• Korean Journal of Environment and Ecology
• /
• v.30 no.3
• /
• pp.320-327
• /
• 2016

Intertidal zone has been restored by the Sihwa Lake tidal power plant is operating in 2012. After restoration, to check the difference of bird group's community change out, the examination has been carried out from 2009 to 2014 when sea dike sluicer runs, the intertidal zone area was increased to $20.3km^2$ after restoring in $5.3km^2$. There was no significant difference in the number of individuals congestion of the whole, but the results of analysis of the differences between the six bird group by number of individuals, it showed a significant difference in Diving ducks(p = 0.237) the Herons (p<0.001), Swans and Geese (p<0.01), Dabbling ducks (p<0.001), showed a significant difference in the Shore birds (p<0.001) gulls (p<0.001) except for diving of ducks. Sihwa Lake intertidal zone was only just been restored, but environment and the improvement of benthic ecosystem has been carried out, It is determined that waterfowls that living based on intertidal zone are also affected. This study is a good example of the restoration of the intertidal zone that disappeared, which hard to find a similar case. It will be utilized as basic data of ecological monitoring for the conservation and management of the future of the intertidal zone later.

• Journal of Korea Port Economic Association
• /
• v.31 no.4
• /
• pp.1-15
• /
• 2015

During global recessions, such as the 2008 financial crisis, Korean shipping companies have been undergoing a liquidity crisis that is comparably worse than other shipping companies worldwide. One of the reasons behind this repetitive vicious cycle can be the lack of ability to foresee the future by analyzing and understanding the volatile shipping market. Traditionally, in order to assimilate the shipping market, larger Korean shipping companies have been purchasing market reports published by Europe-based research companies and shipping brokers, leading to a digital divide by company size. To resolve this issue, the Maritime Exchange Information Center (MEIC) has been publishing shipping market reports that include essential shipping information such as freight rates by different routes; commodity trends for iron ore, grain, and coal; ship-building trends for new-building, second-hand, and demolition markets; as well as bunker price and port congestion. This research was conducted to analyze the effectiveness of four variables-information usefulness, market reflection, information composition, and latest information-on information satisfaction. If the information satisfaction was found to be adequate, the analysis of actual proof was used to determine if the customers would be willing to purchase MEIC's report when it is chargeable. All the four variables were found to have positive effects on information satisfaction. In particular, latest information was found to directly affect the intention to purchase. Furthermore, high information satisfaction was related to the intention to purchase.

• Journal of Korean Academy of Nursing
• /
• v.26 no.4
• /
• pp.963-975
• /
• 1996

The purpose of this study was to call attention to the mental, physical and occupational hazards of the anticancer-drug-handling nurses by examining the possible urinary mutagenicity and measuring physical symptoms and stress level of the nurses exposed to anticancer drugs. The experimental group of the urinary mutagenicity assay was 14 nurses handling anticancer drugs at the medical wards of a hospital located in J city ; the control group was 12 psychiatric nurses of the same hospital. The test material was the nurses' 24hrs urine, which was concentrated by XAD-2 column chromatography. Tester strains were TA98(±S9 mix), TA100(±S9 mix), TA1535(±S9 mix) and TA1537(±S9 mix) ; Salmonella mammalian-microsomal test(Ames test) was employed for the urinary mutagenicity assay. The physical symptoms of which the nurses experienced were investigated through self-reports on open-questionnaires. The stress levels of the experimental group were measured by a stress measuring instrument developed by this author. Reliability of this instrument was found to be adequate (Cronbach's Alpha=0.9079). To ascertain the urinary mutagenicity of the experimental group, the mean and the standard deviation of the colonies of Tester strains appearing on the minimal plates were taken and compared differences between two groups. T-test was employed for the significance test of two groups. The physical symptoms were compared between the two groups through the analysis of the nurse' self-reports. The mean and standard deviation of the stress levels of the experimental group were also calculated and were examined through t-test. The results were summarized as follows : 1. The experimental group revealed significantly higher urinary mutagenicity both in the activation method test and the non-activation method test of the tester strains TA98, TA100 and TA1535. In the case of TA1537, two groups showed no difference in the non-activation method test, but the activation method revealed difference. 2. The physical symptoms were also much more frequently reported in the experimental group. 79.3% of the experimental group reported more than 1 kind of physical symptoms. On the other hand, 33.2% of the control group complained of 1 kind of physical symptom. The items with high symptom frequency were 'headache', 'itching sensation', 'corneal congestion', 'skin allergy' 3. The mean score of stress in the experimental group was 2.41(range 1-4). The experimental group showed the stress level above 2.0 in the 14 of 15 items in all. The highest stress level were recorded in the following items in the order quoted, 'I fear that anticancer drug may touch any part of body while handling it.', 'I feel concerned there is no protective countermeasure against anticancer drug handling.', 'I am afraid the anticancer drug handling may produce a fetal loss in the future'.

