• Title/Summary/Keyword: Absorptive

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The study of the experimental evaluation for the Interference Device on the noise barrier edge (방음벽상단 간섭장치 성능평가에 관한 연구)

  • 장강석;윤제원;김영찬;김두훈
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.844-848
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    • 2001
  • Before we have made known the study of shape development of interference device for vehicle noise control. It's primary object greatly attenuate the noise due to transport vehicle by small products installed on the noise barrier edge. Also, it is able to improve the insertion loss of a noise barrier without increasing the height. The present time, we set up a newly manufactured products on the noise barrier edge and testify to it's the performance make use of an experiment and evaluation. In this paper the performance of noise barriers with attached newly developed products in terms of shape, absorptive material and split panel, are examined using field test.

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A Study on the Sound Transmission Loss Measurement of Sound Isolation Sheets (차음시트의 음향투과손실 측정에 관한 연구)

  • Lee, Dong-Hoon;Kang, Moon;Lee, Ju-Weon;Jung, Gab-Cheol;Kwon, Young-Pil
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.11a
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    • pp.409-414
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    • 2000
  • A new impedance tube method is presented for the measurement of transmission loss of sound isolation sheets. The two-microphone method based on the sound decomposition theory proposed by Seybert and Ross is reviewed in this impedance tube method, which has been used for the determination of absorption coefficient of absorptive materials as well as transmission loss of automotive mufflers. Sound transmission losses for rubber, polyvinyl and asphalt sheets are measured in an impedance tube and reverberation room facility, respectively. By comparing two measurement methods, the reliability of impedance tube method used in this study is validated. From the experimental results, it is shown that the accuracy of sound isolation capability obtained by the impedance tube method depends upon the microphone spacing and the distance of the first microphone from the test sample surface.

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Effects of Social Capital on Individual Task Performance via Knowledge Acquisition and Transformation: An Empirical Study (지식획득과 변환을 통한 사회적 자본의 업무 성과에의 영향에 대한 실증 연구)

  • Son, Hanel;Han, Se Hee;Heo, Dongcheol;Min, Jinyoung;Lee, Heeseok
    • Knowledge Management Research
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    • v.14 no.2
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    • pp.117-135
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    • 2013
  • In a contemporary organization, the role of social capital has been increasingly important in sharpening knowledge management practices. The primary objective of this paper is to propose a research model to measure the effects of social capital on individual performance. The model also investigates the mediating mechanism of knowledge acquisition and knowledge transformation, both of which are critical in fostering an enterprise's absorptive capacity. The field data was collected from a knowledge-centric organization. The analysis result reveals that shared goal is crucial in enabling knowledge processes. Furthermore, it is found that knowledge transformation rather than knowledge acquisition is more likely to lead to individual task performance.

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An Exploratory Research on MNC Parents' Motivation to Facilitate Reverse Knowledge Transfer (다국적기업 본사의 역지식이전 동기요인에 대한 탐색적 연구)

  • Hong, Sung-Jin;Yang, Oh-Suk
    • Asia-Pacific Journal of Business
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    • v.10 no.3
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    • pp.53-67
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    • 2019
  • Reverse knowledge transfer has been an important research theme in the literature on multinational corporations (MNCs). This paper proposes major determinants of MNC headquarters' willingness to adopt and use marketing knowledge from their subsidiaries. We argue that the willingness will be jointly determined by both the headquarter's absorptive capacity and the focal subsidiary's transfer capacity and willingness to transfer. In addition, we argue that these capability and motivation effects are moderated by (1) institutional distance between home and the focal host country, (2) the need to unlearn existing routines, and (3) types of entry modes. This paper contributes to the reverse knowledge transfer literature by proposing the argument that both motivational and capability factors are likely to determine the MNC parents' willingness to adopt and use marketing knowledge from their subsidiaries.

Measurement of Spectral Loss and Cut-off Wavelength of Single Mode Opticla Fiber by Variable Wavelength (파장변화에 따른 단 모드 광섬유의 스펙트랄 로스 및 차단파장 측정)

  • Hong, Bong Sik;Han, Byoung Sung;Koo, Kyoung Wan
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.23 no.2
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    • pp.264-268
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    • 1986
  • A thchnique has been studied for the measurement of the spectral loss and the cut-off wave length, at which the first high-order mode disappears. The near-field patterns of a fiber which is excited by a variable wavelength source are used for the measurement of cut-off wavelength. Because of the absorptive phenomenon of OH- molecular vibration, spectral loss of a single mode optical fiber sample is 5.6dB/km at 1380 nm wavelength and 1dB/km at 1240 nm wavelength. From the near field intensity patterns and the mode field diameter graph for the half power width, the cut-off wavelength of the fiber is measured to be 1120 nm.

