• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.19-32
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• 2007

In Korea, there have been various methods of estimating groundwater recharge which generally can be subdivided into three types: baseflow separation method by means of groundwater recession curve, water budget analysis based on lumped conceptual model in watershed, and water table fluctuation method (WTF) by using the data from groundwater monitoring wells. However, groundwater recharge rate shows the spatial-temporal variability due to climatic condition, land use and hydrogeological heterogeneity, so these methods have various limits to deal with these characteristics. To overcome these limitations, we present a new method of estimating recharge based on water balance components from the SWAT-MODFLOW which is an integrated surface-ground water model. Groundwater levels in the interest area close to the stream have dynamics similar to stream flow, whereas levels further upslope respond to precipitation with a delay. As these behaviours are related to the physical process of recharge, it is needed to account for the time delay in aquifer recharge once the water exits the soil profile to represent these features. In SWAT, a single linear reservoir storage module with an exponential decay weighting function is used to compute the recharge from soil to aquifer on a given day. However, this module has some limitations expressing recharge variation when the delay time is too long and transient recharge trend does not match to the groundwater table time series, the multi-reservoir storage routing module which represents more realistic time delay through vadose zone is newly suggested in this study. In this module, the parameter related to the delay time should be optimized by checking the correlation between simulated recharge and observed groundwater levels. The final step of this procedure is to compare simulated groundwater table with observed one as well as to compare simulated watershed runoff with observed one. This method is applied to Mihocheon watershed in Korea for the purpose of testing the procedure of proper estimation of spatio-temporal groundwater recharge distribution. As the newly suggested method of estimating recharge has the advantages of effectiveness of watershed model as well as the accuracy of WTF method, the estimated daily recharge rate would be an advanced quantity reflecting the heterogeneity of hydrogeology, climatic condition, land use as well as physical behaviour of water in soil layers and aquifers.

• Progress in Medical Physics
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• v.24 no.1
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• pp.1-24
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• 2013

As image-guided radiation therapy (IGRT) has been commonly used for more accurate patient setup and monitoring tumor movement during radiation therapy, the necessity for management of imaging dose is increased. However, it has not been an interest issue to radiation therapy communities because the imaging dose is much lower than the therapeutic dose. However, since the cumulative dose from 4DCT and repeated imaging for daily setup verificationin would not be ignorable, appropriate dose management based on ALARA (As Low As Reasonably Achievable) principle is required. In this study, we aimed that (1) survey on imaging equipments and modalities used for IGRT, (2) estimation of IGRT imaging dose depending on treatment types and equipments, (3) collecting data of effective dose on treatment sites from each equipment and imaging protocol, and thus finally provide guideline for imaging dose reduction and optimization.

• Journal of Life Science
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• v.25 no.12
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• pp.1354-1361
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• 2015

This study was aimed to investigate the distribution status and phylogenetic relationship of Myotis aurascens in Jeju Ialnd, which has not clearly confirmed until now. We found three groups of M. aurascens from three different cave enforcements (CEs). The bat population of Jeju Island had smaller levels of HBL and Hfcu, but greater levels of TL, EL, FAL, and Tra than those of the Korean Peninsula population. Jeju bats had wide range in the lengths of FAL and Hfcu comparing to those of European bats. From the bimonthly monitoring to each finding site, we have actually failed to observe those again, estimating that they use those CEs as the daily-roosting place in activating seasons. The sequences of CYTB and COI genes showed identical sequences among Jeju bats tested, indicating that they are maternally related. The results from molecular phylogeny showed that the sequences of these bats located on the same branch with those for M. aurascens in the phylogenetic trees. Besides, the nucleotide sequences of the Jeju bats showed the closest relation with that of Korean Peninsula. Consequently, these findings indicate that the bats of M. aurascens, verified the natural distribution in Jeju Island, have originated from a single maternal origin and differences in morphological and genetic backgrounds form those of Korean Peninsula and the other countries, and had probably immigrated via Korean Peninsula. These findings will contribute as basic information for understanding the migration history and biogeographic relationship of mammals on Jeju Island in East Asia.

• Pediatric Infection and Vaccine
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• v.16 no.2
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• pp.131-141
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• 2009

Purpose : In February 2007, an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections occurred in two newborns in the neonatal unit of Sahmyook Seoul Hospital. We performed this study to investigate the characteristics of MRSA nasal carriage among neonatal unit staffs and the effective infection control measures. Methods : Nasal swab specimens were obtained from the neonatal unit staff for the presence of MRSA. MRSA-colonized staffs were offered decolonization therapy with oral trimethoprim-sulfamethoxazole or 2% mupirocin ointment. Every 2-4months after decolonizaton, repeat nasal swab specimens were obtained. Also, samples from the neonatal unit environment and room air were collected. Results : Successful decolonization was achieved in 92% of the cases in 2 weeks after decolonization therapy, but most of the staffs were recolonized after several months. The nature of antibiotic susceptibility was changed from multi-drugsusceptible to multi-drug-resistant. The most frequently contaminated objects were dressing carts, computer keyboards, bassinets and washbowls. In environmental cultures using the settle microbe count method, the colony counts were decreased significantly at the last study period compared with the first study period in the neonatal room, breastfeeding room, service room, and dressing room (P <0.05). Conclusion : Effective control of sustained MRSA transmission within an institution may require prompt identification, treatment, and monitoring of colonized and/or infected staffs. However, nasal decolonization therapy may induce multi-drugresistant MRSA infection and had no effect on decreasing the MRSA nasal carriage rate in our study. Other factors might be more important, such as improving staff education, increasing hand hygiene practices, and environmental sterilization for controlling MRSA infections.

