• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.45-50
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• 2008

Purpose: A soft contact lens was manufactured by adding naringin known as natural anti-bacterial material to resin solution. With solution eluted from manufactured contact lens, we examined its optical properties, physical and chemical states of naringin in the polymer, and elution properties. Methods: The soft contact lens with naringin was synthesized by bulk polymerization method. IR spectrum and HPLC were used to define the bonding type of naringin itself in the soft contact lens contained naringin, elution process of naringin to the saline solution, and the amount of naringin solution eluted from the lens with elapsed time. Results: Naringin was continuously eluted with constant concentration from the soft contact lens for about a month and the structure ofnaringin which is eluted was as same as before it was added to resin solution. Any change in optical properties such as transmittance couldn't be found. Bonding state and the structure of naringin in contact lens were explained with IR spectrum and HPLC results. Conclusions: In the contact lens with naringin, naringin remained in the contact lens bonding with weak hydrogen bonding and/or van der Waals force between naringin and polymer. Naringin was continuously eluted from the contact lens contained naringin during about 1 month. Even after 1 month, it showed that the concentration of the naringin eluted was approximately 10 ppm in a day. From the results, adding naringin to the soft contact lens resin is very effective method for manufacturing the soft contact lens which has anti-bacterial function for a period of time.

• Journal of Plant Biotechnology
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• v.41 no.4
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• pp.229-235
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• 2014

Gastrodia elata Blume, an achlorophyllous orchid plant, has been used in traditional medicine and harvests in spring and fall. Here we investigated the quantitative changes of amino acids in G. elata by harvest times and seed tubers. In the results, we found that there was not big difference in contents of total amino acids but the distribution of amino acids differed depending on harvest times. 19% of total amino acids were asparagin and valine, an essential amino acid, occupied 10% within total amino acids in the tubers harvested in October. Among amino acids in the tubers harvested in April, serine occupied 23% and arginine, an essential amino acid, occupied 10% within total amino acids in tuber. Interestingly, the use of sexually propagated seed tubers produced high concentration of total amino acids compared to vegetatively propagated seed tubers. As for sexually propagated seed tubers, essential amino acids contents similar to the tubes harvested in October and nonessential amino acids contents similar to the tubers harvested in April. In this study, we found that amino acids contents in G. elata tubers altered depending on various cultivation practices. Therefore if these results can be applied to food industry, the value of G. elata as a natural food resource will be enhanced to a great extent.

• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.83-99
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• 2014

Fish community of eight lagoons in the east seashore, Korea were investigated from 2007 to 2008. Total 66 species caught during the period were belonged to 34 families, and total biomass was 2,024.8 kg. Also, similarity analysis results of each lagoon were divided three major groups. On the other hand, result of a comparison of the composition ratio of freshwater fish, brackish water fish, and seawater fish which is divided into separate each age data of previous studies has emerged in this study, since the 1990's, freshwater fish is reduced, seawater fish and increase, some changes in the fish community had changed dynamically in the lagoon. These changes considered that against the natural hydrach succession will change to freshwater lake from brackish water lake. Therefore, we considered to ecological characteristics of lagoon and process of hydrach succession when conservation, management, and restoration of the lagoons.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.275-284
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• 2017

As the 3D Greenery system is known to improve the urban environment, it works as new alternative for eco-friendly building and warrants further study for application to the domestic field. This study aimed to apply the design components for eco-friendly composition by investigating the spatial characteristics of the 3D Greenery System reflected in interior and exterior of buildings and to analyze the organization and design elements of domestic and foreign cases. The results showed that instances of the Greenery System tended to be a large scale and high-density development in order to expand various exterior spaces. Although its early forms were often found in such public facilities as exhibition and education purpose, cases of multi-unit dwelling have been growing. Allowing apartment residents to prefer intimate space by providing various such spaces for residential units and offering independent green spaces would induce diverse residents' lifestyles rather than monotonous design. The analysis also indicated that community space composed of various outdoor spaces and atmosphere would change life patterns of multi-housing and establish a real neighborhood through social interaction. Moreover, further investigation of the design patterns of outdoor space arrangement is needed since the Greenery system actively reflects the environmental characteristics of building sites and clearly shows a tendency to utilize natural terrain and slope in building shapes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.584-591
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• 2017

