• Title/Summary/Keyword: small-scale data

Search Result 1,296, Processing Time 0.028 seconds

Linear Measurement Error Variance Estimation based on the Complex Sample Survey Data

  • Heo, Sunyeong;Chang, Duk-Joon
    • Journal of Integrative Natural Science
    • /
    • v.5 no.3
    • /
    • pp.157-162
    • /
    • 2012
  • Measurement error is one of main source of error in survey. It is generally defined as the difference between an observed value and an underlying true value. An observed value with error may be expressed as a function of the true value plus error term. In some cases, the measurement error variance may be also a function of the unknown true value. The error variance function can be rewritten as a function of true value multiplied by a scale factor. This research explore methods for estimation of the measurement error variance based on the data from complex sampling design. We consider the case in which the variance of mesurement error is a linear function of unknown true value, and the error variance scale factor is small. We applied our results to the U.S. Third National Health and Nutrition Examination Survey (the U.S. NHANES III) data for empirical analyses, which has replicate measurements for relatively small subset of initial respondents's group.

Computational simulation of intelligent big data analysis under nanotube rotation

  • Lunan Li;Allam Maalla
    • Advances in nano research
    • /
    • v.14 no.1
    • /
    • pp.67-80
    • /
    • 2023
  • Economic investigation is one of the main issues regarding the design and production of small-scale structures. This paper concerns the creation, implementation, and economic aspects of the cross-section profile of small-scale structures regarding the dynamic response of the free and forced vibration behavior of spinning nanoscale beams based on big data analysis. According to the financial analysis, the three practical non-uniform functions of cross-sections are compared to the uniform beam in the same weight and the equal material used. The previous studies reported that the uniform beams are more stable and contain a better frequency response based on the mechanical analysis. Still, concerning the economic investigation, which means the considered structures should have equal length and have the same weight in the aspect of material used, the conclusion can be different from the mechanical aspect. Consequently, in the current paper, the dynamic response along with computer technology as well as the big data analysis of the free and forced vibration of the nanobeam regarding the economic shape of the cross-section is scrutinized.

Definition of the neutronics benchmark of the NuScale-like core

  • Emil Fridman;Yurii Bilodid;Ville Valtavirta
    • Nuclear Engineering and Technology
    • /
    • v.55 no.10
    • /
    • pp.3639-3647
    • /
    • 2023
  • This paper defines a 3D full core neutronics benchmark which is based on the NuScale small modular reactor (SMR) concept. The paper provides a detailed description of the NuScale-like core, a list of expected outputs, and a reference solution to the benchmark exercises obtained with the Monte Carlo code Serpent. The benchmark was developed in the framework of the Euratom McSAFER project and can be used for verification of computational chains dedicated to 3D full-core neutronics simulations of water cooled SMRs. The paper is supplemented with a digital data set to ease the modeling process.

SMALL-SCALE STRUCTURE OF THE ZODIACAL DUST CLOUD OBSERVED IN FAR-INFRARED WITH AKARI

  • Ootsubo, Takafumi;Doi, Yasuo;Takita, Satoshi;Matsuura, Shuji;Kawada, Mitsunobu;Nakagawa, Takao;Arimatsu, Ko;Tanaka, Masahiro;Kondo, Toru;Ishihara, Daisuke;Usui, Fumihiko;Hattori, Makoto
    • Publications of The Korean Astronomical Society
    • /
    • v.32 no.1
    • /
    • pp.63-65
    • /
    • 2017
  • The zodiacal light emission is the thermal emission from the interplanetary dust and the dominant diffuse radiation in the mid- to far-infrared wavelength region. Even in the far-infrared, the contribution of the zodiacal emission is not negligible at the region near the ecliptic plane. The AKARI far-infrared all-sky survey covered 97% of the whole sky in four photometric bands with band central wavelengths of 65, 90, 140, and $160{\mu}m$. AKARI detected the small-scale structure of the zodiacal dust cloud, such as the asteroidal dust bands and the circumsolar ring, in far-infrared wavelength region. Although the most part of the zodiacal light structure in the AKARI far-infrared all-sky image can be well reproduced with the DIRBE zodiacal light model, there are discrepancies in the small-scale structures. In particular, the intensity and the ecliptic latitude of the peak position of the asteroidal dust bands cannot be reproduced precisely with the DIRBE models. The AKARI observational data during more than one year has advantages over the 10-month DIRBE data in modeling the full-sky zodiacal dust cloud. The resulting small-scale zodiacal light structure template has been used to subtract the zodiacal light from the AKARI all-sky maps.

