• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.2
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• pp.197-208
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• 2000

Choi et al./sup 1)/ presented the total Lagrangian formulation based upon the degenerated shell element. Geometrically correct formulation is developed by updating the direction of normal vectors and taking into account the second order rotation terms in the incremental displacement field. Assumed strain concept is adopted in order to overcome the shear locking phenomena and to eliminate the spurious zero energy mode. In this paper, for the ultimate strength analysis of stiffened shell structures considering effects of residual stresses, the return mapping algorithm based on the consistent elasto-plastic tangent modulus is applied to anisotropic shell structures. In addition, the load/displacement incremental scheme is adopted for non-linear F.E. analysis. Based on such methodology, the computer program is developed and numerical examples to demonstrate the accuracy and the effectiveness of the proposed shell element are presented and compared with the results in literatures.

• Journal of the Korean Geotechnical Society
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• v.20 no.7
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• pp.171-181
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• 2004

This study was conducted to explore the tensile strength models in granular soil at the full range of unsaturated state. Direct tension experiments were carried out with a newly developed direct tension technique. The measured experimental data were compared with theoretical models developed by Rumpf and Schubert for monosized ideal particulate solids at the unsaturated state. To do this, the soil-water characteristic curve obtained from a suction-saturation experiment was used to define the unsaturation state and the negative pore water pressure with different water content levels, which are important factors in theoretical tensile strength models. The nonlinear behavior of the tensile strength for unsaturated granular soil at the pendular state is appropriately simulated with Rumpf's model. For the funicular and capillary states, the predicted trend by Schubert's model is properly matched with the experimental data: tensile strength steadily increases and reaches a maximum value and then decreases until it reaches zero. This comparison supports the concept that the tensile strength of unsaturated real granular soil can be approximately simulated with theoretical models.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.2
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• pp.59-68
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• 1987

Several series of fracture tests were conducted to explore the fracture characteristics and to determine the fracture energy of concrete. A stable three-point bend test was employed to generate the load-deflection curves. The fracture energy may then be calculated from the area under the complete load-deflection curve. The initial notch-to-beam depth ratio (${\alpha}_0$/H) was varied from zero to 0.6. The prediction formula for the fracture energy of concrete is also derived and is found to depend on the tensile strength and aggregate size. The proposed fracture energy formula can be used for the fracture analysis of concrete structures. The present study also devises an equivalent crack length concept to predict the maximum failure loads of concrete beams. A simple formula for the equivalent crack length is proposed.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.2
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• pp.15-19
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• 2012

Wood wastes could be renewable resources by recycling as particleboard manufacturing or energy production. Particle board is the most common item of wood waste recycling and energy production from wood wastes has highlighted for energy recovery to reduce greenhouse gas generation in recent years. The aim of this study was to evaluate the environmental benefits of the processes for particle board manufacturing and energy production. The functional unit was one ton of wood wastes and the environmental impact was analyzed by life cycle assessment methodology. The result was that 112kg of carbon dioxide equivalent was produced from particle board manufacturing process and 382kg of carbon dioxide equivalent was produced from combined heat and power generation process. The concept of temporary biomass carbon storage was to applied to this study.

• Journal of the Korea Society for Simulation
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• v.20 no.1
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• pp.51-59
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• 2011

This paper is concerned with locomotion of dog-like quadruped robots that can adapt to various terrains, mainly dealing with implementation methods and characteristics of static and dynamic gaits. To this end, a 12-DOF robot is built in house, motional trajectories of its body and feet are generated mimicking biological life, and the corresponding leg joint angles are analytically obtained by inverse kinematics. Such joint angle data are then applied to the robot's ADAMS model for computer simulations so that the planned walk and trot gaits are both confirmed dynamically stable. However, contrary to the simulation results, previous trot patterns showed unstable behavior during experiments. This problem led us to analyze the reason, and in the course we discovered the importance of maximally utilizing the concept of WSM rather than ZMP and therefore reducing the gait period to secure the stability of dynamic gaits such as trot.

