• Journal of Chest Surgery
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• v.19 no.2
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• pp.259-264
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• 1986

Broncholithiasis is defined as a cor9ition in which a concretion is present within a bronchus or a cavity in the lung communicating with a bronchus. The usual causes of broncholithiasis are known as tuberculosis, histoplasmosis, silicosis, aspirated calculi, and a few fungal infections. It is generally accepted that the constant motion created by respiration and beating of the heart may cause the peribronchial calcified lymph node to erode into the tracheobronchial tree and to form broncholith. After the analysis of our 6 cases of broncholithiasis which were treated surgically in the Department of Thoracic Surgery, Seoul National University Hospital from 1960 to December, 1985, we could suggest that intrinsic formation of calculi should be regarded as the pathogenesis of broncholithiasis in addition to the extrinsic formation of calculi.

• School Mathematics
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• v.4 no.3
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• pp.415-433
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• 2002

The mathematics education community is seeking to change a teacher-centered class-room culture to a student-centered culture. However, the real transition is not easy, even for teachers who are eager and willing to teach differently. The challenge for teachers is to use the social structure of the classrooms to nurture students' development toward mathematical ways of thinking and communicating as well as their under-standing of mathematical concepts and processes. By introducing an elementary teacher's teaching practice and professional develop-ment along with her classroom episodes, this paper is to make strides toward an enriched understanding of the culture of the elementary mathematics classrooms in which students may have a lot of opportunities to develop conceptual under standing and math-ematical disposition. This paper first provides a detailed description of the classroom flow in terms of general social norms and sociomathematical norms in order to explore how the teacher and the students have established such a student-centered math-ematics microculture. This paper then analyzes the teacher's teaching approach and professional development.

• Journal of Biomedical Engineering Research
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• v.26 no.5
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• pp.301-307
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• 2005

We introduce a new multimedia telemedicine system which is called Telemedicine for Real-time Emergency Multi-consultation(TREM), based on multiple connection between medical specialists. Due to the subdivision of medical specialties, the existing one-to-one telemedicine system needs be modified to a simultaneous multi-consulting system. To facilitate the consultation the designed system includes following modules: high-quality video, video conferenceing, bio-signal transmission, and file transmission. In order to enhance the operability of the system in different network environment, we made it possible for the user to choose appropriate data acquisition sources of multimedia data and video resolutions. We have tested this system set up in three different places: emergency room, radiologist's office, and surgeon's office. All three communicating systems were successful in making connections with the multi-consultation center to exchange data simultaneously in real-time.

• Science of Emotion and Sensibility
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• v.11 no.3
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• pp.339-356
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• 2008

The purpose of this research was to identify the difference between expected and actual corporate image in the market and to verify the possibility of green-oriented corporate identity (CI) visual design as a useful method for communicating with consumers. In addition, this research suggests how green-oriented CI visual design can effectively convey corporate image to consumers. The methods of research used to achieve this aim were case studies and questionnaire surveys. In regard to the results, the difference between consumers'perceived favourable corporate image and companies' expectation about corporate image was found. Moreover, the results show that green-oriented visual identity (VI) design can improve corporate image. In turn, the gap between the expected and actual perception of corporate image can be decreased through green-oriented design. Based on these results, a method of effective development for green-oriented VI design is recommended.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2007.05a
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• pp.105-109
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• 2007

Aging society appears immediate social problem in Korea. Housing for aging is required independent and comfortable housing life to live considering about feature of elderly. It is necessary field to prepare. Aged person who suffers the aging process several stages gets changing weak, so living environment is important aging person aspect of social, psychological and physical point. Finally, aged person living together requires facilities for the naturally communicating and active things. Community of aged person required organization of space for keeping independence and connection with each other. According to space of community, housing for aging should have a different access route. In conclusion, congregate housing of the elderly should be planed organization of space to be solved anxiety and tension and to be aware of joining the community.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.10
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• pp.3557-3571
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• 2014

We develop a secret key generation scheme using phase estimation in ultra-wideband (UWB) wireless fading channels. Based on the reciprocity theorem, two terminals extract the phase of the channel as a common random source to generate secret bits. Moreover, we study the secret key rate by a pair of nodes observing correlated sources and communicating to achieve secret key agreement over public communication channels. As our main results, we establish a more practical upper bound from Cramer-Rao bound (CRB) and compare it with a universally theoretical upper bound on the shared maximum key rate from mutual information of correlated random sources. Derivation and numerical examples are presented to demonstrate the bound. Simulation studies are also provided to validate feasibility and efficiency of the proposed scheme.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.91-94
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• 2004

Ubiquitous sensor network is to manage and collect information autonomously by communicating user around device. Security requirements in Ubiquitous based on sensor network are as follows: a location of sensor, a restriction of performance by low electric power, communication by broadcasting, etc. We propose new mutual authentication protocol using a low power of sensor node. This protocol solved a low power problem by reducing calculation overload of sensor node using two steps, RM(Register Manager) and AM(Authentication Manager). Many operations performing the sensor node itself have a big overload in low power node. Our protocol reduces the operation number from sensor node. Also it is mutual authentication protocol in Ubiquitous network, which satisfies mutual authentication, session key establishment, user and device authentication, MITM attack, confidentiality, integrity, and is safe the security enemy with solving low electric power problem.

• Korean Journal of Computational Design and Engineering
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• v.1 no.2
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• pp.150-157
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• 1996

The hob is considered as an effective gear cutting tool for achieving the various gears such as spur gear, helical gear, worm gear and so on. To enhance the productivity and precision of hobs and the competitive ability of domestic CNC hob relieving lathes, a CAM system for CNC hob relieving lathe needs to be realized. In this study, the CAM system is developed based on the personal computer and C language. Besides the automatic generation of CNC data, the developed CAM system has the various capabilities related to the generation of tool path, the cutting simulation for verifying the generated CNC data and forecasting the cutting time, the DNC operation for communicating the CNC data with CNC controller by RS232C port, and the estimation of undercut length for verifying the hob cutting conditions.

• Research in Mathematical Education
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• v.17 no.3
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• pp.169-180
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• 2013

Communicating about mathematics is an essential component in learning mathematics and is a key standard for successful learning in a mathematics classroom using stories and storytelling as a catalyst to mathematics instruction. This, however, can make learning math for students with language deficiencies since they are working toward mastering both basic language proficiency as well as the specialized language needed for mathematics. This is a particular concern because the number of students of multicultural families is rapidly increasing. In this paper, we discuss the challenges and complexities of language-deficient students learning math in a classroom where communication is a key standard for successful learning, and suggest implications for teaching, by presenting an USA elementrny teacher's scaffolding to make reading and solving word problems less intimidating for her language learner students as well as native speaking students.

• Asia pacific journal of information systems
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• v.13 no.2
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• pp.145-170
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• 2003

Open Decision Support System(DSS) is an automated and transparent system that is built to be shared both within and across organizations. The open DSS has been thought to be a set of decision components that are communicating through Web protocols. These characteristics intuitively invite the Web services concepts, which are currently one of the new trends in network-based business services. However, web services still are not active enough to be autonomous, and to provide for composing functionalities. These lead to the motivation on building a sophisticated web service to contain these features and to utilize web services on behalf of the user. This paper aims to propose a new concept of Meta Web Service, a web service-based open DSS. Decision modules in a dynamic and open DSS can be viewed as a web service. The Meta Web Service understands the users problem statement with ontology, performs web service discovery, web service composition, and automatically generates codes for composite web service execution. A prototype of example web service has been developed to show the feasibility of the proposed idea.