• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.1
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• pp.48-54
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• 2008

MMORPGs may involve a great number of concurrent players, and those servers usually have to manage hundred, or even thousands of avatars co-existing in the same virtual world. So if failing to send a command or an event message, or sending it too late may cause damages to the avatar evolution(death, injury, loss of resources), and may result in unjustified penalties for the player. Many policies could be defined to realize a ranking evaluation of available servers. Unfortunately, due to the highly dynamic characteristics of server loads and network performances, any optimal allocation would soon become sub-optimal. In order to solve those problems we propose the "time-interval based fairness partitioning method"(TIP). TIP will distribute the avatar to the game server equally with time-interval in order to avoid the problems form the unfairness of game servers load.

• Journal of the Korea Concrete Institute
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• v.27 no.2
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• pp.177-184
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• 2015

In order to use the high-volume slag cement as a construction materials, a proper activator which can improve the latent hydraulic reactivity is required. The dissolved aluminum silicon ions from ground granulated blast furnace slag (GGBFS) react with sulfate ions to form ettringite. The proper formation of ettringite can increase the early-age strength of high-volume GGBFS (80%) cement. The aim of this study is to investigate the hydration properties with sulfate activators (sodium sulfate, anhydrite). In this paper, the effects of $Na_2SO_4$ and $CaSO_4$ on setting, compressive strength, hydration, micro-structure were investigated in high-volume GGBFS cement and compared with those of without activator. Test results indicate that equivalent $SO_3$ content of 3~5% improve the early-age hydration properties such as compressive strength, heat evolution rate, micro-pore structure in high-volume GGBFS cement.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.39.4-40
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• 2016

We aim to investigate formation of satellite sub-galactic structures around isolated dwarf galaxies using cosmological hydrodynamic zoom simulations. For this, we modify a cosmological hydrodynamic code, GADGET-3, in a way that includes gas cooling down to T~10K, gas heating by universal reionization when z < 8.9, UV shielding for high density regions of $n_{shield}$ > $0.014cm^{-3}$, star formation in the dense regions ($n_H$ > $100cm^{-3}$), and supernova feedback. To get good statistics, we perform three different simulations for different target galaxies of the same mass of ${\sim}10^{10}M_{sun}$. Each simulation starts in a cubic box of a side length of 1Mpc/h with 17 million particles from z = 49. The mass of dark matter (DM) and gas particle is $M_{DM}=4.1{\times}10^3M_{sun}$ and $M_{gas}=7.9{\times}10^2M_{sun}$, respectively, thus each satellite sub-galactic structure can be resolved with more than hundreds or thousands particles. We analyze total 90 sub-galactic structures that have formed outside of the main halos but infall the main halos. We found that 1) mini halos that interact more with the other mini halos tend to accrete the more mass, 2) mini halos that interact more before the reionization tend to form more stars, 3) mini halos with the more interaction tend to approach closer to the galactic center and have the lower orbital circularity, 4) survivals even in the strong tidal fields evolve baryon dominated system, such as globular clusters.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.3
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• pp.259-259
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• 2003

Genetic algorithms using a Process of genetic evolution of an organism are appropriate for hard problems that have not been solved by any deterministic method. Up to now, the controller design method has been made with the frequency dependent specification but the design method with the time specification has gotten little progress. In this paper, we study the controller design to satisfy the performance of a plant using the generalized Manabe standard form. When dealing with a controller design in the case of two parameter configurations, there are some situations that neither a known pseudo inverse technique nor the inverse method can be applicable. In this case, we propose two methods of designing a controller by the gradient algorithm and the new pseudo inverse method so that the desired closed polynomials are either equalized to or approximated to the designed polynomial. Design methods of the proposed controller are implemented in Java.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.1
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• pp.117-121
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• 1999

Although anejaculation is a relatively uncommon occurrence in the general population, over 12,000 new cases are reported annually. Anejaculation may result from spinal cord injury, retroperitoneal lymph node dissection, diabetes mellitus, transverse myelitis, multiple sclerosis, or psychogenic disorders. At least 30% of men with this problem are or will be married and many will seek help to remedy their infertile state. The evolution of technique and instrumentation over the last 30 years has made electroejaculation an accessible and acceptable form of therapy. Recent successes in inducing ejaculation by means of rectal probe electrostimulation or vibratory stimulation combined with assisted reproductive techniques, such as zygote intrafallopian transfer (ZIFT), gamete intrafallopian transfer (GIFT), and in vitro fertilization (IVF), have provided these men means of producing their own biologic offspring. We have experienced a successful pregnancy with electroejaculation and in vitro fertilization in a infertile patient whose husband had an ejaculatory disturbance due to a spinal cord injury. So we report this case with a brief review of literatures.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.23-29
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• 2020

Since the movements of a machine are driven by a certain principle, there is a fundamental principle that governs the movement of the machine, no matter how complex and diverse it may be. Autonomous movements are a way to avoid repetition, to approach more humane and more natural factors. That's all the more so when it comes to original movements, not cloning. So now, the dynamics of the machine are more multi-sensory by human participation. It is challenging the potential to be expressed and is gradually expanding its sphere of expression in the boundaries of fact and cloning. Theo Jansen's works have changed from period to period to adapt to different circumstances, indicating that his decades-long work has continued to evolve from early to present. The evolution's focus, among other things, can be seen as having the same source of circular motion and horizontal reciprocating motion, which are repeated from the principle of organic coupling between the parts that make up the object.

