• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.40 no.6
• /
• pp.583-592
• /
• 2020

This study assessed source depletion in the vadose zones of contaminated sites. The possible range of infiltration rate in Korea was statistically analyzed. The results showed a trend of decreasing leachate concentration of 13 pollutants used for risk assessment. Among them, benzene, ethylbenzene, toluene, and xylene showed a lower leachate concentration in groundwater over time due to their low distribution coefficient and also possible biodegradation effects. The average values of the relative concentration could be taken as a default index due to a very small range of uncertainties. In the case of heavy metals, it was shown that the leachate concentration in a pollutant does not decrease over time. Considering the annually different infiltration, a site-specific source-depletion scenario was applied to Cheongju in North Chungcheong Province. The result was expressed as a time series of the relative concentration of the leachate concentration, and this was compared to the trend by averaged Korean infiltration. Finally, an open-source code that used Python was used to help calculate the leachate concentration by this site-specific infiltration scenario.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.1
• /
• pp.650-659
• /
• 2021

This study was conducted to identify the factors affecting the health-related quality of life(HRQOL) in married women according to their occupations. The study subjects were 2,555 married women in the 7th National Health and Nutrition Examination Survey, and the SPSS 25.0 program was used for data analysis. The results are as follows. In the case of office workers, the age, household income, obesity etc., were significant factors, and the explanatory power was 8.9% (p<.001). In the case of service workers, the age, education level, weight control, subjective health, and stress were significant factors, and the explanatory power was 16.1% (p<.001). In the case of simple labor, the age, education level, number of household members, hypertension, obesity, weight change, weight control, sitting time, subjective health, subjective body image, and stress were significant factors, and the explanatory power was 24.7(p<.001). In the case of unemployed, the age, household income, number of household members, number of days taking a walk per week, sleeping time, sitting time, subjective health, subjective body image, and stress were significant factors, and the explanatory power was 29.9% (p<.001). In the future, when developing a program to improve the HRQOL, the individual management programs considering the factors affecting the HRQOL according to occupation should be applied.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.66 no.4
• /
• pp.271-278
• /
• 2021

Azolla is a genus of small aquatic ferns native to Asia, Africa, and America. Azolla is potentially significant as a nitrogen source in agriculture, particularly in conjunction with rice (Oryza sativa L.) cultivation. In addition, Azolla may either control weeds or act as a weed depending on management; therefore, we aimed to determine the effect of Azolla incorporation on weed (e.g., Monochoria vaginalis, Rotala indica, Aeschynomene indica, and Cyperus amuricus) control and its other benefits during rice cultivation. The effects of Azolla on weed emergence were evaluated based on plot area coverage by the Azolla mat, which appears as a green sheet over water, and the rate of weed emergence in paddy field. Weed occurrence was investigated 40 days after Azolla inoculation. Soil samples from the experimental plots were collected following harvest in 2014-2015, and analyzed. Moreover, rice growth, yield, and grain quality were measured. Azolla suppressed weed growth by 72%. Azolla mat incorporation in rice fields suppressed weed growth by over 60%. In addition, Azolla promoted nitrogen fixation. Compared with nitrogen management using chemical fertilizers, Azolla incorporation showed the potential for various positive effects, including the improvement of soil fertility by increasing total nitrogen, and organic matter content. Rice grown with Azolla maintained its yield without additional herbicide treatment. Moreover, the palatability of cooked rice was better when grown with Azolla.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.5
• /
• pp.411-422
• /
• 2021

The purpose of this study is to examine the relationships between quality of life and demographic characteristics and health-related behavioral characteristics, and their relevance to variables that represent health conditions among metropolitan-dwelling older adults. The study subjects were 380 senior citizens aged 65 or older living in the D metropolitan area, and data collection was conducted by visiting them for interviews in June 2019. A binomial logistic regression analysis was performed to examine the relationship between independent variables (demographic characteristics, health-related behavioral characteristics, health condition variables) and the dependent variable (quality of life) while controlling for gender and age. As a result, the factors related to quality of life for those surveyed were education level, spousal status, living status, bear for living expenses, average monthly allowance, satisfaction with daily life, evaluation of sleep quality, smoking and eating habits, amount of regular exercise, hobbies, subjective health status, physical disability (if any), hearing ability, visual acuity, mastication ability, urinary incontinence (present or not), and amnesia. The above results suggest that quality of life for the elderly living in urban areas is significantly related to variables that indicate demographic characteristics, health-related behavioral characteristics, and health condition.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.1B
• /
• pp.11-20
• /
• 2008

