• Journal of radiological science and technology
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• v.42 no.6
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• pp.469-476
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• 2019

The purpose of this study examines the education, knowledge and behavior of radiation safety management among dental workers and compares the education, knowledge and behavior between dental hygienist group and other occupational groups. This study was conducted from November 2nd to November14th, 2019. The survey was conducted on dental workers(dental hygienists, nursing, assistants, coordinators, etc.) who worked in dental hospitals and clinics in Busan area. The tool of this study was modified and adapted to the clinical setting based on the questionnaire. Radiation safety education has 39 dental hygienists who had more education than non-dental hygienists (p=0.286). The most common types of radiation safety education were self-education which usually performed by dentistry, followed by conservative education and others. The average of radiation attitudes, knowledge and behaviors was higher in the dental hygienist group then in the non-dental hygienist group. On the item-specific behavior among employees, the question of 'the radiation should be shielded according to the menstrual cycle or pregnancy of the woman of childbearing' was significant (p<0.05). On the item-specific knowledge between occupations, the question of 'the intensity of X-rays decreases over distance' and 'the individual exposure can be measured by TLD badge or film badge' was significant (p<0.05). Taken together, these results indicate that the dental hygienist group is more concerned about radiation safety and that the dental hygienist group is receiving more radiation safety management training. However, if there is a low level of 'has experienced' in the presence or absence of safety management education, it is difficult to train radiation safety management in dentistry. Therefore, it is considered that dentists should be trained in radiation safety management periodically to pay attention to radiation safety accidents.

• Radiation Oncology Journal
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• v.8 no.1
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• pp.79-84
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• 1990

We have analysed 13 patients with malignant obstructive jaundice due to metastasis who were treated with local radiation therapy to the area of porta hepatis at the Radiation Therapy Department of Paik Hospital attached to the Inje University between 1984 and 1988. A good response was observed in 6 out of 7 evaluable paitens receiving a total radiation dose ranging from 2600 to 5480 cGy in 2.6 to 6 weeks. A complete response was noted in 5 patients, a partial response in 1 patient, and no response in 1 patient. The overall median survival for 13 patients was 3 months. But two patients lived more than a year without recurrence of jaundice. Moderate dose, localized field radiation therapy appears to the beneficial in relieving obstructive jaundice and gives a good symptomatic relief.

• Journal of Korean Society on Water Environment
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• v.31 no.6
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• pp.693-699
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• 2015

It has been known that torrential rainfall events have been occurring worldwide due to climate change. The accelerated soil erosion has caused negative impacts on water quality and ecosystem of receiving waterbodies. Since soil security issues have been arising in various areas of the world, intensive interests have been given to topsoil management in Korea. Thus in this study, Web GIS-based computing system of physical, chemical, and biological topsoil quality indices were developed. In this study, five soil quality maps at national scale and top soil erosion potential were prepared for evaluation of soil quality based on soil erosion potential. For this system, the open source Web GIS engine, OpenGeo, was used as core engine of the system. With this system, decision makers or related personnel in areas of soil erosion Best Management Practices (BMPs) would be able to find the most appropriate soil erosion BMPs based on soil erosion potential and soil quality at the area of interest. The Web GIS system would be efficiently used in decision making processes because of ease-of-use interface and scientific data used in this system. This Web GIS system would be efficiently used because this system could provide scientific knowledge to decision makers or stakeholders. Currently various BMP database are being built to be used as a decision support system in topsoil management and topsoil quality areas.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.896-901
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• 2012

In this research, the levels of concentrations from the junction of effluent from wastewater treatment plant during dry days and combined with runoff from the surrounding 11 ha livestock catchment area during wet days were determined to investigate the relationships of the concentration of various pollutants such as particulates, nutrients and organics originating from point and nonpoint sources. Manual sampling was conducted from October 2008 to December 2011 during dry and wet days. Based on the results, the flow rates and concentrations of most pollutant parameters were increased during wet days. It was found out that the effluent wastewater combined with stormwater runoff has low BOD to TN/TP ratio and high TN/TP to BOD ratio. Therefore, it is needed to employ other treatment methods to effectively manage the wastewater and reduce the pollutant discharge to receiving water bodies.

• Archives of Plastic Surgery
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• v.39 no.1
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• pp.51-54
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• 2012

With the gradual increase of cases using fillers, cases of patients treated by non-medical professionals or inexperienced physicians resulting in complications are also increasing. We herein report 2 patients who experienced acute complications after receiving filler injections and were successfully treated with adipose-derived stem cell (ADSCs) therapy. Case 1 was a 23-year-old female patient who received a filler (Restylane) injection in her forehead, glabella, and nose by a non-medical professional. The day after her injection, inflammation was observed with a $3{\times}3cm$ skin necrosis. Case 2 was a 30-year-old woman who received a filler injection of hyaluronic acid gel (Juvederm) on her nasal dorsum and tip at a private clinic. She developed erythema and swelling in the filler-injected area A solution containing ADSCs harvested from each patient's abdominal subcutaneous tissue was injected into the lesion at the subcutaneous and dermis levels. The wounds healed without additional treatment. With continuous follow-up, both patients experienced only fine linear scars 6 months postoperatively. By using adipose-derived stem cells, we successfully treated the acute complications of skin necrosis after the filler injection, resulting in much less scarring, and more satisfactory results were achieved not only in wound healing, but also in esthetics.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.104-110
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• 2010

