• Title/Summary/Keyword: conditional distribution

검색결과 295건 처리시간 0.027초

Dynamic Linkages between Food Inflation and Its Volatility: Evidence from Sri Lankan Economy

  • MOHAMED MUSTAFA, Abdul Majeed;SIVARAJASINGHAM, Selliah
    • The Journal of Asian Finance, Economics and Business
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    • 제6권4호
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    • pp.139-145
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    • 2019
  • This study examines the dynamic linkages between food price inflation and its volatility in the context of Sri Lanka. The empirical evidence derived from the monthly data for the period from 2003M1 to 2017M12 for Sri Lanka. The relationship between inflation rate and inflation volatility has attracted more attention by theoretical and empirical macroeconomists. Empirical studies on the relationship between food inflation and food inflation variability is scarce in the literature. Food price inflation is defined as log difference of food price series. The volatility of a food price inflation is measured by conditional variance generated by the FIGARCH model. Preliminary analysis showed that food inflation is stationary series. Granger causality test reveals that food inflation seems to exert positive impact on inflation variability. We find no evidence for inflation uncertainty affecting food inflation rates. Hence, the findings of the study supports the Friedman-Ball hypothesis in both cases of consumer food price inflation and wholesale food price inflation. This implies that past information on food inflation can help improve the one-step-ahead prediction of food inflation variability but not vice versa. Our results have some important policy implications for the design of monetary policy, food policy thereby promoting macroeconomic stability.

Is Expansionary Fiscal and Monetary Policy Effective in Australia?

  • HSING, Yu
    • Asian Journal of Business Environment
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    • 제9권3호
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    • pp.5-9
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    • 2019
  • Purpose - This paper examines whether fiscal and monetary expansion would affect output in Australia. Research design, data, and methodology - An extended IS-LM model which describes the equilibrium in the goods market and the money market is applied. The real effective exchange rate and the real stock price are included in order to determine whether there may be any substitution or wealth effect. The sample consists of Annual data ranging from 1990 to 2018. The GARCH process is used in empirical work to correct for potential autoregressive conditional heteroscedasticity. Results - Expansionary fiscal policy reduces output; whereas, expansionary monetary policy raises output. In addition, real appreciation of the Australian dollar, a lower U.S. interest rate, a higher real stock price or a lower expected inflation would increase output. The finding that expansionary fiscal policy has a negative impact on real GDP suggests that the negative crowding-out effect on private spending dominates the positive impact. Conclusions - Fiscal prudence needs to be pursued. Real depreciation of the Australian dollar hurts output. Monetary tightening in the U.S. generates a negative effect on Australia's output. A healthy stock market is conducive to economic growth as higher stock prices tend to result in the wealth and other positive effects, increasing consumption and business spending.

표고 구배상에 분포하는 Populus 속 ( 버드나무과 ) 3 종 식물 잎의 엽록소 함량 (Leaf Chlorophyll Contents of Three Populus (Salicaceae) Species Occurring on Elevational Gradient)

  • Cha, Young-Il
    • The Korean Journal of Ecology
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    • 제10권3호
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    • pp.119-127
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    • 1987
  • On the east slope of the front ranges of the Colorado Rockies, USA, three species of Populus are distributed at different elevations from the Great Plains to the timberline. At elevations 1, 720m (P. sargentii), 2, 335m (P.angustifolia) and 3, 190m (P.tremuloides) chlorophyll cotents of leaves of thses dioecious trees were determined. Total chlorophyll content was in the range of 0.86-1.56mg/g leaf, increasing with elevation as a second-degree polynomial, and the peak content was estimated to be reached at about 2, 800m. Total chlorophyll content was greater in female than in male trees in the two higher elevation species, but not in P. sargentii, the low elevation species. Chlorophyll b content was greater than chlorophyll a content in the same two higher elevation species. The increase of chlorophyll b than to increase of chlorophyll a content. These phenomena appear to be the result of adaptation of these species to different environmental conditional at different elevation. Sequential distribution of plant populations on environmental gradients in such a way that variation in given plant characters paralell the environmental gradient must occur not only in ecotypes of a species, but also in different but closely related species.

