• Title/Summary/Keyword: order of convergence

Search Result 6,646, Processing Time 0.031 seconds

Study of spatial temperature distribution during combustion process in a high temperature and pressure constant volume chamber (고온 고압 정적 연소실에서 연소과정에 따른 온도 분포 측정)

  • Kim, Ki-hyun
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.1
    • /
    • pp.345-350
    • /
    • 2017
  • Downsizing is widely applied to diesel engines in order to improve fuel efficiency and reduce exhaust emissions. Engine sizes are becoming smaller but pressure and temperature inside combustion chambers are increasing. Therefore, research for fuel spray under high pressure and temperature conditions is important. A constant volume chamber which simulates high temperature and pressure likely to be found in diesel engines was developed in this study. Pressure and temperature were increased abruptly because of ignition of the pre-mixture in the constant volume chamber. Then pressure and temperature were gradually decreased due to the heat loss through the chamber wall. Fuel spray occurred when temperature and pressure were reached at the target condition. In this experiment, the temperature condition should be exactly defined to understand the relation between fuel evaporation and ambient temperature. A fast response thermocouple was developed and used to measure the temporal and spatial temperature distribution during the combustion process inside the combustion chamber. In the results, the core temperature was slightly higher than the bulk temperature calculated by the gas equation. Ed-note: do you want to say 'ideal gas equation'? This was attributed to the heat transfer loss through the chamber wall. The vertical temperature deviation was higher than the horizontal temperature deviation by 5% which resulted from the buoyancy effect.

Enterprise Human Resource Management using Hybrid Recognition Technique (하이브리드 인식 기술을 이용한 전사적 인적자원관리)

  • Han, Jung-Soo;Lee, Jeong-Heon;Kim, Gui-Jung
    • Journal of Digital Convergence
    • /
    • v.10 no.10
    • /
    • pp.333-338
    • /
    • 2012
  • Human resource management is bringing the various changes with the IT technology. In particular, if HRM is non-scientific method such as group management, physical plant, working hours constraints, personal contacts, etc, the current enterprise human resources management(e-HRM) appeared in the individual dimension management, virtual workspace (for example: smart work center, home work, etc.), working time flexibility and elasticity, computer-based statistical data and the scientific method of analysis and management has been a big difference in the sense. Therefore, depending on changes in the environment, companies have introduced a variety of techniques as RFID card, fingerprint time & attendance systems in order to build more efficient and strategic human resource management system. In this paper, time and attendance, access control management system was developed using multi camera for 2D and 3D face recognition technology-based for efficient enterprise human resource management. We had an issue with existing 2D-style face-recognition technology for lighting and the attitude, and got more than 90% recognition rate against the poor readability. In addition, 3D face recognition has computational complexities, so we could improve hybrid video recognition and the speed using 3D and 2D in parallel.

Study for Spatial Big Data Concept and System Building (공간빅데이터 개념 및 체계 구축방안 연구)

  • Ahn, Jong Wook;Yi, Mi Sook;Shin, Dong Bin
    • Spatial Information Research
    • /
    • v.21 no.5
    • /
    • pp.43-51
    • /
    • 2013
  • In this study, the concept of spatial big data and effective ways to build a spatial big data system are presented. Big Data is defined as 3V(volume, variety, velocity). Spatial big data is the basis for evolution from 3V's big data to 6V's big data(volume, variety, velocity, value, veracity, visualization). In order to build an effective spatial big data, spatial big data system building should be promoted. In addition, spatial big data system should be performed a national spatial information base, convergence platform, service providers, and providers as a factor of production. The spatial big data system is made up of infrastructure(hardware), technology (software), spatial big data(data), human resources, law etc. The goals for the spatial big data system build are spatial-based policy support, spatial big data platform based industries enable, spatial big data fusion-based composition, spatial active in social issues. Strategies for achieving the objectives are build the government-wide cooperation, new industry creation and activation, and spatial big data platform built, technologies competitiveness of spatial big data.