The spillway type of small and midsize dams in Korea is almost overflow weir. To examine flood control capacity of overflow spillway, FLOW-3D was applied to Daesuho dam and analysis was focused on the discharge of dam spillway by changing weir shape. Overflow phases and discharges of linear labyrinth weir and curved labyrinth weir were compared with those of existing linear ogee weir. Hydraulic model experiment was performed to verify numerical result. Verification results showed that overflow behaviors and flow characteristics in the side channel by hydraulic model experiment and numerical simulation are well matched, and water surface elevation at side wall coincides with each other. When the reservoir elevation was increased up to design flood level, in case of the linear ogee weir the flow over the crest ran through smoothly in the side channel, whereas in cases of linear labyrinth weir and curved labyrinth weirs, the flow discharge was increased by 40 cms, and the flow over the weir crest, rotating counter-clockwise, was submerged in the side channel. The results of the water level-discharge curve revealed that labyrinth weir can increase discharge by 71% compared to the discharge of linear ogee weir at low reservoir elevation since it can have longer effective length. But as water surface elevation rises, the slope of water level-discharge curve of labyrinth weir becomes milder by submergence and nappe interference in the side channel.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.5B
• /
• pp.473-482
• /
• 2009

This study numerically discusses wave forces acting on a vertical wall such as breakwaters or revetments, subjected to incident undular or turbulent bores. Due to the complex hydrodynamics of bore, its wave forces have been predicted, mainly through laboratory experiments. Numerical simulations in this paper were carried out by CADMAS-SURF(CDIT, 2001), which is based on Navier-Stokes momentum equations and VOF method (Hirt and Nichols, 1981) for tracking free water surface. Its original source code was also partly revised to generate bore in the numerical water channel. Numerical raw data computed by CADMAS-SURF included great strong spike phenomena that show the abrupt jumps of wave loads. To resolve this undesired noise of raw data, the band-pass filter with the frequency of 5Hz was utilized. The filtered results showed reasonable agreements with the experimental results performed by Matsutomi (1991) and Ramsden (1996). It was confirmed that CADMASSURF can be applied to the design of coastal structures against tsunami bores. In addition, the transformation process and propagation speed of bores in the same 2-d water channel were discussed by the variations of water level for time and space. The numerical results indicated that the propagation speed of bore was changed due to the nonlinear interactions between negative and reflected waves.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.5
• /
• pp.30-39
• /
• 2023

Large dams, which are critical infrastructures for disaster prevention, are exposed to various risks such as aging, floods, and earthquakes. Better dam safety inspection and diagnosis using digital transformation technologies are needed. Traditional visual inspection methods by human inspectors have several limitations, including many inaccessible areas, danger of working at heights, and know-how based subjective inspections. In this study, drone photogrammetry was performed on two large dams to evaluate the applicability of digital data-based dam safety inspection and propose a data management methodology for continuous use. High-quality 3D digital models with GSD (ground sampling distance) within 2.5 cm/pixel were generated by flat double grid missions and manual photography methods, despite reservoir water surface and electromagnetic interferences, and severe altitude differences ranging from 42 m to 99.9 m of dam heights. Geometry profiles of the as-built conditions were easily extracted from the generated 3D mesh models, orthomosaic images, and digital surface models. The effectiveness of monitoring dam deformation by photogrammetry was confirmed. Cracks and deterioration of dam concrete structures, such as spillways and intake towers, were detected and visualized efficiently using the digital 3D models. This can be used for safe inspection of inaccessible areas and avoiding risky tasks at heights. Furthermore, a methodology for mapping the inspection result onto the 3D digital model and structuring a relational database for managing deterioration information history was proposed. As a result of measuring the labor and time required for safety inspection at the SYG Dam spillway, the drone photogrammetry method was found to have a 48% productivity improvement effect compared to the conventional manpower visual inspection method. The drone photogrammetry-based dam safety inspection is considered very effective in improving work productivity and data reliability.

