• Analytical Science and Technology
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• v.8 no.4
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• pp.799-806
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• 1995

In industrial field, a large volume of regenerants (acid and caustic soda) and their washing effluents are regularly disposed off from the water demineralization plant during regeneration of the ion-exchanger units. Of these waste effluents, a part of the wash water discharged from the single bed Anion and Mixed Bed units can be utilized at a certain stage of their washing cycles when its conductivity is fallen down and becomes considerably less than that of the input raw water. The main aim of this specific waste effluent utilization is to dilute the TDS concentration of the input raw water (fed into the single bed ion-exchanger units) by blending. The achievement is the increase of the longevity of the production cycles of the I.E. units along with the improvement of the production quality and decrease of the regeneration frequencies. As a result, regenerant consumption would be saved because of the reduction of ionic load in feed water which will ultimately reduce the water purification cost. At the same time, the environment pollution will also be protected to a considerable extent. This operational measure is quite effective and useful specially where high TDS water is demineralized only by single bed ion-exchangers. In such case, the water treatment plant is very often found to suffer from both production quality and quantity in addition to carrying out of random and restless regenerations. Proper reuses of the aforesaid wash water effluents of the Anion and MB units excellently minimizes the difficulties experienced in practice. This paper contains the utilities and techniques of reuses of the different kinds of waste effluents of the industrial water treatment plant in addition to the specific reuses of the post-regeneration wash waters of the Anion and MB ion-exchanger units.

• Korean Journal of Human Ecology
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• v.20 no.5
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• pp.1075-1091
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• 2011

The purposes of this study were to investigate the actual state of indoor air quality in semi-underground multi-family housing units in early summer, to analyze the influencing factors, and to make suggestions for improvement. A series of field investigations were conducted in four target units between June 22, 2010, and June 28, 2010. The field investigations included measurements of indoor air quality as well as the observation of architectural characteristics and living conditions. In addition to the field investigation, on-site questionnaire surveys were administrated to residents in 90 units. The findings are summarized as follows: (1) The average $CO_2$ levels in each of the four units ranged from 759ppm to 1885ppm. $CO_2$ levels in three units exceeded the evaluation standard (1000ppm), and one unit was lower than the standard. This unit had smaller number of staying person and a large amount of ventilation than others; (2) the average CO levels in each unit were almost 0ppm, but 0.1~1.1 levels of CO were revealed at several times; (3) the average PM-10 levels ranged from $8{\mu}g/m^3$ to $40{\mu}g/m^3$, which distributes within the standard ($150{\mu}g/m^3$). The influencing factors of PM-10 levels were analyzed as inflow from outside, the use of a gas range, and the residents' activities; (4) therefore, it was evaluated to be necessary to improve ventilation for the indoor air quality of semi-underground housing in aspect of $CO_2$ levels.

• Journal of Agricultural Extension & Community Development
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• v.23 no.3
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• pp.285-293
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• 2016

The increase in demand for leisure time by the public and the vitalization of agricultural tourism resulting from the expansion of the five-day work week are expected to greatly contribute to the rural economy, but actual studies analyzing the ripple effect of the agricultural tourism industry are lacking. In order to analyze the economic ripple effect, tourism or agricultural tourism must become an independent sector in the inter-industry relations table's sector classification, but because it is not, the study uses a method of analysis which involves creating a satellite account. However, because agricultural tourism has a clear main agent in farms unlike general tourism which does not, there is one method in which provisions are made by farms or farm villages and another method in which outside products are used. The purpose of the present is to measure the economic ripple effect of agricultural tourism with a focus on 162 subclasses by applying positive data from the education sector input into agricultural tourism. Satellite accounts which considered intermediate input were created and applied to positive data, the analysis of which revealed agricultural tourism to account for 462 billion won, which is 0.01% of the total production amount of 3,503,480 billion won, while the production inducement coefficient was 3.2895 units when the final demand of agricultural tourism occurs. When the production inducement coefficient is at 3.2895 units, highest sector was agricultural tourism at 0.9968 units followed by restaurants and bars at 0.3325 units, roadt transportation services at 0.3183 units, lodging services at 0.1520 units, and petroleum products at 0.1290 units.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.527-537
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• 1995

The effect of calcitonin gene-related peptide (CGRP), substance P (SP) and electrical stimulation of the tooth on the intradental nerve activtiy (INA) was investigated in anesthetized cats. The INA was recorded from single pulp nerve units dissected from the inferior alveolar nerve under stereomicroscope. The INA elicited by 3 minute application of 4M NaCl in deep dentinal cavity was compared before and after stimulation at 10 minute intervals. The magnitude of INA was calculated as the total number of nerve impulses produced in given period, and the changes of INA are expressed as % of control INA. The results obtained were as follows. 1. 16 single pulp nerve units were classified as 14 $A{\delta}$-fibers (3.4~19.4m/sec) and 2-fibers (1.5~1.7m/sec) according to the conduction velocity. 2. 4M NaCl evoked an irregular bursts of spikes which continued until washing out. Isotonic saline did not affect INA to subsequent applications of the hypertonic NaCl solution (P>0.05). 3. Local application of CGRP ($200{\mu}g$/ml) in deep dentinal cavity reduced the INA induced by 4M NaCl in $A{\delta}$-fiber units (P<0.01) and some units of those responded to CGRP during application. 4. Local application of SP ($100{\mu}g$/ml) in deep dentinal cavity reduced the INA induced by 4M NaCl in AS-fiber units (p<0.05), but increased the INA in C-fiber unit coincided with large reduction of the INA of $A{\delta}$-fiber units. 5. Monopolar electrical stimulation applied to the crown at intensities high enough to excite C-fibers (12V, 5ms, 10Hz, 10~30min) decreased the INA in $A{\delta}$-fiber units (P<0.01) and systemic pretreatment with phenoxybenzamine (3mg/kg, i.v.) enhanced this inhibitory effect (P<0.01). On the contrary, electrical stimulation increased the INA in C-fiber unit.

