• Title/Summary/Keyword: The influence vector

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A Study on the Seoul Apartment Jeonse Price after the Global Financial Crisis in 2008 in the Frame of Vecter Auto Regressive Model(VAR) (VAR분석을 활용한 금융위기 이후 서울 아파트 전세가격 변화)

  • Kim, Hyun-woo;Lee, Du-Heon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.6315-6324
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    • 2015
  • This study analyses the effects of household finances on rental price of apartment in Seoul which play a major role in real estate policy. We estimate VAR models using time series data. Economy variables such as sales price of apartment in Seoul, consumer price index, hiring rate, real GNI and loan amount of housing mortgage, which relate to household finances and influence the rental price of apartment, are used for estimation. The main findings are as follows. In the short term, the rental price of apartment is impacted by economy variables. Specifically, Relative contributions of variation in rental price of apartment through structural shock of economy variables are most influenced by their own. However, in the long term, household variables are more influential to the rental price of apartment. These results are expected to contribute to establish housing price stabilization policies through understanding the relationship between economy variables and rental price of apartment.

China's Economic Policy Uncertainty Shocks and South Korea's Exports: A TVP-VAR Approach with an SMSS Structure

  • Liu, Lin;Zhang, Manman;Li, Wei
    • Journal of Korea Trade
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    • v.24 no.4
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    • pp.1-17
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    • 2020
  • Purpose - Since China has been South Korea's biggest export destination, uncertainty shocks originating from it would influence South Korea's exports. This paper evaluates the effects of China's economic policy uncertainty on Korea's exports to explore the transmission channels. Design/methodology - Incorporating endogeneities and nonlinearities, this study employs a quarterly time-varying parameters vector autoregressive model to investigate the relationships between China's economic policy uncertainty and Korea's exports, where the overparameterization due to time-varying specifications is overcome by a novel stochastic model specification search framework. According to previous theoretical studies, this paper assesses two channels, demand shock channel and exchange rate channel, through which foreign uncertainty affects Korea's exports. This paper identifies the primary drivers of Korea's aggregate exports and analyzes the rationales for the time-variant impacts of China's economic policy uncertainty on Korea's exports to China. Findings - Our empirical results reveal that Korea's aggregate exports are less responsive to China's economic policy uncertainty shocks and significantly move together with global demand. In contrast, its bilateral exports to China are highly responsive in a negative and time-variant way. Moreover, Chinese investment is an important channel through which China's economic policy uncertainty affects Korea's exports to China after 2010. Further, the time-variant effects of China's economic policy uncertainty on Korea's exports to China are related to changes in China's foreign trade policies, global economic conditions, and China's degree of economic freedom. Originality/value - Few previous studies touch the effects of external uncertainty shocks on South Korea's exports. This paper attempts to fill this gap and explicitly investigate the impacts of China's economic policy uncertainty on Korea's exports from a time-varying perspective. As Korea is an export-oriented economy, this study provides insights for the Korean government to understand the transmissions of external uncertainty better.

The Impact of Urban Heat Island-induced Temperature Differences on the Hatching Rates of Aedes albopictus (도시열섬 현상에 의한 기온차이가 흰줄숲모기(Aedes albopictus) 부화율에 미치는 영향)

  • Jihun Ryu;Kwang Shik Choi
    • Korean journal of applied entomology
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    • v.63 no.1
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    • pp.77-80
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    • 2024
  • Aedes albopictus, a common species in the Republic of Korea, is internationally known as a major vector for various diseases, and it is well-adapted to urban environments. Recent insect outbreaks in urban areas, attributed to climate change and urban heat islands, have increased the necessity of researching the effects on mosquito populations. This study analyzed climate data from 25 Automatic Weather System (AWS) stations in Seoul, identifying urban areas with pronounced heat island effects and suburban areas with milder effects. Nine urban heat island conditions were established based on this analysis, under which the hatching rates of Ae. albopictus were examined. The results revealed an increase in hatching rates correlating with the intensity of the urban heat island effect. Regression analysis further indicated that this trend accelerates as the strength of the heat island effect increases. This study suggests that temperature variations resulting from urban heat island phenomena can significantly influence the hatching rates of Ae. albopictus.

