• Title/Summary/Keyword: global performance analysis

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Basis of design and numerical modeling of offshore wind turbines

  • Petrini, Francesco;Li, Hui;Bontempi, Franco
    • Structural Engineering and Mechanics
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    • v.36 no.5
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    • pp.599-624
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    • 2010
  • Offshore wind turbines are relatively complex structural and mechanical systems located in a highly demanding environment. In the present paper the fundamental aspects and the major issues related to the design of these special structures are outlined. Particularly, a systemic approach is proposed for a global design of such structures, in order to handle coherently their different parts: the decomposition of these structural systems, the required performance and the acting loads are all considered under this philosophy. According to this strategy, a proper numerical modeling requires the adoption of a suitable technique in order to organize the qualitative and quantitative assessments in various sub-problems, which can be solved by means of sub-models at different levels of detail, for both structural behavior and loads simulation. Specifically, numerical models are developed to assess the safety performances under aerodynamic and hydrodynamic actions. In order to face the problems of the actual design of a wind farm in the Mediterranean Sea, in this paper, three schemes of turbines support structures have been considered and compared: the mono pile, the tripod and the jacket support structure typologies.

Frequency Synchronization Technique for the Equalization Digital On-Channel Repeater (등화형 디지털동일채널중계기의 송수신 신호 간 주파수 동기화 기술)

  • Lee Yong-Tae;Eum Ho-Min;Park Sung-Ik;Seo Jae-Hyun;Kim Heung-Mook;Kim Seung-Won;Seo Jong-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.7A
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    • pp.725-733
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    • 2006
  • In this paper, we propose an algorithm which makes the frequency of output signal synchronize with frequency of input signal in Equalization Digital On-channel Repeater (EDOCR) system which was proposed to overcome the disadvantage of conventional Digital On-Channel Repeater (DOCR). Also, we verify the algorithm by using the mathematical equivalent model and analysis the performance by implying the algorithm to EDOCR. The main idea is to use the frequency offset information, which comes from carrier recovery in the receiving part of EDOCR, when the demodulated symbol is re-modulated in transmitting part. Based on the proposed algorithm, EDOCR not only makes the output signal synchronized with input signal in frequency but also emit the output signal which satisfies the ATSC transmission standard without additional equipments such as Global Positioning System (GSP).

Trade Facilitation Provisions in Regional Trade Agreements: Discriminatory or Non-discriminatory?

  • Park, Innwon;Park, Soonchan
    • East Asian Economic Review
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    • v.20 no.4
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    • pp.447-467
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    • 2016
  • The RTAs with trade facilitation provisions have been expected to generate a larger net trade-creating effect and complement the discriminatory feature of RTAs but have yet to be empirically proven. Recognizing the limitations of existing studies, we conducted a quantitative analysis on the effects of RTAs with and without trade facilitation provisions on both intra- and extra-bloc trade by using a modified gravity equation. We applied the Poisson Pseudo-Maximum Likelihood (PPML) estimation with time varying exporter and importer fixed effect method to panel data consisting of 45,770 country pairs covering 170 countries for 2000-2010. We found that the trade facilitation provisions in existing RTAs are non-discriminatory by generating more intra- and extra-bloc trade in general. In particular, we found that the trade effects of RTAs in the APEC region are much stronger than the general case covering all RTAs in the world. In addition, as we control the trade effect of a country's trade facilitation, which is ranked by the World Bank's logistic performance index, RTAs consisting of trade facilitation provisions are discriminatory for trade in final goods and non-discriminatory for trade in intermediate goods. Overall, we endeavor to "explain," instead of "hypothesizing," why most of the recent RTAs contain trade facilitation provisions, especially in light of the deepening regional interdependence through trade in parts and components under global value chains and support the necessity of multilateralizing RTAs by implementing non-discriminatory trade facilitation provisions.