• Journal of KIISE:Information Networking
• /
• v.31 no.4
• /
• pp.375-383
• /
• 2004

As wireless mobile networks have been widely adopted due to their convenience for deployment, the research for improving their performance has been actively conducted. Since their throughput is restrained by the packet corruption rate not by congestion as in wired networks, however, network simulations for performance evaluation need to select the appropriate wireless channel model representing the behavior of propagation errors for the evaluated channel. The selection of the right model should depend on various factors such as the adopted frequency band, the level of signal power, the existence of obstacles against signal propagation, the sensitivity of protocols to bit errors, and etc. This paper analyzes 10-day bit traces collected from real sensor channels exhibiting the high bit error rate to determine a suitable sensor channel model. For selection, it also evaluates the performance of two error recovery algorithms such as a link layer FEC algorithm and three TCPs (Tahoe, Reno, and Vegas) over several channel models. The comparison analysis shows that CM(Chaotic Map) model predicts 3-time less BER variance and 10-time larger PER(Packet Error Rate) than traces while these differences between the other models and traces are larger than 10-time. The simulation experiments, furthermore, prove that CM model evaluates the performance of these algorithms over sensor channels with the precision at least 10-time more accurate than any other models.

• Journal of Korean Society of Transportation
• /
• v.22 no.5
• /
• pp.99-109
• /
• 2004

Most traffic congestion on a freeway occurs in the merge area, where conflicts between mainline traffic and on-ramp traffic are frequently generated. So far, research on the merge area has mainly dealt with free flow traffic and research on the congested traffic at the merge area is rare. This study investigates the relationships between mainline traffic and on-ramp traffic at three different segments of the merge area. For this purpose, new indicators based on such traffic variables as flow, speed, and density are used. The results show that a negative relationship exists between mainline and on-ramp flow. It is also found that the speed and the density of the right two lanes in the mainline traffic are significantly affected by the on-ramp flow. Based on the correlation analysis of the indicators, it is confirmed that the ramp influence area is the right two lanes of the freeway mainline. The revealed relationships between mainline and on-ramp traffic may help to analyze the capacity of the downstream freeway segment of the merging area in congested traffic. The findings of this studyalso provide a basis to develop a model that estimates the merge traffic volume in congested traffic, which is neither theoretically nor empirically sound in most other traffic flow models developed so far.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.6 no.1 s.12
• /
• pp.13-26
• /
• 2007

A VDS data in the domestic has been used within limits to real time information such as congestion management, incident management, and route guidance service. On the other hand, a VDS data in the foreign countries had been used to various objectives such as transportation policy assessment, transportation construction evaluation, franc safety improvement, and etc. The scope and method of the study is the VDS data which was installed in the uninterrupted flow such as the freeway and the interrupted flow in a diversion route of the leeway. It has investigated and analyzed the VDS as our subject to study, study objective and study methodology for each study generally classified as 1) data collection 2) data processing 3) data store and 4) data quality section. This study has investigated and analyzed the various literatures in domestic and foreign countries regarding the VDS data. And It drew the development direction of the study which is about VDS data in domestic from now.

• Journal of the Society of Disaster Information
• /
• v.16 no.3
• /
• pp.550-557
• /
• 2020

Purpose: Greenhouse gases are one of the major causes of global warming, a global disaster. In this study, the priority that affects when calculating the GHG emissions in the road sector is accurately calculated based on the speed of individual vehicles from the existing section average speed. I have the purpose of finding a possible factor. Method: A comparative analysis is conducted between the conventional method of the general passage section, the rest area section, the entrance section, and the confluence section of the highway and the speed-based emission calculation method of individual vehicles. Result: As a result of analyzing a total of 6 sections of the Gyeongbu Expressway, it was found that the standard deviation of the speed and the congestion of the sections had a great influence. Conclusion: When comparing the existing GHG emission calculation method with the speed-based emission calculation method of individual vehicles, it is clear that the speed-based method of individual vehicles is more precise. However, since it is difficult to apply it all over the country, this study compares the existing method with the speed-based method of individual vehicles and presents factors that have a significant difference.

