• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.6
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• pp.174-186
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• 2001

Excessive outflow of pollutant loads resulting from rapid industrialization has unbalanced the water ecosystem, deteriorating the water quality environment severely. Therefore, measures for improving the water quality are necessary to maintain clean reservoir water and restore water-friendly spaces. A water quality model which is capable of simulating daily reservoir water quality was developed. The model had been applied to Masan reservoir and Wanggung reservoir in Korea. The model appeared to be satisfactory in representing the trend of water quality variations by comparing measured and simulated results. The model had been also applied to assess water purification techniques such as dredged pool, floating island and vegetation purification system. The model was considered to assess the effect of water purification techniques on reservoir water quality improvement. The results of water quality simulation for lake water purification techniques showed that a large facility would be needed to meet the targeted water quality of the reservoir when only one technique is applied. To effectively improve the quality of the polluted reservoir water, it is therefore recommended that pollutant sources should first be controlled, and a combination of the water purification techniques applied to make the utmost use of their secondary effects such as conservation of the reservoir volume capacity, establishment of a recreation space, promotion of bio-diversity, and improvement of the lake landscape.

• Journal of the Korean Electrochemical Society
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• v.8 no.1
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• pp.42-46
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• 2005

It has been known that the synthesis of the cathode materials for the lithium rechargeable batteries by the sol-gel process has many advantages over the conventional solid-state method. It has been, however, a continuing issue that new additional steps should be introduced to commercialize this process. In this work, spray drying was introduced to the existing sol-gel process as a continuous mass production method of the pre-heat treatment precursor materials. The precursors of $LiCoO_2$ and $LiNi_{0.8}Co_{0.2}O_2$ were continuously produced through spray drying from the solution containing stoichiometric amount of lithium, cobalt, and nickel sources as well as a chelating agent. The process variables, such as pH of the starting solution, spray drying conditions, and calcination conditions were optimized. The XRD pattern for the synthesized material indicated a good crystallinity with a layered structure.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2345-2350
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• 2009

As part of an effort to discover bioactive natural products from marine sources, we investigated the bioactive secondary metabolites from two marine isolates of the fungi, Trichoderma viride and Rhizopus stolonifer. Three cyclopentenones, myrothenones A (1) and B (2) and trichodenone A (3), were isolated from T. viride and two cyclopentenones, 2-bromomyrothenone B (4) and botrytinone (5), were isolated from R. stolonifer. The molecular structures and absolute stereochemistries of the cyclopentenones were determined from chemical and physicochemical evidence, including quantum chemistry calculations, X-ray analysis, and the circular dichroism (CD) exciton chirality method. Myrothenone A (1) displays tyrosinase inhibitory activity, with an I$C_{50}$ value of 6.6 ${\mu}M$, and is therefore more active than the positive control, kojic acid.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.83-86
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• 1998

1. Introduction : Low molecular harmful organics such as 1-naphthol and phenol are widely used in industries, and pose serious environmental problems. Wastewater containing low molecular harmful organics may be ejected from various sources including metal-plating industries, circuit-board manufacturing process, photographic and photo-processing industries, refineries and metal-tailing leachate. The pollution of nation harbors, waterways and ground water resources with these organics has reached critical portions, and might also give hazardous influence on human health. Micellar enhanced ultrafiltration(MEUF) is a recently developed process to remove dissolved organics and/or heavy metals present in small or trace quantities from aqueous solution. In this system, the fatal defect is leakage of surfactants especially at low concentration below CMC(critical micelle concentration), which becomes a secondary pollution. Our group proposed to use biosurfactant and polymeric micelle to solve problems mentioned above. In this study we investigated a modified MEUF using PEO-PPO-PEO (polyethyleneoxide-polypropyleneoxide-polyethyleneoxide) block copolymers for the removal of organic solutes such as 1-naphthol and phenol from aqueous wastewater. We proposed PEO-PPO-PEO block copolymers as new surfactants for forming micelles in MEUF, and investigated the solubilization characteristics and efficiency for the removal of 1-naphthol and phenol. PEO-PPO-PEO block copolymers are, environmentally mild and safe as biosurfactants.

• Research in Community and Public Health Nursing
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• v.24 no.1
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• pp.74-86
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• 2013

Purpose: The purpose of this study is to show the development of community health nursing in Korea in light of the life of Lee Keumjeon (1900~1990), who devoted her life to community health nursing. Methods: Primary and secondary sources were collected and analyzed. Results: Lee could get high level education up to college courses, which was very exceptional at that time in Korea. She got nursing and midwifery education in Severance Hospital (1929) and majored in public health nursing at Toronto University (1930). Then, she worked in mother-and-child health practice for more than 10 years. She helped the Korean Nurses' Association to publish Public Health Nursing (1933) and other nursing books. After the liberation of Korea, she became a governmental official in the public health nursing field and tried to establish the national public health nursing system. During the Korean War, she devoted herself to nursing education and practice at nursing schools and hospitals. After the war, she worked as president of the Korean Nurses' Association. In 1959, Lee was given the Nightingale award. Although she retired in 1960, she continued to devote herself to the development of nursing, and published her book Public Health Nursing (1967). Conclusion: Lee worked from 1920s to 1960s for the development of nursing in Korea and during the period Korean nursing showed great development to national system and professional status.