Cost Effective Remote Subscription scheme for Ubiquitous Convergence IP-based Network (유비쿼터스 컨버젼스 IP 기반 대용량 네트워크에서 비용 절감형 리모트-서브스크립션 기법)

  • Shin, Soo-Young;Yoon, Young-Muk;Park, Soo-Hyun
    • The KIPS Transactions:PartC
    • /
    • v.14C no.1 s.111
    • /
    • pp.95-104
    • /
    • 2007
  • Mobile multimedia services such as TV-call or video streaming are gradually becoming popular in the 3rd or more generation mobile network (IMT-2000). Multimedia traffic is expected to continue increasing into the coming years, and IP technology is considered to be the efficient way of transporting such huge volumes of multimedia traffic. IP-based IMT network platform represents an evolution from IMT-2000. The structure of IP-based IMT network as ubiquitous platform is three-layered model : Middleware including Network Control PlatForm (NCPF) and Service Support PlatForm (SSPF), IP-BackBone (IP-BB), access network including sensor network. Mobility Management (MM) architecture in NCPF is proposed for IP-based IMT network in order to manage routing information and location information separately. The generous existing method of multicast control in IP-based IMT network is Remote Subscription. But Remote Subscription has problem that should be reconstructed whole multicast tree when sender in multicast tree moves to another area. To solve this problem, we propose the way to put Multicast-manager in NCPF.

Line Tracer Modeling for Educational Virtual Experiment (교육용 가상실험 라인 트레이서 모델링)

  • Ki, Jang-Geun;Kwon, Kee-Young
    • Journal of Software Assessment and Valuation
    • /
    • v.17 no.2
    • /
    • pp.109-116
    • /
    • 2021
  • Traditionally, the engineering field has been dominated by face-to-face education focused on experimental practice, but demand for online learning has soared due to the rapid development of IT technology and Internet communication networks and recent changes in the social environment such as COVID-19. In order for efficient online education to be conducted in the engineering field, where the proportion of experimental practice is relatively high compared to other fields, virtual laboratory practice content that can replace actual experimental practice is very necessary. In this study, we developed a line tracer model and a virtual experimental software to simulate it for efficient online learning of microprocessor applications that are essential not only in the electric and electronic field but also in the overall engineering field where IT convergence takes place. In the developed line tracer model, the user can set various hardware parameter values in the desired form and write the software in assembly language or C language to test the operation on the computer. The developed line tracer virtual experimental software has been used in actual classes to verify its operation, and is expected to be an efficient virtual experimental practice tool in online non-face-to-face classes.

System Reliability-Based Design Optimization Using Performance Measure Approach (성능치 접근법을 이용한 시스템 신뢰도 기반 최적설계)

  • Kang, Soo-Chang;Koh, Hyun-Moo
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.30 no.3A
    • /
    • pp.193-200
    • /
    • 2010
  • Structural design requires simultaneously to ensure safety by considering quantitatively uncertainties in the applied loadings, material properties and fabrication error and to maximize economical efficiency. As a solution, system reliability-based design optimization (SRBDO), which takes into consideration both uncertainties and economical efficiency, has been extensively researched and numerous attempts have been done to apply it to structural design. Contrary to conventional deterministic optimization, SRBDO involves the evaluation of component and system probabilistic constraints. However, because of the complicated algorithm for calculating component reliability indices and system reliability, excessive computational time is required when the large-scale finite element analysis is involved in evaluating the probabilistic constraints. Accordingly, an algorithm for SRBDO exhibiting improved stability and efficiency needs to be developed for the large-scale problems. In this study, a more stable and efficient SRBDO based on the performance measure approach (PMA) is developed. PMA shows good performance when it is applied to reliability-based design optimization (RBDO) which has only component probabilistic constraints. However, PMA could not be applied to SRBDO because PMA only calculates the probabilistic performance measure for limit state functions and does not evaluate the reliability indices. In order to overcome these difficulties, the decoupled algorithm is proposed where RBDO based on PMA is sequentially performed with updated target component reliability indices until the calculated system reliability index approaches the target system reliability index. Through a mathematical problem and ten-bar truss problem, the proposed method shows better convergence and efficiency than other approaches.

