• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2002.07a
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• pp.25-37
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• 2002

The most important industrial application of gamma radiation in characterizing green compacts is the determination of the density. Examples are given where this method is applied in manufacturing technical components in powder metallurgy. The requirements imposed by modern quality management systems and operation by the workforce in industrial production are described. The accuracy of measurement achieved with this method is demonstrated and a comparison is given with other test methods to measure the density. The advantages and limitations of gamma ray densitometry are outlined. The gamma ray densitometer measures the attenuation of gamma radiation penetrating the test parts (Fig. 1). As the capability of compacts to absorb this type of radiation depends on their density, the attenuation of gamma radiation can serve as a measure of the density. The volume of the part being tested is defined by the size of the aperture screeniing out the radiation. It is a channel with the cross section of the aperture whose length is the height of the test part. The intensity of the radiation identified by the detector is the quantity used to determine the material density. Gamma ray densitometry can equally be performed on green compacts as well as on sintered components. Neither special preparation of test parts nor skilled personnel is required to perform the measurement; neither liquids nor other harmful substances are involved. When parts are exhibiting local density variations, which is normally the case in powder compaction, sectional densities can be determined in different parts of the sample without cutting it into pieces. The test is non-destructive, i.e. the parts can still be used after the measurement and do not have to be scrapped. The measurement is controlled by a special PC based software. All results are available for further processing by in-house quality documentation and supervision of measurements. Tool setting for multi-level components can be much improved by using this test method. When a densitometer is installed on the press shop floor, it can be operated by the tool setter himself. Then he can return to the press and immediately implement the corrections. Transfer of sample parts to the lab for density testing can be eliminated and results for the correction of tool settings are more readily available. This helps to reduce the time required for tool setting and clearly improves the productivity of powder presses. The range of materials where this method can be successfully applied covers almost the entire periodic system of the elements. It reaches from the light elements such as graphite via light metals (AI, Mg, Li, Ti) and their alloys, ceramics ($AI_20_3$, SiC, Si_3N_4, $Zr0_2$, ...), magnetic materials (hard and soft ferrites, AlNiCo, Nd-Fe-B, ...), metals including iron and alloy steels, Cu, Ni and Co based alloys to refractory and heavy metals (W, Mo, ...) as well as hardmetals. The gamma radiation required for the measurement is generated by radioactive sources which are produced by nuclear technology. These nuclear materials are safely encapsulated in stainless steel capsules so that no radioactive material can escape from the protective shielding container. The gamma ray densitometer is subject to the strict regulations for the use of radioactive materials. The radiation shield is so effective that there is no elevation of the natural radiation level outside the instrument. Personal dosimetry by the operating personnel is not required. Even in case of malfunction, loss of power and incorrect operation, the escape of gamma radiation from the instrument is positively prevented.

• Journal of Conservation Science
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• v.24
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• pp.13-22
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• 2008

The identification of species, hygroscopic property, and ability of ethylene gas absorption of 23 ancient charcoals excavated from wooden coffin burials and roof-tile kilns of Chudong-ri cultural site were investigated. All of the 12 charcoals excavated from wooden coffin burials were broad-leaved trees. Among the total 12 samples, 9 samples were Lepidobalanus and others were Celtis spp.. On the other hand, other 11 charcoals from roof-tile kilns were needle-leaved tree, Pinus spp.(hard pine). The broad-leaved tree charcoals from wooden coffin burials showed a higher moisture absorption capacity than needle-leaved tree charcoals from roof-tile kilns. The ethylene gas absorption was greater in the Lepidobalanus charcoal than that of Celtis spp. and Pinus spp. (hard pine) charcoal. The broad-leaved tree charcoal having high absorption ability of substances was due to a large microporous and specific surface area. Therefore, it was estimated that broad-leaved tree charcoals were filled in order to make favorable condition in tomb. The wood quality of pine is soft and easy to burn because of low specific gravity, as well as high calorific value by resin in wood. We could assume that the pine wood was used as fuel for roof-tile kilns because of easy control of heating and thermal power.

