• Title/Summary/Keyword: D/d ratio

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Do Government Subsidies Crowd In or Crowd Out R&D Investment? Evidence from China's Animal Husbandry Companies

  • XU, Jian;SIM, Jaewoo
    • Asian Journal of Business Environment
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    • v.10 no.4
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    • pp.5-13
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    • 2020
  • Purpose: The purpose of this paper is to empirically investigate the relationship between government subsidies and research and development (R&D) investment of animal husbandry companies in China. The moderating effects of firm size, debt ratio, and firm profitability on this relationship are also examined. Research design, data and methodology: The analysis is based on 14 animal husbandry companies listed on the Shanghai and Shenzhen stock exchanges over the period of 2012-2016. Data are obtained from the China Stock Market & Accounting Research (CSMAR) database and the RESSET database, and multiple regression analysis is utilized with the aid of Stata. Results: The empirical results show that government subsidies can promote R&D investment of animal husbandry companies in China. In addition, firm size, debt ratio, and firm profitability have positive moderating effects on the relationship between government subsidies and R&D investment. Conclusions: Based on the results, the paper concludes that government subsidies play an important role in the process of R&D of China's animal husbandry companies. This paper recommends that managers of animal husbandry companies should enhance the utilization efficiency of government subsidies and put great emphasis on R&D investment. The policymakers should implement more incentives to encourage animal husbandry companies to invest more in R&D.

Realization of 1D-2DEG Composite Nanowire FET by Selective Area Molecular Beam Epitaxy (선택적 분자선 에픽택시 방법에 의한 1D-2DEG 혼성 나노선 FET의 구현)

  • Kim, Yun-Joo;Kim, Dong-Ho;Kim, Eun-Hong;Seo, Yoo-Jung;Roh, Cheong-Hyun;Hahn, Cheol-Koo;Ogura, Mutsuo;Kim, Tae-Geun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.11
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    • pp.1005-1009
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    • 2006
  • High quality three-dimensional (3D) heterostructures were constructed by selective area (SA) molecular beam epitaxy (MBE) using a specially patterned GaAs (001) substrate to improve the efficiency of tarrier transport. MBE growth parameters such as substrate temperature, V/III ratio, growth ratio, group V sources (As2, As4) were varied to calibrate the selective area growth conditions and the 3D GaAs-AlGaAs heterostructures were fabricated into the ridge type and the V-groove type. Scanning micro-photoluminescence $({\mu}-PL)$ measurements and the following analysis revealed that the gradually (adiabatically) coupled 1D-2DEG (electron gas) field effect transistor (FET) system was successfully realized. These 3D-heterostructures are expected to be useful for the realization of high-performance mesoscopic electronic devices and circuits since it makes it possible to form direct ohmic contact onto the (quasi) 1D electron channel.

Performance Characteristics of Air Driven Ejector According to the Position Changes and the Shape of Driving Nozzle (공기구동 이젝터의 노즐 형상과 위치 변화에 따른 성능 특성)

  • Ji, Myoung-Kuk;Kim, Pil-Hwan;Park, Ki-Tae;Utomo, Tony;Chung, Han-Shik;Jeong, Hyo-Min
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.4
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    • pp.550-556
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    • 2008
  • The aim of this research is to analyze the influence of motive pressure, driving nozzle position and nozzle throat ratio on the performance of ejector. The experiment was conducted in the variation of motive pressure of 0.196, 0.294, 0.392 and 0.490MPa respectively. The position of driving nozzle was varied in difference locations according to mixing tube diameter(0.5d, 1d, 2d, 3d, 4.15d, 5d and 6d). The experimental results show when the nozzle outlet is located at 3d, the flow characteristics change abruptly. It is shown that the suction flow rate and pressure lift ratio of ejector is influenced by the driving nozzle position. At nozzle position location of the Id of mixing tube diameter the performance of ejector gives the best performance.

