• Nuclear Engineering and Technology
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• 제56권2호
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• pp.688-706
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• 2024

Austenitic stainless steels (ASS) are extensively employed in various sectors such as nuclear, power, petrochemical, oil and gas because of their excellent structural strength and resistance to corrosion. SS304 and SS316 are the predominant choices for piping, pressure vessels, heat exchangers, nuclear reactor core components and support structures, but they are susceptible to stress corrosion cracking (SCC) in chloride-rich environments. Over the course of several decades, extensive research efforts have been directed towards evaluating SCC using diverse methodologies and models, albeit some uncertainties persist regarding the precise progression of cracks. This review paper focuses on the application of Acoustic Emission Technique (AET) for assessing SCC damage mechanism by monitoring the dynamic acoustic emissions or inelastic stress waves generated during the initiation and propagation of cracks. AET serves as a valuable non-destructive technique (NDT) for in-service evaluation of the structural integrity within operational conditions and early detection of critical flaws. By leveraging the time domain and time-frequency domain techniques, various Acoustic Emission (AE) parameters can be characterized and correlated with the multi-stage crack damage phenomena. Further theories of the SCC mechanisms are elucidated, with a focus on both the dissolution-based and cleavage-based damage models. Through the comprehensive insights provided here, this review stands to contribute to an enhanced understanding of SCC damage in stainless steels and the potential AET application in nuclear industry.

• ALGAE
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• 제19권3호
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• pp.257-270
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• 2004

In order to clarify the structure and seasonal dynamics of warm tolerant benthic marine algal community in Korea, the species composition and biomass of marine algae at the discharge canal of Uljin nuclear power plant on the East Coast of Korea were investigated seasonally from February 1992 to October 2000. 107 species of marine algae were found at the discharge canal during the past nine years. In general, the number of species observed was abundant in spring or summer and less in autumn or winter. 27 species (4 blue-green, 5 green, 6 brown and 12 red algae) of marine algae occurred more than 1/ 6 frequency and thus can be categorized as warm tolerant species. Among these, one brown (Dictyota dichotoma) and four red algae (Gelidium amansii, Anphiroa ephedraea, Hydrolithon sargassi, Marginisporum crassissimum) are recorded as warm tolerant marine algae for the first time in Korea. Padina arborescens, Anphiroa zonata and Corallina pilulifera were common species found more than 75% frequency. Seasonal fluctuations of mean biomass were 0-1,330 g dry wt m^(-2) and dominant species in biomass were Corallina pilulifera (contribution to a total biomass proportion 34%), Anphiroa zonata (23%), Padina arborescens (18%) and Sargassum micracanthum (11%). The red algae appeared as predominant algal group at the discharge canal of Uljin nuclear power plant in the qualitative and quantitative aspects. The green algae such as Enterornorpha compressa appeared rather frequently at the discharge canal, but the biomass proportion was very low, in contrast to Kori nuclear power plant where there was definite green algal dominance. Differences in algal communities developed at the discharge canals of Uljin and Kori nuclear power plant on the East Coast of Korea, particularly biomass proportions of green algae, can probably be related to local environmental factors such as water velocity through the canal and natural seawater temperatures.

• Journal of Ecology and Environment
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• 제30권1호
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• pp.101-105
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• 2007

Lammas growth, a rare phenomenon for Korean red pine (Pinus densiflora), occurred in 2006. Lammas shoots showed higher frequency and longer length in Seoul's hotter urban center than in urban boundary or suburban forest sites. Frequency and length showed a close correlation with urbanization density and vegetation cover expressed in NDVI. Air temperature in the late summer of 2006 was more than $1^{\circ}C$ higher than an average year. Of the predominant environmental signals that modulate bud flush, only temperature changed significantly during the year. Differences in temperature between the urban centers, urban boundaries and suburban forests correlated with varying land-use density. The rise in temperature likely spurred lammas growth of the Korean red pine. Symptoms of climate change are being detected throughout the world, and its consequences will be clearer in the future. Considerate interest in the responses of ecological systems to the variable changes is required to prepare for unforeseeable crises. Monitoring of diverse ecological phenomena at Long Term Ecological Research sites could offer harbingers of change.