• Journal of Fashion Business
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• v.15 no.5
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• pp.69-86
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• 2011

The objective of this research is to unveil the dynamic changes of the trends in wedding dresses during the 20th Century. The studies were carried out in two forms; firstly by observing the actual wedding dresses worn by people at that time, and secondly by conducting formative comparisons between those dresses with the ones appeared in movies corresponding to that period. Movies provide an invaluable insight into the era's wedding dresses fashion trends since they function as intimate bridges in connection with the time's audience, and the visible imageries accurately reflect the characteristics embedded within that time frame. As there are no precedent studies regarding this topic, this thesis can serve as vital research data for the wedding dress industry. Research data regarding the actual wedding dresses were collected from books and museum web sites. The object of movies were films produced before World War II that contained both the background settings of the 20th Century and wedding dresses, of which photographic imageries were captured. Research analysis was then conducted by merging these data with findings from relevant books and internet materials. The results of the thesis are as the following: The 1900s was an extension of the 19th Century's popular fashion trend which can be characterized as the S curve silhouettes of the Edwardian period when long trains and long veils symbolized wealth and social power. In the 1910s, high waist silhouettes with soft wrinkles were prevalent as attire suitable for active mobility with practical functionality were highly regarded. During the 1920s, the flapper style became the dominant trend. Hem lines of the skirts were curled in the form of the scallop and laces were the most widely used raw materials. By the 1930s, wedding dresses that reinterpreted the glamorous sheath lines, practical two piece styles, and retro-styles became predominant. The 1940s saw the advent of ready-made wedding dresses made of synthesized materials; practical military style suits and casuals sometimes substituted the wedding dresses. And although the wedding dresses in the movies were primarily costumes to express the personalities of the characters, they were also reinterpreted as manifestations of the formative characteristics of each relative period that pursued very distinct and diverse features.

• Journal of Fashion Business
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• v.8 no.2
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• pp.69-90
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• 2004

The purpose of this study is to find the recognition of Korean image fashion design by U.K fashion specialists. U.K is one of the important countries in design field including fashion design since 1960. For this purpose, literature research and focus individual interview research were carried. First, through the researches precedent, it was found that a national image is related with it's design industry and what is Korean image fashion design, were studied. Second, for individual interviews to 13 U.K fashion specialists, who are teaching and researching in University that has postgraduate course over M.A and had industrial experiences from 7years to 22years, were progressed using open questions and visual image stimulus. The open questions were consisted with four parts : personal educational and industrial background, recognitions about oriental fashion, recognitions about Korean image and Korean fashion design before seeing the visual stimulus, recognition about Korean image fashion design and the characteristics of Korean after seeing the visual stimulus. The results are as follows; First, the 12 U.K specialists have recognized 'oriental fashion' is one of important fashion trends now a days. Japan and Japanese designers are recognized as a represented nation and designer in oriental fashion by them. Two of the specialists referred to need changing the term 'oriental' because the term has been used in the sights of western from colonial age and Japanese is not included the oriental any more. Secondly, 11 interviews have recognized nothing about the Korean national image some of them has negative image due to political situation in Korean Peninsula. However 2 interviews who had been Korea before has positive image. In the questions about Korean fashion and Korean fashion designers, 10 of 13 interviews have nothing and negative recognitions. So it was founded that Korean fashion design was recognized as a lower level by U. K. fashion specialists. Thirdly, in the questions about Korean fashion image and the design characteristics of Korean fashion after seeing the visual stimulus, the response was represented two directions. One is about over decorative image through ethnic design and the other is about simple image differ from Japanese. The 13 interviews felt the Korean Image fashion design such like traditional, decorative, opulent, flat cutting, fresh proportion, loose, layering, natural, simplicity, complicate, adventure, easy, stylish, soft, feminine, young image, adult sexy image. The images were analyzed five image groups : adult sexy image, adult ethnic image, natural image, young avant-garde image, young simple casual image. No one preferred the adult sexy image, adult ethnic image and natural image. However 10 interviews preferred young avant-garde group and 13 interviews preferred the young simple casual image. So this group can be understanded and useful informed as one of competitive power in global fashion industry.

