• The korean journal of orthodontics
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• v.17 no.2
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• pp.223-248
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• 1987

The early tissue reactions in the periodontal tissues of the tension zones following the application of force (30gm) to the maxillary first molar teeth of the albino rats were studied by the light microscopy and electron microscopy The increase of periodontal fibroblasts was evident, particularly in 1 day survival period. Osteoblast differentiation and new bone formation on the alveolar bone surface were occurred from 1 day survival period. Mononuclear phagocytes occurred consistently and in relatively high number adjacent to and at some distance from blood vessel Extensive breakdown of collagen fibers was observed. The increase of the phagocytosis of collagen by the active fibroblasts was evident Also, collagen fibrils were sparse or lost near the macrophage.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.1
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• pp.43-50
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• 2013

The narrow dynamic range of most smart phone cameras is severely limited. It usually is narrower than the dynamic range of most scenes. So we proposes a illuminance dynamic range expansion using multi-point knee for smart phone camera. Such as logarithmic functions the proposed method compress the image sensor output signal. Additionally, the proposed method was merged into the gamma that is essential circuit for any cameras. To justifying multi-point knee effectiveness, we configure the control and quality evaluation system for smart phone camera module. Experimental results show that the lost information by cut off and saturated affectively reconstructed in darker and in brighter areas. Finally this methods have advantage to implement without any changing hardware for conventional smart phones.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.191-196
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• 2012

Objective: The Work-related musculoskeletal disorders(WMSDs) have been a problem on industrial occupational safety and health in Korean shipyard industry. It has been a big social problem. Background: As a result, Korean government enacted a law to prevent musculoskeletal disorders at work and some major companies have already implemented an ergonomics program. Method: This paper presents a study on the effect of an ergonomics program in a Korean shipbuilding company during the last ten years. Conclusion: The Incidence of WMSDs, the worker's compensation cost and the lost time were decreased after implementation of the ergonomics program. Application: The results of the publishing will help efficient operation of MSDs prevention activity in other companies.

• Fire Science and Engineering
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• v.15 no.4
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• pp.57-63
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• 2001

Due to frequent fire incidents in underground culverts, many live are lost and the function of city is paralyzed, and consequently they bring tremendous damages to fortunes and live of people. It brings my attention that there are many problems presented when the current standard of smoke prevention facility is applied to prevent fire. Among many methods to prevent smoke in underground culverts this study concentrates on water-mist method witch is not currently applied in Korea and introduces installation method.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.931-936
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• 2006

This paper presents different issues of the real-time compression algorithms without compromising the video quality in the distributed environment. The theme of this research is to manage the critical processing stages (speed, information lost, redundancy, distortion) having better encoded ratio, without the fluctuation of quantization scale by using IP configuration. In this paper, different techniques such as distortion measure with searching method cover the block phenomenon with motion estimation process while passing technique and floating measurement is configured by discrete cosine transform (DCT) to reduce computational complexity which is implemented in this video codec. While delay of bits in encoded buffer side especially in real-time state is being controlled to produce the video with high quality and maintenance a low buffering delay. Our results show the performance accuracy gain with better achievement in all the above processes in an encouraging mode.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.626-631
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• 2006

가상현실 시스템에서의 가장 기본적인 상호작용은 사용자가 원하는 위치와 방향으로 시야를 이동하는 네비게이션이다. 기존의 관련 연구들은 가상환경 네비게이션의 고전적인 문제인 'lost-in-cyberspace'에 대한 명확한 해결책을 제시하지 못하고 있다. 또한, 직관적이고 사용방법이 쉬운 상호작용에 대한 연구가 충분히 이루어지지 않았다. 본 논문에서는 증강현실 기반의 감각형 오브젝트를 이용한 네비게이션 인터페이스 시스템과, 사용자의 컨텍스트를 활용한 네비게이션 방법을 제안한다. 테이블의 표면에는 프로젝터를 이용한 후면 영사를 통해 가상환경의 지도와 사용자를 위한 네비게이션 정보가 보여진다. 사용자는 테이블 공간에서 카메라를 이용해 추적되는 감각형 오브젝트를 조작함으로써 가상환경을 네비게이션 할 수 있다. 또한, 사용자의 관심 지역 및 가상공간의 중요 지역 등의 컨텍스트는 사용자의 간단한 오브젝트 조작 정보와 결합되어 이동 경로 생성에 이용된다. 제안된 시스템은 본 연구실에서 제작된 Responsive Multimedia System (RMS) 의 인터페이스 시스템으로 연동되어 실험을 수행하였다. 제안된 시스템 및 네비게이션 기법은 사용자에게 전체 가상환경에 대한 인지력을 향상시키고, 직관적인 인터페이스를 제공하며, 최소한의 조작으로 만족스러운 네비게이션을 제공한다.

