• Title/Summary/Keyword: IMF

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Analysis of Wind Vorticity and Divergence in the High-latitude Lower Thermosphere: Dependence on the Interplanetary Magnetic Field (IMF) (고위도 하부 열권 바람의 소용돌이도와 발산 분석: 행성간 자기장(IMF)에 대한 의존도)

  • Kwak, Young-Sil;Lee, Jae-Jin;Ahn, Byung-Ho;Hwang, Jung-A;Kim, Khan-Hyuk;Cho, Kyung-Seok
    • Journal of Astronomy and Space Sciences
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    • v.25 no.4
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    • pp.405-414
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    • 2008
  • To better understand the physical processes that control the high-latitude lower thermospheric dynamics, we analyze the divergence and vorticity of the high-latitude neutral wind field in the lower thermosphere during the southern summertime for different IMF conditions. For this study the National Center for Atmospheric Research Thermosphere-Ionosphere Electrodynamics General Circulation Model (NCAR-TIEG CM) is used. The analysis of the large-scale vorticity and divergence provides basic understanding flow configurations to help elucidate the momentum sources that ulti-mately determine the total wind field in the lower polar thermosphere and provides insight into the relative strengths of the different sources of momentum responsible for driving winds. The mean neutral wind pattern in the high-latitude lower thermosphere is dominated by rotational flow, imparted primarily through the ion drag force, rather than by divergent flow, imparted primarily through Joule and solar heating. The difference vorticity, obtained by subtracting values with zero IMF from those with non-zero IMF, in the high-latitude lower thermosphere is much larger than the difference divergence for all IMF conditions, indicating that a larger response of the thermospheric wind system to enhancement in the momentum input generating the rotational motion with elevated IMF than the corresponding energy input generating the divergent motion. the difference vorticity in the high-latitude lower thermosphere depends on the direction of the IMF. The difference vorticity for negative and positive $B_y$ shows positive and negative, respectively, at higher magnetic latitudes than $-70^{\circ}$. For negative $B_z$, the difference vorticities have positive in the dusk sector and negative in the dawn sector. The difference vorticities for positive $B_z$ have opposite sign. Negative IMF $B_z$ has a stronger effect on the vorticity than does positive $B_z$.

A Study on the Efficiency and Productivity Change of Korean Non-Life Insurance Company After Financial Crisis (금융위기 이후 국내 손해보험회사의 효율성 및 생산성 변화 연구)

  • Park, Chun-Gwang;Kim, Byeong-Chul
    • The Korean Journal of Financial Management
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    • v.23 no.2
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    • pp.57-83
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    • 2006
  • The purpose of this paper is to analyze the efficiency and productivity change and inefficiency cause of the korean non-life insurance companies of the before($1993{\sim}1996$) and after($1998{\sim}2004$) of IMF. we use DEA (Data Envelopment Analysis) model to measure company efficiency and MPI(Malmquist productivity indices) to measure company productivity change and Tobit regression to analyze inefficiency cause. we utilize ten non-life insurance companies in korea and the time-series data for eleven from 1993 to 2004 except 1997. The empirical results show the following findings. First, total cost efficiency shows that the after of IMF decrease of 3.7% over the before of IMF and MPI change indicates that the after of IMF increase 7.7% over the before IMF. Second, the results of Tobit regression to analysis the cause of inefficiency show that total cost efficiency is positively related invested assets, acquisition expenses ratio, collection expenses ratio and is negatively related solicitors ratio, personnel expenses ratio, land & buildings expenses ratio, loss ratio, net operating expenses ratio. Especially inefficiency of small-to-mid sized companies is main cause of total cost efficiency of non-life insurance companies in korea. Small-to-mid sized companies endeavored various aspects of business strategies.

