• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.320-323
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• 2008

In this study, a macroscopic approach was carried out to gain insight into the bending mechanism of metallic sandwich plates. Shear force-punch stroke curves for various clearances were analytically derived for mild steel (CSP 1N) sandwich plates with the total thickness of 3 mm and 0.5 mm face sheets. As the clearance increases, shear force of the inner structures and sensitivity of punch stroke decrease. These data are useful to derive a criterion of judgment for core shear failure and de-bonding failure during U-bending.

• Geomechanics and Engineering
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• v.18 no.4
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• pp.391-406
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• 2019

The aim of this paper was to study the influence of the footing shape and the effect of the roughness of the foundation base on the bearing capacity of shallow foundations on rock masses. For this purpose the finite difference method was used to analyze the bearing capacity of various types and states of rock masses under the assumption of Hoek-Brown failure criterion, for both plane strain and axisymmetric model, and considering smooth and rough interface. The results were analyzed based on a sensitivity study of four varying parameters: foundation width, rock material constant (mo), uniaxial compressive strength and geological strength index. Knowing how each parameter influences the bearing capacity depending on the footing shape (circular vs strip footing) and the footing base interface roughness (smooth vs rough), two correlation factors were developed to estimate the percentage increase of the ultimate bearing capacity as a function of the footing shape and the roughness of the footing base interface.

• Nuclear Engineering and Technology
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• v.51 no.5
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• pp.1272-1278
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• 2019

A lumped kinetic modeling platform is developed to investigate the coupled nuclear/thermo-fluid features of the closed natural circulation loop in a low power lead cooled fast reactor. This coolant material serves a reliable choice with noticeable thermo-physical safety characteristics in terms of natural convection. Boussienesq approximation is resorted to appropriately reduce the governing partial differential equations (PDEs) for the fluid flow into a set of ordinary differential equations (ODEs). As a main contributing step, the coolant circulation speed is accordingly correlated to the loop operational power and temperature levels. Further temporal analysis and control synthesis activities may thus be carried out within a more consistent state space framework. Nyquist stability criterion is thereafter employed to carry out a sensitivity analysis for the system stability at various power and heat sink temperature levels and results confirm a widely stable natural circulation loop.

• Bulletin of the Society of Naval Architects of Korea
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• v.21 no.4
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• pp.1-9
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• 1984

This study is concerned with the economic aspects of $125,000m^3$ class LNG carriers with different propulsion plant such as conventional steam turbine and slow speed diesel engine with reliquefaction plant. The ship's speed and L/B ratio were optimized with criterion of required freight rate(RFR) by using the PROCAL computer program package. In order to investigate the effect of fuel oil price, round trip distance and boil-off rate on the RFR and the optimum speed, sensitivity analysis were also performed.

• Structural Engineering and Mechanics
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• v.91 no.3
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• pp.239-250
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• 2024

With the aim to provide better predication about fracture behavior, a numerical simulating strategy based on the rigid spring model is proposed for reinforced concrete (RC) structures in this study. According to the proposed strategy, concrete is partitioned into a series of irregular rigid blocks based on the Voronoi diagram, which are connected by interface springs. Steel bars are simulated by bar elements, and the bond slip element is defined at bar element nodes to describe the interaction between reinforcement and concrete. A concrete damage evolution model based on the separation criterion is adopted to describe the weakening process of interface spring between adjacent blocks, while a nonlinear bond slip model is introduced to simulate the synergy behaviour of reinforced steel bars and concrete. In the damage evolution model of concrete, the influence of compressive stress perpendicular to the interface on the shear strength is considered. To check the effectiveness and applicability of the proposed modelling, experimental and numerical studies about a simply-supported RC beam and the two-notched concrete plates in Nooru-Mohamed's experiment are conducted, and the grid sensitivity are investigated.

• Journal of Preventive Medicine and Public Health
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• v.29 no.3 s.54
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• pp.507-519
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• 1996

