• Applied Chemistry for Engineering
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• v.17 no.2
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• pp.229-234
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• 2006

The effect of ZnO in the decomposition of poly(vinyl chloride) (PVC) and polystyrene (PS) mixtures in air atmosphere has been studied by thermogravimetry (TG) and gas chromatograph-mass spectrometry (GC-MS) under various mixing ratios and reaction temperatures. From this work, it can be seen that the yields of a liquid product were increased with the increase of PS in mixtures, whereas those of gaseous products were decreased. And the yields of a gaseous product and HCl were decreased with the increase of ZnO in mixtures. It was also found that HCl was rarely produced at ZnO/Mixture = 0.5 by the effect of ZnO in dehydrochlorination of PVC.

• Journal of Digital Convergence
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• v.10 no.6
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• pp.205-211
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• 2012

According to the Hebei Spirit incident, 12,547kl of crude oil was spilled into the sea and a total of approximately 40,000 households was damaged. Also, eleven cities and counties including "Taean" were designated as a Special Disaster District by government. Large oil pollution incidents cause severe impact on the change of the surrounding environment as well as destruction of the natural environment of damaged areas. This study analyzes the impacts on the surrounding environment of damaged areas caused by Hebei Spirit oil pollution incident, focusing on the largest damaged county called Taean. Survey was performed with items which are changes in population and local economy, effects on public health, social conflicts and etc. The result of analysis can be used as an important factor to forecast the impact on a damaged area in case of future oil pollution incidents and to establish effective policy of government.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.4
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• pp.385-392
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• 2009

Maritime safety management needs active public participations because the sea is too wide for a government to respond to all unexpected accidents with limited resources. Marine rescue volunteer organizations of US, UK, Japan and Korea were compared one another on the base of disaster management governance theory, and recommendations for the development of marine rescue volunteer organization of Korea were proposed. The advanced organizations commonly have tradition of marine rescue voluntaryism in the advanced maritime countries. They have nation-wide networks and self-governing structures. Their main activities include public maritime safety education and fundraising programs as well as marine rescue operations. They have cooperative relationships with government agencies in charge of national maritime safety management, which are usually guaranteed by legislations or institutional systems. Donations from the public are major source of their finances. Members mainly consist of civil volunteers, and get basic compensations for their expenses. For the advancement of marine rescue volunteer organization of Korea, efforts are needed to strengthen the membership of civil rescue fleet, to activate public education and fundraising programs, and to amend the related law for institutional support.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.1
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• pp.33-39
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• 2009

The 21st century is often referred to as maritime age. The sea is a rich repository of natural resources, comfort shelters and the hopes and dreams of human being. But there is always possibility of disaster as well as hopes and dreams. Although there have been many advances in the ship building technology, the risk of accidents is on the increase due to the increase of maritime traffic and the revitalization of marine leisure. I like to refer to the systematic search and rescue system for the rapid response by analyzing recent marine accidents. For the safe navigation, it is necessary to establish institutional systems such as ship technology, navigation equipments, excellent human resources, traffic control, etc. and navigation components also have to be well organized each other. It is also necessary to build a prompt accident management system. The search and rescue system for the rapid response and the way of reducing the incidence of marine accidents were reviewed through the analysis of recent marine accidents.

• Structural Engineering and Mechanics
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• v.38 no.1
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• pp.39-63
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• 2011

Referring to the formulation of physical stochastic optimal control of structures and the scheme of optimal polynomial control, a nonlinear stochastic optimal control strategy is developed for a class of structural systems with hysteretic behaviors in the present paper. This control strategy provides an amenable approach to the classical stochastic optimal control strategies, bypasses the dilemma involved in It$\hat{o}$-type stochastic differential equations and is applicable to the dynamical systems driven by practical non-stationary and non-white random excitations, such as earthquake ground motions, strong winds and sea waves. The newly developed generalized optimal control policy is integrated in the nonlinear stochastic optimal control scheme so as to logically distribute the controllers and design their parameters associated with control gains. For illustrative purposes, the stochastic optimal controls of two base-excited multi-degree-of-freedom structural systems with hysteretic behavior in Clough bilinear model and Bouc-Wen differential model, respectively, are investigated. Numerical results reveal that a linear control with the 1st-order controller suffices even for the hysteretic structural systems when a control criterion in exceedance probability performance function for designing the weighting matrices is employed. This is practically meaningful due to the nonlinear controllers which may be associated with dynamical instabilities being saved. It is also noted that using the generalized optimal control policy, the maximum control effectiveness with the few number of control devices can be achieved, allowing for a desirable structural performance. It is remarked, meanwhile, that the response process and energy-dissipation behavior of the hysteretic structures are controlled to a certain extent.