• Korean Journal of Environmental Agriculture
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• v.36 no.2
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• pp.119-128
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• 2017

BACKGROUND: Miscellaneous cereal have been largely consumed in Korea as due to their physiological functions beneficial to human health. The cereals are currently a social concern because they have been found to contain heavy metals. Thus, monitoring heavy metals in the cereals is an important requirement for food safety analysis. In this study, we determined arsenic concentration in the cereals randomly harvested from different markets. METHODS AND RESULTS: Inorganic arsenic was determined by ICP-MS coupled with HPLC system. The HPLC-ICP-MS analysis was optimized based on the limit of detection and recover test to reach $0.13-1.24{\mu}g/kg$ and 94.3-102.1%, respectively. The concentrations of inorganic arsenic equivalent to daily exposure were levels of $19.91{\mu}g/day$ in mixed grain, $1.07{\mu}g/day$ in glutinous rice, $0.77{\mu}g/day$ in black brown rice, $0.13{\mu}g/day$ in barley and $0.11{\mu}g/day$ in soybeans. CONCLUSION: The levels of arsenic in miscellaneous cereals were found lower than the recommended The Joint FAO/WHO Expert Committee on Food Additives (JECFA) levels, suggesting that the cereals marketed in Korea are not potential concern in risk assessment.

• Economic and Environmental Geology
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• v.47 no.1
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• pp.39-48
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• 2014

In coastal region, estuaries have complex environments where dissolved and particulate matters are mixed with marine water and substances. Suspended sediment (SS) dynamics in coastal water, in particular, plays a major role in erosion/deposition processes, biomass primary production and the transport of nutrients, micropollutants, heavy metals, etc. Temporal variation in suspended sediment concentration (SSC) can be used to explain erosion/sedimentation patterns within coastal zones. Remotely sensed data can be an efficient tool for mapping SS in coastal waters. In this study, we analyzed the variation in SSC in coastal water using the Geostationary Ocean Color Imager (GOCI) and Landsat Enhanced Thematic Mapper Plus (ETM+) in Gyeonggi-bay. Daily variations in GOCI-derived SSC showed low values during ebb time. Current velocity and water level at 9 and 10 am is 37.6, 28.65 $cm{\cdot}s^{-1}$ and -1.23, -0.61 m respectively. Water level has increased to 1.18 m at flood time. In other words, strong current velocity and increased water level affected high SSC value before flood time but SSC decreased after flood time. Also, we compared seasonal SSC with the river discharge from the Han River and the Imjin River. In summer season, river discharge showed high amount, when SSC had high value near the inland. At this time SSC in open sea had low value. In contrast, river discharge amount from inland showed low value in winter season and, consequently, SSC in the open sea had high value because of northwest monsoon.

• Science of Emotion and Sensibility
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• v.22 no.4
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• pp.97-106
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• 2019

The purpose of this study was to investigate the effect of the type and measurement location of a fabric strain gauge sensor on the detection performance for respiratory signals. We implemented two types of sensors to measure the respiratory signal and attached them to a band to detect the respiratory signal. Eight healthy males in their 20s were the subject of this study. They were asked to wear two respiratory bands in turns. While the subjects were measured for 30 seconds standing comfortably, the respiratory was given at 15 breaths per minute were synchronized, and then a 10-second break; subsequently, the entire measurement was repeated. Measurement locations were at the chest and abdomen. In addition, to verify the performance of respiratory measurement in the movement state, the subjects were asked to walk in place at a speed of 80 strides per minute(SPM), and the respiratory was measured using the same method mentioned earlier. Meanwhile, to acquire a reference signal, the SS5LB of BIOPAC Systems, Inc., was worn by the subjects simultaneously with the experimental sensor. The Kruskal-Wallis test and Bonferroni post hoc tests were performed using SPSS 24.0 to verify the difference in measurement performances among the group of eight combinations of sensor types, measurement locations, and movement states. In addition, the Wilcoxon test was conducted to examine whether there are differences according to sensor type, measurement location, and movement state. The results showed that the respiratory signal detection performance was the best when the respiratory was measured in the chest using the CNT-coated fabric sensor regardless of the movement state. Based on the results of this study, we will develop a chest belt-type wearable platform that can monitor the various vital signal in real time without disturbing the movements in an outdoor environment or in daily activities.

