• Journal of Engineering Education Research
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• v.14 no.3
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• pp.45-54
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• 2011

The purpose of this study is to analyze performance problems in establishing and improving program educational objectives (PEO) and to set up action strategies for the civil engineering program at the A university. To fulfill the purpose, according to the typical needs analysis model, research problems were defined, current conditions and desired conditions were identified, discrepancies and their reasons were examined, and action strategies were derived. Current conditions and desired conditions were identified by analyzing the A civil engineering program's self study report, conducting surveys and interviews with constituents. After the discrepancies and the reasons were examined, performance problems and field force analysis were conducted to draw short term and long term action strategies to improve PEO. Short term action strategies were to announce PEO to current students, to hold faculty seminars to establish and to improve PEO, to renew the list of constituents regularly, to composite an annual milestone, to define roles of the committees, and to enforce educational opportunity toward industrial advisory board members. For the long term strategies, improvement and documentation of PEO assessment system, collection and analysis of constituents' suggestions, establishment of effective accreditation support system, and arrangement of compensation system for the faculties who are in charge of engineering education accreditation responsibility.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.5
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• pp.27-38
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• 2013

This study was conducted to analyze the correlation between vegetation, environmental factors, and soil characteristic of an endangered species, Eleutherococcus senticosus. Eighteen quadrats in population zones of Seoraksan, Odaesan, Chiaksna, Duckhangsan, Sobaeksan, Juwangsan, and, Jirisan were set up and ordination was analyzed. In the study sites, soil pH, available phosphorous, organic matter and nitrogen were ranged from 5.06~5.43, 24.63~57.77mg/kg, 14.01~18.37%, and 0.63~0.75%, respectively. Eleutherococcus senticosus is classified into Morus bombycis dominant population, Cornus controversa dominant population, and Eleutherococcus senticosus typical population. The importance value of Acer pictum subsp. mono, Morus bombycis, Magnolia sieboldii, Cornus controversa, Tilia taquetii, and Ulmus laciniata in Eleutherococcus senticosus population were 23.76%, 23.61%, 18.06%, 17.82, 15.31%, and 13.57%, respectively. The correlation between vegetation and environmental factors of Eleutherococcus senticosus vegetation distribution were shown to be affected by altitude, slope, and direction.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.5
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• pp.1920-1937
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• 2015

Network environment has been under constant threat from both malicious attackers and inherent vulnerabilities of network infrastructure. Existence of such threats calls for exhaustive vulnerability analyzing to guarantee a secure system. However, due to the diversity of security hazards, analysts have to select from massive alternative hardening strategies, which is laborious and time-consuming. In this paper, we develop an approach to seek for possible hardening strategies and prioritize them to help security analysts to handle the optimal ones. In particular, we apply a Risk Flow Attack Graph (RFAG) to represent network situation and attack scenarios, and analyze them to measure network risk. We also employ a multi-objective genetic algorithm to infer the priority of hardening strategies automatically. Finally, we present some numerical results to show the performance of prioritizing strategies by network risk and hardening cost and illustrate the application of optimal hardening strategy set in typical cases. Our novel approach provides a promising new direction for network and vulnerability analysis to take proper precautions to reduce network risk.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.4153-4169
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• 2014

To recognize F5-like (such as F5 and nsF5) steganographic algorithm from multi-class stego images, a recognition algorithm based on the identifiable statistical feature (IDSF) of F5-like steganography is proposed in this paper. First, this paper analyzes the special modification ways of F5-like steganography to image data, as well as the special changes of statistical properties of image data caused by the modifications. And then, by constructing appropriate feature extraction sources, the IDSF of F5-like steganography distinguished from others is extracted. Lastly, based on the extracted IDSFs and combined with the training of SVM (Support Vector Machine) classifier, a recognition algorithm is presented to recognize F5-like stego images from images set consisting of a large number of multi-class stego images. A series of experimental results based on the detection of five types of typical JPEG steganography (namely F5, nsF5, JSteg, Steghide and Outguess) indicate that, the proposed algorithm can distinguish F5-like stego images reliably from multi-class stego images generated by the steganography mentioned above. Furthermore, even if the types of some detected stego images are unknown, the proposed algorithm can still recognize F5-like stego images correctly with high accuracy.

• Journal of the Korean Institute of Educational Facilities
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• v.13 no.1
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• pp.17-25
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• 2006

Elementary school classroom designs have been developed toward open education system to provide students diverse and improved educational environments since the early of 1990 in Korea. Unfortunately, the quality of music room has not still shown dramatic improvements due to the lack of the acoustical knowledges of architects. This report aims to investigate typical acoustic quality of previous or current music room of elementary schools and show new acoustic treatment technologies to improve the room acoustic of music room by adapting composite perforated panel system and diffusion technology. The music room at Daihyun Elementary school in Yongin was chosen as a case study of this report. The music room was measured to be analyzed using field measurements and the acoustical specifications of composite perforated panel systems and kinds of diffusors were set. Acoustic measurements were performed after the renovation to show the differences between previous room acoustic and after the acoustic renovations. As the result, the case study has shown that the new composite perforated panel systems and diffusion surfaces lowered reverberation time at proper level along with improving the clarity of music, RASTI, and spatial impressions. Also, acoustic interferences such as comb filtering and flutter echoes have been controlled dramatically by diffusive surfaces. The study shows music rooms in elementary schools, middle and high schools can be improved by adapting composite perforated panel systems and diffusors.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.687-689
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• 1998

