• Title/Summary/Keyword: heavy tail

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The Characteristics of Heavy Metal Accumulations in Feral Pigeon (Columba livia) Feathers for Environmental Monitoring (환경모니터링을 위한 집비둘기 깃털의 중금속 축적특성 연구)

  • Lee, Jangho;Lee, Jongchun;Lee, Sang Hee;Kim, Myungjin;Lee, Eugene;Han, Areum;Shim, Kyuyoung
    • Journal of Environmental Impact Assessment
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    • v.23 no.6
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    • pp.492-504
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    • 2014
  • Feral pigeon (Columba livia) has been known as a good indicator for accumulations of chemical pollutants in urban areas. However, it is against the animal rights to kill the indicator species in order to monitor pollutants accumulations in wild birds. Eggs and feathers of birds, therefore, have been used as non-invasive monitoring materials. Even though eggs are a good indicator for accumulations of lipophilic pollutants, but unsuitable for some heavy metals such as lead and cadmium because bird's ovary builds a sort of barrier to inhibit higher accumulations of some heavy metals in the eggs. Therefore, feathers instead of eggs have been used as a non-invasive indicator for accumulations of heavy metals. However, there are few studies of heavy metal accumulations of feral pigeon in Korea. In this study, we characterized the characteristics of heavy metal accumulations of feathers in relation to internal organs (bloods, viscera and bones) in feral pigeons between two sites (Hangang Park representing urban area and Hampyeong Park for rural area). The samples from the Hangang Park showed significantly higher lead (Pb) concentrations in the blood, liver and bone than those from Hampyeong Park. The Pb concentration in the feathers was also significantly higher at Hangang Park than at Hampyeong Park. The analytical result for the breast, wing and tail feathers, and the internal organs (blood, lung, liver, kidney and bone) indicated that the Pb concentrations in the feathers were significantly positively correlated with the levels in the kidney and bone. Overall, feathers of feral pigeon may be candidate for bioindicator to monitor for Pb accumulations in urban areas.

The Historical study of Beef Cooking - I. cookery of soup based on beef - (우육조리법(牛肉調理法)의 역사적(歷史的) 고찰(考察) - I. 우육을 사용한 국류의 조리법을 중심으로 -)

  • Ryu, Kyung-Lim;Kim, Tae-Hong
    • Journal of the Korean Society of Food Culture
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    • v.7 no.3
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    • pp.223-235
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    • 1992
  • 1. There were 21 kinds foods and preservation of beef and the number of dishes were 346 in the literatures written before 1943. 2.Soup(羹) was appeared first, and followed by dried beef(肉脯), steamed(蒸), sliced of boiled beef(熟肉과 片肉), preservation(貯臟), pan broiled beef(濕熱炒), salted beef(肉醬), raw beef(膾), shish kebab(算炙), roasted with seasoning(炙), beef with vegetables cooked in pan(煎鐵), calf`s-hoof jelly(gelatin)(足片), jaban(佐飯), hardboiled beef(boiled in soy sauce), ravioli (饅頭), beef juice(肉汁), thick broth(heavy soup, 助致), grilled beef (煎油魚), mix with the season(muchim), sun(膳) and gruel(粥). 3.The total of 14 different names of soup were found in the literatures which are Yang tang(stomach soup), Dunggol tang(marrow soup), Dogol tang(medulla soup), Sungi kuk(ox-blood soup), Sogogi kuk(beef soup), Gom kuk(bone attached beef and organs soup), Jap tang(bone attached beef, organs and tough beef soup), Yukgaejang(fresh beef, organs and green onion soup), Joujeo tang(foot starched soup), Jok tang(foot soup), Kori tang(ox-tail soup), Kalbi tang(rib soup), Malgun jangkuk(clear soup), Wan ja tang(beef ball soup). 4.The number of staple ingredient were Tripe and fresh meat among 26 kinds of major ingredient, radish, wheat flour, egg among 21 kinds of miner ingredient black pepper, soy sauce and seasame among 22 kinds of seasonings, and Thin layer-fried egg among 9 kinds of decorating ingredient were used commonly in cooking for soup.

