• Journal of dental hygiene science
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• v.14 no.4
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• pp.442-447
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• 2014

The aim of this study was to analyze perception of risk and using status of hand-held dental x-ray unit among dental hygienists in metropolitan area. This research was based on perception of risk and using status of hand-held dental x-ray unit survey in 257 dental hygienists from July 7 to 31, 2014. Data were analyzed with t-test, one way ANOVA, and multivariable logistic regression analysis using SPSS Windows 21.0 program and significance level was set at p<0.05. The hand-held dental x-ray unit to cover all type patients was 24.8%. The 62.6% of patients and 81.3% of operator doesn't wear lead apron, the experience rate of radiation education was 40.1%. The average of risk perception was 3.08 points. The associated factors of risk perception were career, number of radiation exposure per day, and possession of fixed x-ray unit. The increased of accumulated dose when the occupationally exposed work continues, it is necessary to effort of defense against dental radiation.

• Journal of the Korean Dietetic Association
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• v.6 no.2
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• pp.136-147
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• 2000

The aim of this research was to examine the management practices related to foodservice.clinical nutrition service provided by hospital foodservice operations. A survey of 30 hospital food nutrition service departments was undertaken and detailed information was collected from each, including surveys of 176 dietitians and 30 foodservice managers. Statistical data analysis was completed using the SAS/win 6.11 package for descriptive analysis and t-test. The results of this study can be summarized as follows : Out of 30 hospitals, 73.3%(22) were directly operated and 26.7%(8) were under contract foodservice management. Licensed number of beds were 768.7, with an average length of 11.4 days. The general characteristics of the dietitians were that 49.4% were aged between 25-29, and 60.8% were ordinary dietitians. 76.7% had bachelor's degree, 15.9% with master's degree and 7.4% were college graduates. Most hospital dietitians had internship training and 35.2% took a training course of 6 to 12 months. The average space of kitchen was 452.52 $m^2$, with 133.63$m^2$ for modified diet space and 18.13$m^2$ for nutrition counselling room space. The total number of normal meals was 1,255.47, with 502.93 of modified meals. The average calorie of normal meals was 2,145.04kcal, with 91.9g of protein contained in normal meal. The total food waste was 351.40kg. An average monthly cost for disposing food waste was 745,171.67 won. 83.3% of the kitchens were on the 1st basement and only 66.7%(20) of 30 hospitals had its own nutrition counselling room. 80% used dishwashers and 66.7% had an exclusive elevator for delivering meals. 80.0% of hospitals used centralized delivery service. 90% had established an area for hygiene division, 70% used dry zone within the dishwashers for sterilization, 66.7% provided spoon and chopstick, and 100% used dish cover. As means of food waste treatment, most hospitals(56.7%) used animal feed by contracters, followed by means of collection by contracters(30%) and in-house high speed fermentation machines(13.3%). It was found that only 33.3% hospitals regularly checked temperatures of the meals given to patients. Total productivity index was 3.72(meals/hour) in average, with an average productivity index for normal diet of 5.41. Average productivity index for modified diet was 4.62. Productivity indices for patient meals and clinical nutrition were 5.01(meals/hour) and 1.12(cases/hour) respectively and hospitals under self-operated foodservice management received higher points on clinical nutrition productivity index(P<0.01) than hospitals under contract foodservice management.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.4
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• pp.92-103
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• 2017

As a professional occupation, landscape education focuses on fostering professional human resources and is one of the major axes of the landscape industry. In this study, a survey of landscape students on their learning and pedagogics was conducted with the aim to present basic information for the improvement of teaching on landscape construction. A total of 348 people answered 14 questions in the category of the impression of landscape construction classes included in the questionnaire. The results showed that the students found landscape construction classes academically important and recognized the necessity for completing these classes, but they were not satisfied with the learning environments and pedagogics used in these classes. They found what they learned not readily applicable to actual practice and saw these classes as part of their preparations for the landscape engineer qualification test. Their demands in relation to the classes included field practice-oriented teaching and participation in various programs for field practice, which highlights the necessity for human resource management-oriented classes that cover planning, design, construction, and management. Challenges in relation to field practice included the provision of environment, for example offering a variety of opportunities and improving treatment in practice. This study has significance in that it analyzed the views of students and discussed directions for future improvement since there is a lack of studies and discussions about education in the field of landscape construction. This study also has a limitation that only four-year universities were included in the study. Comprehensive studies including investigating junior college and graduate school curricula and case studies of landscape construction curricula overseas are needed in the future.

• Journal of the Korean Geosynthetics Society
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• v.10 no.2
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• pp.67-72
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• 2011

CMDS (Coal Mine Drainage Sludge) is mainly generated from acid mine drainage during physicochemical treatment or electrical purification. CMDS is well worth considering on recycling possibilities in various areas. This research applies the liner and cover materials using waste disposal landfill generally to treat acid mine drainage sludge. In this Part I of the two parts paper, physico-chemical characteristics of CMDS, bentonite and cement to prepare the liner have been identified using XRD, XRF, FESEM. In addition, combining their physicochemical characteristics, the optimum mixing ratio has been determined to be 1: 0.5: 0.3 for CMDS: bentonite: cement by the batch tests. Initial permeability of CMDS was $7.10{\times}10^{-7}cm/s$. Through the leaching test, it was confirmed that its mixture was environmentally safe. In the Part 2, a large-scale Lysimeter was used to simulate the effects of the layer on the freeze/thaw for evaluation on field applicability and stability.