This paper represents fundamental developments in Fuzzy and Neural approaches. The Fuzzy Controller(FC) and plant are cascaded in Adaptive framework. Each of which produces its outputs. The adjustable parameters all pertain to the fuzzy controller is implemented as an Adaptive FC to adjust the environments of the plant. There is an error meaure block which is a difference between the actual state and desired state. We introduce error back propagation algorithm in neural method. To speed up convergence, we follow a steepest decent in the sense that each parameter set update leads to a smaller error measure and is learned by this methodology. Inverted pendulum is a typical testbed to measure the effectiveness of nonlinear control system. finally we simulated the adaptive fuzzy controller to be able to bring back to the upright position of the its angle and angular velocity.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.2
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• pp.952-969
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• 2019

This study develops new analytical solutions to water wave diffraction by vertical truncated cylinders in the context of linear potential theory. Three typical truncated surface-piercing cylinders, a submerged bottom-standing cylinder and a submerged floating cylinder are examined. The analytical solutions utilize the multi-term Galerkin method, which is able to model the cube-root singularity of fluid velocity near the edges of the truncated cylinders by expanding the fluid velocity into a set of basis function involving the Gegenbauer polynomials. The convergence of the present analytical solution is rapid, and a few truncated numbers in the series of the basis function can yield results of six-figure accuracy for wave forces and moments. The present solutions are in good agreement with those by a higher-order BEM (boundary element method) model. Comparisons between present results and experimental results in literature and results by Froude-Krylov theory are conducted. The variation of wave forces and moments with different parameters are presented. This study not only gives a new analytical approach to wave diffraction by truncated cylinders but also provides a reliable benchmark for numerical investigations of wave diffraction by structures.

• Nuclear Engineering and Technology
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• v.50 no.1
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• pp.107-115
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• 2018

To ensure the structural integrity of nuclear power plants, it is essential to predict the lifetime of Alloy 182 weld, which is used for welding in nuclear reactors. The lifetime of Alloy 182 weld is directly related to the crack initiation time. Owing to the large time scatter in most crack initiation tests, a probabilistic model, such as the Weibull distribution, has mainly been adopted for prediction. However, since statistically more advanced methods than current typical methods may be applied, we suggest a statistical procedure for parameter estimation of the crack initiation time of Alloy 182 weld, considering right-censored data and the covariate effect. Furthermore, we suggest a procedure for uncertainty evaluation of the estimators based on the bootstrap method. The suggested statistical procedure can be applied not only to Alloy 182 weld but also to any material degradation data set including right-censored data with covariate effect.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.5
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• pp.537-548
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• 2010

Recently the Government has announced updated water quality standards for wastewater treatment effluent (become effective in 2012). That includes highly enforced regulations for T-P, BOD and COD, and a large budget, in particular for phosphorus removal, was set by the Ministry of environment. Chemical coagulation destabilizes colloidal particles so that particles grow to larger flocs, and solid particles are removed by solid-liquid separation. The efficiency of chemical coagulation depends on a various factors, including coagulant types and costs, construction and operation costs for the treatment facilities and so on. The proper selection should be based on the treatment efficiency of coagulants and underlying costs. The current research was to evaluate the treatment efficiencies of coagulants on a variety of wastewater influents and to develop saturation curves for several water quality parameters. Typical $Al_2(SO_4)_3$ and $FeCl_3$ were tested under a range of coagulant concentrations. The pollutant removal efficiencies of chemical treatment both for the $Al_2(SO_4)_3$ and $FeCl_3$ were especially high for T-P, followed by SS, BOD and COD. Correlation test also proved the highest relationship between SS and T-P.

• Ocean and Polar Research
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• v.32 no.3
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• pp.291-297
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• 2010

In the summer of 2008 (August 4-14), vertical and horizontal distributions of inorganic nutrients and dissolved organic carbon (DOC) were measured in the southwestern East Sea. Concentrations of DOC were determined for the first time in the southwestern East Sea using the high-temperature combustion oxidation (HTCO) method, and results were compared with those measured by another laboratory. Concentrations of DOC ranged from 58 to 104 ${\mu}M$ in the upper 200 m, showing a typical decreasing pattern with depth. Generally, concentrations of DOC were relatively lower, with higher nutrient concentrations, in the upper layer of the coastal upwelling zone. Concentrations of DOC ranged from 54 to 64 ${\mu}M$ in the deep Ulleung Basin (200-1500 m), and were higher than those in the Pacific and Atlantic oceans. In association with rapid vertical ventilation of the euphotic, this difference indicates a larger accumulation of semi-labile DOC in the deep East Sea than in the major oceans. A correlation between apparent oxygen utilization (AOU) and DOC in the deep ocean of the East Sea revealed that only a small portion (<10%) of the sinking DOC, relative to the sinking particulate organic carbon (POC), contributes to microbial degradation. Our results present an important data set of DOC in the East Sea, which plays a critical role in carbon cycle modeling and sequestration.