• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.11 no.2
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• pp.1-5
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• 1993

This paper dealt with the theoretical adjustment of the closed nets with the various links by weight of the observed angles and distances. In addition to the results of checking between this theoretical adjustment method, the compass rule and transit rule, the theoretical adjustment method is more accurate than other adjustments.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.44
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• pp.181-210
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• 2009

This paper discusses global expansion and global strategies of shipping firms. Acknowledging the lack of research on global expansion by freight transport companies, this paper employs the resource-focused model, and explores "why shipping companies emerge" and "why the strategic behaviour of shipping companies is different in the global market". Despite there being a plethora of theoretical and empirical studies on the international operations of business organisations, it is acknowledged that researchers have largely neglected the issues regarding the international expansion within the freight transport industry. Identifying the general lack of contemporary studies concerning the international behaviour of shipping firms, this study addresses the important gap in our knowledge in the theoretical manner. The theoretical analysis suggests that the shipping company's internal resources can be a real reason for the international market participation.

• Korean Journal of Crystallography
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• v.11 no.1
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• pp.34-41
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• 2000

The group-theoretical approach analyzing the domain structure and the domain wall orientations of the ferroelastic crystal was introduced. These theoretical results were investigated by comparing them with the experimental results of several ferroelastic crystals, CsPbCl₃, Pb₃(PO₄)₂, and LiCsSO₄, which were grown by the Czochralski and solution methods, respectively. both results were agreed well and also consistent with those of previous works such s the strain method and the geometrical consideration. The group-theoretical approach showed that the ferroelastic domain walls must be the crystallographical prominent planes with fixed indices and classified by the symmetry elements characterizing the permissible domain walls. So the group-theoretical approach could be suggested as a new method for analyzing the structure of the ferroelastic domain and domain walls.

• Transactions of the Korean Society of Mechanical Engineers
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• v.7 no.3
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• pp.335-343
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• 1983

Modified-Shrink-Fit(MSF) method of compound cylinder is studied to increase elastic load carrying capacity (ELCC) of pressure vessel. The autofrettage and the shrink-fit processes are used to study the MSF process. Theoretical analyses based on the Tresca yield criterion, Hencky's total strain theory and elastic linearly strain-hardening material are carried out to derive closed form solutions. Experimental results are compared with theoretical results with various diameter ratios between outer (SM45C) and inner (SM20C) bloc cylinder. For various diameter ratios, increments of ELCC have errors in strains vs. internal loading pressures between experimental and theoretical results. But experimental results show good agreements with theoretical results in reyield pressurizing state. The increments of ELCC of compound cylinder manufactured by the MSF process is proved by measuring the residual stresses.

• Journal of KSNVE
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• v.8 no.3
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• pp.467-476
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• 1998

The free vibration analysis and design optimization of the rotating composite cylindrical shells with a rectangular cutout are investigated by theoretical method. The Love's thin shell theory is used to derive the frequency equation. The theoretical results are obtained by application of the energy method employing the Rayleigh-Ritz procedure. The used circumferential vibration modes are trigonometric functions, the axial modes are the beam modal functions chosen to satisfy the prescribed boundary conditions. To check the validity, the theoretical results are compared with experimental, FEM and other theoretical results.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.5
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• pp.42-51
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• 2000

The performances of the simple expansion, perforated tube, and conical-connector type as an exhaust muffler are shown in this study. Applying a model in which the method of four-pole parameter is used makes theoretical estimation of the insertion loss. Experiment is performed for the measurement of the insertion loss under four cases according to the variation of the tail pipe length. By comparing the theoretical prediction with the experimental results, the validity of the modeling using the method of four-pole parameter is verified. The personal computer simulation programs for the above mentioned theory on the muffler design have been developed and exhaust sound level measurements have been carried out for simple expansion muffler, conical-connector muffler, perforated tube mufflers and the combined type of conical-connector and simple expansion muffler. The measured results for attenuation characteristics of noise for each muffler are compared with the computed theoretical results to verity the confidence and applicable limits of the theoretical equation derived.

• Journal of the Korean Society of Tobacco Science
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• v.7 no.2
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• pp.189-197
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• 1985

The purpose of this study is to improve the method and the apparatus for recovering freon-11 used in a process for increasing the filling capacity of tobacco. The first, the theoretical recovery rate of freon-11 was calculated from vapour pressure and thermodynamic properties of freon-11. The second, the usability of theoretical data was evaluated by the comparison between the theoretical data and the experimental data from the pilot plant. The result obtained under the present experiment condition was quite similar to the rate at 15kg/cm2 and 5$^{\circ}C$, but the theoretical data evaluated were 0.1 to 0.3% lower than the experimental data at 20 to 25kg/cm2 and 5$^{\circ}C$. The recovery rate of the cooling and the compression system was about 95% with freon-11 used in this system and that with freon-11 concentrate of waste gas was about 3 to 3.6% at 20 to 25kg/cm2 and 5$^{\circ}C$.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.210-214
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• 2005

The purpose of this paper is to study the effects of the flexibility of HDD base plates on spindle vibration via theoretical predictions and experimental measurements. The flexibility of the base plate can significantly affect HDD spindle vibration. This is the most prominent feature in 2.5 inch HDD. Nevertheless, theoretical analysis of the spindle vibration often neglects the flexibility of the non-rotating part including spindle, base plate, and top cover. Our theoretical model developed in University of Washington can include the flexibilities of spindle and base plate. As a result, our theoretical prediction generally agrees well with our experimental measurements in vibration analysis. Moreover, Because of its small form factor, industrial practice is to use flanged disks instead of regular disks in vibration testing of prototypes. Our experimental measurements indicate that flanged disks and regular disks have very different behavior when the frequency is above 1 KHz.

• Magazine of the Korean Society of Agricultural Engineers
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• v.24 no.4
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• pp.80-91
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• 1982

To precict the suspended sediments which are 80% of total sediments in a flood disch- arge, an equation representing vertical distribution of sediment concentration was derived based upon the diffusion theory and the logalithmic velocity distribution function in the tubulent flow mechanism. The hypothesis that the uniform mass transfer is occurred at upper part along the center line of water depth, was established as a preconition to solve the problem. The theorecal and the observed values were compared. And the theoretical equation was modified to be fit the theoretical values the observed values. Observed results are as follow; 1) Equation 12) is the theoretical equation representing the vertical concentration distri- bution of suspended sedimenta 2) Rous&exonential type vertical concentration distribution equation shows signification errors near the water surface. But the equation 12) shows substation cocentration values near the water surface. 3) Equation 15) is the modified theoretical equation which is possible to predict the vertical concentration distribution of suspended sediments.

• Steel and Composite Structures
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• v.2 no.6
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• pp.461-474
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• 2002

This paper presents the experimental and theoretical results of SUS 304 stainless tubes with different diameter-to-thickness ratio (D/t ratio) subjected to pure bending creep. Pure bending creep occurs when a circular tube is bent to a desired moment and held at that moment for a period of time. It was found that the magnitudes of the creep curvature and ovalization of tube cross-section increase faster with a higher hold moment than that with a lower one. Due to continuously increasing curvature, the circular tubes eventually buckle. Finally, a theoretical form was proposed in this study so that it can be used to describe the relationship between the creep curvature and time. Theoretical simulations are compared with the experimental test data, showing that good agreement between the experimental and theoretical results has been achieved.