• Korean Security Journal
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• no.17
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• pp.235-253
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• 2008

In the developed countries, the private investigation system which is part of private security has developed together with police, and OECD countries except South Korea has developed the private investigation system establishing by the Private Investigation ACT. In Korea, there was several attempt to establish the Private Investigation ACT but it was not accomplished because of private security circumstances. In this study, the chapter Iis introduction, theoretical background is in chapter II, chapter III is the operation of private investigation of the developed countries, analysis and direction of the Private Investigation ACT in chapter IV, and conclusion in chapter V. To introduce the private investigation system, it is required to discover the problem of the Private Investigation ACT mentioned in this article and to develop the private investigation system by collecting the opnion of citizen, academic world, and the related agency. It is necessary to associated interest and effort of citizen, academic world, and the related agency for introdection of the private investigation system.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.2
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• pp.208-213
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• 2012

In this study, the mechanical joint performance of the V-Insert clamp applied to automobile exhaust pipes was evaluated through the experimental investigation of its axial load capacity. The axial load of the V-Insert clamp was also determined by using theoretical equations presented by Shoghi and compared with the experimental results. As results of the theoretical prediction, the axial load of the V-Insert clamp tended to increase along with smaller angle of the V-Insert segment and the lower friction coefficient between the V-Insert segment and exhaust pipes. The experimental results under tightening effects were similar to the theoretical results and the axial load of the V-Insert clamp presented maximum values in the range of all torques at distance of 2mm between each exhaust pipes. The experimental results under loading effects were similar to the theoretical results in the range of lower torques but deviated from the theoretical results in the range of higher torques. These results would be beneficial to improve the joint and sealing performance of the V-Insert clamp.

• Wind and Structures
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• v.36 no.2
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• pp.133-147
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• 2023

The random vibration of saddle membrane structures under wind load is studied theoretically and experimentally. First, the nonlinear random vibration differential equations of saddle membrane structures under wind loads are established based on von Karman's large deflection theory, thin shell theory and potential flow theory. The probabilistic density function (PDF) and its corresponding statistical parameters of the displacement response of membrane structure are obtained by using the diffusion process theory and the Fokker Planck Kolmogorov equation method (FPK) to solve the equation. Furthermore, a wind tunnel test is carried out to obtain the displacement time history data of the test model under wind load, and the statistical characteristics of the displacement time history of the prototype model are obtained by similarity theory and probability statistics method. Finally, the rationality of the theoretical model is verified by comparing the experimental model with the theoretical model. The results show that the theoretical model agrees with the experimental model, and the random vibration response can be effectively reduced by increasing the initial pretension force and the rise-span ratio within a certain range. The research methods can provide a theoretical reference for the random vibration of the membrane structure, and also be the foundation of structural reliability of membrane structure based on wind-induced response.

• Korean Security Journal
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• no.32
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• pp.177-204
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• 2012

The purpose of this study is to search for a plan to improve the professionalization of private investigation service through the analysis of its actual condition. To examine the actual condition of the professionalization of private investigation service, 4 factors - professional associations, professional knowledge, curriculum & qualification system and code of ethics - were used for the professionalization analysis based on theoretical background and prior researches concerning structural aspect of professionalization. Based on the results of actual condition analysis, to make an effort for the integration and incorporation of private investigation associations, to overcome the unequal distribution of professional knowledges, to organize and operate the professional curriculum, to introduce recognized qualifications system, and to establish a code of ethics are required to improve the professionalization of private investigation service.

