are main causes of the difference. This study has a significance in that, for smooth contract sum adjustment between contracting parties, it practically proved the real difference between adjustment methods by conducting comparative analysis of the difference in direct correspondence way.

• Korean Journal of Construction Engineering and Management
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• v.12 no.2
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• pp.3-11
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• 2011

There are several causes to recalculate the contract amount in public construction projects. Among them, the escalation clause was introduced in 1969 and now the condition to recalculate the cost is effective after 90 days from the date of contract and the rate of fluctuation should be more than 3% from the date of bidding. The two calculation methods for the rate of fluctuation are item-adjustment and index-adjustment. According to the results of investigation into 4 public institutions and 163 projects, all of them have used the method of index-adjustment and the rate of projects that spend over 6 months obtaining the approval of contract amount adjustment is more than 90%. The reason for spending lots of time is caused by problems of the calculation method on the price fluctuation rate. Therefore, it is necessary that the calculation method should be diversified to cope with the problems and a option of the builder should be expanded as well. Furthermore, if the way to apply correction factors to construction price index and average index based on the producer and consumer price index made by the bank of Korea is added, then the duration will be reduced without additional expenses. This study proposed the diversification of the calculation method using price fluctuation rate and builders' expanded options as improvement on the managerial method of Price Fluctuation System for the prompt and efficient contract amount adjustment.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.9
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• pp.367-374
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• 2021

Stock price prediction is a subject of research in various fields such as economy, statistics, computer engineering, etc. In recent years, researches on predicting the movement of stock prices by learning artificial intelligence models from various indicators such as basic indicators and technical indicators have become active. This study proposes a deep learning model that predicts the ups and downs of KOSPI from overseas indices such as S&P500, past KOSPI indices, and trading trends by KOSPI investors. The proposed model extracts a latent variable using a stacked auto-encoder to predict stock price fluctuations, and predicts the fluctuation of the closing price compared to the market price of the day by learning an LSTM suitable for learning time series data from the extracted latent variable to decide to buy or sell based on the value. As a result of comparing the returns and prediction accuracy of the proposed model and the comparative models, the proposed model showed better performance than the comparative models.

• Economic Analysis
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• v.25 no.2
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• pp.54-95
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• 2019

The purpose of this study is to analyze quantitatively and qualitatively the effects of the increase in online shopping and its effects on real-world commercial outlets. The empirical analysis of this study is based on the results of "Census on Establishments" and "Online Shopping Survey" that cover 15 years, from 2002 to 2016. According to the results of this study, the increase in the number of online transactions affects the decrease in the number of stores in the real-world retail sector. However, non-specialized large stores and chain convenience stores showed an increase in the number of stores. In addition, the number of F&B stores increased the most in line with the increase in online transactions. This is because the increase in online transactions and in internet users led to the use of more delivery applications and the introduction of popular places on blogs or through social media. Street-level rents for medium and large-sized locations increased. In other words, it is seen that the demand for differentiated real-world stores that provide a good user experience increases, even though online transactions also increase. These results suggest that real-world stores should provide good user experiences in their physical locations with a certain size and assortment of goods.

• Proceedings of the Korean Statistical Society Conference
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• 2001.11a
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• pp.99-104
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• 2001

본 연구의 주된 목표는 1997년 주가자료를 데이터마이닝 기법인 로지스틱모형, 의사결정트리, 신경망, SVM(support vector machine), 뉴로퍼지모형을 사용하여 분석한 후 우리나라 경제상황을 진단하고 예측하는데 가장 적합한 모형을 찾고 그 모형을 해석하는데 있다. 1997년 주가자료를 훈련자료로 간주하여 그 당시 경제 상황에 따라 적절한 구간으로 나누고 훈련시킨 결과 중요한 변수로는 주가지수, 등락률 10일 이동분산, 10일 이동분산의 변동비로 나타났으며 적절한 기법으로는 의사결정트리, 신경망, SVM임을 알 수 있다. 1997년 이외의 주가자료를 데이터마이닝 기법(신경망, 의사결정트리, SVM)에 적용한 결과, 우리나라 경제상황을 고려해 볼 때 신경망이 가장 정확도가 좋은 기법으로 보여진다.