• Structural Engineering and Mechanics
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• v.15 no.1
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• pp.39-52
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• 2003

A computer program has been developed for the optimum design of prestressed concrete beams under flexure. Optimum values of prestressing force, tendon configuration, and cross-sectional dimensions are determined subject to constraints on the design variables and stresses. 28 constraints have been used including flexural stresses, cover requirement, the aspect ratios for top and bottom flanges and web part of a beam and ultimate moment. The objective function contains cost of concrete, prestressing force and formwork. Using this function, it is possible to obtain minimum cost design, minimum weight or cross-sectional area of concrete design and minimum prestressing force design. Besides the idealized I-shaped cross-section, which is widely used in literature, a general I-shaped cross-section with eight geometrical design variables are used here. Four examples, one of which is available in the literature and the others are modified form of it, have been solved for minimum cost and minimum cross-sectional area designs and the results are compared. The computer program, which employs modified grid search optimization method, can assist a designer in producing efficient designs rapidly and easily. Considerable savings in computational work are thus made possible.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.3
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• pp.104-117
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• 1998

Rising concern about climate change has evoked interest in the potential for urban vegetation to help reduce the level of atmospheric CO\sub 2\, a major heat-trapping gas. This study quantified the functio of home energy savings and carbon emission reduction by shading, evapotranspiration and windspeed reduction of urban vegetatioin in Chuncheon. Tree and shrub cover averaged approximately 13% in residential land. The effects of shading, evapotranspiration and windspeed reduction annually saved heating energy by 2.2% and cooling energy by 8.8%. The heating and cooling energy savings reduced carbon emissions by 3.0% annually. These avoided emissions equaled the amount of carbon emitted annually from fossil fuel consumption by a population of about 1,230. Carbon emission reduction per residential building was 55kg for detached buildings and 872 kg for multifamily buildings. Urban vegetation annually decreased heating and cooling energy cost by ￦1.1 billions, which were equivalent to annual savings of ￦10,000 savings and carbon emission reduction due to tree plantings in the wrong locations, while windspeed reduction had a great effect. Plantings fo large trees close to the west and east wall of buildings, full tree plantings on the north, and avoidance of shade-tree plantings or selection of solar-friendlytrees on the south were recommended to improve the function of building energy savings and carbon emission reduction by urban vegetation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.11
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• pp.4537-4556
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• 2020

This research was based on the study conducted by Khodaei et al. (2012), namely, the least-significant-bit (LSB) substitution combined with the pixel-value differencing (PVD) steganography, and presented an improved irreversible image steganography method. Such a method was developed through integrating the improved LSB substitution with the modulus function-based PVD steganography to increase steganographic capacity of the original technique while maintaining the quality of images. It partitions the cover image into non-overlapped blocks, each of which consists of 3 consecutive pixels. The 2nd pixel represents the base, in which secret data are embedded by using the 3-bit LSB substitution. Each of the other 2 pixels is paired with the base respectively for embedding secret data by using an improved modulus PVD method. The experiment results showed that the method can greatly increase steganographic capacity in comparison with other PVD-based techniques (by a maximum amount of 135%), on the premise that the quality of images is maintained. Last but not least, 2 security analyses, the pixel difference histogram (PDH) and the content-selective residual (CSR) steganalysis were performed. The results indicated that the method is capable of preventing the detection of the 2 common techniques.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.263-274
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• 2004

High resolution spectroscopic observations of BX And using the BOBS (Bohyunsan Optical Echelle Spectrograph) of Bohyunsan Optical Astronomical Observatory (BOAO) were performod during 26-27, Feb. 2003. From the observations, we obtained 38 line spectra of BX And which cover all phases except the phase interval between $0.^p1$ and $0.^p3$. Both methods of the CCF (Cross-Correlation Function) and BF (Broadening Function) were used to get the radial velocities of primary and secondary components. Both velocities of the primary and secondary stars were calculated with the BF method while only primary velocities were determined with the CCF. Using new radial velocity curves, the maximum radial velocities of the primary and secondary stars were obtained as $K_1=90.1km/s\;and\;K_2=196.6km/s$, respectively. New absolute dimension of BX And was deduced with the combination of our spectroscopic solution with the photometric one of Bell et al. (1990).