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A Study on Information Spillover Effects from Nasdaq to Kosdaq and Jasdaq (나스닥시장의 코스닥 및 자스닥시장에 대한 정보이전효과에 관한 연구)

  • Kim, Chan-Wung;Moon, Gyu-Hyun;Hong, Jung-Hyo
    • The Korean Journal of Financial Management
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    • v.20 no.1
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    • pp.163-190
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    • 2003
  • This study tests the hypothesis of market efficiency through the information spillover effects over price and volatility across countries by using open-to-close(daytime) returns and close-to-open(overnight) returns of NASDAQ, KOSDAQ and JASDAQ data from January 3, 1997 to December 21, 2000. Based on Granger-causality and time-varying AR(1)-GARCH(1, 1)-M models we document that the evidence of statistically significant conditional mean and volatility spillovers effects from the daytime returns and volatility of NASDAQ to the overnight returns and volatility of KOSDAQ is observed both before and after the IMF foreign currency crisis but not to the close-to-open return before the IMF foreign currency crisis. We can understand the information spillover effect from NASDAQ to KOSDAQ on the overnight rather than the daytime grows more significantly after the IMF foreign currency crisis. We also find the interactive information spillover effect between NASDAQ and JASDAQ both before and after the IMF financial crisis, in particular, to close-to-open return. In addition, the market efficiency between KOSDAQ and NASDAQ is on an increasing trend through IMF foreign currency crisis.

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Identification and functional prediction of long noncoding RNAs related to intramuscular fat content in Laiwu pigs

  • Wang, Lixue;Xie, Yuhuai;Chen, Wei;Zhang, Yu;Zeng, Yongqing
    • Animal Bioscience
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    • v.35 no.1
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    • pp.115-125
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    • 2022
  • Objective: Intramuscular fat (IMF) is a critical economic indicator of pork quality. Studies on IMF among different pig breeds have been performed via high-throughput sequencing, but comparisons within the same pig breed remain unreported. Methods: This study was performed to explore the gene profile and identify candidate long noncoding RNA (lncRNAs) and mRNAs associated with IMF deposition among Laiwu pigs with different IMF contents. Based on the longissimus dorsi muscle IMF content, eight pigs from the same breed and management were selected and divided into two groups: a high IMF (>12%, H) and low IMF group (<5%, L). Whole-transcriptome sequencing was performed to explore the differentially expressed (DE) genes between these two groups. Results: The IMF content varied greatly among Laiwu pig individuals (2.17% to 13.93%). Seventeen DE lncRNAs (11 upregulated and 6 downregulated) and 180 mRNAs (112 upregulated and 68 downregulated) were found. Gene Ontology analysis indicated that the following biological processes played an important role in IMF deposition: fatty acid and lipid biosynthetic processes; the extracellular signal-regulated kinase cascade; and white fat cell differentiation. In addition, the peroxisome proliferator-activated receptor, phosphatidylinositol-3-kinase-protein kinase B, and mammalian target of rapamycin pathways were enriched in the pathway analysis. Intersection analysis of the target genes of DE lncRNAs and mRNAs revealed seven candidate genes associated with IMF accumulation. Five DE lncRNAs and 20 DE mRNAs based on the pig quantitative trait locus database were identified and shown to be related to fat deposition. The expression of five DE lncRNAs and mRNAs was verified by quantitative real time polymerase chain reaction (qRT-PCR). The results of qRT-PCR and RNA-sequencing were consistent. Conclusion: These results demonstrated that the different IMF contents among pig individuals may be due to the DE lncRNAs and mRNAs associated with lipid droplets and fat deposition.

Sources of the High-Latitude Thermospheric Neutral Mass Density Variations

  • Kwak, Young-Sil;Richmond, Arthur;Deng, Yue;Ahn, Byung-Ho;Cho, Kyung-Suk
    • Journal of Astronomy and Space Sciences
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    • v.27 no.4
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    • pp.329-335
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    • 2010
  • We investigate the sources of the variation of the high-latitude thermospheric neutral mass density depending on the interplanetary magnetic field (IMF) conditions. For this purpose, we have carried out the National Center for Atmospheric Research Thermosphere-Ionosphere Electrodynamics General Circulation Model (NCAR-TIEGCM) simulations for various IMF conditions under summer condition in the southern hemisphere. The NCAR-TIEGCM is combined with a new empirical model that provides a forcing to the thermosphere in high latitudes. The difference of the high-latitude thermospheric neutral mass density (subtraction of the values for zero IMF condition from the values for non-zero IMF conditions) shows a dependence on the IMF condition: For negative $B_y$ condition, there are significantly enhanced difference densities in the dusk sector and around midnight. Under the positive-$B_y$ condition, there is a decrease in the early morning hours including the dawn side poleward of $-70^{\circ}$. For negative $B_z$, the difference of the thermospheric densities shows a strong enhancement in the cusp region and around midnight, but decreases in the dawn sector. In the dusk sector, those values are relatively larger than those in the dawn sector. The density difference under positive-$B_z$ condition shows decreases generally. The density difference is more significant under negative-$B_z$ condition than under positive-$B_z$ condition. The dependence of the density difference on the IMF conditions in high latitudes, especially, in the dawn and dusk sectors can be explained by the effect of thermospheric winds that are associated with the ionospheric convection and vary following the direction of the IMF. In auroral and cusp regions, heating of thermosphere by ionospheric currents and/or auroral particle precipitation can be also the source of the dependence of the density difference on the IMF conditions.