• English Language & Literature Teaching
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• no.6
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• pp.1-24
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• 2000

Listening comprehension is an integrative and creative process of interaction through which listeners receive speakers' production of linguistic or non-linguistic knowledge. Compared with reading comprehension, it may arouse difficulties and thus impose more burdens on foreign learners. The Audio-Lingual Method focused primarily on speaking. Mimicry, repetition, rote memory, and transformation drills actually interfered with listening comprehension. So learners lost interest and were not highly motivated. Improving listening comprehension requires continual attentiveness and interest. Listening skill can be extended systematically only when students are frequently exposed to a wide range of listening materials with an affective, cultural, social, and psycholinguistic approach. Therefore, teachers should help students learn how to comprehend intactly the overall meaning of intended messages. The literature on teaching listening skill suggests various useful activities: TPR, dictation, role playing, singing, picture recognition, completion, prediction, seeking specific information, summarizing, labeling, humor, jokes, cartoons, media, and so on. Practical classroom teaching necessitates a systematic procedure in which students should take part in meaningful tasks/activities. In addition to this, learners must practice listening comprehension trough a self-study process.

• Journal of the Korean Chemical Society
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• v.60 no.5
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• pp.310-316
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• 2016

Oxidation-reduction cycling (ORC) procedures are widely used for cleaning nanoparticle surfaces when investigating their electrocatalytic activities. In this work, the effect of ORC on the surface structures and electrocatalytic oxygen reduction activity of Au electrodes is analyzed. Different structural changes and variations in electrocatalysis are observed depending on the initial structure of the Au electrodes, such as flat bulk, nanoporous, nanoplate, or dendritic Au. In particular, dendritic Au structures lost their sharp-edge morphology during the ORC process, resulting in a significant decrease in its electrocatalytic oxygen reduction activity. The results shown in this paper provide an insight into the pretreatment of nanoparticle-based electrodes during investigation of their electrocatalytic activities.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.10
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• pp.95-104
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• 1993

IPA(interpattern association) model is a method of feature extraction using a neural network. Even in the case that the reference patterns are simuklar to one another, this model can recover the reference patterns effectively. However, when the pattern whose feature pixels are lost is used as input, this model can not guarantee perfect recovery of the reference pattern. It is proposed a improved interpattern association(IPA) model for the feature extraction using neural network. The improved IPA model that combines the first interconnection weight matrix of the IPA model with the second additional weight matrix is proposed here to overcome the recovery problem of the original IPA model. The results of computer simulation and optical experiment are advanced.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.281-284
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• 2004

This paper presents the design and implementation of a QoS based enhanced collaboration system in MDO. This is an efficient distributed communication tool between designers. It supports text communication, audio/video communication, file transfer and XML data sending/receiving. Specially, this system supports a dynamic QoS self-adaptation by using the improved direct adjustment algorithm (DAA+). The original direct adjustment algorithm adjusts the transmission rate according to the congestion level of the network, based on the end to end real time transport protocol (RTP), and controls the transmission rate by using the information of loss ratio in real time transport control protocol (RTCP). But the direct adjustment algorithm does not consider when the RTCP packets are lost. We suggest an improved direct adjustment algorithm to solve this problem. We apply our improved direct adjustment algorithm to our of QoS (Quality of Service) [1] based collaboration system and show the improved performance of transmission rate and loss ratio.