• Journal of The Korean Astronomical Society
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• v.37 no.2
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• pp.79-85
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• 2004

We developed an algorithm to identify and determine periods of variable sources. With its robustness and high speed, it is expected to become an useful tool for surveys with large volume of data. This new scheme consists of an initial coarse. process of finding several candidate periods followed by a secondary process of much finer period search. With this multi-step approach, best candidates among statistically possible periods are produced without human supervision and also without any prior assumption on the nature of the variable star in question. We tested our algorithm with 381 stars taken from the ASAS survey and the result is encouraging. In about $76\%$ cases, our results are nearly identical as their published periods. Our algorithm failed to provide convincing periods for only about $10\%$ cases. For the remaining $14\%$, our results significantly differ from their periods. We show that, in many of these cases, our periods are superior and much closer to the true periods. However, the existence of failures, and also periods sometimes worse than manually controlled results, indicates that this algorithm needs further improvement. Nevertheless, the present experiment shows that this is a positive step toward a fully automated period analysis for future variability surveys.

• Management & Information Systems Review
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• v.11
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• pp.1-21
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• 2002

Corporate culture is being recognized as essential managerial resources in the future business management and in recently the attempts, though weak, of developing the corporate culture which is corresponded with their own structure and needs are being carried on by some major companies. Then, corporate culture research, drawing attention in nowadays, indicates that it attempts to analyze and search the organization matters in the basical dimension in regard to the assumptions, values and beliefs of organization and provides the solution of organizational negative effects, which have not been settled in the previews research methods of organizational behavior, and that present turbulent management environment demands the whole conversion from the previews hard style to the soft managerial style. For this reason, this study aim at identifying organizational structure and corporate culture in the business group. Futhermore, the influence of organizational structure and organizational culture are examined. The objective of this paper attempts to analyze the ways and results of strong and special culture on the organizational structure and culture. To accomplish this purpose, this study gathers in-depth data form various secondary courses. First, uncertainties in market and technology are the main sources of mimetic isomorphism. Due to the high level of uncertainty is market and technologies. Smallness in size is responsible for the low level of complexity in organizational structure. The rapid changes in market, contents of service, and tastes of customers are responsible for the low level of formalization, which enhances swift decision making and responses.

• The Research Journal of the Costume Culture
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• v.13 no.4 s.57
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• pp.513-525
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• 2005

This article examines how the development process of muff has changed over history as well as considering value. This study is based on secondary sources such as books and fashion magazines. The imminent value of muff based on the results of this historical study can be summarized by its utility, its ornamentation, and its fashion value. First, muff is not only used to protect the hands or to keep them warm, but also as a substitute for the purse. Second, muff is an ornament decorated mainly with fur, using splendid colors, patterns, embroidery etc. Third, muff goes with other clothes as an ornament, and therefore, can be a means to express the attitude or behavior of many circumstances. Muff has vanished in casual wear and could meet by chance in a designers collection. However, the fashion value of muff brings it new attention making various creative fashion images by itself or with other clothes in the modern fashion trend. This study on the history and the aesthetic value of muff could stimulate the appreciation of the ornamentation aside from the clothes and serve to develop a new creative way in fashion design.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.2
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• pp.158-166
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• 2016

To characterize the features of particle apparent density, continuous measurements of particle number size distributions from optical particle sizer (OPS) and 24 hr integrated particle mass concentrations from filter based sampler were conducted at the National institute of environmental research NamBu Supersite (NNBS, $35.22^{\circ}N$, $126.84^{\circ}E$) in Gwangju for 16 days from Nov. 4 in 2014. Source apportionment model was carried out by applying Positive Matrix Factorization (PMF) to particle size distribution data. Three different distributions related to primary and secondary sources were investigated by the diurnal patterns of identified factors. Density estimated by gaussian model has been calculated as $1.69g/cm^3$ with 95% confidence bounds ($1.57{\sim}1.81g/cm^3$).

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.6
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• pp.29-37
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• 1994

Active noise control of random noise which propatate in the vehicle cabin as a form of spherical wave is the target of this study. In the previous study, the adaptive algorithm for adaptive controller is presented for the application in active noise control system. And for the preliminary study of adaptive active noise control in vehicle cabin as a real system, a computer simulation is performed on the effectiveness of the adaptive algorithm in the amplitude of the pressure fluctuation. This work studies the implementation of multi-channel feedforward adaptive algorithm for the reduction of the noise inside a vehicle cabin using a number of secondary sources derived by adaptive filtering of reference noise source. Multi-channel adaptive feedforward algorithm are verified in numerical simulation and semi-experimental justification of developed system is made on a domestic passenger car. In the results of semi-experimental study, the noise of specific region in the interior of automobile are reduced for the appreciabe sound pressure level in the operating engine rpm and finally this study suggests the capabilities of the real time active noise control in 3 dimensional acoustic fields.