• Title/Summary/Keyword: heavy tail

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Species Dependence of Neurofilament Structures: Monte Carlo Simulation studies of Residue-Based Neurofilament Models

  • Kim, Seon-Ok
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.225-235
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    • 2014
  • 6종의 Intermediate filament 중 type IV인 Neurofilaments (NFs)는 신경세포에 존재하는 세포골격세사로 heavy NF(NF-H), medium NF(NF-M), light NF(NF-L) 세가지의 분자 질량 단백질로 구성되어 있다. NF의 side arm은 interfilament spacing과 axonal caliber를 조절하는 중요한 역할을 한다고 생각되어왔다. 또한 이에 대해서 각각의 protein의 역할은 알아내기 위해 isolated NF의 형태와 구조에 대해 많은 연구가 이루어졌는데, NF의 구조적 특성은 NF sidearm의 tail 부분에서 phosphorylation의 정도에 따른 Lys-Ser-Pro(KSP) repeats의 charge distribution을 통해 알 수 있다. 지금까지 NF에 대한 많은 연구가 이루어졌지만 인간에 한해서만 진행되었다. 그렇기 때문에 본 연구에서는 주어진 amino acid sequence와 각 species의 NF-H:NF-M:NF-L의 비율의 정보를 이용하여 The constant-NVT ensemble MC simulation을 통해 인간뿐만이 아닌 다른 species에 대한 NF의 구조적 특성을 알아보고자 한다.

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Development of a 2-row Type Band Furrow Tiller for a Walking Cultivator (보행형 관리기 부착형 2조식 부분 중경제초기의 개발)

  • Kim, C.S.;Kim, K.D.
    • Journal of Biosystems Engineering
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    • v.32 no.4
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    • pp.223-229
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    • 2007
  • This study was conducted to develop a 2 row type band furrow tiller for a walking cultivator. The tillage and weeding operations in the furrow of dry fields has been done manually or chemical herbicide has been applied. The application of herbicide induces soil pollution and manual operation requires heavy labor. This 2-row type implement was developed to substitute this manual operation and to minimize soil pollution. The developed implement was composed of power transmitting device, tilling device, frame and tail wheel. The max. plowing width and depth were 300mm and 180mm, respectively. The revolutions of the hexagonal shaft and the tillage shaft were $227{\sim}376rpm$ and $355{\sim}590rpm$, respectively. The adequate working speed was $0.50{\sim}0.83m/s$ and the field capacity was $0.17{\sim}0.28hr/10a$.

Bragg-curve simulation of carbon-ion beams for particle-therapy applications: A study with the GEANT4 toolkit

  • Hamad, Morad Kh.
    • Nuclear Engineering and Technology
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    • v.53 no.8
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    • pp.2767-2773
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    • 2021
  • We used the GEANT4 Monte Carlo MC Toolkit to simulate carbon ion beams incident on water, tissue, and bone, taking into account nuclear fragmentation reactions. Upon increasing the energy of the primary beam, the position of the Bragg-Peak transfers to a location deeper inside the phantom. For different materials, the peak is located at a shallower depth along the beam direction and becomes sharper with increasing electron density NZ. Subsequently, the generated depth dose of the Bragg curve is then benchmarked with experimental data from GSI in Germany. The results exhibit a reasonable correlation with GSI experimental data with an accuracy of between 0.02 and 0.08 cm, thus establishing the basis to adopt MC in heavy-ion treatment planning. The Kolmogorov-Smirnov K-S test further ascertained from a statistical point of view that the simulation data matched the experimentally measured data very well. The two-dimensional isodose contours at the entrance were compared to those around the peak position and in the tail region beyond the peak, showing that bone produces more dose, in comparison to both water and tissue, due to secondary doses. In the water, the results show that the maximum energy deposited per fragment is mainly attributed to secondary carbon ions, followed by secondary boron and beryllium. Furthermore, the number of protons produced is the highest, thus making the maximum contribution to the total dose deposition in the tail region. Finally, the associated spectra of neutrons and photons were analyzed. The mean neutron energy value was found to be 16.29 MeV, and 1.03 MeV for the secondary gamma. However, the neutron dose was found to be negligible as compared to the total dose due to their longer range.

