• Proceedings of the KWS Conference
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• 2002.10a
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• pp.235-243
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• 2002

Ni-base superalloys are used extensively in industry, both in aeroengines and land based turbines. About 60% by weight of most modern gas turbine engine structural components are made of Ni-base superalloys. To satisfy practical demands, the efficiency of gas turbine engines has been steadily and systematically increased by design modifications to handle higher turbine inlet or firing temperatures. However, the increase in operating temperatures has lead to a decrease in the life of components and increase in costs of replacement. Moreover, around 80% of the large frame size industrial/utility gas turbines operating in the world today were installed in the mid-sixties to early seventies and are now 25 to 30 years old. Consequently, there are greater opportunities now to repair and refurbish the older models. Basically, there are two major factors influencing the weldability of the cast alloys: strain-age cracking and liquation cracking. Susceptibility to strain-age cracking is due to the total Ti plus AI content of the alloy; Liquation cracking is due either to the presence of low melting constituents or constitutional liquation of constituents. Though Rene 41 superalloy has 4.5wt.% total Ti and Al content and falls just below the safe limit proposed by Prager et al., controlled grain size and special heat treatments are needed to obtain crack-free welds. Varying heat treatments and filler materials were used in a laboratory study, then the actual welding of service parts was carried out to verity the possibility of crack-tree weld of components fabricated from Rene 41 superalloy. The microstructural observations indicated that there were two kinds of carbides in the FCC matrix. MC carbides were located along the grain boundaries, while M$_{23}$C$_{6}$ carbide was located both inter and intra granularly. Two kinds of filler materials, Rene 41 and Hastelloy X were used to gas tungsten arc weld a patch into the sheet metal, along with varying pre-weld heat treatments. The microstructure, hardness and tensile tests were determined. The service distressed parts were categorized into three classes: with large cracks, with medium cracks and with small or no visible cracks. No significant difference in microstructure among the specimens was observed. Specimens were cut from the corner and the straight edge of the patch repair, away from the corner. The only cracks present were found to be associated with inadequate surface preparation to remove oxidation. Guidelines for oxide removal and the welding procedures developed in the research enabled crack-free welds to be produced.d.

• Journal of Digital Convergence
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• v.16 no.3
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• pp.429-438
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• 2018

Brad Bird, a screenwriter and animation director in the United States, criticized the situation in which most animations were produced and released for the children since the early 2000s. He said that animation is an art form capable of conveying messages not only to children but also to adults, and that their development potential is high. In this study, I analyzed overall components such as narrative structure, character, subplot, symbol, and foreshadow of Brad Bird's animated feature films , , and examined his narrative features and strategies. As a result, the narrative features of animation as an art form are as follows: First, conveying the message of a serious subject that will deeply sympathize with adults as well as children. Second, expressing the social agenda which criticizes the contradiction of the real world and the periodic mistakes. Third, solid narrative structure through a dense plot based on realistic situation setting. I hope that this study will be used as basic research material for various animation production in the future.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.361-368
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• 2015

This study was to investigate the effect of high energy diet on characteristics of Hanwoo steers distributed by estimated breeding value (EBV). The aim of this experiment was to determine the effect of high energy diet on the high and low beef group distributed by EBV for quality grades. We hypothesized that high energy diet is able to increase quality traits in high EBV groups when fed a high energy diet. A $2{\times}2$ factorial arrangement (High energy, control vs high EBV, low EBV) in a completely random design was used to feed 26 Hanwoo steers. Blood was drawn from each steers from 11 to 28 months. ADG and feed efficiency were not different between high energy and control diet (P>0.05). The level of DMI was greater at calf and early fattening diet in low EBV groups (P<0.05). Serum glucose and tryglyceride conecntrations were increased (P<0.05) by high EBV group from 22 to 28 month old. Serum NEFA concentration were plateau at 24 months at high EBV group and steady reduced by high energy diet (P<0.05). This data indicated that high energy diets increased serum glucose and triglyceride concentrations of high EBV steers at final fattening period.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1396-1408
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• 2020

Filtered containment venting system (FCVS) is one of the severe accident mitigation systems designed to release containment pressurization to maintain its integrity. The thermal-hydraulic behaviors in FCVSs are important since they affect the operation characteristics of the FCVS. In this study, a representative FCVS was modeled by RELAP5/Mod3.3 code, and the Station BlackOut (SBO) was chosen as an accident scenario. The thermal-hydraulic behaviors of an FCVS during long-term operation with two venting strategies (open-and-close strategy, open-and-non-close strategy) and the sensitivity analysis of important parameters were investigated. The results show that the FCVS can operate up to 250 h with a periodic open-and-close strategy during an SBO. Under the combined effects of steam condensation and water evaporation, the solution inventory in the FCVS increases during the venting phase and decreases during the intermission phase, showing a periodic pattern. Under this condition, the appropriate initial water level is 3-4 m; however, it should be adjusted according to the environment temperature. The FCVS can accommodate a decay heat power of 150-260 kW and may need to feed water for a higher decay heat power or drain water for a lower decay heat power during the late phase. The FCVS can function within an opening pressure range from 450 kPa to 500 kPa and a closing pressure range between 250 kPa and 350 kPa. When the open-and-non-close strategy is adopted, the solution inventory increases quickly in the early venting phase due to steam condensation and then decreases gradually due to the evaporation of water; drying-up may occur in the late venting phase. Decreasing the venting pipe diameter and increasing the initial water level can mitigate the evaporation of the scrubbing solution. These results are expected to provide useful references for the design and engineering application of FCVSs.