• Journal of Sericultural and Entomological Science
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• v.22 no.2
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• pp.22-23
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• 1981

The international raw silk grade classification method has been amended for several times since it has been created in 1932. S쳐h rather periodical changes have been raised as problems not because of it was created by scientifical research background or academical base but because of rather commercial aspect. This paper is, however, discussed by throughful academical aspect regardless raw silk sailers or buyers commercial interest. After carring a theoretical approach with thoroughful investigation on this matter, this paper happened to compare the current raw silk grade classification method against the developed theoretical silk grade classification method, which they happened to be much different each other. (omitted)

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.04a
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• pp.253-259
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• 1997

A software for design of turbine bearings has been developed based on both the theoretical analysis and experimental investigation. Static and dynamic performance, i.e. load capacity, frictional loss, temperature distribution, stiffness and damping coefficients, stability etc., can be obtained by using this software taking into account the effects of three dimensional variation of lubricant viscosity, turbulence and inlet pressure. A performance test rig was developed by self-design and technology, which was used to verify static and dynamic characteristics and to investigate the proper boundary conditions for theoretical analysis. Consequently HANJUNG has developed the self-design technology for design of turbine bearings for power plants.

• Journal of Electrochemical Science and Technology
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• v.8 no.3
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• pp.244-249
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• 2017

This paper presents the results of an investigation into the isoamperic point of cyclic voltammograms, which is defined as the singular point where the voltammograms of various scan rates converge. The origin of the unique point is first considered from a theoretical perspective by formulating the voltammetric curves as a system of linear equations, the solution of which indicates that a trivial solution is only available at the potential at which the net current is zero during the reverse potential scan. In addition, by way of a mathematical formulation, it was also shown that the isoamperic point is dependent on the switching potential of the potential scanning. To validate these findings, theoretical and practical cyclic voltammmograms were studied using finite-element based digital simulations and 3-electrode cell experiments. The new understanding of the nature of the isoamperic point provides an opportunity to measure the charge transfer effects without the influence of the mass transfer effects when determining the thermodynamic and kinetic characteristics of a faradaic system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.6
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• pp.857-863
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• 2003

In rotating machinery, unbalance and misalignment are major concerns in vibration. Unbalance can be eliminated by balancing procedure to some degree. but little work has been done on the vibrations that occur in a misaligned rotor system. Currently, no generalized theoretical model based on a rotor system with flexible coupling is available to describe the vibrations caused by misalignment. As a part of systematic investigation on the misalignment, first of all, the study on flexible coupling with misalignment should be preceded. In this study, the geometry and reaction force and moment of a gear coupling with misalignment was investigated, also the theoretical model of a gear coupling with misalignment was presented by using the relationship between geometry and moment of gear coupling. It is expected that the proposed procedure can be applied to derive the theoretical model of other couplings.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.188-193
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• 2012

Recently, the nanofluid which is stably dispersing or suspending of nanoparticles in the conventional heat transfer fluids (HTF) such as water and ethylene glycol has attracted significant interests as a solar thermal energy absorbing medium because they have excellent absorption and thermophysical properties compared to the typical HTF. In the present study, the efficiency of nanofluid-based flat-plate solar collector is analytically evaluated using the theoretical model of energy balance equation. The theoretical model considers the incoming solar radiation as a volumetric heat generation and the water-based single wall carbon nanohorn(SWCNH) nanofluid is used as a solar energy absorbing medium. Finally, the efficiency of nanofluid-based collector is calculated according to the volume fraction of SWCNH using the analytical solution.

• Journal of the Korean Society for Precision Engineering
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• v.7 no.2
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• pp.28-38
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• 1990

The study is concerned with the theoretical and experimental investigation of axisymmetric fluid pressure-driven hydroforming of sheet metal by forming over the die cavity. The rigid-plastic finite element method is employed to calculate the stress and strain distribution. The effect of blank size and die radius is also studied in the finite element analysis. Experiments are carried out for hydroforming of cold-rolled steel sheets under various process conditions. The computational results are compared with the experimental results for the forming pressure vs. pole displacement relations and strain distributions. Comparison has shown that theoretical predictions by the finite element method are in good agreement with the experiment with the experimental observations. Thus, it is shown that the rigid-plastic finite element method is effectively used in the analysis of axisymmetric fluid pressure-driven hydroforming process.