Improvement Index and Characteristic for the Safety Management Level of Domestic Construction Companies (국내 건설회사의 안전관리수준 향상지수 및 특성 분석)

  • Son, Chang-Baek;Lee, Dong-Eun;Choi, Seung-Mo
    • Journal of the Korean Society of Safety
    • /
    • v.22 no.4
    • /
    • pp.51-56
    • /
    • 2007
  • In order to present basic data for the balancing improvement of safety management level in domestic construction companies the improvement index and characteristic of safety management level are offered by comparing the year 2006's safety level with the year 2001's one. The companies under concern are classified into 51 large scale companies and 61 middle and small scale ones. The safety management level of both head office and construction sites is improved for all companies without regard to the scale. Specially, the improvement index of middle and small scale companies shows the higher rate than large ones and head office higher than construction sites.

Developing a Work Procedure for Efficient Map Generalization (효율적인 일반화 자료처리를 위한 작업공정 개발)

  • Choi, Seok-Keun;Kim, Myung-Ho;Hwang, Chang-Sup
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.6 no.3
    • /
    • pp.73-82
    • /
    • 2003
  • This paper proposes a work procedure for generalizing large-scale digital maps ver. 2.0(1/5,000) into a small-scale digital map(1/25,000). Unlike a existent digital map, the digital map ver. 2.0 has a variety of attribute data as well as graphic data. To perform an efficient map generalization with these structural properties, we establish a work procedure as follow; firstly, delete layers which don't exist in small-scale digital map's feature code, and secondly, generalize features which have been classified into 8 layers, and finally merge 8 layers which have been generalized into 1 layer. Therefore, we expect that a work procedure which is proposed in this paper will play a fundamental role in automated generalization system and will contribute to small-scale digital mapping and thematic mapping.

  • PDF

Diverse and predominantly sub-adult Epinephelus sp. groupers from small-scale fisheries in South Sulawesi, Indonesia

  • Nadiarti Nurdin Kadir;Aidah A. Ala Husain;Dody Priosambodo;Muhammad Jamal;Irmawati;Indrabayu;Abigail Mary Moore
    • Fisheries and Aquatic Sciences
    • /
    • v.26 no.6
    • /
    • pp.380-392
    • /
    • 2023
  • Groupers (Family Epinephelidae) are commonly caught in data-poor small-scale multi-species fisheries for sale on both export and domestic markets. This study presents data on the species composition and size/life-stage structure of Epinephelus spp. groupers caught by small-scale fishers and sold locally in the Indonesian province of South Sulawesi. Data were collected from fishing ports and local markets at 12 sites representing the three seaways around South Sulawesi (Makassar Strait, Flores Sea, Gulf of Bone). Each specimen (n = 3,398) was photographed alongside an object of known length, and total length (TL) was obtained using the Rapid Scaling on Object (RASIO). Of the 23 species identified, four (Epinephelus areolatus, Epinephelus ongus, Epinephelus quoyanus, and Epinephelus fasciatus) collectively comprised 69% of the catch, while the 13 least abundant species contributed less than 5%. The catch was dominated (67%) by the subadult life-stage, with just under 20% in the adult class. Juveniles dominated the catch of Epinephelus fuscoguttatus, a valuable export commodity. Observations of early maturity as well as the sizeable gap between length at first capture (Lc) and length at first maturity (Lm) indicate recruitment overfishing of most species, with the notable exception of Epinephelus rivulatus. The proportion of adult fish was low (≈5%-30%) for the twelve most abundant species (E. areolatus, E. ongus, Epinephelus quoyanus, E. fasciatus, Epinephelus coioides, Epinephelus faveatus, Epinephelus sexfasciatus, Epinephelus maculatus, Epinephelus bleekeri, Epinephelus corallicola, E. fuscoguttatus, Epinephelus polyphekadion). For two moderately abundant species (E. faveatus and E. malabaricus), TL < Lm for all specimens. The limited data available indicate spawning ratio is lower than reported from deep-water fisheries of E. areolatus and E. coioides. The results call for targeted research to fill knowledge gaps regarding the biology and ecology of groupers exploited mainly for domestic markets; highlight the need for species-level data to inform management policies such as minimum legal size regulations; and can contribute towards species-level status assessments.

