• Title/Summary/Keyword: d$^2$-law

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건설 안전관리 체계의 개선 방안에 관한 연구

  • 김세영;안병수
    • Proceedings of the Safety Management and Science Conference
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    • 2000.05a
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    • pp.9-26
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    • 2000
  • Eventually so as to realize the construction safety, 1 found out the cause of accident and specificities of the construction industry. This study presented to several situations and problems on construction safety. As a result of this study, the below matters must be improved for more effective the construction safety management system. 1. It need to introduce the total construction safety management system. Because there is not effectiveness in the current safety management to the first on the construction field. a. We must consider the safety in the whole parts of the process of the construction and constructors of each part must devide responsibility of the construction safety as a CDM(The Construction Designed Management) used in UK. b. It is desirable to proceed control of safety in the whole parts of the construction to introduce the total safety coordinator that can consult the matters of safety as a law accepted in EU. c. Like management of the construction safety in USA, direction of the construction safety must be made to work exactly by code or manual. d. To improve the organization of the construction safety on the construction field unefficient, it must be introduced safety supervisor, safety coordinator or institutionalization of safety consultant. 2. The law of the construction safety not only have wasteful element but also decrease efficiency by overlapping of regulation, The Ministry of Labour and The Ministry of Construction & Transportation, So laws related with safety must be instituted. a. To realize total safety management, The Ministry of Labour must legislate the basic law about safety management in whole field. b. To legislate the construction safety under one law, and improve efficiency of the overlapping of regulation and the similar law by The Ministry of Construction & Transportation. c. It must be made the law of construction safety that can proper to change of situation in construction. d. The standard of safety must be instituted belong to international level and improved by year. e. We must improve irrational regulation to realize activity of safety self regulating for progress competition in construction industry

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An exploratory study for designing research security framework (연구보안 관리체계 설계를 위한 탐색적 연구)

  • Na, Onechul;Chang, Hangbae
    • Convergence Security Journal
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    • v.16 no.2
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    • pp.55-62
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    • 2016
  • Recently, research outcome is frequently leaked in the process of progressing domestic R&D. Security system such as research security law and manual is implemented to prepare these leakage. However piecemeal solutions, simply technological measures, have a limit. Consequently, this study organizes a integrated research security framework by designing multidimensional security measures based on the R&D life cycle perspective. Concretely, this study constructs various control items predicated on law, moreover reviews the applicability of research security assessment items.

Finite Element Analysis for Forming Process of Semi-Solid Material Considering Induction Heating (유도가열을 고려한 반용융 재료의 성형공정에 관한 유한요소 해석)

  • Park, W.D.;Ko, D.C.;Kim, B.M.;Park, J.C.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.8
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    • pp.82-91
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    • 1997
  • The major objective of this study is to establish analytical technique in order to analyze the behaviour of semi-solid material considering induction heating of the billet. Induction heating process is analyzed by using commerical finite element software. ANSYS. The finite element program, SFAC2D, for the simulation of deformation in semi-solid state is developed in the present study. The semi-solid behaviour is described by a viscoplastic model for the solid phase, and by the Darcy's law for the liquid flow. Simple compression and closed-die compression process considering induction heating are analyzed, and also it is found that the distribution of initial solid fraction of the billet has an important effect on deformation behaviour of semi-solid material. In order to verify the effectiveness of proposed analytical technique the simulation result is compared with experimental result.

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Effective vibration control of multimodal structures with low power requirement

  • Loukil, Thamina;Ichchou, Mohamed;Bareille, Olivier;Haddar, Mohamed
    • Smart Structures and Systems
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    • v.13 no.3
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    • pp.435-451
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    • 2014
  • In this paper, we investigate the vibration control of multimodal structures and present an efficient control law that requires less energy supply than active strategies. This strategy is called modal global semi-active control and is designed to work as effectively as the active control and consume less power which represents its major limitation. The proposed law is based on an energetic management of the optimal law such that the controller follows this latter only if there is sufficient energy which will be extracted directly from the system vibrations itself. The control algorithm is presented and validated for a cantilever beam structure subjected to external perturbations. Comparisons between the proposed law performances and those obtained by independent modal space control (IMSC) and semi-active control schemes are offered.

