• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.151-158
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• 2010

In line with the requirement of appropriate protocol support for such mission-critical wireless sensor network (WSN) applications as patient monitoring, we investigate the framework for designing medium access control (MAC) schemes. The data traffic in medical systems comes with inherent traffic heterogeneity as well as strict requirement of reliability according to the varied extents of devise-wise criticality in separate cases. This implies that the quality-of-Service (QoS) issues are very distinctly delicate requiring specialized consideration. Besides, there are features in such systems that can be exploited during the design of a MAC scheme. In a monitoring or routine surveillance application, there are degrees of regularity or predictability in traffic as coordinated from a node of central control. The coordinator thus takes on the role of marshaling the resources in a neighborhood of nodes deployed mostly for upstream traffic; in a collision-free scheme, it schedules the time slots for each superframe based on the QoS specifications. In this preliminary study, we identify the key artifacts of such a MAC scheme. We also present basic performance issues like the impact of superframe length on delay incurred, energy efficiency achieved in the network operation as obtained in a typical simulation setup based on this framework.

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.517-521
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• 2006

네트워크 가상현실 시스템은 먼 거리에 떨어진 사용자들 사이에 일관성 있는 가상 세계를 제공하며, 군사, 오락, 건축 등 여러 부분에 응용되고 있다. 본 논문에서는 그 동안 고성능 그래픽 워크스테이션 환경에서 중심적으로 연구되어 왔던 네트워크 가상현실 시스템을 가장 보편적인 플랫폼인 네트워크 환경에서 구현할 때 생기는 3차원 그래픽 처리 성능의 문제 등과 같은 이에 대한 해결책들을 제시하고 미로 환경과 지형 환경에 근거한 가상 세계를 응용 실험 대상으로 삼아 성능을 분석하였다. 실시간으로 상호 작용하는 어플리케이션은 성능을 유지하면서 모든 참가자들에게 동일한 뷰를 보여주는 것이 중요하다. 동일한 뷰를 제공하기 위해 참가자들이 전송하는 이벤트마다 재생 지연 시간을 설정하고, 수신한 이벤트에 대해서는 예정 재생 시각까지 버퍼에 저장하여 모든 참가자들이 동시에 이벤트를 실행하도록 하는 기법이 제안되어 왔다. 그러나 네트워크 트래픽이 동적으로 변하므로 네트워크 상에서 발생하는 전송 지연 시간도 동적으로 변화한다. 그러므로 고정된 재생 지연 시간을 사용할 경우, 네트워크 트래픽 감소에 따라 상호 작용 성능을 향상시킬 수 있는 기회를 상실하게 되고, 네트워크 트래픽 증가에 따라 이벤트 손실률이 크게 증가하게 되어 참가자들 간에 일치하지 않는 뷰를 초래하게 된다. 네트워크 트래픽이 적어서 전송 지연 시간이 짧을 경우 짧은 재생 지연 시간을 적용하여 상호작용 성능을 높여주고, 트래픽이 많은 경우에는 재생 지연 시간을 늘림으로써 상호 작용 성능을 해치지 않는 범위에서 이벤트 손실률을 줄인다. 실험을 통하여 제안하는 기법의 성능을 평가하였으며 그 결과 본 동기화 기법이 고부하(heavily loaded) 네트워크 상태가 지속되는 동안 기존 기법에 비해 참가자들에게 일치된 뷰를 제공할 수 있고, 저부하(lightly loaded) 네트워크 상태에서는 상호 작용 성능을 향상시킬 수 있다는 것을 확인하였다.

