• Title/Summary/Keyword: Main effect

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The Shape Optimization of washing Machine Shaft for High-Speed Rotation through Analysis of Static and Dynamic Characteristics (정특성 및 동특성 해석을 통한 고속세탁기 주축의 형상 최적화)

  • Kim, Eui-Soo;Lee, Jung-Min;Kim, Byung-Min
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.5
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    • pp.132-139
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    • 2008
  • To meet demand of big capacity and high speed rotation for washing machine, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Also, Vibration occurs due to the frequency of the rotating parts. But, shaft has various design factors such as diameter and distance between bearings according to configuration of shaft, the optimal values can't be easily determined. Using a design of experiment (DOE) based on the FEM (Finite Element Method), which has several advantages such as less computing, high accuracy performance and usefulness, this study was performed investigating the interaction effect between the various design factor as well as the main effect of the each design factor under bending, twist and vibration and proposed optimum design using center composition method among response surface derived from regression equation of simulation-based DOE.

The Impact of Government Ownership and Corporate Governance on the Corporate Social Responsibility: Evidence from UAE

  • FARHAN, Ayda;FREIHAT, Abdel Razaq Farah
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.1
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    • pp.851-861
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    • 2021
  • The main objective of this study is to examine the government ownership effect on the United Arab Emirates (UAE) firm's corporate social responsibility (CSR). Government ownership is assumed to affect the CSR either directly or indirectly. That is by moderating the association between corporate governance and CSR. Publicly listed companies on the UAE capital markets (Abu Dhabi and Dubai) from 2010-2013 constituted the study sample. Panel data regression analyses and random effect model is used to examine the effects of board size, board independence, and audit committee characteristics on CSR. Government ownership is used as a moderator variable. The result showed that the existence of government ownership has a moderator effect on the association between corporate governance mechanisms and the CSR. Precisely, the research revealed that the audit committee characteristics become more effective in improving the firm's CSR when the government owns shares in the organization. The main contribution of this study is to examine how firm ownership structure influences good corporate governance and CSR in the UAE. The study contributes to the CSR literature by merging between the existence of governmental ownership and the power to enforce the implementation of corporate governance in an emerging country.

Moon Phase based Threshold Determination for VIIRS Boat Detection

  • Kim, Euihyun;Kim, Sang-Wan;Jung, Hahn Chul;Ryu, Joo-Hyung
    • Korean Journal of Remote Sensing
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    • v.37 no.1
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    • pp.69-84
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    • 2021
  • Awareness of boats is a main issue in areas of fishery management, illegal fishing, and maritime traffic, etc. For the awareness, Automatic Identification System (AIS) and Vessel-Pass System (V-PASS) have been widely used to collect the boat-related information. However, only using these systems makes it difficult to collect the accurate information. Recently, satellite-based data has been increasingly used as a cooperative system. In 2015, U.S. National Oceanic and Atmospheric Administration (NOAA) developed a boat detection algorithm using Visible Infrared Imaging Radiometer Suite (VIIRS) Day & Night Band (DNB) data. Although the detections have been widely utilized in many publications, it is difficult to estimate the night-time fishing boats immediately. Particularly, it is difficult to estimate the threshold due to the lunar irradiation effect. This effect must be corrected to apply a single specific threshold. In this study, the moon phase was considered as the main frequency of this effect. Considering the moon phase, relational expressions are derived and then used as offsets for relative correction. After the correction, it shows a significant reduction in the standard deviation of the threshold compared to the threshold of NOAA. Through the correction, this study can set a constant threshold every day without determination of different thresholds. In conclusion, this study can achieve the detection applying the single specific threshold regardless of the moon phase.

