• The Journal of the Acoustical Society of Korea
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• v.32 no.4
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• pp.301-307
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• 2013

SONAR detection performance is one of the key survivability factors in underwater weapon systems. In order to catch the acoustic ability of SONAR, multilayer SONAR structures are analyzed using the elastic theory. The applied results for the simple models are compared with those from commercial program, ANSYS, and the reliable results are obtained. The analysis of sound pressure level (SPL) and echo reduction (ER) by the thickness change of multilayer SONAR structures are performed using the verified elastic theory. As the thickness of anechoic layer is increased, SPL is distributed evenly and ER is increased slightly with the frequency. In decoupling layers and steel layers, SPL are hardly changed and ER is slightly decreased with the thickness increase of those layers. SPL and ER are not affected by the thickness change of the carbon reinforced plastic (CRP) layer. Therefore, to improve the acoustic ability of multilayer SONAR structures, the thickness increase of the anechoic layer and minimization of the decoupling layer, steel layer and CRP layer are desirable.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.536-540
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• 1996

경험과 학습을 바탕으로 새로운 상황에 대처하는 인간의 신경계에서의 신경세포들의 상호작용을 규명하는 일은 많은 과학자들을 매료시켜 왔다. 이와 함께, 생물학적인 신경계를 닮은 인공적인 신경망을 구축하여 감지하고, 인식하고, 구별하고, 판단하는 일에 이용하고자 하는 노력도 끊임없이 진행되어 왔다. 인공 신경망의 구성은 전적으로 많은 경우의 수에 대한 테스트에 의존하게 되는 데, 이 경우 시간도 대단히 많이 소요 될 뿐더러 체계적으로 가장 좋아 보이는 신경망 모델에 도달하였는 지도 확실치 않다. 따라서 , 본 논문에서는 실험계획법을 다층 퍼셉트론 신경망의구조설계에 적용하여 적은 실험횟수로 적합한 신경망 모델을 구성할 수 있음을 검증하고, 실제사례에 적용하여 그 유용성을 제시하고자 한다.

• Journal of the Korean Geographical Society
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• v.33 no.2
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• pp.309-324
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• 1998

본 연구는 급속한 기술변화와 경쟁심화에 의해 생산체계의 분화가 촉진되고 있는 컴퓨터산업을 사례로 기업간 네트워크의 형성실상과 요인을 분석하였다. 네트워크는 거래원리와 기업간 관계의 측면에서 정의되었으며 하청과 협력네트워크로 구분하였다. 설문조사 결과에 의하면, 하청네트워크는 약 75%, 협력네트워크는 약 85%의 기업이 참여하고 있어 어떤 형태로든 상당수의 기업이 네트워크를 형성하고 있다. 협력네트워크는 물론 하청네트워크도 거래기업간 보완성과 전문성에 의해 지속적인 거래관계로 형성되고 있다. 이것은 기업간 네트워크가 다층화된 생산체계에서 외부기업의 자원을 이용하여 경쟁력을 강화하는 기업전략임을 의미한다. 따라서 기업간 네트워크는 세계화-지방화 시대의 경제공간구조의 변화를 살펴볼 수 있는 중요한 지표가 될 수 있다.

• Korean Journal of School Psychology
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• v.15 no.3
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• pp.399-431
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• 2018

The purpose of this study was to summarize the empirical literature on implementation of positive behavior support (PBS) within a multi-tiered system of supports in American and Korean schools and to compare its key features and outcomes in an attempt to suggest future directions for development of a Korean school-wide PBS model and implementation manuals as well as directions for future research. Twenty-four American articles and 11 Korean articles (total 35 articles) that reported the outcomes of implementation of PBS at a tier 1 and/or tier 2, or tier 3 level and that met established inclusion criteria were analyzed using systematic procedures. Comparisons were made in the areas of key features and outcomes of PBS in addition to general methodology (e.g., participants, design, implementation duration, dependent measures) at each tier of PBS. The results indicated that positive outcomes for student behavior and other areas were reported across tiers in all American and Korean studies. At the tier 1 level, teaching expectations and rules were the primary focus of PBS in American and Korean schools. However, Korean schools focused on modifying the school and classroom environments and teaching social skills whereas American schools focused on teacher training on standardized interventions or curricular by experts and teacher support during implementation of PBS. At the tier 2 level, more American studies reported implementation of tier 2 interventions within school-wide PBS, and Check/In Check/Out (CICO) was found to be the most commonly used tier 2 intervention. The results also indicated that in comparison to Korean schools, American schools were more likely to use systematic screening tools or procedures to identify students who need tier 2 interventions and more likely to promote parental involvement with implementing interventions. At the tier 3 level, more Korean studies reported the outcomes of individualized interventions, but more American studies reported that designing individualized intervention plans based on comprehensive functional behavior assessment results and establishment of systematic screening systems were focused when implementing individualized interventions. Furthermore, few Korean studies reported the assessment of procedural integrity, social validity, and contextual fit in implementing PBS across tiers, indicating the need for development of valid instruments that could be used in assessing these areas. Based on these results, limitations of the study and suggestions for future research are discussed.