• Convergence Security Journal
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• v.22 no.2
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• pp.21-26
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• 2022

Wearing face masks is an effective measure to prevent COVID-19 infection. Infrared thermal image based temperature measurement and identity recognition system has been widely used in many large enterprises and universities in China, so it is totally necessary to research the face mask detection of thermal infrared imaging. Recently introduced MTCNN (Multi-task Cascaded Convolutional Networks)presents a conceptually simple, flexible, general framework for instance segmentation of objects. In this paper, we propose an algorithm for efficiently searching objects of images, while creating a segmentation of heat generation part for an instance which is a heating element in a heat sensed image acquired from a thermal infrared camera. This method called a mask MTCNN is an algorithm that extends MTCNN by adding a branch for predicting an object mask in parallel with an existing branch for recognition of a bounding box. It is easy to generalize the R-CNN to other tasks. In this paper, we proposed an infrared image detection algorithm based on R-CNN and detect heating elements which can not be distinguished by RGB images.

• Journal of Korea Multimedia Society
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• v.16 no.2
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• pp.190-197
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• 2013

Since domestic and foreign platform companies and mobile carriers adopt and use different kinds of smart platforms, developers should develop or convert contents according to each smart platform to provide a single smart content for customers. It takes long time and a lot of money to convert the conventional smart contents in order to serve other smart platforms. For the reason, more attention has been paid on Smart Cross Platform or Hybrid Platform, the core technologies of OSMU(One Source Multi Use) in which, once a program is coded, it can be executed in any platforms regardless of development languages. As a result, PhoneGap and HTML5 based Sencha Touch have been introduced. In this paper, we developed the smart virtual machine, which is built in smart cross platform based smart devices, unlike Android, iOS, Windows Phone devices being dependent of platforms, and helps to download and execute applications, being independent of platforms. the smart virtual machine supports C/C++, and Java language, being differentiated from JVM by sun microsystems that supports only Java language and .NET framework by microsoft that supports only C, C++ and C#. Therefore, it provides contents developers with the environment where they can get a wide range of options in choosing a language and develop smart contents.

• Journal of the Korea Society for Simulation
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• v.22 no.4
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• pp.49-55
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• 2013

Recently the CGF/SAF (Computer Generated Force / Semi-Automated Force) technology has been getting attention to deal with the increasing complexity in a DM&S(Defence Modeling and Simulation) environment. OneSAF is one of well-known CGF/SAF systems, however, it is not able to support the DEVS framework which is an advanced discrete event based modeling and simulation environment. Especially, most DM&S systems in Korea has been developed on the basis of the DEVS framework. In this paper, we have proposed the agent-based SAF design methodology and tool for supporting DEVS M&S environment. The proposed SAF modeling tool is divided into two parts; the agent modeling part and SAF modeling part. In the agent modeling environment, the modeler can simply create the agent model by writing down the necessary rules. It also provides the agent testing environment so that the modeler maybe conveniently verify the prescribed agent model. The SAF model is finally created by combing the individual agents based on the pre-defined structure. DM&S engineers will be able to employ our tools and modeling methodology to design the DEVS-based DM&S system to be developed.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.4
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• pp.104-113
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• 2012

Followed by that HTML5(Hypertext Markup Language5) was introduced, many kinds of program and services based on this have been developed and released. HTML5 is technical standard specifications for cross platform for personal computers and mobile devices so that it is expected that continuing progress and wide application in the both sides of the academic and the industrial fields increase. This study is to design and implement a mobile application program for overlay rendering with DEM and other geo-based image sets using HTML5 WebGL for 3D graphic processing on web environment. Particularly, the blending technique was used for overlay processing with multiple images. Among available WebGL frameworks, CubicVR.js was adopted, and various blending techniques were provided in the user interface for general users. For the actual application in the study area around the Sejong city, serveral types of geo-based data sets were used and processed: KOMPSAT-2 images, ALOS PALSAR SAR images, and grid data by environment measurements. While, DEM for 3D viewing with these geo-based images was produced using contour information of the digital map sets. This work demonstrates possibilities that new types of contents and service system using geo-based images can be extracted and applied.

