• 기술혁신학회지
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• 제9권3호
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• pp.514-537
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• 2006

최근 과학기술이 국가발전에서 차지하는 비중이 더욱 커짐에 따라 각 국가들은 그에 대한 정책과 관련제도를 한층 강화하고 있다. 남북한 역시 1990년대 후반부터 과학기술을 국가의 중요정책으로 취급하고 이를 효율적으로 추진하기 위하여 과학기술 행정체계의 개편과 관련법령에 대한 정비를 지속적으로 시행하고 있다. 이 논문은 남북 과학기술정책의 제도적 기반이 되는 과학기술 기본법제의 우영 상황을 살펴봄으로써, 남북 과학기술 협력 활성화 및 향후의 관련법제의 통일화에 대비한 양 법제간의 정합 가능성을 탐색해 보는 것을 목적으로 하고 있다. 이를 위해 남북 헌법상의 과학기술 관련규정과 과학기술에 관한 총괄규범으로서 기능하는 남한의 과학기술기본법과 북한의 과학기술법에 대하여 그 규정체계와 내용을 개관하고 상호간의 유사점과 차이점을 비교분석하였다.

• Journal of Communications and Networks
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• 제14권5호
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• pp.546-553
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• 2012

Compact routing intends to achieve good tradeoff between the routing path length and the memory overhead, and is recently considered as a main alternative to overcome the fundamental scaling problems of the Internet routing system. Plenty of studies have been conducted on compact routing, and quite a few universal compact routing schemes have been designed for arbitrary network topologies. However, it is generally believed that specialized compact routing schemes for peculiar network topologies can have better performance than universal ones. Studies on complex networks have uncovered that most real-world networks exhibit power-law degree distributions, i.e., a few nodes have very high degrees while many other nodes have low degrees. High-degree nodes play the crucial role of hubs in communication and inter-networking. Based on this fact, we propose two highest-degree landmark based compact routing schemes, namely HDLR and $HDLR^+$. Theoretical analysis on random power-law graphs shows that the two schemes can achieve better space-stretch trade-offs than previous compact routing schemes. Simulations conducted on random power-law graphs and real-world AS-level Internet graph validate the effectiveness of our schemes.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2107-2119
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• 2022

Accurate remaining useful life (RUL) prediction for critical components of nuclear power equipment is an important way to realize aging management of nuclear power equipment. The electric gate valve is one of the most safety-critical and widely distributed mechanical equipment in nuclear power installations. However, the electric gate valve's extended service in nuclear installations causes aging and degradation induced by crack propagation and leakages. Hence, it is necessary to develop a robust RUL prediction method to evaluate its operating state. Although the particle filter(PF) algorithm and its variants can deal with this nonlinear problem effectively, they suffer from severe particle degeneracy and depletion, which leads to its sub-optimal performance. In this study, we combined the whale algorithm with regularized particle filtering(RPF) to rationalize the particle distribution before resampling, so as to solve the problem of particle degradation, and for valve RUL prediction. The valve's crack propagation is studied using the RPF approach, which takes the Paris Law as a condition function. The crack growth is observed and updated using the root-mean-square (RMS) signal collected from the acoustic emission sensor. At the same time, the proposed method is compared with other optimization algorithms, such as particle swarm optimization algorithm, and verified by the realistic valve aging experimental data. The conclusion shows that the proposed method can effectively predict and analyze the typical valve degradation patterns.

• Nuclear Engineering and Technology
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• 제55권6호
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• pp.2011-2017
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• 2023

Gas submerged jet is an outstanding thermohydraulic phenomenon in pool scrubbing of fission products during a severe nuclear accident. Experiments were performed on the hydraulic characteristics in the ranges of air mass flux 0.1-1400 kg/m²s and nozzle diameter 10-80 mm. The results showed that the dependence of inlet pressure on the mass flux follows a power law in subsonic jets and a linear law in sonic jets. The effect of nozzle submerged depth was negligible. The isolated bubbling regime, continuous bubbling regime, transition regime, and jetting regime were observed in turn, as the mass flux increased. In the bubbling regime and jetting regime, the air volume fraction distribution was approximately symmetric in space. Themelis model could capture the jet trajectory well. In the transition regime, the air volume fraction distribution loses symmetry due to the bifurcated secondary plume. The Li correlation and Themelis model showed sufficient accuracy for the prediction of jet penetration length.

• 식품과학과 산업
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• 제51권4호
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• pp.325-333
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• 2018

If private discipline replace the strict administrative regulation, fundamental rights of protective essence can be relativized while if may be beneficial for the individual freedom. Assigning the state power to the private organization is equivalent to giving up the practice of individual liberty to the organized authority. It is important to make use of public law mechanism, particularly under the imperfect juristic system. Regarding the prohibition of prior censorship, it is necessary to consider whether it is desirable to prioritize the freedom of speech over the rest of the legal benefit. Apart from this necessity, new advertisement screening mechanism was irreversibly - and controversially - introduced for the health functional food since the unconstitutional verdict of the prior screening of advertisements. With this, the state must secure the broad order through legal regulations and norms in order to freedom of speech and other legal benefit can be harmoniously and practically guaranteed.

