• Journal of Korean society of Dental Hygiene
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• v.12 no.4
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• pp.723-732
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• 2012

Objectives : This study aims to analyze the tasks, recognition and obstacles in operation of school dental clinics and to examine opinions on installation, operation and prerequisites for toothbrushing facilities. Methods : It conducted a survey t o the persons in charge at 378 school dental clinics in Korea and total 127 sheets, excluding incompletely answered data, were used for analysis by using SPSS 18.0. Results : Two regular dental hygienists visit school dental clinics 2-3 times per week and work 4-6 hours per week on average. Their tasks include oral health education, toothbrushing instruction, oral examination, sending school newsletters, and dental sealants. The obstacles of operation include excessive workload other than the work for the school dental clinic, lack of dentists, and lack of cooperation of principals and teachers in school. The persons in charge think that the chief task of the school dental clinic is the continuous oral health management, and it effectively affects students' oral health improvement. Most of them were for the installation of toothbrushing facilities. They said that it will be effective in students having an adequate toothbrushing habit and their toothbrushing rate increasing higher. They thought that if the school dental clinic is changed to toothbrushing facilities, it will improve students' oral health management. The prerequisites for toothbrushing facilities are the support of manpower in charge, principal's support, and development of operational programs. Conclusions : The most effective function of school dental clinics is constant oral health management. However, when public health doctors are reduced and dental sealants get included in health insurance, the budget of local government will decrease and then it will eventually reduce the work of school dental clinics. Therefore, it is needed to enhance support for school dental clinics or install a toothbrushing facilities rather than a school dental clinic.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.790-793
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• 2002

In this paper, dynamic path planning of two mobile robots using a modified Hopfield neural network is studied. An area which excludes obstacles and allows gradually changing of activation level of neurons is derived in each step. Next moving step can be determined by searching the next highest activated neuron. By learning repeatedly, the steps will be generated from starting to goal points. A path will be constructed from these steps. Simulation showed the constructed paths of two mobile robots, which are moving across each other to their goals.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.414-414
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• 2000

This paper presents a method for building a real-time kernel of autonomous mobile robot control systems. Until now, most of robots have their own operation softwares dedicated only for their use. Sometimes, operation softwares were developed based on MS-DOS or other real -time kernel based on UNIX. However, MS-DOS has many restrictions for use as a robot operation system. Also, mix based real-time kernel has some Limitations for use with mobile robots. So, in this paper, we focus on building a real-time kernel based on Linux. The in this paper, the software modules of Task Management, Memory Management, Intertask Communication, and Synchronization are redesigned. To show the efficiency of the paper, it was applied to run Nomad Super Scout II avoiding obstacles detected by sonar sensor array.

• Proceedings of the Korea Port Economic Association Conference
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• 2006.08a
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• pp.67-102
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• 2006

The Purpose of this study is to improve the deterrent factors in Korea's coastal passenger shipping on the basis of field data collected in order to help stimulate it and enhance its competitiveness. As the representative model of this study, the "P" car-ferry liner was chosen, whereby various deterrent factors were observed in the course of the SWOT analysis and through the questionnaires. The major deterrent factors in summary were inflexible government regulations for additional ship operation, disadvantages of taxes policy, port facility shortages, non-allowing of ship's night operation, complicated and inflexible ship's operation controls by the concerned authorities, unreasonable divisions of steaming areas, and existences of obstacles on the ship's running routes, etc. which considered all are important to activate the liners.

• East Asian mathematical journal
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• v.29 no.4
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• pp.355-392
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• 2013

Generally school algebra is to start with introducing variables and algebraic expressions, which have major cognitive obstacles to students in the transfer from arithmetic to algebra. But the recent studies in the teaching school algebra argue the algebraic thinking from an early algebraic point of view. We compare the Korean elementary mathematics textbooks with Americans from this perspective. First, we discuss the history of school algebra in the school curriculum. And Second, we investigate the recent studies in relation to early algebra. We clarify the goals of this study(the importance of early algebra in the elementary school) through these discussions. Next we examine closely the number sense in the arithmetic and the symbol sense in the algebra. And we conclude that the operation sense can connect these senses within early algebra using the algebraic thinking. Finally, we compare the elementary mathematics books between Korean and American according to the components of the operation sense. In this comparative study, we identify a possibility of teaching algebraic thinking in the elementary mathematics and early algebra can be introduced to the elementary mathematics textbooks from aspects of the operation sense.