A Study on the UX of Shopping Experience in Conversational Agents: Focus on the Difference between the Presence of a Screen, Product Involvement, and Conversation Style (음성 에이전트에서의 쇼핑 경험에 대한 사용자 경험 연구: 화면 유무와 제품관여도, 대화방식의 차이를 중심으로)

  • Lee, Hwayoung;Kim, Dongwhan
    • Journal of Korea Multimedia Society
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    • v.25 no.8
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    • pp.1156-1166
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    • 2022
  • In this study, we examined voice shopping interaction in which consumers can be involved in the decision-making process. Sixteen kinds of voice shopping interaction were designed with differences in the existence of screen/product involvement/conversation style. Their effects on trust, cognitive load, satisfaction, and continuous intention to use were evaluated through a survey experiment. The main effect of conversation style was significant, and it was found that the more deeply involved users have higher trust. The interaction effect between conversation style and product involvement was also significant. Low involvement product buyers had the most positive user experience from the conversation style that included 'Ask for preference,' while high involvement product buyers had the most positive user experience from the conversation style that included both 'Ask for preference' and 'Question and Answer.' The main effect and interaction effect of the existence of screen was not significant. The results indicate that a positive user experience can be obtained when users are deeply involved in consumer decision-making, especially in purchasing high-involvement products.

A Study on Failure Mode and Effect Analysis of Hydrogen Fueling Nozzle Used in Hydrogen Station (수소충전소용 수소 충전 노즐의 고장 유형 및 영향분석 )

  • JUHYEON KIM;GAERYUNG CHO;SANGWON JI
    • Journal of Hydrogen and New Energy
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    • v.34 no.6
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    • pp.682-688
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    • 2023
  • In this paper, analyzes the type of failure and its effect on the hydrogen fueling nozzle used in hydrogen station. Failure of hydrogen fueling nozzle was analyzed using a qualitative risk assessment method, failure mode and effect analysis. The failure data of hydrogen fueling nozzles installed in domestic hydrogen stations are collected, and the failure types are classified, checked the main components causing the failure. Criticality analysis was derived based on frequency and severity depending on the failure mode performed. A quality function is developed by a performance test evaluation item of the hydrogen fueling nozzle, and the priority order of design characteristics is selected. Through the analysis results, the elements to improve the main components for enhancing the quality and maintenance of the hydrogen fueling nozzle were confirmed.

Effects of Grain Size Distribution on the Mechanical Properties of Polycrystalline Graphene

  • Park, Youngho;Hyun, Sangil
    • Journal of the Korean Ceramic Society
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    • v.54 no.6
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    • pp.506-510
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    • 2017
  • One of the characteristics of polycrystalline graphene that determines its material properties is grain size. Mechanical properties such as Young's modulus, yield strain and tensile strength depend on the grain size and show a reverse Hall-Petch effect at small grain size limit for some properties under certain conditions. While there is agreement on the grain size effect for Young's modulus and yield strain, certain MD simulations have led to disagreement for tensile strength. Song et al. showed a decreasing behavior for tensile strength, that is, a pseudo Hall-Petch effect for the small grain size domain up to 5 nm. On the other hand, Sha et al. showed an increasing behavior, a reverse Hall-Petch effect, for grain size domain up to 10 nm. Mortazavi et al. also showed results similar to those of Sha et al. We suspect that the main difference of these two inconsistent results is due to the different modeling. The modeling of polycrystalline graphene with regular size and (hexagonal) shape shows the pseudo Hall-Petch effect, while the modeling with random size and shape shows the reverse Hall-Petch effect. Therefore, this study is conducted to confirm that different modeling is the main reason for the different behavior of tensile strength of the polycrystalline structures. We conducted MD simulations with models derived from the Voronoi tessellation for two types of grain size distributions. One type is grains of relatively similar sizes; the other is grains of random sizes. We found that the pseudo Hall-Petch effect and the reverse Hall-Petch effect of tensile strength were consistently shown for the two different models. We suspect that this result comes from the different crack paths, which are related to the grain patterns in the models.

A Study on Schematic Design of Natural Environment Exhibition (자연환경전시관의 기획설계 연구)

  • Kang, Ho-Seop
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2006.11a
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    • pp.183-186
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    • 2006
  • The growth in human has a close relationship with circumstances and there are two different types of form as a method. One of them Is a great influence of which the environment has a certain effect to human and that is called environmental effect. The other one Is a great reaction of human against the environment which is environmental experience. Human's being loved nature and conservation of nature as a living condition have already processed out for a long time. However, in these days, it is different that a special emphasis on the conservation of nature is being destroyed and it Is perceived the principal of the destruction is human itself. The Museum of Natural Environment has no doubt in a relation with conservation of nature. The main subject of this thesis Is to restore the disappearing beauty in natural environment, an importance of resources in general needs and a change in futuristic perceptions against preservation of the species. Therefore, to produce a complexity in a combination with education and entertainment to a water resource as a main theme is now relieved from its original deteriorated public information center with its simpleness. It Is purposed to secure a cultural space for a community activity and regional peculiarities, dams and lakes, localities of rivers as a main theme to specify their details, to maximize its educational space furtherance with a value as a tourist resource in particular.