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Information Arrival between Price Change and Trading Volume in Crude Palm Oil Futures Market: A Non-linear Approach

  • Go, You-How;Lau, Wee-Yeap
    • The Journal of Asian Finance, Economics and Business
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    • 제3권3호
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    • pp.79-91
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    • 2016
  • This paper is the first of its kind using a non-linear approach based on cross-correlation function (CCF) to investigate the information arrival hypothesis in crude palm oil (CPO) futures market. Based on daily data from 1986 to 2010, our empirical results reveal that: First, the volume of volatility is not a proxy of information flow. Second, dependence causality running from current return to future volume in conditional variance exhibit an asymmetric pattern of time span with different signs of correlation between price and volume series. This finding indicates the presence of noise traders' hypothesis of price-volume interaction in CPO futures market. Both findings suggest that this futures market is weak-form inefficiency. In terms of investors' behavior, they tend to change their expectations on current return based on errors made in previous trade in generating abnormal volume in the subsequent period. As implied, it is advisable for the investors devise their future trading strategies according to time span and changes of return.

Foreign Investors' Abnormal Trading Behavior in the Time of COVID-19

  • KHANTHAVIT, Anya
    • The Journal of Asian Finance, Economics and Business
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    • 제7권9호
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    • pp.63-74
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    • 2020
  • This study investigates the behavior of foreign investors in the Stock Exchange of Thailand (SET) in the time of coronavirus disease 2019 (COVID-19) as to whether trading is abnormal, what strategy is followed, whether herd behavior is present, and whether the actions destabilize the market. Foreign investors' trading behavior is measured by net buying volume divided by market capitalization, whereas the stock market behavior is measured by logged return on the SET index portfolio. The data are daily from Tuesday, August 28, 2018, to Monday, May 18, 2020. The study extends the conditional-regression model in an event-study framework and extracts the unobserved abnormal trading behavior using the Kalman filtering technique. It then applies vector autoregressions and impulse responses to test for the investors' chosen strategy, herd behavior, and market destabilization. The results show that foreign investors' abnormal trading volume is negative and significant. An analysis of the abnormal trading volume with stock returns reveals that foreign investors are not positive-feedback investors, but rather, they self-herd. Although foreign investors' abnormal trading does not destabilize the market, it induces stock-return volatility of a similar size to normal trade. The methodology is new; the findings are useful for researchers, local authorities, and investors.

Determinants of Vietnam Government Bond Yield Volatility: A GARCH Approach

  • TRINH, Quoc Trung;NGUYEN, Anh Phong;NGUYEN, Hoang Anh;NGO, Phu Thanh
    • The Journal of Asian Finance, Economics and Business
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    • 제7권7호
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    • pp.15-25
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    • 2020
  • This empirical research aims to identify the relationship between fiscal and financial macroeconomic fundamentals and the volatility of government bonds' borrowing cost in an emerging country - Vietnam. The study covers the period from July 2006 to December 2019 and it is based on a sample of 1-year, 3-year, and 5-year government bonds, which represent short-term, medium-term and long-term sovereign bonds in Vietnam, respectively. The Generalized AutoRegressive Conditional Heteroskedasticity (GARCH) model and its derivatives such as EGARCH and TGARCH are applied on monthly dataset to examine and suggest a significant effect of fiscal and financial determinants of bond yield volatility. The findings of this study indicate that the variation of Vietnam government bond yields is in compliance with the theories of term structure of interest rate. The results also show that a proportion of the variation in the yields on Vietnam government bonds is attributed to the interest rate itself in the previous period, base rate, foreign interest rate, return of the stock market, fiscal deficit, public debt, and current account balance. Our results could be helpful in the macroeconomic policy formulation for policy-makers and in the investment practice for investors regarding the prediction of bond yield volatility.

