• Journal of Advanced Marine Engineering and Technology
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• v.25 no.5
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• pp.1076-1085
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• 2001

Experimental investigations of the longitudinal vortices, which are produced by wing type vortex generators set up behind a circular cylinder in a rectangular channel, are presented. When the circular cylinder is set up in the rectangular channel, a horseshoe vortex is formed just upsteam of the circular cylinder. It generates a turbulent wake region behind the circular cylinder. Therefore, the region of the pressure loss behind the circular cylinder in increased and the size of the wake is small. These problems can be achieved by longitudinal vortices which are generated by wing-type vortex generator. In order to control the strength of longitudinal vortices, the angle of attack of the vortex generators is varied from 20 degree to 45, but the spacing between the vortex generators is fixed 6cm. The 3-dimensional mean velocity measurements are made using a five-hole probe. The vorticity field and streamwise velocity contour are obtained from the velocity field. The following results are obtained. Circulation strength is the maximum value when the angle of attack($\beta$) is $30^{\circ}$, and the vorticity field and streamwise velocity contour in case of $\beta$=$20^{\circ}$ show the trend similar to these in case of $\beta$=$30^{\circ}$, but do not in case of $\beta$=$45^{\circ}$.

• Journal of the Korean Solar Energy Society
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• v.28 no.6
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• pp.48-57
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• 2008

The research analyzed the distribution of the indoor temperatures of a radiant floor cooling system through mock-up experiments. It investigated the temperature difference of feed water, the vertical temperature difference of indoor air, the temperature difference of floor surface, and so on. The following is the results of the research. First, the research shows that the difference between indoor temperature and outside temperature was the smallest when the temperature of feed water was set at 16$^{\circ}C$. In addition, the temperature changes according to indoor positions (wall, room, floor, and ceiling) were the most uniform. Thus, the research found that the cold water temperature of 16$^{\circ}C$ is the most proper. In addition, it confirmed that the feed water temperature of 18$^{\circ}C$ is effective because the temperature can lower the temperature of a room to 13.55$^{\circ}C$, which is lower than the temperature of a non-cooling mode. Second, an investigation on the temperature distribution of vertical air in indoor space shows that the temperature distribution had a difference of 0.2 to 1.9$^{\circ}C$ on the average, which satisfies the range of 3.0$^{\circ}C$ in the standard of ISO.

• Journal of the Korean Society of School Health
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• v.12 no.1
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• pp.131-141
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• 1999

The purpose of this study was to serve as a basis for the planning of oral health education and the development of an oral health-promotion program for patients who visited dental clinics by examining how much dental hygienists offered oral health education to adult patients at dental clinics. A parent group was selected, being made up of 1,600 dental hygienists who registered with the Dental Hygienist Association and worked in Seoul. The questionnaire survey was carried out and an ${\chi}^2-test$ was made using the data collected from 218 subjects to determine how their practice of oral health education was different according to certain general characteristics(the sort of organization for which they worked, age, the term of their service, and the mean number of patients per day). As a result, the following findings were obtained: 1. Thees general characteristics made the following differences to the content of oral health, education: The sort of organization for which the subjects worked made a significant difference in the following tooth brushing instruction (p<0.05), the effect of oral prophylaxis or education about aftereffects (p<0.05), the regular examination of prosthesis (p<0.05), smoking-prohibition education (p<0.05), and the prevention poor-quality fillings (p<0.01). The mean number of patients per day made significant differences to the regular examination of prosthesis (p<0.05) and the prevention poor-quality fillings (p<0.01). But no significant disparity was generated by age or the term of service. 2. The general characteristics made the following differences to education about nutrition and diet counseling: The sort of organization for which the subjects worked had a significant effect just on the importance of a balanced menu (p<0.05). Age made significant differences in advice for vitamin, mineral, protein or other nutrients (p<0.01), and the importance of balanced menu (p<0.001). The term of service made significant differences in the importance of balanced menu (p<0.01), and advice for nutrients including vitamin, mineral or protein (p<0.01). 3. The general characteristics made the following differences to the recommendation and use of oral hygiene aids: The sort of oragnization for which they worked made significant differences only to a gingival massager and water pick (p<0.05). No significant difference was produced by age, the term of service or the mean number of patients per day. 4. The use of educational media for oral health was different according to the general characteristics: The use of pamphlets or booklets significantly varied depending on the organization for which they worked and with the mean number of patients per day (p<0.05). The use of slides or slide projectors was significantly affected by age (p<0.05). But no significant disparity was yielded by the term of service. 5. The general characteristics made the following difference as to whether a continued oral management system was carried out or not: The sort of organization for which they worked had very a significant effect on this result (p<0.001), and no significant disparity was made by age, the term of service or the mean number of patients per day. 6. The place where oral health education was giver differed according to the following general characteristics: The sort of organization for which they worked made very a significant difference as to the use of an examination room's dental unit chair or waiting room (p<0.01), and to the use of an oral health education room or reception counter (p<0.001). The term of service had a significant effect on the use of a counseling room (p<0.01). And the mean number of patients per day made significant differences in the use of a dental unit chair or reception counter (p<0.05), and to the use of an oral health education room or waiting room (p<0.01).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.3
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• pp.253-266
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• 2016

