• Clean Technology
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• v.24 no.1
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• pp.41-49
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• 2018

Y zeolites with different extra-framework cations, such as $Na^+$, $N^+$, $Ca^{2+}$, and $Cu^{2+}$, with different charge and ionic radius have been investigated to greatly enhance a working capacity (W) of $CO_2$ adsorption at $25^{\circ}C$ and a $CO_2/CO$ selectivity factor (S). A sample of NaY with a very small amount of 0.012% $Ca^{2+}$ was fully reversible for seven times repeated $CO_2$ adsorption/desorption cycles, thereby forming no surface carbonates unlikely earlier reports. Although at pressures above 4 bar, 2.00% CaY, 1.60% CuY and 1.87% LiY all showed a $CO_2$ adsorption very similar to that measured for NaY, they gave a significant decrease in the adsorption at lower pressures, depending on the metal ion. At 0.5 ~ 2.5 bar, the extent of $CO_2$ adsorption was in the order NaY > 1.60% CuY > 2.00% CaY > 1.87% LiY. All the $Na^+-based$ metals-exchanged zeolites have a FAU (faujasite) framework and a Si/Al value near 2.6; thus, there is no discernible difference in the framework topology, framework chemical compositions, effective aperture size, and channel structure between the zeolite samples. Therefore, the distinctive behavior in the adsorption of $CO_2$ with a character as a weak Lewis acid is associated with the site basicity of the zeolites, and the interaction potentials of the cations. Different trend was shown for a CO adsorption due to weaker quadrupole interactions. Adsorption of $CO_2$ and CO on samples of CaY with 0.012 to 5.23% Ca disclosed a significant dependence on the Ca loading. The $CO_2$ adsorption increased when the cation exists up to ca. 0.05%, while it decreased at higher Ca amounts. However, values for both W and S could greatly increase as the bare zeolite is enriched by $Ca^{2+}$ ions. The 5.23% CaY had $W=2.37mmol\;g^{-1}$ and S = 4.37, and the former value was comparable to a benchmark reported in the literature.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.4
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• pp.75-86
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• 2015

The survey was taken from July to August 2012 by users who visited Gyeongju National Park to compare the perceived gap of users regarding management policy by characteristic of Gyeongju National Park district type in this study. Gyeongju National Park users' characteristic, use pattern and perception regarding park management policy were created as survey items. First, district type was classified based on use pattern of the visitor and the key resources of 8 districts in Gyeongju National Park. Tohamsan District, which has many visitors for the purpose of scenery appreciation and recreation with Bulguksa and Seokguram Grotto, is classified as tourism type, Namsan and Daebon District, which bring in many visitors seeking to learn about historical culture and environmental education, could be classified as historical culture education types, and Hwarang, Seoak, Sogeum River, Gumisan District are places residents use for physical training, hiking and walking to improve health, thus classifying them as neighborhood park types. People perceived that the tourism type is where users for historical artifact tours are concentrated, thus consideration for plans that can improve visitors' satisfaction from a user limit policy is required, and a manager's right to control use behavior must be reinforced in historical culture education types. On the other hand, users of neighborhood parks found the lowest necessity for most of the policy, and this showed that users of each of Gyeongju National Park's districts felt differently about the need for policies. This result is expected to be utilized as a database for introducing policy that reflects the perception of users in each districts of Gyeongju National Park in the future.

• Journal of the Korean association of regional geographers
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• v.3 no.1
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• pp.183-198
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• 1997