• 복식
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• 제59권9호
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• pp.97-114
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• 2009

The purpose of this thesis is to contribute to the fashion industry of Korea and China by providing the basic informations of Korean fashion company planning to launch into the Chinese fashion market, and also presenting the Korean fashion style to the China, by the way of searching the sameness and differences of the casual style. The direct picturing method and comparative analysis were applied for the methods of study. The whole body pictures were taken from the major fashion streets of Seoul and Shanghai, then clear 250 photos were selected in each city. The period for two weeks from 1st, July to 14th, July 2008, and from 10AM until 5PM. The results of study are as follows. The sequential order of frequency is easy casual, jean casual, romantic casual and character casual in Seoul and Shanshai. In case of easy casual, there were many similarities of the preferences in the items, colors and coordinations, while showing the differences in the styling of the clothing. Taking the jean casual, there were no specific differences in items between two cities except the styling of clothing in which the tidy style were more prevalent in Seoul, while the sexy style were more predominant in Shanghai. The main item of romantic style was the one-piece dresses. This was preferred in the style of A-line or H-line with short length, in Seoul while X-silhouette showing the body line with knee-length skirts were more popular in Shanghai. Finally the frequency of character casual is below 5% in both cities. In the items, the skirts were more preferred as a bottom in Seoul in contrast with the pants being more prevalent in Shanghai, the sleeveless top popular in both cities. The modest style were noted in Seoul, the sexy style were more prevalent in Shanghai. However many similarities between two cities were found in the speed of acceptabilities of fashion.

• Asian Pacific Journal of Cancer Prevention
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• 제17권1호
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• pp.377-380
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• 2016

Background: Epidemiological data on thyroid cancer and associated risk factors are scarce in our setting. The present study was therefore designed to gather data which could be helpful in providing insights to thyroid physicians and surgeons for better management of affected patients. Purpose: To determine the frequency of carcinoma thyroid among patients presenting with goiter and its association with TSH, Tg/ATg and other demographic factors. Materials and Methods: A total of 73 adult patients of either gender with solitary solid cold nodules and/or multi-ndoular goiter (MNG) with predominant solid cold nodules were enrolled. All surgically resected samples were sent for histopathology. The frequency of thyroid cancer and its subtypes was noted and tested for association with gender, age (< or ${\geq}40years$), recent increase in swelling size, TSH, Tg and ATg. Results: Thyroid cancer was diagnosed in 26% (n=19) of the patients, 14 (73.7%) being diagnosed with papillary thyroid cancer and 5 (26.3%) with follicular thyroid cancer. No other subtypes were noted. Presence of thyroid cancer was significantly associated with recent increase in swelling size and higher TSH Values mean TSH values (P<0.05). No significant association was found with gender, age, Tg and ATg values (P>0.05). Conclusions: Overall percentage of thyroid cancer in our study sample was found to be 26%, with a predominance of papillary over follicular lesions. Rates were significantly higher in patients who had history of recent increase in swelling size and higher and higher pre-surgery TSH values.

• ALGAE
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• 제20권3호
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• pp.217-224
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• 2005

The species composition and biomass of marine algae at the discharge canals of three (Gori, Wolseong and Uljin) nuclear power plants on the east coast of Korea were investigated seasonally from February 1992 to October 2000. As a result, 103-107 species of marine algae were found at the discharge canals during the past nine years. In general, algal communities established at the discharge canals were less diverse than those at the intake canals and control sites. 43 species (6 blue-green, 9 green, 10 brown and 18 red algae) of marine algae occurred more than 1/6 frequency and thus can be categorized as warm tolerant species. Among these, two green (Urospora penicilliformis, Cladophora albida), four brown (Sphacelaria divaricata, S. rigidula, Sargassum coreanum, S. fulvellum) and four red algae (Stylonema alsidii, Bangia atropurpurea, Hypnea charoides, Chondria crassicaulis) are recorded as warm tolerant marine algae for the first time in Korea during this study. Enteromorpha compressa, Padina arborescens, Amphiroa zonata and Ahnfeltiopsis flabelliformis were common species found more than 50% frequency at the discharge canals of all three nuclear power plants investigated. Dominant species in biomass were Padina arborescens and Amphiroa zonata. Results showed that, as a whole, the red algae appeared as predominant algal group at the discharge canals of all three nuclear power plants on the east coast of Korea. However, the biomass proportion of dominant algae at the discharge canals of each nuclear power plant varied over the year during the past nine years.

