• Title/Summary/Keyword: Used Trading

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Statistical Prediction of Used Tablet PC Transaction Price among Consumers (소비자 사이의 중고 태블릿PC 거래 가격의 통계적 예측)

  • Younghee Go;Sohyung Kim;Yujin Chung
    • Journal of Industrial Convergence
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    • v.20 no.12
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    • pp.179-186
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    • 2022
  • This study aims to develop a predictive model to suggest a used sales price to sellers and buyers when trading used tablet PCs. For model development, we analyzed the real used tablet PC transaction data and additionally collected detailed product information. We developed several predictive models and selected the best predictive model among them. Specifically, we considered a multiple linear regression model using the used sales price as a dependent variable and other variables in the integrated data as independent variables, a multiple linear regression model including interactions, and the models from stepwise variable selection in each model. The model with the best predictive performance was finally selected through cross-validation. Through this study, we can predict the sales price of used tablet PCs and suggest appropriate used sales prices to sellers and buyers.

Seismic Performance Assessment of Hollow Reinforced Concrete and Prestressed Concrete Bridge Columns

  • Kim, Tae-Hoon;Seong, Dai-Jeong;Shin, Hyun Mock
    • International Journal of Concrete Structures and Materials
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    • v.6 no.3
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    • pp.165-176
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    • 2012
  • The aim of this study is to assess the seismic performance of hollow reinforced concrete and prestressed concrete bridge columns, and to provide data for developing improved seismic design criteria. By using a sophisticated nonlinear finite element analysis program, the accuracy and objectivity of the assessment process can be enhanced. A computer program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), is used to analyze reinforced concrete and prestressed concrete structures. Tensile, compressive and shear models of cracked concrete and models of reinforcing and prestressing steel were used to account for the material nonlinearity of reinforced concrete and prestressed concrete. The smeared crack approach was incorporated. The proposed numerical method for the seismic performance assessment of hollow reinforced concrete and prestressed concrete bridge columns is verified by comparing it with the reliable experimental results. Additionally, the studies and discussions presented in this investigation provide an insight into the key behavioral aspects of hollow reinforced concrete and prestressed concrete bridge columns.

The Practical Use of Un Standard Message for cargo flow EDI (물류EDI 표준메세지 이용 방안)

  • 박남규;이태우
    • Journal of the Korean Institute of Navigation
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    • v.17 no.2
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    • pp.57-73
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    • 1993
  • Subject : The Practical Use of UN Standard Message for cargo flow EDI Writer : Park, Nam Kyu and Lee, Tae Woo It's necessary to prepare standard message which is agreed on among trading partners for EDI in container transport industry. Now KMPA is carrying out the EDI Project for establishing Korea Logistics Network. It is important to make standard message of documents using in transport industry to succesfully accomodate EDI. The objective of this study is to find out the method of UN standard message utility in Korea. For this study, the UN message guideline is primarily reviewed, and the process that Shipping Request being used in Hanjin Shipping Co. Ltd. is applied to UNSMs as case study. Generally the data format of EDIFACT is so complex and broad for inter-industry standard that the abstract of data format is usually used. Therefore, it is necessary to make the subset of standard message for Shipping Request in ocean industry. In the result of this study, that the ocean industry can use the subset of IFTMBF for Shipping Request is proved, and the subset is suggested. This thesis will contribute toward showing the practical way of standardrization of 350 documents using in trade, customs and transport sectors.

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Tests of a Four-Factor Asset Pricing Model: The Stock Exchange of Thailand

  • POJANAVATEE, Sasipa
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.9
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    • pp.117-123
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    • 2020
  • The objective of this study is to examine whether the four-factor model explains variation in the expected return of stocks on the Stock Exchange of Thailand. The study used individual monthly data for all stock with continuous trading on the Stock Exchange of Thailand. The study used sample data of 429 listed stocks to construct 8 portfolios bases on the industries. In this study, subject to market factors such as size, the book-to-market ratio, the market beta, and stock liquidity are taken into account. The Empirical analysis reveals that not all of the variables included in the four-factor asset pricing model are statistically significant to do affect the formation of the rate of return on stocks calculated on a monthly basis. The result shows that market beta, stock liquidity, and the book-to-market ratio has a significant increase in the rate of return on shares listed on the Consumer Products. It is therefore apparent that at least in respect of monthly analysis, the predictions of bass models in the field of modern finance theory systematic risk measured by the beta coefficient did play a significantly important role in the formation of the rate of return on the Stock Exchange of Thailand.