• Korean journal of food and cookery science
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• v.24 no.3
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• pp.340-348
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• 2008

The purpose of this study was to develop new method for the manufacture of Yukwa, a Korean oil-puffed rice snack with a soft texture, using a far infrared ray electric roaster. The Yukwa base is traditionally expanded using oil, but the Yukwa base tends to develop unpleasant rancid odors or off-flavors during storage. In this study, the DPPH radical scavenging activity of mugwort powder was evaluated. Baked and fried Yukwa samples were added with 0.5, 1.0, 1.5, and 2.0% of mugwort powder and left untreated as a control, and then tested for moisture content, expansion rate, color, hardness, and sensory evaluations. The samples with higher concentrations of mugwort powder, evidenced a more profound tendency toward DPPH radical scavenging activity. The moisture content of Yukwa dough tended to increase with the addition of mugwort powder. As the mugwort powder content increased, the moisture contents of the Yukwa base and the Baked Yukwa increased. The moisture content and expansion rates of the fried Yukwa did not differ significantly. The samples containing the mugwort power evidenced a lower expansion rate than was observed in the control group. The lightness of the baked and fried Yukwa was reduced with increased mugwort powder content. The greenness of the baked and fried Yukwa was at a minimum upon the addition of 2.0% mugwort powder. The yellowness of the baked Yukwa did not differ significantly between the samples. As the mugwort powder content increased, the yellowness of the fried Yukwa increased. The hardness of the baked and fried Yukwa tended to increase with the addition of mugwort powder. In the sensory evaluations, the baked Yukwa scored higher than the fried Yukwa, and all of the sensory characteristics of baked Yukwa scored highest in the samples without mugwort powder, but also scored fairly well with 1.0 and 1.5% mugwort powder. In conclusion, these results demonstrated that 1.0～1.5% of mugwort powder should be added to Yukwa baked in a far infrared ray electrical roaster in order to optimize physiological functions and keep overall acceptability reasonably high.

• Korean journal of communication and information
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• v.56
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• pp.86-116
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• 2011

Recently, media diplomacy takes on a substantial role in information war not only in setting global agenda but also in delivering their favored views and frames. Focusing on its crucial impact, this study attempts to investigate empirically the relationship between national prestigious media's news coverage and it's own foreign policy particularly about the 2011 Libya conflict. The total of 530 news articles in such 24 hour English news channels as BBC World, Cnn International, Russia Today, France24, Al Jazeera English and Deusche Welle were analyzed for this study. The analyses reveal that Libya coverages of those news channels are entirely constructed in the context of the foreign policy. To put it concretely, there was the undeniable level of differences in terms of quoting relevant sources, viewpoints, attitudes and frames for the pursuit of media diplomacy helped by high quality journalism. The authors argue in this regard that protecting information sovereignty should be urgently discussed even in the time of digital revolution. To launch 24-hour English news channel like 'Korea 24' would be a possible strategy for influencing global agenda and perspective in way of supporting national interests.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.9
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• pp.581-588
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• 2016

Piezoelectric thick films of a soft $Pb(Zr,Ti)O_3$ (PZT) based commercial material were produced by a conventional tape casting method. Thereafter, the interdigitated (IDT) Ag-Pd electrode pattern was printed on the $25{\mu}m$ thick piezoelectric film at room temperature. Co-firing of the 10-layer laminated piezoelectric thick films was conducted at $1,100^{\circ}C$ and $1,150^{\circ}C$ for 1 h, respectively. Piezoelectric cantilever energy harvesters were successfully fabricated using the IDT electrode pattern embedded piezoelectric laminates for 3-3 operation mode. Their energy harvesting characteristics were investigated with an excitation of 120 Hz and 1 g under various resistive loads (ranging from $10k{\Omega}$ to $200k{\Omega}$). A parabolic increase of voltage and a linear decrease of current were shown with an increase of resistive load for all the energy harvesters. In particular, a high output power of 3.64 mW at $100k{\Omega}$ was obtained from the energy harvester (sintered at $1,150^{\circ}C$).

