• Title/Summary/Keyword: period error

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Effectiveness of Government R&D on Firm's R&D Spending (정부R&D투자가 기업 규모별 R&D지출에 미치는 영향 분석)

  • Jung, Jun-Ho;Kim, Jae-Soo;Choi, Ki-seok;Lee, Byeong-Hee
    • The Journal of the Korea Contents Association
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    • v.16 no.10
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    • pp.150-162
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    • 2016
  • This study empirically analyze the effect of government R&D investment to find out whether it complements or substitutes for the firm R&D. In order to do it panel data set was constructed for the period of three years from 2012 to 2014 based on the number of 1301 data by utilizing national technology information service(NTIS) and publicly announced financial statement. Analysis was implemented in consideration of size of the firm(large corporation, small and medium sized firm) of which sample was obtained from only listed company. The result of two-way fixed effect model and two-way random effect model is as follows. In case of large corporation, government R&D investment has an effect of substitute for the company's R&D on the other hand, small and medium sized firm shows an complementary effect. It verifies that current R&D policy is appropriate. Therefore government's direct subsidy is expected to be successful to fertilize firm's innovation by allocating government R&D budget efficiently.

TAR and M-TAR Error Correction Models for Asymmetric Gasoline Price in Korea (TAR와 M-TAR 오차수정모형을 이용한 국내 휘발유가격의 비대칭성 분석)

  • Lee, Yang Seob
    • Environmental and Resource Economics Review
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    • v.17 no.4
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    • pp.813-843
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    • 2008
  • This paper investigates the presence of long-run and short-run price asymmetries in weekly gasoline prices from January 1997 to July 2008. In accordance with distribution channels, wholesale and retail stages are analyzed separately. An approach based on TAR and M-TAR cointegration tests, which entail matching asymmetric ECMs, is employed. For wholesale prices, asymmetries in the links with crude oil prices and exchange rates are found for both ECMs in the long-run and short-run. Exchange rates appear to play more significant role than crude oil prices in explaining the short-run price asymmetry. The rise in crude oil prices or exchange rates has statistically significant major impact on the increase of wholesale prices on the second week, not immediately as expected in the concept of 'rockets and feathers'. And asymmetrically, the fall does not have any statistically significant effect on the same period. The finding seems to be somewhat unusual. However, for retail prices, asymmetry m connection with wholesale prices is only revealed in the long-run. A symmetric price adjustment can be assumed in the short-run. Contrary to the long-run asymmetry found in the wholesale stage, in the retail stage, the speed of adjustment for negative deviations toward long-run equilibrium is faster than for positive ones, which is a phenomenon not favorable to consumers.

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IUE SPECTRA OF SEYEERT 1 GALAXY NGC 7469-BLR CHARACTERISTICS OF NGC 7469 (SEYFERT 1 은하 NGC 7469의 IUE SPECTRA-NGC 7469 BLR의 물리적 특성)

  • Son, Dong-Hoon;Hyung, Siek
    • Journal of Astronomy and Space Sciences
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    • v.22 no.3
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    • pp.187-196
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    • 2005
  • From the line ratios of Si III] 1892 to C III] 1909 (Feibelman & Aller 1987), we estimated the BLR electron densities and their changes of Seyfert 1 galaxy NGC 7469 using IUE spectra observed from June 11 to July 29, 1996 (Wanders et al. 1997). We separated blended Si III] and C III] lines using the STARLINK/DIPSO and measured their fluxes within the error of $12.4\%\;and\;6.6\%,$ respectively. Electron density fluctuated from $10^{9.69}\;to\;10^{10.93}$ during about two month period, i.e. 17.3 times density variation within 50 days. We also derived time delays from UV emission line variations .elative to the continuum $(at\;1315{\AA}):$ 2 days for C IV, 4 days for C III], 8 days for Si III]. This suggests that their stratified UV line emission regions are at 0.002 pc, 0.004 pc and 0.006 pc, respectively, from the central region. Based on the BLR sizes and their rotation velocities deduced from the line profiles, we estimate the central black hole mass as about $10^6M_{\odot}$