• Nuclear Engineering and Technology
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• v.45 no.2
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• pp.211-218
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• 2013

Large quantities of irradiated graphite waste from graphite-moderated nuclear reactors exist and are expected to increase in the case of High Temperature Reactor (HTR) deployment [1,2]. This situation indicates the need for a graphite waste management strategy. Of greatest concern for long-term disposal of irradiated graphite is carbon-14 ($^{14}C$), with a half-life of 5730 years. Fachinger et al. [2] have demonstrated that thermal treatment of irradiated graphite removes a significant fraction of the $^{14}C$, which tends to be concentrated on the graphite surface. During thermal treatment, graphite surface carbon atoms interact with naturally adsorbed oxygen complexes to create $CO_x$ gases, i.e. "gasify" graphite. The effectiveness of this process is highly dependent on the availability of adsorbed oxygen compounds. The quantity and form of adsorbed oxygen complexes in pre- and post-irradiated graphite were studied using Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Xray Photoelectron Spectroscopy (XPS) in an effort to better understand the gasification process and to apply that understanding to process optimization. Adsorbed oxygen fragments were detected on both irradiated and unirradiated graphite; however, carbon-oxygen bonds were identified only on the irradiated material. This difference is likely due to a large number of carbon active sites associated with the higher lattice disorder resulting from irradiation. Results of XPS analysis also indicated the potential bonding structures of the oxygen fragments removed during surface impingement. Ester- and carboxyl-like structures were predominant among the identified oxygen-containing fragments. The indicated structures are consistent with those characterized by Fanning and Vannice [3] and later incorporated into an oxidation kinetics model by El-Genk and Tournier [4]. Based on the predicted desorption mechanisms of carbon oxides from the identified compounds, it is expected that a majority of the graphite should gasify as carbon monoxide (CO) rather than carbon dioxide ($CO_2$). Therefore, to optimize the efficiency of thermal treatment the graphite should be heated to temperatures above the surface decomposition temperature increasing the evolution of CO [4].

• Journal of Korea Water Resources Association
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• v.44 no.6
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• pp.429-438
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• 2011

In order to simulate a free surface flow in a trench channel, a three-dimensional incompressible unsteady Reynolds-averaged Navier-Stokes (RANS) equations are closed with the ${\kappa}-{\epsilon}$ model. The artificial compressibility (AC) method is used. Because the pressure fields can be coupled directly with the velocity fields, the incompressible Navier-Stokes (INS) equations can be solved for the unknown variables such as velocity components and pressure. The governing equations are discretized in a conservation form using a second order accurate finite volume method on non-staggered grids. In order to prevent the oscillatory behavior of computed solutions known as odd-even decoupling, an artificial dissipation using the flux-difference splitting upwind scheme is applied. To enhance the efficiency and robustness of the numerical algorithm, the implicit method of the Beam and Warming method is employed. The treatment of the free surface, so-called interface-tracking method, is proposed using the free surface evolution equation and the kinematic free surface boundary conditions at the free surface instead of the dynamic free surface boundary condition. AC method in this paper can be applied only to the hydrodynamic pressure using the decomposition into hydrostatic pressure and hydrodynamic pressure components. In this study, the boundary-fitted grids are used and advanced each time the free surface moved. The accuracy of our RANS solver is compared with the laboratory experimental and numerical data for a fully turbulent shallow-water trench flow. The algorithm yields practically identical velocity profiles that are in good overall agreement with the laboratory experimental measurement for the turbulent flow.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.4
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• pp.454-476
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• 2009

The purpose of this paper is to examine relation between trust building level and linkages's spatial characteristics on the logistics & storage industry of Busan. As a result, First, long-term & repeated interaction, information sharing & reciprocity, and interdependence & asset specificity have an important effect upon the micro trust which implies the highest trust. Proximity and uncertainty impact on the meso trust, the trust of middle level. Culture, norm, and formal institution of firms affect the macro trust, the lowest level of trust. Second, the micro, the meso, and the macro trusts mainly form in the local scale where spatial proximity is great. The higher the trust building levels become, the more spatial dimensions by linkage expand to national and international dimension, respectively. Third, these results appear more clearly in the output linkage than input linkage, in the service areas-many firm, in the horizontal linkage than vertical linkage, in the advanced evolution phases of firm connection, and in the supply chain management than outsourcing.

• The KIPS Transactions:PartD
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• v.8D no.6
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• pp.853-860
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• 2001

In the object-oriented software development, redesigning of classes and reorganizing of class hierarchy structures should be necessary to reduce many of the headaches of object-oriented software design and maintenance. To support this task, in this paper, we propose a theoretical foundation for class hierarchy reorganizations that is relatively complete, correct, formal and easy to understand and use. We introduce the flattened class hierarchy that characterizes the class hierarchy structures in object-oriented software evolution. And we also present an algorithm which transforms a given class hierarchy into the normalized form. The flattened class hierarchy helps us map the inheritance and aggregation paths in a class hierarchy to paths in an object hierarchy that is an instance of the class hierarchy. By applying the algorithm into a given class hierarchy, we can make a new, object-preserved, and flattened class hierarchy that is the cornerstone for reorganization of class hierarchy structure and plays an important role as a bridge on the incremental evolutionary changes and reuse of object-oriented software to reorganize class hierarchies.