• The Journal of Information Systems
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• v.13 no.2
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• pp.225-240
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• 2004

The most critical problem of MIS evaluation is the lack of the systematic framework to cover various factors and viewpoints. To solve this problem, this study takes the multi-level and contingent approach to performance evaluation, composed of three levels: evaluating the contribution of MIS to an organization [strategy level]; evaluating the activities of MIS department or MIS function as an organizational sub-function through the overall MIS lifecycle [function level]; and evaluating the quality or productivity of the application systems as MIS outputs [system level]. Ideal MIS evaluation should include all three levels of the hierarchy with balanced importance. However, MIS evaluationcanbedividedintothreetypes,suchasstrategy-oriented, function-oriented and system-oriented evaluation, depending on the focus and emphasis of evaluation. The usage pattern of each evaluation type is analyzed according to contingent variables of MIS evaluation such as MIS maturity, information intensity and firm size, and top management's intent. It is also found that the firms of higher MIS maturity and top management's intent use the strategy-oriented evaluation type, and the firms with strategy-oriented evaluation type show a higher MIS performance. Further, MIS maturity and top management's intent show contingent effects between evaluation type and MIS performance. Some managerial implications can be drawn based on the results of the study. First, strategy-oriented evaluation of MIS is more important as many firms more often use information technology as a strategic weapon. Second, MIS performance varies with evaluation type. Therefore, the design of MIS evaluation framework should be done carefully in the strategic and managerial contexts. Third, firms are recommend to use a different evaluation type according to organizational characteristics such as MIS maturity and information intensity.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.5
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• pp.39-60
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• 2018

National parks are designated for the purpose of maintenance, conservation and utilization of different habitats. Therefore, it is necessary to select habitats of a high value as a protected area in order to balance conservation and development. However, the existing national park boundary adjustment and new designation criteria only focused on the endangered species and protected area, without proper evaluation of the habitat value of actual species. Therefore, this study aims to quantitatively evaluate habitat function in terms of biodiversity and habitat value, so that it can be referred to for the designation and boundary adjustment of national parks. We assessed species diversity and habitat values for each of the habitat types, for mammals only, as they are able to choose preferred habitats. In order to evaluate biodiversity, we used Maxent to derive species richness map and used InVEST's Habitat quality model to evaluate habitat value. As a result of evaluation, species richness was high in the national park boundary area. Also, even if the same edge is adjacent to the development area depending on the land cover, the species richness is low. Compared with Wolaksan and Sobaeksan National Park, the species richness and habitat value of the northern area, which is connected with other forests, were higher than those of the southern area where roads were developed. Therefore, it is expected that the use of the result of this study for the national park boundary adjustment and management will enhance the function of the national park as a habitat.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.2
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• pp.86-96
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• 2003

A fracture or breakage of the concrete armor units in the primary cover layer of breakwaters is studied by using the reliability analysis which may be defined as the structural stability. The reliability function can be derived as a function of the angle of rotation that represents the rocking of armor units quantitatively. The relative influences of all of random variables related to the material and geometric properties on the fracture of armor units is analyzed in detail. In addition, the probability of failure for the fracture of individual armor unit can be evaluated as a function of the incident wave height. Finally, Bernoulli random process and the allowable fracture ratio may be introduced together in this paper, by which the probability of failure of a breakwater due to the fracture of armer units can be obtained straightforwardly. It is found that the probability of failure of a breakwater due to the fracture of armor units may be varied with the several allowable fracture ratios. Therefore, it should be necessary to consider the structural stability as well as the hydraulic stability for the design of breakwaters with multi-leg slender concrete armor units of large size under wave action in deep water.