The Effect of the Performance of Firefighting Construction Supervision Personnel on the Completion Inspection of Firefighting Facility Construction in Apartments (소방공사감리원의 업무수행능력이 아파트 소방시설공사의 완공검사에 미치는 영향)

  • Kim, Sang-Sig;Kong, Ha-Sung
    • The Journal of the Convergence on Culture Technology
    • /
    • v.5 no.3
    • /
    • pp.43-54
    • /
    • 2019
  • In this study, results of completion inspection are investigated according to the performance of the firefighting construction supervision personnel and according to the necessity of clean air supply in a performance test of the firefighting construction supervision personnel. The results of the completion inspection are measured and the causes of defects in the fire protection facilities after issuance of a completion inspection certificate are analyzed. The findings of this investigation can be used to minimize the risk of apartment fires and improve the performance of firefighting construction supervision personnel. The results of this study are summarized as follows. First, the results of the completion inspection conducted by the firefighting construction supervision personnel varies according to particular occupation. The performance of fire facility supervisors from design companies and fire construction companies were significantly higher than the fire officers. Therefore, it is necessary to employ supervisors who have experience in supervising the construction of apartments, in order to improve the performance of fire construction supervision officers. Second, the analysis of the completion inspection results according to the necessity of a clean air supply for performance tests of firefighting construction supervision personnel showed that the necessity of a clean air supply was significantly higher for fire facility supervisors from design companies and fire construction companies than for the fire officers. In order to improve, the completion inspection should be carried out up until the completion date of the building. In addition, a system needs to be established to ensure that clients are not able to demand that a completion inspection certificate be issued on the construction completion date. Finally, it is found that defects of completion inspection after issuance of a completion inspection certificate affects the result of the completion inspection. The results of the completion inspections conducted by the fire facility supervisors from design companies and fire construction companies were affected significantly less by defects than that of the general contractors. Research shows that faults have occured in firefighting facilities after the issuance of a completion inspection certificate due to the client and the construction company demanding the issuance of the completion inspection certificate.

Assessment of Refuge Safety in Accomodations According to Awareness and Usability of Descending Life Lines and Simple Descending Life Lines (완강기 및 간이완강기의 인지·사용능력에 따른 숙박시설의 피난안전성 평가)

  • Han, Dong-Gew;Kong, Ha-Sung
    • The Journal of the Convergence on Culture Technology
    • /
    • v.5 no.4
    • /
    • pp.11-21
    • /
    • 2019
  • The purpose of this study is to evaluate the awareness and usability of descending life lines and simple descending life lines for fire situations in the accommodation of the public officials who are responsible for supervising the installation and maintenance of descending life lines and simple descending life lines. The main results of the study are summarized as follows. First, in comparison of the ability to distinguish between descending life lines and simple descending life lines, the majority of female public officers in general administrative services do not have the ability to distinguish between descending lifelines and simple descending life lines, so they should be able to improve their ability to distinguish descending life lines. Also, institutional strategies are needed to regularly receive education through the Safety Experience Center in order to prevent safety accidents such as falling in emergency situations. Second, as a result of verifying reusability of simple descending life lines by gender and occupation, most public officers with the exception of half of the firefighting officers were analyzed as having no ability to reuse the simple descending life lines. Therefore, it is necessary to change the relevant laws so that only the installation of descending life lines which can be used continuously is permitted, except for the simple descending life lines among the evacuation instruments to be additionally installed in each room of the accommodation. Third, in terms of the ability to perceive the maximum load of the descending life lines according to occupation, the perception ability of the rescuers was the highest and the perception ability of the fire service personnel was the lowest. In order to improve the perception abilities of the fire service personnel, it is necessary to strengthen the theoretical and practical education of descending life lines in collective education such as the command-enhancing training which is regularly carried out in fire service academy. Lastly, it is believed that it is more effective to conduct the experience training of the descending life lines by imagining the fire in accomodations rather than other facilities, because it is the location where fires are actually seen the most.