This case study was conducted by verification the site characteristics based on the questionnaire and interview obtained from the all factories located at No. 1 developing area in Kumi industrial complex. The site characteristics were presumed from the process of location behavior and spatial linkage. Kumi industrial complex was developed to improve export industry at national levels by providing chief land price and benefiting various tax. Kumi industrial complex which enticed many factories is playing an important role in export industry in Korea. At beginning, the detention of large enterprises promoted the establishment of related small to medium sized factories into the complex. Two distinctive industries. textile and electronic, were reflected by the purpose to establish the complex and industrial characteristics of Taegu city. respectively. In Kumi industrial complex, positive responses on traffic and raw material supply and negative reactions on the environmental impact on social community as well as high labor charge were investigated. Especially the higher labor cost prevented to hire laborers effectively. In the linkages of spatial and raw material, most factories in the complex depended on the availability of out side the Kumi city. For the textile factories, the supply of raw material and parts were relied on Taegu and/or other cities, whereas in electronic factories purchased them mainly from other cities and partly from abroad. Although questionnaire and interview suggested it, most of the parts were supplied by a parts maturing companies on the complex to a few large enterprises. In the marketing linkage, textile factories revealed higher relation-ship with the foreign countries and sewing factories in Korea. On the other hand, electronic factories have strong relation-ships in the marketing linkage to the parts supplying companies in the complex or large-scale resembling companies in other cities. In the textile companies, the right for decision on purchasing raw materials and parts is belonging to the owner whereas mother enterprise usually have the right for the marketing. In the case of the electronic factories, all the purchasing activities are related to the sub-contracting companies. In the service linkage, the Quality of the service created spatial distinction. There was high linkages on inside of Kumi complex for the low grade services such as repairing and installing machines, whereas strong linkages on outside of the complex for the high grade services such as management, law, taxation, new product development. and manufacturing technology. In the linkages of activity on the R&D (research and development), electronic factories do not have sufficiently qualified institutes in the complex. Strong regional linkages in the field of textile and electronic industries revealed limitations of the local industrial complex. In the sub-contracting linkage, high linkage ship within Kumi boundary reflected the characteristics of industrial site in the complex. There, most decisions by the companies centered by the mother enterprise.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.47-56
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• 2020

In this study, three levels of W/B(Water to Binder) ratio (0.37, 0.42, 0.47) and substitution ratio of GGBFS (Ground Granulated Blast Furnace Slag) rate (0 %, 30 %, 50 %) were considered to perform RCPT (Rapid Chloride Diffusion Test) at the 1,095 aged day. Accelerated chloride diffusion coefficient and passed charge of each concrete mixture were assessed according to Tang's method and ASTM C 1202, and improving behaviors of durability performance with increasing aged days are analyzed based on the test results of previous aged days from the preceding study. As the age of concrete increases, the passed charge and diffusion coefficient have been significantly reduced, and especially the concrete specimens containing GGBFS showed a significantly more reduction than OPC(Ordinary Portland Cement) concrete specimen by latent hydraulic activity. In the case of OPC concrete's results of passed charge, at the 1,095 days, two of them were still in the "Moderate" class. So, if only OPC is used as the binder of concrete, the resistance performance for chloride attack is weak. In this study, the time-parameters (m) were derived based on the results of the accelerated chloride diffusion coefficient, and the deterministic and probabilistic analysis for service life were performed by assuming the design variable as a probability function. For probabilistic service life analysis, durability failure probabilities were calculated using Monte Carlo Simulation (MCS) to evaluate service life. The service life of probabilistic method were lower than that of deterministic method, since the target value of PDF (Probability of Durability Failure) was set very low at 10 %. If the target value of PDF suitable for the purpose of using structure can be set and proper variability can be considered for each design variable, it is believed that more economical durability design can be made.

• Journal of Korean Society of Forest Science
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• v.101 no.1
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• pp.36-45
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• 2012

Education on the environment and plants offered by arboretum for today's people not only contribute to foster a better natural environment in urban region but also provide visitors with decent refreshment environment and beyond. In the study, the author undertook the observation on usage behavior and satisfaction model of arboretum visitors expect and investigated the facilities and programs to be offered by arboretum in order to propose the opinion regarding the service. For observation size of variables in a multiple regression analysis of variables is influencing satisfaction rankings walks the line of flow, the educational effect on the environment, cleanliness of the facility, visits pay, natural beauty, diversity of trees, accessibility and friendliness of staff, expansion of facilities in the arboretum and appeared as a complement. In case of visitor attribute, the residents living near the facility showed the highest visit frequency of more than 5 times, especially as part of taking a walk. This proves that the visit to arboretum is considered as part of everyday life, and thus a new program and walk path as well as movement route are needed to be developed for the visitors. In the question relating to the facilities and operation programs in Daegu Arboretum, particularly the requests by visitors, they responded that the establishment of cultural event, beautiful natural scenery, refreshment and convenience facilities is the most critical issue. In addition, the management on withered trees and bare lands is an urgent issue as well. In this sense, the Operation and Management Strategies based upon the visitor behaviors and model of satisfaction are needed to deal with the adoption of diverse events and festivals joined by local residents, ombudsman program, environmental program development for students and teachers within the region, negligent bare lands and withered tree replacement, and cafeteria facility improvement and supplement as well as the bench marking of other facilities than arboretums located in other regions. These items are thought to be sufficiently dealt with by Daegu Arboretum having no more external resources. It is recognized that the visitor satisfaction begins from a minor thing, and a small difference determines a great satisfaction, and thus the software approach rather than hardware one is in need.