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Effects of consecutive earthquakes on increased damage and response of reinforced concrete structures

  • Amiri, Gholamreza Ghodrati;Rajabi, Elham
    • Computers and Concrete
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    • v.21 no.1
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    • pp.55-66
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    • 2018
  • A large main shock may consist of numerous aftershocks with a short period. The aftershocks induced by a large main shock can cause the collapse of a structure that has been already damaged by the preceding main shock. These aftershocks are important factors in structural damages. Furthermore, despite what is often assumed in seismic design codes, earthquakes do not usually occur as a single event, but as a series of strong aftershocks and even fore shocks. For this reason, this study investigates the effect and potential of consecutive earthquakes on the response and behavior of concrete structures. At first, six moment resisting concrete frames with 3, 5, 7, 10, 12 and 15 stories are designed and analyzed under two different records with seismic sequences from real and artificial cases. The damage states of the model frames were then measured by the Park and Ang's damage index. From the results of this investigation, it is observed that the sequences of ground motions can almost double the accumulated damage and increased response of structures. Therefore, it is certainly insufficient to ignore this effect in the design procedure of structures. Also, the use of artificial seismic sequences as design earthquake can lead to non-conservative prediction of behavior and damage of structures under real seismic sequences.

The Factors Affecting Kyrgyzstan's Bilateral Trade: A Gravity-model Approach

  • Allayarov, Piratdin;Mehmed, Bahtiyar;Arefin, Sazzadul;Nurmatov, Norbek
    • The Journal of Asian Finance, Economics and Business
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    • v.5 no.4
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    • pp.95-100
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    • 2018
  • The study investigates the factors that affect Kyrgyzstan's bilateral trade flows with its main trading partners and attempts to predict trade potential for Kyrgyzstan. Using panel data, the gravity model is applied to estimate Kyrgyzstan's trade from 2000 to 2016 for its 35 main trading partners. The coefficients derived from the gravity-model estimation are then used to predict trade potential for Kyrgyzstan. Results proved to be successful and explained 63% of the fluctuations in Kyrgyzstan's trade. According to the results, Kyrgyzstan's and its partners' GDP have a positive effect on trade, while distance and partners' population prove to have a negative effect. Predicted trade potential reveals that neighboring countries (China, Kazakhstan, Uzbekistan, and Tajikistan) and Russia still have a significant trade potential. Kyrgyzstan, being a less developed economy, even by Central Asia standards, can only achieve its goals of reducing poverty and becoming more developed by increasing its overall trade with the rest of the world. Therefore, it is essential to study the main determinants of Kyrgyzstan's bilateral trade. In this way, we can help policy makers formulate policies to expand Kyrgyzstan's trade. This study is the first attempt to apply to the gravity model to Kyrgyzstan in an attempt to predict trade potential.

Effect of Holding Period of Cutting on Sprouts Quality and Sweet Potato Growth

  • Cha, Kwang-Ho;Lee, Byeong-Gook;Yoo, Nam-Hee;Yun, Song-Joong;Park, Kyeong-Gu
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.46 no.1
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    • pp.35-39
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    • 2001
  • It is important to accelerate rooting and establishment of seedlings after transplanting for higher dry matter production and tuber yield in sweet potato cultivation. Therefore, this study was conducted to obtain some information about the effects of vine-cutting holding on rooting and plant growth after transplanting. Vines were cut 20-25cm long and stored for 1, 3, 5, 7 or 9 days in a shade room at 20$\pm$0.5$^{\circ}C$, RH 68$\pm$,/TEX>1%. Peroxidase activity in the vine cuttings increased as the holding period increased and the highest catalase activity was detected in the 5-day holding. Length of main vine, number of branches and nodes on main vine also increased in the 5-day holding. There was little difference in the diameter of main vine among the various holding periods. The data obtained indicate that transplanting of vine cuttings after 5-day holding could promote rooting and vine growth.

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