• Title/Summary/Keyword: Contact Hypothesis

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Individual Human Recognition of Wild Animals: A Review and a Case Study in the Arctic Environment

  • Lee, Won Young;Choe, Jae Chun
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.1 no.1
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    • pp.1-8
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    • 2020
  • Recent studies revealed that many animals identify individual humans. In this account, we review previous literatures on individual human recognition by wild or domestic animals and discuss the three hypotheses: "high cognitive abilities" hypothesis, "close human contact" and "pre-exposure to stimuli" hypothesis. The three hypotheses are not mutually exclusive. Close human contact hypothesis is an ultimate explanation for adaptive benefits whereas high cognitive abilities and pre-exposure to stimuli hypothesis are proximate explanations for mechanisms to perform such discriminatory behaviour. We report a case study of two bird species in a human-free habitat. Long-tailed skuas, which are known for having high cognitive abilities, exhibited the human discriminatory abilities whereas ruddy turnstones did not display such abilities toward approaching humans. This suggests that highly intelligent species may have this type of discriminatory ability so that they could learn to identify individual humans quickly by pre-exposure to stimuli, even in a human-free habitat. Here, we discuss that human recognition is more common in species with rapid learning ability and it could develop for a short period of time between an intelligent species and human.

Estimation of Real Area of Contact and Lubrication Regimes using Electric Contact Resistance (전기 저항을 이용한 실접촉 면적과 윤활 영역의 예측)

  • 이홍철;김대은
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2000.11a
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    • pp.11-17
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    • 2000
  • The electric contact resistance between ball and disk was measured to estimate the real area of contact under dry and lubrication conditions. The results from the measured constriction resistance using the hypothesis of a single circular contact was compared with those of Hertzian contact theory and hardness. The resistance correlated well with the asperity contact area and friction when the ball slides on the flat disk spreaded with lubricant film. Therefore, the constriction resistance method was useful to identify the lubrication regimes with respect to various loads and speeds. The results of this work will aid in better prediction of lubrication regimes with respect to the operating conditions.

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Effect of Stem Design on Contact Pressure and Stress Distribution of End-of-stem in Revision TKR (슬관절 재전치환술용 경골 삽입물 형상이 주대 말단부의 접촉압력과 응력 분포에 미치는 영향)

  • Kim, Yoon-Hyuk;Kwon, Oh-Soo;Park, Si-Mon
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.11 s.188
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    • pp.126-134
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    • 2006
  • In this study, the effect of stem-end design on contact pressure and stress distribution in revision TKR was investigated using finite element method. The finite element model of tibia, including the cortical bone, the cancellous bone and canal, was developed based on CT images. The implant models with various stem lengths, diameters, friction coefficients, and press-fit effects were considered. The results showed that the longer stem length, the stronger press-fit, the bigger stem diameter, and the higher friction coefficient increased both peak contact pressure and Von-Mises stress distributions. The results supported the clinical hypothesis that peak contact pressure and stress are related to the stem end pain. The results of this study will be useful to design the stem and reduce the end-of-stem pain in revision TKR.

Asymmetric Light curves of Contact and Near-Contact Binaries

  • Rittipruk, Pakakaew;Kang, Young-Woon
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.143.1-143.1
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    • 2012
  • We attempt to investigate the main reason of the asymmetrical light curves of contact and near-contact eclipsing binary base on the hypothesis that cool spot was produced on late type star while hot spot was produced from transferred material from their companion star hitting surface. We select 7 eclipsing binary systems which showed asymmetric light curves and mass transfer. Period variation and mass transfer rate were obtained from O-C diagram. Radial velocity curves and light curves of those 7 eclipsing binary system were adopted from available literature in order to obtain the absolute dimension. For four contact eclipsing binary system (AD Phe, EZ Hya, AG Vir and VW Boo), their component stars belonged to spectral type G to K was fitted by cool spot model. While the other two near-contact systems (RT Scl and V1010 Oph) and one contact system (SV Cen) was fitted by cool spot model. The densities of the materials are adopted from stellar model which calculate by stellar structure code. The calculated spot temperature turns out to agree with the photometric solution but there are no correlate between period variation rate and type of spot.

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Multimarket Contact and Risk-Adjusted Profitability in the Banking Sector: Empirical Evidence from Vietnam

  • DAO, Oanh Le Kieu;HO, Tuyen Thi Ngoc;LE, Hac Dinh;DUONG, Nga Quynh
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.3
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    • pp.1171-1180
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    • 2021
  • This study aims to investigate the impact of the multimarket contract on risk-adjusted profitability. Risk-adjusted profitability is measured in terms of risk-adjusted return on assets. This study employs dynamic panel data of 27 commercial banks in Vietnam using the GMM estimator to test the multimarket contact hypothesis in the Vietnamese banking sector. The results show that there is a negative impact of multimarket contact on the profitability of banks. Multimarket contact, deposit to asset ratio, non-interest income to total income, GDP growth rate, Worldwide Governance Indicator (WGI), and operating cost to assets are the major determinants of risk-adjusted profitability of commercial banks. Our main findings show that Vietnamese banks' focus to increase the multimarket contact may lead to lower profitability and there is evidence that supports theory predictions, since the average number of contacts among banks, bank size, and capitalization are positively related to risk-adjusted profitability. The study has policy implications for commercial banks in that they should not only focus on interest as a source of income and diversify their income source from non-interest income as well since it helps to improve risk-adjusted profitability for them.