• Computational Structural Engineering
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• v.9 no.2
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• pp.121-131
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• 1996

This work proposes an optimality criteria applicable to the optimum design of plane frames subject to multiple behavioral constraints on member stresses and lateral displacements of nodes and also to side constraints on design variables. The method makes use of a first order approximation for both deflection and stress constraints instead of the zero order approximation based on the concept of FSD (fully stressed design). A redesign algorithm is derived from a mathematically rigorous method which uses the Newton-Raphson method to solve the system of nonlinear constraint equations and reduces the design space whenever minimum size restrictions become active. When applied to worked examples it proved more accurate and efficient, and it is often found that optimum designs are not fully stressed designs. This fact suggests that this rigorous method is worth what it claims for complicated computing and thus had better replace the crude stress ratio algorithm adopted by the majority of optimality criteria approaches. This is particularly true as long as we enjoy ever-increasing computing power at negligible costs.

• Nuclear Engineering and Technology
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• v.34 no.1
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• pp.42-59
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• 2002

In order to transmute long-lived radioactive nuclides such as transuranics(TRU), Tc-99, and I- l29 in LWR spent fuel, a preliminary conceptual design study has been performed for the accelerator driven subcritical reactor system, called HYPER(Hybrid Power Extraction Reactor) The core has a hybrid neutron energy spectrum: fast and thermal neutrons for the transmutation of TRU and fission products, respectively. TRU is loaded into the HYPER core as a TRU-Zr metal form because a metal type fuel has very good compatibility with the pyre- chemical process which retains the self-protection of transuranics at all times. On the other hand, Tc-99 and I-129 are loaded as pure technetium metal and sodium iodide, respectively. Pb-Bi is chosen as a primary coolant because Pb-Bi can be a good spallation target and produce a very hard neutron energy spectrum. As a result, the HYPER system does not have any independent spallation target system. 9Cr-2WVTa is used as a window material because an advanced ferritic/martensitic steel is known to have a good performance under a highly corrosive and radiation environment. The support ratios of the HYPER system are about 4∼5 for TRU, Tc-99, and I-129. Therefore, a radiologically clean nuclear power, i.e. zero net production of TRU, Tc-99 and I-129 can be achieved by combining 4 ∼5 LWRs with one HYPER system. In addition, the HYPER system, having good proliferation resistance and high nuclear waste transmutation capability, is believed to provide a breakthrough to the spent fuel problems the nuclear industry is faced with.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.4
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• pp.364-371
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• 2008

Ultrasonic waveguide sensor has been developed for under-sodium viewing of reactor internal structures of a sodium-cooled fast reactor (SFR). The structure design concept of a waveguide sensor assembly was suggested and evaluated for the application in SFR. A 10 m long ultrasonic waveguide sensor assembly has been manufactured and the experimental feasibility tests were carried out. The 10 m long distance propagation performance of zero-order antisymmetric $A_0$ Lamb wave has been verified. The feasibility of ultrasonic waveguide sensor has been demonstrated by the C-scanning resolution performance test.

• Journal of Global Scholars of Marketing Science
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• v.20 no.2
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• pp.219-230
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• 2010

