• Journal of Environmental Health Sciences
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• v.38 no.4
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• pp.332-339
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• 2012

Objectives: The purpose of this study was to prevent health problems and environmental contamination resulting from inappropriate management of dental wastes and to provide reference data for revision and supplementation of dental clinic waste management guidelines. Methods: From 640 total of dental clinics registered in 16 cities and counties in Gyeongsangnam-do, 100 (60 in Changwon (Masan, Changwon), 29 in Gimhae, and 11 in Jinju) were included in this study. From July 2010 to September 2010, investigators visited the 100 dental clinics and conducted survey interviews using a structured survey questionnaire regarding disposal methods for liquid wastes (suction pump, spittoon container waste, used liquid disinfectants, and X-ray developer), and disposal methods for solid waste (suction pump, spittoon container waste, and general medical waste). Results: All the 100 dental clinics were found to treat liquid waste from suction pumps and spittoon containers in the same manner as general waste water. Nineteen percent of the clinics treated solid waste that was not filtered through the filter of a suction pump as general waste. Fifty or more percent of the clinics treated solid waste in spittoon containers as general waste. Seventy percent of the clinics used disinfectant solution, although most of them treated used disinfectants in the same manner as general waste water. Some clinics treated used X-ray developer and X-ray fixer in the same manner as general waste water. In most of the clinics, used drapes were washed within the clinic. Conclusions: It was found that waste water and dental wastes at some dental clinics were treated in inappropriately. Thus, in conclusion, the development of guidelines regarding proper management of liquid and solid dental waste at dental clinics is required, and hygiene and environmental training for workers at dental clinics is necessary.

• Journal of KIISE:Software and Applications
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• v.41 no.8
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• pp.557-568
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• 2014

Recently, software projects have been increasing and getting complex. Due to the large number of submitted bug reports, developers' workload increases. Generally in bug triage process, the triagers assign the bug report to fixer (developer) in order to resolve the bug. However, bug reports have been reassigned to other developers because fixers are not suitable. This is why the triagers did not correctly check and understand the bug report and decide the appropriate developers to fix the bug. This results in increase of developers' time and efforts in software maintenance. To resolve these problems, in this paper, we propose a novel method for developer recommendation based on topic model and social network. First, we build a basis of topic(s) from bug reports. Next, when a new bug report (test data set) comes, we select the most similar topic(s) and extract the participated developers from the topic(s). Finally, by applying social network, we analyze the developers' behavior (comment and commit activity) and recommend the appropriate developers. In this paper we compare our work with related studies through performance experiments on open source projects. The results show that our approach is more effective than other studies in bug triage.

• Health Policy and Management
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• v.24 no.3
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• pp.205-218
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• 2014

Background: Most studies on the national health insurance benefit expansion policy have focused on policy tools or decision-making process. Hence there was not enough understanding on how policies are actually implemented within the specific policy context in Korea which has a national mandatory health insurance system with a dominant proportion of private providers. The main objectives of this study is to understand the implementation process of the benefit coverage expansion policy. Unlike other implementation studies, we tried to examine both the process of implementation and decision making and how they interact with each other. Methods: Interviews were conducted with the ex-members of the Health Insurance Policy Review Committee. Medical doctors who implement the policy at the 'street-level' were also interviewed. To figure out major variables and the degree of their influences, the data were analyzed with Winter's Policy Implementation Model which integrates the decision making and implementation phases. Results: As predicted by the Winter model, problems in the decision making phase, such as conflicts among the members of committee, lack of applicable causal theories application of highly symbolic activities, and limited attention of citizen to the issue are key variables that cause the 'implementation failure.' In the implementation phase, hospitals' own financial interests and practitioners' dependence on the hospitals' guidance were barriers to meeting the policy goals of providing a better coverage for patients. Patients, the target group, tend to prefer physicians who prescribe more treatment and medicine. To note, 'fixers' who can link and fill the gap between the decision-makers and implementers were not present. Conclusion: For achieving the policy goal of providing a better and more coverage to patients, the critical roles of medical providers as street-level implementers should be noted. Also decision making process of benefit package expansion policy should incorporate its influence on the implementation phase.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.287-292
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• 2021

In this paper, we propose an efficient CNN application method by analyzing the effect of activation function on the failure diagnosis of the inductive motor stator. Generally, the main purpose of the inductive motor stator failure diagnosis is to prevent the failure by rapidly diagnosing the minute turn short. In the application of activation function, experiments show that the Sigmoid function is 23.23% more useful in accuracy of diagnosis than the ReLu function, although it is shown that ReLu has superiority in overall fixer failure in utilizing the activation function.

