• Korean Journal of Construction Engineering and Management
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• v.4 no.4 s.16
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• pp.106-113
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• 2003

The purpose of this thesis is to provide an appropriate trade-off information for the conflicting interests caused by the various factors between building owner and contractor during selecting the contractor and performing the construction work, in which the construction was contracted by open bidding from the government or private organizations. In order to propose the legitimate evidence, the differences between the domestic contract sheet of drawing change and the process of drawing change and those of the foreign countries were compared and analysed The number of construction ordered in Youngdong area in 2001 whose construction expenses are more than 100,000,000 won is 218 items and 147,005,000,000 won in total cost Among them, the number of 218 items whose total cost amounts to 16,705,000,000 (11.36$\%$) is in case of increase of construction expenses due to the drawing changes, and the number of 48 items whose tool cost amounts to 2,009,000,000 won (1.37$\%$) is the case of decrease. In conclusions, the contractor could have more benefits than the building owner in case they submit the detailed estimate sheet without eliminating the increasing expenses of construction. It is shown that the building owner's loss is increasing whenever the labor cost is higher material cost Therefore, this thesis proposes a proper standards for the harmonious compromise between the contractor and the building owner for the problems caused by the drawing changes when the contract agreement is occurred.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.13 no.4
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• pp.215-222
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• 1984

An analytical study on the thermal instability of fluid in a vertical solt between two permeable walls has been carried out using fast converging power series solution method. For given values of prandtl number Pr and permeability paramter ${\sigma}$, the critical Grashof number $Gr_c$ and the critical wave number ac are found as eigenvalues of the problem formulated by the stability equations and the appropriate boundary conditions which are derived on the basis of linear stability theory. In the case of ${\sigma}\;>\;10^4$, the results approach those of solid boundary case, but in the case of ${\sigma}\;<\;10^3$, the decrease of $Gr_c$ and $a_c$become more prominent. In other words, the permeable walls cause the flow to be more unstable than the solid walls. This is considered to be due to the slip of the fluid on the wail, which decrease the friction force.

• Bulletin of the Korean Chemical Society
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• v.26 no.12
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• pp.1991-1995
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• 2005

Sensitivity factors of elements by a glow discharge mass spectrometry (GD-MS) were intensively investigated and compared with a laser ablation inductively coupled plasma-mass spectrometry (ICP-MS). In case of copper matrix, the sensitivity factor by GD-MS generally decreases with the increase of the mass number of element. The details are a little different between each data measured by Faraday and multiplier detectors. The factor by a multiplier detector drastically decreases with the mass increase in the region of low mass as in Faraday detector’s case, but slowly in the high mass region. On the contrast, the sensitivity factor of solution standard by a conventional ICP-MS slowly increases with the increase of elemental mass number even though there are some exceptions such as gold and also the sensitivity factor by a laser ablation ICP MS generally increases with mass number of element in the specimen of glass type. In case of steel matrix, any definite trends could not be shown in the relationship between the GD-MS’s sensitivity factor and elemental mass.

• Asia pacific journal of information systems
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• v.16 no.1
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• pp.71-84
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• 2006

Case-based reasoning (CBR) is a reasoning technique that reuses past cases to find a solution to the new problem. It often shows significant promise for improving effectiveness of complex and unstructured decision making. It has been applied to various problem-solving areas including manufacturing, finance and marketing for the reason. However, the design of appropriate case indexing and retrieval mechanisms to improve the performance of CBR is still a challenging issue. Most of the previous studies on CBR have focused on the similarity function or optimization of case features and their weights. According to some of the prior research, however, finding the optimal k parameter for the k-nearest neighbor (k-NN) is also crucial for improving the performance of the CBR system. In spite of the fact, there have been few attempts to optimize the number of neighbors, especially using artificial intelligence (AI) techniques. In this study, we introduce a genetic algorithm (GA) to optimize the number of neighbors to combine. This study applies the novel approach to Korean stock market. Experimental results show that the GA-optimized k-NN approach outperforms other AI techniques for stock market prediction.