• Journal of the Korea Concrete Institute
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• v.14 no.2
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• pp.216-222
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• 2002

With deterioration of the nation's infrastructure comes the growing, need for effective means of rehabilitating structures. Possibly one for the most challenging tasks is to upgrade the overall capacity of concrete structure. Therefore, considerable efforts are still being made to develop new construction materials. Rehabilitation of damaged RC structures occasionally requires the removal and replacement of concrete in the tension zone of the structural members. Typical situation where the tension zone repair is necessary is when the concrete in the tension zone in beams or slabs has spalled off as a result of corrosion in the bottom reinforcing bars or due to extensive fire. The rehabilitation of such conditions normally involves the removal of the concrete beyond the reinforcement bars, cleaning or replacing the tensile bars and reinstatement of concrete to cover the steel bars the original shape and size. This study focused on the flexural behavior of reinforced concrete beams strengthened by steel strand and carbon fiber sheet in the tension zone. The properties of beams are 15$\times$25 cm rectangular and over a 200cm span. Test parameters in this experimental study were strengthening methods, jacking volume, the number of sheet. We investigated the flexural behavior of simply supported RC beams which are strengthened with the carbon fiber sheet, monotonic loads. Attention is concentrated upon overall bending capacity, deflection, ductility index, failure mode and crack development of repaired and rehabilitated beams.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.127-138
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• 2004

Background: Crestal bone loss known as saucerization is a frequently observed phenomenon. Recent studies have shown that implants with micothreaded crest module reduced the force concentration in the crestal region thus resulting in no or reduced crestal bone loss. This study presents a clinical, histologic, and histometric evaluation of implants with microthreaded crest module and SLA surface. Methods: The implants were placed in the mandible of 5 beagle dogs weighing 10-15kg. Four premolars were bilaterally extracted 8 weeks prior to implant placement. Mucoperiosteal flap was elevated and drilling with increasing diameter was performed under saline irrigation. After countersinking 2 implants were placed in each side resulting in 4 implants per dog. Healing period of 8 weeks was allowed before sacrificing the animals. Histologic preparation was performed for histologic and histometric analysis. Bone to implant contact as well as percentage of bone area inside threads were measured. T-test was used for statistical analysis with pvalue p<0.05. Results: 1. Healing was uneventful without any cover screw exposure. New bone formation around the implants was observed without any inflammatory infiltration. 2. Bone to implant contact in the microthread and thread were 43.90 ${\pm}$ 20.30 %, and 53.19 ${\pm}$ 20.97 % respectively. The overall bone to implant contact was 48.54 ${\pm}$ 20.95 %. 3. Percentage of bone area inside threads were 54.43 ${\pm}$ 10.39 %, and 38.44 ${\pm}$ 16.44 % for the microthread and thread respectively. There was statistically significant difference(p<0.05). The overall percentage of bone area inside threads was 46.67 ${\pm}$ 15.68 %.

• Journal of Forest and Environmental Science
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• v.32 no.4
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• pp.329-343
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• 2016

The present study was conducted on ridge tops of moist temperate Oak forests in Garhwal Himalaya to assess the plant diversity, regeneration, biomass production and carbon assimilation in different Oak forests. For this purpose, three Oak forest types viz., (a) Quercus leucotrichophora or Banj Oak (FT1; between 1,428-2,578 m asl), (b) Quercus floribunda or Moru Oak (FT2; between 2,430-2,697 m asl) and (c) Quercus semecarpifolia or Kharsu Oak (FT3; between 2,418-3,540 m asl) were selected on different ridge tops in Bhagirathi catchment area of Garhwal Himalaya. A total of 91 plant species including 23 trees (8 gymnosperms and 15 angiosperms), 21 shrubs and 47 herbs species belonging to 46 families were recorded from all the ridge top Oak forests. The highest mean tree density ($607{\pm}33.60trees\;ha^{-1}$) was observed in Q. floribunda forest with lower mean total basal cover (TBC) value ($48.02{\pm}3.67m^2ha^{-1}$), whereas highest TBC value ($80.16{\pm}3.30m^2ha^{-1}$) was recorded for Q. semecarpifolia forest, with lowest mean stem density ($594{\pm}23.43stems\;ha^{-1}$). The total biomass density (TBD) across three Oak forests ranged between $497.32{\pm}83.70$ (FT1) and $663.16{\pm}93.85t\;ha^{-1}$ (FT3), while the total carbon density (TCD) values ranged between $228.75{\pm}22.27$ (FT1) and $304.31{\pm}18.12t\;ha^{-1}$ (FT3). Most of the tree species were found with good regeneration (GR) status (average 45%) in all the forest types whereas, few species were found not regenerating (NR) (average 17%) however, few new recruitments were also recorded. ANOVA (Post-Hoc Tukey's test at 5% significance level) indicated significant forest-wise differences in TBC, TBD and TCD (in tree layer); family and evenness (in shrub layer only) values, while insignificant differences were noticed in density values of tree, seedling and herb layer.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.2
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• pp.10-20
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• 2008