Objectives: This study is for characteristics of asbestos occurrence (NOA, naturally occurring asbestos) from the Gapyeong area and its host rocks, serpentinites. Methods: Representative samples are collected from the serpentinite bodies, following degrees of hydrothermal alteration and metamorphism, after about 2 year field trips. Mineralogical, morphological and optical characteristics of the asbestos and host rocks are confirmed by PLM, XRD EPMA and SEM results. Results: The serpentinites are dunites and harzburgites, and host asbestos, including chrysotile, tremolite and actinolite. The asbestos chrysotiles are found as veins ranging from several millimeters to several centimeters in thickness, while asbestos-tremolite and -actinolite occur along cracks and fractures ranging up to ten centimeters in thickness. The chryostiles occur mainly as cross and slip fibers, while the amphibole asbestos is found as vein, slip and oblique fibers. More tremolitic grains are colorless and commonly show elongated or fiber shapes, whereas the magnesio hornblende grains mainly show light green and occur as subhedral to euhedral diamond grains. Conclusions: Overall characteristics of serpentinites from the Gapyeong area are similar to worldwide orogenic-related Alpine type ultramafic rocks serpentinized and serpentinites in South Chungcheong-do Province, Korea, and occurrences of asbestos are similar to those of the ultramafic bodies in South Chungcheong-do Province.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.3
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• pp.97-109
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• 2016

In Korea, the survival rate of start-up of 5-year after foundation is as low as 29.6% of the country. This low survival rate is from because of insufficient resources in start-ups compared to those of mid-sized companies. Therefore, the marketing characteristics of entrepreneurship has emerged as a major cause. Therefore, In this study, because learning orientation, marketing experience, competition orientation and etc are differently owned in start-ups, marketing impact to marketing strategy in start-up companies are differently investigated. Therefore, the relationship of learning orientation, marketing experience, competition Orientation with marketing strategies was examined. Based on this, Business performance was examined to suggest contents related to eco-system of start-up companies to representative of start-up companies. For this study, Survey was conducted for 250 start-up entrepreneurs within 3 and half year since foundation from Nov. 20 to Dec. 20, 2015. In result of data-cleaning, 207 meaningful samples were gathered. Based on these, conclusion was obtained. Using SPSS 20.0 statistical program, frequency analysis, reliability analysis, correlation analysis and regression analysis were conducted. the following conclusions were drawn. First, in the impact of marketing environment of Phase 1 start-up companies on marketing strategy, product strategy, distribution strategy and promotion strategy were positively affected by learning orientation, marketing experience and competition orientation. Second, in the effect of 2nd phase marketing strategy to business performance, the financial performance and the non-financial performance. Were positively affected by product strategy, distribution strategy and promotion strategies. Third, The effect of learning orientation, marketing experience and competition orientation to financial performance was positively mediated by product strategy and distribution strategy among 3rd phase meditation strategies. the effect of learning orientation, marketing experience and competition orientation to non-financial performance was positively mediated by products strategy. In comprehensive summary, in order to increase business performance in start-up companies, marketing strategy should be applied in. Especially, the role of learning orientation and marketing experience is vital. In increasement of business performance to characteristics of star up marketing, financial performance can be increased by product strategy and distribution strategy. And, both of financial and non-financial performance can be increased by product strategy. Therefore, in conducting of marketing characteristics of start-up, to increase business performance, the apply of marketing strategy to marketing characteristics of start-up should be required.

• Journal of the Korean Society of Costume
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• v.66 no.3
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• pp.18-31
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• 2016

In response to increasing preference for tattoos during the 2000s, the demand for Japanesestyle tattoo fashion increased. Ukiyoe, the prototype of Japanese tattoo popular in the Edo period has been preserved traditional expression techniques to the present, It is characterized by the following: first, the tattoos share literary lyricism through plays borrowed from the classics. second, it displays harmony and equivocal expression of heterogeneous elements samurai and kabuki mono. third, humorous images are expressed in picture-in-picture form. And fourth, presence of fixed characters based on the publication culture. Tattoo fashion is characterized by the following: First, eclectic fashion based on pastiche; second, characters emphasizing fun and comicality; third, the adoption of tattoo models for establishing brand images; and fourth, Cultural association for the new composition of culture consumption. Pastiche, harmony of heterogeneous elements, fun and comicality, and fixed characters were found to be common between tattoo ukiyoe and tattoo fashion. That is, it attempted to meet the sensitive consumers' needs to keep up with the trends by adopting tattoo incorporated into the subculture of neo pop. This shows clearly the characteristics of fashion, which creates new trends through interacting with the contemporary culture.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.6
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• pp.185-199
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• 1994