Metal removal from water has not been explained clearly by either adsorption onto the surface of absorbents or precipitation as metal hydroxides because those occur simultaneously to a certain extent. For a better understanding of the metal removal mechanisms, batch experiments were performed using soil calcined at $850^{\circ}C$ under various pH conditions for Cu, Pb, Zn, Cd, and Cr. The results showed that the metal removal efficiency with the exception of Cr decreased abruptly, even within 5 min, showing more than 90% removal. The pH of each reactant increased gradually from around 7 to 9 with time. The increases in metal removal at higher pH appear to be associated with metal hydroxides precipitation. Comparative experiments, which were carried out changing the pH by reacting with commercial activated carbon (CAC), natural yellow soil (NYS), and calcined yellow soil (CYS), showed that the pH of the CYS only increased with time. Calcination processes might lead to a change in the physical properties of the soil matrix resulting in a high pH when reacted with water. Apart from adsorption onto the surface of the absorbents, these results show that the adsorption and/or precipitation of hydroxides onto the surface of adsorbents also play important roles in regulating the dissolved metals under alkaline conditions.

• Journal of Radiation Industry
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• v.5 no.2
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• pp.159-164
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• 2011

A variety of natural polymers have been used as tissue engineering scaffolds, drug delivery system, and cosmetic materials due to their higher biocompatibility and water uptake. As a major component of extracellular matrix, hyaluronic acid consisting of D-glucuronic acid and N-acetylglucosamine has been popularly used as a hydrogel material. Even though it has good properties to be used in the tissue engineering and cosmetic industry, its higher viscosity has limited a potential use in a variety of applications; only low content should be applied in preparing above products. In the present study, we investigated the effect of electron beam irradiation on the properties of hyaluronic acid. Hyaluronic acid paste containing low contents of water changed to solution after electron beam irradiation ranging from 1 to 10 kGy, which didn't exhibit any alteration of surface properties and morphological change after freeze-drying. However, its viscosity was significantly decreased as absorbed dose increased, which was approximately one by hundred in comparison with the viscosity of original hyaluronic acid solution with same concentration. In addition, it can still interact with positive charged chitosan generating polyelectrolyte complex. Therefore, only viscosity was decreased after electron beam irradiation, whereas other properties of hyaluronic acid maintained. Consequently, these hyaluronic acids with lower viscosities can be used in a variety of applications in tissue engineering, drug delivery, and cosmetic industry.

• Korean Journal of Remote Sensing
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• v.21 no.4
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• pp.253-271
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• 2005

We have analyzed surface water temperature and seasonal stratification of lakes in the Han river system using time-series Landsat images and in situ measurement data. Using NASA equation, at-satellite temperature is derived from 29 Landsat-5 TM and Landsat-7 ETM+ images obtained from 1994 to 2004, and was compared with in situ surface temperature on river-type dam lakes such as Paro, Chuncheon, Euiam, Chongpyong, Paldang, and with 10m-depth temperature on lake-type dam lake Soyang. Although the in situ temperature at the time of satellite data acquisition was interpolated from monthly measurements, the number of images with standard deviation of temperature difference (at-satellite temperature - in situ interpolated temperature) less than $2^{\circ}C$ was 24 on which a novel statistical atmospheric correction could be applied. The correlation coefficient at Lake Soyang was 0.915 (0.950 after correction) and 0.951-0.980 (0.979-0.997 after correction) at other lakes. This high correlation implies that there exist a mixed layer in the shallow river-like dam lakes due to physical mixing from continuous influx and efflux, and the daily and hourly temperature change is not fluctuating. At Lake Soyang, an anomalous temperature difference was observed from April to July where at-satellite temperature is $3-5^{\circ}C$ higher than in situ interpolated temperature. Located in the uppermost part of the Han river system and its influx is governed only by natural precipitation, Lake Soyang develops stratification during this time with rising sun elevation and no physical mixture from influx in this relatively dry season of the year.

• Journal of Korean Philosophical Society
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• v.137
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• pp.193-223
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• 2016

This research examines the recognition of nature as identified by Zhuangzi through the man of truth. Zhuangzi defines inactivity as an act of nature and personifies it as the man of truth, a holy man who achieves salvation. It is the stage that is united with nature by breaking out of secular restriction and achieving the absolute liberal spirit. The man of truth is the origin enabling all the acts of nature. And since the existence of all living things is connected, the change of life and death complies with the operation of nature. It is an irresistible destiny for all human beings. Therefore, the duty of nature recognizes the life and death of all creation into a single perspective. In this sense, the feelings of joy and sorrow that human beings feel are unnecessary. When following the duty of nature and destiny, which is to break out of secular desire and empty the mind, it is possible to go to the stage of futility and enjoy a silent and comfortable life. Zhuangzi explains it as living free from worldly cares, which is the stage of 'Soyoyoo(逍遙遊)'. In this thesis, the principles of courtesy and the virtue of Confucianism are stated and are contrary to the concept of futility asserted by Zhuangzi. But, a different approach could be attempted which recognizes a superman who is even more evolved from the man of truth. The philosophical ideology of Zhuangzi could be a necessary factor for modern people and his oriental natural spirit should be highly appreciated.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.1-1
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• 2016