An Experimental Study on GHG Emissions Reduction and Fuel Economy Improvement of Heavy-Duty Trucks by Using Aerodynamics Device Package (공기저항 저감장치 패키지를 이용한 대형화물차량의 연비개선 및 온실가스 저감효과에 관한 실험적 연구)

  • Park, Seungwon;Dong, Lang;Her, Chulhaeng;Yun, Byoeunggyu;Kim, Daewook
    • Transactions of the Korean Society of Automotive Engineers
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    • v.25 no.2
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    • pp.207-218
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    • 2017
  • Improving fuel consumption, particularly that of commercial vehicles, has become a global concern. The reduction in logistics cost has been a key issue in efforts to improve fuel economy and efficiency of transportation equipment. Typical technologies for reducing reduce fuel usage include air resistance reduction technologies, tire rolling resistance technologies, and idle technologies among others. Air resistance technology is a highly effective method that can be easily applied in a short period. As with air resistance technology, several devices involving side skirt, boat tail and gap fairing have been developed based on an analytical 3-D modeling technique for reducing air resistance attributed to the vehicle configuration. The devices were on a 45 feet tractor-trailer and the emission test was done using PEMS equipment. Fuel economy was evaluated by introducing several devices to reduce outer air resistance. The test was conducted by changing the experimental method of SAE J1321 Joint TMC/SAE Fuel Consumption Test Procedure - Type II test. As a result, air resistance decreased by at least 15 % and fuel economy improved by at least 13 %. This study sought to reduce greenhouse gas and improve fuel economy by applying several devices to a test vehicle to lower air resistance.

Development of Fertilizer-Soil Incorporation Band Tiller for Walking Cultivator (보행관리기 부착형 부분경운-시비 작업기 개발)

  • Kim C. S.;Kwon B. C
    • Journal of Biosystems Engineering
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    • v.29 no.6 s.107
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    • pp.487-494
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    • 2004
  • This study was conducted to develope a fertilizer-soil incorporation band tiller for the walking cultivator. Because the mixing of soil and fertilizer in the furrow of dry-field has been done manually, several time, heavy labor and much man power were required for the job. This rotary type implement is developed to substitute this manual operation for soil-fertilizer incorporation. The results of this study are summarized as follows : 1) This implement was composed of tilling device, fertilizer application device, frame and tail wheel device. 2) The revolution of driving wheel was $11\~28\;rpm$, that of application roller was $13\~14\;rpm$ the application rate range per revolution of driving wheel was $4.43\~11.80\;g$g and the application rate range by the working speed and the opening quantity was $84.12\~557.20\;g/min$. 3) The adequate working speed was $0.20\~0.40\;m/s$ and the required minimum width of open furrow was 250 mm.

Concept of Trend Analysis of Hydrologic Extreme Variables and Nonstationary Frequency Analysis (극치수문자료의 경향성 분석 개념 및 비정상성 빈도해석)

  • Lee, Jeong-Ju;Kwon, Hyun-Han;Kim, Tae-Woong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2010.05a
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    • pp.1448-1452
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    • 2010
  • 최근 기상변동성 증가 및 기후변화 영향으로 수문순환과정이 과거와는 다른 양상으로 전개되고 있으며 전반적으로 극치사상의 빈도 및 강도의 증가현상이 지배적이다. 이러한 영향을 정량적으로 검토하기 위해서 경향성분석 방법 등이 도입되어 극치수문사상의 변동경향을 평가하는데 이용되고 있다. 대표적인 방법으로 선형회귀분석, Mann-Kendall 경향성 분석 등이 있으나 기본적인 가정(assumption)의 제약으로 극치수문자료 계열의 특성을 효과적으로 분석하는데 무리가 있다. 대표적이고 일반적으로 적용되는 선형회귀분석의 경우 자료가 정규분포(normal distribution)의 특성을 가질 때 유효한 방법으로서 극치수문자료와 같이 Heavy Tail를 가지는 분포특성을 표현하는 데는 무리가 따른다. 이밖에도 기존 선형회귀분석을 극치수문자료에 적용할 경우 추정된 결과를 수자원설계의 관심사항인 빈도해석 등에 직접적으로 연계시켜 해석할 수 없는 단점이 있다. 이는 자료계열의 분포특성을 정규분포로 가정하기 때문에 발생하는 문제로서 극치수문자료계열의 분포 특성을 반영할 수 있는 방법론의 개발이 필요하다. 본 연구에서는 이러한 점을 개선하기 위해서 극치분포(extreme distribution)를 선형회귀분석에 적용하는 비정상성빈도해석(nonstationary frequency analysis) 방법론의 개념을 제시하고자 한다. 비정상성빈도해석을 위해서 Bayesian 기법이 도입되며 Bayesian 기법의 특성상 관련변수들이 사후분포(posterior distribution)로 귀결되기 때문에 경향성에 대한 정량적이고 확률적인 분석이 가능한 장점이 있다. 본 연구를 통해 개발된 방법론은 국내외 주요 강수지점에 대해서 적용되며 경향성, 분포특성, 빈도별 강수량에 대한 체계적인 분석이 이루어진다.