Comparative risks of resistant microorganisms in the intestinal track of imported freshwater ornamental fish and cultured marine fish (수입산 담수관상어 및 양식 해산어의 장내세균에서 나타나는 내성균 위험성 비교)

  • Yoon, So-Hye;Jun, Lyu-Jin;Kim, Young-Jin;Jin, Ji-Woong;Jeong, Hyun-Do
    • Journal of fish pathology
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    • v.25 no.2
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    • pp.77-84
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    • 2012
  • Various antibiotics, that could induce the appearance of resistant microorganisms, have been used for treatment or prevention of bacterial diseases in marine and ornamental fish. We determined and characterized the level of antibiotic-resistant bacteria and proportion of multi-drug resistant bacteria in intestinal microflora of both marine fish cultured in Korea and imported ornamental freshwater fish. For this the bacterial species and resistance to antibiotics were investigated in intestine of rock bream Oplegnathus fasciatus cultured in Korea and pearl gourami Trichogaster leeri imported from Singapore to characterise. Although the bacterial species were different, proportions of resistant bacteria to single antibiotics or multi-drug were higher in intestinal microflora of pearl gourami Trichogaster leeri imported from Singapore than in rock bream Oplegnathus fasciatus cultured in Korea. These results indicate that various antibiotics have been being used before trading without measures in the market of asian ornamental fishes, providing high risks for the emergence of multi-drug resistant bacteria.

Learning the Covariance Dynamics of a Large-Scale Environment for Informative Path Planning of Unmanned Aerial Vehicle Sensors

  • Park, Soo-Ho;Choi, Han-Lim;Roy, Nicholas;How, Jonathan P.
    • International Journal of Aeronautical and Space Sciences
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    • v.11 no.4
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    • pp.326-337
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    • 2010
  • This work addresses problems regarding trajectory planning for unmanned aerial vehicle sensors. Such sensors are used for taking measurements of large nonlinear systems. The sensor investigations presented here entails methods for improving estimations and predictions of large nonlinear systems. Thoroughly understanding the global system state typically requires probabilistic state estimation. Thus, in order to meet this requirement, the goal is to find trajectories such that the measurements along each trajectory minimize the expected error of the predicted state of the system. The considerable nonlinearity of the dynamics governing these systems necessitates the use of computationally costly Monte-Carlo estimation techniques, which are needed to update the state distribution over time. This computational burden renders planning to be infeasible since the search process must calculate the covariance of the posterior state estimate for each candidate path. To resolve this challenge, this work proposes to replace the computationally intensive numerical prediction process with an approximate covariance dynamics model learned using a nonlinear time-series regression. The use of autoregressive time-series featuring a regularized least squares algorithm facilitates the learning of accurate and efficient parametric models. The learned covariance dynamics are demonstrated to outperform other approximation strategies, such as linearization and partial ensemble propagation, when used for trajectory optimization, in terms of accuracy and speed, with examples of simplified weather forecasting.