Eutrophication is a well-known phenomenon in lentic habitats, however it is receiving increasing attention in shallow streams of Korea due to the increase of periphyton to a nuisance level. In this study temporal and spatial variation in periphyton standing crop and nutrient concentrations were surveyed in the upper reach of the Han River (the Inbuk Stream) that used to be a pristine rural stream until 1980s. Chlorophyll-a concentration per unit surface area of bottom substrate was examined monthly for one year period at nine sites along the Inbuk Stream together with environmental factors such as phosphorus, nitrogen, and water velocity. The standing crop of periphytic algae ranged from $4{\sim}242mgChl.a/m^2$ with a median of $55mgChl.a/m^2$, often exceeding the nuisance level criterion. Along the stream periphyton increased significantly from $39{\pm}48mgChl.a/m^2$ to $94{\pm}49mgChl.a/m^2$ after merging of a tributary in an intensive agricultural basin with high phosphorus concentrations. Seasonally periphyton biomass was highest in autumn (median $171{\pm}76mgChl.a/m^2$) from October through December when water flow velocity was low (median $0.4{\pm}0.3m/s$), while it was higher in flood season (median $1.2{\pm}0.4m/s$) and freezing season (median $0.2{\pm}0.3m/s$) was lower. The result shows that this rural stream often shows characteristics of eutrophication according to periphyton standing crop and it may be regulated by phosphorus and water velocity.

• Journal of Wetlands Research
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• v.12 no.3
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• pp.165-175
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• 2010

Recently, various development projects have occurred due to rapid industrialization and urbanization. Both industry and population grew rapidly which causes a corresponding rise in pollution. The accumulated pollutants are washed-off during rainy days, highly degrading the water quality of the receiving water body. This is because a lot of non point source (NPS) pollutants were accumulated on the surface during dry periods. This research focuses on the development of Eco-Bio Filter (EBF) system that treats NPS pollutants. It is constructed at Kongju National University campus. The EBF is a type of a structured infiltration system that falls under the category of Low Impact Development (LID) hydrologic design practices. The monitoring of rain events was performed. It includes the development of design, the lessons learned from the post-construction testing and the improvements in the renovation made. After a series of monitoring, the MOE will use the results to apply the design to other areas in the country.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.8
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• pp.2894-2909
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• 2015

As the number of mobile devices such as smart phones and tablets explodes, the need for new services or applications is also rapidly increasing. Smart class application is one of the emerging applications, in which most of contents are distributed to all members of a class simultaneously. It is highly required to select relay nodes to cover shadow area of radio as well as extend coverage, but existing algorithms in a smart class environment suffer from high control packet overhead and delay for exchanging topology information among all pairs of nodes to select relay nodes. In addition, the relay selection procedure should be repeated in order to adapt to the dynamic topology changes caused by link status changes or device's movement. This paper proposes the learning based relay selection algorithm to overcome aforementioned problems. The key idea is that every node keeps track of its relay quality in a fully distributed manner, where RQI (Relay Quality Indicator) is newly defined to measure both the ability of receiving packets from content source and the ability of successfully relaying them to successors. The RQI of each node is updated whenever it receives or relays broadcast packet, and the node having the higher RQI is selected as a relay node in a distributed and run-time manner. Thus, the proposed algorithm not only removes the overhead for obtaining prior knowledge to select relay nodes, but also provides the adaptability to the dynamic topology changes. The network simulation and experimental results prove that the proposed algorithm provides efficient and reliable content distribution to all members in a smart class as well adaptability against network dynamics.

• International Journal of Aeronautical and Space Sciences
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• v.9 no.2
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• pp.121-128
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• 2008

Modularized GPS software defined radio (SDR) has many advantages of applying and modifying algorithm. Hardware based GPS receiver uses many hardware parts (such as RF front, correlators, CPU and other peripherals) that process tracked signal and navigation data to calculate user position, while SDR uses software modules, which run on general purpose CPU platform or embedded DSP. SDR does not have to change hardware part and is not limited by hardware capability when new processing algorithm is applied. The weakness of SDR is that software correlation takes lots of processing time. However, in these days the evolution of processing power of MPU and DSP leads the competitiveness of SDR against the hardware GPS receiver. This paper shows a study of modulization of GPS software platform and it presents development of the GNSS software platform using MATLAB Simulink™. We focus on post processing SDR platform which is usually adapted in research area. The main functions of SDR are GPS signal acquisition, signal tracking, decoding navigation data and calculating stand alone user position from stored data that was down converted and sampled intermediate frequency (IF) data. Each module of SDR platform is categorized by function for applicability for applying for other frequency and GPS signal easily. The developed software platform is tested using stored data which is down-converted and sampled IF data file. The test results present that the software platform calculates user position properly.

• Journal of Broadcast Engineering
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• v.13 no.5
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• pp.636-650
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• 2008

DTV has a great advantage as compared to Analog TV in picture quality under low reception field strength. Various high quality tuners have been developed to result in much smaller Noise Figure of the receivers and many trials for receiving DTV signal through indoor antenna. In this paper, results of intensive field tests on the indoor reception of DTV are presented. Tests were carried out around Seoul-Gyeonggi Metropolitan area. Commercial directional and omni-directional antennas and 5th generation receiver were used for reception availability tests. The effects of heights, locations, and types of the house as well as the distance to the transmitter on the reception performances are analyzed. Our test results will be applied to improve the indoor reception environment of DTV.