• Journal of The Korean Ophthalmological Society
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• v.59 no.11
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• pp.1071-1076
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• 2018

Purpose: To report a case of immunoglobulin G4 (IgG4)-related ophthalmic disease associated with adult xanthogranulomatous disease. Case summary: A 38-year-old male with a history of cholecystectomy visited our clinic for bilateral periorbital swelling. Histopathology of the orbital biopsy showed diffuse infiltration of foamy histiocytes with Touton giant cells and lymphoid follicles, with a diagnosis of adult-onset xanthogranuloma. After excisional biopsy, he was treated with azathioprine and prednisolone. Four years after treatment, he again visited the clinic due to bilateral, yellowish eyelid masses. Serological examinations were all nonspecific findings, except for elevation of IgG and IgG4 levels. Magnetic resonance imaging showed bilateral symmetric soft tissue enlargement with slightly heterogeneous T1/T2 isosignal intensity, with contrast enhancement at the superolateral aspect of extraconal spaces. Excisional biopsy and blepharoplasty were performed. Immunohistochemical sections showed that the IgG4+/IgG plasma cell ratio was 10-20% and the IgG4 plasma cell count was 22/high power field (HPF). His past sections of 2013 from the pathology department were again stained and showed that the IgG4+/IgG plasma cell ratio was 40-50% and the IgG4 plasma cell count was 59/HPF. Thus, he was definitely diagnosed with IgG4-related ophthalmic disease. Conclusions: If there is recurrent eyelid swelling, IgG4-related ophthalmic disease should be considered as a differential diagnosis. And the patient with adult xanthogranulomatous disease can be diagnosed with IgG4-related ophthalmic disease.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.75-84
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• 2021

In this study, the correlation between cement quality(chemical composition, mineral composition, and compressive strength) and amount of waste alternative fuels used in the cement manufacturing process and was investigated. Cement manufacturing facility using coal, soft plastics(plastics that are easily scattered by wind power, such as vinyls), hard plastics(plastics that do not contain foreign substances, waste rubber, PP, etc.) and reclaimed oil was analised. Data was collected for 3 years from 2017 to 2019 and let the amount of fuels used as an independent variable and cement quality data as a dependent variable. As a result, depending on the type and quality of the alternative fuel has not a significant effect on the chemical composition(Cl and LSF) and mineral composition(f-CaO, C3S contents). Contrary to the concern that the compressive strength of cement would decrease, there was a significant positive correlation between amount of alternative fuel used and cement compressive strength.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.375-382
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• 2021

Adolescents with disabilities have unnatural behavior and language, which makes it difficult to use soft and flexible language and behavior, and lack of learning experience has limitations in not being free in mature behavioral communication. Eurhythmics musical rhythm elements were divided into time and space, power and weight, and balance and fluidity and reflected in teaching and learning so that adolescents with disabilities could have comfortable, creative, and original thoughts that bring about changes in thawing. In order to increase the effectiveness of education in the direction of observing the effect of improving self-esteem, communication, and creativity of adolescents with disabilities, the study guide applying the Eurhythmics rhythm element was fused with music education, art education, and physical education, and interviewed by selecting research participants. Based on the questionnaire, an observation method suitable for the study of adolescents with disabilities was conducted. As a result of the study, it was observed that the educational effect of the disabled youth was improved as a result of conducting the class by applying the Eurhythmics rhythm elements time and space, force and weight, balance and fluidity by integrating music, art, and physical education(line dance, playtime). Therefore, to supplement the limitations in this learning process, various educational methods applicable to the education of youth with disabilities, a support system that can reflect Eurhythmics education through physical play, and a method to properly compose various learning tools do.