• Korean Journal of Heritage: History & Science
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• v.53 no.2
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• pp.110-139
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• 2020

Reclamation is the act of creating new lands by constructing dikes in offshore tidal flats to utilize them for various purposes, including the establishment of farmland to secure food for an increasing population. Based on the fact that reclamation has resulted in drastic changes in the environmental, economic, social, and cultural aspects of land expansion and development, population movement, and the formation of cities since ancient times, I reviewed the value of reclamation sites and addressed the issue of how to preserve and utilize them. "Reclamation culture" refers collectively to the recognition and concept system, behavior styles, and cultural products created by changes in the environment, and the tangible, intangible, and natural heritage generated directly and indirectly by reclamation is defined as "reclamation cultural heritage". It shows that the historical background of reclamation accords with prevailing trends, and that the reclamation sites possess cultural heritage value due to their historical, academic, and scarce characteristics. Numerous reclamation cultural heritage sites at the Gwangwhal and Gyehwa dikes are on the verge of being destroyed, with their original function having ended after the construction of Saemangeum Sea Wall. I propose measures to preserve these under the principle that utilization is based on the basic premise of conservation. First of all, modern and contemporary reclamation sites must necessarily be designated and managed as registered cultural properties, local cultural heritage, future heritage, and agricultural heritage. In particular, as it has been confirmed that reclamation sites created after the Goryeo and Joseon dynasties and the 1950s have not been designated as cultural heritage sites. It is necessary to review the characteristics and values of such reclamation sites through a full survey of national reclamation data. Effective and sustainable utilization of reclamation cultural heritage, which has not been acknowledged in the past due to its close relationship with our lives, is necessary to search for hidden stories found within that heritage, to organize governance for the efficient use of reclamation resources, and to build a museum to collect and display the history and culture of the reclaimed areas. Finally, through links with countries with experience in reclamation, we will be able to cope jointly with international issues such as those pertaining to society, culture, and environment, and would be able to implement various projects to further the advancement of human beings.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.66-75
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• 2015

This study investigated eating behaviors (life-style, breakfast pattern, eating environment, snack pattern, and awareness of breakfast) by breakfast frequency (0~2 times, 3~6 times, and 7 times per week) of high school students (146 males and 165 females) in the Yongin region. The percentage of 'mother' as breakfast preparer increased with elevated breakfast frequency, whereas 'myself' was lower for females (P<0.001). Regarding reasons for skipping breakfast, 'getting more sleep' increased with elevated breakfast frequency, whereas 'loosing appetite' decreased in males (P<0.001). Regarding family reaction to skipping breakfast, 'advising' increased with elevated breakfast frequency in females (P<0.001). Skipping breakfast by eating snacks was higher in females (51.6%) than in males (35.6%), and skipping dinner was higher (53.4%) in females. Awareness of breakfast importance increased with elevated breakfast frequency in males (P<0.05) and females (P<0.001). Perception of correlation between health and breakfast was higher in females (54.8%) compared to males (43.9%), and the most important reason was 'energy supplement'. 'Eating now and will eat' increased with elevated breakfast frequency in males (P<0.001) and females (P<0.001), whereas sum of 'not eating now and will not eat' and 'eating now but will not eat' were 19.2% and 14.2% in males and females, respectively. Therefore, appropriate education programs emphasizing importance of eating breakfast and environmental improvement for regularly eating breakfast for high school students are highly required.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.1
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• pp.135-146
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• 2015