The objectives of this study are to investigate the prevalence of occupation related carpal tunnel syndrome(CTS) among workers in a condom industry : to analyse the sensitivity and specificity of clinical signs or symptoms such as hand diagram, Tinel's sign and Phalen's sign in carpal tunnel syndrome : and to test vibration threshold test using audiometry as a technically easy and noninvasive method in the diagnosis of carpal tunnel syndrome in stead of nerve conduction velocity (NCV). The study group was divided into exposed group(39 cases) and non-exposed group(48 cases) based on whether or not excessive use of wrist movements exsist. 1. There are stastically significant differences in symptoms and signs of carpal tunnel syndrome such as hand diagram, Tinel's sign and Phalen's sign between exposed and non-exposed group(p<0.05). 2. Six cases(9 hands) were comfirmed as carpal tunnel syndrome by NCV. Five cases(7 hands) belonged to exposed group, 1 case(2 hands) to nonexposed group. As there are significant differences in prevalence of carpal tunnel syndrome between two groups(p<0.05), excessive use of wrist in occupation is a risk factor of carpal tunnel syndrome. 3. When we use NCV as a gold standard in the diagnosis of carpal tunnel syndrome, sensitivity and specificity of hand diagram, Tinel's sign and Phalen's sign is as followed; hand diagram , sensitivity 88.9%, specificity 84.2% Tinel's sign ; sensitivity 55.6%, specificity 72.8% Phalen's sign ; sensitivity 14.3%, specificity 88.4%. Among above clinical signs and symptoms, hand diagram is the best clinical screening test. 4. The differences of vibration threshold between median and ulnar nerve at the same time are useful in the diagnosis of carpal tunnel syndrome but the time change of vibration threshold of median nerve over time are not sensitive enough. It is concluded that vibration threshold between median and ulnar nerve at the same time can be used as a supplementary or alternative criterion to indicate that the nerve dysfunction is located in the carpal tunnel.

• Journal of Korean Society of Steel Construction
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• v.14 no.6
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• pp.783-791
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• 2002

An improved formulation for multi-objective optimization was proposed. This formulation was applied to steel seismic loads. The multi-objective optimization problem was formulated with minimum structural weight, maximum strstability. The global criterion method was employed to find a rational solution closest to the ideal solution for the optimization problem using standard steel profile, To efficiently solve the optimization problem, the decomposition meth both system-level and element-level was used. In addition, various techniques including efficient reanalysis technique intermediate variables and sensitivity analysis using an automatic differentiation(AD) were incorporated. Moreover the reamong section properties fitted to the section profile used in order to link the system level and the element level. From numerical investigation, it could be stated that the proposed method will lead to the more rational design compared with one.

• Journal of the Korea Concrete Institute
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• v.21 no.6
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• pp.781-788
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• 2009

Mechanical properties of steel-concrete interface were evaluated on the basis of experimental observations. The properties included bond strength, unbounded and bonded friction angles, residual level of friction angle, mode I fracture energy, mode II bonded fracture energy and unbonded slip-friction energy under different levels of normal stress, and shape parameters to define geometrical shape of failure envelope. For this purpose, a typical type of constitutive model of describing steel-concrete interface behavior was presented based on a hyperbolic three-parameter Mohr-Coulomb type failure criterion. The constitutive model depicts the strong dependency of interface behavior on bonding condition of interface, bonded or unbounded. Values of the interface parameters were determined through interpretation of experimental results, geometry of failure envelope and sensitivity analysis. Nonlinear finite element analysis that incorporates steel-concrete interface as well as material nonlinearities of concrete and steel were performed to predict the experimental results.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.18-23
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• 2008

Enterprise's executives who believe methodologies the theories prescribe consideration of consumer as rational and reasonable behavior. However, by recent investigation, consideration of consumer can be defined behavior that is occurred by sensibility. These consideration of consumer affect to a process that purchase a product, consumer's purchase decision process. Consumer make a purchasing decision with sensible criterion, respective of quality after all rather than various rational criterion like price, efficiency and usefulness. Brand image has sensible value to thought in the mind about a product and affect to purchase products. Hence building brand image through positive sensitivity is significant point in strengthening. Research from this point of view makes a content advance with improving product process along storytelling method which kind of affective, sensible communication way as a factor of strengthening brand image.

• The Journal of the Korea Contents Association
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• v.13 no.4
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• pp.389-398
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• 2013

This study aims to support rational security investment decision making through prioritizing on operational level of management measures strategically, in carrying out industrial security activities. For this, AHP survey is conducted against industrial security professionals and analyzed. Thereafter, the importance and the priority of industrial security management measures are determined. As a result, in a comparison evaluation among the criteria, 'ICT service management' represents the highest weight (0.54). And the sub-criteria could be divided into three groups (Group I, II, III), depending on their importance. The sensitivity analysis results show that if the weight of the criterion, 'ICT systems/networks access control' is doubled, the sub-criteria, 'O/S access control', 'application access control', and 'wired/wireless network access control' are enter into top rank group. In case of the criterion, 'physical/environmental security' is doubled, the sub-criteria, 'protection zoning/access control' and 'disaster prevention on business equipment/counter-terrorism' are enter into the top rank group, 'securing utilities' is enter into the mid rank group.