• Korean Journal of Computational Design and Engineering
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• v.21 no.4
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• pp.397-408
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• 2016

VR and AR are widely used in many applications to provide more immersive visualization and natural interaction for learning and experiencing virtual but realistic tasks. Energy saving is considered as one of the most important issues throughout the world in order to overcome global warming and energy crisis. In particular, the awareness of home energy saving is regarded as a first step to deal with this issue. In this paper, we suggest a new learning environment using virtual and augmented reality (VR/AR) for home energy saving experience. In particular, it presents a comparative study of the user experience in home energy awareness using immersive virtual reality and mobile augmented reality. The first person user experience using immersive VR wearing head mounted display (HMD) and the third person user experience using mobile AR are implemented and systematically compared with each other in terms of the learning effect of energy saving and qualitative usability. Implementation results will be given to show the advantage and effectiveness of the proposed approach.

• Journal of Broadcast Engineering
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• v.22 no.4
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• pp.462-472
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• 2017

As network technology evolves fast, media contents of particular countries are being consumed in not only the countries but also other countries around the world. Like this, in case that a particular media content is consumed in various country, method for inserting or replacing in-program ads which are appropriate to national/regional environment seems needed. For this, this paper proposes measures to insert in-program ads on hybrid broadcast environment based on MMT, next generation broadcasting standard. This paper analyzed structure of MMT, designed a system for verifying the proposed system and showed the result of experiment.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.2
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• pp.65-72
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• 2015

An anti-virus is a widely used solution for detecting malicious software in client devices. In particular, signature-based anti-viruses detect malicious software by comparing a file with a signature of a malicious software. Recently, the number of malicious software dramatically increases and hence it results in a performance degradation issue: detection time of signature-based anti-virus increases and throughput decreases. In this paper, we summarize the research results of signature-based anti-viruses which are focusing on solutions overcoming of performance limitations, and propose a new solution. In particular, comparing our solution to SplitScreen which has been known with the best performance, our solution reduces client-side workload and decreases communication cost.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.6
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• pp.1717-1726
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• 2015

Acceleration of globalization in almost all industries, including fisheries, already had been a major paradigm of the age. And It has been weakened its meaning of geographical, cultural and economic boundaries between the nations. In particular, various changes in the fisheries environment have exceeded the area of problem for conventional single country is resolved. And if there is no cooperation with international cooperation other problems also almost nearly impossible to alleviate or solve. So it has emerged in this context, the concept of sustainable development and conceptual diagram of responsible fisheries. However, it has been passed about 20 years since the FAO documents published, there is little interest in it. In this study, analyzed the characteristics of the changes and its constitutive trends and contents of the FAO's responsible fisheries documents. And proposed both the need for analysis and research for the fisheries in an international context for the future and educational aspects. The results of this study show that FAO related documents are hardly to find that have been translated into Korean, in particular since the 2000s. And it is fairly skeptical whether there is a direct effective in fisheries in terms of language barriers. Therefore, the study on responsible fisheries much more important to develop the current status and future-oriented policy of international fisheries even in fisheries related education.

• Smart Structures and Systems
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• v.22 no.5
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• pp.631-641
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• 2018

This paper outlines a computational procedure for the effective merging of diverse sensor measurements, displacement and acceleration signals in particular, in order to successfully monitor and simulate the current health condition of civil structures under dynamic loadings. In particular, it investigates a Kalman Filter implementation for the Heterogeneous Data Fusion of displacement and acceleration response signals of a structural system toward dynamic identification purposes. The procedure is perspectively aimed at enhancing extensive remote displacement measurements (commonly affected by high noise), by possibly integrating them with a few standard acceleration measurements (considered instead as noise-free or corrupted by slight noise only). Within the data fusion analysis, a Kalman Filter algorithm is implemented and its effectiveness in improving noise-corrupted displacement measurements is investigated. The performance of the filter is assessed based on the RMS error between the original (noise-free, numerically-determined) displacement signal and the Kalman Filter displacement estimate, and on the structural modal parameters (natural frequencies) that can be extracted from displacement signals, refined through the combined use of displacement and acceleration recordings, through inverse analysis algorithms for output-only modal dynamics identification, based on displacements.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.6
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• pp.55-61
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• 1982

An analytic solution for the spectral response of linearly-chirped grating filter is derived, which takes the finite physical length of filter into account. In the usual case of broad-band linearly-chirped grating filter the analytic solution is expressed in terms of elementary functions, by approximating asymptotically the involved parabolic cylinder functions over different ranges of its argument. It is also shown that derived results are general enough to include previously-available approximations as particular cases, and that they agree well with the numerical solutions based upon the Runge-Kutta method.