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Mantle Ultrastructure of the Spiny Top Shell, Batillus cornutus (Gastropoda: Turbinidae) (소라(Batillus cornutus) 외투막의 미세구조)

  • Jung, Gui-Kwon;Park, Jung-Jun;Jin, Young-Guk;Ju, Sun-Mi;Lee, Jae-Woo;Jung, Ae-Jin;Lee, Jung-Sick
    • The Korean Journal of Malacology
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    • v.24 no.1
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    • pp.41-50
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    • 2008
  • The histochemical characteristics and ultrastructure of the mantle in the spiny top shell, Batillus cornutus were described using light and electron microscopy. The simple epidermal layer wrapped on the top and bottom of the centrally located connective tissue. And then the epidermal layer were divided into the outer epidermal layer near a shell and the inner epidermal layer closed to the visceral mass. The connective tissue layer was composed of the collagen fiber muscularfiber bundle and hemolymph sinus. Mucous cells in the apical mantle contained acid and neutral mucopolysaccaride, and acidic carboxylated mucopolysaccaride in the mid and marginal mantle. The mantle thickness, epidermal layer thickness and hemolymph sinus area displayed a trend of reduction from the marginal zone to the apical zone. From TEM observation, it was possible to distinguish epithelium, ciliated cell, absorptive cell and secretory cell in the epidermal layer. The epithelia were columnar and the nucleus was elliptical. The free surface were covered with microvilli. The lateral membranes of epithelium was con nected with neighboring cells by the zonular occludens, zonular adherens and membrane interdigitation. Ciliated cell on free surface had cilia and microvilli, and numerous mitochondria in the apical cytoplasm. In the epidermal layer, it observed 2 type cells having absorptive function. The absorptive cells were columnar in shape, and contained microvilli, pinocytotic vesicles, mitochondria and lysosomes of various electron density. Secretory cells can be divided into four types (A, B, C, D) depending on the cell shape and characteristics of secretory granules. These cells were unicellular glands and had similar characteristics to previously reported on the mantle of the gastropod and bivalves.

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Effect of Corporate Characteristics of Startups on Overcoming the Death Valley: Focusing on Moderating Effect of Open Innovation and Venture Capital Support (스타트업의 기업 특성이 데스밸리 극복에 미치는 영향: 개방형 혁신과 벤처캐피탈 지원의 조절효과)

  • Park, Hyun Suk;Na, Hee Kyung;Moon, Gye Wan
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.1
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    • pp.13-29
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    • 2023
  • Overcoming the death valley, a period in which resources are depleted and profitability declines or stagnates in the entrepreneurial process, is an essential procedure for success. In this study, we examined how the strategic orientation(technology, customer, competitor orientations) and absorptive capacity(potential, realized capacities) of startups affect the possibility of startups to overcome the challenges of death valley, and also empirically analyzed whether support of open innovation and venture capital has a moderating influence to the overcoming of death valley. The result of this study shows that customer orientation and realized absorptive capacity have a positive influence on overcoming the death valley. In addition, we found that the support of open innovation and venture capital has a moderating effect only in the technology orientation among the three types of strategic orientations. The result of this research emphasizes (1) the need for startups to take a more customer-oriented approach to overcome the death valley. The customer-oriented behavior and strategies of startups are vital for their longterm survival and success if we consider the fact that most of the companies investigated in this study were technology-based startups and only customer orientation showed significant results in overcoming the death valley. The research outcome also shows that (2) implementing innovation in a more open way and securing venture capital funding can make it easier for startups to overcome the death valley. This study has academic significance in that it empirically analyzed the relationship of key factors influencing the overcoming of death valley in a situation where the majority of existing research remains at the conceptual level of discussion or methodology of case study. Furthermore, this research also provides practical implications for the establishment and implementation of effective strategies to confront the challenges of death valley for startups, government and related organizations.

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Synthesis and Characteristics of Highly Oil-absorptive Expanded Polyurethane (고흡유성 발포 폴리우레탄의 합성과 특성)

  • Lee, Yong-Hun;Kim, Wook;Kim, Won-Ho
    • Polymer(Korea)
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    • v.24 no.2
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    • pp.149-158
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    • 2000
  • Oil-absorptive expanded polyurethane (EPU) was prepared with a lypophilic polyol, polypropyleneglycol (PPG) as the soft segment, and toluenediisocyanate (TDI) and $H_2O$ as the hard segment. PPGs haying various average molecular weights ((equation omitted) : 1000, 2000, 3000) were employed to investigate that the soft segment content was consequent on the oil-absorptivity and the mechanical properties of the EPUs. As (equation omitted) of PPG was decreased from 3000 to 1000, the oil-absorptivity and the tensile strength of the EPUs increased from 1460 to 3010% and from 0.26 to 0.55 $kg_{f}$ /$cm^2$ respectively. As the hard segment content ratio, ${\gamma}$ ([NCO]/[OH]) was increased from 1.0 to 1.2, the tensile strength of the EPUs increased from 0.56 to 0.95 $kg_{f}$ /$cm^2$, due to the formation of allophanate and/or biuret bondings. However, as the surfactant (S-A) content was increased from 1.0 to 2.5 pbw, the oil-absorptivity was decreased from 3634 to 3312%, due to the formation of closed cell structures.