• World Technopolis Review
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• 제5권1호
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• pp.71-82
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• 2016

This paper explores, explains and describes a framework for analyzing collaborative governance, decent work and innovation as fundamental elements of sustainable workplaces through case study of Philippine science and technology (S & T) parks. Rules, or the legal infrastructure, are particularly significant considerations that facilitate or hinder collaboration. Industrial relations/human resource (IR/HR) practices are essential to collaboration and decent work. Employee consultation and labor-management council or committee are examples of IR/HR practices that might contribute to collaboration and decent work in firms and workplaces in S & T parks as they are team approaches to production, too. Collaboration and decent work enhance the capacity to innovate. In the long run, collaborative governance, decent work and innovation tend to converge in the concept of sustainable development. The interdependencies and interactions among collaborative governance, decent work and capacity to innovate in firms operating in S & T parks make possible new solutions to new problems (i.e., innovation) and, thus, sustainable workplaces.

• Advances in aircraft and spacecraft science
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• 제10권1호
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• pp.19-49
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• 2023

The present study proposes a theoretical and numerical investigation on the dynamic response behaviour of a functional graded (FG) ceramic-metal tapered rotor shaft system, by the differential quadrature finite elements method (DQFEM) to identify the natural frequencies for modelling and analysis of the structure with suitable validations. The purpose of this paper is to explore the influence of heat gradients on the natural frequency of rotation of FG shafts via three-dimensional solid elements, as well as a theoretical examination using the Timoshenko beam mode, which took into account the gyroscopic effect and rotational inertia. The functionally graded material's distribution is described by two distribution laws: the power law and the exponential law. To simulate varied thermal conditions, radial temperature distributions are obtained using the nonlinear temperature distribution (NLTD) and exponential temperature distribution (ETD) approaches. This work deals with the results of the effect on the fundamental frequencies of different material's laws gradation and temperature gradients distributions. Attempts are conducted to identify adequate explanations for the behaviours based on material characteristics. The effect of taper angle and material distribution on the dynamic behaviour of the FG conical rotor system is discussed.

• Computers and Concrete
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• 제33권1호
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• pp.1-11
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• 2024

Aggressive environmental conditions, and especially the acidic effects of sulfate ion penetration, have reduced the lifetime of concrete structures in some areas, especially coastal and marine areas. In this research, at first, samples made of type II and V cement were kept in a solution of magnesium sulfate (MgSO₄) for a period of 90 and 180 days, the change of appearance. Field Emission Scanning Electron Microscopy (FE-SEM) and X-Ray Diffraction (XRD), were used to analyze the microstructure and the complex mineral composition of the concrete after exposure to corrosive environments. Then solving the differential equation governing the sulfate ion penetration, which is based on the second Fick law, it has been tried to determine the concentration of sulfate ions inside the concrete. In the following, an attempt has been made to improve the prediction of sulfate ion concentration in concrete by using Crank's penetration equation. At the same time, the coefficient in the Crank's solution have been optimized by using the Particle Swarm Optimization (PSO algorithm). The comparison between the results shows that the values obtained from Crank's relation are closer to the experimental results than the equation obtained from Fick's second law and shows a more accurate prediction.

• 대한수학회논문집
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• 제37권2호
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• pp.503-520
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• 2022

We introduce a new type of fractional derivative, which we call as the right local general truncated M-fractional derivative for α-differentiable functions that generalizes the fractional derivative type introduced by Anastassiou. This newly defined operator generalizes the standard properties and results of the integer order calculus viz. the Rolle's theorem, the mean value theorem and its extension, inverse property, the fundamental theorem of calculus and the theorem of integration by parts. Then we represent a relation of the newly defined fractional derivative with known fractional derivative and in context with this derivative a physical problem, Kirchoff's voltage law, is generalized. Also, the importance of this newly defined operator with respect to the flexibility in the parametric values is described via the comparison of the solutions in the graphs using MATLAB software.

• Journal of Mechanical Science and Technology
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• 제18권4호
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• pp.671-680
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• 2004

We present numerical and experimental results of the periodic flows inside a rectangular container under a background rotation. In numerical computation, a parallel-computation technique with MPI is implemented. Flow visualization and PIV measurement are also performed to obtain velocity fields at the free surface. Through a series of numerical and experimental works, we aim to clarify the fundamental reasons of discrepancy between the two-dimensional computation and the experimental measurement, which was detected in the previous study for the same flow model. Specifically, we check if the various assumptions prerequisite for the validity of the classical Ekman pumping law are satisfied for periodic flows under a background rotation.