• Journal of the Korean Applied Science and Technology
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• v.29 no.2
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• pp.268-277
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• 2012

The thermal decomposition characteristic of waste PVC wires has been studied by using TGA and fixed-bed reactor. The experimental conditions of decomposition temperatures, air flow rates and weight ratio of CaO/PVC were considered in this work. To verify the effectiveness of CaO addition to remove HCl and toxic gases generated from thermal decomposition of PVC wire, the gaseous products obtained from the thermal decomposition of PVC were analyzed by GC/MS(Gas Chromatograph and Mass Spectrometry). To investigate the effect of CaO in thermal decomposition of PVC, liquid products were also analyzed by GC/MS. And the effect of decomposition temperature, air flow rate and CaO/ PVC weight ratio on the yield of liquid, gas and residue fraction have been also studied. From this work, it was found that the removal amount of HCl generated from thermal decomposition of PVC increased with increase of CaO addition.

• Journal of Advanced Navigation Technology
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• v.18 no.3
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• pp.201-208
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• 2014

Due to diversification of ships and limited space of pier, when ships come alongside the shallow water or narrow pier, sea area with small mooring facilities and floating matter is frequently applied. Through these, coming alongside the various space is capable and cost effectiveness is enhanced. However, when ships, applying small mooring facilities and floating matter, come alongside, there can be some impulse by waves between the floating things and ships which possibly leads to mass disaster. Therefore, there should be forecasts and analysis of the movement caused by waves. On this study, we develop measuring system for movement analysis of mooring and floating matters which provides base data with movement traits by measuring 3-D exercise information and acceleration at mokpo maritime university marina facility. Also, the composition and principles of the developed system is explained.

• Journal of Navigation and Port Research
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• v.36 no.10
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• pp.857-864
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• 2012

Reviewing the statistics of harbor shipment of hazardous and noxious substance and the past spill accidents of HNS enabled us to assess the potential risks of transportation of HNS through the major harbors in Korea. Ulsan, Yeosu, Daesan port are relatively evaluated high risk in fire, health and environment disaster. Through the analysis of domestic preparedness to HNS accidents, the supplement of expertise resource to respond the vulnerability of the explosion, the fire and the physiological hazard, is required. Based on this risk assessment and review of the advanced case of Japan in building up HNS response system, a resource model at a national level was proposed which differentiates the sea areas for the proper allocation of resources to respond effectively to HNS accidents in the future.

• Geophysics and Geophysical Exploration
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• v.20 no.1
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• pp.18-24
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• 2017

We performed seismic imaging based on relative S-wave travel times to examine S-wave velocity of upper mantle structure beneath East Asia. We used teleseismic events recorded at 129 broadband stations of the Korea Institute of Geoscience and Mineral Resources (KIGAM), Korea Meteorological Administration (KMA), and National Research Institute for Earth Science and Disaster Prevention (NIED). Relative travel time residuals were obtained by a multi-channel cross-correlation method designed to automatically determine accurate relative phase arrival times. The resulting images show high-velocity anomalies along plate boundaries around the Japanese islands region. These anomalies may indicate subducting Pacific and Philippine Sea plates. On the other hand, a low-velocity anomaly is revealed beneath east of the Korean peninsula down to around 300 km depth, which is thought to be related to the formation of the Ulleung basin and the Ulleung island. Low-velocity anomalies revealed beneath the Jeju island may imply that the formation and volcanism of the Jeju island have been caused by magmatic sources from the deep mantle.

• Journal of IKEEE
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• v.18 no.1
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• pp.45-56
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• 2014

Recently, damages from disasters such as downpours, earthquakes and typhoons are increasing throughout the world. The downpour days of Korean Peninsula are also increasing every year due to rapid climate change. According to statistics over the last 30 years of the earthquakes in Korean Peninsula, the probability of a future earthquake is very high. In addition, super typhoons will hit Korean Peninsula due to the temperature rise in the nearby sea caused by the deepening of global warming. Thus, damage costs of the waterfront structures by natural disasters are also growing. But damage information system for integrated management of waterfront structures are insufficient. In this paper, we designed and implemented a damage information system for integrated management of waterfront structures. First, we classified damage information caused by natural disaster. Then we designed the databases of damage information and implemented damage information system. Lastly, we checked operations and the feasibility by testing queries on the proposed system.