Investigation on the component separation of magnetic signal generated from a ferro-magnetic vessel (함정에서 발생하는 자계신호의 성분분리에 대한 검토)

  • Kim, Young-Hak;Doh, JaeWon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.8
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    • pp.2051-2056
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    • 2014
  • This paper investigated the separation of magnetic signal from a ferro-magnetic object. The magnetic signals were ILM(induced longitudinal magnetization) and IVM(induced vertical magnetization), which were induced by earth magnetic field and PLM(permanent longitudinal magnetization) and PVM(permanent vertical magnetization), which were due to a permanent magnetization of the object, respectively. Magnetic signal separation was based on the fact that magnetization vector could be analyzed according to longitudinal and vertical directions. Also the influence of non-uniform magnetic field from a rectangular coil on the separation was examined. A military vessel with a size close to rectangular coil has more errors on the magnetic signal separation.

Multi-dimensional Analysis and Prediction Model for Tourist Satisfaction

  • Shrestha, Deepanjal;Wenan, Tan;Gaudel, Bijay;Rajkarnikar, Neesha;Jeong, Seung Ryul
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.2
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    • pp.480-502
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    • 2022
  • This work assesses the degree of satisfaction tourists receive as final recipients in a tourism destination based on the fact that satisfied tourists can make a significant contribution to the growth and continuous improvement of a tourism business. The work considers Pokhara, the tourism capital of Nepal as a prefecture of study. A stratified sampling methodology with open-ended survey questions is used as a primary source of data for a sample size of 1019 for both international and domestic tourists. The data collected through a survey is processed using a data mining tool to perform multi-dimensional analysis to discover information patterns and visualize clusters. Further, supervised machine learning algorithms, kNN, Decision tree, Support vector machine, Random forest, Neural network, Naive Bayes, and Gradient boost are used to develop models for training and prediction purposes for the survey data. To find the best model for prediction purposes, different performance matrices are used to evaluate a model for performance, accuracy, and robustness. The best model is used in constructing a learning-enabled model for predicting tourists as satisfied, neutral, and unsatisfied visitors. This work is very important for tourism business personnel, government agencies, and tourism stakeholders to find information on tourist satisfaction and factors that influence it. Though this work was carried out for Pokhara city of Nepal, the study is equally relevant to any other tourism destination of similar nature.

Influence of Liquidity on the Housing Market before and after Macroeconomic Fluctuations (거시경제변동 전후 유동성이 주택시장에 미치는 영향 분석)

  • Lee, Young-Hoon;Kim, Jae-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.5
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    • pp.116-124
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    • 2016
  • In the past, once apartments were built by housing construction companies, their presale went smoothly. Therefore, the developer and construction companies in Korea were extremely competitive in the housing market. However, when the 1997 foreign exchange crisis and 2008 global financial crisis occurred, the quantity of unsold new housing stocks rapidly increased, which caused construction companies to experience a serious liquidity crisis. This paper aims at analyzing the influence of Liquidity on the Housing Market before and after Macroeconomic Fluctuations using VECM. The periods from September 2001 to September 2008 and from October 2008 to October 2015, which were before and after the Subprime financial crisis, were set as Models 1 and 2, respectively. The results are as follows. First, it is important to develop a long-term policy for the housing transaction market to improve household incomes. Second, due to the shortage in the supply of jeonse housing, structural changes in the housing market have appeared. Thus, it is necessary to seek political measures to minimize the impact of transitional changes on the market.

Influence of Trap Type and Location on Tree Trunk on Platypus koryoensis (Coleoptera: Platypodidae) Trapping (트랩 종류와 수간내 위치가 광릉긴나무좀, Platypus koryoensis(딱정벌레목: 긴나무좀과) 포획에 미치는 영향)

  • Kim, Jun-Heon;Lee, Jung-Su;Park, Il-Kwon;Choi, Won-Il
    • Korean journal of applied entomology
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    • v.49 no.2
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    • pp.145-149
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    • 2010
  • Differences in the number of Platypus koryoensis (Murayama) (Coleoptera: Platypodidae) trapped in different trap types, colors and positions on the trunk were evaluated to develop a monitoring trap for Platypus koryoensis, a known vector of Korean oak wilt disease. The experiments were conducted in an oak forest located in Gwangtan-myeon, Paju-si, Gyeonggi-do, Korea using two types of trap: sticky trap and multi-funnel trap. Trapping efficiency of the two trap types was not significantly different. Trapping efficiency of the sticky trap was not affected by four trap colors: yellow, black, white and transparent. The number of beetle caught was higher in the traps facing the upper slope than the lower slope regardress of trap type. Our results showed that both traps type are useful for monitoring Platypus koryoensis.