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The Influence of the Eyebrow Make-up on Facial Image (눈썹화장이 얼굴이미지에 미치는 영향)

  • Gang, Eun-Ju
    • Journal of the Korean Society of Fashion and Beauty
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    • v.3 no.2 s.2
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    • pp.31-38
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    • 2005
  • Make-up changes facial images. In particular, eyebrow make-up is a part of changing expression most easily and effectively. While color make-up is helpful to produce women's desired image with their favorite colors, eyebrow make-up is hidden actor to give a clear impression to others. Therefore, this study connected facial type which is an important factor deciding facial image with eyebrow, examined image of eyebrow make-up and that changed by facial types and aimed to be helpful in producing more effective facial image with eyebrow make-up considering one's facial type. Consequently, it was found that eyebrow make-up was a great factor in making better facial impression and image and complementing the weakness of facial type. h strong impression of facial type can be changed into soft shape or foolish shape in worse case depending on the types of eyebrow make-up. Eyebrow make-up shows charming image as angle of eyebrow is steep, heavy image as eyebrow is horizontal, cold image as eyebrow tail rises and simple and dull image as it lowers. Therefore, it is known that image of eyebrow make-up can be governed by several factors including angle and direction of eyebrow. Consequently, it is thought that most effective eyebrow make-up considers individual facial types, images of their eyes, noses and mouths and factors deciding angle, direction and colors of eyebrow.

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A Study on The IC Design of 1[V] CMOS Operational Amplifier with Rail-to-rail Output Ranges (Rail-to-rail 출력을 갖는 1[V] CMOS Operational Amplifiler 설계 및 IC 화에 관한 연구)

  • Jeon, Dong-Hwan;Son, Sang-Hui
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.4
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    • pp.461-466
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    • 1999
  • A CMOS op amp with rail-to-rail input and output ranges is designed in a one-volt supply. The output stage of the op amp is used in a common source amplifier that operates in sub-threshold region to design a low voltage op amp with rail-to-tail output range. To drive heavy resistor and capacitor loads with rail-to-rail output ranges, a common source amplifier which has a low output resistance is utilized. A bulk-driven differential pair and a bulk-driven folded cascode amplifier are used in the designed op amp to increase input range and achieve 1 V operation. Post layout simulation results show that low frequency gain is about 58 ㏈ and gain bandwidth I MHz. The designed op amp has been fabricated in a 0.8${\mu}{\textrm}{m}$ standard CMOS process. The measured results show that this op amp provides rail-to-rail output range, 56㏈ dc gain with 1 MΩ load and has 0.4 MHz gain-bandwidth with 130 ㎊ and 1 kΩ loads.

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Characterizing the Tail Distribution of Android IO Workload (안드로이드 입출력 부하의 꼬리분포 특성분석)

  • Park, Changhyun;Won, Youjip;Park, Yongjun
    • KIPS Transactions on Computer and Communication Systems
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    • v.8 no.10
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    • pp.245-250
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    • 2019
  • The use of NAND flash memory has increased rapidly due to the development of mobile fields. However, NAND flash memory has a limited lifespan, so studies are underway to predict its lifespan. Workload is one of the factors that significantly affect the life of NAND flash memory, and workload analysis studies in mobile environments are insufficient. In this paper, we analyze the distribution of workload in the mobile environment by collecting traces generated by using Android-based smartphones. The collected traces can be divided into three groups of hotness. Also they are distributed in the form of heavy tails. We fit this to the Pareto, Lognormal, and Weibull distributions, and Traces are closest to the Pareto distribution.

Parametric nonparametric methods for estimating extreme value distribution (극단값 분포 추정을 위한 모수적 비모수적 방법)

  • Woo, Seunghyun;Kang, Kee-Hoon
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.1
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    • pp.531-536
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    • 2022
  • This paper compared the performance of the parametric method and the nonparametric method when estimating the distribution for the tail of the distribution with heavy tails. For the parametric method, the generalized extreme value distribution and the generalized Pareto distribution were used, and for the nonparametric method, the kernel density estimation method was applied. For comparison of the two approaches, the results of function estimation by applying the block maximum value model and the threshold excess model using daily fine dust public data for each observatory in Seoul from 2014 to 2018 are shown together. In addition, the area where high concentrations of fine dust will occur was predicted through the return level.