This study has been performed to present a new automatic tool wear measurement by digital image processing. The purpose of this paper is to develop an automatic tool wear measuring system based on the image processing which can be applied to the quasi-real time measurement of the characteristics of insert tip in turning. Tool wear monitoring is one of the key-problems, for the development of control systems of modern unmanned factory which are not completely solved now. In oredr words at present complete qualitative and quantitative information on tool wear morphology is required, at least on the following aspects : flank wear, its dimensions and distribution on the maximum and mean values on VB pqrqmeter in the various zones of the wearland. crater wear, its main dimensions and values of KT parameters. This research has been performed to this technique made possible by designing a proper lighting system to the worn tool with following features : The flank wear is measured by observing the active cutting part from a proper direction and by lighting the wearland by a diffuser optic system. The crater wear is visualized by lighting the tool by a He-Ne gas laser system developed in this study. By means of this system it is research to evaluate classical parameters of tool wear and to have complete information about tool wear morphology.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.4
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• pp.422-429
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• 1988

The photoconductive multilayer of Se-As(hole blocking layer)/Se-As-Te (photoconductive layer) /Se-As (layer for supporiting hole transport)/Se-As(layer or controlling total capacitance)/Sb2S3(electron blocking layer) was fabricated and its electrical and optical properties were investigated. The photoconductive multilayer is made of evaporated a-Se as the base material, doped with As and Te to prevent the crystallization of a-Se and to enhance red sensitivity, respectively. The multilayer with good image reproducibility has the following deposition condition. The first layer has the thickness of 250\ulcornerat the deposition rate of 250\ulcornersec. The second layer has the thickness of 800\ulcornerat the deposition rate of 250\ulcornersec. The third layer has the thickness of 125\ulcornerat the deposition rate of 250\ulcornersec. The fourth layer has the thickness of 1700\ulcornerunder the Ar gas ambient of 50x10**-3torr. The image pick-up tube, employing this multilayer demonstrates the following characteristics. The photosensitivity is 0.8, the resolution limit is above 300TV line, and the decay lag is about 7%. And spectral response convers the whole visible range. Therfore the application to color TV camera is expected.

• Architectural research
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• v.8 no.2
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• pp.17-26
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• 2006

This paper attempts to identify the term "tectonics" comprehensively by collecting and categorizing existing definitions of tectonics within the architectural area rather than to stress the concept of tectonics of each specific theorist. Although no consensus of opinion on the concept of tectonics exists, architectural tectonics was closely related to the following terms in three categories: 1. $techn\acute{e}$, technique, and technology; 2. construction and structure; and 3. stereotomics. Based on its etymology, system, and material construct, the notion of tectonics common in these three categories signifies "the art of framing construction," in which linear elements are connected with joints and clad or infilled with lightweight material. Thus, the art of framing construction, as a common concept of tectonics, reveals the following characteristics: First, tectonics is based on framing construction in contrast to piling-up construction as the etymology of tectonics signifies the art of carpentry. Then, the term tectonics, dealing as it does with a higher level of construction rather than the mechanical level of structure, incorporates the poetic aspect of techne as well as the rational aspect of technology. Third, Owing to the organic, double system of tectonic frame and incrusting or infilling materials, the tectonic body becomes both the ornament and the structure simultaneously. As the art of framing construction is based on material construction rather than structural or ornamental form, this paper proposes that one can view tectonics as a term that conveys the meaning of the actual material effect on space.

• STI Policy Review
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• v.1 no.1
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• pp.93-109
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• 2010

Over the last decade, some Korean enterprises have emerged to become global players in their specialized products. How have they achieved such tremendous technological progress in a short period of time? This paper explores that question by examining the characteristics of technological innovation activities at major Korean enterprises. The paper begins with a brief review of the stages of economic growth and science and technology development in Korea. Then, the existing literature, explaining the Korean innovation model, is analyzed in order to establish a new framework for the Korean innovation model. Specifically, Korean firms have experienced three sequential phases, and thus, the Korean model, at the firm level, can be coined as "path-following," "path-revealing," and "path-creating." Then, the stylized facts in the first phase (path-following) and the second phase (path-revealing) are discussed, in the context of empirical evidence from the areas of memory chips, automobiles, shipbuilding, and steel. In terms of technology development, the Korean model has evolved as "collective learning" in the first phase, "collective recombination" of existing knowledge and technology in the second phase, and is assumed as "collective creativity" in the third phase. Ultimately, all three can be classified as "collective creation". Korean firms now face a transition in the modes of technological innovation in order to efficiently implement the third phase. To achieve remarkable progress again, as they did in the past, and to sustain the growth momentum, Korean firms should challenge new dimensions such as creative technological ideas, distinctive technological capabilities, and unique innovation systems -- all of which connote 'uniqueness'. Finally, some lessons from the Korean technological innovation experience are addressed.