• International Journal of Concrete Structures and Materials
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• v.8 no.4
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• pp.315-326
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• 2014

This study evaluates the dosages of Class F fly ash, lithium nitrate and their combinations to suppress the excessive expansion caused by alkali-silica reactivity (ASR). In order to serve the proposed objective, the mortar bar specimens were prepared from (1) four dosages of Class F fly ash, such as 15, 20, 25 and 30 % as a partial replacement of Portland cement, (2) up to six dosages of lithium nitrate, such as lithium-to-alkali molar ratios of 0.59, 0.74, 0.89, 1.04, 1.19 and 1.33, and (3) the combination of lithium salt (lithium-to-alkali molar ratio of 0.74) and two dosages of Class F fly ash (15 and 20 % as a partial replacement of Portland cement). Percent contribution to ASR-induced expansion due to the fly ash or lithium content, test duration and their interaction was also evaluated. The results showed that the ASR-induced expansion decreased with an increase in the admixtures in the mortar bar. However, the specimens made with the both Class F fly ash and lithium salt produced more effective mitigation approach when compared to those prepared with fly ash or lithium salt alone. The ASR-induced expansions of fly ash or lithium bearing mortar bars by the proposed models generated a good correlation with those obtained by the experimental procedures.

• Journal of Environmental Science International
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• v.19 no.4
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• pp.389-397
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• 2010

The in vitro toxicities of three crude oils of the Hebei Spirit were examined on laboratory grown plankton, with a focus on the effects of a dispersant. The specific growth rate of phytoplankton and the mortalities of two zooplankton were measured in response to exposure to various concentrations of water accommodated oil, dispersant or both. The effects of the oils varied among the plankton, but were generally low within the range of the oil concentrations used, with little difference in toxicity among the three oils. Such low toxicity appeared to be associated with weathering of the crude oils. Exposure to the dispersant, however, dramatically increased the mortality of zooplankton, with complete inhibition of phytoplankton growth. No synergistic toxic effect was observed with the crude oil and dispersant combination. A better decision making process could be crafted for future application of dispersant in the event of an oil spill in Korean waters to better protect the marine plankton community from the excessive use of dispersant.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.1
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• pp.35-41
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• 2010

Water management is an important issue of PEM fuel cell operation. Water is the product of the electrochemical reactions inside fuel cell. If liquid water accumulation becomes excessive in a fuel cell, water columns will clog the gas flow channel. This condition is referred to as flooding. A number of researchers have examined the water removal methods in order to improve the performance. In this paper, a new water removal method that investigates the use of vibro-acoutic methods is presented. Piezo-actuators which are devices to generate the flexural wave are attached at the end of a cathode bipolar plate. Flexural wave is used to impart energy to resting droplets and thus cause movement of the droplets in the direction of the traveling wave.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.2
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• pp.23-34
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• 1991

Even if we can recover the function of mastication, pronunciation and esthetic using the fixed or removable prosthesis in the loss of teeth or hard tissue in the oral cavity, we use several kinds of implants in order to solve the problem which can be occured when we can't install the denture because of excessive bone resolution or psychlogical affairs. At present Titanium implant plays a major role in this field and has osseointegrated. And the study on the modern material is going on, that result in developing and using the implant which is coated with HA, bone induced material. In this, I studied histologically the change of the bone tissue which is occured when three kinds of HA coated implants. Such as Integral, Sustain, Biovent implanted into mandible of dog and got a 8-weeks healing period. I got the conclusion as follows: 1. Most of the implant which is covered with serveral kinds of HA coating implant in bone after 8 weeks being implanted and has osseointegrated, partially converted into the connective tissue. 2. Biovent formed the connective tissue in the perforated area of inferior alveolar canal and has osseointegrated.

• Journal of Electrical Engineering and Technology
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• v.8 no.3
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• pp.507-515
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• 2013

This paper proposes a compensation method for the $2^{nd}$-order harmonic of single-phase grid-connected wind power generation systems. Theoretically, a single-phase grid-connected inverter system has no choice but to cause the $2^{nd}$-order harmonic to DC-link voltage. The reference active current is affected by the DC-link voltage. The output current from the reference active current is distorted by the $1^{st}$ and $3^{rd}$-order harmonic. The proposed method can compensate, conveniently, the reference active current with the $2^{nd}$-order harmonic. To reduce the $2^{nd}$-order ripple in the reference active current, proposed method takes a PR controller as a feed-forward compensator. PR controllers can implement selective harmonic compensation without excessive computational requirements; the use of these controllers simplifies the method. Both the simulation and experimental results agree well with the theoretical analysis.

