• The Korean Journal of Ecology
• /
• v.27 no.3
• /
• pp.141-146
• /
• 2004

This paper reports on Pb and Cd concentrations in the tissues of 76 individuals of 16 rare bird species found dead across Korea. In most of species, Pb concentration was higher in kidney and bone than in liver. The range of the mean liver Pb was 0.47 (Cygnus cygnus)∼3.74 ㎍/wet g (Asio flammeus). Based on hepatic Pb concentrations, 39 (51.3%) of the 76 individuals were classifed as background level (〈2㎍/wet g), 35 (46.1%) were elevated level (〉2㎍/wet g) and 2 (2.6%) were poisoned level (〉10㎍/wet g). These results were indicated many rare birds were suffered from chronic Pb exposure. Cd concentration was generally higher in kidney than in liver and bone. The range of the mean kidney Cd was 0.06 (Bubo bubo)∼l.75㎍/wet g (falco subbuteo). Only one of the 76 individuals had elevated Cd concentration (〉2.7㎍/wet g) in kidney. These results indicated most of rare birds had low Cd accumulations.

• The Korean Journal of Physiology and Pharmacology
• /
• v.9 no.1
• /
• pp.29-35
• /
• 2005

To prove the buffering contribution of mitochondria to the increase of intracellular $Ca^{2+}$ level ($[Ca^{2+}]_i$) via background nonselective cation channel (background NSCC), we examined whether inhibition of mitochondria by protonophore carbonylcyanide m-chlorophenylhydrazone (CCCP) affects endothelial $Ca^{2+}$ entry and $Ca^{2+}$ buffering in freshly isolated rabbit aortic endothelial cells (RAECs). The ratio of fluorescence by fura-2 AM ($R_{340/380}$) was measured in RAECs. Biological state was checked by application of acetylcholine (ACh) and ACh ($10{\mu}M$) increased $R_{340/380}$ by $1.1{\pm}0.15$ ($mean{\pm}S.E.$, n=6). When the external $Na^+$ was totally replaced by $NMDG^+$, $R_{340/380}$ was increased by $1.19{\pm}0.17$ in a reversible manner (n=27). $NMDG^+$-induced $[Ca^{2+}]_i$ increase was followed by oscillatory decay after $[Ca^{2+}]_i$ reached the peak level. The increase of $[Ca^{2+}]_i$ by $NMDG^+$ was completely suppressed by replacement with $Cs^+$. When $1{\mu}M$ CCCP was applied to bath solution, the ratio of $[Ca^{2+}]_i$ was increased by $0.4{\pm}0.06$ (n=31). When $1{\mu}M$ CCCP was used for pretreatment before application of $NMDG^+$, oscillatory decay of $[Ca^{2+}]_i$ by $NMDG^+$ was significantly inhibited compared to the control (p＜0.05). In addition, $NMDG^+-induced$ increase of $[Ca^{2+}]_i$ was highly enhanced by pretreatment with $2{\mu}M$ CCCP by $320{\pm}93.7$%, compared to the control ($mean{\pm}S.E.$, n=12). From these results, it is concluded that mitochondria might have buffering contribution to the $[Ca^{2+}]_i$ increase through regulation of the background NSCC in RAECs.

• Journal of Navigation and Port Research
• /
• v.35 no.1
• /
• pp.39-44
• /
• 2011

This study aims to inform seafarers to prepare their retired life by researching the life style of ex-seafarers. These information will also help seafarers to increase job satisfaction and government to establish national policy. 217 retirees who have several educational background responded the research questionnaire. Research results are as follows; First, Korean seafarers' retired ages are faster than shore employee due to the isolation from their families and society. Second, life satisfaction of retired seafarers depends on the level of life expenses regardless the educational background or length of sea life. Third, the level of retired life expenses of shore based, higher education background or short sea-life seafarers is higher than the sea based, lower education background or long sea-life seafarers. Forth, life style of retired seafarers is staying at home regardless their expectation during career period. Finally special seafarers' social security is needed and education to the ex-seafarers will help re-enter for sea-life.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2007.05a
• /
• pp.333-336
• /
• 2007