• Toxicological Research
• /
• v.34 no.4
• /
• pp.325-332
• /
• 2018

The mechanism of the previously reported antidiabetic effect of Basella alba is unknown. This study investigated the role of B. alba aqueous leaf extract in the modulation of inflammatory cytokines and islet morphology in streptozotocin-induced diabetic rats. Forty male Wistar rats, between 8 and 10 weeks old, were randomly divided into four groups (n = 10) and administered the following treatments: Healthy control (H-c) and Diabetic control (D-c) animals received normal saline 0.5 mL/100 g body weight daily, while Healthy Treatment (H-Ba) and Diabetic Treatment (D-Ba) rats received the plant extract 200 mg/kg body weight daily. All treatments were administered by oral gavage. Diabetes was induced in D-c and D-Ba rats by a single intraperitoneal injection of streptozotocin (55 mg/kg body). The body weight and fasting blood sugar (FBS) levels were recorded every week for 4 weeks, after which the rats were euthanized and samples collected for further analysis. After the experiment, FBS level was significantly reduced (p < 0.0001) in rats in the D-Ba group, but increased (p < 0.001) in rats in the D-c group. The absolute (H-c and H-Ba vs D-c, p < 0.05) and relative (D-Ba vs H-c, p < 0.05; D-Ba vs H-Ba, p < 0.005) weights of the pancreases were significantly higher after the experiment. The rats in the D-c group had significantly higher levels of serum interleukin-$1{\beta}$ (p < 0.001 vs H-c; p < 0.05 vs H-Ba and D-Ba) and monocyte chemotactic protein-1 (p < 0.0001), but lower levels of interleukin-10 (p < 0.05) in comparison with the other groups. Histopathological examination revealed severe interstitial congestion, reduced islet area (p < 0.0001), and increased islet cell density in the D-c group compared with those in the D-Ba group. From these findings, it was concluded that the aqueous extract of B. alba stimulates the recovery of beta-islet morphology in streptozotocininduced diabetic rats by modulating the peripheral production of inflammatory cytokines.

• Journal of Environmental Science International
• /
• v.20 no.7
• /
• pp.799-809
• /
• 2011

Objectives: This study is aimed at identifying the influential factors on the pulmonary function of ordinary residents in the surrounding areas of Yeosu Industrial Complex. Methods: The PFT (Pulmonary Function Test) was conducted on the target residents numbering 989 people (male 361, female 628). The exposed group (813 people) resided within the radius of 5km from Yeosu Industrial Complex and the control group (176 people) resided in the radius of more than 15 km from May 2007 to November 2007. The survey also took into account other factors including personal characteristics, life habits, respiratory diseases and allergic symptoms, medical histories, and the living environments of the residents in order to further identify influential factors on pulmonary function. Result: When comparing the PFT values of the exposure groups to the control group of the same city, values of the exposure groups were meaningfully lower with an %$FEV_1$ of 107.05% and %FVC of 100.28%. Conversely, the control group reported an %$FEV_1$ and %FVC of 107.26% and 102.85% respectively, indicating that ambient air pollutants reduce lung function. The odds ratio of asthma diagnosis history increased when a subjects residence was close to a heavily trafficked road, traffic amount was huge, a bed was used, and the family had less than four members. However the results were not statistically meaningful. The odds ratios of abnormal pulmonary function were statistically higher among those with asthma(OR=4.29, CI=1.75-10.56), wheezing (OR=2.59, CI=1.24-5.41), and nasal congestion (OR=2.87, CI=1.36-6.08) (p<0.01). The factors affecting $FEV_1$ were symptoms including asthma, passive smoking and allergic eye disease ($R^2$=0.049, p<0.001). For the FVC symptoms including asthma ($R^2$=0.014, p<0.001) were measured. The analysis showed that FVC decreased with increases in $O_3$ and CO(p<0.01). Furthermore, $FEV_1$ decreased with increases in $O_3$(p<0.01). Conclusions: These results will provide preliminary data for establishing responsive measures to protect the health of residents in industrial complexes from air pollution, and to develop lasting environmental health policies.

• Journal of Korea Multimedia Society
• /
• v.7 no.8
• /
• pp.1066-1077
• /
• 2004

Dramatic increase in the number of Internet users want highly qualified service of continuous media contents on the web. To solve these problems, we present two network caching schemes(PPC, PPCwP) which consider the characteristics of continuous media objects and user access pattern in this paper. While there are plenty of reasons to create rich media contents, delivering this high bandwidth contents over the internet presents problems such as server overload, network congestion and client-perceived latency. PPC scheme periodically calculates the popularity of objects based on the playback quantity and determines the optimal size of the initial fraction of a continuous media object to be cached in proportion to the calculated popularity. PPCwP scheme calculates the expected popularity using the series information and prefetches the expected initial fraction of newly created continuous media objects. Under the PPCwP scheme, the initial client-perceived latency and the data transferred from a remote server can be reduced and limited cache storage space can be utilized efficiently. Trace-driven simulation have been performed to evaluate the presented caching schemes using the log-files of iMBC. Through these simulations, PPC and PPCwP outperforms LRU and LFU in terms of BHR and DSR.