• Information Systems Review
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• v.6 no.1
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• pp.67-84
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• 2004

In spite of the widely held belief that e-Marketplace will be expanded continuously, scholars are still reluctant to accept the positive expectation. Many anecdotal evidence and case studies indicate that there are several obstacles that hinder e-business firms from building the e-Marketplaces. Actually, this obstacles has led many e-marketplaces' failures. The purpose of this study is to verify the possibility of the e-Marketplace expansion and to explore how to deal the obstacles in the e-Marketplace operation. To achieve such objectives, a successful e-Marketplace case was investigated. The conclusion of this research is as follows : (1) e-Marketplaces can be built even in the high asset specificity and high complexity of product description market. Therefore it is acceptable that e-marketplace will be expanded continuously as argumented by Malone et al.(1989). (2) But the driving factor is not solely information technologies but the capability of e-business firms that consider technical factors, social factors, and service related factors all together. It was also noted that the capability of e-business firms to handle the inherent obstacles is important for the expansion of e-Marketplaces.

• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.21-34
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• 2005

To control the obstacles surrounding aerodrome is significant for preventing air accident and ensuring the long sustaining of aerodromes. On the other hand, within a scope of ensuring safe flight operations, the application of Shielding is one of the issues to be importantly considered to manage efficiently the obstacles limitation around aerodromes, to dissolute the private asset privilege limitation from regulation on aerodrome circumference, and to decrease the pains to manage the obstacles, in terms of not only operating safely but also utilizing efficiently the airspace around aerodromes. The ICAO and other aviation-advanced states mitigate the construction limitation or exempt the obligation of obstacle sign by applying the shielding theory that the obstacles are not regarded as obstacles where are below the shadow surface. The Republic of Korea inserted the new regulation including the applying shielding similar to ICAO on Aviation Act and regulations. It is, however, hard to manage the aviation obstacles around aerodrome efficiently with these new regulation. Particularly, there exists much rooms to dispute because it cannot suggest the specific standard which is necessary to apply shielding theory at airspace of aerodromes. Therefore, in this study, the international standards on aviation obstacles were reviewed, analyzed and compared with those of domestic status. The direction of which guideline for control of aeronautical obstacles applicable within domestic circumstances as well as correspondent with international standard was suggested. Particularly, as far as the disputable application of shielding theory is concerned, the alternatives for aviation safety and efficient airspace operation by suggesting the clear standards alternatives were suggested.

• The Korean Journal of Community Living Science
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• v.26 no.2
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• pp.335-349
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• 2015

The system of School Meal Service Support Centers was established to support the supply of high-quality food ingredients for school meal services when the School Meal Service Act was amended in 2006. A case study was conducted to examine the operating effects, success factors, and major obstacles of a School Meal Service Support Center which was highly evaluated for its operational efficiency and customer satisfaction. Qualitative data were collected from eight stakeholders (two individuals each from the center, farms, schools, and distributors) through in-depth interviews in July 2013 and analyzed by using the thematic analysis method. The successful operation of the center helped to stabilize income and price among the stakeholders, increase ingredient quality, increase school meal reliability, reduce costs, and promote the consumption of agricultural products. Success factors were identified as the center director's commitment and insights, and the competitive operating system including fair operations, rational pricing, liberal consumer choice, total quality management, and partnerships with distributors. Major obstacles included a lack of diversity in supplied ingredients and a lack of administrative and financial support form the local government. The results can be used as baseline information to vitalize the system of School Meal Service Support Centers and increase the quality of school meal services.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.27 no.4
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• pp.37-43
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• 2019

Obstacle limitation surfaces are imaginary space surfaces that must be clear of obstacles for the aircraft to safely take off and land on the aerodrome. These surfaces are closely related to the safety of the VFR aircraft, which require a pilot to be able to see outside the cockpit, to control the aircraft's altitude, navigate, and avoid obstacles and other aircraft. The Republic of Korea, which has a lot of restrictions on the use of airspace, cannot provide a rich operating environment for VFR aircraft. Under these circumstances, safer operation will not be guaranteed if additional factors that directly or indirectly affect existing VFR routes, such as drone delivery services. This study analyzes and models the track distribution of each VFR section based on radar track data around a specific airport. Through this study, we estimate the three-dimensional space for VFR aircraft and provide the data for future research such as airspace analysis of VFR corridors and correlation with obstacle limitation surfaces.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.259-261
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• 2002

Recently, according to the spread of semiconductor applied technology like motor speed control contrivance, power conversion installation and so on, harmonic ingredients occurred in switching operation flow into a distribution system and increase voltage distortion of distribution system and bring on obstacles like damage, lowering of capability, false operation and so on of various electrical installation. So, in order to consider a countermeasure to limit occurrence quantity of harmonic source, harmonic interception and others, precision measurement and analysis on voltage, current, power, power factor, the each ingredient of harmonic order, the percentage of total harmonic distortion and so forth are needed. In this paper monitoring system to measure and analyze power quality connected with power harmonics was developed and it's performance is verified by measuring and analyzing three-phase voltage and current of R, S, T in the three-phase and four-wire system using the developed measurement system.