• 한국치위생학회지
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• 제12권4호
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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.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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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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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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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.

• 한국항만경제학회:학술대회논문집
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• 한국항만경제학회 2006년도 국제학술대회
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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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• 제29권4호
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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.

• 경영정보학연구
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• 제6권1호
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• pp.67-84
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• 2004

e-마켓플래이스의 영역이 지속적으로 확장될 것이라는 낙관적인 예측에도 불구하고 이에 대한 반론도 꾸준히 제기되어 왔다. 많은 선행 연구들이 e-마켓플래이스의 성공적 구축을 방해하는 여러 장애요인을 제시하였고 현실적으로도 e-마켓플래이스의 성공사례가 드문 편이다. 따라서 본 연구의 목적은 e-마켓플래이스의 확장 가능성을 살펴보고, e-마켓플래이스가 지속적으로 확장하기 위해서 어떤 요소를 극복하고 관리해야 하는지를 알아보는데 있다. 이를 위하여 성공한 e-마켓플래이스의 사례를 분석하였다. 선행 연구와 사례 분석을 통해 연구된 본 연구의 결과는 다음과 같다. 첫째, 자산 특수성과 제품 복잡성이 높은 시장에서도 e-마켓플래이스가 성공적으로 구현될 수 있으므로, e-마켓플래이스의 영역이 지속적으로 확장될 것을 예상할 수 있었다. 둘째, 그러나 정보기술의 발전에 의해 e-마켓플래이스의 영역이 자동적으로 확장되는것이 아니며, e-마켓플래이스의 확장 시 발생하는 여러 장애 요소를 극복하기 위하여 기술적, 사회적, 그리고 서비스 관련 분야 등 다양한 차원의 요소를 고려하고 문제를 해결하는 e-마켓플래이스 기업의 역량이 e-마켓플래이스의 영역 확장에서 매우 중요함을 알 수 있었다.

• 대한교통학회지
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• 제23권3호
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• pp.21-34
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• 2005

항공의 전 분야에 있어 항공안전은 아무리 강조해도 지나치지 않으며 항공안전에 주의를 기울이지 못하여 발생되는 항공기사고(aircraft accidents)는 항공기의 전 비행단계중 약 70%가 비행장주위의 이 착륙단계에서 일어나는 CFIT(Controlled Flight into Terrain) 사고라는 것은 주지의 사실이다. 이러한 점을 고려 할 때에 비행장주위의 장애물(obstacle)을 관리(control)하는 것은 항공기사고를 방지하고 비행장의 장기적인 존속을 보장한다는 측면에서 항공안전차원의 안전운항에 지대한 역할을 한다고 할 수 있다. 그러나 안전운항이 보장되는 범위 내에서 비행장주위의 장애물에 대한 제한을 효율적으로 관리하고 비행장주위의 규제에 따른 사유재산권의 제한을 해소하며, 장애물을 관리하는데 소요되는 노력을 경감하기 위한 차폐이론(Shielding)의 적용 역시, 안전운항과 더불어 비행장주위 공역을 효율적으로 활용할 수 있다는 측면에서 중요하게 고려하여야 할 사항이다. 실제로 국제민간항공기구(ICAO)나 항공선진국들은 기존장애물의 영향이 미치는 음영면 이하의 장애물은 장애물로 간주하지 않는다는 차폐이론 적용하여 건축규제를 완화하거나 장애물 표시등의 의무를 면제하고 있다. 물론 이와 같은 차폐이론의 적용은 국제적으로 통일된 차폐기준에 따라 적용되는 것이 아니며 각 국가의 상황에 따라 또는 각 비행장의 환경에 따라 신규장애물의 차폐 여부를 확인하고 항공학적인 연구를 통하여 안전운항에 영향이 없다는 판단 하에 적용 관리하고 있다. 국내에서도 비행장주위에 장애물제한에 관하여 항공법에 규정하고 있고, 최근 개정안으로 제시되어진 동법 시행규칙에서는 국제민간항공기구의 차폐기준의 적용을 포함하는 신규 규정을 포함시켜 놓았다. 그러나 이러한 규정만으로는 비행장 주위의 항공장애물을 체계적으로 관리하기가 어려우며, 특히 국내 비행장 주위의 공역에서 차폐이론적용에 필요한 세부기준이 제시되어 있지 않다는 점에서 논란의 여지가 많다. 따라서 본 연구에서는 항공장애물과 관련된 국제민간항공기구(ICAO)의 규정 및 항공선진국들의 관련 규정을 검토 분석하고 국내의 현황과 비교 분석한 후 국제기준에 비추어 국내환경에서도 적용 가득한 비행장 공역에서의 항공장애물관리규정(안)의 방향을 제시하고자 한다. 특히 논란의 여지가 많은 차폐이론의 적용에 이어 명확한 기준방안을 제시하여 항공안전과 효율적인 공역운영을 위한 대안을 설정하는데 도움을 주고자 한다.

• 한국지역사회생활과학회지
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• 제26권2호
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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.

• 한국항공운항학회지
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• 제27권4호
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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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.