• Geophysics and Geophysical Exploration
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• v.19 no.1
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• pp.37-44
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• 2016

$CO_2$-EOR (Carbon Dioxide-Enhanced Oil Recovery), one of the enhanced oil recovery methods, helps to not only enhance the production of oil, but also store carbon dioxide in underground. However, if micro fractures occur when during the injection of $CO_2$, it is difficult to make permanent storage of $CO_2$ in reservoir and can cause contamination of groundwater and soil. Therefore, in this study, we performed microseismic monitoring to investigate the occurrence of fractures during the $CO_2$ injection at the Meruap oil reservoir, Indonesia. To pick the first arrivals of microseismic events, Improved MER (Modified Energy Ratio) method was used. After picking the first arrivals, hodogram analysis was carried out by using the data recorded at three component geophones to calculate the back azimuth of events. Finally, locations of microseismic events were decided by using the results of first arrival picking and hodogram analysis. Estimated locations showed that all microseismic events were occurred at surface and any fracture did not occur around the reservoir. Moreover, by analyzing noise characteristic, we confirmed that almost of picked first arrivals were due to the repetitive mechanical noise.

• Bulletin of the Korean Chemical Society
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• v.19 no.1
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• pp.79-82
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• 1998

Novel coordination polymers of general form $[Co(NCS)_2(Py_2L)_2]_n\; (Py_2L=trans-1,2-bis(4-pyridyl)ethylene$ (bpee), 1; 1,2-bis(4-pyridyl)ethane (bpea), 2) have been synthesized by slow diffusion of aqueous solution of $Co(NCS)_2$ with ethanolic solution of appropriate spacer ligand, $Py_2L$, in a mole ratio of 1 : 2. X-ray analyses on both 1 and 2 have provided similar unit and infinite structures with space group Ibam. The local geometry around the cobalt(Ⅱ) atoms is an octahedral arrangement with two NCS groups in trans position (N-Co-N, 180.0° (1); 180.0°(2)) and four pyridine units in propeller fashion. Each spacer ligand connects two cobalt(Ⅱ) ions defining the edges of a $[Co(II)]_4$ rhombus. The most fascinating feature is the occurrence of perpendicular interwoven of independent square grid sheets: this is, one molecular network is perpendicularly interpenetrated through the centers of the $[Co(II)]_4$ rhombuses of another independent network with all of the cobalt(Ⅱ) atoms in a coplanar sheet. The physicochemical properties of the present unique structures were studied.

• The Journal of the Korea Contents Association
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• v.22 no.7
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• pp.18-29
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• 2022

The purpose of this exploratory study is to examine the intellectual structure of data science. For this purpose, this research examined a total of 17,997 bibliographies on data science indexed in Web of Science(WoS) of Clarivate Analytics from 2012 to 2021. This research applied methods such as descriptive analysis, citation analysis, co-author network analysis, co-occurrence network analysis, bibliographic coupling analysis, and co-citation analysis. This research contributes to finding the research directions of future data science topics.

• International Journal of Oral Biology
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• v.49 no.3
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• pp.61-68
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• 2024

Coronavirus disease 2019 (COVID-19) is a highly contagious illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This disease is characterized by a wide spectrum of symptoms, ranging from mild to severe, including fatal outcomes. This study aims to review gustatory and salivary secretion dysfunctions and determine their potential pathogenic mechanisms. Gustatory impairment and salivary dysfunction are prevalent among patients with acute COVID-19 and those recovering from the disease. The mouth serves as a critical entry route for SARS-CoV-2. The cells within the oral epithelium, taste buds, and minor and major salivary glands express key entry factors for SARS-CoV-2, including angiotensin-converting enzyme 2, transmembrane serine protease 2, and furin. The co-occurrence of gustatory and salivary secretion dysfunctions possibly has pathogenetic association with the following factors: the expression of SARS-CoV-2 cellular entry receptors in the taste buds and salivary glands and SARS-CoV-2-induced zinc deficiency, which is crucial for normal taste perception and saliva secretion. Furthermore, the cytokine storm triggered by COVID-19 contributes to secondary damage affecting gustatory and salivary functions.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.422-427
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• 2008