Estimation of Weaning Age Effects on Growth Performance in Berkshire Pigs

  • Do, C.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.2
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    • pp.151-162
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    • 2012
  • Analysis for back fat thickness (BFAT) and daily body weight gains from birth to the end of a performance test were conducted to find an optimal method for estimation of weaning age effects and to ascertain impacts of weaning age on the growth performance of purebred Berkshire pigs from a closed population in Korea. Individual body weights were measured at birth (B), at weaning (W: mean, 22.9 d), at the beginning of the performance test (P: mean, 72.7 d), and at the end of the performance test (T: mean, 152.4 d). Further, the average daily gains in body weight (ADG) of 3,713 pigs were analyzed for the following periods: B to W (DGBW), W to P (DGWP), P to T (DGPT), B to P (DGBP), B to T (DGBT), and W to T (DGWT). Weaning ages ranged from 17 to 34 d, and were treated as fixed (WF), random with (WC) and random without (WU) consideration of an empirical relationship between weaning ages in the models. WF and WC produced the lowest AIC (Akaike Information Criterion) and least fractions of error variance components in multi-traits analysis, respectively. The fractions of variances due to diverse weaning age and the weaning age correlations among ADGs of different stages (when no overlapping allowed) by WC ranged from 0.09 to 0.35 and from -0.03 to 0.44, respectively. The maximum weaning age effects and optimal back fat thicknesses were attained at weaning ages of 27 to 32 d. With the exception of DGBW, the effects of weaning age on the ADGs increased (ranging from 1.50 g/d to 7.14 g/d) with increased weaning age. In addition, BFAT was reduced by 0.106 mm per increased day in weaning age. In conclusion, WC produced reasonable weaning age correlations, and improved the fitness of the model. Weaning age was one of crucial factors (comparable with heritability) influencing growth performance in Berkshire pigs. Further, these studies suggest that increasing weaning age up to 32 d can be an effective management strategy to improve growth performance. However, additional investigations of the costs and losses related to extension of the suckling period and on the extended range of weaning age are necessary to determine the productivity and safety of this practice in a commercial herd and production system.

Estimating the Determinants of Households' Monthly Average Income : A Panel Data Model Approach (패널 데이터모형을 적용한 가구당 월평균 가계소득 결정요인 추정에 관한 연구)

  • Yi, Hyun-Joo;Cheul, Hee-Cheul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.6
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    • pp.2038-2045
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    • 2010
  • Households' monthly average income is composed of various factors. This study paper studies focuses on estimating the determinants of a households' monthly average income. The region for analysis consist of three groups, that is, the whole country, a metropolitan city(such as Busan, Daegu, Incheon, Gwangiu, Daejeon, Ulsan.) and Seoul. Analyzing period be formed over a 57 time points(2005. 01~2009. 09). In this paper the dependent variable setting up the households' monthly average income, explanatory (independent) variables are composed of the consumer price index, employment to population ratio, Index of housing sale price, the preceding composite index, loans of housing mortgage, spending rate for care medical expense and the composite stock price index. In looking at the factors which determine the monthly average income, evidence was produced supporting the hypothesis that there is a significant positive relationship between the composite index and housing loans. The study also produced evidence supporting the view that there is a significant negative relationship between employment ratios, the house sale pricing index and spending rates for care or medical needs. The study found that the consumer price index and composite stock price index were not significant variables. The implications of these findings are discussed for further research.

Determination of Representative Long-term Water Quality Parameters of the Streams in Estuarine Lake (하구호 유입하천의 유역특성에 따른 장기 대표 수질절정)

  • Kim, Young-Chul;Lee, Dong-Ryul;Hwang, Gil-Son
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.3
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    • pp.262-272
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    • 2005
  • This study was undertaken to obtain design concentrations for the natural system treating stream water flowing into estuarine lake(Sapgyo). This lake has three major, so called, national-class streams: one is Gokgyo flowing through two medium-size municipal areas and the others are Muhan and Sapgyo placed in mostly rural area nested with some small towns. The results of three year's investigation showed big changes in water quality during the period between dry and wet seasons. Nitrogen concentration usually decreases as the flow rate increases. The change of phosphorus concentration in Gokgyo was the same pattern as nitrogen, but in other two streams it was inversely related with flow rates. This is probably due to the chemical property of the particles washed out from the different stream basins during wet season. It was found that about 40 to 60% of the total nitrogen are in soluble form and on average, 35% of the total phosphorus consists of dissolved-P. Representative concentration of these streams has to be separately determined based on dry and wet season. TDS and SS could be indicating parameters useful to depict and characterize a change of water quality with respect to flow rate because their measurement is easy and also includes a small analytical error. TDS values measured during dry season are related with high nitrogen concentration while during wet season, SS values effectively reflect a high concentration of phosphorus. For design purpose, cumulative concentration distribution graph presented in this paper can be directly or indirectly applied to other streams through a brief comparative and verificative study.

Availability based Scheduling Scheme for Fair Data Collection with Mobile Sink in Wireless Sensor Networks (무선 센서 네트워크에서 모바일 싱크를 통한 데이터 수집의 균등성 보장을 위한 가용성 기반 스케줄링 기법)

  • Lee, Joa-Hyoung;Jo, Young-Tae;Jung, In-Bum
    • The KIPS Transactions:PartA
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    • v.16A no.3
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    • pp.169-180
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    • 2009
  • With fixed sinks, the network stability could be improved while the network life time could be decreased by the rapid energy dissipation around the fixed sink because of the concentrated network traffic from sensor nodes to the fixed sink in wireless sensor network. To address this problem, mobile sinks, which decentralize the network traffic, has received a lot of attention from many researchers recently. Since a mobile sink has a limited period to communicate with each sensor nodes, it is necessary for a scheduling algorithm to provide the fairness of data collection from each sensor nodes. In the paper, we propose the new scheduling algorithm, ASF(Availability based Scheduling scheme for Fair data collection), for the fair data collection by a mobile in the sensor networks. The ASF takes account of the distance between each sensor nodes and the mobile sink as scheduling metric, as well as the amount of collected data from each sensor nodes. Experiment results shows that the ASF improves the fairness of data collection among the sensor nodes, comparing to existing algorithm.