An Exploration of MIS Quarterly Research Trends: Applying Topic Modeling and Keyword Network Analysis (MIS Quarterly 연구동향 탐색: 토픽모델링 및 키워드 네트워크 분석 활용)

  • Kang, Eunkyung;Jung, Yeonsik;Yang, Seonuk;Kwon, Jiyoon;Yang, Sung-Byung
    • Journal of Intelligence and Information Systems
    • /
    • v.28 no.2
    • /
    • pp.207-235
    • /
    • 2022
  • In a knowledge-based society where knowledge and information industries are the main pillars of the economy, knowledge sharing and diffusion and its systematic management are recognized as essential strategies for improving national competitiveness and sustainable social development. In the field of Information Systems (IS) research, where the convergence of information technology and management takes place in various ways, the evolution of knowledge occurs only when researchers cooperate in turning old knowledge into new knowledge from the perspective of the scientific knowledge network. In particular, it is possible to derive new insights by identifying topics of interest in the relevant research field, applied methodologies, and research trends through network-based interdisciplinary graftings such as citations, co-authorships, and keywords. In previous studies, various attempts have been made to understand the structure of the knowledge system and the research trends of the relevant community by revealing the relationship between research topics, methodologies, and co-authors. However, most studies have compared two or more journals and been limited to a certain period; hence, there is a lack of research that looked at research trends covering the entire history of IS research. Therefore, this study was conducted in the following order for all the papers (from its first issue in 1977 to the first quarter of 2022) published in the MIS Quarterly (MISQ) Journal, which plays a leading role in revealing knowledge in the IS research field: (1) After extracting keywords, (2) classifying the extracted keywords into research topics, methodologies, and theories, and (3) using topic modeling and keyword network analysis in order to identify the changes from the beginning to the present of the IS research in a chronological manner. Through this study, it is expected that by examining the changes in IS research published in MISQ, the developing patterns of IS research can be revealed, and a new research direction can be presented to IS researchers, nurturing the sustainability of future research.

Nomad Thinking Implied in Duchamp's Readymades (뒤샹의 레디메이드에 함의된 노마드적 사유)

  • Song, Hayoung
    • The Journal of the Convergence on Culture Technology
    • /
    • v.7 no.3
    • /
    • pp.215-222
    • /
    • 2021
  • Duchamp chose readymades mainly for his denial of retinal painting and his desire and fluid thinking for changes inside him. His thinking is well presented in his readymade works. One of his early readymades, Bicycle Wheel, expresses correlations between beings and capital. Its essence is capital and the desire of beings. It is connected to Desire or Desire-Machine proposed as a social reform and creation model by Gilles Deleuze and Félix Guattari. Bicycle Wheel does not simply end in desire relations between capital and beings, though. When the desire of beings is converted into positive desire, it can keep inventing and creating something that is repetitive, fluid, and new. Duchamp tried to convey this positive desire through his readymade Fountain. Duchamp created a ready-made article toilet into a work of art in Fountain, being driven by desire flowing inside him. This is connected to the attributes of nomads that refused to settle down and continue to flow in search of new landscapes. This way of his thinking is clearly reflected in his Box in a Valise. He was motivated to create this work by his fluid thinking. In this work, various situations can unfold often according to the directions of two elements, place and arrangement. Here, place guarantees fluidity, and arrangement variability or desire. According to Gilles Deleuze and Félix Guattari, fluidity represents nomads with the characteristics of flow and variation, and desire represents productivity or production or creation. Box in a Valise represents nomads themselves. The nomads defined by Gilles Deleuze and Félix Guattari keep flowing and create a new world. They are in line with the thinking of Duchamp that refused to settle down at one place and escape from the old order to create a new artistic world. This type of nomads can be called revolutionists or creators that acknowledge differences and create. Nomads also contain the concept of resistance to the old order. Deleuze and Guattari proposed a war machine as a model of this resistance. Duchamp and his readymades can thus be called war machines.