We propose a simple method for tracking a nonparameterized subject contour in a single video stream with a moving camera and changing background. Then we present a method to eliminate the tracked contour object by replacing with the background scene we get from other frame. Our method consists of two parts: first we track the object using LOD (Level-of-Detail) canny edge maps, then we generate background of each image frame and replace the tracked object in a scene by a background image from other frame that is not occluded by the tracked object. Our tracking method is based on level-of-detail (LOD) modified Canny edge maps and graph-based routing operations on the LOD maps. To reduce side-effects because of irrelevant edges, we start our basic tracking by using strong Canny edges generated from large image intensity gradients of an input image. We get more edge pixels along LOD hierarchy. LOD Canny edge pixels become nodes in routing, and LOD values of adjacent edge pixels determine routing costs between the nodes. We find the best route to follow Canny edge pixels favoring stronger Canny edge pixels. Our accurate tracking is based on reducing effects from irrelevant edges by selecting the stronger edge pixels, thereby relying on the current frame edge pixel as much as possible. This approach is based on computing camera motion. Our experimental results show that our method works nice for moderate camera movement with small object shape changes.

• Proceedings of the Acoustical Society of Korea Conference
• /
• spring
• /
• pp.269-273
• /
• 1999

Combination of mental stress task with noise background is a traditional tool employed in psychophysiology. However, intensity of background noise is a factor affecting both performance on test and psychophysiological responses associated with stress evoked by mental load in noisy environment. In the current study on 7 subjects we analyzed the influence of white noise (WN) intensity (55, 70, and 85 dB[A] ) on psychophysiological responses during word recognition test performed on noise background. There were recorded following physiological variables: electrodermal activity (EDA) , namely, skin conductance level (SCL), skin conductance response (SCR) amplitude (SCR-A), rise time and total number of SCRs (N-SCR); cardiovascular activity, e.g., heart rate (HR), respiratory sinus arrhythmia (RSA) index, pulse transit time (PTT), finger pulse volume (PV), skin temperature (SKT) and respiratory activity, such as respiration rate (RESP-R) and inspiration wane amplitude (RESP-A) during baseline resting state and 40 s long performance on 3 similar Korean word recognition tests with different WN intensity (55, 70, and 85 dB). Electrodermal responses (SCR-A, SCL, N-SCR) demonstrated gradual increment with increased intensity of noise, and this increase of response magnitude with higher intensity of noise was typical also for r skin temperature (phasic SKT decrease) and pulse volume (phasic and tonic PV decrease). However, some cardiovascular and respiratory responses did not exhibit same tendency of gradual increase of reactivity , namely HR, as well as RESP-R and RESP-A showed decrement of response magnitudes. Important finding in terms of cardiovascular reactivity was that 55 and 70dB evoked similar profiles, while 85dB WN resulted in significantly different profile of reactions, suggesting that there exists a threshold level after which intensive auditory stimulation elicits psychophyslological responses pattern of different quality. There are discussed potential autonomic mechanism involved in mediation of observed physiological responses.

• Journal of the Korean Institute of Educational Facilities
• /
• v.28 no.3
• /
• pp.3-14
• /
• 2021

Speech information of teachers is transmitted to students in classrooms so that appropriate aural environment should be provided for academic purposes. Many researches have been undertaken for classroom acoustics, and acoustic standards of domestic classrooms were suggested based on the reverberation time and background noise level. However, these standards are suitable for middle and high schools and so not consider the auditory ability by ages. As a precedent research, the present study was begun to suggest an acoustic standard for lower grade elementary school classrooms with children under age 9 who have not normal auditory ability. In order to do this, acoustic performances of the lower grade classrooms were measured and compared with the general classrooms. Also, change of acoustic parameters depending on the desk layout was measured and analyzed. The measured acoustic parameters were background noise, signal to noise ratio, RT, STI, D₅₀, and IACC. As a result, it was found that background noise is exceed the standard of 35dB(A) at the schools along the road sides. Also, it was shown that most of acoustic parameters are higher in the classrooms built recently rather than the old classrooms. Generally, there are not much difference of acoustic parameters among the various desk layouts but, better acoustic performances are acquired at the center line and the seats near sound source. Also, Higher IACC was measured at the seats on the center line facing the source squarely.

