• Title/Summary/Keyword: Requirements analysis

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The Analysis of Active Power Control Requirements in the Selected Grid Codes for Wind Farm

  • Kim, Mi-Young;Song, Yong-Un
    • Journal of Electrical Engineering and Technology
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    • v.10 no.4
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    • pp.1408-1414
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    • 2015
  • The renewable energies such as photovoltaic power, wind power and biomass have grown to a greater extent as decarbonization techniques. The renewable energies are interconnected to power systems (or electrical grids) in order to increase benefits from economies of scale, and the extra attention is focused on the Grid Code. A grid code defines technical parameters that power plants must meet to ensure functions of power systems, and the grid code determined by considering power system characteristics is various across the country. Some TSO (Transmission System Operator) and ISO (Independent System Operator) have issued grid code for wind power and the special requirements for offshore wind farm. The main purpose of the above grid code is that wind farm in power systems has to act as the existing power plants. Therefore wind farm developer and wind turbine manufacturer have great difficulty in grasping and meeting grid code requirements. This paper presents the basic understanding for grid codes of developed countries in the wind power and trends of those technical requirements. Moreover, in grid code viewpoint, the active power control of wind power is also discussed in details.

A Study on the Radar Operational and Technical Performance Requirements for Vessel Traffic Service

  • JEON, Joong Sung
    • Journal of Navigation and Port Research
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    • v.44 no.2
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    • pp.110-118
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    • 2020
  • With the expansion of the shipping and port logistics industry in the 21st century, the traffic density is continuously increased because of the increase in volumes of world sea freight and fleets, as well as the increase in the causes of potential marine accidents, such as ship collisions and stranding. Accordingly, the International Maritime Organization (IMO) has requested that the installation and operation of VTS should be applied in areas with high risk of marine traffic, and the request should be included as one of the Safety of Life at Sea (SOLAS) regulations. In this paper, the fundamental requirements of the radar system for vessel traffic services were analyzed and the analyzing factors were based on the IALA guideline.s This paper also includes results for the requirement and recommendation analysis on detection distance, target separation, and the target position accuracy of X-band radar. Also, to check if it satisfies the requirement of detection distance, range and azimuth separation of small point targets, and target position accuracy from the IALA guidelines, the test was conducted through the radar image acquired at the VTS center, and hence, the validity of the technical performance requirements was confirmed.

A Discriminative Collision Resolution Scheme for Wireless MAC Protocol (무선 MAC 프로토콜을 위한 차별적인 충돌해결 기법)

  • Hwang, Seong-Ho;Han, Gi-Jun
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.39 no.5
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    • pp.225-231
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    • 2002
  • This paper proposes a discriminative collision resolution scheme for the wireless Medium Access Control (MAC) protocols to support the Quality of Service (QoS) requirements of real-time applications. Our scheme deals with access requests in different ways depending on their delay requirements. In our scheme, a Collision Resolution Period (CRP) is used to quickly resolve collisions for the delay sensitive traffic in order to support their delay requirements. Performance analysis and simulation results show that our algorithm may successfully meet the delay requirements of real time applications by reducing access delays and collisions.

Preliminary Analysis of Delta-V Requirements for a Lunar CubeSat Impactor with Deployment Altitude Variations

  • Song, Young-Joo;Ho, Jin;Kim, Bang-Yeop
    • Journal of Astronomy and Space Sciences
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    • v.32 no.3
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    • pp.257-268
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    • 2015
  • Characteristics of delta-V requirements for deploying an impactor from a mother-ship at different orbital altitudes are analyzed in order to prepare for a future lunar CubeSat impactor mission. A mother-ship is assumed to be orbiting the moon with a circular orbit at a 90 deg inclination and having 50, 100, 150, 200 km altitudes. Critical design parameters that are directly related to the success of the impactor mission are also analyzed including deploy directions, CubeSat flight time, impact velocity, and associated impact angles. Based on derived delta-V requirements, required thruster burn time and fuel mass are analyzed by adapting four different miniaturized commercial onboard thrusters currently developed for CubeSat applications. As a result, CubeSat impact trajectories as well as thruster burn characteristics deployed at different orbital altitudes are found to satisfy the mission objectives. It is concluded that thrust burn time should considered as the more critical design parameter than the required fuel mass when deducing the onboard propulsion system requirements. Results provided through this work will be helpful in further detailed system definition and design activities for future lunar missions with a CubeSat-based payload.

Comparison of Impact Simulation Result for Rolling Stock Vehicle Coupler System (철도차량 연결기용 완충장치에 대한 충돌해석 결과 비교)

  • Jang, Hyeon-Mog;Kim, Ki-Nam;Park, Young-Il
    • Journal of the Korean Society for Railway
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    • v.13 no.3
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    • pp.251-256
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    • 2010
  • By legislating safety regulations for design, manufacturing and operation of rolling stock through rolling stock safety law, diverse of safety requirements have been established. On the other hands, differences of technical level in practical circumstances between domestic and overseas are pointed out that not be able to be overcome in short period. About collision safety requirements for rolling stock, European countries have been applying TSI requirement to all of rolling stock and domestic collision safety requirements in rolling stock safety law are based on TSI. In following thesis, it is showing an analysis simulation for current rubber cushion and hydraulic buffer system to verify if they are fit to collision safety requirements and result of the simulation program for prior verification. This also suggests a method to prove the performances of coupler system for future.