Identification and characterization of novel single nucleotide polymorphism markers for fat deposition in muscle tissue of pigs using amplified fragment length polymorphism

  • Supakankul, Pantaporn;Kumchoo, Tanavadee;Mekchay, Supamit
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.3
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    • pp.338-346
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    • 2017
  • Objective: This study was conducted to identify and evaluate the effective single nucleotide polymorphism (SNP) markers for fat deposition in the longissimus dorsi muscles of pigs using the amplified fragment length polymorphism (AFLP) approach. Methods: Sixty-four selective primer combinations were used to identify the AFLP markers in the 20 highest- and 20 lowest-intramuscular fat (IMF) content phenotypes. Five AFLP fragments were converted into simple codominant SNP markers. These SNP markers were tested in terms of their association with IMF content and fatty acid (FA) composition traits in 620 commercially crossbred pigs. Results: The SSC7 g.4937240C>G marker showed an association with IMF content (p<0.05). The SSC9 g.5496647_5496662insdel marker showed a significant association with IMF content and arachidonic levels (p<0.05). The SSC10 g.71225134G>A marker revealed an association with palmitoleic and ${\omega}9$ FA levels (p<0.05), while the SSC17 g.61976696G>T marker showed a significant association with IMF content and FA levels of palmitoleic, eicosenoic, arachidonic, monounsaturated fatty acids, and ${\omega}9$ FA levels. However, no significant association of SSC8 g.47338181G>A was observed with any IMF and FA levels in this study. Conclusion: Four SNP markers (SSC7 g.4937240C>G, SSC9 g.5496647_5496662insdel, SSC10 g.71225134G>A, and SSC17 g.61976696G>T) were found to be associated with IMF and/or FA content traits in commercially crossbred pigs. These findings provide evidence of the novel SNP markers as being potentially useful for selecting pigs with the desirable IMF content and FA composition.

The Change in Consciousness and Expenditure on Kyung-Jo after IMF Economic Crisis on Cheju Island (경조비에 대한 의식 및 지출 변화 - IMF경제위기 이후 제주지역을 중심으로 -)

  • 김혜연;김미성
    • Journal of the Korean Home Economics Association
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    • v.39 no.1
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    • pp.65-80
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    • 2001
  • This study aimed to investigate the changed consciousness and expenditure on Kyong-Jo after IMF economic crisis and the some factors which have effects on the change. The expenditure on Kyong-Jo included donations and gifts associated with congratulations and condolences. The data were collected through the personal questionnaire on Cheju Island. The sample consisted of 400 married adults whose age were between 20 to 65. The independent variables were some individual characteristics, household related variables, and Kyong-Jo related variables. The dependent variables included the change in consciousness and expenditure on Kyong-Jo. The data were analyzed by methods such as frequencies, means, Multiple Regression and Logistic Regression analysis. Major results were as follows. The respondents perceived that Kyong-Jo is fundamentally a good custom to help each other when some one is in the hard time. Their perception of the expenditure on Kyong-Jo has not been changed even since IMF economic crisis. 70% of the respondents staid that there was little difference of the expenditure on Kyong-Jo before and after IMF economic crisis. This trend is in contrast to the perception and the expenditure of the people who lived in the other residences after IMF economic crisis. The factors which had significant effects on the respondent's consciousness of the expenditure on Kyong-Jo were occupation, whether owns a house or not, household income, and household assets. The change of household expenditure on Kyong-Jo was effected by the respondent's sex, occupation, household income, household assets, and social network. These results suggested that the respondents on Cheju Island more strongly hold the conservative perception to the expenditure on Kyong-Jo rather than the people in other residences.