• The Journal of the Korea Contents Association
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• v.8 no.12
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• pp.322-333
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• 2008

This research examined use rate and profitability of equipment in hospital scale with about 500 beds to present data including to review before introducing PACS with the checklist included in preparation and proposal based on expected profit suggested by operation department and cost and use rate of the expensive medical equipment were analyzed. It was proved that profit was generated in the research subject hospital if PACS is introduced. Three to five year of lease is proper for the purchase method of medical equipment. Profit after two year of use will surpass investment cost and generate clear profit. Based on the profit generated from operation of radiology department, the purchase amount to introduce PACS at the hospital will be retrieved after about 1.9 years for the investment. The number of reshoot test at radiology department will be decreased and film, development, and fixer will not be necessary to buy so the operation cost will be reduced. Moreover, other than actual profit increased, the hospital can improve its reputation and employees can reduce their works and get better working environment with less stress. Their job satisfaction will be increased so they can improve service quality and it is good for marketing strategy of the hospital. As a result of this research, it was proved that the small and general hospital should have expected profit with introduction of PACS and analyze its contribution to treatment service and profit after the purchase. Then, the hospital should make a proposal for introduction of the medical equipment and establish effective operation plan.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.189-200
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• 2005

Biological nitrogen fixation is an important process for academic and industrial aspects. This review will briefly compare industrial and biological nitrogen fixation and cover the characteristics of biological nitrogen fixation studied in Azotobacter vinelandii. Various organisms can carry out biological nitrogen fixation and recently the researches on the reaction mechanism were concentrated on the free-living microorganism, A. vinelandii. Nitrogen fixation, which transforms atmospheric $N_2$ into ammonia, is chemically a reduction reaction requiring electron donation. Nitrogenase, the biological nitrgen fixer, accepts electrons from biological electron donors, and transfers them to the active site, FeMo-cofactor, through $Fe_4S_4$ cluster in Fe protein and P-cluster in MoFe protein. The electron transport and the proton transport are very important processes in the nitrogenase catalysis to understand its reaction mechanism, and the interactions between FeMo-cofactor and nitrogen molecule are at the center of biological nitrogen fixation mechanism. Spectroscopic studies including protein X-ray crystallography, EPR and $M{\ddot{o}}ssbauer$, biochemical approaches including substrate and inhibitor interactions as well as site-directed mutation study, and chemical approach to synthesize the FeMo-cofactor model compounds were used for biological nitrogen fixation study. Recent research results from these area were presented, and finally, a new nitrogenase reaction mechanism will be proposed based on the various research results.

• Korean Journal of Veterinary Research
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• v.32 no.4
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• pp.489-496
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• 1992

The division, distribution and migration of the macroglial cells in the juvenile mouse brain were investigated with the radioautography. Forty mice (ICR) were randomly subdivided into two groups. The twenty mice from group 1 were weighing initially 5 to 6g, aged 10 to 12 days and were sacrificied at 2 hrs, 2, 3, 5, 7, 10, 15 and 20 days after a single intraperitoneal injection of $^3H$-thymichine ($4{\mu}$ Ci/g of body weight). Twenty mice from group 2 were weighing intially 2.5 to 5g, aged 3 to 8 days and were sacrificed at 2 hrs, 2, 3, 5. 7, 10, 15 and 20 days after a single($4{\mu}$ Ci/g of body weight) and/or after intraperitoneal repeated injections($2{\mu}$ Ci/g of body weight/interval) at 2, 3 and 5 days after the first injection. The brain preparations were processed for autoradiogrouphy using Kodak NTB-3 emulsion following development in Kodak D-19, fixation in Kodak fixer, and then stained with cresyl echt violet or hematoxylin counterstain. The labeling index of the ectodermal glial cells in the subependymal layers of the lateral ventricles (SLLV), corpus callosum (CC), molecular layer of the neocortex (MLN ), inner layer except the molecular layer in the neocortex (ILN) and medulla of the cerebrum (MC) were invested. 1. Labeling cells appeared from 2 hour and some of them sustained in the 20 day after injection. In the single injection group, the peak of the labeling index reached a 7.6% at 3 day, 3.6% at 7 day, 3.3% at 2 day, 5.0% at 3 day and 2.3% at 2 day from the SLLV. CC, MLN, ILN and MC, respectively. In the repeated injecton group, the peak of the labeling index reached a 32.0 at 7 day, 11.0% at 10 day, 89% at 7 day, 16.0% at 10 day and 10.8% at 15 day from the SLLV, CC, MLN, ILM and MC, respectively. 2 The glial cells of the SLLV were recognized as to be migrated into the CC and to be not or less to be into the MC and ILN but to be not into the MLN. Glial cell aggregates in the neocotex and MC were recognized as to be proliferated and then disappeared in the itself regions.