• International Journal of Concrete Structures and Materials
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• v.18 no.2E
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• pp.117-124
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• 2006

Porous concrete has been used recently for the purpose of decreasing the load on the earth environment. It consists solely of cement, water and coarse aggregate of uni form size. Its fundamental properties are considerably affected by the physical properties of aggregate because the aggregate is the main material for the most part in its mix proportion. Because of this reason, this study carried out an investigation of the influence of the size and type of aggregate on the fundamental properties of porous concrete. It is shown that the fundamental properties of porous concrete was seldom affected by the size of aggregate except for the case of using $2.5{\sim}5mm$ aggregate but varied significantly by the type of aggregate. In particular, the compressive strength of porous concrete using $2.5{\sim}5mm$ aggregate was much higher than that using other aggregate, and its void ratio and coefficient of permeability was lower. Moreover, the capacity to maintain the permeability of porous concrete was found to vary by the size and type of aggregate. Of particular notice was that it decreased greatly when $2.5{\sim}5mm$ aggregate was used. Unlike ordinary concrete, porous concrete exhibited very high dynamic modulus of elasticity at early age and continued to increase but slowly afterwards.

• Journal of Ocean Engineering and Technology
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• v.23 no.2
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• pp.74-80
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• 2009

Surface hardening treatments, such as using the high-frequency induction hardening method, are widely used to increase the fatigue life and prevent the failure of materials by locally increasing the surface hardness. This method, in particular, brings an improvement in static strength by compressive residual surface stress due to the hardening. In this study, the mechanical properties of high-frequency induction hardened SCM440 steel were investigated. These results were also compared with those for base metal and a Q/T (tempering after quenching) treatment specimen. The test results showed that partially high-frequency induction hardened SCM440 steel specimens were more improved in static strength, surface hardness, fatigue limit, and anti-wear than the base metal and Q/T treatment specimens. In particular, the fatigue limit of the high-frequency induction hardened SCM440 steel increased by more than about 52% compared to that of base metal and by about 25% compared to that of the Q/T specimen.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.3 no.1
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• pp.41-56
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• 1999

Since UV-B radiation measuring networks have not been established, numerical models which calculate the flux from other readily available meteorological measurements may play an important role. That is, such a problem can be solved by using parameterization models such as two stream approximation, the delta-Eddington method, doubling method, and discrete ordinate method. However, most UV-B radiative transfer models have not been validated with measurements, because such models are not intended as practical computational schemes for providing surface estimates of UV-B radiation. The main concern so far has been to demonstrate model sensitivity for cloudless skies. In particular, few have been concerned with real cloud information. Clouds and aerosols have generally been incorporated as constituents of particular atmospheric layers with specified optical depths and scattering properties. The parameterization model presented here is a combination of a detailed radiative transfer algorithm for a coludless sky radiative process and a more approximate scheme to handle cloud effects. The model input data requires a daily measurement of the total ozone amount plus a daily record of the amount and type of cloud in the atmosphere. Measurements for an examination of the models at the Department of Atmospheric Sciences, Pusan National University have been takenfrom February, 1995. These models can be used to calculate present and future fluxes where measurements have not been taken, and construct climatologies for the period before ozone depletion began.

• Journal of Radiation Protection and Research
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• v.6 no.1
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• pp.1-7
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• 1981

This report presents the results of the environmental radiation program at Korea Advanced Energy Research Institute (KAERI) ($37^{\circ}38'N,\;127^{\circ}05'E$) and its surroundings for the last two decades (January, 1961 through December, 1980). In the 1960s, the monthly mean levels of environmental external radiation encountered ranged from a low of 14.2 microroentgen per hour to a high of 42.2 microroentgen per hour with a mean of 21.7 microroentgen per hour, while in 1970s it ranged from a low of 12.4 microroentgen per hour to a high of 40.8 microroentgen per hour with a mean of 20.4 microroentgen per hour. It may, therefore, be said that environmental radiation dose rates remained almost unchanged for the two decades except for the second half of 1960s and the first half of 1970s during which the off-site and on-site patterns were frequently unlike in form and intensity with appreciable differences between average values. Particular results of interest with respect to the effects of the fallout gamma dose rate on environmental radiation show that elevated levels were encountered in association with the deposits of fresh debris from Chinese and Russian nuclear weapons tests in particular.