Digital content makes big changes to our daily lives while bringing opportunities and challenges for companies. Creative firms integrate pictures, texts, videos, audios, and data by digitalization to develop new products or services and create digital experiences to promote their brands. Most articles on digital content contribute to the basic concept or development of marketing it in literature. Actually, compared with traditional value chains for common products or services, the digital content industry seems to have more potential value. Because quite a bit of digital content is free to the consumer, price is not necessarily perceived as an indicator of the quality or value of information (Rowley 2008). It becomes evident that a current theme in digital content is the issue of "value," and research on customers' perceived value of digital content is a necessity. This article argues that experiential value has an advantage in customers' evaluations of digital content. Two different but related contributions to the understanding of "value" of digital content are made here. First, based on the comparison of digital content with products and services, the article proposes two key characteristics that make experiential strategy available for digital content: intangibility and near-zero reproduction cost. On top of that, based on the discussion of the gap between company's idealized value and customer's perceived value, this article emphasizes that digital content prices and pricing of digital content is different from products and services. As a result of intangibility, prices may not reflect customer value. Moreover, the cost of digital content in the development stage may be very high while reproduction costs shrink dramatically. Moreover, because of the value gap mentioned before, the pricing polices vary for different digital contents. For example, flat price policy is generally used for movies and music (Magiera 2001; Netherby 2002), while for continuous demand, digital content such as online games and anti-virus programs involves a more complicated matter of utility and competitive price levels. Digital content companies have to explore various kinds of strategies to overcome this gap. Rethinking marketing solutions such as advertisements, images, and word-of-mouth and their effect on customers' perceived value becomes essential. China's digital content industry is becoming more and more globalized and drawing special attention from different countries and regions that have respective competitive advantages. The 2008-2009 Annual Report on the Development of China's Digital Content Industry (CCIDConsulting 2009) indicates that, with the driven power of domestic demand and governmental policy support, the country's digital content industry maintained a fast growth of some 30 percent in 2008, obviously indicating the initial stage of industry expansion. In China, anti-virus programs and other software programs which need to be updated use a quarter-based pricing policy. Customers can download a trial version for free and use it for six months or a year. If they want to use it longer, continuous payment is needed. They examine the excellence of the digital content during this trial period and decide whether to pay for continued usage. For China’s music and movie industries, as a result of initial development, experiential strategy has not been much applied, even though firms in other countries find the trial experience and explore important strategies(such as customers listening to music for several seconds for free before downloading it). For the above reasons, anti-virus program may be a representative for digital content industry in China and an exploratory study of the advantage of experiential value in customer's perceived value of digital content is done in the anti-virus market of China. In order to enhance the reliability of the survey data, this study focused on people who were experienced users of anti-virus programs. The empirical results revealed that experiential value has a positive effect on customers' perceived value of digital content. In other words, because digital content is intangible and the reproduction costs are nearly zero, customers' evaluations are based heavily on their experience. Moreover, image and word-of-mouth do not have a positive effect on perceived value, only on experiential value. That is to say, a digital content value chain is different from that of a general product or service. Experiential value has a notable advantage and mediates the effect of image and word-of-mouth on perceived value. The results of this study help provide an understanding of why free digital content downloads exist in developing countries. Customers can perceive the value of digital content only by using and experiencing it. This is also why such governments support the development of digital content. Other developing countries whose digital content business is also in the beginning stage can make use of the suggestions here. Moreover, based on the advantage of experiential strategy, companies should make more of an effort to invest in customers' experience. As a result of the characteristics and value gap of digital content, customers perceive more value in the intangible digital content only by experiencing what they really want. Moreover, because of the near-zero reproduction costs, companies can perhaps use experiential strategy to enhance customer understanding of digital content.

• Strategy21
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• s.46
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• pp.205-238
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• 2020

The origin of mission command can be traced to the era of the Prussian military reforms led by General Gerhard von Scharnhorst after defeats in battle of Jena and Auerstadt in 1806 against Napoleon I. Mission Command is the conduct of military operations through decentralized execution based upon mission-type orders. Commanders issue mission-type orders focused on the purpose of the operation rather than details of how to perform assigned tasks. The mission command has become the command philosophy of the German military and recently many countries in the west accept it as a command philosophy. This study compare and analyze the Battle of St. Vincent and the Battle of Jutland to make sure if the army-initiated mission commands were also useful for the navy. From the late 18th century, represented by the era of Nelson, Royal navy changed from the inherited rigid command culture to guaranteeing the disciplined initiative of its subordinate commanders. In the Battle of St. Vincent in 1797, Nelson acted contrary to the commander's orders at the crucial moment, which gave Britain a decisive victory. On the contrary more than 100 years later, the command culture of the Royal navy changed into a centralized command culture. In the Battle of Jutland in 1916, Royal Navy couldn't win because the rigid command culture did not guarantee initiative of subordinate commanders and subordinate commander's passive attitude of waiting for the commander's instructions even at critical moments. Therefore, a mission command that guarantees the initiative of subordinate commanders is a useful concept even in the navy because it makes subordinate commanders to take full advantage of a sudden change in battle. Today's advanced information and communication technologies have raised questions about mission command. But even advanced technology can't completely eliminate the fundamental nature of the war-the fog of war. War is chaotic and unpredictable. In the flood of lots of informations, senior commander's judgement is not always right because he(she) is also human, he(she) can make mistakes. In the age of informatization, mission command is still effective because it involves increasing interaction and synergy between senior and subordinate commanders by ensuring their independence. Therefore ROK navy also needs to activate mission command. ROK navy must dismantle the zero-defect mentality and apply from educations as Prussian did to establish a mission command culture.