• 한국수산과학회지
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• 제12권4호
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• pp.217-224
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• 1979

조업중의 어선이나 어구로부터 발생되는 수중소음의 음향특성을 구하기 위하여 특별히 고안된 수중녹음장치를 이용하여 트로올어구의 수중소음을 녹음분석한 결과는 다음과 같다. 1. 조업중인 트로올어구에서 측정수 소음에는 어선이 발하는 소음의 영향을 극히 적다. 2. 소음의 주파수분포는 $DC\~6,300\;Hz$이고 그 중 우세한 주파수대는 $100Hz\~6,300Hz$이며 최대음압은 $137db(re\;1:{\mu}Pa$이었다. 3. 뜸줄부보다 발줄부에서 음압준위가 높고 자루부분에서의 음압준위가 가장 낮았다. 4. 예망중일 때보다 양망중일 때가 음압준위가 높고 투망중의 음압준위가 가장 낮았다. 5. 예망중의 트롤어구에서 발생되는 수중소음의 주된 음원은 어구의 ground rope와 해저의 마찰음 및 otter board와 해저와의 마찰음이라고 추정할 수 있다.

• 한국식품과학회지
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• 제48권6호
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• pp.555-559
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• 2016

국내에서 유통되는 조리식품 6종류, 151점의 시료를 수집하여 LC-MS/MS를 이용해 PFCs 잔류 수준을 측정하였다. 총 12종의 PFCs를 분석하였으며, PFBS를 제외한 PFCs의 회수율은 82.2-119.4%였으며, 정밀도는 2.2-28.9%였다. PFCs물질별로는 PFPeA (84.1%)와 PFOA (82.8%) 검출률이 높았고, PFOS의 검출률은 29.1%였으며, 대부분의 시료에서 PFOA가 PFOS보다 잔류 수준이 높은 경향을 보였다. 시료의 총 PFCs의 평균 농도는 $1.68{\pm}1.79ng/g$이었으며, PFPeA와 PFOA의 비중이 높았다.

• 한국수산과학회지
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• 제14권4호
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• pp.260-264
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• 1981

어선에서 발생되는 수중소음을 측정하기 위하여 선미식 트롤어선인 새바다호가 수심 100m인 제주도남쪽 해역에서 운항중일 때의 구중소음을 녹음 분석한 결과를 요약하면 다음과 같다. 1) 새바다호가 운항중일 때 주된 주파수대는 $100\sim500Hz$이며 최대음압은 121dB였다. 2) 항주중의 수중소음은 속도가 증가함에 따라 음압준위가 높아진다. 3) 후진할 때의 소음은 전진할 매와 소음 spectrum도 다르고 음경준위도 높았다. 4) 기관만을 운전할 때보다 항주중일 때의 수중소음이 10dB이상 높았다. 5) 어이에서 발생되는 수중소음의 주음원은 기사소음과 프로펠라의 회전 및 선체의 진동때문인 것으로 생각된다. 6) 거리에 따른 음압의 감쇠는 주파수가 높아짐에 따라 커지고 주파수 제곱에 비례하여 감쇠하였다.

• 한국컴퓨터정보학회논문지
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• 제13권4호
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• pp.79-86
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• 2008

인터넷의 빠른 발전으로 현재 HTML 웹 페이지에 내장된 영상들은 눈에 띄게 두드러졌다. 내용을 묘사하고 주의를 끄는 놀랄만한 함수 때문에 영상들은 웹 페이지에서 사실상 중요하게 되었다. 모든 영상들은 가공할 만한 데이터베이스로 구성되어있다. 게다가. 영상들의 의미론적인 의미도 주변의 텍스트나 링크에 의해 잘 표현된다. 하지만 이들 영상의 소수들이 주요 구에 정확히 할당되고 주요 구들을 현재의 영상에 수작업으로 할당하는 것은 매우 어렵다. 따라서 주요 구들을 추출하는 절차의 자동화는 매우 바람직하다. 본 논문에서는 먼저 저수준 특징, 페이지 태그, 전체적인 단어 빈도수와 지역적 단어 빈도수를 기반으로 한 WWW 영상 주석 방법을 소개한다. 그리고 멀티-큐 통합영상 주석 방법을 전개해 나간다. 또한 실험을 통하여 멀티-큐 영상 주석 방법이 다른 방법보다 우수함을 보여준다.