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Genome-wide association study for intramuscular fat content in Chinese Lulai black pigs

  • Wang, Yanping;Ning, Chao;Wang, Cheng;Guo, Jianfeng;Wang, Jiying;Wu, Ying
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.5
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    • pp.607-613
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    • 2019
  • Objective: Intramuscular fat (IMF) content plays an important role in meat quality. Identification of single nucleotide polymorphisms (SNPs) and genes related to pig IMF, especially using pig populations with high IMF content variation, can help to establish novel molecular breeding tools for optimizing IMF in pork and unveil the mechanisms that underlie fat metabolism. Methods: We collected muscle samples of 453 Chinese Lulai black pigs, measured IMF content by Soxhlet petroleum-ether extraction method, and genotyped genome-wide SNPs using GeneSeek Genomic Profiler Porcine HD BeadChip. Then a genome-wide association study was performed using a linear mixed model implemented in the GEMMA software. Results: A total of 43 SNPs were identified to be significantly associated with IMF content by the cutoff p<0.001. Among these significant SNPs, the greatest number of SNPs (n = 19) were detected on Chr.9, and two linkage disequilibrium blocks were formed among them. Additionally, 17 significant SNPs are mapped to previously reported quantitative trait loci (QTLs) of IMF and confirmed previous QTLs studies. Forty-two annotated genes centering these significant SNPs were obtained from Ensembl database. Overrepresentation test of pathways and gene ontology (GO) terms revealed some enriched reactome pathways and GO terms, which mainly involved regulation of basic material transport, energy metabolic process and signaling pathway. Conclusion: These findings improve our understanding of the genetic architecture of IMF content in pork and facilitate the follow-up study of fine-mapping genes that influence fat deposition in muscle.

기업부실의 원인 변동

  • Nam, Myeong-Su
    • The Korean Journal of Financial Studies
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    • v.5 no.1
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    • pp.1-18
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    • 1999
  • 본 연구의 목적은 IMF구제금융이전의 부도기업과 IMF구제금융 이후의 부도기업을 비교하여 IMF구제금융 이후의 부도원인을 파악하고 향후 관리방향을 제안하는데 있다. IMF구제금융 이후의 부도기업들은 예상외로 유동성이 매우 악화된 상태이고, 또한 높은 부채비율과 이자지급으로 경상이익과 순이익이 매우 저조하였다. 또한 매출액 대비 수익성지표는 매우 양호한 수준을 유지한 것으로 나타나 결국 부채구조와 자산구조의 효율성이 수익에 비해 매우 저조하였음을 볼 수 있었다. 따라서 IMF구제금융 이후의 기업경영관리는 우선적으로 현금흐름을 철저히 관리하여 충분한 채무지급능력과 운전자본을 확보하는 것이 중요하며, 매출액대비 수익성 중에서 영업이익률보다는 경상이익률과 순이익률에 초점을 맞추어 재무구조에 대한 관리를 강화해야 한다. 특히 매출이나 이익에 투하된 자본을 중점적으로 관리함으로써 수익성이 없는 자산과 수익성이 높은 자산을 선별하여 자산구조를 효율적으로 운영하는 것이 매우 중요하다.

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Performance of Noise Mitigation scheme based on EMD for Heterogeneous Networks (이기종 통신 시스템을 위한 EMD 기반 노이즈 완화 기법의 성능)

  • Sim, Isaac;Hwang, Yu Min;Yang, Byong Moon;Kim, Jin Young
    • Journal of Satellite, Information and Communications
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    • v.11 no.1
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    • pp.26-31
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    • 2016
  • In this paper, we proposed a scheme to mitigate noises based on the EMD scheme for heterogeneous communication systems. Noise-corrupted data can be decomposed into a finite number of IMF components. Using the EMD method, we can mitigate noise with eliminate noise-corrupted IMF components. We proposed iteration stop rule for reduce EMD computation time. Simulation results show that proposed EMD scheme based on proposed algorithm for iteration stop rule efficiently mitigates 3 types of noise and reduces its computational time.