Basic Principles of the Validation for Good Laboratory Practice Institutes

  • Cho, Kyu-Hyuk;Kim, Jin-Sung;Jeon, Man-Soo;Lee, Kyu-Hong;Chung, Moon-Koo;Song, Chang-Woo
    • Toxicological Research
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    • v.25 no.1
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    • pp.1-8
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    • 2009
  • Validation specifies and coordinates all relevant activities to ensure compliance with good laboratory practices (GLP) according to suitable international standards. This includes validation activities of past, present and future for the best possible actions to ensure the integrity of non-clinical laboratory data. Recently, validation has become increasingly important, not only in good manufacturing practice (GMP) institutions but also in GLP facilities. In accordance with the guideline for GLP regulations, all equipments used to generate, measure, or assess data should undergo validation to ensure that this equipment is of appropriate design and capacity and that it will consistently function as intended. Therefore, the implantation of validation processes is considered to be an essential step in a global institution. This review describes the procedures and documentations required for validation of GLP. It introduces basic elements such as the validation master plan, risk assessment, gap analysis, design qualification, installation qualification, operational qualification, performance qualification, calibration, traceability, and revalidation.

Evaluating the Official Websites of SAARC Countries on their Web Information on Food Tourism

  • Ashish, Dahiya;Shelley, Duggal
    • Asia pacific journal of information systems
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    • v.25 no.1
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    • pp.143-161
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    • 2015
  • The South Asian Association for Regional Cooperation (SAARC) nations are a potpourri of diverse religions, races and cultures with rich natural and cultural heritage but yet to tap the full potential of tourism. An investigation into the glorifying heritage of these eight SAARC nations pinpoints towards their rich food and culinary heritage that is yet to be explored to carve them as food destinations that would definitely help ameliorating tourism too. The Global Report on Food Tourism of the United Nations World Tourism Organization (UNWTO) reveals results from a survey on food tourism marketing promotion, from which internet marketing tools, such as websites have been effectively utilized to promote food tourism in a particular destination. (UNWTO, 2012). Sensing the importance of the websites in the promotion of food tourism for any destination, the present study aims at the comparative content analysis of the official tourism websites of SAARC nations to evaluate their performance from the perspective of promotion of culinary heritage on world -wide web. The modified Balanced ScoreCard (BSC) approach is incorporated into the evaluation by taking into consideration four perspectives: technical, user friendliness and site attractiveness, tourism effectiveness and food tourism effectiveness. A set of 88 critical success factors representing these four perspectives is then used to examine the websites. The study reflects on the relative strength and weakness of the tourism websites of SAARC nations in promoting food tourism and as well help suggesting the remedial measures catalyzing the food tourism promotion through websites.

The Study on Identify components of CEO image Influence in Brand's value (CEO의 이미지가 브랜드 가치에 미치는 영향)

  • Kim, Mi-Kyung
    • Journal of Fashion Business
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    • v.12 no.1
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    • pp.129-146
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    • 2008
  • The purpose of this study is to identify components of CEO image and to examine predictors to affect company's market value. To explore the social construction of the CEO Image depicted in the popular business newspaper, the Wall Street Journal and daily newspaper of Korea, was analyzed. Then, the reconstructed image of the CEO was compared with the firm's stock price change to see their relationship, if any. This paper focused on the case of Carly Fiorina as previous chief of Hewlett-Packard, who was the Fortune's ranking of the 50 most powerful women in business is presented. The period for the analysis was five years and eight months from her inauguration(July, 1999) to the release(February, 2005). The results, four predictors such as nature, management ability, leadership style, appearance character had statistically significant relationship with both company's market value and the image of CEO. In addition to revealed that media coverage of Carly Filoina was commensurate with the financial performance, particularly stock price change of the Hewlett-Packard. In general, the best image of the CEO is highly transcends to the image of the company as well. Therefore it is need to manage effectively components of CEO image to enhance brand image and its brand value, which are further expected to enhance company's market value.

Performance Analysis of Time Synchronization considering Message Collision Probability in Link-16 (Link-16 의 메시지 충돌 확률을 고려한 시간 동기 성능 분석)