Generally, to acquire an HDR image, many images that cover the entire dynamic range of the scene with different exposure times are required, then these images are fused into one HDR image. This paper proposes an efficient method for the HDR image acquisition with small number of images. First, we estimated scenic dynamic range using two images with different exposure times. These two images contain the upper and lower limit of the scenic dynamic range. Independently of the scene, according to varied exposure times, similar characteristics for both the maximum gray levels in images that include the upper limit and the minimum gray levels in images that include the lower limit are identified. After modeling these characteristics, the scenic dynamic range is estimated using the modeling results. This estimated scenic dynamic range is then used to select the proper exposure times for the acquisition of an HDR image. We selected only three proper exposure times because entire dynamic range of the cameras could be covered by three dynamic range of the cameras with different exposure times. To evaluate the error of the HDR image, experiments using virtual digital camera images were carried out. For several test images, the error of the HDR image using proposed method was comparable to that of the HDR image which utilize more than ten images for the HDR image acquisition.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.18-18
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• 2011

Climate change is impacting and will increasingly impact both the quantity and quality of the world's water resources in a variety of ways. In some areas warming climate results in increased rainfall, surface runoff, and groundwater recharge while in others there may be declines in all of these. Water quality is described by a number of variables. Some are directly impacted by climate change. Temperature is an obvious example. Notably, increased atmospheric concentrations of $CO_2$ triggering climate change increase the $CO_2$ dissolving into water. This has manifold consequences including decreased pH and increased alkalinity, with resultant increases in dissolved concentrations of the minerals in geologic materials contacted by such water. Climate change is also expected to increase the number and intensity of extreme climate events, with related hydrologic changes. A simple framework has been developed in New Zealand for assessing and predicting climate change impacts on water resources. Assessment is largely based on trend analysis of historic data using the non-parametric Mann-Kendall method. Trend analysis requires long-term, regular monitoring data for both climate and hydrologic variables. Data quality is of primary importance and data gaps must be avoided. Quantitative prediction of climate change impacts on the quantity of water resources can be accomplished by computer modelling. This requires the serial coupling of various models. For example, regional downscaling of results from a world-wide general circulation model (GCM) can be used to forecast temperatures and precipitation for various emissions scenarios in specific catchments. Mechanistic or artificial intelligence modelling can then be used with these inputs to simulate climate change impacts over time, such as changes in streamflow, groundwater-surface water interactions, and changes in groundwater levels. The Waimea Plains catchment in New Zealand was selected for a test application of these assessment and prediction methods. This catchment is predicted to undergo relatively minor impacts due to climate change. All available climate and hydrologic databases were obtained and analyzed. These included climate (temperature, precipitation, solar radiation and sunshine hours, evapotranspiration, humidity, and cloud cover) and hydrologic (streamflow and quality and groundwater levels and quality) records. Results varied but there were indications of atmospheric temperature increasing, rainfall decreasing, streamflow decreasing, and groundwater level decreasing trends. Artificial intelligence modelling was applied to predict water usage, rainfall recharge of groundwater, and upstream flow for two regionally downscaled climate change scenarios (A1B and A2). The AI methods used were multi-layer perceptron (MLP) with extended Kalman filtering (EKF), genetic programming (GP), and a dynamic neuro-fuzzy local modelling system (DNFLMS), respectively. These were then used as inputs to a mechanistic groundwater flow-surface water interaction model (MODFLOW). A DNFLMS was also used to simulate downstream flow and groundwater levels for comparison with MODFLOW outputs. MODFLOW and DNFLMS outputs were consistent. They indicated declines in streamflow on the order of 21 to 23% for MODFLOW and DNFLMS (A1B scenario), respectively, and 27% in both cases for the A2 scenario under severe drought conditions by 2058-2059, with little if any change in groundwater levels.

• Korean Journal of Remote Sensing
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• v.31 no.2
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• pp.137-148
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• 2015

The National Institute of Meteorological Research (NIMR) has operated the Fourier Transform InfraRed (FTIR) spectrometer which is the Atmospheric Emitted Radiance Interferometer (AERI) in Anmyeon island, Korea since June 2010. The ground-based AERI with similar hyper-spectral infrared sensor to satellite could be an alternative way to validate satellite-based remote sensing. In this regard, the NIMR has focused on the improvement of retrieval quality from the AERI, particularly cloud-data filtering method. The AERI spectrum which is measured on a typical clear day is selected reference spectrum and we used region of atmospheric window. We performed test of threshold in order to select valid threshold. We retrieved methane using new method which is used reference spectrum, and the other method which is used KLAPS cloud cover information, each retrieved methane was compared with that of ground-based in-situ measurements. The quality of AERI methane retrievals of new method was significantly more improved than method of used KLAPS. In addition, the comparison of vertical total column of methane from AERI and GOSAT shows good result.