• Journal of the Korea Institute of Building Construction
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• v.11 no.2
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• pp.145-153
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• 2011

Since the early 1990s, Korean construction companies have strived to evolve into global Engineering Construction (EC) companies. However, such efforts have been unsuccessful, partly due to a lack of clear objectives and a misunderstanding of the direction that needed to be taken for such a change. A better understanding is required with respect to the need to transform into an EC company in the context of the rapidly changing global construction environment. This research investigates major EC companies from around the world, and assesses the status of domestic companies' efforts for EC transition. The results of these investigations revealed that domestic firms need to better prioritize their strengths for different markets, i.e., decide whether to implement directly, outsource or limit to process management. In addition, the investigations showed that the global market is shifting from monolithic projects to more complex projects. Such projects require firms with the ability to develop and implement high front-end investment strategies, planning capabilities, and pre-design management skills. Accordingly, we recommend that firms differentiate themselves by developing such a skill set required for specific products.

• Korean Journal of Construction Engineering and Management
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• v.21 no.1
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• pp.50-60
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• 2020

Estimates of project costs in the early stages of a construction project have a significant impact on the operator's decision-making in important matters, such as the site's decision or the construction period. However, it is difficult to carry out the initial stage with confidence because information such as design books and specifications is not available. In previous studies, case-based reasoning was used to predict initial construction costs, and genetic algorithms were used to calculate the weight of the inquiry phase among them. However, some say that it is difficult to perform better than the current year because existing genetic algorithms are calculated in random numbers. To overcome these limitations, correlation numbers using correlation analysis rather than random numbers are reflected in the genetic algorithm by method of local search, and weights are calculated using a hybrid genetic algorithm that combines local search and genetic algorithms. A case-based reasoning model was developed using the weights calculated and validated with the data. As a result, it was found that the hybrid GA-CBR applied with local search performed better than the existing GA-CBR.

• Journal of Periodontal and Implant Science
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• v.34 no.4
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• pp.733-746
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• 2004

The present study aimed to examine the effects of topical application of alendronate with a collagen membrane on the healing of the calvarial defect in rats, which has a good experimental design for the healing of tissue destruction, To study the effect of alendronate on bone healing, the collagen membrane containing $200{\mu}g$ alendronate was inserted in the defects of the right side and collagen membrane treated with physiologic saline was inserted in the defects of the left side. After 1, 2 and 4 weeks, observation of histologic feature after H&E staining, cell counting after TRAP staining, and hardness measurement(Knoop) were performed. In histologic finding, similar features were shown for both test and control groups each week. In cell counting only the 1 week test groups showed significant reduction of TRAP(+)cells than control groups(p<0.01) and the control groups showed statistically significant difference for 1, 2, 4weeks(p<0.05). In hardness measurement, The 2 week test groups showed significant higher hardness than control groups.(p<0,05) and not 4 weeks. There was significant increase of hardness for both groups as time goes by.(p<0.0l) Therefore local application of alendronate with collagen membrane was somewhat effective in reducing osteoclastic activity and increasing hardness in the early stage of healing. Further investigation concerning the actual effect of alendronate for bony healing will be necessary to apply the clinical cases

• Journal of architectural history
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• v.12 no.2 s.34
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• pp.41-59
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• 2003

Hugo $H\"{a}ring$(1882-1952) belonged to that special generation of architects born in the 1880s which became responsible for the establishment of Modern Movement in the 1920s as W. Gropius, Mies van der Rohe and Le Corbusier, etc. Although he have been overlooked by many historian, He was a key figure of the Modern architecture and as the main theorist for Organic stream in German architecture. He is well-known for his theory of 'Neues Bauen(New Building)', the organic functionalism that is epitomized as the design process from the inside outwards, starting with the life-processes of dwelling. So he argued that the builder must become aware of the life process his building is to serve, and he should not impose a form but try to find the form. These concepts are expressed well in his key-words, the 'Organwerk(organ-work)' and 'Leistungsform(form as achievement)'s. $H\"{a}ring's$ theory can be found in the short early essay, 'Wege zur Form(approaches to form)' of 1925. But His concept of 'function' is based on the speciality and individual identity that concerned him from the start, not purely pragmatic aspects. After 1940s his theory moved increasingly in this direction. He defined this as the transition from 'Organwerk' to 'Gesetaltwerk', from mere anatomy to essence, being, personality, life. It suggest that Hugo Haring's idea of Gestalt is a dimension of mystical or symbolic meaning. This paper Is about the way in which this theoretical transition can be parallel with contemporary philosophers as E. Cassirer's philosophy of symbolic forms and M. Heldegger's phenomenology. And the key example of this viewpoint is (1921-1926) near Lubuk in Germany, with its 'cowshed' of pear shaped plan devised around the requirements and rituals of farm. This study presents the symbolic conception of Hugo $H\"{a}ring's$ theory can propose the ability of a symbolic intuition as a view that re-integrate technical thinking with knowledge of other kinds beyond the immediate material.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.2
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• pp.143-149
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• 2004

