• Journal of Korea Foundry Society
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• v.37 no.3
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• pp.71-77
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• 2017

Casting defects produced during the casting process seriously affect the mechanical properties of the resulting products, reduce the performance capabilities of the product, and also result in economic losses. Therefore, this paper mainly investigates the causes of defects and methods by which to reduce these defects stemming from molten metal flows in a runner system of the type widely used in the sand mold casting process. The flow characteristics of a molten alloy are difficult to observe during the actual casting process. For this reason, a water model was used to observe the flow in the casting process, and the flow in each case was recorded using high-speed cameras as part of the experimental process of this study. Several repetitive experiments were performed to improve the accuracy of the experimental results. The traditional casting system was modified according to the design rules proposed by Campbell, and the system was termed flow-adaptive gating system with a water model. Comparing the flow characteristics of traditional and adaptive gating systems with a water model shows that the bubbles in the water in the latter case are reduced more significantly than in the former case. A ceramic filter system was adapted to the flow-adaptive gating system to minimize the instability of the flow during filling, which occurs as the fluid velocity in the runner increases. In additional, the flow behavior with and without the filter system were compared. The water model system in this work was shown to be able to verify that the adaptation of the filter system brings improvements by stabilizing the flow and reducing the amount of bubbles in the runner system. Moreover, using the flow-adaptive runner system with the filter system leads to considerably stable flows in the runner system.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.1
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• pp.33-42
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• 2001

Recently, the interests in the 3D image, generated from the range data and CAD, have exceedingly increased, accordingly a various 3D image database is being constructed. The efficient and fast scheme to access the desired image data is the important issue in the application area of the Internet and digital library. However, it is difficult to manage the 3D image database because of its huge size. Therefore, a proper descriptor is necessary to manage the data efficiently, including the content-based search. In this paper, the proposed shape descriptor is based on the voxelization of the 3D image. The medial axis transform, stemming from the mathematical morphology, is performed on the voxelized 3D image and the graph, which is composed of node and edge, is generated from skeletons. The generated graph is adequate to the novel shape descriptor due to no loss of geometric information and the similarity of the insight of the human. Therefore the proposed shape descriptor would be useful for the recognition of 3D object, compression, and content-based search.

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.130-134
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• 2016

The influence of Au/Ni-based contact formed on a lightly-doped (7.3×1017cm−3, Zn-doped) InGaAsP layer for electrical compensation of surface plasmon polariton (SPP) propagation under various rapid thermal annealing (RTA) conditions has been studied. The active control of SPP propagation is realized by electrically pumping the InGaAsP multiple quantum wells (MQWs) beneath the metal planar waveguide. The metal planar film acts as the electric contact layer and SPP waveguide, simultaneously. The RTA process can lower the metal-semiconductor electric contact resistance. Nevertheless, it inevitably increases the contact interface morphological roughness, which is detrimental to SPP propagation. Based on this dilemma, in this work we focus on studying the influence of RTA conditions on electrical control of SPPs. The experimental results indicate that there is obvious degradation of electrical pumping compensation for SPP propagation loss in the devices annealed at 400℃ compared to those with no annealing treatment. With increasing annealing duration time, more significant degradation of the active performance is observed even under sufficient current injection. When the annealing temperature is set at 400℃ and the duration time approaches 60s, the SPP propagation is nearly no longer supported as the waveguide surface morphology is severely changed. It seems that eutectic mixture stemming from the RTA process significantly increases the metal film roughness and interferes with the SPP signal propagation.

• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.179-201
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• 2004

Online traffic flow modeling is attracting more attention due to intelligent transport systems and technologies. The flow-density relation plays an important role in traffic flow modeling and provides a basic way to illustrate traffic flow behavior under different traffic flow and traffic density conditions. Until now the research effort has focused mainly on the shape of the relation. The time series of the relation has not been identified clearly, even though the time series of the relation reflects the upstream/downstream traffic conditions and should be considered in the traffic flow modeling. In this paper the flow-density relation is analyzed dynamically and interpreted as a states diagram. The dynamic flow-density relation is quantified by applying fuzzy logic. The quantified dynamic flow-density relation builds the basis for online application of a macroscopic traffic flow model. The new approach to online modeling of traffic flow applying the dynamic flow-density relation alleviates parameter calibration problems stemming from the static flow-density relation.

• Journal of Science and Technology Studies
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• v.4 no.1 s.7
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• pp.31-57
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• 2004

Controversies over NEIS(Network of Education Information System) began with very deep concern about infringement of human rights stemming from NEIS. A large information system which accumulates and uses huge size of individual information is always able to deeply infringe on human rights. But the ministry of education would not do the best not to be 'Big Brother' being dazzled by instrumental efficiency of information technology. NEIS has demonstrated problems of the information policy of Korea strongly driven in the name of 'E-goverment'. It has very strong characteristic of the statist economic growth policy focusing on more economic possibility than other. In this situation, making money is easily considered more important than protecting human rights. Information capitalism is nurtured at the sacrifice of human rights. So, we have to face problems of 'E-goverment' in order to correct the NEIS problem, The most important task to correct the NEIS problem is to make an element law protecting privacy and to establish an independent national institute protecting privacy

• Fashion & Textile Research Journal
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• v.16 no.5
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• pp.756-765
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• 2014

