• 한국패류학회지
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• 제31권1호
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• pp.61-67
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• 2015

The occurrence of 'algal bloom', caused by the mass proliferation of phytoplankton, causes serious problems in streams and lakes in Korea. Therefore, in this study, the phytoplankton filter-feeding trait of Unio douglasiae, a type of freshwater clam, was used to reduce the algal bloom in outdoor water tanks during the summer. This involved the construction of a U. douglasiae cultivation apparatus, wherein 1,000 clams were divided into 8 rectangular baskets arranged in the shape of an empty square. The control tank was manufactured in exactly the same shape within the water tank, but without the addition of clams. The algal bloom-reducing effect of U. douglasiae was confirmed by the measurement of (and comparing between) the water quality at the center and periphery of the test and control cultivation apparatus. Water quality measurements included the measurement of water temperature, pH, turbidity, dissolved oxygen (DO) content, and chlorophyll-${\alpha}$ concentrations; the water quality was measured twice a month between June and November 2014.The results of these analyses did not show a significant difference in water quality (temperature, pH, turbidity, DO) between the center and periphery of the test and control tanks. However, the chlorophyll-${\alpha}$ concentration was observed to be much lower at the center of the test tank compared to that at the center and periphery of the control tank, as well as at the periphery of the test tank. This was believed to be a result of the U. douglasiae surrounding the center of the test tank, which prevented the influx of plankton from the periphery. Accordingly, the results of these analyses suggest the possibility that U. douglasiae cultivation could reduce the proliferation of algal blooms in lakes and streams during the summer. In particular, these results indicate possible improvements in U. douglasiae activity (reduction in algal blooms) by their effective arrangement in the water bodies.

• Restorative Dentistry and Endodontics
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• 제6권1호
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• pp.133-139
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• 1980

In this experiment, etching was performed on the incisor enamel surfaces of 13 Albino rats, weighted about 130gm, with both 30% and 50% concentrations of the phosphoric, citric acids, and EDTA solution for 60 seconds. Immediately after extraction of the animal teeth, laboratory procedures for scanning electron microscopic observations were made and the author derived the following conclusions: 1. On the enamel surface treated with 30% and 50% phosphoric acids, all of the periphery, center of the enamel rods, and the enamel matrices were severely etched. 2. In the etched with 30% citric acid group, only the small part of the enamel rods were etched out. In case of 50% citric acid the periphery, center of enamel rods were partially or entirely etched, and the intermatrix spaces were widened. 3. In the 30% and 50% of the EDTA etched groups, the periphery of the enamel rods explicitely were etched, and the spaces between matrices were widened.

• 수완나부미
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• 제9권1호
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• pp.85-108
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• 2017

This paper argues that Thailand's internal colonial model is facing severe challenges: no longer is it so possible to suppress local and regional identities, or to submerge ethnic difference in an all-embracing but potentially suffocating blanket of "Thainess." In recent decades, Thailand's diverse localities have become increasingly assertive. This is most acutely the case in the insurgency-affected southern border provinces of Pattani, Yala, and Narathiwat, but also applies in the "red' (pro-Thaksin) dominated North and Northeast. As the old ruling elite faces serious legitimacy challenges, Thailand's emerging post-colonial politics may require a radical rethinking of the relationship between center and periphery.

• 영미문화
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• 제14권1호
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• pp.219-239
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• 2014

Arjun Appadurai contends that "the new global cultural economy has to be seen as a complex, overlapping, disjunctive order that cannot any longer be understood in terms of existing center-periphery models" (32); though discerning and perhaps becoming more and more apt, Appadurai's observation of the breakdown of the "center-periphery" binary appears as mere "academic jargon" in the lives of new immigrants, tackling the murky waters of identity politics in the transcultural technoscape of modern America in Kunzru's Transmission. Kunzru's antihero is Arjun Mehta, a software technician, who comes to America with high hopes of realizing the "American Dream." To a certain extent, Arjun himself is culpable of resurrecting the "center" as he prioritizes America and its values over all else. Despite his best efforts, Arjun cannot prevail in the perilous politics of exclusion/inclusion, and is relegated into a "high-tech coolie," exploited for his technological savvy. Even as the "center-periphery" binary stays intact in the production of an (Asian) American identity, it becomes undone in the hands of this "would-be" American; ultimately denied inclusion into America, Arjun unleashes a destructive virus that has major global consequences. In a sense, the boundary that separates the center and the periphery comes down as both collectively become victims to Arjun's retributive malfeasance. Arjun seems to rely on the "American" promise that old allegiances (to a national identity) are now defunct and new ones can be easily forged; as Kunzru's Transmission demonstrates with the tragic story of Arjun, the complex politics of identity production in America does not necessarily deliver on this promise. This essay hence aims to examine the politics of (national) belonging in the age of transnationalism.

