• Korean Journal of Construction Engineering and Management
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• v.17 no.5
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• pp.78-88
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• 2016

Recently BIM technology has been expanded for using in construction project. However its spread has been delayed than the initial expectations, due to the high-cost of BIM infrastructure development, the lack of regulations, the lack of process and so forth. In design phase, especially, collaboration based on BIM system has being a key factor for successful next generation building project. Through the analysis of current research trend about IT technologies, virtualization and BIM service, data exchange such as drawing, 3D model, object data, properties using cloud computing and virtual server system is defined as a most successful solution. In various industrial fields, cloud computing technology is utilized as a promising solution which can reduce time and cost of hardware infrastructure. Among the cloud computing technology, VDI is receiving a great deal of attention from it market as an essential part cloud computing. VDI enables to host multiple individual virtual machines by using hypervisor. It has an advantage to easy main device management. Therefore, this study implements a step-by-step user's DaaS by analyzing the desktop resource data of the workers from Pre-design phase to Schematic design, Design develop and Construction design phase. It also develops BIM environment based on test of BIM modeler and designers in architectural design firm. The goal of the study is to enable the cloud computing BIM server. It provides cost saving, high-performance quality of working environment and cooperation's convenience and high security when doing BIM work in small and medium sized architectural design firm.

• Composites Research
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• v.29 no.1
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• pp.40-44
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• 2016

Nuclear fuel cladding used in a nuclear power plant must possess superior oxidation resistance in the coolant atmosphere of high temperature/high pressure. However, as was the case for the critical LOCA (loss-of-coolant accident) accident that took place in the Fukushima disaster, there is a risk of hydrogen explosion when the nuclear fuel cladding and steam reacts dramatically to cause a rapid high-temperature oxidation accompanied by generation of a huge amount of hydrogen. Hence, an active search is ongoing for an alternative material to be used for manufacturing of nuclear fuel cladding. Studies are currently aimed at improving the safety of this cladding. In particular, ceramic-based nuclear fuel cladding, such as SiC, is receiving much attention due to the excellent radiation resistance, high strength, chemical durability against oxidation and corrosion, and excellent thermal conduction of ceramics. In the present study, cladding with $SiC_f/SiC$ protective films was fabricated using a process that forms a matrix phase by polymer impregnation of polycarbosilane (PCS) after filament-winding the SiC fiber onto an existing Zry-4 cladding tube. It is analyzed the oxidation and microstructure of the metal cladding with $SiC_f/SiC$ composite protective films using a drop tube furnace for thermal shock test.

• Ocean Systems Engineering
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• v.6 no.1
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• pp.23-60
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• 2016

The major objective of this study was to develop further understanding of 3D nearshore hydrodynamics under a variety of wave and tidal forcing conditions. The main tool used was a comprehensive 3D numerical model - combining the flow module of Delft3D with the WAVE solver of XBeach - of nearshore hydro- and morphodynamics that can simulate flow, sediment transport, and morphological evolution. Surf-swash zone hydrodynamics were modeled using the 3D Navier-Stokes equations, combined with various turbulence models (${\kappa}-{\varepsilon}$, ${\kappa}-L$, ATM and H-LES). Sediment transport and resulting foreshore profile changes were approximated using different sediment transport relations that consider both bed- and suspended-load transport of non-cohesive sediments. The numerical set-up was tested against field data, with good agreement found. Different numerical experiments under a range of bed characteristics and incident wave and tidal conditions were run to test the model's capability to reproduce 3D flow, wave propagation, sediment transport and morphodynamics in the nearshore at the field scale. The results were interpreted according to existing understanding of surf and swash zone processes. Our numerical experiments confirm that the angle between the crest line of the approaching wave and the shoreline defines the direction and strength of the longshore current, while the longshore current velocity varies across the nearshore zone. The model simulates the undertow, hydraulic cell and rip-current patterns generated by radiation stresses and longshore variability in wave heights. Numerical results show that a non-uniform seabed is crucial for generation of rip currents in the nearshore (when bed slope is uniform, rips are not generated). Increasing the wave height increases the peaks of eddy viscosity and TKE (turbulent kinetic energy), while increasing the tidal amplitude reduces these peaks. Wave and tide interaction has most striking effects on the foreshore profile with the formation of the intertidal bar. High values of eddy viscosity, TKE and wave set-up are spread offshore for coarser grain sizes. Beach profile steepness modifies the nearshore circulation pattern, significantly enhancing the vertical component of the flow. The local recirculation within the longshore current in the inshore region causes a transient offshore shift and strengthening of the longshore current. Overall, the analysis shows that, with reasonable hypotheses, it is possible to simulate the nearshore hydrodynamics subjected to oceanic forcing, consistent with existing understanding of this area. Part II of this work presents 3D nearshore morphodynamics induced by the tides and waves.

