• Korean Chemical Engineering Research
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• v.52 no.4
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• pp.413-424
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• 2014

The potential of using the biogas as energy source has long been widely recognised and current techniques are being developed to upgrade the technical quality and to enhance energy efficiency. The objective of this paper is to present efficient and effective pre-treatment methods of increasing the amount of produced biogas in anaerobic digestion of activated sludge treatment process. The paper also presents a review of the effect on biogas production between pre-treated and raw sludge, and also put forward the advantages and disadvantages of each pre-treatment method.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.113-120
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• 2005

Soil nailing system can be mentioned to a method of supporting as the shear strength of in-situ soils is increased by passive inclusions. In the general soil nailing system, facing walls are used in two kind of a lattice concrete block or a cast in placed concrete wall. A case of lattice concrete blocks is used in slow slopes greater than 1:0.7. Also, a case of a cast in placed concrete wall is used in steep slopes less than 1:0.5. The cast in placed concrete walls are constructed to 30cm thick together with a shotcrete facing. In this study, the assembling soil nailing method as a new soil nailing system is proposed. This method is constructed assembly using precast concrete panels. Therefore ability of the construction and quality of the facings can be modified than a usual soil nailing system. Also, this method can be obtained the effects that a global slope stability increase, as precast concrete panels is put on cutting face after excavating a slope.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.3
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• pp.619-629
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• 2016

This study was a descriptive study to investigate emotional labor, clinical practice stress and satisfaction of clinical practice in nursing college students. The data were collected using an self-reporting questionnaire from June 1 to July 12, 2015. Collected data were analysed on SPSS Win 20.0. The study results were summarized as follows : The students' emotional labor was $3.13{\pm}0.54$ in average on a scale of 5. The clinical practice stress was $3.65{\pm}0.47$ in average, and students' satisfaction of clinical practice was $3.41{\pm}0.43$. The emotional labor has positive correlation significantly with clinical practice stress(r=0.353, p<.001), and negative correlation with satisfaction of clinical practice (r=-0.170, p<.007). In stepwise multiple regression to put control variables, emotional labor and clinical practice stress were no significant influence toward satisfaction of clinical practice. According the result, to improve the satisfaction of clinical practices emotional labor should be released. Moreover it is necessary to attention to the health care of nursing students and it is needed to boost up the students satisfaction with major, more friendly relations should be built with co-trainees.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.5
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• pp.353-360
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• 2015

In a essay that was published on 'Science' in December 2014 as a part of the supplement "The Art and Science of Traditional Medicine," the eastern and western medical theories are discussed with reference to the model-dependent realism suggested by Stephen Hawking and Leonard Mlodinow. This paper examines what the model-dependent realism is, and how it affects the future direction of researches in traditional Korean medical theories. The model-dependent realism holds a meaning in that it puts traditional medical theories in a perspective of models, and allows for application of recent studies in scientific philosophy for researches in traditional medical theories. Especially, the model studies by R. Giere et al. will help elaborate the traditional medical theories from a model perspective. From a model perspective, the 'visceral manifestation', 'meridian and collateral', 'qi-blood', 'eight principles' and 'constitution' theories of traditional medicine have the potentials to develop into valid models, and the traditional medical theory's phenomenological and holistic perspective distinguishes it from western medicine, giving it a competitive edge. In addition, the epistemological pluralism of model-dependent realism can serve as an alternative to relativism or rationalism perspective which put eastern and western medicine in opposition until now.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.349-354
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• 2011

Tuned mass damper is widely used in many applications of industry. The main advantage of tuned mass damper is that it can increase the damping ratio of system and reduce the vibration amplitude. Meanwhile, the natural frequency of system will be divided by two peaks, and the peak speeds are closely related to the mass and the stiffness of auxiliary mass system added. In addition, the damping ratio will also affect the peak frequency of the dynamic response. In the present research, the nonlinear mechanical characteristics of rubber is investigated and put into use, since it is usually manufactured as the spring element of tuned mass damper. By the sense of the nonlinear stiffness as well as the damping ratio which can be changed by preload applied on, the shape memory alloy is proposed to control the auxiliary mass system by self-optimizing. Supported by the experiment data of rubber, the 1 DOF theoretical model and finite element model based on computer simulation are implemented to perform the feasibility of the proposed semi-active tuned mass damper working on the drive shaft.

