• 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.

• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.237-245
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• 2000

The regional distribution and relative frequency of somatostatin-immunoreactive cells in the gastrointestinal tract were studied during the postnatal development(1 day old, 1 month old, 6-month-old and adult) of the Korean native goat by immunohistochemical methods. Somatostatin-immunoreactive cells were found in the entire gastrointestinal tract and were most predominant in the fundic gland region except for the pyloric gland region of the 1 day old. The number of these cells was observed to decrease along the gastrointestinal tract and to decrease according to the increase with age in all postnatal stages. In this study, immunoreactive cells revealed the differences of regional distribution and the relative frequency in the gastrointestinal tract during postnatal development. These results suggest that although the functional significance of fetal endocrine cells remains unknown, this was caused by changing of feeding habits and physiological conditions during different ages.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.27 no.2
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• pp.139-145
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• 2016

Objectives: As a preliminary study on the prevalence of mental disorders in Korean children and adolescents, we investigated the diagnosis distribution of mental disorders in people under 19 years of age using the health insurance data. Methods: From the 2011 health insurance data of 1,375,842 people, the data of 286,465 people under 19 years old were extracted. Among them, we selected 10,778 with psychiatric diagnoses; male 6,453 (59.9%) and female 4,325 (40.1%). The frequency of psychiatric diagnoses in the males was 10,140 (62.7%) cases, which was significantly higher than that (6,031; 37.3%) in the females. We categorized the groups into 3 year intervals. Results: In the males under 3 years old, F80 was the most prevalent diagnosis, followed by F98. F90 and F41 were the most prevalent in the 4-15 and above 16 years old groups, respectively. In the females, F98 was the most prevalent in the children up to 3 years old, while F80 was the second most prevalent. In the 4-6 years of age group, F98 was the most prevalent, followed by F93. F90 and F41 were predominant in the 7-12 and above 12 years old groups, respectively. Conclusion: In the analysis of the frequency of diagnosis of mental disorders in the population under 19 years old, there were significant differences in the distribution based on age and gender.

• Structural Engineering and Mechanics
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• v.29 no.5
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• pp.505-530
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• 2008

This paper proposes the application of active multiple tuned mass dampers (AMTMD) for translational and torsional response control of a simplified two-degree-of-freedom (2DOF) structure, able to represent the dynamic characteristics of general asymmetric structures, under the ground acceleration. This 2DOF structure is a generalized 2DOF system of an asymmetric structure with predominant translational and torsional responses under earthquake excitations using the mode reduced-order method. Depending on the ratio of the torsional to the translational eigenfrequency, i.e. the torsional to translational frequency ratio (TTFR), of asymmetric structures, the following three cases can be distinguished: (1) torsionally flexible structures (TTFR < 1.0), (2) torsionally intermediate stiff structures (TTFR = 1.0), and (3) torsionally stiff structures (TTFR > 1.0). The even distribution of the AMTMD within the whole width and half width of the asymmetric structure, thus leading to three cases of installing the AMTMD (referred to as the AMTMD of case 1, AMTMD of case 2, AMTMD of case 3, respectively), is taken into account. In the present study, the criterion for searching the optimum parameters of the AMTMD is defined as the minimization of the minimum values of the maximum translational and torsional displacement dynamic magnification factors (DMF) of an asymmetric structure with the AMTMD. The criterion used for assessing the effectiveness of the AMTMD is selected as the ratio of the minimization of the minimum values of the maximum translational and torsional displacement DMF of the asymmetric structure with the AMTMD to the maximum translational and torsional displacement DMF of the asymmetric structure without the AMTMD. By resorting to these two criteria, a careful examination of the effects of the normalized eccentricity ratio (NER) on the effectiveness and robustness of the AMTMD are carried out in the mitigation of both the translational and torsional responses of the asymmetric structure. Likewise, the effectiveness of a single ATMD with the optimum positions is presented and compared with that of the AMTMD.

• Earthquakes and Structures
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• v.16 no.5
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• pp.563-573
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• 2019

