• Journal of Korean society of Dental Hygiene
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• v.4 no.1
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• pp.49-64
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• 2004

This study is designed to conduct a questionnaire research into the safety control and the actual condition of radiography by working with dentistry belonging to university hospitals, dental hospitals and dental clinics for three months ranging from August, 2003 to October, 2003. The researcher came to the following conclusions. 1. The research on the current condition of possessed radiational equipment shows that 61.2 percent of the subjects had one intraoral radiation medicine and that 70.1 percent of the subjects had more than one extraoral radiation medicine and that 37.3 percent of the subjects had more than one digital radiation medicine. 2. Most of intraoral radiography (82.1%) was conducted by dental hygienists, and 7.5 percent of intraoral radiography was conducted by nurse aids. On the other hand, most of extraoral radiography (76.6%) was conducted by dental hygienists and digital radiography was conducted by dental hygienists(60.6%), dentists(32.0%) and radiographer(80.0%). 3. The less-than 1-meter-long distance between cone and the radiographer accounted for 44.8 percent. And the more-than 1.6-meter-long distance accounted for no more than 13.4 percent. The exposure time per standard film which was adjusted to each part accounted for 71.6 percent. Fixing the film on the part of healthy patients accounted for 76.1 percent. Fixing the film of elderly patients and children patients by the radiographer accounted for 43.3 percent. 4. The average daily photographing frequency of standard films stood at six to ten pieces(31.3%), and the average weekly photographing frequency of bitewing films stood at less than one piece(47.8%), and the dentistries where bitewing films were not employed accounted for 25.4%. The subjects whose average weekly photographing freqeuncy of occlusal films stood at less than a piece accounted for 59.7 percent. The dentistries whose average weekly photographing frequency of pediatric films stood at one to five pieces accounted for 41.8 percent. In case of panorama & cephalo, one to five pieces on a weekly average accounted for 36.2 percent. The dentistries whose average daily photographing frequency of digital radiation medicine stood at less than 1 piece accounted for 40.0 percent. 5. The research on the use of protective clothes shows that pregnant ·women only accounted for 31.3 percent. In regard to the use of protective clothes in case of the radiographers fixing films, the cases where no protective clothes were employed accounted for 88.1 percent. The reason was said to he attributable to the trouble related to wearing the clothes(54.2%). 6. The survey on the measurement of exposure dose shows that the cases where no measurement was made accounted for 76.1 percent. As far as the measurement methods of exposure dose was concerned, the employment of film badge accounted for 68.8 percent. The subjects turned out to conduct measurement of exposure dose every third month, which accounted for 43.8 percent. The barriers to the measurement of measurement of exposure dose were attributable to the recognition that a little amount of exposure dose need not be measured(29.9%). 7. The survey on the distinction of radiation rooms and clinic rooms reveals that the cases where radiation rooms exclusively existed accounted for 67.2 percent. 43.3 percent of the subjects turned out to have only one protective garment, and 49.3 percent of the subjects proved to conduct a periodical checkup of radiational equipment. The survey on the examination certificates of radiational generators and protective facilities indicates that 80.6 percent of the subjects had the certificates. The research also shows that the subjects with the marks indicating the radiational areas accounted for 70.1 percent. And trustees turned out to handle developing solutions and fixing solutions.

• Journal of Animal Environmental Science
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• v.4 no.2
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• pp.97-104
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• 1998

In order to advise how to solve the problems and suggest on the mechanization of beef farm, the facilities and equipment for feeding and supplying water to the animals and transporting manure, and farm machineries of sixty-seven beef cattle farms in western Chungnam Province were surveyed. The results are as follows; 1. The proportions of number of heads per farm for above 70, 50∼70, 30∼50, 10∼30 and below 10 heads were 26, 18, 29, 13 and 13, respectively. The farms with the annual income more than 30 million won are consisted of 67.6% of the farms surveyed which showed to be higher than national average. 2. Only 19% of farms had automatic feeding system. Water was supplied by water cup(45%), opening and shutting water tab(27.6%) and bucket. 3. Cattle manure was transported by manpower (46%) by loader (34%) and by gravitational flow (14%). Most of manure(97%) was composted after treatment of drying or piling up outside. 4. More instruction and education were required because of the insufficient routine checking and fixing for farming machines, and unsystematic education for learning skills. 5. 65% of farms felt unsatisfied about after service(A/S) for their machinery. The main reason why the farmers were not satisfied was that it took too much time to be repaired. 6. When the farms purchased facilities, equipment and machinery, they did not analyze economic value of them and keep a diary. To make effective use of machines, the most available model for purchasing and managing of machines must be developed and applied to various scales of management.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.26-29
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• 2017

KARI has been conducting R&D for independent development of KSLV-II since 2010. Vehicle holding device is a device for vertically standing SLV on the launch pad of launch complex and fixing the lower part of vehicle in order to firmly fix vehicle so that SLV does not fall from an external load such as a wind load. When thrust generated after the 1st stage engine ignition of SLV must exceed the takeoff weight of vehicle, and holding device should be quickly released so that it does not interfere with takeoff of vehicle like other ground equipment at the beginning of the launch. Pyro-valve is one of the key components constituting VHD, and it should have high reliability and quick response characteristics with similar functional parts applied to launch vehicle separation device and satellite separation device. Through this paper, I intend to broaden the overall understanding of the development process of pyro-valve for VHD and KSLV-II.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.9
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• pp.29-35
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• 2019

The structure of the machinery industry due to the 4th industrial revolution is changing from precision and durability to intelligent and smart machinery through sensing and interconnection(IoT). There is a growing need for research on prognostics and health management(PHM) that can prevent abnormalities in processing machines and accurately predict and diagnose conditions. PHM is a technology that monitors the condition of a mechanical system, diagnoses signs of failure, and predicts the remaining life of the object. In this study, the vibration generated during machining is measured and a classification algorithm for normal and fault signals is developed. Arbitrary fault signal is collected by changing the conditions of un stable supply cutting oil and fixing jig. The signal processing is performed to apply the measured signal to the learning model. The sampling rate is changed for high speed operation and performed machine learning using raw signal without FFT. The fault classification algorithm for 1D convolution neural network composed of 2 convolution layers is developed.