• Journal of the Korean GEO-environmental Society
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• v.18 no.2
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• pp.47-51
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• 2017

In this study, the optimization algorithm by inverse analysis that is the core of the adaptive management technique was adopted to update the soil engineering properties based on the ground response during the construction. Adaptive management technique is the framework wherein construction and design procedures are adjusted based on observations and measurements made as construction proceeds. To evaluate the performance of the adaptive management technique, the numerical simulation for the triaxial tests and the synthetic deep excavation were conducted with the Hardening Soil model. To effectively conduct the analysis, the effective parameters among the parameters employed in the model were selected based on the composite scaled sensitivity analysis. The results from the undrained triaxial tests performed with soft Chicago clays were used for the parameter calibration. The simulation for the synthetic deep excavation were conducted assuming that the soil engineering parameters obtained from the triaxial simulation represent the actual field condition. These values were used as the reference values. The observation for the synthetic deep excavation simulations was the horizontal displacement of the support wall that has the highest composite scaled sensitivity among the other possible observations. It was found that the horizontal displacement of the support wall with the various initial soil properties were converged to the reference displacement by using the adaptive management technique.

• Journal of the Korean Association of Geographic Information Studies
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• v.19 no.3
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• pp.16-28
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• 2016

Advancing geo-spatial web technologies and their applications require compatible and interoperable heterogeneous browsers and platforms. Reduction of common or supporting components for web-based system development is also necessary. If properly understood and applied, OGC-based standards can be utilized as effective solutions for these problems. Thus, OGC standards are central to the design and development of web-based geo-spatial systems, and are particularly applicable to web services, which contain data processing modules. However, the application for OGC WPS 2.0 is at an early stage as compared with other OGC standards; thus, this study describes a test implementation of a web-based geo-spatial processing system with OGC WPS 2.0 focused on asynchronous processing functionality. While a binary thresholding algorithm was tested in this system, further experiments with other processing modules can be performed on requests for many types of processing from multiple users. The client system of the implemented product was based on open sources such as jQuery and OpenLayers, and server-side running on Spring framework also used various types of open sources such as ZOO project, and GeoServer. The results of geo-spatial image processing by this system implies further applicability and extensibility of OGC WPS 2.0 on user interfaces for practical applications.

• Journal of KIISE
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• v.41 no.11
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• pp.892-899
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• 2014

Dynamic binary instrumentation is a code insertion technique for debugging a program without scattering its execution flow, while the program is running. Most dynamic instrumentations are implemented using dynamic binary translation techniques. Existing studies translated program codes dynamically by parsing the machine code stream to intermediate representation (IR) and then applying compilation techniques for IRs. However, they have high overhead during translation, which is a major cause of difficulty in applying the dynamic binary translation technique to the program which requires high responsiveness. In this paper, we introduce a light-weight dynamic binary instrumentation framework based on a novel dynamic binary translation technique which has low overhead while translating the program code. In order to reduce the translation overhead, our approach adopts a tabular-based address translation and exploits a translation bypassing scheme, which stores the translated address of a frequently called library function in advance. It then accesses the translated address and executes function codes without code translation when calling the function. Our experiment results demonstrated that the proposed approach outperforms the prior dynamic binary translation techniques from 2% up to 65%.

• The KIPS Transactions:PartC
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• v.8C no.5
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• pp.573-584
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• 2001

Policy-Based Network Management (PBNM) architecture is to meet various needs of network users and to provide effective management facilities in distributed and large scale networks to network managers. In PBNM, network managers perform network management operations by stipulating a set of rules rather than control each network component. On the other hand, providing security services such as authentication, privacy of messages as well as a new flexible and extensible administration framework, SNMPv3 enables network managers to monitor and control the operation of network components more secure way than ever before. Despite of its enhanced security services, SNMPv3 has difficulties in managing distributed, large-scaled network because it does not provide centralized security management facilities. In this paper, we propose a new security model called Role-based Security Management model (RSM) with security management policy to support scalable and centralized security management for SNMP-based networks. Also, the structure and the operation of the security system as well as the efficiency analysis of RSM in terms of security management are also described.