• Nuclear Engineering and Technology
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• v.56 no.2
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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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• v.19 no.3
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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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• v.30 no.1
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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.

• Journal of the Korean Society of Costume
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• v.59 no.9
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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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• v.17 no.1
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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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• v.20 no.3
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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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.217-224
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• 1979

The main purpose of the present study is to measure the sound spectra of the underwater noises generated by moving trawl net. An underwater recording system was designed to detect underwater noise generated by moving trawl net. The acoustic analysis was made by a heterodyne analyzer (B & K 2010) and level recorder (B & K 2307). The noises generated by the trawl net are appreciably higher (about 10dB) than the background noise in the presence of the fishing vessel. The frequency distribution of underwater noise was DC-6,300 Hz and predominant frequency range was 100-200 Hz, and maximum sound pressure level was $137\;db(re\;1{\mu}Pa)$. Sound pressure level recorded at the ground rope was higher than that recorded at the head rope. The sound pressure level meosured in the course of hawling was higher than that measured in the course of towing. When tile net is being casted tile sound pressure level showed the lowest value.

• Korean Journal of Food Science and Technology
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• v.48 no.6
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• pp.555-559
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• 2016

Perfluorinated compounds (PFCs) are linked to adverse effect on human healths, therefore, the aim of this study was to determine the levels of PFCs in prepared food. One hundred and fifty-one samples of six prepared food groups were purchased from retail food establishments in Korea. Twelve PFCs were detected in the sample, the accuracy ranged between 80.8-119.4% and precision ranged between 2.2-2.89% high and low concentrations in PFCs spiked samples. The detection frequency of perfluoro-pentanoic acid (PFPeA) was and perfluorooctanoic acid (PFOA) above the limit of detection, which was 84.1 and 82.8%, respectively, but positive detection frequency of perfluorooctanesulphonic acid (PFOS) was as shown as low as 29.1%. Residual PFOA levels in most of the samples were higher than the PFOS levels. The average concentration of total PFCs in the samples was $1.68{\pm}1.79ng/g$, and PFPeA and PFOA were the predominant PFCs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.260-264
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• 1981

The purpose of the present study is to measure the sound spectrum of the underwater noise generated by a stern trawler M/S Saebada (2,275 GT, 3600 ps) in the various operational conditions. Underwater noises were recorded by a hydrophone (B & K 8100) and analyses were made rising a digital frequency analyzer (B & K 2131) and level recorder (B & K 2370). The predominant frequency range was 100-500 Hz, and maximum sound pressure level was 121 dB(re. $1{\mu}Pa$). Underwater noise level increased with the increased speed of the vessel. Sound pressure level measured in the course of astern cruising was higher than that measured in the course of ahead cruising and also the noise spectrums were different in these two cases. At the time of cruising the underwater noise was higher than 10 dB compared to those values measured at the time at rest with only engine operation. The underwater noise of the vessel was mainly due to the main engine revolution of the propeller and the vibration of hull.

• Journal of the Korea Society of Computer and Information
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• v.13 no.4
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• pp.79-86
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• 2008

As the rapid development of the Internet, the embedded images in HTML web pages nowadays become predominant. For its amazing function in describing the content and attracting attention, images become substantially important in web pages. All these images consist a considerable database. What's more, the semantic meanings of images are well presented by the surrounding text and links. But only a small minority of these images have precise assigned keyphrases. and manually assigning keyphrases to existing images is very laborious. Therefore it is highly desirable to automate the keyphrases extraction process. In this paper, we first introduce WWW image annotation methods, based on low level features, page tags, overall word frequency and local word frequency. Then we put forward our method of multi-cues integration image annotation. Also, show multi-cue image annotation method is more superior than other method through an experiment.