• Journal of Korea Foresty Energy
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• v.22 no.3
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• pp.1-10
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• 2003

The successional status and potential natural vegetation were examined in the natural deciduous forest in Mt. Chombong area. The examination was based on the subsequent process of generation replacement by understory saplings for the dominant canopy trees within 106 20mx20m square sample plots. The transition matrix model, which was modified from mathematical theory of Markov chain, was employed to analyze the successional status of the study forest. The model suggests that study forest is still seral, and it is considered to be more than 500 years away from the steady state or climax in terms of species composition. The simulations predict a remarkable decrease in the proportion of species composition of the present dominant Quercus mongolica and Kalopanax pictus from current 42.6% and 8.1% to less than 13.3% and 0.5%, respectively, at the steady state. On the contrary, the proportions of Abies holophylla, Acer mono, Fraxinus mandshurica, Tilia amurensis, and Acer pseudo-sieboldianum will increase at the steady state. The change of predicted composition ratio was generally coincide with the result of tolerance index to be compared with the study model. The hypothesis and sensitivity of the model were also discussed to evaluate the applicability to the real situation. The overall results indicated that the present dynamics of the forest must reflect the seral state due to previous disturbance mainly by human related interference.

• Journal of Korean Academy of Nursing
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• v.28 no.1
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• pp.70-80
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• 1998

This study is designed to contribute to the nursing intervention of adolescent domestic violence victims by describing specifically what they go through and on this basis work out a grounded theory on the adolescent's experience in domestic violence. The data were analyzed in the framework of grounded theory as mapped out by Strauss & Corbin(1990). The major findings of this research are as follows : The core category was found to be the the adaptation of "Joyudeum" or “Straight jacketing”. The sub-categories identified in the process of grounded data analysis were 'menacing', 'being harassed', 'being pressed', 'being attacked', 'being strapped', 'being filled with anger'. 'getting angry', 'being oppressed', 'being strained', 'becoming hard', 'endurance', 'regulation', 'seriousness'. 'repitition'. 'being helpful', 'dependence', 'thinking oriented', 'blowing off', 'going astray', 'self-deprecating', 'shaking off', 'covering up', 'governing', 'being devoted', 'performing', 'being transformed'. 'bolting', 'being shaken', 'withdrawing', 'disliking', 'bitterness'. These categories were again grouped into 13 categories including 'threatening'. 'straight jacketing', 'tolerance', 'violence', 'supporter', 'supporting type', 'thinking oriented'. 'impulsive response', 'self-controlled', 'response', 'self-reliance', 'wandering', 'withdrawal' and pain'. Of these the five sub-categories 'being filled with anger'. 'getting angry', 'being oppressed', 'being strained', 'becoming hard' were grouped into a core category "straight jacketing". Those adolescents brought up in a violent family go through three stages of the adaptation of "straight Jacketing". that is, generation, response and adaptation. The following four theses were confirmed on the basis of repetitive relations : 1) If a subject's tolerance is strong, the episodes of the violence are frequent and serious, with the resulting straight jacketing being stronger but the subject's supporter is highly mature, the supporting type is concrete and the thinking oriented is wishful, the responses to the straight jacketing result in a self-control whose consequence is self-reliance with part of it resulted in withdrawal and pain. 2) If a subject's tolerance is weak, the episodes of the violence are frequent but not serious, with the resulting straight jacketing being weaker but the subject's supporter is immature, the supporting type is superficial and the thinking oriented is extemporary, the responses to the straight jacketing result in an impulsion whose consequence is wandering with part of it resulted in withdrawal and pain. 3) If a subject's tolerance is weak, the episodes of the violence are frequent and serious, the straight jacketing is strong, the subject's supporter is immature and the supporting type is superficial but the thinking oriented is wishful, the responses to the straight jacketing result in an impulsion whose consequence is withdrawal and pain with part of it resulted in wandering. 4) If a subject's tolerance is strong and the episodes of the violence are infrequent and not serious, the straight jacketing is weak, the subject's supporter is immature and the supporting type is superficial but the thinking oriented is wishful, the responses to the straight jacketing result in a self-control whose consequence is withdrawal and pain with part of it resulted in self-reliance.