• Journal of dental hygiene science
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• v.13 no.4
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• pp.518-527
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• 2013

In 2011, South Korea's Ministry of Health and Welfare started a national tooth brushing room program without a pilot project. This study aimed to assess the effect of the implementation of this program in Gangneung, Korea. One-year outcomes of oral health behavior and self-reported oral symptoms in the study group after installation of the tooth brushing room were evaluated and compared with those of the control group using chi-square test. The prevalence rate of good self-rated oral health in grade 1-3 students increased from 35.7% immediately after installation to 48.9% after 6 months (p=0.031) compared to 37.3% in the control group (p=0.051). Immediately after installation of the tooth brushing room, 53.5% of grade 1-3 students in the study group brushed their teeth every day, but after 6 months, only 35.5% of students brushed daily (p<0.001) compared to 28.6% in the control group (p=0.007). The prevalence rate of bad breath in grade 1-3 students was 26.2% for the study group immediately after installation compared to 25.5% in the control group (p=0.065), but it declined 16.5% after 6 months (p=0.055). The prevalence rate of bad breath in grade 4~6 students was 14.7% for the study group after 6 months compared to 25.3% in the control group (p=0.016). We recommend the creation of a healthy school environment through a school-based tooth brushing program under the active supervision of classroom teachers and the continuous monitoring of program processes in order to promote children's oral health.

• Journal of Veterinary Clinics
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• v.20 no.1
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• pp.12-21
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• 2003

In this study, we evaluated effects of three anastomotic techniques of small intestine on adhesions in the dog. Twenty six healthy mixed dogs were randomly assigned to three groups. Group I(n = 8) was sutured with a simple continuous suture, group II(n = 7) was sutured with a simple interrupted approximating suture and group III(n = 11) was sutured with a single layer continuous Connell suture. On completion of any intestinal anastomosis, a pedicle of greater omentum was wrapped around the suture line in all experimental dogs. One percent sodium carboxymeth-ylcellulose (5ml/kg) was administrated into the abdomen by feeding tube prior to closing the last part of peritoneum in all dogs. Postoperative adhesions were evaluated at 14th day after operation. The adhesions consisted primarily in two dogs in group I, three dogs in group II and group III. There were adhesions between intestinal serosal surfaces in eight dogs in all groups, but there were no intestinal serosa-visceral peritoneum adhesion and intestinal serosa-mesentery adhesion. Mean adhesion scores were less than score 2 in all groups. Between anastomotic site and omental graft, there were 13.13$\pm$4.97 mm (mean$\pm$S.D.) adhesion formation in group I and 17.29$\pm$4.68 mm in group II and 14.64$\pm$3.80mm in group III. A simple continuous suture resulted in the least adhesion formation and a simple interrupted approximating suture resulted in the greatest adhesion formation among the groups. However, there were no significant differences among three suture techniques in the severity of adhesions. Intestinal intussusception only encountered in one dog during the 14 days, the dog operated and survived. Daily monitoring of temperature, activity, appetite, defecation and micturition were done. All of those vital signs were within normal values and there were no obvious differences among the groups. In conclusion, even though there were no significant differences among three groups, a simple continous suture pattern is recommended to prevent adhesions when operating intestinal anastomosis in dogs.

• Journal of radiological science and technology
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• v.35 no.2
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• pp.141-149
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• 2012

The aims of this study are to assess external radiation exposed doses of body and hands of nuclear medicine workers who handle radiation sources, and to measure radiation exposed doses of the hands induced by a whole body bone scan with high frequency and handling a radioactive sources like $^{99m}Tc$-HDP and $^{18}F$-FDG in the PET/CT examination. Skillful workers, who directly dispense and inject from radiation sources, were asked to wear a TLD on the chest and ring finger. Then, radiation exposed dose and duration exposed from daily radiation sources for each section were measured by using a pocket dosimeter for the accumulated external doses and the absorbed dose to the hands. In the survey of four medical institutions in Incheon Metropolitan City, only one of four institutions has a radiation dosimeter for local area like hands. Most of institutions uses radiation shielding devices for the purpose of protecting the body trunk, not local area. Even some institutions were revealed not to use such a shielding device. The exposed doses on the hands of nuclear medicine workers who directly handles radioactive sources were approximately twice as much as those on the body. The radiation exposure level for each section of the whole body bone scan with high frequency and that of the PET/CT examination showed that radiation doses were revealed in decreasing order of synthesis of radioactive medicine and installation to a dispensing container, dispensing, administering and transferring. Furthermore, there were statistically significant differences of radiation exposure doses of the hands before and after wearing a syringe shielder in administration of a radioactive sources. In this study, although it did not reach the permissible effective dose for nuclear medicine, the occupational workers were exposed by relatively higher dose level than the non-occupational workers. Therefore, the workers, who closely exposed to radioactive sources should be in compliance with safety management regulations, and take actions to maximally reduce locally exposed dose to hands monitoring with ring TLD.