• Proceedings of the Korean Information Science Society Conference
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• 2007.10b
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• pp.435-440
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• 2007

Wireless sensor networks are sensing, computing, and communication infrastructures that allow us to sense events in the harsh environment. The networks consist of many deployed sensor nodes. Each sensor node senses and transmits the sensed data to the administrator or base station of the networks. The sensor nodes are generally remotely-deployed, and therefore, software update must be done at run-time via communication channel. The software code update protocol should be energy-efficient to maximize lifetime of the sensor nodes. In this paper, we present a MCUP, which is a multi-level code update protocol for resource-constrained sensor nodes. MCUP enables energy-efficient code update by supporting multi-level code management. Our simulation results show that MCUP can reduce energy consumption compared with the existing one-level code update schemes.

• Journal of Digital Convergence
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• v.17 no.10
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• pp.169-176
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• 2019

Recently, the Korean economy is congested with Japan's economic retaliation, the US-China trade war, the Bank of Korea's 0.25% base rate cut and Korea's economic growth forecast revision. The purpose of this study is to analyze the KOSPI, CPI, Treasury bonds(3 years) Interest rate & sales performance of all industries, and examine the impact of each index on the KOSPI. The analysis period is from January 2003 to June 2019, and the effect of each index on the KOSPI is analyzed. In numerical analysis, we performed correlation coefficients and regression analysis. In the model analysis, the distribution, quadrant, scatter, box-plot and impulse response were examined. This study examined the volatility and dynamic characteristics of each index. As a result, the KOSPI showed a high correlation with sales and Treasury bonds, but showed a very low correlation with the CPI. The KOSPI will continue to be affected by sales and interest rates.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2696-2707
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• 2021

The purpose of this study is to investigate the efficiency of various structural modeling schemes for evaluating seismic performances and fragility of the reactor containment building (RCB) structure in the advanced power reactor 1400 (APR1400) nuclear power plant (NPP). Four structural modeling schemes, i.e. lumped-mass stick model (LMSM), solid-based finite element model (Solid FEM), multi-layer shell model (MLSM), and beam-truss model (BTM), are developed to simulate the seismic behaviors of the containment structure. A full three-dimensional finite element model (full 3D FEM) is additionally constructed to verify the previous numerical models. A set of input ground motions with response spectra matching to the US NRC 1.60 design spectrum is generated to perform linear and nonlinear time-history analyses. Floor response spectra (FRS) and floor displacements are obtained at the different elevations of the structure since they are critical outputs for evaluating the seismic vulnerability of RCB and secondary components. The results show that the difference in seismic responses between linear and nonlinear analyses gets larger as an earthquake intensity increases. It is observed that the linear analysis underestimates floor displacements while it overestimates floor accelerations. Moreover, a systematic assessment of the capability and efficiency of each structural model is presented thoroughly. MLSM can be an alternative approach to a full 3D FEM, which is complicated in modeling and extremely time-consuming in dynamic analyses. Specifically, BTM is recommended as the optimal model for evaluating the nonlinear seismic performance of NPP structures. Thereafter, linear and nonlinear BTM are employed in a series of time-history analyses to develop fragility curves of RCB for different damage states. It is shown that the linear analysis underestimates the probability of damage of RCB at a given earthquake intensity when compared to the nonlinear analysis. The nonlinear analysis approach is highly suggested for assessing the vulnerability of NPP structures.

• Journal of the Regional Association of Architectural Institute of Korea
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• v.20 no.6
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• pp.41-46
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• 2018

The context of innovation in which we evolve today, subtracts us in a spacial reality and virtuality (digital) that aimed less and less to interact with natural processes which could converge to new possible relationships in the world. We constantly live in presence of fluctuations and imperceptible natural energies (wind, solar radiation, etc.) defined by flows, their own physicality, which remains without being virtual, elusive. This study first outlines how these energies already exploited within the framework of production, could be thought as interactive of our habitat's space dimension, as a prolongation of a physical and material environment built by men and for men, giving rise to new social, cultural dynamics, and making natural complexity of our space vivid, comprehensible with new visual and physical clues. In recent days, where lifestyles are changing, architecture no longer needs to limit its scope of creation to only built structures. Based on a deeper understanding of human and through new potential advanced technologies (kinetic system, etc), it is time to fundamentally diagnose what environments or devices contribute to our lives. Architecture becomes ${\ll}interface{\gg}$, step up its fundamental role, and newly defines the sturdy image and tectonics of existing environment, establishing a stance to search for a new typology. In the end, building will show two simultaneous and distinctive connections related to its physical existence: reality in its function and irreductibility, in its ability to forge new dynamic connections with its environment, hybridizing the spatial dimension to a new form of physicality, adaptive and incessantly flexible in the dimension time, becoming a vessel for ever changing contemporary lifestyles.