• Journal of Korean Philosophical Society
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• v.146
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• pp.137-162
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• 2018

Zen Psychology refers to the psychology of Zen Buddhism as a field of Buddhist psychology. This paper examines the psychology of human beings, focusing on the "Platform Sutra" written by Huineng, the founder of Patriarchal Zen, and the southern Zen school. According to the classification of Buddhist psychology, Zen psychology is divided into theory of Zen mind, theory of Zend mind function, and Zen psychotherapy. In theory of Zen mind, Huineng explains the mind based on self-nature, and explains the theory of dharma, theory of humanity, theory of dependent origination, and worldview though self-nature. Every human mind has its own original character of self-nature. When one's own mind with self-nature is revealed, it is the basic mind. When it is covered, it is the mind of common people. Self-nature is characterized by dharma construction, incompetence, non-naming, cleanliness, equality, and self-Buddhahood. In the theory of dharma, dharma is non-dual and is equal. The theory of humanity is divided into two groups according to the sharpness and dullness or capacity of the human being. From theory of dependent origination, you can see the mobility of cover and revealment, enlightment and delusion, sacred and common. In the worldview, the world and phenomena are the functions of self-nature and one's own mind. The theory of Zen mind function deals with wisdom and defilement of common people. The function of wisdom is to know the whole and one at the same time, and is intangible. Defilement of common people is an inner common people that cover the functions of wisdom. In Zen psychotherapy, in order to eliminate the gap between human and dharma, seeing into self-nature is suggested and the goal. In teleology, the goal is to reveal and see the self-nature covered by defilements. As a methodology from cover to revealment, Huineng interprets the traditional methodology as a new interpretation from the viewpoint of the mind, and presents Sammu as its own methodology. Based on the absence of attachment, Huineng proposed a methodology of No-abiding, No-thought and No-form, to gather mind on reality and treat all things equally. Based on this, Huineng proposed a new methodology for dealing with karma through repentance and vows, and a methodology for edification. In view of the Four Noble Truth, it is the phenomenon that self-nature is covered, the cause of defilement and the mind, the aim of seeing the self-nature which is covered, and the way of revealing the covered self-nature is presented. In this sense, the Zen Psychology of Platform Sutra is psychology of self-nature.

• Journal of Korea Water Resources Association
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• v.52 no.12
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• pp.1057-1066
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• 2019

The storage function method is used as a flood prediction model for four flood control offices in Korea as a method to analyze the actual rainfall-runoff relationship with non-linearity. It is essential to accurately estimate the parameters of the storage function method for accurate runoff analysis. However, the parameters of the storage function method currently in use are estimated by the empirical formula developed by the limited hydrological analysis in 2012; therefore, they are somewhat inaccurate. The kinematic wave method is a method based on physical variables of watershed and channel and is widely used for rainfall-runoff analysis. By adopting the two-term storage function method by the conversion of the kinematic wave method, parameters can be estimated based on physical variables, which can increase the accuracy of runoff calculation. In this research, the reproducibility of the kinematic wave method by the two-term storage function method was investigated. It is very easy to estimate the parameters because equivalent roughness, which is an important physical variable in watershed runoff, can be easily obtained by using land use and land cover, and the physical variable of channel runoff can be easily obtained from the basic river planning report or topographic map. In addition, this research examined the applicability of the two-term storage function method to runoff simulation of Naechon Stream, a tributary of the Hongcheon River in the Han River basin. As a result, it is considered that more accurate runoff calculation results could be obtained than the existing one-term storage function method. It is expected that the utilization of the storage function method can be increased because the parameters can be easily estimated using physical variables even in unmeasured watersheds and channels.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.842-845
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• 2004

The aim of this study is to compare the classification results for choosing the fuzzy membership function within fuzzy rules. There are various methods of extracting rules from training data in the process of fuzzy rules generation. Pattern distribution characteristics are considered to produce fuzzy rules. The accuracy of classification results are depended on not only considering the characteristics of fuzzy subspaces but also choosing the fuzzy membership functions. This paper shows how to produce various type of fuzzy rules from the partitioning the pattern spaces and results of land cover classification in satellite remote sensing images by adopting various fuzzy membership functions. The experiments of this study is applied to Landsat TM image and the results of classification are compared by fuzzy membership functions.