• Journal of Advanced Navigation Technology
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• v.25 no.1
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• pp.78-83
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• 2021

Due to rapidly increasing air traffic congestion and airspace restrictions, the International Civil Aviation Organization (ICAO) is urging all aircraft to use SBAS by 2025, in order to implement Performance-based navigation to increase airspace capacity. In line with this, research and development of Korean-style SBAS, which reflects the characteristics of Korea's airspace environment, continues in Korea. Since there is no flight inspection procedure for performance testing and verification of SBAS in Korea yet, this paper analyzes FAA, ICAO Regulations, and laws enacted by the Ministry of Land, Infrastructure and Transport to derive essential evaluations and parameters of Korean SBAS, and presents the optimal design using RTK-DGPS as a position fixing system.

• The Korean Journal of Emergency Medical Services
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• v.7 no.1
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• pp.179-198
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• 2003

If see disaster administration system of our country, start in terms of is coping by countermeasure after four immediately after disaster occurrence many problems blessing with a sons by tribe and so on of link nature between formation, disaster administration complete charge utensil's absence, disaster charge manpower and budget be indicated and join. If examine improvement way accordingly, is as following ; Necessity of synthetic disaster administration system, Fire fighting formation's independence guarantee, Integration of fire fighting connection similarity business, Disaster administration's permanent establishment complete charge utensil's necessity, Disaster administration midautumn complete charge utensil at a metropolitan autonomous fire fighting system reorganization, Role division of labor between center and local government, Disaster administration professional human strength positivity, Disaster administration information system construction practical use, Equipment and improvement of budget state, Education public information for safety culture consciousness fixing, Internationalization of fire fighting business, globalization propulsion, Structure, member of rescue confrontation system and efficiency. Fire fighting environment is changing greatly, and fire fighting must become center to correspond to do confrontation that do one thing troble when produce disaster.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.1962-1969
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• 2008

According to the increase of power demand and expansion of downtown, it is necessary to install transformers additionally in operating substations and construct substations in residential area. But the public complaint is increased due to the transformer noise of the substation. KEPCO has used a vibration preventing pad, various soundproof walls and an encloser to transformers in outdoor substations, and a soundproof door, shutter and wind-path soundproof equipment in indoor substations to block the sound propagation of the transformers. But these noise reduction methods are not satisfied. It should be considered to reduce transformer noise itself. In this paper, we investigated core noise reduction techniques to develope a low noise transformer. The techniques to reduce core noise of the transformer are application of high permeability grain oriented silicon sheets, decrease of magnetic flux density of core, application of 6step-lap core stacking method, improvement of core binding method(binding addition, band fixing) and application of rubber damper in oder to reduce transmission of core vibration, etc.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1626-1631
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• 2007

The purpose of the study is to simulate the displacement of the LCD glass during process of a large size imprint. During this process, a small temperature variation makes thermal stress, which causes the horizontal variation of mold and glass. During alignment process to fix the LCD glass on a alignment stage, the vertical displacement is made by the absorption pressure and the shear stress. This study simulates the horizontal displacement of mold and glass due to temperature variation, the vertical displacement depending on the shape of absorption surface fixing the LCD glass in the alignment process, and the horizontal and vertical displacement which occurs in the LCD glass at the alignment process. Algor which is a FEM code for a framework simulation was applied. Temperature variation above ${\pm}$ $0.1^{\circ}C$ on mold and glass causes the horizontal displacement of 150nm due to thermal expansion. The vertical displacement due to the circular is ten times of the case of rectangular absorption nozzle. The displacement of the LCD glass in the alignment process is about 49nm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2569-2574
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• 2012

HMS(Hull Mount Sonar) equipment mounted on PCC(Patrol Combat Corvette) is suitably designed for active mode, and the specific character of sensor or system is not appropriate for the frequency range to detect a torpedo. In this article, in order to implement the function of detecting torpedoes with HMS of existing PCC, I will analyze the feature of input signals each PCCs and design a circuit to compensate reversely for the input signal in certain frequency. And also, I will suggest the most adequate torpedo defense system suitable for the special operating environment and the characteristic of naval vessels, implementing functions such as AGC of input signal and fixing the frequency range of different input signals per different warships.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.349-352
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• 2011

HMS(Hull Mount Sonar) equipment mounted on PCC(Patrol Combat Corvette) is suitably designed for active mode, and the specific character of sensor or system is not appropriate for the frequency range to detect a torpedo. In this article, in order to implement the function of detecting torpedoes with HMS of existing PCC, I will analyze the feature of input signals each PCCs and design a circuit to compensate reversly for the input signal in certain frequency. And also, I will suggest the most adequate torpedo defense system suitable for the special operating environment and the charateristic of naval vessels, implementing functions such as AGC of input signal and fixing the frequency range of different input signals per different warships.