• Journal of Korean Medical classics
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• v.23 no.1
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• pp.1-10
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• 2010

Wi Syndrome(痿證) mainly occurs from fluid damages[津液損傷] caused by heat in Gi(氣) phase of the Five viscera, while it sometimes come from the outside. Although the symptoms are presented in the limbs, the disorder roots in the Five viscera, most deeply located in the human body, Therefore, to approach the disorder, we must apply differentiation of the Five viscera in diagnosis. The Lungs, as the head of the Five viscera control the production and distribution of bodily fluids in the body. Functional disorder of the Lungs bring about Wi Syndrome regardless of it being in the Gi phase. Also, psychological depression leads to Wi Syndrome, In other words, depression and uneasiness easily results in the state of Gi blocking and fluid exhaustion in this modern society where there is less manual labor and excessive use of the brain. Besides Gi blockage, the top muscle[宗筋] theory is another important mechanism in the occurrence of Wi Syndrome. Moreover, the disorder is related to Yangmyeong(陽明), which is the sea of food, Chungmaek(衝脈) which is the sea of meridian, in addition to Immaek(任脈), Dokmeak (督脈) and Deameak(帶脈) which are all involved in Wi Syndrome. In conclusion, the Wi Syndrome happens when various factors involved lose balance and harmony with each other.

• International Commerce and Information Review
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• v.7 no.1
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• pp.95-117
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• 2005

The purpose of this study is to provide a conceptual understanding of ASP service for ERP implementation in small-to-medium enterprises under the current market situation in which the significance of information systems was standing out to respond to the rapid changes of managerial environment caused by the spread of Internet. In addition, it was to extract practical causes of introduction of ERP through ASP services by analyzing the causes and benefits considered by small-to-medium enterprises which use it. This study confirms that using ASP is better, faster and cheaper. Therefore, it is inevitable. The enterprises can reduce many risks of in-House ERP system such as excessive initial investment and operational expenses, lengthened constructional time, and the possibility of failure while achieving the benefit of ERP solution. However, there are many considerations which the enterprise carefully take into in order to implement the systems successfully such as selecting the system which is right for the enterprise's environment by setting the goal of implementing the system clearly, reducing the construction time by minimizing the customizing of the system, including the core people who knows the business process well, enough education before and after the implementation, and considering many aspect of ASP service provider. Also, the service provider should develop new way to provide customized service with cheap price while guaranteeing the reliability and supporting the customer's needs actively.

• Health Policy and Management
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• v.8 no.1
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• pp.97-111
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• 1998

Do managers in health center perceive red tape in their organizations\ulcorner Most people would think so, but researchers have often found that health center organizations do not necessarily have higher levels of rule intensity than private hospitals. It there are higher levels in health center organizations, what explains their existence\ulcorner In this article, I discuss the results of a survey of health center managers that explored their perceptions of red tape in their organizations. Red Tape can be defined as rule and procedures that occured a excessive regulation. The survey included two dimensions and two hypotheses of red tape in health center managers. The hypotheses included health center and size that claims cause managers to create red tape. 119 managers who working in health center and private hospitals in Chonbuk area, participated in this study which was conducted by direct interview. The results show some support for two hypothses. The results showed some differences between health center and private hospital managers' perceptions about certain aspects of red tape. I also found differences between large size and small size managers' perceptions. The study call for more systematic analysis of red tape, including the use of methods, in support of current reform efforts aimed at reducing red tape.

• Journal of muscle and joint health
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• v.21 no.3
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• pp.255-264
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• 2014

Purpose: The purpose of the study were to analyze the research trends of compassion fatigue in Korea nurses and to suggest future research directions. Methods: For this study, RISS, KISTI, KISS, National Assembly Library databases were searched using the key words 'compassion fatigue', 'secondary traumatic stress', 'professional quality of life' that contains compassion fatigue as a sub-element, and 'nurses' for this study. A total of 124 articles published in June 2014 were searched and analyzed 19 articles for the final analysis. Results: The most frequently used study design was descriptive (N=17, 89.5%). High compassion fatigue was reported in this study. Factors affecting compassion fatigue were personal factors (e.g., age, health state, and sleep hours), work-related factors (e.g., experience with traumatized patients), and psychological factors (e.g., job stress, anxiety, excessive empathy, social support, and coping strategy). Finally, Consequence factors of compassion fatigue was reported burnout, silencing response and turnover intention. Conclusion: There was a few studies on compassion fatigue. Further research on compassion fatigue needs to use a variety of study designs instruments suitable for Korean nurses, and to develop management programs on compassion fatigue in nurses.

• 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.