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Optimization of Diesel Engine Performance with Dual Loop EGR considering Boost Pressure, Back Pressure, Start of Injection and Injection Mass (과급압력, 배압, 분사 시기 및 분사량에 따른 복합 방식 배기 재순환 시스템 적용 디젤 엔진의 최적화에 대한 연구)

  • Park, Jung-Soo;Lee, Kyo-Seung;Song, Soon-Ho;Chun, Kwang-Min
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.5
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    • pp.136-144
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    • 2010
  • Exhaust gas recirculation (EGR) is an emission control technology allowing significant NOx emission reduction from light-and heavy duty diesel engines. The future EGR type, dual loop EGR, combining features of high pressure loop EGR and low pressure loop EGR, was developed and optimized by using a commercial engine simulation program, GT-POWER. Some variables were selected to control dual loop EGR system such as VGT (Variable Geometry Turbocharger)performance, especially turbo speed, flap valve opening diameter at the exhaust tail pipe, and EGR valve opening diameter. Applying the dual loop EGR system in the light-duty diesel engine might cause some problems, such as decrease of engine performance and increase of brake specific fuel consumption (BSFC). So proper EGR rate (or mass flow) control would be needed because there are trade-offs of two types of the EGR (HPL and LPL) features. In this study, a diesel engine under dual loop EGR system was optimized by using design of experiment (DoE). Some dominant variables were determined which had effects on torque, BSFC, NOx, and EGR rate. As a result, optimization was performed to compensate the torque and BSFC by controlling start of injection (SOI), injection mass and EGR valves, etc.

Analysis of Extreme Values of Daily Percentage Increases and Decreases in Crude Oil Spot Prices (국제현물원유가의 일일 상승 및 하락율의 극단값 분석)

  • Yun, Seok-Hoon
    • The Korean Journal of Applied Statistics
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    • v.23 no.5
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    • pp.835-844
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    • 2010
  • Tools for statistical analysis of extreme values include the classical annual maximum method, the modern threshold method and variants improving the second one. While the annual maximum method is to t th generalized extreme value distribution to the annual maxima of a time series, the threshold method is to the generalized Pareto distribution to the excesses over a high threshold from the series. In this paper we deal with the Poisson-GPD method, a variant of the threshold method with a further assumption that the total number of exceedances follows the Poisson distribution, and apply it to the daily percentage increases and decreases computed from the spot prices of West Texas Intermediate, which were collected from January 4th, 1988 until December 31st, 2009. According to this analysis, the distribution of daily percentage increases as well as decreases turns out to have a heavy tail, unlike the normal distribution, which coincides well with the general phenomenon appearing in the analysis of lots of nowaday nancial data.

GARCH Model with Conditional Return Distribution of Unbounded Johnson (Unbounded Johnson 분포를 이용한 GARCH 수익률 모형의 적용)

  • Jung, Seung-Hyun;Oh, Jung-Jun;Kim, Sung-Gon
    • The Korean Journal of Applied Statistics
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    • v.25 no.1
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    • pp.29-43
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    • 2012
  • Financial data such as stock index returns and exchange rates have the properties of heavy tail and asymmetry compared to normal distribution. When we estimate VaR using the GARCH model (with the conditional return distribution of normal) it shows the tendency of the lower estimation and clustering in the losses over the estimated VaR. In this paper, we argue that this problem can be resolved through the adaptation of the unbounded Johnson distribution as that of the condition return. We also compare this model with the GARCH with the conditional return distribution of normal and student-t. Using the losses exceed the ex-ante VaR, estimates, we check the validity of the GARCH models through the failure proportion test and the clustering test. We nd that the GARCH model with conditional return distribution of unbounded Johnson provides an appropriate estimation of the VaR and does not occur the clustering of violations.

PtdIns(3,5)P2 5-phosphatase Fig4 Interacts with Kinesin Superfamily 5A (KIF5A) (PI(3,5)P2 5-phosphatase Fig4와 Kinesin superfamily 5A (KIF5A)의 결합)

  • Jang, Won Hee;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.24 no.1
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    • pp.14-19
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    • 2014
  • Kinesin-1 consists of two heavy chains (KHCs), also called KIF5s, and two light chains (KLCs) that form a heterotetrameric complex. Here, we demonstrate the binding of a neuronal KHC, KIF5A, to the carboxyl (C)-terminal tail region of Fig4 (also known as Sac3), a phosphatase that removes the 5-phosphate from phosphatidylinositol-3,5-bisphosphate ($PtdIns(3,5)P_2$). Fig4 bound to the C-terminal region of KIF5A but not to other KHCs (KIF5B and KIF5C) and KLC1 in yeast two-hybrid assays. The interaction was further confirmed in a glutathione S-transferase pull-down assay and by co-immunoprecipitation. Anti-KIF5A antibody co-immunoprecipitated Fig4 with KIF5A from mouse brain extracts. These results suggest that kinesin-1 could transport the Fig4-associated protein complex or cargo in cells.