The Long-Run Relationship between House Prices and Economic Fundamentals: Evidence from Korean Panel Data (주택가격과 기초경제여건의 장기 관계: 우리나라의 패널 자료를 이용하여)

  • Sim, Sunghoon
    • International Area Studies Review
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    • v.16 no.1
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    • pp.3-27
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    • 2012
  • This paper adopts recently developed panel unit root test that is cross-sectionally robust. Cointegration test is also used to find whether regional house prices are in line with gross regional domestic production (GRDP) in the long run in Korea during 1989-2009. Based on the panel VECM and the panel ARDL models, we examine causal relationships among the variables and estimate the long-run elasticity. We find evidence of cointegration and bidirectional causal relationships between regional house prices and GRDP. The results of long-run estimates, using both fixed effect and ARDL models, show that house prices positively and significantly influence on the GRDP and vice versa. Together with these results, the findings of ARDL-ECM imply that there exists a long-run equilibrium relationship between house prices and regional economic variables even if there is a possibility of short-run deviation from its long-run path.

Molecular cloning, identification, transcriptional analysis, and silencing of enolase on the life cycle of Haemaphysalis longicornis (Acari, Ixodidae) tick

  • Md. Samiul Haque;Md. Khalesur Rahman;Mohammad Saiful Islam;Myung-Jo You
    • Parasites, Hosts and Diseases
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    • v.62 no.2
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    • pp.226-237
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    • 2024
  • Ticks, blood-sucking ectoparasites, spread diseases to humans and animals. Haemaphysalis longicornis is a significant vector for tick-borne diseases in medical and veterinary contexts. Identifying protective antigens in H. longicornis for an anti-tick vaccine is a key tick control strategy. Enolase, a multifunctional protein, significantly converts D-2-phosphoglycerate and phosphoenolpyruvate in glycolysis and gluconeogenesis in cell cytoplasm. This study cloned a complete open reading frame (ORF) of enolase from the H. longicornis tick and characterized its transcriptional and silencing effect. We amplified the full-length cDNA of the enolase gene using rapid amplification of cDNA ends. The complete cDNA, with an ORF of 1,297 nucleotides, encoded a 432-amino acid polypeptide. Enolase of the Jeju strain H. longicornis exhibited the highest sequence similarity with H. flava (98%), followed by Dermacentor silvarum (82%). The enolase motifs identified included N-terminal and C-terminal regions, magnesium binding sites, and several phosphorylation sites. Reverse transcription-polymerase chain reaction (RT-PCR) analysis indicated that enolase mRNA transcripts were expressed across all developmental stages of ticks and organs such as salivary gland and midgut. RT-PCR showed higher transcript levels in syn-ganglia, suggesting that synganglion nerves influence enolase's role in tick salivary glands. We injected enolase double-stranded RNA into adult unfed female ticks, after which they were subsequently fed with normal unfed males until they spontaneously dropped off. RNA interference significantly (P<0.05) reduced feeding and reproduction, along with abnormalities in eggs (no embryos) and hatching. These findings suggest enolase is a promising target for future tick control strategies.

The Relationship Between International Capital Flows and Foreign Exchange Volatility (국제 자본이동과 환율 변동성에 관한 연구: 주요 통화대비 원화 환율을 중심으로)

  • Choi, Don-Seung
    • Korea Trade Review
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    • v.42 no.4
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    • pp.1-20
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    • 2017
  • This study is to investigate the dynamic relationship between international capital flows and won exchange rate to the major currency in Korea. As the results of Granger causality test, international capital flows Granger-cause currency rate volatility in the short term. However, over time, won exchange rate volatility Granger-cause international capital flows in Korea. According to the results by period divided based on 2008 financial crisis, international capital flows have the significant effects on won-dollar exchange rate volatility before 2008 crisis although currency rate volatility Granger-cause international capital flows after the crisis. As the results of impulse-response function of the basis of VAR, foreign exchange rate volatility has no connection with international capital flows before the crisis while it doesn't after. After the crisis, currency rate volatility has promoted international capital flows, while its influence diminishes as time passes. As these results, the uncertainty of foreign exchange market tend to influence the international capital flows rather than vice versa in Korea. Thus, it would be a more effective policy to control the uncertainty of market than the direct restrictions international capital flows.

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