• Journal of National Security and Military Science
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• s.4
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• pp.83-118
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• 2006

This study is to develop digital leadership in a field of national defense. Today, korean society is facing the crisis of national security. But national defense leadership is not show in the circumstance of national security crisis. As you know, national defense leadership is a process that make use of influence. Which means it converges people's interest and demands well and also show people the right vision of national defense and make them to comply the policy about national security. Because of the environmental change, our national defense leadership is having a new turning point. First, international order, which is under post-cold war, raises possibility of guarantee of peace and security in international society but also, cause the increase of multiple uncertainty and small size troubles in security circumstance. In addition, Korean society is rushing into democratization and localization period by success in peaceful change of political power went through about three times. The issue of political neutralization of military is stepping into settlement but still, negative inheritance of old military regime is worrying about it. In this situation, we can't expect rise in estimation about the importance of security and military's reason for being. So, military have to give their concern to not only internal maintenance of order and control and growth of soldiers but also developing external leadership to strength influence to society and military's the reason for being. So for these alternative I'm suggesting a digital leadership of national defense which fits digital era. This digital leadership is the leadership which can accept and understand digital technology and lead the digital organization. To construct digital national defense we need a practical leadership. The leadership has to be digital leadership with digital competence that can direct vision of digital national defense and carry out the policy. A leader who ha s digital leadership can lead the digital society. The ultimate key to construct digital government, digital corporate and digital citizen depends on digital leader with digital mind. To be more specific, digital leadership has network leadership, next generation leadership, knowledge driven management leadership, innovation oriented leadership. A leader with this kind of leadership is the real person with digital leadership. From now on, to rise this, we have to build up human resource development strategy and develop educational training program.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.469-474
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• 2002

In recent years, modularization of engine parts has increased the application of plastic products in air intake systems. Plastic intake manifolds provide many advantages including reduced weight, contracted cost, and lower intake air temperatures. These manifolds, however, have some weakness when compared with customary aluminium intake manifolds, in that they have low sound transmission loss because of their lower material density. This low transmission loss of plastic intake manifolds causes several problems related to flow noise, especially when the throttle is opened quickly. The physical processes, responsible for this flow noise, include turbulent fluid motion and relative motion of the throttle to the airflow. The former is generated by high-speed airflow in the splits between the throttle valve and the inner-surface of the throttle body and surge-tank, which can be categorized into the quadrupole source. The latter induces the unsteady force on the flow, which can be classified into the dipole source. In this paper, the mechanism of noise generation from the turbulence is only investigated as a preliminary study. Stochastic noise source synthesis method is adopted for the analysis of turbulence-induced, i.e. quadrupole noise by throttle at quick opening state. The method consists of three procedures. The first step corresponds to the preliminary time-averaged Navier-Stokes computation with a $k-\varepsilon$ turbulence model providing mean flow field characteristics. The second step is the synthesis of time-dependent turbulent velocity field associated with quadrupole noise sources. The final step is devoted to the determination of acoustic source terms associated with turbulent velocity. For the first step, we used market available analysis tools such as STAR-CD, the trade names of fluid analysis tools available on the market. The steady state flows at three open angle of throttle valve, i.e. 20, 35 and 60 degree, are numerically analyzed. Then, time-dependent turbulent velocity fields are produced by using the stochastic model and the flow analysis results. Using this turbulent velocity field, the turbulence-originated noise sources, i.e. the self-noise and shear-noise sources are synthesized. Based on these numerical results, it is found that the origin of the turbulent flow and noise might be attributed to the process of formulation and the interaction of two vortex lines formed in the downstream of the throttle valve. These vortex lines are produced by the non-uniform splits between the throttle valve and inner cylinder surface. Based on the analysis, we present the low-noise design of the inner geometry of throttle body.