• International Area Studies Review
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• v.15 no.3
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• pp.285-306
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• 2011

This paper analyzed the effects the regional competitiveness index on the characteristics of the regional growth. This study divides the regions in the US based on the static and dynamic standard of income for the characteristics of the regional growth. The results of the analysis are as follows. First some regions such as Alaska, Connecticut, Maryland, Massachusetts, Virginia, Washington and Wyoming have higher levels of SCI and both the rate of growth and per capita income than the national average. These are considered prosperous regions based on their high level of SCI. Second, in regards to the relation between the income level and regional competitiveness index for the regional growth, the variables such as human resource, science technology, business incubation, openness, safety and environmental policy are significant. Third, infrastructure, human resource, science technology and openness are the significant variables concerning the relation between the rate of income growth and regional competitiveness index for the regional growth.

• International Area Studies Review
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• v.13 no.2
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• pp.255-276
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• 2009

This article has examined the international transmission of returns among S&P500, Nikkei225 and SENSEX stock index cash markets using the daily closing prices covered from January 4, 2002 to February 6, 2009. For this purpose we employed dynamic time series models such as the Granger causality analysis and variance decomposition analysis based on VAR model. The main empirical results are as follows; First, according to Granger causality tests we find that S&P500 stock index has a significant prediction power on the changes of SENSEX and Nikkei225 stock index market and vice versa. However, US stock market's influence is dominant to the other stock markets at a significant level statistically. Second, according to variance decomposition, SENSEX stock index is more sensitive to the movement of S&P500 than that of Nikkei225 stock index. These kinds of empirical results shows that the three stock markets are integrated over times and these results will be informative for the international investors to build the world-wide investment portfolio and risk management strategies, etc.

• Journal of The Geomorphological Association of Korea
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• v.19 no.3
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• pp.153-163
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• 2012

The Earth's surface deforms vertically in response to a variety of sources relating to lithospheric and sub-lithospheric processes, and distinguishing the continental mechanisms for vertical motions of the lithosphere remains a fundamental challenge in geosciences. A key prerequisite to the challenge is documentation of the temporal and spatial pattern of vertical motions in different tectonic settings. This study is aimed at elucidating the geodynamic factors that can contribute to vertical motions of the Earth's surface in intraplate continental settings including the Neogene uplift in the Korean peninsula based on numerous recent achievements in relevant fields. Ultimately, deciphering the interplay between the Earth's surface and the Earth's interior processes leads us to the notion of "the importance of geomorphic landscape" as a prism to view the dynamics of the Earth's inside.

• The Korean Journal of Applied Statistics
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• v.34 no.3
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• pp.477-489
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• 2021

COVID-19 has spread seriously around the world in 2020 and it is still significantly affecting our whole daily life. Currently, the whole world is still undergoing the pandemic and South Korea is no exception to it. During the pandemic, South Korea had several events that prevented or accelerated its spread. To establish the prevention policies for infectious diseases, it is very important to evaluate the intervention effect of such events. The susceptible-infected-removed (SIR) model is often used to describe the dynamic behavior of the spread of infectious diseases through ordinary differential equations. However, the SIR model is a deterministic model without considering the uncertainty of observed data. To consider the uncertainty in the SIR model, the Bayesian approach can be employed, and this approach allows us to evaluate the intervention effects by time-varying functions of the infection rate in the SIR model. In this study, we describe the time trend of the spread of COVID-19 in South Korea and investigate the intervention effects for the events using the stochastic SIR model based on the Bayesian approach.

• Journal of the Daesoon Academy of Sciences
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• v.35
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• pp.393-426
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• 2020

In the past, holy sites were mainly designated on a basis of archaeological norms and endowed with a specific fixed identity according to historical, religious, and contextual interpretations. However, approaches to these sites are more flexible in recent times. These locations transcend the boundaries of space and time to enable the experience of diverse transformation and reveal multiple religious identities which are embedded in the complex interaction between power and authority. In this regard, the dynamic meanings of the religious symbology of Daesoon Jinrihoe's temple complexes, imagery, and the spatial structures enable us to grant them a new identity by re-establishing these structures as World Heritage sites. Temple complexes (dojang) correspond to the outstanding universal values identified by UNESCO in that the spiritual activities conducted at these holy sites draw the same attention as would be drawn by historical value. In this context, this study aims to explore the potential for Daesoon Jinrihoe's temple complexes to be designated UNESCO world heritage sites. To carry out this study, existing religious heritage sites such as Mount Athos Monasteries in Greece and Lumbini in Nepal are examined as case studies, and the operational plan, conservation, protection of relics, and interaction with its neighboring community and tourists are likewise closely examined in this study.

• Journal of Korea Entertainment Industry Association
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• v.14 no.5
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• pp.49-57
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• 2020

This paper analyzed maximized the tension not by functional restriction but by psychological response inducement to form the tension of the horror game from the point of space time view. In order that, We arranged three major situations inducing the tension in the horror game and prepared space time analysis base. Pure fiction time of game itself is applied on game time excluding the time creating the cut-scene and the game space is organized with various combination of three space types. This analysis result can help horror game design by discovering the relationship between space time structure and tension forming of the horror game. These analysis results allow us to find guidelines for the time and space design of horror games that can be flexibly linked to game events and contexts by controlling the player's dynamic/static tension and temporary/continuous tension.