This study was carried out to understand ecological characteristics of Korean goral such as home range, seasonal home range and habitat use and used for Korean goral restoration and conservation, through a pair of gorals in the north Gyeongbuk province of Korea. With data from GPS collars, we analyzed the behavioral characteristics of the endangered Korean gorals(n=2) in Uljin area from June 2013 to July 2014. As a result, their home range was $1.38{\pm}0.24km^2$ in MCP 95%, $0.81{\pm}0.09km^2$ in FK 95% and $0.15{\pm}0.16km^2$ in FK 50% (t=8.118, p>0.05). Seasonal home range for MCP 95% was $0.74{\pm}0.31km^2$ > (winter) > $0.71{\pm}0.27km^2$ (spring) > $0.61{\pm}0.06km^2$ (autumn) > $0.27{\pm}0.04km^2$ (summer) (F=2.135 p>0.05). It showed that home range in winter was the largest and that in summer was the smallest. Mean elevation of male for seasonal habitat use was $440.18{\pm}71.32m$ in summer and that of female was $727.25{\pm}99.98m$ in spring. The lowest altitude for male was $372.72{\pm}70.79$ and female was $664.60{\pm}139.71m$. It meant that there were seasonal change and thus annual and seasonal behavior characteristics for both sexes had different correlation according to elevation change. Although in this study the correlation with prey in habitat and the changes of habitat disturbance were not clearly investigated, We could understand goral home range and habitat use through research data.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.90-104
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• 2019

In this study, CALPUFF modeling was performed, using a real surface and upper air meterological data to predict trustworthy modeling-results. Pollutant-releases from windscreen chambers of enclosed poultry farms, P1 and P2, and from a open poultry farm, P3, and their diffusing behavior were modeled by CALPUFF modeling with volume sources as well as by finally-adjusted CALPUFF modeling where a linear velocity of upward-exit gas averaged with the weight of each directional-emitting area was applied as a model-linear velocity ($u^M_y$) at a stack, with point sources. In addition, based upon the scenario of poultry farm-releasing odor and particulate matter (PM) removal efficiencies of 0, 20, 50 and 80% or their corresponding emission rates of 100, 80, 50 and 20%, respectively, CALPUFF modeling was performed and concentrations of odor and PM were predicted at the region as a discrete receptor where civil complaints had been frequently filed. The predicted concentrations of ammonia, hydrogen sulfide, $PM_{2.5}$ and $PM_{10}$ were compared with those required to meet according to the offensive odor control law or the atmospheric environmental law. Subsequently their required removal efficiencies at poultry farms of P1, P2 and P3 were estimated. As a result, a priori assumption that pollutant concentrations at their discrete receptors are reduced by the same fraction as pollutant concentrations at P1, P2 and P3 as volume source or point source, were controlled and reduced, was proven applicable in this study. In case of volume source-adopted CALPUFF modeling, its required removal efficiencies of P1 compared with those of point source-adopted CALPUFF modeling, were predicted similar each other. However, In case of volume source-adopted CALPUFF modeling, its required removal efficiencies of both ammonia and $PM_{10}$ at not only P2 but also P3 were predicted higher than those of point source-adopted CALPUFF modeling. Nonetheless, the volume source-adopted CALPUFF modeling was preferred as a safe approach to resolve civil complaints. Accordingly, the required degrees of pollution prevention against ammonia, hydrogen sulfide, $PM_{2.5}$ and $PM_{10}$ at P1 and P2, were estimated in a proper manner.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.3
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• pp.158-169
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• 2019

A probabilistic model that can predict the residual useful lifetime of structure is formulated by using the gamma process which is one of the stochastic processes. The formulated stochastic model can take into account both the sampling uncertainty associated with damages measured up to now and the temporal uncertainty of cumulative damage over time. A method estimating several parameters of stochastic model is additionally proposed by introducing of the least square method and the method of moments, so that the age of a structure, the operational environment, and the evolution of damage with time can be considered. Some features related to the residual useful lifetime are firstly investigated into through the sensitivity analysis on parameters under a simple setting of single damage data measured at the current age. The stochastic model are then applied to the rubble-mound breakwater straightforwardly. The parameters of gamma process can be estimated for several experimental data on the damage processes of armor rocks of rubble-mound breakwater. The expected damage levels over time, which are numerically simulated with the estimated parameters, are in very good agreement with those from the flume testing. It has been found from various numerical calculations that the probabilities exceeding the failure limit are converged to the constraint that the model must be satisfied after lasting for a long time from now. Meanwhile, the expected residual useful lifetimes evaluated from the failure probabilities are seen to be different with respect to the behavior of damage history. As the coefficient of variation of cumulative damage is becoming large, in particular, it has been shown that the expected residual useful lifetimes have significant discrepancies from those of the deterministic regression model. This is mainly due to the effect of sampling and temporal uncertainties associated with damage, by which the first time to failure tends to be widely distributed. Therefore, the stochastic model presented in this paper for predicting the residual useful lifetime of structure can properly implement the probabilistic assessment on current damage state of structure as well as take account of the temporal uncertainty of future cumulative damage.