Effect of a Hydrologic Similarity Unit and Storm Sewer Resolution on the SWMM Model Performance (수문학적 유사단위와 우수관망의 공간정밀도가 SWMM모형 성과에 미치는 영향)

  • Ha, Sung-Ryong;Lee, Kang-Won
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.2
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    • pp.79-90
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    • 2006
  • The partitioning level of a catchment becomes an issue if the calculated results from different levels show the same performance regardless of the levels. This study aims to identify the proper processing level of spatial resolution for the SWMM model application in an urban area. Using GIS overlaying technique, the division of subcatchments as a hydrologic similarity unit (HSU) is achieved with a comprehensive consideration of surface slope conditions, flow directions of storm sewers, and current land cover situation. Three surface-sewer alternatives are made on the basis of three different levels of surface divisions as well as the number of sewer connections and used as runoff simulation fields for the application of SWMM. As the result, it is found that the effect of a spatial resolution on the surface runoff results is not significant. On the other hand, the accumulated pollution load from an unit subcatchment, which is built by aggregation of several unit subcatchments consisting of various land cover conditions is reduced through the deterioration of surface spatial resolution. Although overall runoff pattern and accumulated runoff are little affected by spatial resolution, the simulated runoff from sewer outlet shows slight difference at the peak appearance time. The gap between surface pollution load accumulated and it discharged from the sewer outlet in a surface-sewer alternative during runoff period is monitored but the level of error is less than 5-10% except the lowest spatial resolution case.

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Site Characterization using Shear-Wave Velocities Inverted from Rayleigh-Wave Dispersion in Wonju, Korea (레일리파 분산을 역산하여 구한 횡파속도를 이용한 원주시의 부지특성)

  • Kim, Chungho;Ali, Abid;Kim, Ki Young
    • Geophysics and Geophysical Exploration
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    • v.17 no.1
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    • pp.11-20
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    • 2014
  • To reveal shear-wave velocities ($v_s$) and site characterization of Wonju, Korea, Rayleigh waves were recorded at 78 sites of lower altitude using 12 to 24 4.5-Hz vertical geophones for 20 days during the period of February to September 2013. Dispersion curves of the Rayleigh waves obtained by the extended spatial autocorrelation method were inverted using the damped least-squares method to derive $v_s$ models. From these 1-D models, the average $v_s$ to a depth of 30 m ($v_s30$), $v_s$ of weathered rocks, depths to these basement rocks, and average $v_s$ of the overburden layer were derived to be $16.3{\pm}0.7m$, $576{\pm}8m/s$, $290{\pm}7m/s$, and $418{\pm}13m/s$, respectively, in the 95% confidence range. To determine adequate proxies for $v_s30$, we computed correlation coefficients of $v_s30$ with topographic slope (r = 0.46) and elevation (r = 0.43). An empirical linear relationship is presented as a combination of individually estimated $v_s30$ with weighting factors of 0.45, 0.45, and 0.1 for topographic slope, elevation, and mapped lithology, respectively. Due to a weak correlation between $v_s30$ obtained from inversion of dispersion curves and the proxy-based estimation (r = 0.50), however, the relatively large error range should be considered for applications of this relationship.

An Estimation Model for the Replacement Parts based on the Operational Availability of Hi-Pass System (하이패스 운용가용도를 이용한 부품의 교체 추정 모델)

  • Hwang, Eui-duk;Heo, Seo Jeong;Kim, Chang Suk;Cheul, Son Dong
    • Journal of the Korea Convergence Society
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    • v.6 no.6
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    • pp.285-291
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    • 2015
  • FTMS, TCS, ITS equipment such as high-pass highway are just a situation that does not lack traceability and passive surveillance is related to fault DB has so far consisted of an integrated operations management to maximize utilization of the facility. In addition, there is no replacement parts are replaced when a failure occurs, increasing the number of parts and repair time I have trouble growing, and becoming a service interruption whenever you replace each time. In this study, proactively manage the failure history of a highway facility ITS tries to preventive maintenance. Therefore, the error history is based on the reliability of the high-pass facilities theory to calculate the reliability of the system through a systematic statistical analysis Operational Availability. The fault number and the time the replacement period through the estimate decreases and can reduce the budget expenses by securing the spare parts quantity, establish a management plan in part by improving the quality of the system through constant preventive maintenance, quality of service at all times It may direct the non-stop operation state of the available state.