The major cause of Concrete Spalling at high temperatures can be divided into the Vapor Pressure Rising, caused by the increase in free water temperature within the concrete, and Pore Pressure Rising induced by the vapor moving into dense pores within the concrete. Although the occurrence of spalling within concrete caused by these pressure increases can be assessed experimentally, a close examination into Mechanistic influence against various spalling factors shall be carried out first by using Mathematical Modeling and Theoretical Equations. The Spalling Prospect Process by theoretical mechanism is expedited in order of the following; selection of heating condition (fire strength and flame heating direction), a selection of constituent elements, an analysis of heat transmission, an analysis of moisture movement, distribution of water content, an analysis of pore/vapor pressure, and assessment of spalling occurrence.

• The Journal of the Korean life insurance medical association
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• v.2 no.1
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• pp.37-44
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• 1985

A study on the occurrence of hepatitis B has been done for 2,680 employees in Daehan Life Insurance Company. The positive rates of HBsAg and anti-HBs were 6.56% and 18.9% respectively. The positive rates of HBsAg and anti-HBs were higher by 2.25% and 2.06% respectively in male than in female. HBsAg and anti-HBs positives were higher at age of 30 to 50 years than other age groups. The drinker group shows higher positive of HBsAg and anti-HBs by 10.44% and 4.26% respectively than non-drinker group. Most of the results of liver function tests in HBsAg positive cases were within reference ranges. HBsAg or anti-HBs positive rate in the family members of HBsAg or anti-HBs positive employees was higher than the over-all positive rates of all subjects, by 14.55% in case of HBsAg and by 2.21% in case of Anti-HBs.

• International Journal of Fluid Machinery and Systems
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• v.2 no.4
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• pp.418-425
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• 2009

A vertical bulb turbine unit with elbow type draft tube has been developed due to avoidance of complicated assembling and long standstill period at overhaul in comparison with conventional horizontal bulb turbine unit. Before designing the prototype vertical bulb unit, a hydrographic model test was carried out to establish the ideal design concept for this innovative generating unit. Froude similarity is not available for vortex occurrence. Consequently, an intake structure without air entraining vortices under all the flow conditions is developed, and it is confirmed that the surge wave at load rejection is not affected harmful influence for other constructions.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.239-241
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• 2003

The development of industry environment honored dust matter is diversify industry part eliminate the source of pollution besides usually life in and around pollution by livestock farming pollution matter and pollution by used agricultural medicines particular eutrophic of in and around a reservoir present of occurrence accelerate. The paper is a study of dissolved characteristics by ozone contactor type and ozone generated quantity.

• Language and Information
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• v.8 no.1
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• pp.77-100
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• 2004

This paper aims to account for direct combination of an entity type noun with the verb HA- 'do' (ex. piano-rul ha- 'piano-ACC do') in Korean, based on Generative Lexicon Theory (Pustejovsky, 1995). The verb HA-'do' coerces some entity type nouns (e.g., pap 'boiled rice') into event type ones, by virtue of the qualia of the nouns. Typically, a telic-based type coercion supplies individual predication to the HA- construction and an agentive-based type coercion evokes a stage-level interpretation. Type coercion has certain constraints on the choice of qualia. We further point out that qualia cannot be a warehouse of pragmatic information. Qualia are composed of necessary information to explain the lattice structure of lexical meaning and co-occurrence constraints, distinct from accidental information. Finally, we seriously consider co-composition as an alternative to type coercion for the crucial operation of type shift.

• Proceedings of the Korean Reliability Society Conference
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• 2005.06a
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• pp.385-392
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• 2005

The restriction of the use of hazardous substances in electrical and electronic equipment legislation mandates the substitution of lead and other hazardous substances in electronics products by July 2006. Due to this legislative pressure, the electronics industry is moving to adoption of lead free solders. In this paper, we investigated a flux to restrict generating electrochemical migration in lead-free solder. The lead-free solders used in this study were Sn-0.7Cu-0.01P and Sn-3.0Ag-0.5Cu. To measure the resistance of electrochemical migration, the dew-cycle test and water drop test were adopted. As the result, now flux having high durable of electrochemical migration was developed.