• Journal of Korean Society of Steel Construction
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• v.15 no.6 s.67
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• pp.661-672
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• 2003

The advanced analysis and optimal design of semi-rigid frame were presented. Advanced analysis can predict the combined nonlinear effects of connection, geometry, and material on the behavior and strength of semi-rigid frames. The Kishi-Chen power model was used to describe the nonlinear behavior of semi-rigid connections. Geometric nonlinearity was determined using stability functions. On the other hand, material nonlinearity was determined using the Column Research Council (CRC) tangent modulus and parabolic function. The direct search method proposed by Choi and Kim was used as optimization technique. The member with the largest unit value evaluated using the LRFD interaction equation was replaced one by one with an adjacent larger member selected from the database. The objective function was assumed as the weight of steel frame, with the constraint functions accounting for load-carrying capacities, deflections. inter-story drifts, and ductility requirement. Member sizes determined by the proposed method were compared with those derived using the conventional LRFD method.

• Structural Engineering and Mechanics
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• v.2 no.4
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• pp.313-326
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• 1994

Some structures under the action of some specific loads can be treated as consisting of rigid and deformable parts. The paper presents a way to include rigid elements into a finite element model accounting for geometrical and material nonlinearities. Lagrange multipliers technique is used to derive equations of motion for the coupled deformable-rigid system. Solution algorithm based on the elimination of the Lagrangian multipliers and dependent kinematic unknowns at the element level is described. A follow-up paper(Rojek and Kleiber 1993) complements the discussion by giving details of the computer implementation and presenting some realistic test examples.

• Magazine of the Korean Society of Agricultural Engineers
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• v.33 no.4
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• pp.61-72
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• 1991

A lumped deterministic model(DAWAST model) was developed to predict the daily streamflow. Since the streamflow is dominantly determined by the soil water storage in the watershed, the model takes the soil water accounting procedures which are based on three linear reservoirs representing the surface, unsaturated, and saturated soil layers. The variation of soil water storage in the unsaturated zone is traced from the soil water balance on a daily basis. DAWAST model consists of 5 parameters for water balance and 3 parameters for routing. A optimization technique of unconstrained nonlinear Simplex method was applied for the determination of the optimal parameters for water balance. Model verification was carried out to the 7 hydrologic watersheds with areas of 5.89-7,126km$^2$ and the results were generally satisfactory. The daily streamflow can be arbitrarily simulated with the input data of daily rainfall and pan evaporation by the DAWAST model at the station where the observed streamflow data of short periods are available to calibrate the model parameters.

• Structural Engineering and Mechanics
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• v.12 no.1
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• pp.51-69
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• 2001

Whereas the potential of static inelastic analysis methods is recognised in earthquake design and assessment, especially in contrast with elastic analysis under scaled forces, they have inherent shortcomings. In this paper, critical issues in the application of inelastic static (pushover) analysis are discussed and their effect on the obtained results appraised. Areas of possible developments that would render the method more applicable to the prediction of dynamic response are explored. New developments towards a fully adaptive pushover method accounting for spread of inelasticity, geometric nonlinearity, full multi-modal, spectral amplification and period elongation, within a framework of fibre modelling of materials, are discussed and preliminary results are given. These developments lead to static analysis results that are closer than ever to inelastic time-history analysis. It is concluded that there is great scope for improvements of this simple and powerful technique that would increase confidence in its employment as the primary tool for seismic analysis in practice.

• Korean Management Science Review
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• v.29 no.2
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• pp.167-184
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• 2012

Business diversification is inevitable to survive under the current competitive business environments. The advent of new businesses makes corporate governance more complicated through corporate combinations. Recent introduction of new accounting standard, International Financial Reporting Standards(IFRS), accelerates the need for corporate governance analysis. This study analyses the complex corporate governance system and its relation to the business performance using social network analysis. Corporate inter-governance networks can be visualized easily in a social network diagram. 552 corporate governance data are empirically analysed in the Korean stock market. The changes in In-Degree between networks are positively related with the changes in corporate sales volume. We can find the same results using operating profits as corporate performance proxy. The results show that social network analysis technique can be applied to investments in the stock markets.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.73-87
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• 1998

Recently the international transfer pricing became the most popular topic in accounting of the research as well as of the practice. Modern corporations have been experiencing a lot of changes in managerial control technique as their scale and scope of activities grows and the environment in which they operate changes rapidly. If there are internal transactions in a decentralized firm, the necessity of coordination among the divisions is inevitable. Transfer pricing in a decentalized company provides an excellent example of the coordinating role of information. One of the most important reason for a form to have a decentalized structure is the improved decision making at the lower level due to better access to information. International transfer pricing is not merely a problem of pricing but coordination of transfers and other collective or individual actions to derive rents from intergration. Such coordination can be achived through the performance evaluation scheme which is partly based upon transfer price.

• Journal of applied mathematics & informatics
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• v.14 no.1_2
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• pp.353-363
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• 2004

The purpose of this paper is to present a model to design the layout of the user interface components that handles many numbers of qualitative factors. An alternate rating system is also proposed for the closeness relationship ratings between the various pairs of components evaluated by using GOMS (goals, operators, methods and selection rules) technique. The proposed model is applied to the design of the part of the user interface in order to obtain the best layout of the components. The results of the proposed model are compared with that of an existing model, which handles single qualitative factor applied to obtain the layouts of user interface components.

• Ceramist
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• v.21 no.2
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• pp.75-82
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• 2018

In the photovoltaics (PV) industry, there were many efforts to reduce the cost of production with high efficiency. The single most important cost factor in silicon technology is the wafer, accounting presently for ~35% of the module cost. it was already shown that the solar cell efficiency can be maintained up to the thickness range of $40-60{\mu}m$. The direct production of ultra-thin silicon wafer is very attractive and numerous different techniques, such as electrochemical process, ion implantation, and epitaxial growth, have been proposed and developed in many academic and industrial laboratories.

• Journal of Chest Surgery
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• v.25 no.1
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• pp.105-111
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• 1992

Total atherosclerotic obstruction of the juxtarenal abdominal aorta is a relatively rarely encountered form of atherosclerotic vascsular disease, accounting for less than 5% of all arterial obstrutive disease. We have encountered two patients with such lesions, both of whom were admitted for intermittent claudication of the lower extremities and symptoms of vascular ischemia. Digital subtraction angiography[DSA] was performed on both patients, the results of which revealed total obstruction of the aorta just inferior to the renal arteries without involving the latter. Operative technique involved the use of the sup-raceliac aorta as the site of proximal anastomosis of aortofemoral bypass followed by a fem-orofemoral bypass graft with Smm sized Woven Dacron[Vascutek] through a subcutaneous tunnel within the retroperitoneal space. Both patients experienced restoration of blood flow distal to the obstruction postoperatively without any complications, and OPD follow-up one month postoperatively and postoperative DSA showed evidence of continued graft patency with persistent symptomatic improvement.

• Journal of Korean Foot and Ankle Society
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• v.21 no.2
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• pp.75-78
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• 2017

Tendoachilles rupture has recently seen an increase in frequency, accounting for up to 40% of all tendon ruptures. However, an acute segmental rupture of the Achilles tendon is very rare with only one case caused by predisposing factors, such as steroid injection. In this report, we highlight an unusual clinical presentation of a segmental rupture of the Achilles tendon without any underling predisposing factor and without direct trauma. Herein, we discuss its mechanism. Twelve months after surgical repair with open technique, this patient became fully functional again in daily activity.