• 헤리티지:역사와 과학
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• 제51권2호
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• pp.108-123
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• 2018

본 논문은 청동기와 인문경도, 원시자기 같은 희소자원의 생산, 유통을 사례로 들어 상대 전 중기에 자원문제가 중심과 주변의 관계에 미친 영향을 논하였다. 중심과 주변의 관계는 상문화 구역 내부에서의 관계, 상문화 구역 외부에서의 관계 등으로 나누어 살펴볼 수 있다. 상문화 구역 내부에서는 지방에서 생산된 인문경도와 원시자기 등의 자원을 반룡성에서 취합한 후 정주상성으로 운반하였다. 그러나 반룡성에서는 자체적으로 청동기를 생산하거나 인문경도와 원시자기를 독자적인 방식으로 사용하는 현상도 확인된다. 반룡성은 자원 획득의 성격을 지닌 비교적 독립적인 거점이었다. 상문화 구역의 외부에서는 정주상성에서 성양지역으로 청동기 완제품이 유통되었으며, 청동 원료도 유통되었을 것이다. 남방 복건 강서지역의 인문경도와 원시자기는 반룡성을 통해서 중원지역으로 유입되었는데, 각 지역에서 인문경도와 원시자기의 기능과 의미는 다르게 사용되었다. 이상을 통해서 상문화구역 내부와 외부에서 중심과 주변 간의 자원유통은 쌍방향적이었으며, 이러한 자원의 유통은 중심과 주변의 관계를 형성하는 중요한 요소였음을 알 수 있다.

• 한국신뢰성학회지:신뢰성응용연구
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• 제18권2호
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• pp.95-103
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• 2018

Purpose: Environment test aim to validate the guarantee of required capability of materiel against various environment conditions which exposed during materiel life-cycle. In this paper, environment test design procedure and tailoring guideline for Korean peninsula and periphery climate are proposed. Methods: To design tailoring guideline, climate data which are regarding Korean peninsula and periphery regions provided from Korea Meteorological Administration (KMA) and National Climatic Data Center (NCDC) are used. Conclusion: For effective environment test, it is important that environment test have to design in considering environment conditions during materiel life-cycle. It is concluded that the high temperature test level can be softer than the test criteria in MIL-HDBK-310, however, the low temperature test level will be expected to be $2{\sim}6^{\circ}C$ harsher than MIL-HDBK-310.

• Nuclear Engineering and Technology
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• 제42권1호
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• pp.79-88
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• 2010

Spent $UO_2$ nuclear fuel discharged from a nuclear power plant (NPP) contains fission products, U, Pu, and other actinides. Due to neutron capture by $^{238}U$ in the rim region and a temperature gradient between the center and the rim of a fuel pellet, a considerable increase in the concentration of fission products, Pu, and other actinides are expected in the pellet periphery of high burnup fuel. The characterization of the radial profiles of the various isotopic concentrations is our main concern. For an analysis, spent nuclear fuels originating from the Yeonggwang-2 pressurized water reactor (PWR) were chosen as the test specimens. In this work, the distributions of some actinide isotopes were measured from center to rim of the spent fuel specimens by a radiation shielded laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS) system. Sampling was performed along the diameter of the specimen by reducing the sampling intervals from 500 ${\mu}m$ in the center to 100 ${\mu}m$ in the pellet periphery region. It was observed that the isotopic concentration ratios for minor actinides in the center of the specimen remain almost constant and increase near the pellet periphery due to the rim effect apart from the $^{236}U$ to $^{235}U$ ratio, which remains approximately constant. In addition, the distributions of local burnup were derived from the measured isotope ratios by applying the relationship between burnup and isotopic ratio for plutonium and minor actinides calculated by the ORIGEN2 code.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• 제2호
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• pp.164-170
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• 2004

Suburban green space is an important component part of urban ecological system, the third largest space between urban center and peripheral countryside. Because of the specific regional location of the suburban green space, it differs from the green space in the center of the city in the respects of construction and planning. Anyhow, it has the features of less investment, quicker efficiency, free and easy management and good ecological effects. The writer of this paper holds that urban ecological construction should be planned rationally and laid out in an overall way under the prerequisite of making full use of and protecting local species so as to further extend the green ecological space at urban periphery, to create dense green surroundings, and to explore a way for ecological construction to develop in a scientific, effective and healthy way.

• 과학기술학연구
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• 제18권3호
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• pp.45-101
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• 2018

This paper discusses an important dimension of the globalization of science by investigating the lived experiences of nineteen expatriate scientists in six institutions in South Korea. Although much has been written on the globalization and science, few works have dealt with scientific experts? migration across national borders in contemporary contexts. In this regard, the lives of foreign science professors in Korea offer an interesting case, as they illustrate how the ideas of global science both clash with and appropriate Korea?s local practices and discourses. I argue that the globality of science is a main factor that fosters the continued Korean stay of many foreign scientists, who manage and appropriate what is entailed in this globality, namely, Korea?s perceived status as a peripheral country in the dynamics between "center" and "periphery." This includes several strategies and unintended situations differing according to each foreign scientist?s ethnic origins, professional experiences, and institutional circumstances, which lead them to make sense of their continued stay in Korea.

• Current Optics and Photonics
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• 제7권6호
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• pp.755-760
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• 2023

In this paper, an illumination optical system that can mitigate the saturation phenomenon in the center of an image (caused by the typical flexible-endoscope illumination system using LEDs with Lambertian light distribution) is designed. When an LED with Lambertian light distribution is used as a light source, the amount of light in the center of the endoscopic illumination system is relatively high, compared to the periphery, causing saturation in the image. Since this phenomenon causes difficulty in detecting the patient's lesion, it is necessary to find a lighting-system design that can alleviate the saturation phenomenon. Therefore, in this paper a lighting system with bat-wing light distribution, which can lower the intensity at the center and secure the maximum amount of light at the maximum light distribution angle, is designed. In addition, to check the performance of the designed lighting system, a simulation of illumination and luminance is conducted for a system using a common aspherical lens with otherwise the same components. As a result, it is confirmed that the lighting system designed in this paper effectively reduces the luminance value at the center and secures more luminance values at the periphery than the familiar lighting system.