When generating spectrum-compatible artificial ground motion in engineering practices, the effect of the variation in fitting parameters on the distribution of the peak ground displacement (PGD) has not yet drawn enough attention. In this study, a method for simulating ground motion matching for multiple targets is developed. In this method, a frequency-dependent amplitude envelope function with statistical parameters is introduced to simulate the nonstationarity of the frequency in earthquake ground motion. Then, several groups of time-history acceleration with different temporal and spectral nonstationarities were generated to analyze the effect of nonstationary parameter variations on the distribution of PGD. The following conclusions are drawn from the results: (1) In the simulation of spectrum-compatible artificial ground motion, if the acceleration time-history is generated with random initial phases, the corresponding PGD distribution is quite discrete and an uncertain number of PGD values lower than the limit value are observed. Nevertheless, the mean values of PGD always meet the requirement in every group. (2) If the nonstationary frequencies of the ground motion are taken into account when fitting the target spectrum, the corresponding PGD values will increase. A correlation analysis shows that the change in the mean and the dispersion values, from before the frequencies are controlled to after, correlates with the modal parameters of the predominant frequencies. (3) Extending the maximum period of the target spectrum will increase the corresponding PGD value and, simultaneously, decrease the PGD dispersion. Finally, in order to control the PGD effectively, the ground motion simulation method suggested in this study was revised to target a specified PGD. This novel method can generate ground motion that satisfies not only the required precision of the target spectrum, peak ground acceleration (PGA), and nonstationarity characteristics of the ground motion but also meets the required limit of the PGD, improving engineering practices.

• Journal of the Korean Society of School Health
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• v.12 no.2
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• pp.217-230
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• 1999

The purpose of this study is to find out problems in obesity management through survey and analysis of the actual conditions from the view of a elementary schools school-nurses and to establish fundamental data for efficient obesity management. The subjects for this study were 313 numbers of elementary school-nurses in Kyung-Sang-Pook-Do. The data were collected through mail questionaries from November 1 to November 30, 1997. The major findings in this survey were as follows: 49.8% of the school-nurses who responded in the survey were in their 30s. The average career was 7.3years. The average service duration in their present school was 2.3 years, 55.6% of them were serving at schools which have less than ten classes total 77.2% of them were serving rural areas, 79.6% of them were serving at schools with fewer than 100 obese students. The total obesity prevalence rate was 11.4%, 13.3% were girls, 9.3% were boys. The measurement of height and weight is performed once a year for all surveyed students (91.7%), but obese students were measured as much five times (51.1%). The rate of obesity management planning was 74.1%, however the rates of evaluation and role assignment were 41. 2%, and 24.3%. 79.6% of the surveyed schools have health education classes for obesity, the rate compared (8.0 periods per year) to the whole of health education (79.1 periods per year) is 10.1%. 99.9% of the schools had counseling rooms for obesity (combined with nursing rooms) but they were used. The roote of individual counseling was 84.3%. The frequency counseling was six times a year for about 15 minutes. Obesity counseling records were kept 93.6% of the time and individual information cards were kept 98.7% of the time. The frequency of parents counseling was 42.8% and the survey shows that the main problem here was insufficient counseling facilities. The frequency of dietary guidance and exercise therapy was 84.3% and the dietary instructor was usually the school nurse at 51.7%. The frequency of obesity student exercise was 1-2 times a week and more-than-10-minutes at a time. They skip rope during the morning self-study class. The number on problem of exercise guidance at 56.2% was students' non-cooperativeness. School-nurses, 87.9%, answered that obesity management at school is necessary and 86.9% mentioned the shortage of obesity related information in present physical exercise books. From the plural responses of executing the obesity management, there are many similar problems: lack of knowledge and non-cooperation in parents at 41.9%, is predominant followed by of knowledge and non-cooperation in the children. The third problem is the lack of funds and facilities.

• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.247-256
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• 2000

The regional distributions and relative frequencies of endocrine cells were studied histochemically (Grimelius and Masson-Hamperl (M-H) silver methods) in the alimentary tract of the red-eared slider, Trachemys scripta elegans. Samples were taken from the esophagus, fundus, pylorus, duodenum, jejunum, ileum and large intestine. Argyrophil (Grimelius-positive) cells and argentaffin (M-H-positive) cells were found in the whole alimentary tract in this study. Spherical to spindle and/or oval to round-shaped argyrophil or argentaffin cells were located in the gastric glands of the stomach regions, in the basal portion of the epithelium of intestinal tract or the esophagus with variable frequencies. Argentaffin cells were more numerously detected in the whole alimentary tract compared with those of argyrophil cells in this study. Argyrophil cells were observed in the whole alimentary tract including the esophagus and the most predominant region was the rectum with moderate frequency. The relative frequency of these cells was rare in the esophagus, fundus, duodenum, jejunum and ileum, respectively and a few frequency in the pylorus. Argentaffin cells were also observed in the whole alimentary tract including the esophagus and the most numerously demonstrated region was the rectum with numerous frequency. They were observed with a few frequencies in the remaining regions of the alimentary tract except for the rectum, respectively. However, to know the exact type of the argyrophil cells and argentaffin cells that were observed in this study, more developmental methods such as immunohistochemistry were needed.