Background: Some clinical trials have reported that a new analgesic combination of tramadol and acetaminophen provides good efficacy in various pain models. For the more clinical uses of this agent, comparisons about the onset of analgesia and analgesic efficacy in the acute state of pain with the other drugs known as strong analgesics were needed. Purpose: The goal of this study was to compare the times to onset of analgesia and the other analgesic efficacy of 75 mg tramadol/650 mg acetaminophen and 20 mg codeine/500 mg acetaminophen/400 mg ibuprofen in the treatment of acute pain after oral surgery. Patients and Methods: Using a randomized, single-dose, parallel-group, single-center, and active-controlled test design, this clinical study compared the times to onset of analgesia using a two-stopwatch technique and the other analgesic efficacy of the single-dose tramadol/acetaminophen and codeine/acetaminophen/ibuprofen. These were assessed in 128 healthy subjects with pain from oral surgical procedures involving extraction of one or more impacted third molars requiring bone removal. From the time of pain development, the times to onset of perceptible and meaningful pain relief, pain intensity, pain relief, an overall assessment, and adverse events of the study medications were recorded for 6 hours. Results: The demographic distribution and baseline pain data in the two groups were statistically similar. The median times to onset of perceptible pain relief were 21.0 and 24.4 minutes in the tramadol/acetaminophen and codeine/acetaminophen/ibuprofen groups respectively and those to onset of meaningful pain relief were 56.4 and 57.3 minutes, which were statistically similar. The other efficacy variables such as mean total pain relief (TOTPAR) and the sum of pain intensity differences (SPID) were also similar in the early period after pain development and drug dosing. The safety of tramadol/acetaminophen was well tolerated and very comparable to that of codeine/acetaminophen/ibuprofen. Conclusions: In this acute dental pain model, the onset of analgesia and analgesic efficacy of tramadol/acetaminophen was comparable to that of codeine/acetaminophen/ibuprofen. These results showed that tramadol/acetaminophen was recommendable for fast and effective treatment in the management of postoperative acute pain.

• Journal of the Korean Society of Costume
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• v.36
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• pp.239-262
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• 1998

The pursuit of freedom by the individual--desire to be liberated from all forms of restrictions-- is one of the defining character-istic of the modern society. As costume is, in part, a product of the spirit of the times, it was only natural that this desire for freedom would find its expression in modern costume as well. Among various forms of restrictions, differentiaton by sex has placed one of the most significant binding influences on individual behavior. From early times, the dichotomous division by sex was incorporated into the disign of costume, and the traditional differestriction of costume by sex imposed a significant restriction on the background,“the modern androhynous look”was born as a by-product of the sexual liberation movement in the second half of the 20th century, based on the concept of the individual as a complete human being rather than as a member exclusively of either the male or the female sex. This paper seeks to examine the androgynous look within a coherent theoretical frame-work, and explore new design possibilities by analyzing and understanding the visual characteristics of the androgynous look. In addition, this paper seeks to define the functional aspects of the androgynous look based on the premise that costume is an embodiment of the spirit of the times. As for research methodology, both theoretical and historical methods are employed. Through a theoretical examination of historical documents, the meaning of the androgynous look is explored from various angles, and order to examine its place in modern fashion, an-drogynous styles are categorized and system atically analyzed. The main findings of the paper can be summarized as follows : 1. Androgyny is a compound word consisting of“andro-”(meaning man) and“gyn-”(meaning woman). In modern times, this word has been associated with the socio-cultural aspect of gender rather than the physical or physiological aspect with the pshchological characteristics of the male and female sexes. Androgynous styles also appear in fashion and general arts such as drama, film, dance, and music. In fashion, the androgynous look, represented by the visual superimposition of “masculine”and “faminine”elements, has emerged as a major element of the 20th-century costume, and has gained broad acceptance among those free spirits wishing to be liberated from the conventional conceptions of male clothing, and the unisex look. 3. The androgynous look in modern fashion reflects the spirit of the 20th century society and culture, and performs various functions as follows : expression of fun, change in gender roles, expression of the inner consciousness, and pursuit of the ideal human type.