• Economic and Environmental Geology
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• v.13 no.4
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• pp.229-239
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• 1980

A various kinds of harmful gases in the gallery and the increasing quantity of in-flow water are the important factors causing mainly the decline in production. In this thesis, the increase and decrease of in-flow water which effects the out put have been investigated and analysed in the statistical method. Through the results obtained together with the stastistical data some typical interreation formula between the quantity of in-flow water and production have been induced and the productive percentage in season was examined with special reference to Changsung Coal Mine. The formulas are as fallows: (1) Underground in-flow water to production; $Y=-5.74x^2+108.9x+6,346.6$ where, Y: production(tons/day): x:in-flow water($m^3/min$), (2) Rain and Snow fall to production; P=6.555-1.591 R+1.282S where, P;production(tons/day); R:rain fall(mm); S : snowfall(cm), (3) Productivity ratio in season compared with the average annual production; 1st quarter of year:100.1%, 2nd quarter of year: 100.3%, 3rd quarter of year: 97.2%, 4th quarter of year: 102.4%.

• Journal of The Korean Astronomical Society
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• v.43 no.6
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• pp.191-200
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• 2010

We present the Korea Institute for Advanced Study Value-Added Galaxy Catalog (KIAS VAGC), a catalog of galaxies based on the Large Scale Structure (LSS) sample of New York University Value-Added Galaxy Catalog (NYU VAGC) Data Release 7. Our catalog supplements redshifts of 10,497 galaxies with 10 < $r_P\;{\leq}\;17.6$ (1455 with 10 < $r_P\;{\leq}\;14.5$) to the NYU VAGC LSS sample. Redshifts from various existing catalogs such as the Updated Zwicky Catalog, the IRAS Point Source Catalog Redshift Survey, the Third Reference Catalogue of Bright Galaxies, and the Two Degree Field Galaxy Redshift Survey have been put into the NYU VAGC photometric catalog. Our supplementation significantly improves spectroscopic completeness: the area covered by the spectroscopic sample with completeness higher than 95% increases from 2.119 to 1.737 sr. Our catalog also provides morphological types of all galaxies that are determined by the automated morphology classification scheme of Park & Choi (2005), and related parameters, together with fundamental photometry parameters supplied by the NYU VAGC. Our catalog contains matches to objects in the Max Planck for Astronomy (MPA) & Johns Hopkins University (JHU) spectrum measurements (Data Release 7). This new catalog, the KIAS VAGC, is complementary to the NYU VAGC and MPA-JHU catalog.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.2
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• pp.55-62
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• 2016

Economic and social damages are expected due to yellow dust, occurring every year in Korea and risk of citizens is getting higher accordingly. This study acquired tweet data for yellow dust, which had been the greatest since 2009 for 11 days before and after February 23, 2015. After that, it conducted an analysis on the issue words and association rule. Regarding acquired tweet data, the results of analyzing issue words by using open source R, statistics language shows that 'Mask' was ranked to be the highest, followed by health-related issue words. This indicates that people put the priority in the use of mask for keeping their health, as a result of the occurrence of yellow dust, and subsequently, they showed an interest in diseases, caused by yellow dust. In addition, yellow dust-related diseases, 'cold', 'rhinitis', 'flu', 'asthma', 'bronchitis' were found as issue words, revealing that people had a high concern on the disease occurrence of the respiratory system. The analytical results are judged to reflect the citizen's thought effectively in the process of establishing measures for the prevention of yellow dust.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.1
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• pp.48-53
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• 2014

In December 2011 and July 2012, two sets of 840MVA hydro-generator of Three Gorges on Yangtze River with Close-loop-self-circulating evaporative cooling (CLSCEC) system were put into commercial operation. In this paper, we make engineering summary of these two generators with CLSCEC system. We also make a comparison between the internal water cooling (IWC) hydro-generator and the CLSCEC hydro-generator used in Three Gorges power plant in fields of their operating characteristics, working performances, technical features, working safety and reliability. In addition, engineering structures, type tests' results and systematic emulating calculation of CLSCEC schemes are analyzed.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.4
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• pp.135-144
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• 2005

The Effects of intake swirl and combustion parameters on the performance and emission characteristics in a V8 type turbocharged intercooler D.I. diesel engine of the displacement $16.7\iota$ were studied experimentally in this paper. Generally the swirl in the combustion process of diesel engine promotes mixing of the injection fuel and the intake air. Also, TCI diesel engine is put to practically use intercooler in order to increase boost efficiency which is cooled boost air. As a result of steady flow test, when the swirl ratio is increased, the mean flow coefficient is decreased, whereas the Gulf factor is increased. And through engine test, its can be effected to meet performance and emission by optimizing the main parameters; the swirl ratio is 2.25, compression ratio is 17.5, combustion bowl is re-entrant $8.5^{\circ}$, nozzle hole diameter is $\phi0.33^{\ast}3+\phi0.35^{\ast}2$, injection timing is BTDC $12^{\circ}CA$ and turbocharger is T02 model which are compressor 0.6A/R+46trim and turbine 1.0A/R+57trim.