Strategy of the Fracture Network Characterization for Groundwater Modeling

  • Ji, Sung-Hoon;Park, Young-Jin;Lee, Kang-Kun;Kim, Kyoung-Su
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2009년도 학술논문요약집
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    • pp.186-186
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    • 2009
  • The characterization strategy of fracture networks are classified into a deterministic or statistical characterization according to the type of required information. A deterministic characterization is most efficient for a sparsely fractured system, while the statistics are sufficient for densely fractured rock. In this study, the ensemble mean and variability of the effective connectivity is systematically analyzed with various density values for different network structures of a power law size distribution. The results of high resolution Monte Carlo analyses show that statistical characteristics can be a necessary information to determine the transport properties of a fracture system when fracture density is greater than a percolation threshold. When the percolation probability (II) approaches unity with increasing fracture density, the effective connectivity of the network can be safely estimated using statistics only (sufficient condition). It is inferred from conditional simulations that deterministic information for main pathways can reduce the uncertainty in estimation of system properties when the network becomes denser. Overall results imply that most pathways need to be identified when II < 0.5 statistics are sufficient when II $\rightarrow$ 1 and statistics are necessary and the identification of main pathways can significantly reduce the uncertainty in estimation of transport properties when 0.5$\ll$1. It is suggested that the proper estimation of the percolation probability of a fracture network is a prerequisite for an appropriate conceptualization and further characterization.

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Quantum Secret Sharing Scheme with Credible Authentication based on Quantum Walk

  • Li, Xue-Yang;Chang, Yan;Zhang, Shi-Bin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권7호
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    • pp.3116-3133
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    • 2020
  • Based on the teleportation by quantum walk, a quantum secret sharing scheme with credible authentication is proposed. Using the Hash function and quantum local operation, combined with the two-step quantum walks circuit on the line, the identity authentication and the teleportation of the secret information in distribution phase are realized. Participants collaborate honestly to recover secret information based on particle measurement results, preventing untrusted agents and external attacks from obtaining useful information. Due to the application of quantum walk, the sender does not need to prepare the necessary entangled state in advance, simply encodes the information to be sent in the coin state, and applies the conditional shift operator between the coin space and the position space to produce the entangled state necessary for quantum teleportation. Security analysis shows that the protocol can effectively resist intercept/resend attacks, entanglement attacks, participant attacks, and impersonation attacks. In addition, the quantum walk circuit used has been implemented in many different physical systems and experiments, so this quantum secret sharing scheme may be achievable in the future.

대화형 에이전트의 주제 추론을 위한 계층적 베이지안 네트워크의 자동 생성 (Automatic Construction of Hierarchical Bayesian Networks for Topic Inference of Conversational Agent)

  • 임성수;조성배
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제33권10호
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    • pp.877-885
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    • 2006
  • 최근에 대화형 에이전트에서 사용자 질의의 주제 추론을 위하여 베이지안 네트워크가 효과임이 발표되었다. 하지만 베이지안 네트워크는 설계에 있어서 많은 시간이 소요되며, 스크립트(대화를 위한 데이타베이스)의 추가 변경시에는 베이지안 네트워크도 같이 수정해야 하는 번거로움이 있어 대화형 에이전트의 확장성을 저해하고 있다. 본 논문에서는 스크림트로부터 베이지안 네트워크를 자동으로 생성함으로써 베이지안 네트워크를 이용한 대화형 에이전트의 확장성을 높이는 방법을 제안한다. 제안한 방법은 베이지안 네트워크의 구성노드를 계층적으로 설계하고, Noisy-OR gate를 사용하여 베이지안 네트워크의 조건부 확률 테이블을 구성한다. 피험자 10명이 대화형 에이전트를 위한 베이지안 네트워크를 수동 설계한 것과 비교한 결과 제안하는 방법이 효과적임을 알 수 있었다.

마찰열기계적 공정을 이용한 AC4A 합금의 표면개질 (Surface Modification of AC4A Aluminum Alloy Castings Using Friction Thermomechanical Process)

  • 윤태욱;고영봉;고병천;박경채
    • 한국표면공학회지
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    • 제43권5호
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    • pp.230-237
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    • 2010
  • FTMP(friction thermo-mechanical process) is an adaptation of friction stir welding, and can be used as a generic process to modify the microstructure at selective locations. In this study, in order to analyze characteristics of surface modification of ACA4 castings by FTMP, change of rotating speed(R/S) and traveling speed(T/S) of tool were applied as conditional parameter. Analysis of microstructure, hardness, surface roughness and depth of modified zone(MZ) were searched. The best condition were obtained at R/S 600 rpm and T/S 100 mm/min. At this time, hardness was 82 HV, the surface roughness was 0.07 mm and the depth at MZ was 1.72 mm. Free defects microstructure and fine Si particles formation and strong forging effects were analyzed at MZ.