Characteristics of Stress-Displacement on Uplift Loaded Group Piles (인발력을 받는 무리말뚝의 응력-변위 특성)

  • Lee, Jun-Dae;Ahn, Byeong-Cheol
    • Journal of the Korean Society of Safety
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    • v.20 no.3 s.71
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    • pp.152-157
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    • 2005
  • This experimental study was devoted to investigate skin friction of H group piles with uplift loading conditions in granite soil under laboratory test. Model piles made of steel embedded in weathered granite soil were used in this study. Pile arrangements($2{\times}2,\;3{\times}3$), pile space(2D, 4D, 6D), and soil density($D_r=40%,\;80%$) were tested. The main results obtained from the model tests can be summarized as follows. The series of tests found that ultimate uplift load and displacement for group piles were increased as piles space ratio increases to $D_r=40%$ of soil density. In the relative density of $D_r=80%$, bearing capacity for group piles was greater than for single pile. In the relative density of $D_r=40%$, the theoretical value of skin friction for group piles was greater than practical value. In the relative density of $D_r=80%$, both theoretical and practical value of skin friction for group piles were increased as piles space ratio increases.

Comparative study: nonsynonymous and synonymous substitution of SARS-CoV-2, SARS-CoV, and MERS-CoV genome

  • Sohpal, Vipan Kumar
    • Genomics & Informatics
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    • v.19 no.2
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    • pp.15.1-15.7
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    • 2021
  • The direction of evolution can estimate based on the variation among nonsynonymous to synonymous substitution. The simulative study investigated the nucleotide sequence of closely related strains of respiratory syndrome viruses, codon-by-codon with maximum likelihood analysis, z selection, and the divergence time. The simulated results, dN/dS > 1 signify that an entire substitution model tends towards the hypothesis's positive evolution. The effect of transition/transversion proportion, Z-test of selection, and the evolution associated with these respiratory syndromes, are also analyzed. Z-test of selection for neutral and positive evolution indicates lower to positive values of dN-dS (0.012, 0.019) due to multiple substitutions in a short span. Modified Nei-Gojobori (P) statistical technique results also favor multiple substitutions with the transition/transversion rate from 1 to 7. The divergence time analysis also supports the result of dN/dS and imparts substantiating proof of evolution. Results conclude that a positive evolution model, higher dN-dS, and transition/transversion ratio significantly analyzes the evolution trend of severe acute respiratory syndrome coronavirus 2, severe acute respiratory syndrome coronavirus, and Middle East respiratory syndrome coronavirus.

Numerical Study on an E-D Nozzle Characteristics with Various Pintle Inflection Angles (핀틀 변곡 각도에 따른 E-D 노즐 특성에 대한 전산수치해석 연구)

  • Park, Sanghyeon;Moon, Taeseok;Huh, Hwanil
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.6
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    • pp.19-27
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    • 2018
  • In this study, a numerical study was conducted to characterize the E-D nozzle which changes according to the nozzle pressure ratios. Three different numerical analysis models were designed by changing the pintle inflection angles. When the nozzle pressure ratio is low, the outside air flows into the E-D nozzle to form an open flow field. As the nozzle pressure ratio increases, the flow transition occurs to become the closed flow field where the recirculation region is isolated inside the nozzle. Also, the highest thrust coefficient was obtained in the analytical model with high pintle inflection angle at all nozzle pressure ratios.

Evaluation of 3D printability of cementitious materials according to thixotropy behavior

  • Lee, Keon-Woo;Choi, Myoung Sung
    • Advances in concrete construction
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    • v.11 no.2
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    • pp.141-149
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    • 2021
  • This study is a basic research for evaluating the buildability of cementitious materials for three-dimensional (3D) printing. In the cement paste step, the thixotropy behavior according to the resting time, which represents the time interval between each layer, was analyzed. In addition, the relationship between the thixotropy behavior and 3D concrete printing buildability was derived by proposing a measurement method that simulates the 3D concrete printing buildup process. The analysis of the tendency of the thixotropy behavior according to the resting time revealed that the area of the hysteresis loop (AHyst) showed a tendency to increase and then converge as the resting time increased, which means hysteresis loop approach critical resting time for sufficient buildability. In the thixotropy behavior analysis that simulates the 3D concrete printing buildup process, the buildup ratio, which is the recovery rate of the shear stress, showed a tendency to increase and then converge as the resting time increased, which are similar results like hysteresis loop. It was concluded that AHyst and the buildup ratio can be used as parameters for determining the resting time, and they have close relationships with 3D concrete printing buildability.