Many of the world's large ecosystems are severely stressed due to population growth, water quality and quantity problems, vulnerability to flood and drought, and the loss of native species and cultural resources. Consequences of climate change further increase uncertainties about the future. These major societal challenges must be addressed through innovations in governance, policy, and ways of implementing management strategies. Science and engineering play a critical role in helping define possible alternative futures that could be achieved and the possible consequences to economic development, quality of life, and sustainability of ecosystem services. Science has advanced rapidly during the past decade with the emergence of science communities coalescing around 'Grand Challenges' and the maturation of how these communities function has resulted in large interdisciplinary research networks. An example is the River Experiment Center of KICT that engages researchers from throughout Korea and the world. This trend has been complemented by major advances in sensor technologies and data synthesis to accelerate knowledge discovery. These factors combine to allow scientific debate to occur in a more open and transparent manner. The availability of information and improved communication of scientific and engineering issues is raising the level of dialogue at the science-policy interface. However, severe challenges persist since scientific discovery does not occur on the same timeframe as management actions, policy decisions or at the pace sometimes expected by elected officials. Common challenges include the need to make decisions in the face of considerable uncertainty, ensuring research results are actionable and preventing science being used by special interests to delay or obsfucate decisions. These challenges are explored in the context of examples from the United States, including the California Bay-Delta system. California transfers water from the wetter northern part of the state to the drier southern part of the state through the Central Valley Project since 1940 and this was supplemented by the State Water Project in 1973. The scale of these activities is remarkable: approximately two thirds of the population of Californians rely on water from the Delta, these waters also irrigate up to 45% of the fruits & vegetables produced in the US, and about 80% of California's commercial fishery species live in or migrate through the Bay-Delta. This Delta region is a global hotspot for biodiversity that provides habitat for over 700 species, but is also a hotspot for the loss of biodiversity with more than 25 species currently listed by the Endangered Species Act. Understanding the decline of the fragile ecosystem of the Bay-Delta system and the potential consequences to economic growth if water transfers are reduced for the environment, the California State Legislature passed landmark legislation in 2009 (CA Water Code SS 85054) that established "Coequal goals of providing a more reliable water supply for California and protecting, restoring, and enhancing the Delta ecosystem". The legislation also stated that "The coequal goals shall be achieved in a manner that protects and enhances the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place." The challenges of integrating policy, management and scientific research will be described through this and other international examples.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.232-232
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• 2019

The persistence of drought periods and water scarcity is a growing public concern, as climate change projections indicate a more critical scenario in the future. The sustainability of water resources for the increasing population, and to ensuring crop production will unarguably be a daunting task for the water resources managers, with a projected 9.8 billion people by 2050 as well as the need to increase food production by 70 to 100%. Consequently, there is a need for significant irrigation water use for more crop production in the face of stiff competition among water users. However, the available natural resources are already over-constrained, and the allocation of more resources for food production is not feasible. Currently, about two-thirds of global water withdrawer is used by the agricultural sector while 48% of water resources in Korea is used for agricultural production. Despite the apparent ecological deficit and unfavorable conditions of resources utilization, a staggering amount of food waste occurs in the country. Moreover, wastage of food translates to waste of all the resources involved in the food production including water resources. Food waste can also be considered a serious potential for economic and environmental problems. Hence, exploring an alternative approach to efficient resources utilization in a more sustainable way can ensure considerable resources conservation. We hypothesized that reducing food waste will decline the demand for food production and consequently reduce the pressure on water resources. We investigated the food wastage across the food supply chain using the top-down datasets based on the FAO mass balance model. Furthermore, the water footprint of the estimated food wastage was assessed using the representative of selected food crops. The study revealed that the average annual food wastage across the food supply chain is 9.05 million tonnes, signifying 0.51 kg/capita/day and 48% of domestic food production. Similarly, an average of 6.29 Gm3 per annum of water resources was lost to food wastage, which translates to 40% of the total allotted water resources for agriculture in the country. These considerable resources could have been conserved or efficiently used for other purposes. This study demonstrated that zero food waste generation would significantly reduce the impact on freshwater resources and ensure its conservation. There is a need for further investigation on the food waste study using the bottom-up approach, specifically at the consumer food waste, since the top-down approach is based on estimations and many assumptions were made.