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Absorption and Distribution for Subtoxic Level of Selenite by Vascularly Perfused Small Intestine in Rats (랫드의 소장-혈관의 이중 관류를 통한 저독성 농도의 selenite 흡수와 분포)

  • Park, Yeong-Chul;Yoon, Mi-Sook;Kim, Jong-Bong
    • Journal of Life Science
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    • v.20 no.2
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    • pp.169-175
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    • 2010
  • Intestinally absorptive and distributive aspects of the subtoxic level of selenite in rats were investigated using a double perfusion system. The double-perfusion technique is an in situ, in vitro preparation in which the intestinal lumen and its vasculature are perfused simultaneously. In the previous study, the subtoxic level of sodium selenite was determined to be 1.2 mM through inhibition of 3-0-methyl glucose (3MG) absorption. Thus, the selenite used to identify the intestinally absorptive mechanism of selenite was perfused at a luminal concentration of 1, 10, 50, 100 and $200\;{\mu}M$. Appearance of radiolabeled-Selenium (Se) was identified in three compartments: luminal perfusate, small intestine and vascular perfusate. Dose-response curves for Se in the three compartments indicate that selenite is absorbed by non-mediated passive diffusion. Regarding the distributive aspect, $21.02{\pm}3.92%$ of the total amount of selenite in the lumen was transported into the blood vessels across the small intestine. However, $4.75{\pm}1.75%$ of the total amount of selenite in the lumen is retained by the small intestine. Therefore, a total of $25.67{\pm}4.46%$ of the test dose was taken up from the luminal perfusate.

Effects of Non-protein Energy Intake on Whole Body Protein Synthesis, Nitrogen Retention and Glucose Turnover in Goats

  • Fujita, Tadahisa;Kajita, Masahiro;Sano, Hiroaki
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.4
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    • pp.536-542
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    • 2007
  • The responses of whole body protein and glucose kinetics and of nitrogen (N) metabolism to non-protein energy intake (NPEI) were determined using an isotope dilution approach and measurement of N balance in three adult male goats. The diets containing 1.0, 1.5 and 2.0 times ME maintenance requirement, with fixed intake of CP (1.5 times maintenance) and percentage of hay (33%), were fed twice daily for each 21 d experimental period. After an adaptation period of 11 d, N balance was determined over 3 d. On day 17, whole body protein synthesis (WBPS) and glucose irreversible loss rate (ILR) were determined during the absorptive state by a primed-continuous infusion of [$^2H_5$]phenylalanine, [$^2H_2$]tyrosine, [$^2H_4$]tyrosine and [$^{13}C_6$]glucose, with simultaneous measurements of plasma concentrations of metabolites and insulin. Ruminal characteristics were also measured at 6 h after feeding over 3 d. Nitrogen retention tended to increase (p<0.10) with increasing NPEI, although digestible N decreased linearly (p<0.05). Increasing NPEI decreased (p<0.01) ammonia N concentration, but increased acetate (p<0.05) and propionate (p<0.05) concentrations in the rumen. Despite decreased plasma urea N concentration (p<0.01), increased plasma tyrosine concentration (p<0.05), and trends toward increased plasma total amino N (p<0.10) and phenylalanine concentrations (p<0.10) were found in response to increasing NPEI. Increasing NPEI increased ILR of both glucose (p<0.01) and phenylalanine (p<0.05), but did not affect ($p{\geq}0.10$) that of tyrosine. Whole body protein synthesis increased (p<0.05) in response to increasing NPEI, resulting from increased utilization rate for protein synthesis (p<0.05) and unchanged hydroxylation rate of phenylalanine ($p{\geq}0.10$). These results suggest that increasing NPEI may enhance WBPS and glucose turnover at the absorptive state and improve the efficiency of digestible N retention in goats, with possibly decreased ammonia and increased amino acid absorption. In addition, simultaneous increases in WBPS and glucose ILR suggest stimulatory effect of glucose availability on WBPS, especially when sufficient amino acid is supplied.