• Journal of Navigation and Port Research
• /
• v.42 no.4
• /
• pp.245-252
• /
• 2018

A method of transmitting an alert signal in case of man-overboard (MOB) systems in a small fishing vessel navigating within coastal area is being operated as VHF-DSC equipment via a distress alert button and V-P ass Equipment via alert button or beacon separation. However, a small fishing vessel with a couple of crews on board is an inappropriate way to alert a man-overboard condition. However, internationally, MOB equipment using VHF-DSC, AIS, and Bluetooth technologies is used to transmit alert signals directly to the mother ship and other radio stations. In order to analyze the performance and technology of the MOB equipment operating in foreign countries, it was confirmed that the alarm signal can be received within a maximum of one nautical mile when the MOB device is on the water surface. An MOB device that meets domestic conditions needs to send an alarm signal to a station within the VHF communication range. However, in order to reduce the false alert signal, it is most appropriate to operate the VHF-DSC radio equipment installed on the ship remotely. Analysis of various technologies connecting the MOB and the VHF-DSC revealed that the Bluetooth system has advantages such as device miniaturization. When an emergency signal is transmitted from the MOB device, it can be received by a dedicated receiver and recognized through an external input terminal of the VHF-DSC equipment generating its own alarm. If the emergency situation cannot be processed at the mother ship, a distress alert is sent to all radio stations via VHF-DSC for response under emergencies faced by small fishing vessels.

• Journal of Hospice and Palliative Care
• /
• v.3 no.1
• /
• pp.18-27
• /
• 2000

Purpose : This study aims to find out the quality of life of patients admitted to the hospice unit at Kangnam St. Mary's Hospital, at admission and after weeks hospice service and to assess the effects of hospice service on the quality of life of terminal cancer patients. Methods : This study subjects were 100 patients admitted to the hospice unit at Kangnam St. Mary's Hospital, Catholic University between October 1999 and March 2000, and their primary caregivers. Quality of life data were collected using a questionnaire revised by the authors and were analyzed by means of repeated measures ANOVA. Results : 1) Patient's quality of life as perceived by the primary caregiver was significantly improved and the mean score was 3.31, 3.68, 3.56, 3.73, 3.75 at admission and week 1, 2, 3, 4. With the detailed item analysis, the following items were shown to be significantly improved: "clean bodies"(F=6.50, P=0.0001) "pain control"(F=18.01, P=0.0001) constipate"(F=2.96, P=0.0237) "sleep"(F=3.99, P=0.0048) "nausea/vomiting"(F=4.50, P=0.0022) "medical team's comfortable care" (F=3.95, P=0.0051) "family's care"(F=2.76, P=0.0317) "anxiety" (F=3.14, P=0.0177) "comfort"(F=3.63, P=0.0085) "treat with dignity"(F=3.32, P=0.0136). The item of "death is not the end of life rather the beginning" was significantly decreased(F=2.54, P=0.0450). 2) Patient's quality of life as perceived by the patient showed an improvement but statistically insignificant and the mean score was 3.63 and 3.83 at admission and week 1. With the detailed item analysis, the item of "pain control" was shown to be significantly improved(F=9.19, P=0.0251). 3) The quality of score in the last week of life of patient were 3.48, 3.51, 3.44, 3.46, 3.50, respectively, from 5 week prior to 1 week prior to death and these changes were insignificant. Conclusion : The findings of this study showed a positive effect of hospice service on quality of life of the terminal cancer patients admitted to the hospice unit. To improve the quality of life, we need first of all to develop hospice interventions with a particular emphasis on the spiritual aspect of patient. Secondly, measurement instruments need to be developed to collect the quality of life of the hospice patients who become weakened especially in the last weeks of their life and with this effort more representative data of hospice patients may be collected.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.32 no.3
• /
• pp.517-524
• /
• 2005

Despite the widespread use of chloral hydrate with hydroxyzine in the sedation of children, there is little agreement among pediatric dentists regarding its therapeutic dosage for the management of very uncooperative young children. Also, increasing concern has been raised with respect to its frequent failure to provide adequate levels of sedation when used according to the manufacturer's recommended dosage. Therefore, there has been many suggestions with respect to sedative effectiveness and safety of varying drug dosage, and some pediatric dental articles have advocated dosages exceeding manufacturer's recommendations. This study was performed to compare the effectiveness and safety in behavior management of the manufacturer's recommended dose of chloral hydrate(50mg/kg) with those of a higher dose(70mg/kg) used together with hydroxyzine(2mg/kg) and nitrous oxide(50%) when young children were sedated for dental treatment. The following results were obtained; 1. II group(70mg/kg) displayed higher mean score compared to I group(50mg/kg) with regard to the degree of sleep, crying, movement and overall behavior. The difference was statistically significant(p<0.05). 2. In comparison of success rates for sedation between the two groups, I group and II group showed 38.7% and 71.0% success rates respectively. An analysis of variance was statistically significant(p<0.05). 3. Comparing the occurrence rate hypoxia between the two groups, there were 22.6% and 19.4% occurrence of hypoxia in I group and II group. An analysis of variance was not statistically significant(p>0.05).