The Study of Follow-up Audit Compliance for Quality Management System in Subcontractors of Shipbuilding Industry Based on ISO 9000 Requirements Changes (ISO 9000 품질경영시스템 규격변화에 따른 조선업 협력업체의 사후관리심사에 관한 연구)

  • Park, Dong-Joon;Kang, In-Seon
    • Journal of the Korea Safety Management & Science
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    • v.13 no.4
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    • pp.161-169
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    • 2011
  • International Organization for Standardization has recently published ISO 9001:2008 which is the basic requirements for a quality management system that an organization must fulfil to demonstrate its ability to consistently provide products that enhance customer satisfaction and meet applicable statutory and regulatory requirements. Not many empirical researches based on ISO 9001:2008 have been done up until now. In this article we outline transitional features for ISO 9000 quality management system (QMS) since its first publication in 1987. In order to effectively maintain ISO 9001:2008 QMS certification and continuously enhance quality management activities, we perform statistical analysis for the minor nonconformity data generated from follow-up audits for subcontractors of shipbuilding industry based on ISO 9001:2008 requirements. A Kruskal-Wallis test is used to show relationships between the minor nonconformity data and three classification criteria: the type of business, the size of business, and the number of follow-up audits.

A study on an Improved Model for Requirements Traceability (요구사항 추적모델 개선 연구 -공공부문 정보시스템 구축 사례를 중심으로-)

  • Kim, Chan-Hoe;Kim, Jong-Bae
    • Journal of Digital Contents Society
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    • v.13 no.2
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    • pp.247-254
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    • 2012
  • The management of user requirements for information system development is a key element. The traceability has been studied in a specific method as using a traceability table or SOA related to the requirement management. But there are few case about proposing a objective and quantified evaluation method and judgement criterion for none-technical business managers. This researcher has proposed, easy to access by unprofessional and objective and qualifiable, evaluation methods and criteria of Judging for adequacy of requirements reflection in the development process of information system for the government office through a previous case study. In this study, I will give consideration to study the limitations of previous studies and improve the evaluation formula for measuring the reflection of the requirements and derive, reviewed to provide a variety of criteria for each business, through business case analysis.

Do Oil and Gas Companies Comply with Requirements of IFRS 6?: Evidence from India and Global Companies

  • POSWAL, Dhanraj;CHAUHAN, Pragati
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.3
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    • pp.399-409
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    • 2021
  • This study examines whether oil and gas companies comply with the requirements of the International Financial Reporting Standards (IFRS) 6 on Exploration and Evaluation (E&E) of Mineral Resources. For this purpose, a comprehensive checklist divided into eight different parameters was prepared by including every requirement of IFRS 6. While building on the previous studies, the annual reports of the top five Indian and top five Global companies engaged in this business have been investigated in detail against the checklist using content analysis as the research method. Results show that a majority of the companies (both Indian as well as global companies) have not been complying with the requirements of IFRS 6. In five out of eight parameters the companies have not complied with even half of the requirements. The overall compliance ratio is as low as 41.54 percent and 43.68 percent for Indian and Global companies respectively. While analyzing the non-compliance, it has been observed that despite having distinct accounting standards, different kinds of companies are reporting differently. Thus, it is not in line or consistent with the goal of IFRS i.e., to establish a universal language for the companies to prepare the accounting statements. The research findings identify the exact area of non-compliance while citing the relevant paragraph number of IFRS 6.

Requirements of Fashion as Popular Art in Contemporary Culture

  • Seunghee, Suh
    • Journal of Fashion Business
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    • v.26 no.6
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    • pp.94-104
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    • 2022
  • The purpose of this study is to analyze the art world's perspective on popular art and the contact point with pure art and to present the requirements of fashion as a popular art. To analyze the artistic value of fashion, this study analyzed and presented the requirements of art by linking the innate characteristics of fashion premised on mass consumption of popular art. The research method consisted of content analysis focusing on books and papers on art and fashion. A critical perspective on expansion of the artistic field amid the blurred boundaries of art is the basis of a critical comparison between popular art and avant-garde art and a critique of popular art as opposed to value-oriented art. Conversely, as a point of contact with popular art with fine art, art is discussed against the ideological strategy of fine art and the shift in hegemony brought about by erosion of the barrier between art and everyday life. In addition, the non-essentialist perspective contradicts the division theory of popular art. The requirements of fashion as a popular art were analyzed based on the value of self-expression through the aesthetic pursuit of creativity and aesthetic expression, discourse as art, and expansion of modern art from the inessentialist perspective of popular art.

Influence of climate change on crop water requirements to improve water management and maize crop productivity

  • Adeola, Adeyemi Khalid;Adelodun, Bashir;Odey, Golden;Choi, Kyung Sook
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.126-126
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    • 2022
  • Climate change has continued to impact meteorological factors like rainfall in many countries including Nigeria. Thus, altering the rainfall patterns which subsequently affect the crop yield. Maize is an important cereal grown in northern Nigeria, along with sorghum, rice, and millet. Due to the challenge of water scarcity during the dry season, it has become critical to design appropriate strategies for planning, developing, and management of the limited available water resources to increase the maize yield. This study, therefore, determines the quantity of water required to produce maize from planting to harvesting and the impact of drought on maize during different growth stages in the region. Rainfall data from six rain gauge stations for a period of 36 years (1979-2014) was considered for the analysis. The standardized precipitation and evapotranspiration index (SPEI) is used to evaluate the severity of drought. Using the CROPWAT model, the evapotranspiration was calculated using the Penman-Monteith method, while the crop water requirements (CWRs) and irrigation scheduling for the maize crop was also determined. Irrigation was considered for 100% of critical soil moisture loss. At different phases of maize crop growth, the model predicted daily and monthly crop water requirements. The crop water requirement was found to be 319.0 mm and the irrigation requirement was 15.5 mm. The CROPWAT 8.0 model adequately estimated the yield reduction caused by water stress and climatic impacts, which makes this model appropriate for determining the crop water requirements, irrigation planning, and management.

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