Impact of Work Motivation on Satisfaction and Turnover of Public Universities Lecturers

  • PHAM, Chinh D.;HOANG, Thao P.D.;NGUYEN, Yen T.
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.1135-1146
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    • 2021
  • The paper aims to examine the relationship between various types of motivation and satisfaction as well as turnover intentions of public university lecturers. Intrinsic motivation is found to affect both satisfaction and turnover, while for extrinsic motivation, only one type has a significant effect on satisfaction. The web-based questionnaire with convenience sampling was chosen to approach target respondents. Data was collected by sending a link of the questionnaire to the lecturers' email. There were 700 questionnaires collected. Of which 681 valid responses, after screening out unusual questionnaires. In order to fulfill these aims, the authors employed structural equation modeling with maximum likelihood method supported by AMOS software with 681 valid samples. The evidence confirms the high correlation between intrinsic motivation and satisfaction for university lecturers which has been shown in previous studies. With regard to extrinsic motivation, extrinsic regulation (material) is found to have a positive influence on satisfaction, meaning financial rewards and job security will lead to his contentment while introjected regulation is a source of dissatisfaction. The results also demonstrate that intrinsic motivation is negatively correlated with turnover intentions. A person who is interested in the job itself is less likely to leave his or her job due to a keen passion for it.

Prediction of the Friction Factor forTurbulent Flow in a Rod Bundle Using Law of the Wall (벽면의 법칙(Law of the Wall)을 이용한 봉다발의 난류마찰계수 예측)

  • 김내현;전태현;이상근;김시환
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.8
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    • pp.1545-1551
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    • 1992
  • This work is concerned with the prediction of turbulent friction factors in rod bundles. In this study, the Law of the Wall is assumed to be valid over the entire flow area. The flow channel is divided into element channels, and the algebraic form of the "Law of the Wall" is integrated over each element channel to yield an analytic expression for the pressure drop in the rod bundle. The method is applied to rod bundles with 1.2

1D finite element artificial boundary method for layered half space site response from obliquely incident earthquake

  • Zhao, Mi;Yin, Houquan;Du, Xiuli;Liu, Jingbo;Liang, Lingyu
    • Earthquakes and Structures
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    • v.9 no.1
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    • pp.173-194
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    • 2015
  • Site response analysis is an important topic in earthquake engineering. A time-domain numerical method called as one-dimensional (1D) finite element artificial boundary method is proposed to simulate the homogeneous plane elastic wave propagation in a layered half space subjected to the obliquely incident plane body wave. In this method, an exact artificial boundary condition combining the absorbing boundary condition with the inputting boundary condition is developed to model the wave absorption and input effects of the truncated half space under layer system. The spatially two-dimensional (2D) problem consisting of the layer system with the artificial boundary condition is transformed equivalently into a 1D one along the vertical direction according to Snell's law. The resulting 1D problem is solved by the finite element method with a new explicit time integration algorithm. The 1D finite element artificial boundary method is verified by analyzing two engineering sites in time domain and by comparing with the frequency-domain transfer matrix method with fast Fourier transform.

Scaled Down Experiment of Retention Basin with a Rotatable Bucket Using 3D Printer (3D 프린터를 이용한 회전 버킷이 부착된 저류조의 모형 실험)

  • Park, Seong-Jik;Lee, Chang-Gu;Lee, Jemyung;Choi, Won
    • Journal of The Korean Society of Agricultural Engineers
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    • v.59 no.2
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    • pp.49-55
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    • 2017
  • Recently climate change and urbananization have been increased surface runoff, resulting in flooding. Retention basins have been constructed to control urban flooding by reducing peak flow rate. Recently, the retention basin plays a role in controlling combined sewer overflows (CSOs) as well as urban flooding. In this study, the retention basin with a rotatable bucket was suggested and scale down experiments was performed for the optimum design of the retention basin. Scaled down model was produced using a 3D printer after it was designed as law of similarity. Two times for operating a rotary bucket is required to sweep out the sediments deposited on the bottom of the basin. Optimized dimensions for the retention basin were width of 5 m, height of 5 m, bucket radius of 0.5 m, and bottom slope of 5.0 %. It can be concluded that the results obtained from this study can be used to design the retention basin with a rotatable bucket which does not require energy to operate.

The Origin of 1/t Pressure (1/t 배기의 근원)

  • Ha, Taekyun
    • Vacuum Magazine
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    • v.1 no.1
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    • pp.11-16
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    • 2014
  • A variety of metal vacuum systems displays the celebrated 1/t pressure, namely, power-law dependence on time t, with the exponent close to unity, as to the origin of which there has been long-standing controversy. Here we propose a chemisorption model for water adsorbates, based on the argument for 2D fermion behavior of water adsorbed on a metal surface, and obtain analytically the power-law behavior of pressure with an exponent unity. Further, the model predicts that the pressure should depend on the temperature T according to $T^{1.5}$, which is indeed confirmed by our experiment.