How Managers React to Crisis?: A Planned Behavior Theory Approach

  • Cinar, Gokhan;Isin, Ferruh;Hushmat, Adnan
    • Asian Journal of Business Environment
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    • v.6 no.4
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    • pp.5-12
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    • 2016
  • Purpose - Not all firms are able to completely eliminate the risk arising out of the crisis. Success hides in the ability to perceive the market expectations accurately and take correct decisions. This study aims to analyze the firms' decisions at gross-root level. Research Design, Data, and Methodology - Primary data is obtained with the help of specially designed questionnaires from the agriproducts export firms that are members of export union of Turkey. The study is based on four theoretical structures: general planned behavior theory model, perception-leading behavior control and subjective norm model, perceived-behavioral-control leading perception and subjective norm models, and perceptions and subjective norms leading behavior control model. Structural Equation Models (SEM) is used to conduct the empirical analysis. Results - The findings show perceptions and subjective norms leading behavior control model as the best one, concluding that the environmental pressures and positive perceptions have significant effect on the strategic decisions of the agriproducts export firms. Conclusion - Policy tools like creating positive perception in the markets, providing sufficient information and financial support to the firms and increasing market competition can be used effectively to achieve the said objective.

Expiration-Day Effects on Index Futures: Evidence from Indian Market

  • SAMINENI, Ravi Kumar;PUPPALA, Raja Babu;MUTHANGI, Ramesh;KULAPATHI, Syamsundar
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.95-100
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    • 2020
  • Nifty Bank Index has started trading in futures and options (F&O) segment from 13th June 2005 in National Stock Exchange. The purpose of the study is to enhance the literature by examining expiration effect on the price volatility and price reversal of Underlying Index in India. Historical data used for the current study primarily comprise of daily close prices of Nifty Bank which is the only equity sectoral index in India which is traded in derivatives market and its Future contract value is derived from the underlying CNX Bank Index during the period 1st January 2010 till 31st March 2020. To check stationarity of the data, Augmented Dicky Fuller test was used. The study employed ARMA- EGARCH model for analysing the data. The empirical results revealed that there is no effect on the mean returns of underlying Index and EGARCH (1,1) model furthermore shows there is existence of leverage effect in the Bank Index i.e., negative shocks causes more fluctuations in the Index than positive news of similar magnitude. The outcome of the study specifies that there is no effect on volatility on the underlying sectoral index due to expiration days and also observed no price reversal effect once the expiration days are over.

A Study on the Strategy for Optimizing Investment Portfolios (최적 투자 포트폴리오 구성전략에 관한 연구)

  • Gu, Seung-Hwan;Jang, Seong-Yong
    • IE interfaces
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    • v.23 no.4
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    • pp.300-310
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    • 2010
  • This paper is about an optimal investment portfolio strategy. Financial data of stocks, bonds, and savings from January 2. 2001 through October 30. 2009 were utilized in order to suggest the optimal portfolio strategies. Fundamental analysis and technical analysis were used in stocks-related strategy, whereas passive investment strategy and active investment strategy were used in bond-related strategy. The score is assigned to each stock index according to the suggested strategies and set trading rules are based on the scores. The simulation has been executed about each 29,400-portfolios and we figured out with the simulation result that 26.75% of 7,864 portfolios are more profitable than average stock market profit (22.6%, Annualized). The outcome of this research is summarized in two parts. First, it's the rebalancing strategy of portfolio. The result shows that value-oriented investment(long-term investment) strategy yields much higher than short-term investment strategies of stocks or active investment of bonds. Second, it's about the rebalancing cycle forming the portfolios. The result shows that the rate of return for the portfolio is the best when rebalancing cycle is 12 or 18 months.

Generation of Forensic Evidence Data from Script (Script에서 Forensic 증거자료 확보 방안)

  • Kim, Seul-gi;Park, Dea-woo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.10a
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    • pp.353-355
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    • 2017
  • Recently developed digital devices are being used in cyberspace. Digital device users are engaged in activities such as financial settlement and e-commerce using cyber-connected terminals. With the activation of cyber trading, cyber crimes against users are increasing. Forensic evidence should be obtained from investigations of cybercrime. However, there is a lot of information to analyze digital forensic evidence. In many of these digital information, Scripts are an effective way to secure evidence for cybercrime. In this paper, we study how to secure forensic evidence using scripts. Extract evidence from EnCase and study how to obtain evidence using scripts. This study will be used as the basic data for cyber security for the safe life of the people.

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