• Nuclear Engineering and Technology
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• v.25 no.1
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• pp.125-135
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• 1993

The safe and efficient operation of nuclear plants is recognized to be accomplished through the application of plant automation using digital technology, which is one of main targets of the next generation nuclear plants. For plant level automation, it is first required that each major subsystem be digitalized, and the steam generator water level control system is discussed in this study. The transfer functions between inputs and the level are derived by employing the thermal hydraulic model of the steam generator and are applied to the analysis of the current three-element control system. Since the control scheme in this study includes the steam generator itself as a process plant, the system order is high and the numerical instability arises in digitalizing. Together with this, the unreliability of the feedwater feedback signal at low power level leads to the proposal of a two-element control system with a proper digital controller. The digital PI controller developed for this system has the initial power adaptive gain and integration time constant. And it makes the overall system response satisfy the stability and other necessary control specifications simultaneously. Since the two-element control system using this controller depends on the initial power only, it is simple to define and it shows a similar level response behavior to that of its corresponding analog system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.2
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• pp.133-142
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• 2014

Landsat is one of the popular satellites for observing land surface that is used in various areas including monitoring, detecting and classifying changes in land surface. However, shades, which cloud itself and its shadow, interrupted often clear observation and analysis of ground surface. For this reason, the process of removing shades and restoring original ground surfaces are critical for geospatial users. This study is planned to recommend a methodology for more accurate and clear images of Landsat-8 sensor, which provided two additional bands of costal/aerosol and cirrus. In fact, those bands are known as functioned effectively in detecting and restoring shades. Otsu's thresholding technique to detect clouds, we replaced those detective shades by using experimental and reference images. In accurate assessment, the overall accuracy and kappa coefficients were about 85% and 0.7128, respectively. This indicates that the proposed technique is effective for recovering the original land surface.

• Journal of Families and Better Life
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• v.29 no.3
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• pp.23-41
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• 2011

The purpose of this study is to explore social supports for elderly housing and their residential lives in small cities along rural counties of the United States and Canada, and suggest future implications for age-concentrated rural villages in Korea. In this study, five small and medium cities in non-metropolitan counties of California and Ontario province were visited and elderly residents and service experts were interviewed about their perceptions of community integrated social support networks for senior residences. The senior housing complexes were built due to influx of both metropolitan and rural residents seeking warm localities, traffic connections, business purposes in active production areas. and leisure attractions. There are five main social support networks for senior housing issues in these areas. First, the areas are claimed for senior zones and accordingly health industries are encouraged by local authorities. Second, the community is homogeneously constructed as a senior friendly environment and include features such as an RV park and mobile cottages. Third, senior-helping seniors are offered active work through golf-cluster active retirement communities. Fourth, traditional theme production camps are mobilized by the elderly workers. Lastly, an information system is maintained for screening volunteers and for senior abuse prevention. On the other hand, residential lives are occasionally negatively influenced by unbalanced concentrations of elderly facilities such as nursing stations and funeral homes. For the future of Korean rural elderly policies, suggestions are made as follows: first, an integrated urban and rural township that contains attractive places for early retiring people who seek a warm atmosphere in later life needs to be constructed. Second, an integrated model retirement village of urban and rural retirement life needs to be initiated as a measure of evaluating the adaptation process of movers in senior concentrated zones. Third, a cooperation system among governmental ministries needs to be formed with the long- term goal of establishing a traditional rural town of independent housing districts and medical facilities in rural areas. Fourth, productive and active lifestyles need to be maintained as the local community and government develop successful retirement rural villages, by limiting the expansion of nursing related facilities. Finally, generation integrated visiting welfare programs and services need to be further developed for the housing areas especially in the winter, when social integration and activity are relatively low.