• Journal of Aerospace System Engineering
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• v.16 no.5
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• pp.43-48
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• 2022

The Kinzal missile launched by Russia in Ukraine and flew on March 5 or more speeds is the first hypersonic cruise missile used in combat. High speed leads to destructive solid power, and the security system's interception time is significantly reduced. Therefore, hypersonic missiles could be a game-changer. Even the United States, with its multi-layered defense system, admits the difficulty of intercepting it. Military powers like the United States, Russia, China and North Korea are focus on developing hypersonic missiles as offensive weapons, but their defense system capabilities are inadeqate. From this perspective, this paper identifies significant countrie's hypersonic missile development status and defense system capabilities and seeks to derive a countermeasure for the ROK military.

• Journal of Educational Research in Mathematics
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• v.26 no.3
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• pp.355-370
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• 2016

This research intends to and understand a prospective teacher, Kim's mathematics lesson in the perspective of Activity Theory. In this study, Kim's mathematics lesson was explored in the aspects of subject, object, tools, division of labor, community, and rule which are main constituent of Activity Theory and Activity System suggested by $Engestr{\ddot{o}}m$. As the result of study, we discussed the phenomena such as the fluctuation between object and tool, the multi-voicedness between object, rule, outcome and student subject, and the dissonance between division of labor, community and rule were appeared in Kim's mathematics lesson as an activity system.

• Journal of Korea Game Society
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• v.13 no.2
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• pp.5-16
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• 2013

The purpose of this study is how to occur the temporality in Digital Gameplay. There is two types of time in Gameplay. One is Irreversibility time that goes passed through a game world like a chronology order. Another is Reversibility time that returns and renews the time. The time's duality is caused by player's intervene and experience. And the polychronic temporality in gameplay makes the rhythm as replay and eternal cyclic time.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.807-809
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• 2020

기존의 CCTV 관리 체계는 사건·사고에 대한 신속한 조치가 불가능하고 정황 파악이나 증거자료 확보 등 사후조치의 성격이 강하다. 본 논문에서는 Mask R-CNN(Regions with CNN)을 이용하여 CCTV가 읽어 들이는 객체가 응급상황인지 판단하는 방법을 제시한다. 사람으로 인식되는 영역을 다층 퍼셉트론(MLP, Multi-Layer Perceptron)으로 학습시켜 해당 대상이 처한 상황을 인지하고 응급상황으로 인식되는 상황이 지속될 경우 관리 모니터를 통해 사용자에게 알림을 준다. 본 연구를 통해 실시간 상호작용적인 CCTV 관리 체계를 구축하여 도움이 필요한 사람의 골든타임을 놓치지 않게 될 것으로 기대한다.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.1
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• pp.9-16
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• 2016

As the need of eco-friendly transportation systems for sustainable development increases, public transport accessibility has been considered as an important element of transportation system design. When analyzing the accessibility, shortest path algorithms can be utilized to reflect the actual movement and we can obtain high resolution accessibility for all other stations on the network with shortest distance and time. This study used the algorithm improved by reflecting the penalty of number of transfers and waiting time of overlapped routes to get the accessibility. KTX Seoul Station is a target place and this algorithm is applied to multi-layer subway bus network of Seoul to calculate the accessibility, therefore this study presented the accessibility of KTX Seoul station by stations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.11
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• pp.2264-2275
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• 1994

In this paper, image compression based on neural networks is presented with block classification and coding. Multilayer neural networks with error back-propagation learning algorithm are used to transform the normalized image date into the compressed hidden values by reducing spatial redundancies. Image compression can basically be achieved with smaller number of hidden neurons than the numbers of input and output neurons. Additionally, the image blocks can be grouped for adaptive compression rates depending on the characteristics of the complexity of the blocks in accordance with the sensitivity of the human visual system(HVS). The quantized output of the hidden neuron can also be entropy coded for an efficient transmission. In computer simulation, this approach lie in the good performances even with images outside the training set and about 25:1 compression rate was achieved using the entropy coding without much degradation of the reconstructed images.