• Journal of Internet of Things and Convergence
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• v.6 no.4
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• pp.21-26
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• 2020

An autonomous driving system is based on the deep learning system built by big data which are obtained by various IoT sensors. The miniaturization and high performance of the IoT sensors are needed for diverse devices including the autonomous driving system. Specially, the miniaturization of the sensors leads to compel the miniaturization of the fixer structures. In the viewpoint of the miniaturization, metallic structure is a best solution to attach the small IoT sensors to the main body. However, it is hard to manufacture the small metallic structure with a conventional machining process or manufacturing cost greatly increases. As one of solutions for the problems, in this work, metallic FDM (Fused depositon modeling) based on metallic filament was proposed and the FDM process was investigated to fabricate the small metallic structure. Final part was obtained by the post-process that consists of debinding and sintering. In this work, the relationship between infill rate and the density of the part after the post-process was investigated. The investigation of the relationship is based on the fact that the infill rate and the density obtained from the post-processing is not same. It can be said that this work is a fundamental research to obtain the higher density of the printed part.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.1
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• pp.23-28
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• 1977

Acetylene-ethylene($C_2H_2-C_2H_4$) assay was carried out to find the heterotrophic nitrogen-fixing activities and distribution of nitrogen fixers in eleven different soil series which are located in Kyeonggi province. Following are the summaries of this study. 1. Acetylene-reducing activities were higher in Gwanghwal, Mangyeong and Buyong series which are derived from fluviomarine deposite than in Yeongsan, Hamchang and Pyeongtack series which are observed from continental alluvial plain. The lowest activities are observed in Yecheon, Hoegog, and Jisan series which are situated in local valley region. 2. Estimated amouts of $N_2$ per annum fixed by $N_2$-fixing heterotrophs were about 3.2kg in fuluvio marine soils, 2.6kg in continental alluvial plain and 2.0kg/10a in local valley region, respectively. 3. Azotobacter and Beijerinckia were not detected in any of the ten different soil series except in Pyeongtaeg series. However, Clostridia, anaerobic nitrogen fixer, was detected in order of ${\times}10^2$. It is assumed that these population are not enough to contribute to the nitrogen supply by the biological fixation in paddy soil. 4. For the assesment of heterotrophic nitrogen fixation in paddy soil, it must be presumed that aerobes, anaerobes and phototrophs which can grow on nitrogen free media may greatly contribute for the asymbiotic netrogen fixation.

• The Journal of Korean Society for Radiation Therapy
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• v.19 no.1
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• pp.51-54
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• 2007

Purpose: Total body irradiation is used to kill the total malignant cell and for immunosuppression component of preparatory regimens for bone-marrow restitution of patients. Beam spoiler is used to increase the dose to the superficial tissues. This paper finds the property of the distance between beam spoiler and patient. Materials and Methods: Set-up conditions are 6 MV-Xray, 300 MU, SAD = 400 cm, field size = $40{\times}40cm^2$. The parallel plate chamber located in surface, midpoint and exit of solid water phantom. The surface dose is measured while the distance between beam spoiler and patient is altered. Because it should be found proper distance. The solid water phantom is fixer and beam spoiler is moving. Results: Central dose of phantom is 10.7 cGy and exit dose is 6.7 cGy. In case of distance of 50 cm to 60 cm between beam spoiler and solid water phantom, incidence dose is $14.58{\sim}14.92cGy$. Therefore, The surface dose was measured $99.4{\sim}101%$ with got near most to the prescription dose. Conclusion: In clinical case, distance between beam spoiler and patient affect surface dose. If once $50{\sim}60cm$ of distance between beam spoiler and patient, surface dose of patient got near prescription dose. It would be taken distance between beam spoiler and patient into account in clinical therapy.