Measures to Reduce Industrial Accidents by Investigating them at Small Scale Construction Sites in Rural Area (농촌지역 소규모 건축공사 현장의 재해조사를 통한 저감방안 고찰)

  • Kim, Byung-Yun
    • Journal of the Korean Institute of Rural Architecture
    • /
    • v.16 no.1
    • /
    • pp.95-102
    • /
    • 2014
  • The number of industrial accident victims in the construction industry accounts for 1/3 of those in the entire industries and about 30% of the total compensation costs are spent in the construction industry. As such, the construction industry is a typical industry causing numerous safety accidents. This study analyzes the status of industrial accidents in small scale construction sites to build maximum five-story buildings by examining statistical data for the past five years, investigating those construction sites and conducting interviews with the workers. This study also seeks the causes of and measures for industrial accidents in the small scale construction industry through comparison with relevant systems. The findings are as follows: (1) To reduce hazard rate, shaping the working environment and safety measures that take into account the physically weak classes of the middle aged and the aging are urgently required, because 62.9% of the industrial accidents in the construction industry occurred to those who are 50 years of age or older. (2) The hazard rate at small scale construction sites with less than 10 construction workers accounts for 55% of that of the entire industries. The government, in this context, needs to support finance or technology and improve system by selecting the small scale construction sites, where industrial accidents occur frequently. (3) Because the hazard rate of unskilled workers with less than 6 months of work experience accounts for 90.95% of the total, safety education needs to be concentrated on those unskilled workers. (4) The relevant standards need to be segmented and revised and bolstered, given that 64.79% of death disaster in the construction industry occurs in the temporary structures including scaffolds and ladders.

Cosmological Tests using Redshift Space Clustering in BOSS DR11

  • Song, Yong-Seon;Sabiu, Cristiano G.;Okumura, Teppei;Oh, Minji;Linder, Eric V.
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.40 no.1
    • /
    • pp.43.3-44
    • /
    • 2015
  • We analyze the clustering of large scale structure in the Universe in a model independent method, accounting for anisotropic effects along and transverse to the line of sight. A large sample of 690,000 galaxies from The Baryon Oscillation Spectroscopy Survey Data Release 11 are used to determine the Hubble expansion H, angular distance D_A, and growth rate GT at an effective redshift of z=0.57. After careful bias and convergence studies of the effects from small scale clustering, we find that cutting transverse separations below 40 Mpc/h delivers robust results while smaller scale data leads to a bias due to unmodelled nonlinear and velocity effects. The converged results are in agreement with concordance LCDM cosmology, general relativity, and minimal neutrino mass, all within the $68{\backslash}%$ confidence level. We also present results separately for the northern and southern hemisphere sky, finding a slight tension in the growth rate -- potentially a signature of anisotropic stress, or just covariance with small scale velocities -- but within $68{\backslash}%$ CL.

  • PDF

A Study of Environmental Effects on Galaxy Spin Using MaNGA Data

  • Lee, Jong Chul;Hwang, Ho Seong;Chung, Haeun
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.42 no.2
    • /
    • pp.47.2-47.2
    • /
    • 2017
  • We investigate the environmental effects on galaxy spin using the sample of ~1100 galaxies from the first public data of MaNGA integral field unit survey. We determine the spin parameter ${\lambda}_{Re}$ of galaxies by analyzing the two-dimensional stellar kinematic measurements within the effective radius, and study its dependence on the large-scale (background mass density determined with 20 nearby galaxies) and small-scale (distance to and morphology of the nearest neighbor galaxy) environments. We first examine the mass dependence of galaxy spin, and find that the spin parameter decreases with stellar mass at log ($M_{\ast}/M_{\odot}$) > 10, consistent with previous studies. We then divide the galaxies into three subsamples using their stellar masses to minimize the mass effects on galaxy spin. The spin parameter of galaxies in each subsample does not change with the background density, but do change with the distance to and morphology of the nearest neighbor. The spin parameter increases when late-type neighbors are within the virial radius, and decreases when early-type neighbors are within the virial radius. These results suggest that the large-scale environments hardly affect the galaxy spin, but the effects of small-scale environments such as hydrodynamic galaxy-galaxy interactions are substantial.

  • PDF