Microparticle Impact Motion with Adhesion and Frictional Forces (부착력과 마찰력이 개재된 마이크로 입자 충돌 운동)

  • Han, In-Hwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.8
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    • pp.1698-1708
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    • 2002
  • The main topic covered in this paper is that of the impact process, that is, where two bodies come into contact and rebound or stick together. This paper presents how to determine the rebound velocities of a microparticle that approaches a surface with arbitrary initial velocities and relate the impact process to the physical properties of the materials and to the adhesion force. Actual adhesion forces demonstrate a significant amount of energy dissipation in the form of hysteresis, and act generally in a normal to the contact surfaces. Microparticles must also contend with forces tangent to the contact surfaces, namely Coulomb dry friction. The developed model has an algebraic form based on the principle of impulse and momentum and hypothesis of energy dissipation. Finally, several analyses are carried out in order to estimate impact parameters and the developed analytical model is validated using experimental results.

Bilateralization Phenomena in Korean Families: A Qualitative Approach (질적 연구를 통한 한국 가족의 양계화 현상에 대한 진단적 접근)

  • Sung Mi-Ai
    • Journal of Families and Better Life
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    • v.24 no.3 s.81
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    • pp.59-72
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    • 2006
  • This article explores bilateralization phenomena in Korean families through intimacy and interaction with matrilineal kins. In-depth interviews were conducted with married men and women aged from their mid-30s to mid-40s. The findings indicate that the intimacy range of participants was restricted to blood-based kins. The power hypothesis was supported for male participants. Some wanted to actively contact their spouse's family members, while others did not want to be connected with the spouse's families. Interaction with wives' families was based on the exchange perspective. In contrast, a complicated mechanism existed in the intimacy and interaction of female participants. Most of them were connected with in-laws in a passive way but actively interacted with their family-of-origin. However, some female respondents did not have good relationships with their mothers. Undifferentiation between mothers and married daughters negatively influenced their relationships. Therefore, it could be concluded that bilateralization phenomena in Korean families is another kind of shackle of patrilineal norms.

Cross-Cultural Difference between Female Young Adults in Korea and Indonesia in Perceiving Hijabis in the Media

  • Sintowoko, Dyah Ayu Wiwid;Lee, Yoon;Lee, Hye Eun
    • International Journal of Internet, Broadcasting and Communication
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    • v.12 no.3
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    • pp.177-188
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    • 2020
  • The Muslim population is growing significantly in Asian countries. By conducting an experiment, this study examines the cultural differences between South Korean and Indonesian female, young adults, and their perception of hijabis who are represented in the media. The main goal of this study is to compare the perception towards hijabis in a homogenous country new to Muslims against a Muslim-majority country. Results showed that non-hijabis were deemed more physically attractive, empathetic, and enjoyable among Koreans when compared to Indonesians. Through this study, we provide a theoretical explanation using cultivation theory and (parasocial) contact hypothesisto clarify the differences between South Korea and Indonesia. Thisstudy provides a baseline of understanding to determine where both cultures are at in perceiving hijabis. Our results suggest that it will be compelling to correct media representation in order to reduce stereotypes and lead to a successful understanding of both cultures.

CRM Marketing of Shopmasters in Designer Brand Products (디자이너 브랜드 샵마스터의 CRM에 관한 연구)

  • 이승희;이병화
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.2
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    • pp.239-249
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    • 2003
  • The purpose of this research was to investigate influential factors for shopmaster's CRM (Customer Relationship Management) in the designer brand products, and to indicate the future fashion marketing strategies. The questionnaires were distributed to 74 shopmasters of the Designer shop in domestic L. S and H Department stores. Descriptive statistics, factor analysis, and path analysis from Lisrel program were used to analyze the data. The results were as follows; Firstly. for shopmaster's CRM variables, four factors of customer management variables were found and labeled as interest, DB construction, contact opportunity, and materials. Also, four (actors of shopmaster's knowledge regarding apparel materials were found and labeled as professionalism, manner, sense, and persuasion. For service variables, four factors such as precision, variety, rapidity, positiveness, and convenience of shopping were found. Secondly, for the results of hypothesis, all of the independent variables had direct influences on forming the relationship with customers. Therefore, it is concluded that the main elements of Shopmaster's CRM are highly important variables in customer relationship marketing strategy.

Uniformity Among Magnaporthe grisea Isolates on Appressorium Formation by cDNA and Hydrophobicity of Contact Surface (cAMP와 표면 소수성에 의한 도열병균의 부착기 형성)

  • 이용환;최우봉
    • Korean Journal Plant Pathology
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    • v.10 no.4
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    • pp.254-260
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    • 1994
  • Magnaporthe grisea, a causal agent of blast, forms a specialized infection structure, an appressorium, to infect host. Hydrophobicity of contact surface and cAMP have been suggested as a primary environmental signal and a second messenger to trigger and mediate appressorium formation in this fungus, respectively. To generalize these factors in field isolates of M. girsea, twenty isolates originated from rice and other gramineous hosts were tested. Seventeen including rice and non-rice isolates formed appressoria on hydrophobic surface, but none of isolates formed appressoria on hydrophilic surface. Eighteen isolates formed appressoria on hydrophilic surface in the presence of IBMX, an inhibitor of phosphodiesterase, except two rice isolates. These results strongly support the hypothesis that appressorium formation by M. grisea is induced by hydrophobic hard surface and regulated by the endogenous level of cAMP in the cells. Understanding fungal development is not only of biological interest but provides new targets for novel disease control strategies.

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