Distribution fitting for the rate of return and value at risk (수익률 분포의 적합과 리스크값 추정)

  • Hong, Chong-Sun;Kwon, Tae-Wan
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.2
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    • pp.219-229
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    • 2010
  • There have been many researches on the risk management due to rapid increase of various risk factors for financial assets. Aa a method for comprehensive risk management, Value at Risk (VaR) is developed. For estimation of VaR, it is important task to solve the problem of asymmetric distribution of the return rate with heavy tail. Most real distributions of the return rate have high positive kurtosis and low negative skewness. In this paper, some alternative distributions are used to be fitted to real distributions of the return rate of financial asset. And estimates of VaR obtained by using these fitting distributions are compared with those obtained from real distribution. It is found that normal mixture distribution is the most fitted where its skewness and kurtosis of practical distribution are close to real ones, and the VaR estimation using normal mixture distribution is more accurate than any others using other distributions including normal distribution.

Modeling Heavy-tailed Behavior of 802.11b Wireless LAN Traffic (무선 랜 802.11b 트래픽의 두꺼운 꼬리분포 모델링)

  • Yamkhin, Dashdorj;Won, You-Jip
    • Journal of Digital Contents Society
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    • v.10 no.2
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    • pp.357-365
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    • 2009
  • To effectively exploit the underlying network bandwidth while maximizing user perceivable QoS, mandatory to make proper estimation on packet loss and queuing delay of the underling network. This issue is further emphasized in wireless network environment where network bandwidth is scarce resource. In this work, we focus our effort on developing performance model for wireless network. We collect packet trace from actually wireless network environment. We find that packet count process and bandwidth process in wireless environment exhibits long range property. We extract key performance parameters of the underlying network traffic. We develop an analytical model for buffer overflow probability and waiting time. We obtain the tail probability of the queueing system using Fractional Brown Motion (FBM). We represent average queuing delay from queue length model. Through our study based upon empirical data, it is found that our performance model well represent the physical characteristics of the IEEE 802.11b network traffic.

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Squared Log-return and TGARCH Model : Asymmetric Volatility in Domestic Time Series (제곱수익률 그래프와 TGARCH 모형을 이용한 비대칭 변동성 분석)

  • Park, J.A.;Song, Y.J.;Baek, J.S.;Hwang, S.Y.;Choi, M.S.
    • The Korean Journal of Applied Statistics
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    • v.20 no.3
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    • pp.487-497
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    • 2007
  • As is pointed out by Gourieroux (1997), the volatility effects in financial time series vary according to the signs of the return rates and therefore asymmetric Threshold-GARCH (TGARCH, henceforth) processes are natural extensions of the standard GARCH toward asymmetric volatility modeling. For preliminary detection of asymmetry in volatility, we suggest graphs of squared-log-returns for various financial time series including KOSPI, KOSDAQ and won-Euro exchange rate. Next, asymmetric TGARCH(1,1) model fits are provided in comparisons with standard GARCH(1.1) models.

Kinesin-1-dependent transport of the βPIX/GIT complex in neuronal cells

  • Shin, Eun-Young;Lee, Chan-Soo;Kim, Han-Byeol;Park, Jin-Hee;Oh, Kwangseok;Lee, Gun-Wu;Cho, Eun-Yul;Kim, Hyong Kyu;Kim, Eung-Gook
    • BMB Reports
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    • v.54 no.7
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    • pp.380-385
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    • 2021
  • Proper targeting of the βPAK-interacting exchange factor (βPIX)/G protein-coupled receptor kinase-interacting target protein (GIT) complex into distinct cellular compartments is essential for its diverse functions including neurite extension and synaptogenesis. However, the mechanism for translocation of this complex is still unknown. In the present study, we reported that the conventional kinesin, called kinesin-1, can transport the βPIX/GIT complex. Additionally, βPIX bind to KIF5A, a neuronal isoform of kinesin-1 heavy chain, but not KIF1 and KIF3. Mapping analysis revealed that the tail of KIF5s and LZ domain of βPIX were the respective binding domains. Silencing KIF5A or the expression of a variety of mutant forms of KIF5A inhibited βPIX targeting the neurite tips in PC12 cells. Furthermore, truncated mutants of βPIX without LZ domain did not interact with KIF5A, and were unable to target the neurite tips in PC12 cells. These results defined kinesin-1 as a motor protein of βPIX, and may provide new insights into βPIX/GIT complex-dependent neuronal pathophysiology.