• Ocean and Polar Research
• /
• v.44 no.4
• /
• pp.287-296
• /
• 2022

High-frequency (HF) radar measures sea surface currents from the radio waves transmitted and received by antenna on land. Since the data quality of HF radar measurements sensitively depend on the radio wave environment around antenna, Antenna Pattern Measurements (APM) plays an important role in evaluating the accuracy of measured surface currents. In this study, APM was performed by selecting the times when the background noise level around antenna was high and low, and radial data were generated by applying the ideal pattern and measured pattern. The measured antenna pattern for each case was verified with the current velocity data collected by drifters. The radial velocity to which the ideal pattern was applied was not affected by the background noise level around antenna. However, the radial velocity obtained with APM in the period of high background noise was significantly lower in quality than the radial velocity in a low noise environment. It is recomended that APM be carried out in consideration of the radio wave environment around antenna, and that the applied result be compared and verified with the current velocity measurements by drifters. If it is difficult to re-measure APM, we suggest using radial velocity in generating total vector with the ideal pattern through comparative verification, rather than poorly measured patterns, for better data quality.

• Journal of Families and Better Life
• /
• v.11 no.2
• /
• pp.169-181
• /
• 1993

The purpose of this study was to investigate the implementing level of housewife's manage-ment behavior related to reducing environmental pollution and the effects of three variable-groups on management behavior related to reducing environmental pollution. The research data were collected by structured questionnare and 544 cases were finnally selected. The data analysis was conducted by the method of frequency mean Pearson's correla-tion multiple regression. The major findings were as follows: 1) The implementing level of housewife's overall management behavior slightly high. 2) Wife's value(ecologicalism materialism expediency social-enviromental resources(degree of masscom contact degree of meeting with neighbors. refuse box) were significant predictors of the level of overall management behavior And Background variables(wife's aged and educa-tion level & job household income occupation of husband) had not significant effect on the level of overall management behavior. The most influential variable-group on the level of overall management behavior and buying cleaning & dishwashing cooking laundry activities was Wife's value. But the most influential variable-group on the implementing level of disposing trash was social-environmental resources.

• Culinary science and hospitality research
• /
• v.22 no.4
• /
• pp.81-94
• /
• 2016

The purpose of this study is to measure the relative importance of the factors that affect school to work transition that food service-related majors and workers recognize. To this end, this study composed such factors into a second hierarchy level of individual background, educational background, and preparation effort to enter labor market. The study made us of the analytic hierarchy process(AHP), which calculates the importance of each factor through the relative evaluation of each factor in the hierarchy. The results of analysis are as follows. First, in the second hierarchy level, effort to enter the labor market exhibited the highest relative importance. In the case of four-year college students, educational background had the highest relative importance. Second, in case of third hierarchy level factors relating to personal background, gender had the highest relative importance. As for educational background, the type of college had the highest relative importance. As to the effort to enter labor market, overseas working experience while in college and job searching channels had high relative importance, while vocational training experience had the lowest relative importance. Third, the analysis result of complex weighted value showed that the type of college had the highest complex weighted value. In future studies, the type of businesses and business conditions in the food service industry should be subdivided for an analysis of influential factors, and, based on this, customized career guidance should be made for specific career paths of each student.

• Journal of Environmental Science International
• /
• v.20 no.12
• /
• pp.1585-1598
• /
• 2011

Emission reduction program for in-use diesel vehicles (ERPDV) has been enacted since 2004 over the Seoul metropolitan area, and diesel emission reduction is forced to fulfill this regulation. This study was performed to evaluate the ERPDV using $PM_{10}$ concentrations of both road-side monitoring and national background network during the period of 2004-2010. In order to assess the pure road emission, we first eliminated the long range transport effect by deducting the trend of annual national background concentrations from the road-side $PM_{10}$ concentrations, and then analyzed the time series of the resultant $PM_{10}$ concentrations over Seoul metropolitan area. The annual rates of variations of road-side $PM_{10}$ with the deduction of trend of background level show -3.2, +0.4, and -2.4 ${\mu}g/m^3$/year, in Seoul, Incheon, and Gyonggi province, respectively. There are steadily decreasing trend in Seoul with all of statistic parameters such as mean, mediam, 5%ile, 10%ile, 25%ile, 75%ile, 90%ile, and 95%ile concentrations. Incheon shows some fluctuations with positive with no significant trend, and Gyonggi province shows overall decreasing but not consistent. Student-t test shows 95% significant level of ERPDV effect in Seoul, but there exists no significant level greater than 90% in both Incheon, and Kyonggi province. Total annual averaged trend over the whole Seoul metropolitan area is estimated to lie in approximately $-2.9{\mu}g/m^3$/year in this study, implying the intimate involvement of ERPDV to a large extent. This is also suggesting that the further research cost-effectiveness of ERPDV with consideration of the long range transport process would be needed over the Seoul metropolitan area.