Customer-company (C-C) identification is the perceived fit between the identities of a consumer and an organization. If a consumer identifies with a company that places a high priority on being socially responsible, a consumer who also values social responsibility may support and patronize that business because of the link between something that is important to both them and the company. Because C-C identification may explain the success of cause-related marketing (CRM) in the fashion industry, we investigated the effect of an image resulting from CRM on ratings of brand attributes (e.g., distinctiveness, credibility, attractiveness), identification with the brand, attitude toward the brand, and customer loyalty. Participants also responded to open-ended questions reflecting their rationale for their ratings of brand attributes. Data were collected from a convenience sample of undergraduates (n = 228) enrolled at Midwestern University in the U.S. Structural equation modeling revealed that as ratings of the social responsibility of the cause-related marketing effort increased so did perceptions of the brand's distinctiveness, credibility, and attractiveness. Participants identified with a brand when they rated the brand as attractive. Participants' identification with a brand had a significant impact on attitudes toward the brand and customer loyalty (e.g., purchase intention, willingness to spread positive word-of-mouth). Content analyses of open-ended responses supported the idea that brand images stemming from CRM exert an important influence on consumer's ratings of brand attributes. Fashion marketers interested in cause-related marketing will find success with efforts that increase customer identification.

• The Journal of the Korea Contents Association
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• v.16 no.1
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• pp.13-23
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• 2016

This research studies the discrepancy between the perception and reality of the early childhood educators regarding the creative competency of the early childhood education institutions, and the differences stemming from the background characteristics of the educators. Subjects were 114 early childhood educators drawn from kindergartens in Daegu and Gyeongbuk province. 180 questionnaires were delivered through physical visit or mail to the institutions. The collected data were analyzed using t-tests, one-way ANOVA and the Scheffe post hoc test, and the result is as thus. Firstly, the discrepancy between the perception and the reality of the educators was significantly different in all sub-domains. Secondly, The discrepancy between the perception and reality, according to the background characteristics, showed significantly different in the following domains: according to the position of the educators, in some sub-domains of autonomy; according to the academic background, in some sub-domains of the leadership; according to the career of the educators, in some sub-domains of diversity; and according to the age of the educators, in some sub-domains of diversity and leadership.

• Preventive Nutrition and Food Science
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• v.11 no.4
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• pp.348-357
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• 2006

Nano is a unit that designates a billionth; accordingly nanotechnology could be described as the study and applications of the unique characteristics and phenomena of nanometer size materials. Applications of nanotechnology fall into two categories (one is top-down and the other is bottom-up). Currently, most products are the results of the top-down approach. Nanofoods have distinct functional characteristics stemming from the size, mass, chemical combinations, electrolytic features, magnetic properties of food sources at the nano level and which can be applied for safe absorption and delivery into the body. The greatest advantage of nanofood is that it permits the efficient use of small quantities of nutritional elements by increasing digestive absorption ability and by delivering natural elements without any change in their original characteristics. On the other hand, there are still unsolved problems, such as questions about safety and introduction of harmful material. The demand for new commercial food products is increasing, and commercial food producers are gradually combining nanotechnology and traditional food preparation methods. Nanofoods will improve our eating habits remarkably in the future. Tomorrow we will design nanofoods by shaping molecules and atoms. It will have a big impact on the food and food-processing industries. The future belongs to new products and new processes with the goals of customizing and personalizing consumer products. Nanotechnology is expected to be applied to not only foods themselves, but also to food packaging, production, safety, processing and storage. Also, it is believed that nanotechnology will be applied tracking finished products back to production facilities and even to specific processing equipment in those facilities. The aim of this study is the introduction of technology, applications, products, markets, R&D, and perspectives of nanofoods in the food industry.

• Journal of Acupuncture Research
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• v.33 no.3
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• pp.153-159
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• 2016

Objectives : The purpose of this study is to report the effect of Miniscalpel acupuncture therapy on a patient with traumatic tears of both meniscuses. Methods : We treated a patient with tears in both meniscuses stemming from a traffic injury. The clinical effects of this treatment are measured by Visual Analog Scale (VAS), European Quality of Life - 5 Dimensions (EQ-5D), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Results : After Miniscalpel acupuncture therapy, the VAS score of the left knee changed from 7 to 3, while the VAS score of the right knee changed from 7 to 2~3. WOMAC of both knees changed from 70 to 8. Night pain and day-to-day pain have disappeared, with only a slightly heavy feeling remaining. Conclusion : These results suggest that Miniscalpel acupuncture therapy may be effective for treating traumatic meniscus tear.

• Journal of Korea Multimedia Society
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• v.11 no.1
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• pp.53-60
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• 2008

Fingerprint verification method based on minutiae has been widely used for its speed and size stemming from utilizing only a few data, but it is vulnerable to some errors caused by the false minutiae extractions. A number of suggestions have been made to correct these problems. However, because it is very difficult to avoid all the external factors, such as noises that occur when fingerprints are collected, and all the internal factors that occur during the process of them, there is a limit in minimizing errors by improving the whole process. On the other hand, a fingerprint verification method based on images yields fewer errors because it makes direct comparison between images not using minutiae. Image-based fingerprint verification method has its limitations in aligning images with accuracy. Therefore, this paper proposes a new methodology to improve the performance utilizing both image-based and minutiae-based verification methods effectively. As the result of experimenting with both images and minutiae, the false accept rate and the false reject rate have been improved from 2.7% to 0.8% and from 6.5% to 5.5%, respectively.