  • Ko, Sangsoon;Baek, Hoki;Yu, Jepung;Lim, Jaesung
    • Annual Conference of KIPS
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    • 2014.04a
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    • pp.157-159
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    • 2014
  • 전술데이터링크는 전장 환경에서 모든 플랫폼들을 네트워크를 통해 하나로 묶어 전쟁 효과를 극대화할 수 있는 기반이 되는 통신 기술이다. 이러한 전술데이터링크의 원활한 운영을 위해 플랫폼간 시간 동기가 필수적이며, 대부분 GPS(Global Positioning System)를 사용하고 있다. 전세계적으로 가장 널리 사용되고 있는 전술데이터링크인 Link-16 에서는 네트워크에 가입하면서 NTR(Network Time Reference) 과의 시간을 동기화하는 절차를 제공한다. 이러한 시간 동기 절차는 대략적인 동기와 정밀한 동기의 두 단계로 구분된다. 대략적인 동기는 프레임이 시작하는 첫 타임 슬롯에서 주변 노드로부터 IEM(Initial Entry Message)을 수신하여 전송 시간만큼의 오류를 포함하는 시간 동기 방식이다. 본 논문에서는 모의 실험을 통해 IEM 을 전송하는 노드의 거리에 따른 메시지의 충돌 확률을 구하고, 그 충돌 확률에 따라 시간 동기에 소요되는 시간으로 Link-16 의 시간 동기 성능을 분석하였다.

The Pahlev Reliability Index: A measurement for the resilience of power generation technologies versus climate change

  • Norouzi, Nima
    • Nuclear Engineering and Technology
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    • v.53 no.5
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    • pp.1658-1663
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    • 2021
  • Research on climate change and global warming on the power generation systems are rapidly increasing because of the Importance of the sustainable energy supply, thus the electricity supply since its growing share, in the end, uses energy supply. However, some researchers conducted this field, but many research gaps are not mentioned and filled in this field's literature since the lack of general statements and the quantitative models and formulation of the issue. In this research, an exergy-based model is implemented to model a set of six power generation technologies (combined cycle, gas turbine, nuclear plant, solar PV, and wind turbine) and use this model to simulate each technology's responses to climate change impacts. Finally, using these responses to define and calculate a formulation for the relationship between the system's energy performance in different environmental situations and a dimensionless index to quantize each power technology's reliability against the climate change impacts called the Pahlev reliability index (P-index) of the power technology. The results have shown that solar and nuclear technologies are the most, and wind turbines are the least reliable power generation technologies.

A Study on An Enhancement Scheme of Privacy and Anonymity through Convergence of Security Mechanisms in Blockchain Environments (블록체인 환경에서 보안 기법들의 융합을 통한 프라이버시 및 익명성 강화 기법에 대한 연구)

  • Kang, Yong-Hyeog
    • Journal of the Korea Convergence Society
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    • v.9 no.11
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    • pp.75-81
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    • 2018
  • Anonymity and privacy issues are becoming important as all transactions in the blockchain are open to users. Public blockchains appear to guarantee anonymity by using public-key addresses on behalf of users, but they can weaken anonymity by tracking with various analytic techniques based on transaction graph. In this paper, we propose a scheme to protect anonymity and privacy by converging various security techniques such as k-anonymity, mixing, blind signature, multi-phase processing, random selection, and zero-knowledge proof techniques with incentive mechanism and contributor participation. Through performance analysis, our proposed scheme shows that it is difficult to invade privacy and anonymity through collusion attacks if the number of contributors is larger than that of conspirators.

A Study on Factors Affecting the Use Intention of Virtual Reality(VR) Devices: Based on UTAUT and VAM Model

  • Li, Zhou-Yang;Yoon, Sung-Joon;Liu, Zi-Yang
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.4
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    • pp.35-43
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    • 2019
  • The purposes of this study is to derive the influence factors of Virtual Reality(VR) technologies acceptance based on the study of unified theory of acceptance and use of technology and value-based acceptance model to test the use and acceptance of VR devices. The survey methods were used for this study, and the data from a total of 400 consumers were used for the analysis. And the structural equation model was used to analyze the data. The results of the study are as follows: First, benefit components perceived enjoyment(EN) and sacrifice components personal innovative(PI) of VR devices were positively related to perceived values and use intention of VR devices, although the benefit components performance expectancy(PE) was positively related to perceived values(PV) but was not positively related to the use intention of VR devices. Second, sacrifice components perceived cost(PC) and anxiety(ANX) of VR devices were negatively related to perceived value(PV), but were not negatively related to the use intention of VR devices. Third, perceived values was not obvious related to the use intention(UI) of VR devices. The results of this study contribute to the literature as a new attempt to examining the effect on consumer use intention in VR technology areas.