Detecting Rectangular Image Regions in a Window Image for 3D Conversion (3D 변환을 위한 윈도우영상에서 사각 이미지 영역 검출)

  • Gil, Jong In;Lee, Jun Seok;Kim, Manbae
    • Journal of Broadcast Engineering
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    • v.18 no.6
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    • pp.795-807
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    • 2013
  • In recent years, 2D-to-3D conversion techniques have gained much attraction. Most of conventional methods focused on natural images such as movie, animation and so forth. However, it is difficult to apply these techniques to window images mixed with text, image, logo, and icon. Also, different depth values of text pixels will cause distortion and a proper 3D image can not be delivered in some situations. To solve this problem, we propose a method to classify a given image into either a window or a natural image. For the window image, only rectangular image regions (RIR) are detected and converted in 3D. Other text and background are displayed in 2D. The proposed method was performed on more than 10,000 test images. In the experimental results, the detection ratio of window image reaches 97% and RIR detection ratio is 87%.

A Novel Frequency Planning and Power Control Scheme for Device-to-Device Communication in OFDMA-TDD Based Cellular Networks Using Soft Frequency Reuse (OFDMA-TDD 기반 셀룰러 시스템에서 디바이스간 직접통신을 위한 SFR 자원할당 및 전송 전력조절 방법)

  • Kim, Tae-Sub;Lee, Sang-Joon;Lim, Chi-Hun;Ryu, Seungwan;Cho, Choong-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37A no.10
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    • pp.885-894
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    • 2012
  • Currently, Demand of data traffic has rapidly increased by popular of smart device. It is very difficult to accommodate demand of data traffic by limited resource of base station (BS). To solve this problem, method has proposed that the Device-to-Device (D2D) reduce frequency overload of the BS and all of the user equipment (UE) inside the BS and neighbor BS don't allow communicating directly to BS. However, in LTE-Advance system cellular link and sharing radio resources of D2D link, the strong interference of the cellular network is still high. So we need to eliminate or mitigate the interference. In this paper, we use the transmission power control method and Soft Frequency Reuse (SFR) resource allocation method to mitigate the interference of the cellular link and D2D link. Simulation results show that the proposed scheme has high performance in terms of Signal to Noise Ratio (SINR) and system average throughput.

Development of a demand estimation method by using multiclass traffic assignment based on traffic counts (다차종통행배분을 이용한 통행량기반 수요추정기법개발)

  • 김종형;이승재
    • Journal of Korean Society of Transportation
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    • v.19 no.1
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    • pp.77-88
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    • 2001
  • Until now, though most of the studies related to demand estimation method using traffic counts use methods based on singleclass, travel demands or flows are made by mixing various vehicles in real networks. In general, existing demand estimation methods based on traffic counts estimate O/D by converting a multiclass O/D matrix and traffic counts into a singleclass O/D matrix and traffic counts through PCE conversion, and analyze a O/D matrix by dividing into a multiclass O/D matrix and traffic counts after multiplying an estimated O/D matrix by the fixed ratio of a singleclass O/D matrix and traffic counts before PCE conversion. However, the merits of a demand estimation method based on multiclass calculate each route choice ratio about multiclass O/D, and maximize the estimation capability of multiclass by calculating each gradient, the reduction direction of objective function. Therefore, this study aims to establish a demand estimation method which considers congestion between vehicle and vehicle by using multiclass instead of singleclass.

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