• Education of Primary School Mathematics
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• v.23 no.2
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• pp.87-116
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• 2020

The purpose of this study is to explore how units-coordination ability is related to understanding fraction concepts. For this purpose, a teaching experiment was conducted with one fourth grade student, Eunseo for four months(2019.3. ~ 2019.6.). We analyzed in details how Eunseo's units-coordinating operations related to her understanding of fraction changed during the teaching experiment. At an early stage, Eunseo with a partitive fraction scheme recognized fractions as another kind of natural numbers by manipulating fractions within a two-levels-of-units structure. As she simultaneously recognized proper fraction and a referent whole unit as a multiple of the unit fraction, she became to distinguish fractions from natural numbers in manipulating proper fractions. Eunseo with a reversible partitive fraction scheme constructed a natural number greater than 1, as having an interiorized three-levels-of-units structure and established an improper fraction with three levels of units in activity. Based on the results of this study, conclusions and pedagogical implications were presented.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.33 no.12
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• pp.53-63
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• 2017

The purpose of this study is to present an integrated analysis for energy use and its patterns as vertical locations of the dwelling units in apartment buildings which are located in an urban area and constructed by a renowned contractor. In order to enhance the effectiveness of the method, the original data of electricity, water, and gas bills which directly reflect the energy use are sorted and analyzed into several groups as vertical locations in each building. And also, by use of comparing and contrasting the data on a monthly and yearly basis, the accuracy of analyses for seasonal energy use and its patterns is strengthened. Comparative analyses used in this study describe the results that vertical locations of dwelling units do not have much influence on electricity and water usage, but are closely related with gas usage for a heating season. According to the analysis of gas usage, the units on the ground and right above pilotis need enhancement in the insulations for heating to mitigate energy loss. Also, the analysis for the middle floor units in each group describe the fact that the gas usage of the units on the ground is consumes 1.5 times greater than that of the typical floors. Therefore, enhanced insulation strategies need to be considered against the adverse condition that the heat loss increases as the wall facing the outside air increases or as the wind velocity increases through the pilotis.

• Proceedings of the Korea Society of Design Studies Conference
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• 1998.04a
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• pp.48-49
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• 1998

• Korean Architects
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• no.3 s.180
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• pp.76-84
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• 1984

• Journal of the Korea Concrete Institute
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• v.19 no.1
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• pp.83-90
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• 2007

The present study reports a simple unbonded-type shear strengthening technique for reinforced concrete beams using wire rope units. Fifteen beams failed in shear were repaired and strengthened with wire rope units, and then retested to failure. Influence of the prestressing force, orientation and spacing of wire rope units on the shear behavior of strengthened beams having shear span-to-depth ratios of 1.5, 2.5, or 3.25 were investigated. Test results showed that beams strengthened with wire rope units exhibited a higher shear strength and a larger post-failure deformation than the corresponding original beams. Inclined wire rope units was more effective for shear strength enhancement than vertical wire rope units. The increase of the prestressing force in wire rope units causes the decrease of the principal tensile stress in concrete, as a result, the diagonal tensile cracking strength of strengthened beams was higher than that of the corresponding original beams. Shear capacity of strengthened beams is compared with predictions obtained from ACI 318-05 and EC 2. Shear capacity of strengthened beams having shear span-to-depth ratio below 2.5 is reasonably predicted using ACI 318-05 formula. On the other hand, EC 2 overestimates the shear transfer capacity of wire rope units for beams having shear span-to-depth ratio above 2.5.

• Journal of Korean Home Economics Education Association
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• v.22 no.3
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• pp.55-75
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• 2010

The purpose of this study is to analyze how the emphasis of the 2007 curriculum revision is reflected on the units of 'Adolescence Self-Management' and 'Adolescence Consumption life' in the Technology·Home Economics textbooks that are used in middle school from this year. The entry style of large, middle, and small units, the objectives statements, the main contents, the activities, illustrations/tables/pictures, the supplemental materials, and the ending style of middle and large units of 12 Technology·Home Economics textbooks were analyzed. Among the several specific emphasis in the 2007 curriculum revision, 3 major emphasis were selected. The 3 major emphasis that were selected were: practical reasoning process, sustainable consumption life, and career education. How these 3 emphasis were reflected in the various parts of the 12 textbooks were analyzed using the criteria found in the literature. The purpose of this study is to analyze how the emphasis of the 2007 curriculum revision is reflected on the units of 'Adolescence Self-Management' and 'Adolescence Consumption life' in the Technology·Home Economics textbooks that are used in middle school from this year. The entry style of large, middle, and small units, the objectives statements, the main contents, the activities, illustrations/tables/pictures, the supplemental materials, and the ending style of middle and large units of 12 Technology·Home Economics textbooks were analyzed. Among the several specific emphasis in the 2007 curriculum revision, 3 major emphasis were selected. The 3 major emphasis that were selected were: practical reasoning process, sustainable consumption life, and career education. How these 3 emphasis were reflected in the various parts of the 12 textbooks were analyzed using the criteria found in the literature.