• Fashion & Textile Research Journal
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• v.11 no.6
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• pp.942-946
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• 2009

The trends of patents related to natural dyeing were examined in order to guide the development of natural dyeing into a high value-added technology. Total 181 patents data provided from KISTI were analyzed and following results were drawn. Korea had the overwhelming number of patents related to natural dyeing over Japan or United States of America from 1970 to 2007. In case of domestic, the number of patent applications were heavily focused on the metropolitan area in 1990's, but started to increase in the Honam region and Youngnam region in the first half of the year 2000 which indicated that the researches and the developments of natural dyeing were very active. In the case of foreign countries, most of their patent applications comes from the corporation such as a company while the number of patents applications from individuals overwhelms that of corporation in South Korea. Also, more of individuals' patent applications were denied than corporations' patents applications. The vegetable dye, a type of dyestuff which is a research subject for patent application, had the most research done above all other dyestuff.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.2
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• pp.15-19
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• 1990

This survey was carried to determine the crowd In the city parks on the basis of the crowding and using denSity. The using density was vary different by season and day, and the density was much higher in this experiment than in the case of the foreign countries. This survey shows a high correlation between the using density and crowd as the crowd level was more influenced by the increasing number of park - users in the case of low using density than the high using density. The possible using space per individual was around 10㎥ in the parks, which means a strong endurance of the surveying group to the massing space, in the saturated crowding value that the crowd was not significantly affected by the increasing number of users.

• Journal of the Ergonomics Society of Korea
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• v.4 no.1
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• pp.7-10
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• 1985

Eye blinking in case of three visual tasks is studied; wall hard-copy and color monitor. The eye blinking is checked by eye-status detector. The data observed are (1) the average number of eye blinking (2) the average time of eye blinking for three minutes in case of all three visual tasks. The results are as follows: (1) The average times (or numbers) of eye blinking are different among three tasks. (2) The average time (or number) of eye blinking of wall is different from hard-copy and color monitor tasks. (3) But the average time (or number) of eye blinking of hard-copy is not different from that of color monitor.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.1
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• pp.107-112
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• 2012

Air flow and its pressure at electric fan according to three, four and five blades are analyzed in this study. As the number of blades increases at the same condition of specification, air tends to converge and becomes natural wind but higher power is consumed. And the velocity of wind is decreased as the space between winds becomes narrow. The turbulent flow is happened in the center of the body of revolution and the kinetic energy becomes largest in case of three blades. The pressure is decreased than atmospheric pressure from fan to outlet. As the number of blades increases, the pressure drop becomes smaller and is smallest in case of the fan with three blades. As the study result, The electric fan with three blades is thought to be effective in view of power consumption and design.

• Journal of Engineering Education Research
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• v.19 no.6
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• pp.57-62
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• 2016

In this work, we present a case study of using the assessments for the enhancement of students' learning motivation in engineering education. The assessments, given in between summative assessments such as midterms and finals, may have a component of formative evaluation, which are reported as very effective tools as the sources of feedback to improve teaching and learning. We studied how the students' performance is improved by additional tests in engineering education. Also, we examined the factors of successful results of the cooperative learning model, Student Teams-Achievement Division, which is based on imposing a number of tests, achieved in our previous work.

• Journal of Mechanical Science and Technology
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• v.15 no.6
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• pp.764-775
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• 2001

Oscillartory thermocapillary flow of high Prandtl number fluids in the half-zone configuration is investigated. Based on experimental observations, one oscillation cycle consists of an active period where the surface flow is strong and the hot corner region is extended and a slow period where the opposite occurs. It is found that during oscillations the deformation of free surface plays an important role and a surface deformation parameter S correlates the experimental data well on the onset of oscillations. A scaling analysis is performed to analyze the basic steady flow in the parametric ranges of previous ground-based experiments and shows that the flow is viscous dominant and is mainly driven in the hot corner. The predicted scaling laws agree well with the numerical results. It is postulated that the oscillations are caused by a time lag between the surface and return flows. A deformation parameter S represents the response time of the return flow to the surface flow.